Annotation of src/usr.bin/ssh/channels.c, Revision 1.368
1.368 ! djm 1: /* $OpenBSD: channels.c,v 1.367 2017/09/12 06:32:07 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>
1.367 djm 57: #include <stdarg.h>
1.341 millert 58: #include <stdint.h>
1.263 stevesk 59: #include <stdio.h>
1.262 stevesk 60: #include <stdlib.h>
1.260 stevesk 61: #include <string.h>
1.233 stevesk 62: #include <termios.h>
1.256 stevesk 63: #include <unistd.h>
1.1 deraadt 64:
1.265 deraadt 65: #include "xmalloc.h"
1.1 deraadt 66: #include "ssh.h"
1.82 markus 67: #include "ssh2.h"
1.354 markus 68: #include "ssherr.h"
1.367 djm 69: #include "sshbuf.h"
1.1 deraadt 70: #include "packet.h"
1.82 markus 71: #include "log.h"
72: #include "misc.h"
1.14 markus 73: #include "channels.h"
74: #include "compat.h"
1.82 markus 75: #include "canohost.h"
1.64 markus 76: #include "key.h"
77: #include "authfd.h"
1.147 stevesk 78: #include "pathnames.h"
1.1 deraadt 79:
1.367 djm 80: /* -- agent forwarding */
81: #define NUM_SOCKS 10
1.12 markus 82:
1.367 djm 83: /* -- tcp forwarding */
84: /* special-case port number meaning allow any port */
85: #define FWD_PERMIT_ANY_PORT 0
1.1 deraadt 86:
1.367 djm 87: /* special-case wildcard meaning allow any host */
88: #define FWD_PERMIT_ANY_HOST "*"
1.1 deraadt 89:
1.367 djm 90: /* -- X11 forwarding */
91: /* Maximum number of fake X11 displays to try. */
92: #define MAX_DISPLAYS 1000
1.1 deraadt 93:
1.27 markus 94: /*
95: * Data structure for storing which hosts are permitted for forward requests.
96: * The local sides of any remote forwards are stored in this array to prevent
97: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
98: * network (which might be behind a firewall).
99: */
1.336 millert 100: /* XXX: streamlocal wants a path instead of host:port */
101: /* Overload host_to_connect; we could just make this match Forward */
102: /* XXX - can we use listen_host instead of listen_path? */
1.25 markus 103: typedef struct {
1.41 markus 104: char *host_to_connect; /* Connect to 'host'. */
1.336 millert 105: int port_to_connect; /* Connect to 'port'. */
1.333 markus 106: char *listen_host; /* Remote side should listen address. */
1.336 millert 107: char *listen_path; /* Remote side should listen path. */
108: int listen_port; /* Remote side should listen port. */
1.354 markus 109: Channel *downstream; /* Downstream mux*/
1.1 deraadt 110: } ForwardPermission;
111:
1.367 djm 112: typedef void chan_fn(struct ssh *, Channel *c,
113: fd_set *readset, fd_set *writeset);
1.121 markus 114:
1.367 djm 115: /* Master structure for channels state */
116: struct ssh_channels {
117: /*
118: * Pointer to an array containing all allocated channels. The array
119: * is dynamically extended as needed.
120: */
121: Channel **channels;
1.257 dtucker 122:
1.367 djm 123: /*
124: * Size of the channel array. All slots of the array must always be
125: * initialized (at least the type field); unused slots set to NULL
126: */
127: u_int channels_alloc;
1.257 dtucker 128:
1.367 djm 129: /*
130: * Maximum file descriptor value used in any of the channels. This is
131: * updated in channel_new.
132: */
133: int channel_max_fd;
1.257 dtucker 134:
1.367 djm 135: /*
136: * 'channel_pre*' are called just before select() to add any bits
137: * relevant to channels in the select bitmasks.
138: *
139: * 'channel_post*': perform any appropriate operations for
140: * channels which have events pending.
141: */
142: chan_fn **channel_pre;
143: chan_fn **channel_post;
1.314 dtucker 144:
1.367 djm 145: /* -- tcp forwarding */
1.351 dtucker 146:
1.367 djm 147: /* List of all permitted host/port pairs to connect by the user. */
148: ForwardPermission *permitted_opens;
1.1 deraadt 149:
1.367 djm 150: /* List of all permitted host/port pairs to connect by the admin. */
151: ForwardPermission *permitted_adm_opens;
1.121 markus 152:
1.367 djm 153: /*
154: * Number of permitted host/port pairs in the array permitted by
155: * the user.
156: */
157: u_int num_permitted_opens;
1.121 markus 158:
1.367 djm 159: /*
160: * Number of permitted host/port pair in the array permitted by
161: * the admin.
162: */
163: u_int num_adm_permitted_opens;
1.121 markus 164:
1.367 djm 165: /*
166: * If this is true, all opens are permitted. This is the case on
167: * the server on which we have to trust the client anyway, and the
168: * user could do anything after logging in anyway.
169: */
170: int all_opens_permitted;
1.219 djm 171:
1.367 djm 172: /* -- X11 forwarding */
1.121 markus 173:
1.367 djm 174: /* Saved X11 local (client) display. */
175: char *x11_saved_display;
1.121 markus 176:
1.367 djm 177: /* Saved X11 authentication protocol name. */
178: char *x11_saved_proto;
1.347 djm 179:
1.367 djm 180: /* Saved X11 authentication data. This is the real data. */
181: char *x11_saved_data;
182: u_int x11_saved_data_len;
1.121 markus 183:
1.367 djm 184: /* Deadline after which all X11 connections are refused */
185: u_int x11_refuse_time;
1.121 markus 186:
1.367 djm 187: /*
188: * Fake X11 authentication data. This is what the server will be
189: * sending us; we should replace any occurrences of this by the
190: * real data.
191: */
192: u_char *x11_fake_data;
193: u_int x11_fake_data_len;
1.121 markus 194:
1.367 djm 195: /* AF_UNSPEC or AF_INET or AF_INET6 */
196: int IPv4or6;
197: };
1.1 deraadt 198:
1.121 markus 199: /* helper */
1.367 djm 200: static void port_open_helper(struct ssh *ssh, Channel *c, char *rtype);
1.354 markus 201: static const char *channel_rfwd_bind_host(const char *listen_host);
1.103 markus 202:
1.276 djm 203: /* non-blocking connect helpers */
204: static int connect_next(struct channel_connect *);
205: static void channel_connect_ctx_free(struct channel_connect *);
206:
1.367 djm 207: /* Setup helper */
208: static void channel_handler_init(struct ssh_channels *sc);
209:
1.121 markus 210: /* -- channel core */
1.41 markus 211:
1.367 djm 212: void
213: channel_init_channels(struct ssh *ssh)
214: {
215: struct ssh_channels *sc;
216:
217: if ((sc = calloc(1, sizeof(*sc))) == NULL ||
218: (sc->channel_pre = calloc(SSH_CHANNEL_MAX_TYPE,
219: sizeof(*sc->channel_pre))) == NULL ||
220: (sc->channel_post = calloc(SSH_CHANNEL_MAX_TYPE,
221: sizeof(*sc->channel_post))) == NULL)
222: fatal("%s: allocation failed", __func__);
223: sc->channels_alloc = 10;
224: sc->channels = xcalloc(sc->channels_alloc, sizeof(*sc->channels));
225: sc->IPv4or6 = AF_UNSPEC;
226: channel_handler_init(sc);
227:
228: ssh->chanctxt = sc;
229: }
230:
1.41 markus 231: Channel *
1.367 djm 232: channel_by_id(struct ssh *ssh, int id)
1.41 markus 233: {
234: Channel *c;
1.113 markus 235:
1.367 djm 236: if (id < 0 || (u_int)id >= ssh->chanctxt->channels_alloc) {
237: logit("%s: %d: bad id", __func__, id);
1.41 markus 238: return NULL;
239: }
1.367 djm 240: c = ssh->chanctxt->channels[id];
1.113 markus 241: if (c == NULL) {
1.367 djm 242: logit("%s: %d: bad id: channel free", __func__, id);
1.41 markus 243: return NULL;
244: }
245: return c;
1.55 markus 246: }
247:
1.354 markus 248: Channel *
1.368 ! djm 249: channel_by_remote_id(struct ssh *ssh, u_int remote_id)
1.354 markus 250: {
251: Channel *c;
252: u_int i;
253:
1.367 djm 254: for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
255: c = ssh->chanctxt->channels[i];
1.368 ! djm 256: if (c != NULL && c->have_remote_id && c->remote_id == remote_id)
1.354 markus 257: return c;
258: }
259: return NULL;
260: }
261:
1.27 markus 262: /*
1.229 markus 263: * Returns the channel if it is allowed to receive protocol messages.
264: * Private channels, like listening sockets, may not receive messages.
265: */
266: Channel *
1.367 djm 267: channel_lookup(struct ssh *ssh, int id)
1.229 markus 268: {
269: Channel *c;
270:
1.367 djm 271: if ((c = channel_by_id(ssh, id)) == NULL)
272: return NULL;
1.229 markus 273:
1.237 deraadt 274: switch (c->type) {
1.229 markus 275: case SSH_CHANNEL_X11_OPEN:
276: case SSH_CHANNEL_LARVAL:
277: case SSH_CHANNEL_CONNECTING:
278: case SSH_CHANNEL_DYNAMIC:
279: case SSH_CHANNEL_OPENING:
280: case SSH_CHANNEL_OPEN:
1.323 dtucker 281: case SSH_CHANNEL_ABANDONED:
1.354 markus 282: case SSH_CHANNEL_MUX_PROXY:
1.367 djm 283: return c;
1.229 markus 284: }
285: logit("Non-public channel %d, type %d.", id, c->type);
1.367 djm 286: return NULL;
1.229 markus 287: }
288:
289: /*
1.55 markus 290: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 291: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 292: */
1.127 itojun 293: static void
1.367 djm 294: channel_register_fds(struct ssh *ssh, Channel *c, int rfd, int wfd, int efd,
1.282 dtucker 295: int extusage, int nonblock, int is_tty)
1.1 deraadt 296: {
1.367 djm 297: struct ssh_channels *sc = ssh->chanctxt;
298:
1.25 markus 299: /* Update the maximum file descriptor value. */
1.367 djm 300: sc->channel_max_fd = MAXIMUM(sc->channel_max_fd, rfd);
301: sc->channel_max_fd = MAXIMUM(sc->channel_max_fd, wfd);
302: sc->channel_max_fd = MAXIMUM(sc->channel_max_fd, efd);
1.84 markus 303:
1.298 dtucker 304: if (rfd != -1)
305: fcntl(rfd, F_SETFD, FD_CLOEXEC);
306: if (wfd != -1 && wfd != rfd)
307: fcntl(wfd, F_SETFD, FD_CLOEXEC);
308: if (efd != -1 && efd != rfd && efd != wfd)
309: fcntl(efd, F_SETFD, FD_CLOEXEC);
1.55 markus 310:
1.52 markus 311: c->rfd = rfd;
312: c->wfd = wfd;
313: c->sock = (rfd == wfd) ? rfd : -1;
314: c->efd = efd;
315: c->extended_usage = extusage;
1.71 markus 316:
1.282 dtucker 317: if ((c->isatty = is_tty) != 0)
1.194 markus 318: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 319:
1.71 markus 320: /* enable nonblocking mode */
321: if (nonblock) {
322: if (rfd != -1)
323: set_nonblock(rfd);
324: if (wfd != -1)
325: set_nonblock(wfd);
326: if (efd != -1)
327: set_nonblock(efd);
328: }
1.52 markus 329: }
330:
331: /*
332: * Allocate a new channel object and set its type and socket. This will cause
333: * remote_name to be freed.
334: */
1.113 markus 335: Channel *
1.367 djm 336: channel_new(struct ssh *ssh, char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 337: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 338: {
1.367 djm 339: struct ssh_channels *sc = ssh->chanctxt;
340: u_int i, found;
1.52 markus 341: Channel *c;
1.25 markus 342:
343: /* Try to find a free slot where to put the new channel. */
1.367 djm 344: for (i = 0; i < sc->channels_alloc; i++) {
345: if (sc->channels[i] == NULL) {
1.25 markus 346: /* Found a free slot. */
1.367 djm 347: found = i;
1.25 markus 348: break;
349: }
1.367 djm 350: }
351: if (i >= sc->channels_alloc) {
352: /*
353: * There are no free slots. Take last+1 slot and expand
354: * the array.
355: */
356: found = sc->channels_alloc;
357: if (sc->channels_alloc > CHANNELS_MAX_CHANNELS)
358: fatal("%s: internal error: channels_alloc %d too big",
359: __func__, sc->channels_alloc);
360: sc->channels = xrecallocarray(sc->channels, sc->channels_alloc,
361: sc->channels_alloc + 10, sizeof(*sc->channels));
362: sc->channels_alloc += 10;
363: debug2("channel: expanding %d", sc->channels_alloc);
1.25 markus 364: }
1.113 markus 365: /* Initialize and return new channel. */
1.367 djm 366: c = sc->channels[found] = xcalloc(1, sizeof(Channel));
367: if ((c->input = sshbuf_new()) == NULL ||
368: (c->output = sshbuf_new()) == NULL ||
369: (c->extended = sshbuf_new()) == NULL)
370: fatal("%s: sshbuf_new failed", __func__);
1.159 markus 371: c->ostate = CHAN_OUTPUT_OPEN;
372: c->istate = CHAN_INPUT_OPEN;
1.367 djm 373: channel_register_fds(ssh, c, rfd, wfd, efd, extusage, nonblock, 0);
1.25 markus 374: c->self = found;
375: c->type = type;
1.41 markus 376: c->ctype = ctype;
1.51 markus 377: c->local_window = window;
378: c->local_window_max = window;
379: c->local_maxpacket = maxpack;
1.190 markus 380: c->remote_name = xstrdup(remote_name);
1.302 djm 381: c->ctl_chan = -1;
1.299 markus 382: c->delayed = 1; /* prevent call to channel_post handler */
1.275 djm 383: TAILQ_INIT(&c->status_confirms);
1.25 markus 384: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 385: return c;
1.1 deraadt 386: }
1.52 markus 387:
1.367 djm 388: static void
389: channel_find_maxfd(struct ssh_channels *sc)
1.132 markus 390: {
1.209 avsm 391: u_int i;
392: int max = 0;
1.132 markus 393: Channel *c;
394:
1.367 djm 395: for (i = 0; i < sc->channels_alloc; i++) {
396: c = sc->channels[i];
1.132 markus 397: if (c != NULL) {
1.352 deraadt 398: max = MAXIMUM(max, c->rfd);
399: max = MAXIMUM(max, c->wfd);
400: max = MAXIMUM(max, c->efd);
1.132 markus 401: }
402: }
1.367 djm 403: sc->channel_max_fd = max;
1.132 markus 404: }
405:
406: int
1.367 djm 407: channel_close_fd(struct ssh *ssh, int *fdp)
1.132 markus 408: {
1.367 djm 409: struct ssh_channels *sc = ssh->chanctxt;
1.132 markus 410: int ret = 0, fd = *fdp;
411:
412: if (fd != -1) {
413: ret = close(fd);
414: *fdp = -1;
1.367 djm 415: if (fd == sc->channel_max_fd)
416: channel_find_maxfd(sc);
1.132 markus 417: }
418: return ret;
419: }
420:
1.52 markus 421: /* Close all channel fd/socket. */
1.127 itojun 422: static void
1.367 djm 423: channel_close_fds(struct ssh *ssh, Channel *c)
424: {
425: channel_close_fd(ssh, &c->sock);
426: channel_close_fd(ssh, &c->rfd);
427: channel_close_fd(ssh, &c->wfd);
428: channel_close_fd(ssh, &c->efd);
429: }
430:
431: static void
432: fwd_perm_clear(ForwardPermission *fp)
1.52 markus 433: {
1.367 djm 434: free(fp->host_to_connect);
435: free(fp->listen_host);
436: free(fp->listen_path);
437: bzero(fp, sizeof(*fp));
438: }
439:
440: enum { FWDPERM_USER, FWDPERM_ADMIN };
441:
442: static int
443: fwd_perm_list_add(struct ssh *ssh, int which,
444: const char *host_to_connect, int port_to_connect,
445: const char *listen_host, const char *listen_path, int listen_port,
446: Channel *downstream)
447: {
448: ForwardPermission **fpl;
449: u_int n, *nfpl;
450:
451: switch (which) {
452: case FWDPERM_USER:
453: fpl = &ssh->chanctxt->permitted_opens;
454: nfpl = &ssh->chanctxt->num_permitted_opens;
455: break;
456: case FWDPERM_ADMIN:
457: fpl = &ssh->chanctxt->permitted_adm_opens;
458: nfpl = &ssh->chanctxt->num_adm_permitted_opens;
459: break;
460: default:
461: fatal("%s: invalid list %d", __func__, which);
462: }
463:
464: if (*nfpl >= INT_MAX)
465: fatal("%s: overflow", __func__);
466:
467: *fpl = xrecallocarray(*fpl, *nfpl, *nfpl + 1, sizeof(**fpl));
468: n = (*nfpl)++;
469: #define MAYBE_DUP(s) ((s == NULL) ? NULL : xstrdup(s))
470: (*fpl)[n].host_to_connect = MAYBE_DUP(host_to_connect);
471: (*fpl)[n].port_to_connect = port_to_connect;
472: (*fpl)[n].listen_host = MAYBE_DUP(listen_host);
473: (*fpl)[n].listen_path = MAYBE_DUP(listen_path);
474: (*fpl)[n].listen_port = listen_port;
475: (*fpl)[n].downstream = downstream;
476: #undef MAYBE_DUP
477: return (int)n;
478: }
479:
480: static void
481: mux_remove_remote_forwardings(struct ssh *ssh, Channel *c)
482: {
483: struct ssh_channels *sc = ssh->chanctxt;
484: ForwardPermission *fp;
485: int r;
486: u_int i;
487:
488: for (i = 0; i < sc->num_permitted_opens; i++) {
489: fp = &sc->permitted_opens[i];
490: if (fp->downstream != c)
491: continue;
492:
493: /* cancel on the server, since mux client is gone */
494: debug("channel %d: cleanup remote forward for %s:%u",
495: c->self, fp->listen_host, fp->listen_port);
496: if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
497: (r = sshpkt_put_cstring(ssh,
498: "cancel-tcpip-forward")) != 0 ||
499: (r = sshpkt_put_u8(ssh, 0)) != 0 ||
500: (r = sshpkt_put_cstring(ssh,
501: channel_rfwd_bind_host(fp->listen_host))) != 0 ||
502: (r = sshpkt_put_u32(ssh, fp->listen_port)) != 0 ||
503: (r = sshpkt_send(ssh)) != 0) {
504: fatal("%s: channel %i: %s", __func__,
505: c->self, ssh_err(r));
506: }
507: fwd_perm_clear(fp); /* unregister */
508: }
1.121 markus 509: }
510:
511: /* Free the channel and close its fd/socket. */
512: void
1.367 djm 513: channel_free(struct ssh *ssh, Channel *c)
1.121 markus 514: {
1.367 djm 515: struct ssh_channels *sc = ssh->chanctxt;
1.121 markus 516: char *s;
1.209 avsm 517: u_int i, n;
1.354 markus 518: Channel *other;
1.275 djm 519: struct channel_confirm *cc;
1.121 markus 520:
1.367 djm 521: for (n = 0, i = 0; i < sc->channels_alloc; i++) {
522: if ((other = sc->channels[i]) == NULL)
523: continue;
524: n++;
525: /* detach from mux client and prepare for closing */
526: if (c->type == SSH_CHANNEL_MUX_CLIENT &&
527: other->type == SSH_CHANNEL_MUX_PROXY &&
528: other->mux_ctx == c) {
529: other->mux_ctx = NULL;
530: other->type = SSH_CHANNEL_OPEN;
531: other->istate = CHAN_INPUT_CLOSED;
532: other->ostate = CHAN_OUTPUT_CLOSED;
1.354 markus 533: }
534: }
1.209 avsm 535: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 536: c->remote_name ? c->remote_name : "???", n);
537:
1.367 djm 538: if (c->type == SSH_CHANNEL_MUX_CLIENT)
539: mux_remove_remote_forwardings(ssh, c);
1.354 markus 540:
1.367 djm 541: s = channel_open_message(ssh);
1.194 markus 542: debug3("channel %d: status: %s", c->self, s);
1.321 djm 543: free(s);
1.121 markus 544:
1.367 djm 545: channel_close_fds(ssh, c);
546: sshbuf_free(c->input);
547: sshbuf_free(c->output);
548: sshbuf_free(c->extended);
549: c->input = c->output = c->extended = NULL;
1.321 djm 550: free(c->remote_name);
551: c->remote_name = NULL;
552: free(c->path);
553: c->path = NULL;
554: free(c->listening_addr);
555: c->listening_addr = NULL;
1.275 djm 556: while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
557: if (cc->abandon_cb != NULL)
1.367 djm 558: cc->abandon_cb(ssh, c, cc->ctx);
1.275 djm 559: TAILQ_REMOVE(&c->status_confirms, cc, entry);
1.329 tedu 560: explicit_bzero(cc, sizeof(*cc));
1.321 djm 561: free(cc);
1.275 djm 562: }
1.280 djm 563: if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
1.367 djm 564: c->filter_cleanup(ssh, c->self, c->filter_ctx);
565: sc->channels[c->self] = NULL;
566: bzero(c, sizeof(*c));
1.321 djm 567: free(c);
1.121 markus 568: }
569:
570: void
1.367 djm 571: channel_free_all(struct ssh *ssh)
1.121 markus 572: {
1.209 avsm 573: u_int i;
1.121 markus 574:
1.367 djm 575: for (i = 0; i < ssh->chanctxt->channels_alloc; i++)
576: if (ssh->chanctxt->channels[i] != NULL)
577: channel_free(ssh, ssh->chanctxt->channels[i]);
1.131 markus 578: }
579:
1.121 markus 580: /*
581: * Closes the sockets/fds of all channels. This is used to close extra file
582: * descriptors after a fork.
583: */
584: void
1.367 djm 585: channel_close_all(struct ssh *ssh)
1.121 markus 586: {
1.209 avsm 587: u_int i;
1.121 markus 588:
1.367 djm 589: for (i = 0; i < ssh->chanctxt->channels_alloc; i++)
590: if (ssh->chanctxt->channels[i] != NULL)
591: channel_close_fds(ssh, ssh->chanctxt->channels[i]);
1.121 markus 592: }
593:
594: /*
1.131 markus 595: * Stop listening to channels.
596: */
597: void
1.367 djm 598: channel_stop_listening(struct ssh *ssh)
1.131 markus 599: {
1.209 avsm 600: u_int i;
1.131 markus 601: Channel *c;
602:
1.367 djm 603: for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
604: c = ssh->chanctxt->channels[i];
1.131 markus 605: if (c != NULL) {
606: switch (c->type) {
607: case SSH_CHANNEL_AUTH_SOCKET:
608: case SSH_CHANNEL_PORT_LISTENER:
609: case SSH_CHANNEL_RPORT_LISTENER:
610: case SSH_CHANNEL_X11_LISTENER:
1.336 millert 611: case SSH_CHANNEL_UNIX_LISTENER:
612: case SSH_CHANNEL_RUNIX_LISTENER:
1.367 djm 613: channel_close_fd(ssh, &c->sock);
614: channel_free(ssh, c);
1.131 markus 615: break;
616: }
617: }
618: }
619: }
620:
621: /*
1.121 markus 622: * Returns true if no channel has too much buffered data, and false if one or
623: * more channel is overfull.
