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Annotation of src/usr.bin/ssh/channels.c, Revision 1.428

1.428   ! dtucker     1: /* $OpenBSD: channels.c,v 1.427 2023/01/18 02:00:10 djm Exp $ */
1.1       deraadt     2: /*
1.26      deraadt     3:  * Author: Tatu Ylonen <ylo@cs.hut.fi>
                      4:  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
                      5:  *                    All rights reserved
                      6:  * This file contains functions for generic socket connection forwarding.
                      7:  * There is also code for initiating connection forwarding for X11 connections,
                      8:  * arbitrary tcp/ip connections, and the authentication agent connection.
1.49      markus      9:  *
1.67      deraadt    10:  * As far as I am concerned, the code I have written for this software
                     11:  * can be used freely for any purpose.  Any derived versions of this
                     12:  * software must be clearly marked as such, and if the derived work is
                     13:  * incompatible with the protocol description in the RFC file, it must be
                     14:  * called by a name other than "ssh" or "Secure Shell".
                     15:  *
1.44      markus     16:  * SSH2 support added by Markus Friedl.
1.156     markus     17:  * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl.  All rights reserved.
1.67      deraadt    18:  * Copyright (c) 1999 Dug Song.  All rights reserved.
                     19:  * Copyright (c) 1999 Theo de Raadt.  All rights reserved.
                     20:  *
                     21:  * Redistribution and use in source and binary forms, with or without
                     22:  * modification, are permitted provided that the following conditions
                     23:  * are met:
                     24:  * 1. Redistributions of source code must retain the above copyright
                     25:  *    notice, this list of conditions and the following disclaimer.
                     26:  * 2. Redistributions in binary form must reproduce the above copyright
                     27:  *    notice, this list of conditions and the following disclaimer in the
                     28:  *    documentation and/or other materials provided with the distribution.
                     29:  *
                     30:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
                     31:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
                     32:  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
                     33:  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
                     34:  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
                     35:  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
                     36:  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
                     37:  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
                     38:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
                     39:  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.26      deraadt    40:  */
1.1       deraadt    41:
1.265     deraadt    42: #include <sys/types.h>
1.336     millert    43: #include <sys/stat.h>
1.234     stevesk    44: #include <sys/ioctl.h>
1.235     stevesk    45: #include <sys/un.h>
1.251     stevesk    46: #include <sys/socket.h>
1.261     stevesk    47: #include <sys/time.h>
1.275     djm        48: #include <sys/queue.h>
1.251     stevesk    49:
                     50: #include <netinet/in.h>
                     51: #include <arpa/inet.h>
1.233     stevesk    52:
1.254     stevesk    53: #include <errno.h>
1.298     dtucker    54: #include <fcntl.h>
1.367     djm        55: #include <limits.h>
1.255     stevesk    56: #include <netdb.h>
1.411     djm        57: #include <poll.h>
1.367     djm        58: #include <stdarg.h>
1.341     millert    59: #include <stdint.h>
1.263     stevesk    60: #include <stdio.h>
1.262     stevesk    61: #include <stdlib.h>
1.260     stevesk    62: #include <string.h>
1.233     stevesk    63: #include <termios.h>
1.256     stevesk    64: #include <unistd.h>
1.1       deraadt    65:
1.265     deraadt    66: #include "xmalloc.h"
1.1       deraadt    67: #include "ssh.h"
1.82      markus     68: #include "ssh2.h"
1.354     markus     69: #include "ssherr.h"
1.367     djm        70: #include "sshbuf.h"
1.1       deraadt    71: #include "packet.h"
1.82      markus     72: #include "log.h"
                     73: #include "misc.h"
1.14      markus     74: #include "channels.h"
                     75: #include "compat.h"
1.82      markus     76: #include "canohost.h"
1.383     markus     77: #include "sshkey.h"
1.64      markus     78: #include "authfd.h"
1.147     stevesk    79: #include "pathnames.h"
1.381     djm        80: #include "match.h"
1.388     djm        81:
1.411     djm        82: /* XXX remove once we're satisfied there's no lurking bugs */
                     83: /* #define DEBUG_CHANNEL_POLL 1 */
                     84:
1.367     djm        85: /* -- agent forwarding */
                     86: #define        NUM_SOCKS       10
1.12      markus     87:
1.367     djm        88: /* -- tcp forwarding */
                     89: /* special-case port number meaning allow any port */
                     90: #define FWD_PERMIT_ANY_PORT    0
1.1       deraadt    91:
1.367     djm        92: /* special-case wildcard meaning allow any host */
                     93: #define FWD_PERMIT_ANY_HOST    "*"
1.1       deraadt    94:
1.367     djm        95: /* -- X11 forwarding */
                     96: /* Maximum number of fake X11 displays to try. */
                     97: #define MAX_DISPLAYS  1000
1.1       deraadt    98:
1.411     djm        99: /* Per-channel callback for pre/post IO actions */
1.410     djm       100: typedef void chan_fn(struct ssh *, Channel *c);
1.381     djm       101:
1.27      markus    102: /*
                    103:  * Data structure for storing which hosts are permitted for forward requests.
                    104:  * The local sides of any remote forwards are stored in this array to prevent
                    105:  * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
                    106:  * network (which might be behind a firewall).
                    107:  */
1.336     millert   108: /* XXX: streamlocal wants a path instead of host:port */
                    109: /*      Overload host_to_connect; we could just make this match Forward */
                    110: /*     XXX - can we use listen_host instead of listen_path? */
1.381     djm       111: struct permission {
1.41      markus    112:        char *host_to_connect;          /* Connect to 'host'. */
1.336     millert   113:        int port_to_connect;            /* Connect to 'port'. */
1.333     markus    114:        char *listen_host;              /* Remote side should listen address. */
1.336     millert   115:        char *listen_path;              /* Remote side should listen path. */
                    116:        int listen_port;                /* Remote side should listen port. */
1.354     markus    117:        Channel *downstream;            /* Downstream mux*/
1.381     djm       118: };
                    119:
                    120: /*
                    121:  * Stores the forwarding permission state for a single direction (local or
                    122:  * remote).
                    123:  */
                    124: struct permission_set {
                    125:        /*
                    126:         * List of all local permitted host/port pairs to allow for the
                    127:         * user.
                    128:         */
                    129:        u_int num_permitted_user;
                    130:        struct permission *permitted_user;
1.1       deraadt   131:
1.381     djm       132:        /*
                    133:         * List of all permitted host/port pairs to allow for the admin.
                    134:         */
                    135:        u_int num_permitted_admin;
                    136:        struct permission *permitted_admin;
                    137:
                    138:        /*
                    139:         * If this is true, all opens/listens are permitted.  This is the
                    140:         * case on the server on which we have to trust the client anyway,
                    141:         * and the user could do anything after logging in.
                    142:         */
                    143:        int all_permitted;
                    144: };
1.121     markus    145:
1.426     djm       146: /* Used to record timeouts per channel type */
                    147: struct ssh_channel_timeout {
                    148:        char *type_pattern;
                    149:        u_int timeout_secs;
                    150: };
                    151:
1.367     djm       152: /* Master structure for channels state */
                    153: struct ssh_channels {
                    154:        /*
                    155:         * Pointer to an array containing all allocated channels.  The array
                    156:         * is dynamically extended as needed.
                    157:         */
                    158:        Channel **channels;
1.257     dtucker   159:
1.367     djm       160:        /*
                    161:         * Size of the channel array.  All slots of the array must always be
                    162:         * initialized (at least the type field); unused slots set to NULL
                    163:         */
                    164:        u_int channels_alloc;
1.257     dtucker   165:
1.367     djm       166:        /*
1.411     djm       167:         * 'channel_pre*' are called just before IO to add any bits
                    168:         * relevant to channels in the c->io_want bitmasks.
1.367     djm       169:         *
                    170:         * 'channel_post*': perform any appropriate operations for
1.411     djm       171:         * channels which have c->io_ready events pending.
1.367     djm       172:         */
                    173:        chan_fn **channel_pre;
                    174:        chan_fn **channel_post;
1.314     dtucker   175:
1.367     djm       176:        /* -- tcp forwarding */
1.381     djm       177:        struct permission_set local_perms;
                    178:        struct permission_set remote_perms;
1.219     djm       179:
1.367     djm       180:        /* -- X11 forwarding */
1.121     markus    181:
1.367     djm       182:        /* Saved X11 local (client) display. */
                    183:        char *x11_saved_display;
1.121     markus    184:
1.367     djm       185:        /* Saved X11 authentication protocol name. */
                    186:        char *x11_saved_proto;
1.347     djm       187:
1.367     djm       188:        /* Saved X11 authentication data.  This is the real data. */
                    189:        char *x11_saved_data;
                    190:        u_int x11_saved_data_len;
1.121     markus    191:
1.367     djm       192:        /* Deadline after which all X11 connections are refused */
1.428   ! dtucker   193:        time_t x11_refuse_time;
1.121     markus    194:
1.367     djm       195:        /*
                    196:         * Fake X11 authentication data.  This is what the server will be
                    197:         * sending us; we should replace any occurrences of this by the
                    198:         * real data.
                    199:         */
                    200:        u_char *x11_fake_data;
                    201:        u_int x11_fake_data_len;
1.121     markus    202:
1.367     djm       203:        /* AF_UNSPEC or AF_INET or AF_INET6 */
                    204:        int IPv4or6;
1.426     djm       205:
                    206:        /* Channel timeouts by type */
                    207:        struct ssh_channel_timeout *timeouts;
                    208:        size_t ntimeouts;
1.367     djm       209: };
1.1       deraadt   210:
1.121     markus    211: /* helper */
1.367     djm       212: static void port_open_helper(struct ssh *ssh, Channel *c, char *rtype);
1.354     markus    213: static const char *channel_rfwd_bind_host(const char *listen_host);
1.103     markus    214:
1.276     djm       215: /* non-blocking connect helpers */
                    216: static int connect_next(struct channel_connect *);
                    217: static void channel_connect_ctx_free(struct channel_connect *);
1.372     markus    218: static Channel *rdynamic_connect_prepare(struct ssh *, char *, char *);
                    219: static int rdynamic_connect_finish(struct ssh *, Channel *);
1.276     djm       220:
1.367     djm       221: /* Setup helper */
                    222: static void channel_handler_init(struct ssh_channels *sc);
                    223:
1.121     markus    224: /* -- channel core */
1.41      markus    225:
1.367     djm       226: void
                    227: channel_init_channels(struct ssh *ssh)
                    228: {
                    229:        struct ssh_channels *sc;
                    230:
1.387     djm       231:        if ((sc = calloc(1, sizeof(*sc))) == NULL)
1.403     djm       232:                fatal_f("allocation failed");
1.367     djm       233:        sc->channels_alloc = 10;
                    234:        sc->channels = xcalloc(sc->channels_alloc, sizeof(*sc->channels));
                    235:        sc->IPv4or6 = AF_UNSPEC;
                    236:        channel_handler_init(sc);
                    237:
                    238:        ssh->chanctxt = sc;
                    239: }
                    240:
1.41      markus    241: Channel *
1.367     djm       242: channel_by_id(struct ssh *ssh, int id)
1.41      markus    243: {
                    244:        Channel *c;
1.113     markus    245:
1.367     djm       246:        if (id < 0 || (u_int)id >= ssh->chanctxt->channels_alloc) {
1.403     djm       247:                logit_f("%d: bad id", id);
1.41      markus    248:                return NULL;
                    249:        }
1.367     djm       250:        c = ssh->chanctxt->channels[id];
1.113     markus    251:        if (c == NULL) {
1.403     djm       252:                logit_f("%d: bad id: channel free", id);
1.41      markus    253:                return NULL;
                    254:        }
                    255:        return c;
1.55      markus    256: }
                    257:
1.354     markus    258: Channel *
1.368     djm       259: channel_by_remote_id(struct ssh *ssh, u_int remote_id)
1.354     markus    260: {
                    261:        Channel *c;
                    262:        u_int i;
                    263:
1.367     djm       264:        for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
                    265:                c = ssh->chanctxt->channels[i];
1.368     djm       266:                if (c != NULL && c->have_remote_id && c->remote_id == remote_id)
1.354     markus    267:                        return c;
                    268:        }
                    269:        return NULL;
                    270: }
                    271:
1.27      markus    272: /*
1.229     markus    273:  * Returns the channel if it is allowed to receive protocol messages.
                    274:  * Private channels, like listening sockets, may not receive messages.
                    275:  */
                    276: Channel *
1.367     djm       277: channel_lookup(struct ssh *ssh, int id)
1.229     markus    278: {
                    279:        Channel *c;
                    280:
1.367     djm       281:        if ((c = channel_by_id(ssh, id)) == NULL)
                    282:                return NULL;
1.229     markus    283:
1.237     deraadt   284:        switch (c->type) {
1.229     markus    285:        case SSH_CHANNEL_X11_OPEN:
                    286:        case SSH_CHANNEL_LARVAL:
                    287:        case SSH_CHANNEL_CONNECTING:
                    288:        case SSH_CHANNEL_DYNAMIC:
1.372     markus    289:        case SSH_CHANNEL_RDYNAMIC_OPEN:
                    290:        case SSH_CHANNEL_RDYNAMIC_FINISH:
1.229     markus    291:        case SSH_CHANNEL_OPENING:
                    292:        case SSH_CHANNEL_OPEN:
1.323     dtucker   293:        case SSH_CHANNEL_ABANDONED:
1.354     markus    294:        case SSH_CHANNEL_MUX_PROXY:
1.367     djm       295:                return c;
1.229     markus    296:        }
                    297:        logit("Non-public channel %d, type %d.", id, c->type);
1.367     djm       298:        return NULL;
1.229     markus    299: }
                    300:
                    301: /*
1.426     djm       302:  * Add a timeout for open channels whose c->ctype (or c->xctype if it is set)
                    303:  * match type_pattern.
                    304:  */
                    305: void
                    306: channel_add_timeout(struct ssh *ssh, const char *type_pattern,
                    307:     u_int timeout_secs)
                    308: {
                    309:        struct ssh_channels *sc = ssh->chanctxt;
                    310:
                    311:        debug2_f("channel type \"%s\" timeout %u seconds",
                    312:            type_pattern, timeout_secs);
                    313:        sc->timeouts = xrecallocarray(sc->timeouts, sc->ntimeouts,
                    314:            sc->ntimeouts + 1, sizeof(*sc->timeouts));
                    315:        sc->timeouts[sc->ntimeouts].type_pattern = xstrdup(type_pattern);
                    316:        sc->timeouts[sc->ntimeouts].timeout_secs = timeout_secs;
                    317:        sc->ntimeouts++;
                    318: }
                    319:
                    320: /* Clears all previously-added channel timeouts */
                    321: void
                    322: channel_clear_timeouts(struct ssh *ssh)
                    323: {
                    324:        struct ssh_channels *sc = ssh->chanctxt;
                    325:        size_t i;
                    326:
                    327:        debug3_f("clearing");
                    328:        for (i = 0; i < sc->ntimeouts; i++)
                    329:                free(sc->timeouts[i].type_pattern);
                    330:        free(sc->timeouts);
                    331:        sc->timeouts = NULL;
                    332:        sc->ntimeouts = 0;
                    333: }
                    334:
                    335: static u_int
                    336: lookup_timeout(struct ssh *ssh, const char *type)
                    337: {
                    338:        struct ssh_channels *sc = ssh->chanctxt;
                    339:        size_t i;
                    340:
                    341:        for (i = 0; i < sc->ntimeouts; i++) {
                    342:                if (match_pattern(type, sc->timeouts[i].type_pattern))
                    343:                        return sc->timeouts[i].timeout_secs;
                    344:        }
                    345:
                    346:        return 0;
                    347: }
                    348:
                    349: /*
1.425     djm       350:  * Sets "extended type" of a channel; used by session layer to add additional
                    351:  * information about channel types (e.g. shell, login, subsystem) that can then
                    352:  * be used to select timeouts.
1.426     djm       353:  * Will reset c->inactive_deadline as a side-effect.
1.425     djm       354:  */
                    355: void
                    356: channel_set_xtype(struct ssh *ssh, int id, const char *xctype)
                    357: {
                    358:        Channel *c;
                    359:
                    360:        if ((c = channel_by_id(ssh, id)) == NULL)
                    361:                fatal_f("missing channel %d", id);
                    362:        if (c->xctype != NULL)
                    363:                free(c->xctype);
                    364:        c->xctype = xstrdup(xctype);
1.426     djm       365:        /* Type has changed, so look up inactivity deadline again */
                    366:        c->inactive_deadline = lookup_timeout(ssh, c->xctype);
                    367:        debug2_f("labeled channel %d as %s (inactive timeout %u)", id, xctype,
                    368:            c->inactive_deadline);
1.425     djm       369: }
                    370:
                    371: /*
1.55      markus    372:  * Register filedescriptors for a channel, used when allocating a channel or
1.52      markus    373:  * when the channel consumer/producer is ready, e.g. shell exec'd
1.27      markus    374:  */
1.127     itojun    375: static void
1.367     djm       376: channel_register_fds(struct ssh *ssh, Channel *c, int rfd, int wfd, int efd,
1.282     dtucker   377:     int extusage, int nonblock, int is_tty)
1.1       deraadt   378: {
1.418     markus    379:        int val;
                    380:
1.298     dtucker   381:        if (rfd != -1)
                    382:                fcntl(rfd, F_SETFD, FD_CLOEXEC);
                    383:        if (wfd != -1 && wfd != rfd)
                    384:                fcntl(wfd, F_SETFD, FD_CLOEXEC);
                    385:        if (efd != -1 && efd != rfd && efd != wfd)
                    386:                fcntl(efd, F_SETFD, FD_CLOEXEC);
1.55      markus    387:
1.52      markus    388:        c->rfd = rfd;
                    389:        c->wfd = wfd;
                    390:        c->sock = (rfd == wfd) ? rfd : -1;
                    391:        c->efd = efd;
                    392:        c->extended_usage = extusage;
1.71      markus    393:
1.282     dtucker   394:        if ((c->isatty = is_tty) != 0)
1.194     markus    395:                debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91      markus    396:
1.71      markus    397:        /* enable nonblocking mode */
1.407     djm       398:        c->restore_block = 0;
                    399:        if (nonblock == CHANNEL_NONBLOCK_STDIO) {
                    400:                /*
                    401:                 * Special handling for stdio file descriptors: do not set
                    402:                 * non-blocking mode if they are TTYs. Otherwise prepare to
                    403:                 * restore their blocking state on exit to avoid interfering
                    404:                 * with other programs that follow.
                    405:                 */
1.418     markus    406:                if (rfd != -1 && !isatty(rfd) &&
                    407:                    (val = fcntl(rfd, F_GETFL)) != -1 && !(val & O_NONBLOCK)) {
1.427     djm       408:                        c->restore_flags[0] = val;
1.407     djm       409:                        c->restore_block |= CHANNEL_RESTORE_RFD;
                    410:                        set_nonblock(rfd);
                    411:                }
1.418     markus    412:                if (wfd != -1 && !isatty(wfd) &&
                    413:                    (val = fcntl(wfd, F_GETFL)) != -1 && !(val & O_NONBLOCK)) {
1.427     djm       414:                        c->restore_flags[1] = val;
1.407     djm       415:                        c->restore_block |= CHANNEL_RESTORE_WFD;
                    416:                        set_nonblock(wfd);
                    417:                }
1.418     markus    418:                if (efd != -1 && !isatty(efd) &&
                    419:                    (val = fcntl(efd, F_GETFL)) != -1 && !(val & O_NONBLOCK)) {
1.427     djm       420:                        c->restore_flags[2] = val;
1.407     djm       421:                        c->restore_block |= CHANNEL_RESTORE_EFD;
                    422:                        set_nonblock(efd);
                    423:                }
                    424:        } else if (nonblock) {
1.71      markus    425:                if (rfd != -1)
                    426:                        set_nonblock(rfd);
                    427:                if (wfd != -1)
                    428:                        set_nonblock(wfd);
                    429:                if (efd != -1)
                    430:                        set_nonblock(efd);
                    431:        }
1.52      markus    432: }
                    433:
                    434: /*
1.419     djm       435:  * Allocate a new channel object and set its type and socket.
1.52      markus    436:  */
1.113     markus    437: Channel *
1.367     djm       438: channel_new(struct ssh *ssh, char *ctype, int type, int rfd, int wfd, int efd,
1.419     djm       439:     u_int window, u_int maxpack, int extusage, const char *remote_name,
                    440:     int nonblock)
1.52      markus    441: {
1.367     djm       442:        struct ssh_channels *sc = ssh->chanctxt;
                    443:        u_int i, found;
1.52      markus    444:        Channel *c;
1.402     djm       445:        int r;
1.25      markus    446:
                    447:        /* Try to find a free slot where to put the new channel. */
1.367     djm       448:        for (i = 0; i < sc->channels_alloc; i++) {
                    449:                if (sc->channels[i] == NULL) {
1.25      markus    450:                        /* Found a free slot. */
1.367     djm       451:                        found = i;
1.25      markus    452:                        break;
                    453:                }
1.367     djm       454:        }
                    455:        if (i >= sc->channels_alloc) {
                    456:                /*
                    457:                 * There are no free slots. Take last+1 slot and expand
                    458:                 * the array.
                    459:                 */
                    460:                found = sc->channels_alloc;
                    461:                if (sc->channels_alloc > CHANNELS_MAX_CHANNELS)
1.403     djm       462:                        fatal_f("internal error: channels_alloc %d too big",
                    463:                            sc->channels_alloc);
1.367     djm       464:                sc->channels = xrecallocarray(sc->channels, sc->channels_alloc,
                    465:                    sc->channels_alloc + 10, sizeof(*sc->channels));
                    466:                sc->channels_alloc += 10;
                    467:                debug2("channel: expanding %d", sc->channels_alloc);
1.25      markus    468:        }
1.113     markus    469:        /* Initialize and return new channel. */
1.367     djm       470:        c = sc->channels[found] = xcalloc(1, sizeof(Channel));
                    471:        if ((c->input = sshbuf_new()) == NULL ||
                    472:            (c->output = sshbuf_new()) == NULL ||
                    473:            (c->extended = sshbuf_new()) == NULL)
1.403     djm       474:                fatal_f("sshbuf_new failed");
1.402     djm       475:        if ((r = sshbuf_set_max_size(c->input, CHAN_INPUT_MAX)) != 0)
1.403     djm       476:                fatal_fr(r, "sshbuf_set_max_size");
1.159     markus    477:        c->ostate = CHAN_OUTPUT_OPEN;
                    478:        c->istate = CHAN_INPUT_OPEN;
1.367     djm       479:        channel_register_fds(ssh, c, rfd, wfd, efd, extusage, nonblock, 0);
1.25      markus    480:        c->self = found;
                    481:        c->type = type;
1.41      markus    482:        c->ctype = ctype;
1.51      markus    483:        c->local_window = window;
                    484:        c->local_window_max = window;
                    485:        c->local_maxpacket = maxpack;
1.190     markus    486:        c->remote_name = xstrdup(remote_name);
1.302     djm       487:        c->ctl_chan = -1;
1.299     markus    488:        c->delayed = 1;         /* prevent call to channel_post handler */
1.426     djm       489:        c->inactive_deadline = lookup_timeout(ssh, c->ctype);
1.275     djm       490:        TAILQ_INIT(&c->status_confirms);
1.426     djm       491:        debug("channel %d: new %s [%s] (inactive timeout: %u)",
                    492:            found, c->ctype, remote_name, c->inactive_deadline);
1.113     markus    493:        return c;
1.1       deraadt   494: }
1.52      markus    495:
1.132     markus    496: int
1.407     djm       497: channel_close_fd(struct ssh *ssh, Channel *c, int *fdp)
1.132     markus    498: {
1.407     djm       499:        int ret, fd = *fdp;
1.132     markus    500:
1.407     djm       501:        if (fd == -1)
                    502:                return 0;
                    503:
1.427     djm       504:        /* restore blocking */
                    505:        if (*fdp == c->rfd &&
                    506:            (c->restore_block & CHANNEL_RESTORE_RFD) != 0)
                    507:                (void)fcntl(*fdp, F_SETFL, c->restore_flags[0]);
                    508:        else if (*fdp == c->wfd &&
                    509:            (c->restore_block & CHANNEL_RESTORE_WFD) != 0)
                    510:                (void)fcntl(*fdp, F_SETFL, c->restore_flags[1]);
                    511:        else if (*fdp == c->efd &&
                    512:            (c->restore_block & CHANNEL_RESTORE_EFD) != 0)
                    513:                (void)fcntl(*fdp, F_SETFL, c->restore_flags[2]);
1.407     djm       514:
1.411     djm       515:        if (*fdp == c->rfd) {
                    516:                c->io_want &= ~SSH_CHAN_IO_RFD;
                    517:                c->io_ready &= ~SSH_CHAN_IO_RFD;
                    518:                c->rfd = -1;
1.415     djm       519:                c->pfds[0] = -1;
1.411     djm       520:        }
                    521:        if (*fdp == c->wfd) {
                    522:                c->io_want &= ~SSH_CHAN_IO_WFD;
                    523:                c->io_ready &= ~SSH_CHAN_IO_WFD;
                    524:                c->wfd = -1;
1.415     djm       525:                c->pfds[1] = -1;
1.411     djm       526:        }
                    527:        if (*fdp == c->efd) {
                    528:                c->io_want &= ~SSH_CHAN_IO_EFD;
                    529:                c->io_ready &= ~SSH_CHAN_IO_EFD;
                    530:                c->efd = -1;
1.415     djm       531:                c->pfds[2] = -1;
1.411     djm       532:        }
                    533:        if (*fdp == c->sock) {
                    534:                c->io_want &= ~SSH_CHAN_IO_SOCK;
                    535:                c->io_ready &= ~SSH_CHAN_IO_SOCK;
                    536:                c->sock = -1;
1.415     djm       537:                c->pfds[3] = -1;
1.411     djm       538:        }
                    539:
1.407     djm       540:        ret = close(fd);
1.411     djm       541:        *fdp = -1; /* probably redundant */
1.132     markus    542:        return ret;
                    543: }
                    544:
1.52      markus    545: /* Close all channel fd/socket. */
1.127     itojun    546: static void
1.367     djm       547: channel_close_fds(struct ssh *ssh, Channel *c)
                    548: {
1.379     tb        549:        int sock = c->sock, rfd = c->rfd, wfd = c->wfd, efd = c->efd;
                    550:
1.407     djm       551:        channel_close_fd(ssh, c, &c->sock);
1.379     tb        552:        if (rfd != sock)
1.407     djm       553:                channel_close_fd(ssh, c, &c->rfd);
1.379     tb        554:        if (wfd != sock && wfd != rfd)
1.407     djm       555:                channel_close_fd(ssh, c, &c->wfd);
1.379     tb        556:        if (efd != sock && efd != rfd && efd != wfd)
1.407     djm       557:                channel_close_fd(ssh, c, &c->efd);
1.367     djm       558: }
                    559:
                    560: static void
1.381     djm       561: fwd_perm_clear(struct permission *perm)
1.52      markus    562: {
1.381     djm       563:        free(perm->host_to_connect);
                    564:        free(perm->listen_host);
                    565:        free(perm->listen_path);
1.398     dtucker   566:        memset(perm, 0, sizeof(*perm));
1.367     djm       567: }
                    568:
1.381     djm       569: /* Returns an printable name for the specified forwarding permission list */
                    570: static const char *
                    571: fwd_ident(int who, int where)
                    572: {
                    573:        if (who == FORWARD_ADM) {
                    574:                if (where == FORWARD_LOCAL)
                    575:                        return "admin local";
                    576:                else if (where == FORWARD_REMOTE)
                    577:                        return "admin remote";
                    578:        } else if (who == FORWARD_USER) {
                    579:                if (where == FORWARD_LOCAL)
                    580:                        return "user local";
                    581:                else if (where == FORWARD_REMOTE)
                    582:                        return "user remote";
                    583:        }
                    584:        fatal("Unknown forward permission list %d/%d", who, where);
                    585: }
                    586:
                    587: /* Returns the forwarding permission list for the specified direction */
                    588: static struct permission_set *
                    589: permission_set_get(struct ssh *ssh, int where)
                    590: {
                    591:        struct ssh_channels *sc = ssh->chanctxt;
1.367     djm       592:
1.381     djm       593:        switch (where) {
                    594:        case FORWARD_LOCAL:
                    595:                return &sc->local_perms;
                    596:                break;
                    597:        case FORWARD_REMOTE:
                    598:                return &sc->remote_perms;
                    599:                break;
                    600:        default:
1.403     djm       601:                fatal_f("invalid forwarding direction %d", where);
1.381     djm       602:        }
                    603: }
                    604:
1.392     dtucker   605: /* Returns pointers to the specified forwarding list and its element count */
1.381     djm       606: static void
                    607: permission_set_get_array(struct ssh *ssh, int who, int where,
                    608:     struct permission ***permpp, u_int **npermpp)
                    609: {
                    610:        struct permission_set *pset = permission_set_get(ssh, where);
                    611:
                    612:        switch (who) {
                    613:        case FORWARD_USER:
                    614:                *permpp = &pset->permitted_user;
                    615:                *npermpp = &pset->num_permitted_user;
                    616:                break;
                    617:        case FORWARD_ADM:
                    618:                *permpp = &pset->permitted_admin;
                    619:                *npermpp = &pset->num_permitted_admin;
                    620:                break;
                    621:        default:
1.403     djm       622:                fatal_f("invalid forwarding client %d", who);
1.381     djm       623:        }
                    624: }
                    625:
1.409     jsg       626: /* Adds an entry to the specified forwarding list */
1.367     djm       627: static int
1.381     djm       628: permission_set_add(struct ssh *ssh, int who, int where,
1.367     djm       629:     const char *host_to_connect, int port_to_connect,
                    630:     const char *listen_host, const char *listen_path, int listen_port,
                    631:     Channel *downstream)
                    632: {
1.381     djm       633:        struct permission **permp;
                    634:        u_int n, *npermp;
1.367     djm       635:
1.381     djm       636:        permission_set_get_array(ssh, who, where, &permp, &npermp);
1.367     djm       637:
1.381     djm       638:        if (*npermp >= INT_MAX)
1.403     djm       639:                fatal_f("%s overflow", fwd_ident(who, where));
1.367     djm       640:
1.381     djm       641:        *permp = xrecallocarray(*permp, *npermp, *npermp + 1, sizeof(**permp));
                    642:        n = (*npermp)++;
1.367     djm       643: #define MAYBE_DUP(s) ((s == NULL) ? NULL : xstrdup(s))
1.381     djm       644:        (*permp)[n].host_to_connect = MAYBE_DUP(host_to_connect);
                    645:        (*permp)[n].port_to_connect = port_to_connect;
                    646:        (*permp)[n].listen_host = MAYBE_DUP(listen_host);
                    647:        (*permp)[n].listen_path = MAYBE_DUP(listen_path);
                    648:        (*permp)[n].listen_port = listen_port;
                    649:        (*permp)[n].downstream = downstream;
1.367     djm       650: #undef MAYBE_DUP
                    651:        return (int)n;
                    652: }
                    653:
                    654: static void
                    655: mux_remove_remote_forwardings(struct ssh *ssh, Channel *c)
                    656: {
                    657:        struct ssh_channels *sc = ssh->chanctxt;
1.381     djm       658:        struct permission_set *pset = &sc->local_perms;
                    659:        struct permission *perm;
1.367     djm       660:        int r;
                    661:        u_int i;
                    662:
1.381     djm       663:        for (i = 0; i < pset->num_permitted_user; i++) {
                    664:                perm = &pset->permitted_user[i];
                    665:                if (perm->downstream != c)
1.367     djm       666:                        continue;
                    667:
                    668:                /* cancel on the server, since mux client is gone */
                    669:                debug("channel %d: cleanup remote forward for %s:%u",
1.381     djm       670:                    c->self, perm->listen_host, perm->listen_port);
1.367     djm       671:                if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
                    672:                    (r = sshpkt_put_cstring(ssh,
                    673:                    "cancel-tcpip-forward")) != 0 ||
                    674:                    (r = sshpkt_put_u8(ssh, 0)) != 0 ||
                    675:                    (r = sshpkt_put_cstring(ssh,
1.381     djm       676:                    channel_rfwd_bind_host(perm->listen_host))) != 0 ||
                    677:                    (r = sshpkt_put_u32(ssh, perm->listen_port)) != 0 ||
1.367     djm       678:                    (r = sshpkt_send(ssh)) != 0) {
1.403     djm       679:                        fatal_fr(r, "channel %i", c->self);
1.367     djm       680:                }
1.381     djm       681:                fwd_perm_clear(perm); /* unregister */
1.367     djm       682:        }
1.121     markus    683: }
                    684:
                    685: /* Free the channel and close its fd/socket. */
                    686: void
1.367     djm       687: channel_free(struct ssh *ssh, Channel *c)
1.121     markus    688: {
1.367     djm       689:        struct ssh_channels *sc = ssh->chanctxt;
1.121     markus    690:        char *s;
1.209     avsm      691:        u_int i, n;
1.354     markus    692:        Channel *other;
1.275     djm       693:        struct channel_confirm *cc;
1.121     markus    694:
1.367     djm       695:        for (n = 0, i = 0; i < sc->channels_alloc; i++) {
                    696:                if ((other = sc->channels[i]) == NULL)
                    697:                        continue;
                    698:                n++;
                    699:                /* detach from mux client and prepare for closing */
                    700:                if (c->type == SSH_CHANNEL_MUX_CLIENT &&
                    701:                    other->type == SSH_CHANNEL_MUX_PROXY &&
                    702:                    other->mux_ctx == c) {
                    703:                        other->mux_ctx = NULL;
                    704:                        other->type = SSH_CHANNEL_OPEN;
                    705:                        other->istate = CHAN_INPUT_CLOSED;
                    706:                        other->ostate = CHAN_OUTPUT_CLOSED;
1.354     markus    707:                }
                    708:        }
1.209     avsm      709:        debug("channel %d: free: %s, nchannels %u", c->self,
1.121     markus    710:            c->remote_name ? c->remote_name : "???", n);
                    711:
1.408     mbuhl     712:        if (c->type == SSH_CHANNEL_MUX_CLIENT) {
1.367     djm       713:                mux_remove_remote_forwardings(ssh, c);
1.408     mbuhl     714:                free(c->mux_ctx);
                    715:                c->mux_ctx = NULL;
                    716:        } else if (c->type == SSH_CHANNEL_MUX_LISTENER) {
1.401     djm       717:                free(c->mux_ctx);
                    718:                c->mux_ctx = NULL;
                    719:        }
1.354     markus    720:
1.384     markus    721:        if (log_level_get() >= SYSLOG_LEVEL_DEBUG3) {
                    722:                s = channel_open_message(ssh);
                    723:                debug3("channel %d: status: %s", c->self, s);
                    724:                free(s);
                    725:        }
1.121     markus    726:
1.367     djm       727:        channel_close_fds(ssh, c);
                    728:        sshbuf_free(c->input);
                    729:        sshbuf_free(c->output);
                    730:        sshbuf_free(c->extended);
                    731:        c->input = c->output = c->extended = NULL;
1.321     djm       732:        free(c->remote_name);
                    733:        c->remote_name = NULL;
                    734:        free(c->path);
                    735:        c->path = NULL;
                    736:        free(c->listening_addr);
                    737:        c->listening_addr = NULL;
1.425     djm       738:        free(c->xctype);
                    739:        c->xctype = NULL;
1.275     djm       740:        while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
                    741:                if (cc->abandon_cb != NULL)
1.367     djm       742:                        cc->abandon_cb(ssh, c, cc->ctx);
1.275     djm       743:                TAILQ_REMOVE(&c->status_confirms, cc, entry);
1.396     jsg       744:                freezero(cc, sizeof(*cc));
1.275     djm       745:        }
1.280     djm       746:        if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
1.367     djm       747:                c->filter_cleanup(ssh, c->self, c->filter_ctx);
                    748:        sc->channels[c->self] = NULL;
1.396     jsg       749:        freezero(c, sizeof(*c));
1.121     markus    750: }
                    751:
                    752: void
1.367     djm       753: channel_free_all(struct ssh *ssh)
1.121     markus    754: {
1.209     avsm      755:        u_int i;
1.390     dtucker   756:        struct ssh_channels *sc = ssh->chanctxt;
1.121     markus    757:
1.390     dtucker   758:        for (i = 0; i < sc->channels_alloc; i++)
                    759:                if (sc->channels[i] != NULL)
                    760:                        channel_free(ssh, sc->channels[i]);
                    761:
                    762:        free(sc->channels);
                    763:        sc->channels = NULL;
                    764:        sc->channels_alloc = 0;
                    765:
                    766:        free(sc->x11_saved_display);
                    767:        sc->x11_saved_display = NULL;
                    768:
                    769:        free(sc->x11_saved_proto);
                    770:        sc->x11_saved_proto = NULL;
                    771:
                    772:        free(sc->x11_saved_data);
                    773:        sc->x11_saved_data = NULL;
                    774:        sc->x11_saved_data_len = 0;
                    775:
                    776:        free(sc->x11_fake_data);
                    777:        sc->x11_fake_data = NULL;
                    778:        sc->x11_fake_data_len = 0;
1.131     markus    779: }
                    780:
1.121     markus    781: /*
                    782:  * Closes the sockets/fds of all channels.  This is used to close extra file
                    783:  * descriptors after a fork.
