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4866a6d6 1/* $OpenBSD: channels.c,v 1.292 2009/01/14 01:38:06 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,
b3784859 224 int extusage, int nonblock, int is_tty)
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
b3784859 240 if ((c->isatty = is_tty) != 0)
d7ac5f18 241 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
245f4d36 242 c->wfd_isatty = is_tty || isatty(c->wfd);
0ae4fe1d 243
a22aff1f 244 /* enable nonblocking mode */
245 if (nonblock) {
246 if (rfd != -1)
247 set_nonblock(rfd);
248 if (wfd != -1)
249 set_nonblock(wfd);
250 if (efd != -1)
251 set_nonblock(efd);
252 }
0fbe8c74 253}
254
255/*
256 * Allocate a new channel object and set its type and socket. This will cause
257 * remote_name to be freed.
258 */
719fc62f 259Channel *
0fbe8c74 260channel_new(char *ctype, int type, int rfd, int wfd, int efd,
f91d9a89 261 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
0fbe8c74 262{
9a995072 263 int found;
264 u_int i;
0fbe8c74 265 Channel *c;
5260325f 266
267 /* Do initial allocation if this is the first call. */
268 if (channels_alloc == 0) {
269 channels_alloc = 10;
52e3daed 270 channels = xcalloc(channels_alloc, sizeof(Channel *));
5260325f 271 for (i = 0; i < channels_alloc; i++)
719fc62f 272 channels[i] = NULL;
5260325f 273 }
274 /* Try to find a free slot where to put the new channel. */
275 for (found = -1, i = 0; i < channels_alloc; i++)
719fc62f 276 if (channels[i] == NULL) {
5260325f 277 /* Found a free slot. */
9a995072 278 found = (int)i;
5260325f 279 break;
280 }
9a995072 281 if (found < 0) {
aa3378df 282 /* There are no free slots. Take last+1 slot and expand the array. */
5260325f 283 found = channels_alloc;
5df8c731 284 if (channels_alloc > 10000)
285 fatal("channel_new: internal error: channels_alloc %d "
286 "too big.", channels_alloc);
c5d10563 287 channels = xrealloc(channels, channels_alloc + 10,
288 sizeof(Channel *));
20419cc1 289 channels_alloc += 10;
de273eef 290 debug2("channel: expanding %d", channels_alloc);
5260325f 291 for (i = found; i < channels_alloc; i++)
719fc62f 292 channels[i] = NULL;
5260325f 293 }
719fc62f 294 /* Initialize and return new channel. */
52e3daed 295 c = channels[found] = xcalloc(1, sizeof(Channel));
5260325f 296 buffer_init(&c->input);
297 buffer_init(&c->output);
7368a6c8 298 buffer_init(&c->extended);
70bef40e 299 c->ostate = CHAN_OUTPUT_OPEN;
300 c->istate = CHAN_INPUT_OPEN;
301 c->flags = 0;
c9478090 302 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
5260325f 303 c->self = found;
304 c->type = type;
7368a6c8 305 c->ctype = ctype;
0b242b12 306 c->local_window = window;
307 c->local_window_max = window;
308 c->local_consumed = 0;
309 c->local_maxpacket = maxpack;
5260325f 310 c->remote_id = -1;
0d942eff 311 c->remote_name = xstrdup(remote_name);
7368a6c8 312 c->remote_window = 0;
313 c->remote_maxpacket = 0;
a5f82435 314 c->force_drain = 0;
ac151b18 315 c->single_connection = 0;
3cf2be58 316 c->detach_user = NULL;
8cd0437d 317 c->detach_close = 0;
3593bdc0 318 c->open_confirm = NULL;
319 c->open_confirm_ctx = NULL;
2e73a022 320 c->input_filter = NULL;
c1c6a032 321 c->output_filter = NULL;
e74caf1e 322 c->filter_ctx = NULL;
323 c->filter_cleanup = NULL;
3593bdc0 324 TAILQ_INIT(&c->status_confirms);
5260325f 325 debug("channel %d: new [%s]", found, remote_name);
719fc62f 326 return c;
7368a6c8 327}
8efc0c15 328
489aa2e9 329static int
330channel_find_maxfd(void)
331{
9a995072 332 u_int i;
333 int max = 0;
489aa2e9 334 Channel *c;
335
336 for (i = 0; i < channels_alloc; i++) {
337 c = channels[i];
338 if (c != NULL) {
339 max = MAX(max, c->rfd);
340 max = MAX(max, c->wfd);
341 max = MAX(max, c->efd);
342 }
343 }
344 return max;
345}
346
347int
348channel_close_fd(int *fdp)
349{
350 int ret = 0, fd = *fdp;
351
352 if (fd != -1) {
353 ret = close(fd);
354 *fdp = -1;
355 if (fd == channel_max_fd)
356 channel_max_fd = channel_find_maxfd();
357 }
358 return ret;
359}
360
0fbe8c74 361/* Close all channel fd/socket. */
396c147e 362static void
0fbe8c74 363channel_close_fds(Channel *c)
364{
5e96b616 365 debug3("channel %d: close_fds r %d w %d e %d c %d",
366 c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
6fd8622b 367
489aa2e9 368 channel_close_fd(&c->sock);
5e96b616 369 channel_close_fd(&c->ctl_fd);
489aa2e9 370 channel_close_fd(&c->rfd);
371 channel_close_fd(&c->wfd);
372 channel_close_fd(&c->efd);
0fbe8c74 373}
374
8e7895b8 375/* Free the channel and close its fd/socket. */
8e7895b8 376void
377channel_free(Channel *c)
378{
379 char *s;
9a995072 380 u_int i, n;
3593bdc0 381 struct channel_confirm *cc;
8e7895b8 382
383 for (n = 0, i = 0; i < channels_alloc; i++)
384 if (channels[i])
385 n++;
9a995072 386 debug("channel %d: free: %s, nchannels %u", c->self,
8e7895b8 387 c->remote_name ? c->remote_name : "???", n);
388
389 s = channel_open_message();
d7ac5f18 390 debug3("channel %d: status: %s", c->self, s);
8e7895b8 391 xfree(s);
392
8e7895b8 393 if (c->sock != -1)
394 shutdown(c->sock, SHUT_RDWR);
5e96b616 395 if (c->ctl_fd != -1)
396 shutdown(c->ctl_fd, SHUT_RDWR);
8e7895b8 397 channel_close_fds(c);
398 buffer_free(&c->input);
399 buffer_free(&c->output);
400 buffer_free(&c->extended);
401 if (c->remote_name) {
402 xfree(c->remote_name);
403 c->remote_name = NULL;
404 }
3593bdc0 405 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
406 if (cc->abandon_cb != NULL)
407 cc->abandon_cb(c, cc->ctx);
408 TAILQ_REMOVE(&c->status_confirms, cc, entry);
409 bzero(cc, sizeof(*cc));
410 xfree(cc);
411 }
e74caf1e 412 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
413 c->filter_cleanup(c->self, c->filter_ctx);
8e7895b8 414 channels[c->self] = NULL;
415 xfree(c);
416}
417
8e7895b8 418void
d6746a0b 419channel_free_all(void)
8e7895b8 420{
9a995072 421 u_int i;
8e7895b8 422
d6746a0b 423 for (i = 0; i < channels_alloc; i++)
424 if (channels[i] != NULL)
425 channel_free(channels[i]);
8e7895b8 426}
427
428/*
429 * Closes the sockets/fds of all channels. This is used to close extra file
430 * descriptors after a fork.
431 */
8e7895b8 432void
d5bb9418 433channel_close_all(void)
8e7895b8 434{
9a995072 435 u_int i;
8e7895b8 436
437 for (i = 0; i < channels_alloc; i++)
438 if (channels[i] != NULL)
439 channel_close_fds(channels[i]);
440}
441
3cf2be58 442/*
443 * Stop listening to channels.
444 */
3cf2be58 445void
446channel_stop_listening(void)
447{
9a995072 448 u_int i;
3cf2be58 449 Channel *c;
450
451 for (i = 0; i < channels_alloc; i++) {
452 c = channels[i];
453 if (c != NULL) {
454 switch (c->type) {
455 case SSH_CHANNEL_AUTH_SOCKET:
456 case SSH_CHANNEL_PORT_LISTENER:
457 case SSH_CHANNEL_RPORT_LISTENER:
458 case SSH_CHANNEL_X11_LISTENER:
489aa2e9 459 channel_close_fd(&c->sock);
3cf2be58 460 channel_free(c);
461 break;
462 }
463 }
464 }
465}
466
8e7895b8 467/*
468 * Returns true if no channel has too much buffered data, and false if one or
469 * more channel is overfull.
470 */
8e7895b8 471int
d5bb9418 472channel_not_very_much_buffered_data(void)
8e7895b8 473{
474 u_int i;
475 Channel *c;
476
477 for (i = 0; i < channels_alloc; i++) {
478 c = channels[i];
479 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
0c139bd1 480#if 0
481 if (!compat20 &&
482 buffer_len(&c->input) > packet_get_maxsize()) {
faa483fa 483 debug2("channel %d: big input buffer %d",
8e7895b8 484 c->self, buffer_len(&c->input));
485 return 0;
486 }
0c139bd1 487#endif
8e7895b8 488 if (buffer_len(&c->output) > packet_get_maxsize()) {
a27002e5 489 debug2("channel %d: big output buffer %u > %u",
0c139bd1 490 c->self, buffer_len(&c->output),
491 packet_get_maxsize());
8e7895b8 492 return 0;
493 }
494 }
495 }
496 return 1;
497}
498
499/* Returns true if any channel is still open. */
8e7895b8 500int
d5bb9418 501channel_still_open(void)
8e7895b8 502{
9a995072 503 u_int i;
8e7895b8 504 Channel *c;
505
506 for (i = 0; i < channels_alloc; i++) {
507 c = channels[i];
508 if (c == NULL)
509 continue;
510 switch (c->type) {
511 case SSH_CHANNEL_X11_LISTENER:
512 case SSH_CHANNEL_PORT_LISTENER:
513 case SSH_CHANNEL_RPORT_LISTENER:
514 case SSH_CHANNEL_CLOSED:
515 case SSH_CHANNEL_AUTH_SOCKET:
516 case SSH_CHANNEL_DYNAMIC:
517 case SSH_CHANNEL_CONNECTING:
518 case SSH_CHANNEL_ZOMBIE:
519 continue;
520 case SSH_CHANNEL_LARVAL:
521 if (!compat20)
522 fatal("cannot happen: SSH_CHANNEL_LARVAL");
523 continue;
524 case SSH_CHANNEL_OPENING:
525 case SSH_CHANNEL_OPEN:
526 case SSH_CHANNEL_X11_OPEN:
527 return 1;
528 case SSH_CHANNEL_INPUT_DRAINING:
529 case SSH_CHANNEL_OUTPUT_DRAINING:
530 if (!compat13)
531 fatal("cannot happen: OUT_DRAIN");
532 return 1;
533 default:
534 fatal("channel_still_open: bad channel type %d", c->type);
535 /* NOTREACHED */
536 }
537 }
538 return 0;
539}
540
541/* Returns the id of an open channel suitable for keepaliving */
8e7895b8 542int
d5bb9418 543channel_find_open(void)
8e7895b8 544{
9a995072 545 u_int i;
8e7895b8 546 Channel *c;
547
548 for (i = 0; i < channels_alloc; i++) {
549 c = channels[i];
13de3560 550 if (c == NULL || c->remote_id < 0)
8e7895b8 551 continue;
552 switch (c->type) {
553 case SSH_CHANNEL_CLOSED:
554 case SSH_CHANNEL_DYNAMIC:
555 case SSH_CHANNEL_X11_LISTENER:
556 case SSH_CHANNEL_PORT_LISTENER:
557 case SSH_CHANNEL_RPORT_LISTENER:
558 case SSH_CHANNEL_OPENING:
559 case SSH_CHANNEL_CONNECTING:
560 case SSH_CHANNEL_ZOMBIE:
561 continue;
562 case SSH_CHANNEL_LARVAL:
563 case SSH_CHANNEL_AUTH_SOCKET:
564 case SSH_CHANNEL_OPEN:
565 case SSH_CHANNEL_X11_OPEN:
566 return i;
567 case SSH_CHANNEL_INPUT_DRAINING:
568 case SSH_CHANNEL_OUTPUT_DRAINING:
569 if (!compat13)
570 fatal("cannot happen: OUT_DRAIN");
571 return i;
572 default:
573 fatal("channel_find_open: bad channel type %d", c->type);
574 /* NOTREACHED */
575 }
576 }
577 return -1;
578}
579
580
581/*
582 * Returns a message describing the currently open forwarded connections,
583 * suitable for sending to the client. The message contains crlf pairs for
584 * newlines.
