Annotation of src/usr.bin/ssh/channels.c, Revision 1.315
1.315 ! markus 1: /* $OpenBSD: channels.c,v 1.314 2011/09/23 00:22:04 dtucker 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>
1.234 stevesk 43: #include <sys/ioctl.h>
1.235 stevesk 44: #include <sys/un.h>
1.251 stevesk 45: #include <sys/socket.h>
1.261 stevesk 46: #include <sys/time.h>
1.275 djm 47: #include <sys/queue.h>
1.251 stevesk 48:
49: #include <netinet/in.h>
50: #include <arpa/inet.h>
1.233 stevesk 51:
1.254 stevesk 52: #include <errno.h>
1.298 dtucker 53: #include <fcntl.h>
1.255 stevesk 54: #include <netdb.h>
1.263 stevesk 55: #include <stdio.h>
1.262 stevesk 56: #include <stdlib.h>
1.260 stevesk 57: #include <string.h>
1.233 stevesk 58: #include <termios.h>
1.256 stevesk 59: #include <unistd.h>
1.265 deraadt 60: #include <stdarg.h>
1.1 deraadt 61:
1.265 deraadt 62: #include "xmalloc.h"
1.1 deraadt 63: #include "ssh.h"
1.82 markus 64: #include "ssh1.h"
65: #include "ssh2.h"
1.1 deraadt 66: #include "packet.h"
1.82 markus 67: #include "log.h"
68: #include "misc.h"
1.265 deraadt 69: #include "buffer.h"
1.14 markus 70: #include "channels.h"
71: #include "compat.h"
1.82 markus 72: #include "canohost.h"
1.64 markus 73: #include "key.h"
74: #include "authfd.h"
1.147 stevesk 75: #include "pathnames.h"
1.1 deraadt 76:
1.121 markus 77: /* -- channel core */
1.12 markus 78:
1.27 markus 79: /*
80: * Pointer to an array containing all allocated channels. The array is
81: * dynamically extended as needed.
82: */
1.113 markus 83: static Channel **channels = NULL;
1.1 deraadt 84:
1.27 markus 85: /*
86: * Size of the channel array. All slots of the array must always be
1.113 markus 87: * initialized (at least the type field); unused slots set to NULL
1.27 markus 88: */
1.209 avsm 89: static u_int channels_alloc = 0;
1.1 deraadt 90:
1.27 markus 91: /*
92: * Maximum file descriptor value used in any of the channels. This is
1.113 markus 93: * updated in channel_new.
1.27 markus 94: */
1.84 markus 95: static int channel_max_fd = 0;
1.1 deraadt 96:
97:
1.121 markus 98: /* -- tcp forwarding */
1.1 deraadt 99:
1.27 markus 100: /*
101: * Data structure for storing which hosts are permitted for forward requests.
102: * The local sides of any remote forwards are stored in this array to prevent
103: * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
104: * network (which might be behind a firewall).
105: */
1.25 markus 106: typedef struct {
1.41 markus 107: char *host_to_connect; /* Connect to 'host'. */
108: u_short port_to_connect; /* Connect to 'port'. */
109: u_short listen_port; /* Remote side should listen port number. */
1.1 deraadt 110: } ForwardPermission;
111:
1.257 dtucker 112: /* List of all permitted host/port pairs to connect by the user. */
1.305 djm 113: static ForwardPermission *permitted_opens = NULL;
1.121 markus 114:
1.257 dtucker 115: /* List of all permitted host/port pairs to connect by the admin. */
1.305 djm 116: static ForwardPermission *permitted_adm_opens = NULL;
1.257 dtucker 117:
118: /* Number of permitted host/port pairs in the array permitted by the user. */
1.1 deraadt 119: static int num_permitted_opens = 0;
1.257 dtucker 120:
121: /* Number of permitted host/port pair in the array permitted by the admin. */
122: static int num_adm_permitted_opens = 0;
123:
1.314 dtucker 124: /* special-case port number meaning allow any port */
125: #define FWD_PERMIT_ANY_PORT 0
126:
1.27 markus 127: /*
128: * If this is true, all opens are permitted. This is the case on the server
129: * on which we have to trust the client anyway, and the user could do
130: * anything after logging in anyway.
131: */
1.1 deraadt 132: static int all_opens_permitted = 0;
133:
1.121 markus 134:
135: /* -- X11 forwarding */
136:
137: /* Maximum number of fake X11 displays to try. */
138: #define MAX_DISPLAYS 1000
139:
1.219 djm 140: /* Saved X11 local (client) display. */
141: static char *x11_saved_display = NULL;
142:
1.121 markus 143: /* Saved X11 authentication protocol name. */
144: static char *x11_saved_proto = NULL;
145:
146: /* Saved X11 authentication data. This is the real data. */
147: static char *x11_saved_data = NULL;
148: static u_int x11_saved_data_len = 0;
149:
150: /*
151: * Fake X11 authentication data. This is what the server will be sending us;
152: * we should replace any occurrences of this by the real data.
153: */
1.240 deraadt 154: static u_char *x11_fake_data = NULL;
1.121 markus 155: static u_int x11_fake_data_len;
156:
157:
158: /* -- agent forwarding */
159:
160: #define NUM_SOCKS 10
161:
1.82 markus 162: /* AF_UNSPEC or AF_INET or AF_INET6 */
1.135 markus 163: static int IPv4or6 = AF_UNSPEC;
1.1 deraadt 164:
1.121 markus 165: /* helper */
1.127 itojun 166: static void port_open_helper(Channel *c, char *rtype);
1.103 markus 167:
1.276 djm 168: /* non-blocking connect helpers */
169: static int connect_next(struct channel_connect *);
170: static void channel_connect_ctx_free(struct channel_connect *);
171:
1.121 markus 172: /* -- channel core */
1.41 markus 173:
174: Channel *
1.229 markus 175: channel_by_id(int id)
1.41 markus 176: {
177: Channel *c;
1.113 markus 178:
1.209 avsm 179: if (id < 0 || (u_int)id >= channels_alloc) {
1.229 markus 180: logit("channel_by_id: %d: bad id", id);
1.41 markus 181: return NULL;
182: }
1.113 markus 183: c = channels[id];
184: if (c == NULL) {
1.229 markus 185: logit("channel_by_id: %d: bad id: channel free", id);
1.41 markus 186: return NULL;
187: }
188: return c;
1.55 markus 189: }
190:
1.27 markus 191: /*
1.229 markus 192: * Returns the channel if it is allowed to receive protocol messages.
193: * Private channels, like listening sockets, may not receive messages.
194: */
195: Channel *
196: channel_lookup(int id)
197: {
198: Channel *c;
199:
200: if ((c = channel_by_id(id)) == NULL)
201: return (NULL);
202:
1.237 deraadt 203: switch (c->type) {
1.229 markus 204: case SSH_CHANNEL_X11_OPEN:
205: case SSH_CHANNEL_LARVAL:
206: case SSH_CHANNEL_CONNECTING:
207: case SSH_CHANNEL_DYNAMIC:
208: case SSH_CHANNEL_OPENING:
209: case SSH_CHANNEL_OPEN:
210: case SSH_CHANNEL_INPUT_DRAINING:
211: case SSH_CHANNEL_OUTPUT_DRAINING:
212: return (c);
213: }
214: logit("Non-public channel %d, type %d.", id, c->type);
215: return (NULL);
216: }
217:
218: /*
1.55 markus 219: * Register filedescriptors for a channel, used when allocating a channel or
1.52 markus 220: * when the channel consumer/producer is ready, e.g. shell exec'd
1.27 markus 221: */
1.127 itojun 222: static void
1.71 markus 223: channel_register_fds(Channel *c, int rfd, int wfd, int efd,
1.282 dtucker 224: int extusage, int nonblock, int is_tty)
1.1 deraadt 225: {
1.25 markus 226: /* Update the maximum file descriptor value. */
1.84 markus 227: channel_max_fd = MAX(channel_max_fd, rfd);
228: channel_max_fd = MAX(channel_max_fd, wfd);
229: channel_max_fd = MAX(channel_max_fd, efd);
230:
1.298 dtucker 231: if (rfd != -1)
232: fcntl(rfd, F_SETFD, FD_CLOEXEC);
233: if (wfd != -1 && wfd != rfd)
234: fcntl(wfd, F_SETFD, FD_CLOEXEC);
235: if (efd != -1 && efd != rfd && efd != wfd)
236: fcntl(efd, F_SETFD, FD_CLOEXEC);
1.55 markus 237:
1.52 markus 238: c->rfd = rfd;
239: c->wfd = wfd;
240: c->sock = (rfd == wfd) ? rfd : -1;
241: c->efd = efd;
242: c->extended_usage = extusage;
1.71 markus 243:
1.282 dtucker 244: if ((c->isatty = is_tty) != 0)
1.194 markus 245: debug2("channel %d: rfd %d isatty", c->self, c->rfd);
1.91 markus 246:
1.71 markus 247: /* enable nonblocking mode */
248: if (nonblock) {
249: if (rfd != -1)
250: set_nonblock(rfd);
251: if (wfd != -1)
252: set_nonblock(wfd);
253: if (efd != -1)
254: set_nonblock(efd);
255: }
1.52 markus 256: }
257:
258: /*
259: * Allocate a new channel object and set its type and socket. This will cause
260: * remote_name to be freed.
261: */
1.113 markus 262: Channel *
1.52 markus 263: channel_new(char *ctype, int type, int rfd, int wfd, int efd,
1.178 markus 264: u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
1.52 markus 265: {
1.209 avsm 266: int found;
267: u_int i;
1.52 markus 268: Channel *c;
1.25 markus 269:
270: /* Do initial allocation if this is the first call. */
271: if (channels_alloc == 0) {
272: channels_alloc = 10;
1.242 djm 273: channels = xcalloc(channels_alloc, sizeof(Channel *));
1.25 markus 274: for (i = 0; i < channels_alloc; i++)
1.113 markus 275: channels[i] = NULL;
1.25 markus 276: }
277: /* Try to find a free slot where to put the new channel. */
278: for (found = -1, i = 0; i < channels_alloc; i++)
1.113 markus 279: if (channels[i] == NULL) {
1.25 markus 280: /* Found a free slot. */
1.209 avsm 281: found = (int)i;
1.25 markus 282: break;
283: }
1.209 avsm 284: if (found < 0) {
1.27 markus 285: /* There are no free slots. Take last+1 slot and expand the array. */
1.25 markus 286: found = channels_alloc;
1.179 markus 287: if (channels_alloc > 10000)
288: fatal("channel_new: internal error: channels_alloc %d "
289: "too big.", channels_alloc);
1.243 djm 290: channels = xrealloc(channels, channels_alloc + 10,
291: sizeof(Channel *));
1.195 markus 292: channels_alloc += 10;
1.70 markus 293: debug2("channel: expanding %d", channels_alloc);
1.25 markus 294: for (i = found; i < channels_alloc; i++)
1.113 markus 295: channels[i] = NULL;
1.25 markus 296: }
1.113 markus 297: /* Initialize and return new channel. */
1.242 djm 298: c = channels[found] = xcalloc(1, sizeof(Channel));
1.25 markus 299: buffer_init(&c->input);
300: buffer_init(&c->output);
1.41 markus 301: buffer_init(&c->extended);
1.293 djm 302: c->path = NULL;
1.312 djm 303: c->listening_addr = NULL;
304: c->listening_port = 0;
1.159 markus 305: c->ostate = CHAN_OUTPUT_OPEN;
306: c->istate = CHAN_INPUT_OPEN;
307: c->flags = 0;
1.281 djm 308: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
1.25 markus 309: c->self = found;
310: c->type = type;
1.41 markus 311: c->ctype = ctype;
1.51 markus 312: c->local_window = window;
313: c->local_window_max = window;
314: c->local_consumed = 0;
315: c->local_maxpacket = maxpack;
1.25 markus 316: c->remote_id = -1;
1.190 markus 317: c->remote_name = xstrdup(remote_name);
1.41 markus 318: c->remote_window = 0;
319: c->remote_maxpacket = 0;
1.133 markus 320: c->force_drain = 0;
1.149 markus 321: c->single_connection = 0;
1.131 markus 322: c->detach_user = NULL;
1.225 djm 323: c->detach_close = 0;
1.275 djm 324: c->open_confirm = NULL;
325: c->open_confirm_ctx = NULL;
1.65 markus 326: c->input_filter = NULL;
1.231 reyk 327: c->output_filter = NULL;
1.280 djm 328: c->filter_ctx = NULL;
329: c->filter_cleanup = NULL;
1.302 djm 330: c->ctl_chan = -1;
331: c->mux_rcb = NULL;
332: c->mux_ctx = NULL;
1.304 djm 333: c->mux_pause = 0;
1.299 markus 334: c->delayed = 1; /* prevent call to channel_post handler */
1.275 djm 335: TAILQ_INIT(&c->status_confirms);
1.25 markus 336: debug("channel %d: new [%s]", found, remote_name);
1.113 markus 337: return c;
1.1 deraadt 338: }
1.52 markus 339:
1.132 markus 340: static int
341: channel_find_maxfd(void)
342: {
1.209 avsm 343: u_int i;
344: int max = 0;
1.132 markus 345: Channel *c;
346:
347: for (i = 0; i < channels_alloc; i++) {
348: c = channels[i];
349: if (c != NULL) {
350: max = MAX(max, c->rfd);
351: max = MAX(max, c->wfd);
352: max = MAX(max, c->efd);
353: }
354: }
355: return max;
356: }
357:
358: int
359: channel_close_fd(int *fdp)
360: {
361: int ret = 0, fd = *fdp;
362:
363: if (fd != -1) {
364: ret = close(fd);
365: *fdp = -1;
366: if (fd == channel_max_fd)
367: channel_max_fd = channel_find_maxfd();
368: }
369: return ret;
370: }
371:
1.52 markus 372: /* Close all channel fd/socket. */
1.127 itojun 373: static void
1.52 markus 374: channel_close_fds(Channel *c)
375: {
1.132 markus 376: channel_close_fd(&c->sock);
377: channel_close_fd(&c->rfd);
378: channel_close_fd(&c->wfd);
379: channel_close_fd(&c->efd);
1.121 markus 380: }
381:
382: /* Free the channel and close its fd/socket. */
383: void
384: channel_free(Channel *c)
385: {
386: char *s;
1.209 avsm 387: u_int i, n;
1.275 djm 388: struct channel_confirm *cc;
1.121 markus 389:
390: for (n = 0, i = 0; i < channels_alloc; i++)
391: if (channels[i])
392: n++;
1.209 avsm 393: debug("channel %d: free: %s, nchannels %u", c->self,
1.121 markus 394: c->remote_name ? c->remote_name : "???", n);
395:
396: s = channel_open_message();
1.194 markus 397: debug3("channel %d: status: %s", c->self, s);
1.121 markus 398: xfree(s);
399:
400: if (c->sock != -1)
401: shutdown(c->sock, SHUT_RDWR);
402: channel_close_fds(c);
403: buffer_free(&c->input);
404: buffer_free(&c->output);
405: buffer_free(&c->extended);
406: if (c->remote_name) {
407: xfree(c->remote_name);
408: c->remote_name = NULL;
409: }
1.293 djm 410: if (c->path) {
411: xfree(c->path);
412: c->path = NULL;
413: }
1.312 djm 414: if (c->listening_addr) {
415: xfree(c->listening_addr);
416: c->listening_addr = NULL;
417: }
1.275 djm 418: while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
419: if (cc->abandon_cb != NULL)
420: cc->abandon_cb(c, cc->ctx);
421: TAILQ_REMOVE(&c->status_confirms, cc, entry);
422: bzero(cc, sizeof(*cc));
423: xfree(cc);
424: }
1.280 djm 425: if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
426: c->filter_cleanup(c->self, c->filter_ctx);
1.121 markus 427: channels[c->self] = NULL;
428: xfree(c);
429: }
430:
431: void
1.126 markus 432: channel_free_all(void)
1.121 markus 433: {
1.209 avsm 434: u_int i;
1.121 markus 435:
1.126 markus 436: for (i = 0; i < channels_alloc; i++)
437: if (channels[i] != NULL)
438: channel_free(channels[i]);
1.131 markus 439: }
440:
1.121 markus 441: /*
442: * Closes the sockets/fds of all channels. This is used to close extra file
443: * descriptors after a fork.
444: */
445: void
1.142 itojun 446: channel_close_all(void)
1.121 markus 447: {
1.209 avsm 448: u_int i;
1.121 markus 449:
450: for (i = 0; i < channels_alloc; i++)
451: if (channels[i] != NULL)
452: channel_close_fds(channels[i]);
453: }
454:
455: /*
1.131 markus 456: * Stop listening to channels.
457: */
458: void
459: channel_stop_listening(void)
460: {
1.209 avsm 461: u_int i;
1.131 markus 462: Channel *c;
463:
464: for (i = 0; i < channels_alloc; i++) {
465: c = channels[i];
466: if (c != NULL) {
467: switch (c->type) {
468: case SSH_CHANNEL_AUTH_SOCKET:
469: case SSH_CHANNEL_PORT_LISTENER:
470: case SSH_CHANNEL_RPORT_LISTENER:
471: case SSH_CHANNEL_X11_LISTENER:
1.132 markus 472: channel_close_fd(&c->sock);
1.131 markus 473: channel_free(c);
474: break;
475: }
476: }
477: }
478: }
479:
480: /*
1.121 markus 481: * Returns true if no channel has too much buffered data, and false if one or
482: * more channel is overfull.