                    784:  */
                    785: void
1.367     djm       786: channel_close_all(struct ssh *ssh)
1.121     markus    787: {
1.209     avsm      788:        u_int i;
1.121     markus    789:
1.367     djm       790:        for (i = 0; i < ssh->chanctxt->channels_alloc; i++)
                    791:                if (ssh->chanctxt->channels[i] != NULL)
                    792:                        channel_close_fds(ssh, ssh->chanctxt->channels[i]);
1.121     markus    793: }
                    794:
                    795: /*
1.131     markus    796:  * Stop listening to channels.
                    797:  */
                    798: void
1.367     djm       799: channel_stop_listening(struct ssh *ssh)
1.131     markus    800: {
1.209     avsm      801:        u_int i;
1.131     markus    802:        Channel *c;
                    803:
1.367     djm       804:        for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
                    805:                c = ssh->chanctxt->channels[i];
1.131     markus    806:                if (c != NULL) {
                    807:                        switch (c->type) {
                    808:                        case SSH_CHANNEL_AUTH_SOCKET:
                    809:                        case SSH_CHANNEL_PORT_LISTENER:
                    810:                        case SSH_CHANNEL_RPORT_LISTENER:
                    811:                        case SSH_CHANNEL_X11_LISTENER:
1.336     millert   812:                        case SSH_CHANNEL_UNIX_LISTENER:
                    813:                        case SSH_CHANNEL_RUNIX_LISTENER:
1.407     djm       814:                                channel_close_fd(ssh, c, &c->sock);
1.367     djm       815:                                channel_free(ssh, c);
1.131     markus    816:                                break;
                    817:                        }
                    818:                }
                    819:        }
                    820: }
                    821:
                    822: /*
1.121     markus    823:  * Returns true if no channel has too much buffered data, and false if one or
                    824:  * more channel is overfull.
                    825:  */
                    826: int
1.367     djm       827: channel_not_very_much_buffered_data(struct ssh *ssh)
1.121     markus    828: {
                    829:        u_int i;
1.367     djm       830:        u_int maxsize = ssh_packet_get_maxsize(ssh);
1.121     markus    831:        Channel *c;
                    832:
1.367     djm       833:        for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
                    834:                c = ssh->chanctxt->channels[i];
                    835:                if (c == NULL || c->type != SSH_CHANNEL_OPEN)
                    836:                        continue;
                    837:                if (sshbuf_len(c->output) > maxsize) {
                    838:                        debug2("channel %d: big output buffer %zu > %u",
                    839:                            c->self, sshbuf_len(c->output), maxsize);
                    840:                        return 0;
1.121     markus    841:                }
                    842:        }
                    843:        return 1;
                    844: }
                    845:
                    846: /* Returns true if any channel is still open. */
                    847: int
1.367     djm       848: channel_still_open(struct ssh *ssh)
1.121     markus    849: {
1.209     avsm      850:        u_int i;
1.121     markus    851:        Channel *c;
                    852:
1.367     djm       853:        for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
                    854:                c = ssh->chanctxt->channels[i];
1.121     markus    855:                if (c == NULL)
                    856:                        continue;
                    857:                switch (c->type) {
                    858:                case SSH_CHANNEL_X11_LISTENER:
                    859:                case SSH_CHANNEL_PORT_LISTENER:
                    860:                case SSH_CHANNEL_RPORT_LISTENER:
1.302     djm       861:                case SSH_CHANNEL_MUX_LISTENER:
1.121     markus    862:                case SSH_CHANNEL_CLOSED:
                    863:                case SSH_CHANNEL_AUTH_SOCKET:
                    864:                case SSH_CHANNEL_DYNAMIC:
1.372     markus    865:                case SSH_CHANNEL_RDYNAMIC_OPEN:
1.121     markus    866:                case SSH_CHANNEL_CONNECTING:
                    867:                case SSH_CHANNEL_ZOMBIE:
1.323     dtucker   868:                case SSH_CHANNEL_ABANDONED:
1.336     millert   869:                case SSH_CHANNEL_UNIX_LISTENER:
                    870:                case SSH_CHANNEL_RUNIX_LISTENER:
1.121     markus    871:                        continue;
                    872:                case SSH_CHANNEL_LARVAL:
                    873:                        continue;
                    874:                case SSH_CHANNEL_OPENING:
                    875:                case SSH_CHANNEL_OPEN:
1.372     markus    876:                case SSH_CHANNEL_RDYNAMIC_FINISH:
1.121     markus    877:                case SSH_CHANNEL_X11_OPEN:
1.302     djm       878:                case SSH_CHANNEL_MUX_CLIENT:
1.354     markus    879:                case SSH_CHANNEL_MUX_PROXY:
1.121     markus    880:                        return 1;
                    881:                default:
1.403     djm       882:                        fatal_f("bad channel type %d", c->type);
1.121     markus    883:                        /* NOTREACHED */
                    884:                }
                    885:        }
                    886:        return 0;
                    887: }
                    888:
                    889: /* Returns the id of an open channel suitable for keepaliving */
                    890: int
1.367     djm       891: channel_find_open(struct ssh *ssh)
1.121     markus    892: {
1.209     avsm      893:        u_int i;
1.121     markus    894:        Channel *c;
                    895:
1.367     djm       896:        for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
                    897:                c = ssh->chanctxt->channels[i];
1.368     djm       898:                if (c == NULL || !c->have_remote_id)
1.121     markus    899:                        continue;
                    900:                switch (c->type) {
                    901:                case SSH_CHANNEL_CLOSED:
                    902:                case SSH_CHANNEL_DYNAMIC:
1.372     markus    903:                case SSH_CHANNEL_RDYNAMIC_OPEN:
                    904:                case SSH_CHANNEL_RDYNAMIC_FINISH:
1.121     markus    905:                case SSH_CHANNEL_X11_LISTENER:
                    906:                case SSH_CHANNEL_PORT_LISTENER:
                    907:                case SSH_CHANNEL_RPORT_LISTENER:
1.302     djm       908:                case SSH_CHANNEL_MUX_LISTENER:
                    909:                case SSH_CHANNEL_MUX_CLIENT:
1.354     markus    910:                case SSH_CHANNEL_MUX_PROXY:
1.121     markus    911:                case SSH_CHANNEL_OPENING:
                    912:                case SSH_CHANNEL_CONNECTING:
                    913:                case SSH_CHANNEL_ZOMBIE:
1.323     dtucker   914:                case SSH_CHANNEL_ABANDONED:
1.336     millert   915:                case SSH_CHANNEL_UNIX_LISTENER:
                    916:                case SSH_CHANNEL_RUNIX_LISTENER:
1.121     markus    917:                        continue;
                    918:                case SSH_CHANNEL_LARVAL:
                    919:                case SSH_CHANNEL_AUTH_SOCKET:
                    920:                case SSH_CHANNEL_OPEN:
                    921:                case SSH_CHANNEL_X11_OPEN:
                    922:                        return i;
                    923:                default:
1.403     djm       924:                        fatal_f("bad channel type %d", c->type);
1.121     markus    925:                        /* NOTREACHED */
                    926:                }
                    927:        }
                    928:        return -1;
                    929: }
                    930:
1.385     djm       931: /* Returns the state of the channel's extended usage flag */
                    932: const char *
                    933: channel_format_extended_usage(const Channel *c)
                    934: {
                    935:        if (c->efd == -1)
                    936:                return "closed";
                    937:
                    938:        switch (c->extended_usage) {
                    939:        case CHAN_EXTENDED_WRITE:
                    940:                return "write";
                    941:        case CHAN_EXTENDED_READ:
                    942:                return "read";
                    943:        case CHAN_EXTENDED_IGNORE:
                    944:                return "ignore";
                    945:        default:
                    946:                return "UNKNOWN";
                    947:        }
                    948: }
                    949:
1.386     djm       950: static char *
                    951: channel_format_status(const Channel *c)
                    952: {
                    953:        char *ret = NULL;
                    954:
1.425     djm       955:        xasprintf(&ret, "t%d [%s] %s%u i%u/%zu o%u/%zu e[%s]/%zu "
1.411     djm       956:            "fd %d/%d/%d sock %d cc %d io 0x%02x/0x%02x",
1.425     djm       957:            c->type, c->xctype != NULL ? c->xctype : c->ctype,
1.386     djm       958:            c->have_remote_id ? "r" : "nr", c->remote_id,
                    959:            c->istate, sshbuf_len(c->input),
                    960:            c->ostate, sshbuf_len(c->output),
                    961:            channel_format_extended_usage(c), sshbuf_len(c->extended),
1.411     djm       962:            c->rfd, c->wfd, c->efd, c->sock, c->ctl_chan,
                    963:            c->io_want, c->io_ready);
1.386     djm       964:        return ret;
                    965: }
                    966:
1.121     markus    967: /*
                    968:  * Returns a message describing the currently open forwarded connections,
                    969:  * suitable for sending to the client.  The message contains crlf pairs for
                    970:  * newlines.
                    971:  */
                    972: char *
1.367     djm       973: channel_open_message(struct ssh *ssh)
1.121     markus    974: {
1.367     djm       975:        struct sshbuf *buf;
1.121     markus    976:        Channel *c;
1.209     avsm      977:        u_int i;
1.367     djm       978:        int r;
1.386     djm       979:        char *cp, *ret;
1.121     markus    980:
1.367     djm       981:        if ((buf = sshbuf_new()) == NULL)
1.403     djm       982:                fatal_f("sshbuf_new");
1.367     djm       983:        if ((r = sshbuf_putf(buf,
                    984:            "The following connections are open:\r\n")) != 0)
1.403     djm       985:                fatal_fr(r, "sshbuf_putf");
1.367     djm       986:        for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
                    987:                c = ssh->chanctxt->channels[i];
1.121     markus    988:                if (c == NULL)
                    989:                        continue;
                    990:                switch (c->type) {
                    991:                case SSH_CHANNEL_X11_LISTENER:
                    992:                case SSH_CHANNEL_PORT_LISTENER:
                    993:                case SSH_CHANNEL_RPORT_LISTENER:
                    994:                case SSH_CHANNEL_CLOSED:
                    995:                case SSH_CHANNEL_AUTH_SOCKET:
                    996:                case SSH_CHANNEL_ZOMBIE:
1.323     dtucker   997:                case SSH_CHANNEL_ABANDONED:
1.302     djm       998:                case SSH_CHANNEL_MUX_LISTENER:
1.336     millert   999:                case SSH_CHANNEL_UNIX_LISTENER:
                   1000:                case SSH_CHANNEL_RUNIX_LISTENER:
1.121     markus   1001:                        continue;
                   1002:                case SSH_CHANNEL_LARVAL:
                   1003:                case SSH_CHANNEL_OPENING:
                   1004:                case SSH_CHANNEL_CONNECTING:
                   1005:                case SSH_CHANNEL_DYNAMIC:
1.372     markus   1006:                case SSH_CHANNEL_RDYNAMIC_OPEN:
                   1007:                case SSH_CHANNEL_RDYNAMIC_FINISH:
1.121     markus   1008:                case SSH_CHANNEL_OPEN:
                   1009:                case SSH_CHANNEL_X11_OPEN:
1.354     markus   1010:                case SSH_CHANNEL_MUX_PROXY:
                   1011:                case SSH_CHANNEL_MUX_CLIENT:
1.386     djm      1012:                        cp = channel_format_status(c);
                   1013:                        if ((r = sshbuf_putf(buf, "  #%d %.300s (%s)\r\n",
                   1014:                            c->self, c->remote_name, cp)) != 0) {
                   1015:                                free(cp);
1.403     djm      1016:                                fatal_fr(r, "sshbuf_putf");
1.386     djm      1017:                        }
                   1018:                        free(cp);
1.121     markus   1019:                        continue;
                   1020:                default:
1.403     djm      1021:                        fatal_f("bad channel type %d", c->type);
1.121     markus   1022:                        /* NOTREACHED */
                   1023:                }
                   1024:        }
1.367     djm      1025:        if ((ret = sshbuf_dup_string(buf)) == NULL)
1.403     djm      1026:                fatal_f("sshbuf_dup_string");
1.367     djm      1027:        sshbuf_free(buf);
                   1028:        return ret;
                   1029: }
                   1030:
                   1031: static void
                   1032: open_preamble(struct ssh *ssh, const char *where, Channel *c, const char *type)
                   1033: {
                   1034:        int r;
                   1035:
                   1036:        if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN)) != 0 ||
                   1037:            (r = sshpkt_put_cstring(ssh, type)) != 0 ||
                   1038:            (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
                   1039:            (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
                   1040:            (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0) {
1.403     djm      1041:                fatal_r(r, "%s: channel %i: open", where, c->self);
1.367     djm      1042:        }
1.121     markus   1043: }
                   1044:
                   1045: void
1.367     djm      1046: channel_send_open(struct ssh *ssh, int id)
1.121     markus   1047: {
1.367     djm      1048:        Channel *c = channel_lookup(ssh, id);
                   1049:        int r;
1.180     deraadt  1050:
1.121     markus   1051:        if (c == NULL) {
1.188     itojun   1052:                logit("channel_send_open: %d: bad id", id);
1.121     markus   1053:                return;
                   1054:        }
1.184     markus   1055:        debug2("channel %d: send open", id);
1.367     djm      1056:        open_preamble(ssh, __func__, c, c->ctype);
                   1057:        if ((r = sshpkt_send(ssh)) != 0)
1.403     djm      1058:                fatal_fr(r, "channel %i", c->self);
1.121     markus   1059: }
                   1060:
                   1061: void
1.367     djm      1062: channel_request_start(struct ssh *ssh, int id, char *service, int wantconfirm)
1.121     markus   1063: {
1.367     djm      1064:        Channel *c = channel_lookup(ssh, id);
                   1065:        int r;
1.180     deraadt  1066:
1.121     markus   1067:        if (c == NULL) {
1.403     djm      1068:                logit_f("%d: unknown channel id", id);
1.121     markus   1069:                return;
                   1070:        }
1.368     djm      1071:        if (!c->have_remote_id)
1.403     djm      1072:                fatal_f("channel %d: no remote id", c->self);
1.368     djm      1073:
1.204     djm      1074:        debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.367     djm      1075:        if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_REQUEST)) != 0 ||
                   1076:            (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
                   1077:            (r = sshpkt_put_cstring(ssh, service)) != 0 ||
                   1078:            (r = sshpkt_put_u8(ssh, wantconfirm)) != 0) {
1.403     djm      1079:                fatal_fr(r, "channel %i", c->self);
1.367     djm      1080:        }
1.121     markus   1081: }
1.241     deraadt  1082:
1.121     markus   1083: void
1.367     djm      1084: channel_register_status_confirm(struct ssh *ssh, int id,
                   1085:     channel_confirm_cb *cb, channel_confirm_abandon_cb *abandon_cb, void *ctx)
1.275     djm      1086: {
                   1087:        struct channel_confirm *cc;
                   1088:        Channel *c;
                   1089:
1.367     djm      1090:        if ((c = channel_lookup(ssh, id)) == NULL)
1.403     djm      1091:                fatal_f("%d: bad id", id);
1.275     djm      1092:
1.327     djm      1093:        cc = xcalloc(1, sizeof(*cc));
1.275     djm      1094:        cc->cb = cb;
                   1095:        cc->abandon_cb = abandon_cb;
                   1096:        cc->ctx = ctx;
                   1097:        TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
                   1098: }
                   1099:
                   1100: void
1.367     djm      1101: channel_register_open_confirm(struct ssh *ssh, int id,
                   1102:     channel_open_fn *fn, void *ctx)
1.121     markus   1103: {
1.367     djm      1104:        Channel *c = channel_lookup(ssh, id);
1.180     deraadt  1105:
1.121     markus   1106:        if (c == NULL) {
1.403     djm      1107:                logit_f("%d: bad id", id);
1.121     markus   1108:                return;
                   1109:        }
1.275     djm      1110:        c->open_confirm = fn;
                   1111:        c->open_confirm_ctx = ctx;
1.121     markus   1112: }
1.241     deraadt  1113:
1.121     markus   1114: void
1.367     djm      1115: channel_register_cleanup(struct ssh *ssh, int id,
                   1116:     channel_callback_fn *fn, int do_close)
1.121     markus   1117: {
1.367     djm      1118:        Channel *c = channel_by_id(ssh, id);
1.180     deraadt  1119:
1.121     markus   1120:        if (c == NULL) {
1.403     djm      1121:                logit_f("%d: bad id", id);
1.121     markus   1122:                return;
                   1123:        }
1.131     markus   1124:        c->detach_user = fn;
1.225     djm      1125:        c->detach_close = do_close;
1.121     markus   1126: }
1.241     deraadt  1127:
1.121     markus   1128: void
1.367     djm      1129: channel_cancel_cleanup(struct ssh *ssh, int id)
1.121     markus   1130: {
1.367     djm      1131:        Channel *c = channel_by_id(ssh, id);
1.180     deraadt  1132:
1.121     markus   1133:        if (c == NULL) {
1.403     djm      1134:                logit_f("%d: bad id", id);
1.121     markus   1135:                return;
1.52      markus   1136:        }
1.131     markus   1137:        c->detach_user = NULL;
1.225     djm      1138:        c->detach_close = 0;
1.121     markus   1139: }
1.241     deraadt  1140:
1.121     markus   1141: void
1.367     djm      1142: channel_register_filter(struct ssh *ssh, int id, channel_infilter_fn *ifn,
1.280     djm      1143:     channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
1.121     markus   1144: {
1.367     djm      1145:        Channel *c = channel_lookup(ssh, id);
1.180     deraadt  1146:
1.121     markus   1147:        if (c == NULL) {
1.403     djm      1148:                logit_f("%d: bad id", id);
1.121     markus   1149:                return;
1.52      markus   1150:        }
1.231     reyk     1151:        c->input_filter = ifn;
                   1152:        c->output_filter = ofn;
1.279     djm      1153:        c->filter_ctx = ctx;
1.280     djm      1154:        c->filter_cleanup = cfn;
1.52      markus   1155: }
                   1156:
1.49      markus   1157: void
1.367     djm      1158: channel_set_fds(struct ssh *ssh, int id, int rfd, int wfd, int efd,
1.282     dtucker  1159:     int extusage, int nonblock, int is_tty, u_int window_max)
1.1       deraadt  1160: {
1.367     djm      1161:        Channel *c = channel_lookup(ssh, id);
                   1162:        int r;
1.180     deraadt  1163:
1.121     markus   1164:        if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
                   1165:                fatal("channel_activate for non-larval channel %d.", id);
1.368     djm      1166:        if (!c->have_remote_id)
1.403     djm      1167:                fatal_f("channel %d: no remote id", c->self);
1.368     djm      1168:
1.367     djm      1169:        channel_register_fds(ssh, c, rfd, wfd, efd, extusage, nonblock, is_tty);
1.121     markus   1170:        c->type = SSH_CHANNEL_OPEN;
1.426     djm      1171:        c->lastused = monotime();
1.168     markus   1172:        c->local_window = c->local_window_max = window_max;
1.367     djm      1173:
                   1174:        if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST)) != 0 ||
                   1175:            (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
                   1176:            (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
                   1177:            (r = sshpkt_send(ssh)) != 0)
1.403     djm      1178:                fatal_fr(r, "channel %i", c->self);
1.1       deraadt  1179: }
                   1180:
1.127     itojun   1181: static void
1.410     djm      1182: channel_pre_listener(struct ssh *ssh, Channel *c)
1.41      markus   1183: {
1.410     djm      1184:        c->io_want = SSH_CHAN_IO_SOCK_R;
1.41      markus   1185: }
                   1186:
1.127     itojun   1187: static void
1.410     djm      1188: channel_pre_connecting(struct ssh *ssh, Channel *c)
1.75      markus   1189: {
                   1190:        debug3("channel %d: waiting for connection", c->self);
1.410     djm      1191:        c->io_want = SSH_CHAN_IO_SOCK_W;
1.75      markus   1192: }
                   1193:
1.127     itojun   1194: static void
1.410     djm      1195: channel_pre_open(struct ssh *ssh, Channel *c)
1.41      markus   1196: {
1.410     djm      1197:        c->io_want = 0;
1.44      markus   1198:        if (c->istate == CHAN_INPUT_OPEN &&
1.358     djm      1199:            c->remote_window > 0 &&
1.367     djm      1200:            sshbuf_len(c->input) < c->remote_window &&
                   1201:            sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
1.410     djm      1202:                c->io_want |= SSH_CHAN_IO_RFD;
1.44      markus   1203:        if (c->ostate == CHAN_OUTPUT_OPEN ||
                   1204:            c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.367     djm      1205:                if (sshbuf_len(c->output) > 0) {
1.410     djm      1206:                        c->io_want |= SSH_CHAN_IO_WFD;
1.44      markus   1207:                } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172     markus   1208:                        if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.367     djm      1209:                                debug2("channel %d: "
                   1210:                                    "obuf_empty delayed efd %d/(%zu)", c->self,
                   1211:                                    c->efd, sshbuf_len(c->extended));
1.172     markus   1212:                        else
1.367     djm      1213:                                chan_obuf_empty(ssh, c);
1.44      markus   1214:                }
                   1215:        }
                   1216:        /** XXX check close conditions, too */
1.358     djm      1217:        if (c->efd != -1 && !(c->istate == CHAN_INPUT_CLOSED &&
                   1218:            c->ostate == CHAN_OUTPUT_CLOSED)) {
1.44      markus   1219:                if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1.367     djm      1220:                    sshbuf_len(c->extended) > 0)
1.410     djm      1221:                        c->io_want |= SSH_CHAN_IO_EFD_W;
1.306     djm      1222:                else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
                   1223:                    (c->extended_usage == CHAN_EXTENDED_READ ||
                   1224:                    c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.367     djm      1225:                    sshbuf_len(c->extended) < c->remote_window)
1.410     djm      1226:                        c->io_want |= SSH_CHAN_IO_EFD_R;
1.44      markus   1227:        }
1.204     djm      1228:        /* XXX: What about efd? races? */
1.44      markus   1229: }
                   1230:
1.41      markus   1231: /*
                   1232:  * This is a special state for X11 authentication spoofing.  An opened X11
                   1233:  * connection (when authentication spoofing is being done) remains in this
                   1234:  * state until the first packet has been completely read.  The authentication
                   1235:  * data in that packet is then substituted by the real data if it matches the
                   1236:  * fake data, and the channel is put into normal mode.
1.51      markus   1237:  * XXX All this happens at the client side.
1.121     markus   1238:  * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41      markus   1239:  */
1.127     itojun   1240: static int
1.367     djm      1241: x11_open_helper(struct ssh *ssh, struct sshbuf *b)
1.1       deraadt  1242: {
1.367     djm      1243:        struct ssh_channels *sc = ssh->chanctxt;
1.77      markus   1244:        u_char *ucp;
                   1245:        u_int proto_len, data_len;
1.25      markus   1246:
1.347     djm      1247:        /* Is this being called after the refusal deadline? */
1.367     djm      1248:        if (sc->x11_refuse_time != 0 &&
1.428   ! dtucker  1249:            monotime() >= sc->x11_refuse_time) {
1.347     djm      1250:                verbose("Rejected X11 connection after ForwardX11Timeout "
                   1251:                    "expired");
                   1252:                return -1;
                   1253:        }
                   1254:
1.41      markus   1255:        /* Check if the fixed size part of the packet is in buffer. */
1.367     djm      1256:        if (sshbuf_len(b) < 12)
1.41      markus   1257:                return 0;
                   1258:
                   1259:        /* Parse the lengths of variable-length fields. */
1.367     djm      1260:        ucp = sshbuf_mutable_ptr(b);
1.41      markus   1261:        if (ucp[0] == 0x42) {   /* Byte order MSB first. */
                   1262:                proto_len = 256 * ucp[6] + ucp[7];
                   1263:                data_len = 256 * ucp[8] + ucp[9];
                   1264:        } else if (ucp[0] == 0x6c) {    /* Byte order LSB first. */
                   1265:                proto_len = ucp[6] + 256 * ucp[7];
                   1266:                data_len = ucp[8] + 256 * ucp[9];
                   1267:        } else {
1.194     markus   1268:                debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148     deraadt  1269:                    ucp[0]);
1.41      markus   1270:                return -1;
                   1271:        }
                   1272:
                   1273:        /* Check if the whole packet is in buffer. */
1.367     djm      1274:        if (sshbuf_len(b) <
1.41      markus   1275:            12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
                   1276:                return 0;
                   1277:
                   1278:        /* Check if authentication protocol matches. */
1.367     djm      1279:        if (proto_len != strlen(sc->x11_saved_proto) ||
                   1280:            memcmp(ucp + 12, sc->x11_saved_proto, proto_len) != 0) {
1.194     markus   1281:                debug2("X11 connection uses different authentication protocol.");
1.41      markus   1282:                return -1;
                   1283:        }
                   1284:        /* Check if authentication data matches our fake data. */
1.367     djm      1285:        if (data_len != sc->x11_fake_data_len ||
1.308     djm      1286:            timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
1.367     djm      1287:                sc->x11_fake_data, sc->x11_fake_data_len) != 0) {
1.194     markus   1288:                debug2("X11 auth data does not match fake data.");
1.41      markus   1289:                return -1;
                   1290:        }
                   1291:        /* Check fake data length */
1.367     djm      1292:        if (sc->x11_fake_data_len != sc->x11_saved_data_len) {
1.41      markus   1293:                error("X11 fake_data_len %d != saved_data_len %d",
1.367     djm      1294:                    sc->x11_fake_data_len, sc->x11_saved_data_len);
1.41      markus   1295:                return -1;
                   1296:        }
                   1297:        /*
                   1298:         * Received authentication protocol and data match
                   1299:         * our fake data. Substitute the fake data with real
                   1300:         * data.
