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5156b1a1 1/* $OpenBSD: channels.c,v 1.286 2008/07/16 11:52:19 djm Exp $ */
3c0ef626 2/*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
6 * This file contains functions for generic socket connection forwarding.
7 * There is also code for initiating connection forwarding for X11 connections,
8 * arbitrary tcp/ip connections, and the authentication agent connection.
9 *
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 *
16 * SSH2 support added by Markus Friedl.
473db5ab 17 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
3c0ef626 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.
40 */
41
42#include "includes.h"
3c0ef626 43
30460aeb 44#include <sys/types.h>
45#include <sys/ioctl.h>
46#include <sys/un.h>
47#include <sys/socket.h>
48#ifdef HAVE_SYS_TIME_H
49# include <sys/time.h>
50#endif
51
52#include <netinet/in.h>
53#include <arpa/inet.h>
54
55#include <errno.h>
56#include <netdb.h>
57#include <stdio.h>
58#include <stdlib.h>
59#include <string.h>
60#include <termios.h>
61#include <unistd.h>
62#include <stdarg.h>
63
5156b1a1 64#include "openbsd-compat/sys-queue.h"
30460aeb 65#include "xmalloc.h"
3c0ef626 66#include "ssh.h"
67#include "ssh1.h"
68#include "ssh2.h"
69#include "packet.h"
3c0ef626 70#include "log.h"
71#include "misc.h"
30460aeb 72#include "buffer.h"
3c0ef626 73#include "channels.h"
74#include "compat.h"
75#include "canohost.h"
76#include "key.h"
77#include "authfd.h"
473db5ab 78#include "pathnames.h"
a7213e65 79
3c0ef626 80/* -- channel core */
81
82/*
83 * Pointer to an array containing all allocated channels. The array is
84 * dynamically extended as needed.
85 */
86static Channel **channels = NULL;
87
88/*
89 * Size of the channel array. All slots of the array must always be
90 * initialized (at least the type field); unused slots set to NULL
91 */
473db5ab 92static u_int channels_alloc = 0;
3c0ef626 93
94/*
95 * Maximum file descriptor value used in any of the channels. This is
96 * updated in channel_new.
97 */
98static int channel_max_fd = 0;
99
100
101/* -- tcp forwarding */
102
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 */
109typedef struct {
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. */
113} ForwardPermission;
114
30460aeb 115/* List of all permitted host/port pairs to connect by the user. */
3c0ef626 116static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
117
30460aeb 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. */
3c0ef626 122static int num_permitted_opens = 0;
30460aeb 123
124/* Number of permitted host/port pair in the array permitted by the admin. */
125static int num_adm_permitted_opens = 0;
126
3c0ef626 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 */
132static int all_opens_permitted = 0;
133
134
135/* -- X11 forwarding */
136
137/* Maximum number of fake X11 displays to try. */
138#define MAX_DISPLAYS 1000
139
473db5ab 140/* Saved X11 local (client) display. */
141static char *x11_saved_display = NULL;
142
3c0ef626 143/* Saved X11 authentication protocol name. */
144static char *x11_saved_proto = NULL;
145
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 */
30460aeb 154static u_char *x11_fake_data = NULL;
3c0ef626 155static u_int x11_fake_data_len;
156
157
158/* -- agent forwarding */
159
160#define NUM_SOCKS 10
161
3c0ef626 162/* AF_UNSPEC or AF_INET or AF_INET6 */
163static int IPv4or6 = AF_UNSPEC;
164
165/* helper */
166static void port_open_helper(Channel *c, char *rtype);
167
5156b1a1 168/* non-blocking connect helpers */
169static int connect_next(struct channel_connect *);
170static void channel_connect_ctx_free(struct channel_connect *);
171
3c0ef626 172/* -- channel core */
173
174Channel *
08822d99 175channel_by_id(int id)
3c0ef626 176{
177 Channel *c;
178
473db5ab 179 if (id < 0 || (u_int)id >= channels_alloc) {
08822d99 180 logit("channel_by_id: %d: bad id", id);
3c0ef626 181 return NULL;
182 }
183 c = channels[id];
184 if (c == NULL) {
08822d99 185 logit("channel_by_id: %d: bad id: channel free", id);
3c0ef626 186 return NULL;
187 }
188 return c;
189}
190
08822d99 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
30460aeb 203 switch (c->type) {
08822d99 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);
08822d99 213 }
214 logit("Non-public channel %d, type %d.", id, c->type);
215 return (NULL);
216}
217
3c0ef626 218/*
219 * Register filedescriptors for a channel, used when allocating a channel or
220 * when the channel consumer/producer is ready, e.g. shell exec'd
221 */
3c0ef626 222static void
223channel_register_fds(Channel *c, int rfd, int wfd, int efd,
5156b1a1 224 int extusage, int nonblock, int is_tty)
3c0ef626 225{
226 /* Update the maximum file descriptor value. */
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
231 /* XXX set close-on-exec -markus */
232
233 c->rfd = rfd;
234 c->wfd = wfd;
235 c->sock = (rfd == wfd) ? rfd : -1;
473db5ab 236 c->ctl_fd = -1; /* XXX: set elsewhere */
3c0ef626 237 c->efd = efd;
238 c->extended_usage = extusage;
239
5156b1a1 240 if ((c->isatty = is_tty) != 0)
473db5ab 241 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
5156b1a1 242 c->wfd_isatty = is_tty || isatty(c->wfd);
3c0ef626 243
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 }
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 */
3c0ef626 259Channel *
260channel_new(char *ctype, int type, int rfd, int wfd, int efd,
473db5ab 261 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
3c0ef626 262{
473db5ab 263 int found;
264 u_int i;
3c0ef626 265 Channel *c;
266
267 /* Do initial allocation if this is the first call. */
268 if (channels_alloc == 0) {
3c0ef626 269 channels_alloc = 10;
30460aeb 270 channels = xcalloc(channels_alloc, sizeof(Channel *));
3c0ef626 271 for (i = 0; i < channels_alloc; i++)
272 channels[i] = NULL;
3c0ef626 273 }
274 /* Try to find a free slot where to put the new channel. */
275 for (found = -1, i = 0; i < channels_alloc; i++)
276 if (channels[i] == NULL) {
277 /* Found a free slot. */
473db5ab 278 found = (int)i;
3c0ef626 279 break;
280 }
473db5ab 281 if (found < 0) {
3c0ef626 282 /* There are no free slots. Take last+1 slot and expand the array. */
283 found = channels_alloc;
473db5ab 284 if (channels_alloc > 10000)
285 fatal("channel_new: internal error: channels_alloc %d "
286 "too big.", channels_alloc);
30460aeb 287 channels = xrealloc(channels, channels_alloc + 10,
288 sizeof(Channel *));
3c0ef626 289 channels_alloc += 10;
290 debug2("channel: expanding %d", channels_alloc);
3c0ef626 291 for (i = found; i < channels_alloc; i++)
292 channels[i] = NULL;
293 }
294 /* Initialize and return new channel. */
30460aeb 295 c = channels[found] = xcalloc(1, sizeof(Channel));
3c0ef626 296 buffer_init(&c->input);
297 buffer_init(&c->output);
298 buffer_init(&c->extended);
473db5ab 299 c->ostate = CHAN_OUTPUT_OPEN;
300 c->istate = CHAN_INPUT_OPEN;
301 c->flags = 0;
5156b1a1 302 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
3c0ef626 303 c->self = found;
304 c->type = type;
305 c->ctype = ctype;
306 c->local_window = window;
307 c->local_window_max = window;
308 c->local_consumed = 0;
309 c->local_maxpacket = maxpack;
473db5ab 310 c->dynamic_window = 0;
3c0ef626 311 c->remote_id = -1;
473db5ab 312 c->remote_name = xstrdup(remote_name);
3c0ef626 313 c->remote_window = 0;
314 c->remote_maxpacket = 0;
3c0ef626 315 c->force_drain = 0;
473db5ab 316 c->single_connection = 0;
3c0ef626 317 c->detach_user = NULL;
08822d99 318 c->detach_close = 0;
5156b1a1 319 c->open_confirm = NULL;
320 c->open_confirm_ctx = NULL;
3c0ef626 321 c->input_filter = NULL;
08822d99 322 c->output_filter = NULL;
5156b1a1 323 c->filter_ctx = NULL;
324 c->filter_cleanup = NULL;
325 TAILQ_INIT(&c->status_confirms);
3c0ef626 326 debug("channel %d: new [%s]", found, remote_name);
327 return c;
328}
329
330static int
331channel_find_maxfd(void)
332{
473db5ab 333 u_int i;
334 int max = 0;
3c0ef626 335 Channel *c;
336
337 for (i = 0; i < channels_alloc; i++) {
338 c = channels[i];
339 if (c != NULL) {
340 max = MAX(max, c->rfd);
341 max = MAX(max, c->wfd);
342 max = MAX(max, c->efd);
343 }
344 }
345 return max;
346}
347
348int
349channel_close_fd(int *fdp)
350{
351 int ret = 0, fd = *fdp;
352
353 if (fd != -1) {
354 ret = close(fd);
355 *fdp = -1;
356 if (fd == channel_max_fd)
357 channel_max_fd = channel_find_maxfd();
358 }
359 return ret;
360}
361
362/* Close all channel fd/socket. */
3c0ef626 363static void
364channel_close_fds(Channel *c)
365{
473db5ab 366 debug3("channel %d: close_fds r %d w %d e %d c %d",
367 c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
3c0ef626 368
369 channel_close_fd(&c->sock);
473db5ab 370 channel_close_fd(&c->ctl_fd);
3c0ef626 371 channel_close_fd(&c->rfd);
372 channel_close_fd(&c->wfd);
373 channel_close_fd(&c->efd);
374}
375
376/* Free the channel and close its fd/socket. */
3c0ef626 377void
378channel_free(Channel *c)
379{
380 char *s;
473db5ab 381 u_int i, n;
5156b1a1 382 struct channel_confirm *cc;
3c0ef626 383
384 for (n = 0, i = 0; i < channels_alloc; i++)
385 if (channels[i])
386 n++;
473db5ab 387 debug("channel %d: free: %s, nchannels %u", c->self,
3c0ef626 388 c->remote_name ? c->remote_name : "???", n);
389
390 s = channel_open_message();
473db5ab 391 debug3("channel %d: status: %s", c->self, s);
3c0ef626 392 xfree(s);
393
394 if (c->sock != -1)
395 shutdown(c->sock, SHUT_RDWR);
473db5ab 396 if (c->ctl_fd != -1)
397 shutdown(c->ctl_fd, SHUT_RDWR);
3c0ef626 398 channel_close_fds(c);
399 buffer_free(&c->input);
400 buffer_free(&c->output);
401 buffer_free(&c->extended);
402 if (c->remote_name) {
403 xfree(c->remote_name);
404 c->remote_name = NULL;
405 }
5156b1a1 406 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
407 if (cc->abandon_cb != NULL)
408 cc->abandon_cb(c, cc->ctx);
409 TAILQ_REMOVE(&c->status_confirms, cc, entry);
410 bzero(cc, sizeof(*cc));
411 xfree(cc);
412 }
413 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
414 c->filter_cleanup(c->self, c->filter_ctx);
3c0ef626 415 channels[c->self] = NULL;
416 xfree(c);
417}
418
419void
420channel_free_all(void)
421{
473db5ab 422 u_int i;
3c0ef626 423
424 for (i = 0; i < channels_alloc; i++)
425 if (channels[i] != NULL)
426 channel_free(channels[i]);
427}
428
429/*
430 * Closes the sockets/fds of all channels. This is used to close extra file
431 * descriptors after a fork.