624: */
625: int
1.367 djm 626: channel_not_very_much_buffered_data(struct ssh *ssh)
1.121 markus 627: {
628: u_int i;
1.367 djm 629: u_int maxsize = ssh_packet_get_maxsize(ssh);
1.121 markus 630: Channel *c;
631:
1.367 djm 632: for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
633: c = ssh->chanctxt->channels[i];
634: if (c == NULL || c->type != SSH_CHANNEL_OPEN)
635: continue;
636: if (sshbuf_len(c->output) > maxsize) {
637: debug2("channel %d: big output buffer %zu > %u",
638: c->self, sshbuf_len(c->output), maxsize);
639: return 0;
1.121 markus 640: }
641: }
642: return 1;
643: }
644:
645: /* Returns true if any channel is still open. */
646: int
1.367 djm 647: channel_still_open(struct ssh *ssh)
1.121 markus 648: {
1.209 avsm 649: u_int i;
1.121 markus 650: Channel *c;
651:
1.367 djm 652: for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
653: c = ssh->chanctxt->channels[i];
1.121 markus 654: if (c == NULL)
655: continue;
656: switch (c->type) {
657: case SSH_CHANNEL_X11_LISTENER:
658: case SSH_CHANNEL_PORT_LISTENER:
659: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 660: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 661: case SSH_CHANNEL_CLOSED:
662: case SSH_CHANNEL_AUTH_SOCKET:
663: case SSH_CHANNEL_DYNAMIC:
664: case SSH_CHANNEL_CONNECTING:
665: case SSH_CHANNEL_ZOMBIE:
1.323 dtucker 666: case SSH_CHANNEL_ABANDONED:
1.336 millert 667: case SSH_CHANNEL_UNIX_LISTENER:
668: case SSH_CHANNEL_RUNIX_LISTENER:
1.121 markus 669: continue;
670: case SSH_CHANNEL_LARVAL:
671: continue;
672: case SSH_CHANNEL_OPENING:
673: case SSH_CHANNEL_OPEN:
674: case SSH_CHANNEL_X11_OPEN:
1.302 djm 675: case SSH_CHANNEL_MUX_CLIENT:
1.354 markus 676: case SSH_CHANNEL_MUX_PROXY:
1.121 markus 677: return 1;
678: default:
1.358 djm 679: fatal("%s: bad channel type %d", __func__, c->type);
1.121 markus 680: /* NOTREACHED */
681: }
682: }
683: return 0;
684: }
685:
686: /* Returns the id of an open channel suitable for keepaliving */
687: int
1.367 djm 688: channel_find_open(struct ssh *ssh)
1.121 markus 689: {
1.209 avsm 690: u_int i;
1.121 markus 691: Channel *c;
692:
1.367 djm 693: for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
694: c = ssh->chanctxt->channels[i];
1.368 ! djm 695: if (c == NULL || !c->have_remote_id)
1.121 markus 696: continue;
697: switch (c->type) {
698: case SSH_CHANNEL_CLOSED:
699: case SSH_CHANNEL_DYNAMIC:
700: case SSH_CHANNEL_X11_LISTENER:
701: case SSH_CHANNEL_PORT_LISTENER:
702: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 703: case SSH_CHANNEL_MUX_LISTENER:
704: case SSH_CHANNEL_MUX_CLIENT:
1.354 markus 705: case SSH_CHANNEL_MUX_PROXY:
1.121 markus 706: case SSH_CHANNEL_OPENING:
707: case SSH_CHANNEL_CONNECTING:
708: case SSH_CHANNEL_ZOMBIE:
1.323 dtucker 709: case SSH_CHANNEL_ABANDONED:
1.336 millert 710: case SSH_CHANNEL_UNIX_LISTENER:
711: case SSH_CHANNEL_RUNIX_LISTENER:
1.121 markus 712: continue;
713: case SSH_CHANNEL_LARVAL:
714: case SSH_CHANNEL_AUTH_SOCKET:
715: case SSH_CHANNEL_OPEN:
716: case SSH_CHANNEL_X11_OPEN:
717: return i;
718: default:
1.358 djm 719: fatal("%s: bad channel type %d", __func__, c->type);
1.121 markus 720: /* NOTREACHED */
721: }
722: }
723: return -1;
724: }
725:
726: /*
727: * Returns a message describing the currently open forwarded connections,
728: * suitable for sending to the client. The message contains crlf pairs for
729: * newlines.
730: */
731: char *
1.367 djm 732: channel_open_message(struct ssh *ssh)
1.121 markus 733: {
1.367 djm 734: struct sshbuf *buf;
1.121 markus 735: Channel *c;
1.209 avsm 736: u_int i;
1.367 djm 737: int r;
738: char *ret;
1.121 markus 739:
1.367 djm 740: if ((buf = sshbuf_new()) == NULL)
741: fatal("%s: sshbuf_new", __func__);
742: if ((r = sshbuf_putf(buf,
743: "The following connections are open:\r\n")) != 0)
744: fatal("%s: sshbuf_putf: %s", __func__, ssh_err(r));
745: for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
746: c = ssh->chanctxt->channels[i];
1.121 markus 747: if (c == NULL)
748: continue;
749: switch (c->type) {
750: case SSH_CHANNEL_X11_LISTENER:
751: case SSH_CHANNEL_PORT_LISTENER:
752: case SSH_CHANNEL_RPORT_LISTENER:
753: case SSH_CHANNEL_CLOSED:
754: case SSH_CHANNEL_AUTH_SOCKET:
755: case SSH_CHANNEL_ZOMBIE:
1.323 dtucker 756: case SSH_CHANNEL_ABANDONED:
1.302 djm 757: case SSH_CHANNEL_MUX_LISTENER:
1.336 millert 758: case SSH_CHANNEL_UNIX_LISTENER:
759: case SSH_CHANNEL_RUNIX_LISTENER:
1.121 markus 760: continue;
761: case SSH_CHANNEL_LARVAL:
762: case SSH_CHANNEL_OPENING:
763: case SSH_CHANNEL_CONNECTING:
764: case SSH_CHANNEL_DYNAMIC:
765: case SSH_CHANNEL_OPEN:
766: case SSH_CHANNEL_X11_OPEN:
1.354 markus 767: case SSH_CHANNEL_MUX_PROXY:
768: case SSH_CHANNEL_MUX_CLIENT:
1.367 djm 769: if ((r = sshbuf_putf(buf, " #%d %.300s "
1.368 ! djm 770: "(t%d %s%u i%u/%zu o%u/%zu fd %d/%d cc %d)\r\n",
1.121 markus 771: c->self, c->remote_name,
1.368 ! djm 772: c->type,
! 773: c->have_remote_id ? "r" : "nr", c->remote_id,
1.367 djm 774: c->istate, sshbuf_len(c->input),
775: c->ostate, sshbuf_len(c->output),
776: c->rfd, c->wfd, c->ctl_chan)) != 0)
777: fatal("%s: sshbuf_putf: %s",
778: __func__, ssh_err(r));
1.121 markus 779: continue;
780: default:
1.367 djm 781: fatal("%s: bad channel type %d", __func__, c->type);
1.121 markus 782: /* NOTREACHED */
783: }
784: }
1.367 djm 785: if ((ret = sshbuf_dup_string(buf)) == NULL)
786: fatal("%s: sshbuf_dup_string", __func__);
787: sshbuf_free(buf);
788: return ret;
789: }
790:
791: static void
792: open_preamble(struct ssh *ssh, const char *where, Channel *c, const char *type)
793: {
794: int r;
795:
796: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN)) != 0 ||
797: (r = sshpkt_put_cstring(ssh, type)) != 0 ||
798: (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
799: (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
800: (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0) {
801: fatal("%s: channel %i: open: %s", where, c->self, ssh_err(r));
802: }
1.121 markus 803: }
804:
805: void
1.367 djm 806: channel_send_open(struct ssh *ssh, int id)
1.121 markus 807: {
1.367 djm 808: Channel *c = channel_lookup(ssh, id);
809: int r;
1.180 deraadt 810:
1.121 markus 811: if (c == NULL) {
1.188 itojun 812: logit("channel_send_open: %d: bad id", id);
1.121 markus 813: return;
814: }
1.184 markus 815: debug2("channel %d: send open", id);
1.367 djm 816: open_preamble(ssh, __func__, c, c->ctype);
817: if ((r = sshpkt_send(ssh)) != 0)
818: fatal("%s: channel %i: %s", __func__, c->self, ssh_err(r));
1.121 markus 819: }
820:
821: void
1.367 djm 822: channel_request_start(struct ssh *ssh, int id, char *service, int wantconfirm)
1.121 markus 823: {
1.367 djm 824: Channel *c = channel_lookup(ssh, id);
825: int r;
1.180 deraadt 826:
1.121 markus 827: if (c == NULL) {
1.367 djm 828: logit("%s: %d: unknown channel id", __func__, id);
1.121 markus 829: return;
830: }
1.368 ! djm 831: if (!c->have_remote_id)
! 832: fatal(":%s: channel %d: no remote id", __func__, c->self);
! 833:
1.204 djm 834: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.367 djm 835: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_REQUEST)) != 0 ||
836: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
837: (r = sshpkt_put_cstring(ssh, service)) != 0 ||
838: (r = sshpkt_put_u8(ssh, wantconfirm)) != 0) {
839: fatal("%s: channel %i: %s", __func__, c->self, ssh_err(r));
840: }
1.121 markus 841: }
1.241 deraadt 842:
1.121 markus 843: void
1.367 djm 844: channel_register_status_confirm(struct ssh *ssh, int id,
845: channel_confirm_cb *cb, channel_confirm_abandon_cb *abandon_cb, void *ctx)
1.275 djm 846: {
847: struct channel_confirm *cc;
848: Channel *c;
849:
1.367 djm 850: if ((c = channel_lookup(ssh, id)) == NULL)
851: fatal("%s: %d: bad id", __func__, id);
1.275 djm 852:
1.327 djm 853: cc = xcalloc(1, sizeof(*cc));
1.275 djm 854: cc->cb = cb;
855: cc->abandon_cb = abandon_cb;
856: cc->ctx = ctx;
857: TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
858: }
859:
860: void
1.367 djm 861: channel_register_open_confirm(struct ssh *ssh, int id,
862: channel_open_fn *fn, void *ctx)
1.121 markus 863: {
1.367 djm 864: Channel *c = channel_lookup(ssh, id);
1.180 deraadt 865:
1.121 markus 866: if (c == NULL) {
1.367 djm 867: logit("%s: %d: bad id", __func__, id);
1.121 markus 868: return;
869: }
1.275 djm 870: c->open_confirm = fn;
871: c->open_confirm_ctx = ctx;
1.121 markus 872: }
1.241 deraadt 873:
1.121 markus 874: void
1.367 djm 875: channel_register_cleanup(struct ssh *ssh, int id,
876: channel_callback_fn *fn, int do_close)
1.121 markus 877: {
1.367 djm 878: Channel *c = channel_by_id(ssh, id);
1.180 deraadt 879:
1.121 markus 880: if (c == NULL) {
1.367 djm 881: logit("%s: %d: bad id", __func__, id);
1.121 markus 882: return;
883: }
1.131 markus 884: c->detach_user = fn;
1.225 djm 885: c->detach_close = do_close;
1.121 markus 886: }
1.241 deraadt 887:
1.121 markus 888: void
1.367 djm 889: channel_cancel_cleanup(struct ssh *ssh, int id)
1.121 markus 890: {
1.367 djm 891: Channel *c = channel_by_id(ssh, id);
1.180 deraadt 892:
1.121 markus 893: if (c == NULL) {
1.367 djm 894: logit("%s: %d: bad id", __func__, id);
1.121 markus 895: return;
1.52 markus 896: }
1.131 markus 897: c->detach_user = NULL;
1.225 djm 898: c->detach_close = 0;
1.121 markus 899: }
1.241 deraadt 900:
1.121 markus 901: void
1.367 djm 902: channel_register_filter(struct ssh *ssh, int id, channel_infilter_fn *ifn,
1.280 djm 903: channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
1.121 markus 904: {
1.367 djm 905: Channel *c = channel_lookup(ssh, id);
1.180 deraadt 906:
1.121 markus 907: if (c == NULL) {
1.367 djm 908: logit("%s: %d: bad id", __func__, id);
1.121 markus 909: return;
1.52 markus 910: }
1.231 reyk 911: c->input_filter = ifn;
912: c->output_filter = ofn;
1.279 djm 913: c->filter_ctx = ctx;
1.280 djm 914: c->filter_cleanup = cfn;
1.52 markus 915: }
916:
1.49 markus 917: void
1.367 djm 918: channel_set_fds(struct ssh *ssh, int id, int rfd, int wfd, int efd,
1.282 dtucker 919: int extusage, int nonblock, int is_tty, u_int window_max)
1.1 deraadt 920: {
1.367 djm 921: Channel *c = channel_lookup(ssh, id);
922: int r;
1.180 deraadt 923:
1.121 markus 924: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
925: fatal("channel_activate for non-larval channel %d.", id);
1.368 ! djm 926: if (!c->have_remote_id)
! 927: fatal(":%s: channel %d: no remote id", __func__, c->self);
! 928:
1.367 djm 929: channel_register_fds(ssh, c, rfd, wfd, efd, extusage, nonblock, is_tty);
1.121 markus 930: c->type = SSH_CHANNEL_OPEN;
1.168 markus 931: c->local_window = c->local_window_max = window_max;
1.367 djm 932:
933: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST)) != 0 ||
934: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
935: (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
936: (r = sshpkt_send(ssh)) != 0)
937: fatal("%s: channel %i: %s", __func__, c->self, ssh_err(r));
1.1 deraadt 938: }
939:
1.127 itojun 940: static void
1.367 djm 941: channel_pre_listener(struct ssh *ssh, Channel *c,
942: fd_set *readset, fd_set *writeset)
1.41 markus 943: {
944: FD_SET(c->sock, readset);
945: }
946:
1.127 itojun 947: static void
1.367 djm 948: channel_pre_connecting(struct ssh *ssh, Channel *c,
949: fd_set *readset, fd_set *writeset)
1.75 markus 950: {
951: debug3("channel %d: waiting for connection", c->self);
952: FD_SET(c->sock, writeset);
953: }
954:
1.127 itojun 955: static void
1.367 djm 956: channel_pre_open(struct ssh *ssh, Channel *c,
957: fd_set *readset, fd_set *writeset)
1.41 markus 958: {
1.44 markus 959: if (c->istate == CHAN_INPUT_OPEN &&
1.358 djm 960: c->remote_window > 0 &&
1.367 djm 961: sshbuf_len(c->input) < c->remote_window &&
962: sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
1.44 markus 963: FD_SET(c->rfd, readset);
964: if (c->ostate == CHAN_OUTPUT_OPEN ||
965: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.367 djm 966: if (sshbuf_len(c->output) > 0) {
1.44 markus 967: FD_SET(c->wfd, writeset);
968: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 969: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.367 djm 970: debug2("channel %d: "
971: "obuf_empty delayed efd %d/(%zu)", c->self,
972: c->efd, sshbuf_len(c->extended));
1.172 markus 973: else
1.367 djm 974: chan_obuf_empty(ssh, c);
1.44 markus 975: }
976: }
977: /** XXX check close conditions, too */
1.358 djm 978: if (c->efd != -1 && !(c->istate == CHAN_INPUT_CLOSED &&
979: c->ostate == CHAN_OUTPUT_CLOSED)) {
1.44 markus 980: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1.367 djm 981: sshbuf_len(c->extended) > 0)
1.44 markus 982: FD_SET(c->efd, writeset);
1.306 djm 983: else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
984: (c->extended_usage == CHAN_EXTENDED_READ ||
985: c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.367 djm 986: sshbuf_len(c->extended) < c->remote_window)
1.44 markus 987: FD_SET(c->efd, readset);
988: }
1.204 djm 989: /* XXX: What about efd? races? */
1.44 markus 990: }
991:
1.41 markus 992: /*
993: * This is a special state for X11 authentication spoofing. An opened X11
994: * connection (when authentication spoofing is being done) remains in this
995: * state until the first packet has been completely read. The authentication
996: * data in that packet is then substituted by the real data if it matches the
997: * fake data, and the channel is put into normal mode.
1.51 markus 998: * XXX All this happens at the client side.
1.121 markus 999: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 1000: */
1.127 itojun 1001: static int
1.367 djm 1002: x11_open_helper(struct ssh *ssh, struct sshbuf *b)
1.1 deraadt 1003: {
1.367 djm 1004: struct ssh_channels *sc = ssh->chanctxt;
1.77 markus 1005: u_char *ucp;
1006: u_int proto_len, data_len;
1.25 markus 1007:
1.347 djm 1008: /* Is this being called after the refusal deadline? */
1.367 djm 1009: if (sc->x11_refuse_time != 0 &&
1010: (u_int)monotime() >= sc->x11_refuse_time) {
1.347 djm 1011: verbose("Rejected X11 connection after ForwardX11Timeout "
1012: "expired");
1013: return -1;
1014: }
1015:
1.41 markus 1016: /* Check if the fixed size part of the packet is in buffer. */
1.367 djm 1017: if (sshbuf_len(b) < 12)
1.41 markus 1018: return 0;
1019:
1020: /* Parse the lengths of variable-length fields. */
1.367 djm 1021: ucp = sshbuf_mutable_ptr(b);
1.41 markus 1022: if (ucp[0] == 0x42) { /* Byte order MSB first. */
1023: proto_len = 256 * ucp[6] + ucp[7];
1024: data_len = 256 * ucp[8] + ucp[9];
1025: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
1026: proto_len = ucp[6] + 256 * ucp[7];
1027: data_len = ucp[8] + 256 * ucp[9];
1028: } else {
1.194 markus 1029: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 1030: ucp[0]);
1.41 markus 1031: return -1;
1032: }
1033:
1034: /* Check if the whole packet is in buffer. */
1.367 djm 1035: if (sshbuf_len(b) <
1.41 markus 1036: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
1037: return 0;
1038:
1039: /* Check if authentication protocol matches. */
1.367 djm 1040: if (proto_len != strlen(sc->x11_saved_proto) ||
1041: memcmp(ucp + 12, sc->x11_saved_proto, proto_len) != 0) {
1.194 markus 1042: debug2("X11 connection uses different authentication protocol.");
1.41 markus 1043: return -1;
1044: }
1045: /* Check if authentication data matches our fake data. */
1.367 djm 1046: if (data_len != sc->x11_fake_data_len ||
1.308 djm 1047: timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
1.367 djm 1048: sc->x11_fake_data, sc->x11_fake_data_len) != 0) {
1.194 markus 1049: debug2("X11 auth data does not match fake data.");
1.41 markus 1050: return -1;
1051: }
1052: /* Check fake data length */
1.367 djm 1053: if (sc->x11_fake_data_len != sc->x11_saved_data_len) {
1.41 markus 1054: error("X11 fake_data_len %d != saved_data_len %d",
1.367 djm 1055: sc->x11_fake_data_len, sc->x11_saved_data_len);
1.41 markus 1056: return -1;
1057: }
1058: /*
1059: * Received authentication protocol and data match
1060: * our fake data. Substitute the fake data with real
1061: * data.