                   1301:         */
                   1302:        memcpy(ucp + 12 + ((proto_len + 3) & ~3),
1.367     djm      1303:            sc->x11_saved_data, sc->x11_saved_data_len);
1.41      markus   1304:        return 1;
                   1305: }
                   1306:
1.423     djm      1307: void
                   1308: channel_force_close(struct ssh *ssh, Channel *c, int abandon)
                   1309: {
                   1310:        debug3_f("channel %d: forcibly closing", c->self);
                   1311:        if (c->istate == CHAN_INPUT_OPEN)
                   1312:                chan_read_failed(ssh, c);
                   1313:        if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
                   1314:                sshbuf_reset(c->input);
                   1315:                chan_ibuf_empty(ssh, c);
                   1316:        }
                   1317:        if (c->ostate == CHAN_OUTPUT_OPEN ||
                   1318:            c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
                   1319:                sshbuf_reset(c->output);
                   1320:                chan_write_failed(ssh, c);
                   1321:        }
                   1322:        if (c->detach_user)
                   1323:                c->detach_user(ssh, c->self, 1, NULL);
                   1324:        if (c->efd != -1)
                   1325:                channel_close_fd(ssh, c, &c->efd);
                   1326:        if (abandon)
                   1327:                c->type = SSH_CHANNEL_ABANDONED;
1.426     djm      1328:        /* exempt from inactivity timeouts */
                   1329:        c->inactive_deadline = 0;
                   1330:        c->lastused = 0;
1.423     djm      1331: }
                   1332:
1.127     itojun   1333: static void
1.410     djm      1334: channel_pre_x11_open(struct ssh *ssh, Channel *c)
1.41      markus   1335: {
1.367     djm      1336:        int ret = x11_open_helper(ssh, c->output);
1.133     markus   1337:
                   1338:        /* c->force_drain = 1; */
                   1339:
1.41      markus   1340:        if (ret == 1) {
                   1341:                c->type = SSH_CHANNEL_OPEN;
1.426     djm      1342:                c->lastused = monotime();
1.410     djm      1343:                channel_pre_open(ssh, c);
1.41      markus   1344:        } else if (ret == -1) {
1.423     djm      1345:                logit("X11 connection rejected because of wrong "
                   1346:                    "authentication.");
1.367     djm      1347:                debug2("X11 rejected %d i%d/o%d",
                   1348:                    c->self, c->istate, c->ostate);
1.423     djm      1349:                channel_force_close(ssh, c, 0);
1.41      markus   1350:        }
                   1351: }
1.25      markus   1352:
1.302     djm      1353: static void
1.410     djm      1354: channel_pre_mux_client(struct ssh *ssh, Channel *c)
1.302     djm      1355: {
1.410     djm      1356:        c->io_want = 0;
1.304     djm      1357:        if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1.367     djm      1358:            sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
1.410     djm      1359:                c->io_want |= SSH_CHAN_IO_RFD;
1.302     djm      1360:        if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
                   1361:                /* clear buffer immediately (discard any partial packet) */
1.367     djm      1362:                sshbuf_reset(c->input);
                   1363:                chan_ibuf_empty(ssh, c);
1.302     djm      1364:                /* Start output drain. XXX just kill chan? */
1.367     djm      1365:                chan_rcvd_oclose(ssh, c);
1.302     djm      1366:        }
                   1367:        if (c->ostate == CHAN_OUTPUT_OPEN ||
                   1368:            c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.367     djm      1369:                if (sshbuf_len(c->output) > 0)
1.410     djm      1370:                        c->io_want |= SSH_CHAN_IO_WFD;
1.302     djm      1371:                else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1.367     djm      1372:                        chan_obuf_empty(ssh, c);
1.302     djm      1373:        }
                   1374: }
                   1375:
1.104     markus   1376: /* try to decode a socks4 header */
1.127     itojun   1377: static int
1.372     markus   1378: channel_decode_socks4(Channel *c, struct sshbuf *input, struct sshbuf *output)
1.103     markus   1379: {
1.367     djm      1380:        const u_char *p;
                   1381:        char *host;
1.292     djm      1382:        u_int len, have, i, found, need;
1.148     deraadt  1383:        char username[256];
1.103     markus   1384:        struct {
                   1385:                u_int8_t version;
                   1386:                u_int8_t command;
                   1387:                u_int16_t dest_port;
1.104     markus   1388:                struct in_addr dest_addr;
1.103     markus   1389:        } s4_req, s4_rsp;
1.367     djm      1390:        int r;
1.103     markus   1391:
1.104     markus   1392:        debug2("channel %d: decode socks4", c->self);
1.109     markus   1393:
1.372     markus   1394:        have = sshbuf_len(input);
1.109     markus   1395:        len = sizeof(s4_req);
                   1396:        if (have < len)
                   1397:                return 0;
1.372     markus   1398:        p = sshbuf_ptr(input);
1.292     djm      1399:
                   1400:        need = 1;
                   1401:        /* SOCKS4A uses an invalid IP address 0.0.0.x */
                   1402:        if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
                   1403:                debug2("channel %d: socks4a request", c->self);
                   1404:                /* ... and needs an extra string (the hostname) */
                   1405:                need = 2;
                   1406:        }
                   1407:        /* Check for terminating NUL on the string(s) */
1.109     markus   1408:        for (found = 0, i = len; i < have; i++) {
                   1409:                if (p[i] == '\0') {
1.292     djm      1410:                        found++;
                   1411:                        if (found == need)
                   1412:                                break;
1.109     markus   1413:                }
                   1414:                if (i > 1024) {
                   1415:                        /* the peer is probably sending garbage */
                   1416:                        debug("channel %d: decode socks4: too long",
                   1417:                            c->self);
                   1418:                        return -1;
                   1419:                }
                   1420:        }
1.292     djm      1421:        if (found < need)
1.109     markus   1422:                return 0;
1.372     markus   1423:        if ((r = sshbuf_get(input, &s4_req.version, 1)) != 0 ||
                   1424:            (r = sshbuf_get(input, &s4_req.command, 1)) != 0 ||
                   1425:            (r = sshbuf_get(input, &s4_req.dest_port, 2)) != 0 ||
                   1426:            (r = sshbuf_get(input, &s4_req.dest_addr, 4)) != 0) {
1.403     djm      1427:                debug_r(r, "channels %d: decode socks4", c->self);
1.367     djm      1428:                return -1;
                   1429:        }
1.372     markus   1430:        have = sshbuf_len(input);
                   1431:        p = sshbuf_ptr(input);
1.364     djm      1432:        if (memchr(p, '\0', have) == NULL) {
1.403     djm      1433:                error("channel %d: decode socks4: unterminated user", c->self);
1.364     djm      1434:                return -1;
                   1435:        }
1.103     markus   1436:        len = strlen(p);
1.106     markus   1437:        debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.367     djm      1438:        len++; /* trailing '\0' */
1.103     markus   1439:        strlcpy(username, p, sizeof(username));
1.403     djm      1440:        if ((r = sshbuf_consume(input, len)) != 0)
                   1441:                fatal_fr(r, "channel %d: consume", c->self);
1.321     djm      1442:        free(c->path);
                   1443:        c->path = NULL;
1.292     djm      1444:        if (need == 1) {                        /* SOCKS4: one string */
                   1445:                host = inet_ntoa(s4_req.dest_addr);
1.293     djm      1446:                c->path = xstrdup(host);
1.292     djm      1447:        } else {                                /* SOCKS4A: two strings */
1.372     markus   1448:                have = sshbuf_len(input);
                   1449:                p = sshbuf_ptr(input);
1.364     djm      1450:                if (memchr(p, '\0', have) == NULL) {
                   1451:                        error("channel %d: decode socks4a: host not nul "
                   1452:                            "terminated", c->self);
                   1453:                        return -1;
                   1454:                }
1.292     djm      1455:                len = strlen(p);
                   1456:                debug2("channel %d: decode socks4a: host %s/%d",
                   1457:                    c->self, p, len);
                   1458:                len++;                          /* trailing '\0' */
1.293     djm      1459:                if (len > NI_MAXHOST) {
1.292     djm      1460:                        error("channel %d: hostname \"%.100s\" too long",
                   1461:                            c->self, p);
                   1462:                        return -1;
                   1463:                }
1.293     djm      1464:                c->path = xstrdup(p);
1.403     djm      1465:                if ((r = sshbuf_consume(input, len)) != 0)
                   1466:                        fatal_fr(r, "channel %d: consume", c->self);
1.292     djm      1467:        }
1.103     markus   1468:        c->host_port = ntohs(s4_req.dest_port);
1.148     deraadt  1469:
1.194     markus   1470:        debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.292     djm      1471:            c->self, c->path, c->host_port, s4_req.command);
1.103     markus   1472:
1.104     markus   1473:        if (s4_req.command != 1) {
1.292     djm      1474:                debug("channel %d: cannot handle: %s cn %d",
                   1475:                    c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1.104     markus   1476:                return -1;
1.103     markus   1477:        }
1.104     markus   1478:        s4_rsp.version = 0;                     /* vn: 0 for reply */
                   1479:        s4_rsp.command = 90;                    /* cd: req granted */
1.103     markus   1480:        s4_rsp.dest_port = 0;                   /* ignored */
1.104     markus   1481:        s4_rsp.dest_addr.s_addr = INADDR_ANY;   /* ignored */
1.403     djm      1482:        if ((r = sshbuf_put(output, &s4_rsp, sizeof(s4_rsp))) != 0)
                   1483:                fatal_fr(r, "channel %d: append reply", c->self);
1.104     markus   1484:        return 1;
                   1485: }
                   1486:
1.193     markus   1487: /* try to decode a socks5 header */
                   1488: #define SSH_SOCKS5_AUTHDONE    0x1000
                   1489: #define SSH_SOCKS5_NOAUTH      0x00
                   1490: #define SSH_SOCKS5_IPV4                0x01
                   1491: #define SSH_SOCKS5_DOMAIN      0x03
                   1492: #define SSH_SOCKS5_IPV6                0x04
                   1493: #define SSH_SOCKS5_CONNECT     0x01
                   1494: #define SSH_SOCKS5_SUCCESS     0x00
                   1495:
                   1496: static int
1.372     markus   1497: channel_decode_socks5(Channel *c, struct sshbuf *input, struct sshbuf *output)
1.193     markus   1498: {
1.367     djm      1499:        /* XXX use get/put_u8 instead of trusting struct padding */
1.193     markus   1500:        struct {
                   1501:                u_int8_t version;
                   1502:                u_int8_t command;
                   1503:                u_int8_t reserved;
                   1504:                u_int8_t atyp;
                   1505:        } s5_req, s5_rsp;
                   1506:        u_int16_t dest_port;
1.324     djm      1507:        char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1.367     djm      1508:        const u_char *p;
1.252     djm      1509:        u_int have, need, i, found, nmethods, addrlen, af;
1.367     djm      1510:        int r;
1.193     markus   1511:
                   1512:        debug2("channel %d: decode socks5", c->self);
1.372     markus   1513:        p = sshbuf_ptr(input);
1.193     markus   1514:        if (p[0] != 0x05)
                   1515:                return -1;
1.372     markus   1516:        have = sshbuf_len(input);
1.193     markus   1517:        if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
                   1518:                /* format: ver | nmethods | methods */
1.198     djm      1519:                if (have < 2)
1.193     markus   1520:                        return 0;
                   1521:                nmethods = p[1];
                   1522:                if (have < nmethods + 2)
                   1523:                        return 0;
                   1524:                /* look for method: "NO AUTHENTICATION REQUIRED" */
1.268     stevesk  1525:                for (found = 0, i = 2; i < nmethods + 2; i++) {
1.264     stevesk  1526:                        if (p[i] == SSH_SOCKS5_NOAUTH) {
1.193     markus   1527:                                found = 1;
                   1528:                                break;
                   1529:                        }
                   1530:                }
                   1531:                if (!found) {
                   1532:                        debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
                   1533:                            c->self);
                   1534:                        return -1;
                   1535:                }
1.403     djm      1536:                if ((r = sshbuf_consume(input, nmethods + 2)) != 0)
                   1537:                        fatal_fr(r, "channel %d: consume", c->self);
1.367     djm      1538:                /* version, method */
1.372     markus   1539:                if ((r = sshbuf_put_u8(output, 0x05)) != 0 ||
1.403     djm      1540:                    (r = sshbuf_put_u8(output, SSH_SOCKS5_NOAUTH)) != 0)
                   1541:                        fatal_fr(r, "channel %d: append reply", c->self);
1.193     markus   1542:                c->flags |= SSH_SOCKS5_AUTHDONE;
                   1543:                debug2("channel %d: socks5 auth done", c->self);
                   1544:                return 0;                               /* need more */
                   1545:        }
                   1546:        debug2("channel %d: socks5 post auth", c->self);
                   1547:        if (have < sizeof(s5_req)+1)
                   1548:                return 0;                       /* need more */
1.247     deraadt  1549:        memcpy(&s5_req, p, sizeof(s5_req));
1.193     markus   1550:        if (s5_req.version != 0x05 ||
                   1551:            s5_req.command != SSH_SOCKS5_CONNECT ||
                   1552:            s5_req.reserved != 0x00) {
1.194     markus   1553:                debug2("channel %d: only socks5 connect supported", c->self);
1.193     markus   1554:                return -1;
                   1555:        }
1.213     deraadt  1556:        switch (s5_req.atyp){
1.193     markus   1557:        case SSH_SOCKS5_IPV4:
                   1558:                addrlen = 4;
                   1559:                af = AF_INET;
                   1560:                break;
                   1561:        case SSH_SOCKS5_DOMAIN:
                   1562:                addrlen = p[sizeof(s5_req)];
                   1563:                af = -1;
                   1564:                break;
                   1565:        case SSH_SOCKS5_IPV6:
                   1566:                addrlen = 16;
                   1567:                af = AF_INET6;
                   1568:                break;
                   1569:        default:
1.194     markus   1570:                debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193     markus   1571:                return -1;
                   1572:        }
1.252     djm      1573:        need = sizeof(s5_req) + addrlen + 2;
                   1574:        if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
                   1575:                need++;
                   1576:        if (have < need)
1.193     markus   1577:                return 0;
1.403     djm      1578:        if ((r = sshbuf_consume(input, sizeof(s5_req))) != 0)
                   1579:                fatal_fr(r, "channel %d: consume", c->self);
1.367     djm      1580:        if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
                   1581:                /* host string length */
1.403     djm      1582:                if ((r = sshbuf_consume(input, 1)) != 0)
                   1583:                        fatal_fr(r, "channel %d: consume", c->self);
1.367     djm      1584:        }
1.372     markus   1585:        if ((r = sshbuf_get(input, &dest_addr, addrlen)) != 0 ||
                   1586:            (r = sshbuf_get(input, &dest_port, 2)) != 0) {
1.403     djm      1587:                debug_r(r, "channel %d: parse addr/port", c->self);
1.367     djm      1588:                return -1;
                   1589:        }
1.193     markus   1590:        dest_addr[addrlen] = '\0';
1.321     djm      1591:        free(c->path);
                   1592:        c->path = NULL;
1.293     djm      1593:        if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1.294     djm      1594:                if (addrlen >= NI_MAXHOST) {
1.293     djm      1595:                        error("channel %d: dynamic request: socks5 hostname "
                   1596:                            "\"%.100s\" too long", c->self, dest_addr);
                   1597:                        return -1;
                   1598:                }
                   1599:                c->path = xstrdup(dest_addr);
                   1600:        } else {
                   1601:                if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
                   1602:                        return -1;
                   1603:                c->path = xstrdup(ntop);
                   1604:        }
1.193     markus   1605:        c->host_port = ntohs(dest_port);
1.198     djm      1606:
1.194     markus   1607:        debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193     markus   1608:            c->self, c->path, c->host_port, s5_req.command);
                   1609:
                   1610:        s5_rsp.version = 0x05;
                   1611:        s5_rsp.command = SSH_SOCKS5_SUCCESS;
                   1612:        s5_rsp.reserved = 0;                    /* ignored */
                   1613:        s5_rsp.atyp = SSH_SOCKS5_IPV4;
                   1614:        dest_port = 0;                          /* ignored */
                   1615:
1.372     markus   1616:        if ((r = sshbuf_put(output, &s5_rsp, sizeof(s5_rsp))) != 0 ||
                   1617:            (r = sshbuf_put_u32(output, ntohl(INADDR_ANY))) != 0 ||
                   1618:            (r = sshbuf_put(output, &dest_port, sizeof(dest_port))) != 0)
1.403     djm      1619:                fatal_fr(r, "channel %d: append reply", c->self);
1.193     markus   1620:        return 1;
1.301     dtucker  1621: }
                   1622:
                   1623: Channel *
1.367     djm      1624: channel_connect_stdio_fwd(struct ssh *ssh,
1.407     djm      1625:     const char *host_to_connect, u_short port_to_connect,
                   1626:     int in, int out, int nonblock)
1.301     dtucker  1627: {
                   1628:        Channel *c;
                   1629:
1.403     djm      1630:        debug_f("%s:%d", host_to_connect, port_to_connect);
1.301     dtucker  1631:
1.367     djm      1632:        c = channel_new(ssh, "stdio-forward", SSH_CHANNEL_OPENING, in, out,
1.301     dtucker  1633:            -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.407     djm      1634:            0, "stdio-forward", nonblock);
1.301     dtucker  1635:
                   1636:        c->path = xstrdup(host_to_connect);
                   1637:        c->host_port = port_to_connect;
                   1638:        c->listening_port = 0;
                   1639:        c->force_drain = 1;
                   1640:
1.367     djm      1641:        channel_register_fds(ssh, c, in, out, -1, 0, 1, 0);
                   1642:        port_open_helper(ssh, c, "direct-tcpip");
1.301     dtucker  1643:
                   1644:        return c;
1.193     markus   1645: }
                   1646:
1.104     markus   1647: /* dynamic port forwarding */
1.127     itojun   1648: static void
1.410     djm      1649: channel_pre_dynamic(struct ssh *ssh, Channel *c)
1.104     markus   1650: {
1.367     djm      1651:        const u_char *p;
1.217     djm      1652:        u_int have;
                   1653:        int ret;
1.103     markus   1654:
1.410     djm      1655:        c->io_want = 0;
1.367     djm      1656:        have = sshbuf_len(c->input);
1.104     markus   1657:        debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.367     djm      1658:        /* sshbuf_dump(c->input, stderr); */
1.104     markus   1659:        /* check if the fixed size part of the packet is in buffer. */
1.193     markus   1660:        if (have < 3) {
1.104     markus   1661:                /* need more */
1.410     djm      1662:                c->io_want |= SSH_CHAN_IO_RFD;
1.104     markus   1663:                return;
                   1664:        }
                   1665:        /* try to guess the protocol */
1.367     djm      1666:        p = sshbuf_ptr(c->input);
                   1667:        /* XXX sshbuf_peek_u8? */
1.104     markus   1668:        switch (p[0]) {
                   1669:        case 0x04:
1.372     markus   1670:                ret = channel_decode_socks4(c, c->input, c->output);
1.193     markus   1671:                break;
                   1672:        case 0x05:
1.372     markus   1673:                ret = channel_decode_socks5(c, c->input, c->output);
1.104     markus   1674:                break;
                   1675:        default:
                   1676:                ret = -1;
                   1677:                break;
                   1678:        }
                   1679:        if (ret < 0) {
1.367     djm      1680:                chan_mark_dead(ssh, c);
1.104     markus   1681:        } else if (ret == 0) {
                   1682:                debug2("channel %d: pre_dynamic: need more", c->self);
                   1683:                /* need more */
1.410     djm      1684:                c->io_want |= SSH_CHAN_IO_RFD;
1.372     markus   1685:                if (sshbuf_len(c->output))
1.410     djm      1686:                        c->io_want |= SSH_CHAN_IO_WFD;
1.104     markus   1687:        } else {
                   1688:                /* switch to the next state */
                   1689:                c->type = SSH_CHANNEL_OPENING;
1.367     djm      1690:                port_open_helper(ssh, c, "direct-tcpip");
1.104     markus   1691:        }
1.103     markus   1692: }
                   1693:
1.372     markus   1694: /* simulate read-error */
                   1695: static void
                   1696: rdynamic_close(struct ssh *ssh, Channel *c)
                   1697: {
                   1698:        c->type = SSH_CHANNEL_OPEN;
1.423     djm      1699:        channel_force_close(ssh, c, 0);
1.372     markus   1700: }
                   1701:
                   1702: /* reverse dynamic port forwarding */
                   1703: static void
1.411     djm      1704: channel_before_prepare_io_rdynamic(struct ssh *ssh, Channel *c)
1.372     markus   1705: {
                   1706:        const u_char *p;
                   1707:        u_int have, len;
                   1708:        int r, ret;
                   1709:
                   1710:        have = sshbuf_len(c->output);
                   1711:        debug2("channel %d: pre_rdynamic: have %d", c->self, have);
                   1712:        /* sshbuf_dump(c->output, stderr); */
                   1713:        /* EOF received */
                   1714:        if (c->flags & CHAN_EOF_RCVD) {
1.403     djm      1715:                if ((r = sshbuf_consume(c->output, have)) != 0)
                   1716:                        fatal_fr(r, "channel %d: consume", c->self);
1.372     markus   1717:                rdynamic_close(ssh, c);
                   1718:                return;
                   1719:        }
                   1720:        /* check if the fixed size part of the packet is in buffer. */
                   1721:        if (have < 3)
                   1722:                return;
                   1723:        /* try to guess the protocol */
                   1724:        p = sshbuf_ptr(c->output);
                   1725:        switch (p[0]) {
                   1726:        case 0x04:
                   1727:                /* switch input/output for reverse forwarding */
                   1728:                ret = channel_decode_socks4(c, c->output, c->input);
                   1729:                break;
                   1730:        case 0x05:
                   1731:                ret = channel_decode_socks5(c, c->output, c->input);
                   1732:                break;
                   1733:        default:
                   1734:                ret = -1;
                   1735:                break;
                   1736:        }
                   1737:        if (ret < 0) {
                   1738:                rdynamic_close(ssh, c);
                   1739:        } else if (ret == 0) {
                   1740:                debug2("channel %d: pre_rdynamic: need more", c->self);
                   1741:                /* send socks request to peer */
                   1742:                len = sshbuf_len(c->input);
                   1743:                if (len > 0 && len < c->remote_window) {
                   1744:                        if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
                   1745:                            (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
                   1746:                            (r = sshpkt_put_stringb(ssh, c->input)) != 0 ||
                   1747:                            (r = sshpkt_send(ssh)) != 0) {
1.403     djm      1748:                                fatal_fr(r, "channel %i: rdynamic", c->self);
1.372     markus   1749:                        }
1.403     djm      1750:                        if ((r = sshbuf_consume(c->input, len)) != 0)
                   1751:                                fatal_fr(r, "channel %d: consume", c->self);
1.372     markus   1752:                        c->remote_window -= len;
                   1753:                }
                   1754:        } else if (rdynamic_connect_finish(ssh, c) < 0) {
                   1755:                /* the connect failed */
                   1756:                rdynamic_close(ssh, c);
                   1757:        }
                   1758: }
                   1759:
1.41      markus   1760: /* This is our fake X11 server socket. */
1.127     itojun   1761: static void
1.410     djm      1762: channel_post_x11_listener(struct ssh *ssh, Channel *c)
1.41      markus   1763: {
1.113     markus   1764:        Channel *nc;
1.285     djm      1765:        struct sockaddr_storage addr;
1.367     djm      1766:        int r, newsock, oerrno, remote_port;
1.41      markus   1767:        socklen_t addrlen;
1.85      markus   1768:        char buf[16384], *remote_ipaddr;
1.25      markus   1769:
1.410     djm      1770:        if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
1.367     djm      1771:                return;
                   1772:
                   1773:        debug("X11 connection requested.");
                   1774:        addrlen = sizeof(addr);
                   1775:        newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
                   1776:        if (c->single_connection) {
                   1777:                oerrno = errno;
                   1778:                debug2("single_connection: closing X11 listener.");
1.407     djm      1779:                channel_close_fd(ssh, c, &c->sock);
1.367     djm      1780:                chan_mark_dead(ssh, c);
                   1781:                errno = oerrno;
                   1782:        }
1.393     deraadt  1783:        if (newsock == -1) {
1.367     djm      1784:                if (errno != EINTR && errno != EWOULDBLOCK &&
                   1785:                    errno != ECONNABORTED)
                   1786:                        error("accept: %.100s", strerror(errno));
                   1787:                if (errno == EMFILE || errno == ENFILE)
                   1788:                        c->notbefore = monotime() + 1;
                   1789:                return;
                   1790:        }
                   1791:        set_nodelay(newsock);
                   1792:        remote_ipaddr = get_peer_ipaddr(newsock);
                   1793:        remote_port = get_peer_port(newsock);
                   1794:        snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
                   1795:            remote_ipaddr, remote_port);
                   1796:
1.424     djm      1797:        nc = channel_new(ssh, "x11-connection",
1.367     djm      1798:            SSH_CHANNEL_OPENING, newsock, newsock, -1,
                   1799:            c->local_window_max, c->local_maxpacket, 0, buf, 1);
                   1800:        open_preamble(ssh, __func__, nc, "x11");
1.378     djm      1801:        if ((r = sshpkt_put_cstring(ssh, remote_ipaddr)) != 0 ||
                   1802:            (r = sshpkt_put_u32(ssh, remote_port)) != 0) {
1.403     djm      1803:                fatal_fr(r, "channel %i: reply", c->self);
1.41      markus   1804:        }
1.367     djm      1805:        if ((r = sshpkt_send(ssh)) != 0)
1.403     djm      1806:                fatal_fr(r, "channel %i: send", c->self);
1.367     djm      1807:        free(remote_ipaddr);
1.41      markus   1808: }
1.25      markus   1809:
1.127     itojun   1810: static void
1.367     djm      1811: port_open_helper(struct ssh *ssh, Channel *c, char *rtype)
1.103     markus   1812: {
1.328     djm      1813:        char *local_ipaddr = get_local_ipaddr(c->sock);
1.350     djm      1814:        int local_port = c->sock == -1 ? 65536 : get_local_port(c->sock);
1.103     markus   1815:        char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216     markus   1816:        int remote_port = get_peer_port(c->sock);
1.367     djm      1817:        int r;
1.303     djm      1818:
                   1819:        if (remote_port == -1) {
                   1820:                /* Fake addr/port to appease peers that validate it (Tectia) */
1.321     djm      1821:                free(remote_ipaddr);
1.303     djm      1822:                remote_ipaddr = xstrdup("127.0.0.1");
                   1823:                remote_port = 65535;
                   1824:        }
1.103     markus   1825:
1.367     djm      1826:        free(c->remote_name);
                   1827:        xasprintf(&c->remote_name,
1.103     markus   1828:            "%s: listening port %d for %.100s port %d, "
1.328     djm      1829:            "connect from %.200s port %d to %.100s port %d",
1.103     markus   1830:            rtype, c->listening_port, c->path, c->host_port,
1.328     djm      1831:            remote_ipaddr, remote_port, local_ipaddr, local_port);
1.103     markus   1832:
1.367     djm      1833:        open_preamble(ssh, __func__, c, rtype);
1.358     djm      1834:        if (strcmp(rtype, "direct-tcpip") == 0) {
                   1835:                /* target host, port */
1.367     djm      1836:                if ((r = sshpkt_put_cstring(ssh, c->path)) != 0 ||
1.403     djm      1837:                    (r = sshpkt_put_u32(ssh, c->host_port)) != 0)
                   1838:                        fatal_fr(r, "channel %i: reply", c->self);
1.358     djm      1839:        } else if (strcmp(rtype, "direct-streamlocal@openssh.com") == 0) {
                   1840:                /* target path */
1.403     djm      1841:                if ((r = sshpkt_put_cstring(ssh, c->path)) != 0)
                   1842:                        fatal_fr(r, "channel %i: reply", c->self);
1.358     djm      1843:        } else if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
                   1844:                /* listen path */
1.403     djm      1845:                if ((r = sshpkt_put_cstring(ssh, c->path)) != 0)
                   1846:                        fatal_fr(r, "channel %i: reply", c->self);
1.103     markus   1847:        } else {
1.358     djm      1848:                /* listen address, port */
1.367     djm      1849:                if ((r = sshpkt_put_cstring(ssh, c->path)) != 0 ||
1.403     djm      1850:                    (r = sshpkt_put_u32(ssh, local_port)) != 0)
                   1851:                        fatal_fr(r, "channel %i: reply", c->self);
1.358     djm      1852:        }
                   1853:        if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
                   1854:                /* reserved for future owner/mode info */
1.403     djm      1855:                if ((r = sshpkt_put_cstring(ssh, "")) != 0)
                   1856:                        fatal_fr(r, "channel %i: reply", c->self);
1.358     djm      1857:        } else {
                   1858:                /* originator host and port */
1.367     djm      1859:                if ((r = sshpkt_put_cstring(ssh, remote_ipaddr)) != 0 ||
1.403     djm      1860:                    (r = sshpkt_put_u32(ssh, (u_int)remote_port)) != 0)
                   1861:                        fatal_fr(r, "channel %i: reply", c->self);
1.103     markus   1862:        }
1.367     djm      1863:        if ((r = sshpkt_send(ssh)) != 0)
1.403     djm      1864:                fatal_fr(r, "channel %i: send", c->self);
1.321     djm      1865:        free(remote_ipaddr);
1.328     djm      1866:        free(local_ipaddr);
1.103     markus   1867: }
                   1868:
1.347     djm      1869: void
1.428   ! dtucker  1870: channel_set_x11_refuse_time(struct ssh *ssh, time_t refuse_time)
1.347     djm      1871: {
1.367     djm      1872:        ssh->chanctxt->x11_refuse_time = refuse_time;
1.226     djm      1873: }
                   1874:
1.41      markus   1875: /*
                   1876:  * This socket is listening for connections to a forwarded TCP/IP port.
                   1877:  */
1.127     itojun   1878: static void
1.410     djm      1879: channel_post_port_listener(struct ssh *ssh, Channel *c)
1.41      markus   1880: {
1.103     markus   1881:        Channel *nc;
1.285     djm      1882:        struct sockaddr_storage addr;
1.113     markus   1883:        int newsock, nextstate;
1.41      markus   1884:        socklen_t addrlen;
1.103     markus   1885:        char *rtype;
1.73      markus   1886:
1.410     djm      1887:        if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
1.367     djm      1888:                return;
                   1889:
                   1890:        debug("Connection to port %d forwarding to %.100s port %d requested.",
                   1891:            c->listening_port, c->path, c->host_port);
1.103     markus   1892:
1.367     djm      1893:        if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
                   1894:                nextstate = SSH_CHANNEL_OPENING;
                   1895:                rtype = "forwarded-tcpip";
                   1896:        } else if (c->type == SSH_CHANNEL_RUNIX_LISTENER) {
                   1897:                nextstate = SSH_CHANNEL_OPENING;
                   1898:                rtype = "forwarded-streamlocal@openssh.com";
                   1899:        } else if (c->host_port == PORT_STREAMLOCAL) {
                   1900:                nextstate = SSH_CHANNEL_OPENING;
                   1901:                rtype = "direct-streamlocal@openssh.com";
                   1902:        } else if (c->host_port == 0) {
                   1903:                nextstate = SSH_CHANNEL_DYNAMIC;
                   1904:                rtype = "dynamic-tcpip";
                   1905:        } else {
                   1906:                nextstate = SSH_CHANNEL_OPENING;
                   1907:                rtype = "direct-tcpip";
                   1908:        }
1.103     markus   1909:
1.367     djm      1910:        addrlen = sizeof(addr);
                   1911:        newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.393     deraadt  1912:        if (newsock == -1) {
1.367     djm      1913:                if (errno != EINTR && errno != EWOULDBLOCK &&
                   1914:                    errno != ECONNABORTED)
                   1915:                        error("accept: %.100s", strerror(errno));
                   1916:                if (errno == EMFILE || errno == ENFILE)
                   1917:                        c->notbefore = monotime() + 1;
                   1918:                return;
1.41      markus   1919:        }
1.367     djm      1920:        if (c->host_port != PORT_STREAMLOCAL)
                   1921:                set_nodelay(newsock);
                   1922:        nc = channel_new(ssh, rtype, nextstate, newsock, newsock, -1,
                   1923:            c->local_window_max, c->local_maxpacket, 0, rtype, 1);
                   1924:        nc->listening_port = c->listening_port;
                   1925:        nc->host_port = c->host_port;
                   1926:        if (c->path != NULL)
                   1927:                nc->path = xstrdup(c->path);
                   1928:
                   1929:        if (nextstate != SSH_CHANNEL_DYNAMIC)
                   1930:                port_open_helper(ssh, nc, rtype);
1.41      markus   1931: }
1.25      markus   1932:
1.41      markus   1933: /*
                   1934:  * This is the authentication agent socket listening for connections from
                   1935:  * clients.