483: */
484: int
1.142 itojun 485: channel_not_very_much_buffered_data(void)
1.121 markus 486: {
487: u_int i;
488: Channel *c;
489:
490: for (i = 0; i < channels_alloc; i++) {
491: c = channels[i];
492: if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
1.136 markus 493: #if 0
494: if (!compat20 &&
495: buffer_len(&c->input) > packet_get_maxsize()) {
1.185 markus 496: debug2("channel %d: big input buffer %d",
1.121 markus 497: c->self, buffer_len(&c->input));
498: return 0;
499: }
1.136 markus 500: #endif
1.121 markus 501: if (buffer_len(&c->output) > packet_get_maxsize()) {
1.191 markus 502: debug2("channel %d: big output buffer %u > %u",
1.136 markus 503: c->self, buffer_len(&c->output),
504: packet_get_maxsize());
1.121 markus 505: return 0;
506: }
507: }
508: }
509: return 1;
510: }
511:
512: /* Returns true if any channel is still open. */
513: int
1.142 itojun 514: channel_still_open(void)
1.121 markus 515: {
1.209 avsm 516: u_int i;
1.121 markus 517: Channel *c;
518:
519: for (i = 0; i < channels_alloc; i++) {
520: c = channels[i];
521: if (c == NULL)
522: continue;
523: switch (c->type) {
524: case SSH_CHANNEL_X11_LISTENER:
525: case SSH_CHANNEL_PORT_LISTENER:
526: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 527: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 528: case SSH_CHANNEL_CLOSED:
529: case SSH_CHANNEL_AUTH_SOCKET:
530: case SSH_CHANNEL_DYNAMIC:
531: case SSH_CHANNEL_CONNECTING:
532: case SSH_CHANNEL_ZOMBIE:
533: continue;
534: case SSH_CHANNEL_LARVAL:
535: if (!compat20)
536: fatal("cannot happen: SSH_CHANNEL_LARVAL");
537: continue;
538: case SSH_CHANNEL_OPENING:
539: case SSH_CHANNEL_OPEN:
540: case SSH_CHANNEL_X11_OPEN:
1.302 djm 541: case SSH_CHANNEL_MUX_CLIENT:
1.121 markus 542: return 1;
543: case SSH_CHANNEL_INPUT_DRAINING:
544: case SSH_CHANNEL_OUTPUT_DRAINING:
545: if (!compat13)
546: fatal("cannot happen: OUT_DRAIN");
547: return 1;
548: default:
549: fatal("channel_still_open: bad channel type %d", c->type);
550: /* NOTREACHED */
551: }
552: }
553: return 0;
554: }
555:
556: /* Returns the id of an open channel suitable for keepaliving */
557: int
1.142 itojun 558: channel_find_open(void)
1.121 markus 559: {
1.209 avsm 560: u_int i;
1.121 markus 561: Channel *c;
562:
563: for (i = 0; i < channels_alloc; i++) {
564: c = channels[i];
1.206 djm 565: if (c == NULL || c->remote_id < 0)
1.121 markus 566: continue;
567: switch (c->type) {
568: case SSH_CHANNEL_CLOSED:
569: case SSH_CHANNEL_DYNAMIC:
570: case SSH_CHANNEL_X11_LISTENER:
571: case SSH_CHANNEL_PORT_LISTENER:
572: case SSH_CHANNEL_RPORT_LISTENER:
1.302 djm 573: case SSH_CHANNEL_MUX_LISTENER:
574: case SSH_CHANNEL_MUX_CLIENT:
1.121 markus 575: case SSH_CHANNEL_OPENING:
576: case SSH_CHANNEL_CONNECTING:
577: case SSH_CHANNEL_ZOMBIE:
578: continue;
579: case SSH_CHANNEL_LARVAL:
580: case SSH_CHANNEL_AUTH_SOCKET:
581: case SSH_CHANNEL_OPEN:
582: case SSH_CHANNEL_X11_OPEN:
583: return i;
584: case SSH_CHANNEL_INPUT_DRAINING:
585: case SSH_CHANNEL_OUTPUT_DRAINING:
586: if (!compat13)
587: fatal("cannot happen: OUT_DRAIN");
588: return i;
589: default:
590: fatal("channel_find_open: bad channel type %d", c->type);
591: /* NOTREACHED */
592: }
593: }
594: return -1;
595: }
596:
597:
598: /*
599: * Returns a message describing the currently open forwarded connections,
600: * suitable for sending to the client. The message contains crlf pairs for
601: * newlines.
602: */
603: char *
1.142 itojun 604: channel_open_message(void)
1.121 markus 605: {
606: Buffer buffer;
607: Channel *c;
608: char buf[1024], *cp;
1.209 avsm 609: u_int i;
1.121 markus 610:
611: buffer_init(&buffer);
612: snprintf(buf, sizeof buf, "The following connections are open:\r\n");
613: buffer_append(&buffer, buf, strlen(buf));
614: for (i = 0; i < channels_alloc; i++) {
615: c = channels[i];
616: if (c == NULL)
617: continue;
618: switch (c->type) {
619: case SSH_CHANNEL_X11_LISTENER:
620: case SSH_CHANNEL_PORT_LISTENER:
621: case SSH_CHANNEL_RPORT_LISTENER:
622: case SSH_CHANNEL_CLOSED:
623: case SSH_CHANNEL_AUTH_SOCKET:
624: case SSH_CHANNEL_ZOMBIE:
1.302 djm 625: case SSH_CHANNEL_MUX_CLIENT:
626: case SSH_CHANNEL_MUX_LISTENER:
1.121 markus 627: continue;
628: case SSH_CHANNEL_LARVAL:
629: case SSH_CHANNEL_OPENING:
630: case SSH_CHANNEL_CONNECTING:
631: case SSH_CHANNEL_DYNAMIC:
632: case SSH_CHANNEL_OPEN:
633: case SSH_CHANNEL_X11_OPEN:
634: case SSH_CHANNEL_INPUT_DRAINING:
635: case SSH_CHANNEL_OUTPUT_DRAINING:
1.204 djm 636: snprintf(buf, sizeof buf,
1.302 djm 637: " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
1.121 markus 638: c->self, c->remote_name,
639: c->type, c->remote_id,
640: c->istate, buffer_len(&c->input),
641: c->ostate, buffer_len(&c->output),
1.302 djm 642: c->rfd, c->wfd, c->ctl_chan);
1.121 markus 643: buffer_append(&buffer, buf, strlen(buf));
644: continue;
645: default:
646: fatal("channel_open_message: bad channel type %d", c->type);
647: /* NOTREACHED */
648: }
649: }
650: buffer_append(&buffer, "\0", 1);
651: cp = xstrdup(buffer_ptr(&buffer));
652: buffer_free(&buffer);
653: return cp;
654: }
655:
656: void
657: channel_send_open(int id)
658: {
659: Channel *c = channel_lookup(id);
1.180 deraadt 660:
1.121 markus 661: if (c == NULL) {
1.188 itojun 662: logit("channel_send_open: %d: bad id", id);
1.121 markus 663: return;
664: }
1.184 markus 665: debug2("channel %d: send open", id);
1.121 markus 666: packet_start(SSH2_MSG_CHANNEL_OPEN);
667: packet_put_cstring(c->ctype);
668: packet_put_int(c->self);
669: packet_put_int(c->local_window);
670: packet_put_int(c->local_maxpacket);
671: packet_send();
672: }
673:
674: void
1.184 markus 675: channel_request_start(int id, char *service, int wantconfirm)
1.121 markus 676: {
1.184 markus 677: Channel *c = channel_lookup(id);
1.180 deraadt 678:
1.121 markus 679: if (c == NULL) {
1.188 itojun 680: logit("channel_request_start: %d: unknown channel id", id);
1.121 markus 681: return;
682: }
1.204 djm 683: debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
1.121 markus 684: packet_start(SSH2_MSG_CHANNEL_REQUEST);
685: packet_put_int(c->remote_id);
686: packet_put_cstring(service);
687: packet_put_char(wantconfirm);
688: }
1.241 deraadt 689:
1.121 markus 690: void
1.275 djm 691: channel_register_status_confirm(int id, channel_confirm_cb *cb,
692: channel_confirm_abandon_cb *abandon_cb, void *ctx)
693: {
694: struct channel_confirm *cc;
695: Channel *c;
696:
697: if ((c = channel_lookup(id)) == NULL)
698: fatal("channel_register_expect: %d: bad id", id);
699:
700: cc = xmalloc(sizeof(*cc));
701: cc->cb = cb;
702: cc->abandon_cb = abandon_cb;
703: cc->ctx = ctx;
704: TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
705: }
706:
707: void
1.304 djm 708: channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
1.121 markus 709: {
710: Channel *c = channel_lookup(id);
1.180 deraadt 711:
1.121 markus 712: if (c == NULL) {
1.287 stevesk 713: logit("channel_register_open_confirm: %d: bad id", id);
1.121 markus 714: return;
715: }
1.275 djm 716: c->open_confirm = fn;
717: c->open_confirm_ctx = ctx;
1.121 markus 718: }
1.241 deraadt 719:
1.121 markus 720: void
1.225 djm 721: channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
1.121 markus 722: {
1.229 markus 723: Channel *c = channel_by_id(id);
1.180 deraadt 724:
1.121 markus 725: if (c == NULL) {
1.188 itojun 726: logit("channel_register_cleanup: %d: bad id", id);
1.121 markus 727: return;
728: }
1.131 markus 729: c->detach_user = fn;
1.225 djm 730: c->detach_close = do_close;
1.121 markus 731: }
1.241 deraadt 732:
1.121 markus 733: void
734: channel_cancel_cleanup(int id)
735: {
1.229 markus 736: Channel *c = channel_by_id(id);
1.180 deraadt 737:
1.121 markus 738: if (c == NULL) {
1.188 itojun 739: logit("channel_cancel_cleanup: %d: bad id", id);
1.121 markus 740: return;
1.52 markus 741: }
1.131 markus 742: c->detach_user = NULL;
1.225 djm 743: c->detach_close = 0;
1.121 markus 744: }
1.241 deraadt 745:
1.121 markus 746: void
1.231 reyk 747: channel_register_filter(int id, channel_infilter_fn *ifn,
1.280 djm 748: channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
1.121 markus 749: {
750: Channel *c = channel_lookup(id);
1.180 deraadt 751:
1.121 markus 752: if (c == NULL) {
1.188 itojun 753: logit("channel_register_filter: %d: bad id", id);
1.121 markus 754: return;
1.52 markus 755: }
1.231 reyk 756: c->input_filter = ifn;
757: c->output_filter = ofn;
1.279 djm 758: c->filter_ctx = ctx;
1.280 djm 759: c->filter_cleanup = cfn;
1.52 markus 760: }
761:
1.49 markus 762: void
1.121 markus 763: channel_set_fds(int id, int rfd, int wfd, int efd,
1.282 dtucker 764: int extusage, int nonblock, int is_tty, u_int window_max)
1.1 deraadt 765: {
1.121 markus 766: Channel *c = channel_lookup(id);
1.180 deraadt 767:
1.121 markus 768: if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
769: fatal("channel_activate for non-larval channel %d.", id);
1.282 dtucker 770: channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
1.121 markus 771: c->type = SSH_CHANNEL_OPEN;
1.168 markus 772: c->local_window = c->local_window_max = window_max;
1.121 markus 773: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
774: packet_put_int(c->remote_id);
775: packet_put_int(c->local_window);
776: packet_send();
1.1 deraadt 777: }
778:
1.27 markus 779: /*
1.41 markus 780: * 'channel_pre*' are called just before select() to add any bits relevant to
781: * channels in the select bitmasks.
782: */
783: /*
784: * 'channel_post*': perform any appropriate operations for channels which
785: * have events pending.
1.27 markus 786: */
1.237 deraadt 787: typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
1.41 markus 788: chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
789: chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
790:
1.259 stevesk 791: /* ARGSUSED */
1.127 itojun 792: static void
1.237 deraadt 793: channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 794: {
795: FD_SET(c->sock, readset);
796: }
797:
1.259 stevesk 798: /* ARGSUSED */
1.127 itojun 799: static void
1.237 deraadt 800: channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 801: {
802: debug3("channel %d: waiting for connection", c->self);
803: FD_SET(c->sock, writeset);
804: }
805:
1.127 itojun 806: static void
1.237 deraadt 807: channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 808: {
809: if (buffer_len(&c->input) < packet_get_maxsize())
810: FD_SET(c->sock, readset);
811: if (buffer_len(&c->output) > 0)
812: FD_SET(c->sock, writeset);
813: }
1.1 deraadt 814:
1.127 itojun 815: static void
1.237 deraadt 816: channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 817: {
1.157 markus 818: u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
1.41 markus 819:
1.44 markus 820: if (c->istate == CHAN_INPUT_OPEN &&
1.157 markus 821: limit > 0 &&
1.250 djm 822: buffer_len(&c->input) < limit &&
823: buffer_check_alloc(&c->input, CHAN_RBUF))
1.44 markus 824: FD_SET(c->rfd, readset);
825: if (c->ostate == CHAN_OUTPUT_OPEN ||
826: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
827: if (buffer_len(&c->output) > 0) {
828: FD_SET(c->wfd, writeset);
829: } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1.172 markus 830: if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
1.223 djm 831: debug2("channel %d: obuf_empty delayed efd %d/(%d)",
832: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 833: else
834: chan_obuf_empty(c);
1.44 markus 835: }
836: }
837: /** XXX check close conditions, too */
1.277 markus 838: if (compat20 && c->efd != -1 &&
839: !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
1.44 markus 840: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
841: buffer_len(&c->extended) > 0)
842: FD_SET(c->efd, writeset);
1.306 djm 843: else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
844: (c->extended_usage == CHAN_EXTENDED_READ ||
845: c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.44 markus 846: buffer_len(&c->extended) < c->remote_window)
847: FD_SET(c->efd, readset);
848: }
1.204 djm 849: /* XXX: What about efd? races? */
1.44 markus 850: }
851:
1.259 stevesk 852: /* ARGSUSED */
1.127 itojun 853: static void
1.237 deraadt 854: channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 855: {
856: if (buffer_len(&c->input) == 0) {
857: packet_start(SSH_MSG_CHANNEL_CLOSE);
858: packet_put_int(c->remote_id);
859: packet_send();
860: c->type = SSH_CHANNEL_CLOSED;
1.194 markus 861: debug2("channel %d: closing after input drain.", c->self);
1.41 markus 862: }
863: }
864:
1.259 stevesk 865: /* ARGSUSED */
1.127 itojun 866: static void
1.237 deraadt 867: channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 868: {
869: if (buffer_len(&c->output) == 0)
1.113 markus 870: chan_mark_dead(c);
1.49 markus 871: else
1.41 markus 872: FD_SET(c->sock, writeset);
873: }
874:
875: /*
876: * This is a special state for X11 authentication spoofing. An opened X11
877: * connection (when authentication spoofing is being done) remains in this
878: * state until the first packet has been completely read. The authentication
879: * data in that packet is then substituted by the real data if it matches the
880: * fake data, and the channel is put into normal mode.
1.51 markus 881: * XXX All this happens at the client side.
1.121 markus 882: * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
1.41 markus 883: */
1.127 itojun 884: static int
1.121 markus 885: x11_open_helper(Buffer *b)
1.1 deraadt 886: {
1.77 markus 887: u_char *ucp;
888: u_int proto_len, data_len;
1.25 markus 889:
1.41 markus 890: /* Check if the fixed size part of the packet is in buffer. */
1.121 markus 891: if (buffer_len(b) < 12)
1.41 markus 892: return 0;
893:
894: /* Parse the lengths of variable-length fields. */
1.155 stevesk 895: ucp = buffer_ptr(b);
1.41 markus 896: if (ucp[0] == 0x42) { /* Byte order MSB first. */
897: proto_len = 256 * ucp[6] + ucp[7];
898: data_len = 256 * ucp[8] + ucp[9];
899: } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
900: proto_len = ucp[6] + 256 * ucp[7];
901: data_len = ucp[8] + 256 * ucp[9];
902: } else {
1.194 markus 903: debug2("Initial X11 packet contains bad byte order byte: 0x%x",
1.148 deraadt 904: ucp[0]);
1.41 markus 905: return -1;
906: }
907:
908: /* Check if the whole packet is in buffer. */
1.121 markus 909: if (buffer_len(b) <
1.41 markus 910: 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
911: return 0;
912:
913: /* Check if authentication protocol matches. */
914: if (proto_len != strlen(x11_saved_proto) ||
915: memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
1.194 markus 916: debug2("X11 connection uses different authentication protocol.");
1.41 markus 917: return -1;
918: }
919: /* Check if authentication data matches our fake data. */
920: if (data_len != x11_fake_data_len ||
1.308 djm 921: timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
1.41 markus 922: x11_fake_data, x11_fake_data_len) != 0) {
1.194 markus 923: debug2("X11 auth data does not match fake data.");
1.41 markus 924: return -1;
925: }
926: /* Check fake data length */
927: if (x11_fake_data_len != x11_saved_data_len) {
928: error("X11 fake_data_len %d != saved_data_len %d",
929: x11_fake_data_len, x11_saved_data_len);
930: return -1;
931: }
932: /*
933: * Received authentication protocol and data match
934: * our fake data. Substitute the fake data with real
935: * data.
936: */
937: memcpy(ucp + 12 + ((proto_len + 3) & ~3),
938: x11_saved_data, x11_saved_data_len);
939: return 1;
940: }
941:
1.127 itojun 942: static void
1.237 deraadt 943: channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 944: {
1.121 markus 945: int ret = x11_open_helper(&c->output);
1.180 deraadt 946:
1.41 markus 947: if (ret == 1) {
948: /* Start normal processing for the channel. */
949: c->type = SSH_CHANNEL_OPEN;
1.47 markus 950: channel_pre_open_13(c, readset, writeset);
1.41 markus 951: } else if (ret == -1) {
952: /*
953: * We have received an X11 connection that has bad
954: * authentication information.
