]> andersk Git - openssh.git/blame - channels.c
andersk / openssh.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
- dtucker@cvs.openbsd.org 2008/06/15 16:58:40
[openssh.git] / channels.c
CommitLineData
e74caf1e 1/* $OpenBSD: channels.c,v 1.280 2008/06/12 15:19:17 djm Exp $ */
8efc0c15 2/*
5260325f 3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
5260325f 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
5260325f 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.
6ae2364d 9 *
bcbf86ec 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 *
7e7327a1 16 * SSH2 support added by Markus Friedl.
8341f420 17 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
bcbf86ec 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.
5260325f 40 */
8efc0c15 41
42#include "includes.h"
bd7c69ea 43
cebb4c24 44#include <sys/types.h>
31652869 45#include <sys/ioctl.h>
cebb4c24 46#include <sys/un.h>
319d6b41 47#include <sys/socket.h>
e264ac72 48#ifdef HAVE_SYS_TIME_H
49# include <sys/time.h>
50#endif
319d6b41 51
52#include <netinet/in.h>
53#include <arpa/inet.h>
1d3e026f 54
028094f4 55#include <errno.h>
28cb0a43 56#include <netdb.h>
cf851879 57#include <stdio.h>
ffa517a8 58#include <stdlib.h>
00146caa 59#include <string.h>
1d3e026f 60#include <termios.h>
5188ba17 61#include <unistd.h>
31652869 62#include <stdarg.h>
8efc0c15 63
3593bdc0 64#include "openbsd-compat/sys-queue.h"
31652869 65#include "xmalloc.h"
8efc0c15 66#include "ssh.h"
42f11eb2 67#include "ssh1.h"
68#include "ssh2.h"
8efc0c15 69#include "packet.h"
42f11eb2 70#include "log.h"
71#include "misc.h"
31652869 72#include "buffer.h"
8efc0c15 73#include "channels.h"
8efc0c15 74#include "compat.h"
42f11eb2 75#include "canohost.h"
4c8722d9 76#include "key.h"
77#include "authfd.h"
805e659f 78#include "pathnames.h"
8efc0c15 79
8e7895b8 80/* -- channel core */
8efc0c15 81
aa3378df 82/*
83 * Pointer to an array containing all allocated channels. The array is
84 * dynamically extended as needed.
85 */
719fc62f 86static Channel **channels = NULL;
8efc0c15 87
aa3378df 88/*
89 * Size of the channel array. All slots of the array must always be
719fc62f 90 * initialized (at least the type field); unused slots set to NULL
aa3378df 91 */
9a995072 92static u_int channels_alloc = 0;
8efc0c15 93
aa3378df 94/*
95 * Maximum file descriptor value used in any of the channels. This is
719fc62f 96 * updated in channel_new.
aa3378df 97 */
39929cdb 98static int channel_max_fd = 0;
8efc0c15 99
8efc0c15 100
8e7895b8 101/* -- tcp forwarding */
8efc0c15 102
aa3378df 103/*
104 * Data structure for storing which hosts are permitted for forward requests.
105 * The local sides of any remote forwards are stored in this array to prevent
106 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
107 * network (which might be behind a firewall).
108 */
5260325f 109typedef struct {
7368a6c8 110 char *host_to_connect; /* Connect to 'host'. */
111 u_short port_to_connect; /* Connect to 'port'. */
112 u_short listen_port; /* Remote side should listen port number. */
8efc0c15 113} ForwardPermission;
114
2fefbadf 115/* List of all permitted host/port pairs to connect by the user. */
8efc0c15 116static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
8e7895b8 117
2fefbadf 118/* List of all permitted host/port pairs to connect by the admin. */
119static ForwardPermission permitted_adm_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
120
121/* Number of permitted host/port pairs in the array permitted by the user. */
8efc0c15 122static int num_permitted_opens = 0;
2fefbadf 123
124/* Number of permitted host/port pair in the array permitted by the admin. */
125static int num_adm_permitted_opens = 0;
126
aa3378df 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 */
8efc0c15 132static int all_opens_permitted = 0;
133
8efc0c15 134
8e7895b8 135/* -- X11 forwarding */
42f11eb2 136
8e7895b8 137/* Maximum number of fake X11 displays to try. */
138#define MAX_DISPLAYS 1000
0490e609 139
ef07103c 140/* Saved X11 local (client) display. */
141static char *x11_saved_display = NULL;
142
8e7895b8 143/* Saved X11 authentication protocol name. */
144static char *x11_saved_proto = NULL;
8efc0c15 145
8e7895b8 146/* Saved X11 authentication data. This is the real data. */
147static char *x11_saved_data = NULL;
148static 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 */
338eb2ab 154static u_char *x11_fake_data = NULL;
8e7895b8 155static u_int x11_fake_data_len;
156
157
158/* -- agent forwarding */
8efc0c15 159
8e7895b8 160#define NUM_SOCKS 10
161
8e7895b8 162/* AF_UNSPEC or AF_INET or AF_INET6 */
5e4a7219 163static int IPv4or6 = AF_UNSPEC;
8e7895b8 164
165/* helper */
396c147e 166static void port_open_helper(Channel *c, char *rtype);
8e7895b8 167
e07e21ad 168/* non-blocking connect helpers */
169static int connect_next(struct channel_connect *);
170static void channel_connect_ctx_free(struct channel_connect *);
171
8e7895b8 172/* -- channel core */
7368a6c8 173
174Channel *
b872f7f0 175channel_by_id(int id)
7368a6c8 176{
177 Channel *c;
719fc62f 178
9a995072 179 if (id < 0 || (u_int)id >= channels_alloc) {
b872f7f0 180 logit("channel_by_id: %d: bad id", id);
7368a6c8 181 return NULL;
182 }
719fc62f 183 c = channels[id];
184 if (c == NULL) {
b872f7f0 185 logit("channel_by_id: %d: bad id: channel free", id);
7368a6c8 186 return NULL;
187 }
188 return c;
189}
190
b872f7f0 191/*
192 * Returns the channel if it is allowed to receive protocol messages.
193 * Private channels, like listening sockets, may not receive messages.
194 */
195Channel *
196channel_lookup(int id)
197{
198 Channel *c;
199
200 if ((c = channel_by_id(id)) == NULL)
201 return (NULL);
202
c8e9c167 203 switch (c->type) {
b872f7f0 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);
b872f7f0 213 }
214 logit("Non-public channel %d, type %d.", id, c->type);
215 return (NULL);
216}
217
aa3378df 218/*
1d1ffb87 219 * Register filedescriptors for a channel, used when allocating a channel or
0fbe8c74 220 * when the channel consumer/producer is ready, e.g. shell exec'd
aa3378df 221 */
396c147e 222static void
a22aff1f 223channel_register_fds(Channel *c, int rfd, int wfd, int efd,
224 int extusage, int nonblock)
8efc0c15 225{
5260325f 226 /* Update the maximum file descriptor value. */
39929cdb 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
aa3378df 231 /* XXX set close-on-exec -markus */
1d1ffb87 232
0fbe8c74 233 c->rfd = rfd;
234 c->wfd = wfd;
235 c->sock = (rfd == wfd) ? rfd : -1;
5e96b616 236 c->ctl_fd = -1; /* XXX: set elsewhere */
0fbe8c74 237 c->efd = efd;
238 c->extended_usage = extusage;
a22aff1f 239
0ae4fe1d 240 /* XXX ugly hack: nonblock is only set by the server */
241 if (nonblock && isatty(c->rfd)) {
d7ac5f18 242 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
0ae4fe1d 243 c->isatty = 1;
244 if (!isatty(c->wfd)) {
94dfb550 245 error("channel %d: wfd %d is not a tty?",
0ae4fe1d 246 c->self, c->wfd);
247 }
248 } else {
249 c->isatty = 0;
250 }
21c2c5cd 251 c->wfd_isatty = isatty(c->wfd);
0ae4fe1d 252
a22aff1f 253 /* enable nonblocking mode */
254 if (nonblock) {
255 if (rfd != -1)
256 set_nonblock(rfd);
257 if (wfd != -1)
258 set_nonblock(wfd);
259 if (efd != -1)
260 set_nonblock(efd);
261 }
0fbe8c74 262}
263
264/*
265 * Allocate a new channel object and set its type and socket. This will cause
266 * remote_name to be freed.
267 */
719fc62f 268Channel *
0fbe8c74 269channel_new(char *ctype, int type, int rfd, int wfd, int efd,
f91d9a89 270 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
0fbe8c74 271{
9a995072 272 int found;
273 u_int i;
0fbe8c74 274 Channel *c;
5260325f 275
276 /* Do initial allocation if this is the first call. */
277 if (channels_alloc == 0) {
278 channels_alloc = 10;
52e3daed 279 channels = xcalloc(channels_alloc, sizeof(Channel *));
5260325f 280 for (i = 0; i < channels_alloc; i++)
719fc62f 281 channels[i] = NULL;
5260325f 282 }
283 /* Try to find a free slot where to put the new channel. */
284 for (found = -1, i = 0; i < channels_alloc; i++)
719fc62f 285 if (channels[i] == NULL) {
5260325f 286 /* Found a free slot. */
9a995072 287 found = (int)i;
5260325f 288 break;
289 }
9a995072 290 if (found < 0) {
aa3378df 291 /* There are no free slots. Take last+1 slot and expand the array. */
5260325f 292 found = channels_alloc;
5df8c731 293 if (channels_alloc > 10000)
294 fatal("channel_new: internal error: channels_alloc %d "
295 "too big.", channels_alloc);
c5d10563 296 channels = xrealloc(channels, channels_alloc + 10,
297 sizeof(Channel *));
20419cc1 298 channels_alloc += 10;
de273eef 299 debug2("channel: expanding %d", channels_alloc);
5260325f 300 for (i = found; i < channels_alloc; i++)
719fc62f 301 channels[i] = NULL;
5260325f 302 }
719fc62f 303 /* Initialize and return new channel. */
52e3daed 304 c = channels[found] = xcalloc(1, sizeof(Channel));
5260325f 305 buffer_init(&c->input);
306 buffer_init(&c->output);
7368a6c8 307 buffer_init(&c->extended);
70bef40e 308 c->ostate = CHAN_OUTPUT_OPEN;
309 c->istate = CHAN_INPUT_OPEN;
310 c->flags = 0;
a22aff1f 311 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
5260325f 312 c->self = found;
313 c->type = type;
7368a6c8 314 c->ctype = ctype;
0b242b12 315 c->local_window = window;
316 c->local_window_max = window;
317 c->local_consumed = 0;
318 c->local_maxpacket = maxpack;
5260325f 319 c->remote_id = -1;
0d942eff 320 c->remote_name = xstrdup(remote_name);
7368a6c8 321 c->remote_window = 0;
322 c->remote_maxpacket = 0;
a5f82435 323 c->force_drain = 0;
ac151b18 324 c->single_connection = 0;
3cf2be58 325 c->detach_user = NULL;
8cd0437d 326 c->detach_close = 0;
3593bdc0 327 c->open_confirm = NULL;
328 c->open_confirm_ctx = NULL;
2e73a022 329 c->input_filter = NULL;
c1c6a032 330 c->output_filter = NULL;
e74caf1e 331 c->filter_ctx = NULL;
332 c->filter_cleanup = NULL;
3593bdc0 333 TAILQ_INIT(&c->status_confirms);
5260325f 334 debug("channel %d: new [%s]", found, remote_name);
719fc62f 335 return c;
7368a6c8 336}
8efc0c15 337
489aa2e9 338static int
339channel_find_maxfd(void)
340{
9a995072 341 u_int i;
342 int max = 0;
489aa2e9 343 Channel *c;
344
345 for (i = 0; i < channels_alloc; i++) {
346 c = channels[i];
347 if (c != NULL) {
348 max = MAX(max, c->rfd);
349 max = MAX(max, c->wfd);
350 max = MAX(max, c->efd);
351 }
352 }
353 return max;
354}
355
356int
357channel_close_fd(int *fdp)
358{
359 int ret = 0, fd = *fdp;
360
361 if (fd != -1) {
362 ret = close(fd);
363 *fdp = -1;
364 if (fd == channel_max_fd)
365 channel_max_fd = channel_find_maxfd();
366 }
367 return ret;
368}
369
0fbe8c74 370/* Close all channel fd/socket. */
396c147e 371static void
0fbe8c74 372channel_close_fds(Channel *c)
373{
5e96b616 374 debug3("channel %d: close_fds r %d w %d e %d c %d",
375 c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
6fd8622b 376
489aa2e9 377 channel_close_fd(&c->sock);
5e96b616 378 channel_close_fd(&c->ctl_fd);
489aa2e9 379 channel_close_fd(&c->rfd);
380 channel_close_fd(&c->wfd);
381 channel_close_fd(&c->efd);
0fbe8c74 382}
383
8e7895b8 384/* Free the channel and close its fd/socket. */
8e7895b8 385void
386channel_free(Channel *c)
387{
388 char *s;
9a995072 389 u_int i, n;
3593bdc0 390 struct channel_confirm *cc;
8e7895b8 391
392 for (n = 0, i = 0; i < channels_alloc; i++)
393 if (channels[i])
394 n++;
9a995072 395 debug("channel %d: free: %s, nchannels %u", c->self,
8e7895b8 396 c->remote_name ? c->remote_name : "???", n);
397
398 s = channel_open_message();
d7ac5f18 399 debug3("channel %d: status: %s", c->self, s);
8e7895b8 400 xfree(s);
401
8e7895b8 402 if (c->sock != -1)
403 shutdown(c->sock, SHUT_RDWR);
5e96b616 404 if (c->ctl_fd != -1)
405 shutdown(c->ctl_fd, SHUT_RDWR);
8e7895b8 406 channel_close_fds(c);
407 buffer_free(&c->input);
408 buffer_free(&c->output);
409 buffer_free(&c->extended);
410 if (c->remote_name) {
411 xfree(c->remote_name);
412 c->remote_name = NULL;
413 }
3593bdc0 414 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
415 if (cc->abandon_cb != NULL)
416 cc->abandon_cb(c, cc->ctx);
417 TAILQ_REMOVE(&c->status_confirms, cc, entry);
418 bzero(cc, sizeof(*cc));
419 xfree(cc);
420 }
e74caf1e 421 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
422 c->filter_cleanup(c->self, c->filter_ctx);
8e7895b8 423 channels[c->self] = NULL;
424 xfree(c);
425}
426
8e7895b8 427void
d6746a0b 428channel_free_all(void)
8e7895b8 429{
9a995072 430 u_int i;
8e7895b8 431
d6746a0b 432 for (i = 0; i < channels_alloc; i++)
433 if (channels[i] != NULL)
434 channel_free(channels[i]);
8e7895b8 435}
436
437/*
438 * Closes the sockets/fds of all channels. This is used to close extra file
439 * descriptors after a fork.
440 */
8e7895b8 441void
d5bb9418 442channel_close_all(void)
8e7895b8 443{
9a995072 444 u_int i;
8e7895b8 445
446 for (i = 0; i < channels_alloc; i++)
447 if (channels[i] != NULL)
448 channel_close_fds(channels[i]);
449}
450
3cf2be58 451/*
452 * Stop listening to channels.