585 */
8e7895b8 586char *
d5bb9418 587channel_open_message(void)
8e7895b8 588{
589 Buffer buffer;
590 Channel *c;
591 char buf[1024], *cp;
9a995072 592 u_int i;
8e7895b8 593
594 buffer_init(&buffer);
595 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
596 buffer_append(&buffer, buf, strlen(buf));
597 for (i = 0; i < channels_alloc; i++) {
598 c = channels[i];
599 if (c == NULL)
600 continue;
601 switch (c->type) {
602 case SSH_CHANNEL_X11_LISTENER:
603 case SSH_CHANNEL_PORT_LISTENER:
604 case SSH_CHANNEL_RPORT_LISTENER:
605 case SSH_CHANNEL_CLOSED:
606 case SSH_CHANNEL_AUTH_SOCKET:
607 case SSH_CHANNEL_ZOMBIE:
608 continue;
609 case SSH_CHANNEL_LARVAL:
610 case SSH_CHANNEL_OPENING:
611 case SSH_CHANNEL_CONNECTING:
612 case SSH_CHANNEL_DYNAMIC:
613 case SSH_CHANNEL_OPEN:
614 case SSH_CHANNEL_X11_OPEN:
615 case SSH_CHANNEL_INPUT_DRAINING:
616 case SSH_CHANNEL_OUTPUT_DRAINING:
5e96b616 617 snprintf(buf, sizeof buf,
618 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
8e7895b8 619 c->self, c->remote_name,
620 c->type, c->remote_id,
621 c->istate, buffer_len(&c->input),
622 c->ostate, buffer_len(&c->output),
5e96b616 623 c->rfd, c->wfd, c->ctl_fd);
8e7895b8 624 buffer_append(&buffer, buf, strlen(buf));
625 continue;
626 default:
627 fatal("channel_open_message: bad channel type %d", c->type);
628 /* NOTREACHED */
629 }
630 }
631 buffer_append(&buffer, "\0", 1);
632 cp = xstrdup(buffer_ptr(&buffer));
633 buffer_free(&buffer);
634 return cp;
635}
636
637void
638channel_send_open(int id)
639{
640 Channel *c = channel_lookup(id);
e1feb9bf 641
8e7895b8 642 if (c == NULL) {
bbe88b6d 643 logit("channel_send_open: %d: bad id", id);
8e7895b8 644 return;
645 }
6226a8f8 646 debug2("channel %d: send open", id);
8e7895b8 647 packet_start(SSH2_MSG_CHANNEL_OPEN);
648 packet_put_cstring(c->ctype);
649 packet_put_int(c->self);
650 packet_put_int(c->local_window);
651 packet_put_int(c->local_maxpacket);
652 packet_send();
653}
654
655void
6226a8f8 656channel_request_start(int id, char *service, int wantconfirm)
8e7895b8 657{
6226a8f8 658 Channel *c = channel_lookup(id);
e1feb9bf 659
8e7895b8 660 if (c == NULL) {
bbe88b6d 661 logit("channel_request_start: %d: unknown channel id", id);
8e7895b8 662 return;
663 }
5e96b616 664 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
8e7895b8 665 packet_start(SSH2_MSG_CHANNEL_REQUEST);
666 packet_put_int(c->remote_id);
667 packet_put_cstring(service);
668 packet_put_char(wantconfirm);
669}
a7137f6b 670
8e7895b8 671void
3593bdc0 672channel_register_status_confirm(int id, channel_confirm_cb *cb,
673 channel_confirm_abandon_cb *abandon_cb, void *ctx)
674{
675 struct channel_confirm *cc;
676 Channel *c;
677
678 if ((c = channel_lookup(id)) == NULL)
679 fatal("channel_register_expect: %d: bad id", id);
680
681 cc = xmalloc(sizeof(*cc));
682 cc->cb = cb;
683 cc->abandon_cb = abandon_cb;
684 cc->ctx = ctx;
685 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
686}
687
688void
689channel_register_open_confirm(int id, channel_callback_fn *fn, void *ctx)
8e7895b8 690{
691 Channel *c = channel_lookup(id);
e1feb9bf 692
8e7895b8 693 if (c == NULL) {
2ea438c2 694 logit("channel_register_open_confirm: %d: bad id", id);
8e7895b8 695 return;
696 }
3593bdc0 697 c->open_confirm = fn;
698 c->open_confirm_ctx = ctx;
8e7895b8 699}
a7137f6b 700
8e7895b8 701void
8cd0437d 702channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
8e7895b8 703{
b872f7f0 704 Channel *c = channel_by_id(id);
e1feb9bf 705
8e7895b8 706 if (c == NULL) {
bbe88b6d 707 logit("channel_register_cleanup: %d: bad id", id);
8e7895b8 708 return;
709 }
3cf2be58 710 c->detach_user = fn;
8cd0437d 711 c->detach_close = do_close;
8e7895b8 712}
a7137f6b 713
8e7895b8 714void
715channel_cancel_cleanup(int id)
716{
b872f7f0 717 Channel *c = channel_by_id(id);
e1feb9bf 718
8e7895b8 719 if (c == NULL) {
bbe88b6d 720 logit("channel_cancel_cleanup: %d: bad id", id);
8e7895b8 721 return;
722 }
3cf2be58 723 c->detach_user = NULL;
8cd0437d 724 c->detach_close = 0;
8e7895b8 725}
a7137f6b 726
8e7895b8 727void
c1c6a032 728channel_register_filter(int id, channel_infilter_fn *ifn,
e74caf1e 729 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
8e7895b8 730{
731 Channel *c = channel_lookup(id);
e1feb9bf 732
8e7895b8 733 if (c == NULL) {
bbe88b6d 734 logit("channel_register_filter: %d: bad id", id);
8e7895b8 735 return;
736 }
c1c6a032 737 c->input_filter = ifn;
738 c->output_filter = ofn;
f17f705b 739 c->filter_ctx = ctx;
e74caf1e 740 c->filter_cleanup = cfn;
8e7895b8 741}
742
6ae2364d 743void
8e7895b8 744channel_set_fds(int id, int rfd, int wfd, int efd,
b3784859 745 int extusage, int nonblock, int is_tty, u_int window_max)
8efc0c15 746{
8e7895b8 747 Channel *c = channel_lookup(id);
e1feb9bf 748
8e7895b8 749 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
750 fatal("channel_activate for non-larval channel %d.", id);
b3784859 751 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
8e7895b8 752 c->type = SSH_CHANNEL_OPEN;
399d1ea6 753 c->local_window = c->local_window_max = window_max;
8e7895b8 754 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
755 packet_put_int(c->remote_id);
756 packet_put_int(c->local_window);
757 packet_send();
8efc0c15 758}
759
aa3378df 760/*
7368a6c8 761 * 'channel_pre*' are called just before select() to add any bits relevant to
762 * channels in the select bitmasks.
aa3378df 763 */
7368a6c8 764/*
765 * 'channel_post*': perform any appropriate operations for channels which
766 * have events pending.
767 */
c8e9c167 768typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
7368a6c8 769chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
770chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
8efc0c15 771
ebb90778 772/* ARGSUSED */
396c147e 773static void
c8e9c167 774channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
8efc0c15 775{
7368a6c8 776 FD_SET(c->sock, readset);
777}
5260325f 778
ebb90778 779/* ARGSUSED */
396c147e 780static void
c8e9c167 781channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
97fb6912 782{
783 debug3("channel %d: waiting for connection", c->self);
784 FD_SET(c->sock, writeset);
785}
786
396c147e 787static void
c8e9c167 788channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 789{
790 if (buffer_len(&c->input) < packet_get_maxsize())
791 FD_SET(c->sock, readset);
792 if (buffer_len(&c->output) > 0)
793 FD_SET(c->sock, writeset);
794}
5260325f 795
396c147e 796static void
c8e9c167 797channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 798{
0c0738d5 799 u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
5260325f 800
7e7327a1 801 if (c->istate == CHAN_INPUT_OPEN &&
0c0738d5 802 limit > 0 &&
69d9d413 803 buffer_len(&c->input) < limit &&
804 buffer_check_alloc(&c->input, CHAN_RBUF))
7e7327a1 805 FD_SET(c->rfd, readset);
806 if (c->ostate == CHAN_OUTPUT_OPEN ||
807 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
808 if (buffer_len(&c->output) > 0) {
809 FD_SET(c->wfd, writeset);
810 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
d2296ed7 811 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
4e2e5cfd 812 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
813 c->self, c->efd, buffer_len(&c->extended));
d2296ed7 814 else
815 chan_obuf_empty(c);
7e7327a1 816 }
817 }
818 /** XXX check close conditions, too */
271f4a13 819 if (compat20 && c->efd != -1 &&
820 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
7e7327a1 821 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
822 buffer_len(&c->extended) > 0)
823 FD_SET(c->efd, writeset);
d2296ed7 824 else if (!(c->flags & CHAN_EOF_SENT) &&
825 c->extended_usage == CHAN_EXTENDED_READ &&
7e7327a1 826 buffer_len(&c->extended) < c->remote_window)
827 FD_SET(c->efd, readset);
828 }
5e96b616 829 /* XXX: What about efd? races? */
f2107e97 830 if (compat20 && c->ctl_fd != -1 &&
5e96b616 831 c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
832 FD_SET(c->ctl_fd, readset);
7e7327a1 833}
834
ebb90778 835/* ARGSUSED */
396c147e 836static void
c8e9c167 837channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 838{
839 if (buffer_len(&c->input) == 0) {
840 packet_start(SSH_MSG_CHANNEL_CLOSE);
841 packet_put_int(c->remote_id);
842 packet_send();
843 c->type = SSH_CHANNEL_CLOSED;
d7ac5f18 844 debug2("channel %d: closing after input drain.", c->self);
7368a6c8 845 }
846}
5260325f 847
ebb90778 848/* ARGSUSED */
396c147e 849static void
c8e9c167 850channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 851{
852 if (buffer_len(&c->output) == 0)
719fc62f 853 chan_mark_dead(c);
6ae2364d 854 else
7368a6c8 855 FD_SET(c->sock, writeset);
856}
5260325f 857
7368a6c8 858/*
859 * This is a special state for X11 authentication spoofing. An opened X11
860 * connection (when authentication spoofing is being done) remains in this
861 * state until the first packet has been completely read. The authentication
862 * data in that packet is then substituted by the real data if it matches the
863 * fake data, and the channel is put into normal mode.
0b242b12 864 * XXX All this happens at the client side.
8e7895b8 865 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
7368a6c8 866 */
396c147e 867static int
8e7895b8 868x11_open_helper(Buffer *b)
7368a6c8 869{
1e3b8b07 870 u_char *ucp;
871 u_int proto_len, data_len;
5260325f 872
7368a6c8 873 /* Check if the fixed size part of the packet is in buffer. */
8e7895b8 874 if (buffer_len(b) < 12)
7368a6c8 875 return 0;
876
877 /* Parse the lengths of variable-length fields. */
20905a8e 878 ucp = buffer_ptr(b);
7368a6c8 879 if (ucp[0] == 0x42) { /* Byte order MSB first. */
880 proto_len = 256 * ucp[6] + ucp[7];
881 data_len = 256 * ucp[8] + ucp[9];
882 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
883 proto_len = ucp[6] + 256 * ucp[7];
884 data_len = ucp[8] + 256 * ucp[9];
885 } else {
d7ac5f18 886 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
184eed6a 887 ucp[0]);
7368a6c8 888 return -1;
889 }
5260325f 890
7368a6c8 891 /* Check if the whole packet is in buffer. */
8e7895b8 892 if (buffer_len(b) <
7368a6c8 893 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
894 return 0;
5260325f 895
7368a6c8 896 /* Check if authentication protocol matches. */
897 if (proto_len != strlen(x11_saved_proto) ||
898 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
d7ac5f18 899 debug2("X11 connection uses different authentication protocol.");
7368a6c8 900 return -1;
901 }
902 /* Check if authentication data matches our fake data. */
903 if (data_len != x11_fake_data_len ||
904 memcmp(ucp + 12 + ((proto_len + 3) & ~3),
905 x11_fake_data, x11_fake_data_len) != 0) {
d7ac5f18 906 debug2("X11 auth data does not match fake data.");
7368a6c8 907 return -1;
908 }
909 /* Check fake data length */
910 if (x11_fake_data_len != x11_saved_data_len) {
911 error("X11 fake_data_len %d != saved_data_len %d",
912 x11_fake_data_len, x11_saved_data_len);
913 return -1;
914 }
915 /*
916 * Received authentication protocol and data match
917 * our fake data. Substitute the fake data with real
918 * data.
919 */
920 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
921 x11_saved_data, x11_saved_data_len);
922 return 1;
923}
5260325f 924
396c147e 925static void
c8e9c167 926channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 927{
8e7895b8 928 int ret = x11_open_helper(&c->output);
e1feb9bf 929
7368a6c8 930 if (ret == 1) {
931 /* Start normal processing for the channel. */
932 c->type = SSH_CHANNEL_OPEN;
a8be9f80 933 channel_pre_open_13(c, readset, writeset);
7368a6c8 934 } else if (ret == -1) {
935 /*
936 * We have received an X11 connection that has bad
937 * authentication information.