955: */
1.188 itojun 956: logit("X11 connection rejected because of wrong authentication.");
1.41 markus 957: buffer_clear(&c->input);
958: buffer_clear(&c->output);
1.132 markus 959: channel_close_fd(&c->sock);
1.41 markus 960: c->sock = -1;
961: c->type = SSH_CHANNEL_CLOSED;
962: packet_start(SSH_MSG_CHANNEL_CLOSE);
963: packet_put_int(c->remote_id);
964: packet_send();
965: }
966: }
1.25 markus 967:
1.127 itojun 968: static void
1.237 deraadt 969: channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 970: {
1.121 markus 971: int ret = x11_open_helper(&c->output);
1.133 markus 972:
973: /* c->force_drain = 1; */
974:
1.41 markus 975: if (ret == 1) {
976: c->type = SSH_CHANNEL_OPEN;
1.157 markus 977: channel_pre_open(c, readset, writeset);
1.41 markus 978: } else if (ret == -1) {
1.188 itojun 979: logit("X11 connection rejected because of wrong authentication.");
1.194 markus 980: debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1.156 markus 981: chan_read_failed(c);
982: buffer_clear(&c->input);
983: chan_ibuf_empty(c);
984: buffer_clear(&c->output);
985: /* for proto v1, the peer will send an IEOF */
986: if (compat20)
987: chan_write_failed(c);
988: else
989: c->type = SSH_CHANNEL_OPEN;
1.194 markus 990: debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1.41 markus 991: }
992: }
1.25 markus 993:
1.302 djm 994: static void
995: channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
996: {
1.304 djm 997: if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1.302 djm 998: buffer_check_alloc(&c->input, CHAN_RBUF))
999: FD_SET(c->rfd, readset);
1000: if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1001: /* clear buffer immediately (discard any partial packet) */
1002: buffer_clear(&c->input);
1003: chan_ibuf_empty(c);
1004: /* Start output drain. XXX just kill chan? */
1005: chan_rcvd_oclose(c);
1006: }
1007: if (c->ostate == CHAN_OUTPUT_OPEN ||
1008: c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1009: if (buffer_len(&c->output) > 0)
1010: FD_SET(c->wfd, writeset);
1011: else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1012: chan_obuf_empty(c);
1013: }
1014: }
1015:
1.104 markus 1016: /* try to decode a socks4 header */
1.259 stevesk 1017: /* ARGSUSED */
1.127 itojun 1018: static int
1.237 deraadt 1019: channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1.103 markus 1020: {
1.181 markus 1021: char *p, *host;
1.292 djm 1022: u_int len, have, i, found, need;
1.148 deraadt 1023: char username[256];
1.103 markus 1024: struct {
1025: u_int8_t version;
1026: u_int8_t command;
1027: u_int16_t dest_port;
1.104 markus 1028: struct in_addr dest_addr;
1.103 markus 1029: } s4_req, s4_rsp;
1030:
1.104 markus 1031: debug2("channel %d: decode socks4", c->self);
1.109 markus 1032:
1033: have = buffer_len(&c->input);
1034: len = sizeof(s4_req);
1035: if (have < len)
1036: return 0;
1037: p = buffer_ptr(&c->input);
1.292 djm 1038:
1039: need = 1;
1040: /* SOCKS4A uses an invalid IP address 0.0.0.x */
1041: if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1042: debug2("channel %d: socks4a request", c->self);
1043: /* ... and needs an extra string (the hostname) */
1044: need = 2;
1045: }
1046: /* Check for terminating NUL on the string(s) */
1.109 markus 1047: for (found = 0, i = len; i < have; i++) {
1048: if (p[i] == '\0') {
1.292 djm 1049: found++;
1050: if (found == need)
1051: break;
1.109 markus 1052: }
1053: if (i > 1024) {
1054: /* the peer is probably sending garbage */
1055: debug("channel %d: decode socks4: too long",
1056: c->self);
1057: return -1;
1058: }
1059: }
1.292 djm 1060: if (found < need)
1.109 markus 1061: return 0;
1.103 markus 1062: buffer_get(&c->input, (char *)&s4_req.version, 1);
1063: buffer_get(&c->input, (char *)&s4_req.command, 1);
1064: buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1.104 markus 1065: buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1.109 markus 1066: have = buffer_len(&c->input);
1.103 markus 1067: p = buffer_ptr(&c->input);
1068: len = strlen(p);
1.106 markus 1069: debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1.292 djm 1070: len++; /* trailing '\0' */
1.103 markus 1071: if (len > have)
1.104 markus 1072: fatal("channel %d: decode socks4: len %d > have %d",
1.103 markus 1073: c->self, len, have);
1074: strlcpy(username, p, sizeof(username));
1075: buffer_consume(&c->input, len);
1076:
1.293 djm 1077: if (c->path != NULL) {
1078: xfree(c->path);
1079: c->path = NULL;
1080: }
1.292 djm 1081: if (need == 1) { /* SOCKS4: one string */
1082: host = inet_ntoa(s4_req.dest_addr);
1.293 djm 1083: c->path = xstrdup(host);
1.292 djm 1084: } else { /* SOCKS4A: two strings */
1085: have = buffer_len(&c->input);
1086: p = buffer_ptr(&c->input);
1087: len = strlen(p);
1088: debug2("channel %d: decode socks4a: host %s/%d",
1089: c->self, p, len);
1090: len++; /* trailing '\0' */
1091: if (len > have)
1092: fatal("channel %d: decode socks4a: len %d > have %d",
1093: c->self, len, have);
1.293 djm 1094: if (len > NI_MAXHOST) {
1.292 djm 1095: error("channel %d: hostname \"%.100s\" too long",
1096: c->self, p);
1097: return -1;
1098: }
1.293 djm 1099: c->path = xstrdup(p);
1.292 djm 1100: buffer_consume(&c->input, len);
1101: }
1.103 markus 1102: c->host_port = ntohs(s4_req.dest_port);
1.148 deraadt 1103:
1.194 markus 1104: debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1.292 djm 1105: c->self, c->path, c->host_port, s4_req.command);
1.103 markus 1106:
1.104 markus 1107: if (s4_req.command != 1) {
1.292 djm 1108: debug("channel %d: cannot handle: %s cn %d",
1109: c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1.104 markus 1110: return -1;
1.103 markus 1111: }
1.104 markus 1112: s4_rsp.version = 0; /* vn: 0 for reply */
1113: s4_rsp.command = 90; /* cd: req granted */
1.103 markus 1114: s4_rsp.dest_port = 0; /* ignored */
1.104 markus 1115: s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1.246 deraadt 1116: buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1.104 markus 1117: return 1;
1118: }
1119:
1.193 markus 1120: /* try to decode a socks5 header */
1121: #define SSH_SOCKS5_AUTHDONE 0x1000
1122: #define SSH_SOCKS5_NOAUTH 0x00
1123: #define SSH_SOCKS5_IPV4 0x01
1124: #define SSH_SOCKS5_DOMAIN 0x03
1125: #define SSH_SOCKS5_IPV6 0x04
1126: #define SSH_SOCKS5_CONNECT 0x01
1127: #define SSH_SOCKS5_SUCCESS 0x00
1128:
1.259 stevesk 1129: /* ARGSUSED */
1.193 markus 1130: static int
1.237 deraadt 1131: channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1.193 markus 1132: {
1133: struct {
1134: u_int8_t version;
1135: u_int8_t command;
1136: u_int8_t reserved;
1137: u_int8_t atyp;
1138: } s5_req, s5_rsp;
1139: u_int16_t dest_port;
1.293 djm 1140: u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1.252 djm 1141: u_int have, need, i, found, nmethods, addrlen, af;
1.193 markus 1142:
1143: debug2("channel %d: decode socks5", c->self);
1144: p = buffer_ptr(&c->input);
1145: if (p[0] != 0x05)
1146: return -1;
1147: have = buffer_len(&c->input);
1148: if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1149: /* format: ver | nmethods | methods */
1.198 djm 1150: if (have < 2)
1.193 markus 1151: return 0;
1152: nmethods = p[1];
1153: if (have < nmethods + 2)
1154: return 0;
1155: /* look for method: "NO AUTHENTICATION REQUIRED" */
1.268 stevesk 1156: for (found = 0, i = 2; i < nmethods + 2; i++) {
1.264 stevesk 1157: if (p[i] == SSH_SOCKS5_NOAUTH) {
1.193 markus 1158: found = 1;
1159: break;
1160: }
1161: }
1162: if (!found) {
1163: debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1164: c->self);
1165: return -1;
1166: }
1167: buffer_consume(&c->input, nmethods + 2);
1168: buffer_put_char(&c->output, 0x05); /* version */
1169: buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1170: FD_SET(c->sock, writeset);
1171: c->flags |= SSH_SOCKS5_AUTHDONE;
1172: debug2("channel %d: socks5 auth done", c->self);
1173: return 0; /* need more */
1174: }
1175: debug2("channel %d: socks5 post auth", c->self);
1176: if (have < sizeof(s5_req)+1)
1177: return 0; /* need more */
1.247 deraadt 1178: memcpy(&s5_req, p, sizeof(s5_req));
1.193 markus 1179: if (s5_req.version != 0x05 ||
1180: s5_req.command != SSH_SOCKS5_CONNECT ||
1181: s5_req.reserved != 0x00) {
1.194 markus 1182: debug2("channel %d: only socks5 connect supported", c->self);
1.193 markus 1183: return -1;
1184: }
1.213 deraadt 1185: switch (s5_req.atyp){
1.193 markus 1186: case SSH_SOCKS5_IPV4:
1187: addrlen = 4;
1188: af = AF_INET;
1189: break;
1190: case SSH_SOCKS5_DOMAIN:
1191: addrlen = p[sizeof(s5_req)];
1192: af = -1;
1193: break;
1194: case SSH_SOCKS5_IPV6:
1195: addrlen = 16;
1196: af = AF_INET6;
1197: break;
1198: default:
1.194 markus 1199: debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1.193 markus 1200: return -1;
1201: }
1.252 djm 1202: need = sizeof(s5_req) + addrlen + 2;
1203: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1204: need++;
1205: if (have < need)
1.193 markus 1206: return 0;
1207: buffer_consume(&c->input, sizeof(s5_req));
1208: if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1209: buffer_consume(&c->input, 1); /* host string length */
1210: buffer_get(&c->input, (char *)&dest_addr, addrlen);
1211: buffer_get(&c->input, (char *)&dest_port, 2);
1212: dest_addr[addrlen] = '\0';
1.293 djm 1213: if (c->path != NULL) {
1214: xfree(c->path);
1215: c->path = NULL;
1216: }
1217: if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1.294 djm 1218: if (addrlen >= NI_MAXHOST) {
1.293 djm 1219: error("channel %d: dynamic request: socks5 hostname "
1220: "\"%.100s\" too long", c->self, dest_addr);
1221: return -1;
1222: }
1223: c->path = xstrdup(dest_addr);
1224: } else {
1225: if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1226: return -1;
1227: c->path = xstrdup(ntop);
1228: }
1.193 markus 1229: c->host_port = ntohs(dest_port);
1.198 djm 1230:
1.194 markus 1231: debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1.193 markus 1232: c->self, c->path, c->host_port, s5_req.command);
1233:
1234: s5_rsp.version = 0x05;
1235: s5_rsp.command = SSH_SOCKS5_SUCCESS;
1236: s5_rsp.reserved = 0; /* ignored */
1237: s5_rsp.atyp = SSH_SOCKS5_IPV4;
1238: ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1239: dest_port = 0; /* ignored */
1240:
1.246 deraadt 1241: buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1242: buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1243: buffer_append(&c->output, &dest_port, sizeof(dest_port));
1.193 markus 1244: return 1;
1.301 dtucker 1245: }
1246:
1247: Channel *
1.302 djm 1248: channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1249: int in, int out)
1.301 dtucker 1250: {
1251: Channel *c;
1252:
1253: debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1254: port_to_connect);
1255:
1256: c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1257: -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1258: 0, "stdio-forward", /*nonblock*/0);
1259:
1260: c->path = xstrdup(host_to_connect);
1261: c->host_port = port_to_connect;
1262: c->listening_port = 0;
1263: c->force_drain = 1;
1264:
1265: channel_register_fds(c, in, out, -1, 0, 1, 0);
1266: port_open_helper(c, "direct-tcpip");
1267:
1268: return c;
1.193 markus 1269: }
1270:
1.104 markus 1271: /* dynamic port forwarding */
1.127 itojun 1272: static void
1.237 deraadt 1273: channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1.104 markus 1274: {
1275: u_char *p;
1.217 djm 1276: u_int have;
1277: int ret;
1.103 markus 1278:
1.104 markus 1279: have = buffer_len(&c->input);
1280: debug2("channel %d: pre_dynamic: have %d", c->self, have);
1.105 markus 1281: /* buffer_dump(&c->input); */
1.104 markus 1282: /* check if the fixed size part of the packet is in buffer. */
1.193 markus 1283: if (have < 3) {
1.104 markus 1284: /* need more */
1285: FD_SET(c->sock, readset);
1286: return;
1287: }
1288: /* try to guess the protocol */
1289: p = buffer_ptr(&c->input);
1290: switch (p[0]) {
1291: case 0x04:
1292: ret = channel_decode_socks4(c, readset, writeset);
1.193 markus 1293: break;
1294: case 0x05:
1295: ret = channel_decode_socks5(c, readset, writeset);
1.104 markus 1296: break;
1297: default:
1298: ret = -1;
1299: break;
1300: }
1301: if (ret < 0) {
1.113 markus 1302: chan_mark_dead(c);
1.104 markus 1303: } else if (ret == 0) {
1304: debug2("channel %d: pre_dynamic: need more", c->self);
1305: /* need more */
1306: FD_SET(c->sock, readset);
1307: } else {
1308: /* switch to the next state */
1309: c->type = SSH_CHANNEL_OPENING;
1310: port_open_helper(c, "direct-tcpip");
1311: }
1.103 markus 1312: }
1313:
1.41 markus 1314: /* This is our fake X11 server socket. */
1.259 stevesk 1315: /* ARGSUSED */
1.127 itojun 1316: static void
1.237 deraadt 1317: channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1318: {
1.113 markus 1319: Channel *nc;
1.285 djm 1320: struct sockaddr_storage addr;
1.162 stevesk 1321: int newsock;
1.41 markus 1322: socklen_t addrlen;
1.85 markus 1323: char buf[16384], *remote_ipaddr;
1.51 markus 1324: int remote_port;
1.25 markus 1325:
1.41 markus 1326: if (FD_ISSET(c->sock, readset)) {
1327: debug("X11 connection requested.");
1328: addrlen = sizeof(addr);
1.285 djm 1329: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.149 markus 1330: if (c->single_connection) {
1.194 markus 1331: debug2("single_connection: closing X11 listener.");
1.149 markus 1332: channel_close_fd(&c->sock);
1333: chan_mark_dead(c);
1334: }
1.41 markus 1335: if (newsock < 0) {
1336: error("accept: %.100s", strerror(errno));
1337: return;
1338: }
1.162 stevesk 1339: set_nodelay(newsock);
1.85 markus 1340: remote_ipaddr = get_peer_ipaddr(newsock);
1.51 markus 1341: remote_port = get_peer_port(newsock);
1.41 markus 1342: snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1.85 markus 1343: remote_ipaddr, remote_port);
1.51 markus 1344:
1.113 markus 1345: nc = channel_new("accepted x11 socket",
1.51 markus 1346: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1.190 markus 1347: c->local_window_max, c->local_maxpacket, 0, buf, 1);
1.51 markus 1348: if (compat20) {
1349: packet_start(SSH2_MSG_CHANNEL_OPEN);
1350: packet_put_cstring("x11");
1.113 markus 1351: packet_put_int(nc->self);
1.149 markus 1352: packet_put_int(nc->local_window_max);
1353: packet_put_int(nc->local_maxpacket);
1.85 markus 1354: /* originator ipaddr and port */
1355: packet_put_cstring(remote_ipaddr);
1.57 markus 1356: if (datafellows & SSH_BUG_X11FWD) {
1.194 markus 1357: debug2("ssh2 x11 bug compat mode");
1.57 markus 1358: } else {
1359: packet_put_int(remote_port);
1360: }
1.51 markus 1361: packet_send();
1362: } else {
1363: packet_start(SSH_SMSG_X11_OPEN);
1.113 markus 1364: packet_put_int(nc->self);
1.121 markus 1365: if (packet_get_protocol_flags() &
1366: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.125 markus 1367: packet_put_cstring(buf);
1.51 markus 1368: packet_send();
1369: }
1.85 markus 1370: xfree(remote_ipaddr);
1.41 markus 1371: }
1372: }
1.25 markus 1373:
1.127 itojun 1374: static void
1.103 markus 1375: port_open_helper(Channel *c, char *rtype)
1376: {
1377: int direct;
1378: char buf[1024];
1379: char *remote_ipaddr = get_peer_ipaddr(c->sock);
1.216 markus 1380: int remote_port = get_peer_port(c->sock);
1.303 djm 1381:
1382: if (remote_port == -1) {
1383: /* Fake addr/port to appease peers that validate it (Tectia) */
1384: xfree(remote_ipaddr);
1385: remote_ipaddr = xstrdup("127.0.0.1");
1386: remote_port = 65535;
1387: }
1.103 markus 1388:
1389: direct = (strcmp(rtype, "direct-tcpip") == 0);
1390:
1391: snprintf(buf, sizeof buf,
1392: "%s: listening port %d for %.100s port %d, "
1393: "connect from %.200s port %d",
1394: rtype, c->listening_port, c->path, c->host_port,
1395: remote_ipaddr, remote_port);
1396:
1397: xfree(c->remote_name);
1398: c->remote_name = xstrdup(buf);
1399:
1400: if (compat20) {
1401: packet_start(SSH2_MSG_CHANNEL_OPEN);
1402: packet_put_cstring(rtype);
1403: packet_put_int(c->self);
1404: packet_put_int(c->local_window_max);
1405: packet_put_int(c->local_maxpacket);
1406: if (direct) {
1407: /* target host, port */
1408: packet_put_cstring(c->path);
1409: packet_put_int(c->host_port);
1410: } else {
1411: /* listen address, port */
1412: packet_put_cstring(c->path);
1413: packet_put_int(c->listening_port);
1414: }
1415: /* originator host and port */
1416: packet_put_cstring(remote_ipaddr);
1.216 markus 1417: packet_put_int((u_int)remote_port);
1.103 markus 1418: packet_send();
1419: } else {
1420: packet_start(SSH_MSG_PORT_OPEN);
1421: packet_put_int(c->self);
1422: packet_put_cstring(c->path);
1423: packet_put_int(c->host_port);
1.121 markus 1424: if (packet_get_protocol_flags() &
1425: SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1.103 markus 1426: packet_put_cstring(c->remote_name);
1427: packet_send();
1428: }
1429: xfree(remote_ipaddr);
1430: }
1431:
1.226 djm 1432: static void
1433: channel_set_reuseaddr(int fd)
1434: {
1435: int on = 1;
1436:
1437: /*
1438: * Set socket options.