1062: */
1063: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
1.367 djm 1064: sc->x11_saved_data, sc->x11_saved_data_len);
1.41 markus 1065: return 1;
1066: }
1067:
1.127 itojun 1068: static void
1.367 djm 1069: channel_pre_x11_open(struct ssh *ssh, Channel *c,
1070: fd_set *readset, fd_set *writeset)
1.41 markus 1071: {
1.367 djm 1072: int ret = x11_open_helper(ssh, c->output);
1.133 markus 1073:
1074: /* c->force_drain = 1; */
1075:
1.41 markus 1076: if (ret == 1) {
1077: c->type = SSH_CHANNEL_OPEN;
1.367 djm 1078: channel_pre_open(ssh, c, readset, writeset);
1.41 markus 1079: } else if (ret == -1) {
1.188 itojun 1080: logit("X11 connection rejected because of wrong authentication.");
1.367 djm 1081: debug2("X11 rejected %d i%d/o%d",
1082: c->self, c->istate, c->ostate);
1083: chan_read_failed(ssh, c);
1084: sshbuf_reset(c->input);
1085: chan_ibuf_empty(ssh, c);
1086: sshbuf_reset(c->output);
1087: chan_write_failed(ssh, c);
1.194 markus 1088: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 1089: }
1090: }
1.25 markus 1091:
1.302 djm 1092: static void
1.367 djm 1093: channel_pre_mux_client(struct ssh *ssh,
1094: Channel *c, fd_set *readset, fd_set *writeset)
1.302 djm 1095: {
1.304 djm 1096: if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1.367 djm 1097: sshbuf_check_reserve(c->input, CHAN_RBUF) == 0)
1.302 djm 1098: FD_SET(c->rfd, readset);
1099: if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1100: /* clear buffer immediately (discard any partial packet) */
1.367 djm 1101: sshbuf_reset(c->input);
1102: chan_ibuf_empty(ssh, c);
1.302 djm 1103: /* Start output drain. XXX just kill chan? */
1.367 djm 1104: chan_rcvd_oclose(ssh, c);
1.302 djm 1105: }
1106: if (c->ostate == CHAN_OUTPUT_OPEN ||
1107: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.367 djm 1108: if (sshbuf_len(c->output) > 0)
1.302 djm 1109: FD_SET(c->wfd, writeset);
1110: else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1.367 djm 1111: chan_obuf_empty(ssh, c);
1.302 djm 1112: }
1113: }
1114:
1.104 markus 1115: /* try to decode a socks4 header */
1.127 itojun 1116: static int
1.367 djm 1117: channel_decode_socks4(struct ssh *ssh, Channel *c,
1118: fd_set *readset, fd_set *writeset)
1.103 markus 1119: {
1.367 djm 1120: const u_char *p;
1121: char *host;
1.292 djm 1122: u_int len, have, i, found, need;
1.148 deraadt 1123: char username[256];
1.103 markus 1124: struct {
1125: u_int8_t version;
1126: u_int8_t command;
1127: u_int16_t dest_port;
1.104 markus 1128: struct in_addr dest_addr;
1.103 markus 1129: } s4_req, s4_rsp;
1.367 djm 1130: int r;
1.103 markus 1131:
1.104 markus 1132: debug2("channel %d: decode socks4", c->self);
1.109 markus 1133:
1.367 djm 1134: have = sshbuf_len(c->input);
1.109 markus 1135: len = sizeof(s4_req);
1136: if (have < len)
1137: return 0;
1.367 djm 1138: p = sshbuf_ptr(c->input);
1.292 djm 1139:
1140: need = 1;
1141: /* SOCKS4A uses an invalid IP address 0.0.0.x */
1142: if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1143: debug2("channel %d: socks4a request", c->self);
1144: /* ... and needs an extra string (the hostname) */
1145: need = 2;
1146: }
1147: /* Check for terminating NUL on the string(s) */
1.109 markus 1148: for (found = 0, i = len; i < have; i++) {
1149: if (p[i] == '\0') {
1.292 djm 1150: found++;
1151: if (found == need)
1152: break;
1.109 markus 1153: }
1154: if (i > 1024) {
1155: /* the peer is probably sending garbage */
1156: debug("channel %d: decode socks4: too long",
1157: c->self);
1158: return -1;
1159: }
1160: }
1.292 djm 1161: if (found < need)
1.109 markus 1162: return 0;
1.367 djm 1163: if ((r = sshbuf_get(c->input, &s4_req.version, 1)) != 0 ||
1164: (r = sshbuf_get(c->input, &s4_req.command, 1)) != 0 ||
1165: (r = sshbuf_get(c->input, &s4_req.dest_port, 2)) != 0 ||
1166: (r = sshbuf_get(c->input, &s4_req.dest_addr, 4)) != 0) {
1167: debug("channels %d: decode socks4: %s", c->self, ssh_err(r));
1168: return -1;
1169: }
1170: have = sshbuf_len(c->input);
1171: p = sshbuf_ptr(c->input);
1.364 djm 1172: if (memchr(p, '\0', have) == NULL) {
1173: error("channel %d: decode socks4: user not nul terminated",
1.331 djm 1174: c->self);
1.364 djm 1175: return -1;
1176: }
1.103 markus 1177: len = strlen(p);
1.106 markus 1178: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.367 djm 1179: len++; /* trailing '\0' */
1.103 markus 1180: strlcpy(username, p, sizeof(username));
1.367 djm 1181: if ((r = sshbuf_consume(c->input, len)) != 0) {
1182: fatal("%s: channel %d: consume: %s", __func__,
1183: c->self, ssh_err(r));
1184: }
1.321 djm 1185: free(c->path);
1186: c->path = NULL;
1.292 djm 1187: if (need == 1) { /* SOCKS4: one string */
1188: host = inet_ntoa(s4_req.dest_addr);
1.293 djm 1189: c->path = xstrdup(host);
1.292 djm 1190: } else { /* SOCKS4A: two strings */
1.367 djm 1191: have = sshbuf_len(c->input);
1192: p = sshbuf_ptr(c->input);
1.364 djm 1193: if (memchr(p, '\0', have) == NULL) {
1194: error("channel %d: decode socks4a: host not nul "
1195: "terminated", c->self);
1196: return -1;
1197: }
1.292 djm 1198: len = strlen(p);
1199: debug2("channel %d: decode socks4a: host %s/%d",
1200: c->self, p, len);
1201: len++; /* trailing '\0' */
1.293 djm 1202: if (len > NI_MAXHOST) {
1.292 djm 1203: error("channel %d: hostname \"%.100s\" too long",
1204: c->self, p);
1205: return -1;
1206: }
1.293 djm 1207: c->path = xstrdup(p);
1.367 djm 1208: if ((r = sshbuf_consume(c->input, len)) != 0) {
1209: fatal("%s: channel %d: consume: %s", __func__,
1210: c->self, ssh_err(r));
1211: }
1.292 djm 1212: }
1.103 markus 1213: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 1214:
1.194 markus 1215: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.292 djm 1216: c->self, c->path, c->host_port, s4_req.command);
1.103 markus 1217:
1.104 markus 1218: if (s4_req.command != 1) {
1.292 djm 1219: debug("channel %d: cannot handle: %s cn %d",
1220: c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1.104 markus 1221: return -1;
1.103 markus 1222: }
1.104 markus 1223: s4_rsp.version = 0; /* vn: 0 for reply */
1224: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 1225: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 1226: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.367 djm 1227: if ((r = sshbuf_put(c->output, &s4_rsp, sizeof(s4_rsp))) != 0) {
1228: fatal("%s: channel %d: append reply: %s", __func__,
1229: c->self, ssh_err(r));
1230: }
1.104 markus 1231: return 1;
1232: }
1233:
1.193 markus 1234: /* try to decode a socks5 header */
1235: #define SSH_SOCKS5_AUTHDONE 0x1000
1236: #define SSH_SOCKS5_NOAUTH 0x00
1237: #define SSH_SOCKS5_IPV4 0x01
1238: #define SSH_SOCKS5_DOMAIN 0x03
1239: #define SSH_SOCKS5_IPV6 0x04
1240: #define SSH_SOCKS5_CONNECT 0x01
1241: #define SSH_SOCKS5_SUCCESS 0x00
1242:
1243: static int
1.367 djm 1244: channel_decode_socks5(struct ssh *ssh, Channel *c,
1245: fd_set *readset, fd_set *writeset)
1.193 markus 1246: {
1.367 djm 1247: /* XXX use get/put_u8 instead of trusting struct padding */
1.193 markus 1248: struct {
1249: u_int8_t version;
1250: u_int8_t command;
1251: u_int8_t reserved;
1252: u_int8_t atyp;
1253: } s5_req, s5_rsp;
1254: u_int16_t dest_port;
1.324 djm 1255: char dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1.367 djm 1256: const u_char *p;
1.252 djm 1257: u_int have, need, i, found, nmethods, addrlen, af;
1.367 djm 1258: int r;
1.193 markus 1259:
1260: debug2("channel %d: decode socks5", c->self);
1.367 djm 1261: p = sshbuf_ptr(c->input);
1.193 markus 1262: if (p[0] != 0x05)
1263: return -1;
1.367 djm 1264: have = sshbuf_len(c->input);
1.193 markus 1265: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1266: /* format: ver | nmethods | methods */
1.198 djm 1267: if (have < 2)
1.193 markus 1268: return 0;
1269: nmethods = p[1];
1270: if (have < nmethods + 2)
1271: return 0;
1272: /* look for method: "NO AUTHENTICATION REQUIRED" */
1.268 stevesk 1273: for (found = 0, i = 2; i < nmethods + 2; i++) {
1.264 stevesk 1274: if (p[i] == SSH_SOCKS5_NOAUTH) {
1.193 markus 1275: found = 1;
1276: break;
1277: }
1278: }
1279: if (!found) {
1280: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1281: c->self);
1282: return -1;
1283: }
1.367 djm 1284: if ((r = sshbuf_consume(c->input, nmethods + 2)) != 0) {
1285: fatal("%s: channel %d: consume: %s", __func__,
1286: c->self, ssh_err(r));
1287: }
1288: /* version, method */
1289: if ((r = sshbuf_put_u8(c->output, 0x05)) != 0 ||
1290: (r = sshbuf_put_u8(c->output, SSH_SOCKS5_NOAUTH)) != 0) {
1291: fatal("%s: channel %d: append reply: %s", __func__,
1292: c->self, ssh_err(r));
1293: }
1.193 markus 1294: FD_SET(c->sock, writeset);
1295: c->flags |= SSH_SOCKS5_AUTHDONE;
1296: debug2("channel %d: socks5 auth done", c->self);
1297: return 0; /* need more */
1298: }
1299: debug2("channel %d: socks5 post auth", c->self);
1300: if (have < sizeof(s5_req)+1)
1301: return 0; /* need more */
1.247 deraadt 1302: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1303: if (s5_req.version != 0x05 ||
1304: s5_req.command != SSH_SOCKS5_CONNECT ||
1305: s5_req.reserved != 0x00) {
1.194 markus 1306: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1307: return -1;
1308: }
1.213 deraadt 1309: switch (s5_req.atyp){
1.193 markus 1310: case SSH_SOCKS5_IPV4:
1311: addrlen = 4;
1312: af = AF_INET;
1313: break;
1314: case SSH_SOCKS5_DOMAIN:
1315: addrlen = p[sizeof(s5_req)];
1316: af = -1;
1317: break;
1318: case SSH_SOCKS5_IPV6:
1319: addrlen = 16;
1320: af = AF_INET6;
1321: break;
1322: default:
1.194 markus 1323: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1324: return -1;
1325: }
1.252 djm 1326: need = sizeof(s5_req) + addrlen + 2;
1327: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1328: need++;
1329: if (have < need)
1.193 markus 1330: return 0;
1.367 djm 1331: if ((r = sshbuf_consume(c->input, sizeof(s5_req))) != 0) {
1332: fatal("%s: channel %d: consume: %s", __func__,
1333: c->self, ssh_err(r));
1334: }
1335: if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1336: /* host string length */
1337: if ((r = sshbuf_consume(c->input, 1)) != 0) {
1338: fatal("%s: channel %d: consume: %s", __func__,
1339: c->self, ssh_err(r));
1340: }
1341: }
1342: if ((r = sshbuf_get(c->input, &dest_addr, addrlen)) != 0 ||
1343: (r = sshbuf_get(c->input, &dest_port, 2)) != 0) {
1344: debug("channel %d: parse addr/port: %s", c->self, ssh_err(r));
1345: return -1;
1346: }
1.193 markus 1347: dest_addr[addrlen] = '\0';
1.321 djm 1348: free(c->path);
1349: c->path = NULL;
1.293 djm 1350: if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1.294 djm 1351: if (addrlen >= NI_MAXHOST) {
1.293 djm 1352: error("channel %d: dynamic request: socks5 hostname "
1353: "\"%.100s\" too long", c->self, dest_addr);
1354: return -1;
1355: }
1356: c->path = xstrdup(dest_addr);
1357: } else {
1358: if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1359: return -1;
1360: c->path = xstrdup(ntop);
1361: }
1.193 markus 1362: c->host_port = ntohs(dest_port);
1.198 djm 1363:
1.194 markus 1364: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1365: c->self, c->path, c->host_port, s5_req.command);
1366:
1367: s5_rsp.version = 0x05;
1368: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1369: s5_rsp.reserved = 0; /* ignored */
1370: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1371: dest_port = 0; /* ignored */
1372:
1.367 djm 1373: if ((r = sshbuf_put(c->output, &s5_rsp, sizeof(s5_rsp))) != 0 ||
1374: (r = sshbuf_put_u32(c->output, ntohl(INADDR_ANY))) != 0 ||
1375: (r = sshbuf_put(c->output, &dest_port, sizeof(dest_port))) != 0)
1376: fatal("%s: channel %d: append reply: %s", __func__,
1377: c->self, ssh_err(r));
1.193 markus 1378: return 1;
1.301 dtucker 1379: }
1380:
1381: Channel *
1.367 djm 1382: channel_connect_stdio_fwd(struct ssh *ssh,
1383: const char *host_to_connect, u_short port_to_connect, int in, int out)
1.301 dtucker 1384: {
1385: Channel *c;
1386:
1.367 djm 1387: debug("%s %s:%d", __func__, host_to_connect, port_to_connect);
1.301 dtucker 1388:
1.367 djm 1389: c = channel_new(ssh, "stdio-forward", SSH_CHANNEL_OPENING, in, out,
1.301 dtucker 1390: -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1391: 0, "stdio-forward", /*nonblock*/0);
1392:
1393: c->path = xstrdup(host_to_connect);
1394: c->host_port = port_to_connect;
1395: c->listening_port = 0;
1396: c->force_drain = 1;
1397:
1.367 djm 1398: channel_register_fds(ssh, c, in, out, -1, 0, 1, 0);
1399: port_open_helper(ssh, c, "direct-tcpip");
1.301 dtucker 1400:
1401: return c;
1.193 markus 1402: }
1403:
1.104 markus 1404: /* dynamic port forwarding */
1.127 itojun 1405: static void
1.367 djm 1406: channel_pre_dynamic(struct ssh *ssh, Channel *c,
1407: fd_set *readset, fd_set *writeset)
1.104 markus 1408: {
1.367 djm 1409: const u_char *p;
1.217 djm 1410: u_int have;
1411: int ret;
1.103 markus 1412:
1.367 djm 1413: have = sshbuf_len(c->input);
1.104 markus 1414: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.367 djm 1415: /* sshbuf_dump(c->input, stderr); */
1.104 markus 1416: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1417: if (have < 3) {
1.104 markus 1418: /* need more */
1419: FD_SET(c->sock, readset);
1420: return;
1421: }
1422: /* try to guess the protocol */
1.367 djm 1423: p = sshbuf_ptr(c->input);
1424: /* XXX sshbuf_peek_u8? */
1.104 markus 1425: switch (p[0]) {
1426: case 0x04:
1.367 djm 1427: ret = channel_decode_socks4(ssh, c, readset, writeset);
1.193 markus 1428: break;
1429: case 0x05:
1.367 djm 1430: ret = channel_decode_socks5(ssh, c, readset, writeset);
1.104 markus 1431: break;
1432: default:
1433: ret = -1;
1434: break;
1435: }
1436: if (ret < 0) {
1.367 djm 1437: chan_mark_dead(ssh, c);
1.104 markus 1438: } else if (ret == 0) {
1439: debug2("channel %d: pre_dynamic: need more", c->self);
1440: /* need more */
1441: FD_SET(c->sock, readset);
1442: } else {
1443: /* switch to the next state */
1444: c->type = SSH_CHANNEL_OPENING;
1.367 djm 1445: port_open_helper(ssh, c, "direct-tcpip");
1.104 markus 1446: }
1.103 markus 1447: }
1448:
1.41 markus 1449: /* This is our fake X11 server socket. */
1.127 itojun 1450: static void
1.367 djm 1451: channel_post_x11_listener(struct ssh *ssh, Channel *c,
1452: fd_set *readset, fd_set *writeset)
1.41 markus 1453: {
1.113 markus 1454: Channel *nc;
1.285 djm 1455: struct sockaddr_storage addr;
1.367 djm 1456: int r, newsock, oerrno, remote_port;
1.41 markus 1457: socklen_t addrlen;
1.85 markus 1458: char buf[16384], *remote_ipaddr;
1.25 markus 1459:
1.367 djm 1460: if (!FD_ISSET(c->sock, readset))
1461: return;
1462:
1463: debug("X11 connection requested.");
1464: addrlen = sizeof(addr);
1465: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1466: if (c->single_connection) {
1467: oerrno = errno;
1468: debug2("single_connection: closing X11 listener.");
1469: channel_close_fd(ssh, &c->sock);
1470: chan_mark_dead(ssh, c);
1471: errno = oerrno;
1472: }
1473: if (newsock < 0) {
1474: if (errno != EINTR && errno != EWOULDBLOCK &&
1475: errno != ECONNABORTED)
1476: error("accept: %.100s", strerror(errno));
1477: if (errno == EMFILE || errno == ENFILE)
1478: c->notbefore = monotime() + 1;
1479: return;
1480: }
1481: set_nodelay(newsock);
1482: remote_ipaddr = get_peer_ipaddr(newsock);
1483: remote_port = get_peer_port(newsock);
1484: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1485: remote_ipaddr, remote_port);
1486:
1487: nc = channel_new(ssh, "accepted x11 socket",
1488: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1489: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1490: open_preamble(ssh, __func__, nc, "x11");
1491: if ((r = sshpkt_put_cstring(ssh, remote_ipaddr)) != 0) {
1492: fatal("%s: channel %i: reply %s", __func__,
1493: c->self, ssh_err(r));
1494: }
1495: if ((datafellows & SSH_BUG_X11FWD) != 0)
1496: debug2("channel %d: ssh2 x11 bug compat mode", nc->self);
1497: else if ((r = sshpkt_put_u32(ssh, remote_port)) != 0) {
1498: fatal("%s: channel %i: reply %s", __func__,
1499: c->self, ssh_err(r));
1.41 markus 1500: }
1.367 djm 1501: if ((r = sshpkt_send(ssh)) != 0)
1502: fatal("%s: channel %i: send %s", __func__, c->self, ssh_err(r));
1503: free(remote_ipaddr);
1.41 markus 1504: }
1.25 markus 1505:
1.127 itojun 1506: static void
1.367 djm 1507: port_open_helper(struct ssh *ssh, Channel *c, char *rtype)
1.103 markus 1508: {
1.328 djm 1509: char *local_ipaddr = get_local_ipaddr(c->sock);
1.350 djm 1510: int local_port = c->sock == -1 ? 65536 : get_local_port(c->sock);
1.103 markus 1511: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1512: int remote_port = get_peer_port(c->sock);
1.367 djm 1513: int r;
1.303 djm 1514:
1515: if (remote_port == -1) {
1516: /* Fake addr/port to appease peers that validate it (Tectia) */
1.321 djm 1517: free(remote_ipaddr);
1.303 djm 1518: remote_ipaddr = xstrdup("127.0.0.1");
1519: remote_port = 65535;
1520: }
1.103 markus 1521:
1.367 djm 1522: free(c->remote_name);
1523: xasprintf(&c->remote_name,
1.103 markus 1524: "%s: listening port %d for %.100s port %d, "
1.328 djm 1525: "connect from %.200s port %d to %.100s port %d",
1.103 markus 1526: rtype, c->listening_port, c->path, c->host_port,
1.328 djm 1527: remote_ipaddr, remote_port, local_ipaddr, local_port);
1.103 markus 1528:
1.367 djm 1529: open_preamble(ssh, __func__, c, rtype);
1.358 djm 1530: if (strcmp(rtype, "direct-tcpip") == 0) {
1531: /* target host, port */
1.367 djm 1532: if ((r = sshpkt_put_cstring(ssh, c->path)) != 0 ||
1533: (r = sshpkt_put_u32(ssh, c->host_port)) != 0) {
1534: fatal("%s: channel %i: reply %s", __func__,
1535: c->self, ssh_err(r));
1536: }
1.358 djm 1537: } else if (strcmp(rtype, "direct-streamlocal@openssh.com") == 0) {
1538: /* target path */
1.367 djm 1539: if ((r = sshpkt_put_cstring(ssh, c->path)) != 0) {
1540: fatal("%s: channel %i: reply %s", __func__,
1541: c->self, ssh_err(r));
1542: }
1.358 djm 1543: } else if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1544: /* listen path */
1.367 djm 1545: if ((r = sshpkt_put_cstring(ssh, c->path)) != 0) {
1546: fatal("%s: channel %i: reply %s", __func__,
1547: c->self, ssh_err(r));
1548: }
1.103 markus 1549: } else {
1.358 djm 1550: /* listen address, port */
1.367 djm 1551: if ((r = sshpkt_put_cstring(ssh, c->path)) != 0 ||
1552: (r = sshpkt_put_u32(ssh, local_port)) != 0) {
1553: fatal("%s: channel %i: reply %s", __func__,
1554: c->self, ssh_err(r));
1555: }
1.358 djm 1556: }
1557: if (strcmp(rtype, "forwarded-streamlocal@openssh.com") == 0) {
1558: /* reserved for future owner/mode info */
1.367 djm 1559: if ((r = sshpkt_put_cstring(ssh, "")) != 0) {
1560: fatal("%s: channel %i: reply %s", __func__,
1561: c->self, ssh_err(r));
1562: }
1.358 djm 1563: } else {
1564: /* originator host and port */
1.367 djm 1565: if ((r = sshpkt_put_cstring(ssh, remote_ipaddr)) != 0 ||
1566: (r = sshpkt_put_u32(ssh, (u_int)remote_port)) != 0) {
1567: fatal("%s: channel %i: reply %s", __func__,
1568: c->self, ssh_err(r));
1569: }
1.103 markus 1570: }
1.367 djm 1571: if ((r = sshpkt_send(ssh)) != 0)
1572: fatal("%s: channel %i: send %s", __func__, c->self, ssh_err(r));
1.321 djm 1573: free(remote_ipaddr);
1.328 djm 1574: free(local_ipaddr);
1.103 markus 1575: }
1576:
1.226 djm 1577: static void
1578: channel_set_reuseaddr(int fd)
1579: {
1580: int on = 1;
1581:
1582: /*
1583: * Set socket options.
1584: * Allow local port reuse in TIME_WAIT.
1585: */
1586: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1587: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1.347 djm 1588: }
1589:
1590: void
1.367 djm 1591: channel_set_x11_refuse_time(struct ssh *ssh, u_int refuse_time)
1.347 djm 1592: {
1.367 djm 1593: ssh->chanctxt->x11_refuse_time = refuse_time;
1.226 djm 1594: }
1595:
1.41 markus 1596: /*
1597: * This socket is listening for connections to a forwarded TCP/IP port.
1598: */
1.127 itojun 1599: static void
1.367 djm 1600: channel_post_port_listener(struct ssh *ssh, Channel *c,
1601: fd_set *readset, fd_set *writeset)
1.41 markus 1602: {
1.103 markus 1603: Channel *nc;
1.285 djm 1604: struct sockaddr_storage addr;
1.113 markus 1605: int newsock, nextstate;
1.41 markus 1606: socklen_t addrlen;
1.103 markus 1607: char *rtype;
1.73 markus 1608:
1.367 djm 1609: if (!FD_ISSET(c->sock, readset))
1610: return;
1611:
1612: debug("Connection to port %d forwarding to %.100s port %d requested.",
1613: c->listening_port, c->path, c->host_port);
1.103 markus 1614:
1.367 djm 1615: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1616: nextstate = SSH_CHANNEL_OPENING;
1617: rtype = "forwarded-tcpip";
1618: } else if (c->type == SSH_CHANNEL_RUNIX_LISTENER) {
1619: nextstate = SSH_CHANNEL_OPENING;
1620: rtype = "forwarded-streamlocal@openssh.com";
1621: } else if (c->host_port == PORT_STREAMLOCAL) {
1622: nextstate = SSH_CHANNEL_OPENING;
1623: rtype = "direct-streamlocal@openssh.com";
1624: } else if (c->host_port == 0) {
1625: nextstate = SSH_CHANNEL_DYNAMIC;
1626: rtype = "dynamic-tcpip";
1627: } else {
1628: nextstate = SSH_CHANNEL_OPENING;
1629: rtype = "direct-tcpip";
1630: }
1.103 markus 1631:
1.367 djm 1632: addrlen = sizeof(addr);
1633: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1634: if (newsock < 0) {
1635: if (errno != EINTR && errno != EWOULDBLOCK &&
1636: errno != ECONNABORTED)
1637: error("accept: %.100s", strerror(errno));
1638: if (errno == EMFILE || errno == ENFILE)
1639: c->notbefore = monotime() + 1;
1640: return;
1.41 markus 1641: }
1.367 djm 1642: if (c->host_port != PORT_STREAMLOCAL)
1643: set_nodelay(newsock);
1644: nc = channel_new(ssh, rtype, nextstate, newsock, newsock, -1,
1645: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1646: nc->listening_port = c->listening_port;
1647: nc->host_port = c->host_port;
1648: if (c->path != NULL)
1649: nc->path = xstrdup(c->path);
1650:
1651: if (nextstate != SSH_CHANNEL_DYNAMIC)
1652: port_open_helper(ssh, nc, rtype);
1.41 markus 1653: }
1.25 markus 1654:
1.41 markus 1655: /*
1656: * This is the authentication agent socket listening for connections from
1657: * clients.