432 */
3c0ef626 433void
473db5ab 434channel_close_all(void)
3c0ef626 435{
473db5ab 436 u_int i;
3c0ef626 437
438 for (i = 0; i < channels_alloc; i++)
439 if (channels[i] != NULL)
440 channel_close_fds(channels[i]);
441}
442
443/*
444 * Stop listening to channels.
445 */
3c0ef626 446void
447channel_stop_listening(void)
448{
473db5ab 449 u_int i;
3c0ef626 450 Channel *c;
451
452 for (i = 0; i < channels_alloc; i++) {
453 c = channels[i];
454 if (c != NULL) {
455 switch (c->type) {
456 case SSH_CHANNEL_AUTH_SOCKET:
457 case SSH_CHANNEL_PORT_LISTENER:
458 case SSH_CHANNEL_RPORT_LISTENER:
459 case SSH_CHANNEL_X11_LISTENER:
460 channel_close_fd(&c->sock);
461 channel_free(c);
462 break;
463 }
464 }
465 }
466}
467
468/*
469 * Returns true if no channel has too much buffered data, and false if one or
470 * more channel is overfull.
471 */
3c0ef626 472int
473db5ab 473channel_not_very_much_buffered_data(void)
3c0ef626 474{
475 u_int i;
476 Channel *c;
477
478 for (i = 0; i < channels_alloc; i++) {
479 c = channels[i];
480 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
481#if 0
482 if (!compat20 &&
483 buffer_len(&c->input) > packet_get_maxsize()) {
473db5ab 484 debug2("channel %d: big input buffer %d",
3c0ef626 485 c->self, buffer_len(&c->input));
486 return 0;
487 }
488#endif
489 if (buffer_len(&c->output) > packet_get_maxsize()) {
473db5ab 490 debug2("channel %d: big output buffer %u > %u",
3c0ef626 491 c->self, buffer_len(&c->output),
492 packet_get_maxsize());
493 return 0;
494 }
495 }
496 }
497 return 1;
498}
499
500/* Returns true if any channel is still open. */
3c0ef626 501int
473db5ab 502channel_still_open(void)
3c0ef626 503{
473db5ab 504 u_int i;
3c0ef626 505 Channel *c;
506
507 for (i = 0; i < channels_alloc; i++) {
508 c = channels[i];
509 if (c == NULL)
510 continue;
511 switch (c->type) {
512 case SSH_CHANNEL_X11_LISTENER:
513 case SSH_CHANNEL_PORT_LISTENER:
514 case SSH_CHANNEL_RPORT_LISTENER:
515 case SSH_CHANNEL_CLOSED:
516 case SSH_CHANNEL_AUTH_SOCKET:
517 case SSH_CHANNEL_DYNAMIC:
518 case SSH_CHANNEL_CONNECTING:
519 case SSH_CHANNEL_ZOMBIE:
520 continue;
521 case SSH_CHANNEL_LARVAL:
522 if (!compat20)
523 fatal("cannot happen: SSH_CHANNEL_LARVAL");
524 continue;
525 case SSH_CHANNEL_OPENING:
526 case SSH_CHANNEL_OPEN:
527 case SSH_CHANNEL_X11_OPEN:
528 return 1;
529 case SSH_CHANNEL_INPUT_DRAINING:
530 case SSH_CHANNEL_OUTPUT_DRAINING:
531 if (!compat13)
532 fatal("cannot happen: OUT_DRAIN");
533 return 1;
534 default:
535 fatal("channel_still_open: bad channel type %d", c->type);
536 /* NOTREACHED */
537 }
538 }
539 return 0;
540}
541
542/* Returns the id of an open channel suitable for keepaliving */
3c0ef626 543int
473db5ab 544channel_find_open(void)
3c0ef626 545{
473db5ab 546 u_int i;
3c0ef626 547 Channel *c;
548
549 for (i = 0; i < channels_alloc; i++) {
550 c = channels[i];
473db5ab 551 if (c == NULL || c->remote_id < 0)
3c0ef626 552 continue;
553 switch (c->type) {
554 case SSH_CHANNEL_CLOSED:
555 case SSH_CHANNEL_DYNAMIC:
556 case SSH_CHANNEL_X11_LISTENER:
557 case SSH_CHANNEL_PORT_LISTENER:
558 case SSH_CHANNEL_RPORT_LISTENER:
559 case SSH_CHANNEL_OPENING:
560 case SSH_CHANNEL_CONNECTING:
561 case SSH_CHANNEL_ZOMBIE:
562 continue;
563 case SSH_CHANNEL_LARVAL:
564 case SSH_CHANNEL_AUTH_SOCKET:
565 case SSH_CHANNEL_OPEN:
566 case SSH_CHANNEL_X11_OPEN:
567 return i;
568 case SSH_CHANNEL_INPUT_DRAINING:
569 case SSH_CHANNEL_OUTPUT_DRAINING:
570 if (!compat13)
571 fatal("cannot happen: OUT_DRAIN");
572 return i;
573 default:
574 fatal("channel_find_open: bad channel type %d", c->type);
575 /* NOTREACHED */
576 }
577 }
578 return -1;
579}
580
581
582/*
583 * Returns a message describing the currently open forwarded connections,
584 * suitable for sending to the client. The message contains crlf pairs for
585 * newlines.
586 */
3c0ef626 587char *
473db5ab 588channel_open_message(void)
3c0ef626 589{
590 Buffer buffer;
591 Channel *c;
592 char buf[1024], *cp;
473db5ab 593 u_int i;
3c0ef626 594
595 buffer_init(&buffer);
596 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
597 buffer_append(&buffer, buf, strlen(buf));
598 for (i = 0; i < channels_alloc; i++) {
599 c = channels[i];
600 if (c == NULL)
601 continue;
602 switch (c->type) {
603 case SSH_CHANNEL_X11_LISTENER:
604 case SSH_CHANNEL_PORT_LISTENER:
605 case SSH_CHANNEL_RPORT_LISTENER:
606 case SSH_CHANNEL_CLOSED:
607 case SSH_CHANNEL_AUTH_SOCKET:
608 case SSH_CHANNEL_ZOMBIE:
609 continue;
610 case SSH_CHANNEL_LARVAL:
611 case SSH_CHANNEL_OPENING:
612 case SSH_CHANNEL_CONNECTING:
613 case SSH_CHANNEL_DYNAMIC:
614 case SSH_CHANNEL_OPEN:
615 case SSH_CHANNEL_X11_OPEN:
616 case SSH_CHANNEL_INPUT_DRAINING:
617 case SSH_CHANNEL_OUTPUT_DRAINING:
473db5ab 618 snprintf(buf, sizeof buf,
619 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
3c0ef626 620 c->self, c->remote_name,
621 c->type, c->remote_id,
622 c->istate, buffer_len(&c->input),
623 c->ostate, buffer_len(&c->output),
473db5ab 624 c->rfd, c->wfd, c->ctl_fd);
3c0ef626 625 buffer_append(&buffer, buf, strlen(buf));
626 continue;
627 default:
628 fatal("channel_open_message: bad channel type %d", c->type);
629 /* NOTREACHED */
630 }
631 }
632 buffer_append(&buffer, "\0", 1);
633 cp = xstrdup(buffer_ptr(&buffer));
634 buffer_free(&buffer);
635 return cp;
636}
637
638void
639channel_send_open(int id)
640{
641 Channel *c = channel_lookup(id);
473db5ab 642
3c0ef626 643 if (c == NULL) {
473db5ab 644 logit("channel_send_open: %d: bad id", id);
3c0ef626 645 return;
646 }
473db5ab 647 debug2("channel %d: send open", id);
3c0ef626 648 packet_start(SSH2_MSG_CHANNEL_OPEN);
649 packet_put_cstring(c->ctype);
650 packet_put_int(c->self);
651 packet_put_int(c->local_window);
652 packet_put_int(c->local_maxpacket);
653 packet_send();
654}
655
3c0ef626 656void
657channel_request_start(int id, char *service, int wantconfirm)
658{
659 Channel *c = channel_lookup(id);
473db5ab 660
3c0ef626 661 if (c == NULL) {
473db5ab 662 logit("channel_request_start: %d: unknown channel id", id);
3c0ef626 663 return;
664 }
473db5ab 665 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
3c0ef626 666 packet_start(SSH2_MSG_CHANNEL_REQUEST);
667 packet_put_int(c->remote_id);
668 packet_put_cstring(service);
669 packet_put_char(wantconfirm);
670}
30460aeb 671
3c0ef626 672void
5156b1a1 673channel_register_status_confirm(int id, channel_confirm_cb *cb,
674 channel_confirm_abandon_cb *abandon_cb, void *ctx)
675{
676 struct channel_confirm *cc;
677 Channel *c;
678
679 if ((c = channel_lookup(id)) == NULL)
680 fatal("channel_register_expect: %d: bad id", id);
681
682 cc = xmalloc(sizeof(*cc));
683 cc->cb = cb;
684 cc->abandon_cb = abandon_cb;
685 cc->ctx = ctx;
686 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
687}
688
689void
690channel_register_open_confirm(int id, channel_callback_fn *fn, void *ctx)
3c0ef626 691{
692 Channel *c = channel_lookup(id);
473db5ab 693
3c0ef626 694 if (c == NULL) {
5156b1a1 695 logit("channel_register_open_comfirm: %d: bad id", id);
3c0ef626 696 return;
697 }
5156b1a1 698 c->open_confirm = fn;
699 c->open_confirm_ctx = ctx;
3c0ef626 700}
30460aeb 701
3c0ef626 702void
08822d99 703channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
3c0ef626 704{
08822d99 705 Channel *c = channel_by_id(id);
473db5ab 706
3c0ef626 707 if (c == NULL) {
473db5ab 708 logit("channel_register_cleanup: %d: bad id", id);
3c0ef626 709 return;
710 }
711 c->detach_user = fn;
08822d99 712 c->detach_close = do_close;
3c0ef626 713}
30460aeb 714
3c0ef626 715void
716channel_cancel_cleanup(int id)
717{
08822d99 718 Channel *c = channel_by_id(id);
473db5ab 719
3c0ef626 720 if (c == NULL) {
473db5ab 721 logit("channel_cancel_cleanup: %d: bad id", id);
3c0ef626 722 return;
723 }
724 c->detach_user = NULL;
08822d99 725 c->detach_close = 0;
3c0ef626 726}
30460aeb 727
3c0ef626 728void
08822d99 729channel_register_filter(int id, channel_infilter_fn *ifn,
5156b1a1 730 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
3c0ef626 731{
732 Channel *c = channel_lookup(id);
473db5ab 733
3c0ef626 734 if (c == NULL) {
473db5ab 735 logit("channel_register_filter: %d: bad id", id);
3c0ef626 736 return;
737 }
08822d99 738 c->input_filter = ifn;
739 c->output_filter = ofn;
5156b1a1 740 c->filter_ctx = ctx;
741 c->filter_cleanup = cfn;
3c0ef626 742}
743
744void
745channel_set_fds(int id, int rfd, int wfd, int efd,
5156b1a1 746 int extusage, int nonblock, int is_tty, u_int window_max)
3c0ef626 747{
748 Channel *c = channel_lookup(id);
473db5ab 749
3c0ef626 750 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
751 fatal("channel_activate for non-larval channel %d.", id);
5156b1a1 752 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
3c0ef626 753 c->type = SSH_CHANNEL_OPEN;
473db5ab 754 c->local_window = c->local_window_max = window_max;
3c0ef626 755 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
756 packet_put_int(c->remote_id);
757 packet_put_int(c->local_window);
758 packet_send();
759}
760
761/*
762 * 'channel_pre*' are called just before select() to add any bits relevant to
763 * channels in the select bitmasks.