938 */
bbe88b6d 939 logit("X11 connection rejected because of wrong authentication.");
7368a6c8 940 buffer_clear(&c->input);
941 buffer_clear(&c->output);
489aa2e9 942 channel_close_fd(&c->sock);
7368a6c8 943 c->sock = -1;
944 c->type = SSH_CHANNEL_CLOSED;
945 packet_start(SSH_MSG_CHANNEL_CLOSE);
946 packet_put_int(c->remote_id);
947 packet_send();
948 }
949}
5260325f 950
396c147e 951static void
c8e9c167 952channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 953{
8e7895b8 954 int ret = x11_open_helper(&c->output);
a5f82435 955
956 /* c->force_drain = 1; */
957
7368a6c8 958 if (ret == 1) {
959 c->type = SSH_CHANNEL_OPEN;
0c0738d5 960 channel_pre_open(c, readset, writeset);
7368a6c8 961 } else if (ret == -1) {
bbe88b6d 962 logit("X11 connection rejected because of wrong authentication.");
d7ac5f18 963 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
8341f420 964 chan_read_failed(c);
965 buffer_clear(&c->input);
966 chan_ibuf_empty(c);
967 buffer_clear(&c->output);
968 /* for proto v1, the peer will send an IEOF */
969 if (compat20)
970 chan_write_failed(c);
971 else
972 c->type = SSH_CHANNEL_OPEN;
d7ac5f18 973 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
7368a6c8 974 }
975}
5260325f 976
28b9cb4d 977/* try to decode a socks4 header */
ebb90778 978/* ARGSUSED */
396c147e 979static int
c8e9c167 980channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
0490e609 981{
661e45a0 982 char *p, *host;
4866a6d6 983 u_int len, have, i, found, need;
184eed6a 984 char username[256];
0490e609 985 struct {
986 u_int8_t version;
987 u_int8_t command;
988 u_int16_t dest_port;
28b9cb4d 989 struct in_addr dest_addr;
0490e609 990 } s4_req, s4_rsp;
991
28b9cb4d 992 debug2("channel %d: decode socks4", c->self);
53b8fe68 993
994 have = buffer_len(&c->input);
995 len = sizeof(s4_req);
996 if (have < len)
997 return 0;
998 p = buffer_ptr(&c->input);
4866a6d6 999
1000 need = 1;
1001 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1002 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1003 debug2("channel %d: socks4a request", c->self);
1004 /* ... and needs an extra string (the hostname) */
1005 need = 2;
1006 }
1007 /* Check for terminating NUL on the string(s) */
53b8fe68 1008 for (found = 0, i = len; i < have; i++) {
1009 if (p[i] == '\0') {
4866a6d6 1010 found++;
1011 if (found == need)
1012 break;
53b8fe68 1013 }
1014 if (i > 1024) {
1015 /* the peer is probably sending garbage */
1016 debug("channel %d: decode socks4: too long",
1017 c->self);
1018 return -1;
1019 }
1020 }
4866a6d6 1021 if (found < need)
53b8fe68 1022 return 0;
0490e609 1023 buffer_get(&c->input, (char *)&s4_req.version, 1);
1024 buffer_get(&c->input, (char *)&s4_req.command, 1);
1025 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
28b9cb4d 1026 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
53b8fe68 1027 have = buffer_len(&c->input);
0490e609 1028 p = buffer_ptr(&c->input);
1029 len = strlen(p);
6683b40f 1030 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
4866a6d6 1031 len++; /* trailing '\0' */
0490e609 1032 if (len > have)
28b9cb4d 1033 fatal("channel %d: decode socks4: len %d > have %d",
0490e609 1034 c->self, len, have);
1035 strlcpy(username, p, sizeof(username));
1036 buffer_consume(&c->input, len);
0490e609 1037
4866a6d6 1038 if (need == 1) { /* SOCKS4: one string */
1039 host = inet_ntoa(s4_req.dest_addr);
1040 strlcpy(c->path, host, sizeof(c->path));
1041 } else { /* SOCKS4A: two strings */
1042 have = buffer_len(&c->input);
1043 p = buffer_ptr(&c->input);
1044 len = strlen(p);
1045 debug2("channel %d: decode socks4a: host %s/%d",
1046 c->self, p, len);
1047 len++; /* trailing '\0' */
1048 if (len > have)
1049 fatal("channel %d: decode socks4a: len %d > have %d",
1050 c->self, len, have);
1051 if (strlcpy(c->path, p, sizeof(c->path)) >= sizeof(c->path)) {
1052 error("channel %d: hostname \"%.100s\" too long",
1053 c->self, p);
1054 return -1;
1055 }
1056 buffer_consume(&c->input, len);
1057 }
0490e609 1058 c->host_port = ntohs(s4_req.dest_port);
184eed6a 1059
d7ac5f18 1060 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
4866a6d6 1061 c->self, c->path, c->host_port, s4_req.command);
0490e609 1062
28b9cb4d 1063 if (s4_req.command != 1) {
4866a6d6 1064 debug("channel %d: cannot handle: %s cn %d",
1065 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
28b9cb4d 1066 return -1;
0490e609 1067 }
28b9cb4d 1068 s4_rsp.version = 0; /* vn: 0 for reply */
1069 s4_rsp.command = 90; /* cd: req granted */
0490e609 1070 s4_rsp.dest_port = 0; /* ignored */
28b9cb4d 1071 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
15dd2c4f 1072 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
28b9cb4d 1073 return 1;
0490e609 1074}
1075
f49658f5 1076/* try to decode a socks5 header */
1077#define SSH_SOCKS5_AUTHDONE 0x1000
1078#define SSH_SOCKS5_NOAUTH 0x00
1079#define SSH_SOCKS5_IPV4 0x01
1080#define SSH_SOCKS5_DOMAIN 0x03
1081#define SSH_SOCKS5_IPV6 0x04
1082#define SSH_SOCKS5_CONNECT 0x01
1083#define SSH_SOCKS5_SUCCESS 0x00
1084
ebb90778 1085/* ARGSUSED */
f49658f5 1086static int
c8e9c167 1087channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
f49658f5 1088{
1089 struct {
1090 u_int8_t version;
1091 u_int8_t command;
1092 u_int8_t reserved;
1093 u_int8_t atyp;
1094 } s5_req, s5_rsp;
1095 u_int16_t dest_port;
1096 u_char *p, dest_addr[255+1];
a217e418 1097 u_int have, need, i, found, nmethods, addrlen, af;
f49658f5 1098
1099 debug2("channel %d: decode socks5", c->self);
1100 p = buffer_ptr(&c->input);
1101 if (p[0] != 0x05)
1102 return -1;
1103 have = buffer_len(&c->input);
1104 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1105 /* format: ver | nmethods | methods */
aff51935 1106 if (have < 2)
f49658f5 1107 return 0;
1108 nmethods = p[1];
1109 if (have < nmethods + 2)
1110 return 0;
1111 /* look for method: "NO AUTHENTICATION REQUIRED" */
4f6e2ba9 1112 for (found = 0, i = 2; i < nmethods + 2; i++) {
d4f40d92 1113 if (p[i] == SSH_SOCKS5_NOAUTH) {
f49658f5 1114 found = 1;
1115 break;
1116 }
1117 }
1118 if (!found) {
1119 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1120 c->self);
1121 return -1;
1122 }
1123 buffer_consume(&c->input, nmethods + 2);
1124 buffer_put_char(&c->output, 0x05); /* version */
1125 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1126 FD_SET(c->sock, writeset);
1127 c->flags |= SSH_SOCKS5_AUTHDONE;
1128 debug2("channel %d: socks5 auth done", c->self);
1129 return 0; /* need more */
1130 }
1131 debug2("channel %d: socks5 post auth", c->self);
1132 if (have < sizeof(s5_req)+1)
1133 return 0; /* need more */
5b5f6af7 1134 memcpy(&s5_req, p, sizeof(s5_req));
f49658f5 1135 if (s5_req.version != 0x05 ||
1136 s5_req.command != SSH_SOCKS5_CONNECT ||
1137 s5_req.reserved != 0x00) {
d7ac5f18 1138 debug2("channel %d: only socks5 connect supported", c->self);
f49658f5 1139 return -1;
1140 }
f8cc7664 1141 switch (s5_req.atyp){
f49658f5 1142 case SSH_SOCKS5_IPV4:
1143 addrlen = 4;
1144 af = AF_INET;
1145 break;
1146 case SSH_SOCKS5_DOMAIN:
1147 addrlen = p[sizeof(s5_req)];
1148 af = -1;
1149 break;
1150 case SSH_SOCKS5_IPV6:
1151 addrlen = 16;
1152 af = AF_INET6;
1153 break;
1154 default:
d7ac5f18 1155 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
f49658f5 1156 return -1;
1157 }
a217e418 1158 need = sizeof(s5_req) + addrlen + 2;
1159 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1160 need++;
1161 if (have < need)
f49658f5 1162 return 0;
1163 buffer_consume(&c->input, sizeof(s5_req));
1164 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1165 buffer_consume(&c->input, 1); /* host string length */
1166 buffer_get(&c->input, (char *)&dest_addr, addrlen);
1167 buffer_get(&c->input, (char *)&dest_port, 2);
1168 dest_addr[addrlen] = '\0';
1169 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
f6be21a0 1170 strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
f49658f5 1171 else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1172 return -1;
1173 c->host_port = ntohs(dest_port);
b6453d99 1174
d7ac5f18 1175 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
f49658f5 1176 c->self, c->path, c->host_port, s5_req.command);
1177
1178 s5_rsp.version = 0x05;
1179 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1180 s5_rsp.reserved = 0; /* ignored */
1181 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1182 ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1183 dest_port = 0; /* ignored */
1184
15dd2c4f 1185 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1186 buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1187 buffer_append(&c->output, &dest_port, sizeof(dest_port));
f49658f5 1188 return 1;
1189}
1190
28b9cb4d 1191/* dynamic port forwarding */
396c147e 1192static void
c8e9c167 1193channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
28b9cb4d 1194{
1195 u_char *p;
2ceb8101 1196 u_int have;
1197 int ret;
28b9cb4d 1198
1199 have = buffer_len(&c->input);
639cb8ab 1200 c->delayed = 0;
28b9cb4d 1201 debug2("channel %d: pre_dynamic: have %d", c->self, have);
070adba2 1202 /* buffer_dump(&c->input); */
28b9cb4d 1203 /* check if the fixed size part of the packet is in buffer. */
f49658f5 1204 if (have < 3) {
28b9cb4d 1205 /* need more */
1206 FD_SET(c->sock, readset);
1207 return;
1208 }
1209 /* try to guess the protocol */
1210 p = buffer_ptr(&c->input);
1211 switch (p[0]) {
6683b40f 1212 case 0x04:
1213 ret = channel_decode_socks4(c, readset, writeset);
1214 break;
f49658f5 1215 case 0x05:
1216 ret = channel_decode_socks5(c, readset, writeset);
1217 break;
28b9cb4d 1218 default:
1219 ret = -1;
1220 break;
1221 }
1222 if (ret < 0) {
719fc62f 1223 chan_mark_dead(c);
28b9cb4d 1224 } else if (ret == 0) {
1225 debug2("channel %d: pre_dynamic: need more", c->self);
1226 /* need more */
1227 FD_SET(c->sock, readset);
1228 } else {
1229 /* switch to the next state */
1230 c->type = SSH_CHANNEL_OPENING;
1231 port_open_helper(c, "direct-tcpip");
1232 }
1233}
0490e609 1234
7368a6c8 1235/* This is our fake X11 server socket. */
ebb90778 1236/* ARGSUSED */
396c147e 1237static void
c8e9c167 1238channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1239{
719fc62f 1240 Channel *nc;
9fb764ab 1241 struct sockaddr_storage addr;
bcc0381e 1242 int newsock;
7368a6c8 1243 socklen_t addrlen;
865ac82e 1244 char buf[16384], *remote_ipaddr;
0b242b12 1245 int remote_port;
7368a6c8 1246
1247 if (FD_ISSET(c->sock, readset)) {
1248 debug("X11 connection requested.");
1249 addrlen = sizeof(addr);
9fb764ab 1250 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
ac151b18 1251 if (c->single_connection) {
d7ac5f18 1252 debug2("single_connection: closing X11 listener.");
ac151b18 1253 channel_close_fd(&c->sock);
1254 chan_mark_dead(c);
1255 }
7368a6c8 1256 if (newsock < 0) {
1257 error("accept: %.100s", strerror(errno));
1258 return;
5260325f 1259 }
bcc0381e 1260 set_nodelay(newsock);
865ac82e 1261 remote_ipaddr = get_peer_ipaddr(newsock);
0b242b12 1262 remote_port = get_peer_port(newsock);
7368a6c8 1263 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
865ac82e 1264 remote_ipaddr, remote_port);
0b242b12 1265
719fc62f 1266 nc = channel_new("accepted x11 socket",
0b242b12 1267 SSH_CHANNEL_OPENING, newsock, newsock, -1,
0d942eff 1268 c->local_window_max, c->local_maxpacket, 0, buf, 1);
0b242b12 1269 if (compat20) {
1270 packet_start(SSH2_MSG_CHANNEL_OPEN);
1271 packet_put_cstring("x11");
719fc62f 1272 packet_put_int(nc->self);
ac151b18 1273 packet_put_int(nc->local_window_max);
1274 packet_put_int(nc->local_maxpacket);
865ac82e 1275 /* originator ipaddr and port */
1276 packet_put_cstring(remote_ipaddr);
d0c832f3 1277 if (datafellows & SSH_BUG_X11FWD) {
d7ac5f18 1278 debug2("ssh2 x11 bug compat mode");
d0c832f3 1279 } else {
1280 packet_put_int(remote_port);
1281 }
0b242b12 1282 packet_send();
1283 } else {
1284 packet_start(SSH_SMSG_X11_OPEN);
719fc62f 1285 packet_put_int(nc->self);
8e7895b8 1286 if (packet_get_protocol_flags() &
1287 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
449c5ba5 1288 packet_put_cstring(buf);
0b242b12 1289 packet_send();
1290 }
865ac82e 1291 xfree(remote_ipaddr);
8efc0c15 1292 }
8efc0c15 1293}
1294
396c147e 1295static void
0490e609 1296port_open_helper(Channel *c, char *rtype)
1297{
1298 int direct;
1299 char buf[1024];
1300 char *remote_ipaddr = get_peer_ipaddr(c->sock);
29798ed0 1301 int remote_port = get_peer_port(c->sock);
0490e609 1302
1303 direct = (strcmp(rtype, "direct-tcpip") == 0);
1304
1305 snprintf(buf, sizeof buf,
1306 "%s: listening port %d for %.100s port %d, "
1307 "connect from %.200s port %d",
1308 rtype, c->listening_port, c->path, c->host_port,
1309 remote_ipaddr, remote_port);
1310
1311 xfree(c->remote_name);
1312 c->remote_name = xstrdup(buf);
1313
1314 if (compat20) {
1315 packet_start(SSH2_MSG_CHANNEL_OPEN);
1316 packet_put_cstring(rtype);
1317 packet_put_int(c->self);
1318 packet_put_int(c->local_window_max);
1319 packet_put_int(c->local_maxpacket);
1320 if (direct) {
1321 /* target host, port */
1322 packet_put_cstring(c->path);
1323 packet_put_int(c->host_port);
1324 } else {
1325 /* listen address, port */
1326 packet_put_cstring(c->path);
1327 packet_put_int(c->listening_port);
1328 }
1329 /* originator host and port */
1330 packet_put_cstring(remote_ipaddr);
29798ed0 1331 packet_put_int((u_int)remote_port);
0490e609 1332 packet_send();
1333 } else {
1334 packet_start(SSH_MSG_PORT_OPEN);
1335 packet_put_int(c->self);
1336 packet_put_cstring(c->path);
1337 packet_put_int(c->host_port);
8e7895b8 1338 if (packet_get_protocol_flags() &
1339 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
0490e609 1340 packet_put_cstring(c->remote_name);
1341 packet_send();
1342 }
1343 xfree(remote_ipaddr);
1344}
1345
442aee3a 1346static void
1347channel_set_reuseaddr(int fd)
1348{
1349 int on = 1;
1350
1351 /*
1352 * Set socket options.
1353 * Allow local port reuse in TIME_WAIT.
1354 */
1355 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1356 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1357}
1358
aa3378df 1359/*
7368a6c8 1360 * This socket is listening for connections to a forwarded TCP/IP port.
aa3378df 1361 */
ebb90778 1362/* ARGSUSED */
396c147e 1363static void
c8e9c167 1364channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1365{
0490e609 1366 Channel *nc;
9fb764ab 1367 struct sockaddr_storage addr;
719fc62f 1368 int newsock, nextstate;
7368a6c8 1369 socklen_t addrlen;
0490e609 1370 char *rtype;
fa08c86b 1371
7368a6c8 1372 if (FD_ISSET(c->sock, readset)) {
1373 debug("Connection to port %d forwarding "
1374 "to %.100s port %d requested.",
1375 c->listening_port, c->path, c->host_port);
0490e609 1376
639cb8ab 1377 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1378 nextstate = SSH_CHANNEL_OPENING;
1379 rtype = "forwarded-tcpip";
1380 } else {
1381 if (c->host_port == 0) {
1382 nextstate = SSH_CHANNEL_DYNAMIC;
f3964cb9 1383 rtype = "dynamic-tcpip";
639cb8ab 1384 } else {
1385 nextstate = SSH_CHANNEL_OPENING;
1386 rtype = "direct-tcpip";
1387 }
1388 }
0490e609 1389
7368a6c8 1390 addrlen = sizeof(addr);
9fb764ab 1391 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
7368a6c8 1392 if (newsock < 0) {
1393 error("accept: %.100s", strerror(errno));
1394 return;
1395 }
811a6342 1396 set_nodelay(newsock);
0d942eff 1397 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1398 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
0490e609 1399 nc->listening_port = c->listening_port;
1400 nc->host_port = c->host_port;
1401 strlcpy(nc->path, c->path, sizeof(nc->path));
1402
639cb8ab 1403 if (nextstate == SSH_CHANNEL_DYNAMIC) {
1404 /*
1405 * do not call the channel_post handler until
1406 * this flag has been reset by a pre-handler.
1407 * otherwise the FD_ISSET calls might overflow
1408 */
1409 nc->delayed = 1;
1410 } else {
0490e609 1411 port_open_helper(nc, rtype);
639cb8ab 1412 }
7368a6c8 1413 }
1414}
8efc0c15 1415
7368a6c8 1416/*
1417 * This is the authentication agent socket listening for connections from
1418 * clients.