453 */
3cf2be58 454void
455channel_stop_listening(void)
456{
9a995072 457 u_int i;
3cf2be58 458 Channel *c;
459
460 for (i = 0; i < channels_alloc; i++) {
461 c = channels[i];
462 if (c != NULL) {
463 switch (c->type) {
464 case SSH_CHANNEL_AUTH_SOCKET:
465 case SSH_CHANNEL_PORT_LISTENER:
466 case SSH_CHANNEL_RPORT_LISTENER:
467 case SSH_CHANNEL_X11_LISTENER:
489aa2e9 468 channel_close_fd(&c->sock);
3cf2be58 469 channel_free(c);
470 break;
471 }
472 }
473 }
474}
475
8e7895b8 476/*
477 * Returns true if no channel has too much buffered data, and false if one or
478 * more channel is overfull.
479 */
8e7895b8 480int
d5bb9418 481channel_not_very_much_buffered_data(void)
8e7895b8 482{
483 u_int i;
484 Channel *c;
485
486 for (i = 0; i < channels_alloc; i++) {
487 c = channels[i];
488 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
0c139bd1 489#if 0
490 if (!compat20 &&
491 buffer_len(&c->input) > packet_get_maxsize()) {
faa483fa 492 debug2("channel %d: big input buffer %d",
8e7895b8 493 c->self, buffer_len(&c->input));
494 return 0;
495 }
0c139bd1 496#endif
8e7895b8 497 if (buffer_len(&c->output) > packet_get_maxsize()) {
a27002e5 498 debug2("channel %d: big output buffer %u > %u",
0c139bd1 499 c->self, buffer_len(&c->output),
500 packet_get_maxsize());
8e7895b8 501 return 0;
502 }
503 }
504 }
505 return 1;
506}
507
508/* Returns true if any channel is still open. */
8e7895b8 509int
d5bb9418 510channel_still_open(void)
8e7895b8 511{
9a995072 512 u_int i;
8e7895b8 513 Channel *c;
514
515 for (i = 0; i < channels_alloc; i++) {
516 c = channels[i];
517 if (c == NULL)
518 continue;
519 switch (c->type) {
520 case SSH_CHANNEL_X11_LISTENER:
521 case SSH_CHANNEL_PORT_LISTENER:
522 case SSH_CHANNEL_RPORT_LISTENER:
523 case SSH_CHANNEL_CLOSED:
524 case SSH_CHANNEL_AUTH_SOCKET:
525 case SSH_CHANNEL_DYNAMIC:
526 case SSH_CHANNEL_CONNECTING:
527 case SSH_CHANNEL_ZOMBIE:
528 continue;
529 case SSH_CHANNEL_LARVAL:
530 if (!compat20)
531 fatal("cannot happen: SSH_CHANNEL_LARVAL");
532 continue;
533 case SSH_CHANNEL_OPENING:
534 case SSH_CHANNEL_OPEN:
535 case SSH_CHANNEL_X11_OPEN:
536 return 1;
537 case SSH_CHANNEL_INPUT_DRAINING:
538 case SSH_CHANNEL_OUTPUT_DRAINING:
539 if (!compat13)
540 fatal("cannot happen: OUT_DRAIN");
541 return 1;
542 default:
543 fatal("channel_still_open: bad channel type %d", c->type);
544 /* NOTREACHED */
545 }
546 }
547 return 0;
548}
549
550/* Returns the id of an open channel suitable for keepaliving */
8e7895b8 551int
d5bb9418 552channel_find_open(void)
8e7895b8 553{
9a995072 554 u_int i;
8e7895b8 555 Channel *c;
556
557 for (i = 0; i < channels_alloc; i++) {
558 c = channels[i];
13de3560 559 if (c == NULL || c->remote_id < 0)
8e7895b8 560 continue;
561 switch (c->type) {
562 case SSH_CHANNEL_CLOSED:
563 case SSH_CHANNEL_DYNAMIC:
564 case SSH_CHANNEL_X11_LISTENER:
565 case SSH_CHANNEL_PORT_LISTENER:
566 case SSH_CHANNEL_RPORT_LISTENER:
567 case SSH_CHANNEL_OPENING:
568 case SSH_CHANNEL_CONNECTING:
569 case SSH_CHANNEL_ZOMBIE:
570 continue;
571 case SSH_CHANNEL_LARVAL:
572 case SSH_CHANNEL_AUTH_SOCKET:
573 case SSH_CHANNEL_OPEN:
574 case SSH_CHANNEL_X11_OPEN:
575 return i;
576 case SSH_CHANNEL_INPUT_DRAINING:
577 case SSH_CHANNEL_OUTPUT_DRAINING:
578 if (!compat13)
579 fatal("cannot happen: OUT_DRAIN");
580 return i;
581 default:
582 fatal("channel_find_open: bad channel type %d", c->type);
583 /* NOTREACHED */
584 }
585 }
586 return -1;
587}
588
589
590/*
591 * Returns a message describing the currently open forwarded connections,
592 * suitable for sending to the client. The message contains crlf pairs for
593 * newlines.
594 */
8e7895b8 595char *
d5bb9418 596channel_open_message(void)
8e7895b8 597{
598 Buffer buffer;
599 Channel *c;
600 char buf[1024], *cp;
9a995072 601 u_int i;
8e7895b8 602
603 buffer_init(&buffer);
604 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
605 buffer_append(&buffer, buf, strlen(buf));
606 for (i = 0; i < channels_alloc; i++) {
607 c = channels[i];
608 if (c == NULL)
609 continue;
610 switch (c->type) {
611 case SSH_CHANNEL_X11_LISTENER:
612 case SSH_CHANNEL_PORT_LISTENER:
613 case SSH_CHANNEL_RPORT_LISTENER:
614 case SSH_CHANNEL_CLOSED:
615 case SSH_CHANNEL_AUTH_SOCKET:
616 case SSH_CHANNEL_ZOMBIE:
617 continue;
618 case SSH_CHANNEL_LARVAL:
619 case SSH_CHANNEL_OPENING:
620 case SSH_CHANNEL_CONNECTING:
621 case SSH_CHANNEL_DYNAMIC:
622 case SSH_CHANNEL_OPEN:
623 case SSH_CHANNEL_X11_OPEN:
624 case SSH_CHANNEL_INPUT_DRAINING:
625 case SSH_CHANNEL_OUTPUT_DRAINING:
5e96b616 626 snprintf(buf, sizeof buf,
627 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
8e7895b8 628 c->self, c->remote_name,
629 c->type, c->remote_id,
630 c->istate, buffer_len(&c->input),
631 c->ostate, buffer_len(&c->output),
5e96b616 632 c->rfd, c->wfd, c->ctl_fd);
8e7895b8 633 buffer_append(&buffer, buf, strlen(buf));
634 continue;
635 default:
636 fatal("channel_open_message: bad channel type %d", c->type);
637 /* NOTREACHED */
638 }
639 }
640 buffer_append(&buffer, "\0", 1);
641 cp = xstrdup(buffer_ptr(&buffer));
642 buffer_free(&buffer);
643 return cp;
644}
645
646void
647channel_send_open(int id)
648{
649 Channel *c = channel_lookup(id);
e1feb9bf 650
8e7895b8 651 if (c == NULL) {
bbe88b6d 652 logit("channel_send_open: %d: bad id", id);
8e7895b8 653 return;
654 }
6226a8f8 655 debug2("channel %d: send open", id);
8e7895b8 656 packet_start(SSH2_MSG_CHANNEL_OPEN);
657 packet_put_cstring(c->ctype);
658 packet_put_int(c->self);
659 packet_put_int(c->local_window);
660 packet_put_int(c->local_maxpacket);
661 packet_send();
662}
663
664void
6226a8f8 665channel_request_start(int id, char *service, int wantconfirm)
8e7895b8 666{
6226a8f8 667 Channel *c = channel_lookup(id);
e1feb9bf 668
8e7895b8 669 if (c == NULL) {
bbe88b6d 670 logit("channel_request_start: %d: unknown channel id", id);
8e7895b8 671 return;
672 }
5e96b616 673 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
8e7895b8 674 packet_start(SSH2_MSG_CHANNEL_REQUEST);
675 packet_put_int(c->remote_id);
676 packet_put_cstring(service);
677 packet_put_char(wantconfirm);
678}
a7137f6b 679
8e7895b8 680void
3593bdc0 681channel_register_status_confirm(int id, channel_confirm_cb *cb,
682 channel_confirm_abandon_cb *abandon_cb, void *ctx)
683{
684 struct channel_confirm *cc;
685 Channel *c;
686
687 if ((c = channel_lookup(id)) == NULL)
688 fatal("channel_register_expect: %d: bad id", id);
689
690 cc = xmalloc(sizeof(*cc));
691 cc->cb = cb;
692 cc->abandon_cb = abandon_cb;
693 cc->ctx = ctx;
694 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
695}
696
697void
698channel_register_open_confirm(int id, channel_callback_fn *fn, void *ctx)
8e7895b8 699{
700 Channel *c = channel_lookup(id);
e1feb9bf 701
8e7895b8 702 if (c == NULL) {
3593bdc0 703 logit("channel_register_open_comfirm: %d: bad id", id);
8e7895b8 704 return;
705 }
3593bdc0 706 c->open_confirm = fn;
707 c->open_confirm_ctx = ctx;
8e7895b8 708}
a7137f6b 709
8e7895b8 710void
8cd0437d 711channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
8e7895b8 712{
b872f7f0 713 Channel *c = channel_by_id(id);
e1feb9bf 714
8e7895b8 715 if (c == NULL) {
bbe88b6d 716 logit("channel_register_cleanup: %d: bad id", id);
8e7895b8 717 return;
718 }
3cf2be58 719 c->detach_user = fn;
8cd0437d 720 c->detach_close = do_close;
8e7895b8 721}
a7137f6b 722
8e7895b8 723void
724channel_cancel_cleanup(int id)
725{
b872f7f0 726 Channel *c = channel_by_id(id);
e1feb9bf 727
8e7895b8 728 if (c == NULL) {
bbe88b6d 729 logit("channel_cancel_cleanup: %d: bad id", id);
8e7895b8 730 return;
731 }
3cf2be58 732 c->detach_user = NULL;
8cd0437d 733 c->detach_close = 0;
8e7895b8 734}
a7137f6b 735
8e7895b8 736void
c1c6a032 737channel_register_filter(int id, channel_infilter_fn *ifn,
e74caf1e 738 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
8e7895b8 739{
740 Channel *c = channel_lookup(id);
e1feb9bf 741
8e7895b8 742 if (c == NULL) {
bbe88b6d 743 logit("channel_register_filter: %d: bad id", id);
8e7895b8 744 return;
745 }
c1c6a032 746 c->input_filter = ifn;
747 c->output_filter = ofn;
f17f705b 748 c->filter_ctx = ctx;
e74caf1e 749 c->filter_cleanup = cfn;
8e7895b8 750}
751
6ae2364d 752void
8e7895b8 753channel_set_fds(int id, int rfd, int wfd, int efd,
399d1ea6 754 int extusage, int nonblock, u_int window_max)
8efc0c15 755{
8e7895b8 756 Channel *c = channel_lookup(id);
e1feb9bf 757
8e7895b8 758 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
759 fatal("channel_activate for non-larval channel %d.", id);
760 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
761 c->type = SSH_CHANNEL_OPEN;
399d1ea6 762 c->local_window = c->local_window_max = window_max;
8e7895b8 763 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
764 packet_put_int(c->remote_id);
765 packet_put_int(c->local_window);
766 packet_send();
8efc0c15 767}
768
aa3378df 769/*
7368a6c8 770 * 'channel_pre*' are called just before select() to add any bits relevant to
771 * channels in the select bitmasks.
aa3378df 772 */
7368a6c8 773/*
774 * 'channel_post*': perform any appropriate operations for channels which
775 * have events pending.
776 */
c8e9c167 777typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
7368a6c8 778chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
779chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
8efc0c15 780
ebb90778 781/* ARGSUSED */
396c147e 782static void
c8e9c167 783channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
8efc0c15 784{
7368a6c8 785 FD_SET(c->sock, readset);
786}
5260325f 787
ebb90778 788/* ARGSUSED */
396c147e 789static void
c8e9c167 790channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
97fb6912 791{
792 debug3("channel %d: waiting for connection", c->self);
793 FD_SET(c->sock, writeset);
794}
795
396c147e 796static void
c8e9c167 797channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 798{
799 if (buffer_len(&c->input) < packet_get_maxsize())
800 FD_SET(c->sock, readset);
801 if (buffer_len(&c->output) > 0)
802 FD_SET(c->sock, writeset);
803}
5260325f 804
396c147e 805static void
c8e9c167 806channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 807{
0c0738d5 808 u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
5260325f 809
7e7327a1 810 if (c->istate == CHAN_INPUT_OPEN &&
0c0738d5 811 limit > 0 &&
69d9d413 812 buffer_len(&c->input) < limit &&
813 buffer_check_alloc(&c->input, CHAN_RBUF))
7e7327a1 814 FD_SET(c->rfd, readset);
815 if (c->ostate == CHAN_OUTPUT_OPEN ||
816 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
817 if (buffer_len(&c->output) > 0) {
818 FD_SET(c->wfd, writeset);
819 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
d2296ed7 820 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
4e2e5cfd 821 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
822 c->self, c->efd, buffer_len(&c->extended));
d2296ed7 823 else
824 chan_obuf_empty(c);
7e7327a1 825 }
826 }
827 /** XXX check close conditions, too */
271f4a13 828 if (compat20 && c->efd != -1 &&
829 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
7e7327a1 830 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
831 buffer_len(&c->extended) > 0)
832 FD_SET(c->efd, writeset);
d2296ed7 833 else if (!(c->flags & CHAN_EOF_SENT) &&
834 c->extended_usage == CHAN_EXTENDED_READ &&
7e7327a1 835 buffer_len(&c->extended) < c->remote_window)
836 FD_SET(c->efd, readset);
837 }
5e96b616 838 /* XXX: What about efd? races? */
f2107e97 839 if (compat20 && c->ctl_fd != -1 &&
5e96b616 840 c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
841 FD_SET(c->ctl_fd, readset);
7e7327a1 842}
843
ebb90778 844/* ARGSUSED */
396c147e 845static void
c8e9c167 846channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 847{
848 if (buffer_len(&c->input) == 0) {
849 packet_start(SSH_MSG_CHANNEL_CLOSE);
850 packet_put_int(c->remote_id);
851 packet_send();
852 c->type = SSH_CHANNEL_CLOSED;
d7ac5f18 853 debug2("channel %d: closing after input drain.", c->self);
7368a6c8 854 }
855}
5260325f 856
ebb90778 857/* ARGSUSED */
396c147e 858static void
c8e9c167 859channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 860{
861 if (buffer_len(&c->output) == 0)
719fc62f 862 chan_mark_dead(c);
6ae2364d 863 else
7368a6c8 864 FD_SET(c->sock, writeset);
865}
5260325f 866
7368a6c8 867/*
868 * This is a special state for X11 authentication spoofing. An opened X11
869 * connection (when authentication spoofing is being done) remains in this
870 * state until the first packet has been completely read. The authentication
871 * data in that packet is then substituted by the real data if it matches the
872 * fake data, and the channel is put into normal mode.
0b242b12 873 * XXX All this happens at the client side.