764 */
765/*
766 * 'channel_post*': perform any appropriate operations for channels which
767 * have events pending.
768 */
30460aeb 769typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
3c0ef626 770chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
771chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
772
30460aeb 773/* ARGSUSED */
3c0ef626 774static void
30460aeb 775channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 776{
777 FD_SET(c->sock, readset);
778}
779
30460aeb 780/* ARGSUSED */
3c0ef626 781static void
30460aeb 782channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 783{
784 debug3("channel %d: waiting for connection", c->self);
785 FD_SET(c->sock, writeset);
786}
787
788static void
30460aeb 789channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 790{
791 if (buffer_len(&c->input) < packet_get_maxsize())
792 FD_SET(c->sock, readset);
793 if (buffer_len(&c->output) > 0)
794 FD_SET(c->sock, writeset);
795}
796
f713db99 797int channel_tcpwinsz () {
798 u_int32_t tcpwinsz = 0;
799 socklen_t optsz = sizeof(tcpwinsz);
800 int ret = -1;
6df46d40 801
802 /* if we aren't on a socket return 128KB*/
f713db99 803 if(!packet_connection_is_on_socket())
6df46d40 804 return(128*1024);
f713db99 805 ret = getsockopt(packet_get_connection_in(),
806 SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz);
6df46d40 807 /* return no more than 64MB */
f713db99 808 if ((ret == 0) && tcpwinsz > BUFFER_MAX_LEN_HPN)
809 tcpwinsz = BUFFER_MAX_LEN_HPN;
810 debug2("tcpwinsz: %d for connection: %d", tcpwinsz,
811 packet_get_connection_in());
812 return(tcpwinsz);
813}
814
3c0ef626 815static void
30460aeb 816channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 817{
473db5ab 818 u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
f472818d 819
f713db99 820 /* check buffer limits */
6df46d40 821 if ((!c->tcpwinsz) || (c->dynamic_window > 0))
f713db99 822 c->tcpwinsz = channel_tcpwinsz();
f713db99 823
824 limit = MIN(limit, 2 * c->tcpwinsz);
825
3c0ef626 826 if (c->istate == CHAN_INPUT_OPEN &&
473db5ab 827 limit > 0 &&
30460aeb 828 buffer_len(&c->input) < limit &&
829 buffer_check_alloc(&c->input, CHAN_RBUF))
3c0ef626 830 FD_SET(c->rfd, readset);
831 if (c->ostate == CHAN_OUTPUT_OPEN ||
832 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
833 if (buffer_len(&c->output) > 0) {
834 FD_SET(c->wfd, writeset);
835 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
473db5ab 836 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
837 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
838 c->self, c->efd, buffer_len(&c->extended));
839 else
840 chan_obuf_empty(c);
3c0ef626 841 }
842 }
843 /** XXX check close conditions, too */
5156b1a1 844 if (compat20 && c->efd != -1 &&
845 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
3c0ef626 846 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
847 buffer_len(&c->extended) > 0)
848 FD_SET(c->efd, writeset);
473db5ab 849 else if (!(c->flags & CHAN_EOF_SENT) &&
850 c->extended_usage == CHAN_EXTENDED_READ &&
3c0ef626 851 buffer_len(&c->extended) < c->remote_window)
852 FD_SET(c->efd, readset);
853 }
473db5ab 854 /* XXX: What about efd? races? */
855 if (compat20 && c->ctl_fd != -1 &&
856 c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
857 FD_SET(c->ctl_fd, readset);
3c0ef626 858}
859
30460aeb 860/* ARGSUSED */
3c0ef626 861static void
30460aeb 862channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 863{
864 if (buffer_len(&c->input) == 0) {
865 packet_start(SSH_MSG_CHANNEL_CLOSE);
866 packet_put_int(c->remote_id);
867 packet_send();
868 c->type = SSH_CHANNEL_CLOSED;
473db5ab 869 debug2("channel %d: closing after input drain.", c->self);
3c0ef626 870 }
871}
872
30460aeb 873/* ARGSUSED */
3c0ef626 874static void
30460aeb 875channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 876{
877 if (buffer_len(&c->output) == 0)
878 chan_mark_dead(c);
879 else
880 FD_SET(c->sock, writeset);
881}
882
883/*
884 * This is a special state for X11 authentication spoofing. An opened X11
885 * connection (when authentication spoofing is being done) remains in this
886 * state until the first packet has been completely read. The authentication
887 * data in that packet is then substituted by the real data if it matches the
888 * fake data, and the channel is put into normal mode.
889 * XXX All this happens at the client side.
890 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
891 */
892static int
893x11_open_helper(Buffer *b)
894{
895 u_char *ucp;
896 u_int proto_len, data_len;
897
898 /* Check if the fixed size part of the packet is in buffer. */
899 if (buffer_len(b) < 12)
900 return 0;
901
902 /* Parse the lengths of variable-length fields. */
473db5ab 903 ucp = buffer_ptr(b);
3c0ef626 904 if (ucp[0] == 0x42) { /* Byte order MSB first. */
905 proto_len = 256 * ucp[6] + ucp[7];
906 data_len = 256 * ucp[8] + ucp[9];
907 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
908 proto_len = ucp[6] + 256 * ucp[7];
909 data_len = ucp[8] + 256 * ucp[9];
910 } else {
473db5ab 911 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
912 ucp[0]);
3c0ef626 913 return -1;
914 }
915
916 /* Check if the whole packet is in buffer. */
917 if (buffer_len(b) <
918 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
919 return 0;
920
921 /* Check if authentication protocol matches. */
922 if (proto_len != strlen(x11_saved_proto) ||
923 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
473db5ab 924 debug2("X11 connection uses different authentication protocol.");
3c0ef626 925 return -1;
926 }
927 /* Check if authentication data matches our fake data. */
928 if (data_len != x11_fake_data_len ||
929 memcmp(ucp + 12 + ((proto_len + 3) & ~3),
930 x11_fake_data, x11_fake_data_len) != 0) {
473db5ab 931 debug2("X11 auth data does not match fake data.");
3c0ef626 932 return -1;
933 }
934 /* Check fake data length */
935 if (x11_fake_data_len != x11_saved_data_len) {
936 error("X11 fake_data_len %d != saved_data_len %d",
937 x11_fake_data_len, x11_saved_data_len);
938 return -1;
939 }
940 /*
941 * Received authentication protocol and data match
942 * our fake data. Substitute the fake data with real
943 * data.
944 */
945 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
946 x11_saved_data, x11_saved_data_len);
947 return 1;
948}
949
950static void
30460aeb 951channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 952{
953 int ret = x11_open_helper(&c->output);
473db5ab 954
3c0ef626 955 if (ret == 1) {
956 /* Start normal processing for the channel. */
957 c->type = SSH_CHANNEL_OPEN;
958 channel_pre_open_13(c, readset, writeset);
959 } else if (ret == -1) {
960 /*
961 * We have received an X11 connection that has bad
962 * authentication information.