                   1936:  */
1.127     itojun   1937: static void
1.410     djm      1938: channel_post_auth_listener(struct ssh *ssh, Channel *c)
1.41      markus   1939: {
1.113     markus   1940:        Channel *nc;
1.367     djm      1941:        int r, newsock;
1.285     djm      1942:        struct sockaddr_storage addr;
1.41      markus   1943:        socklen_t addrlen;
1.25      markus   1944:
1.410     djm      1945:        if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
1.367     djm      1946:                return;
                   1947:
                   1948:        addrlen = sizeof(addr);
                   1949:        newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.393     deraadt  1950:        if (newsock == -1) {
1.367     djm      1951:                error("accept from auth socket: %.100s", strerror(errno));
                   1952:                if (errno == EMFILE || errno == ENFILE)
                   1953:                        c->notbefore = monotime() + 1;
                   1954:                return;
1.41      markus   1955:        }
1.424     djm      1956:        nc = channel_new(ssh, "agent-connection",
1.367     djm      1957:            SSH_CHANNEL_OPENING, newsock, newsock, -1,
                   1958:            c->local_window_max, c->local_maxpacket,
                   1959:            0, "accepted auth socket", 1);
                   1960:        open_preamble(ssh, __func__, nc, "auth-agent@openssh.com");
                   1961:        if ((r = sshpkt_send(ssh)) != 0)
1.403     djm      1962:                fatal_fr(r, "channel %i", c->self);
1.41      markus   1963: }
1.25      markus   1964:
1.127     itojun   1965: static void
1.410     djm      1966: channel_post_connecting(struct ssh *ssh, Channel *c)
1.75      markus   1967: {
1.372     markus   1968:        int err = 0, sock, isopen, r;
1.129     stevesk  1969:        socklen_t sz = sizeof(err);
1.114     markus   1970:
1.410     djm      1971:        if ((c->io_ready & SSH_CHAN_IO_SOCK_W) == 0)
1.367     djm      1972:                return;
1.368     djm      1973:        if (!c->have_remote_id)
1.403     djm      1974:                fatal_f("channel %d: no remote id", c->self);
1.372     markus   1975:        /* for rdynamic the OPEN_CONFIRMATION has been sent already */
                   1976:        isopen = (c->type == SSH_CHANNEL_RDYNAMIC_FINISH);
1.393     deraadt  1977:        if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) == -1) {
1.367     djm      1978:                err = errno;
                   1979:                error("getsockopt SO_ERROR failed");
                   1980:        }
                   1981:        if (err == 0) {
                   1982:                debug("channel %d: connected to %s port %d",
                   1983:                    c->self, c->connect_ctx.host, c->connect_ctx.port);
                   1984:                channel_connect_ctx_free(&c->connect_ctx);
                   1985:                c->type = SSH_CHANNEL_OPEN;
1.426     djm      1986:                c->lastused = monotime();
1.372     markus   1987:                if (isopen) {
                   1988:                        /* no message necessary */
                   1989:                } else {
                   1990:                        if ((r = sshpkt_start(ssh,
                   1991:                            SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
                   1992:                            (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
                   1993:                            (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
                   1994:                            (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
1.403     djm      1995:                            (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
                   1996:                            (r = sshpkt_send(ssh)) != 0)
                   1997:                                fatal_fr(r, "channel %i open confirm", c->self);
1.367     djm      1998:                }
                   1999:        } else {
                   2000:                debug("channel %d: connection failed: %s",
                   2001:                    c->self, strerror(err));
                   2002:                /* Try next address, if any */
                   2003:                if ((sock = connect_next(&c->connect_ctx)) > 0) {
                   2004:                        close(c->sock);
                   2005:                        c->sock = c->rfd = c->wfd = sock;
                   2006:                        return;
                   2007:                }
                   2008:                /* Exhausted all addresses */
                   2009:                error("connect_to %.100s port %d: failed.",
                   2010:                    c->connect_ctx.host, c->connect_ctx.port);
                   2011:                channel_connect_ctx_free(&c->connect_ctx);
1.372     markus   2012:                if (isopen) {
                   2013:                        rdynamic_close(ssh, c);
                   2014:                } else {
                   2015:                        if ((r = sshpkt_start(ssh,
                   2016:                            SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
                   2017:                            (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1.378     djm      2018:                            (r = sshpkt_put_u32(ssh,
                   2019:                            SSH2_OPEN_CONNECT_FAILED)) != 0 ||
                   2020:                            (r = sshpkt_put_cstring(ssh, strerror(err))) != 0 ||
1.403     djm      2021:                            (r = sshpkt_put_cstring(ssh, "")) != 0 ||
                   2022:                            (r = sshpkt_send(ssh)) != 0)
                   2023:                                fatal_fr(r, "channel %i: failure", c->self);
1.372     markus   2024:                        chan_mark_dead(ssh, c);
1.75      markus   2025:                }
                   2026:        }
                   2027: }
                   2028:
1.127     itojun   2029: static int
1.410     djm      2030: channel_handle_rfd(struct ssh *ssh, Channel *c)
1.41      markus   2031: {
1.214     markus   2032:        char buf[CHAN_RBUF];
1.367     djm      2033:        ssize_t len;
                   2034:        int r;
1.426     djm      2035:        size_t nr = 0, have, avail, maxlen = CHANNEL_MAX_READ;
1.25      markus   2036:
1.410     djm      2037:        if ((c->io_ready & SSH_CHAN_IO_RFD) == 0)
1.412     djm      2038:                return 1; /* Shouldn't happen */
                   2039:        if ((avail = sshbuf_avail(c->input)) == 0)
                   2040:                return 1; /* Shouldn't happen */
                   2041:
                   2042:        /*
                   2043:         * For "simple" channels (i.e. not datagram or filtered), we can
                   2044:         * read directly to the channel buffer.
                   2045:         */
                   2046:        if (c->input_filter == NULL && !c->datagram) {
                   2047:                /* Only OPEN channels have valid rwin */
                   2048:                if (c->type == SSH_CHANNEL_OPEN) {
                   2049:                        if ((have = sshbuf_len(c->input)) >= c->remote_window)
                   2050:                                return 1; /* shouldn't happen */
                   2051:                        if (maxlen > c->remote_window - have)
                   2052:                                maxlen = c->remote_window - have;
                   2053:                }
                   2054:                if (maxlen > avail)
                   2055:                        maxlen = avail;
1.426     djm      2056:                if ((r = sshbuf_read(c->rfd, c->input, maxlen, &nr)) != 0) {
1.413     djm      2057:                        if (errno == EINTR || errno == EAGAIN)
                   2058:                                return 1;
1.412     djm      2059:                        debug2("channel %d: read failed rfd %d maxlen %zu: %s",
                   2060:                            c->self, c->rfd, maxlen, ssh_err(r));
                   2061:                        goto rfail;
                   2062:                }
1.426     djm      2063:                if (nr != 0)
                   2064:                        c->lastused = monotime();
1.367     djm      2065:                return 1;
1.412     djm      2066:        }
1.367     djm      2067:
                   2068:        len = read(c->rfd, buf, sizeof(buf));
1.393     deraadt  2069:        if (len == -1 && (errno == EINTR || errno == EAGAIN))
1.367     djm      2070:                return 1;
                   2071:        if (len <= 0) {
1.412     djm      2072:                debug2("channel %d: read<=0 rfd %d len %zd: %s",
                   2073:                    c->self, c->rfd, len,
                   2074:                    len == 0 ? "closed" : strerror(errno));
                   2075:  rfail:
1.367     djm      2076:                if (c->type != SSH_CHANNEL_OPEN) {
                   2077:                        debug2("channel %d: not open", c->self);
                   2078:                        chan_mark_dead(ssh, c);
1.41      markus   2079:                        return -1;
1.65      markus   2080:                } else {
1.367     djm      2081:                        chan_read_failed(ssh, c);
1.65      markus   2082:                }
1.367     djm      2083:                return -1;
                   2084:        }
1.426     djm      2085:        c->lastused = monotime();
1.367     djm      2086:        if (c->input_filter != NULL) {
                   2087:                if (c->input_filter(ssh, c, buf, len) == -1) {
                   2088:                        debug2("channel %d: filter stops", c->self);
                   2089:                        chan_read_failed(ssh, c);
                   2090:                }
                   2091:        } else if (c->datagram) {
                   2092:                if ((r = sshbuf_put_string(c->input, buf, len)) != 0)
1.403     djm      2093:                        fatal_fr(r, "channel %i: put datagram", c->self);
1.412     djm      2094:        }
1.41      markus   2095:        return 1;
                   2096: }
1.241     deraadt  2097:
1.127     itojun   2098: static int
1.410     djm      2099: channel_handle_wfd(struct ssh *ssh, Channel *c)
1.41      markus   2100: {
1.95      markus   2101:        struct termios tio;
1.367     djm      2102:        u_char *data = NULL, *buf; /* XXX const; need filter API change */
                   2103:        size_t dlen, olen = 0;
                   2104:        int r, len;
                   2105:
1.410     djm      2106:        if ((c->io_ready & SSH_CHAN_IO_WFD) == 0)
                   2107:                return 1;
                   2108:        if (sshbuf_len(c->output) == 0)
1.367     djm      2109:                return 1;
1.25      markus   2110:
1.41      markus   2111:        /* Send buffered output data to the socket. */
1.367     djm      2112:        olen = sshbuf_len(c->output);
                   2113:        if (c->output_filter != NULL) {
                   2114:                if ((buf = c->output_filter(ssh, c, &data, &dlen)) == NULL) {
                   2115:                        debug2("channel %d: filter stops", c->self);
                   2116:                        if (c->type != SSH_CHANNEL_OPEN)
                   2117:                                chan_mark_dead(ssh, c);
                   2118:                        else
                   2119:                                chan_write_failed(ssh, c);
                   2120:                        return -1;
1.231     reyk     2121:                }
1.367     djm      2122:        } else if (c->datagram) {
                   2123:                if ((r = sshbuf_get_string(c->output, &data, &dlen)) != 0)
1.403     djm      2124:                        fatal_fr(r, "channel %i: get datagram", c->self);
1.369     djm      2125:                buf = data;
1.367     djm      2126:        } else {
                   2127:                buf = data = sshbuf_mutable_ptr(c->output);
                   2128:                dlen = sshbuf_len(c->output);
                   2129:        }
1.231     reyk     2130:
1.367     djm      2131:        if (c->datagram) {
                   2132:                /* ignore truncated writes, datagrams might get lost */
1.374     djm      2133:                len = write(c->wfd, buf, dlen);
1.367     djm      2134:                free(data);
1.393     deraadt  2135:                if (len == -1 && (errno == EINTR || errno == EAGAIN))
1.53      markus   2136:                        return 1;
1.367     djm      2137:                if (len <= 0)
                   2138:                        goto write_fail;
                   2139:                goto out;
                   2140:        }
                   2141:
                   2142:        len = write(c->wfd, buf, dlen);
1.393     deraadt  2143:        if (len == -1 && (errno == EINTR || errno == EAGAIN))
1.367     djm      2144:                return 1;
                   2145:        if (len <= 0) {
                   2146:  write_fail:
                   2147:                if (c->type != SSH_CHANNEL_OPEN) {
                   2148:                        debug2("channel %d: not open", c->self);
                   2149:                        chan_mark_dead(ssh, c);
1.41      markus   2150:                        return -1;
1.367     djm      2151:                } else {
                   2152:                        chan_write_failed(ssh, c);
1.91      markus   2153:                }
1.367     djm      2154:                return -1;
                   2155:        }
1.426     djm      2156:        c->lastused = monotime();
1.367     djm      2157:        if (c->isatty && dlen >= 1 && buf[0] != '\r') {
                   2158:                if (tcgetattr(c->wfd, &tio) == 0 &&
                   2159:                    !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
                   2160:                        /*
                   2161:                         * Simulate echo to reduce the impact of
                   2162:                         * traffic analysis. We need to match the
                   2163:                         * size of a SSH2_MSG_CHANNEL_DATA message
                   2164:                         * (4 byte channel id + buf)
                   2165:                         */
                   2166:                        if ((r = sshpkt_msg_ignore(ssh, 4+len)) != 0 ||
                   2167:                            (r = sshpkt_send(ssh)) != 0)
1.403     djm      2168:                                fatal_fr(r, "channel %i: ignore", c->self);
1.25      markus   2169:                }
1.367     djm      2170:        }
1.403     djm      2171:        if ((r = sshbuf_consume(c->output, len)) != 0)
                   2172:                fatal_fr(r, "channel %i: consume", c->self);
1.309     djm      2173:  out:
1.367     djm      2174:        c->local_consumed += olen - sshbuf_len(c->output);
                   2175:
                   2176:        return 1;
                   2177: }
                   2178:
                   2179: static int
1.410     djm      2180: channel_handle_efd_write(struct ssh *ssh, Channel *c)
1.367     djm      2181: {
                   2182:        int r;
                   2183:        ssize_t len;
                   2184:
1.410     djm      2185:        if ((c->io_ready & SSH_CHAN_IO_EFD_W) == 0)
                   2186:                return 1;
                   2187:        if (sshbuf_len(c->extended) == 0)
1.367     djm      2188:                return 1;
                   2189:
                   2190:        len = write(c->efd, sshbuf_ptr(c->extended),
                   2191:            sshbuf_len(c->extended));
                   2192:        debug2("channel %d: written %zd to efd %d", c->self, len, c->efd);
1.393     deraadt  2193:        if (len == -1 && (errno == EINTR || errno == EAGAIN))
1.367     djm      2194:                return 1;
                   2195:        if (len <= 0) {
                   2196:                debug2("channel %d: closing write-efd %d", c->self, c->efd);
1.407     djm      2197:                channel_close_fd(ssh, c, &c->efd);
1.367     djm      2198:        } else {
1.403     djm      2199:                if ((r = sshbuf_consume(c->extended, len)) != 0)
                   2200:                        fatal_fr(r, "channel %i: consume", c->self);
1.367     djm      2201:                c->local_consumed += len;
1.426     djm      2202:                c->lastused = monotime();
1.367     djm      2203:        }
1.44      markus   2204:        return 1;
                   2205: }
1.241     deraadt  2206:
1.127     itojun   2207: static int
1.410     djm      2208: channel_handle_efd_read(struct ssh *ssh, Channel *c)
1.44      markus   2209: {
1.214     markus   2210:        char buf[CHAN_RBUF];
1.367     djm      2211:        int r;
                   2212:        ssize_t len;
                   2213:
1.410     djm      2214:        if ((c->io_ready & SSH_CHAN_IO_EFD_R) == 0)
1.367     djm      2215:                return 1;
1.44      markus   2216:
1.367     djm      2217:        len = read(c->efd, buf, sizeof(buf));
                   2218:        debug2("channel %d: read %zd from efd %d", c->self, len, c->efd);
1.393     deraadt  2219:        if (len == -1 && (errno == EINTR || errno == EAGAIN))
1.367     djm      2220:                return 1;
                   2221:        if (len <= 0) {
1.403     djm      2222:                debug2("channel %d: closing read-efd %d", c->self, c->efd);
1.407     djm      2223:                channel_close_fd(ssh, c, &c->efd);
1.426     djm      2224:                return 1;
                   2225:        }
                   2226:        c->lastused = monotime();
                   2227:        if (c->extended_usage == CHAN_EXTENDED_IGNORE)
1.403     djm      2228:                debug3("channel %d: discard efd", c->self);
                   2229:        else if ((r = sshbuf_put(c->extended, buf, len)) != 0)
                   2230:                fatal_fr(r, "channel %i: append", c->self);
1.44      markus   2231:        return 1;
                   2232: }
1.241     deraadt  2233:
1.127     itojun   2234: static int
1.410     djm      2235: channel_handle_efd(struct ssh *ssh, Channel *c)
1.44      markus   2236: {
1.367     djm      2237:        if (c->efd == -1)
                   2238:                return 1;
                   2239:
                   2240:        /** XXX handle drain efd, too */
                   2241:
                   2242:        if (c->extended_usage == CHAN_EXTENDED_WRITE)
1.410     djm      2243:                return channel_handle_efd_write(ssh, c);
1.367     djm      2244:        else if (c->extended_usage == CHAN_EXTENDED_READ ||
                   2245:            c->extended_usage == CHAN_EXTENDED_IGNORE)
1.410     djm      2246:                return channel_handle_efd_read(ssh, c);
1.367     djm      2247:
                   2248:        return 1;
                   2249: }
                   2250:
                   2251: static int
                   2252: channel_check_window(struct ssh *ssh, Channel *c)
                   2253: {
                   2254:        int r;
                   2255:
1.104     markus   2256:        if (c->type == SSH_CHANNEL_OPEN &&
                   2257:            !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.270     dtucker  2258:            ((c->local_window_max - c->local_window >
1.269     markus   2259:            c->local_maxpacket*3) ||
                   2260:            c->local_window < c->local_window_max/2) &&
1.44      markus   2261:            c->local_consumed > 0) {
1.368     djm      2262:                if (!c->have_remote_id)
1.403     djm      2263:                        fatal_f("channel %d: no remote id", c->self);
1.367     djm      2264:                if ((r = sshpkt_start(ssh,
                   2265:                    SSH2_MSG_CHANNEL_WINDOW_ADJUST)) != 0 ||
                   2266:                    (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
                   2267:                    (r = sshpkt_put_u32(ssh, c->local_consumed)) != 0 ||
                   2268:                    (r = sshpkt_send(ssh)) != 0) {
1.403     djm      2269:                        fatal_fr(r, "channel %i", c->self);
1.367     djm      2270:                }
1.403     djm      2271:                debug2("channel %d: window %d sent adjust %d", c->self,
                   2272:                    c->local_window, c->local_consumed);
1.44      markus   2273:                c->local_window += c->local_consumed;
                   2274:                c->local_consumed = 0;
1.1       deraadt  2275:        }
1.41      markus   2276:        return 1;
1.1       deraadt  2277: }
                   2278:
1.127     itojun   2279: static void
1.410     djm      2280: channel_post_open(struct ssh *ssh, Channel *c)
1.41      markus   2281: {
1.410     djm      2282:        channel_handle_rfd(ssh, c);
                   2283:        channel_handle_wfd(ssh, c);
                   2284:        channel_handle_efd(ssh, c);
1.367     djm      2285:        channel_check_window(ssh, c);
1.44      markus   2286: }
                   2287:
1.302     djm      2288: static u_int
1.367     djm      2289: read_mux(struct ssh *ssh, Channel *c, u_int need)
1.302     djm      2290: {
                   2291:        char buf[CHAN_RBUF];
1.367     djm      2292:        ssize_t len;
1.302     djm      2293:        u_int rlen;
1.367     djm      2294:        int r;
1.302     djm      2295:
1.367     djm      2296:        if (sshbuf_len(c->input) < need) {
                   2297:                rlen = need - sshbuf_len(c->input);
1.352     deraadt  2298:                len = read(c->rfd, buf, MINIMUM(rlen, CHAN_RBUF));
1.393     deraadt  2299:                if (len == -1 && (errno == EINTR || errno == EAGAIN))
1.367     djm      2300:                        return sshbuf_len(c->input);
1.302     djm      2301:                if (len <= 0) {
1.367     djm      2302:                        debug2("channel %d: ctl read<=0 rfd %d len %zd",
1.349     naddy    2303:                            c->self, c->rfd, len);
1.367     djm      2304:                        chan_read_failed(ssh, c);
1.349     naddy    2305:                        return 0;
1.403     djm      2306:                } else if ((r = sshbuf_put(c->input, buf, len)) != 0)
                   2307:                        fatal_fr(r, "channel %i: append", c->self);
1.302     djm      2308:        }
1.367     djm      2309:        return sshbuf_len(c->input);
1.302     djm      2310: }
                   2311:
                   2312: static void
1.410     djm      2313: channel_post_mux_client_read(struct ssh *ssh, Channel *c)
1.302     djm      2314: {
                   2315:        u_int need;
                   2316:
1.410     djm      2317:        if ((c->io_ready & SSH_CHAN_IO_RFD) == 0)
1.367     djm      2318:                return;
                   2319:        if (c->istate != CHAN_INPUT_OPEN && c->istate != CHAN_INPUT_WAIT_DRAIN)
                   2320:                return;
                   2321:        if (c->mux_pause)
                   2322:                return;
                   2323:
                   2324:        /*
                   2325:         * Don't not read past the precise end of packets to
                   2326:         * avoid disrupting fd passing.
                   2327:         */
                   2328:        if (read_mux(ssh, c, 4) < 4) /* read header */
                   2329:                return;
                   2330:        /* XXX sshbuf_peek_u32 */
                   2331:        need = PEEK_U32(sshbuf_ptr(c->input));
1.302     djm      2332: #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1.367     djm      2333:        if (need > CHANNEL_MUX_MAX_PACKET) {
                   2334:                debug2("channel %d: packet too big %u > %u",
                   2335:                    c->self, CHANNEL_MUX_MAX_PACKET, need);
                   2336:                chan_rcvd_oclose(ssh, c);
                   2337:                return;
                   2338:        }
                   2339:        if (read_mux(ssh, c, need + 4) < need + 4) /* read body */
                   2340:                return;
                   2341:        if (c->mux_rcb(ssh, c) != 0) {
                   2342:                debug("channel %d: mux_rcb failed", c->self);
                   2343:                chan_mark_dead(ssh, c);
                   2344:                return;
1.302     djm      2345:        }
1.367     djm      2346: }
                   2347:
                   2348: static void
1.410     djm      2349: channel_post_mux_client_write(struct ssh *ssh, Channel *c)
1.367     djm      2350: {
                   2351:        ssize_t len;
                   2352:        int r;
1.302     djm      2353:
1.410     djm      2354:        if ((c->io_ready & SSH_CHAN_IO_WFD) == 0)
                   2355:                return;
                   2356:        if (sshbuf_len(c->output) == 0)
1.367     djm      2357:                return;
                   2358:
                   2359:        len = write(c->wfd, sshbuf_ptr(c->output), sshbuf_len(c->output));
1.393     deraadt  2360:        if (len == -1 && (errno == EINTR || errno == EAGAIN))
1.367     djm      2361:                return;
                   2362:        if (len <= 0) {
                   2363:                chan_mark_dead(ssh, c);
                   2364:                return;
1.302     djm      2365:        }
1.367     djm      2366:        if ((r = sshbuf_consume(c->output, len)) != 0)
1.403     djm      2367:                fatal_fr(r, "channel %i: consume", c->self);
1.367     djm      2368: }
                   2369:
                   2370: static void
1.410     djm      2371: channel_post_mux_client(struct ssh *ssh, Channel *c)
1.367     djm      2372: {
1.410     djm      2373:        channel_post_mux_client_read(ssh, c);
                   2374:        channel_post_mux_client_write(ssh, c);
1.302     djm      2375: }
                   2376:
                   2377: static void
1.410     djm      2378: channel_post_mux_listener(struct ssh *ssh, Channel *c)
1.302     djm      2379: {
                   2380:        Channel *nc;
                   2381:        struct sockaddr_storage addr;
                   2382:        socklen_t addrlen;
                   2383:        int newsock;
                   2384:        uid_t euid;
                   2385:        gid_t egid;
                   2386:
1.410     djm      2387:        if ((c->io_ready & SSH_CHAN_IO_SOCK_R) == 0)
1.302     djm      2388:                return;
                   2389:
                   2390:        debug("multiplexing control connection");
                   2391:
                   2392:        /*
                   2393:         * Accept connection on control socket
                   2394:         */
                   2395:        memset(&addr, 0, sizeof(addr));
                   2396:        addrlen = sizeof(addr);
                   2397:        if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
                   2398:            &addrlen)) == -1) {
1.403     djm      2399:                error_f("accept: %s", strerror(errno));
1.317     djm      2400:                if (errno == EMFILE || errno == ENFILE)
1.322     dtucker  2401:                        c->notbefore = monotime() + 1;
1.302     djm      2402:                return;
                   2403:        }
                   2404:
1.393     deraadt  2405:        if (getpeereid(newsock, &euid, &egid) == -1) {
1.403     djm      2406:                error_f("getpeereid failed: %s", strerror(errno));
1.302     djm      2407:                close(newsock);
                   2408:                return;
                   2409:        }
                   2410:        if ((euid != 0) && (getuid() != euid)) {
                   2411:                error("multiplex uid mismatch: peer euid %u != uid %u",
                   2412:                    (u_int)euid, (u_int)getuid());
                   2413:                close(newsock);
                   2414:                return;
                   2415:        }
1.424     djm      2416:        nc = channel_new(ssh, "mux-control", SSH_CHANNEL_MUX_CLIENT,
1.302     djm      2417:            newsock, newsock, -1, c->local_window_max,
                   2418:            c->local_maxpacket, 0, "mux-control", 1);
                   2419:        nc->mux_rcb = c->mux_rcb;
1.403     djm      2420:        debug3_f("new mux channel %d fd %d", nc->self, nc->sock);
1.302     djm      2421:        /* establish state */
1.367     djm      2422:        nc->mux_rcb(ssh, nc);
1.302     djm      2423:        /* mux state transitions must not elicit protocol messages */
                   2424:        nc->flags |= CHAN_LOCAL;
                   2425: }
                   2426:
1.127     itojun   2427: static void
1.367     djm      2428: channel_handler_init(struct ssh_channels *sc)
1.1       deraadt  2429: {
1.367     djm      2430:        chan_fn **pre, **post;
                   2431:
                   2432:        if ((pre = calloc(SSH_CHANNEL_MAX_TYPE, sizeof(*pre))) == NULL ||
1.406     djm      2433:            (post = calloc(SSH_CHANNEL_MAX_TYPE, sizeof(*post))) == NULL)
1.403     djm      2434:                fatal_f("allocation failed");
1.367     djm      2435:
                   2436:        pre[SSH_CHANNEL_OPEN] =                 &channel_pre_open;
                   2437:        pre[SSH_CHANNEL_X11_OPEN] =             &channel_pre_x11_open;
                   2438:        pre[SSH_CHANNEL_PORT_LISTENER] =        &channel_pre_listener;
                   2439:        pre[SSH_CHANNEL_RPORT_LISTENER] =       &channel_pre_listener;
                   2440:        pre[SSH_CHANNEL_UNIX_LISTENER] =        &channel_pre_listener;
                   2441:        pre[SSH_CHANNEL_RUNIX_LISTENER] =       &channel_pre_listener;
                   2442:        pre[SSH_CHANNEL_X11_LISTENER] =         &channel_pre_listener;
                   2443:        pre[SSH_CHANNEL_AUTH_SOCKET] =          &channel_pre_listener;
                   2444:        pre[SSH_CHANNEL_CONNECTING] =           &channel_pre_connecting;
                   2445:        pre[SSH_CHANNEL_DYNAMIC] =              &channel_pre_dynamic;
1.372     markus   2446:        pre[SSH_CHANNEL_RDYNAMIC_FINISH] =      &channel_pre_connecting;
1.367     djm      2447:        pre[SSH_CHANNEL_MUX_LISTENER] =         &channel_pre_listener;
                   2448:        pre[SSH_CHANNEL_MUX_CLIENT] =           &channel_pre_mux_client;
                   2449:
                   2450:        post[SSH_CHANNEL_OPEN] =                &channel_post_open;
                   2451:        post[SSH_CHANNEL_PORT_LISTENER] =       &channel_post_port_listener;
                   2452:        post[SSH_CHANNEL_RPORT_LISTENER] =      &channel_post_port_listener;
                   2453:        post[SSH_CHANNEL_UNIX_LISTENER] =       &channel_post_port_listener;
                   2454:        post[SSH_CHANNEL_RUNIX_LISTENER] =      &channel_post_port_listener;
                   2455:        post[SSH_CHANNEL_X11_LISTENER] =        &channel_post_x11_listener;
                   2456:        post[SSH_CHANNEL_AUTH_SOCKET] =         &channel_post_auth_listener;
                   2457:        post[SSH_CHANNEL_CONNECTING] =          &channel_post_connecting;
                   2458:        post[SSH_CHANNEL_DYNAMIC] =             &channel_post_open;
1.372     markus   2459:        post[SSH_CHANNEL_RDYNAMIC_FINISH] =     &channel_post_connecting;
1.367     djm      2460:        post[SSH_CHANNEL_MUX_LISTENER] =        &channel_post_mux_listener;
                   2461:        post[SSH_CHANNEL_MUX_CLIENT] =          &channel_post_mux_client;
1.180     deraadt  2462:
1.367     djm      2463:        sc->channel_pre = pre;
                   2464:        sc->channel_post = post;
1.44      markus   2465: }
                   2466:
1.140     markus   2467: /* gc dead channels */
                   2468: static void
1.367     djm      2469: channel_garbage_collect(struct ssh *ssh, Channel *c)
1.140     markus   2470: {
                   2471:        if (c == NULL)
                   2472:                return;
                   2473:        if (c->detach_user != NULL) {
1.367     djm      2474:                if (!chan_is_dead(ssh, c, c->detach_close))
1.140     markus   2475:                        return;
1.385     djm      2476:
1.194     markus   2477:                debug2("channel %d: gc: notify user", c->self);
1.423     djm      2478:                c->detach_user(ssh, c->self, 0, NULL);
1.140     markus   2479:                /* if we still have a callback */
                   2480:                if (c->detach_user != NULL)
                   2481:                        return;
1.194     markus   2482:                debug2("channel %d: gc: user detached", c->self);
1.140     markus   2483:        }
1.367     djm      2484:        if (!chan_is_dead(ssh, c, 1))
1.140     markus   2485:                return;
1.194     markus   2486:        debug2("channel %d: garbage collecting", c->self);
1.367     djm      2487:        channel_free(ssh, c);
1.140     markus   2488: }
                   2489:
1.367     djm      2490: enum channel_table { CHAN_PRE, CHAN_POST };
                   2491:
1.127     itojun   2492: static void
1.422     djm      2493: channel_handler(struct ssh *ssh, int table, struct timespec *timeout)
1.41      markus   2494: {
1.367     djm      2495:        struct ssh_channels *sc = ssh->chanctxt;
                   2496:        chan_fn **ftab = table == CHAN_PRE ? sc->channel_pre : sc->channel_post;
1.299     markus   2497:        u_int i, oalloc;
1.41      markus   2498:        Channel *c;
1.317     djm      2499:        time_t now;
1.25      markus   2500:
1.322     dtucker  2501:        now = monotime();
1.367     djm      2502:        for (i = 0, oalloc = sc->channels_alloc; i < oalloc; i++) {
                   2503:                c = sc->channels[i];
1.113     markus   2504:                if (c == NULL)
1.41      markus   2505:                        continue;
1.417     djm      2506:                /* Try to keep IO going while rekeying */
                   2507:                if (ssh_packet_is_rekeying(ssh) && c->type != SSH_CHANNEL_OPEN)
                   2508:                        continue;
1.299     markus   2509:                if (c->delayed) {
1.367     djm      2510:                        if (table == CHAN_PRE)
1.299     markus   2511:                                c->delayed = 0;
                   2512:                        else
                   2513:                                continue;
                   2514:                }
1.317     djm      2515:                if (ftab[c->type] != NULL) {
1.426     djm      2516:                        if (table == CHAN_PRE &&
                   2517:                            c->type == SSH_CHANNEL_OPEN &&
                   2518:                            c->inactive_deadline != 0 && c->lastused != 0 &&
                   2519:                            now >= c->lastused + c->inactive_deadline) {
                   2520:                                /* channel closed for inactivity */
                   2521:                                verbose("channel %d: closing after %u seconds "
                   2522:                                    "of inactivity", c->self,
                   2523:                                    c->inactive_deadline);
                   2524:                                channel_force_close(ssh, c, 1);
                   2525:                        } else if (c->notbefore <= now) {
                   2526:                                /* Run handlers that are not paused. */
1.410     djm      2527:                                (*ftab[c->type])(ssh, c);
1.426     djm      2528:                                /* inactivity timeouts must interrupt poll() */
                   2529:                                if (timeout != NULL &&
                   2530:                                    c->type == SSH_CHANNEL_OPEN &&
                   2531:                                    c->lastused != 0 &&
                   2532:                                    c->inactive_deadline != 0) {
                   2533:                                        ptimeout_deadline_monotime(timeout,
                   2534:                                            c->lastused + c->inactive_deadline);
                   2535:                                }
                   2536:                        } else if (timeout != NULL) {
1.317     djm      2537:                                /*
1.426     djm      2538:                                 * Arrange for poll() wakeup when channel pause
1.422     djm      2539:                                 * timer expires.
1.317     djm      2540:                                 */
1.422     djm      2541:                                ptimeout_deadline_monotime(timeout,
                   2542:                                    c->notbefore);
1.317     djm      2543:                        }
                   2544:                }
1.367     djm      2545:                channel_garbage_collect(ssh, c);
1.1       deraadt  2546:        }
                   2547: }
                   2548:
1.121     markus   2549: /*
1.411     djm      2550:  * Create sockets before preparing IO.
1.372     markus   2551:  * This is necessary for things that need to happen after reading
1.411     djm      2552:  * the network-input but need to be completed before IO event setup, e.g.
                   2553:  * because they may create new channels.
1.372     markus   2554:  */
                   2555: static void
1.411     djm      2556: channel_before_prepare_io(struct ssh *ssh)
1.372     markus   2557: {
                   2558:        struct ssh_channels *sc = ssh->chanctxt;
                   2559:        Channel *c;
                   2560:        u_int i, oalloc;
                   2561:
                   2562:        for (i = 0, oalloc = sc->channels_alloc; i < oalloc; i++) {
                   2563:                c = sc->channels[i];
                   2564:                if (c == NULL)
                   2565:                        continue;
                   2566:                if (c->type == SSH_CHANNEL_RDYNAMIC_OPEN)
1.411     djm      2567:                        channel_before_prepare_io_rdynamic(ssh, c);
                   2568:        }
                   2569: }
                   2570:
                   2571: static void
                   2572: dump_channel_poll(const char *func, const char *what, Channel *c,
                   2573:     u_int pollfd_offset, struct pollfd *pfd)
                   2574: {
                   2575: #ifdef DEBUG_CHANNEL_POLL
1.415     djm      2576:        debug3("%s: channel %d: %s r%d w%d e%d s%d c->pfds [ %d %d %d %d ] "
                   2577:            "io_want 0x%02x io_ready 0x%02x pfd[%u].fd=%d "
                   2578:            "pfd.ev 0x%02x pfd.rev 0x%02x", func, c->self, what,
                   2579:            c->rfd, c->wfd, c->efd, c->sock,
                   2580:            c->pfds[0], c->pfds[1], c->pfds[2], c->pfds[3],
                   2581:            c->io_want, c->io_ready,
                   2582:            pollfd_offset, pfd->fd, pfd->events, pfd->revents);
1.411     djm      2583: #endif
                   2584: }
                   2585:
                   2586: /* Prepare pollfd entries for a single channel */
                   2587: static void
                   2588: channel_prepare_pollfd(Channel *c, u_int *next_pollfd,
                   2589:     struct pollfd *pfd, u_int npfd)
                   2590: {
1.415     djm      2591:        u_int ev, p = *next_pollfd;
1.411     djm      2592:
                   2593:        if (c == NULL)
                   2594:                return;
                   2595:        if (p + 4 > npfd) {
                   2596:                /* Shouldn't happen */
                   2597:                fatal_f("channel %d: bad pfd offset %u (max %u)",
                   2598:                    c->self, p, npfd);
                   2599:        }
1.415     djm      2600:        c->pfds[0] = c->pfds[1] = c->pfds[2] = c->pfds[3] = -1;
1.411     djm      2601:        /*
                   2602:         * prepare c->rfd
                   2603:         *
                   2604:         * This is a special case, since c->rfd might be the same as
                   2605:         * c->wfd, c->efd and/or c->sock. Handle those here if they want
                   2606:         * IO too.