8e7895b8 874 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
7368a6c8 875 */
396c147e 876static int
8e7895b8 877x11_open_helper(Buffer *b)
7368a6c8 878{
1e3b8b07 879 u_char *ucp;
880 u_int proto_len, data_len;
5260325f 881
7368a6c8 882 /* Check if the fixed size part of the packet is in buffer. */
8e7895b8 883 if (buffer_len(b) < 12)
7368a6c8 884 return 0;
885
886 /* Parse the lengths of variable-length fields. */
20905a8e 887 ucp = buffer_ptr(b);
7368a6c8 888 if (ucp[0] == 0x42) { /* Byte order MSB first. */
889 proto_len = 256 * ucp[6] + ucp[7];
890 data_len = 256 * ucp[8] + ucp[9];
891 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
892 proto_len = ucp[6] + 256 * ucp[7];
893 data_len = ucp[8] + 256 * ucp[9];
894 } else {
d7ac5f18 895 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
184eed6a 896 ucp[0]);
7368a6c8 897 return -1;
898 }
5260325f 899
7368a6c8 900 /* Check if the whole packet is in buffer. */
8e7895b8 901 if (buffer_len(b) <
7368a6c8 902 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
903 return 0;
5260325f 904
7368a6c8 905 /* Check if authentication protocol matches. */
906 if (proto_len != strlen(x11_saved_proto) ||
907 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
d7ac5f18 908 debug2("X11 connection uses different authentication protocol.");
7368a6c8 909 return -1;
910 }
911 /* Check if authentication data matches our fake data. */
912 if (data_len != x11_fake_data_len ||
913 memcmp(ucp + 12 + ((proto_len + 3) & ~3),
914 x11_fake_data, x11_fake_data_len) != 0) {
d7ac5f18 915 debug2("X11 auth data does not match fake data.");
7368a6c8 916 return -1;
917 }
918 /* Check fake data length */
919 if (x11_fake_data_len != x11_saved_data_len) {
920 error("X11 fake_data_len %d != saved_data_len %d",
921 x11_fake_data_len, x11_saved_data_len);
922 return -1;
923 }
924 /*
925 * Received authentication protocol and data match
926 * our fake data. Substitute the fake data with real
927 * data.
928 */
929 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
930 x11_saved_data, x11_saved_data_len);
931 return 1;
932}
5260325f 933
396c147e 934static void
c8e9c167 935channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 936{
8e7895b8 937 int ret = x11_open_helper(&c->output);
e1feb9bf 938
7368a6c8 939 if (ret == 1) {
940 /* Start normal processing for the channel. */
941 c->type = SSH_CHANNEL_OPEN;
a8be9f80 942 channel_pre_open_13(c, readset, writeset);
7368a6c8 943 } else if (ret == -1) {
944 /*
945 * We have received an X11 connection that has bad
946 * authentication information.
947 */
bbe88b6d 948 logit("X11 connection rejected because of wrong authentication.");
7368a6c8 949 buffer_clear(&c->input);
950 buffer_clear(&c->output);
489aa2e9 951 channel_close_fd(&c->sock);
7368a6c8 952 c->sock = -1;
953 c->type = SSH_CHANNEL_CLOSED;
954 packet_start(SSH_MSG_CHANNEL_CLOSE);
955 packet_put_int(c->remote_id);
956 packet_send();
957 }
958}
5260325f 959
396c147e 960static void
c8e9c167 961channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 962{
8e7895b8 963 int ret = x11_open_helper(&c->output);
a5f82435 964
965 /* c->force_drain = 1; */
966
7368a6c8 967 if (ret == 1) {
968 c->type = SSH_CHANNEL_OPEN;
0c0738d5 969 channel_pre_open(c, readset, writeset);
7368a6c8 970 } else if (ret == -1) {
bbe88b6d 971 logit("X11 connection rejected because of wrong authentication.");
d7ac5f18 972 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
8341f420 973 chan_read_failed(c);
974 buffer_clear(&c->input);
975 chan_ibuf_empty(c);
976 buffer_clear(&c->output);
977 /* for proto v1, the peer will send an IEOF */
978 if (compat20)
979 chan_write_failed(c);
980 else
981 c->type = SSH_CHANNEL_OPEN;
d7ac5f18 982 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
7368a6c8 983 }
984}
5260325f 985
28b9cb4d 986/* try to decode a socks4 header */
ebb90778 987/* ARGSUSED */
396c147e 988static int
c8e9c167 989channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
0490e609 990{
661e45a0 991 char *p, *host;
2ceb8101 992 u_int len, have, i, found;
184eed6a 993 char username[256];
0490e609 994 struct {
995 u_int8_t version;
996 u_int8_t command;
997 u_int16_t dest_port;
28b9cb4d 998 struct in_addr dest_addr;
0490e609 999 } s4_req, s4_rsp;
1000
28b9cb4d 1001 debug2("channel %d: decode socks4", c->self);
53b8fe68 1002
1003 have = buffer_len(&c->input);
1004 len = sizeof(s4_req);
1005 if (have < len)
1006 return 0;
1007 p = buffer_ptr(&c->input);
1008 for (found = 0, i = len; i < have; i++) {
1009 if (p[i] == '\0') {
1010 found = 1;
1011 break;
1012 }
1013 if (i > 1024) {
1014 /* the peer is probably sending garbage */
1015 debug("channel %d: decode socks4: too long",
1016 c->self);
1017 return -1;
1018 }
1019 }
1020 if (!found)
1021 return 0;
0490e609 1022 buffer_get(&c->input, (char *)&s4_req.version, 1);
1023 buffer_get(&c->input, (char *)&s4_req.command, 1);
1024 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
28b9cb4d 1025 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
53b8fe68 1026 have = buffer_len(&c->input);
0490e609 1027 p = buffer_ptr(&c->input);
1028 len = strlen(p);
6683b40f 1029 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
0490e609 1030 if (len > have)
28b9cb4d 1031 fatal("channel %d: decode socks4: len %d > have %d",
0490e609 1032 c->self, len, have);
1033 strlcpy(username, p, sizeof(username));
1034 buffer_consume(&c->input, len);
1035 buffer_consume(&c->input, 1); /* trailing '\0' */
1036
28b9cb4d 1037 host = inet_ntoa(s4_req.dest_addr);
0490e609 1038 strlcpy(c->path, host, sizeof(c->path));
1039 c->host_port = ntohs(s4_req.dest_port);
184eed6a 1040
d7ac5f18 1041 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
6683b40f 1042 c->self, host, c->host_port, s4_req.command);
0490e609 1043
28b9cb4d 1044 if (s4_req.command != 1) {
1045 debug("channel %d: cannot handle: socks4 cn %d",
1046 c->self, s4_req.command);
1047 return -1;
0490e609 1048 }
28b9cb4d 1049 s4_rsp.version = 0; /* vn: 0 for reply */
1050 s4_rsp.command = 90; /* cd: req granted */
0490e609 1051 s4_rsp.dest_port = 0; /* ignored */
28b9cb4d 1052 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
15dd2c4f 1053 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
28b9cb4d 1054 return 1;
0490e609 1055}
1056
f49658f5 1057/* try to decode a socks5 header */
1058#define SSH_SOCKS5_AUTHDONE 0x1000
1059#define SSH_SOCKS5_NOAUTH 0x00
1060#define SSH_SOCKS5_IPV4 0x01
1061#define SSH_SOCKS5_DOMAIN 0x03
1062#define SSH_SOCKS5_IPV6 0x04
1063#define SSH_SOCKS5_CONNECT 0x01
1064#define SSH_SOCKS5_SUCCESS 0x00
1065
ebb90778 1066/* ARGSUSED */
f49658f5 1067static int
c8e9c167 1068channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
f49658f5 1069{
1070 struct {
1071 u_int8_t version;
1072 u_int8_t command;
1073 u_int8_t reserved;
1074 u_int8_t atyp;
1075 } s5_req, s5_rsp;
1076 u_int16_t dest_port;
1077 u_char *p, dest_addr[255+1];
a217e418 1078 u_int have, need, i, found, nmethods, addrlen, af;
f49658f5 1079
1080 debug2("channel %d: decode socks5", c->self);
1081 p = buffer_ptr(&c->input);
1082 if (p[0] != 0x05)
1083 return -1;
1084 have = buffer_len(&c->input);
1085 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1086 /* format: ver | nmethods | methods */
aff51935 1087 if (have < 2)
f49658f5 1088 return 0;
1089 nmethods = p[1];
1090 if (have < nmethods + 2)
1091 return 0;
1092 /* look for method: "NO AUTHENTICATION REQUIRED" */
4f6e2ba9 1093 for (found = 0, i = 2; i < nmethods + 2; i++) {
d4f40d92 1094 if (p[i] == SSH_SOCKS5_NOAUTH) {
f49658f5 1095 found = 1;
1096 break;
1097 }
1098 }
1099 if (!found) {
1100 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1101 c->self);
1102 return -1;
1103 }
1104 buffer_consume(&c->input, nmethods + 2);
1105 buffer_put_char(&c->output, 0x05); /* version */
1106 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1107 FD_SET(c->sock, writeset);
1108 c->flags |= SSH_SOCKS5_AUTHDONE;
1109 debug2("channel %d: socks5 auth done", c->self);
1110 return 0; /* need more */
1111 }
1112 debug2("channel %d: socks5 post auth", c->self);
1113 if (have < sizeof(s5_req)+1)
1114 return 0; /* need more */
5b5f6af7 1115 memcpy(&s5_req, p, sizeof(s5_req));
f49658f5 1116 if (s5_req.version != 0x05 ||
1117 s5_req.command != SSH_SOCKS5_CONNECT ||
1118 s5_req.reserved != 0x00) {
d7ac5f18 1119 debug2("channel %d: only socks5 connect supported", c->self);
f49658f5 1120 return -1;
1121 }
f8cc7664 1122 switch (s5_req.atyp){
f49658f5 1123 case SSH_SOCKS5_IPV4:
1124 addrlen = 4;
1125 af = AF_INET;
1126 break;
1127 case SSH_SOCKS5_DOMAIN:
1128 addrlen = p[sizeof(s5_req)];
1129 af = -1;
1130 break;
1131 case SSH_SOCKS5_IPV6:
1132 addrlen = 16;
1133 af = AF_INET6;
1134 break;
1135 default:
d7ac5f18 1136 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
f49658f5 1137 return -1;
1138 }
a217e418 1139 need = sizeof(s5_req) + addrlen + 2;
1140 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1141 need++;
1142 if (have < need)
f49658f5 1143 return 0;
1144 buffer_consume(&c->input, sizeof(s5_req));
1145 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1146 buffer_consume(&c->input, 1); /* host string length */
1147 buffer_get(&c->input, (char *)&dest_addr, addrlen);
1148 buffer_get(&c->input, (char *)&dest_port, 2);
1149 dest_addr[addrlen] = '\0';
1150 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
f6be21a0 1151 strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
f49658f5 1152 else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1153 return -1;
1154 c->host_port = ntohs(dest_port);
b6453d99 1155
d7ac5f18 1156 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
f49658f5 1157 c->self, c->path, c->host_port, s5_req.command);
1158
1159 s5_rsp.version = 0x05;
1160 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1161 s5_rsp.reserved = 0; /* ignored */
1162 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1163 ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1164 dest_port = 0; /* ignored */
1165
15dd2c4f 1166 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1167 buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1168 buffer_append(&c->output, &dest_port, sizeof(dest_port));
f49658f5 1169 return 1;
1170}
1171
28b9cb4d 1172/* dynamic port forwarding */
396c147e 1173static void
c8e9c167 1174channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
28b9cb4d 1175{
1176 u_char *p;
2ceb8101 1177 u_int have;
1178 int ret;
28b9cb4d 1179
1180 have = buffer_len(&c->input);
639cb8ab 1181 c->delayed = 0;
28b9cb4d 1182 debug2("channel %d: pre_dynamic: have %d", c->self, have);
070adba2 1183 /* buffer_dump(&c->input); */
28b9cb4d 1184 /* check if the fixed size part of the packet is in buffer. */
f49658f5 1185 if (have < 3) {
28b9cb4d 1186 /* need more */
1187 FD_SET(c->sock, readset);
1188 return;
1189 }
1190 /* try to guess the protocol */
1191 p = buffer_ptr(&c->input);
1192 switch (p[0]) {
6683b40f 1193 case 0x04:
1194 ret = channel_decode_socks4(c, readset, writeset);
1195 break;
f49658f5 1196 case 0x05:
1197 ret = channel_decode_socks5(c, readset, writeset);
1198 break;
28b9cb4d 1199 default:
1200 ret = -1;
1201 break;
1202 }
1203 if (ret < 0) {
719fc62f 1204 chan_mark_dead(c);
28b9cb4d 1205 } else if (ret == 0) {
1206 debug2("channel %d: pre_dynamic: need more", c->self);
1207 /* need more */
1208 FD_SET(c->sock, readset);
1209 } else {
1210 /* switch to the next state */
1211 c->type = SSH_CHANNEL_OPENING;
1212 port_open_helper(c, "direct-tcpip");
1213 }
1214}
0490e609 1215
7368a6c8 1216/* This is our fake X11 server socket. */
ebb90778 1217/* ARGSUSED */
396c147e 1218static void
c8e9c167 1219channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1220{
719fc62f 1221 Channel *nc;
7368a6c8 1222 struct sockaddr addr;
bcc0381e 1223 int newsock;
7368a6c8 1224 socklen_t addrlen;
865ac82e 1225 char buf[16384], *remote_ipaddr;
0b242b12 1226 int remote_port;
7368a6c8 1227
1228 if (FD_ISSET(c->sock, readset)) {
1229 debug("X11 connection requested.");
1230 addrlen = sizeof(addr);
1231 newsock = accept(c->sock, &addr, &addrlen);
ac151b18 1232 if (c->single_connection) {
d7ac5f18 1233 debug2("single_connection: closing X11 listener.");
ac151b18 1234 channel_close_fd(&c->sock);
1235 chan_mark_dead(c);
1236 }
7368a6c8 1237 if (newsock < 0) {
1238 error("accept: %.100s", strerror(errno));
1239 return;
5260325f 1240 }
bcc0381e 1241 set_nodelay(newsock);
865ac82e 1242 remote_ipaddr = get_peer_ipaddr(newsock);
0b242b12 1243 remote_port = get_peer_port(newsock);
7368a6c8 1244 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
865ac82e 1245 remote_ipaddr, remote_port);
0b242b12 1246
719fc62f 1247 nc = channel_new("accepted x11 socket",
0b242b12 1248 SSH_CHANNEL_OPENING, newsock, newsock, -1,
0d942eff 1249 c->local_window_max, c->local_maxpacket, 0, buf, 1);
0b242b12 1250 if (compat20) {
1251 packet_start(SSH2_MSG_CHANNEL_OPEN);
1252 packet_put_cstring("x11");
719fc62f 1253 packet_put_int(nc->self);
ac151b18 1254 packet_put_int(nc->local_window_max);
1255 packet_put_int(nc->local_maxpacket);
865ac82e 1256 /* originator ipaddr and port */
1257 packet_put_cstring(remote_ipaddr);
d0c832f3 1258 if (datafellows & SSH_BUG_X11FWD) {
d7ac5f18 1259 debug2("ssh2 x11 bug compat mode");
d0c832f3 1260 } else {
1261 packet_put_int(remote_port);
1262 }
0b242b12 1263 packet_send();
1264 } else {
1265 packet_start(SSH_SMSG_X11_OPEN);
719fc62f 1266 packet_put_int(nc->self);
8e7895b8 1267 if (packet_get_protocol_flags() &
1268 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
449c5ba5 1269 packet_put_cstring(buf);
0b242b12 1270 packet_send();
1271 }
865ac82e 1272 xfree(remote_ipaddr);
8efc0c15 1273 }
8efc0c15 1274}
1275
396c147e 1276static void
0490e609 1277port_open_helper(Channel *c, char *rtype)
1278{
1279 int direct;
1280 char buf[1024];
1281 char *remote_ipaddr = get_peer_ipaddr(c->sock);
29798ed0 1282 int remote_port = get_peer_port(c->sock);
0490e609 1283
1284 direct = (strcmp(rtype, "direct-tcpip") == 0);
1285
1286 snprintf(buf, sizeof buf,
1287 "%s: listening port %d for %.100s port %d, "
1288 "connect from %.200s port %d",
1289 rtype, c->listening_port, c->path, c->host_port,
1290 remote_ipaddr, remote_port);
1291
1292 xfree(c->remote_name);
1293 c->remote_name = xstrdup(buf);
1294
1295 if (compat20) {
1296 packet_start(SSH2_MSG_CHANNEL_OPEN);
1297 packet_put_cstring(rtype);
1298 packet_put_int(c->self);
1299 packet_put_int(c->local_window_max);
1300 packet_put_int(c->local_maxpacket);
1301 if (direct) {
1302 /* target host, port */
1303 packet_put_cstring(c->path);
1304 packet_put_int(c->host_port);
1305 } else {
1306 /* listen address, port */
1307 packet_put_cstring(c->path);
1308 packet_put_int(c->listening_port);
1309 }
1310 /* originator host and port */
1311 packet_put_cstring(remote_ipaddr);
29798ed0 1312 packet_put_int((u_int)remote_port);
0490e609 1313 packet_send();
1314 } else {
1315 packet_start(SSH_MSG_PORT_OPEN);
1316 packet_put_int(c->self);
1317 packet_put_cstring(c->path);
1318 packet_put_int(c->host_port);
8e7895b8 1319 if (packet_get_protocol_flags() &
1320 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
0490e609 1321 packet_put_cstring(c->remote_name);
1322 packet_send();
1323 }
1324 xfree(remote_ipaddr);
1325}
1326
442aee3a 1327static void
1328channel_set_reuseaddr(int fd)
1329{
1330 int on = 1;
1331
1332 /*
1333 * Set socket options.