963 */
473db5ab 964 logit("X11 connection rejected because of wrong authentication.");
3c0ef626 965 buffer_clear(&c->input);
966 buffer_clear(&c->output);
967 channel_close_fd(&c->sock);
968 c->sock = -1;
969 c->type = SSH_CHANNEL_CLOSED;
970 packet_start(SSH_MSG_CHANNEL_CLOSE);
971 packet_put_int(c->remote_id);
972 packet_send();
973 }
974}
975
976static void
30460aeb 977channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 978{
979 int ret = x11_open_helper(&c->output);
980
981 /* c->force_drain = 1; */
982
983 if (ret == 1) {
984 c->type = SSH_CHANNEL_OPEN;
473db5ab 985 channel_pre_open(c, readset, writeset);
986 } else if (ret == -1) {
987 logit("X11 connection rejected because of wrong authentication.");
988 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
989 chan_read_failed(c);
990 buffer_clear(&c->input);
991 chan_ibuf_empty(c);
992 buffer_clear(&c->output);
993 /* for proto v1, the peer will send an IEOF */
3c0ef626 994 if (compat20)
473db5ab 995 chan_write_failed(c);
3c0ef626 996 else
473db5ab 997 c->type = SSH_CHANNEL_OPEN;
998 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
3c0ef626 999 }
1000}
1001
1002/* try to decode a socks4 header */
30460aeb 1003/* ARGSUSED */
3c0ef626 1004static int
30460aeb 1005channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1006{
473db5ab 1007 char *p, *host;
1008 u_int len, have, i, found;
1009 char username[256];
3c0ef626 1010 struct {
1011 u_int8_t version;
1012 u_int8_t command;
1013 u_int16_t dest_port;
1014 struct in_addr dest_addr;
1015 } s4_req, s4_rsp;
1016
1017 debug2("channel %d: decode socks4", c->self);
1018
1019 have = buffer_len(&c->input);
1020 len = sizeof(s4_req);
1021 if (have < len)
1022 return 0;
1023 p = buffer_ptr(&c->input);
1024 for (found = 0, i = len; i < have; i++) {
1025 if (p[i] == '\0') {
1026 found = 1;
1027 break;
1028 }
1029 if (i > 1024) {
1030 /* the peer is probably sending garbage */
1031 debug("channel %d: decode socks4: too long",
1032 c->self);
1033 return -1;
1034 }
1035 }
1036 if (!found)
1037 return 0;
1038 buffer_get(&c->input, (char *)&s4_req.version, 1);
1039 buffer_get(&c->input, (char *)&s4_req.command, 1);
1040 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1041 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1042 have = buffer_len(&c->input);
1043 p = buffer_ptr(&c->input);
1044 len = strlen(p);
1045 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1046 if (len > have)
1047 fatal("channel %d: decode socks4: len %d > have %d",
1048 c->self, len, have);
1049 strlcpy(username, p, sizeof(username));
1050 buffer_consume(&c->input, len);
1051 buffer_consume(&c->input, 1); /* trailing '\0' */
1052
1053 host = inet_ntoa(s4_req.dest_addr);
1054 strlcpy(c->path, host, sizeof(c->path));
1055 c->host_port = ntohs(s4_req.dest_port);
473db5ab 1056
1057 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
3c0ef626 1058 c->self, host, c->host_port, s4_req.command);
1059
1060 if (s4_req.command != 1) {
1061 debug("channel %d: cannot handle: socks4 cn %d",
1062 c->self, s4_req.command);
1063 return -1;
1064 }
1065 s4_rsp.version = 0; /* vn: 0 for reply */
1066 s4_rsp.command = 90; /* cd: req granted */
1067 s4_rsp.dest_port = 0; /* ignored */
1068 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
30460aeb 1069 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
3c0ef626 1070 return 1;
1071}
1072
473db5ab 1073/* try to decode a socks5 header */
1074#define SSH_SOCKS5_AUTHDONE 0x1000
1075#define SSH_SOCKS5_NOAUTH 0x00
1076#define SSH_SOCKS5_IPV4 0x01
1077#define SSH_SOCKS5_DOMAIN 0x03
1078#define SSH_SOCKS5_IPV6 0x04
1079#define SSH_SOCKS5_CONNECT 0x01
1080#define SSH_SOCKS5_SUCCESS 0x00
1081
30460aeb 1082/* ARGSUSED */
473db5ab 1083static int
30460aeb 1084channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
473db5ab 1085{
1086 struct {
1087 u_int8_t version;
1088 u_int8_t command;
1089 u_int8_t reserved;
1090 u_int8_t atyp;
1091 } s5_req, s5_rsp;
1092 u_int16_t dest_port;
1093 u_char *p, dest_addr[255+1];
30460aeb 1094 u_int have, need, i, found, nmethods, addrlen, af;
473db5ab 1095
1096 debug2("channel %d: decode socks5", c->self);
1097 p = buffer_ptr(&c->input);
1098 if (p[0] != 0x05)
1099 return -1;
1100 have = buffer_len(&c->input);
1101 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1102 /* format: ver | nmethods | methods */
1103 if (have < 2)
1104 return 0;
1105 nmethods = p[1];
1106 if (have < nmethods + 2)
1107 return 0;
1108 /* look for method: "NO AUTHENTICATION REQUIRED" */
0b90ac93 1109 for (found = 0, i = 2; i < nmethods + 2; i++) {
30460aeb 1110 if (p[i] == SSH_SOCKS5_NOAUTH) {
473db5ab 1111 found = 1;
1112 break;
1113 }
1114 }
1115 if (!found) {
1116 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1117 c->self);
1118 return -1;
1119 }
1120 buffer_consume(&c->input, nmethods + 2);
1121 buffer_put_char(&c->output, 0x05); /* version */
1122 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1123 FD_SET(c->sock, writeset);
1124 c->flags |= SSH_SOCKS5_AUTHDONE;
1125 debug2("channel %d: socks5 auth done", c->self);
1126 return 0; /* need more */
1127 }
1128 debug2("channel %d: socks5 post auth", c->self);
1129 if (have < sizeof(s5_req)+1)
1130 return 0; /* need more */
30460aeb 1131 memcpy(&s5_req, p, sizeof(s5_req));
473db5ab 1132 if (s5_req.version != 0x05 ||
1133 s5_req.command != SSH_SOCKS5_CONNECT ||
1134 s5_req.reserved != 0x00) {
1135 debug2("channel %d: only socks5 connect supported", c->self);
1136 return -1;
1137 }
1138 switch (s5_req.atyp){
1139 case SSH_SOCKS5_IPV4:
1140 addrlen = 4;
1141 af = AF_INET;
1142 break;
1143 case SSH_SOCKS5_DOMAIN:
1144 addrlen = p[sizeof(s5_req)];
1145 af = -1;
1146 break;
1147 case SSH_SOCKS5_IPV6:
1148 addrlen = 16;
1149 af = AF_INET6;
1150 break;
1151 default:
1152 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1153 return -1;
1154 }
30460aeb 1155 need = sizeof(s5_req) + addrlen + 2;
1156 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1157 need++;
1158 if (have < need)
473db5ab 1159 return 0;
1160 buffer_consume(&c->input, sizeof(s5_req));
1161 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1162 buffer_consume(&c->input, 1); /* host string length */
1163 buffer_get(&c->input, (char *)&dest_addr, addrlen);
1164 buffer_get(&c->input, (char *)&dest_port, 2);
1165 dest_addr[addrlen] = '\0';
1166 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1167 strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1168 else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1169 return -1;
1170 c->host_port = ntohs(dest_port);
1171
1172 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1173 c->self, c->path, c->host_port, s5_req.command);
1174
1175 s5_rsp.version = 0x05;
1176 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1177 s5_rsp.reserved = 0; /* ignored */
1178 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1179 ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1180 dest_port = 0; /* ignored */
1181
30460aeb 1182 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1183 buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1184 buffer_append(&c->output, &dest_port, sizeof(dest_port));
473db5ab 1185 return 1;
1186}
1187
3c0ef626 1188/* dynamic port forwarding */
1189static void
30460aeb 1190channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1191{
1192 u_char *p;
473db5ab 1193 u_int have;
1194 int ret;
3c0ef626 1195
1196 have = buffer_len(&c->input);
1197 c->delayed = 0;
1198 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1199 /* buffer_dump(&c->input); */
1200 /* check if the fixed size part of the packet is in buffer. */
473db5ab 1201 if (have < 3) {
3c0ef626 1202 /* need more */
1203 FD_SET(c->sock, readset);
1204 return;
1205 }
1206 /* try to guess the protocol */
1207 p = buffer_ptr(&c->input);
1208 switch (p[0]) {
1209 case 0x04:
1210 ret = channel_decode_socks4(c, readset, writeset);
1211 break;
473db5ab 1212 case 0x05:
1213 ret = channel_decode_socks5(c, readset, writeset);
1214 break;
3c0ef626 1215 default:
1216 ret = -1;
1217 break;
1218 }
1219 if (ret < 0) {
1220 chan_mark_dead(c);
1221 } else if (ret == 0) {
1222 debug2("channel %d: pre_dynamic: need more", c->self);
1223 /* need more */
1224 FD_SET(c->sock, readset);
1225 } else {
1226 /* switch to the next state */
1227 c->type = SSH_CHANNEL_OPENING;
1228 port_open_helper(c, "direct-tcpip");
1229 }
1230}
1231
1232/* This is our fake X11 server socket. */
30460aeb 1233/* ARGSUSED */
3c0ef626 1234static void
30460aeb 1235channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1236{
1237 Channel *nc;
5156b1a1 1238 struct sockaddr_storage addr;
3c0ef626 1239 int newsock;
1240 socklen_t addrlen;
1241 char buf[16384], *remote_ipaddr;
1242 int remote_port;
1243
1244 if (FD_ISSET(c->sock, readset)) {
1245 debug("X11 connection requested.");
1246 addrlen = sizeof(addr);
5156b1a1 1247 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
473db5ab 1248 if (c->single_connection) {
1249 debug2("single_connection: closing X11 listener.");
1250 channel_close_fd(&c->sock);
1251 chan_mark_dead(c);
1252 }
3c0ef626 1253 if (newsock < 0) {
1254 error("accept: %.100s", strerror(errno));
1255 return;
1256 }
473db5ab 1257 set_nodelay(newsock);
3c0ef626 1258 remote_ipaddr = get_peer_ipaddr(newsock);
1259 remote_port = get_peer_port(newsock);
1260 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1261 remote_ipaddr, remote_port);
1262
1263 nc = channel_new("accepted x11 socket",
1264 SSH_CHANNEL_OPENING, newsock, newsock, -1,
473db5ab 1265 c->local_window_max, c->local_maxpacket, 0, buf, 1);
3c0ef626 1266 if (compat20) {
1267 packet_start(SSH2_MSG_CHANNEL_OPEN);
1268 packet_put_cstring("x11");
1269 packet_put_int(nc->self);
473db5ab 1270 packet_put_int(nc->local_window_max);
1271 packet_put_int(nc->local_maxpacket);
3c0ef626 1272 /* originator ipaddr and port */
1273 packet_put_cstring(remote_ipaddr);
1274 if (datafellows & SSH_BUG_X11FWD) {
473db5ab 1275 debug2("ssh2 x11 bug compat mode");
3c0ef626 1276 } else {
1277 packet_put_int(remote_port);
1278 }
1279 packet_send();
1280 } else {
1281 packet_start(SSH_SMSG_X11_OPEN);
1282 packet_put_int(nc->self);
1283 if (packet_get_protocol_flags() &
1284 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1285 packet_put_cstring(buf);
1286 packet_send();
1287 }
1288 xfree(remote_ipaddr);
1289 }
1290}
1291
1292static void
1293port_open_helper(Channel *c, char *rtype)
1294{
1295 int direct;
1296 char buf[1024];
1297 char *remote_ipaddr = get_peer_ipaddr(c->sock);
473db5ab 1298 int remote_port = get_peer_port(c->sock);
3c0ef626 1299
1300 direct = (strcmp(rtype, "direct-tcpip") == 0);
1301
1302 snprintf(buf, sizeof buf,
1303 "%s: listening port %d for %.100s port %d, "
1304 "connect from %.200s port %d",
1305 rtype, c->listening_port, c->path, c->host_port,
1306 remote_ipaddr, remote_port);
1307
1308 xfree(c->remote_name);
1309 c->remote_name = xstrdup(buf);
1310
1311 if (compat20) {
1312 packet_start(SSH2_MSG_CHANNEL_OPEN);
1313 packet_put_cstring(rtype);
1314 packet_put_int(c->self);
1315 packet_put_int(c->local_window_max);
1316 packet_put_int(c->local_maxpacket);
1317 if (direct) {
1318 /* target host, port */
1319 packet_put_cstring(c->path);
1320 packet_put_int(c->host_port);
1321 } else {
1322 /* listen address, port */
1323 packet_put_cstring(c->path);
1324 packet_put_int(c->listening_port);
1325 }
1326 /* originator host and port */
1327 packet_put_cstring(remote_ipaddr);
473db5ab 1328 packet_put_int((u_int)remote_port);
3c0ef626 1329 packet_send();
1330 } else {
1331 packet_start(SSH_MSG_PORT_OPEN);
1332 packet_put_int(c->self);
1333 packet_put_cstring(c->path);
1334 packet_put_int(c->host_port);
1335 if (packet_get_protocol_flags() &
1336 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1337 packet_put_cstring(c->remote_name);
1338 packet_send();
1339 }
1340 xfree(remote_ipaddr);
1341}
1342
08822d99 1343static void
1344channel_set_reuseaddr(int fd)
1345{
1346 int on = 1;
1347
1348 /*
1349 * Set socket options.