1658: */
1.127 itojun 1659: static void
1.367 djm 1660: channel_post_auth_listener(struct ssh *ssh, Channel *c,
1661: fd_set *readset, fd_set *writeset)
1.41 markus 1662: {
1.113 markus 1663: Channel *nc;
1.367 djm 1664: int r, newsock;
1.285 djm 1665: struct sockaddr_storage addr;
1.41 markus 1666: socklen_t addrlen;
1.25 markus 1667:
1.367 djm 1668: if (!FD_ISSET(c->sock, readset))
1669: return;
1670:
1671: addrlen = sizeof(addr);
1672: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1673: if (newsock < 0) {
1674: error("accept from auth socket: %.100s", strerror(errno));
1675: if (errno == EMFILE || errno == ENFILE)
1676: c->notbefore = monotime() + 1;
1677: return;
1.41 markus 1678: }
1.367 djm 1679: nc = channel_new(ssh, "accepted auth socket",
1680: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1681: c->local_window_max, c->local_maxpacket,
1682: 0, "accepted auth socket", 1);
1683: open_preamble(ssh, __func__, nc, "auth-agent@openssh.com");
1684: if ((r = sshpkt_send(ssh)) != 0)
1685: fatal("%s: channel %i: %s", __func__, c->self, ssh_err(r));
1.41 markus 1686: }
1.25 markus 1687:
1.127 itojun 1688: static void
1.367 djm 1689: channel_post_connecting(struct ssh *ssh, Channel *c,
1690: fd_set *readset, fd_set *writeset)
1.75 markus 1691: {
1.367 djm 1692: int err = 0, sock, r;
1.129 stevesk 1693: socklen_t sz = sizeof(err);
1.114 markus 1694:
1.367 djm 1695: if (!FD_ISSET(c->sock, writeset))
1696: return;
1.368 ! djm 1697: if (!c->have_remote_id)
! 1698: fatal(":%s: channel %d: no remote id", __func__, c->self);
1.367 djm 1699:
1700: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1701: err = errno;
1702: error("getsockopt SO_ERROR failed");
1703: }
1704: if (err == 0) {
1705: debug("channel %d: connected to %s port %d",
1706: c->self, c->connect_ctx.host, c->connect_ctx.port);
1707: channel_connect_ctx_free(&c->connect_ctx);
1708: c->type = SSH_CHANNEL_OPEN;
1709: if ((r = sshpkt_start(ssh,
1710: SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
1711: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1712: (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
1713: (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
1714: (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0) {
1715: fatal("%s: channel %i: confirm: %s", __func__,
1716: c->self, ssh_err(r));
1717: }
1718: } else {
1719: debug("channel %d: connection failed: %s",
1720: c->self, strerror(err));
1721: /* Try next address, if any */
1722: if ((sock = connect_next(&c->connect_ctx)) > 0) {
1723: close(c->sock);
1724: c->sock = c->rfd = c->wfd = sock;
1725: channel_find_maxfd(ssh->chanctxt);
1726: return;
1727: }
1728: /* Exhausted all addresses */
1729: error("connect_to %.100s port %d: failed.",
1730: c->connect_ctx.host, c->connect_ctx.port);
1731: channel_connect_ctx_free(&c->connect_ctx);
1732: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
1733: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1734: (r = sshpkt_put_u32(ssh, SSH2_OPEN_CONNECT_FAILED)) != 0) {
1735: fatal("%s: channel %i: failure: %s", __func__,
1736: c->self, ssh_err(r));
1737: }
1738: if ((datafellows & SSH_BUG_OPENFAILURE) == 0 &&
1739: ((r = sshpkt_put_cstring(ssh, strerror(err))) != 0 ||
1740: (r = sshpkt_put_cstring(ssh, "")) != 0)) {
1741: fatal("%s: channel %i: failure: %s", __func__,
1742: c->self, ssh_err(r));
1.75 markus 1743: }
1.367 djm 1744: chan_mark_dead(ssh, c);
1.75 markus 1745: }
1.367 djm 1746: if ((r = sshpkt_send(ssh)) != 0)
1747: fatal("%s: channel %i: %s", __func__, c->self, ssh_err(r));
1.75 markus 1748: }
1749:
1.127 itojun 1750: static int
1.367 djm 1751: channel_handle_rfd(struct ssh *ssh, Channel *c,
1752: fd_set *readset, fd_set *writeset)
1.41 markus 1753: {
1.214 markus 1754: char buf[CHAN_RBUF];
1.367 djm 1755: ssize_t len;
1756: int r;
1.25 markus 1757:
1.367 djm 1758: if (c->rfd == -1 || !FD_ISSET(c->rfd, readset))
1759: return 1;
1760:
1761: len = read(c->rfd, buf, sizeof(buf));
1762: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1763: return 1;
1764: if (len <= 0) {
1765: debug2("channel %d: read<=0 rfd %d len %zd",
1766: c->self, c->rfd, len);
1767: if (c->type != SSH_CHANNEL_OPEN) {
1768: debug2("channel %d: not open", c->self);
1769: chan_mark_dead(ssh, c);
1.41 markus 1770: return -1;
1.65 markus 1771: } else {
1.367 djm 1772: chan_read_failed(ssh, c);
1.65 markus 1773: }
1.367 djm 1774: return -1;
1775: }
1776: if (c->input_filter != NULL) {
1777: if (c->input_filter(ssh, c, buf, len) == -1) {
1778: debug2("channel %d: filter stops", c->self);
1779: chan_read_failed(ssh, c);
1780: }
1781: } else if (c->datagram) {
1782: if ((r = sshbuf_put_string(c->input, buf, len)) != 0)
1783: fatal("%s: channel %d: put datagram: %s", __func__,
1784: c->self, ssh_err(r));
1785: } else if ((r = sshbuf_put(c->input, buf, len)) != 0) {
1786: fatal("%s: channel %d: put data: %s", __func__,
1787: c->self, ssh_err(r));
1.41 markus 1788: }
1789: return 1;
1790: }
1.241 deraadt 1791:
1.127 itojun 1792: static int
1.367 djm 1793: channel_handle_wfd(struct ssh *ssh, Channel *c,
1794: fd_set *readset, fd_set *writeset)
1.41 markus 1795: {
1.95 markus 1796: struct termios tio;
1.367 djm 1797: u_char *data = NULL, *buf; /* XXX const; need filter API change */
1798: size_t dlen, olen = 0;
1799: int r, len;
1800:
1801: if (c->wfd == -1 || !FD_ISSET(c->wfd, writeset) ||
1802: sshbuf_len(c->output) == 0)
1803: return 1;
1.25 markus 1804:
1.41 markus 1805: /* Send buffered output data to the socket. */
1.367 djm 1806: olen = sshbuf_len(c->output);
1807: if (c->output_filter != NULL) {
1808: if ((buf = c->output_filter(ssh, c, &data, &dlen)) == NULL) {
1809: debug2("channel %d: filter stops", c->self);
1810: if (c->type != SSH_CHANNEL_OPEN)
1811: chan_mark_dead(ssh, c);
1812: else
1813: chan_write_failed(ssh, c);
1814: return -1;
1.231 reyk 1815: }
1.367 djm 1816: } else if (c->datagram) {
1817: if ((r = sshbuf_get_string(c->output, &data, &dlen)) != 0)
1818: fatal("%s: channel %d: get datagram: %s", __func__,
1819: c->self, ssh_err(r));
1820: } else {
1821: buf = data = sshbuf_mutable_ptr(c->output);
1822: dlen = sshbuf_len(c->output);
1823: }
1.231 reyk 1824:
1.367 djm 1825: if (c->datagram) {
1826: /* ignore truncated writes, datagrams might get lost */
1827: len = write(c->wfd, data, dlen);
1828: free(data);
1.53 markus 1829: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1830: return 1;
1.367 djm 1831: if (len <= 0)
1832: goto write_fail;
1833: goto out;
1834: }
1835:
1836: len = write(c->wfd, buf, dlen);
1837: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1838: return 1;
1839: if (len <= 0) {
1840: write_fail:
1841: if (c->type != SSH_CHANNEL_OPEN) {
1842: debug2("channel %d: not open", c->self);
1843: chan_mark_dead(ssh, c);
1.41 markus 1844: return -1;
1.367 djm 1845: } else {
1846: chan_write_failed(ssh, c);
1.91 markus 1847: }
1.367 djm 1848: return -1;
1849: }
1850: if (c->isatty && dlen >= 1 && buf[0] != '\r') {
1851: if (tcgetattr(c->wfd, &tio) == 0 &&
1852: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1853: /*
1854: * Simulate echo to reduce the impact of
1855: * traffic analysis. We need to match the
1856: * size of a SSH2_MSG_CHANNEL_DATA message
1857: * (4 byte channel id + buf)
1858: */
1859: if ((r = sshpkt_msg_ignore(ssh, 4+len)) != 0 ||
1860: (r = sshpkt_send(ssh)) != 0)
1861: fatal("%s: channel %d: ignore: %s",
1862: __func__, c->self, ssh_err(r));
1.25 markus 1863: }
1.367 djm 1864: }
1865: if ((r = sshbuf_consume(c->output, len)) != 0) {
1866: fatal("%s: channel %d: consume: %s",
1867: __func__, c->self, ssh_err(r));
1.44 markus 1868: }
1.309 djm 1869: out:
1.367 djm 1870: c->local_consumed += olen - sshbuf_len(c->output);
1871:
1872: return 1;
1873: }
1874:
1875: static int
1876: channel_handle_efd_write(struct ssh *ssh, Channel *c,
1877: fd_set *readset, fd_set *writeset)
1878: {
1879: int r;
1880: ssize_t len;
1881:
1882: if (!FD_ISSET(c->efd, writeset) || sshbuf_len(c->extended) == 0)
1883: return 1;
1884:
1885: len = write(c->efd, sshbuf_ptr(c->extended),
1886: sshbuf_len(c->extended));
1887: debug2("channel %d: written %zd to efd %d", c->self, len, c->efd);
1888: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1889: return 1;
1890: if (len <= 0) {
1891: debug2("channel %d: closing write-efd %d", c->self, c->efd);
1892: channel_close_fd(ssh, &c->efd);
1893: } else {
1894: if ((r = sshbuf_consume(c->extended, len)) != 0) {
1895: fatal("%s: channel %d: consume: %s",
1896: __func__, c->self, ssh_err(r));
1897: }
1898: c->local_consumed += len;
1899: }
1.44 markus 1900: return 1;
1901: }
1.241 deraadt 1902:
1.127 itojun 1903: static int
1.367 djm 1904: channel_handle_efd_read(struct ssh *ssh, Channel *c,
1905: fd_set *readset, fd_set *writeset)
1.44 markus 1906: {
1.214 markus 1907: char buf[CHAN_RBUF];
1.367 djm 1908: int r;
1909: ssize_t len;
1910:
1911: if (!FD_ISSET(c->efd, readset))
1912: return 1;
1.44 markus 1913:
1.367 djm 1914: len = read(c->efd, buf, sizeof(buf));
1915: debug2("channel %d: read %zd from efd %d", c->self, len, c->efd);
1916: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1917: return 1;
1918: if (len <= 0) {
1919: debug2("channel %d: closing read-efd %d",
1920: c->self, c->efd);
1921: channel_close_fd(ssh, &c->efd);
1922: } else {
1923: if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1924: debug3("channel %d: discard efd",
1925: c->self);
1926: } else if ((r = sshbuf_put(c->extended, buf, len)) != 0) {
1927: fatal("%s: channel %d: append: %s",
1928: __func__, c->self, ssh_err(r));
1.44 markus 1929: }
1930: }
1931: return 1;
1932: }
1.241 deraadt 1933:
1.127 itojun 1934: static int
1.367 djm 1935: channel_handle_efd(struct ssh *ssh, Channel *c,
1936: fd_set *readset, fd_set *writeset)
1.44 markus 1937: {
1.367 djm 1938: if (c->efd == -1)
1939: return 1;
1940:
1941: /** XXX handle drain efd, too */
1942:
1943: if (c->extended_usage == CHAN_EXTENDED_WRITE)
1944: return channel_handle_efd_write(ssh, c, readset, writeset);
1945: else if (c->extended_usage == CHAN_EXTENDED_READ ||
1946: c->extended_usage == CHAN_EXTENDED_IGNORE)
1947: return channel_handle_efd_read(ssh, c, readset, writeset);
1948:
1949: return 1;
1950: }
1951:
1952: static int
1953: channel_check_window(struct ssh *ssh, Channel *c)
1954: {
1955: int r;
1956:
1.104 markus 1957: if (c->type == SSH_CHANNEL_OPEN &&
1958: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.270 dtucker 1959: ((c->local_window_max - c->local_window >
1.269 markus 1960: c->local_maxpacket*3) ||
1961: c->local_window < c->local_window_max/2) &&
1.44 markus 1962: c->local_consumed > 0) {
1.368 ! djm 1963: if (!c->have_remote_id)
! 1964: fatal(":%s: channel %d: no remote id",
! 1965: __func__, c->self);
1.367 djm 1966: if ((r = sshpkt_start(ssh,
1967: SSH2_MSG_CHANNEL_WINDOW_ADJUST)) != 0 ||
1968: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1969: (r = sshpkt_put_u32(ssh, c->local_consumed)) != 0 ||
1970: (r = sshpkt_send(ssh)) != 0) {
1971: fatal("%s: channel %i: %s", __func__,
1972: c->self, ssh_err(r));
1973: }
1.70 markus 1974: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1975: c->self, c->local_window,
1976: c->local_consumed);
1977: c->local_window += c->local_consumed;
1978: c->local_consumed = 0;
1.1 deraadt 1979: }
1.41 markus 1980: return 1;
1.1 deraadt 1981: }
1982:
1.127 itojun 1983: static void
1.367 djm 1984: channel_post_open(struct ssh *ssh, Channel *c,
1985: fd_set *readset, fd_set *writeset)
1.41 markus 1986: {
1.367 djm 1987: channel_handle_rfd(ssh, c, readset, writeset);
1988: channel_handle_wfd(ssh, c, readset, writeset);
1989: channel_handle_efd(ssh, c, readset, writeset);
1990: channel_check_window(ssh, c);
1.44 markus 1991: }
1992:
1.302 djm 1993: static u_int
1.367 djm 1994: read_mux(struct ssh *ssh, Channel *c, u_int need)
1.302 djm 1995: {
1996: char buf[CHAN_RBUF];
1.367 djm 1997: ssize_t len;
1.302 djm 1998: u_int rlen;
1.367 djm 1999: int r;
1.302 djm 2000:
1.367 djm 2001: if (sshbuf_len(c->input) < need) {
2002: rlen = need - sshbuf_len(c->input);
1.352 deraadt 2003: len = read(c->rfd, buf, MINIMUM(rlen, CHAN_RBUF));
1.349 naddy 2004: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1.367 djm 2005: return sshbuf_len(c->input);
1.302 djm 2006: if (len <= 0) {
1.367 djm 2007: debug2("channel %d: ctl read<=0 rfd %d len %zd",
1.349 naddy 2008: c->self, c->rfd, len);
1.367 djm 2009: chan_read_failed(ssh, c);
1.349 naddy 2010: return 0;
1.367 djm 2011: } else if ((r = sshbuf_put(c->input, buf, len)) != 0) {
2012: fatal("%s: channel %d: append: %s",
2013: __func__, c->self, ssh_err(r));
2014: }
1.302 djm 2015: }
1.367 djm 2016: return sshbuf_len(c->input);
1.302 djm 2017: }
2018:
2019: static void
1.367 djm 2020: channel_post_mux_client_read(struct ssh *ssh, Channel *c,
2021: fd_set *readset, fd_set *writeset)
1.302 djm 2022: {
2023: u_int need;
2024:
1.367 djm 2025: if (c->rfd == -1 || !FD_ISSET(c->rfd, readset))
2026: return;
2027: if (c->istate != CHAN_INPUT_OPEN && c->istate != CHAN_INPUT_WAIT_DRAIN)
2028: return;
2029: if (c->mux_pause)
2030: return;
2031:
2032: /*
2033: * Don't not read past the precise end of packets to
2034: * avoid disrupting fd passing.
2035: */
2036: if (read_mux(ssh, c, 4) < 4) /* read header */
2037: return;
2038: /* XXX sshbuf_peek_u32 */
2039: need = PEEK_U32(sshbuf_ptr(c->input));
1.302 djm 2040: #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1.367 djm 2041: if (need > CHANNEL_MUX_MAX_PACKET) {
2042: debug2("channel %d: packet too big %u > %u",
2043: c->self, CHANNEL_MUX_MAX_PACKET, need);
2044: chan_rcvd_oclose(ssh, c);
2045: return;
2046: }
2047: if (read_mux(ssh, c, need + 4) < need + 4) /* read body */
2048: return;
2049: if (c->mux_rcb(ssh, c) != 0) {
2050: debug("channel %d: mux_rcb failed", c->self);
2051: chan_mark_dead(ssh, c);
2052: return;
1.302 djm 2053: }
1.367 djm 2054: }
2055:
2056: static void
2057: channel_post_mux_client_write(struct ssh *ssh, Channel *c,
2058: fd_set *readset, fd_set *writeset)
2059: {
2060: ssize_t len;
2061: int r;
1.302 djm 2062:
1.367 djm 2063: if (c->wfd == -1 || !FD_ISSET(c->wfd, writeset) ||
2064: sshbuf_len(c->output) == 0)
2065: return;
2066:
2067: len = write(c->wfd, sshbuf_ptr(c->output), sshbuf_len(c->output));
2068: if (len < 0 && (errno == EINTR || errno == EAGAIN))
2069: return;
2070: if (len <= 0) {
2071: chan_mark_dead(ssh, c);
2072: return;
1.302 djm 2073: }
1.367 djm 2074: if ((r = sshbuf_consume(c->output, len)) != 0)
2075: fatal("%s: channel %d: consume: %s", __func__,
2076: c->self, ssh_err(r));
2077: }
2078:
2079: static void
2080: channel_post_mux_client(struct ssh *ssh, Channel *c,
2081: fd_set *readset, fd_set *writeset)
2082: {
2083: channel_post_mux_client_read(ssh, c, readset, writeset);
2084: channel_post_mux_client_write(ssh, c, readset, writeset);
1.302 djm 2085: }
2086:
2087: static void
1.367 djm 2088: channel_post_mux_listener(struct ssh *ssh, Channel *c,
2089: fd_set *readset, fd_set *writeset)
1.302 djm 2090: {
2091: Channel *nc;
2092: struct sockaddr_storage addr;
2093: socklen_t addrlen;
2094: int newsock;
2095: uid_t euid;
2096: gid_t egid;
2097:
2098: if (!FD_ISSET(c->sock, readset))
2099: return;
2100:
2101: debug("multiplexing control connection");
2102:
2103: /*
2104: * Accept connection on control socket
2105: */
2106: memset(&addr, 0, sizeof(addr));
2107: addrlen = sizeof(addr);
2108: if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
2109: &addrlen)) == -1) {
2110: error("%s accept: %s", __func__, strerror(errno));
1.317 djm 2111: if (errno == EMFILE || errno == ENFILE)
1.322 dtucker 2112: c->notbefore = monotime() + 1;
1.302 djm 2113: return;
2114: }
2115:
2116: if (getpeereid(newsock, &euid, &egid) < 0) {
2117: error("%s getpeereid failed: %s", __func__,
2118: strerror(errno));
2119: close(newsock);
2120: return;
2121: }
2122: if ((euid != 0) && (getuid() != euid)) {
2123: error("multiplex uid mismatch: peer euid %u != uid %u",
2124: (u_int)euid, (u_int)getuid());
2125: close(newsock);
2126: return;
2127: }
1.367 djm 2128: nc = channel_new(ssh, "multiplex client", SSH_CHANNEL_MUX_CLIENT,
1.302 djm 2129: newsock, newsock, -1, c->local_window_max,
2130: c->local_maxpacket, 0, "mux-control", 1);
2131: nc->mux_rcb = c->mux_rcb;
1.367 djm 2132: debug3("%s: new mux channel %d fd %d", __func__, nc->self, nc->sock);
1.302 djm 2133: /* establish state */
1.367 djm 2134: nc->mux_rcb(ssh, nc);
1.302 djm 2135: /* mux state transitions must not elicit protocol messages */
2136: nc->flags |= CHAN_LOCAL;
2137: }
2138:
1.127 itojun 2139: static void
1.367 djm 2140: channel_handler_init(struct ssh_channels *sc)
1.1 deraadt 2141: {
1.367 djm 2142: chan_fn **pre, **post;
2143:
2144: if ((pre = calloc(SSH_CHANNEL_MAX_TYPE, sizeof(*pre))) == NULL ||
2145: (post = calloc(SSH_CHANNEL_MAX_TYPE, sizeof(*post))) == NULL)
2146: fatal("%s: allocation failed", __func__);
2147:
2148: pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2149: pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2150: pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2151: pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2152: pre[SSH_CHANNEL_UNIX_LISTENER] = &channel_pre_listener;
2153: pre[SSH_CHANNEL_RUNIX_LISTENER] = &channel_pre_listener;
2154: pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2155: pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2156: pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2157: pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2158: pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2159: pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2160:
2161: post[SSH_CHANNEL_OPEN] = &channel_post_open;
2162: post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2163: post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2164: post[SSH_CHANNEL_UNIX_LISTENER] = &channel_post_port_listener;
2165: post[SSH_CHANNEL_RUNIX_LISTENER] = &channel_post_port_listener;
2166: post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2167: post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2168: post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2169: post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2170: post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2171: post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
1.180 deraadt 2172:
1.367 djm 2173: sc->channel_pre = pre;
2174: sc->channel_post = post;
1.44 markus 2175: }
2176:
1.140 markus 2177: /* gc dead channels */
2178: static void
1.367 djm 2179: channel_garbage_collect(struct ssh *ssh, Channel *c)
1.140 markus 2180: {
2181: if (c == NULL)
2182: return;
2183: if (c->detach_user != NULL) {
1.367 djm 2184: if (!chan_is_dead(ssh, c, c->detach_close))
1.140 markus 2185: return;
1.194 markus 2186: debug2("channel %d: gc: notify user", c->self);
1.367 djm 2187: c->detach_user(ssh, c->self, NULL);
1.140 markus 2188: /* if we still have a callback */
2189: if (c->detach_user != NULL)
2190: return;
1.194 markus 2191: debug2("channel %d: gc: user detached", c->self);
1.140 markus 2192: }
1.367 djm 2193: if (!chan_is_dead(ssh, c, 1))
1.140 markus 2194: return;
1.194 markus 2195: debug2("channel %d: garbage collecting", c->self);
1.367 djm 2196: channel_free(ssh, c);
1.140 markus 2197: }
2198:
1.367 djm 2199: enum channel_table { CHAN_PRE, CHAN_POST };
2200:
1.127 itojun 2201: static void
1.367 djm 2202: channel_handler(struct ssh *ssh, int table,
1.366 djm 2203: fd_set *readset, fd_set *writeset, time_t *unpause_secs)
1.41 markus 2204: {
1.367 djm 2205: struct ssh_channels *sc = ssh->chanctxt;
2206: chan_fn **ftab = table == CHAN_PRE ? sc->channel_pre : sc->channel_post;
1.299 markus 2207: u_int i, oalloc;
1.41 markus 2208: Channel *c;
1.317 djm 2209: time_t now;
1.25 markus 2210:
1.322 dtucker 2211: now = monotime();
1.317 djm 2212: if (unpause_secs != NULL)
2213: *unpause_secs = 0;
1.367 djm 2214: for (i = 0, oalloc = sc->channels_alloc; i < oalloc; i++) {
2215: c = sc->channels[i];
1.113 markus 2216: if (c == NULL)
1.41 markus 2217: continue;
1.299 markus 2218: if (c->delayed) {
1.367 djm 2219: if (table == CHAN_PRE)
1.299 markus 2220: c->delayed = 0;
2221: else
2222: continue;
2223: }
1.317 djm 2224: if (ftab[c->type] != NULL) {
2225: /*
2226: * Run handlers that are not paused.
2227: */
2228: if (c->notbefore <= now)
1.367 djm 2229: (*ftab[c->type])(ssh, c, readset, writeset);
1.317 djm 2230: else if (unpause_secs != NULL) {
2231: /*
2232: * Collect the time that the earliest
2233: * channel comes off pause.
2234: */
2235: debug3("%s: chan %d: skip for %d more seconds",
2236: __func__, c->self,
2237: (int)(c->notbefore - now));
2238: if (*unpause_secs == 0 ||
2239: (c->notbefore - now) < *unpause_secs)
2240: *unpause_secs = c->notbefore - now;
2241: }
2242: }
1.367 djm 2243: channel_garbage_collect(ssh, c);
1.1 deraadt 2244: }
1.317 djm 2245: if (unpause_secs != NULL && *unpause_secs != 0)
2246: debug3("%s: first channel unpauses in %d seconds",
2247: __func__, (int)*unpause_secs);
1.1 deraadt 2248: }
2249:
1.121 markus 2250: /*
2251: * Allocate/update select bitmasks and add any bits relevant to channels in
2252: * select bitmasks.