1419 */
ebb90778 1420/* ARGSUSED */
396c147e 1421static void
c8e9c167 1422channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
8efc0c15 1423{
719fc62f 1424 Channel *nc;
1425 int newsock;
9fb764ab 1426 struct sockaddr_storage addr;
48e671d5 1427 socklen_t addrlen;
5260325f 1428
7368a6c8 1429 if (FD_ISSET(c->sock, readset)) {
1430 addrlen = sizeof(addr);
9fb764ab 1431 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
7368a6c8 1432 if (newsock < 0) {
1433 error("accept from auth socket: %.100s", strerror(errno));
1434 return;
1435 }
719fc62f 1436 nc = channel_new("accepted auth socket",
fa08c86b 1437 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1438 c->local_window_max, c->local_maxpacket,
0d942eff 1439 0, "accepted auth socket", 1);
fa08c86b 1440 if (compat20) {
1441 packet_start(SSH2_MSG_CHANNEL_OPEN);
1442 packet_put_cstring("auth-agent@openssh.com");
719fc62f 1443 packet_put_int(nc->self);
fa08c86b 1444 packet_put_int(c->local_window_max);
1445 packet_put_int(c->local_maxpacket);
1446 } else {
1447 packet_start(SSH_SMSG_AGENT_OPEN);
719fc62f 1448 packet_put_int(nc->self);
fa08c86b 1449 }
7368a6c8 1450 packet_send();
1451 }
1452}
5260325f 1453
ebb90778 1454/* ARGSUSED */
396c147e 1455static void
c8e9c167 1456channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
97fb6912 1457{
e07e21ad 1458 int err = 0, sock;
8ab2cb35 1459 socklen_t sz = sizeof(err);
d18e0850 1460
97fb6912 1461 if (FD_ISSET(c->sock, writeset)) {
db518d9b 1462 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
d18e0850 1463 err = errno;
1464 error("getsockopt SO_ERROR failed");
1465 }
1466 if (err == 0) {
e07e21ad 1467 debug("channel %d: connected to %s port %d",
1468 c->self, c->connect_ctx.host, c->connect_ctx.port);
1469 channel_connect_ctx_free(&c->connect_ctx);
d18e0850 1470 c->type = SSH_CHANNEL_OPEN;
1471 if (compat20) {
1472 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1473 packet_put_int(c->remote_id);
1474 packet_put_int(c->self);
1475 packet_put_int(c->local_window);
1476 packet_put_int(c->local_maxpacket);
1477 } else {
1478 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1479 packet_put_int(c->remote_id);
1480 packet_put_int(c->self);
1481 }
97fb6912 1482 } else {
e07e21ad 1483 debug("channel %d: connection failed: %s",
d18e0850 1484 c->self, strerror(err));
e07e21ad 1485 /* Try next address, if any */
1486 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1487 close(c->sock);
1488 c->sock = c->rfd = c->wfd = sock;
1489 channel_max_fd = channel_find_maxfd();
1490 return;
1491 }
1492 /* Exhausted all addresses */
1493 error("connect_to %.100s port %d: failed.",
1494 c->connect_ctx.host, c->connect_ctx.port);
1495 channel_connect_ctx_free(&c->connect_ctx);
d18e0850 1496 if (compat20) {
1497 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1498 packet_put_int(c->remote_id);
1499 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1500 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1501 packet_put_cstring(strerror(err));
1502 packet_put_cstring("");
1503 }
97fb6912 1504 } else {
d18e0850 1505 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1506 packet_put_int(c->remote_id);
97fb6912 1507 }
d18e0850 1508 chan_mark_dead(c);
97fb6912 1509 }
d18e0850 1510 packet_send();
97fb6912 1511 }
1512}
1513
ebb90778 1514/* ARGSUSED */
396c147e 1515static int
c8e9c167 1516channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1517{
fa1d7d85 1518 char buf[CHAN_RBUF];
bd6a1355 1519 int len, force;
7368a6c8 1520
bd6a1355 1521 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1522 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
ea8c44d9 1523 errno = 0;
7368a6c8 1524 len = read(c->rfd, buf, sizeof(buf));
5a0c8771 1525 if (len < 0 && (errno == EINTR ||
1526 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
0fbe8c74 1527 return 1;
ea8c44d9 1528#ifndef PTY_ZEROREAD
7368a6c8 1529 if (len <= 0) {
ea8c44d9 1530#else
9c04d67d 1531 if ((!c->isatty && len <= 0) ||
1532 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
ea8c44d9 1533#endif
d7ac5f18 1534 debug2("channel %d: read<=0 rfd %d len %d",
7368a6c8 1535 c->self, c->rfd, len);
28b9cb4d 1536 if (c->type != SSH_CHANNEL_OPEN) {
d7ac5f18 1537 debug2("channel %d: not open", c->self);
719fc62f 1538 chan_mark_dead(c);
0490e609 1539 return -1;
28b9cb4d 1540 } else if (compat13) {
9c50edcf 1541 buffer_clear(&c->output);
7368a6c8 1542 c->type = SSH_CHANNEL_INPUT_DRAINING;
d7ac5f18 1543 debug2("channel %d: input draining.", c->self);
7368a6c8 1544 } else {
1545 chan_read_failed(c);
5260325f 1546 }
7368a6c8 1547 return -1;
1548 }
6aacefa7 1549 if (c->input_filter != NULL) {
2e73a022 1550 if (c->input_filter(c, buf, len) == -1) {
d7ac5f18 1551 debug2("channel %d: filter stops", c->self);
2e73a022 1552 chan_read_failed(c);
1553 }
d20f3c9e 1554 } else if (c->datagram) {
1555 buffer_put_string(&c->input, buf, len);
2e73a022 1556 } else {
1557 buffer_append(&c->input, buf, len);
1558 }
7368a6c8 1559 }
1560 return 1;
1561}
a7137f6b 1562
ebb90778 1563/* ARGSUSED */
396c147e 1564static int
c8e9c167 1565channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1566{
95ce5599 1567 struct termios tio;
c1c6a032 1568 u_char *data = NULL, *buf;
780a9951 1569 u_int dlen;
7368a6c8 1570 int len;
1571
1572 /* Send buffered output data to the socket. */
6fd8622b 1573 if (c->wfd != -1 &&
7368a6c8 1574 FD_ISSET(c->wfd, writeset) &&
1575 buffer_len(&c->output) > 0) {
c1c6a032 1576 if (c->output_filter != NULL) {
1577 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1578 debug2("channel %d: filter stops", c->self);
d7b37427 1579 if (c->type != SSH_CHANNEL_OPEN)
1580 chan_mark_dead(c);
1581 else
1582 chan_write_failed(c);
1583 return -1;
c1c6a032 1584 }
1585 } else if (c->datagram) {
1586 buf = data = buffer_get_string(&c->output, &dlen);
1587 } else {
1588 buf = data = buffer_ptr(&c->output);
1589 dlen = buffer_len(&c->output);
1590 }
1591
d20f3c9e 1592 if (c->datagram) {
d20f3c9e 1593 /* ignore truncated writes, datagrams might get lost */
1594 c->local_consumed += dlen + 4;
c1c6a032 1595 len = write(c->wfd, buf, dlen);
d20f3c9e 1596 xfree(data);
5a0c8771 1597 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1598 errno == EWOULDBLOCK))
d20f3c9e 1599 return 1;
1600 if (len <= 0) {
1601 if (c->type != SSH_CHANNEL_OPEN)
1602 chan_mark_dead(c);
1603 else
1604 chan_write_failed(c);
1605 return -1;
1606 }
1607 return 1;
1608 }
64c0ce80 1609#ifdef _AIX
aff51935 1610 /* XXX: Later AIX versions can't push as much data to tty */
7fbb4189 1611 if (compat20 && c->wfd_isatty)
1612 dlen = MIN(dlen, 8*1024);
64c0ce80 1613#endif
c1c6a032 1614
1615 len = write(c->wfd, buf, dlen);
5a0c8771 1616 if (len < 0 &&
1617 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
0fbe8c74 1618 return 1;
7368a6c8 1619 if (len <= 0) {
28b9cb4d 1620 if (c->type != SSH_CHANNEL_OPEN) {
d7ac5f18 1621 debug2("channel %d: not open", c->self);
719fc62f 1622 chan_mark_dead(c);
28b9cb4d 1623 return -1;
1624 } else if (compat13) {
9c50edcf 1625 buffer_clear(&c->output);
d7ac5f18 1626 debug2("channel %d: input draining.", c->self);
7368a6c8 1627 c->type = SSH_CHANNEL_INPUT_DRAINING;
1628 } else {
1629 chan_write_failed(c);
5260325f 1630 }
7368a6c8 1631 return -1;
1632 }
c1c6a032 1633 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
0ae4fe1d 1634 if (tcgetattr(c->wfd, &tio) == 0 &&
1635 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1636 /*
1637 * Simulate echo to reduce the impact of
355724fc 1638 * traffic analysis. We need to match the
95ce5599 1639 * size of a SSH2_MSG_CHANNEL_DATA message
c1c6a032 1640 * (4 byte channel id + buf)
0ae4fe1d 1641 */
95ce5599 1642 packet_send_ignore(4 + len);
0ae4fe1d 1643 packet_send();
0ae4fe1d 1644 }
1645 }
7368a6c8 1646 buffer_consume(&c->output, len);
7e7327a1 1647 if (compat20 && len > 0) {
1648 c->local_consumed += len;
1649 }
1650 }
1651 return 1;
1652}
a7137f6b 1653
396c147e 1654static int
c8e9c167 1655channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
7e7327a1 1656{
fa1d7d85 1657 char buf[CHAN_RBUF];
7e7327a1 1658 int len;
1659
8ce64345 1660/** XXX handle drain efd, too */
7e7327a1 1661 if (c->efd != -1) {
1662 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1663 FD_ISSET(c->efd, writeset) &&
1664 buffer_len(&c->extended) > 0) {
1665 len = write(c->efd, buffer_ptr(&c->extended),
1666 buffer_len(&c->extended));
de273eef 1667 debug2("channel %d: written %d to efd %d",
7e7327a1 1668 c->self, len, c->efd);
5a0c8771 1669 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1670 errno == EWOULDBLOCK))
ee55dacf 1671 return 1;
1672 if (len <= 0) {
1673 debug2("channel %d: closing write-efd %d",
1674 c->self, c->efd);
489aa2e9 1675 channel_close_fd(&c->efd);
ee55dacf 1676 } else {
7e7327a1 1677 buffer_consume(&c->extended, len);
1678 c->local_consumed += len;
1679 }
1680 } else if (c->extended_usage == CHAN_EXTENDED_READ &&
34640ce6 1681 (c->detach_close || FD_ISSET(c->efd, readset))) {
7e7327a1 1682 len = read(c->efd, buf, sizeof(buf));
de273eef 1683 debug2("channel %d: read %d from efd %d",
184eed6a 1684 c->self, len, c->efd);
5a0c8771 1685 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1686 errno == EWOULDBLOCK) && !c->detach_close)))
ee55dacf 1687 return 1;
1688 if (len <= 0) {
1689 debug2("channel %d: closing read-efd %d",
8ce64345 1690 c->self, c->efd);
489aa2e9 1691 channel_close_fd(&c->efd);
ee55dacf 1692 } else {
7e7327a1 1693 buffer_append(&c->extended, buf, len);
ee55dacf 1694 }
7e7327a1 1695 }
1696 }
1697 return 1;
1698}
a7137f6b 1699
ebb90778 1700/* ARGSUSED */
396c147e 1701static int
c8e9c167 1702channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset)
5e96b616 1703{
1704 char buf[16];
1705 int len;
1706
1707 /* Monitor control fd to detect if the slave client exits */
1708 if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1709 len = read(c->ctl_fd, buf, sizeof(buf));
5a0c8771 1710 if (len < 0 &&
1711 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
5e96b616 1712 return 1;
1713 if (len <= 0) {
1714 debug2("channel %d: ctl read<=0", c->self);
1715 if (c->type != SSH_CHANNEL_OPEN) {
1716 debug2("channel %d: not open", c->self);
1717 chan_mark_dead(c);
1718 return -1;
1719 } else {
1720 chan_read_failed(c);
1721 chan_write_failed(c);
1722 }
1723 return -1;
1724 } else
1725 fatal("%s: unexpected data on ctl fd", __func__);
1726 }
1727 return 1;
1728}
a7137f6b 1729
5e96b616 1730static int
ee55dacf 1731channel_check_window(Channel *c)
7e7327a1 1732{
28b9cb4d 1733 if (c->type == SSH_CHANNEL_OPEN &&
1734 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
d9245683 1735 ((c->local_window_max - c->local_window >
68a73f53 1736 c->local_maxpacket*3) ||
1737 c->local_window < c->local_window_max/2) &&
7e7327a1 1738 c->local_consumed > 0) {
1739 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1740 packet_put_int(c->remote_id);
1741 packet_put_int(c->local_consumed);
1742 packet_send();
de273eef 1743 debug2("channel %d: window %d sent adjust %d",
7e7327a1 1744 c->self, c->local_window,
1745 c->local_consumed);
1746 c->local_window += c->local_consumed;
1747 c->local_consumed = 0;
7368a6c8 1748 }
1749 return 1;
1750}
5260325f 1751
396c147e 1752static void
c8e9c167 1753channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1754{
639cb8ab 1755 if (c->delayed)
1756 return;
7368a6c8 1757 channel_handle_rfd(c, readset, writeset);
1758 channel_handle_wfd(c, readset, writeset);
0c0738d5 1759 if (!compat20)
639cb8ab 1760 return;
7e7327a1 1761 channel_handle_efd(c, readset, writeset);
5e96b616 1762 channel_handle_ctl(c, readset, writeset);
ee55dacf 1763 channel_check_window(c);
7e7327a1 1764}
1765
ebb90778 1766/* ARGSUSED */
396c147e 1767static void
c8e9c167 1768channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
7368a6c8 1769{
1770 int len;
e1feb9bf 1771
7368a6c8 1772 /* Send buffered output data to the socket. */
1773 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1774 len = write(c->sock, buffer_ptr(&c->output),
1775 buffer_len(&c->output));
1776 if (len <= 0)
9c50edcf 1777 buffer_clear(&c->output);
7368a6c8 1778 else
1779 buffer_consume(&c->output, len);
1780 }
1781}
5260325f 1782
396c147e 1783static void
7e7327a1 1784channel_handler_init_20(void)
1785{
0c0738d5 1786 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
0b242b12 1787 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
7e7327a1 1788 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
fa08c86b 1789 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
0b242b12 1790 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
fa08c86b 1791 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
97fb6912 1792 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
0490e609 1793 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
7e7327a1 1794
0c0738d5 1795 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
7e7327a1 1796 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
fa08c86b 1797 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
0b242b12 1798 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
fa08c86b 1799 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
97fb6912 1800 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
0c0738d5 1801 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
7e7327a1 1802}
1803
396c147e 1804static void
7368a6c8 1805channel_handler_init_13(void)
1806{
1807 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1808 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1809 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1810 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1811 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1812 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1813 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
97fb6912 1814 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
0490e609 1815 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
7368a6c8 1816
0c0738d5 1817 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
7368a6c8 1818 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1819 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1820 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1821 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
97fb6912 1822 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
0c0738d5 1823 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
7368a6c8 1824}
5260325f 1825
396c147e 1826static void
7368a6c8 1827channel_handler_init_15(void)
1828{
0c0738d5 1829 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
0b242b12 1830 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
7368a6c8 1831 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1832 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1833 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
97fb6912 1834 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
0490e609 1835 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
7368a6c8 1836
1837 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1838 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1839 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
0c0738d5 1840 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
97fb6912 1841 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
0c0738d5 1842 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
7368a6c8 1843}
1844
396c147e 1845static void
7368a6c8 1846channel_handler_init(void)
1847{
1848 int i;
e1feb9bf 1849
184eed6a 1850 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
7368a6c8 1851 channel_pre[i] = NULL;
1852 channel_post[i] = NULL;
1853 }
7e7327a1 1854 if (compat20)
1855 channel_handler_init_20();
1856 else if (compat13)
7368a6c8 1857 channel_handler_init_13();
1858 else
1859 channel_handler_init_15();
1860}
1861
418e724c 1862/* gc dead channels */
1863static void
1864channel_garbage_collect(Channel *c)
1865{
1866 if (c == NULL)
1867 return;
1868 if (c->detach_user != NULL) {
8cd0437d 1869 if (!chan_is_dead(c, c->detach_close))
418e724c 1870 return;
d7ac5f18 1871 debug2("channel %d: gc: notify user", c->self);
418e724c 1872 c->detach_user(c->self, NULL);
1873 /* if we still have a callback */
1874 if (c->detach_user != NULL)
1875 return;
d7ac5f18 1876 debug2("channel %d: gc: user detached", c->self);
418e724c 1877 }
1878 if (!chan_is_dead(c, 1))
1879 return;
d7ac5f18 1880 debug2("channel %d: garbage collecting", c->self);
418e724c 1881 channel_free(c);
1882}
1883
396c147e 1884static void
c8e9c167 1885channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
7368a6c8 1886{
1887 static int did_init = 0;
9a995072 1888 u_int i;
7368a6c8 1889 Channel *c;
1890
1891 if (!did_init) {
1892 channel_handler_init();
1893 did_init = 1;
1894 }
1895 for (i = 0; i < channels_alloc; i++) {
719fc62f 1896 c = channels[i];
1897 if (c == NULL)
5260325f 1898 continue;
6fd8622b 1899 if (ftab[c->type] != NULL)
1900 (*ftab[c->type])(c, readset, writeset);
418e724c 1901 channel_garbage_collect(c);
8efc0c15 1902 }
8efc0c15 1903}
1904
8e7895b8 1905/*
1906 * Allocate/update select bitmasks and add any bits relevant to channels in
1907 * select bitmasks.