1350 * Allow local port reuse in TIME_WAIT.
1351 */
1352 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1353 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1354}
1355
3c0ef626 1356/*
1357 * This socket is listening for connections to a forwarded TCP/IP port.
1358 */
30460aeb 1359/* ARGSUSED */
3c0ef626 1360static void
30460aeb 1361channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1362{
1363 Channel *nc;
5156b1a1 1364 struct sockaddr_storage addr;
3c0ef626 1365 int newsock, nextstate;
1366 socklen_t addrlen;
1367 char *rtype;
1368
1369 if (FD_ISSET(c->sock, readset)) {
1370 debug("Connection to port %d forwarding "
1371 "to %.100s port %d requested.",
1372 c->listening_port, c->path, c->host_port);
1373
1374 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1375 nextstate = SSH_CHANNEL_OPENING;
1376 rtype = "forwarded-tcpip";
1377 } else {
1378 if (c->host_port == 0) {
1379 nextstate = SSH_CHANNEL_DYNAMIC;
1380 rtype = "dynamic-tcpip";
1381 } else {
1382 nextstate = SSH_CHANNEL_OPENING;
1383 rtype = "direct-tcpip";
1384 }
1385 }
1386
1387 addrlen = sizeof(addr);
5156b1a1 1388 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
3c0ef626 1389 if (newsock < 0) {
1390 error("accept: %.100s", strerror(errno));
1391 return;
1392 }
473db5ab 1393 set_nodelay(newsock);
1394 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1395 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
3c0ef626 1396 nc->listening_port = c->listening_port;
1397 nc->host_port = c->host_port;
1398 strlcpy(nc->path, c->path, sizeof(nc->path));
1399
1400 if (nextstate == SSH_CHANNEL_DYNAMIC) {
1401 /*
1402 * do not call the channel_post handler until
1403 * this flag has been reset by a pre-handler.
1404 * otherwise the FD_ISSET calls might overflow
1405 */
1406 nc->delayed = 1;
1407 } else {
1408 port_open_helper(nc, rtype);
1409 }
1410 }
1411}
1412
1413/*
1414 * This is the authentication agent socket listening for connections from
1415 * clients.
1416 */
30460aeb 1417/* ARGSUSED */
3c0ef626 1418static void
30460aeb 1419channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1420{
1421 Channel *nc;
3c0ef626 1422 int newsock;
5156b1a1 1423 struct sockaddr_storage addr;
3c0ef626 1424 socklen_t addrlen;
1425
1426 if (FD_ISSET(c->sock, readset)) {
1427 addrlen = sizeof(addr);
5156b1a1 1428 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
3c0ef626 1429 if (newsock < 0) {
1430 error("accept from auth socket: %.100s", strerror(errno));
1431 return;
1432 }
3c0ef626 1433 nc = channel_new("accepted auth socket",
1434 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1435 c->local_window_max, c->local_maxpacket,
473db5ab 1436 0, "accepted auth socket", 1);
3c0ef626 1437 if (compat20) {
1438 packet_start(SSH2_MSG_CHANNEL_OPEN);
1439 packet_put_cstring("auth-agent@openssh.com");
1440 packet_put_int(nc->self);
1441 packet_put_int(c->local_window_max);
1442 packet_put_int(c->local_maxpacket);
1443 } else {
1444 packet_start(SSH_SMSG_AGENT_OPEN);
1445 packet_put_int(nc->self);
1446 }
1447 packet_send();
1448 }
1449}
1450
30460aeb 1451/* ARGSUSED */
3c0ef626 1452static void
30460aeb 1453channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1454{
5156b1a1 1455 int err = 0, sock;
3c0ef626 1456 socklen_t sz = sizeof(err);
1457
1458 if (FD_ISSET(c->sock, writeset)) {
473db5ab 1459 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
3c0ef626 1460 err = errno;
1461 error("getsockopt SO_ERROR failed");
1462 }
1463 if (err == 0) {
5156b1a1 1464 debug("channel %d: connected to %s port %d",
1465 c->self, c->connect_ctx.host, c->connect_ctx.port);
1466 channel_connect_ctx_free(&c->connect_ctx);
3c0ef626 1467 c->type = SSH_CHANNEL_OPEN;
1468 if (compat20) {
1469 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1470 packet_put_int(c->remote_id);
1471 packet_put_int(c->self);
1472 packet_put_int(c->local_window);
1473 packet_put_int(c->local_maxpacket);
1474 } else {
1475 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1476 packet_put_int(c->remote_id);
1477 packet_put_int(c->self);
1478 }
1479 } else {
5156b1a1 1480 debug("channel %d: connection failed: %s",
3c0ef626 1481 c->self, strerror(err));
5156b1a1 1482 /* Try next address, if any */
1483 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1484 close(c->sock);
1485 c->sock = c->rfd = c->wfd = sock;
1486 channel_max_fd = channel_find_maxfd();
1487 return;
1488 }
1489 /* Exhausted all addresses */
1490 error("connect_to %.100s port %d: failed.",
1491 c->connect_ctx.host, c->connect_ctx.port);
1492 channel_connect_ctx_free(&c->connect_ctx);
3c0ef626 1493 if (compat20) {
1494 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1495 packet_put_int(c->remote_id);
1496 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1497 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1498 packet_put_cstring(strerror(err));
1499 packet_put_cstring("");
1500 }
1501 } else {
1502 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1503 packet_put_int(c->remote_id);
1504 }
1505 chan_mark_dead(c);
1506 }
1507 packet_send();
1508 }
1509}
1510
30460aeb 1511/* ARGSUSED */
3c0ef626 1512static int
30460aeb 1513channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1514{
473db5ab 1515 char buf[CHAN_RBUF];
fa0f0f45 1516 int len, force;
3c0ef626 1517
fa0f0f45 1518 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1519 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
30460aeb 1520 errno = 0;
3c0ef626 1521 len = read(c->rfd, buf, sizeof(buf));
5156b1a1 1522 if (len < 0 && (errno == EINTR ||
1523 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
3c0ef626 1524 return 1;
30460aeb 1525#ifndef PTY_ZEROREAD
3c0ef626 1526 if (len <= 0) {
30460aeb 1527#else
1528 if ((!c->isatty && len <= 0) ||
1529 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1530#endif
473db5ab 1531 debug2("channel %d: read<=0 rfd %d len %d",
3c0ef626 1532 c->self, c->rfd, len);
1533 if (c->type != SSH_CHANNEL_OPEN) {
473db5ab 1534 debug2("channel %d: not open", c->self);
3c0ef626 1535 chan_mark_dead(c);
1536 return -1;
1537 } else if (compat13) {
473db5ab 1538 buffer_clear(&c->output);
3c0ef626 1539 c->type = SSH_CHANNEL_INPUT_DRAINING;
473db5ab 1540 debug2("channel %d: input draining.", c->self);
3c0ef626 1541 } else {
1542 chan_read_failed(c);
1543 }
1544 return -1;
1545 }
473db5ab 1546 if (c->input_filter != NULL) {
3c0ef626 1547 if (c->input_filter(c, buf, len) == -1) {
473db5ab 1548 debug2("channel %d: filter stops", c->self);
3c0ef626 1549 chan_read_failed(c);
1550 }
08822d99 1551 } else if (c->datagram) {
1552 buffer_put_string(&c->input, buf, len);
3c0ef626 1553 } else {
1554 buffer_append(&c->input, buf, len);
1555 }
1556 }
1557 return 1;
1558}
30460aeb 1559
1560/* ARGSUSED */
3c0ef626 1561static int
30460aeb 1562channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1563{
1564 struct termios tio;
08822d99 1565 u_char *data = NULL, *buf;
3c0ef626 1566 u_int dlen;
1567 int len;
1568
1569 /* Send buffered output data to the socket. */
1570 if (c->wfd != -1 &&
1571 FD_ISSET(c->wfd, writeset) &&
1572 buffer_len(&c->output) > 0) {
08822d99 1573 if (c->output_filter != NULL) {
1574 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1575 debug2("channel %d: filter stops", c->self);
1576 if (c->type != SSH_CHANNEL_OPEN)
1577 chan_mark_dead(c);
1578 else
1579 chan_write_failed(c);
1580 return -1;
1581 }
1582 } else if (c->datagram) {
1583 buf = data = buffer_get_string(&c->output, &dlen);
1584 } else {
1585 buf = data = buffer_ptr(&c->output);
1586 dlen = buffer_len(&c->output);
1587 }
1588
1589 if (c->datagram) {
1590 /* ignore truncated writes, datagrams might get lost */
1591 c->local_consumed += dlen + 4;
1592 len = write(c->wfd, buf, dlen);
1593 xfree(data);
5156b1a1 1594 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1595 errno == EWOULDBLOCK))
08822d99 1596 return 1;
1597 if (len <= 0) {
1598 if (c->type != SSH_CHANNEL_OPEN)
1599 chan_mark_dead(c);
1600 else
1601 chan_write_failed(c);
1602 return -1;
1603 }
1604 return 1;
1605 }
473db5ab 1606#ifdef _AIX
1607 /* XXX: Later AIX versions can't push as much data to tty */
1608 if (compat20 && c->wfd_isatty)
1609 dlen = MIN(dlen, 8*1024);
1610#endif
08822d99 1611
1612 len = write(c->wfd, buf, dlen);
5156b1a1 1613 if (len < 0 &&
1614 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
3c0ef626 1615 return 1;
1616 if (len <= 0) {
1617 if (c->type != SSH_CHANNEL_OPEN) {
473db5ab 1618 debug2("channel %d: not open", c->self);
3c0ef626 1619 chan_mark_dead(c);
1620 return -1;
1621 } else if (compat13) {
473db5ab 1622 buffer_clear(&c->output);
1623 debug2("channel %d: input draining.", c->self);
3c0ef626 1624 c->type = SSH_CHANNEL_INPUT_DRAINING;
1625 } else {
1626 chan_write_failed(c);
1627 }
1628 return -1;
1629 }
08822d99 1630 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
3c0ef626 1631 if (tcgetattr(c->wfd, &tio) == 0 &&
1632 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1633 /*
1634 * Simulate echo to reduce the impact of
1635 * traffic analysis. We need to match the
1636 * size of a SSH2_MSG_CHANNEL_DATA message
08822d99 1637 * (4 byte channel id + buf)
3c0ef626 1638 */
1639 packet_send_ignore(4 + len);