2253: */
1.49 markus 2254: void
1.366 djm 2255: channel_prepare_select(struct ssh *ssh, fd_set **readsetp, fd_set **writesetp,
2256: int *maxfdp, u_int *nallocp, time_t *minwait_secs)
1.41 markus 2257: {
1.243 djm 2258: u_int n, sz, nfdset;
1.84 markus 2259:
1.367 djm 2260: n = MAXIMUM(*maxfdp, ssh->chanctxt->channel_max_fd);
1.84 markus 2261:
1.243 djm 2262: nfdset = howmany(n+1, NFDBITS);
2263: /* Explicitly test here, because xrealloc isn't always called */
1.341 millert 2264: if (nfdset && SIZE_MAX / nfdset < sizeof(fd_mask))
1.243 djm 2265: fatal("channel_prepare_select: max_fd (%d) is too large", n);
2266: sz = nfdset * sizeof(fd_mask);
2267:
1.132 markus 2268: /* perhaps check sz < nalloc/2 and shrink? */
2269: if (*readsetp == NULL || sz > *nallocp) {
1.342 deraadt 2270: *readsetp = xreallocarray(*readsetp, nfdset, sizeof(fd_mask));
2271: *writesetp = xreallocarray(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 2272: *nallocp = sz;
1.84 markus 2273: }
1.132 markus 2274: *maxfdp = n;
1.84 markus 2275: memset(*readsetp, 0, sz);
2276: memset(*writesetp, 0, sz);
2277:
1.366 djm 2278: if (!ssh_packet_is_rekeying(ssh))
1.367 djm 2279: channel_handler(ssh, CHAN_PRE, *readsetp, *writesetp,
1.317 djm 2280: minwait_secs);
1.41 markus 2281: }
2282:
1.121 markus 2283: /*
2284: * After select, perform any appropriate operations for channels which have
2285: * events pending.
2286: */
1.49 markus 2287: void
1.366 djm 2288: channel_after_select(struct ssh *ssh, fd_set *readset, fd_set *writeset)
1.41 markus 2289: {
1.367 djm 2290: channel_handler(ssh, CHAN_POST, readset, writeset, NULL);
2291: }
2292:
2293: /*
2294: * Enqueue data for channels with open or draining c->input.
2295: */
2296: static void
2297: channel_output_poll_input_open(struct ssh *ssh, Channel *c)
2298: {
2299: size_t len, dlen;
2300: int r;
2301:
2302: if ((len = sshbuf_len(c->input)) == 0) {
2303: if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2304: /*
2305: * input-buffer is empty and read-socket shutdown:
2306: * tell peer, that we will not send more data:
2307: * send IEOF.
2308: * hack for extended data: delay EOF if EFD still
2309: * in use.
2310: */
2311: if (CHANNEL_EFD_INPUT_ACTIVE(c))
2312: debug2("channel %d: "
2313: "ibuf_empty delayed efd %d/(%zu)",
2314: c->self, c->efd, sshbuf_len(c->extended));
2315: else
2316: chan_ibuf_empty(ssh, c);
2317: }
2318: return;
2319: }
2320:
1.368 ! djm 2321: if (!c->have_remote_id)
! 2322: fatal(":%s: channel %d: no remote id", __func__, c->self);
! 2323:
1.367 djm 2324: if (c->datagram) {
2325: /* Check datagram will fit; drop if not */
2326: if ((r = sshbuf_peek_string_direct(c->input, NULL, &dlen)) != 0)
2327: fatal("%s: channel %d: peek datagram: %s", __func__,
2328: c->self, ssh_err(r));
2329: /*
2330: * XXX this does tail-drop on the datagram queue which is
2331: * usually suboptimal compared to head-drop. Better to have
2332: * backpressure at read time? (i.e. read + discard)
2333: */
2334: if (dlen > c->remote_window || dlen > c->remote_maxpacket) {
2335: debug("channel %d: datagram too big", c->self);
2336: return;
2337: }
2338: /* Enqueue it */
2339: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
2340: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2341: (r = sshpkt_put_stringb(ssh, c->input)) != 0 ||
2342: (r = sshpkt_send(ssh)) != 0) {
2343: fatal("%s: channel %i: datagram: %s", __func__,
2344: c->self, ssh_err(r));
2345: }
2346: c->remote_window -= dlen;
2347: return;
2348: }
2349:
2350: /* Enqueue packet for buffered data. */
2351: if (len > c->remote_window)
2352: len = c->remote_window;
2353: if (len > c->remote_maxpacket)
2354: len = c->remote_maxpacket;
2355: if (len == 0)
2356: return;
2357: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_DATA)) != 0 ||
2358: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2359: (r = sshpkt_put_string(ssh, sshbuf_ptr(c->input), len)) != 0 ||
2360: (r = sshpkt_send(ssh)) != 0) {
2361: fatal("%s: channel %i: data: %s", __func__,
2362: c->self, ssh_err(r));
2363: }
2364: if ((r = sshbuf_consume(c->input, len)) != 0)
2365: fatal("%s: channel %i: consume: %s", __func__,
2366: c->self, ssh_err(r));
2367: c->remote_window -= len;
1.41 markus 2368: }
2369:
1.367 djm 2370: /*
2371: * Enqueue data for channels with open c->extended in read mode.
2372: */
2373: static void
2374: channel_output_poll_extended_read(struct ssh *ssh, Channel *c)
2375: {
2376: size_t len;
2377: int r;
2378:
2379: if ((len = sshbuf_len(c->extended)) == 0)
2380: return;
2381:
2382: debug2("channel %d: rwin %u elen %zu euse %d", c->self,
2383: c->remote_window, sshbuf_len(c->extended), c->extended_usage);
2384: if (len > c->remote_window)
2385: len = c->remote_window;
2386: if (len > c->remote_maxpacket)
2387: len = c->remote_maxpacket;
2388: if (len == 0)
2389: return;
1.368 ! djm 2390: if (!c->have_remote_id)
! 2391: fatal(":%s: channel %d: no remote id", __func__, c->self);
1.367 djm 2392: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA)) != 0 ||
2393: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
2394: (r = sshpkt_put_u32(ssh, SSH2_EXTENDED_DATA_STDERR)) != 0 ||
2395: (r = sshpkt_put_string(ssh, sshbuf_ptr(c->extended), len)) != 0 ||
2396: (r = sshpkt_send(ssh)) != 0) {
2397: fatal("%s: channel %i: data: %s", __func__,
2398: c->self, ssh_err(r));
2399: }
2400: if ((r = sshbuf_consume(c->extended, len)) != 0)
2401: fatal("%s: channel %i: consume: %s", __func__,
2402: c->self, ssh_err(r));
2403: c->remote_window -= len;
2404: debug2("channel %d: sent ext data %zu", c->self, len);
2405: }
1.121 markus 2406:
1.84 markus 2407: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 2408: void
1.367 djm 2409: channel_output_poll(struct ssh *ssh)
1.1 deraadt 2410: {
1.367 djm 2411: struct ssh_channels *sc = ssh->chanctxt;
1.41 markus 2412: Channel *c;
1.367 djm 2413: u_int i;
1.1 deraadt 2414:
1.367 djm 2415: for (i = 0; i < sc->channels_alloc; i++) {
2416: c = sc->channels[i];
1.113 markus 2417: if (c == NULL)
2418: continue;
1.37 markus 2419:
1.121 markus 2420: /*
2421: * We are only interested in channels that can have buffered
2422: * incoming data.
2423: */
1.358 djm 2424: if (c->type != SSH_CHANNEL_OPEN)
2425: continue;
2426: if ((c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 2427: /* XXX is this true? */
1.367 djm 2428: debug3("channel %d: will not send data after close",
2429: c->self);
1.44 markus 2430: continue;
2431: }
1.25 markus 2432:
2433: /* Get the amount of buffered data for this channel. */
1.367 djm 2434: if (c->istate == CHAN_INPUT_OPEN ||
2435: c->istate == CHAN_INPUT_WAIT_DRAIN)
2436: channel_output_poll_input_open(ssh, c);
1.44 markus 2437: /* Send extended data, i.e. stderr */
1.358 djm 2438: if (!(c->flags & CHAN_EOF_SENT) &&
1.367 djm 2439: c->extended_usage == CHAN_EXTENDED_READ)
2440: channel_output_poll_extended_read(ssh, c);
1.25 markus 2441: }
1.1 deraadt 2442: }
2443:
1.354 markus 2444: /* -- mux proxy support */
2445:
2446: /*
2447: * When multiplexing channel messages for mux clients we have to deal
2448: * with downstream messages from the mux client and upstream messages
2449: * from the ssh server:
2450: * 1) Handling downstream messages is straightforward and happens
2451: * in channel_proxy_downstream():
2452: * - We forward all messages (mostly) unmodified to the server.
2453: * - However, in order to route messages from upstream to the correct
2454: * downstream client, we have to replace the channel IDs used by the
2455: * mux clients with a unique channel ID because the mux clients might
2456: * use conflicting channel IDs.
2457: * - so we inspect and change both SSH2_MSG_CHANNEL_OPEN and
2458: * SSH2_MSG_CHANNEL_OPEN_CONFIRMATION messages, create a local
2459: * SSH_CHANNEL_MUX_PROXY channel and replace the mux clients ID
2460: * with the newly allocated channel ID.
2461: * 2) Upstream messages are received by matching SSH_CHANNEL_MUX_PROXY
2462: * channels and procesed by channel_proxy_upstream(). The local channel ID
2463: * is then translated back to the original mux client ID.
2464: * 3) In both cases we need to keep track of matching SSH2_MSG_CHANNEL_CLOSE
2465: * messages so we can clean up SSH_CHANNEL_MUX_PROXY channels.
2466: * 4) The SSH_CHANNEL_MUX_PROXY channels also need to closed when the
2467: * downstream mux client are removed.
2468: * 5) Handling SSH2_MSG_CHANNEL_OPEN messages from the upstream server
2469: * requires more work, because they are not addressed to a specific
2470: * channel. E.g. client_request_forwarded_tcpip() needs to figure
2471: * out whether the request is addressed to the local client or a
2472: * specific downstream client based on the listen-address/port.
2473: * 6) Agent and X11-Forwarding have a similar problem and are currenly
2474: * not supported as the matching session/channel cannot be identified
2475: * easily.
2476: */
2477:
2478: /*
2479: * receive packets from downstream mux clients:
2480: * channel callback fired on read from mux client, creates
2481: * SSH_CHANNEL_MUX_PROXY channels and translates channel IDs
2482: * on channel creation.
2483: */
2484: int
1.367 djm 2485: channel_proxy_downstream(struct ssh *ssh, Channel *downstream)
1.354 markus 2486: {
2487: Channel *c = NULL;
2488: struct sshbuf *original = NULL, *modified = NULL;
2489: const u_char *cp;
2490: char *ctype = NULL, *listen_host = NULL;
2491: u_char type;
2492: size_t have;
1.355 djm 2493: int ret = -1, r, idx;
2494: u_int id, remote_id, listen_port;
1.354 markus 2495:
1.367 djm 2496: /* sshbuf_dump(downstream->input, stderr); */
2497: if ((r = sshbuf_get_string_direct(downstream->input, &cp, &have))
1.354 markus 2498: != 0) {
2499: error("%s: malformed message: %s", __func__, ssh_err(r));
2500: return -1;
2501: }
2502: if (have < 2) {
2503: error("%s: short message", __func__);
2504: return -1;
2505: }
2506: type = cp[1];
2507: /* skip padlen + type */
2508: cp += 2;
2509: have -= 2;
2510: if (ssh_packet_log_type(type))
2511: debug3("%s: channel %u: down->up: type %u", __func__,
2512: downstream->self, type);
2513:
2514: switch (type) {
2515: case SSH2_MSG_CHANNEL_OPEN:
2516: if ((original = sshbuf_from(cp, have)) == NULL ||
2517: (modified = sshbuf_new()) == NULL) {
2518: error("%s: alloc", __func__);
2519: goto out;
2520: }
2521: if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0 ||
2522: (r = sshbuf_get_u32(original, &id)) != 0) {
2523: error("%s: parse error %s", __func__, ssh_err(r));
2524: goto out;
2525: }
1.367 djm 2526: c = channel_new(ssh, "mux proxy", SSH_CHANNEL_MUX_PROXY,
1.354 markus 2527: -1, -1, -1, 0, 0, 0, ctype, 1);
2528: c->mux_ctx = downstream; /* point to mux client */
2529: c->mux_downstream_id = id; /* original downstream id */
2530: if ((r = sshbuf_put_cstring(modified, ctype)) != 0 ||
2531: (r = sshbuf_put_u32(modified, c->self)) != 0 ||
2532: (r = sshbuf_putb(modified, original)) != 0) {
2533: error("%s: compose error %s", __func__, ssh_err(r));
1.367 djm 2534: channel_free(ssh, c);
1.354 markus 2535: goto out;
2536: }
2537: break;
2538: case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
2539: /*
2540: * Almost the same as SSH2_MSG_CHANNEL_OPEN, except then we
2541: * need to parse 'remote_id' instead of 'ctype'.
2542: */
2543: if ((original = sshbuf_from(cp, have)) == NULL ||
2544: (modified = sshbuf_new()) == NULL) {
2545: error("%s: alloc", __func__);
2546: goto out;
2547: }
2548: if ((r = sshbuf_get_u32(original, &remote_id)) != 0 ||
2549: (r = sshbuf_get_u32(original, &id)) != 0) {
2550: error("%s: parse error %s", __func__, ssh_err(r));
2551: goto out;
2552: }
1.367 djm 2553: c = channel_new(ssh, "mux proxy", SSH_CHANNEL_MUX_PROXY,
1.354 markus 2554: -1, -1, -1, 0, 0, 0, "mux-down-connect", 1);
2555: c->mux_ctx = downstream; /* point to mux client */
2556: c->mux_downstream_id = id;
2557: c->remote_id = remote_id;
1.368 ! djm 2558: c->have_remote_id = 1;
1.354 markus 2559: if ((r = sshbuf_put_u32(modified, remote_id)) != 0 ||
2560: (r = sshbuf_put_u32(modified, c->self)) != 0 ||
2561: (r = sshbuf_putb(modified, original)) != 0) {
2562: error("%s: compose error %s", __func__, ssh_err(r));
1.367 djm 2563: channel_free(ssh, c);
1.354 markus 2564: goto out;
2565: }
2566: break;
2567: case SSH2_MSG_GLOBAL_REQUEST:
2568: if ((original = sshbuf_from(cp, have)) == NULL) {
2569: error("%s: alloc", __func__);
2570: goto out;
2571: }
2572: if ((r = sshbuf_get_cstring(original, &ctype, NULL)) != 0) {
2573: error("%s: parse error %s", __func__, ssh_err(r));
2574: goto out;
2575: }
2576: if (strcmp(ctype, "tcpip-forward") != 0) {
2577: error("%s: unsupported request %s", __func__, ctype);
2578: goto out;
2579: }
2580: if ((r = sshbuf_get_u8(original, NULL)) != 0 ||
2581: (r = sshbuf_get_cstring(original, &listen_host, NULL)) != 0 ||
2582: (r = sshbuf_get_u32(original, &listen_port)) != 0) {
2583: error("%s: parse error %s", __func__, ssh_err(r));
2584: goto out;
2585: }
1.355 djm 2586: if (listen_port > 65535) {
2587: error("%s: tcpip-forward for %s: bad port %u",
2588: __func__, listen_host, listen_port);
2589: goto out;
2590: }
1.354 markus 2591: /* Record that connection to this host/port is permitted. */
1.367 djm 2592: idx = fwd_perm_list_add(ssh, FWDPERM_USER, "<mux>", -1,
2593: listen_host, NULL, (int)listen_port, downstream);
1.354 markus 2594: listen_host = NULL;
2595: break;
2596: case SSH2_MSG_CHANNEL_CLOSE:
2597: if (have < 4)
2598: break;
2599: remote_id = PEEK_U32(cp);
1.367 djm 2600: if ((c = channel_by_remote_id(ssh, remote_id)) != NULL) {
1.354 markus 2601: if (c->flags & CHAN_CLOSE_RCVD)
1.367 djm 2602: channel_free(ssh, c);
1.354 markus 2603: else
2604: c->flags |= CHAN_CLOSE_SENT;
2605: }
2606: break;
2607: }
2608: if (modified) {
2609: if ((r = sshpkt_start(ssh, type)) != 0 ||
2610: (r = sshpkt_putb(ssh, modified)) != 0 ||
2611: (r = sshpkt_send(ssh)) != 0) {
2612: error("%s: send %s", __func__, ssh_err(r));
2613: goto out;
2614: }
2615: } else {
2616: if ((r = sshpkt_start(ssh, type)) != 0 ||
2617: (r = sshpkt_put(ssh, cp, have)) != 0 ||
2618: (r = sshpkt_send(ssh)) != 0) {
2619: error("%s: send %s", __func__, ssh_err(r));
2620: goto out;
2621: }
2622: }
2623: ret = 0;
2624: out:
2625: free(ctype);
2626: free(listen_host);
2627: sshbuf_free(original);
2628: sshbuf_free(modified);
2629: return ret;
2630: }
2631:
2632: /*
2633: * receive packets from upstream server and de-multiplex packets
2634: * to correct downstream:
2635: * implemented as a helper for channel input handlers,
2636: * replaces local (proxy) channel ID with downstream channel ID.
2637: */
2638: int
1.363 markus 2639: channel_proxy_upstream(Channel *c, int type, u_int32_t seq, struct ssh *ssh)
1.354 markus 2640: {
2641: struct sshbuf *b = NULL;
2642: Channel *downstream;
2643: const u_char *cp = NULL;
2644: size_t len;
2645: int r;
2646:
2647: /*
2648: * When receiving packets from the peer we need to check whether we
2649: * need to forward the packets to the mux client. In this case we
2650: * restore the orignal channel id and keep track of CLOSE messages,
2651: * so we can cleanup the channel.
2652: */
2653: if (c == NULL || c->type != SSH_CHANNEL_MUX_PROXY)
2654: return 0;
2655: if ((downstream = c->mux_ctx) == NULL)
2656: return 0;
2657: switch (type) {
2658: case SSH2_MSG_CHANNEL_CLOSE:
2659: case SSH2_MSG_CHANNEL_DATA:
2660: case SSH2_MSG_CHANNEL_EOF:
2661: case SSH2_MSG_CHANNEL_EXTENDED_DATA:
2662: case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
2663: case SSH2_MSG_CHANNEL_OPEN_FAILURE:
2664: case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
2665: case SSH2_MSG_CHANNEL_SUCCESS:
2666: case SSH2_MSG_CHANNEL_FAILURE:
2667: case SSH2_MSG_CHANNEL_REQUEST:
2668: break;
2669: default:
2670: debug2("%s: channel %u: unsupported type %u", __func__,
2671: c->self, type);
2672: return 0;
2673: }
2674: if ((b = sshbuf_new()) == NULL) {
2675: error("%s: alloc reply", __func__);
2676: goto out;
2677: }
2678: /* get remaining payload (after id) */
2679: cp = sshpkt_ptr(ssh, &len);
2680: if (cp == NULL) {
2681: error("%s: no packet", __func__);
2682: goto out;
2683: }
2684: /* translate id and send to muxclient */
2685: if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */
2686: (r = sshbuf_put_u8(b, type)) != 0 ||
2687: (r = sshbuf_put_u32(b, c->mux_downstream_id)) != 0 ||
2688: (r = sshbuf_put(b, cp, len)) != 0 ||
1.367 djm 2689: (r = sshbuf_put_stringb(downstream->output, b)) != 0) {
1.354 markus 2690: error("%s: compose for muxclient %s", __func__, ssh_err(r));
2691: goto out;
2692: }
2693: /* sshbuf_dump(b, stderr); */
2694: if (ssh_packet_log_type(type))
2695: debug3("%s: channel %u: up->down: type %u", __func__, c->self,
2696: type);
2697: out:
2698: /* update state */
2699: switch (type) {
2700: case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
2701: /* record remote_id for SSH2_MSG_CHANNEL_CLOSE */
1.368 ! djm 2702: if (cp && len > 4) {
1.354 markus 2703: c->remote_id = PEEK_U32(cp);
1.368 ! djm 2704: c->have_remote_id = 1;
! 2705: }
1.354 markus 2706: break;
2707: case SSH2_MSG_CHANNEL_CLOSE:
2708: if (c->flags & CHAN_CLOSE_SENT)
1.367 djm 2709: channel_free(ssh, c);
1.354 markus 2710: else
2711: c->flags |= CHAN_CLOSE_RCVD;
2712: break;
2713: }
2714: sshbuf_free(b);
2715: return 1;
2716: }
1.121 markus 2717:
2718: /* -- protocol input */
1.249 djm 2719:
1.367 djm 2720: /* Parse a channel ID from the current packet */
2721: static int
2722: channel_parse_id(struct ssh *ssh, const char *where, const char *what)
2723: {
2724: u_int32_t id;
2725: int r;
2726:
2727: if ((r = sshpkt_get_u32(ssh, &id)) != 0) {
2728: error("%s: parse id: %s", where, ssh_err(r));
2729: ssh_packet_disconnect(ssh, "Invalid %s message", what);
2730: }
2731: if (id > INT_MAX) {
2732: error("%s: bad channel id %u: %s", where, id, ssh_err(r));
2733: ssh_packet_disconnect(ssh, "Invalid %s channel id", what);
2734: }
2735: return (int)id;
2736: }
2737:
2738: /* Lookup a channel from an ID in the current packet */
2739: static Channel *
2740: channel_from_packet_id(struct ssh *ssh, const char *where, const char *what)
2741: {
2742: int id = channel_parse_id(ssh, where, what);
2743: Channel *c;
2744:
2745: if ((c = channel_lookup(ssh, id)) == NULL) {
2746: ssh_packet_disconnect(ssh,
2747: "%s packet referred to nonexistent channel %d", what, id);
2748: }
2749: return c;
2750: }
2751:
1.339 markus 2752: int
1.363 markus 2753: channel_input_data(int type, u_int32_t seq, struct ssh *ssh)
1.1 deraadt 2754: {
1.332 djm 2755: const u_char *data;
1.367 djm 2756: size_t data_len, win_len;
2757: Channel *c = channel_from_packet_id(ssh, __func__, "data");
2758: int r;
1.25 markus 2759:
1.363 markus 2760: if (channel_proxy_upstream(c, type, seq, ssh))
1.354 markus 2761: return 0;
1.25 markus 2762:
2763: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 2764: if (c->type != SSH_CHANNEL_OPEN &&
2765: c->type != SSH_CHANNEL_X11_OPEN)
1.339 markus 2766: return 0;
1.37 markus 2767:
1.25 markus 2768: /* Get the data. */
1.367 djm 2769: if ((r = sshpkt_get_string_direct(ssh, &data, &data_len)) != 0)
2770: fatal("%s: channel %d: get data: %s", __func__,
2771: c->self, ssh_err(r));
2772: ssh_packet_check_eom(ssh);
2773:
1.309 djm 2774: win_len = data_len;
2775: if (c->datagram)
2776: win_len += 4; /* string length header */
1.200 markus 2777:
2778: /*
1.367 djm 2779: * The sending side reduces its window as it sends data, so we
2780: * must 'fake' consumption of the data in order to ensure that window
2781: * updates are sent back. Otherwise the connection might deadlock.