1439: * Allow local port reuse in TIME_WAIT.
1440: */
1441: if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1442: error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1443: }
1444:
1.41 markus 1445: /*
1446: * This socket is listening for connections to a forwarded TCP/IP port.
1447: */
1.259 stevesk 1448: /* ARGSUSED */
1.127 itojun 1449: static void
1.237 deraadt 1450: channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1451: {
1.103 markus 1452: Channel *nc;
1.285 djm 1453: struct sockaddr_storage addr;
1.113 markus 1454: int newsock, nextstate;
1.41 markus 1455: socklen_t addrlen;
1.103 markus 1456: char *rtype;
1.73 markus 1457:
1.41 markus 1458: if (FD_ISSET(c->sock, readset)) {
1459: debug("Connection to port %d forwarding "
1460: "to %.100s port %d requested.",
1461: c->listening_port, c->path, c->host_port);
1.103 markus 1462:
1.137 markus 1463: if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1464: nextstate = SSH_CHANNEL_OPENING;
1465: rtype = "forwarded-tcpip";
1466: } else {
1467: if (c->host_port == 0) {
1468: nextstate = SSH_CHANNEL_DYNAMIC;
1.138 markus 1469: rtype = "dynamic-tcpip";
1.137 markus 1470: } else {
1471: nextstate = SSH_CHANNEL_OPENING;
1472: rtype = "direct-tcpip";
1473: }
1474: }
1.103 markus 1475:
1.41 markus 1476: addrlen = sizeof(addr);
1.285 djm 1477: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1478: if (newsock < 0) {
1479: error("accept: %.100s", strerror(errno));
1480: return;
1481: }
1.169 stevesk 1482: set_nodelay(newsock);
1.190 markus 1483: nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1484: c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1.103 markus 1485: nc->listening_port = c->listening_port;
1486: nc->host_port = c->host_port;
1.293 djm 1487: if (c->path != NULL)
1488: nc->path = xstrdup(c->path);
1.103 markus 1489:
1.299 markus 1490: if (nextstate != SSH_CHANNEL_DYNAMIC)
1.103 markus 1491: port_open_helper(nc, rtype);
1.41 markus 1492: }
1493: }
1.25 markus 1494:
1.41 markus 1495: /*
1496: * This is the authentication agent socket listening for connections from
1497: * clients.
1498: */
1.259 stevesk 1499: /* ARGSUSED */
1.127 itojun 1500: static void
1.237 deraadt 1501: channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1502: {
1.113 markus 1503: Channel *nc;
1504: int newsock;
1.285 djm 1505: struct sockaddr_storage addr;
1.41 markus 1506: socklen_t addrlen;
1.25 markus 1507:
1.41 markus 1508: if (FD_ISSET(c->sock, readset)) {
1509: addrlen = sizeof(addr);
1.285 djm 1510: newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1.41 markus 1511: if (newsock < 0) {
1512: error("accept from auth socket: %.100s", strerror(errno));
1513: return;
1514: }
1.113 markus 1515: nc = channel_new("accepted auth socket",
1.73 markus 1516: SSH_CHANNEL_OPENING, newsock, newsock, -1,
1517: c->local_window_max, c->local_maxpacket,
1.190 markus 1518: 0, "accepted auth socket", 1);
1.73 markus 1519: if (compat20) {
1520: packet_start(SSH2_MSG_CHANNEL_OPEN);
1521: packet_put_cstring("auth-agent@openssh.com");
1.113 markus 1522: packet_put_int(nc->self);
1.73 markus 1523: packet_put_int(c->local_window_max);
1524: packet_put_int(c->local_maxpacket);
1525: } else {
1526: packet_start(SSH_SMSG_AGENT_OPEN);
1.113 markus 1527: packet_put_int(nc->self);
1.73 markus 1528: }
1.41 markus 1529: packet_send();
1530: }
1531: }
1.25 markus 1532:
1.259 stevesk 1533: /* ARGSUSED */
1.127 itojun 1534: static void
1.237 deraadt 1535: channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1.75 markus 1536: {
1.276 djm 1537: int err = 0, sock;
1.129 stevesk 1538: socklen_t sz = sizeof(err);
1.114 markus 1539:
1.75 markus 1540: if (FD_ISSET(c->sock, writeset)) {
1.170 stevesk 1541: if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1.114 markus 1542: err = errno;
1543: error("getsockopt SO_ERROR failed");
1544: }
1545: if (err == 0) {
1.276 djm 1546: debug("channel %d: connected to %s port %d",
1547: c->self, c->connect_ctx.host, c->connect_ctx.port);
1548: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1549: c->type = SSH_CHANNEL_OPEN;
1550: if (compat20) {
1551: packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1552: packet_put_int(c->remote_id);
1553: packet_put_int(c->self);
1554: packet_put_int(c->local_window);
1555: packet_put_int(c->local_maxpacket);
1556: } else {
1557: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1558: packet_put_int(c->remote_id);
1559: packet_put_int(c->self);
1560: }
1.75 markus 1561: } else {
1.276 djm 1562: debug("channel %d: connection failed: %s",
1.114 markus 1563: c->self, strerror(err));
1.276 djm 1564: /* Try next address, if any */
1565: if ((sock = connect_next(&c->connect_ctx)) > 0) {
1566: close(c->sock);
1567: c->sock = c->rfd = c->wfd = sock;
1568: channel_max_fd = channel_find_maxfd();
1569: return;
1570: }
1571: /* Exhausted all addresses */
1572: error("connect_to %.100s port %d: failed.",
1573: c->connect_ctx.host, c->connect_ctx.port);
1574: channel_connect_ctx_free(&c->connect_ctx);
1.114 markus 1575: if (compat20) {
1576: packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1577: packet_put_int(c->remote_id);
1578: packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1579: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1580: packet_put_cstring(strerror(err));
1581: packet_put_cstring("");
1582: }
1.75 markus 1583: } else {
1.114 markus 1584: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1585: packet_put_int(c->remote_id);
1.75 markus 1586: }
1.114 markus 1587: chan_mark_dead(c);
1.75 markus 1588: }
1.114 markus 1589: packet_send();
1.75 markus 1590: }
1591: }
1592:
1.259 stevesk 1593: /* ARGSUSED */
1.127 itojun 1594: static int
1.237 deraadt 1595: channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1596: {
1.214 markus 1597: char buf[CHAN_RBUF];
1.41 markus 1598: int len;
1.25 markus 1599:
1.118 markus 1600: if (c->rfd != -1 &&
1.41 markus 1601: FD_ISSET(c->rfd, readset)) {
1602: len = read(c->rfd, buf, sizeof(buf));
1.53 markus 1603: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1604: return 1;
1.41 markus 1605: if (len <= 0) {
1.194 markus 1606: debug2("channel %d: read<=0 rfd %d len %d",
1.41 markus 1607: c->self, c->rfd, len);
1.104 markus 1608: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1609: debug2("channel %d: not open", c->self);
1.113 markus 1610: chan_mark_dead(c);
1.103 markus 1611: return -1;
1.104 markus 1612: } else if (compat13) {
1.158 markus 1613: buffer_clear(&c->output);
1.41 markus 1614: c->type = SSH_CHANNEL_INPUT_DRAINING;
1.194 markus 1615: debug2("channel %d: input draining.", c->self);
1.25 markus 1616: } else {
1.41 markus 1617: chan_read_failed(c);
1.25 markus 1618: }
1.41 markus 1619: return -1;
1620: }
1.143 deraadt 1621: if (c->input_filter != NULL) {
1.66 markus 1622: if (c->input_filter(c, buf, len) == -1) {
1.194 markus 1623: debug2("channel %d: filter stops", c->self);
1.65 markus 1624: chan_read_failed(c);
1625: }
1.228 reyk 1626: } else if (c->datagram) {
1627: buffer_put_string(&c->input, buf, len);
1.65 markus 1628: } else {
1629: buffer_append(&c->input, buf, len);
1630: }
1.41 markus 1631: }
1632: return 1;
1633: }
1.241 deraadt 1634:
1.259 stevesk 1635: /* ARGSUSED */
1.127 itojun 1636: static int
1.237 deraadt 1637: channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1638: {
1.95 markus 1639: struct termios tio;
1.231 reyk 1640: u_char *data = NULL, *buf;
1.309 djm 1641: u_int dlen, olen = 0;
1.41 markus 1642: int len;
1.25 markus 1643:
1.41 markus 1644: /* Send buffered output data to the socket. */
1.118 markus 1645: if (c->wfd != -1 &&
1.41 markus 1646: FD_ISSET(c->wfd, writeset) &&
1647: buffer_len(&c->output) > 0) {
1.309 djm 1648: olen = buffer_len(&c->output);
1.231 reyk 1649: if (c->output_filter != NULL) {
1650: if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1651: debug2("channel %d: filter stops", c->self);
1.232 reyk 1652: if (c->type != SSH_CHANNEL_OPEN)
1653: chan_mark_dead(c);
1654: else
1655: chan_write_failed(c);
1656: return -1;
1.231 reyk 1657: }
1658: } else if (c->datagram) {
1659: buf = data = buffer_get_string(&c->output, &dlen);
1660: } else {
1661: buf = data = buffer_ptr(&c->output);
1662: dlen = buffer_len(&c->output);
1663: }
1664:
1.228 reyk 1665: if (c->datagram) {
1666: /* ignore truncated writes, datagrams might get lost */
1.231 reyk 1667: len = write(c->wfd, buf, dlen);
1.228 reyk 1668: xfree(data);
1669: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1670: return 1;
1671: if (len <= 0) {
1672: if (c->type != SSH_CHANNEL_OPEN)
1673: chan_mark_dead(c);
1674: else
1675: chan_write_failed(c);
1676: return -1;
1677: }
1.309 djm 1678: goto out;
1.228 reyk 1679: }
1.231 reyk 1680:
1681: len = write(c->wfd, buf, dlen);
1.53 markus 1682: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1683: return 1;
1.41 markus 1684: if (len <= 0) {
1.104 markus 1685: if (c->type != SSH_CHANNEL_OPEN) {
1.194 markus 1686: debug2("channel %d: not open", c->self);
1.113 markus 1687: chan_mark_dead(c);
1.104 markus 1688: return -1;
1689: } else if (compat13) {
1.158 markus 1690: buffer_clear(&c->output);
1.194 markus 1691: debug2("channel %d: input draining.", c->self);
1.41 markus 1692: c->type = SSH_CHANNEL_INPUT_DRAINING;
1693: } else {
1694: chan_write_failed(c);
1695: }
1696: return -1;
1.91 markus 1697: }
1.231 reyk 1698: if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1.91 markus 1699: if (tcgetattr(c->wfd, &tio) == 0 &&
1700: !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1701: /*
1702: * Simulate echo to reduce the impact of
1.96 markus 1703: * traffic analysis. We need to match the
1.95 markus 1704: * size of a SSH2_MSG_CHANNEL_DATA message
1.231 reyk 1705: * (4 byte channel id + buf)
1.91 markus 1706: */
1.95 markus 1707: packet_send_ignore(4 + len);
1.91 markus 1708: packet_send();
1709: }
1.25 markus 1710: }
1.41 markus 1711: buffer_consume(&c->output, len);
1.44 markus 1712: }
1.309 djm 1713: out:
1714: if (compat20 && olen > 0)
1715: c->local_consumed += olen - buffer_len(&c->output);
1.44 markus 1716: return 1;
1717: }
1.241 deraadt 1718:
1.127 itojun 1719: static int
1.237 deraadt 1720: channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1.44 markus 1721: {
1.214 markus 1722: char buf[CHAN_RBUF];
1.44 markus 1723: int len;
1724:
1.45 markus 1725: /** XXX handle drain efd, too */
1.44 markus 1726: if (c->efd != -1) {
1727: if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1728: FD_ISSET(c->efd, writeset) &&
1729: buffer_len(&c->extended) > 0) {
1730: len = write(c->efd, buffer_ptr(&c->extended),
1731: buffer_len(&c->extended));
1.70 markus 1732: debug2("channel %d: written %d to efd %d",
1.44 markus 1733: c->self, len, c->efd);
1.93 markus 1734: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1735: return 1;
1736: if (len <= 0) {
1737: debug2("channel %d: closing write-efd %d",
1738: c->self, c->efd);
1.132 markus 1739: channel_close_fd(&c->efd);
1.93 markus 1740: } else {
1.44 markus 1741: buffer_consume(&c->extended, len);
1742: c->local_consumed += len;
1743: }
1.306 djm 1744: } else if (c->efd != -1 &&
1745: (c->extended_usage == CHAN_EXTENDED_READ ||
1746: c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1.44 markus 1747: FD_ISSET(c->efd, readset)) {
1748: len = read(c->efd, buf, sizeof(buf));
1.70 markus 1749: debug2("channel %d: read %d from efd %d",
1.148 deraadt 1750: c->self, len, c->efd);
1.93 markus 1751: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1752: return 1;
1753: if (len <= 0) {
1754: debug2("channel %d: closing read-efd %d",
1.45 markus 1755: c->self, c->efd);
1.132 markus 1756: channel_close_fd(&c->efd);
1.93 markus 1757: } else {
1.306 djm 1758: if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1759: debug3("channel %d: discard efd",
1760: c->self);
1761: } else
1762: buffer_append(&c->extended, buf, len);
1.93 markus 1763: }
1.44 markus 1764: }
1765: }
1766: return 1;
1767: }
1.241 deraadt 1768:
1.259 stevesk 1769: /* ARGSUSED */
1.127 itojun 1770: static int
1.93 markus 1771: channel_check_window(Channel *c)
1.44 markus 1772: {
1.104 markus 1773: if (c->type == SSH_CHANNEL_OPEN &&
1774: !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1.270 dtucker 1775: ((c->local_window_max - c->local_window >
1.269 markus 1776: c->local_maxpacket*3) ||
1777: c->local_window < c->local_window_max/2) &&
1.44 markus 1778: c->local_consumed > 0) {
1779: packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1780: packet_put_int(c->remote_id);
1781: packet_put_int(c->local_consumed);
1782: packet_send();
1.70 markus 1783: debug2("channel %d: window %d sent adjust %d",
1.44 markus 1784: c->self, c->local_window,
1785: c->local_consumed);
1786: c->local_window += c->local_consumed;
1787: c->local_consumed = 0;
1.1 deraadt 1788: }
1.41 markus 1789: return 1;
1.1 deraadt 1790: }
1791:
1.127 itojun 1792: static void
1.237 deraadt 1793: channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1.41 markus 1794: {
1795: channel_handle_rfd(c, readset, writeset);
1796: channel_handle_wfd(c, readset, writeset);
1.157 markus 1797: if (!compat20)
1.137 markus 1798: return;
1.44 markus 1799: channel_handle_efd(c, readset, writeset);
1.93 markus 1800: channel_check_window(c);
1.44 markus 1801: }
1802:
1.302 djm 1803: static u_int
1804: read_mux(Channel *c, u_int need)
1805: {
1806: char buf[CHAN_RBUF];
1807: int len;
1808: u_int rlen;
1809:
1810: if (buffer_len(&c->input) < need) {
1811: rlen = need - buffer_len(&c->input);
1812: len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1813: if (len <= 0) {
1814: if (errno != EINTR && errno != EAGAIN) {
1815: debug2("channel %d: ctl read<=0 rfd %d len %d",
1816: c->self, c->rfd, len);
1817: chan_read_failed(c);
1818: return 0;
1819: }
1820: } else
1821: buffer_append(&c->input, buf, len);
1822: }
1823: return buffer_len(&c->input);
1824: }
1825:
1826: static void
1827: channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1828: {
1829: u_int need;
1830: ssize_t len;
1831:
1832: if (!compat20)
1833: fatal("%s: entered with !compat20", __func__);
1834:
1.304 djm 1835: if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1.302 djm 1836: (c->istate == CHAN_INPUT_OPEN ||
1837: c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1838: /*
1839: * Don't not read past the precise end of packets to
1840: * avoid disrupting fd passing.