                   2607:         */
                   2608:        if (c->rfd != -1) {
1.415     djm      2609:                ev = 0;
1.411     djm      2610:                if ((c->io_want & SSH_CHAN_IO_RFD) != 0)
1.415     djm      2611:                        ev |= POLLIN;
1.411     djm      2612:                /* rfd == wfd */
1.415     djm      2613:                if (c->wfd == c->rfd) {
                   2614:                        if ((c->io_want & SSH_CHAN_IO_WFD) != 0)
                   2615:                                ev |= POLLOUT;
                   2616:                }
1.411     djm      2617:                /* rfd == efd */
1.415     djm      2618:                if (c->efd == c->rfd) {
                   2619:                        if ((c->io_want & SSH_CHAN_IO_EFD_R) != 0)
                   2620:                                ev |= POLLIN;
                   2621:                        if ((c->io_want & SSH_CHAN_IO_EFD_W) != 0)
                   2622:                                ev |= POLLOUT;
                   2623:                }
1.411     djm      2624:                /* rfd == sock */
1.415     djm      2625:                if (c->sock == c->rfd) {
                   2626:                        if ((c->io_want & SSH_CHAN_IO_SOCK_R) != 0)
                   2627:                                ev |= POLLIN;
                   2628:                        if ((c->io_want & SSH_CHAN_IO_SOCK_W) != 0)
                   2629:                                ev |= POLLOUT;
                   2630:                }
                   2631:                /* Pack a pfd entry if any event armed for this fd */
                   2632:                if (ev != 0) {
                   2633:                        c->pfds[0] = p;
                   2634:                        pfd[p].fd = c->rfd;
                   2635:                        pfd[p].events = ev;
                   2636:                        dump_channel_poll(__func__, "rfd", c, p, &pfd[p]);
                   2637:                        p++;
                   2638:                }
1.411     djm      2639:        }
1.415     djm      2640:        /* prepare c->wfd if wanting IO and not already handled above */
1.411     djm      2641:        if (c->wfd != -1 && c->rfd != c->wfd) {
1.415     djm      2642:                ev = 0;
                   2643:                if ((c->io_want & SSH_CHAN_IO_WFD))
                   2644:                        ev |= POLLOUT;
                   2645:                /* Pack a pfd entry if any event armed for this fd */
                   2646:                if (ev != 0) {
                   2647:                        c->pfds[1] = p;
                   2648:                        pfd[p].fd = c->wfd;
                   2649:                        pfd[p].events = ev;
                   2650:                        dump_channel_poll(__func__, "wfd", c, p, &pfd[p]);
                   2651:                        p++;
                   2652:                }
1.411     djm      2653:        }
1.415     djm      2654:        /* prepare c->efd if wanting IO and not already handled above */
1.411     djm      2655:        if (c->efd != -1 && c->rfd != c->efd) {
1.415     djm      2656:                ev = 0;
1.411     djm      2657:                if ((c->io_want & SSH_CHAN_IO_EFD_R) != 0)
1.415     djm      2658:                        ev |= POLLIN;
1.411     djm      2659:                if ((c->io_want & SSH_CHAN_IO_EFD_W) != 0)
1.415     djm      2660:                        ev |= POLLOUT;
                   2661:                /* Pack a pfd entry if any event armed for this fd */
                   2662:                if (ev != 0) {
                   2663:                        c->pfds[2] = p;
                   2664:                        pfd[p].fd = c->efd;
                   2665:                        pfd[p].events = ev;
                   2666:                        dump_channel_poll(__func__, "efd", c, p, &pfd[p]);
                   2667:                        p++;
                   2668:                }
1.411     djm      2669:        }
1.415     djm      2670:        /* prepare c->sock if wanting IO and not already handled above */
1.411     djm      2671:        if (c->sock != -1 && c->rfd != c->sock) {
1.415     djm      2672:                ev = 0;
1.411     djm      2673:                if ((c->io_want & SSH_CHAN_IO_SOCK_R) != 0)
1.415     djm      2674:                        ev |= POLLIN;
1.411     djm      2675:                if ((c->io_want & SSH_CHAN_IO_SOCK_W) != 0)
1.415     djm      2676:                        ev |= POLLOUT;
                   2677:                /* Pack a pfd entry if any event armed for this fd */
                   2678:                if (ev != 0) {
                   2679:                        c->pfds[3] = p;
                   2680:                        pfd[p].fd = c->sock;
                   2681:                        pfd[p].events = 0;
                   2682:                        dump_channel_poll(__func__, "sock", c, p, &pfd[p]);
                   2683:                        p++;
                   2684:                }
1.372     markus   2685:        }
1.411     djm      2686:        *next_pollfd = p;
1.372     markus   2687: }
                   2688:
1.411     djm      2689: /* * Allocate/prepare poll structure */
1.49      markus   2690: void
1.411     djm      2691: channel_prepare_poll(struct ssh *ssh, struct pollfd **pfdp, u_int *npfd_allocp,
1.422     djm      2692:     u_int *npfd_activep, u_int npfd_reserved, struct timespec *timeout)
1.41      markus   2693: {
1.410     djm      2694:        struct ssh_channels *sc = ssh->chanctxt;
1.411     djm      2695:        u_int i, oalloc, p, npfd = npfd_reserved;
                   2696:
                   2697:        channel_before_prepare_io(ssh); /* might create a new channel */
1.416     djm      2698:        /* clear out I/O flags from last poll */
                   2699:        for (i = 0; i < sc->channels_alloc; i++) {
                   2700:                if (sc->channels[i] == NULL)
                   2701:                        continue;
                   2702:                sc->channels[i]->io_want = sc->channels[i]->io_ready = 0;
                   2703:        }
1.411     djm      2704:        /* Allocate 4x pollfd for each channel (rfd, wfd, efd, sock) */
                   2705:        if (sc->channels_alloc >= (INT_MAX / 4) - npfd_reserved)
                   2706:                fatal_f("too many channels"); /* shouldn't happen */
1.417     djm      2707:        npfd += sc->channels_alloc * 4;
1.411     djm      2708:        if (npfd > *npfd_allocp) {
                   2709:                *pfdp = xrecallocarray(*pfdp, *npfd_allocp,
                   2710:                    npfd, sizeof(**pfdp));
                   2711:                *npfd_allocp = npfd;
                   2712:        }
                   2713:        *npfd_activep = npfd_reserved;
                   2714:        oalloc = sc->channels_alloc;
1.372     markus   2715:
1.422     djm      2716:        channel_handler(ssh, CHAN_PRE, timeout);
1.84      markus   2717:
1.411     djm      2718:        if (oalloc != sc->channels_alloc) {
                   2719:                /* shouldn't happen */
                   2720:                fatal_f("channels_alloc changed during CHAN_PRE "
                   2721:                    "(was %u, now %u)", oalloc, sc->channels_alloc);
                   2722:        }
1.84      markus   2723:
1.411     djm      2724:        /* Prepare pollfd */
                   2725:        p = npfd_reserved;
                   2726:        for (i = 0; i < sc->channels_alloc; i++)
                   2727:                channel_prepare_pollfd(sc->channels[i], &p, *pfdp, npfd);
                   2728:        *npfd_activep = p;
                   2729: }
                   2730:
                   2731: static void
1.415     djm      2732: fd_ready(Channel *c, int p, struct pollfd *pfds, u_int npfd, int fd,
1.411     djm      2733:     const char *what, u_int revents_mask, u_int ready)
                   2734: {
                   2735:        struct pollfd *pfd = &pfds[p];
1.410     djm      2736:
1.411     djm      2737:        if (fd == -1)
                   2738:                return;
1.415     djm      2739:        if (p == -1 || (u_int)p >= npfd)
                   2740:                fatal_f("channel %d: bad pfd %d (max %u)", c->self, p, npfd);
1.411     djm      2741:        dump_channel_poll(__func__, what, c, p, pfd);
                   2742:        if (pfd->fd != fd) {
                   2743:                fatal("channel %d: inconsistent %s fd=%d pollfd[%u].fd %d "
                   2744:                    "r%d w%d e%d s%d", c->self, what, fd, p, pfd->fd,
                   2745:                    c->rfd, c->wfd, c->efd, c->sock);
                   2746:        }
                   2747:        if ((pfd->revents & POLLNVAL) != 0) {
                   2748:                fatal("channel %d: invalid %s pollfd[%u].fd %d r%d w%d e%d s%d",
                   2749:                    c->self, what, p, pfd->fd, c->rfd, c->wfd, c->efd, c->sock);
1.410     djm      2750:        }
1.411     djm      2751:        if ((pfd->revents & (revents_mask|POLLHUP|POLLERR)) != 0)
                   2752:                c->io_ready |= ready & c->io_want;
1.41      markus   2753: }
                   2754:
1.121     markus   2755: /*
1.411     djm      2756:  * After poll, perform any appropriate operations for channels which have
1.121     markus   2757:  * events pending.
                   2758:  */
1.49      markus   2759: void
1.411     djm      2760: channel_after_poll(struct ssh *ssh, struct pollfd *pfd, u_int npfd)
1.41      markus   2761: {
1.410     djm      2762:        struct ssh_channels *sc = ssh->chanctxt;
1.415     djm      2763:        u_int i;
                   2764:        int p;
1.410     djm      2765:        Channel *c;
                   2766:
1.411     djm      2767: #ifdef DEBUG_CHANNEL_POLL
1.415     djm      2768:        for (p = 0; p < (int)npfd; p++) {
1.411     djm      2769:                if (pfd[p].revents == 0)
                   2770:                        continue;
                   2771:                debug_f("pfd[%u].fd %d rev 0x%04x",
                   2772:                    p, pfd[p].fd, pfd[p].revents);
                   2773:        }
                   2774: #endif
                   2775:
                   2776:        /* Convert pollfd into c->io_ready */
                   2777:        for (i = 0; i < sc->channels_alloc; i++) {
1.410     djm      2778:                c = sc->channels[i];
1.415     djm      2779:                if (c == NULL)
1.410     djm      2780:                        continue;
1.411     djm      2781:                /* if rfd is shared with efd/sock then wfd should be too */
                   2782:                if (c->rfd != -1 && c->wfd != -1 && c->rfd != c->wfd &&
                   2783:                    (c->rfd == c->efd || c->rfd == c->sock)) {
                   2784:                        /* Shouldn't happen */
                   2785:                        fatal_f("channel %d: unexpected fds r%d w%d e%d s%d",
                   2786:                            c->self, c->rfd, c->wfd, c->efd, c->sock);
                   2787:                }
1.410     djm      2788:                c->io_ready = 0;
1.411     djm      2789:                /* rfd, potentially shared with wfd, efd and sock */
1.415     djm      2790:                if (c->rfd != -1 && (p = c->pfds[0]) != -1) {
                   2791:                        fd_ready(c, p, pfd, npfd, c->rfd,
                   2792:                            "rfd", POLLIN, SSH_CHAN_IO_RFD);
1.411     djm      2793:                        if (c->rfd == c->wfd) {
1.415     djm      2794:                                fd_ready(c, p, pfd, npfd, c->wfd,
                   2795:                                    "wfd/r", POLLOUT, SSH_CHAN_IO_WFD);
1.411     djm      2796:                        }
                   2797:                        if (c->rfd == c->efd) {
1.415     djm      2798:                                fd_ready(c, p, pfd, npfd, c->efd,
                   2799:                                    "efdr/r", POLLIN, SSH_CHAN_IO_EFD_R);
                   2800:                                fd_ready(c, p, pfd, npfd, c->efd,
                   2801:                                    "efdw/r", POLLOUT, SSH_CHAN_IO_EFD_W);
1.411     djm      2802:                        }
                   2803:                        if (c->rfd == c->sock) {
1.415     djm      2804:                                fd_ready(c, p, pfd, npfd, c->sock,
                   2805:                                    "sockr/r", POLLIN, SSH_CHAN_IO_SOCK_R);
                   2806:                                fd_ready(c, p, pfd, npfd, c->sock,
                   2807:                                    "sockw/r", POLLOUT, SSH_CHAN_IO_SOCK_W);
1.411     djm      2808:                        }
1.415     djm      2809:                        dump_channel_poll(__func__, "rfd", c, p, pfd);
1.411     djm      2810:                }
                   2811:                /* wfd */
1.415     djm      2812:                if (c->wfd != -1 && c->wfd != c->rfd &&
                   2813:                    (p = c->pfds[1]) != -1) {
                   2814:                        fd_ready(c, p, pfd, npfd, c->wfd,
                   2815:                            "wfd", POLLOUT, SSH_CHAN_IO_WFD);
                   2816:                        dump_channel_poll(__func__, "wfd", c, p, pfd);
1.411     djm      2817:                }
                   2818:                /* efd */
1.415     djm      2819:                if (c->efd != -1 && c->efd != c->rfd &&
                   2820:                    (p = c->pfds[2]) != -1) {
                   2821:                        fd_ready(c, p, pfd, npfd, c->efd,
                   2822:                            "efdr", POLLIN, SSH_CHAN_IO_EFD_R);
                   2823:                        fd_ready(c, p, pfd, npfd, c->efd,
                   2824:                            "efdw", POLLOUT, SSH_CHAN_IO_EFD_W);
                   2825:                        dump_channel_poll(__func__, "efd", c, p, pfd);
1.411     djm      2826:                }
                   2827:                /* sock */
1.415     djm      2828:                if (c->sock != -1 && c->sock != c->rfd &&
                   2829:                    (p = c->pfds[3]) != -1) {
                   2830:                        fd_ready(c, p, pfd, npfd, c->sock,
                   2831:                            "sockr", POLLIN, SSH_CHAN_IO_SOCK_R);
                   2832:                        fd_ready(c, p, pfd, npfd, c->sock,
                   2833:                            "sockw", POLLOUT, SSH_CHAN_IO_SOCK_W);
                   2834:                        dump_channel_poll(__func__, "sock", c, p, pfd);
1.411     djm      2835:                }
1.410     djm      2836:        }
                   2837:        channel_handler(ssh, CHAN_POST, NULL);
1.367     djm      2838: }
                   2839:
                   2840: /*
                   2841:  * Enqueue data for channels with open or draining c->input.
                   2842:  */
                   2843: static void
                   2844: channel_output_poll_input_open(struct ssh *ssh, Channel *c)
                   2845: {
1.373     djm      2846:        size_t len, plen;
                   2847:        const u_char *pkt;
1.367     djm      2848:        int r;
                   2849:
                   2850:        if ((len = sshbuf_len(c->input)) == 0) {
                   2851:                if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
                   2852:                        /*
                   2853:                         * input-buffer is empty and read-socket shutdown:
                   2854:                         * tell peer, that we will not send more data:
                   2855:                         * send IEOF.
                   2856:                         * hack for extended data: delay EOF if EFD still
                   2857:                         * in use.
                   2858:                         */
                   2859:                        if (CHANNEL_EFD_INPUT_ACTIVE(c))
                   2860:                                debug2("channel %d: "
                   2861:                                    "ibuf_empty delayed efd %d/(%zu)",
                   2862:                                    c->self, c->efd, sshbuf_len(c->extended));
                   2863:                        else
                   2864:                                chan_ibuf_empty(ssh, c);
                   2865:                }
                   2866:                return;
                   2867:        }
                   2868:
1.368     djm      2869:        if (!c->have_remote_id)
1.403     djm      2870:                fatal_f("channel %d: no remote id", c->self);
1.368     djm      2871:
1.367     djm      2872:        if (c->datagram) {
                   2873:                /* Check datagram will fit; drop if not */
1.373     djm      2874:                if ((r = sshbuf_get_string_direct(c->input, &pkt, &plen)) != 0)
1.403     djm      2875:                        fatal_fr(r, "channel %i: get datagram", c->self);
1.367     djm      2876:                /*
                   2877:                 * XXX this does tail-drop on the datagram queue which is
                   2878:                 * usually suboptimal compared to head-drop. Better to have
                   2879:                 * backpressure at read time? (i.e. read + discard)
                   2880:                 */
1.373     djm      2881:                if (plen > c->remote_window || plen > c->remote_maxpacket) {
1.367     djm      2882:                        debug("channel %d: datagram too big", c->self);
                   2883:                        return;
                   2884:                }
                   2885:                /* Enqueue it */
                   2886:                if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
                   2887:                    (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1.373     djm      2888:                    (r = sshpkt_put_string(ssh, pkt, plen)) != 0 ||
1.403     djm      2889:                    (r = sshpkt_send(ssh)) != 0)
                   2890:                        fatal_fr(r, "channel %i: send datagram", c->self);
1.373     djm      2891:                c->remote_window -= plen;
1.367     djm      2892:                return;
                   2893:        }
                   2894:
                   2895:        /* Enqueue packet for buffered data. */
                   2896:        if (len > c->remote_window)
                   2897:                len = c->remote_window;
                   2898:        if (len > c->remote_maxpacket)
                   2899:                len = c->remote_maxpacket;
                   2900:        if (len == 0)
                   2901:                return;
                   2902:        if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
                   2903:            (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
                   2904:            (r = sshpkt_put_string(ssh, sshbuf_ptr(c->input), len)) != 0 ||
1.403     djm      2905:            (r = sshpkt_send(ssh)) != 0)
                   2906:                fatal_fr(r, "channel %i: send data", c->self);
1.367     djm      2907:        if ((r = sshbuf_consume(c->input, len)) != 0)
1.403     djm      2908:                fatal_fr(r, "channel %i: consume", c->self);
1.367     djm      2909:        c->remote_window -= len;
1.41      markus   2910: }
                   2911:
1.367     djm      2912: /*
                   2913:  * Enqueue data for channels with open c->extended in read mode.
                   2914:  */
                   2915: static void
                   2916: channel_output_poll_extended_read(struct ssh *ssh, Channel *c)
                   2917: {
                   2918:        size_t len;
                   2919:        int r;
                   2920:
                   2921:        if ((len = sshbuf_len(c->extended)) == 0)
                   2922:                return;
                   2923:
                   2924:        debug2("channel %d: rwin %u elen %zu euse %d", c->self,
                   2925:            c->remote_window, sshbuf_len(c->extended), c->extended_usage);
                   2926:        if (len > c->remote_window)
                   2927:                len = c->remote_window;
                   2928:        if (len > c->remote_maxpacket)
                   2929:                len = c->remote_maxpacket;
                   2930:        if (len == 0)
                   2931:                return;
1.368     djm      2932:        if (!c->have_remote_id)
1.403     djm      2933:                fatal_f("channel %d: no remote id", c->self);
1.367     djm      2934:        if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA)) != 0 ||
                   2935:            (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
                   2936:            (r = sshpkt_put_u32(ssh, SSH2_EXTENDED_DATA_STDERR)) != 0 ||
                   2937:            (r = sshpkt_put_string(ssh, sshbuf_ptr(c->extended), len)) != 0 ||
1.403     djm      2938:            (r = sshpkt_send(ssh)) != 0)
                   2939:                fatal_fr(r, "channel %i: data", c->self);
1.367     djm      2940:        if ((r = sshbuf_consume(c->extended, len)) != 0)
1.403     djm      2941:                fatal_fr(r, "channel %i: consume", c->self);
1.367     djm      2942:        c->remote_window -= len;
                   2943:        debug2("channel %d: sent ext data %zu", c->self, len);
                   2944: }
1.121     markus   2945:
1.84      markus   2946: /* If there is data to send to the connection, enqueue some of it now. */
1.49      markus   2947: void
1.367     djm      2948: channel_output_poll(struct ssh *ssh)
1.1       deraadt  2949: {
1.367     djm      2950:        struct ssh_channels *sc = ssh->chanctxt;
1.41      markus   2951:        Channel *c;
1.367     djm      2952:        u_int i;
1.1       deraadt  2953:
1.367     djm      2954:        for (i = 0; i < sc->channels_alloc; i++) {
                   2955:                c = sc->channels[i];
1.113     markus   2956:                if (c == NULL)
                   2957:                        continue;
1.37      markus   2958:
1.121     markus   2959:                /*
                   2960:                 * We are only interested in channels that can have buffered
                   2961:                 * incoming data.
                   2962:                 */
1.358     djm      2963:                if (c->type != SSH_CHANNEL_OPEN)
                   2964:                        continue;
                   2965:                if ((c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93      markus   2966:                        /* XXX is this true? */
1.367     djm      2967:                        debug3("channel %d: will not send data after close",
                   2968:                            c->self);
1.44      markus   2969:                        continue;
                   2970:                }
1.25      markus   2971:
                   2972:                /* Get the amount of buffered data for this channel. */
1.367     djm      2973:                if (c->istate == CHAN_INPUT_OPEN ||
                   2974:                    c->istate == CHAN_INPUT_WAIT_DRAIN)
                   2975:                        channel_output_poll_input_open(ssh, c);
1.44      markus   2976:                /* Send extended data, i.e. stderr */
1.358     djm      2977:                if (!(c->flags & CHAN_EOF_SENT) &&
1.367     djm      2978:                    c->extended_usage == CHAN_EXTENDED_READ)
                   2979:                        channel_output_poll_extended_read(ssh, c);
1.25      markus   2980:        }
1.1       deraadt  2981: }
                   2982:
1.354     markus   2983: /* -- mux proxy support  */
                   2984:
                   2985: /*
                   2986:  * When multiplexing channel messages for mux clients we have to deal
                   2987:  * with downstream messages from the mux client and upstream messages
                   2988:  * from the ssh server:
                   2989:  * 1) Handling downstream messages is straightforward and happens
                   2990:  *    in channel_proxy_downstream():
                   2991:  *    - We forward all messages (mostly) unmodified to the server.
                   2992:  *    - However, in order to route messages from upstream to the correct
                   2993:  *      downstream client, we have to replace the channel IDs used by the
                   2994:  *      mux clients with a unique channel ID because the mux clients might
                   2995:  *      use conflicting channel IDs.
                   2996:  *    - so we inspect and change both SSH2_MSG_CHANNEL_OPEN and
                   2997:  *      SSH2_MSG_CHANNEL_OPEN_CONFIRMATION messages, create a local
                   2998:  *      SSH_CHANNEL_MUX_PROXY channel and replace the mux clients ID
                   2999:  *      with the newly allocated channel ID.
                   3000:  * 2) Upstream messages are received by matching SSH_CHANNEL_MUX_PROXY
1.380     djm      3001:  *    channels and processed by channel_proxy_upstream(). The local channel ID
1.354     markus   3002:  *    is then translated back to the original mux client ID.
                   3003:  * 3) In both cases we need to keep track of matching SSH2_MSG_CHANNEL_CLOSE
                   3004:  *    messages so we can clean up SSH_CHANNEL_MUX_PROXY channels.
                   3005:  * 4) The SSH_CHANNEL_MUX_PROXY channels also need to closed when the
                   3006:  *    downstream mux client are removed.
                   3007:  * 5) Handling SSH2_MSG_CHANNEL_OPEN messages from the upstream server
                   3008:  *    requires more work, because they are not addressed to a specific
                   3009:  *    channel. E.g. client_request_forwarded_tcpip() needs to figure
                   3010:  *    out whether the request is addressed to the local client or a
                   3011:  *    specific downstream client based on the listen-address/port.
1.380     djm      3012:  * 6) Agent and X11-Forwarding have a similar problem and are currently
1.354     markus   3013:  *    not supported as the matching session/channel cannot be identified
                   3014:  *    easily.
                   3015:  */
                   3016:
                   3017: /*
                   3018:  * receive packets from downstream mux clients:
                   3019:  * channel callback fired on read from mux client, creates
                   3020:  * SSH_CHANNEL_MUX_PROXY channels and translates channel IDs
                   3021:  * on channel creation.
                   3022:  */
                   3023: int
1.367     djm      3024: channel_proxy_downstream(struct ssh *ssh, Channel *downstream)
1.354     markus   3025: {
                   3026:        Channel *c = NULL;
                   3027:        struct sshbuf *original = NULL, *modified = NULL;
                   3028:        const u_char *cp;
                   3029:        char *ctype = NULL, *listen_host = NULL;
                   3030:        u_char type;
                   3031:        size_t have;
1.370     djm      3032:        int ret = -1, r;
1.355     djm      3033:        u_int id, remote_id, listen_port;
1.354     markus   3034:
1.367     djm      3035:        /* sshbuf_dump(downstream->input, stderr); */
                   3036:        if ((r = sshbuf_get_string_direct(downstream->input, &cp, &have))
1.354     markus   3037:            != 0) {
1.403     djm      3038:                error_fr(r, "parse");
1.354     markus   3039:                return -1;
                   3040:        }
                   3041:        if (have < 2) {
1.403     djm      3042:                error_f("short message");
1.354     markus   3043:                return -1;
                   3044:        }
                   3045:        type = cp[1];
                   3046:        /* skip padlen + type */
                   3047:        cp += 2;
                   3048:        have -= 2;
                   3049:        if (ssh_packet_log_type(type))
1.403     djm      3050:                debug3_f("channel %u: down->up: type %u",
1.354     markus   3051:                    downstream->self, type);
                   3052:
                   3053:        switch (type) {
                   3054:        case SSH2_MSG_CHANNEL_OPEN:
                   3055:                if ((original = sshbuf_from(cp, have)) == NULL ||
                   3056:                    (modified = sshbuf_new()) == NULL) {
1.403     djm      3057:                        error_f("alloc");
1.354     markus   3058:                        goto out;
                   3059:                }
                   3060:                if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0 ||
                   3061:                    (r = sshbuf_get_u32(original, &id)) != 0) {
1.403     djm      3062:                        error_fr(r, "parse");
1.354     markus   3063:                        goto out;
                   3064:                }
1.424     djm      3065:                c = channel_new(ssh, "mux-proxy", SSH_CHANNEL_MUX_PROXY,
1.406     djm      3066:                    -1, -1, -1, 0, 0, 0, ctype, 1);
1.354     markus   3067:                c->mux_ctx = downstream;        /* point to mux client */
                   3068:                c->mux_downstream_id = id;      /* original downstream id */
                   3069:                if ((r = sshbuf_put_cstring(modified, ctype)) != 0 ||
                   3070:                    (r = sshbuf_put_u32(modified, c->self)) != 0 ||
                   3071:                    (r = sshbuf_putb(modified, original)) != 0) {
1.403     djm      3072:                        error_fr(r, "compose");
1.367     djm      3073:                        channel_free(ssh, c);
1.354     markus   3074:                        goto out;
                   3075:                }
                   3076:                break;
                   3077:        case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
                   3078:                /*
                   3079:                 * Almost the same as SSH2_MSG_CHANNEL_OPEN, except then we
                   3080:                 * need to parse 'remote_id' instead of 'ctype'.
                   3081:                 */
                   3082:                if ((original = sshbuf_from(cp, have)) == NULL ||
                   3083:                    (modified = sshbuf_new()) == NULL) {
1.403     djm      3084:                        error_f("alloc");
1.354     markus   3085:                        goto out;
                   3086:                }
                   3087:                if ((r = sshbuf_get_u32(original, &remote_id)) != 0 ||
                   3088:                    (r = sshbuf_get_u32(original, &id)) != 0) {
1.403     djm      3089:                        error_fr(r, "parse");
1.354     markus   3090:                        goto out;
                   3091:                }
1.424     djm      3092:                c = channel_new(ssh, "mux-proxy", SSH_CHANNEL_MUX_PROXY,
1.406     djm      3093:                    -1, -1, -1, 0, 0, 0, "mux-down-connect", 1);
1.354     markus   3094:                c->mux_ctx = downstream;        /* point to mux client */
                   3095:                c->mux_downstream_id = id;
                   3096:                c->remote_id = remote_id;
1.368     djm      3097:                c->have_remote_id = 1;
1.354     markus   3098:                if ((r = sshbuf_put_u32(modified, remote_id)) != 0 ||
                   3099:                    (r = sshbuf_put_u32(modified, c->self)) != 0 ||
                   3100:                    (r = sshbuf_putb(modified, original)) != 0) {
1.403     djm      3101:                        error_fr(r, "compose");
1.367     djm      3102:                        channel_free(ssh, c);
1.354     markus   3103:                        goto out;
                   3104:                }
                   3105:                break;
                   3106:        case SSH2_MSG_GLOBAL_REQUEST:
                   3107:                if ((original = sshbuf_from(cp, have)) == NULL) {
1.403     djm      3108:                        error_f("alloc");
1.354     markus   3109:                        goto out;
                   3110:                }
                   3111:                if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0) {
1.403     djm      3112:                        error_fr(r, "parse");
1.354     markus   3113:                        goto out;
                   3114:                }
                   3115:                if (strcmp(ctype, "tcpip-forward") != 0) {
1.403     djm      3116:                        error_f("unsupported request %s", ctype);
1.354     markus   3117:                        goto out;
                   3118:                }
                   3119:                if ((r = sshbuf_get_u8(original, NULL)) != 0 ||
                   3120:                    (r = sshbuf_get_cstring(original, &listen_host, NULL)) != 0 ||
                   3121:                    (r = sshbuf_get_u32(original, &listen_port)) != 0) {
1.403     djm      3122:                        error_fr(r, "parse");
1.354     markus   3123:                        goto out;
                   3124:                }
1.355     djm      3125:                if (listen_port > 65535) {
1.403     djm      3126:                        error_f("tcpip-forward for %s: bad port %u",
                   3127:                            listen_host, listen_port);
1.355     djm      3128:                        goto out;
                   3129:                }
1.354     markus   3130:                /* Record that connection to this host/port is permitted. */
1.381     djm      3131:                permission_set_add(ssh, FORWARD_USER, FORWARD_LOCAL, "<mux>", -1,
1.367     djm      3132:                    listen_host, NULL, (int)listen_port, downstream);
1.354     markus   3133:                listen_host = NULL;
                   3134:                break;
                   3135:        case SSH2_MSG_CHANNEL_CLOSE:
                   3136:                if (have < 4)
                   3137:                        break;
                   3138:                remote_id = PEEK_U32(cp);
1.367     djm      3139:                if ((c = channel_by_remote_id(ssh, remote_id)) != NULL) {
1.354     markus   3140:                        if (c->flags & CHAN_CLOSE_RCVD)
1.367     djm      3141:                                channel_free(ssh, c);
1.354     markus   3142:                        else
                   3143:                                c->flags |= CHAN_CLOSE_SENT;
                   3144:                }
                   3145:                break;
                   3146:        }
                   3147:        if (modified) {
                   3148:                if ((r = sshpkt_start(ssh, type)) != 0 ||
                   3149:                    (r = sshpkt_putb(ssh, modified)) != 0 ||
                   3150:                    (r = sshpkt_send(ssh)) != 0) {
1.403     djm      3151:                        error_fr(r, "send");
1.354     markus   3152:                        goto out;
                   3153:                }
                   3154:        } else {
                   3155:                if ((r = sshpkt_start(ssh, type)) != 0 ||
                   3156:                    (r = sshpkt_put(ssh, cp, have)) != 0 ||
                   3157:                    (r = sshpkt_send(ssh)) != 0) {
1.403     djm      3158:                        error_fr(r, "send");
1.354     markus   3159:                        goto out;
                   3160:                }
                   3161:        }
                   3162:        ret = 0;
                   3163:  out:
                   3164:        free(ctype);
                   3165:        free(listen_host);
                   3166:        sshbuf_free(original);
                   3167:        sshbuf_free(modified);
                   3168:        return ret;
                   3169: }
                   3170:
                   3171: /*
                   3172:  * receive packets from upstream server and de-multiplex packets
                   3173:  * to correct downstream:
                   3174:  * implemented as a helper for channel input handlers,
                   3175:  * replaces local (proxy) channel ID with downstream channel ID.
                   3176:  */
                   3177: int
1.363     markus   3178: channel_proxy_upstream(Channel *c, int type, u_int32_t seq, struct ssh *ssh)
1.354     markus   3179: {
                   3180:        struct sshbuf *b = NULL;
                   3181:        Channel *downstream;
                   3182:        const u_char *cp = NULL;
                   3183:        size_t len;
                   3184:        int r;
                   3185:
                   3186:        /*
                   3187:         * When receiving packets from the peer we need to check whether we
                   3188:         * need to forward the packets to the mux client. In this case we
1.380     djm      3189:         * restore the original channel id and keep track of CLOSE messages,
1.354     markus   3190:         * so we can cleanup the channel.