1.200 markus 2782: */
1.358 djm 2783: if (c->ostate != CHAN_OUTPUT_OPEN) {
2784: c->local_window -= win_len;
2785: c->local_consumed += win_len;
1.339 markus 2786: return 0;
1.200 markus 2787: }
1.41 markus 2788:
1.358 djm 2789: if (win_len > c->local_maxpacket) {
1.367 djm 2790: logit("channel %d: rcvd big packet %zu, maxpack %u",
1.358 djm 2791: c->self, win_len, c->local_maxpacket);
1.367 djm 2792: return 0;
1.358 djm 2793: }
2794: if (win_len > c->local_window) {
1.367 djm 2795: logit("channel %d: rcvd too much data %zu, win %u",
1.358 djm 2796: c->self, win_len, c->local_window);
2797: return 0;
1.44 markus 2798: }
1.358 djm 2799: c->local_window -= win_len;
2800:
1.367 djm 2801: if (c->datagram) {
2802: if ((r = sshbuf_put_string(c->output, data, data_len)) != 0)
2803: fatal("%s: channel %d: append datagram: %s",
2804: __func__, c->self, ssh_err(r));
2805: } else if ((r = sshbuf_put(c->output, data, data_len)) != 0)
2806: fatal("%s: channel %d: append data: %s",
2807: __func__, c->self, ssh_err(r));
2808:
1.339 markus 2809: return 0;
1.1 deraadt 2810: }
1.121 markus 2811:
1.339 markus 2812: int
1.363 markus 2813: channel_input_extended_data(int type, u_int32_t seq, struct ssh *ssh)
1.44 markus 2814: {
1.367 djm 2815: const u_char *data;
2816: size_t data_len;
2817: u_int32_t tcode;
2818: Channel *c = channel_from_packet_id(ssh, __func__, "extended data");
2819: int r;
1.44 markus 2820:
1.363 markus 2821: if (channel_proxy_upstream(c, type, seq, ssh))
1.354 markus 2822: return 0;
1.44 markus 2823: if (c->type != SSH_CHANNEL_OPEN) {
1.367 djm 2824: logit("channel %d: ext data for non open", c->self);
1.339 markus 2825: return 0;
1.172 markus 2826: }
2827: if (c->flags & CHAN_EOF_RCVD) {
2828: if (datafellows & SSH_BUG_EXTEOF)
1.367 djm 2829: debug("channel %d: accepting ext data after eof",
2830: c->self);
1.172 markus 2831: else
1.367 djm 2832: ssh_packet_disconnect(ssh, "Received extended_data "
2833: "after EOF on channel %d.", c->self);
2834: }
2835:
2836: if ((r = sshpkt_get_u32(ssh, &tcode)) != 0) {
2837: error("%s: parse tcode: %s", __func__, ssh_err(r));
2838: ssh_packet_disconnect(ssh, "Invalid extended_data message");
1.44 markus 2839: }
2840: if (c->efd == -1 ||
2841: c->extended_usage != CHAN_EXTENDED_WRITE ||
2842: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2843: logit("channel %d: bad ext data", c->self);
1.339 markus 2844: return 0;
1.44 markus 2845: }
1.367 djm 2846: if ((r = sshpkt_get_string_direct(ssh, &data, &data_len)) != 0) {
2847: error("%s: parse data: %s", __func__, ssh_err(r));
2848: ssh_packet_disconnect(ssh, "Invalid extended_data message");
2849: }
2850: ssh_packet_check_eom(ssh);
2851:
1.44 markus 2852: if (data_len > c->local_window) {
1.367 djm 2853: logit("channel %d: rcvd too much extended_data %zu, win %u",
1.44 markus 2854: c->self, data_len, c->local_window);
1.339 markus 2855: return 0;
1.44 markus 2856: }
1.367 djm 2857: debug2("channel %d: rcvd ext data %zu", c->self, data_len);
2858: /* XXX sshpkt_getb? */
2859: if ((r = sshbuf_put(c->extended, data, data_len)) != 0)
2860: error("%s: append: %s", __func__, ssh_err(r));
1.44 markus 2861: c->local_window -= data_len;
1.339 markus 2862: return 0;
1.44 markus 2863: }
2864:
1.339 markus 2865: int
1.363 markus 2866: channel_input_ieof(int type, u_int32_t seq, struct ssh *ssh)
1.41 markus 2867: {
1.367 djm 2868: Channel *c = channel_from_packet_id(ssh, __func__, "ieof");
2869:
2870: ssh_packet_check_eom(ssh);
1.41 markus 2871:
1.363 markus 2872: if (channel_proxy_upstream(c, type, seq, ssh))
1.354 markus 2873: return 0;
1.367 djm 2874: chan_rcvd_ieof(ssh, c);
1.133 markus 2875:
2876: /* XXX force input close */
1.156 markus 2877: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2878: debug("channel %d: FORCE input drain", c->self);
2879: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.367 djm 2880: if (sshbuf_len(c->input) == 0)
2881: chan_ibuf_empty(ssh, c);
1.133 markus 2882: }
1.339 markus 2883: return 0;
1.41 markus 2884: }
1.1 deraadt 2885:
1.339 markus 2886: int
1.363 markus 2887: channel_input_oclose(int type, u_int32_t seq, struct ssh *ssh)
1.41 markus 2888: {
1.367 djm 2889: Channel *c = channel_from_packet_id(ssh, __func__, "oclose");
1.151 markus 2890:
1.363 markus 2891: if (channel_proxy_upstream(c, type, seq, ssh))
1.354 markus 2892: return 0;
1.367 djm 2893: ssh_packet_check_eom(ssh);
2894: chan_rcvd_oclose(ssh, c);
1.339 markus 2895: return 0;
1.1 deraadt 2896: }
2897:
1.339 markus 2898: int
1.363 markus 2899: channel_input_open_confirmation(int type, u_int32_t seq, struct ssh *ssh)
1.1 deraadt 2900: {
1.367 djm 2901: Channel *c = channel_from_packet_id(ssh, __func__, "open confirmation");
2902: u_int32_t remote_window, remote_maxpacket;
2903: int r;
1.25 markus 2904:
1.363 markus 2905: if (channel_proxy_upstream(c, type, seq, ssh))
1.354 markus 2906: return 0;
2907: if (c->type != SSH_CHANNEL_OPENING)
1.41 markus 2908: packet_disconnect("Received open confirmation for "
1.367 djm 2909: "non-opening channel %d.", c->self);
2910: /*
2911: * Record the remote channel number and mark that the channel
2912: * is now open.
2913: */
1.368 ! djm 2914: if ((r = sshpkt_get_u32(ssh, &c->remote_id)) != 0 ||
! 2915: (r = sshpkt_get_u32(ssh, &remote_window)) != 0 ||
1.367 djm 2916: (r = sshpkt_get_u32(ssh, &remote_maxpacket)) != 0) {
2917: error("%s: window/maxpacket: %s", __func__, ssh_err(r));
2918: packet_disconnect("Invalid open confirmation message");
2919: }
2920: ssh_packet_check_eom(ssh);
2921:
1.368 ! djm 2922: c->have_remote_id = 1;
1.367 djm 2923: c->remote_window = remote_window;
2924: c->remote_maxpacket = remote_maxpacket;
1.41 markus 2925: c->type = SSH_CHANNEL_OPEN;
1.358 djm 2926: if (c->open_confirm) {
1.367 djm 2927: debug2("%s: channel %d: callback start", __func__, c->self);
2928: c->open_confirm(ssh, c->self, 1, c->open_confirm_ctx);
2929: debug2("%s: channel %d: callback done", __func__, c->self);
1.44 markus 2930: }
1.358 djm 2931: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2932: c->remote_window, c->remote_maxpacket);
1.339 markus 2933: return 0;
1.1 deraadt 2934: }
2935:
1.127 itojun 2936: static char *
1.114 markus 2937: reason2txt(int reason)
2938: {
1.143 deraadt 2939: switch (reason) {
1.114 markus 2940: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2941: return "administratively prohibited";
2942: case SSH2_OPEN_CONNECT_FAILED:
2943: return "connect failed";
2944: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2945: return "unknown channel type";
2946: case SSH2_OPEN_RESOURCE_SHORTAGE:
2947: return "resource shortage";
2948: }
1.117 stevesk 2949: return "unknown reason";
1.114 markus 2950: }
2951:
1.339 markus 2952: int
1.363 markus 2953: channel_input_open_failure(int type, u_int32_t seq, struct ssh *ssh)
1.1 deraadt 2954: {
1.367 djm 2955: Channel *c = channel_from_packet_id(ssh, __func__, "open failure");
2956: u_int32_t reason;
2957: char *msg = NULL;
2958: int r;
1.25 markus 2959:
1.363 markus 2960: if (channel_proxy_upstream(c, type, seq, ssh))
1.354 markus 2961: return 0;
2962: if (c->type != SSH_CHANNEL_OPENING)
1.41 markus 2963: packet_disconnect("Received open failure for "
1.367 djm 2964: "non-opening channel %d.", c->self);
2965: if ((r = sshpkt_get_u32(ssh, &reason)) != 0) {
2966: error("%s: reason: %s", __func__, ssh_err(r));
2967: packet_disconnect("Invalid open failure message");
2968: }
2969: if ((datafellows & SSH_BUG_OPENFAILURE) == 0) {
2970: /* skip language */
2971: if ((r = sshpkt_get_cstring(ssh, &msg, NULL)) != 0 ||
2972: (r = sshpkt_get_string_direct(ssh, NULL, NULL)) == 0) {
2973: error("%s: message/lang: %s", __func__, ssh_err(r));
2974: packet_disconnect("Invalid open failure message");
2975: }
1.358 djm 2976: }
1.367 djm 2977: ssh_packet_check_eom(ssh);
2978: logit("channel %d: open failed: %s%s%s", c->self,
1.358 djm 2979: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2980: free(msg);
2981: if (c->open_confirm) {
1.367 djm 2982: debug2("%s: channel %d: callback start", __func__, c->self);
2983: c->open_confirm(ssh, c->self, 0, c->open_confirm_ctx);
2984: debug2("%s: channel %d: callback done", __func__, c->self);
1.44 markus 2985: }
1.291 djm 2986: /* Schedule the channel for cleanup/deletion. */
1.367 djm 2987: chan_mark_dead(ssh, c);
1.339 markus 2988: return 0;
1.44 markus 2989: }
2990:
1.339 markus 2991: int
1.363 markus 2992: channel_input_window_adjust(int type, u_int32_t seq, struct ssh *ssh)
1.121 markus 2993: {
1.367 djm 2994: int id = channel_parse_id(ssh, __func__, "window adjust");
1.121 markus 2995: Channel *c;
1.367 djm 2996: u_int32_t adjust;
2997: u_int new_rwin;
2998: int r;
1.1 deraadt 2999:
1.367 djm 3000: if ((c = channel_lookup(ssh, id)) == NULL) {
1.229 markus 3001: logit("Received window adjust for non-open channel %d.", id);
1.339 markus 3002: return 0;
1.367 djm 3003: }
3004:
1.363 markus 3005: if (channel_proxy_upstream(c, type, seq, ssh))
1.354 markus 3006: return 0;
1.367 djm 3007: if ((r = sshpkt_get_u32(ssh, &adjust)) != 0) {
3008: error("%s: adjust: %s", __func__, ssh_err(r));
3009: packet_disconnect("Invalid window adjust message");
3010: }
3011: ssh_packet_check_eom(ssh);
3012: debug2("channel %d: rcvd adjust %u", c->self, adjust);
3013: if ((new_rwin = c->remote_window + adjust) < c->remote_window) {
1.346 djm 3014: fatal("channel %d: adjust %u overflows remote window %u",
1.367 djm 3015: c->self, adjust, c->remote_window);
3016: }
3017: c->remote_window = new_rwin;
1.339 markus 3018: return 0;
1.121 markus 3019: }
1.1 deraadt 3020:
1.339 markus 3021: int
1.363 markus 3022: channel_input_status_confirm(int type, u_int32_t seq, struct ssh *ssh)
1.275 djm 3023: {
1.367 djm 3024: int id = channel_parse_id(ssh, __func__, "status confirm");
1.275 djm 3025: Channel *c;
3026: struct channel_confirm *cc;
3027:
3028: /* Reset keepalive timeout */
1.296 andreas 3029: packet_set_alive_timeouts(0);
1.275 djm 3030:
1.367 djm 3031: debug2("%s: type %d id %d", __func__, type, id);
1.275 djm 3032:
1.367 djm 3033: if ((c = channel_lookup(ssh, id)) == NULL) {
3034: logit("%s: %d: unknown", __func__, id);
1.339 markus 3035: return 0;
1.367 djm 3036: }
1.363 markus 3037: if (channel_proxy_upstream(c, type, seq, ssh))
1.354 markus 3038: return 0;
1.367 djm 3039: ssh_packet_check_eom(ssh);
1.275 djm 3040: if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
1.339 markus 3041: return 0;
1.367 djm 3042: cc->cb(ssh, type, c, cc->ctx);
1.275 djm 3043: TAILQ_REMOVE(&c->status_confirms, cc, entry);
1.329 tedu 3044: explicit_bzero(cc, sizeof(*cc));
1.321 djm 3045: free(cc);
1.339 markus 3046: return 0;
1.275 djm 3047: }
1.121 markus 3048:
3049: /* -- tcp forwarding */
1.135 markus 3050:
3051: void
1.367 djm 3052: channel_set_af(struct ssh *ssh, int af)
1.135 markus 3053: {
1.367 djm 3054: ssh->chanctxt->IPv4or6 = af;
1.135 markus 3055: }
1.121 markus 3056:
1.312 djm 3057:
3058: /*
3059: * Determine whether or not a port forward listens to loopback, the
3060: * specified address or wildcard. On the client, a specified bind
3061: * address will always override gateway_ports. On the server, a
3062: * gateway_ports of 1 (``yes'') will override the client's specification
3063: * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
3064: * will bind to whatever address the client asked for.
3065: *
3066: * Special-case listen_addrs are:
3067: *
3068: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
3069: * "" (empty string), "*" -> wildcard v4/v6
3070: * "localhost" -> loopback v4/v6
1.334 djm 3071: * "127.0.0.1" / "::1" -> accepted even if gateway_ports isn't set
1.312 djm 3072: */
3073: static const char *
3074: channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
1.336 millert 3075: int is_client, struct ForwardOptions *fwd_opts)
1.312 djm 3076: {
3077: const char *addr = NULL;
3078: int wildcard = 0;
3079:
3080: if (listen_addr == NULL) {
3081: /* No address specified: default to gateway_ports setting */
1.336 millert 3082: if (fwd_opts->gateway_ports)
1.312 djm 3083: wildcard = 1;
1.336 millert 3084: } else if (fwd_opts->gateway_ports || is_client) {
1.312 djm 3085: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
3086: strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
3087: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
1.336 millert 3088: (!is_client && fwd_opts->gateway_ports == 1)) {
1.312 djm 3089: wildcard = 1;
1.326 djm 3090: /*
3091: * Notify client if they requested a specific listen
3092: * address and it was overridden.
3093: */
3094: if (*listen_addr != '\0' &&
3095: strcmp(listen_addr, "0.0.0.0") != 0 &&
3096: strcmp(listen_addr, "*") != 0) {
3097: packet_send_debug("Forwarding listen address "
3098: "\"%s\" overridden by server "
3099: "GatewayPorts", listen_addr);
3100: }
1.334 djm 3101: } else if (strcmp(listen_addr, "localhost") != 0 ||
3102: strcmp(listen_addr, "127.0.0.1") == 0 ||
3103: strcmp(listen_addr, "::1") == 0) {
3104: /* Accept localhost address when GatewayPorts=yes */
3105: addr = listen_addr;
1.326 djm 3106: }
1.334 djm 3107: } else if (strcmp(listen_addr, "127.0.0.1") == 0 ||
3108: strcmp(listen_addr, "::1") == 0) {
3109: /*
3110: * If a specific IPv4/IPv6 localhost address has been
3111: * requested then accept it even if gateway_ports is in
3112: * effect. This allows the client to prefer IPv4 or IPv6.
3113: */
3114: addr = listen_addr;
1.312 djm 3115: }
3116: if (wildcardp != NULL)
3117: *wildcardp = wildcard;
3118: return addr;
3119: }
3120:
1.160 markus 3121: static int
1.367 djm 3122: channel_setup_fwd_listener_tcpip(struct ssh *ssh, int type,
3123: struct Forward *fwd, int *allocated_listen_port,
3124: struct ForwardOptions *fwd_opts)
1.25 markus 3125: {
1.113 markus 3126: Channel *c;
1.226 djm 3127: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 3128: struct addrinfo hints, *ai, *aitop;
1.212 djm 3129: const char *host, *addr;
1.35 markus 3130: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.295 djm 3131: in_port_t *lport_p;
1.25 markus 3132:
1.212 djm 3133: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 3134:
1.344 millert 3135: if (is_client && fwd->connect_path != NULL) {
3136: host = fwd->connect_path;
3137: } else {
3138: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
3139: fwd->listen_host : fwd->connect_host;
3140: if (host == NULL) {
3141: error("No forward host name.");
3142: return 0;
3143: }
3144: if (strlen(host) >= NI_MAXHOST) {
3145: error("Forward host name too long.");
3146: return 0;
3147: }
1.87 markus 3148: }
1.25 markus 3149:
1.312 djm 3150: /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
1.336 millert 3151: addr = channel_fwd_bind_addr(fwd->listen_host, &wildcard,
3152: is_client, fwd_opts);
3153: debug3("%s: type %d wildcard %d addr %s", __func__,
1.212 djm 3154: type, wildcard, (addr == NULL) ? "NULL" : addr);
3155:
3156: /*
1.35 markus 3157: * getaddrinfo returns a loopback address if the hostname is
3158: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 3159: */
1.35 markus 3160: memset(&hints, 0, sizeof(hints));
1.367 djm 3161: hints.ai_family = ssh->chanctxt->IPv4or6;
1.212 djm 3162: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 3163: hints.ai_socktype = SOCK_STREAM;
1.336 millert 3164: snprintf(strport, sizeof strport, "%d", fwd->listen_port);
1.212 djm 3165: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
3166: if (addr == NULL) {
3167: /* This really shouldn't happen */
3168: packet_disconnect("getaddrinfo: fatal error: %s",
1.271 dtucker 3169: ssh_gai_strerror(r));
1.212 djm 3170: } else {
1.336 millert 3171: error("%s: getaddrinfo(%.64s): %s", __func__, addr,
1.271 dtucker 3172: ssh_gai_strerror(r));
1.212 djm 3173: }
1.218 markus 3174: return 0;
1.212 djm 3175: }
1.295 djm 3176: if (allocated_listen_port != NULL)
3177: *allocated_listen_port = 0;
1.35 markus 3178: for (ai = aitop; ai; ai = ai->ai_next) {
1.295 djm 3179: switch (ai->ai_family) {
3180: case AF_INET:
3181: lport_p = &((struct sockaddr_in *)ai->ai_addr)->
3182: sin_port;
3183: break;
3184: case AF_INET6:
3185: lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
3186: sin6_port;
3187: break;
3188: default:
1.35 markus 3189: continue;
1.295 djm 3190: }
3191: /*
3192: * If allocating a port for -R forwards, then use the
3193: * same port for all address families.
3194: */
1.367 djm 3195: if (type == SSH_CHANNEL_RPORT_LISTENER &&
3196: fwd->listen_port == 0 && allocated_listen_port != NULL &&
3197: *allocated_listen_port > 0)
1.295 djm 3198: *lport_p = htons(*allocated_listen_port);
3199:
1.35 markus 3200: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
1.367 djm 3201: strport, sizeof(strport),
3202: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.336 millert 3203: error("%s: getnameinfo failed", __func__);
1.35 markus 3204: continue;
3205: }
3206: /* Create a port to listen for the host. */
1.300 dtucker 3207: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 3208: if (sock < 0) {
3209: /* this is no error since kernel may not support ipv6 */
3210: verbose("socket: %.100s", strerror(errno));
3211: continue;
3212: }
1.226 djm 3213:
3214: channel_set_reuseaddr(sock);
1.182 stevesk 3215:
1.295 djm 3216: debug("Local forwarding listening on %s port %s.",
3217: ntop, strport);
1.35 markus 3218:
3219: /* Bind the socket to the address. */
3220: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.367 djm 3221: /*
3222: * address can be in if use ipv6 address is
3223: * already bound
3224: */
1.35 markus 3225: verbose("bind: %.100s", strerror(errno));
3226: close(sock);
3227: continue;
3228: }
3229: /* Start listening for connections on the socket. */
1.199 markus 3230: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 3231: error("listen: %.100s", strerror(errno));
3232: close(sock);
3233: continue;
3234: }
1.295 djm 3235:
3236: /*
1.336 millert 3237: * fwd->listen_port == 0 requests a dynamically allocated port -
1.295 djm 3238: * record what we got.