1841: */
1842: if (read_mux(c, 4) < 4) /* read header */
1843: return;
1844: need = get_u32(buffer_ptr(&c->input));
1845: #define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1846: if (need > CHANNEL_MUX_MAX_PACKET) {
1847: debug2("channel %d: packet too big %u > %u",
1848: c->self, CHANNEL_MUX_MAX_PACKET, need);
1849: chan_rcvd_oclose(c);
1850: return;
1851: }
1852: if (read_mux(c, need + 4) < need + 4) /* read body */
1853: return;
1854: if (c->mux_rcb(c) != 0) {
1855: debug("channel %d: mux_rcb failed", c->self);
1856: chan_mark_dead(c);
1857: return;
1858: }
1859: }
1860:
1861: if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1862: buffer_len(&c->output) > 0) {
1863: len = write(c->wfd, buffer_ptr(&c->output),
1864: buffer_len(&c->output));
1865: if (len < 0 && (errno == EINTR || errno == EAGAIN))
1866: return;
1867: if (len <= 0) {
1868: chan_mark_dead(c);
1869: return;
1870: }
1871: buffer_consume(&c->output, len);
1872: }
1873: }
1874:
1875: static void
1876: channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1877: {
1878: Channel *nc;
1879: struct sockaddr_storage addr;
1880: socklen_t addrlen;
1881: int newsock;
1882: uid_t euid;
1883: gid_t egid;
1884:
1885: if (!FD_ISSET(c->sock, readset))
1886: return;
1887:
1888: debug("multiplexing control connection");
1889:
1890: /*
1891: * Accept connection on control socket
1892: */
1893: memset(&addr, 0, sizeof(addr));
1894: addrlen = sizeof(addr);
1895: if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1896: &addrlen)) == -1) {
1897: error("%s accept: %s", __func__, strerror(errno));
1898: return;
1899: }
1900:
1901: if (getpeereid(newsock, &euid, &egid) < 0) {
1902: error("%s getpeereid failed: %s", __func__,
1903: strerror(errno));
1904: close(newsock);
1905: return;
1906: }
1907: if ((euid != 0) && (getuid() != euid)) {
1908: error("multiplex uid mismatch: peer euid %u != uid %u",
1909: (u_int)euid, (u_int)getuid());
1910: close(newsock);
1911: return;
1912: }
1913: nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1914: newsock, newsock, -1, c->local_window_max,
1915: c->local_maxpacket, 0, "mux-control", 1);
1916: nc->mux_rcb = c->mux_rcb;
1917: debug3("%s: new mux channel %d fd %d", __func__,
1918: nc->self, nc->sock);
1919: /* establish state */
1920: nc->mux_rcb(nc);
1921: /* mux state transitions must not elicit protocol messages */
1922: nc->flags |= CHAN_LOCAL;
1923: }
1924:
1.259 stevesk 1925: /* ARGSUSED */
1.127 itojun 1926: static void
1.237 deraadt 1927: channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1.1 deraadt 1928: {
1.41 markus 1929: int len;
1.180 deraadt 1930:
1.41 markus 1931: /* Send buffered output data to the socket. */
1932: if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1933: len = write(c->sock, buffer_ptr(&c->output),
1934: buffer_len(&c->output));
1935: if (len <= 0)
1.158 markus 1936: buffer_clear(&c->output);
1.41 markus 1937: else
1938: buffer_consume(&c->output, len);
1939: }
1940: }
1.25 markus 1941:
1.127 itojun 1942: static void
1.44 markus 1943: channel_handler_init_20(void)
1944: {
1.157 markus 1945: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1946: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.44 markus 1947: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1.73 markus 1948: channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1.51 markus 1949: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1.73 markus 1950: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1951: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1952: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.302 djm 1953: channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
1954: channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
1.44 markus 1955:
1.157 markus 1956: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.44 markus 1957: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1.73 markus 1958: channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1.51 markus 1959: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1.73 markus 1960: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.75 markus 1961: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1962: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.302 djm 1963: channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
1964: channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
1.44 markus 1965: }
1966:
1.127 itojun 1967: static void
1.41 markus 1968: channel_handler_init_13(void)
1969: {
1970: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1971: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1972: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1973: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1974: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1975: channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1976: channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1.75 markus 1977: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1978: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1979:
1.157 markus 1980: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.41 markus 1981: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1982: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1983: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1984: channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1.75 markus 1985: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 1986: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 1987: }
1.25 markus 1988:
1.127 itojun 1989: static void
1.41 markus 1990: channel_handler_init_15(void)
1991: {
1.157 markus 1992: channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
1.51 markus 1993: channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1.41 markus 1994: channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1995: channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1996: channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1.75 markus 1997: channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1.103 markus 1998: channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1.25 markus 1999:
1.41 markus 2000: channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2001: channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2002: channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1.157 markus 2003: channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
1.75 markus 2004: channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
1.157 markus 2005: channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
1.41 markus 2006: }
1.27 markus 2007:
1.127 itojun 2008: static void
1.41 markus 2009: channel_handler_init(void)
2010: {
2011: int i;
1.180 deraadt 2012:
1.148 deraadt 2013: for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
1.41 markus 2014: channel_pre[i] = NULL;
2015: channel_post[i] = NULL;
2016: }
1.44 markus 2017: if (compat20)
2018: channel_handler_init_20();
2019: else if (compat13)
1.41 markus 2020: channel_handler_init_13();
2021: else
2022: channel_handler_init_15();
2023: }
1.25 markus 2024:
1.140 markus 2025: /* gc dead channels */
2026: static void
2027: channel_garbage_collect(Channel *c)
2028: {
2029: if (c == NULL)
2030: return;
2031: if (c->detach_user != NULL) {
1.225 djm 2032: if (!chan_is_dead(c, c->detach_close))
1.140 markus 2033: return;
1.194 markus 2034: debug2("channel %d: gc: notify user", c->self);
1.140 markus 2035: c->detach_user(c->self, NULL);
2036: /* if we still have a callback */
2037: if (c->detach_user != NULL)
2038: return;
1.194 markus 2039: debug2("channel %d: gc: user detached", c->self);
1.140 markus 2040: }
2041: if (!chan_is_dead(c, 1))
2042: return;
1.194 markus 2043: debug2("channel %d: garbage collecting", c->self);
1.140 markus 2044: channel_free(c);
2045: }
2046:
1.127 itojun 2047: static void
1.237 deraadt 2048: channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
1.41 markus 2049: {
2050: static int did_init = 0;
1.299 markus 2051: u_int i, oalloc;
1.41 markus 2052: Channel *c;
1.25 markus 2053:
1.41 markus 2054: if (!did_init) {
2055: channel_handler_init();
2056: did_init = 1;
2057: }
1.299 markus 2058: for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
1.113 markus 2059: c = channels[i];
2060: if (c == NULL)
1.41 markus 2061: continue;
1.299 markus 2062: if (c->delayed) {
2063: if (ftab == channel_pre)
2064: c->delayed = 0;
2065: else
2066: continue;
2067: }
1.118 markus 2068: if (ftab[c->type] != NULL)
2069: (*ftab[c->type])(c, readset, writeset);
1.140 markus 2070: channel_garbage_collect(c);
1.1 deraadt 2071: }
2072: }
2073:
1.121 markus 2074: /*
2075: * Allocate/update select bitmasks and add any bits relevant to channels in
2076: * select bitmasks.
2077: */
1.49 markus 2078: void
1.100 markus 2079: channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.209 avsm 2080: u_int *nallocp, int rekeying)
1.41 markus 2081: {
1.243 djm 2082: u_int n, sz, nfdset;
1.84 markus 2083:
2084: n = MAX(*maxfdp, channel_max_fd);
2085:
1.243 djm 2086: nfdset = howmany(n+1, NFDBITS);
2087: /* Explicitly test here, because xrealloc isn't always called */
2088: if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2089: fatal("channel_prepare_select: max_fd (%d) is too large", n);
2090: sz = nfdset * sizeof(fd_mask);
2091:
1.132 markus 2092: /* perhaps check sz < nalloc/2 and shrink? */
2093: if (*readsetp == NULL || sz > *nallocp) {
1.243 djm 2094: *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2095: *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
1.132 markus 2096: *nallocp = sz;
1.84 markus 2097: }
1.132 markus 2098: *maxfdp = n;
1.84 markus 2099: memset(*readsetp, 0, sz);
2100: memset(*writesetp, 0, sz);
2101:
1.100 markus 2102: if (!rekeying)
2103: channel_handler(channel_pre, *readsetp, *writesetp);
1.41 markus 2104: }
2105:
1.121 markus 2106: /*
2107: * After select, perform any appropriate operations for channels which have
2108: * events pending.
2109: */
1.49 markus 2110: void
1.237 deraadt 2111: channel_after_select(fd_set *readset, fd_set *writeset)
1.41 markus 2112: {
2113: channel_handler(channel_post, readset, writeset);
2114: }
2115:
1.121 markus 2116:
1.84 markus 2117: /* If there is data to send to the connection, enqueue some of it now. */
1.49 markus 2118: void
1.142 itojun 2119: channel_output_poll(void)
1.1 deraadt 2120: {
1.41 markus 2121: Channel *c;
1.209 avsm 2122: u_int i, len;
1.1 deraadt 2123:
1.25 markus 2124: for (i = 0; i < channels_alloc; i++) {
1.113 markus 2125: c = channels[i];
2126: if (c == NULL)
2127: continue;
1.37 markus 2128:
1.121 markus 2129: /*
2130: * We are only interested in channels that can have buffered
2131: * incoming data.
2132: */
1.37 markus 2133: if (compat13) {
1.41 markus 2134: if (c->type != SSH_CHANNEL_OPEN &&
2135: c->type != SSH_CHANNEL_INPUT_DRAINING)
1.37 markus 2136: continue;
2137: } else {
1.41 markus 2138: if (c->type != SSH_CHANNEL_OPEN)
1.37 markus 2139: continue;
2140: }
1.46 markus 2141: if (compat20 &&
2142: (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1.93 markus 2143: /* XXX is this true? */
1.140 markus 2144: debug3("channel %d: will not send data after close", c->self);
1.44 markus 2145: continue;
2146: }
1.25 markus 2147:
2148: /* Get the amount of buffered data for this channel. */
1.93 markus 2149: if ((c->istate == CHAN_INPUT_OPEN ||
2150: c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2151: (len = buffer_len(&c->input)) > 0) {
1.228 reyk 2152: if (c->datagram) {
2153: if (len > 0) {
2154: u_char *data;
2155: u_int dlen;
2156:
2157: data = buffer_get_string(&c->input,
2158: &dlen);
1.309 djm 2159: if (dlen > c->remote_window ||
2160: dlen > c->remote_maxpacket) {
2161: debug("channel %d: datagram "
2162: "too big for channel",
2163: c->self);
2164: xfree(data);
2165: continue;
2166: }
1.228 reyk 2167: packet_start(SSH2_MSG_CHANNEL_DATA);
2168: packet_put_int(c->remote_id);
2169: packet_put_string(data, dlen);
2170: packet_send();
2171: c->remote_window -= dlen + 4;
2172: xfree(data);
2173: }
2174: continue;
2175: }
1.121 markus 2176: /*
2177: * Send some data for the other side over the secure
2178: * connection.
2179: */
1.44 markus 2180: if (compat20) {
2181: if (len > c->remote_window)
2182: len = c->remote_window;
2183: if (len > c->remote_maxpacket)
2184: len = c->remote_maxpacket;
1.25 markus 2185: } else {
1.44 markus 2186: if (packet_is_interactive()) {
2187: if (len > 1024)
2188: len = 512;
2189: } else {
2190: /* Keep the packets at reasonable size. */
2191: if (len > packet_get_maxsize()/2)
2192: len = packet_get_maxsize()/2;
2193: }
1.25 markus 2194: }
1.41 markus 2195: if (len > 0) {
1.44 markus 2196: packet_start(compat20 ?
2197: SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1.41 markus 2198: packet_put_int(c->remote_id);
2199: packet_put_string(buffer_ptr(&c->input), len);
2200: packet_send();
2201: buffer_consume(&c->input, len);
2202: c->remote_window -= len;
2203: }
2204: } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1.25 markus 2205: if (compat13)
2206: fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1.27 markus 2207: /*
2208: * input-buffer is empty and read-socket shutdown:
1.172 markus 2209: * tell peer, that we will not send more data: send IEOF.
2210: * hack for extended data: delay EOF if EFD still in use.
1.27 markus 2211: */
1.172 markus 2212: if (CHANNEL_EFD_INPUT_ACTIVE(c))
1.223 djm 2213: debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2214: c->self, c->efd, buffer_len(&c->extended));
1.172 markus 2215: else
2216: chan_ibuf_empty(c);
1.25 markus 2217: }
1.44 markus 2218: /* Send extended data, i.e. stderr */
2219: if (compat20 &&
1.172 markus 2220: !(c->flags & CHAN_EOF_SENT) &&
1.44 markus 2221: c->remote_window > 0 &&
2222: (len = buffer_len(&c->extended)) > 0 &&
2223: c->extended_usage == CHAN_EXTENDED_READ) {
1.178 markus 2224: debug2("channel %d: rwin %u elen %u euse %d",
1.93 markus 2225: c->self, c->remote_window, buffer_len(&c->extended),
2226: c->extended_usage);
1.44 markus 2227: if (len > c->remote_window)
2228: len = c->remote_window;
2229: if (len > c->remote_maxpacket)
2230: len = c->remote_maxpacket;
2231: packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2232: packet_put_int(c->remote_id);
2233: packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2234: packet_put_string(buffer_ptr(&c->extended), len);
2235: packet_send();
2236: buffer_consume(&c->extended, len);
2237: c->remote_window -= len;
1.93 markus 2238: debug2("channel %d: sent ext data %d", c->self, len);
1.44 markus 2239: }
1.25 markus 2240: }
1.1 deraadt 2241: }
2242:
1.121 markus 2243:
2244: /* -- protocol input */
1.249 djm 2245:
2246: /* ARGSUSED */
1.49 markus 2247: void
1.154 markus 2248: channel_input_data(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2249: {
1.37 markus 2250: int id;
1.25 markus 2251: char *data;
1.309 djm 2252: u_int data_len, win_len;
1.41 markus 2253: Channel *c;
1.25 markus 2254:
2255: /* Get the channel number and verify it. */
1.37 markus 2256: id = packet_get_int();
1.41 markus 2257: c = channel_lookup(id);
2258: if (c == NULL)
1.37 markus 2259: packet_disconnect("Received data for nonexistent channel %d.", id);
1.25 markus 2260:
2261: /* Ignore any data for non-open channels (might happen on close) */
1.41 markus 2262: if (c->type != SSH_CHANNEL_OPEN &&
2263: c->type != SSH_CHANNEL_X11_OPEN)
1.37 markus 2264: return;
2265:
1.25 markus 2266: /* Get the data. */
1.274 markus 2267: data = packet_get_string_ptr(&data_len);
1.309 djm 2268: win_len = data_len;
2269: if (c->datagram)
2270: win_len += 4; /* string length header */
1.200 markus 2271:
2272: /*
2273: * Ignore data for protocol > 1.3 if output end is no longer open.
2274: * For protocol 2 the sending side is reducing its window as it sends
2275: * data, so we must 'fake' consumption of the data in order to ensure
2276: * that window updates are sent back. Otherwise the connection might
2277: * deadlock.
2278: */
2279: if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2280: if (compat20) {
1.309 djm 2281: c->local_window -= win_len;
2282: c->local_consumed += win_len;
1.200 markus 2283: }
2284: return;
2285: }
1.41 markus 2286:
1.143 deraadt 2287: if (compat20) {
1.309 djm 2288: if (win_len > c->local_maxpacket) {
1.188 itojun 2289: logit("channel %d: rcvd big packet %d, maxpack %d",
1.309 djm 2290: c->self, win_len, c->local_maxpacket);
1.44 markus 2291: }
1.309 djm 2292: if (win_len > c->local_window) {
1.188 itojun 2293: logit("channel %d: rcvd too much data %d, win %d",
1.309 djm 2294: c->self, win_len, c->local_window);
1.44 markus 2295: return;
2296: }
1.309 djm 2297: c->local_window -= win_len;
1.44 markus 2298: }
1.228 reyk 2299: if (c->datagram)
2300: buffer_put_string(&c->output, data, data_len);
2301: else
2302: buffer_append(&c->output, data, data_len);
1.274 markus 2303: packet_check_eom();
1.1 deraadt 2304: }
1.121 markus 2305:
1.249 djm 2306: /* ARGSUSED */
1.49 markus 2307: void
1.154 markus 2308: channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
1.44 markus 2309: {
2310: int id;
2311: char *data;
1.177 markus 2312: u_int data_len, tcode;
1.44 markus 2313: Channel *c;
2314:
2315: /* Get the channel number and verify it. */
2316: id = packet_get_int();
2317: c = channel_lookup(id);
2318:
2319: if (c == NULL)
2320: packet_disconnect("Received extended_data for bad channel %d.", id);
2321: if (c->type != SSH_CHANNEL_OPEN) {
1.188 itojun 2322: logit("channel %d: ext data for non open", id);
1.44 markus 2323: return;
1.172 markus 2324: }
2325: if (c->flags & CHAN_EOF_RCVD) {
2326: if (datafellows & SSH_BUG_EXTEOF)
2327: debug("channel %d: accepting ext data after eof", id);
2328: else
2329: packet_disconnect("Received extended_data after EOF "
2330: "on channel %d.", id);
1.44 markus 2331: }
2332: tcode = packet_get_int();
2333: if (c->efd == -1 ||
2334: c->extended_usage != CHAN_EXTENDED_WRITE ||
2335: tcode != SSH2_EXTENDED_DATA_STDERR) {
1.188 itojun 2336: logit("channel %d: bad ext data", c->self);
1.44 markus 2337: return;
2338: }
2339: data = packet_get_string(&data_len);
1.152 markus 2340: packet_check_eom();
1.44 markus 2341: if (data_len > c->local_window) {
1.188 itojun 2342: logit("channel %d: rcvd too much extended_data %d, win %d",
1.44 markus 2343: c->self, data_len, c->local_window);
2344: xfree(data);
2345: return;
2346: }
1.70 markus 2347: debug2("channel %d: rcvd ext data %d", c->self, data_len);
1.44 markus 2348: c->local_window -= data_len;
2349: buffer_append(&c->extended, data, data_len);
2350: xfree(data);
2351: }
2352:
1.249 djm 2353: /* ARGSUSED */
1.49 markus 2354: void
1.154 markus 2355: channel_input_ieof(int type, u_int32_t seq, void *ctxt)
1.41 markus 2356: {
2357: int id;
2358: Channel *c;
2359:
2360: id = packet_get_int();
1.152 markus 2361: packet_check_eom();
1.41 markus 2362: c = channel_lookup(id);
2363: if (c == NULL)
2364: packet_disconnect("Received ieof for nonexistent channel %d.", id);
2365: chan_rcvd_ieof(c);
1.133 markus 2366:
2367: /* XXX force input close */
1.156 markus 2368: if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
1.133 markus 2369: debug("channel %d: FORCE input drain", c->self);
2370: c->istate = CHAN_INPUT_WAIT_DRAIN;
1.161 markus 2371: if (buffer_len(&c->input) == 0)
2372: chan_ibuf_empty(c);
1.133 markus 2373: }
2374:
1.41 markus 2375: }
1.1 deraadt 2376:
1.249 djm 2377: /* ARGSUSED */
1.49 markus 2378: void
1.154 markus 2379: channel_input_close(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2380: {
1.41 markus 2381: int id;
2382: Channel *c;
1.1 deraadt 2383:
1.41 markus 2384: id = packet_get_int();
1.152 markus 2385: packet_check_eom();
1.41 markus 2386: c = channel_lookup(id);
2387: if (c == NULL)
2388: packet_disconnect("Received close for nonexistent channel %d.", id);
1.27 markus 2389:
2390: /*
2391: * Send a confirmation that we have closed the channel and no more
2392: * data is coming for it.