1334 * Allow local port reuse in TIME_WAIT.
1335 */
1336 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1337 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1338}
1339
aa3378df 1340/*
7368a6c8 1341 * This socket is listening for connections to a forwarded TCP/IP port.
aa3378df 1342 */
ebb90778 1343/* ARGSUSED */
396c147e 1344static void
c8e9c167 1345channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1346{
0490e609 1347 Channel *nc;
7368a6c8 1348 struct sockaddr addr;
719fc62f 1349 int newsock, nextstate;
7368a6c8 1350 socklen_t addrlen;
0490e609 1351 char *rtype;
fa08c86b 1352
7368a6c8 1353 if (FD_ISSET(c->sock, readset)) {
1354 debug("Connection to port %d forwarding "
1355 "to %.100s port %d requested.",
1356 c->listening_port, c->path, c->host_port);
0490e609 1357
639cb8ab 1358 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1359 nextstate = SSH_CHANNEL_OPENING;
1360 rtype = "forwarded-tcpip";
1361 } else {
1362 if (c->host_port == 0) {
1363 nextstate = SSH_CHANNEL_DYNAMIC;
f3964cb9 1364 rtype = "dynamic-tcpip";
639cb8ab 1365 } else {
1366 nextstate = SSH_CHANNEL_OPENING;
1367 rtype = "direct-tcpip";
1368 }
1369 }
0490e609 1370
7368a6c8 1371 addrlen = sizeof(addr);
1372 newsock = accept(c->sock, &addr, &addrlen);
1373 if (newsock < 0) {
1374 error("accept: %.100s", strerror(errno));
1375 return;
1376 }
811a6342 1377 set_nodelay(newsock);
0d942eff 1378 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1379 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
0490e609 1380 nc->listening_port = c->listening_port;
1381 nc->host_port = c->host_port;
1382 strlcpy(nc->path, c->path, sizeof(nc->path));
1383
639cb8ab 1384 if (nextstate == SSH_CHANNEL_DYNAMIC) {
1385 /*
1386 * do not call the channel_post handler until
1387 * this flag has been reset by a pre-handler.
1388 * otherwise the FD_ISSET calls might overflow
1389 */
1390 nc->delayed = 1;
1391 } else {
0490e609 1392 port_open_helper(nc, rtype);
639cb8ab 1393 }
7368a6c8 1394 }
1395}
8efc0c15 1396
7368a6c8 1397/*
1398 * This is the authentication agent socket listening for connections from
1399 * clients.
1400 */
ebb90778 1401/* ARGSUSED */
396c147e 1402static void
c8e9c167 1403channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
8efc0c15 1404{
719fc62f 1405 Channel *nc;
1406 int newsock;
5260325f 1407 struct sockaddr addr;
48e671d5 1408 socklen_t addrlen;
5260325f 1409
7368a6c8 1410 if (FD_ISSET(c->sock, readset)) {
1411 addrlen = sizeof(addr);
1412 newsock = accept(c->sock, &addr, &addrlen);
1413 if (newsock < 0) {
1414 error("accept from auth socket: %.100s", strerror(errno));
1415 return;
1416 }
719fc62f 1417 nc = channel_new("accepted auth socket",
fa08c86b 1418 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1419 c->local_window_max, c->local_maxpacket,
0d942eff 1420 0, "accepted auth socket", 1);
fa08c86b 1421 if (compat20) {
1422 packet_start(SSH2_MSG_CHANNEL_OPEN);
1423 packet_put_cstring("auth-agent@openssh.com");
719fc62f 1424 packet_put_int(nc->self);
fa08c86b 1425 packet_put_int(c->local_window_max);
1426 packet_put_int(c->local_maxpacket);
1427 } else {
1428 packet_start(SSH_SMSG_AGENT_OPEN);
719fc62f 1429 packet_put_int(nc->self);
fa08c86b 1430 }
7368a6c8 1431 packet_send();
1432 }
1433}
5260325f 1434
ebb90778 1435/* ARGSUSED */
396c147e 1436static void
c8e9c167 1437channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
97fb6912 1438{
e07e21ad 1439 int err = 0, sock;
8ab2cb35 1440 socklen_t sz = sizeof(err);
d18e0850 1441
97fb6912 1442 if (FD_ISSET(c->sock, writeset)) {
db518d9b 1443 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
d18e0850 1444 err = errno;
1445 error("getsockopt SO_ERROR failed");
1446 }
1447 if (err == 0) {
e07e21ad 1448 debug("channel %d: connected to %s port %d",
1449 c->self, c->connect_ctx.host, c->connect_ctx.port);
1450 channel_connect_ctx_free(&c->connect_ctx);
d18e0850 1451 c->type = SSH_CHANNEL_OPEN;
1452 if (compat20) {
1453 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1454 packet_put_int(c->remote_id);
1455 packet_put_int(c->self);
1456 packet_put_int(c->local_window);
1457 packet_put_int(c->local_maxpacket);
1458 } else {
1459 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1460 packet_put_int(c->remote_id);
1461 packet_put_int(c->self);
1462 }
97fb6912 1463 } else {
e07e21ad 1464 debug("channel %d: connection failed: %s",
d18e0850 1465 c->self, strerror(err));
e07e21ad 1466 /* Try next address, if any */
1467 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1468 close(c->sock);
1469 c->sock = c->rfd = c->wfd = sock;
1470 channel_max_fd = channel_find_maxfd();
1471 return;
1472 }
1473 /* Exhausted all addresses */
1474 error("connect_to %.100s port %d: failed.",
1475 c->connect_ctx.host, c->connect_ctx.port);
1476 channel_connect_ctx_free(&c->connect_ctx);
d18e0850 1477 if (compat20) {
1478 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1479 packet_put_int(c->remote_id);
1480 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1481 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1482 packet_put_cstring(strerror(err));
1483 packet_put_cstring("");
1484 }
97fb6912 1485 } else {
d18e0850 1486 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1487 packet_put_int(c->remote_id);
97fb6912 1488 }
d18e0850 1489 chan_mark_dead(c);
97fb6912 1490 }
d18e0850 1491 packet_send();
97fb6912 1492 }
1493}
1494
ebb90778 1495/* ARGSUSED */
396c147e 1496static int
c8e9c167 1497channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1498{
fa1d7d85 1499 char buf[CHAN_RBUF];
bd6a1355 1500 int len, force;
7368a6c8 1501
bd6a1355 1502 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1503 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
ea8c44d9 1504 errno = 0;
7368a6c8 1505 len = read(c->rfd, buf, sizeof(buf));
bd6a1355 1506 if (len < 0 && (errno == EINTR || (errno == EAGAIN && !force)))
0fbe8c74 1507 return 1;
ea8c44d9 1508#ifndef PTY_ZEROREAD
7368a6c8 1509 if (len <= 0) {
ea8c44d9 1510#else
9c04d67d 1511 if ((!c->isatty && len <= 0) ||
1512 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
ea8c44d9 1513#endif
d7ac5f18 1514 debug2("channel %d: read<=0 rfd %d len %d",
7368a6c8 1515 c->self, c->rfd, len);
28b9cb4d 1516 if (c->type != SSH_CHANNEL_OPEN) {
d7ac5f18 1517 debug2("channel %d: not open", c->self);
719fc62f 1518 chan_mark_dead(c);
0490e609 1519 return -1;
28b9cb4d 1520 } else if (compat13) {
9c50edcf 1521 buffer_clear(&c->output);
7368a6c8 1522 c->type = SSH_CHANNEL_INPUT_DRAINING;
d7ac5f18 1523 debug2("channel %d: input draining.", c->self);
7368a6c8 1524 } else {
1525 chan_read_failed(c);
5260325f 1526 }
7368a6c8 1527 return -1;
1528 }
6aacefa7 1529 if (c->input_filter != NULL) {
2e73a022 1530 if (c->input_filter(c, buf, len) == -1) {
d7ac5f18 1531 debug2("channel %d: filter stops", c->self);
2e73a022 1532 chan_read_failed(c);
1533 }
d20f3c9e 1534 } else if (c->datagram) {
1535 buffer_put_string(&c->input, buf, len);
2e73a022 1536 } else {
1537 buffer_append(&c->input, buf, len);
1538 }
7368a6c8 1539 }
1540 return 1;
1541}
a7137f6b 1542
ebb90778 1543/* ARGSUSED */
396c147e 1544static int
c8e9c167 1545channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1546{
95ce5599 1547 struct termios tio;
c1c6a032 1548 u_char *data = NULL, *buf;
780a9951 1549 u_int dlen;
7368a6c8 1550 int len;
1551
1552 /* Send buffered output data to the socket. */
6fd8622b 1553 if (c->wfd != -1 &&
7368a6c8 1554 FD_ISSET(c->wfd, writeset) &&
1555 buffer_len(&c->output) > 0) {
c1c6a032 1556 if (c->output_filter != NULL) {
1557 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1558 debug2("channel %d: filter stops", c->self);
d7b37427 1559 if (c->type != SSH_CHANNEL_OPEN)
1560 chan_mark_dead(c);
1561 else
1562 chan_write_failed(c);
1563 return -1;
c1c6a032 1564 }
1565 } else if (c->datagram) {
1566 buf = data = buffer_get_string(&c->output, &dlen);
1567 } else {
1568 buf = data = buffer_ptr(&c->output);
1569 dlen = buffer_len(&c->output);
1570 }
1571
d20f3c9e 1572 if (c->datagram) {
d20f3c9e 1573 /* ignore truncated writes, datagrams might get lost */
1574 c->local_consumed += dlen + 4;
c1c6a032 1575 len = write(c->wfd, buf, dlen);
d20f3c9e 1576 xfree(data);
1577 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1578 return 1;
1579 if (len <= 0) {
1580 if (c->type != SSH_CHANNEL_OPEN)
1581 chan_mark_dead(c);
1582 else
1583 chan_write_failed(c);
1584 return -1;
1585 }
1586 return 1;
1587 }
64c0ce80 1588#ifdef _AIX
aff51935 1589 /* XXX: Later AIX versions can't push as much data to tty */
7fbb4189 1590 if (compat20 && c->wfd_isatty)
1591 dlen = MIN(dlen, 8*1024);
64c0ce80 1592#endif
c1c6a032 1593
1594 len = write(c->wfd, buf, dlen);
0fbe8c74 1595 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1596 return 1;
7368a6c8 1597 if (len <= 0) {
28b9cb4d 1598 if (c->type != SSH_CHANNEL_OPEN) {
d7ac5f18 1599 debug2("channel %d: not open", c->self);
719fc62f 1600 chan_mark_dead(c);
28b9cb4d 1601 return -1;
1602 } else if (compat13) {
9c50edcf 1603 buffer_clear(&c->output);
d7ac5f18 1604 debug2("channel %d: input draining.", c->self);
7368a6c8 1605 c->type = SSH_CHANNEL_INPUT_DRAINING;
1606 } else {
1607 chan_write_failed(c);
5260325f 1608 }
7368a6c8 1609 return -1;
1610 }
c1c6a032 1611 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
0ae4fe1d 1612 if (tcgetattr(c->wfd, &tio) == 0 &&
1613 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1614 /*
1615 * Simulate echo to reduce the impact of
355724fc 1616 * traffic analysis. We need to match the
95ce5599 1617 * size of a SSH2_MSG_CHANNEL_DATA message
c1c6a032 1618 * (4 byte channel id + buf)
0ae4fe1d 1619 */
95ce5599 1620 packet_send_ignore(4 + len);
0ae4fe1d 1621 packet_send();
0ae4fe1d 1622 }
1623 }
7368a6c8 1624 buffer_consume(&c->output, len);
7e7327a1 1625 if (compat20 && len > 0) {
1626 c->local_consumed += len;
1627 }
1628 }
1629 return 1;
1630}
a7137f6b 1631
396c147e 1632static int
c8e9c167 1633channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
7e7327a1 1634{
fa1d7d85 1635 char buf[CHAN_RBUF];
7e7327a1 1636 int len;
1637
8ce64345 1638/** XXX handle drain efd, too */
7e7327a1 1639 if (c->efd != -1) {
1640 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1641 FD_ISSET(c->efd, writeset) &&
1642 buffer_len(&c->extended) > 0) {
1643 len = write(c->efd, buffer_ptr(&c->extended),
1644 buffer_len(&c->extended));
de273eef 1645 debug2("channel %d: written %d to efd %d",
7e7327a1 1646 c->self, len, c->efd);
ee55dacf 1647 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1648 return 1;
1649 if (len <= 0) {
1650 debug2("channel %d: closing write-efd %d",
1651 c->self, c->efd);
489aa2e9 1652 channel_close_fd(&c->efd);
ee55dacf 1653 } else {
7e7327a1 1654 buffer_consume(&c->extended, len);
1655 c->local_consumed += len;
1656 }
1657 } else if (c->extended_usage == CHAN_EXTENDED_READ &&
34640ce6 1658 (c->detach_close || FD_ISSET(c->efd, readset))) {
7e7327a1 1659 len = read(c->efd, buf, sizeof(buf));
de273eef 1660 debug2("channel %d: read %d from efd %d",
184eed6a 1661 c->self, len, c->efd);
34640ce6 1662 if (len < 0 && (errno == EINTR ||
1663 (errno == EAGAIN && !c->detach_close)))
ee55dacf 1664 return 1;
1665 if (len <= 0) {
1666 debug2("channel %d: closing read-efd %d",
8ce64345 1667 c->self, c->efd);
489aa2e9 1668 channel_close_fd(&c->efd);
ee55dacf 1669 } else {
7e7327a1 1670 buffer_append(&c->extended, buf, len);
ee55dacf 1671 }
7e7327a1 1672 }
1673 }
1674 return 1;
1675}
a7137f6b 1676
ebb90778 1677/* ARGSUSED */
396c147e 1678static int
c8e9c167 1679channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset)
5e96b616 1680{
1681 char buf[16];
1682 int len;
1683
1684 /* Monitor control fd to detect if the slave client exits */
1685 if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1686 len = read(c->ctl_fd, buf, sizeof(buf));
1687 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1688 return 1;
1689 if (len <= 0) {
1690 debug2("channel %d: ctl read<=0", c->self);
1691 if (c->type != SSH_CHANNEL_OPEN) {
1692 debug2("channel %d: not open", c->self);
1693 chan_mark_dead(c);
1694 return -1;
1695 } else {
1696 chan_read_failed(c);
1697 chan_write_failed(c);
1698 }
1699 return -1;
1700 } else
1701 fatal("%s: unexpected data on ctl fd", __func__);
1702 }
1703 return 1;
1704}
a7137f6b 1705
5e96b616 1706static int
ee55dacf 1707channel_check_window(Channel *c)
7e7327a1 1708{
28b9cb4d 1709 if (c->type == SSH_CHANNEL_OPEN &&
1710 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
d9245683 1711 ((c->local_window_max - c->local_window >
68a73f53 1712 c->local_maxpacket*3) ||
1713 c->local_window < c->local_window_max/2) &&
7e7327a1 1714 c->local_consumed > 0) {
1715 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1716 packet_put_int(c->remote_id);