1908 */
6ae2364d 1909void
c422989b 1910channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
9a995072 1911 u_int *nallocp, int rekeying)
7368a6c8 1912{
c5d10563 1913 u_int n, sz, nfdset;
39929cdb 1914
1915 n = MAX(*maxfdp, channel_max_fd);
1916
c5d10563 1917 nfdset = howmany(n+1, NFDBITS);
1918 /* Explicitly test here, because xrealloc isn't always called */
1919 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
1920 fatal("channel_prepare_select: max_fd (%d) is too large", n);
1921 sz = nfdset * sizeof(fd_mask);
1922
489aa2e9 1923 /* perhaps check sz < nalloc/2 and shrink? */
1924 if (*readsetp == NULL || sz > *nallocp) {
c5d10563 1925 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
1926 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
489aa2e9 1927 *nallocp = sz;
39929cdb 1928 }
489aa2e9 1929 *maxfdp = n;
39929cdb 1930 memset(*readsetp, 0, sz);
1931 memset(*writesetp, 0, sz);
1932
c422989b 1933 if (!rekeying)
1934 channel_handler(channel_pre, *readsetp, *writesetp);
7368a6c8 1935}
1936
8e7895b8 1937/*
1938 * After select, perform any appropriate operations for channels which have
1939 * events pending.
1940 */
6ae2364d 1941void
c8e9c167 1942channel_after_select(fd_set *readset, fd_set *writeset)
7368a6c8 1943{
1944 channel_handler(channel_post, readset, writeset);
1945}
1946
8e7895b8 1947
39929cdb 1948/* If there is data to send to the connection, enqueue some of it now. */
6ae2364d 1949void
d5bb9418 1950channel_output_poll(void)
8efc0c15 1951{
7368a6c8 1952 Channel *c;
9a995072 1953 u_int i, len;
5260325f 1954
1955 for (i = 0; i < channels_alloc; i++) {
719fc62f 1956 c = channels[i];
1957 if (c == NULL)
1958 continue;
48e671d5 1959
8e7895b8 1960 /*
1961 * We are only interested in channels that can have buffered
1962 * incoming data.
1963 */
48e671d5 1964 if (compat13) {
7368a6c8 1965 if (c->type != SSH_CHANNEL_OPEN &&
1966 c->type != SSH_CHANNEL_INPUT_DRAINING)
48e671d5 1967 continue;
1968 } else {
7368a6c8 1969 if (c->type != SSH_CHANNEL_OPEN)
48e671d5 1970 continue;
48e671d5 1971 }
e78a59f5 1972 if (compat20 &&
1973 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
ee55dacf 1974 /* XXX is this true? */
418e724c 1975 debug3("channel %d: will not send data after close", c->self);
7e7327a1 1976 continue;
1977 }
5260325f 1978
1979 /* Get the amount of buffered data for this channel. */
ee55dacf 1980 if ((c->istate == CHAN_INPUT_OPEN ||
1981 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1982 (len = buffer_len(&c->input)) > 0) {
d20f3c9e 1983 if (c->datagram) {
1984 if (len > 0) {
1985 u_char *data;
1986 u_int dlen;
1987
1988 data = buffer_get_string(&c->input,
1989 &dlen);
1990 packet_start(SSH2_MSG_CHANNEL_DATA);
1991 packet_put_int(c->remote_id);
1992 packet_put_string(data, dlen);
1993 packet_send();
1994 c->remote_window -= dlen + 4;
1995 xfree(data);
1996 }
1997 continue;
1998 }
8e7895b8 1999 /*
2000 * Send some data for the other side over the secure
2001 * connection.
2002 */
7e7327a1 2003 if (compat20) {
2004 if (len > c->remote_window)
2005 len = c->remote_window;
2006 if (len > c->remote_maxpacket)
2007 len = c->remote_maxpacket;
5260325f 2008 } else {
7e7327a1 2009 if (packet_is_interactive()) {
2010 if (len > 1024)
2011 len = 512;
2012 } else {
2013 /* Keep the packets at reasonable size. */
2014 if (len > packet_get_maxsize()/2)
2015 len = packet_get_maxsize()/2;
2016 }
5260325f 2017 }
7368a6c8 2018 if (len > 0) {
7e7327a1 2019 packet_start(compat20 ?
2020 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
7368a6c8 2021 packet_put_int(c->remote_id);
2022 packet_put_string(buffer_ptr(&c->input), len);
2023 packet_send();
2024 buffer_consume(&c->input, len);
2025 c->remote_window -= len;
7368a6c8 2026 }
2027 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
5260325f 2028 if (compat13)
2029 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
aa3378df 2030 /*
2031 * input-buffer is empty and read-socket shutdown:
d2296ed7 2032 * tell peer, that we will not send more data: send IEOF.
2033 * hack for extended data: delay EOF if EFD still in use.
aa3378df 2034 */
d2296ed7 2035 if (CHANNEL_EFD_INPUT_ACTIVE(c))
4e2e5cfd 2036 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2037 c->self, c->efd, buffer_len(&c->extended));
d2296ed7 2038 else
2039 chan_ibuf_empty(c);
5260325f 2040 }
7e7327a1 2041 /* Send extended data, i.e. stderr */
2042 if (compat20 &&
d2296ed7 2043 !(c->flags & CHAN_EOF_SENT) &&
7e7327a1 2044 c->remote_window > 0 &&
2045 (len = buffer_len(&c->extended)) > 0 &&
2046 c->extended_usage == CHAN_EXTENDED_READ) {
f91d9a89 2047 debug2("channel %d: rwin %u elen %u euse %d",
ee55dacf 2048 c->self, c->remote_window, buffer_len(&c->extended),
2049 c->extended_usage);
7e7327a1 2050 if (len > c->remote_window)
2051 len = c->remote_window;
2052 if (len > c->remote_maxpacket)
2053 len = c->remote_maxpacket;
2054 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2055 packet_put_int(c->remote_id);
2056 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2057 packet_put_string(buffer_ptr(&c->extended), len);
2058 packet_send();
2059 buffer_consume(&c->extended, len);
2060 c->remote_window -= len;
ee55dacf 2061 debug2("channel %d: sent ext data %d", c->self, len);
7e7327a1 2062 }
8efc0c15 2063 }
8efc0c15 2064}
2065
8e7895b8 2066
2067/* -- protocol input */
04aa9e67 2068
2069/* ARGSUSED */
6ae2364d 2070void
7819b5c3 2071channel_input_data(int type, u_int32_t seq, void *ctxt)
8efc0c15 2072{
48e671d5 2073 int id;
5260325f 2074 char *data;
1e3b8b07 2075 u_int data_len;
7368a6c8 2076 Channel *c;
5260325f 2077
2078 /* Get the channel number and verify it. */
48e671d5 2079 id = packet_get_int();
7368a6c8 2080 c = channel_lookup(id);
2081 if (c == NULL)
48e671d5 2082 packet_disconnect("Received data for nonexistent channel %d.", id);
5260325f 2083
2084 /* Ignore any data for non-open channels (might happen on close) */
7368a6c8 2085 if (c->type != SSH_CHANNEL_OPEN &&
2086 c->type != SSH_CHANNEL_X11_OPEN)
48e671d5 2087 return;
2088
5260325f 2089 /* Get the data. */
17f02f0a 2090 data = packet_get_string_ptr(&data_len);
7368a6c8 2091
7741e239 2092 /*
2093 * Ignore data for protocol > 1.3 if output end is no longer open.
2094 * For protocol 2 the sending side is reducing its window as it sends
2095 * data, so we must 'fake' consumption of the data in order to ensure
2096 * that window updates are sent back. Otherwise the connection might
2097 * deadlock.
2098 */
2099 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2100 if (compat20) {
2101 c->local_window -= data_len;
2102 c->local_consumed += data_len;
2103 }
7741e239 2104 return;
2105 }
2106
6aacefa7 2107 if (compat20) {
7e7327a1 2108 if (data_len > c->local_maxpacket) {
bbe88b6d 2109 logit("channel %d: rcvd big packet %d, maxpack %d",
7e7327a1 2110 c->self, data_len, c->local_maxpacket);
2111 }
2112 if (data_len > c->local_window) {
bbe88b6d 2113 logit("channel %d: rcvd too much data %d, win %d",
7e7327a1 2114 c->self, data_len, c->local_window);
7e7327a1 2115 return;
2116 }
2117 c->local_window -= data_len;
7e7327a1 2118 }
d20f3c9e 2119 if (c->datagram)
2120 buffer_put_string(&c->output, data, data_len);
2121 else
2122 buffer_append(&c->output, data, data_len);
17f02f0a 2123 packet_check_eom();
8efc0c15 2124}
8e7895b8 2125
04aa9e67 2126/* ARGSUSED */
6ae2364d 2127void
7819b5c3 2128channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
7e7327a1 2129{
2130 int id;
7e7327a1 2131 char *data;
a594fa74 2132 u_int data_len, tcode;
7e7327a1 2133 Channel *c;
2134
2135 /* Get the channel number and verify it. */
2136 id = packet_get_int();
2137 c = channel_lookup(id);
2138
2139 if (c == NULL)
2140 packet_disconnect("Received extended_data for bad channel %d.", id);
2141 if (c->type != SSH_CHANNEL_OPEN) {
bbe88b6d 2142 logit("channel %d: ext data for non open", id);
7e7327a1 2143 return;
2144 }
d2296ed7 2145 if (c->flags & CHAN_EOF_RCVD) {
2146 if (datafellows & SSH_BUG_EXTEOF)
2147 debug("channel %d: accepting ext data after eof", id);
2148 else
2149 packet_disconnect("Received extended_data after EOF "
2150 "on channel %d.", id);
2151 }
7e7327a1 2152 tcode = packet_get_int();
2153 if (c->efd == -1 ||
2154 c->extended_usage != CHAN_EXTENDED_WRITE ||
2155 tcode != SSH2_EXTENDED_DATA_STDERR) {
bbe88b6d 2156 logit("channel %d: bad ext data", c->self);
7e7327a1 2157 return;
2158 }
2159 data = packet_get_string(&data_len);
95500969 2160 packet_check_eom();
7e7327a1 2161 if (data_len > c->local_window) {
bbe88b6d 2162 logit("channel %d: rcvd too much extended_data %d, win %d",
7e7327a1 2163 c->self, data_len, c->local_window);
2164 xfree(data);
2165 return;
2166 }
de273eef 2167 debug2("channel %d: rcvd ext data %d", c->self, data_len);
7e7327a1 2168 c->local_window -= data_len;
2169 buffer_append(&c->extended, data, data_len);
2170 xfree(data);
2171}
2172
04aa9e67 2173/* ARGSUSED */
6ae2364d 2174void
7819b5c3 2175channel_input_ieof(int type, u_int32_t seq, void *ctxt)
7368a6c8 2176{
2177 int id;
2178 Channel *c;
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 ieof for nonexistent channel %d.", id);
2185 chan_rcvd_ieof(c);
a5f82435 2186
2187 /* XXX force input close */
8341f420 2188 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
a5f82435 2189 debug("channel %d: FORCE input drain", c->self);
2190 c->istate = CHAN_INPUT_WAIT_DRAIN;
32e7d71f 2191 if (buffer_len(&c->input) == 0)
2192 chan_ibuf_empty(c);
a5f82435 2193 }
2194
7368a6c8 2195}
8efc0c15 2196
04aa9e67 2197/* ARGSUSED */
6ae2364d 2198void
7819b5c3 2199channel_input_close(int type, u_int32_t seq, void *ctxt)
8efc0c15 2200{
7368a6c8 2201 int id;
2202 Channel *c;
5260325f 2203
7368a6c8 2204 id = packet_get_int();
95500969 2205 packet_check_eom();
7368a6c8 2206 c = channel_lookup(id);
2207 if (c == NULL)
2208 packet_disconnect("Received close for nonexistent channel %d.", id);
aa3378df 2209
2210 /*
2211 * Send a confirmation that we have closed the channel and no more
2212 * data is coming for it.