2393: */
1.25 markus 2394: packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
1.41 markus 2395: packet_put_int(c->remote_id);
1.25 markus 2396: packet_send();
2397:
1.27 markus 2398: /*
2399: * If the channel is in closed state, we have sent a close request,
2400: * and the other side will eventually respond with a confirmation.
2401: * Thus, we cannot free the channel here, because then there would be
2402: * no-one to receive the confirmation. The channel gets freed when
2403: * the confirmation arrives.
2404: */
1.41 markus 2405: if (c->type != SSH_CHANNEL_CLOSED) {
1.27 markus 2406: /*
2407: * Not a closed channel - mark it as draining, which will
2408: * cause it to be freed later.
2409: */
1.158 markus 2410: buffer_clear(&c->input);
1.41 markus 2411: c->type = SSH_CHANNEL_OUTPUT_DRAINING;
1.25 markus 2412: }
1.1 deraadt 2413: }
2414:
1.41 markus 2415: /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
1.249 djm 2416: /* ARGSUSED */
1.49 markus 2417: void
1.154 markus 2418: channel_input_oclose(int type, u_int32_t seq, void *ctxt)
1.41 markus 2419: {
2420: int id = packet_get_int();
2421: Channel *c = channel_lookup(id);
1.151 markus 2422:
1.152 markus 2423: packet_check_eom();
1.41 markus 2424: if (c == NULL)
2425: packet_disconnect("Received oclose for nonexistent channel %d.", id);
2426: chan_rcvd_oclose(c);
2427: }
1.1 deraadt 2428:
1.249 djm 2429: /* ARGSUSED */
1.49 markus 2430: void
1.154 markus 2431: channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2432: {
1.41 markus 2433: int id = packet_get_int();
2434: Channel *c = channel_lookup(id);
1.1 deraadt 2435:
1.152 markus 2436: packet_check_eom();
1.41 markus 2437: if (c == NULL)
2438: packet_disconnect("Received close confirmation for "
2439: "out-of-range channel %d.", id);
2440: if (c->type != SSH_CHANNEL_CLOSED)
2441: packet_disconnect("Received close confirmation for "
2442: "non-closed channel %d (type %d).", id, c->type);
1.113 markus 2443: channel_free(c);
1.1 deraadt 2444: }
2445:
1.249 djm 2446: /* ARGSUSED */
1.49 markus 2447: void
1.154 markus 2448: channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2449: {
1.41 markus 2450: int id, remote_id;
2451: Channel *c;
1.1 deraadt 2452:
1.41 markus 2453: id = packet_get_int();
2454: c = channel_lookup(id);
1.25 markus 2455:
1.41 markus 2456: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2457: packet_disconnect("Received open confirmation for "
2458: "non-opening channel %d.", id);
2459: remote_id = packet_get_int();
1.27 markus 2460: /* Record the remote channel number and mark that the channel is now open. */
1.41 markus 2461: c->remote_id = remote_id;
2462: c->type = SSH_CHANNEL_OPEN;
1.44 markus 2463:
2464: if (compat20) {
2465: c->remote_window = packet_get_int();
2466: c->remote_maxpacket = packet_get_int();
1.275 djm 2467: if (c->open_confirm) {
1.70 markus 2468: debug2("callback start");
1.304 djm 2469: c->open_confirm(c->self, 1, c->open_confirm_ctx);
1.70 markus 2470: debug2("callback done");
1.44 markus 2471: }
1.194 markus 2472: debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
1.44 markus 2473: c->remote_window, c->remote_maxpacket);
2474: }
1.152 markus 2475: packet_check_eom();
1.1 deraadt 2476: }
2477:
1.127 itojun 2478: static char *
1.114 markus 2479: reason2txt(int reason)
2480: {
1.143 deraadt 2481: switch (reason) {
1.114 markus 2482: case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2483: return "administratively prohibited";
2484: case SSH2_OPEN_CONNECT_FAILED:
2485: return "connect failed";
2486: case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2487: return "unknown channel type";
2488: case SSH2_OPEN_RESOURCE_SHORTAGE:
2489: return "resource shortage";
2490: }
1.117 stevesk 2491: return "unknown reason";
1.114 markus 2492: }
2493:
1.249 djm 2494: /* ARGSUSED */
1.49 markus 2495: void
1.154 markus 2496: channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2497: {
1.86 markus 2498: int id, reason;
2499: char *msg = NULL, *lang = NULL;
1.41 markus 2500: Channel *c;
2501:
2502: id = packet_get_int();
2503: c = channel_lookup(id);
1.25 markus 2504:
1.41 markus 2505: if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2506: packet_disconnect("Received open failure for "
2507: "non-opening channel %d.", id);
1.44 markus 2508: if (compat20) {
1.86 markus 2509: reason = packet_get_int();
1.110 markus 2510: if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1.86 markus 2511: msg = packet_get_string(NULL);
2512: lang = packet_get_string(NULL);
2513: }
1.188 itojun 2514: logit("channel %d: open failed: %s%s%s", id,
1.114 markus 2515: reason2txt(reason), msg ? ": ": "", msg ? msg : "");
1.86 markus 2516: if (msg != NULL)
2517: xfree(msg);
2518: if (lang != NULL)
2519: xfree(lang);
1.304 djm 2520: if (c->open_confirm) {
2521: debug2("callback start");
2522: c->open_confirm(c->self, 0, c->open_confirm_ctx);
2523: debug2("callback done");
2524: }
1.44 markus 2525: }
1.152 markus 2526: packet_check_eom();
1.291 djm 2527: /* Schedule the channel for cleanup/deletion. */
2528: chan_mark_dead(c);
1.44 markus 2529: }
2530:
1.249 djm 2531: /* ARGSUSED */
1.121 markus 2532: void
1.154 markus 2533: channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
1.121 markus 2534: {
2535: Channel *c;
1.178 markus 2536: int id;
2537: u_int adjust;
1.121 markus 2538:
2539: if (!compat20)
2540: return;
2541:
2542: /* Get the channel number and verify it. */
2543: id = packet_get_int();
2544: c = channel_lookup(id);
1.1 deraadt 2545:
1.229 markus 2546: if (c == NULL) {
2547: logit("Received window adjust for non-open channel %d.", id);
1.121 markus 2548: return;
2549: }
2550: adjust = packet_get_int();
1.152 markus 2551: packet_check_eom();
1.178 markus 2552: debug2("channel %d: rcvd adjust %u", id, adjust);
1.121 markus 2553: c->remote_window += adjust;
2554: }
1.1 deraadt 2555:
1.249 djm 2556: /* ARGSUSED */
1.121 markus 2557: void
1.154 markus 2558: channel_input_port_open(int type, u_int32_t seq, void *ctxt)
1.1 deraadt 2559: {
1.121 markus 2560: Channel *c = NULL;
2561: u_short host_port;
2562: char *host, *originator_string;
1.276 djm 2563: int remote_id;
1.121 markus 2564:
2565: remote_id = packet_get_int();
2566: host = packet_get_string(NULL);
2567: host_port = packet_get_int();
1.25 markus 2568:
1.121 markus 2569: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2570: originator_string = packet_get_string(NULL);
2571: } else {
2572: originator_string = xstrdup("unknown (remote did not supply name)");
2573: }
1.152 markus 2574: packet_check_eom();
1.276 djm 2575: c = channel_connect_to(host, host_port,
2576: "connected socket", originator_string);
1.190 markus 2577: xfree(originator_string);
1.276 djm 2578: xfree(host);
1.121 markus 2579: if (c == NULL) {
2580: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2581: packet_put_int(remote_id);
2582: packet_send();
1.276 djm 2583: } else
2584: c->remote_id = remote_id;
1.1 deraadt 2585: }
2586:
1.275 djm 2587: /* ARGSUSED */
2588: void
2589: channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2590: {
2591: Channel *c;
2592: struct channel_confirm *cc;
1.289 markus 2593: int id;
1.275 djm 2594:
2595: /* Reset keepalive timeout */
1.296 andreas 2596: packet_set_alive_timeouts(0);
1.275 djm 2597:
1.289 markus 2598: id = packet_get_int();
1.275 djm 2599: packet_check_eom();
2600:
1.289 markus 2601: debug2("channel_input_status_confirm: type %d id %d", type, id);
1.275 djm 2602:
1.289 markus 2603: if ((c = channel_lookup(id)) == NULL) {
2604: logit("channel_input_status_confirm: %d: unknown", id);
1.275 djm 2605: return;
2606: }
2607: ;
2608: if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2609: return;
2610: cc->cb(type, c, cc->ctx);
2611: TAILQ_REMOVE(&c->status_confirms, cc, entry);
2612: bzero(cc, sizeof(*cc));
2613: xfree(cc);
2614: }
1.121 markus 2615:
2616: /* -- tcp forwarding */
1.135 markus 2617:
2618: void
2619: channel_set_af(int af)
2620: {
2621: IPv4or6 = af;
2622: }
1.121 markus 2623:
1.312 djm 2624:
2625: /*
2626: * Determine whether or not a port forward listens to loopback, the
2627: * specified address or wildcard. On the client, a specified bind
2628: * address will always override gateway_ports. On the server, a
2629: * gateway_ports of 1 (``yes'') will override the client's specification
2630: * and force a wildcard bind, whereas a value of 2 (``clientspecified'')
2631: * will bind to whatever address the client asked for.
2632: *
2633: * Special-case listen_addrs are:
2634: *
2635: * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2636: * "" (empty string), "*" -> wildcard v4/v6
2637: * "localhost" -> loopback v4/v6
2638: */
2639: static const char *
2640: channel_fwd_bind_addr(const char *listen_addr, int *wildcardp,
2641: int is_client, int gateway_ports)
2642: {
2643: const char *addr = NULL;
2644: int wildcard = 0;
2645:
2646: if (listen_addr == NULL) {
2647: /* No address specified: default to gateway_ports setting */
2648: if (gateway_ports)
2649: wildcard = 1;
2650: } else if (gateway_ports || is_client) {
2651: if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2652: strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2653: *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2654: (!is_client && gateway_ports == 1))
2655: wildcard = 1;
2656: else if (strcmp(listen_addr, "localhost") != 0)
2657: addr = listen_addr;
2658: }
2659: if (wildcardp != NULL)
2660: *wildcardp = wildcard;
2661: return addr;
2662: }
2663:
1.160 markus 2664: static int
1.295 djm 2665: channel_setup_fwd_listener(int type, const char *listen_addr,
2666: u_short listen_port, int *allocated_listen_port,
1.160 markus 2667: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
1.25 markus 2668: {
1.113 markus 2669: Channel *c;
1.226 djm 2670: int sock, r, success = 0, wildcard = 0, is_client;
1.35 markus 2671: struct addrinfo hints, *ai, *aitop;
1.212 djm 2672: const char *host, *addr;
1.35 markus 2673: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1.295 djm 2674: in_port_t *lport_p;
1.25 markus 2675:
1.160 markus 2676: host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2677: listen_addr : host_to_connect;
1.212 djm 2678: is_client = (type == SSH_CHANNEL_PORT_LISTENER);
1.87 markus 2679:
1.160 markus 2680: if (host == NULL) {
2681: error("No forward host name.");
1.218 markus 2682: return 0;
1.73 markus 2683: }
1.294 djm 2684: if (strlen(host) >= NI_MAXHOST) {
1.87 markus 2685: error("Forward host name too long.");
1.218 markus 2686: return 0;
1.87 markus 2687: }
1.25 markus 2688:
1.312 djm 2689: /* Determine the bind address, cf. channel_fwd_bind_addr() comment */
2690: addr = channel_fwd_bind_addr(listen_addr, &wildcard,
2691: is_client, gateway_ports);
1.212 djm 2692: debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2693: type, wildcard, (addr == NULL) ? "NULL" : addr);
2694:
2695: /*
1.35 markus 2696: * getaddrinfo returns a loopback address if the hostname is
2697: * set to NULL and hints.ai_flags is not AI_PASSIVE
1.28 markus 2698: */
1.35 markus 2699: memset(&hints, 0, sizeof(hints));
2700: hints.ai_family = IPv4or6;
1.212 djm 2701: hints.ai_flags = wildcard ? AI_PASSIVE : 0;
1.35 markus 2702: hints.ai_socktype = SOCK_STREAM;
1.73 markus 2703: snprintf(strport, sizeof strport, "%d", listen_port);
1.212 djm 2704: if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2705: if (addr == NULL) {
2706: /* This really shouldn't happen */
2707: packet_disconnect("getaddrinfo: fatal error: %s",
1.271 dtucker 2708: ssh_gai_strerror(r));
1.212 djm 2709: } else {
1.218 markus 2710: error("channel_setup_fwd_listener: "
1.271 dtucker 2711: "getaddrinfo(%.64s): %s", addr,
2712: ssh_gai_strerror(r));
1.212 djm 2713: }
1.218 markus 2714: return 0;
1.212 djm 2715: }
1.295 djm 2716: if (allocated_listen_port != NULL)
2717: *allocated_listen_port = 0;
1.35 markus 2718: for (ai = aitop; ai; ai = ai->ai_next) {
1.295 djm 2719: switch (ai->ai_family) {
2720: case AF_INET:
2721: lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2722: sin_port;
2723: break;
2724: case AF_INET6:
2725: lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2726: sin6_port;
2727: break;
2728: default:
1.35 markus 2729: continue;
1.295 djm 2730: }
2731: /*
2732: * If allocating a port for -R forwards, then use the
2733: * same port for all address families.
2734: */
2735: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2736: allocated_listen_port != NULL && *allocated_listen_port > 0)
2737: *lport_p = htons(*allocated_listen_port);
2738:
1.35 markus 2739: if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2740: strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1.160 markus 2741: error("channel_setup_fwd_listener: getnameinfo failed");
1.35 markus 2742: continue;
2743: }
2744: /* Create a port to listen for the host. */
1.300 dtucker 2745: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 2746: if (sock < 0) {
2747: /* this is no error since kernel may not support ipv6 */
2748: verbose("socket: %.100s", strerror(errno));
2749: continue;
2750: }
1.226 djm 2751:
2752: channel_set_reuseaddr(sock);
1.182 stevesk 2753:
1.295 djm 2754: debug("Local forwarding listening on %s port %s.",
2755: ntop, strport);
1.35 markus 2756:
2757: /* Bind the socket to the address. */
2758: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2759: /* address can be in use ipv6 address is already bound */
2760: verbose("bind: %.100s", strerror(errno));
2761: close(sock);
2762: continue;
2763: }
2764: /* Start listening for connections on the socket. */
1.199 markus 2765: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 2766: error("listen: %.100s", strerror(errno));
2767: close(sock);
2768: continue;
2769: }
1.295 djm 2770:
2771: /*
2772: * listen_port == 0 requests a dynamically allocated port -
2773: * record what we got.