1717 packet_put_int(c->local_consumed);
1718 packet_send();
de273eef 1719 debug2("channel %d: window %d sent adjust %d",
7e7327a1 1720 c->self, c->local_window,
1721 c->local_consumed);
1722 c->local_window += c->local_consumed;
1723 c->local_consumed = 0;
7368a6c8 1724 }
1725 return 1;
1726}
5260325f 1727
396c147e 1728static void
c8e9c167 1729channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1730{
639cb8ab 1731 if (c->delayed)
1732 return;
7368a6c8 1733 channel_handle_rfd(c, readset, writeset);
1734 channel_handle_wfd(c, readset, writeset);
0c0738d5 1735 if (!compat20)
639cb8ab 1736 return;
7e7327a1 1737 channel_handle_efd(c, readset, writeset);
5e96b616 1738 channel_handle_ctl(c, readset, writeset);
ee55dacf 1739 channel_check_window(c);
7e7327a1 1740}
1741
ebb90778 1742/* ARGSUSED */
396c147e 1743static void
c8e9c167 1744channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1745{
1746 int len;
e1feb9bf 1747
7368a6c8 1748 /* Send buffered output data to the socket. */
1749 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1750 len = write(c->sock, buffer_ptr(&c->output),
1751 buffer_len(&c->output));
1752 if (len <= 0)
9c50edcf 1753 buffer_clear(&c->output);
7368a6c8 1754 else
1755 buffer_consume(&c->output, len);
1756 }
1757}
5260325f 1758
396c147e 1759static void
7e7327a1 1760channel_handler_init_20(void)
1761{
0c0738d5 1762 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
0b242b12 1763 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
7e7327a1 1764 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
fa08c86b 1765 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
0b242b12 1766 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
fa08c86b 1767 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
97fb6912 1768 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
0490e609 1769 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
7e7327a1 1770
0c0738d5 1771 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
7e7327a1 1772 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
fa08c86b 1773 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
0b242b12 1774 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
fa08c86b 1775 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
97fb6912 1776 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
0c0738d5 1777 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
7e7327a1 1778}
1779
396c147e 1780static void
7368a6c8 1781channel_handler_init_13(void)
1782{
1783 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1784 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1785 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1786 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1787 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1788 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1789 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
97fb6912 1790 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
0490e609 1791 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
7368a6c8 1792
0c0738d5 1793 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
7368a6c8 1794 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1795 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1796 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1797 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
97fb6912 1798 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
0c0738d5 1799 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
7368a6c8 1800}
5260325f 1801
396c147e 1802static void
7368a6c8 1803channel_handler_init_15(void)
1804{
0c0738d5 1805 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
0b242b12 1806 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
7368a6c8 1807 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1808 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1809 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
97fb6912 1810 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
0490e609 1811 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
7368a6c8 1812
1813 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1814 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1815 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
0c0738d5 1816 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
97fb6912 1817 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
0c0738d5 1818 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
7368a6c8 1819}
1820
396c147e 1821static void
7368a6c8 1822channel_handler_init(void)
1823{
1824 int i;
e1feb9bf 1825
184eed6a 1826 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
7368a6c8 1827 channel_pre[i] = NULL;
1828 channel_post[i] = NULL;
1829 }
7e7327a1 1830 if (compat20)
1831 channel_handler_init_20();
1832 else if (compat13)
7368a6c8 1833 channel_handler_init_13();
1834 else
1835 channel_handler_init_15();
1836}
1837
418e724c 1838/* gc dead channels */
1839static void
1840channel_garbage_collect(Channel *c)
1841{
1842 if (c == NULL)
1843 return;
1844 if (c->detach_user != NULL) {
8cd0437d 1845 if (!chan_is_dead(c, c->detach_close))
418e724c 1846 return;
d7ac5f18 1847 debug2("channel %d: gc: notify user", c->self);
418e724c 1848 c->detach_user(c->self, NULL);
1849 /* if we still have a callback */
1850 if (c->detach_user != NULL)
1851 return;
d7ac5f18 1852 debug2("channel %d: gc: user detached", c->self);
418e724c 1853 }
1854 if (!chan_is_dead(c, 1))
1855 return;
d7ac5f18 1856 debug2("channel %d: garbage collecting", c->self);
418e724c 1857 channel_free(c);
1858}
1859
396c147e 1860static void
c8e9c167 1861channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
7368a6c8 1862{
1863 static int did_init = 0;
9a995072 1864 u_int i;
7368a6c8 1865 Channel *c;
1866
1867 if (!did_init) {
1868 channel_handler_init();
1869 did_init = 1;
1870 }
1871 for (i = 0; i < channels_alloc; i++) {
719fc62f 1872 c = channels[i];
1873 if (c == NULL)
5260325f 1874 continue;
6fd8622b 1875 if (ftab[c->type] != NULL)
1876 (*ftab[c->type])(c, readset, writeset);
418e724c 1877 channel_garbage_collect(c);
8efc0c15 1878 }
8efc0c15 1879}
1880
8e7895b8 1881/*
1882 * Allocate/update select bitmasks and add any bits relevant to channels in
1883 * select bitmasks.
1884 */
6ae2364d 1885void
c422989b 1886channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
9a995072 1887 u_int *nallocp, int rekeying)
7368a6c8 1888{
c5d10563 1889 u_int n, sz, nfdset;
39929cdb 1890
1891 n = MAX(*maxfdp, channel_max_fd);
1892
c5d10563 1893 nfdset = howmany(n+1, NFDBITS);
1894 /* Explicitly test here, because xrealloc isn't always called */
1895 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
1896 fatal("channel_prepare_select: max_fd (%d) is too large", n);
1897 sz = nfdset * sizeof(fd_mask);
1898
489aa2e9 1899 /* perhaps check sz < nalloc/2 and shrink? */
1900 if (*readsetp == NULL || sz > *nallocp) {
c5d10563 1901 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
1902 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
489aa2e9 1903 *nallocp = sz;
39929cdb 1904 }
489aa2e9 1905 *maxfdp = n;
39929cdb 1906 memset(*readsetp, 0, sz);
1907 memset(*writesetp, 0, sz);
1908
c422989b 1909 if (!rekeying)
1910 channel_handler(channel_pre, *readsetp, *writesetp);
7368a6c8 1911}
1912
8e7895b8 1913/*
1914 * After select, perform any appropriate operations for channels which have
1915 * events pending.
1916 */
6ae2364d 1917void
c8e9c167 1918channel_after_select(fd_set *readset, fd_set *writeset)
7368a6c8 1919{
1920 channel_handler(channel_post, readset, writeset);
1921}
1922
8e7895b8 1923
39929cdb 1924/* If there is data to send to the connection, enqueue some of it now. */
6ae2364d 1925void
d5bb9418 1926channel_output_poll(void)
8efc0c15 1927{
7368a6c8 1928 Channel *c;
9a995072 1929 u_int i, len;
5260325f 1930
1931 for (i = 0; i < channels_alloc; i++) {
719fc62f 1932 c = channels[i];
1933 if (c == NULL)
1934 continue;
48e671d5 1935
8e7895b8 1936 /*
1937 * We are only interested in channels that can have buffered
1938 * incoming data.
1939 */
48e671d5 1940 if (compat13) {
7368a6c8 1941 if (c->type != SSH_CHANNEL_OPEN &&
1942 c->type != SSH_CHANNEL_INPUT_DRAINING)
48e671d5 1943 continue;
1944 } else {
7368a6c8 1945 if (c->type != SSH_CHANNEL_OPEN)
48e671d5 1946 continue;
48e671d5 1947 }
e78a59f5 1948 if (compat20 &&
1949 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
ee55dacf 1950 /* XXX is this true? */
418e724c 1951 debug3("channel %d: will not send data after close", c->self);
7e7327a1 1952 continue;
1953 }
5260325f 1954
1955 /* Get the amount of buffered data for this channel. */
ee55dacf 1956 if ((c->istate == CHAN_INPUT_OPEN ||
1957 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1958 (len = buffer_len(&c->input)) > 0) {
d20f3c9e 1959 if (c->datagram) {
1960 if (len > 0) {
1961 u_char *data;
1962 u_int dlen;
1963
1964 data = buffer_get_string(&c->input,
1965 &dlen);
1966 packet_start(SSH2_MSG_CHANNEL_DATA);
1967 packet_put_int(c->remote_id);
1968 packet_put_string(data, dlen);
1969 packet_send();
1970 c->remote_window -= dlen + 4;
1971 xfree(data);
1972 }
1973 continue;
1974 }
8e7895b8 1975 /*
1976 * Send some data for the other side over the secure
1977 * connection.
1978 */
7e7327a1 1979 if (compat20) {
1980 if (len > c->remote_window)
1981 len = c->remote_window;
1982 if (len > c->remote_maxpacket)
1983 len = c->remote_maxpacket;
5260325f 1984 } else {
7e7327a1 1985 if (packet_is_interactive()) {
1986 if (len > 1024)
1987 len = 512;
1988 } else {
1989 /* Keep the packets at reasonable size. */
1990 if (len > packet_get_maxsize()/2)
1991 len = packet_get_maxsize()/2;
1992 }
5260325f 1993 }
7368a6c8 1994 if (len > 0) {
7e7327a1 1995 packet_start(compat20 ?
1996 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
7368a6c8 1997 packet_put_int(c->remote_id);
1998 packet_put_string(buffer_ptr(&c->input), len);
1999 packet_send();
2000 buffer_consume(&c->input, len);
2001 c->remote_window -= len;
7368a6c8 2002 }
2003 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
5260325f 2004 if (compat13)
2005 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
aa3378df 2006 /*
2007 * input-buffer is empty and read-socket shutdown:
d2296ed7 2008 * tell peer, that we will not send more data: send IEOF.
2009 * hack for extended data: delay EOF if EFD still in use.
aa3378df 2010 */
d2296ed7 2011 if (CHANNEL_EFD_INPUT_ACTIVE(c))
4e2e5cfd 2012 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2013 c->self, c->efd, buffer_len(&c->extended));
d2296ed7 2014 else
2015 chan_ibuf_empty(c);
5260325f 2016 }
7e7327a1 2017 /* Send extended data, i.e. stderr */
2018 if (compat20 &&
d2296ed7 2019 !(c->flags & CHAN_EOF_SENT) &&
7e7327a1 2020 c->remote_window > 0 &&
2021 (len = buffer_len(&c->extended)) > 0 &&
2022 c->extended_usage == CHAN_EXTENDED_READ) {
f91d9a89 2023 debug2("channel %d: rwin %u elen %u euse %d",
ee55dacf 2024 c->self, c->remote_window, buffer_len(&c->extended),
2025 c->extended_usage);
7e7327a1 2026 if (len > c->remote_window)
2027 len = c->remote_window;
2028 if (len > c->remote_maxpacket)
2029 len = c->remote_maxpacket;
2030 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2031 packet_put_int(c->remote_id);
2032 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2033 packet_put_string(buffer_ptr(&c->extended), len);
2034 packet_send();
2035 buffer_consume(&c->extended, len);
2036 c->remote_window -= len;
ee55dacf 2037 debug2("channel %d: sent ext data %d", c->self, len);
7e7327a1 2038 }
8efc0c15 2039 }
8efc0c15 2040}
2041
8e7895b8 2042
2043/* -- protocol input */
04aa9e67 2044
2045/* ARGSUSED */
6ae2364d 2046void
7819b5c3 2047channel_input_data(int type, u_int32_t seq, void *ctxt)
8efc0c15 2048{
48e671d5 2049 int id;
5260325f 2050 char *data;
1e3b8b07 2051 u_int data_len;
7368a6c8 2052 Channel *c;
5260325f 2053
2054 /* Get the channel number and verify it. */
48e671d5 2055 id = packet_get_int();
7368a6c8 2056 c = channel_lookup(id);
2057 if (c == NULL)
48e671d5 2058 packet_disconnect("Received data for nonexistent channel %d.", id);
5260325f 2059
2060 /* Ignore any data for non-open channels (might happen on close) */
7368a6c8 2061 if (c->type != SSH_CHANNEL_OPEN &&
2062 c->type != SSH_CHANNEL_X11_OPEN)
48e671d5 2063 return;
2064
5260325f 2065 /* Get the data. */
17f02f0a 2066 data = packet_get_string_ptr(&data_len);
7368a6c8 2067
7741e239 2068 /*
2069 * Ignore data for protocol > 1.3 if output end is no longer open.
2070 * For protocol 2 the sending side is reducing its window as it sends
2071 * data, so we must 'fake' consumption of the data in order to ensure
2072 * that window updates are sent back. Otherwise the connection might
2073 * deadlock.