                   3191:         */
                   3192:        if (c == NULL || c->type != SSH_CHANNEL_MUX_PROXY)
                   3193:                return 0;
                   3194:        if ((downstream = c->mux_ctx) == NULL)
                   3195:                return 0;
                   3196:        switch (type) {
                   3197:        case SSH2_MSG_CHANNEL_CLOSE:
                   3198:        case SSH2_MSG_CHANNEL_DATA:
                   3199:        case SSH2_MSG_CHANNEL_EOF:
                   3200:        case SSH2_MSG_CHANNEL_EXTENDED_DATA:
                   3201:        case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
                   3202:        case SSH2_MSG_CHANNEL_OPEN_FAILURE:
                   3203:        case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
                   3204:        case SSH2_MSG_CHANNEL_SUCCESS:
                   3205:        case SSH2_MSG_CHANNEL_FAILURE:
                   3206:        case SSH2_MSG_CHANNEL_REQUEST:
                   3207:                break;
                   3208:        default:
1.403     djm      3209:                debug2_f("channel %u: unsupported type %u", c->self, type);
1.354     markus   3210:                return 0;
                   3211:        }
                   3212:        if ((b = sshbuf_new()) == NULL) {
1.403     djm      3213:                error_f("alloc reply");
1.354     markus   3214:                goto out;
                   3215:        }
                   3216:        /* get remaining payload (after id) */
                   3217:        cp = sshpkt_ptr(ssh, &len);
                   3218:        if (cp == NULL) {
1.403     djm      3219:                error_f("no packet");
1.354     markus   3220:                goto out;
                   3221:        }
                   3222:        /* translate id and send to muxclient */
                   3223:        if ((r = sshbuf_put_u8(b, 0)) != 0 ||   /* padlen */
                   3224:            (r = sshbuf_put_u8(b, type)) != 0 ||
                   3225:            (r = sshbuf_put_u32(b, c->mux_downstream_id)) != 0 ||
                   3226:            (r = sshbuf_put(b, cp, len)) != 0 ||
1.367     djm      3227:            (r = sshbuf_put_stringb(downstream->output, b)) != 0) {
1.403     djm      3228:                error_fr(r, "compose muxclient");
1.354     markus   3229:                goto out;
                   3230:        }
                   3231:        /* sshbuf_dump(b, stderr); */
                   3232:        if (ssh_packet_log_type(type))
1.403     djm      3233:                debug3_f("channel %u: up->down: type %u", c->self, type);
1.354     markus   3234:  out:
                   3235:        /* update state */
                   3236:        switch (type) {
                   3237:        case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
                   3238:                /* record remote_id for SSH2_MSG_CHANNEL_CLOSE */
1.368     djm      3239:                if (cp && len > 4) {
1.354     markus   3240:                        c->remote_id = PEEK_U32(cp);
1.368     djm      3241:                        c->have_remote_id = 1;
                   3242:                }
1.354     markus   3243:                break;
                   3244:        case SSH2_MSG_CHANNEL_CLOSE:
                   3245:                if (c->flags & CHAN_CLOSE_SENT)
1.367     djm      3246:                        channel_free(ssh, c);
1.354     markus   3247:                else
                   3248:                        c->flags |= CHAN_CLOSE_RCVD;
                   3249:                break;
                   3250:        }
                   3251:        sshbuf_free(b);
                   3252:        return 1;
                   3253: }
1.121     markus   3254:
                   3255: /* -- protocol input */
1.249     djm      3256:
1.367     djm      3257: /* Parse a channel ID from the current packet */
                   3258: static int
                   3259: channel_parse_id(struct ssh *ssh, const char *where, const char *what)
                   3260: {
                   3261:        u_int32_t id;
                   3262:        int r;
                   3263:
                   3264:        if ((r = sshpkt_get_u32(ssh, &id)) != 0) {
1.403     djm      3265:                error_r(r, "%s: parse id", where);
1.367     djm      3266:                ssh_packet_disconnect(ssh, "Invalid %s message", what);
                   3267:        }
                   3268:        if (id > INT_MAX) {
1.403     djm      3269:                error_r(r, "%s: bad channel id %u", where, id);
1.367     djm      3270:                ssh_packet_disconnect(ssh, "Invalid %s channel id", what);
                   3271:        }
                   3272:        return (int)id;
                   3273: }
                   3274:
                   3275: /* Lookup a channel from an ID in the current packet */
                   3276: static Channel *
                   3277: channel_from_packet_id(struct ssh *ssh, const char *where, const char *what)
                   3278: {
                   3279:        int id = channel_parse_id(ssh, where, what);
                   3280:        Channel *c;
                   3281:
                   3282:        if ((c = channel_lookup(ssh, id)) == NULL) {
                   3283:                ssh_packet_disconnect(ssh,
                   3284:                    "%s packet referred to nonexistent channel %d", what, id);
                   3285:        }
                   3286:        return c;
                   3287: }
                   3288:
1.339     markus   3289: int
1.363     markus   3290: channel_input_data(int type, u_int32_t seq, struct ssh *ssh)
1.1       deraadt  3291: {
1.332     djm      3292:        const u_char *data;
1.367     djm      3293:        size_t data_len, win_len;
                   3294:        Channel *c = channel_from_packet_id(ssh, __func__, "data");
                   3295:        int r;
1.25      markus   3296:
1.363     markus   3297:        if (channel_proxy_upstream(c, type, seq, ssh))
1.354     markus   3298:                return 0;
1.25      markus   3299:
                   3300:        /* Ignore any data for non-open channels (might happen on close) */
1.41      markus   3301:        if (c->type != SSH_CHANNEL_OPEN &&
1.372     markus   3302:            c->type != SSH_CHANNEL_RDYNAMIC_OPEN &&
                   3303:            c->type != SSH_CHANNEL_RDYNAMIC_FINISH &&
1.41      markus   3304:            c->type != SSH_CHANNEL_X11_OPEN)
1.339     markus   3305:                return 0;
1.37      markus   3306:
1.25      markus   3307:        /* Get the data. */
1.389     djm      3308:        if ((r = sshpkt_get_string_direct(ssh, &data, &data_len)) != 0 ||
                   3309:             (r = sshpkt_get_end(ssh)) != 0)
1.403     djm      3310:                fatal_fr(r, "channel %i: get data", c->self);
1.367     djm      3311:
1.309     djm      3312:        win_len = data_len;
                   3313:        if (c->datagram)
                   3314:                win_len += 4;  /* string length header */
1.200     markus   3315:
                   3316:        /*
1.367     djm      3317:         * The sending side reduces its window as it sends data, so we
                   3318:         * must 'fake' consumption of the data in order to ensure that window
                   3319:         * updates are sent back. Otherwise the connection might deadlock.
1.200     markus   3320:         */
1.358     djm      3321:        if (c->ostate != CHAN_OUTPUT_OPEN) {
                   3322:                c->local_window -= win_len;
                   3323:                c->local_consumed += win_len;
1.339     markus   3324:                return 0;
1.200     markus   3325:        }
1.41      markus   3326:
1.358     djm      3327:        if (win_len > c->local_maxpacket) {
1.367     djm      3328:                logit("channel %d: rcvd big packet %zu, maxpack %u",
1.358     djm      3329:                    c->self, win_len, c->local_maxpacket);
1.367     djm      3330:                return 0;
1.358     djm      3331:        }
                   3332:        if (win_len > c->local_window) {
1.367     djm      3333:                logit("channel %d: rcvd too much data %zu, win %u",
1.358     djm      3334:                    c->self, win_len, c->local_window);
                   3335:                return 0;
1.44      markus   3336:        }
1.358     djm      3337:        c->local_window -= win_len;
                   3338:
1.367     djm      3339:        if (c->datagram) {
                   3340:                if ((r = sshbuf_put_string(c->output, data, data_len)) != 0)
1.403     djm      3341:                        fatal_fr(r, "channel %i: append datagram", c->self);
1.367     djm      3342:        } else if ((r = sshbuf_put(c->output, data, data_len)) != 0)
1.403     djm      3343:                fatal_fr(r, "channel %i: append data", c->self);
1.367     djm      3344:
1.339     markus   3345:        return 0;
1.1       deraadt  3346: }
1.121     markus   3347:
1.339     markus   3348: int
1.363     markus   3349: channel_input_extended_data(int type, u_int32_t seq, struct ssh *ssh)
1.44      markus   3350: {
1.367     djm      3351:        const u_char *data;
                   3352:        size_t data_len;
                   3353:        u_int32_t tcode;
                   3354:        Channel *c = channel_from_packet_id(ssh, __func__, "extended data");
                   3355:        int r;
1.44      markus   3356:
1.363     markus   3357:        if (channel_proxy_upstream(c, type, seq, ssh))
1.354     markus   3358:                return 0;
1.44      markus   3359:        if (c->type != SSH_CHANNEL_OPEN) {
1.367     djm      3360:                logit("channel %d: ext data for non open", c->self);
1.339     markus   3361:                return 0;
1.172     markus   3362:        }
                   3363:        if (c->flags & CHAN_EOF_RCVD) {
1.404     djm      3364:                if (ssh->compat & SSH_BUG_EXTEOF)
1.367     djm      3365:                        debug("channel %d: accepting ext data after eof",
                   3366:                            c->self);
1.172     markus   3367:                else
1.367     djm      3368:                        ssh_packet_disconnect(ssh, "Received extended_data "
                   3369:                            "after EOF on channel %d.", c->self);
                   3370:        }
                   3371:
                   3372:        if ((r = sshpkt_get_u32(ssh, &tcode)) != 0) {
1.403     djm      3373:                error_fr(r, "parse tcode");
1.367     djm      3374:                ssh_packet_disconnect(ssh, "Invalid extended_data message");
1.44      markus   3375:        }
                   3376:        if (c->efd == -1 ||
                   3377:            c->extended_usage != CHAN_EXTENDED_WRITE ||
                   3378:            tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188     itojun   3379:                logit("channel %d: bad ext data", c->self);
1.339     markus   3380:                return 0;
1.44      markus   3381:        }
1.389     djm      3382:        if ((r = sshpkt_get_string_direct(ssh, &data, &data_len)) != 0 ||
                   3383:             (r = sshpkt_get_end(ssh)) != 0) {
1.403     djm      3384:                error_fr(r, "parse data");
1.367     djm      3385:                ssh_packet_disconnect(ssh, "Invalid extended_data message");
                   3386:        }
                   3387:
1.44      markus   3388:        if (data_len > c->local_window) {
1.367     djm      3389:                logit("channel %d: rcvd too much extended_data %zu, win %u",
1.44      markus   3390:                    c->self, data_len, c->local_window);
1.339     markus   3391:                return 0;
1.44      markus   3392:        }
1.367     djm      3393:        debug2("channel %d: rcvd ext data %zu", c->self, data_len);
                   3394:        /* XXX sshpkt_getb? */
                   3395:        if ((r = sshbuf_put(c->extended, data, data_len)) != 0)
1.403     djm      3396:                error_fr(r, "append");
1.44      markus   3397:        c->local_window -= data_len;
1.339     markus   3398:        return 0;
1.44      markus   3399: }
                   3400:
1.339     markus   3401: int
1.363     markus   3402: channel_input_ieof(int type, u_int32_t seq, struct ssh *ssh)
1.41      markus   3403: {
1.367     djm      3404:        Channel *c = channel_from_packet_id(ssh, __func__, "ieof");
1.389     djm      3405:        int r;
1.367     djm      3406:
1.389     djm      3407:         if ((r = sshpkt_get_end(ssh)) != 0) {
1.403     djm      3408:                error_fr(r, "parse data");
1.389     djm      3409:                ssh_packet_disconnect(ssh, "Invalid ieof message");
                   3410:        }
1.41      markus   3411:
1.363     markus   3412:        if (channel_proxy_upstream(c, type, seq, ssh))
1.354     markus   3413:                return 0;
1.367     djm      3414:        chan_rcvd_ieof(ssh, c);
1.133     markus   3415:
                   3416:        /* XXX force input close */
1.156     markus   3417:        if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133     markus   3418:                debug("channel %d: FORCE input drain", c->self);
                   3419:                c->istate = CHAN_INPUT_WAIT_DRAIN;
1.367     djm      3420:                if (sshbuf_len(c->input) == 0)
                   3421:                        chan_ibuf_empty(ssh, c);
1.133     markus   3422:        }
1.339     markus   3423:        return 0;
1.41      markus   3424: }
1.1       deraadt  3425:
1.339     markus   3426: int
1.363     markus   3427: channel_input_oclose(int type, u_int32_t seq, struct ssh *ssh)
1.41      markus   3428: {
1.367     djm      3429:        Channel *c = channel_from_packet_id(ssh, __func__, "oclose");
1.389     djm      3430:        int r;
1.151     markus   3431:
1.363     markus   3432:        if (channel_proxy_upstream(c, type, seq, ssh))
1.354     markus   3433:                return 0;
1.389     djm      3434:         if ((r = sshpkt_get_end(ssh)) != 0) {
1.403     djm      3435:                error_fr(r, "parse data");
1.389     djm      3436:                ssh_packet_disconnect(ssh, "Invalid oclose message");
                   3437:        }
1.367     djm      3438:        chan_rcvd_oclose(ssh, c);
1.339     markus   3439:        return 0;
1.1       deraadt  3440: }
                   3441:
1.339     markus   3442: int
1.363     markus   3443: channel_input_open_confirmation(int type, u_int32_t seq, struct ssh *ssh)
1.1       deraadt  3444: {
1.367     djm      3445:        Channel *c = channel_from_packet_id(ssh, __func__, "open confirmation");
                   3446:        u_int32_t remote_window, remote_maxpacket;
                   3447:        int r;
1.25      markus   3448:
1.363     markus   3449:        if (channel_proxy_upstream(c, type, seq, ssh))
1.354     markus   3450:                return 0;
                   3451:        if (c->type != SSH_CHANNEL_OPENING)
1.389     djm      3452:                ssh_packet_disconnect(ssh, "Received open confirmation for "
1.367     djm      3453:                    "non-opening channel %d.", c->self);
                   3454:        /*
                   3455:         * Record the remote channel number and mark that the channel
                   3456:         * is now open.
                   3457:         */
1.368     djm      3458:        if ((r = sshpkt_get_u32(ssh, &c->remote_id)) != 0 ||
                   3459:            (r = sshpkt_get_u32(ssh, &remote_window)) != 0 ||
1.389     djm      3460:            (r = sshpkt_get_u32(ssh, &remote_maxpacket)) != 0 ||
                   3461:             (r = sshpkt_get_end(ssh)) != 0) {
1.403     djm      3462:                error_fr(r, "window/maxpacket");
1.389     djm      3463:                ssh_packet_disconnect(ssh, "Invalid open confirmation message");
1.367     djm      3464:        }
                   3465:
1.368     djm      3466:        c->have_remote_id = 1;
1.367     djm      3467:        c->remote_window = remote_window;
                   3468:        c->remote_maxpacket = remote_maxpacket;
1.41      markus   3469:        c->type = SSH_CHANNEL_OPEN;
1.358     djm      3470:        if (c->open_confirm) {
1.403     djm      3471:                debug2_f("channel %d: callback start", c->self);
1.367     djm      3472:                c->open_confirm(ssh, c->self, 1, c->open_confirm_ctx);
1.403     djm      3473:                debug2_f("channel %d: callback done", c->self);
1.44      markus   3474:        }
1.426     djm      3475:        c->lastused = monotime();
1.358     djm      3476:        debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
                   3477:            c->remote_window, c->remote_maxpacket);
1.339     markus   3478:        return 0;
1.1       deraadt  3479: }
                   3480:
1.127     itojun   3481: static char *
1.114     markus   3482: reason2txt(int reason)
                   3483: {
1.143     deraadt  3484:        switch (reason) {
1.114     markus   3485:        case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
                   3486:                return "administratively prohibited";
                   3487:        case SSH2_OPEN_CONNECT_FAILED:
                   3488:                return "connect failed";
                   3489:        case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
                   3490:                return "unknown channel type";
                   3491:        case SSH2_OPEN_RESOURCE_SHORTAGE:
                   3492:                return "resource shortage";
                   3493:        }
1.117     stevesk  3494:        return "unknown reason";
1.114     markus   3495: }
                   3496:
1.339     markus   3497: int
1.363     markus   3498: channel_input_open_failure(int type, u_int32_t seq, struct ssh *ssh)
1.1       deraadt  3499: {
1.367     djm      3500:        Channel *c = channel_from_packet_id(ssh, __func__, "open failure");
                   3501:        u_int32_t reason;
                   3502:        char *msg = NULL;
                   3503:        int r;
1.25      markus   3504:
1.363     markus   3505:        if (channel_proxy_upstream(c, type, seq, ssh))
1.354     markus   3506:                return 0;
                   3507:        if (c->type != SSH_CHANNEL_OPENING)
1.389     djm      3508:                ssh_packet_disconnect(ssh, "Received open failure for "
1.367     djm      3509:                    "non-opening channel %d.", c->self);
                   3510:        if ((r = sshpkt_get_u32(ssh, &reason)) != 0) {
1.403     djm      3511:                error_fr(r, "parse reason");
1.389     djm      3512:                ssh_packet_disconnect(ssh, "Invalid open failure message");
1.367     djm      3513:        }
1.378     djm      3514:        /* skip language */
                   3515:        if ((r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
1.389     djm      3516:            (r = sshpkt_get_string_direct(ssh, NULL, NULL)) != 0 ||
                   3517:             (r = sshpkt_get_end(ssh)) != 0) {
1.403     djm      3518:                error_fr(r, "parse msg/lang");
1.389     djm      3519:                ssh_packet_disconnect(ssh, "Invalid open failure message");
1.358     djm      3520:        }
1.367     djm      3521:        logit("channel %d: open failed: %s%s%s", c->self,
1.358     djm      3522:            reason2txt(reason), msg ? ": ": "", msg ? msg : "");
                   3523:        free(msg);
                   3524:        if (c->open_confirm) {
1.403     djm      3525:                debug2_f("channel %d: callback start", c->self);
1.367     djm      3526:                c->open_confirm(ssh, c->self, 0, c->open_confirm_ctx);
1.403     djm      3527:                debug2_f("channel %d: callback done", c->self);
1.44      markus   3528:        }
1.291     djm      3529:        /* Schedule the channel for cleanup/deletion. */
1.367     djm      3530:        chan_mark_dead(ssh, c);
1.339     markus   3531:        return 0;
1.44      markus   3532: }
                   3533:
1.339     markus   3534: int
1.363     markus   3535: channel_input_window_adjust(int type, u_int32_t seq, struct ssh *ssh)
1.121     markus   3536: {
1.367     djm      3537:        int id = channel_parse_id(ssh, __func__, "window adjust");
1.121     markus   3538:        Channel *c;
1.367     djm      3539:        u_int32_t adjust;
                   3540:        u_int new_rwin;
                   3541:        int r;
1.1       deraadt  3542:
1.367     djm      3543:        if ((c = channel_lookup(ssh, id)) == NULL) {
1.229     markus   3544:                logit("Received window adjust for non-open channel %d.", id);
1.339     markus   3545:                return 0;
1.372     markus   3546:        }
1.367     djm      3547:
1.363     markus   3548:        if (channel_proxy_upstream(c, type, seq, ssh))
1.354     markus   3549:                return 0;
1.389     djm      3550:        if ((r = sshpkt_get_u32(ssh, &adjust)) != 0 ||
                   3551:             (r = sshpkt_get_end(ssh)) != 0) {
1.403     djm      3552:                error_fr(r, "parse adjust");
1.389     djm      3553:                ssh_packet_disconnect(ssh, "Invalid window adjust message");
1.367     djm      3554:        }
                   3555:        debug2("channel %d: rcvd adjust %u", c->self, adjust);
                   3556:        if ((new_rwin = c->remote_window + adjust) < c->remote_window) {
1.346     djm      3557:                fatal("channel %d: adjust %u overflows remote window %u",
1.367     djm      3558:                    c->self, adjust, c->remote_window);
                   3559:        }
                   3560:        c->remote_window = new_rwin;
1.339     markus   3561:        return 0;
1.121     markus   3562: }
1.1       deraadt  3563:
1.339     markus   3564: int
1.363     markus   3565: channel_input_status_confirm(int type, u_int32_t seq, struct ssh *ssh)
1.275     djm      3566: {
1.367     djm      3567:        int id = channel_parse_id(ssh, __func__, "status confirm");
1.275     djm      3568:        Channel *c;
                   3569:        struct channel_confirm *cc;
                   3570:
                   3571:        /* Reset keepalive timeout */
1.389     djm      3572:        ssh_packet_set_alive_timeouts(ssh, 0);
1.275     djm      3573:
1.403     djm      3574:        debug2_f("type %d id %d", type, id);
1.275     djm      3575:
1.367     djm      3576:        if ((c = channel_lookup(ssh, id)) == NULL) {
1.403     djm      3577:                logit_f("%d: unknown", id);
1.339     markus   3578:                return 0;
1.367     djm      3579:        }
1.363     markus   3580:        if (channel_proxy_upstream(c, type, seq, ssh))
1.354     markus   3581:                return 0;
1.394     dtucker  3582:         if (sshpkt_get_end(ssh) != 0)
1.389     djm      3583:                ssh_packet_disconnect(ssh, "Invalid status confirm message");
1.275     djm      3584:        if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
1.339     markus   3585:                return 0;
1.367     djm      3586:        cc->cb(ssh, type, c, cc->ctx);
1.275     djm      3587:        TAILQ_REMOVE(&c->status_confirms, cc, entry);
1.396     jsg      3588:        freezero(cc, sizeof(*cc));
1.339     markus   3589:        return 0;
1.275     djm      3590: }
1.121     markus   3591:
                   3592: /* -- tcp forwarding */
1.135     markus   3593:
                   3594: void
1.367     djm      3595: channel_set_af(struct ssh *ssh, int af)
1.135     markus   3596: {
1.367     djm      3597:        ssh->chanctxt->IPv4or6 = af;
1.135     markus   3598: }
1.121     markus   3599:
1.312     djm      3600:
                   3601: /*
                   3602:  * Determine whether or not a port forward listens to loopback, the
                   3603:  * specified address or wildcard. On the client, a specified bind
                   3604:  * address will always override gateway_ports. On the server, a
                   3605:  * gateway_ports of 1 (``yes'') will override the client's specification
                   3606:  * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
                   3607:  * will bind to whatever address the client asked for.
                   3608:  *
                   3609:  * Special-case listen_addrs are:
                   3610:  *
                   3611:  * "0.0.0.0"               -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
                   3612:  * "" (empty string), "*"  -> wildcard v4/v6
                   3613:  * "localhost"             -> loopback v4/v6
1.334     djm      3614:  * "127.0.0.1" / "::1"     -> accepted even if gateway_ports isn't set
1.312     djm      3615:  */
                   3616: static const char *
1.389     djm      3617: channel_fwd_bind_addr(struct ssh *ssh, const char *listen_addr, int *wildcardp,
1.336     millert  3618:     int is_client, struct ForwardOptions *fwd_opts)
1.312     djm      3619: {
                   3620:        const char *addr = NULL;
                   3621:        int wildcard = 0;
                   3622:
                   3623:        if (listen_addr == NULL) {
                   3624:                /* No address specified: default to gateway_ports setting */
1.336     millert  3625:                if (fwd_opts->gateway_ports)
1.312     djm      3626:                        wildcard = 1;
1.336     millert  3627:        } else if (fwd_opts->gateway_ports || is_client) {
1.404     djm      3628:                if (((ssh->compat & SSH_OLD_FORWARD_ADDR) &&
1.312     djm      3629:                    strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
                   3630:                    *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
1.336     millert  3631:                    (!is_client && fwd_opts->gateway_ports == 1)) {
1.312     djm      3632:                        wildcard = 1;
1.326     djm      3633:                        /*
                   3634:                         * Notify client if they requested a specific listen
                   3635:                         * address and it was overridden.
                   3636:                         */
                   3637:                        if (*listen_addr != '\0' &&
                   3638:                            strcmp(listen_addr, "0.0.0.0") != 0 &&
                   3639:                            strcmp(listen_addr, "*") != 0) {
1.389     djm      3640:                                ssh_packet_send_debug(ssh,
                   3641:                                    "Forwarding listen address "
1.326     djm      3642:                                    "\"%s\" overridden by server "
                   3643:                                    "GatewayPorts", listen_addr);
                   3644:                        }
1.334     djm      3645:                } else if (strcmp(listen_addr, "localhost") != 0 ||
                   3646:                    strcmp(listen_addr, "127.0.0.1") == 0 ||
                   3647:                    strcmp(listen_addr, "::1") == 0) {
1.395     djm      3648:                        /*
                   3649:                         * Accept explicit localhost address when
                   3650:                         * GatewayPorts=yes. The "localhost" hostname is
                   3651:                         * deliberately skipped here so it will listen on all
                   3652:                         * available local address families.
                   3653:                         */
1.334     djm      3654:                        addr = listen_addr;
1.326     djm      3655:                }
1.334     djm      3656:        } else if (strcmp(listen_addr, "127.0.0.1") == 0 ||
                   3657:            strcmp(listen_addr, "::1") == 0) {
                   3658:                /*
                   3659:                 * If a specific IPv4/IPv6 localhost address has been
                   3660:                 * requested then accept it even if gateway_ports is in
                   3661:                 * effect. This allows the client to prefer IPv4 or IPv6.
                   3662:                 */
                   3663:                addr = listen_addr;
1.312     djm      3664:        }
                   3665:        if (wildcardp != NULL)
                   3666:                *wildcardp = wildcard;
                   3667:        return addr;
                   3668: }
                   3669:
1.160     markus   3670: static int
1.367     djm      3671: channel_setup_fwd_listener_tcpip(struct ssh *ssh, int type,
                   3672:     struct Forward *fwd, int *allocated_listen_port,
                   3673:     struct ForwardOptions *fwd_opts)
1.25      markus   3674: {
1.113     markus   3675:        Channel *c;
1.226     djm      3676:        int sock, r, success = 0, wildcard = 0, is_client;
1.35      markus   3677:        struct addrinfo hints, *ai, *aitop;
1.212     djm      3678:        const char *host, *addr;
1.35      markus   3679:        char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.295     djm      3680:        in_port_t *lport_p;
1.25      markus   3681:
1.212     djm      3682:        is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87      markus   3683:
1.344     millert  3684:        if (is_client && fwd->connect_path != NULL) {
                   3685:                host = fwd->connect_path;
                   3686:        } else {
                   3687:                host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
                   3688:                    fwd->listen_host : fwd->connect_host;
                   3689:                if (host == NULL) {
                   3690:                        error("No forward host name.");
                   3691:                        return 0;
                   3692:                }
                   3693:                if (strlen(host) >= NI_MAXHOST) {
                   3694:                        error("Forward host name too long.");
                   3695:                        return 0;
                   3696:                }
1.87      markus   3697:        }
1.25      markus   3698:
1.312     djm      3699:        /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
1.389     djm      3700:        addr = channel_fwd_bind_addr(ssh, fwd->listen_host, &wildcard,
1.336     millert  3701:            is_client, fwd_opts);
1.403     djm      3702:        debug3_f("type %d wildcard %d addr %s", type, wildcard,
                   3703:            (addr == NULL) ? "NULL" : addr);
1.212     djm      3704:
                   3705:        /*
1.35      markus   3706:         * getaddrinfo returns a loopback address if the hostname is
                   3707:         * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28      markus   3708:         */
1.35      markus   3709:        memset(&hints, 0, sizeof(hints));
1.367     djm      3710:        hints.ai_family = ssh->chanctxt->IPv4or6;
1.212     djm      3711:        hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35      markus   3712:        hints.ai_socktype = SOCK_STREAM;
1.336     millert  3713:        snprintf(strport, sizeof strport, "%d", fwd->listen_port);
1.212     djm      3714:        if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
                   3715:                if (addr == NULL) {
                   3716:                        /* This really shouldn't happen */
1.389     djm      3717:                        ssh_packet_disconnect(ssh, "getaddrinfo: fatal error: %s",
1.271     dtucker  3718:                            ssh_gai_strerror(r));
1.212     djm      3719:                } else {
1.403     djm      3720:                        error_f("getaddrinfo(%.64s): %s", addr,
1.271     dtucker  3721:                            ssh_gai_strerror(r));
1.212     djm      3722:                }
1.218     markus   3723:                return 0;
1.212     djm      3724:        }
1.295     djm      3725:        if (allocated_listen_port != NULL)
                   3726:                *allocated_listen_port = 0;
1.35      markus   3727:        for (ai = aitop; ai; ai = ai->ai_next) {
1.295     djm      3728:                switch (ai->ai_family) {
                   3729:                case AF_INET:
                   3730:                        lport_p = &((struct sockaddr_in *)ai->ai_addr)->
                   3731:                            sin_port;
                   3732:                        break;
                   3733:                case AF_INET6:
                   3734:                        lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
                   3735:                            sin6_port;
                   3736:                        break;
                   3737:                default:
1.35      markus   3738:                        continue;
1.295     djm      3739:                }
                   3740:                /*
                   3741:                 * If allocating a port for -R forwards, then use the
                   3742:                 * same port for all address families.
                   3743:                 */
1.367     djm      3744:                if (type == SSH_CHANNEL_RPORT_LISTENER &&
                   3745:                    fwd->listen_port == 0 && allocated_listen_port != NULL &&
                   3746:                    *allocated_listen_port > 0)
1.295     djm      3747:                        *lport_p = htons(*allocated_listen_port);
                   3748:
1.35      markus   3749:                if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1.367     djm      3750:                    strport, sizeof(strport),
                   3751:                    NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.403     djm      3752:                        error_f("getnameinfo failed");
1.35      markus   3753:                        continue;
                   3754:                }
                   3755:                /* Create a port to listen for the host. */
1.300     dtucker  3756:                sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.393     deraadt  3757:                if (sock == -1) {
1.35      markus   3758:                        /* this is no error since kernel may not support ipv6 */
1.377     djm      3759:                        verbose("socket [%s]:%s: %.100s", ntop, strport,
                   3760:                            strerror(errno));
1.35      markus   3761:                        continue;
                   3762:                }
1.226     djm      3763:
1.376     djm      3764:                set_reuseaddr(sock);
1.182     stevesk  3765:
1.295     djm      3766:                debug("Local forwarding listening on %s port %s.",
                   3767:                    ntop, strport);
1.35      markus   3768:
                   3769:                /* Bind the socket to the address. */
1.393     deraadt  3770:                if (bind(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
1.367     djm      3771:                        /*
                   3772:                         * address can be in if use ipv6 address is
                   3773:                         * already bound
                   3774:                         */
1.377     djm      3775:                        verbose("bind [%s]:%s: %.100s",
                   3776:                            ntop, strport, strerror(errno));
1.35      markus   3777:                        close(sock);
                   3778:                        continue;
                   3779:                }
                   3780:                /* Start listening for connections on the socket. */
1.393     deraadt  3781:                if (listen(sock, SSH_LISTEN_BACKLOG) == -1) {
1.377     djm      3782:                        error("listen [%s]:%s: %.100s", ntop, strport,
                   3783:                            strerror(errno));
1.35      markus   3784:                        close(sock);
                   3785:                        continue;
                   3786:                }
1.295     djm      3787:
                   3788:                /*
1.336     millert  3789:                 * fwd->listen_port == 0 requests a dynamically allocated port -
1.295     djm      3790:                 * record what we got.