2774: */
2775: if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2776: allocated_listen_port != NULL &&
2777: *allocated_listen_port == 0) {
2778: *allocated_listen_port = get_sock_port(sock, 1);
2779: debug("Allocated listen port %d",
2780: *allocated_listen_port);
2781: }
2782:
1.35 markus 2783: /* Allocate a channel number for the socket. */
1.121 markus 2784: c = channel_new("port listener", type, sock, sock, -1,
1.51 markus 2785: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1.190 markus 2786: 0, "port listener", 1);
1.293 djm 2787: c->path = xstrdup(host);
1.113 markus 2788: c->host_port = port_to_connect;
1.312 djm 2789: c->listening_addr = addr == NULL ? NULL : xstrdup(addr);
1.315 ! markus 2790: if (listen_port == 0 && allocated_listen_port != NULL &&
! 2791: !(datafellows & SSH_BUG_DYNAMIC_RPORT))
! 2792: c->listening_port = *allocated_listen_port;
! 2793: else
! 2794: c->listening_port = listen_port;
1.35 markus 2795: success = 1;
2796: }
2797: if (success == 0)
1.160 markus 2798: error("channel_setup_fwd_listener: cannot listen to port: %d",
1.87 markus 2799: listen_port);
1.35 markus 2800: freeaddrinfo(aitop);
1.87 markus 2801: return success;
1.25 markus 2802: }
1.1 deraadt 2803:
1.202 djm 2804: int
2805: channel_cancel_rport_listener(const char *host, u_short port)
2806: {
1.209 avsm 2807: u_int i;
2808: int found = 0;
1.202 djm 2809:
1.213 deraadt 2810: for (i = 0; i < channels_alloc; i++) {
1.202 djm 2811: Channel *c = channels[i];
1.312 djm 2812: if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER)
2813: continue;
2814: if (strcmp(c->path, host) == 0 && c->listening_port == port) {
2815: debug2("%s: close channel %d", __func__, i);
2816: channel_free(c);
2817: found = 1;
2818: }
2819: }
2820:
2821: return (found);
2822: }
2823:
2824: int
2825: channel_cancel_lport_listener(const char *lhost, u_short lport,
1.313 markus 2826: int cport, int gateway_ports)
1.312 djm 2827: {
2828: u_int i;
2829: int found = 0;
2830: const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, gateway_ports);
1.202 djm 2831:
1.312 djm 2832: for (i = 0; i < channels_alloc; i++) {
2833: Channel *c = channels[i];
2834: if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER)
2835: continue;
1.313 markus 2836: if (c->listening_port != lport)
1.312 djm 2837: continue;
1.313 markus 2838: if (cport == CHANNEL_CANCEL_PORT_STATIC) {
2839: /* skip dynamic forwardings */
2840: if (c->host_port == 0)
2841: continue;
2842: } else {
2843: if (c->host_port != cport)
2844: continue;
2845: }
1.312 djm 2846: if ((c->listening_addr == NULL && addr != NULL) ||
2847: (c->listening_addr != NULL && addr == NULL))
2848: continue;
2849: if (addr == NULL || strcmp(c->listening_addr, addr) == 0) {
1.210 djm 2850: debug2("%s: close channel %d", __func__, i);
1.202 djm 2851: channel_free(c);
2852: found = 1;
2853: }
2854: }
2855:
2856: return (found);
2857: }
2858:
1.160 markus 2859: /* protocol local port fwd, used by ssh (and sshd in v1) */
2860: int
1.212 djm 2861: channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
1.160 markus 2862: const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2863: {
2864: return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
1.295 djm 2865: listen_host, listen_port, NULL, host_to_connect, port_to_connect,
1.212 djm 2866: gateway_ports);
1.160 markus 2867: }
2868:
2869: /* protocol v2 remote port fwd, used by sshd */
2870: int
2871: channel_setup_remote_fwd_listener(const char *listen_address,
1.295 djm 2872: u_short listen_port, int *allocated_listen_port, int gateway_ports)
1.160 markus 2873: {
2874: return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
1.295 djm 2875: listen_address, listen_port, allocated_listen_port,
2876: NULL, 0, gateway_ports);
1.160 markus 2877: }
2878:
1.27 markus 2879: /*
1.312 djm 2880: * Translate the requested rfwd listen host to something usable for
2881: * this server.
2882: */
2883: static const char *
2884: channel_rfwd_bind_host(const char *listen_host)
2885: {
2886: if (listen_host == NULL) {
2887: if (datafellows & SSH_BUG_RFWD_ADDR)
2888: return "127.0.0.1";
2889: else
2890: return "localhost";
2891: } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) {
2892: if (datafellows & SSH_BUG_RFWD_ADDR)
2893: return "0.0.0.0";
2894: else
2895: return "";
2896: } else
2897: return listen_host;
2898: }
2899:
2900: /*
1.27 markus 2901: * Initiate forwarding of connections to port "port" on remote host through
2902: * the secure channel to host:port from local side.
1.315 ! markus 2903: * Returns handle (index) for updating the dynamic listen port with
! 2904: * channel_update_permitted_opens().
1.27 markus 2905: */
1.253 markus 2906: int
1.212 djm 2907: channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
1.73 markus 2908: const char *host_to_connect, u_short port_to_connect)
1.25 markus 2909: {
1.315 ! markus 2910: int type, success = 0, idx = -1;
1.73 markus 2911:
1.25 markus 2912: /* Send the forward request to the remote side. */
1.44 markus 2913: if (compat20) {
2914: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2915: packet_put_cstring("tcpip-forward");
1.312 djm 2916: packet_put_char(1); /* boolean: want reply */
2917: packet_put_cstring(channel_rfwd_bind_host(listen_host));
1.44 markus 2918: packet_put_int(listen_port);
1.73 markus 2919: packet_send();
2920: packet_write_wait();
2921: /* Assume that server accepts the request */
2922: success = 1;
1.44 markus 2923: } else {
2924: packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
1.50 markus 2925: packet_put_int(listen_port);
2926: packet_put_cstring(host_to_connect);
1.44 markus 2927: packet_put_int(port_to_connect);
2928: packet_send();
2929: packet_write_wait();
1.73 markus 2930:
2931: /* Wait for response from the remote side. */
1.153 markus 2932: type = packet_read();
1.73 markus 2933: switch (type) {
2934: case SSH_SMSG_SUCCESS:
2935: success = 1;
2936: break;
2937: case SSH_SMSG_FAILURE:
2938: break;
2939: default:
2940: /* Unknown packet */
2941: packet_disconnect("Protocol error for port forward request:"
2942: "received packet type %d.", type);
2943: }
2944: }
2945: if (success) {
1.305 djm 2946: /* Record that connection to this host/port is permitted. */
2947: permitted_opens = xrealloc(permitted_opens,
2948: num_permitted_opens + 1, sizeof(*permitted_opens));
1.315 ! markus 2949: idx = num_permitted_opens++;
! 2950: permitted_opens[idx].host_to_connect = xstrdup(host_to_connect);
! 2951: permitted_opens[idx].port_to_connect = port_to_connect;
! 2952: permitted_opens[idx].listen_port = listen_port;
1.44 markus 2953: }
1.315 ! markus 2954: return (idx);
1.1 deraadt 2955: }
2956:
1.27 markus 2957: /*
1.208 deraadt 2958: * Request cancellation of remote forwarding of connection host:port from
1.202 djm 2959: * local side.
2960: */
1.312 djm 2961: int
1.212 djm 2962: channel_request_rforward_cancel(const char *host, u_short port)
1.202 djm 2963: {
2964: int i;
2965:
2966: if (!compat20)
1.312 djm 2967: return -1;
1.202 djm 2968:
2969: for (i = 0; i < num_permitted_opens; i++) {
1.208 deraadt 2970: if (permitted_opens[i].host_to_connect != NULL &&
1.202 djm 2971: permitted_opens[i].listen_port == port)
2972: break;
2973: }
2974: if (i >= num_permitted_opens) {
2975: debug("%s: requested forward not found", __func__);
1.312 djm 2976: return -1;
1.202 djm 2977: }
2978: packet_start(SSH2_MSG_GLOBAL_REQUEST);
2979: packet_put_cstring("cancel-tcpip-forward");
2980: packet_put_char(0);
1.312 djm 2981: packet_put_cstring(channel_rfwd_bind_host(host));
1.202 djm 2982: packet_put_int(port);
2983: packet_send();
2984:
2985: permitted_opens[i].listen_port = 0;
2986: permitted_opens[i].port_to_connect = 0;
1.227 stevesk 2987: xfree(permitted_opens[i].host_to_connect);
1.202 djm 2988: permitted_opens[i].host_to_connect = NULL;
1.312 djm 2989:
2990: return 0;
1.202 djm 2991: }
2992:
2993: /*
1.27 markus 2994: * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2995: * listening for the port, and sends back a success reply (or disconnect
1.253 markus 2996: * message if there was an error).
1.27 markus 2997: */
1.253 markus 2998: int
1.56 markus 2999: channel_input_port_forward_request(int is_root, int gateway_ports)
1.1 deraadt 3000: {
1.31 markus 3001: u_short port, host_port;
1.253 markus 3002: int success = 0;
1.25 markus 3003: char *hostname;
1.1 deraadt 3004:
1.25 markus 3005: /* Get arguments from the packet. */
3006: port = packet_get_int();
3007: hostname = packet_get_string(NULL);
3008: host_port = packet_get_int();
3009:
1.27 markus 3010: /*
3011: * Check that an unprivileged user is not trying to forward a
3012: * privileged port.
3013: */
1.25 markus 3014: if (port < IPPORT_RESERVED && !is_root)
1.192 markus 3015: packet_disconnect(
3016: "Requested forwarding of port %d but user is not root.",
3017: port);
3018: if (host_port == 0)
3019: packet_disconnect("Dynamic forwarding denied.");
3020:
1.73 markus 3021: /* Initiate forwarding */
1.253 markus 3022: success = channel_setup_local_fwd_listener(NULL, port, hostname,
1.212 djm 3023: host_port, gateway_ports);
1.25 markus 3024:
3025: /* Free the argument string. */
3026: xfree(hostname);
1.253 markus 3027:
3028: return (success ? 0 : -1);
1.1 deraadt 3029: }
3030:
1.99 markus 3031: /*
3032: * Permits opening to any host/port if permitted_opens[] is empty. This is
3033: * usually called by the server, because the user could connect to any port
3034: * anyway, and the server has no way to know but to trust the client anyway.
3035: */
3036: void
1.142 itojun 3037: channel_permit_all_opens(void)
1.99 markus 3038: {
3039: if (num_permitted_opens == 0)
3040: all_opens_permitted = 1;
3041: }
3042:
1.101 markus 3043: void
1.99 markus 3044: channel_add_permitted_opens(char *host, int port)
3045: {
3046: debug("allow port forwarding to host %s port %d", host, port);
3047:
1.305 djm 3048: permitted_opens = xrealloc(permitted_opens,
3049: num_permitted_opens + 1, sizeof(*permitted_opens));
1.99 markus 3050: permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3051: permitted_opens[num_permitted_opens].port_to_connect = port;
3052: num_permitted_opens++;
3053:
3054: all_opens_permitted = 0;
1.315 ! markus 3055: }
! 3056:
! 3057: /*
! 3058: * Update the listen port for a dynamic remote forward, after
! 3059: * the actual 'newport' has been allocated. If 'newport' < 0 is
! 3060: * passed then they entry will be invalidated.
! 3061: */
! 3062: void
! 3063: channel_update_permitted_opens(int idx, int newport)
! 3064: {
! 3065: if (idx < 0 || idx >= num_permitted_opens) {
! 3066: debug("channel_update_permitted_opens: index out of range:"
! 3067: " %d num_permitted_opens %d", idx, num_permitted_opens);
! 3068: return;
! 3069: }
! 3070: debug("%s allowed port %d for forwarding to host %s port %d",
! 3071: newport > 0 ? "Updating" : "Removing",
! 3072: newport,
! 3073: permitted_opens[idx].host_to_connect,
! 3074: permitted_opens[idx].port_to_connect);
! 3075: if (newport >= 0) {
! 3076: permitted_opens[idx].listen_port =
! 3077: (datafellows & SSH_BUG_DYNAMIC_RPORT) ? 0 : newport;
! 3078: } else {
! 3079: permitted_opens[idx].listen_port = 0;
! 3080: permitted_opens[idx].port_to_connect = 0;
! 3081: xfree(permitted_opens[idx].host_to_connect);
! 3082: permitted_opens[idx].host_to_connect = NULL;
! 3083: }
1.99 markus 3084: }
3085:
1.258 dtucker 3086: int
1.257 dtucker 3087: channel_add_adm_permitted_opens(char *host, int port)
3088: {
1.258 dtucker 3089: debug("config allows port forwarding to host %s port %d", host, port);
1.257 dtucker 3090:
1.305 djm 3091: permitted_adm_opens = xrealloc(permitted_adm_opens,
3092: num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
1.257 dtucker 3093: permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3094: = xstrdup(host);
3095: permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
1.258 dtucker 3096: return ++num_adm_permitted_opens;
1.257 dtucker 3097: }
3098:
3099: void
1.99 markus 3100: channel_clear_permitted_opens(void)
3101: {
3102: int i;
3103:
3104: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 3105: if (permitted_opens[i].host_to_connect != NULL)
3106: xfree(permitted_opens[i].host_to_connect);
1.305 djm 3107: if (num_permitted_opens > 0) {
3108: xfree(permitted_opens);
3109: permitted_opens = NULL;
3110: }
1.99 markus 3111: num_permitted_opens = 0;
1.257 dtucker 3112: }
3113:
3114: void
3115: channel_clear_adm_permitted_opens(void)
3116: {
3117: int i;
1.99 markus 3118:
1.257 dtucker 3119: for (i = 0; i < num_adm_permitted_opens; i++)
3120: if (permitted_adm_opens[i].host_to_connect != NULL)
3121: xfree(permitted_adm_opens[i].host_to_connect);
1.305 djm 3122: if (num_adm_permitted_opens > 0) {
3123: xfree(permitted_adm_opens);
3124: permitted_adm_opens = NULL;
3125: }
1.257 dtucker 3126: num_adm_permitted_opens = 0;
1.278 dtucker 3127: }
3128:
3129: void
3130: channel_print_adm_permitted_opens(void)
3131: {
1.286 djm 3132: int i;
1.278 dtucker 3133:
1.290 stevesk 3134: printf("permitopen");
1.288 stevesk 3135: if (num_adm_permitted_opens == 0) {
1.290 stevesk 3136: printf(" any\n");
1.288 stevesk 3137: return;
3138: }
1.278 dtucker 3139: for (i = 0; i < num_adm_permitted_opens; i++)
3140: if (permitted_adm_opens[i].host_to_connect != NULL)
3141: printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3142: permitted_adm_opens[i].port_to_connect);
1.290 stevesk 3143: printf("\n");
1.99 markus 3144: }
3145:
1.314 dtucker 3146: /* returns port number, FWD_PERMIT_ANY_PORT or -1 on error */
3147: int
3148: permitopen_port(const char *p)
3149: {
3150: int port;
3151:
3152: if (strcmp(p, "*") == 0)
3153: return FWD_PERMIT_ANY_PORT;
3154: if ((port = a2port(p)) > 0)
3155: return port;
3156: return -1;
3157: }
3158:
3159: static int
3160: port_match(u_short allowedport, u_short requestedport)
3161: {
3162: if (allowedport == FWD_PERMIT_ANY_PORT ||
3163: allowedport == requestedport)
3164: return 1;
3165: return 0;
3166: }
3167:
1.276 djm 3168: /* Try to start non-blocking connect to next host in cctx list */
1.127 itojun 3169: static int
1.276 djm 3170: connect_next(struct channel_connect *cctx)
1.41 markus 3171: {
1.276 djm 3172: int sock, saved_errno;
1.41 markus 3173: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3174:
1.276 djm 3175: for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3176: if (cctx->ai->ai_family != AF_INET &&
3177: cctx->ai->ai_family != AF_INET6)
1.41 markus 3178: continue;
1.276 djm 3179: if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3180: ntop, sizeof(ntop), strport, sizeof(strport),
3181: NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3182: error("connect_next: getnameinfo failed");
1.41 markus 3183: continue;
3184: }
1.300 dtucker 3185: if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3186: cctx->ai->ai_protocol)) == -1) {
1.276 djm 3187: if (cctx->ai->ai_next == NULL)
1.186 djm 3188: error("socket: %.100s", strerror(errno));
3189: else
3190: verbose("socket: %.100s", strerror(errno));
1.41 markus 3191: continue;
3192: }
1.205 djm 3193: if (set_nonblock(sock) == -1)
3194: fatal("%s: set_nonblock(%d)", __func__, sock);
1.276 djm 3195: if (connect(sock, cctx->ai->ai_addr,
3196: cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3197: debug("connect_next: host %.100s ([%.100s]:%s): "
3198: "%.100s", cctx->host, ntop, strport,
1.41 markus 3199: strerror(errno));
1.276 djm 3200: saved_errno = errno;
1.41 markus 3201: close(sock);
1.276 djm 3202: errno = saved_errno;
1.89 stevesk 3203: continue; /* fail -- try next */
1.41 markus 3204: }
1.276 djm 3205: debug("connect_next: host %.100s ([%.100s]:%s) "
3206: "in progress, fd=%d", cctx->host, ntop, strport, sock);
3207: cctx->ai = cctx->ai->ai_next;
3208: set_nodelay(sock);
3209: return sock;
3210: }
3211: return -1;
3212: }
1.41 markus 3213:
1.276 djm 3214: static void
3215: channel_connect_ctx_free(struct channel_connect *cctx)
3216: {
3217: xfree(cctx->host);
3218: if (cctx->aitop)
3219: freeaddrinfo(cctx->aitop);
3220: bzero(cctx, sizeof(*cctx));
3221: cctx->host = NULL;
3222: cctx->ai = cctx->aitop = NULL;
3223: }
3224:
3225: /* Return CONNECTING channel to remote host, port */
3226: static Channel *
3227: connect_to(const char *host, u_short port, char *ctype, char *rname)
3228: {
3229: struct addrinfo hints;
3230: int gaierr;
3231: int sock = -1;
3232: char strport[NI_MAXSERV];
3233: struct channel_connect cctx;
3234: Channel *c;
3235:
1.284 djm 3236: memset(&cctx, 0, sizeof(cctx));
1.276 djm 3237: memset(&hints, 0, sizeof(hints));
3238: hints.ai_family = IPv4or6;
3239: hints.ai_socktype = SOCK_STREAM;
3240: snprintf(strport, sizeof strport, "%d", port);
3241: if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3242: error("connect_to %.100s: unknown host (%s)", host,
3243: ssh_gai_strerror(gaierr));
3244: return NULL;
1.41 markus 3245: }
1.276 djm 3246:
3247: cctx.host = xstrdup(host);
3248: cctx.port = port;
3249: cctx.ai = cctx.aitop;
3250:
3251: if ((sock = connect_next(&cctx)) == -1) {
3252: error("connect to %.100s port %d failed: %s",
3253: host, port, strerror(errno));
3254: channel_connect_ctx_free(&cctx);
3255: return NULL;
1.41 markus 3256: }
1.276 djm 3257: c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3258: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3259: c->connect_ctx = cctx;
3260: return c;
1.41 markus 3261: }
1.99 markus 3262:
1.276 djm 3263: Channel *
3264: channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
1.73 markus 3265: {
3266: int i;
1.99 markus 3267:
1.276 djm 3268: for (i = 0; i < num_permitted_opens; i++) {
1.202 djm 3269: if (permitted_opens[i].host_to_connect != NULL &&
1.314 dtucker 3270: port_match(permitted_opens[i].listen_port, listen_port)) {
1.99 markus 3271: return connect_to(
1.73 markus 3272: permitted_opens[i].host_to_connect,
1.276 djm 3273: permitted_opens[i].port_to_connect, ctype, rname);
3274: }
3275: }
1.74 markus 3276: error("WARNING: Server requests forwarding for unknown listen_port %d",
3277: listen_port);
1.276 djm 3278: return NULL;
1.73 markus 3279: }
3280:
1.99 markus 3281: /* Check if connecting to that port is permitted and connect. */
1.276 djm 3282: Channel *
3283: channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
1.99 markus 3284: {
1.257 dtucker 3285: int i, permit, permit_adm = 1;
1.99 markus 3286:
3287: permit = all_opens_permitted;
3288: if (!permit) {
3289: for (i = 0; i < num_permitted_opens; i++)
1.202 djm 3290: if (permitted_opens[i].host_to_connect != NULL &&
1.314 dtucker 3291: port_match(permitted_opens[i].port_to_connect, port) &&
1.99 markus 3292: strcmp(permitted_opens[i].host_to_connect, host) == 0)
3293: permit = 1;
1.257 dtucker 3294: }
1.99 markus 3295:
1.257 dtucker 3296: if (num_adm_permitted_opens > 0) {
3297: permit_adm = 0;
3298: for (i = 0; i < num_adm_permitted_opens; i++)
3299: if (permitted_adm_opens[i].host_to_connect != NULL &&
1.314 dtucker 3300: port_match(permitted_adm_opens[i].port_to_connect, port) &&
1.257 dtucker 3301: strcmp(permitted_adm_opens[i].host_to_connect, host)
3302: == 0)
3303: permit_adm = 1;
1.99 markus 3304: }
1.257 dtucker 3305:
3306: if (!permit || !permit_adm) {
1.188 itojun 3307: logit("Received request to connect to host %.100s port %d, "
1.99 markus 3308: "but the request was denied.", host, port);
1.276 djm 3309: return NULL;
1.99 markus 3310: }
1.276 djm 3311: return connect_to(host, port, ctype, rname);
1.204 djm 3312: }
3313:
3314: void
3315: channel_send_window_changes(void)
3316: {
1.209 avsm 3317: u_int i;
1.204 djm 3318: struct winsize ws;
3319:
3320: for (i = 0; i < channels_alloc; i++) {
1.213 deraadt 3321: if (channels[i] == NULL || !channels[i]->client_tty ||
1.204 djm 3322: channels[i]->type != SSH_CHANNEL_OPEN)
3323: continue;
3324: if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3325: continue;
3326: channel_request_start(i, "window-change", 0);
1.238 deraadt 3327: packet_put_int((u_int)ws.ws_col);
3328: packet_put_int((u_int)ws.ws_row);
3329: packet_put_int((u_int)ws.ws_xpixel);
3330: packet_put_int((u_int)ws.ws_ypixel);
1.204 djm 3331: packet_send();
3332: }
1.99 markus 3333: }
3334:
1.121 markus 3335: /* -- X11 forwarding */
1.1 deraadt 3336:
1.27 markus 3337: /*
3338: * Creates an internet domain socket for listening for X11 connections.