1640 packet_send();
1641 }
1642 }
1643 buffer_consume(&c->output, len);
1644 if (compat20 && len > 0) {
1645 c->local_consumed += len;
1646 }
1647 }
1648 return 1;
1649}
30460aeb 1650
3c0ef626 1651static int
30460aeb 1652channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1653{
473db5ab 1654 char buf[CHAN_RBUF];
3c0ef626 1655 int len;
1656
1657/** XXX handle drain efd, too */
1658 if (c->efd != -1) {
1659 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1660 FD_ISSET(c->efd, writeset) &&
1661 buffer_len(&c->extended) > 0) {
1662 len = write(c->efd, buffer_ptr(&c->extended),
1663 buffer_len(&c->extended));
1664 debug2("channel %d: written %d to efd %d",
1665 c->self, len, c->efd);
5156b1a1 1666 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1667 errno == EWOULDBLOCK))
3c0ef626 1668 return 1;
1669 if (len <= 0) {
1670 debug2("channel %d: closing write-efd %d",
1671 c->self, c->efd);
1672 channel_close_fd(&c->efd);
1673 } else {
1674 buffer_consume(&c->extended, len);
1675 c->local_consumed += len;
1676 }
1677 } else if (c->extended_usage == CHAN_EXTENDED_READ &&
0b90ac93 1678 (c->detach_close || FD_ISSET(c->efd, readset))) {
3c0ef626 1679 len = read(c->efd, buf, sizeof(buf));
1680 debug2("channel %d: read %d from efd %d",
473db5ab 1681 c->self, len, c->efd);
5156b1a1 1682 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1683 errno == EWOULDBLOCK) && !c->detach_close)))
3c0ef626 1684 return 1;
1685 if (len <= 0) {
1686 debug2("channel %d: closing read-efd %d",
1687 c->self, c->efd);
1688 channel_close_fd(&c->efd);
1689 } else {
1690 buffer_append(&c->extended, buf, len);
1691 }
1692 }
1693 }
1694 return 1;
1695}
30460aeb 1696
1697/* ARGSUSED */
3c0ef626 1698static int
30460aeb 1699channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset)
473db5ab 1700{
1701 char buf[16];
1702 int len;
1703
1704 /* Monitor control fd to detect if the slave client exits */
1705 if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1706 len = read(c->ctl_fd, buf, sizeof(buf));
5156b1a1 1707 if (len < 0 &&
1708 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
473db5ab 1709 return 1;
1710 if (len <= 0) {
1711 debug2("channel %d: ctl read<=0", c->self);
1712 if (c->type != SSH_CHANNEL_OPEN) {
1713 debug2("channel %d: not open", c->self);
1714 chan_mark_dead(c);
1715 return -1;
1716 } else {
1717 chan_read_failed(c);
1718 chan_write_failed(c);
1719 }
1720 return -1;
1721 } else
1722 fatal("%s: unexpected data on ctl fd", __func__);
1723 }
1724 return 1;
1725}
30460aeb 1726
473db5ab 1727static int
3c0ef626 1728channel_check_window(Channel *c)
1729{
1730 if (c->type == SSH_CHANNEL_OPEN &&
1731 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
fa0f0f45 1732 ((c->local_window_max - c->local_window >
1733 c->local_maxpacket*3) ||
1734 c->local_window < c->local_window_max/2) &&
3c0ef626 1735 c->local_consumed > 0) {
a7213e65 1736 u_int addition = 0;
1737 /* adjust max window size if we are in a dynamic environment */
1738 if (c->dynamic_window && (c->tcpwinsz > c->local_window_max)) {
6df46d40 1739 /* grow the window somewhat aggressively to maintain pressure */
1740 addition = 1.5*(c->tcpwinsz - c->local_window_max);
473db5ab 1741 c->local_window_max += addition;
1742 }
3c0ef626 1743 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1744 packet_put_int(c->remote_id);
473db5ab 1745 packet_put_int(c->local_consumed + addition);
3c0ef626 1746 packet_send();
1747 debug2("channel %d: window %d sent adjust %d",
1748 c->self, c->local_window,
1749 c->local_consumed);
473db5ab 1750 c->local_window += c->local_consumed + addition;
3c0ef626 1751 c->local_consumed = 0;
1752 }
1753 return 1;
1754}
1755
1756static void
30460aeb 1757channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1758{
1759 if (c->delayed)
1760 return;
1761 channel_handle_rfd(c, readset, writeset);
1762 channel_handle_wfd(c, readset, writeset);
473db5ab 1763 if (!compat20)
3c0ef626 1764 return;
3c0ef626 1765 channel_handle_efd(c, readset, writeset);
473db5ab 1766 channel_handle_ctl(c, readset, writeset);
3c0ef626 1767 channel_check_window(c);
1768}
1769
30460aeb 1770/* ARGSUSED */
3c0ef626 1771static void
30460aeb 1772channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1773{
1774 int len;
473db5ab 1775
3c0ef626 1776 /* Send buffered output data to the socket. */
1777 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1778 len = write(c->sock, buffer_ptr(&c->output),
1779 buffer_len(&c->output));
1780 if (len <= 0)
473db5ab 1781 buffer_clear(&c->output);
3c0ef626 1782 else
1783 buffer_consume(&c->output, len);
1784 }
1785}
1786
1787static void
1788channel_handler_init_20(void)
1789{
473db5ab 1790 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
3c0ef626 1791 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1792 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1793 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1794 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1795 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1796 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1797 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1798
473db5ab 1799 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
3c0ef626 1800 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1801 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1802 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1803 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1804 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
473db5ab 1805 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
3c0ef626 1806}
1807
1808static void
1809channel_handler_init_13(void)
1810{
1811 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1812 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1813 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1814 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1815 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1816 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1817 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1818 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1819 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1820
473db5ab 1821 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
3c0ef626 1822 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1823 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1824 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1825 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1826 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
473db5ab 1827 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
3c0ef626 1828}
1829
1830static void
1831channel_handler_init_15(void)
1832{
473db5ab 1833 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
3c0ef626 1834 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1835 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1836 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1837 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1838 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1839 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1840
1841 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1842 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1843 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
473db5ab 1844 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
3c0ef626 1845 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
473db5ab 1846 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
3c0ef626 1847}
1848
1849static void
1850channel_handler_init(void)
1851{
1852 int i;
473db5ab 1853
1854 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
3c0ef626 1855 channel_pre[i] = NULL;
1856 channel_post[i] = NULL;
1857 }
1858 if (compat20)
1859 channel_handler_init_20();
1860 else if (compat13)
1861 channel_handler_init_13();
1862 else
1863 channel_handler_init_15();
1864}
1865
1866/* gc dead channels */
1867static void
1868channel_garbage_collect(Channel *c)
1869{
1870 if (c == NULL)
1871 return;
1872 if (c->detach_user != NULL) {
08822d99 1873 if (!chan_is_dead(c, c->detach_close))
3c0ef626 1874 return;
473db5ab 1875 debug2("channel %d: gc: notify user", c->self);
3c0ef626 1876 c->detach_user(c->self, NULL);
1877 /* if we still have a callback */
1878 if (c->detach_user != NULL)
1879 return;
473db5ab 1880 debug2("channel %d: gc: user detached", c->self);
3c0ef626 1881 }
1882 if (!chan_is_dead(c, 1))
1883 return;
473db5ab 1884 debug2("channel %d: garbage collecting", c->self);
3c0ef626 1885 channel_free(c);
1886}
1887
1888static void
30460aeb 1889channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
3c0ef626 1890{
1891 static int did_init = 0;
473db5ab 1892 u_int i;
3c0ef626 1893 Channel *c;
1894
1895 if (!did_init) {
1896 channel_handler_init();
1897 did_init = 1;
1898 }
1899 for (i = 0; i < channels_alloc; i++) {
1900 c = channels[i];
1901 if (c == NULL)
1902 continue;
1903 if (ftab[c->type] != NULL)
1904 (*ftab[c->type])(c, readset, writeset);
1905 channel_garbage_collect(c);
1906 }
1907}
1908
1909/*
1910 * Allocate/update select bitmasks and add any bits relevant to channels in
1911 * select bitmasks.