2213 */
5260325f 2214 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
7368a6c8 2215 packet_put_int(c->remote_id);
5260325f 2216 packet_send();
2217
aa3378df 2218 /*
2219 * If the channel is in closed state, we have sent a close request,
2220 * and the other side will eventually respond with a confirmation.
2221 * Thus, we cannot free the channel here, because then there would be
2222 * no-one to receive the confirmation. The channel gets freed when
2223 * the confirmation arrives.
2224 */
7368a6c8 2225 if (c->type != SSH_CHANNEL_CLOSED) {
aa3378df 2226 /*
2227 * Not a closed channel - mark it as draining, which will
2228 * cause it to be freed later.
2229 */
9c50edcf 2230 buffer_clear(&c->input);
7368a6c8 2231 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
5260325f 2232 }
8efc0c15 2233}
2234
7368a6c8 2235/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
04aa9e67 2236/* ARGSUSED */
6ae2364d 2237void
7819b5c3 2238channel_input_oclose(int type, u_int32_t seq, void *ctxt)
8efc0c15 2239{
7368a6c8 2240 int id = packet_get_int();
2241 Channel *c = channel_lookup(id);
a8a21a53 2242
95500969 2243 packet_check_eom();
7368a6c8 2244 if (c == NULL)
2245 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2246 chan_rcvd_oclose(c);
8efc0c15 2247}
2248
04aa9e67 2249/* ARGSUSED */
6ae2364d 2250void
7819b5c3 2251channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
7368a6c8 2252{
2253 int id = packet_get_int();
2254 Channel *c = channel_lookup(id);
2255
95500969 2256 packet_check_eom();
7368a6c8 2257 if (c == NULL)
2258 packet_disconnect("Received close confirmation for "
2259 "out-of-range channel %d.", id);
2260 if (c->type != SSH_CHANNEL_CLOSED)
2261 packet_disconnect("Received close confirmation for "
2262 "non-closed channel %d (type %d).", id, c->type);
719fc62f 2263 channel_free(c);
7368a6c8 2264}
8efc0c15 2265
04aa9e67 2266/* ARGSUSED */
6ae2364d 2267void
7819b5c3 2268channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
8efc0c15 2269{
7368a6c8 2270 int id, remote_id;
2271 Channel *c;
5260325f 2272
7368a6c8 2273 id = packet_get_int();
2274 c = channel_lookup(id);
5260325f 2275
7368a6c8 2276 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2277 packet_disconnect("Received open confirmation for "
2278 "non-opening channel %d.", id);
2279 remote_id = packet_get_int();
aa3378df 2280 /* Record the remote channel number and mark that the channel is now open. */
7368a6c8 2281 c->remote_id = remote_id;
2282 c->type = SSH_CHANNEL_OPEN;
7e7327a1 2283
2284 if (compat20) {
2285 c->remote_window = packet_get_int();
2286 c->remote_maxpacket = packet_get_int();
3593bdc0 2287 if (c->open_confirm) {
de273eef 2288 debug2("callback start");
3593bdc0 2289 c->open_confirm(c->self, c->open_confirm_ctx);
de273eef 2290 debug2("callback done");
7e7327a1 2291 }
d7ac5f18 2292 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
7e7327a1 2293 c->remote_window, c->remote_maxpacket);
2294 }
95500969 2295 packet_check_eom();
8efc0c15 2296}
2297
396c147e 2298static char *
d18e0850 2299reason2txt(int reason)
2300{
6aacefa7 2301 switch (reason) {
d18e0850 2302 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2303 return "administratively prohibited";
2304 case SSH2_OPEN_CONNECT_FAILED:
2305 return "connect failed";
2306 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2307 return "unknown channel type";
2308 case SSH2_OPEN_RESOURCE_SHORTAGE:
2309 return "resource shortage";
2310 }
7e8c18e9 2311 return "unknown reason";
d18e0850 2312}
2313
04aa9e67 2314/* ARGSUSED */
6ae2364d 2315void
7819b5c3 2316channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
8efc0c15 2317{
02a024dd 2318 int id, reason;
2319 char *msg = NULL, *lang = NULL;
7368a6c8 2320 Channel *c;
5260325f 2321
7368a6c8 2322 id = packet_get_int();
2323 c = channel_lookup(id);
2324
2325 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2326 packet_disconnect("Received open failure for "
2327 "non-opening channel %d.", id);
7e7327a1 2328 if (compat20) {
02a024dd 2329 reason = packet_get_int();
fbe90f7b 2330 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
02a024dd 2331 msg = packet_get_string(NULL);
2332 lang = packet_get_string(NULL);
2333 }
bbe88b6d 2334 logit("channel %d: open failed: %s%s%s", id,
d18e0850 2335 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
02a024dd 2336 if (msg != NULL)
2337 xfree(msg);
2338 if (lang != NULL)
2339 xfree(lang);
7e7327a1 2340 }
95500969 2341 packet_check_eom();
6cf44b6a 2342 /* Schedule the channel for cleanup/deletion. */
2343 chan_mark_dead(c);
8efc0c15 2344}
2345
04aa9e67 2346/* ARGSUSED */
8e7895b8 2347void
7819b5c3 2348channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
8e7895b8 2349{
2350 Channel *c;
f91d9a89 2351 int id;
2352 u_int adjust;
3ffc6336 2353
8e7895b8 2354 if (!compat20)
2355 return;
8efc0c15 2356
8e7895b8 2357 /* Get the channel number and verify it. */
2358 id = packet_get_int();
2359 c = channel_lookup(id);
2360
b872f7f0 2361 if (c == NULL) {
2362 logit("Received window adjust for non-open channel %d.", id);
8e7895b8 2363 return;
2364 }
2365 adjust = packet_get_int();
95500969 2366 packet_check_eom();
f91d9a89 2367 debug2("channel %d: rcvd adjust %u", id, adjust);
8e7895b8 2368 c->remote_window += adjust;
2369}
2370
04aa9e67 2371/* ARGSUSED */
8e7895b8 2372void
7819b5c3 2373channel_input_port_open(int type, u_int32_t seq, void *ctxt)
8efc0c15 2374{
8e7895b8 2375 Channel *c = NULL;
2376 u_short host_port;
2377 char *host, *originator_string;
e07e21ad 2378 int remote_id;
5260325f 2379
8e7895b8 2380 remote_id = packet_get_int();
2381 host = packet_get_string(NULL);
2382 host_port = packet_get_int();
2383
2384 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2385 originator_string = packet_get_string(NULL);
2386 } else {
2387 originator_string = xstrdup("unknown (remote did not supply name)");
2388 }
95500969 2389 packet_check_eom();
e07e21ad 2390 c = channel_connect_to(host, host_port,
2391 "connected socket", originator_string);
0d942eff 2392 xfree(originator_string);
e07e21ad 2393 xfree(host);
8e7895b8 2394 if (c == NULL) {
2395 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2396 packet_put_int(remote_id);
2397 packet_send();
e07e21ad 2398 } else
2399 c->remote_id = remote_id;
8efc0c15 2400}
2401
3593bdc0 2402/* ARGSUSED */
2403void
2404channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2405{
2406 Channel *c;
2407 struct channel_confirm *cc;
b09b559d 2408 int id;
3593bdc0 2409
2410 /* Reset keepalive timeout */
2411 keep_alive_timeouts = 0;
2412
b09b559d 2413 id = packet_get_int();
3593bdc0 2414 packet_check_eom();
2415
b09b559d 2416 debug2("channel_input_status_confirm: type %d id %d", type, id);
3593bdc0 2417
b09b559d 2418 if ((c = channel_lookup(id)) == NULL) {
2419 logit("channel_input_status_confirm: %d: unknown", id);
3593bdc0 2420 return;
2421 }
2422 ;
2423 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2424 return;
2425 cc->cb(type, c, cc->ctx);
2426 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2427 bzero(cc, sizeof(*cc));
2428 xfree(cc);
2429}
8e7895b8 2430
2431/* -- tcp forwarding */
2432
5e4a7219 2433void
2434channel_set_af(int af)
2435{
2436 IPv4or6 = af;
2437}
2438
5641aefa 2439static int
2440channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
2441 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
8efc0c15 2442{
719fc62f 2443 Channel *c;
442aee3a 2444 int sock, r, success = 0, wildcard = 0, is_client;
48e671d5 2445 struct addrinfo hints, *ai, *aitop;
3867aa0a 2446 const char *host, *addr;
5641aefa 2447 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
5260325f 2448
5641aefa 2449 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2450 listen_addr : host_to_connect;
3867aa0a 2451 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
02a024dd 2452
5641aefa 2453 if (host == NULL) {
2454 error("No forward host name.");
38946c65 2455 return 0;
fa08c86b 2456 }
719fc62f 2457 if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
02a024dd 2458 error("Forward host name too long.");
38946c65 2459 return 0;
02a024dd 2460 }
5260325f 2461
3867aa0a 2462 /*
2463 * Determine whether or not a port forward listens to loopback,
f8cc7664 2464 * specified address or wildcard. On the client, a specified bind
2465 * address will always override gateway_ports. On the server, a
2466 * gateway_ports of 1 (``yes'') will override the client's
2467 * specification and force a wildcard bind, whereas a value of 2
2468 * (``clientspecified'') will bind to whatever address the client
3867aa0a 2469 * asked for.
2470 *
2471 * Special-case listen_addrs are:
2472 *
2473 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2474 * "" (empty string), "*" -> wildcard v4/v6
2475 * "localhost" -> loopback v4/v6
2476 */
2477 addr = NULL;
2478 if (listen_addr == NULL) {
2479 /* No address specified: default to gateway_ports setting */
2480 if (gateway_ports)
2481 wildcard = 1;
2482 } else if (gateway_ports || is_client) {
2483 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
bc4cc956 2484 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
3867aa0a 2485 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2486 (!is_client && gateway_ports == 1))
2487 wildcard = 1;
2488 else if (strcmp(listen_addr, "localhost") != 0)
2489 addr = listen_addr;
2490 }
2491
2492 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2493 type, wildcard, (addr == NULL) ? "NULL" : addr);
2494
aa3378df 2495 /*
48e671d5 2496 * getaddrinfo returns a loopback address if the hostname is
2497 * set to NULL and hints.ai_flags is not AI_PASSIVE
aa3378df 2498 */
48e671d5 2499 memset(&hints, 0, sizeof(hints));
2500 hints.ai_family = IPv4or6;
3867aa0a 2501 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
48e671d5 2502 hints.ai_socktype = SOCK_STREAM;
fa08c86b 2503 snprintf(strport, sizeof strport, "%d", listen_port);
3867aa0a 2504 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2505 if (addr == NULL) {
2506 /* This really shouldn't happen */
2507 packet_disconnect("getaddrinfo: fatal error: %s",
bb4626fe 2508 ssh_gai_strerror(r));
3867aa0a 2509 } else {
38946c65 2510 error("channel_setup_fwd_listener: "
bb4626fe 2511 "getaddrinfo(%.64s): %s", addr,
2512 ssh_gai_strerror(r));
3867aa0a 2513 }
38946c65 2514 return 0;
3867aa0a 2515 }
48e671d5 2516
48e671d5 2517 for (ai = aitop; ai; ai = ai->ai_next) {
2518 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2519 continue;
2520 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2521 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
5641aefa 2522 error("channel_setup_fwd_listener: getnameinfo failed");
48e671d5 2523 continue;
2524 }
2525 /* Create a port to listen for the host. */
3e131a6d 2526 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
48e671d5 2527 if (sock < 0) {
2528 /* this is no error since kernel may not support ipv6 */
2529 verbose("socket: %.100s", strerror(errno));
2530 continue;
2531 }
442aee3a 2532
2533 channel_set_reuseaddr(sock);
facfd613 2534
48e671d5 2535 debug("Local forwarding listening on %s port %s.", ntop, strport);
2536
2537 /* Bind the socket to the address. */
2538 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2539 /* address can be in use ipv6 address is already bound */
16218745 2540 if (!ai->ai_next)
2541 error("bind: %.100s", strerror(errno));
2542 else
2543 verbose("bind: %.100s", strerror(errno));
2b87da3b 2544
48e671d5 2545 close(sock);
2546 continue;
2547 }
2548 /* Start listening for connections on the socket. */
fce39749 2549 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
48e671d5 2550 error("listen: %.100s", strerror(errno));
2551 close(sock);
2552 continue;
2553 }
2554 /* Allocate a channel number for the socket. */
8e7895b8 2555 c = channel_new("port listener", type, sock, sock, -1,
0b242b12 2556 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
0d942eff 2557 0, "port listener", 1);
719fc62f 2558 strlcpy(c->path, host, sizeof(c->path));
2559 c->host_port = port_to_connect;
2560 c->listening_port = listen_port;
48e671d5 2561 success = 1;
2562 }
2563 if (success == 0)
5641aefa 2564 error("channel_setup_fwd_listener: cannot listen to port: %d",
02a024dd 2565 listen_port);
48e671d5 2566 freeaddrinfo(aitop);
02a024dd 2567 return success;
5260325f 2568}
8efc0c15 2569
d740ec16 2570int
2571channel_cancel_rport_listener(const char *host, u_short port)
2572{
9a995072 2573 u_int i;
2574 int found = 0;
d740ec16 2575
f8cc7664 2576 for (i = 0; i < channels_alloc; i++) {
d740ec16 2577 Channel *c = channels[i];
2578
2579 if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2580 strncmp(c->path, host, sizeof(c->path)) == 0 &&
f2107e97 2581 c->listening_port == port) {
2912cbd6 2582 debug2("%s: close channel %d", __func__, i);
d740ec16 2583 channel_free(c);
2584 found = 1;
2585 }
2586 }
2587
2588 return (found);
2589}
2590
5641aefa 2591/* protocol local port fwd, used by ssh (and sshd in v1) */
2592int
3867aa0a 2593channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
5641aefa 2594 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2595{
2596 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
3867aa0a 2597 listen_host, listen_port, host_to_connect, port_to_connect,
2598 gateway_ports);
5641aefa 2599}
2600
2601/* protocol v2 remote port fwd, used by sshd */
2602int
2603channel_setup_remote_fwd_listener(const char *listen_address,
2604 u_short listen_port, int gateway_ports)
2605{
2606 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2607 listen_address, listen_port, NULL, 0, gateway_ports);
2608}
2609
aa3378df 2610/*
2611 * Initiate forwarding of connections to port "port" on remote host through
2612 * the secure channel to host:port from local side.