1.176 deraadt 3339: * Returns 0 and a suitable display number for the DISPLAY variable
3340: * stored in display_numberp , or -1 if an error occurs.
1.27 markus 3341: */
1.141 stevesk 3342: int
1.163 stevesk 3343: x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
1.222 djm 3344: int single_connection, u_int *display_numberp, int **chanids)
1.1 deraadt 3345: {
1.149 markus 3346: Channel *nc = NULL;
1.31 markus 3347: int display_number, sock;
3348: u_short port;
1.35 markus 3349: struct addrinfo hints, *ai, *aitop;
3350: char strport[NI_MAXSERV];
3351: int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
1.25 markus 3352:
1.224 markus 3353: if (chanids == NULL)
3354: return -1;
3355:
1.33 markus 3356: for (display_number = x11_display_offset;
1.148 deraadt 3357: display_number < MAX_DISPLAYS;
3358: display_number++) {
1.25 markus 3359: port = 6000 + display_number;
1.35 markus 3360: memset(&hints, 0, sizeof(hints));
3361: hints.ai_family = IPv4or6;
1.163 stevesk 3362: hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
1.35 markus 3363: hints.ai_socktype = SOCK_STREAM;
3364: snprintf(strport, sizeof strport, "%d", port);
3365: if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3366: error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
1.141 stevesk 3367: return -1;
1.25 markus 3368: }
1.35 markus 3369: for (ai = aitop; ai; ai = ai->ai_next) {
3370: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3371: continue;
1.300 dtucker 3372: sock = socket(ai->ai_family, ai->ai_socktype,
3373: ai->ai_protocol);
1.35 markus 3374: if (sock < 0) {
3375: error("socket: %.100s", strerror(errno));
1.203 markus 3376: freeaddrinfo(aitop);
1.141 stevesk 3377: return -1;
1.35 markus 3378: }
1.226 djm 3379: channel_set_reuseaddr(sock);
1.35 markus 3380: if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.194 markus 3381: debug2("bind port %d: %.100s", port, strerror(errno));
1.35 markus 3382: close(sock);
1.183 itojun 3383:
1.35 markus 3384: for (n = 0; n < num_socks; n++) {
3385: close(socks[n]);
3386: }
3387: num_socks = 0;
3388: break;
3389: }
3390: socks[num_socks++] = sock;
3391: if (num_socks == NUM_SOCKS)
3392: break;
1.25 markus 3393: }
1.83 stevesk 3394: freeaddrinfo(aitop);
1.35 markus 3395: if (num_socks > 0)
3396: break;
1.25 markus 3397: }
3398: if (display_number >= MAX_DISPLAYS) {
3399: error("Failed to allocate internet-domain X11 display socket.");
1.141 stevesk 3400: return -1;
1.25 markus 3401: }
3402: /* Start listening for connections on the socket. */
1.35 markus 3403: for (n = 0; n < num_socks; n++) {
3404: sock = socks[n];
1.199 markus 3405: if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
1.35 markus 3406: error("listen: %.100s", strerror(errno));
3407: close(sock);
1.141 stevesk 3408: return -1;
1.35 markus 3409: }
1.25 markus 3410: }
1.35 markus 3411:
3412: /* Allocate a channel for each socket. */
1.242 djm 3413: *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
1.35 markus 3414: for (n = 0; n < num_socks; n++) {
3415: sock = socks[n];
1.149 markus 3416: nc = channel_new("x11 listener",
1.51 markus 3417: SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3418: CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
1.190 markus 3419: 0, "X11 inet listener", 1);
1.167 markus 3420: nc->single_connection = single_connection;
1.224 markus 3421: (*chanids)[n] = nc->self;
1.35 markus 3422: }
1.224 markus 3423: (*chanids)[n] = -1;
1.1 deraadt 3424:
1.141 stevesk 3425: /* Return the display number for the DISPLAY environment variable. */
1.176 deraadt 3426: *display_numberp = display_number;
3427: return (0);
1.1 deraadt 3428: }
3429:
1.127 itojun 3430: static int
1.77 markus 3431: connect_local_xsocket(u_int dnr)
1.1 deraadt 3432: {
1.25 markus 3433: int sock;
3434: struct sockaddr_un addr;
3435:
1.147 stevesk 3436: sock = socket(AF_UNIX, SOCK_STREAM, 0);
3437: if (sock < 0)
3438: error("socket: %.100s", strerror(errno));
3439: memset(&addr, 0, sizeof(addr));
3440: addr.sun_family = AF_UNIX;
3441: snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
1.239 deraadt 3442: if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
1.147 stevesk 3443: return sock;
3444: close(sock);
1.25 markus 3445: error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3446: return -1;
1.1 deraadt 3447: }
3448:
1.51 markus 3449: int
3450: x11_connect_display(void)
1.1 deraadt 3451: {
1.248 deraadt 3452: u_int display_number;
1.25 markus 3453: const char *display;
1.51 markus 3454: char buf[1024], *cp;
1.35 markus 3455: struct addrinfo hints, *ai, *aitop;
3456: char strport[NI_MAXSERV];
1.248 deraadt 3457: int gaierr, sock = 0;
1.25 markus 3458:
3459: /* Try to open a socket for the local X server. */
3460: display = getenv("DISPLAY");
3461: if (!display) {
3462: error("DISPLAY not set.");
1.51 markus 3463: return -1;
1.25 markus 3464: }
1.27 markus 3465: /*
3466: * Now we decode the value of the DISPLAY variable and make a
3467: * connection to the real X server.
3468: */
3469:
3470: /*
3471: * Check if it is a unix domain socket. Unix domain displays are in
3472: * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3473: */
1.25 markus 3474: if (strncmp(display, "unix:", 5) == 0 ||
3475: display[0] == ':') {
3476: /* Connect to the unix domain socket. */
1.248 deraadt 3477: if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
1.25 markus 3478: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 3479: display);
1.51 markus 3480: return -1;
1.25 markus 3481: }
3482: /* Create a socket. */
3483: sock = connect_local_xsocket(display_number);
3484: if (sock < 0)
1.51 markus 3485: return -1;
1.25 markus 3486:
3487: /* OK, we now have a connection to the display. */
1.51 markus 3488: return sock;
1.25 markus 3489: }
1.27 markus 3490: /*
3491: * Connect to an inet socket. The DISPLAY value is supposedly
3492: * hostname:d[.s], where hostname may also be numeric IP address.
3493: */
1.145 stevesk 3494: strlcpy(buf, display, sizeof(buf));
1.25 markus 3495: cp = strchr(buf, ':');
3496: if (!cp) {
3497: error("Could not find ':' in DISPLAY: %.100s", display);
1.51 markus 3498: return -1;
1.25 markus 3499: }
3500: *cp = 0;
1.27 markus 3501: /* buf now contains the host name. But first we parse the display number. */
1.248 deraadt 3502: if (sscanf(cp + 1, "%u", &display_number) != 1) {
1.25 markus 3503: error("Could not parse display number from DISPLAY: %.100s",
1.148 deraadt 3504: display);
1.51 markus 3505: return -1;
1.25 markus 3506: }
1.35 markus 3507:
3508: /* Look up the host address */
3509: memset(&hints, 0, sizeof(hints));
3510: hints.ai_family = IPv4or6;
3511: hints.ai_socktype = SOCK_STREAM;
1.248 deraadt 3512: snprintf(strport, sizeof strport, "%u", 6000 + display_number);
1.35 markus 3513: if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
1.271 dtucker 3514: error("%.100s: unknown host. (%s)", buf,
3515: ssh_gai_strerror(gaierr));
1.51 markus 3516: return -1;
1.25 markus 3517: }
1.35 markus 3518: for (ai = aitop; ai; ai = ai->ai_next) {
3519: /* Create a socket. */
1.300 dtucker 3520: sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1.35 markus 3521: if (sock < 0) {
1.194 markus 3522: debug2("socket: %.100s", strerror(errno));
1.41 markus 3523: continue;
3524: }
3525: /* Connect it to the display. */
3526: if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1.248 deraadt 3527: debug2("connect %.100s port %u: %.100s", buf,
1.41 markus 3528: 6000 + display_number, strerror(errno));
3529: close(sock);
3530: continue;
3531: }
3532: /* Success */
3533: break;
1.35 markus 3534: }
3535: freeaddrinfo(aitop);
3536: if (!ai) {
1.248 deraadt 3537: error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
1.35 markus 3538: strerror(errno));
1.51 markus 3539: return -1;
1.25 markus 3540: }
1.162 stevesk 3541: set_nodelay(sock);
1.51 markus 3542: return sock;
3543: }
3544:
3545: /*
3546: * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3547: * the remote channel number. We should do whatever we want, and respond
3548: * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3549: */
3550:
1.259 stevesk 3551: /* ARGSUSED */
1.51 markus 3552: void
1.154 markus 3553: x11_input_open(int type, u_int32_t seq, void *ctxt)
1.51 markus 3554: {
1.113 markus 3555: Channel *c = NULL;
3556: int remote_id, sock = 0;
1.51 markus 3557: char *remote_host;
1.25 markus 3558:
1.113 markus 3559: debug("Received X11 open request.");
1.51 markus 3560:
1.113 markus 3561: remote_id = packet_get_int();
1.121 markus 3562:
3563: if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
1.113 markus 3564: remote_host = packet_get_string(NULL);
1.51 markus 3565: } else {
3566: remote_host = xstrdup("unknown (remote did not supply name)");
3567: }
1.152 markus 3568: packet_check_eom();
1.25 markus 3569:
1.51 markus 3570: /* Obtain a connection to the real X display. */
3571: sock = x11_connect_display();
1.113 markus 3572: if (sock != -1) {
3573: /* Allocate a channel for this connection. */
3574: c = channel_new("connected x11 socket",
3575: SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3576: remote_host, 1);
1.167 markus 3577: c->remote_id = remote_id;
3578: c->force_drain = 1;
1.113 markus 3579: }
1.190 markus 3580: xfree(remote_host);
1.113 markus 3581: if (c == NULL) {
1.51 markus 3582: /* Send refusal to the remote host. */
3583: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1.113 markus 3584: packet_put_int(remote_id);
1.51 markus 3585: } else {
3586: /* Send a confirmation to the remote host. */
3587: packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1.113 markus 3588: packet_put_int(remote_id);
3589: packet_put_int(c->self);
1.51 markus 3590: }
1.113 markus 3591: packet_send();
1.72 markus 3592: }
3593:
3594: /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
1.259 stevesk 3595: /* ARGSUSED */
1.72 markus 3596: void
1.154 markus 3597: deny_input_open(int type, u_int32_t seq, void *ctxt)
1.72 markus 3598: {
3599: int rchan = packet_get_int();
1.180 deraadt 3600:
1.143 deraadt 3601: switch (type) {
1.72 markus 3602: case SSH_SMSG_AGENT_OPEN:
3603: error("Warning: ssh server tried agent forwarding.");
3604: break;
3605: case SSH_SMSG_X11_OPEN:
3606: error("Warning: ssh server tried X11 forwarding.");
3607: break;
3608: default:
1.154 markus 3609: error("deny_input_open: type %d", type);
1.72 markus 3610: break;
3611: }
1.230 stevesk 3612: error("Warning: this is probably a break-in attempt by a malicious server.");
1.72 markus 3613: packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3614: packet_put_int(rchan);
3615: packet_send();
1.1 deraadt 3616: }
3617:
1.27 markus 3618: /*
3619: * Requests forwarding of X11 connections, generates fake authentication
3620: * data, and enables authentication spoofing.
1.121 markus 3621: * This should be called in the client only.
1.27 markus 3622: */
1.49 markus 3623: void
1.215 djm 3624: x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
1.311 djm 3625: const char *proto, const char *data, int want_reply)
1.1 deraadt 3626: {
1.77 markus 3627: u_int data_len = (u_int) strlen(data) / 2;
1.219 djm 3628: u_int i, value;
1.25 markus 3629: char *new_data;
3630: int screen_number;
3631: const char *cp;
1.207 avsm 3632: u_int32_t rnd = 0;
1.25 markus 3633:
1.220 markus 3634: if (x11_saved_display == NULL)
3635: x11_saved_display = xstrdup(disp);
3636: else if (strcmp(disp, x11_saved_display) != 0) {
1.219 djm 3637: error("x11_request_forwarding_with_spoofing: different "
3638: "$DISPLAY already forwarded");
3639: return;
3640: }
3641:
1.266 djm 3642: cp = strchr(disp, ':');
1.25 markus 3643: if (cp)
3644: cp = strchr(cp, '.');
3645: if (cp)
1.245 deraadt 3646: screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
1.25 markus 3647: else
3648: screen_number = 0;
3649:
1.219 djm 3650: if (x11_saved_proto == NULL) {
3651: /* Save protocol name. */
3652: x11_saved_proto = xstrdup(proto);
3653: /*
1.221 djm 3654: * Extract real authentication data and generate fake data
1.219 djm 3655: * of the same length.
3656: */
3657: x11_saved_data = xmalloc(data_len);
3658: x11_fake_data = xmalloc(data_len);
3659: for (i = 0; i < data_len; i++) {
3660: if (sscanf(data + 2 * i, "%2x", &value) != 1)
3661: fatal("x11_request_forwarding: bad "
3662: "authentication data: %.100s", data);
3663: if (i % 4 == 0)
3664: rnd = arc4random();
3665: x11_saved_data[i] = value;
3666: x11_fake_data[i] = rnd & 0xff;
3667: rnd >>= 8;
3668: }
3669: x11_saved_data_len = data_len;
3670: x11_fake_data_len = data_len;
1.25 markus 3671: }
3672:
3673: /* Convert the fake data into hex. */
1.219 djm 3674: new_data = tohex(x11_fake_data, data_len);
1.25 markus 3675:
3676: /* Send the request packet. */
1.51 markus 3677: if (compat20) {
1.311 djm 3678: channel_request_start(client_session_id, "x11-req", want_reply);
1.51 markus 3679: packet_put_char(0); /* XXX bool single connection */
3680: } else {
3681: packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3682: }
3683: packet_put_cstring(proto);
3684: packet_put_cstring(new_data);
1.25 markus 3685: packet_put_int(screen_number);
3686: packet_send();
3687: packet_write_wait();
3688: xfree(new_data);
1.1 deraadt 3689: }
3690:
1.121 markus 3691:
3692: /* -- agent forwarding */
3693:
1.1 deraadt 3694: /* Sends a message to the server to request authentication fd forwarding. */
3695:
1.49 markus 3696: void
1.142 itojun 3697: auth_request_forwarding(void)
1.1 deraadt 3698: {
1.25 markus 3699: packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3700: packet_send();
3701: packet_write_wait();
1.1 deraadt 3702: }
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