2074 */
2075 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2076 if (compat20) {
2077 c->local_window -= data_len;
2078 c->local_consumed += data_len;
2079 }
7741e239 2080 return;
2081 }
2082
6aacefa7 2083 if (compat20) {
7e7327a1 2084 if (data_len > c->local_maxpacket) {
bbe88b6d 2085 logit("channel %d: rcvd big packet %d, maxpack %d",
7e7327a1 2086 c->self, data_len, c->local_maxpacket);
2087 }
2088 if (data_len > c->local_window) {
bbe88b6d 2089 logit("channel %d: rcvd too much data %d, win %d",
7e7327a1 2090 c->self, data_len, c->local_window);
7e7327a1 2091 return;
2092 }
2093 c->local_window -= data_len;
7e7327a1 2094 }
d20f3c9e 2095 if (c->datagram)
2096 buffer_put_string(&c->output, data, data_len);
2097 else
2098 buffer_append(&c->output, data, data_len);
17f02f0a 2099 packet_check_eom();
8efc0c15 2100}
8e7895b8 2101
04aa9e67 2102/* ARGSUSED */
6ae2364d 2103void
7819b5c3 2104channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
7e7327a1 2105{
2106 int id;
7e7327a1 2107 char *data;
a594fa74 2108 u_int data_len, tcode;
7e7327a1 2109 Channel *c;
2110
2111 /* Get the channel number and verify it. */
2112 id = packet_get_int();
2113 c = channel_lookup(id);
2114
2115 if (c == NULL)
2116 packet_disconnect("Received extended_data for bad channel %d.", id);
2117 if (c->type != SSH_CHANNEL_OPEN) {
bbe88b6d 2118 logit("channel %d: ext data for non open", id);
7e7327a1 2119 return;
2120 }
d2296ed7 2121 if (c->flags & CHAN_EOF_RCVD) {
2122 if (datafellows & SSH_BUG_EXTEOF)
2123 debug("channel %d: accepting ext data after eof", id);
2124 else
2125 packet_disconnect("Received extended_data after EOF "
2126 "on channel %d.", id);
2127 }
7e7327a1 2128 tcode = packet_get_int();
2129 if (c->efd == -1 ||
2130 c->extended_usage != CHAN_EXTENDED_WRITE ||
2131 tcode != SSH2_EXTENDED_DATA_STDERR) {
bbe88b6d 2132 logit("channel %d: bad ext data", c->self);
7e7327a1 2133 return;
2134 }
2135 data = packet_get_string(&data_len);
95500969 2136 packet_check_eom();
7e7327a1 2137 if (data_len > c->local_window) {
bbe88b6d 2138 logit("channel %d: rcvd too much extended_data %d, win %d",
7e7327a1 2139 c->self, data_len, c->local_window);
2140 xfree(data);
2141 return;
2142 }
de273eef 2143 debug2("channel %d: rcvd ext data %d", c->self, data_len);
7e7327a1 2144 c->local_window -= data_len;
2145 buffer_append(&c->extended, data, data_len);
2146 xfree(data);
2147}
2148
04aa9e67 2149/* ARGSUSED */
6ae2364d 2150void
7819b5c3 2151channel_input_ieof(int type, u_int32_t seq, void *ctxt)
7368a6c8 2152{
2153 int id;
2154 Channel *c;
2155
7368a6c8 2156 id = packet_get_int();
95500969 2157 packet_check_eom();
7368a6c8 2158 c = channel_lookup(id);
2159 if (c == NULL)
2160 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2161 chan_rcvd_ieof(c);
a5f82435 2162
2163 /* XXX force input close */
8341f420 2164 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
a5f82435 2165 debug("channel %d: FORCE input drain", c->self);
2166 c->istate = CHAN_INPUT_WAIT_DRAIN;
32e7d71f 2167 if (buffer_len(&c->input) == 0)
2168 chan_ibuf_empty(c);
a5f82435 2169 }
2170
7368a6c8 2171}
8efc0c15 2172
04aa9e67 2173/* ARGSUSED */
6ae2364d 2174void
7819b5c3 2175channel_input_close(int type, u_int32_t seq, void *ctxt)
8efc0c15 2176{
7368a6c8 2177 int id;
2178 Channel *c;
5260325f 2179
7368a6c8 2180 id = packet_get_int();
95500969 2181 packet_check_eom();
7368a6c8 2182 c = channel_lookup(id);
2183 if (c == NULL)
2184 packet_disconnect("Received close for nonexistent channel %d.", id);
aa3378df 2185
2186 /*
2187 * Send a confirmation that we have closed the channel and no more
2188 * data is coming for it.
2189 */
5260325f 2190 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
7368a6c8 2191 packet_put_int(c->remote_id);
5260325f 2192 packet_send();
2193
aa3378df 2194 /*
2195 * If the channel is in closed state, we have sent a close request,
2196 * and the other side will eventually respond with a confirmation.
2197 * Thus, we cannot free the channel here, because then there would be
2198 * no-one to receive the confirmation. The channel gets freed when
2199 * the confirmation arrives.
2200 */
7368a6c8 2201 if (c->type != SSH_CHANNEL_CLOSED) {
aa3378df 2202 /*
2203 * Not a closed channel - mark it as draining, which will
2204 * cause it to be freed later.
2205 */
9c50edcf 2206 buffer_clear(&c->input);
7368a6c8 2207 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
5260325f 2208 }
8efc0c15 2209}
2210
7368a6c8 2211/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
04aa9e67 2212/* ARGSUSED */
6ae2364d 2213void
7819b5c3 2214channel_input_oclose(int type, u_int32_t seq, void *ctxt)
8efc0c15 2215{
7368a6c8 2216 int id = packet_get_int();
2217 Channel *c = channel_lookup(id);
a8a21a53 2218
95500969 2219 packet_check_eom();
7368a6c8 2220 if (c == NULL)
2221 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2222 chan_rcvd_oclose(c);
8efc0c15 2223}
2224
04aa9e67 2225/* ARGSUSED */
6ae2364d 2226void
7819b5c3 2227channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
7368a6c8 2228{
2229 int id = packet_get_int();
2230 Channel *c = channel_lookup(id);
2231
95500969 2232 packet_check_eom();
7368a6c8 2233 if (c == NULL)
2234 packet_disconnect("Received close confirmation for "
2235 "out-of-range channel %d.", id);
2236 if (c->type != SSH_CHANNEL_CLOSED)
2237 packet_disconnect("Received close confirmation for "
2238 "non-closed channel %d (type %d).", id, c->type);
719fc62f 2239 channel_free(c);
7368a6c8 2240}
8efc0c15 2241
04aa9e67 2242/* ARGSUSED */
6ae2364d 2243void
7819b5c3 2244channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
8efc0c15 2245{
7368a6c8 2246 int id, remote_id;
2247 Channel *c;
5260325f 2248
7368a6c8 2249 id = packet_get_int();
2250 c = channel_lookup(id);
5260325f 2251
7368a6c8 2252 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2253 packet_disconnect("Received open confirmation for "
2254 "non-opening channel %d.", id);
2255 remote_id = packet_get_int();
aa3378df 2256 /* Record the remote channel number and mark that the channel is now open. */
7368a6c8 2257 c->remote_id = remote_id;
2258 c->type = SSH_CHANNEL_OPEN;
7e7327a1 2259
2260 if (compat20) {
2261 c->remote_window = packet_get_int();
2262 c->remote_maxpacket = packet_get_int();
3593bdc0 2263 if (c->open_confirm) {
de273eef 2264 debug2("callback start");
3593bdc0 2265 c->open_confirm(c->self, c->open_confirm_ctx);
de273eef 2266 debug2("callback done");
7e7327a1 2267 }
d7ac5f18 2268 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
7e7327a1 2269 c->remote_window, c->remote_maxpacket);
2270 }
95500969 2271 packet_check_eom();
8efc0c15 2272}
2273
396c147e 2274static char *
d18e0850 2275reason2txt(int reason)
2276{
6aacefa7 2277 switch (reason) {
d18e0850 2278 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2279 return "administratively prohibited";
2280 case SSH2_OPEN_CONNECT_FAILED:
2281 return "connect failed";
2282 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2283 return "unknown channel type";
2284 case SSH2_OPEN_RESOURCE_SHORTAGE:
2285 return "resource shortage";
2286 }
7e8c18e9 2287 return "unknown reason";
d18e0850 2288}
2289
04aa9e67 2290/* ARGSUSED */
6ae2364d 2291void
7819b5c3 2292channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
8efc0c15 2293{
02a024dd 2294 int id, reason;
2295 char *msg = NULL, *lang = NULL;
7368a6c8 2296 Channel *c;
5260325f 2297
7368a6c8 2298 id = packet_get_int();
2299 c = channel_lookup(id);
2300
2301 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2302 packet_disconnect("Received open failure for "
2303 "non-opening channel %d.", id);
7e7327a1 2304 if (compat20) {
02a024dd 2305 reason = packet_get_int();
fbe90f7b 2306 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
02a024dd 2307 msg = packet_get_string(NULL);
2308 lang = packet_get_string(NULL);
2309 }
bbe88b6d 2310 logit("channel %d: open failed: %s%s%s", id,
d18e0850 2311 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
02a024dd 2312 if (msg != NULL)
2313 xfree(msg);
2314 if (lang != NULL)
2315 xfree(lang);
7e7327a1 2316 }
95500969 2317 packet_check_eom();
5260325f 2318 /* Free the channel. This will also close the socket. */
719fc62f 2319 channel_free(c);
8efc0c15 2320}
2321
04aa9e67 2322/* ARGSUSED */
8e7895b8 2323void
7819b5c3 2324channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
8e7895b8 2325{
2326 Channel *c;
f91d9a89 2327 int id;
2328 u_int adjust;
3ffc6336 2329
8e7895b8 2330 if (!compat20)
2331 return;
8efc0c15 2332
8e7895b8 2333 /* Get the channel number and verify it. */
2334 id = packet_get_int();
2335 c = channel_lookup(id);
2336
b872f7f0 2337 if (c == NULL) {
2338 logit("Received window adjust for non-open channel %d.", id);
8e7895b8 2339 return;
2340 }
2341 adjust = packet_get_int();
95500969 2342 packet_check_eom();
f91d9a89 2343 debug2("channel %d: rcvd adjust %u", id, adjust);
8e7895b8 2344 c->remote_window += adjust;
2345}
2346
04aa9e67 2347/* ARGSUSED */
8e7895b8 2348void
7819b5c3 2349channel_input_port_open(int type, u_int32_t seq, void *ctxt)
8efc0c15 2350{
8e7895b8 2351 Channel *c = NULL;
2352 u_short host_port;
2353 char *host, *originator_string;
e07e21ad 2354 int remote_id;
5260325f 2355
8e7895b8 2356 remote_id = packet_get_int();
2357 host = packet_get_string(NULL);
2358 host_port = packet_get_int();
2359
2360 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2361 originator_string = packet_get_string(NULL);
2362 } else {
2363 originator_string = xstrdup("unknown (remote did not supply name)");
2364 }
95500969 2365 packet_check_eom();
e07e21ad 2366 c = channel_connect_to(host, host_port,
2367 "connected socket", originator_string);
0d942eff 2368 xfree(originator_string);
e07e21ad 2369 xfree(host);
8e7895b8 2370 if (c == NULL) {
2371 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2372 packet_put_int(remote_id);
2373 packet_send();
e07e21ad 2374 } else
2375 c->remote_id = remote_id;
8efc0c15 2376}
2377
3593bdc0 2378/* ARGSUSED */
2379void
2380channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2381{
2382 Channel *c;
2383 struct channel_confirm *cc;
2384 int remote_id;
2385
2386 /* Reset keepalive timeout */
2387 keep_alive_timeouts = 0;
2388
2389 remote_id = packet_get_int();
2390 packet_check_eom();
2391
2392 debug2("channel_input_confirm: type %d id %d", type, remote_id);
2393
2394 if ((c = channel_lookup(remote_id)) == NULL) {
2395 logit("channel_input_success_failure: %d: unknown", remote_id);
2396 return;
2397 }
2398 ;
2399 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2400 return;
2401 cc->cb(type, c, cc->ctx);
2402 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2403 bzero(cc, sizeof(*cc));
2404 xfree(cc);
2405}
8e7895b8 2406
2407/* -- tcp forwarding */
2408
5e4a7219 2409void
2410channel_set_af(int af)
2411{
2412 IPv4or6 = af;
2413}
2414
5641aefa 2415static int
2416channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2417 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
8efc0c15 2418{
719fc62f 2419 Channel *c;
442aee3a 2420 int sock, r, success = 0, wildcard = 0, is_client;
48e671d5 2421 struct addrinfo hints, *ai, *aitop;
3867aa0a 2422 const char *host, *addr;
5641aefa 2423 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
5260325f 2424
5641aefa 2425 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2426 listen_addr : host_to_connect;
3867aa0a 2427 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
02a024dd 2428
5641aefa 2429 if (host == NULL) {
2430 error("No forward host name.");
38946c65 2431 return 0;
fa08c86b 2432 }
719fc62f 2433 if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
02a024dd 2434 error("Forward host name too long.");
38946c65 2435 return 0;
02a024dd 2436 }
5260325f 2437
3867aa0a 2438 /*
2439 * Determine whether or not a port forward listens to loopback,
f8cc7664 2440 * specified address or wildcard. On the client, a specified bind
2441 * address will always override gateway_ports. On the server, a
2442 * gateway_ports of 1 (``yes'') will override the client's
2443 * specification and force a wildcard bind, whereas a value of 2
2444 * (``clientspecified'') will bind to whatever address the client
3867aa0a 2445 * asked for.
2446 *
2447 * Special-case listen_addrs are:
2448 *
2449 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2450 * "" (empty string), "*" -> wildcard v4/v6
2451 * "localhost" -> loopback v4/v6
2452 */
2453 addr = NULL;
2454 if (listen_addr == NULL) {
2455 /* No address specified: default to gateway_ports setting */
2456 if (gateway_ports)
2457 wildcard = 1;
2458 } else if (gateway_ports || is_client) {
2459 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
bc4cc956 2460 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
3867aa0a 2461 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2462 (!is_client && gateway_ports == 1))
2463 wildcard = 1;
2464 else if (strcmp(listen_addr, "localhost") != 0)
2465 addr = listen_addr;
2466 }
2467
2468 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2469 type, wildcard, (addr == NULL) ? "NULL" : addr);
2470
aa3378df 2471 /*
48e671d5 2472 * getaddrinfo returns a loopback address if the hostname is
2473 * set to NULL and hints.ai_flags is not AI_PASSIVE
aa3378df 2474 */
48e671d5 2475 memset(&hints, 0, sizeof(hints));
2476 hints.ai_family = IPv4or6;
3867aa0a 2477 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
48e671d5 2478 hints.ai_socktype = SOCK_STREAM;
fa08c86b 2479 snprintf(strport, sizeof strport, "%d", listen_port);
3867aa0a 2480 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2481 if (addr == NULL) {
2482 /* This really shouldn't happen */
2483 packet_disconnect("getaddrinfo: fatal error: %s",
bb4626fe 2484 ssh_gai_strerror(r));
3867aa0a 2485 } else {
38946c65 2486 error("channel_setup_fwd_listener: "
bb4626fe 2487 "getaddrinfo(%.64s): %s", addr,
2488 ssh_gai_strerror(r));
3867aa0a 2489 }
38946c65 2490 return 0;
3867aa0a 2491 }
48e671d5 2492
48e671d5 2493 for (ai = aitop; ai; ai = ai->ai_next) {
2494 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2495 continue;
2496 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2497 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
5641aefa 2498 error("channel_setup_fwd_listener: getnameinfo failed");
48e671d5 2499 continue;
2500 }
2501 /* Create a port to listen for the host. */
3e131a6d 2502 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
48e671d5 2503 if (sock < 0) {
2504 /* this is no error since kernel may not support ipv6 */
2505 verbose("socket: %.100s", strerror(errno));
2506 continue;
2507 }
442aee3a 2508
2509 channel_set_reuseaddr(sock);
facfd613 2510
48e671d5 2511 debug("Local forwarding listening on %s port %s.", ntop, strport);
2512
2513 /* Bind the socket to the address. */
2514 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2515 /* address can be in use ipv6 address is already bound */
16218745 2516 if (!ai->ai_next)
2517 error("bind: %.100s", strerror(errno));
2518 else
2519 verbose("bind: %.100s", strerror(errno));
2b87da3b 2520
48e671d5 2521 close(sock);
2522 continue;
2523 }
2524 /* Start listening for connections on the socket. */
fce39749 2525 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
48e671d5 2526 error("listen: %.100s", strerror(errno));
2527 close(sock);
2528 continue;
2529 }
2530 /* Allocate a channel number for the socket. */
8e7895b8 2531 c = channel_new("port listener", type, sock, sock, -1,
0b242b12 2532 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
0d942eff 2533 0, "port listener", 1);
719fc62f 2534 strlcpy(c->path, host, sizeof(c->path));
2535 c->host_port = port_to_connect;
2536 c->listening_port = listen_port;
48e671d5 2537 success = 1;
2538 }
2539 if (success == 0)
5641aefa 2540 error("channel_setup_fwd_listener: cannot listen to port: %d",
02a024dd 2541 listen_port);
48e671d5 2542 freeaddrinfo(aitop);
02a024dd 2543 return success;
5260325f 2544}
8efc0c15 2545
d740ec16 2546int
2547channel_cancel_rport_listener(const char *host, u_short port)
2548{
9a995072 2549 u_int i;
2550 int found = 0;
d740ec16 2551
f8cc7664 2552 for (i = 0; i < channels_alloc; i++) {
d740ec16 2553 Channel *c = channels[i];
2554
2555 if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2556 strncmp(c->path, host, sizeof(c->path)) == 0 &&
f2107e97 2557 c->listening_port == port) {
2912cbd6 2558 debug2("%s: close channel %d", __func__, i);
d740ec16 2559 channel_free(c);
2560 found = 1;
2561 }
2562 }
2563
2564 return (found);
2565}
2566
5641aefa 2567/* protocol local port fwd, used by ssh (and sshd in v1) */
2568int
3867aa0a 2569channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
5641aefa 2570 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2571{
2572 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
3867aa0a 2573 listen_host, listen_port, host_to_connect, port_to_connect,
2574 gateway_ports);
5641aefa 2575}
2576
2577/* protocol v2 remote port fwd, used by sshd */
2578int
2579channel_setup_remote_fwd_listener(const char *listen_address,
2580 u_short listen_port, int gateway_ports)
2581{
2582 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2583 listen_address, listen_port, NULL, 0, gateway_ports);
2584}
2585
aa3378df 2586/*
2587 * Initiate forwarding of connections to port "port" on remote host through
2588 * the secure channel to host:port from local side.