2613 */
8efc0c15 2614
42ea6f5e 2615int
3867aa0a 2616channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
fa08c86b 2617 const char *host_to_connect, u_short port_to_connect)
8efc0c15 2618{
54a5250f 2619 int type, success = 0;
fa08c86b 2620
5260325f 2621 /* Record locally that connection to this host/port is permitted. */
2622 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2623 fatal("channel_request_remote_forwarding: too many forwards");
2624
5260325f 2625 /* Send the forward request to the remote side. */
7e7327a1 2626 if (compat20) {
3867aa0a 2627 const char *address_to_bind;
04efe9b0 2628 if (listen_host == NULL) {
2629 if (datafellows & SSH_BUG_RFWD_ADDR)
2630 address_to_bind = "127.0.0.1";
2631 else
2632 address_to_bind = "localhost";
2633 } else if (*listen_host == '\0' ||
2634 strcmp(listen_host, "*") == 0) {
2635 if (datafellows & SSH_BUG_RFWD_ADDR)
2636 address_to_bind = "0.0.0.0";
2637 else
2638 address_to_bind = "";
2639 } else
3867aa0a 2640 address_to_bind = listen_host;
2641
7e7327a1 2642 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2643 packet_put_cstring("tcpip-forward");
e0ae8728 2644 packet_put_char(1); /* boolean: want reply */
7e7327a1 2645 packet_put_cstring(address_to_bind);
2646 packet_put_int(listen_port);
fa08c86b 2647 packet_send();
2648 packet_write_wait();
2649 /* Assume that server accepts the request */
2650 success = 1;
7e7327a1 2651 } else {
2652 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
7e7327a1 2653 packet_put_int(listen_port);
d6f24e45 2654 packet_put_cstring(host_to_connect);
2655 packet_put_int(port_to_connect);
7e7327a1 2656 packet_send();
2657 packet_write_wait();
fa08c86b 2658
2659 /* Wait for response from the remote side. */
54a5250f 2660 type = packet_read();
fa08c86b 2661 switch (type) {
2662 case SSH_SMSG_SUCCESS:
2663 success = 1;
2664 break;
2665 case SSH_SMSG_FAILURE:
fa08c86b 2666 break;
2667 default:
2668 /* Unknown packet */
2669 packet_disconnect("Protocol error for port forward request:"
2670 "received packet type %d.", type);
2671 }
2672 }
2673 if (success) {
2674 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2675 permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2676 permitted_opens[num_permitted_opens].listen_port = listen_port;
2677 num_permitted_opens++;
7e7327a1 2678 }
42ea6f5e 2679 return (success ? 0 : -1);
8efc0c15 2680}
2681
d740ec16 2682/*
f2107e97 2683 * Request cancellation of remote forwarding of connection host:port from
d740ec16 2684 * local side.
2685 */
d740ec16 2686void
3867aa0a 2687channel_request_rforward_cancel(const char *host, u_short port)
d740ec16 2688{
2689 int i;
d740ec16 2690
2691 if (!compat20)
2692 return;
2693
2694 for (i = 0; i < num_permitted_opens; i++) {
f2107e97 2695 if (permitted_opens[i].host_to_connect != NULL &&
d740ec16 2696 permitted_opens[i].listen_port == port)
2697 break;
2698 }
2699 if (i >= num_permitted_opens) {
2700 debug("%s: requested forward not found", __func__);
2701 return;
2702 }
2703 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2704 packet_put_cstring("cancel-tcpip-forward");
2705 packet_put_char(0);
3867aa0a 2706 packet_put_cstring(host == NULL ? "" : host);
d740ec16 2707 packet_put_int(port);
2708 packet_send();
2709
2710 permitted_opens[i].listen_port = 0;
2711 permitted_opens[i].port_to_connect = 0;
8c4bd764 2712 xfree(permitted_opens[i].host_to_connect);
d740ec16 2713 permitted_opens[i].host_to_connect = NULL;
2714}
2715
aa3378df 2716/*
2717 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2718 * listening for the port, and sends back a success reply (or disconnect
42ea6f5e 2719 * message if there was an error).
aa3378df 2720 */
42ea6f5e 2721int
1d1ffb87 2722channel_input_port_forward_request(int is_root, int gateway_ports)
8efc0c15 2723{
57112b5a 2724 u_short port, host_port;
42ea6f5e 2725 int success = 0;
5260325f 2726 char *hostname;
2727
2728 /* Get arguments from the packet. */
2729 port = packet_get_int();
2730 hostname = packet_get_string(NULL);
2731 host_port = packet_get_int();
2732
3c62e7eb 2733#ifndef HAVE_CYGWIN
aa3378df 2734 /*
2735 * Check that an unprivileged user is not trying to forward a
2736 * privileged port.
2737 */
5260325f 2738 if (port < IPPORT_RESERVED && !is_root)
8e7c9afc 2739 packet_disconnect(
2740 "Requested forwarding of port %d but user is not root.",
2741 port);
2742 if (host_port == 0)
2743 packet_disconnect("Dynamic forwarding denied.");
3c62e7eb 2744#endif
8e7c9afc 2745
fa08c86b 2746 /* Initiate forwarding */
42ea6f5e 2747 success = channel_setup_local_fwd_listener(NULL, port, hostname,
3867aa0a 2748 host_port, gateway_ports);
5260325f 2749
2750 /* Free the argument string. */
2751 xfree(hostname);
42ea6f5e 2752
2753 return (success ? 0 : -1);
8efc0c15 2754}
2755
01794848 2756/*
2757 * Permits opening to any host/port if permitted_opens[] is empty. This is
2758 * usually called by the server, because the user could connect to any port
2759 * anyway, and the server has no way to know but to trust the client anyway.
2760 */
2761void
d5bb9418 2762channel_permit_all_opens(void)
01794848 2763{
2764 if (num_permitted_opens == 0)
2765 all_opens_permitted = 1;
2766}
2767
cd332296 2768void
01794848 2769channel_add_permitted_opens(char *host, int port)
2770{
2771 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
42ea6f5e 2772 fatal("channel_add_permitted_opens: too many forwards");
01794848 2773 debug("allow port forwarding to host %s port %d", host, port);
2774
2775 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2776 permitted_opens[num_permitted_opens].port_to_connect = port;
2777 num_permitted_opens++;
2778
2779 all_opens_permitted = 0;
2780}
2781
ea46e550 2782int
2fefbadf 2783channel_add_adm_permitted_opens(char *host, int port)
2784{
2785 if (num_adm_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2786 fatal("channel_add_adm_permitted_opens: too many forwards");
ea46e550 2787 debug("config allows port forwarding to host %s port %d", host, port);
2fefbadf 2788
2789 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
2790 = xstrdup(host);
2791 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
ea46e550 2792 return ++num_adm_permitted_opens;
2fefbadf 2793}
2794
cd332296 2795void
01794848 2796channel_clear_permitted_opens(void)
2797{
2798 int i;
2799
2800 for (i = 0; i < num_permitted_opens; i++)
d740ec16 2801 if (permitted_opens[i].host_to_connect != NULL)
2802 xfree(permitted_opens[i].host_to_connect);
01794848 2803 num_permitted_opens = 0;
2fefbadf 2804}
2805
2806void
2807channel_clear_adm_permitted_opens(void)
2808{
2809 int i;
01794848 2810
2fefbadf 2811 for (i = 0; i < num_adm_permitted_opens; i++)
2812 if (permitted_adm_opens[i].host_to_connect != NULL)
2813 xfree(permitted_adm_opens[i].host_to_connect);
2814 num_adm_permitted_opens = 0;
01794848 2815}
2816
1760c982 2817void
2818channel_print_adm_permitted_opens(void)
2819{
cdfbc829 2820 int i;
1760c982 2821
68405671 2822 printf("permitopen");
861e9e53 2823 if (num_adm_permitted_opens == 0) {
68405671 2824 printf(" any\n");
861e9e53 2825 return;
2826 }
1760c982 2827 for (i = 0; i < num_adm_permitted_opens; i++)
2828 if (permitted_adm_opens[i].host_to_connect != NULL)
2829 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
2830 permitted_adm_opens[i].port_to_connect);
68405671 2831 printf("\n");
1760c982 2832}
2833
e07e21ad 2834/* Try to start non-blocking connect to next host in cctx list */
396c147e 2835static int
e07e21ad 2836connect_next(struct channel_connect *cctx)
8efc0c15 2837{
e07e21ad 2838 int sock, saved_errno;
48e671d5 2839 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
48e671d5 2840
e07e21ad 2841 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
2842 if (cctx->ai->ai_family != AF_INET &&
2843 cctx->ai->ai_family != AF_INET6)
48e671d5 2844 continue;
e07e21ad 2845 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
2846 ntop, sizeof(ntop), strport, sizeof(strport),
2847 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2848 error("connect_next: getnameinfo failed");
48e671d5 2849 continue;
5260325f 2850 }
e07e21ad 2851 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
2852 cctx->ai->ai_protocol)) == -1) {
2853 if (cctx->ai->ai_next == NULL)
4940c411 2854 error("socket: %.100s", strerror(errno));
2855 else
2856 verbose("socket: %.100s", strerror(errno));
48e671d5 2857 continue;
5260325f 2858 }
170694d7 2859 if (set_nonblock(sock) == -1)
2860 fatal("%s: set_nonblock(%d)", __func__, sock);
e07e21ad 2861 if (connect(sock, cctx->ai->ai_addr,
2862 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
2863 debug("connect_next: host %.100s ([%.100s]:%s): "
2864 "%.100s", cctx->host, ntop, strport,
48e671d5 2865 strerror(errno));
e07e21ad 2866 saved_errno = errno;
48e671d5 2867 close(sock);
e07e21ad 2868 errno = saved_errno;
2b87da3b 2869 continue; /* fail -- try next */
48e671d5 2870 }
e07e21ad 2871 debug("connect_next: host %.100s ([%.100s]:%s) "
2872 "in progress, fd=%d", cctx->host, ntop, strport, sock);
2873 cctx->ai = cctx->ai->ai_next;
2874 set_nodelay(sock);
2875 return sock;
2876 }
2877 return -1;
2878}
2879
2880static void
2881channel_connect_ctx_free(struct channel_connect *cctx)
2882{
2883 xfree(cctx->host);
2884 if (cctx->aitop)
2885 freeaddrinfo(cctx->aitop);
2886 bzero(cctx, sizeof(*cctx));
2887 cctx->host = NULL;
2888 cctx->ai = cctx->aitop = NULL;
2889}
2890
2891/* Return CONNECTING channel to remote host, port */
2892static Channel *
2893connect_to(const char *host, u_short port, char *ctype, char *rname)
2894{
2895 struct addrinfo hints;
2896 int gaierr;
2897 int sock = -1;
2898 char strport[NI_MAXSERV];
2899 struct channel_connect cctx;
2900 Channel *c;
5260325f 2901
267d5589 2902 memset(&cctx, 0, sizeof(cctx));
e07e21ad 2903 memset(&hints, 0, sizeof(hints));
2904 hints.ai_family = IPv4or6;
2905 hints.ai_socktype = SOCK_STREAM;
2906 snprintf(strport, sizeof strport, "%d", port);
2907 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
2908 error("connect_to %.100s: unknown host (%s)", host,
2909 ssh_gai_strerror(gaierr));
2910 return NULL;
5260325f 2911 }
e07e21ad 2912
2913 cctx.host = xstrdup(host);
2914 cctx.port = port;
2915 cctx.ai = cctx.aitop;
2916
2917 if ((sock = connect_next(&cctx)) == -1) {
2918 error("connect to %.100s port %d failed: %s",
2919 host, port, strerror(errno));
2920 channel_connect_ctx_free(&cctx);
2921 return NULL;
8efc0c15 2922 }
e07e21ad 2923 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
2924 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
2925 c->connect_ctx = cctx;
2926 return c;
7368a6c8 2927}
01794848 2928
e07e21ad 2929Channel *
2930channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
fa08c86b 2931{
2932 int i;
01794848 2933
e07e21ad 2934 for (i = 0; i < num_permitted_opens; i++) {
d740ec16 2935 if (permitted_opens[i].host_to_connect != NULL &&
e07e21ad 2936 permitted_opens[i].listen_port == listen_port) {
01794848 2937 return connect_to(
fa08c86b 2938 permitted_opens[i].host_to_connect,
e07e21ad 2939 permitted_opens[i].port_to_connect, ctype, rname);
2940 }
2941 }
0b6fbf03 2942 error("WARNING: Server requests forwarding for unknown listen_port %d",
2943 listen_port);
e07e21ad 2944 return NULL;
fa08c86b 2945}
48e671d5 2946
01794848 2947/* Check if connecting to that port is permitted and connect. */
e07e21ad 2948Channel *
2949channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
01794848 2950{
2fefbadf 2951 int i, permit, permit_adm = 1;
01794848 2952
2953 permit = all_opens_permitted;
2954 if (!permit) {
2955 for (i = 0; i < num_permitted_opens; i++)
d740ec16 2956 if (permitted_opens[i].host_to_connect != NULL &&
2957 permitted_opens[i].port_to_connect == port &&
01794848 2958 strcmp(permitted_opens[i].host_to_connect, host) == 0)
2959 permit = 1;
2fefbadf 2960 }
01794848 2961
2fefbadf 2962 if (num_adm_permitted_opens > 0) {
2963 permit_adm = 0;
2964 for (i = 0; i < num_adm_permitted_opens; i++)
2965 if (permitted_adm_opens[i].host_to_connect != NULL &&
2966 permitted_adm_opens[i].port_to_connect == port &&
2967 strcmp(permitted_adm_opens[i].host_to_connect, host)
2968 == 0)
2969 permit_adm = 1;
01794848 2970 }
2fefbadf 2971
2972 if (!permit || !permit_adm) {
bbe88b6d 2973 logit("Received request to connect to host %.100s port %d, "
01794848 2974 "but the request was denied.", host, port);
e07e21ad 2975 return NULL;
01794848 2976 }
e07e21ad 2977 return connect_to(host, port, ctype, rname);
01794848 2978}
2979
5e96b616 2980void
2981channel_send_window_changes(void)
2982{
9a995072 2983 u_int i;
5e96b616 2984 struct winsize ws;
2985
2986 for (i = 0; i < channels_alloc; i++) {
f8cc7664 2987 if (channels[i] == NULL || !channels[i]->client_tty ||
5e96b616 2988 channels[i]->type != SSH_CHANNEL_OPEN)
2989 continue;
2990 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2991 continue;
2992 channel_request_start(i, "window-change", 0);
148de80c 2993 packet_put_int((u_int)ws.ws_col);
2994 packet_put_int((u_int)ws.ws_row);
2995 packet_put_int((u_int)ws.ws_xpixel);
2996 packet_put_int((u_int)ws.ws_ypixel);
5e96b616 2997 packet_send();
2998 }
2999}
3000
8e7895b8 3001/* -- X11 forwarding */
8efc0c15 3002
aa3378df 3003/*
3004 * Creates an internet domain socket for listening for X11 connections.