                   3791:                 */
1.367     djm      3792:                if (type == SSH_CHANNEL_RPORT_LISTENER &&
                   3793:                    fwd->listen_port == 0 &&
1.295     djm      3794:                    allocated_listen_port != NULL &&
                   3795:                    *allocated_listen_port == 0) {
1.350     djm      3796:                        *allocated_listen_port = get_local_port(sock);
1.295     djm      3797:                        debug("Allocated listen port %d",
                   3798:                            *allocated_listen_port);
                   3799:                }
                   3800:
1.35      markus   3801:                /* Allocate a channel number for the socket. */
1.424     djm      3802:                c = channel_new(ssh, "port-listener", type, sock, sock, -1,
1.51      markus   3803:                    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190     markus   3804:                    0, "port listener", 1);
1.293     djm      3805:                c->path = xstrdup(host);
1.336     millert  3806:                c->host_port = fwd->connect_port;
1.312     djm      3807:                c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
1.336     millert  3808:                if (fwd->listen_port == 0 && allocated_listen_port != NULL &&
1.404     djm      3809:                    !(ssh->compat & SSH_BUG_DYNAMIC_RPORT))
1.315     markus   3810:                        c->listening_port = *allocated_listen_port;
                   3811:                else
1.336     millert  3812:                        c->listening_port = fwd->listen_port;
1.35      markus   3813:                success = 1;
                   3814:        }
                   3815:        if (success == 0)
1.403     djm      3816:                error_f("cannot listen to port: %d", fwd->listen_port);
1.35      markus   3817:        freeaddrinfo(aitop);
1.87      markus   3818:        return success;
1.25      markus   3819: }
1.1       deraadt  3820:
1.336     millert  3821: static int
1.367     djm      3822: channel_setup_fwd_listener_streamlocal(struct ssh *ssh, int type,
                   3823:     struct Forward *fwd, struct ForwardOptions *fwd_opts)
1.336     millert  3824: {
                   3825:        struct sockaddr_un sunaddr;
                   3826:        const char *path;
                   3827:        Channel *c;
                   3828:        int port, sock;
                   3829:        mode_t omask;
                   3830:
                   3831:        switch (type) {
                   3832:        case SSH_CHANNEL_UNIX_LISTENER:
                   3833:                if (fwd->connect_path != NULL) {
                   3834:                        if (strlen(fwd->connect_path) > sizeof(sunaddr.sun_path)) {
                   3835:                                error("Local connecting path too long: %s",
                   3836:                                    fwd->connect_path);
                   3837:                                return 0;
                   3838:                        }
                   3839:                        path = fwd->connect_path;
                   3840:                        port = PORT_STREAMLOCAL;
                   3841:                } else {
                   3842:                        if (fwd->connect_host == NULL) {
                   3843:                                error("No forward host name.");
                   3844:                                return 0;
                   3845:                        }
                   3846:                        if (strlen(fwd->connect_host) >= NI_MAXHOST) {
                   3847:                                error("Forward host name too long.");
                   3848:                                return 0;
                   3849:                        }
                   3850:                        path = fwd->connect_host;
                   3851:                        port = fwd->connect_port;
                   3852:                }
                   3853:                break;
                   3854:        case SSH_CHANNEL_RUNIX_LISTENER:
                   3855:                path = fwd->listen_path;
                   3856:                port = PORT_STREAMLOCAL;
                   3857:                break;
                   3858:        default:
1.403     djm      3859:                error_f("unexpected channel type %d", type);
1.336     millert  3860:                return 0;
                   3861:        }
                   3862:
                   3863:        if (fwd->listen_path == NULL) {
                   3864:                error("No forward path name.");
                   3865:                return 0;
                   3866:        }
                   3867:        if (strlen(fwd->listen_path) > sizeof(sunaddr.sun_path)) {
                   3868:                error("Local listening path too long: %s", fwd->listen_path);
                   3869:                return 0;
                   3870:        }
                   3871:
1.403     djm      3872:        debug3_f("type %d path %s", type, fwd->listen_path);
1.336     millert  3873:
                   3874:        /* Start a Unix domain listener. */
                   3875:        omask = umask(fwd_opts->streamlocal_bind_mask);
                   3876:        sock = unix_listener(fwd->listen_path, SSH_LISTEN_BACKLOG,
                   3877:            fwd_opts->streamlocal_bind_unlink);
                   3878:        umask(omask);
                   3879:        if (sock < 0)
                   3880:                return 0;
                   3881:
                   3882:        debug("Local forwarding listening on path %s.", fwd->listen_path);
                   3883:
                   3884:        /* Allocate a channel number for the socket. */
1.424     djm      3885:        c = channel_new(ssh, "unix-listener", type, sock, sock, -1,
1.336     millert  3886:            CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
                   3887:            0, "unix listener", 1);
                   3888:        c->path = xstrdup(path);
                   3889:        c->host_port = port;
                   3890:        c->listening_port = PORT_STREAMLOCAL;
                   3891:        c->listening_addr = xstrdup(fwd->listen_path);
                   3892:        return 1;
                   3893: }
                   3894:
                   3895: static int
1.367     djm      3896: channel_cancel_rport_listener_tcpip(struct ssh *ssh,
                   3897:     const char *host, u_short port)
1.202     djm      3898: {
1.209     avsm     3899:        u_int i;
                   3900:        int found = 0;
1.202     djm      3901:
1.367     djm      3902:        for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
                   3903:                Channel *c = ssh->chanctxt->channels[i];
1.312     djm      3904:                if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
                   3905:                        continue;
                   3906:                if (strcmp(c->path, host) == 0 && c->listening_port == port) {
1.403     djm      3907:                        debug2_f("close channel %d", i);
1.367     djm      3908:                        channel_free(ssh, c);
1.312     djm      3909:                        found = 1;
                   3910:                }
                   3911:        }
                   3912:
1.367     djm      3913:        return found;
1.312     djm      3914: }
                   3915:
1.336     millert  3916: static int
1.367     djm      3917: channel_cancel_rport_listener_streamlocal(struct ssh *ssh, const char *path)
1.336     millert  3918: {
                   3919:        u_int i;
                   3920:        int found = 0;
                   3921:
1.367     djm      3922:        for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
                   3923:                Channel *c = ssh->chanctxt->channels[i];
1.336     millert  3924:                if (c == NULL || c->type != SSH_CHANNEL_RUNIX_LISTENER)
                   3925:                        continue;
                   3926:                if (c->path == NULL)
                   3927:                        continue;
                   3928:                if (strcmp(c->path, path) == 0) {
1.403     djm      3929:                        debug2_f("close channel %d", i);
1.367     djm      3930:                        channel_free(ssh, c);
1.336     millert  3931:                        found = 1;
                   3932:                }
                   3933:        }
                   3934:
1.367     djm      3935:        return found;
1.336     millert  3936: }
                   3937:
1.312     djm      3938: int
1.367     djm      3939: channel_cancel_rport_listener(struct ssh *ssh, struct Forward *fwd)
1.336     millert  3940: {
1.367     djm      3941:        if (fwd->listen_path != NULL) {
                   3942:                return channel_cancel_rport_listener_streamlocal(ssh,
                   3943:                    fwd->listen_path);
                   3944:        } else {
                   3945:                return channel_cancel_rport_listener_tcpip(ssh,
                   3946:                    fwd->listen_host, fwd->listen_port);
                   3947:        }
1.336     millert  3948: }
                   3949:
                   3950: static int
1.367     djm      3951: channel_cancel_lport_listener_tcpip(struct ssh *ssh,
                   3952:     const char *lhost, u_short lport, int cport,
                   3953:     struct ForwardOptions *fwd_opts)
1.312     djm      3954: {
                   3955:        u_int i;
                   3956:        int found = 0;
1.389     djm      3957:        const char *addr = channel_fwd_bind_addr(ssh, lhost, NULL, 1, fwd_opts);
1.202     djm      3958:
1.367     djm      3959:        for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
                   3960:                Channel *c = ssh->chanctxt->channels[i];
1.312     djm      3961:                if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
                   3962:                        continue;
1.313     markus   3963:                if (c->listening_port != lport)
1.312     djm      3964:                        continue;
1.313     markus   3965:                if (cport == CHANNEL_CANCEL_PORT_STATIC) {
                   3966:                        /* skip dynamic forwardings */
                   3967:                        if (c->host_port == 0)
                   3968:                                continue;
                   3969:                } else {
                   3970:                        if (c->host_port != cport)
                   3971:                                continue;
                   3972:                }
1.312     djm      3973:                if ((c->listening_addr == NULL && addr != NULL) ||
                   3974:                    (c->listening_addr != NULL && addr == NULL))
                   3975:                        continue;
                   3976:                if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
1.403     djm      3977:                        debug2_f("close channel %d", i);
1.367     djm      3978:                        channel_free(ssh, c);
1.202     djm      3979:                        found = 1;
                   3980:                }
                   3981:        }
                   3982:
1.367     djm      3983:        return found;
1.202     djm      3984: }
                   3985:
1.336     millert  3986: static int
1.367     djm      3987: channel_cancel_lport_listener_streamlocal(struct ssh *ssh, const char *path)
1.336     millert  3988: {
                   3989:        u_int i;
                   3990:        int found = 0;
                   3991:
                   3992:        if (path == NULL) {
1.403     djm      3993:                error_f("no path specified.");
1.336     millert  3994:                return 0;
                   3995:        }
                   3996:
1.367     djm      3997:        for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
                   3998:                Channel *c = ssh->chanctxt->channels[i];
1.336     millert  3999:                if (c == NULL || c->type != SSH_CHANNEL_UNIX_LISTENER)
                   4000:                        continue;
                   4001:                if (c->listening_addr == NULL)
                   4002:                        continue;
                   4003:                if (strcmp(c->listening_addr, path) == 0) {
1.403     djm      4004:                        debug2_f("close channel %d", i);
1.367     djm      4005:                        channel_free(ssh, c);
1.336     millert  4006:                        found = 1;
                   4007:                }
                   4008:        }
                   4009:
1.367     djm      4010:        return found;
1.336     millert  4011: }
                   4012:
                   4013: int
1.367     djm      4014: channel_cancel_lport_listener(struct ssh *ssh,
                   4015:     struct Forward *fwd, int cport, struct ForwardOptions *fwd_opts)
1.336     millert  4016: {
1.367     djm      4017:        if (fwd->listen_path != NULL) {
                   4018:                return channel_cancel_lport_listener_streamlocal(ssh,
                   4019:                    fwd->listen_path);
                   4020:        } else {
                   4021:                return channel_cancel_lport_listener_tcpip(ssh,
                   4022:                    fwd->listen_host, fwd->listen_port, cport, fwd_opts);
                   4023:        }
1.336     millert  4024: }
                   4025:
1.362     markus   4026: /* protocol local port fwd, used by ssh */
1.160     markus   4027: int
1.367     djm      4028: channel_setup_local_fwd_listener(struct ssh *ssh,
                   4029:     struct Forward *fwd, struct ForwardOptions *fwd_opts)
1.160     markus   4030: {
1.336     millert  4031:        if (fwd->listen_path != NULL) {
1.367     djm      4032:                return channel_setup_fwd_listener_streamlocal(ssh,
1.336     millert  4033:                    SSH_CHANNEL_UNIX_LISTENER, fwd, fwd_opts);
                   4034:        } else {
1.367     djm      4035:                return channel_setup_fwd_listener_tcpip(ssh,
                   4036:                    SSH_CHANNEL_PORT_LISTENER, fwd, NULL, fwd_opts);
1.336     millert  4037:        }
1.160     markus   4038: }
                   4039:
1.381     djm      4040: /* Matches a remote forwarding permission against a requested forwarding */
                   4041: static int
                   4042: remote_open_match(struct permission *allowed_open, struct Forward *fwd)
                   4043: {
                   4044:        int ret;
                   4045:        char *lhost;
                   4046:
                   4047:        /* XXX add ACLs for streamlocal */
                   4048:        if (fwd->listen_path != NULL)
                   4049:                return 1;
                   4050:
                   4051:        if (fwd->listen_host == NULL || allowed_open->listen_host == NULL)
                   4052:                return 0;
                   4053:
                   4054:        if (allowed_open->listen_port != FWD_PERMIT_ANY_PORT &&
                   4055:            allowed_open->listen_port != fwd->listen_port)
                   4056:                return 0;
                   4057:
                   4058:        /* Match hostnames case-insensitively */
                   4059:        lhost = xstrdup(fwd->listen_host);
                   4060:        lowercase(lhost);
                   4061:        ret = match_pattern(lhost, allowed_open->listen_host);
                   4062:        free(lhost);
                   4063:
                   4064:        return ret;
                   4065: }
                   4066:
                   4067: /* Checks whether a requested remote forwarding is permitted */
                   4068: static int
                   4069: check_rfwd_permission(struct ssh *ssh, struct Forward *fwd)
                   4070: {
                   4071:        struct ssh_channels *sc = ssh->chanctxt;
                   4072:        struct permission_set *pset = &sc->remote_perms;
                   4073:        u_int i, permit, permit_adm = 1;
                   4074:        struct permission *perm;
                   4075:
                   4076:        /* XXX apply GatewayPorts override before checking? */
                   4077:
                   4078:        permit = pset->all_permitted;
                   4079:        if (!permit) {
                   4080:                for (i = 0; i < pset->num_permitted_user; i++) {
                   4081:                        perm = &pset->permitted_user[i];
                   4082:                        if (remote_open_match(perm, fwd)) {
                   4083:                                permit = 1;
                   4084:                                break;
                   4085:                        }
                   4086:                }
                   4087:        }
                   4088:
                   4089:        if (pset->num_permitted_admin > 0) {
                   4090:                permit_adm = 0;
                   4091:                for (i = 0; i < pset->num_permitted_admin; i++) {
                   4092:                        perm = &pset->permitted_admin[i];
                   4093:                        if (remote_open_match(perm, fwd)) {
                   4094:                                permit_adm = 1;
                   4095:                                break;
                   4096:                        }
                   4097:                }
                   4098:        }
                   4099:
                   4100:        return permit && permit_adm;
                   4101: }
                   4102:
1.160     markus   4103: /* protocol v2 remote port fwd, used by sshd */
                   4104: int
1.367     djm      4105: channel_setup_remote_fwd_listener(struct ssh *ssh, struct Forward *fwd,
1.336     millert  4106:     int *allocated_listen_port, struct ForwardOptions *fwd_opts)
1.160     markus   4107: {
1.381     djm      4108:        if (!check_rfwd_permission(ssh, fwd)) {
1.389     djm      4109:                ssh_packet_send_debug(ssh, "port forwarding refused");
1.391     florian  4110:                if (fwd->listen_path != NULL)
                   4111:                        /* XXX always allowed, see remote_open_match() */
                   4112:                        logit("Received request from %.100s port %d to "
                   4113:                            "remote forward to path \"%.100s\", "
                   4114:                            "but the request was denied.",
                   4115:                            ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
                   4116:                            fwd->listen_path);
                   4117:                else if(fwd->listen_host != NULL)
                   4118:                        logit("Received request from %.100s port %d to "
                   4119:                            "remote forward to host %.100s port %d, "
                   4120:                            "but the request was denied.",
                   4121:                            ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
                   4122:                            fwd->listen_host, fwd->listen_port );
                   4123:                else
                   4124:                        logit("Received request from %.100s port %d to remote "
                   4125:                            "forward, but the request was denied.",
                   4126:                            ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.381     djm      4127:                return 0;
                   4128:        }
1.336     millert  4129:        if (fwd->listen_path != NULL) {
1.367     djm      4130:                return channel_setup_fwd_listener_streamlocal(ssh,
1.336     millert  4131:                    SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts);
                   4132:        } else {
1.367     djm      4133:                return channel_setup_fwd_listener_tcpip(ssh,
1.336     millert  4134:                    SSH_CHANNEL_RPORT_LISTENER, fwd, allocated_listen_port,
                   4135:                    fwd_opts);
                   4136:        }
1.160     markus   4137: }
                   4138:
1.27      markus   4139: /*
1.312     djm      4140:  * Translate the requested rfwd listen host to something usable for
                   4141:  * this server.
                   4142:  */
                   4143: static const char *
                   4144: channel_rfwd_bind_host(const char *listen_host)
                   4145: {
                   4146:        if (listen_host == NULL) {
1.378     djm      4147:                return "localhost";
1.312     djm      4148:        } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
1.378     djm      4149:                return "";
1.312     djm      4150:        } else
                   4151:                return listen_host;
                   4152: }
                   4153:
                   4154: /*
1.27      markus   4155:  * Initiate forwarding of connections to port "port" on remote host through
                   4156:  * the secure channel to host:port from local side.
1.315     markus   4157:  * Returns handle (index) for updating the dynamic listen port with
1.381     djm      4158:  * channel_update_permission().
1.27      markus   4159:  */
1.253     markus   4160: int
1.367     djm      4161: channel_request_remote_forwarding(struct ssh *ssh, struct Forward *fwd)
1.25      markus   4162: {
1.367     djm      4163:        int r, success = 0, idx = -1;
1.421     mbuhl    4164:        const char *host_to_connect, *listen_host, *listen_path;
1.367     djm      4165:        int port_to_connect, listen_port;
1.73      markus   4166:
1.25      markus   4167:        /* Send the forward request to the remote side. */
1.358     djm      4168:        if (fwd->listen_path != NULL) {
1.367     djm      4169:                if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
                   4170:                    (r = sshpkt_put_cstring(ssh,
                   4171:                    "streamlocal-forward@openssh.com")) != 0 ||
                   4172:                    (r = sshpkt_put_u8(ssh, 1)) != 0 || /* want reply */
                   4173:                    (r = sshpkt_put_cstring(ssh, fwd->listen_path)) != 0 ||
                   4174:                    (r = sshpkt_send(ssh)) != 0 ||
                   4175:                    (r = ssh_packet_write_wait(ssh)) != 0)
1.403     djm      4176:                        fatal_fr(r, "request streamlocal");
1.336     millert  4177:        } else {
1.367     djm      4178:                if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
                   4179:                    (r = sshpkt_put_cstring(ssh, "tcpip-forward")) != 0 ||
                   4180:                    (r = sshpkt_put_u8(ssh, 1)) != 0 || /* want reply */
                   4181:                    (r = sshpkt_put_cstring(ssh,
                   4182:                    channel_rfwd_bind_host(fwd->listen_host))) != 0 ||
                   4183:                    (r = sshpkt_put_u32(ssh, fwd->listen_port)) != 0 ||
                   4184:                    (r = sshpkt_send(ssh)) != 0 ||
                   4185:                    (r = ssh_packet_write_wait(ssh)) != 0)
1.403     djm      4186:                        fatal_fr(r, "request tcpip-forward");
1.73      markus   4187:        }
1.358     djm      4188:        /* Assume that server accepts the request */
                   4189:        success = 1;
1.73      markus   4190:        if (success) {
1.305     djm      4191:                /* Record that connection to this host/port is permitted. */
1.367     djm      4192:                host_to_connect = listen_host = listen_path = NULL;
                   4193:                port_to_connect = listen_port = 0;
1.336     millert  4194:                if (fwd->connect_path != NULL) {
1.421     mbuhl    4195:                        host_to_connect = fwd->connect_path;
1.367     djm      4196:                        port_to_connect = PORT_STREAMLOCAL;
1.336     millert  4197:                } else {
1.421     mbuhl    4198:                        host_to_connect = fwd->connect_host;
1.367     djm      4199:                        port_to_connect = fwd->connect_port;
1.336     millert  4200:                }
                   4201:                if (fwd->listen_path != NULL) {
1.421     mbuhl    4202:                        listen_path = fwd->listen_path;
1.367     djm      4203:                        listen_port = PORT_STREAMLOCAL;
1.336     millert  4204:                } else {
1.421     mbuhl    4205:                        listen_host = fwd->listen_host;
1.367     djm      4206:                        listen_port = fwd->listen_port;
                   4207:                }
1.381     djm      4208:                idx = permission_set_add(ssh, FORWARD_USER, FORWARD_LOCAL,
1.367     djm      4209:                    host_to_connect, port_to_connect,
                   4210:                    listen_host, listen_path, listen_port, NULL);
1.44      markus   4211:        }
1.367     djm      4212:        return idx;
1.1       deraadt  4213: }
                   4214:
1.333     markus   4215: static int
1.381     djm      4216: open_match(struct permission *allowed_open, const char *requestedhost,
1.336     millert  4217:     int requestedport)
1.333     markus   4218: {
                   4219:        if (allowed_open->host_to_connect == NULL)
                   4220:                return 0;
                   4221:        if (allowed_open->port_to_connect != FWD_PERMIT_ANY_PORT &&
                   4222:            allowed_open->port_to_connect != requestedport)
                   4223:                return 0;
1.351     dtucker  4224:        if (strcmp(allowed_open->host_to_connect, FWD_PERMIT_ANY_HOST) != 0 &&
                   4225:            strcmp(allowed_open->host_to_connect, requestedhost) != 0)
1.333     markus   4226:                return 0;
                   4227:        return 1;
                   4228: }
                   4229:
                   4230: /*
1.336     millert  4231:  * Note that in the listen host/port case
1.333     markus   4232:  * we don't support FWD_PERMIT_ANY_PORT and
                   4233:  * need to translate between the configured-host (listen_host)
                   4234:  * and what we've sent to the remote server (channel_rfwd_bind_host)
                   4235:  */
                   4236: static int
1.381     djm      4237: open_listen_match_tcpip(struct permission *allowed_open,
1.336     millert  4238:     const char *requestedhost, u_short requestedport, int translate)
1.333     markus   4239: {
                   4240:        const char *allowed_host;
                   4241:
                   4242:        if (allowed_open->host_to_connect == NULL)
                   4243:                return 0;
                   4244:        if (allowed_open->listen_port != requestedport)
                   4245:                return 0;
1.335     djm      4246:        if (!translate && allowed_open->listen_host == NULL &&
                   4247:            requestedhost == NULL)
                   4248:                return 1;
1.333     markus   4249:        allowed_host = translate ?
                   4250:            channel_rfwd_bind_host(allowed_open->listen_host) :
                   4251:            allowed_open->listen_host;
1.382     djm      4252:        if (allowed_host == NULL || requestedhost == NULL ||
1.333     markus   4253:            strcmp(allowed_host, requestedhost) != 0)
                   4254:                return 0;
                   4255:        return 1;
                   4256: }
                   4257:
1.336     millert  4258: static int
1.381     djm      4259: open_listen_match_streamlocal(struct permission *allowed_open,
1.336     millert  4260:     const char *requestedpath)
                   4261: {
                   4262:        if (allowed_open->host_to_connect == NULL)
                   4263:                return 0;
                   4264:        if (allowed_open->listen_port != PORT_STREAMLOCAL)
                   4265:                return 0;
                   4266:        if (allowed_open->listen_path == NULL ||
                   4267:            strcmp(allowed_open->listen_path, requestedpath) != 0)
                   4268:                return 0;
                   4269:        return 1;
                   4270: }
                   4271:
1.27      markus   4272: /*
1.208     deraadt  4273:  * Request cancellation of remote forwarding of connection host:port from
1.202     djm      4274:  * local side.
                   4275:  */
1.336     millert  4276: static int
1.367     djm      4277: channel_request_rforward_cancel_tcpip(struct ssh *ssh,
                   4278:     const char *host, u_short port)
1.202     djm      4279: {
1.367     djm      4280:        struct ssh_channels *sc = ssh->chanctxt;
1.381     djm      4281:        struct permission_set *pset = &sc->local_perms;
1.367     djm      4282:        int r;
                   4283:        u_int i;
1.397     markus   4284:        struct permission *perm = NULL;
1.202     djm      4285:
1.381     djm      4286:        for (i = 0; i < pset->num_permitted_user; i++) {
                   4287:                perm = &pset->permitted_user[i];
                   4288:                if (open_listen_match_tcpip(perm, host, port, 0))
1.202     djm      4289:                        break;
1.381     djm      4290:                perm = NULL;
1.202     djm      4291:        }
1.381     djm      4292:        if (perm == NULL) {
1.403     djm      4293:                debug_f("requested forward not found");
1.312     djm      4294:                return -1;
1.202     djm      4295:        }
1.367     djm      4296:        if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
                   4297:            (r = sshpkt_put_cstring(ssh, "cancel-tcpip-forward")) != 0 ||
                   4298:            (r = sshpkt_put_u8(ssh, 0)) != 0 || /* want reply */
                   4299:            (r = sshpkt_put_cstring(ssh, channel_rfwd_bind_host(host))) != 0 ||
                   4300:            (r = sshpkt_put_u32(ssh, port)) != 0 ||
                   4301:            (r = sshpkt_send(ssh)) != 0)
1.403     djm      4302:                fatal_fr(r, "send cancel");
1.367     djm      4303:
1.381     djm      4304:        fwd_perm_clear(perm); /* unregister */
1.336     millert  4305:
                   4306:        return 0;
                   4307: }
                   4308:
                   4309: /*
                   4310:  * Request cancellation of remote forwarding of Unix domain socket
                   4311:  * path from local side.
                   4312:  */
                   4313: static int
1.367     djm      4314: channel_request_rforward_cancel_streamlocal(struct ssh *ssh, const char *path)
1.336     millert  4315: {
1.367     djm      4316:        struct ssh_channels *sc = ssh->chanctxt;
1.381     djm      4317:        struct permission_set *pset = &sc->local_perms;
1.367     djm      4318:        int r;
                   4319:        u_int i;
1.397     markus   4320:        struct permission *perm = NULL;
1.336     millert  4321:
1.381     djm      4322:        for (i = 0; i < pset->num_permitted_user; i++) {
                   4323:                perm = &pset->permitted_user[i];
                   4324:                if (open_listen_match_streamlocal(perm, path))
1.336     millert  4325:                        break;
1.381     djm      4326:                perm = NULL;
1.336     millert  4327:        }
1.381     djm      4328:        if (perm == NULL) {
1.403     djm      4329:                debug_f("requested forward not found");
1.336     millert  4330:                return -1;
                   4331:        }
1.367     djm      4332:        if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
                   4333:            (r = sshpkt_put_cstring(ssh,
                   4334:            "cancel-streamlocal-forward@openssh.com")) != 0 ||
                   4335:            (r = sshpkt_put_u8(ssh, 0)) != 0 || /* want reply */
                   4336:            (r = sshpkt_put_cstring(ssh, path)) != 0 ||
                   4337:            (r = sshpkt_send(ssh)) != 0)
1.403     djm      4338:                fatal_fr(r, "send cancel");
1.367     djm      4339:
1.381     djm      4340:        fwd_perm_clear(perm); /* unregister */
1.312     djm      4341:
                   4342:        return 0;
1.202     djm      4343: }
                   4344:
                   4345: /*
1.336     millert  4346:  * Request cancellation of remote forwarding of a connection from local side.
                   4347:  */
                   4348: int
1.367     djm      4349: channel_request_rforward_cancel(struct ssh *ssh, struct Forward *fwd)
1.336     millert  4350: {
                   4351:        if (fwd->listen_path != NULL) {
1.367     djm      4352:                return channel_request_rforward_cancel_streamlocal(ssh,
                   4353:                    fwd->listen_path);
1.336     millert  4354:        } else {
1.367     djm      4355:                return channel_request_rforward_cancel_tcpip(ssh,
                   4356:                    fwd->listen_host,
                   4357:                    fwd->listen_port ? fwd->listen_port : fwd->allocated_port);
1.336     millert  4358:        }
1.1       deraadt  4359: }
                   4360:
1.99      markus   4361: /*
1.381     djm      4362:  * Permits opening to any host/port if permitted_user[] is empty.  This is
1.99      markus   4363:  * usually called by the server, because the user could connect to any port
                   4364:  * anyway, and the server has no way to know but to trust the client anyway.
                   4365:  */
                   4366: void
1.381     djm      4367: channel_permit_all(struct ssh *ssh, int where)
                   4368: {
                   4369:        struct permission_set *pset = permission_set_get(ssh, where);
                   4370:
                   4371:        if (pset->num_permitted_user == 0)
                   4372:                pset->all_permitted = 1;
                   4373: }
                   4374:
                   4375: /*
                   4376:  * Permit the specified host/port for forwarding.
                   4377:  */
                   4378: void
                   4379: channel_add_permission(struct ssh *ssh, int who, int where,
                   4380:     char *host, int port)
                   4381: {
                   4382:        int local = where == FORWARD_LOCAL;
                   4383:        struct permission_set *pset = permission_set_get(ssh, where);
                   4384:
                   4385:        debug("allow %s forwarding to host %s port %d",
                   4386:            fwd_ident(who, where), host, port);
                   4387:        /*
                   4388:         * Remote forwards set listen_host/port, local forwards set
                   4389:         * host/port_to_connect.
                   4390:         */
                   4391:        permission_set_add(ssh, who, where,
                   4392:            local ? host : 0, local ? port : 0,
                   4393:            local ? NULL : host, NULL, local ? 0 : port, NULL);
                   4394:        pset->all_permitted = 0;
                   4395: }
                   4396:
                   4397: /*
                   4398:  * Administratively disable forwarding.
                   4399:  */
                   4400: void
                   4401: channel_disable_admin(struct ssh *ssh, int where)
1.99      markus   4402: {
1.381     djm      4403:        channel_clear_permission(ssh, FORWARD_ADM, where);
                   4404:        permission_set_add(ssh, FORWARD_ADM, where,
                   4405:            NULL, 0, NULL, NULL, 0, NULL);
1.99      markus   4406: }
                   4407:
1.381     djm      4408: /*
                   4409:  * Clear a list of permitted opens.
                   4410:  */
1.101     markus   4411: void
1.381     djm      4412: channel_clear_permission(struct ssh *ssh, int who, int where)
1.99      markus   4413: {
1.381     djm      4414:        struct permission **permp;
                   4415:        u_int *npermp;
1.367     djm      4416:
1.381     djm      4417:        permission_set_get_array(ssh, who, where, &permp, &npermp);
                   4418:        *permp = xrecallocarray(*permp, *npermp, 0, sizeof(**permp));
                   4419:        *npermp = 0;
1.315     markus   4420: }
                   4421:
                   4422: /*
                   4423:  * Update the listen port for a dynamic remote forward, after
                   4424:  * the actual 'newport' has been allocated. If 'newport' < 0 is
                   4425:  * passed then they entry will be invalidated.
                   4426:  */
                   4427: void
1.381     djm      4428: channel_update_permission(struct ssh *ssh, int idx, int newport)
1.315     markus   4429: {
1.381     djm      4430:        struct permission_set *pset = &ssh->chanctxt->local_perms;
1.367     djm      4431:
1.381     djm      4432:        if (idx < 0 || (u_int)idx >= pset->num_permitted_user) {
1.403     djm      4433:                debug_f("index out of range: %d num_permitted_user %d",
                   4434:                    idx, pset->num_permitted_user);
1.315     markus   4435:                return;
                   4436:        }
                   4437:        debug("%s allowed port %d for forwarding to host %s port %d",
                   4438:            newport > 0 ? "Updating" : "Removing",
                   4439:            newport,
1.381     djm      4440:            pset->permitted_user[idx].host_to_connect,
                   4441:            pset->permitted_user[idx].port_to_connect);
1.367     djm      4442:        if (newport <= 0)
1.381     djm      4443:                fwd_perm_clear(&pset->permitted_user[idx]);
1.367     djm      4444:        else {
1.381     djm      4445:                pset->permitted_user[idx].listen_port =
1.404     djm      4446:                    (ssh->compat & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
1.315     markus   4447:        }
1.99      markus   4448: }
                   4449:
1.314     dtucker  4450: /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
                   4451: int
                   4452: permitopen_port(const char *p)
                   4453: {
                   4454:        int port;
                   4455:
                   4456:        if (strcmp(p, "*") == 0)
                   4457:                return FWD_PERMIT_ANY_PORT;
                   4458:        if ((port = a2port(p)) > 0)
                   4459:                return port;
                   4460:        return -1;
                   4461: }
                   4462:
1.276     djm      4463: /* Try to start non-blocking connect to next host in cctx list */
1.127     itojun   4464: static int
1.276     djm      4465: connect_next(struct channel_connect *cctx)
1.41      markus   4466: {
1.276     djm      4467:        int sock, saved_errno;
1.336     millert  4468:        struct sockaddr_un *sunaddr;
1.367     djm      4469:        char ntop[NI_MAXHOST];
                   4470:        char strport[MAXIMUM(NI_MAXSERV, sizeof(sunaddr->sun_path))];
1.41      markus   4471:
1.276     djm      4472:        for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
1.336     millert  4473:                switch (cctx->ai->ai_family) {
                   4474:                case AF_UNIX:
                   4475:                        /* unix:pathname instead of host:port */
                   4476:                        sunaddr = (struct sockaddr_un *)cctx->ai->ai_addr;
                   4477:                        strlcpy(ntop, "unix", sizeof(ntop));
                   4478:                        strlcpy(strport, sunaddr->sun_path, sizeof(strport));
                   4479:                        break;
                   4480:                case AF_INET:
                   4481:                case AF_INET6:
                   4482:                        if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
                   4483:                            ntop, sizeof(ntop), strport, sizeof(strport),
                   4484:                            NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.420     djm      4485:                                error_f("getnameinfo failed");
1.336     millert  4486:                                continue;
                   4487:                        }
                   4488:                        break;
                   4489:                default:
1.41      markus   4490:                        continue;
                   4491:                }
1.420     djm      4492:                debug_f("start for host %.100s ([%.100s]:%s)",
                   4493:                    cctx->host, ntop, strport);
1.300     dtucker  4494:                if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
                   4495:                    cctx->ai->ai_protocol)) == -1) {
1.276     djm      4496:                        if (cctx->ai->ai_next == NULL)
1.186     djm      4497:                                error("socket: %.100s", strerror(errno));
                   4498:                        else
                   4499:                                verbose("socket: %.100s", strerror(errno));
1.41      markus   4500:                        continue;
                   4501:                }
1.205     djm      4502:                if (set_nonblock(sock) == -1)
1.403     djm      4503:                        fatal_f("set_nonblock(%d)", sock);
1.276     djm      4504:                if (connect(sock, cctx->ai->ai_addr,
                   4505:                    cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
1.420     djm      4506:                        debug_f("host %.100s ([%.100s]:%s): %.100s",
                   4507:                            cctx->host, ntop, strport, strerror(errno));
1.276     djm      4508:                        saved_errno = errno;
1.41      markus   4509:                        close(sock);
1.276     djm      4510:                        errno = saved_errno;
1.89      stevesk  4511:                        continue;       /* fail -- try next */
1.41      markus   4512:                }
1.336     millert  4513:                if (cctx->ai->ai_family != AF_UNIX)
                   4514:                        set_nodelay(sock);
1.420     djm      4515:                debug_f("connect host %.100s ([%.100s]:%s) in progress, fd=%d",
                   4516:                    cctx->host, ntop, strport, sock);
1.276     djm      4517:                cctx->ai = cctx->ai->ai_next;
                   4518:                return sock;
                   4519:        }
                   4520:        return -1;
                   4521: }
1.41      markus   4522:
1.276     djm      4523: static void
                   4524: channel_connect_ctx_free(struct channel_connect *cctx)
                   4525: {
1.321     djm      4526:        free(cctx->host);
1.336     millert  4527:        if (cctx->aitop) {
                   4528:                if (cctx->aitop->ai_family == AF_UNIX)
                   4529:                        free(cctx->aitop);
                   4530:                else
                   4531:                        freeaddrinfo(cctx->aitop);
                   4532:        }
1.329     tedu     4533:        memset(cctx, 0, sizeof(*cctx));
1.276     djm      4534: }
                   4535:
1.357     dtucker  4536: /*
1.372     markus   4537:  * Return connecting socket to remote host:port or local socket path,
1.357     dtucker  4538:  * passing back the failure reason if appropriate.