2589 */
8efc0c15 2590
42ea6f5e 2591int
3867aa0a 2592channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
fa08c86b 2593 const char *host_to_connect, u_short port_to_connect)
8efc0c15 2594{
54a5250f 2595 int type, success = 0;
fa08c86b 2596
5260325f 2597 /* Record locally that connection to this host/port is permitted. */
2598 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2599 fatal("channel_request_remote_forwarding: too many forwards");
2600
5260325f 2601 /* Send the forward request to the remote side. */
7e7327a1 2602 if (compat20) {
3867aa0a 2603 const char *address_to_bind;
04efe9b0 2604 if (listen_host == NULL) {
2605 if (datafellows & SSH_BUG_RFWD_ADDR)
2606 address_to_bind = "127.0.0.1";
2607 else
2608 address_to_bind = "localhost";
2609 } else if (*listen_host == '\0' ||
2610 strcmp(listen_host, "*") == 0) {
2611 if (datafellows & SSH_BUG_RFWD_ADDR)
2612 address_to_bind = "0.0.0.0";
2613 else
2614 address_to_bind = "";
2615 } else
3867aa0a 2616 address_to_bind = listen_host;
2617
7e7327a1 2618 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2619 packet_put_cstring("tcpip-forward");
e0ae8728 2620 packet_put_char(1); /* boolean: want reply */
7e7327a1 2621 packet_put_cstring(address_to_bind);
2622 packet_put_int(listen_port);
fa08c86b 2623 packet_send();
2624 packet_write_wait();
2625 /* Assume that server accepts the request */
2626 success = 1;
7e7327a1 2627 } else {
2628 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
7e7327a1 2629 packet_put_int(listen_port);
d6f24e45 2630 packet_put_cstring(host_to_connect);
2631 packet_put_int(port_to_connect);
7e7327a1 2632 packet_send();
2633 packet_write_wait();
fa08c86b 2634
2635 /* Wait for response from the remote side. */
54a5250f 2636 type = packet_read();
fa08c86b 2637 switch (type) {
2638 case SSH_SMSG_SUCCESS:
2639 success = 1;
2640 break;
2641 case SSH_SMSG_FAILURE:
fa08c86b 2642 break;
2643 default:
2644 /* Unknown packet */
2645 packet_disconnect("Protocol error for port forward request:"
2646 "received packet type %d.", type);
2647 }
2648 }
2649 if (success) {
2650 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2651 permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2652 permitted_opens[num_permitted_opens].listen_port = listen_port;
2653 num_permitted_opens++;
7e7327a1 2654 }
42ea6f5e 2655 return (success ? 0 : -1);
8efc0c15 2656}
2657
d740ec16 2658/*
f2107e97 2659 * Request cancellation of remote forwarding of connection host:port from
d740ec16 2660 * local side.
2661 */
d740ec16 2662void
3867aa0a 2663channel_request_rforward_cancel(const char *host, u_short port)
d740ec16 2664{
2665 int i;
d740ec16 2666
2667 if (!compat20)
2668 return;
2669
2670 for (i = 0; i < num_permitted_opens; i++) {
f2107e97 2671 if (permitted_opens[i].host_to_connect != NULL &&
d740ec16 2672 permitted_opens[i].listen_port == port)
2673 break;
2674 }
2675 if (i >= num_permitted_opens) {
2676 debug("%s: requested forward not found", __func__);
2677 return;
2678 }
2679 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2680 packet_put_cstring("cancel-tcpip-forward");
2681 packet_put_char(0);
3867aa0a 2682 packet_put_cstring(host == NULL ? "" : host);
d740ec16 2683 packet_put_int(port);
2684 packet_send();
2685
2686 permitted_opens[i].listen_port = 0;
2687 permitted_opens[i].port_to_connect = 0;
8c4bd764 2688 xfree(permitted_opens[i].host_to_connect);
d740ec16 2689 permitted_opens[i].host_to_connect = NULL;
2690}
2691
aa3378df 2692/*
2693 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2694 * listening for the port, and sends back a success reply (or disconnect
42ea6f5e 2695 * message if there was an error).
aa3378df 2696 */
42ea6f5e 2697int
1d1ffb87 2698channel_input_port_forward_request(int is_root, int gateway_ports)
8efc0c15 2699{
57112b5a 2700 u_short port, host_port;
42ea6f5e 2701 int success = 0;
5260325f 2702 char *hostname;
2703
2704 /* Get arguments from the packet. */
2705 port = packet_get_int();
2706 hostname = packet_get_string(NULL);
2707 host_port = packet_get_int();
2708
3c62e7eb 2709#ifndef HAVE_CYGWIN
aa3378df 2710 /*
2711 * Check that an unprivileged user is not trying to forward a
2712 * privileged port.
2713 */
5260325f 2714 if (port < IPPORT_RESERVED && !is_root)
8e7c9afc 2715 packet_disconnect(
2716 "Requested forwarding of port %d but user is not root.",
2717 port);
2718 if (host_port == 0)
2719 packet_disconnect("Dynamic forwarding denied.");
3c62e7eb 2720#endif
8e7c9afc 2721
fa08c86b 2722 /* Initiate forwarding */
42ea6f5e 2723 success = channel_setup_local_fwd_listener(NULL, port, hostname,
3867aa0a 2724 host_port, gateway_ports);
5260325f 2725
2726 /* Free the argument string. */
2727 xfree(hostname);
42ea6f5e 2728
2729 return (success ? 0 : -1);
8efc0c15 2730}
2731
01794848 2732/*
2733 * Permits opening to any host/port if permitted_opens[] is empty. This is
2734 * usually called by the server, because the user could connect to any port
2735 * anyway, and the server has no way to know but to trust the client anyway.
2736 */
2737void
d5bb9418 2738channel_permit_all_opens(void)
01794848 2739{
2740 if (num_permitted_opens == 0)
2741 all_opens_permitted = 1;
2742}
2743
cd332296 2744void
01794848 2745channel_add_permitted_opens(char *host, int port)
2746{
2747 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
42ea6f5e 2748 fatal("channel_add_permitted_opens: too many forwards");
01794848 2749 debug("allow port forwarding to host %s port %d", host, port);
2750
2751 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2752 permitted_opens[num_permitted_opens].port_to_connect = port;
2753 num_permitted_opens++;
2754
2755 all_opens_permitted = 0;
2756}
2757
ea46e550 2758int
2fefbadf 2759channel_add_adm_permitted_opens(char *host, int port)
2760{
2761 if (num_adm_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2762 fatal("channel_add_adm_permitted_opens: too many forwards");
ea46e550 2763 debug("config allows port forwarding to host %s port %d", host, port);
2fefbadf 2764
2765 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
2766 = xstrdup(host);
2767 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
ea46e550 2768 return ++num_adm_permitted_opens;
2fefbadf 2769}
2770
cd332296 2771void
01794848 2772channel_clear_permitted_opens(void)
2773{
2774 int i;
2775
2776 for (i = 0; i < num_permitted_opens; i++)
d740ec16 2777 if (permitted_opens[i].host_to_connect != NULL)
2778 xfree(permitted_opens[i].host_to_connect);
01794848 2779 num_permitted_opens = 0;
2fefbadf 2780}
2781
2782void
2783channel_clear_adm_permitted_opens(void)
2784{
2785 int i;
01794848 2786
2fefbadf 2787 for (i = 0; i < num_adm_permitted_opens; i++)
2788 if (permitted_adm_opens[i].host_to_connect != NULL)
2789 xfree(permitted_adm_opens[i].host_to_connect);
2790 num_adm_permitted_opens = 0;
01794848 2791}
2792
1760c982 2793void
2794channel_print_adm_permitted_opens(void)
2795{
2796 static int i;
2797
2798 for (i = 0; i < num_adm_permitted_opens; i++)
2799 if (permitted_adm_opens[i].host_to_connect != NULL)
2800 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
2801 permitted_adm_opens[i].port_to_connect);
2802}
2803
e07e21ad 2804/* Try to start non-blocking connect to next host in cctx list */
396c147e 2805static int
e07e21ad 2806connect_next(struct channel_connect *cctx)
8efc0c15 2807{
e07e21ad 2808 int sock, saved_errno;
48e671d5 2809 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
48e671d5 2810
e07e21ad 2811 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
2812 if (cctx->ai->ai_family != AF_INET &&
2813 cctx->ai->ai_family != AF_INET6)
48e671d5 2814 continue;
e07e21ad 2815 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
2816 ntop, sizeof(ntop), strport, sizeof(strport),
2817 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2818 error("connect_next: getnameinfo failed");
48e671d5 2819 continue;
5260325f 2820 }
e07e21ad 2821 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
2822 cctx->ai->ai_protocol)) == -1) {
2823 if (cctx->ai->ai_next == NULL)
4940c411 2824 error("socket: %.100s", strerror(errno));
2825 else
2826 verbose("socket: %.100s", strerror(errno));
48e671d5 2827 continue;
5260325f 2828 }
170694d7 2829 if (set_nonblock(sock) == -1)
2830 fatal("%s: set_nonblock(%d)", __func__, sock);
e07e21ad 2831 if (connect(sock, cctx->ai->ai_addr,
2832 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
2833 debug("connect_next: host %.100s ([%.100s]:%s): "
2834 "%.100s", cctx->host, ntop, strport,
48e671d5 2835 strerror(errno));
e07e21ad 2836 saved_errno = errno;
48e671d5 2837 close(sock);
e07e21ad 2838 errno = saved_errno;
2b87da3b 2839 continue; /* fail -- try next */
48e671d5 2840 }
e07e21ad 2841 debug("connect_next: host %.100s ([%.100s]:%s) "
2842 "in progress, fd=%d", cctx->host, ntop, strport, sock);
2843 cctx->ai = cctx->ai->ai_next;
2844 set_nodelay(sock);
2845 return sock;
2846 }
2847 return -1;
2848}
2849
2850static void
2851channel_connect_ctx_free(struct channel_connect *cctx)
2852{
2853 xfree(cctx->host);
2854 if (cctx->aitop)
2855 freeaddrinfo(cctx->aitop);
2856 bzero(cctx, sizeof(*cctx));
2857 cctx->host = NULL;
2858 cctx->ai = cctx->aitop = NULL;
2859}
2860
2861/* Return CONNECTING channel to remote host, port */
2862static Channel *
2863connect_to(const char *host, u_short port, char *ctype, char *rname)
2864{
2865 struct addrinfo hints;
2866 int gaierr;
2867 int sock = -1;
2868 char strport[NI_MAXSERV];
2869 struct channel_connect cctx;
2870 Channel *c;
5260325f 2871
e07e21ad 2872 memset(&hints, 0, sizeof(hints));
2873 hints.ai_family = IPv4or6;
2874 hints.ai_socktype = SOCK_STREAM;
2875 snprintf(strport, sizeof strport, "%d", port);
2876 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
2877 error("connect_to %.100s: unknown host (%s)", host,
2878 ssh_gai_strerror(gaierr));
2879 return NULL;
5260325f 2880 }
e07e21ad 2881
2882 cctx.host = xstrdup(host);
2883 cctx.port = port;
2884 cctx.ai = cctx.aitop;
2885
2886 if ((sock = connect_next(&cctx)) == -1) {
2887 error("connect to %.100s port %d failed: %s",
2888 host, port, strerror(errno));
2889 channel_connect_ctx_free(&cctx);
2890 return NULL;
8efc0c15 2891 }
e07e21ad 2892 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
2893 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
2894 c->connect_ctx = cctx;
2895 return c;
7368a6c8 2896}
01794848 2897
e07e21ad 2898Channel *
2899channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
fa08c86b 2900{
2901 int i;
01794848 2902
e07e21ad 2903 for (i = 0; i < num_permitted_opens; i++) {
d740ec16 2904 if (permitted_opens[i].host_to_connect != NULL &&
e07e21ad 2905 permitted_opens[i].listen_port == listen_port) {
01794848 2906 return connect_to(
fa08c86b 2907 permitted_opens[i].host_to_connect,
e07e21ad 2908 permitted_opens[i].port_to_connect, ctype, rname);
2909 }
2910 }
0b6fbf03 2911 error("WARNING: Server requests forwarding for unknown listen_port %d",
2912 listen_port);
e07e21ad 2913 return NULL;
fa08c86b 2914}
48e671d5 2915
01794848 2916/* Check if connecting to that port is permitted and connect. */
e07e21ad 2917Channel *
2918channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
01794848 2919{
2fefbadf 2920 int i, permit, permit_adm = 1;
01794848 2921
2922 permit = all_opens_permitted;
2923 if (!permit) {
2924 for (i = 0; i < num_permitted_opens; i++)
d740ec16 2925 if (permitted_opens[i].host_to_connect != NULL &&
2926 permitted_opens[i].port_to_connect == port &&
01794848 2927 strcmp(permitted_opens[i].host_to_connect, host) == 0)
2928 permit = 1;
2fefbadf 2929 }
01794848 2930
2fefbadf 2931 if (num_adm_permitted_opens > 0) {
2932 permit_adm = 0;
2933 for (i = 0; i < num_adm_permitted_opens; i++)
2934 if (permitted_adm_opens[i].host_to_connect != NULL &&
2935 permitted_adm_opens[i].port_to_connect == port &&
2936 strcmp(permitted_adm_opens[i].host_to_connect, host)
2937 == 0)
2938 permit_adm = 1;
01794848 2939 }
2fefbadf 2940
2941 if (!permit || !permit_adm) {
bbe88b6d 2942 logit("Received request to connect to host %.100s port %d, "
01794848 2943 "but the request was denied.", host, port);
e07e21ad 2944 return NULL;
01794848 2945 }
e07e21ad 2946 return connect_to(host, port, ctype, rname);
01794848 2947}
2948
5e96b616 2949void
2950channel_send_window_changes(void)
2951{
9a995072 2952 u_int i;
5e96b616 2953 struct winsize ws;
2954
2955 for (i = 0; i < channels_alloc; i++) {
f8cc7664 2956 if (channels[i] == NULL || !channels[i]->client_tty ||
5e96b616 2957 channels[i]->type != SSH_CHANNEL_OPEN)
2958 continue;
2959 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2960 continue;
2961 channel_request_start(i, "window-change", 0);
148de80c 2962 packet_put_int((u_int)ws.ws_col);
2963 packet_put_int((u_int)ws.ws_row);
2964 packet_put_int((u_int)ws.ws_xpixel);
2965 packet_put_int((u_int)ws.ws_ypixel);
5e96b616 2966 packet_send();
2967 }
2968}
2969
8e7895b8 2970/* -- X11 forwarding */
8efc0c15 2971
aa3378df 2972/*
2973 * Creates an internet domain socket for listening for X11 connections.