57f228e8 3005 * Returns 0 and a suitable display number for the DISPLAY variable
3006 * stored in display_numberp , or -1 if an error occurs.
aa3378df 3007 */
c9d0ad9b 3008int
e6e573bd 3009x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
d08341e6 3010 int single_connection, u_int *display_numberp, int **chanids)
8efc0c15 3011{
ac151b18 3012 Channel *nc = NULL;
57112b5a 3013 int display_number, sock;
3014 u_short port;
48e671d5 3015 struct addrinfo hints, *ai, *aitop;
3016 char strport[NI_MAXSERV];
3017 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
5260325f 3018
59e5aff5 3019 if (chanids == NULL)
3020 return -1;
3021
95f1eccc 3022 for (display_number = x11_display_offset;
184eed6a 3023 display_number < MAX_DISPLAYS;
3024 display_number++) {
5260325f 3025 port = 6000 + display_number;
48e671d5 3026 memset(&hints, 0, sizeof(hints));
3027 hints.ai_family = IPv4or6;
e6e573bd 3028 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
48e671d5 3029 hints.ai_socktype = SOCK_STREAM;
3030 snprintf(strport, sizeof strport, "%d", port);
3031 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
bb4626fe 3032 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
c9d0ad9b 3033 return -1;
5260325f 3034 }
48e671d5 3035 for (ai = aitop; ai; ai = ai->ai_next) {
3036 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3037 continue;
3e131a6d 3038 sock = socket(ai->ai_family, ai->ai_socktype,
3039 ai->ai_protocol);
48e671d5 3040 if (sock < 0) {
4ee81249 3041 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) {
80a44451 3042 error("socket: %.100s", strerror(errno));
0ea89f7e 3043 freeaddrinfo(aitop);
c9d0ad9b 3044 return -1;
80a44451 3045 } else {
22d89d24 3046 debug("x11_create_display_inet: Socket family %d not supported",
3047 ai->ai_family);
80a44451 3048 continue;
3049 }
48e671d5 3050 }
688aaeda 3051#ifdef IPV6_V6ONLY
3052 if (ai->ai_family == AF_INET6) {
3053 int on = 1;
3054 if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0)
3055 error("setsockopt IPV6_V6ONLY: %.100s", strerror(errno));
3056 }
3057#endif
554ebbed 3058 if (x11_use_localhost)
3059 channel_set_reuseaddr(sock);
48e671d5 3060 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
d7ac5f18 3061 debug2("bind port %d: %.100s", port, strerror(errno));
48e671d5 3062 close(sock);
16218745 3063
48e671d5 3064 for (n = 0; n < num_socks; n++) {
48e671d5 3065 close(socks[n]);
3066 }
3067 num_socks = 0;
3068 break;
3069 }
3070 socks[num_socks++] = sock;
3071 if (num_socks == NUM_SOCKS)
3072 break;
5260325f 3073 }
4ccb01d6 3074 freeaddrinfo(aitop);
48e671d5 3075 if (num_socks > 0)
3076 break;
5260325f 3077 }
3078 if (display_number >= MAX_DISPLAYS) {
3079 error("Failed to allocate internet-domain X11 display socket.");
c9d0ad9b 3080 return -1;
8efc0c15 3081 }
5260325f 3082 /* Start listening for connections on the socket. */
48e671d5 3083 for (n = 0; n < num_socks; n++) {
3084 sock = socks[n];
fce39749 3085 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
48e671d5 3086 error("listen: %.100s", strerror(errno));
48e671d5 3087 close(sock);
c9d0ad9b 3088 return -1;
a7effaac 3089 }
a7effaac 3090 }
5260325f 3091
48e671d5 3092 /* Allocate a channel for each socket. */
52e3daed 3093 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
48e671d5 3094 for (n = 0; n < num_socks; n++) {
3095 sock = socks[n];
ac151b18 3096 nc = channel_new("x11 listener",
0b242b12 3097 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3098 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
0d942eff 3099 0, "X11 inet listener", 1);
3a0d3d54 3100 nc->single_connection = single_connection;
59e5aff5 3101 (*chanids)[n] = nc->self;
48e671d5 3102 }
59e5aff5 3103 (*chanids)[n] = -1;
5260325f 3104
c9d0ad9b 3105 /* Return the display number for the DISPLAY environment variable. */
57f228e8 3106 *display_numberp = display_number;
3107 return (0);
8efc0c15 3108}
3109
396c147e 3110static int
b5a1596f 3111connect_local_xsocket_path(const char *pathname)
8efc0c15 3112{
5260325f 3113 int sock;
3114 struct sockaddr_un addr;
5260325f 3115
805e659f 3116 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3117 if (sock < 0)
3118 error("socket: %.100s", strerror(errno));
3119 memset(&addr, 0, sizeof(addr));
3120 addr.sun_family = AF_UNIX;
b5a1596f 3121 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
32596c7b 3122 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
805e659f 3123 return sock;
3124 close(sock);
5260325f 3125 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3126 return -1;
8efc0c15 3127}
3128
b5a1596f 3129static int
3130connect_local_xsocket(u_int dnr)
3131{
3132 char buf[1024];
3133 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
3134 return connect_local_xsocket_path(buf);
3135}
3136
0b242b12 3137int
3138x11_connect_display(void)
8efc0c15 3139{
4f16046f 3140 u_int display_number;
5260325f 3141 const char *display;
0b242b12 3142 char buf[1024], *cp;
48e671d5 3143 struct addrinfo hints, *ai, *aitop;
3144 char strport[NI_MAXSERV];
4f16046f 3145 int gaierr, sock = 0;
5260325f 3146
5260325f 3147 /* Try to open a socket for the local X server. */
3148 display = getenv("DISPLAY");
3149 if (!display) {
3150 error("DISPLAY not set.");
0b242b12 3151 return -1;
5260325f 3152 }
aa3378df 3153 /*
3154 * Now we decode the value of the DISPLAY variable and make a
3155 * connection to the real X server.
3156 */
3157
b5a1596f 3158 /* Check if the display is from launchd. */
3159#ifdef __APPLE__
3160 if (strncmp(display, "/tmp/launch", 11) == 0) {
3161 sock = connect_local_xsocket_path(display);
3162 if (sock < 0)
3163 return -1;
3164
3165 /* OK, we now have a connection to the display. */
3166 return sock;
3167 }
3168#endif
aa3378df 3169 /*
3170 * Check if it is a unix domain socket. Unix domain displays are in
3171 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3172 */
5260325f 3173 if (strncmp(display, "unix:", 5) == 0 ||
3174 display[0] == ':') {
3175 /* Connect to the unix domain socket. */
4f16046f 3176 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
5260325f 3177 error("Could not parse display number from DISPLAY: %.100s",
184eed6a 3178 display);
0b242b12 3179 return -1;
5260325f 3180 }
3181 /* Create a socket. */
3182 sock = connect_local_xsocket(display_number);
3183 if (sock < 0)
0b242b12 3184 return -1;
5260325f 3185
3186 /* OK, we now have a connection to the display. */
0b242b12 3187 return sock;
5260325f 3188 }
aa3378df 3189 /*
3190 * Connect to an inet socket. The DISPLAY value is supposedly
3191 * hostname:d[.s], where hostname may also be numeric IP address.
3192 */
74860245 3193 strlcpy(buf, display, sizeof(buf));
5260325f 3194 cp = strchr(buf, ':');
3195 if (!cp) {
3196 error("Could not find ':' in DISPLAY: %.100s", display);
0b242b12 3197 return -1;
5260325f 3198 }
3199 *cp = 0;
aa3378df 3200 /* buf now contains the host name. But first we parse the display number. */
4f16046f 3201 if (sscanf(cp + 1, "%u", &display_number) != 1) {
5260325f 3202 error("Could not parse display number from DISPLAY: %.100s",
184eed6a 3203 display);
0b242b12 3204 return -1;
5260325f 3205 }
5260325f 3206
48e671d5 3207 /* Look up the host address */
3208 memset(&hints, 0, sizeof(hints));
3209 hints.ai_family = IPv4or6;
3210 hints.ai_socktype = SOCK_STREAM;
4f16046f 3211 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
48e671d5 3212 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
bb4626fe 3213 error("%.100s: unknown host. (%s)", buf,
3214 ssh_gai_strerror(gaierr));
0b242b12 3215 return -1;
8efc0c15 3216 }
48e671d5 3217 for (ai = aitop; ai; ai = ai->ai_next) {
3218 /* Create a socket. */
3e131a6d 3219 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
48e671d5 3220 if (sock < 0) {
d7ac5f18 3221 debug2("socket: %.100s", strerror(errno));
7368a6c8 3222 continue;
3223 }
3224 /* Connect it to the display. */
3225 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
4f16046f 3226 debug2("connect %.100s port %u: %.100s", buf,
7368a6c8 3227 6000 + display_number, strerror(errno));
3228 close(sock);
3229 continue;
3230 }
3231 /* Success */
3232 break;
48e671d5 3233 }
48e671d5 3234 freeaddrinfo(aitop);
3235 if (!ai) {
4f16046f 3236 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
48e671d5 3237 strerror(errno));
0b242b12 3238 return -1;
8efc0c15 3239 }
bcc0381e 3240 set_nodelay(sock);
0b242b12 3241 return sock;
3242}
5260325f 3243
0b242b12 3244/*
3245 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3246 * the remote channel number. We should do whatever we want, and respond
3247 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3248 */
5260325f 3249
ebb90778 3250/* ARGSUSED */
0b242b12 3251void
7819b5c3 3252x11_input_open(int type, u_int32_t seq, void *ctxt)
0b242b12 3253{
719fc62f 3254 Channel *c = NULL;
3255 int remote_id, sock = 0;
0b242b12 3256 char *remote_host;
5260325f 3257
719fc62f 3258 debug("Received X11 open request.");
5260325f 3259
719fc62f 3260 remote_id = packet_get_int();
8e7895b8 3261
3262 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
719fc62f 3263 remote_host = packet_get_string(NULL);
0b242b12 3264 } else {
3265 remote_host = xstrdup("unknown (remote did not supply name)");
0b242b12 3266 }
95500969 3267 packet_check_eom();
0b242b12 3268
3269 /* Obtain a connection to the real X display. */
3270 sock = x11_connect_display();
719fc62f 3271 if (sock != -1) {
3272 /* Allocate a channel for this connection. */
3273 c = channel_new("connected x11 socket",
3274 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3275 remote_host, 1);
3a0d3d54 3276 c->remote_id = remote_id;
3277 c->force_drain = 1;
719fc62f 3278 }
0d942eff 3279 xfree(remote_host);
719fc62f 3280 if (c == NULL) {
0b242b12 3281 /* Send refusal to the remote host. */
3282 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
719fc62f 3283 packet_put_int(remote_id);
0b242b12 3284 } else {
0b242b12 3285 /* Send a confirmation to the remote host. */
3286 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
719fc62f 3287 packet_put_int(remote_id);
3288 packet_put_int(c->self);
0b242b12 3289 }
719fc62f 3290 packet_send();
8efc0c15 3291}
3292
a22aff1f 3293/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
ebb90778 3294/* ARGSUSED */
a22aff1f 3295void
7819b5c3 3296deny_input_open(int type, u_int32_t seq, void *ctxt)
a22aff1f 3297{
3298 int rchan = packet_get_int();
e1feb9bf 3299
6aacefa7 3300 switch (type) {
a22aff1f 3301 case SSH_SMSG_AGENT_OPEN:
3302 error("Warning: ssh server tried agent forwarding.");
3303 break;
3304 case SSH_SMSG_X11_OPEN:
3305 error("Warning: ssh server tried X11 forwarding.");
3306 break;
3307 default:
7819b5c3 3308 error("deny_input_open: type %d", type);
a22aff1f 3309 break;
3310 }
1908529f 3311 error("Warning: this is probably a break-in attempt by a malicious server.");
a22aff1f 3312 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3313 packet_put_int(rchan);
3314 packet_send();
3315}
3316
aa3378df 3317/*
3318 * Requests forwarding of X11 connections, generates fake authentication
3319 * data, and enables authentication spoofing.
8e7895b8 3320 * This should be called in the client only.
aa3378df 3321 */
6ae2364d 3322void
9bf083eb 3323x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
0b242b12 3324 const char *proto, const char *data)
8efc0c15 3325{
1e3b8b07 3326 u_int data_len = (u_int) strlen(data) / 2;
ef07103c 3327 u_int i, value;
5260325f 3328 char *new_data;
3329 int screen_number;
3330 const char *cp;
ca75d7de 3331 u_int32_t rnd = 0;
5260325f 3332
4297b666 3333 if (x11_saved_display == NULL)
3334 x11_saved_display = xstrdup(disp);
3335 else if (strcmp(disp, x11_saved_display) != 0) {
ef07103c 3336 error("x11_request_forwarding_with_spoofing: different "
3337 "$DISPLAY already forwarded");
3338 return;
3339 }
3340
0875ae22 3341 cp = strchr(disp, ':');
5260325f 3342 if (cp)
3343 cp = strchr(cp, '.');
3344 if (cp)
d6d4897e 3345 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
5260325f 3346 else
3347 screen_number = 0;
3348
ef07103c 3349 if (x11_saved_proto == NULL) {
3350 /* Save protocol name. */
3351 x11_saved_proto = xstrdup(proto);
3352 /*
56964485 3353 * Extract real authentication data and generate fake data
ef07103c 3354 * of the same length.
3355 */
3356 x11_saved_data = xmalloc(data_len);
3357 x11_fake_data = xmalloc(data_len);
3358 for (i = 0; i < data_len; i++) {
3359 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3360 fatal("x11_request_forwarding: bad "
3361 "authentication data: %.100s", data);
3362 if (i % 4 == 0)
3363 rnd = arc4random();
3364 x11_saved_data[i] = value;
3365 x11_fake_data[i] = rnd & 0xff;
3366 rnd >>= 8;
3367 }
3368 x11_saved_data_len = data_len;
3369 x11_fake_data_len = data_len;
3370 }
5260325f 3371
3372 /* Convert the fake data into hex. */
ef07103c 3373 new_data = tohex(x11_fake_data, data_len);
5260325f 3374
3375 /* Send the request packet. */
0b242b12 3376 if (compat20) {
3377 channel_request_start(client_session_id, "x11-req", 0);
3378 packet_put_char(0); /* XXX bool single connection */
3379 } else {
3380 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3381 }
3382 packet_put_cstring(proto);
3383 packet_put_cstring(new_data);
5260325f 3384 packet_put_int(screen_number);
3385 packet_send();
3386 packet_write_wait();
3387 xfree(new_data);
8efc0c15 3388}
3389
8e7895b8 3390
3391/* -- agent forwarding */
3392
8efc0c15 3393/* Sends a message to the server to request authentication fd forwarding. */
3394
6ae2364d 3395void
d5bb9418 3396auth_request_forwarding(void)
8efc0c15 3397{
5260325f 3398 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3399 packet_send();
3400 packet_write_wait();
8efc0c15 3401}
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