                   4539:  */
1.372     markus   4540: static int
                   4541: connect_to_helper(struct ssh *ssh, const char *name, int port, int socktype,
                   4542:     char *ctype, char *rname, struct channel_connect *cctx,
                   4543:     int *reason, const char **errmsg)
1.276     djm      4544: {
                   4545:        struct addrinfo hints;
                   4546:        int gaierr;
                   4547:        int sock = -1;
                   4548:        char strport[NI_MAXSERV];
1.336     millert  4549:
                   4550:        if (port == PORT_STREAMLOCAL) {
                   4551:                struct sockaddr_un *sunaddr;
                   4552:                struct addrinfo *ai;
                   4553:
                   4554:                if (strlen(name) > sizeof(sunaddr->sun_path)) {
                   4555:                        error("%.100s: %.100s", name, strerror(ENAMETOOLONG));
1.372     markus   4556:                        return -1;
1.336     millert  4557:                }
                   4558:
                   4559:                /*
                   4560:                 * Fake up a struct addrinfo for AF_UNIX connections.
                   4561:                 * channel_connect_ctx_free() must check ai_family
                   4562:                 * and use free() not freeaddirinfo() for AF_UNIX.
                   4563:                 */
                   4564:                ai = xmalloc(sizeof(*ai) + sizeof(*sunaddr));
                   4565:                memset(ai, 0, sizeof(*ai) + sizeof(*sunaddr));
                   4566:                ai->ai_addr = (struct sockaddr *)(ai + 1);
                   4567:                ai->ai_addrlen = sizeof(*sunaddr);
                   4568:                ai->ai_family = AF_UNIX;
1.372     markus   4569:                ai->ai_socktype = socktype;
1.336     millert  4570:                ai->ai_protocol = PF_UNSPEC;
                   4571:                sunaddr = (struct sockaddr_un *)ai->ai_addr;
                   4572:                sunaddr->sun_family = AF_UNIX;
                   4573:                strlcpy(sunaddr->sun_path, name, sizeof(sunaddr->sun_path));
1.372     markus   4574:                cctx->aitop = ai;
1.336     millert  4575:        } else {
                   4576:                memset(&hints, 0, sizeof(hints));
1.367     djm      4577:                hints.ai_family = ssh->chanctxt->IPv4or6;
1.372     markus   4578:                hints.ai_socktype = socktype;
1.336     millert  4579:                snprintf(strport, sizeof strport, "%d", port);
1.372     markus   4580:                if ((gaierr = getaddrinfo(name, strport, &hints, &cctx->aitop))
1.357     dtucker  4581:                    != 0) {
                   4582:                        if (errmsg != NULL)
                   4583:                                *errmsg = ssh_gai_strerror(gaierr);
                   4584:                        if (reason != NULL)
                   4585:                                *reason = SSH2_OPEN_CONNECT_FAILED;
1.336     millert  4586:                        error("connect_to %.100s: unknown host (%s)", name,
                   4587:                            ssh_gai_strerror(gaierr));
1.372     markus   4588:                        return -1;
1.336     millert  4589:                }
1.41      markus   4590:        }
1.276     djm      4591:
1.372     markus   4592:        cctx->host = xstrdup(name);
                   4593:        cctx->port = port;
                   4594:        cctx->ai = cctx->aitop;
1.276     djm      4595:
1.372     markus   4596:        if ((sock = connect_next(cctx)) == -1) {
1.276     djm      4597:                error("connect to %.100s port %d failed: %s",
1.336     millert  4598:                    name, port, strerror(errno));
1.372     markus   4599:                return -1;
                   4600:        }
                   4601:
                   4602:        return sock;
                   4603: }
                   4604:
                   4605: /* Return CONNECTING channel to remote host:port or local socket path */
                   4606: static Channel *
                   4607: connect_to(struct ssh *ssh, const char *host, int port,
                   4608:     char *ctype, char *rname)
                   4609: {
                   4610:        struct channel_connect cctx;
                   4611:        Channel *c;
                   4612:        int sock;
                   4613:
                   4614:        memset(&cctx, 0, sizeof(cctx));
                   4615:        sock = connect_to_helper(ssh, host, port, SOCK_STREAM, ctype, rname,
                   4616:            &cctx, NULL, NULL);
                   4617:        if (sock == -1) {
1.276     djm      4618:                channel_connect_ctx_free(&cctx);
                   4619:                return NULL;
1.41      markus   4620:        }
1.367     djm      4621:        c = channel_new(ssh, ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
1.276     djm      4622:            CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
1.372     markus   4623:        c->host_port = port;
                   4624:        c->path = xstrdup(host);
1.276     djm      4625:        c->connect_ctx = cctx;
1.372     markus   4626:
1.276     djm      4627:        return c;
1.41      markus   4628: }
1.99      markus   4629:
1.354     markus   4630: /*
                   4631:  * returns either the newly connected channel or the downstream channel
                   4632:  * that needs to deal with this connection.
                   4633:  */
1.276     djm      4634: Channel *
1.367     djm      4635: channel_connect_by_listen_address(struct ssh *ssh, const char *listen_host,
1.333     markus   4636:     u_short listen_port, char *ctype, char *rname)
1.73      markus   4637: {
1.367     djm      4638:        struct ssh_channels *sc = ssh->chanctxt;
1.381     djm      4639:        struct permission_set *pset = &sc->local_perms;
1.367     djm      4640:        u_int i;
1.381     djm      4641:        struct permission *perm;
1.99      markus   4642:
1.381     djm      4643:        for (i = 0; i < pset->num_permitted_user; i++) {
                   4644:                perm = &pset->permitted_user[i];
                   4645:                if (open_listen_match_tcpip(perm,
                   4646:                    listen_host, listen_port, 1)) {
                   4647:                        if (perm->downstream)
                   4648:                                return perm->downstream;
                   4649:                        if (perm->port_to_connect == 0)
1.372     markus   4650:                                return rdynamic_connect_prepare(ssh,
                   4651:                                    ctype, rname);
1.367     djm      4652:                        return connect_to(ssh,
1.381     djm      4653:                            perm->host_to_connect, perm->port_to_connect,
1.367     djm      4654:                            ctype, rname);
1.276     djm      4655:                }
                   4656:        }
1.74      markus   4657:        error("WARNING: Server requests forwarding for unknown listen_port %d",
                   4658:            listen_port);
1.276     djm      4659:        return NULL;
1.73      markus   4660: }
                   4661:
1.336     millert  4662: Channel *
1.367     djm      4663: channel_connect_by_listen_path(struct ssh *ssh, const char *path,
                   4664:     char *ctype, char *rname)
1.336     millert  4665: {
1.367     djm      4666:        struct ssh_channels *sc = ssh->chanctxt;
1.381     djm      4667:        struct permission_set *pset = &sc->local_perms;
1.367     djm      4668:        u_int i;
1.381     djm      4669:        struct permission *perm;
1.336     millert  4670:
1.381     djm      4671:        for (i = 0; i < pset->num_permitted_user; i++) {
                   4672:                perm = &pset->permitted_user[i];
                   4673:                if (open_listen_match_streamlocal(perm, path)) {
1.367     djm      4674:                        return connect_to(ssh,
1.381     djm      4675:                            perm->host_to_connect, perm->port_to_connect,
1.367     djm      4676:                            ctype, rname);
1.336     millert  4677:                }
                   4678:        }
                   4679:        error("WARNING: Server requests forwarding for unknown path %.100s",
                   4680:            path);
                   4681:        return NULL;
                   4682: }
                   4683:
1.99      markus   4684: /* Check if connecting to that port is permitted and connect. */
1.276     djm      4685: Channel *
1.367     djm      4686: channel_connect_to_port(struct ssh *ssh, const char *host, u_short port,
                   4687:     char *ctype, char *rname, int *reason, const char **errmsg)
1.99      markus   4688: {
1.367     djm      4689:        struct ssh_channels *sc = ssh->chanctxt;
1.381     djm      4690:        struct permission_set *pset = &sc->local_perms;
1.372     markus   4691:        struct channel_connect cctx;
                   4692:        Channel *c;
1.367     djm      4693:        u_int i, permit, permit_adm = 1;
1.372     markus   4694:        int sock;
1.381     djm      4695:        struct permission *perm;
1.99      markus   4696:
1.381     djm      4697:        permit = pset->all_permitted;
1.99      markus   4698:        if (!permit) {
1.381     djm      4699:                for (i = 0; i < pset->num_permitted_user; i++) {
                   4700:                        perm = &pset->permitted_user[i];
                   4701:                        if (open_match(perm, host, port)) {
1.99      markus   4702:                                permit = 1;
1.333     markus   4703:                                break;
                   4704:                        }
1.367     djm      4705:                }
1.257     dtucker  4706:        }
1.99      markus   4707:
1.381     djm      4708:        if (pset->num_permitted_admin > 0) {
1.257     dtucker  4709:                permit_adm = 0;
1.381     djm      4710:                for (i = 0; i < pset->num_permitted_admin; i++) {
                   4711:                        perm = &pset->permitted_admin[i];
                   4712:                        if (open_match(perm, host, port)) {
1.257     dtucker  4713:                                permit_adm = 1;
1.333     markus   4714:                                break;
                   4715:                        }
1.367     djm      4716:                }
1.99      markus   4717:        }
1.257     dtucker  4718:
                   4719:        if (!permit || !permit_adm) {
1.391     florian  4720:                logit("Received request from %.100s port %d to connect to "
                   4721:                    "host %.100s port %d, but the request was denied.",
                   4722:                    ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), host, port);
1.357     dtucker  4723:                if (reason != NULL)
                   4724:                        *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
1.276     djm      4725:                return NULL;
1.99      markus   4726:        }
1.372     markus   4727:
                   4728:        memset(&cctx, 0, sizeof(cctx));
                   4729:        sock = connect_to_helper(ssh, host, port, SOCK_STREAM, ctype, rname,
                   4730:            &cctx, reason, errmsg);
                   4731:        if (sock == -1) {
                   4732:                channel_connect_ctx_free(&cctx);
                   4733:                return NULL;
                   4734:        }
                   4735:
                   4736:        c = channel_new(ssh, ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
                   4737:            CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
                   4738:        c->host_port = port;
                   4739:        c->path = xstrdup(host);
                   4740:        c->connect_ctx = cctx;
                   4741:
                   4742:        return c;
1.336     millert  4743: }
                   4744:
                   4745: /* Check if connecting to that path is permitted and connect. */
                   4746: Channel *
1.367     djm      4747: channel_connect_to_path(struct ssh *ssh, const char *path,
                   4748:     char *ctype, char *rname)
1.336     millert  4749: {
1.367     djm      4750:        struct ssh_channels *sc = ssh->chanctxt;
1.381     djm      4751:        struct permission_set *pset = &sc->local_perms;
1.367     djm      4752:        u_int i, permit, permit_adm = 1;
1.381     djm      4753:        struct permission *perm;
1.336     millert  4754:
1.381     djm      4755:        permit = pset->all_permitted;
1.336     millert  4756:        if (!permit) {
1.381     djm      4757:                for (i = 0; i < pset->num_permitted_user; i++) {
                   4758:                        perm = &pset->permitted_user[i];
                   4759:                        if (open_match(perm, path, PORT_STREAMLOCAL)) {
1.336     millert  4760:                                permit = 1;
                   4761:                                break;
                   4762:                        }
1.367     djm      4763:                }
1.336     millert  4764:        }
                   4765:
1.381     djm      4766:        if (pset->num_permitted_admin > 0) {
1.336     millert  4767:                permit_adm = 0;
1.381     djm      4768:                for (i = 0; i < pset->num_permitted_admin; i++) {
                   4769:                        perm = &pset->permitted_admin[i];
                   4770:                        if (open_match(perm, path, PORT_STREAMLOCAL)) {
1.336     millert  4771:                                permit_adm = 1;
                   4772:                                break;
                   4773:                        }
1.367     djm      4774:                }
1.336     millert  4775:        }
                   4776:
                   4777:        if (!permit || !permit_adm) {
                   4778:                logit("Received request to connect to path %.100s, "
                   4779:                    "but the request was denied.", path);
                   4780:                return NULL;
                   4781:        }
1.367     djm      4782:        return connect_to(ssh, path, PORT_STREAMLOCAL, ctype, rname);
1.204     djm      4783: }
                   4784:
                   4785: void
1.367     djm      4786: channel_send_window_changes(struct ssh *ssh)
1.204     djm      4787: {
1.367     djm      4788:        struct ssh_channels *sc = ssh->chanctxt;
                   4789:        struct winsize ws;
                   4790:        int r;
1.209     avsm     4791:        u_int i;
1.204     djm      4792:
1.367     djm      4793:        for (i = 0; i < sc->channels_alloc; i++) {
                   4794:                if (sc->channels[i] == NULL || !sc->channels[i]->client_tty ||
                   4795:                    sc->channels[i]->type != SSH_CHANNEL_OPEN)
1.204     djm      4796:                        continue;
1.393     deraadt  4797:                if (ioctl(sc->channels[i]->rfd, TIOCGWINSZ, &ws) == -1)
1.204     djm      4798:                        continue;
1.367     djm      4799:                channel_request_start(ssh, i, "window-change", 0);
                   4800:                if ((r = sshpkt_put_u32(ssh, (u_int)ws.ws_col)) != 0 ||
                   4801:                    (r = sshpkt_put_u32(ssh, (u_int)ws.ws_row)) != 0 ||
                   4802:                    (r = sshpkt_put_u32(ssh, (u_int)ws.ws_xpixel)) != 0 ||
                   4803:                    (r = sshpkt_put_u32(ssh, (u_int)ws.ws_ypixel)) != 0 ||
                   4804:                    (r = sshpkt_send(ssh)) != 0)
1.403     djm      4805:                        fatal_fr(r, "channel %u; send window-change", i);
1.204     djm      4806:        }
1.372     markus   4807: }
                   4808:
                   4809: /* Return RDYNAMIC_OPEN channel: channel allows SOCKS, but is not connected */
                   4810: static Channel *
                   4811: rdynamic_connect_prepare(struct ssh *ssh, char *ctype, char *rname)
                   4812: {
                   4813:        Channel *c;
                   4814:        int r;
                   4815:
                   4816:        c = channel_new(ssh, ctype, SSH_CHANNEL_RDYNAMIC_OPEN, -1, -1, -1,
                   4817:            CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
                   4818:        c->host_port = 0;
                   4819:        c->path = NULL;
                   4820:
                   4821:        /*
                   4822:         * We need to open the channel before we have a FD,
                   4823:         * so that we can get SOCKS header from peer.
                   4824:         */
                   4825:        if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
                   4826:            (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
                   4827:            (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
                   4828:            (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
1.403     djm      4829:            (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0)
                   4830:                fatal_fr(r, "channel %i; confirm", c->self);
1.372     markus   4831:        return c;
                   4832: }
                   4833:
                   4834: /* Return CONNECTING socket to remote host:port or local socket path */
                   4835: static int
                   4836: rdynamic_connect_finish(struct ssh *ssh, Channel *c)
                   4837: {
1.405     markus   4838:        struct ssh_channels *sc = ssh->chanctxt;
                   4839:        struct permission_set *pset = &sc->local_perms;
                   4840:        struct permission *perm;
1.372     markus   4841:        struct channel_connect cctx;
1.405     markus   4842:        u_int i, permit_adm = 1;
1.372     markus   4843:        int sock;
1.405     markus   4844:
                   4845:        if (pset->num_permitted_admin > 0) {
                   4846:                permit_adm = 0;
                   4847:                for (i = 0; i < pset->num_permitted_admin; i++) {
                   4848:                        perm = &pset->permitted_admin[i];
                   4849:                        if (open_match(perm, c->path, c->host_port)) {
                   4850:                                permit_adm = 1;
                   4851:                                break;
                   4852:                        }
                   4853:                }
                   4854:        }
                   4855:        if (!permit_adm) {
                   4856:                debug_f("requested forward not permitted");
                   4857:                return -1;
                   4858:        }
1.372     markus   4859:
                   4860:        memset(&cctx, 0, sizeof(cctx));
                   4861:        sock = connect_to_helper(ssh, c->path, c->host_port, SOCK_STREAM, NULL,
                   4862:            NULL, &cctx, NULL, NULL);
                   4863:        if (sock == -1)
                   4864:                channel_connect_ctx_free(&cctx);
                   4865:        else {
                   4866:                /* similar to SSH_CHANNEL_CONNECTING but we've already sent the open */
                   4867:                c->type = SSH_CHANNEL_RDYNAMIC_FINISH;
                   4868:                c->connect_ctx = cctx;
                   4869:                channel_register_fds(ssh, c, sock, sock, -1, 0, 1, 0);
                   4870:        }
                   4871:        return sock;
1.99      markus   4872: }
                   4873:
1.121     markus   4874: /* -- X11 forwarding */
1.1       deraadt  4875:
1.27      markus   4876: /*
                   4877:  * Creates an internet domain socket for listening for X11 connections.
1.176     deraadt  4878:  * Returns 0 and a suitable display number for the DISPLAY variable
                   4879:  * stored in display_numberp , or -1 if an error occurs.
1.27      markus   4880:  */
1.141     stevesk  4881: int
1.367     djm      4882: x11_create_display_inet(struct ssh *ssh, int x11_display_offset,
                   4883:     int x11_use_localhost, int single_connection,
                   4884:     u_int *display_numberp, int **chanids)
1.1       deraadt  4885: {
1.149     markus   4886:        Channel *nc = NULL;
1.31      markus   4887:        int display_number, sock;
                   4888:        u_short port;
1.35      markus   4889:        struct addrinfo hints, *ai, *aitop;
                   4890:        char strport[NI_MAXSERV];
                   4891:        int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25      markus   4892:
1.224     markus   4893:        if (chanids == NULL)
                   4894:                return -1;
                   4895:
1.33      markus   4896:        for (display_number = x11_display_offset;
1.148     deraadt  4897:            display_number < MAX_DISPLAYS;
                   4898:            display_number++) {
1.25      markus   4899:                port = 6000 + display_number;
1.35      markus   4900:                memset(&hints, 0, sizeof(hints));
1.367     djm      4901:                hints.ai_family = ssh->chanctxt->IPv4or6;
1.163     stevesk  4902:                hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35      markus   4903:                hints.ai_socktype = SOCK_STREAM;
                   4904:                snprintf(strport, sizeof strport, "%d", port);
1.367     djm      4905:                if ((gaierr = getaddrinfo(NULL, strport,
                   4906:                    &hints, &aitop)) != 0) {
1.271     dtucker  4907:                        error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
1.141     stevesk  4908:                        return -1;
1.25      markus   4909:                }
1.35      markus   4910:                for (ai = aitop; ai; ai = ai->ai_next) {
1.367     djm      4911:                        if (ai->ai_family != AF_INET &&
                   4912:                            ai->ai_family != AF_INET6)
1.35      markus   4913:                                continue;
1.300     dtucker  4914:                        sock = socket(ai->ai_family, ai->ai_socktype,
                   4915:                            ai->ai_protocol);
1.393     deraadt  4916:                        if (sock == -1) {
1.35      markus   4917:                                error("socket: %.100s", strerror(errno));
1.203     markus   4918:                                freeaddrinfo(aitop);
1.141     stevesk  4919:                                return -1;
1.35      markus   4920:                        }
1.376     djm      4921:                        set_reuseaddr(sock);
1.393     deraadt  4922:                        if (bind(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
1.403     djm      4923:                                debug2_f("bind port %d: %.100s", port,
                   4924:                                    strerror(errno));
1.35      markus   4925:                                close(sock);
1.367     djm      4926:                                for (n = 0; n < num_socks; n++)
1.35      markus   4927:                                        close(socks[n]);
                   4928:                                num_socks = 0;
                   4929:                                break;
                   4930:                        }
                   4931:                        socks[num_socks++] = sock;
                   4932:                        if (num_socks == NUM_SOCKS)
                   4933:                                break;
1.25      markus   4934:                }
1.83      stevesk  4935:                freeaddrinfo(aitop);
1.35      markus   4936:                if (num_socks > 0)
                   4937:                        break;
1.25      markus   4938:        }
                   4939:        if (display_number >= MAX_DISPLAYS) {
                   4940:                error("Failed to allocate internet-domain X11 display socket.");
1.141     stevesk  4941:                return -1;
1.25      markus   4942:        }
                   4943:        /* Start listening for connections on the socket. */
1.35      markus   4944:        for (n = 0; n < num_socks; n++) {
                   4945:                sock = socks[n];
1.393     deraadt  4946:                if (listen(sock, SSH_LISTEN_BACKLOG) == -1) {
1.35      markus   4947:                        error("listen: %.100s", strerror(errno));
                   4948:                        close(sock);
1.141     stevesk  4949:                        return -1;
1.35      markus   4950:                }
1.25      markus   4951:        }
1.35      markus   4952:
                   4953:        /* Allocate a channel for each socket. */
1.242     djm      4954:        *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35      markus   4955:        for (n = 0; n < num_socks; n++) {
                   4956:                sock = socks[n];
1.424     djm      4957:                nc = channel_new(ssh, "x11-listener",
1.51      markus   4958:                    SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
                   4959:                    CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190     markus   4960:                    0, "X11 inet listener", 1);
1.167     markus   4961:                nc->single_connection = single_connection;
1.224     markus   4962:                (*chanids)[n] = nc->self;
1.35      markus   4963:        }
1.224     markus   4964:        (*chanids)[n] = -1;
1.1       deraadt  4965:
1.141     stevesk  4966:        /* Return the display number for the DISPLAY environment variable. */
1.176     deraadt  4967:        *display_numberp = display_number;
1.367     djm      4968:        return 0;
1.1       deraadt  4969: }
                   4970:
1.127     itojun   4971: static int
1.77      markus   4972: connect_local_xsocket(u_int dnr)
1.1       deraadt  4973: {
1.25      markus   4974:        int sock;
                   4975:        struct sockaddr_un addr;
                   4976:
1.147     stevesk  4977:        sock = socket(AF_UNIX, SOCK_STREAM, 0);
1.393     deraadt  4978:        if (sock == -1)
1.147     stevesk  4979:                error("socket: %.100s", strerror(errno));
                   4980:        memset(&addr, 0, sizeof(addr));
                   4981:        addr.sun_family = AF_UNIX;
                   4982:        snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239     deraadt  4983:        if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147     stevesk  4984:                return sock;
                   4985:        close(sock);
1.25      markus   4986:        error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
                   4987:        return -1;
1.1       deraadt  4988: }
                   4989:
1.51      markus   4990: int
1.367     djm      4991: x11_connect_display(struct ssh *ssh)
1.1       deraadt  4992: {
1.248     deraadt  4993:        u_int display_number;
1.25      markus   4994:        const char *display;
1.51      markus   4995:        char buf[1024], *cp;
1.35      markus   4996:        struct addrinfo hints, *ai, *aitop;
                   4997:        char strport[NI_MAXSERV];
1.248     deraadt  4998:        int gaierr, sock = 0;
1.25      markus   4999:
                   5000:        /* Try to open a socket for the local X server. */
                   5001:        display = getenv("DISPLAY");
                   5002:        if (!display) {
                   5003:                error("DISPLAY not set.");
1.51      markus   5004:                return -1;
1.25      markus   5005:        }
1.27      markus   5006:        /*
                   5007:         * Now we decode the value of the DISPLAY variable and make a
                   5008:         * connection to the real X server.
                   5009:         */
                   5010:
                   5011:        /*
                   5012:         * Check if it is a unix domain socket.  Unix domain displays are in
                   5013:         * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
                   5014:         */
1.25      markus   5015:        if (strncmp(display, "unix:", 5) == 0 ||
                   5016:            display[0] == ':') {
                   5017:                /* Connect to the unix domain socket. */
1.367     djm      5018:                if (sscanf(strrchr(display, ':') + 1, "%u",
                   5019:                    &display_number) != 1) {
                   5020:                        error("Could not parse display number from DISPLAY: "
                   5021:                            "%.100s", display);
1.51      markus   5022:                        return -1;
1.25      markus   5023:                }
                   5024:                /* Create a socket. */
                   5025:                sock = connect_local_xsocket(display_number);
                   5026:                if (sock < 0)
1.51      markus   5027:                        return -1;
1.25      markus   5028:
                   5029:                /* OK, we now have a connection to the display. */
1.51      markus   5030:                return sock;
1.25      markus   5031:        }
1.27      markus   5032:        /*
                   5033:         * Connect to an inet socket.  The DISPLAY value is supposedly
                   5034:         * hostname:d[.s], where hostname may also be numeric IP address.
                   5035:         */
1.145     stevesk  5036:        strlcpy(buf, display, sizeof(buf));
1.25      markus   5037:        cp = strchr(buf, ':');
                   5038:        if (!cp) {
                   5039:                error("Could not find ':' in DISPLAY: %.100s", display);
1.51      markus   5040:                return -1;
1.25      markus   5041:        }
                   5042:        *cp = 0;
1.367     djm      5043:        /*
                   5044:         * buf now contains the host name.  But first we parse the
                   5045:         * display number.
                   5046:         */
1.248     deraadt  5047:        if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25      markus   5048:                error("Could not parse display number from DISPLAY: %.100s",
1.148     deraadt  5049:                    display);
1.51      markus   5050:                return -1;
1.25      markus   5051:        }
1.35      markus   5052:
                   5053:        /* Look up the host address */
                   5054:        memset(&hints, 0, sizeof(hints));
1.367     djm      5055:        hints.ai_family = ssh->chanctxt->IPv4or6;
1.35      markus   5056:        hints.ai_socktype = SOCK_STREAM;
1.248     deraadt  5057:        snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35      markus   5058:        if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
1.271     dtucker  5059:                error("%.100s: unknown host. (%s)", buf,
                   5060:                ssh_gai_strerror(gaierr));
1.51      markus   5061:                return -1;
1.25      markus   5062:        }
1.35      markus   5063:        for (ai = aitop; ai; ai = ai->ai_next) {
                   5064:                /* Create a socket. */
1.300     dtucker  5065:                sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.393     deraadt  5066:                if (sock == -1) {
1.194     markus   5067:                        debug2("socket: %.100s", strerror(errno));
1.41      markus   5068:                        continue;
                   5069:                }
                   5070:                /* Connect it to the display. */
1.393     deraadt  5071:                if (connect(sock, ai->ai_addr, ai->ai_addrlen) == -1) {
1.248     deraadt  5072:                        debug2("connect %.100s port %u: %.100s", buf,
1.41      markus   5073:                            6000 + display_number, strerror(errno));
                   5074:                        close(sock);
                   5075:                        continue;
                   5076:                }
                   5077:                /* Success */
                   5078:                break;
1.35      markus   5079:        }
                   5080:        freeaddrinfo(aitop);
                   5081:        if (!ai) {
1.367     djm      5082:                error("connect %.100s port %u: %.100s", buf,
                   5083:                    6000 + display_number, strerror(errno));
1.51      markus   5084:                return -1;
1.25      markus   5085:        }
1.162     stevesk  5086:        set_nodelay(sock);
1.51      markus   5087:        return sock;
                   5088: }
                   5089:
                   5090: /*
1.27      markus   5091:  * Requests forwarding of X11 connections, generates fake authentication
                   5092:  * data, and enables authentication spoofing.
1.121     markus   5093:  * This should be called in the client only.
1.27      markus   5094:  */
1.49      markus   5095: void
1.367     djm      5096: x11_request_forwarding_with_spoofing(struct ssh *ssh, int client_session_id,
                   5097:     const char *disp, const char *proto, const char *data, int want_reply)
1.1       deraadt  5098: {
1.367     djm      5099:        struct ssh_channels *sc = ssh->chanctxt;
1.77      markus   5100:        u_int data_len = (u_int) strlen(data) / 2;
1.219     djm      5101:        u_int i, value;
1.367     djm      5102:        const char *cp;
1.25      markus   5103:        char *new_data;
1.367     djm      5104:        int r, screen_number;
1.25      markus   5105:
1.367     djm      5106:        if (sc->x11_saved_display == NULL)
                   5107:                sc->x11_saved_display = xstrdup(disp);
                   5108:        else if (strcmp(disp, sc->x11_saved_display) != 0) {
1.219     djm      5109:                error("x11_request_forwarding_with_spoofing: different "
                   5110:                    "$DISPLAY already forwarded");
                   5111:                return;
                   5112:        }
                   5113:
1.266     djm      5114:        cp = strchr(disp, ':');
1.25      markus   5115:        if (cp)
                   5116:                cp = strchr(cp, '.');
                   5117:        if (cp)
1.245     deraadt  5118:                screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25      markus   5119:        else
                   5120:                screen_number = 0;
                   5121:
1.367     djm      5122:        if (sc->x11_saved_proto == NULL) {
1.219     djm      5123:                /* Save protocol name. */
1.367     djm      5124:                sc->x11_saved_proto = xstrdup(proto);
1.353     natano   5125:
                   5126:                /* Extract real authentication data. */
1.367     djm      5127:                sc->x11_saved_data = xmalloc(data_len);
1.219     djm      5128:                for (i = 0; i < data_len; i++) {
1.403     djm      5129:                        if (sscanf(data + 2 * i, "%2x", &value) != 1) {
1.219     djm      5130:                                fatal("x11_request_forwarding: bad "
                   5131:                                    "authentication data: %.100s", data);
1.403     djm      5132:                        }
1.367     djm      5133:                        sc->x11_saved_data[i] = value;
1.219     djm      5134:                }
1.367     djm      5135:                sc->x11_saved_data_len = data_len;
1.353     natano   5136:
                   5137:                /* Generate fake data of the same length. */
1.367     djm      5138:                sc->x11_fake_data = xmalloc(data_len);
                   5139:                arc4random_buf(sc->x11_fake_data, data_len);
                   5140:                sc->x11_fake_data_len = data_len;
1.25      markus   5141:        }
                   5142:
                   5143:        /* Convert the fake data into hex. */
1.367     djm      5144:        new_data = tohex(sc->x11_fake_data, data_len);
1.25      markus   5145:
                   5146:        /* Send the request packet. */
1.367     djm      5147:        channel_request_start(ssh, client_session_id, "x11-req", want_reply);
                   5148:        if ((r = sshpkt_put_u8(ssh, 0)) != 0 || /* bool: single connection */
                   5149:            (r = sshpkt_put_cstring(ssh, proto)) != 0 ||
                   5150:            (r = sshpkt_put_cstring(ssh, new_data)) != 0 ||
                   5151:            (r = sshpkt_put_u32(ssh, screen_number)) != 0 ||
                   5152:            (r = sshpkt_send(ssh)) != 0 ||
                   5153:            (r = ssh_packet_write_wait(ssh)) != 0)
1.403     djm      5154:                fatal_fr(r, "send x11-req");
1.321     djm      5155:        free(new_data);
1.1       deraadt  5156: }