3239: */
1.367 djm 3240: if (type == SSH_CHANNEL_RPORT_LISTENER &&
3241: fwd->listen_port == 0 &&
1.295 djm 3242: allocated_listen_port != NULL &&
3243: *allocated_listen_port == 0) {
1.350 djm 3244: *allocated_listen_port = get_local_port(sock);
1.295 djm 3245: debug("Allocated listen port %d",
3246: *allocated_listen_port);
3247: }
3248:
1.35 markus 3249: /* Allocate a channel number for the socket. */
1.367 djm 3250: c = channel_new(ssh, "port listener", type, sock, sock, -1,
1.51 markus 3251: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 3252: 0, "port listener", 1);
1.293 djm 3253: c->path = xstrdup(host);
1.336 millert 3254: c->host_port = fwd->connect_port;
1.312 djm 3255: c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
1.336 millert 3256: if (fwd->listen_port == 0 && allocated_listen_port != NULL &&
1.315 markus 3257: !(datafellows & SSH_BUG_DYNAMIC_RPORT))
3258: c->listening_port = *allocated_listen_port;
3259: else
1.336 millert 3260: c->listening_port = fwd->listen_port;
1.35 markus 3261: success = 1;
3262: }
3263: if (success == 0)
1.336 millert 3264: error("%s: cannot listen to port: %d", __func__,
3265: fwd->listen_port);
1.35 markus 3266: freeaddrinfo(aitop);
1.87 markus 3267: return success;
1.25 markus 3268: }
1.1 deraadt 3269:
1.336 millert 3270: static int
1.367 djm 3271: channel_setup_fwd_listener_streamlocal(struct ssh *ssh, int type,
3272: struct Forward *fwd, struct ForwardOptions *fwd_opts)
1.336 millert 3273: {
3274: struct sockaddr_un sunaddr;
3275: const char *path;
3276: Channel *c;
3277: int port, sock;
3278: mode_t omask;
3279:
3280: switch (type) {
3281: case SSH_CHANNEL_UNIX_LISTENER:
3282: if (fwd->connect_path != NULL) {
3283: if (strlen(fwd->connect_path) > sizeof(sunaddr.sun_path)) {
3284: error("Local connecting path too long: %s",
3285: fwd->connect_path);
3286: return 0;
3287: }
3288: path = fwd->connect_path;
3289: port = PORT_STREAMLOCAL;
3290: } else {
3291: if (fwd->connect_host == NULL) {
3292: error("No forward host name.");
3293: return 0;
3294: }
3295: if (strlen(fwd->connect_host) >= NI_MAXHOST) {
3296: error("Forward host name too long.");
3297: return 0;
3298: }
3299: path = fwd->connect_host;
3300: port = fwd->connect_port;
3301: }
3302: break;
3303: case SSH_CHANNEL_RUNIX_LISTENER:
3304: path = fwd->listen_path;
3305: port = PORT_STREAMLOCAL;
3306: break;
3307: default:
3308: error("%s: unexpected channel type %d", __func__, type);
3309: return 0;
3310: }
3311:
3312: if (fwd->listen_path == NULL) {
3313: error("No forward path name.");
3314: return 0;
3315: }
3316: if (strlen(fwd->listen_path) > sizeof(sunaddr.sun_path)) {
3317: error("Local listening path too long: %s", fwd->listen_path);
3318: return 0;
3319: }
3320:
3321: debug3("%s: type %d path %s", __func__, type, fwd->listen_path);
3322:
3323: /* Start a Unix domain listener. */
3324: omask = umask(fwd_opts->streamlocal_bind_mask);
3325: sock = unix_listener(fwd->listen_path, SSH_LISTEN_BACKLOG,
3326: fwd_opts->streamlocal_bind_unlink);
3327: umask(omask);
3328: if (sock < 0)
3329: return 0;
3330:
3331: debug("Local forwarding listening on path %s.", fwd->listen_path);
3332:
3333: /* Allocate a channel number for the socket. */
1.367 djm 3334: c = channel_new(ssh, "unix listener", type, sock, sock, -1,
1.336 millert 3335: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
3336: 0, "unix listener", 1);
3337: c->path = xstrdup(path);
3338: c->host_port = port;
3339: c->listening_port = PORT_STREAMLOCAL;
3340: c->listening_addr = xstrdup(fwd->listen_path);
3341: return 1;
3342: }
3343:
3344: static int
1.367 djm 3345: channel_cancel_rport_listener_tcpip(struct ssh *ssh,
3346: const char *host, u_short port)
1.202 djm 3347: {
1.209 avsm 3348: u_int i;
3349: int found = 0;
1.202 djm 3350:
1.367 djm 3351: for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
3352: Channel *c = ssh->chanctxt->channels[i];
1.312 djm 3353: if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
3354: continue;
3355: if (strcmp(c->path, host) == 0 && c->listening_port == port) {
3356: debug2("%s: close channel %d", __func__, i);
1.367 djm 3357: channel_free(ssh, c);
1.312 djm 3358: found = 1;
3359: }
3360: }
3361:
1.367 djm 3362: return found;
1.312 djm 3363: }
3364:
1.336 millert 3365: static int
1.367 djm 3366: channel_cancel_rport_listener_streamlocal(struct ssh *ssh, const char *path)
1.336 millert 3367: {
3368: u_int i;
3369: int found = 0;
3370:
1.367 djm 3371: for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
3372: Channel *c = ssh->chanctxt->channels[i];
1.336 millert 3373: if (c == NULL || c->type != SSH_CHANNEL_RUNIX_LISTENER)
3374: continue;
3375: if (c->path == NULL)
3376: continue;
3377: if (strcmp(c->path, path) == 0) {
3378: debug2("%s: close channel %d", __func__, i);
1.367 djm 3379: channel_free(ssh, c);
1.336 millert 3380: found = 1;
3381: }
3382: }
3383:
1.367 djm 3384: return found;
1.336 millert 3385: }
3386:
1.312 djm 3387: int
1.367 djm 3388: channel_cancel_rport_listener(struct ssh *ssh, struct Forward *fwd)
1.336 millert 3389: {
1.367 djm 3390: if (fwd->listen_path != NULL) {
3391: return channel_cancel_rport_listener_streamlocal(ssh,
3392: fwd->listen_path);
3393: } else {
3394: return channel_cancel_rport_listener_tcpip(ssh,
3395: fwd->listen_host, fwd->listen_port);
3396: }
1.336 millert 3397: }
3398:
3399: static int
1.367 djm 3400: channel_cancel_lport_listener_tcpip(struct ssh *ssh,
3401: const char *lhost, u_short lport, int cport,
3402: struct ForwardOptions *fwd_opts)
1.312 djm 3403: {
3404: u_int i;
3405: int found = 0;
1.336 millert 3406: const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, fwd_opts);
1.202 djm 3407:
1.367 djm 3408: for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
3409: Channel *c = ssh->chanctxt->channels[i];
1.312 djm 3410: if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
3411: continue;
1.313 markus 3412: if (c->listening_port != lport)
1.312 djm 3413: continue;
1.313 markus 3414: if (cport == CHANNEL_CANCEL_PORT_STATIC) {
3415: /* skip dynamic forwardings */
3416: if (c->host_port == 0)
3417: continue;
3418: } else {
3419: if (c->host_port != cport)
3420: continue;
3421: }
1.312 djm 3422: if ((c->listening_addr == NULL && addr != NULL) ||
3423: (c->listening_addr != NULL && addr == NULL))
3424: continue;
3425: if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
1.210 djm 3426: debug2("%s: close channel %d", __func__, i);
1.367 djm 3427: channel_free(ssh, c);
1.202 djm 3428: found = 1;
3429: }
3430: }
3431:
1.367 djm 3432: return found;
1.202 djm 3433: }
3434:
1.336 millert 3435: static int
1.367 djm 3436: channel_cancel_lport_listener_streamlocal(struct ssh *ssh, const char *path)
1.336 millert 3437: {
3438: u_int i;
3439: int found = 0;
3440:
3441: if (path == NULL) {
3442: error("%s: no path specified.", __func__);
3443: return 0;
3444: }
3445:
1.367 djm 3446: for (i = 0; i < ssh->chanctxt->channels_alloc; i++) {
3447: Channel *c = ssh->chanctxt->channels[i];
1.336 millert 3448: if (c == NULL || c->type != SSH_CHANNEL_UNIX_LISTENER)
3449: continue;
3450: if (c->listening_addr == NULL)
3451: continue;
3452: if (strcmp(c->listening_addr, path) == 0) {
3453: debug2("%s: close channel %d", __func__, i);
1.367 djm 3454: channel_free(ssh, c);
1.336 millert 3455: found = 1;
3456: }
3457: }
3458:
1.367 djm 3459: return found;
1.336 millert 3460: }
3461:
3462: int
1.367 djm 3463: channel_cancel_lport_listener(struct ssh *ssh,
3464: struct Forward *fwd, int cport, struct ForwardOptions *fwd_opts)
1.336 millert 3465: {
1.367 djm 3466: if (fwd->listen_path != NULL) {
3467: return channel_cancel_lport_listener_streamlocal(ssh,
3468: fwd->listen_path);
3469: } else {
3470: return channel_cancel_lport_listener_tcpip(ssh,
3471: fwd->listen_host, fwd->listen_port, cport, fwd_opts);
3472: }
1.336 millert 3473: }
3474:
1.362 markus 3475: /* protocol local port fwd, used by ssh */
1.160 markus 3476: int
1.367 djm 3477: channel_setup_local_fwd_listener(struct ssh *ssh,
3478: struct Forward *fwd, struct ForwardOptions *fwd_opts)
1.160 markus 3479: {
1.336 millert 3480: if (fwd->listen_path != NULL) {
1.367 djm 3481: return channel_setup_fwd_listener_streamlocal(ssh,
1.336 millert 3482: SSH_CHANNEL_UNIX_LISTENER, fwd, fwd_opts);
3483: } else {
1.367 djm 3484: return channel_setup_fwd_listener_tcpip(ssh,
3485: SSH_CHANNEL_PORT_LISTENER, fwd, NULL, fwd_opts);
1.336 millert 3486: }
1.160 markus 3487: }
3488:
3489: /* protocol v2 remote port fwd, used by sshd */
3490: int
1.367 djm 3491: channel_setup_remote_fwd_listener(struct ssh *ssh, struct Forward *fwd,
1.336 millert 3492: int *allocated_listen_port, struct ForwardOptions *fwd_opts)
1.160 markus 3493: {
1.336 millert 3494: if (fwd->listen_path != NULL) {
1.367 djm 3495: return channel_setup_fwd_listener_streamlocal(ssh,
1.336 millert 3496: SSH_CHANNEL_RUNIX_LISTENER, fwd, fwd_opts);
3497: } else {
1.367 djm 3498: return channel_setup_fwd_listener_tcpip(ssh,
1.336 millert 3499: SSH_CHANNEL_RPORT_LISTENER, fwd, allocated_listen_port,
3500: fwd_opts);
3501: }
1.160 markus 3502: }
3503:
1.27 markus 3504: /*
1.312 djm 3505: * Translate the requested rfwd listen host to something usable for
3506: * this server.
3507: */
3508: static const char *
3509: channel_rfwd_bind_host(const char *listen_host)
3510: {
3511: if (listen_host == NULL) {
3512: if (datafellows & SSH_BUG_RFWD_ADDR)
3513: return "127.0.0.1";
3514: else
3515: return "localhost";
3516: } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
3517: if (datafellows & SSH_BUG_RFWD_ADDR)
3518: return "0.0.0.0";
3519: else
3520: return "";
3521: } else
3522: return listen_host;
3523: }
3524:
3525: /*
1.27 markus 3526: * Initiate forwarding of connections to port "port" on remote host through
3527: * the secure channel to host:port from local side.
1.315 markus 3528: * Returns handle (index) for updating the dynamic listen port with
3529: * channel_update_permitted_opens().
1.27 markus 3530: */
1.253 markus 3531: int
1.367 djm 3532: channel_request_remote_forwarding(struct ssh *ssh, struct Forward *fwd)
1.25 markus 3533: {
1.367 djm 3534: int r, success = 0, idx = -1;
3535: char *host_to_connect, *listen_host, *listen_path;
3536: int port_to_connect, listen_port;
1.73 markus 3537:
1.25 markus 3538: /* Send the forward request to the remote side. */
1.358 djm 3539: if (fwd->listen_path != NULL) {
1.367 djm 3540: if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
3541: (r = sshpkt_put_cstring(ssh,
3542: "streamlocal-forward@openssh.com")) != 0 ||
3543: (r = sshpkt_put_u8(ssh, 1)) != 0 || /* want reply */
3544: (r = sshpkt_put_cstring(ssh, fwd->listen_path)) != 0 ||
3545: (r = sshpkt_send(ssh)) != 0 ||
3546: (r = ssh_packet_write_wait(ssh)) != 0)
3547: fatal("%s: request streamlocal: %s",
3548: __func__, ssh_err(r));
1.336 millert 3549: } else {
1.367 djm 3550: if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
3551: (r = sshpkt_put_cstring(ssh, "tcpip-forward")) != 0 ||
3552: (r = sshpkt_put_u8(ssh, 1)) != 0 || /* want reply */
3553: (r = sshpkt_put_cstring(ssh,
3554: channel_rfwd_bind_host(fwd->listen_host))) != 0 ||
3555: (r = sshpkt_put_u32(ssh, fwd->listen_port)) != 0 ||
3556: (r = sshpkt_send(ssh)) != 0 ||
3557: (r = ssh_packet_write_wait(ssh)) != 0)
3558: fatal("%s: request tcpip-forward: %s",
3559: __func__, ssh_err(r));
1.73 markus 3560: }
1.358 djm 3561: /* Assume that server accepts the request */
3562: success = 1;
1.73 markus 3563: if (success) {
1.305 djm 3564: /* Record that connection to this host/port is permitted. */
1.367 djm 3565: host_to_connect = listen_host = listen_path = NULL;
3566: port_to_connect = listen_port = 0;
1.336 millert 3567: if (fwd->connect_path != NULL) {
1.367 djm 3568: host_to_connect = xstrdup(fwd->connect_path);
3569: port_to_connect = PORT_STREAMLOCAL;
1.336 millert 3570: } else {
1.367 djm 3571: host_to_connect = xstrdup(fwd->connect_host);
3572: port_to_connect = fwd->connect_port;
1.336 millert 3573: }
3574: if (fwd->listen_path != NULL) {
1.367 djm 3575: listen_path = xstrdup(fwd->listen_path);
3576: listen_port = PORT_STREAMLOCAL;
1.336 millert 3577: } else {
1.367 djm 3578: if (fwd->listen_host != NULL)
3579: listen_host = xstrdup(fwd->listen_host);
3580: listen_port = fwd->listen_port;
3581: }
3582: idx = fwd_perm_list_add(ssh, FWDPERM_USER,
3583: host_to_connect, port_to_connect,
3584: listen_host, listen_path, listen_port, NULL);
1.44 markus 3585: }
1.367 djm 3586: return idx;
1.1 deraadt 3587: }
3588:
1.333 markus 3589: static int
3590: open_match(ForwardPermission *allowed_open, const char *requestedhost,
1.336 millert 3591: int requestedport)
1.333 markus 3592: {
3593: if (allowed_open->host_to_connect == NULL)
3594: return 0;
3595: if (allowed_open->port_to_connect != FWD_PERMIT_ANY_PORT &&
3596: allowed_open->port_to_connect != requestedport)
3597: return 0;
1.351 dtucker 3598: if (strcmp(allowed_open->host_to_connect, FWD_PERMIT_ANY_HOST) != 0 &&
3599: strcmp(allowed_open->host_to_connect, requestedhost) != 0)
1.333 markus 3600: return 0;
3601: return 1;
3602: }
3603:
3604: /*
1.336 millert 3605: * Note that in the listen host/port case
1.333 markus 3606: * we don't support FWD_PERMIT_ANY_PORT and
3607: * need to translate between the configured-host (listen_host)
3608: * and what we've sent to the remote server (channel_rfwd_bind_host)
3609: */
3610: static int
1.336 millert 3611: open_listen_match_tcpip(ForwardPermission *allowed_open,
3612: const char *requestedhost, u_short requestedport, int translate)
1.333 markus 3613: {
3614: const char *allowed_host;
3615:
3616: if (allowed_open->host_to_connect == NULL)
3617: return 0;
3618: if (allowed_open->listen_port != requestedport)
3619: return 0;
1.335 djm 3620: if (!translate && allowed_open->listen_host == NULL &&
3621: requestedhost == NULL)
3622: return 1;
1.333 markus 3623: allowed_host = translate ?
3624: channel_rfwd_bind_host(allowed_open->listen_host) :
3625: allowed_open->listen_host;
3626: if (allowed_host == NULL ||
3627: strcmp(allowed_host, requestedhost) != 0)
3628: return 0;
3629: return 1;
3630: }
3631:
1.336 millert 3632: static int
3633: open_listen_match_streamlocal(ForwardPermission *allowed_open,
3634: const char *requestedpath)
3635: {
3636: if (allowed_open->host_to_connect == NULL)
3637: return 0;
3638: if (allowed_open->listen_port != PORT_STREAMLOCAL)
3639: return 0;
3640: if (allowed_open->listen_path == NULL ||
3641: strcmp(allowed_open->listen_path, requestedpath) != 0)
3642: return 0;
3643: return 1;
3644: }
3645:
1.27 markus 3646: /*
1.208 deraadt 3647: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 3648: * local side.
3649: */
1.336 millert 3650: static int
1.367 djm 3651: channel_request_rforward_cancel_tcpip(struct ssh *ssh,
3652: const char *host, u_short port)
1.202 djm 3653: {
1.367 djm 3654: struct ssh_channels *sc = ssh->chanctxt;
3655: int r;
3656: u_int i;
3657: ForwardPermission *fp;
1.202 djm 3658:
1.367 djm 3659: for (i = 0; i < sc->num_permitted_opens; i++) {
3660: fp = &sc->permitted_opens[i];
3661: if (open_listen_match_tcpip(fp, host, port, 0))
1.202 djm 3662: break;
1.367 djm 3663: fp = NULL;
1.202 djm 3664: }
1.367 djm 3665: if (fp == NULL) {
1.202 djm 3666: debug("%s: requested forward not found", __func__);
1.312 djm 3667: return -1;
1.202 djm 3668: }
1.367 djm 3669: if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
3670: (r = sshpkt_put_cstring(ssh, "cancel-tcpip-forward")) != 0 ||
3671: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* want reply */
3672: (r = sshpkt_put_cstring(ssh, channel_rfwd_bind_host(host))) != 0 ||
3673: (r = sshpkt_put_u32(ssh, port)) != 0 ||
3674: (r = sshpkt_send(ssh)) != 0)
3675: fatal("%s: send cancel: %s", __func__, ssh_err(r));
3676:
3677: fwd_perm_clear(fp); /* unregister */
1.336 millert 3678:
3679: return 0;
3680: }
3681:
3682: /*
3683: * Request cancellation of remote forwarding of Unix domain socket
3684: * path from local side.
3685: */
3686: static int
1.367 djm 3687: channel_request_rforward_cancel_streamlocal(struct ssh *ssh, const char *path)
1.336 millert 3688: {
1.367 djm 3689: struct ssh_channels *sc = ssh->chanctxt;
3690: int r;
3691: u_int i;
3692: ForwardPermission *fp;
1.336 millert 3693:
1.367 djm 3694: for (i = 0; i < sc->num_permitted_opens; i++) {
3695: fp = &sc->permitted_opens[i];
3696: if (open_listen_match_streamlocal(fp, path))
1.336 millert 3697: break;
1.367 djm 3698: fp = NULL;
1.336 millert 3699: }
1.367 djm 3700: if (fp == NULL) {
1.336 millert 3701: debug("%s: requested forward not found", __func__);
3702: return -1;
3703: }
1.367 djm 3704: if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
3705: (r = sshpkt_put_cstring(ssh,
3706: "cancel-streamlocal-forward@openssh.com")) != 0 ||
3707: (r = sshpkt_put_u8(ssh, 0)) != 0 || /* want reply */
3708: (r = sshpkt_put_cstring(ssh, path)) != 0 ||
3709: (r = sshpkt_send(ssh)) != 0)
3710: fatal("%s: send cancel: %s", __func__, ssh_err(r));
3711:
3712: fwd_perm_clear(fp); /* unregister */
1.312 djm 3713:
3714: return 0;
1.202 djm 3715: }
3716:
3717: /*
1.336 millert 3718: * Request cancellation of remote forwarding of a connection from local side.
3719: */
3720: int
1.367 djm 3721: channel_request_rforward_cancel(struct ssh *ssh, struct Forward *fwd)
1.336 millert 3722: {
3723: if (fwd->listen_path != NULL) {
1.367 djm 3724: return channel_request_rforward_cancel_streamlocal(ssh,
3725: fwd->listen_path);
1.336 millert 3726: } else {
1.367 djm 3727: return channel_request_rforward_cancel_tcpip(ssh,
3728: fwd->listen_host,
3729: fwd->listen_port ? fwd->listen_port : fwd->allocated_port);
1.336 millert 3730: }
1.1 deraadt 3731: }
3732:
1.99 markus 3733: /*
3734: * Permits opening to any host/port if permitted_opens[] is empty. This is
3735: * usually called by the server, because the user could connect to any port
3736: * anyway, and the server has no way to know but to trust the client anyway.
3737: */
3738: void
1.367 djm 3739: channel_permit_all_opens(struct ssh *ssh)
1.99 markus 3740: {
1.367 djm 3741: if (ssh->chanctxt->num_permitted_opens == 0)
3742: ssh->chanctxt->all_opens_permitted = 1;
1.99 markus 3743: }
3744:
1.101 markus 3745: void
1.367 djm 3746: channel_add_permitted_opens(struct ssh *ssh, char *host, int port)
1.99 markus 3747: {
1.367 djm 3748: struct ssh_channels *sc = ssh->chanctxt;
3749:
1.99 markus 3750: debug("allow port forwarding to host %s port %d", host, port);
1.367 djm 3751: fwd_perm_list_add(ssh, FWDPERM_USER, host, port, NULL, NULL, 0, NULL);
3752: sc->all_opens_permitted = 0;
1.315 markus 3753: }
3754:
3755: /*
3756: * Update the listen port for a dynamic remote forward, after
3757: * the actual 'newport' has been allocated. If 'newport' < 0 is
3758: * passed then they entry will be invalidated.
3759: */
3760: void
1.367 djm 3761: channel_update_permitted_opens(struct ssh *ssh, int idx, int newport)
1.315 markus 3762: {
1.367 djm 3763: struct ssh_channels *sc = ssh->chanctxt;
3764:
3765: if (idx < 0 || (u_int)idx >= sc->num_permitted_opens) {
3766: debug("%s: index out of range: %d num_permitted_opens %d",
3767: __func__, idx, sc->num_permitted_opens);
1.315 markus 3768: return;
3769: }
3770: debug("%s allowed port %d for forwarding to host %s port %d",
3771: newport > 0 ? "Updating" : "Removing",
3772: newport,
1.367 djm 3773: sc->permitted_opens[idx].host_to_connect,
3774: sc->permitted_opens[idx].port_to_connect);
3775: if (newport <= 0)
3776: fwd_perm_clear(&sc->permitted_opens[idx]);
3777: else {
3778: sc->permitted_opens[idx].listen_port =
1.315 markus 3779: (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
3780: }
1.99 markus 3781: }
3782:
1.258 dtucker 3783: int
1.367 djm 3784: channel_add_adm_permitted_opens(struct ssh *ssh, char *host, int port)
1.257 dtucker 3785: {
1.258 dtucker 3786: debug("config allows port forwarding to host %s port %d", host, port);
1.367 djm 3787: return fwd_perm_list_add(ssh, FWDPERM_ADMIN, host, port,
3788: NULL, NULL, 0, NULL);
1.316 dtucker 3789: }
3790:
3791: void
1.367 djm 3792: channel_disable_adm_local_opens(struct ssh *ssh)
1.99 markus 3793: {
1.367 djm 3794: channel_clear_adm_permitted_opens(ssh);
3795: fwd_perm_list_add(ssh, FWDPERM_ADMIN, NULL, 0, NULL, NULL, 0, NULL);
1.257 dtucker 3796: }
3797:
3798: void
1.367 djm 3799: channel_clear_permitted_opens(struct ssh *ssh)
1.257 dtucker 3800: {
1.367 djm 3801: struct ssh_channels *sc = ssh->chanctxt;
1.99 markus 3802:
1.367 djm 3803: sc->permitted_opens = xrecallocarray(sc->permitted_opens,
3804: sc->num_permitted_opens, 0, sizeof(*sc->permitted_opens));
3805: sc->num_permitted_opens = 0;
1.278 dtucker 3806: }
3807:
3808: void
1.367 djm 3809: channel_clear_adm_permitted_opens(struct ssh *ssh)
1.278 dtucker 3810: {
1.367 djm 3811: struct ssh_channels *sc = ssh->chanctxt;
1.278 dtucker 3812:
1.367 djm 3813: sc->permitted_adm_opens = xrecallocarray(sc->permitted_adm_opens,
3814: sc->num_adm_permitted_opens, 0, sizeof(*sc->permitted_adm_opens));
3815: sc->num_adm_permitted_opens = 0;
1.99 markus 3816: }
3817:
1.314 dtucker 3818: /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
3819: int
3820: permitopen_port(const char *p)
3821: {
3822: int port;
3823:
3824: if (strcmp(p, "*") == 0)
3825: return FWD_PERMIT_ANY_PORT;
3826: if ((port = a2port(p)) > 0)
3827: return port;
3828: return -1;
3829: }
3830:
1.276 djm 3831: /* Try to start non-blocking connect to next host in cctx list */
1.127 itojun 3832: static int
1.276 djm 3833: connect_next(struct channel_connect *cctx)
1.41 markus 3834: {
1.276 djm 3835: int sock, saved_errno;
1.336 millert 3836: struct sockaddr_un *sunaddr;
1.367 djm 3837: char ntop[NI_MAXHOST];
3838: char strport[MAXIMUM(NI_MAXSERV, sizeof(sunaddr->sun_path))];
1.41 markus 3839:
1.276 djm 3840: for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
1.336 millert 3841: switch (cctx->ai->ai_family) {
3842: case AF_UNIX:
3843: /* unix:pathname instead of host:port */
3844: sunaddr = (struct sockaddr_un *)cctx->ai->ai_addr;
3845: strlcpy(ntop, "unix", sizeof(ntop));
3846: strlcpy(strport, sunaddr->sun_path, sizeof(strport));
3847: break;
3848: case AF_INET:
3849: case AF_INET6:
3850: if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3851: ntop, sizeof(ntop), strport, sizeof(strport),
3852: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3853: error("connect_next: getnameinfo failed");
3854: continue;
3855: }
3856: break;
3857: default:
1.41 markus 3858: continue;
3859: }
1.300 dtucker 3860: if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3861: cctx->ai->ai_protocol)) == -1) {
1.276 djm 3862: if (cctx->ai->ai_next == NULL)
1.186 djm 3863: error("socket: %.100s", strerror(errno));
3864: else
3865: verbose("socket: %.100s", strerror(errno));
1.41 markus 3866: continue;
3867: }
1.205 djm 3868: if (set_nonblock(sock) == -1)
3869: fatal("%s: set_nonblock(%d)", __func__, sock);
1.276 djm 3870: if (connect(sock, cctx->ai->ai_addr,
3871: cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3872: debug("connect_next: host %.100s ([%.100s]:%s): "
3873: "%.100s", cctx->host, ntop, strport,
1.41 markus 3874: strerror(errno));
1.276 djm 3875: saved_errno = errno;
1.41 markus 3876: close(sock);
1.276 djm 3877: errno = saved_errno;
1.89 stevesk 3878: continue; /* fail -- try next */
1.41 markus 3879: }
1.336 millert 3880: if (cctx->ai->ai_family != AF_UNIX)
3881: set_nodelay(sock);
1.276 djm 3882: debug("connect_next: host %.100s ([%.100s]:%s) "
3883: "in progress, fd=%d", cctx->host, ntop, strport, sock);
3884: cctx->ai = cctx->ai->ai_next;
3885: return sock;
3886: }
3887: return -1;
3888: }
1.41 markus 3889:
1.276 djm 3890: static void
3891: channel_connect_ctx_free(struct channel_connect *cctx)
3892: {
1.321 djm 3893: free(cctx->host);
1.336 millert 3894: if (cctx->aitop) {
3895: if (cctx->aitop->ai_family == AF_UNIX)
3896: free(cctx->aitop);
3897: else
3898: freeaddrinfo(cctx->aitop);
3899: }
1.329 tedu 3900: memset(cctx, 0, sizeof(*cctx));
1.276 djm 3901: }
3902:
1.357 dtucker 3903: /*
3904: * Return CONNECTING channel to remote host:port or local socket path,
3905: * passing back the failure reason if appropriate.