57f228e8 2974 * Returns 0 and a suitable display number for the DISPLAY variable
2975 * stored in display_numberp , or -1 if an error occurs.
aa3378df 2976 */
c9d0ad9b 2977int
e6e573bd 2978x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
d08341e6 2979 int single_connection, u_int *display_numberp, int **chanids)
8efc0c15 2980{
ac151b18 2981 Channel *nc = NULL;
57112b5a 2982 int display_number, sock;
2983 u_short port;
48e671d5 2984 struct addrinfo hints, *ai, *aitop;
2985 char strport[NI_MAXSERV];
2986 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
5260325f 2987
59e5aff5 2988 if (chanids == NULL)
2989 return -1;
2990
95f1eccc 2991 for (display_number = x11_display_offset;
184eed6a 2992 display_number < MAX_DISPLAYS;
2993 display_number++) {
5260325f 2994 port = 6000 + display_number;
48e671d5 2995 memset(&hints, 0, sizeof(hints));
2996 hints.ai_family = IPv4or6;
e6e573bd 2997 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
48e671d5 2998 hints.ai_socktype = SOCK_STREAM;
2999 snprintf(strport, sizeof strport, "%d", port);
3000 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
bb4626fe 3001 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
c9d0ad9b 3002 return -1;
5260325f 3003 }
48e671d5 3004 for (ai = aitop; ai; ai = ai->ai_next) {
3005 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3006 continue;
3e131a6d 3007 sock = socket(ai->ai_family, ai->ai_socktype,
3008 ai->ai_protocol);
48e671d5 3009 if (sock < 0) {
4ee81249 3010 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) {
80a44451 3011 error("socket: %.100s", strerror(errno));
0ea89f7e 3012 freeaddrinfo(aitop);
c9d0ad9b 3013 return -1;
80a44451 3014 } else {
22d89d24 3015 debug("x11_create_display_inet: Socket family %d not supported",
3016 ai->ai_family);
80a44451 3017 continue;
3018 }
48e671d5 3019 }
688aaeda 3020#ifdef IPV6_V6ONLY
3021 if (ai->ai_family == AF_INET6) {
3022 int on = 1;
3023 if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0)
3024 error("setsockopt IPV6_V6ONLY: %.100s", strerror(errno));
3025 }
3026#endif
554ebbed 3027 if (x11_use_localhost)
3028 channel_set_reuseaddr(sock);
48e671d5 3029 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
d7ac5f18 3030 debug2("bind port %d: %.100s", port, strerror(errno));
48e671d5 3031 close(sock);
16218745 3032
48e671d5 3033 for (n = 0; n < num_socks; n++) {
48e671d5 3034 close(socks[n]);
3035 }
3036 num_socks = 0;
3037 break;
3038 }
3039 socks[num_socks++] = sock;
3040 if (num_socks == NUM_SOCKS)
3041 break;
5260325f 3042 }
4ccb01d6 3043 freeaddrinfo(aitop);
48e671d5 3044 if (num_socks > 0)
3045 break;
5260325f 3046 }
3047 if (display_number >= MAX_DISPLAYS) {
3048 error("Failed to allocate internet-domain X11 display socket.");
c9d0ad9b 3049 return -1;
8efc0c15 3050 }
5260325f 3051 /* Start listening for connections on the socket. */
48e671d5 3052 for (n = 0; n < num_socks; n++) {
3053 sock = socks[n];
fce39749 3054 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
48e671d5 3055 error("listen: %.100s", strerror(errno));
48e671d5 3056 close(sock);
c9d0ad9b 3057 return -1;
a7effaac 3058 }
a7effaac 3059 }
5260325f 3060
48e671d5 3061 /* Allocate a channel for each socket. */
52e3daed 3062 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
48e671d5 3063 for (n = 0; n < num_socks; n++) {
3064 sock = socks[n];
ac151b18 3065 nc = channel_new("x11 listener",
0b242b12 3066 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3067 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
0d942eff 3068 0, "X11 inet listener", 1);
3a0d3d54 3069 nc->single_connection = single_connection;
59e5aff5 3070 (*chanids)[n] = nc->self;
48e671d5 3071 }
59e5aff5 3072 (*chanids)[n] = -1;
5260325f 3073
c9d0ad9b 3074 /* Return the display number for the DISPLAY environment variable. */
57f228e8 3075 *display_numberp = display_number;
3076 return (0);
8efc0c15 3077}
3078
396c147e 3079static int
1e3b8b07 3080connect_local_xsocket(u_int dnr)
8efc0c15 3081{
5260325f 3082 int sock;
3083 struct sockaddr_un addr;
5260325f 3084
805e659f 3085 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3086 if (sock < 0)
3087 error("socket: %.100s", strerror(errno));
3088 memset(&addr, 0, sizeof(addr));
3089 addr.sun_family = AF_UNIX;
3090 snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
32596c7b 3091 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
805e659f 3092 return sock;
3093 close(sock);
5260325f 3094 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3095 return -1;
8efc0c15 3096}
3097
0b242b12 3098int
3099x11_connect_display(void)
8efc0c15 3100{
4f16046f 3101 u_int display_number;
5260325f 3102 const char *display;
0b242b12 3103 char buf[1024], *cp;
48e671d5 3104 struct addrinfo hints, *ai, *aitop;
3105 char strport[NI_MAXSERV];
4f16046f 3106 int gaierr, sock = 0;
5260325f 3107
5260325f 3108 /* Try to open a socket for the local X server. */
3109 display = getenv("DISPLAY");
3110 if (!display) {
3111 error("DISPLAY not set.");
0b242b12 3112 return -1;
5260325f 3113 }
aa3378df 3114 /*
3115 * Now we decode the value of the DISPLAY variable and make a
3116 * connection to the real X server.
3117 */
3118
3119 /*
3120 * Check if it is a unix domain socket. Unix domain displays are in
3121 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3122 */
5260325f 3123 if (strncmp(display, "unix:", 5) == 0 ||
3124 display[0] == ':') {
3125 /* Connect to the unix domain socket. */
4f16046f 3126 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
5260325f 3127 error("Could not parse display number from DISPLAY: %.100s",
184eed6a 3128 display);
0b242b12 3129 return -1;
5260325f 3130 }
3131 /* Create a socket. */
3132 sock = connect_local_xsocket(display_number);
3133 if (sock < 0)
0b242b12 3134 return -1;
5260325f 3135
3136 /* OK, we now have a connection to the display. */
0b242b12 3137 return sock;
5260325f 3138 }
aa3378df 3139 /*
3140 * Connect to an inet socket. The DISPLAY value is supposedly
3141 * hostname:d[.s], where hostname may also be numeric IP address.
3142 */
74860245 3143 strlcpy(buf, display, sizeof(buf));
5260325f 3144 cp = strchr(buf, ':');
3145 if (!cp) {
3146 error("Could not find ':' in DISPLAY: %.100s", display);
0b242b12 3147 return -1;
5260325f 3148 }
3149 *cp = 0;
aa3378df 3150 /* buf now contains the host name. But first we parse the display number. */
4f16046f 3151 if (sscanf(cp + 1, "%u", &display_number) != 1) {
5260325f 3152 error("Could not parse display number from DISPLAY: %.100s",
184eed6a 3153 display);
0b242b12 3154 return -1;
5260325f 3155 }
5260325f 3156
48e671d5 3157 /* Look up the host address */
3158 memset(&hints, 0, sizeof(hints));
3159 hints.ai_family = IPv4or6;
3160 hints.ai_socktype = SOCK_STREAM;
4f16046f 3161 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
48e671d5 3162 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
bb4626fe 3163 error("%.100s: unknown host. (%s)", buf,
3164 ssh_gai_strerror(gaierr));
0b242b12 3165 return -1;
8efc0c15 3166 }
48e671d5 3167 for (ai = aitop; ai; ai = ai->ai_next) {
3168 /* Create a socket. */
3e131a6d 3169 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
48e671d5 3170 if (sock < 0) {
d7ac5f18 3171 debug2("socket: %.100s", strerror(errno));
7368a6c8 3172 continue;
3173 }
3174 /* Connect it to the display. */
3175 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
4f16046f 3176 debug2("connect %.100s port %u: %.100s", buf,
7368a6c8 3177 6000 + display_number, strerror(errno));
3178 close(sock);
3179 continue;
3180 }
3181 /* Success */
3182 break;
48e671d5 3183 }
48e671d5 3184 freeaddrinfo(aitop);
3185 if (!ai) {
4f16046f 3186 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
48e671d5 3187 strerror(errno));
0b242b12 3188 return -1;
8efc0c15 3189 }
bcc0381e 3190 set_nodelay(sock);
0b242b12 3191 return sock;
3192}
5260325f 3193
0b242b12 3194/*
3195 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3196 * the remote channel number. We should do whatever we want, and respond
3197 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3198 */
5260325f 3199
ebb90778 3200/* ARGSUSED */
0b242b12 3201void
7819b5c3 3202x11_input_open(int type, u_int32_t seq, void *ctxt)
0b242b12 3203{
719fc62f 3204 Channel *c = NULL;
3205 int remote_id, sock = 0;
0b242b12 3206 char *remote_host;
5260325f 3207
719fc62f 3208 debug("Received X11 open request.");
5260325f 3209
719fc62f 3210 remote_id = packet_get_int();
8e7895b8 3211
3212 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
719fc62f 3213 remote_host = packet_get_string(NULL);
0b242b12 3214 } else {
3215 remote_host = xstrdup("unknown (remote did not supply name)");
0b242b12 3216 }
95500969 3217 packet_check_eom();
0b242b12 3218
3219 /* Obtain a connection to the real X display. */
3220 sock = x11_connect_display();
719fc62f 3221 if (sock != -1) {
3222 /* Allocate a channel for this connection. */
3223 c = channel_new("connected x11 socket",
3224 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3225 remote_host, 1);
3a0d3d54 3226 c->remote_id = remote_id;
3227 c->force_drain = 1;
719fc62f 3228 }
0d942eff 3229 xfree(remote_host);
719fc62f 3230 if (c == NULL) {
0b242b12 3231 /* Send refusal to the remote host. */
3232 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
719fc62f 3233 packet_put_int(remote_id);
0b242b12 3234 } else {
0b242b12 3235 /* Send a confirmation to the remote host. */
3236 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
719fc62f 3237 packet_put_int(remote_id);
3238 packet_put_int(c->self);
0b242b12 3239 }
719fc62f 3240 packet_send();
8efc0c15 3241}
3242
a22aff1f 3243/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
ebb90778 3244/* ARGSUSED */
a22aff1f 3245void
7819b5c3 3246deny_input_open(int type, u_int32_t seq, void *ctxt)
a22aff1f 3247{
3248 int rchan = packet_get_int();
e1feb9bf 3249
6aacefa7 3250 switch (type) {
a22aff1f 3251 case SSH_SMSG_AGENT_OPEN:
3252 error("Warning: ssh server tried agent forwarding.");
3253 break;
3254 case SSH_SMSG_X11_OPEN:
3255 error("Warning: ssh server tried X11 forwarding.");
3256 break;
3257 default:
7819b5c3 3258 error("deny_input_open: type %d", type);
a22aff1f 3259 break;
3260 }
1908529f 3261 error("Warning: this is probably a break-in attempt by a malicious server.");
a22aff1f 3262 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3263 packet_put_int(rchan);
3264 packet_send();
3265}
3266
aa3378df 3267/*
3268 * Requests forwarding of X11 connections, generates fake authentication
3269 * data, and enables authentication spoofing.
8e7895b8 3270 * This should be called in the client only.
aa3378df 3271 */
6ae2364d 3272void
9bf083eb 3273x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
0b242b12 3274 const char *proto, const char *data)
8efc0c15 3275{
1e3b8b07 3276 u_int data_len = (u_int) strlen(data) / 2;
ef07103c 3277 u_int i, value;
5260325f 3278 char *new_data;
3279 int screen_number;
3280 const char *cp;
ca75d7de 3281 u_int32_t rnd = 0;
5260325f 3282
4297b666 3283 if (x11_saved_display == NULL)
3284 x11_saved_display = xstrdup(disp);
3285 else if (strcmp(disp, x11_saved_display) != 0) {
ef07103c 3286 error("x11_request_forwarding_with_spoofing: different "
3287 "$DISPLAY already forwarded");
3288 return;
3289 }
3290
0875ae22 3291 cp = strchr(disp, ':');
5260325f 3292 if (cp)
3293 cp = strchr(cp, '.');
3294 if (cp)
d6d4897e 3295 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
5260325f 3296 else
3297 screen_number = 0;
3298
ef07103c 3299 if (x11_saved_proto == NULL) {
3300 /* Save protocol name. */
3301 x11_saved_proto = xstrdup(proto);
3302 /*
56964485 3303 * Extract real authentication data and generate fake data
ef07103c 3304 * of the same length.
3305 */
3306 x11_saved_data = xmalloc(data_len);
3307 x11_fake_data = xmalloc(data_len);
3308 for (i = 0; i < data_len; i++) {
3309 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3310 fatal("x11_request_forwarding: bad "
3311 "authentication data: %.100s", data);
3312 if (i % 4 == 0)
3313 rnd = arc4random();
3314 x11_saved_data[i] = value;
3315 x11_fake_data[i] = rnd & 0xff;
3316 rnd >>= 8;
3317 }
3318 x11_saved_data_len = data_len;
3319 x11_fake_data_len = data_len;
3320 }
5260325f 3321
3322 /* Convert the fake data into hex. */
ef07103c 3323 new_data = tohex(x11_fake_data, data_len);
5260325f 3324
3325 /* Send the request packet. */
0b242b12 3326 if (compat20) {
3327 channel_request_start(client_session_id, "x11-req", 0);
3328 packet_put_char(0); /* XXX bool single connection */
3329 } else {
3330 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3331 }
3332 packet_put_cstring(proto);
3333 packet_put_cstring(new_data);
5260325f 3334 packet_put_int(screen_number);
3335 packet_send();
3336 packet_write_wait();
3337 xfree(new_data);
8efc0c15 3338}
3339
8e7895b8 3340
3341/* -- agent forwarding */
3342
8efc0c15 3343/* Sends a message to the server to request authentication fd forwarding. */
3344
6ae2364d 3345void
d5bb9418 3346auth_request_forwarding(void)
8efc0c15 3347{
5260325f 3348 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3349 packet_send();
3350 packet_write_wait();
8efc0c15 3351}
git-cvsimport mirror of OpenSSH
This page took 0.93959 seconds and 5 git commands to generate.