1912 */
1913void
1914channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
473db5ab 1915 u_int *nallocp, int rekeying)
3c0ef626 1916{
30460aeb 1917 u_int n, sz, nfdset;
3c0ef626 1918
1919 n = MAX(*maxfdp, channel_max_fd);
1920
30460aeb 1921 nfdset = howmany(n+1, NFDBITS);
1922 /* Explicitly test here, because xrealloc isn't always called */
1923 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
1924 fatal("channel_prepare_select: max_fd (%d) is too large", n);
1925 sz = nfdset * sizeof(fd_mask);
1926
3c0ef626 1927 /* perhaps check sz < nalloc/2 and shrink? */
1928 if (*readsetp == NULL || sz > *nallocp) {
30460aeb 1929 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
1930 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
3c0ef626 1931 *nallocp = sz;
1932 }
1933 *maxfdp = n;
1934 memset(*readsetp, 0, sz);
1935 memset(*writesetp, 0, sz);
1936
1937 if (!rekeying)
1938 channel_handler(channel_pre, *readsetp, *writesetp);
1939}
1940
1941/*
1942 * After select, perform any appropriate operations for channels which have
1943 * events pending.
1944 */
1945void
30460aeb 1946channel_after_select(fd_set *readset, fd_set *writeset)
3c0ef626 1947{
1948 channel_handler(channel_post, readset, writeset);
1949}
1950
1951
1952/* If there is data to send to the connection, enqueue some of it now. */
fa7499cc 1953int
473db5ab 1954channel_output_poll(void)
3c0ef626 1955{
3c0ef626 1956 Channel *c;
473db5ab 1957 u_int i, len;
fa7499cc 1958 int packet_length = 0;
3c0ef626 1959
1960 for (i = 0; i < channels_alloc; i++) {
1961 c = channels[i];
1962 if (c == NULL)
1963 continue;
1964
1965 /*
1966 * We are only interested in channels that can have buffered
1967 * incoming data.
1968 */
1969 if (compat13) {
1970 if (c->type != SSH_CHANNEL_OPEN &&
1971 c->type != SSH_CHANNEL_INPUT_DRAINING)
1972 continue;
1973 } else {
1974 if (c->type != SSH_CHANNEL_OPEN)
1975 continue;
1976 }
1977 if (compat20 &&
1978 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1979 /* XXX is this true? */
1980 debug3("channel %d: will not send data after close", c->self);
1981 continue;
1982 }
1983
1984 /* Get the amount of buffered data for this channel. */
1985 if ((c->istate == CHAN_INPUT_OPEN ||
1986 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1987 (len = buffer_len(&c->input)) > 0) {
08822d99 1988 if (c->datagram) {
1989 if (len > 0) {
1990 u_char *data;
1991 u_int dlen;
1992
1993 data = buffer_get_string(&c->input,
1994 &dlen);
1995 packet_start(SSH2_MSG_CHANNEL_DATA);
1996 packet_put_int(c->remote_id);
1997 packet_put_string(data, dlen);
fa7499cc 1998 packet_length = packet_send();
08822d99 1999 c->remote_window -= dlen + 4;
2000 xfree(data);
2001 }
2002 continue;
2003 }
3c0ef626 2004 /*
2005 * Send some data for the other side over the secure
2006 * connection.
2007 */
2008 if (compat20) {
2009 if (len > c->remote_window)
2010 len = c->remote_window;
2011 if (len > c->remote_maxpacket)
2012 len = c->remote_maxpacket;
2013 } else {
2014 if (packet_is_interactive()) {
2015 if (len > 1024)
2016 len = 512;
2017 } else {
2018 /* Keep the packets at reasonable size. */
2019 if (len > packet_get_maxsize()/2)
2020 len = packet_get_maxsize()/2;
2021 }
2022 }
2023 if (len > 0) {
2024 packet_start(compat20 ?
2025 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2026 packet_put_int(c->remote_id);
2027 packet_put_string(buffer_ptr(&c->input), len);
fa7499cc 2028 packet_length = packet_send();
3c0ef626 2029 buffer_consume(&c->input, len);
2030 c->remote_window -= len;
2031 }
2032 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2033 if (compat13)
2034 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2035 /*
2036 * input-buffer is empty and read-socket shutdown:
473db5ab 2037 * tell peer, that we will not send more data: send IEOF.
2038 * hack for extended data: delay EOF if EFD still in use.
3c0ef626 2039 */
473db5ab 2040 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2041 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2042 c->self, c->efd, buffer_len(&c->extended));
2043 else
2044 chan_ibuf_empty(c);
3c0ef626 2045 }
2046 /* Send extended data, i.e. stderr */
2047 if (compat20 &&
473db5ab 2048 !(c->flags & CHAN_EOF_SENT) &&
3c0ef626 2049 c->remote_window > 0 &&
2050 (len = buffer_len(&c->extended)) > 0 &&
2051 c->extended_usage == CHAN_EXTENDED_READ) {
473db5ab 2052 debug2("channel %d: rwin %u elen %u euse %d",
3c0ef626 2053 c->self, c->remote_window, buffer_len(&c->extended),
2054 c->extended_usage);
2055 if (len > c->remote_window)
2056 len = c->remote_window;
2057 if (len > c->remote_maxpacket)
2058 len = c->remote_maxpacket;
2059 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2060 packet_put_int(c->remote_id);
2061 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2062 packet_put_string(buffer_ptr(&c->extended), len);
fa7499cc 2063 packet_length = packet_send();
3c0ef626 2064 buffer_consume(&c->extended, len);
2065 c->remote_window -= len;
2066 debug2("channel %d: sent ext data %d", c->self, len);
2067 }
2068 }
fa7499cc 2069 return (packet_length);
3c0ef626 2070}
2071
2072
2073/* -- protocol input */
2074
30460aeb 2075/* ARGSUSED */
3c0ef626 2076void
473db5ab 2077channel_input_data(int type, u_int32_t seq, void *ctxt)
3c0ef626 2078{
2079 int id;
2080 char *data;
2081 u_int data_len;
2082 Channel *c;
2083
2084 /* Get the channel number and verify it. */
2085 id = packet_get_int();
2086 c = channel_lookup(id);
2087 if (c == NULL)
2088 packet_disconnect("Received data for nonexistent channel %d.", id);
2089
2090 /* Ignore any data for non-open channels (might happen on close) */
2091 if (c->type != SSH_CHANNEL_OPEN &&
2092 c->type != SSH_CHANNEL_X11_OPEN)
2093 return;
2094
3c0ef626 2095 /* Get the data. */
5156b1a1 2096 data = packet_get_string_ptr(&data_len);
3c0ef626 2097
473db5ab 2098 /*
2099 * Ignore data for protocol > 1.3 if output end is no longer open.
2100 * For protocol 2 the sending side is reducing its window as it sends
2101 * data, so we must 'fake' consumption of the data in order to ensure
2102 * that window updates are sent back. Otherwise the connection might
2103 * deadlock.
2104 */
2105 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2106 if (compat20) {
2107 c->local_window -= data_len;
2108 c->local_consumed += data_len;
2109 }
473db5ab 2110 return;
2111 }
2112
2113 if (compat20) {
3c0ef626 2114 if (data_len > c->local_maxpacket) {
473db5ab 2115 logit("channel %d: rcvd big packet %d, maxpack %d",
3c0ef626 2116 c->self, data_len, c->local_maxpacket);
2117 }
2118 if (data_len > c->local_window) {
473db5ab 2119 logit("channel %d: rcvd too much data %d, win %d",
3c0ef626 2120 c->self, data_len, c->local_window);
3c0ef626 2121 return;
2122 }
2123 c->local_window -= data_len;
3c0ef626 2124 }
08822d99 2125 if (c->datagram)
2126 buffer_put_string(&c->output, data, data_len);
2127 else
2128 buffer_append(&c->output, data, data_len);
5156b1a1 2129 packet_check_eom();
3c0ef626 2130}
2131
30460aeb 2132/* ARGSUSED */
3c0ef626 2133void
473db5ab 2134channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
3c0ef626 2135{
2136 int id;
3c0ef626 2137 char *data;
473db5ab 2138 u_int data_len, tcode;
3c0ef626 2139 Channel *c;
2140
2141 /* Get the channel number and verify it. */
2142 id = packet_get_int();
2143 c = channel_lookup(id);
2144
2145 if (c == NULL)
2146 packet_disconnect("Received extended_data for bad channel %d.", id);
2147 if (c->type != SSH_CHANNEL_OPEN) {
473db5ab 2148 logit("channel %d: ext data for non open", id);
3c0ef626 2149 return;
2150 }
473db5ab 2151 if (c->flags & CHAN_EOF_RCVD) {
2152 if (datafellows & SSH_BUG_EXTEOF)
2153 debug("channel %d: accepting ext data after eof", id);
2154 else
2155 packet_disconnect("Received extended_data after EOF "
2156 "on channel %d.", id);
2157 }
3c0ef626 2158 tcode = packet_get_int();
2159 if (c->efd == -1 ||
2160 c->extended_usage != CHAN_EXTENDED_WRITE ||
2161 tcode != SSH2_EXTENDED_DATA_STDERR) {
473db5ab 2162 logit("channel %d: bad ext data", c->self);
3c0ef626 2163 return;
2164 }
2165 data = packet_get_string(&data_len);
473db5ab 2166 packet_check_eom();
3c0ef626 2167 if (data_len > c->local_window) {
473db5ab 2168 logit("channel %d: rcvd too much extended_data %d, win %d",
3c0ef626 2169 c->self, data_len, c->local_window);
2170 xfree(data);
2171 return;
2172 }
2173 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2174 c->local_window -= data_len;
2175 buffer_append(&c->extended, data, data_len);
2176 xfree(data);
2177}
2178
30460aeb 2179/* ARGSUSED */
3c0ef626 2180void
473db5ab 2181channel_input_ieof(int type, u_int32_t seq, void *ctxt)
3c0ef626 2182{
2183 int id;
2184 Channel *c;
2185
3c0ef626 2186 id = packet_get_int();
473db5ab 2187 packet_check_eom();
3c0ef626 2188 c = channel_lookup(id);
2189 if (c == NULL)
2190 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2191 chan_rcvd_ieof(c);
2192
2193 /* XXX force input close */
473db5ab 2194 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
3c0ef626 2195 debug("channel %d: FORCE input drain", c->self);
2196 c->istate = CHAN_INPUT_WAIT_DRAIN;
473db5ab 2197 if (buffer_len(&c->input) == 0)
2198 chan_ibuf_empty(c);
3c0ef626 2199 }
2200
2201}
2202
30460aeb 2203/* ARGSUSED */
3c0ef626 2204void
473db5ab 2205channel_input_close(int type, u_int32_t seq, void *ctxt)
3c0ef626 2206{
2207 int id;
2208 Channel *c;
2209
3c0ef626 2210 id = packet_get_int();
473db5ab 2211 packet_check_eom();
3c0ef626 2212 c = channel_lookup(id);
2213 if (c == NULL)
2214 packet_disconnect("Received close for nonexistent channel %d.", id);
2215
2216 /*
2217 * Send a confirmation that we have closed the channel and no more
2218 * data is coming for it.