3906: */
1.276 djm 3907: static Channel *
1.367 djm 3908: connect_to_reason(struct ssh *ssh, const char *name, int port,
3909: char *ctype, char *rname, int *reason, const char **errmsg)
1.276 djm 3910: {
3911: struct addrinfo hints;
3912: int gaierr;
3913: int sock = -1;
3914: char strport[NI_MAXSERV];
3915: struct channel_connect cctx;
3916: Channel *c;
3917:
1.284 djm 3918: memset(&cctx, 0, sizeof(cctx));
1.336 millert 3919:
3920: if (port == PORT_STREAMLOCAL) {
3921: struct sockaddr_un *sunaddr;
3922: struct addrinfo *ai;
3923:
3924: if (strlen(name) > sizeof(sunaddr->sun_path)) {
3925: error("%.100s: %.100s", name, strerror(ENAMETOOLONG));
3926: return (NULL);
3927: }
3928:
3929: /*
3930: * Fake up a struct addrinfo for AF_UNIX connections.
3931: * channel_connect_ctx_free() must check ai_family
3932: * and use free() not freeaddirinfo() for AF_UNIX.
3933: */
3934: ai = xmalloc(sizeof(*ai) + sizeof(*sunaddr));
3935: memset(ai, 0, sizeof(*ai) + sizeof(*sunaddr));
3936: ai->ai_addr = (struct sockaddr *)(ai + 1);
3937: ai->ai_addrlen = sizeof(*sunaddr);
3938: ai->ai_family = AF_UNIX;
3939: ai->ai_socktype = SOCK_STREAM;
3940: ai->ai_protocol = PF_UNSPEC;
3941: sunaddr = (struct sockaddr_un *)ai->ai_addr;
3942: sunaddr->sun_family = AF_UNIX;
3943: strlcpy(sunaddr->sun_path, name, sizeof(sunaddr->sun_path));
3944: cctx.aitop = ai;
3945: } else {
3946: memset(&hints, 0, sizeof(hints));
1.367 djm 3947: hints.ai_family = ssh->chanctxt->IPv4or6;
1.336 millert 3948: hints.ai_socktype = SOCK_STREAM;
3949: snprintf(strport, sizeof strport, "%d", port);
1.357 dtucker 3950: if ((gaierr = getaddrinfo(name, strport, &hints, &cctx.aitop))
3951: != 0) {
3952: if (errmsg != NULL)
3953: *errmsg = ssh_gai_strerror(gaierr);
3954: if (reason != NULL)
3955: *reason = SSH2_OPEN_CONNECT_FAILED;
1.336 millert 3956: error("connect_to %.100s: unknown host (%s)", name,
3957: ssh_gai_strerror(gaierr));
3958: return NULL;
3959: }
1.41 markus 3960: }
1.276 djm 3961:
1.336 millert 3962: cctx.host = xstrdup(name);
1.276 djm 3963: cctx.port = port;
3964: cctx.ai = cctx.aitop;
3965:
3966: if ((sock = connect_next(&cctx)) == -1) {
3967: error("connect to %.100s port %d failed: %s",
1.336 millert 3968: name, port, strerror(errno));
1.276 djm 3969: channel_connect_ctx_free(&cctx);
3970: return NULL;
1.41 markus 3971: }
1.367 djm 3972: c = channel_new(ssh, ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
1.276 djm 3973: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3974: c->connect_ctx = cctx;
3975: return c;
1.41 markus 3976: }
1.99 markus 3977:
1.357 dtucker 3978: /* Return CONNECTING channel to remote host:port or local socket path */
3979: static Channel *
1.367 djm 3980: connect_to(struct ssh *ssh, const char *name, int port,
3981: char *ctype, char *rname)
1.357 dtucker 3982: {
1.367 djm 3983: return connect_to_reason(ssh, name, port, ctype, rname, NULL, NULL);
1.357 dtucker 3984: }
3985:
1.354 markus 3986: /*
3987: * returns either the newly connected channel or the downstream channel
3988: * that needs to deal with this connection.
3989: */
1.276 djm 3990: Channel *
1.367 djm 3991: channel_connect_by_listen_address(struct ssh *ssh, const char *listen_host,
1.333 markus 3992: u_short listen_port, char *ctype, char *rname)
1.73 markus 3993: {
1.367 djm 3994: struct ssh_channels *sc = ssh->chanctxt;
3995: u_int i;
3996: ForwardPermission *fp;
1.99 markus 3997:
1.367 djm 3998: for (i = 0; i < sc->num_permitted_opens; i++) {
3999: fp = &sc->permitted_opens[i];
4000: if (open_listen_match_tcpip(fp, listen_host, listen_port, 1)) {
4001: if (fp->downstream)
4002: return fp->downstream;
4003: return connect_to(ssh,
4004: fp->host_to_connect, fp->port_to_connect,
4005: ctype, rname);
1.276 djm 4006: }
4007: }
1.74 markus 4008: error("WARNING: Server requests forwarding for unknown listen_port %d",
4009: listen_port);
1.276 djm 4010: return NULL;
1.73 markus 4011: }
4012:
1.336 millert 4013: Channel *
1.367 djm 4014: channel_connect_by_listen_path(struct ssh *ssh, const char *path,
4015: char *ctype, char *rname)
1.336 millert 4016: {
1.367 djm 4017: struct ssh_channels *sc = ssh->chanctxt;
4018: u_int i;
4019: ForwardPermission *fp;
1.336 millert 4020:
1.367 djm 4021: for (i = 0; i < sc->num_permitted_opens; i++) {
4022: fp = &sc->permitted_opens[i];
4023: if (open_listen_match_streamlocal(fp, path)) {
4024: return connect_to(ssh,
4025: fp->host_to_connect, fp->port_to_connect,
4026: ctype, rname);
1.336 millert 4027: }
4028: }
4029: error("WARNING: Server requests forwarding for unknown path %.100s",
4030: path);
4031: return NULL;
4032: }
4033:
1.99 markus 4034: /* Check if connecting to that port is permitted and connect. */
1.276 djm 4035: Channel *
1.367 djm 4036: channel_connect_to_port(struct ssh *ssh, const char *host, u_short port,
4037: char *ctype, char *rname, int *reason, const char **errmsg)
1.99 markus 4038: {
1.367 djm 4039: struct ssh_channels *sc = ssh->chanctxt;
4040: u_int i, permit, permit_adm = 1;
4041: ForwardPermission *fp;
1.99 markus 4042:
1.367 djm 4043: permit = sc->all_opens_permitted;
1.99 markus 4044: if (!permit) {
1.367 djm 4045: for (i = 0; i < sc->num_permitted_opens; i++) {
4046: fp = &sc->permitted_opens[i];
4047: if (open_match(fp, host, port)) {
1.99 markus 4048: permit = 1;
1.333 markus 4049: break;
4050: }
1.367 djm 4051: }
1.257 dtucker 4052: }
1.99 markus 4053:
1.367 djm 4054: if (sc->num_adm_permitted_opens > 0) {
1.257 dtucker 4055: permit_adm = 0;
1.367 djm 4056: for (i = 0; i < sc->num_adm_permitted_opens; i++) {
4057: fp = &sc->permitted_adm_opens[i];
4058: if (open_match(fp, host, port)) {
1.257 dtucker 4059: permit_adm = 1;
1.333 markus 4060: break;
4061: }
1.367 djm 4062: }
1.99 markus 4063: }
1.257 dtucker 4064:
4065: if (!permit || !permit_adm) {
1.188 itojun 4066: logit("Received request to connect to host %.100s port %d, "
1.99 markus 4067: "but the request was denied.", host, port);
1.357 dtucker 4068: if (reason != NULL)
4069: *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
1.276 djm 4070: return NULL;
1.99 markus 4071: }
1.367 djm 4072: return connect_to_reason(ssh, host, port, ctype, rname, reason, errmsg);
1.336 millert 4073: }
4074:
4075: /* Check if connecting to that path is permitted and connect. */
4076: Channel *
1.367 djm 4077: channel_connect_to_path(struct ssh *ssh, const char *path,
4078: char *ctype, char *rname)
1.336 millert 4079: {
1.367 djm 4080: struct ssh_channels *sc = ssh->chanctxt;
4081: u_int i, permit, permit_adm = 1;
4082: ForwardPermission *fp;
1.336 millert 4083:
1.367 djm 4084: permit = sc->all_opens_permitted;
1.336 millert 4085: if (!permit) {
1.367 djm 4086: for (i = 0; i < sc->num_permitted_opens; i++) {
4087: fp = &sc->permitted_opens[i];
4088: if (open_match(fp, path, PORT_STREAMLOCAL)) {
1.336 millert 4089: permit = 1;
4090: break;
4091: }
1.367 djm 4092: }
1.336 millert 4093: }
4094:
1.367 djm 4095: if (sc->num_adm_permitted_opens > 0) {
1.336 millert 4096: permit_adm = 0;
1.367 djm 4097: for (i = 0; i < sc->num_adm_permitted_opens; i++) {
4098: fp = &sc->permitted_adm_opens[i];
4099: if (open_match(fp, path, PORT_STREAMLOCAL)) {
1.336 millert 4100: permit_adm = 1;
4101: break;
4102: }
1.367 djm 4103: }
1.336 millert 4104: }
4105:
4106: if (!permit || !permit_adm) {
4107: logit("Received request to connect to path %.100s, "
4108: "but the request was denied.", path);
4109: return NULL;
4110: }
1.367 djm 4111: return connect_to(ssh, path, PORT_STREAMLOCAL, ctype, rname);
1.204 djm 4112: }
4113:
4114: void
1.367 djm 4115: channel_send_window_changes(struct ssh *ssh)
1.204 djm 4116: {
1.367 djm 4117: struct ssh_channels *sc = ssh->chanctxt;
4118: struct winsize ws;
4119: int r;
1.209 avsm 4120: u_int i;
1.204 djm 4121:
1.367 djm 4122: for (i = 0; i < sc->channels_alloc; i++) {
4123: if (sc->channels[i] == NULL || !sc->channels[i]->client_tty ||
4124: sc->channels[i]->type != SSH_CHANNEL_OPEN)
1.204 djm 4125: continue;
1.367 djm 4126: if (ioctl(sc->channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
1.204 djm 4127: continue;
1.367 djm 4128: channel_request_start(ssh, i, "window-change", 0);
4129: if ((r = sshpkt_put_u32(ssh, (u_int)ws.ws_col)) != 0 ||
4130: (r = sshpkt_put_u32(ssh, (u_int)ws.ws_row)) != 0 ||
4131: (r = sshpkt_put_u32(ssh, (u_int)ws.ws_xpixel)) != 0 ||
4132: (r = sshpkt_put_u32(ssh, (u_int)ws.ws_ypixel)) != 0 ||
4133: (r = sshpkt_send(ssh)) != 0)
4134: fatal("%s: channel %u: send window-change: %s",
4135: __func__, i, ssh_err(r));
1.204 djm 4136: }
1.99 markus 4137: }
4138:
1.121 markus 4139: /* -- X11 forwarding */
1.1 deraadt 4140:
1.27 markus 4141: /*
4142: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 4143: * Returns 0 and a suitable display number for the DISPLAY variable
4144: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 4145: */
1.141 stevesk 4146: int
1.367 djm 4147: x11_create_display_inet(struct ssh *ssh, int x11_display_offset,
4148: int x11_use_localhost, int single_connection,
4149: u_int *display_numberp, int **chanids)
1.1 deraadt 4150: {
1.149 markus 4151: Channel *nc = NULL;
1.31 markus 4152: int display_number, sock;
4153: u_short port;
1.35 markus 4154: struct addrinfo hints, *ai, *aitop;
4155: char strport[NI_MAXSERV];
4156: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 4157:
1.224 markus 4158: if (chanids == NULL)
4159: return -1;
4160:
1.33 markus 4161: for (display_number = x11_display_offset;
1.148 deraadt 4162: display_number < MAX_DISPLAYS;
4163: display_number++) {
1.25 markus 4164: port = 6000 + display_number;
1.35 markus 4165: memset(&hints, 0, sizeof(hints));
1.367 djm 4166: hints.ai_family = ssh->chanctxt->IPv4or6;
1.163 stevesk 4167: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 4168: hints.ai_socktype = SOCK_STREAM;
4169: snprintf(strport, sizeof strport, "%d", port);
1.367 djm 4170: if ((gaierr = getaddrinfo(NULL, strport,
4171: &hints, &aitop)) != 0) {
1.271 dtucker 4172: error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
1.141 stevesk 4173: return -1;
1.25 markus 4174: }
1.35 markus 4175: for (ai = aitop; ai; ai = ai->ai_next) {
1.367 djm 4176: if (ai->ai_family != AF_INET &&
4177: ai->ai_family != AF_INET6)
1.35 markus 4178: continue;
1.300 dtucker 4179: sock = socket(ai->ai_family, ai->ai_socktype,
4180: ai->ai_protocol);
1.35 markus 4181: if (sock < 0) {
4182: error("socket: %.100s", strerror(errno));
1.203 markus 4183: freeaddrinfo(aitop);
1.141 stevesk 4184: return -1;
1.35 markus 4185: }
1.226 djm 4186: channel_set_reuseaddr(sock);
1.35 markus 4187: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.367 djm 4188: debug2("%s: bind port %d: %.100s", __func__,
4189: port, strerror(errno));
1.35 markus 4190: close(sock);
1.367 djm 4191: for (n = 0; n < num_socks; n++)
1.35 markus 4192: close(socks[n]);
4193: num_socks = 0;
4194: break;
4195: }
4196: socks[num_socks++] = sock;
4197: if (num_socks == NUM_SOCKS)
4198: break;
1.25 markus 4199: }
1.83 stevesk 4200: freeaddrinfo(aitop);
1.35 markus 4201: if (num_socks > 0)
4202: break;
1.25 markus 4203: }
4204: if (display_number >= MAX_DISPLAYS) {
4205: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 4206: return -1;
1.25 markus 4207: }
4208: /* Start listening for connections on the socket. */
1.35 markus 4209: for (n = 0; n < num_socks; n++) {
4210: sock = socks[n];
1.199 markus 4211: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 4212: error("listen: %.100s", strerror(errno));
4213: close(sock);
1.141 stevesk 4214: return -1;
1.35 markus 4215: }
1.25 markus 4216: }
1.35 markus 4217:
4218: /* Allocate a channel for each socket. */
1.242 djm 4219: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 4220: for (n = 0; n < num_socks; n++) {
4221: sock = socks[n];
1.367 djm 4222: nc = channel_new(ssh, "x11 listener",
1.51 markus 4223: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
4224: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 4225: 0, "X11 inet listener", 1);
1.167 markus 4226: nc->single_connection = single_connection;
1.224 markus 4227: (*chanids)[n] = nc->self;
1.35 markus 4228: }
1.224 markus 4229: (*chanids)[n] = -1;
1.1 deraadt 4230:
1.141 stevesk 4231: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 4232: *display_numberp = display_number;
1.367 djm 4233: return 0;
1.1 deraadt 4234: }
4235:
1.127 itojun 4236: static int
1.77 markus 4237: connect_local_xsocket(u_int dnr)
1.1 deraadt 4238: {
1.25 markus 4239: int sock;
4240: struct sockaddr_un addr;
4241:
1.147 stevesk 4242: sock = socket(AF_UNIX, SOCK_STREAM, 0);
4243: if (sock < 0)
4244: error("socket: %.100s", strerror(errno));
4245: memset(&addr, 0, sizeof(addr));
4246: addr.sun_family = AF_UNIX;
4247: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 4248: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 4249: return sock;
4250: close(sock);
1.25 markus 4251: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
4252: return -1;
1.1 deraadt 4253: }
4254:
1.51 markus 4255: int
1.367 djm 4256: x11_connect_display(struct ssh *ssh)
1.1 deraadt 4257: {
1.248 deraadt 4258: u_int display_number;
1.25 markus 4259: const char *display;
1.51 markus 4260: char buf[1024], *cp;
1.35 markus 4261: struct addrinfo hints, *ai, *aitop;
4262: char strport[NI_MAXSERV];
1.248 deraadt 4263: int gaierr, sock = 0;
1.25 markus 4264:
4265: /* Try to open a socket for the local X server. */
4266: display = getenv("DISPLAY");
4267: if (!display) {
4268: error("DISPLAY not set.");
1.51 markus 4269: return -1;
1.25 markus 4270: }
1.27 markus 4271: /*
4272: * Now we decode the value of the DISPLAY variable and make a
4273: * connection to the real X server.
4274: */
4275:
4276: /*
4277: * Check if it is a unix domain socket. Unix domain displays are in
4278: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
4279: */
1.25 markus 4280: if (strncmp(display, "unix:", 5) == 0 ||
4281: display[0] == ':') {
4282: /* Connect to the unix domain socket. */
1.367 djm 4283: if (sscanf(strrchr(display, ':') + 1, "%u",
4284: &display_number) != 1) {
4285: error("Could not parse display number from DISPLAY: "
4286: "%.100s", display);
1.51 markus 4287: return -1;
1.25 markus 4288: }
4289: /* Create a socket. */
4290: sock = connect_local_xsocket(display_number);
4291: if (sock < 0)
1.51 markus 4292: return -1;
1.25 markus 4293:
4294: /* OK, we now have a connection to the display. */
1.51 markus 4295: return sock;
1.25 markus 4296: }
1.27 markus 4297: /*
4298: * Connect to an inet socket. The DISPLAY value is supposedly
4299: * hostname:d[.s], where hostname may also be numeric IP address.
4300: */
1.145 stevesk 4301: strlcpy(buf, display, sizeof(buf));
1.25 markus 4302: cp = strchr(buf, ':');
4303: if (!cp) {
4304: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 4305: return -1;
1.25 markus 4306: }
4307: *cp = 0;
1.367 djm 4308: /*
4309: * buf now contains the host name. But first we parse the
4310: * display number.
4311: */
1.248 deraadt 4312: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 4313: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 4314: display);
1.51 markus 4315: return -1;
1.25 markus 4316: }
1.35 markus 4317:
4318: /* Look up the host address */
4319: memset(&hints, 0, sizeof(hints));
1.367 djm 4320: hints.ai_family = ssh->chanctxt->IPv4or6;
1.35 markus 4321: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 4322: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 4323: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
1.271 dtucker 4324: error("%.100s: unknown host. (%s)", buf,
4325: ssh_gai_strerror(gaierr));
1.51 markus 4326: return -1;
1.25 markus 4327: }
1.35 markus 4328: for (ai = aitop; ai; ai = ai->ai_next) {
4329: /* Create a socket. */
1.300 dtucker 4330: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 4331: if (sock < 0) {
1.194 markus 4332: debug2("socket: %.100s", strerror(errno));
1.41 markus 4333: continue;
4334: }
4335: /* Connect it to the display. */
4336: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 4337: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 4338: 6000 + display_number, strerror(errno));
4339: close(sock);
4340: continue;
4341: }
4342: /* Success */
4343: break;
1.35 markus 4344: }
4345: freeaddrinfo(aitop);
4346: if (!ai) {
1.367 djm 4347: error("connect %.100s port %u: %.100s", buf,
4348: 6000 + display_number, strerror(errno));
1.51 markus 4349: return -1;
1.25 markus 4350: }
1.162 stevesk 4351: set_nodelay(sock);
1.51 markus 4352: return sock;
4353: }
4354:
4355: /*
1.27 markus 4356: * Requests forwarding of X11 connections, generates fake authentication
4357: * data, and enables authentication spoofing.
1.121 markus 4358: * This should be called in the client only.
1.27 markus 4359: */
1.49 markus 4360: void
1.367 djm 4361: x11_request_forwarding_with_spoofing(struct ssh *ssh, int client_session_id,
4362: const char *disp, const char *proto, const char *data, int want_reply)
1.1 deraadt 4363: {
1.367 djm 4364: struct ssh_channels *sc = ssh->chanctxt;
1.77 markus 4365: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 4366: u_int i, value;
1.367 djm 4367: const char *cp;
1.25 markus 4368: char *new_data;
1.367 djm 4369: int r, screen_number;
1.25 markus 4370:
1.367 djm 4371: if (sc->x11_saved_display == NULL)
4372: sc->x11_saved_display = xstrdup(disp);
4373: else if (strcmp(disp, sc->x11_saved_display) != 0) {
1.219 djm 4374: error("x11_request_forwarding_with_spoofing: different "
4375: "$DISPLAY already forwarded");
4376: return;
4377: }
4378:
1.266 djm 4379: cp = strchr(disp, ':');
1.25 markus 4380: if (cp)
4381: cp = strchr(cp, '.');
4382: if (cp)
1.245 deraadt 4383: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 4384: else
4385: screen_number = 0;
4386:
1.367 djm 4387: if (sc->x11_saved_proto == NULL) {
1.219 djm 4388: /* Save protocol name. */
1.367 djm 4389: sc->x11_saved_proto = xstrdup(proto);
1.353 natano 4390:
4391: /* Extract real authentication data. */
1.367 djm 4392: sc->x11_saved_data = xmalloc(data_len);
1.219 djm 4393: for (i = 0; i < data_len; i++) {
4394: if (sscanf(data + 2 * i, "%2x", &value) != 1)
4395: fatal("x11_request_forwarding: bad "
4396: "authentication data: %.100s", data);
1.367 djm 4397: sc->x11_saved_data[i] = value;
1.219 djm 4398: }
1.367 djm 4399: sc->x11_saved_data_len = data_len;
1.353 natano 4400:
4401: /* Generate fake data of the same length. */
1.367 djm 4402: sc->x11_fake_data = xmalloc(data_len);
4403: arc4random_buf(sc->x11_fake_data, data_len);
4404: sc->x11_fake_data_len = data_len;
1.25 markus 4405: }
4406:
4407: /* Convert the fake data into hex. */
1.367 djm 4408: new_data = tohex(sc->x11_fake_data, data_len);
1.25 markus 4409:
4410: /* Send the request packet. */
1.367 djm 4411: channel_request_start(ssh, client_session_id, "x11-req", want_reply);
4412: if ((r = sshpkt_put_u8(ssh, 0)) != 0 || /* bool: single connection */
4413: (r = sshpkt_put_cstring(ssh, proto)) != 0 ||
4414: (r = sshpkt_put_cstring(ssh, new_data)) != 0 ||
4415: (r = sshpkt_put_u32(ssh, screen_number)) != 0 ||
4416: (r = sshpkt_send(ssh)) != 0 ||
4417: (r = ssh_packet_write_wait(ssh)) != 0)
4418: fatal("%s: send x11-req: %s", __func__, ssh_err(r));
1.321 djm 4419: free(new_data);
1.1 deraadt 4420: }
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