2219 */
2220 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2221 packet_put_int(c->remote_id);
2222 packet_send();
2223
2224 /*
2225 * If the channel is in closed state, we have sent a close request,
2226 * and the other side will eventually respond with a confirmation.
2227 * Thus, we cannot free the channel here, because then there would be
2228 * no-one to receive the confirmation. The channel gets freed when
2229 * the confirmation arrives.
2230 */
2231 if (c->type != SSH_CHANNEL_CLOSED) {
2232 /*
2233 * Not a closed channel - mark it as draining, which will
2234 * cause it to be freed later.
2235 */
473db5ab 2236 buffer_clear(&c->input);
3c0ef626 2237 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2238 }
2239}
2240
2241/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
30460aeb 2242/* ARGSUSED */
3c0ef626 2243void
473db5ab 2244channel_input_oclose(int type, u_int32_t seq, void *ctxt)
3c0ef626 2245{
2246 int id = packet_get_int();
2247 Channel *c = channel_lookup(id);
473db5ab 2248
2249 packet_check_eom();
3c0ef626 2250 if (c == NULL)
2251 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2252 chan_rcvd_oclose(c);
2253}
2254
30460aeb 2255/* ARGSUSED */
3c0ef626 2256void
473db5ab 2257channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
3c0ef626 2258{
2259 int id = packet_get_int();
2260 Channel *c = channel_lookup(id);
2261
473db5ab 2262 packet_check_eom();
3c0ef626 2263 if (c == NULL)
2264 packet_disconnect("Received close confirmation for "
2265 "out-of-range channel %d.", id);
2266 if (c->type != SSH_CHANNEL_CLOSED)
2267 packet_disconnect("Received close confirmation for "
2268 "non-closed channel %d (type %d).", id, c->type);
2269 channel_free(c);
2270}
2271
30460aeb 2272/* ARGSUSED */
3c0ef626 2273void
473db5ab 2274channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
3c0ef626 2275{
2276 int id, remote_id;
2277 Channel *c;
2278
3c0ef626 2279 id = packet_get_int();
2280 c = channel_lookup(id);
2281
2282 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2283 packet_disconnect("Received open confirmation for "
2284 "non-opening channel %d.", id);
2285 remote_id = packet_get_int();
2286 /* Record the remote channel number and mark that the channel is now open. */
2287 c->remote_id = remote_id;
2288 c->type = SSH_CHANNEL_OPEN;
2289
2290 if (compat20) {
2291 c->remote_window = packet_get_int();
2292 c->remote_maxpacket = packet_get_int();
5156b1a1 2293 if (c->open_confirm) {
3c0ef626 2294 debug2("callback start");
5156b1a1 2295 c->open_confirm(c->self, c->open_confirm_ctx);
3c0ef626 2296 debug2("callback done");
2297 }
473db5ab 2298 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
3c0ef626 2299 c->remote_window, c->remote_maxpacket);
2300 }
473db5ab 2301 packet_check_eom();
3c0ef626 2302}
2303
2304static char *
2305reason2txt(int reason)
2306{
473db5ab 2307 switch (reason) {
3c0ef626 2308 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2309 return "administratively prohibited";
2310 case SSH2_OPEN_CONNECT_FAILED:
2311 return "connect failed";
2312 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2313 return "unknown channel type";
2314 case SSH2_OPEN_RESOURCE_SHORTAGE:
2315 return "resource shortage";
2316 }
2317 return "unknown reason";
2318}
2319
30460aeb 2320/* ARGSUSED */
3c0ef626 2321void
473db5ab 2322channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
3c0ef626 2323{
2324 int id, reason;
2325 char *msg = NULL, *lang = NULL;
2326 Channel *c;
2327
3c0ef626 2328 id = packet_get_int();
2329 c = channel_lookup(id);
2330
2331 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2332 packet_disconnect("Received open failure for "
2333 "non-opening channel %d.", id);
2334 if (compat20) {
2335 reason = packet_get_int();
2336 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2337 msg = packet_get_string(NULL);
2338 lang = packet_get_string(NULL);
2339 }
473db5ab 2340 logit("channel %d: open failed: %s%s%s", id,
3c0ef626 2341 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2342 if (msg != NULL)
2343 xfree(msg);
2344 if (lang != NULL)
2345 xfree(lang);
2346 }
473db5ab 2347 packet_check_eom();
3c0ef626 2348 /* Free the channel. This will also close the socket. */
2349 channel_free(c);
2350}
2351
30460aeb 2352/* ARGSUSED */
3c0ef626 2353void
473db5ab 2354channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
3c0ef626 2355{
3c0ef626 2356 Channel *c;
473db5ab 2357 int id;
2358 u_int adjust;
3c0ef626 2359
2360 if (!compat20)
2361 return;
2362
2363 /* Get the channel number and verify it. */
2364 id = packet_get_int();
2365 c = channel_lookup(id);
2366
08822d99 2367 if (c == NULL) {
2368 logit("Received window adjust for non-open channel %d.", id);
3c0ef626 2369 return;
2370 }
2371 adjust = packet_get_int();
473db5ab 2372 packet_check_eom();
2373 debug2("channel %d: rcvd adjust %u", id, adjust);
3c0ef626 2374 c->remote_window += adjust;
2375}
2376
30460aeb 2377/* ARGSUSED */
3c0ef626 2378void
473db5ab 2379channel_input_port_open(int type, u_int32_t seq, void *ctxt)
3c0ef626 2380{
2381 Channel *c = NULL;
2382 u_short host_port;
2383 char *host, *originator_string;
5156b1a1 2384 int remote_id;
3c0ef626 2385
2386 remote_id = packet_get_int();
2387 host = packet_get_string(NULL);
2388 host_port = packet_get_int();
2389
2390 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2391 originator_string = packet_get_string(NULL);
2392 } else {
2393 originator_string = xstrdup("unknown (remote did not supply name)");
2394 }
473db5ab 2395 packet_check_eom();
5156b1a1 2396 c = channel_connect_to(host, host_port,
2397 "connected socket", originator_string);
473db5ab 2398 xfree(originator_string);
5156b1a1 2399 xfree(host);
3c0ef626 2400 if (c == NULL) {
2401 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2402 packet_put_int(remote_id);
2403 packet_send();
5156b1a1 2404 } else
2405 c->remote_id = remote_id;
3c0ef626 2406}
2407
5156b1a1 2408/* ARGSUSED */
2409void
2410channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2411{
2412 Channel *c;
2413 struct channel_confirm *cc;
2414 int remote_id;
2415
2416 /* Reset keepalive timeout */
2417 keep_alive_timeouts = 0;
2418
2419 remote_id = packet_get_int();
2420 packet_check_eom();
2421
2422 debug2("channel_input_confirm: type %d id %d", type, remote_id);
2423
2424 if ((c = channel_lookup(remote_id)) == NULL) {
2425 logit("channel_input_success_failure: %d: unknown", remote_id);
2426 return;
2427 }
2428 ;
2429 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2430 return;
2431 cc->cb(type, c, cc->ctx);
2432 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2433 bzero(cc, sizeof(*cc));
2434 xfree(cc);
2435}
3c0ef626 2436
2437/* -- tcp forwarding */
2438
2439void
2440channel_set_af(int af)
2441{
2442 IPv4or6 = af;
2443}
2444
473db5ab 2445static int
2446channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
a7213e65 2447 const char *host_to_connect, u_short port_to_connect, int gateway_ports,
2448 int hpn_disabled, int hpn_buffer_size)
3c0ef626 2449{
2450 Channel *c;
08822d99 2451 int sock, r, success = 0, wildcard = 0, is_client;
3c0ef626 2452 struct addrinfo hints, *ai, *aitop;
473db5ab 2453 const char *host, *addr;
3c0ef626 2454 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3c0ef626 2455
473db5ab 2456 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2457 listen_addr : host_to_connect;
2458 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
3c0ef626 2459
473db5ab 2460 if (host == NULL) {
2461 error("No forward host name.");
2462 return 0;
3c0ef626 2463 }
3c0ef626 2464 if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
2465 error("Forward host name too long.");
473db5ab 2466 return 0;
3c0ef626 2467 }
2468
473db5ab 2469 /*
2470 * Determine whether or not a port forward listens to loopback,
2471 * specified address or wildcard. On the client, a specified bind
2472 * address will always override gateway_ports. On the server, a
2473 * gateway_ports of 1 (``yes'') will override the client's
2474 * specification and force a wildcard bind, whereas a value of 2
2475 * (``clientspecified'') will bind to whatever address the client
2476 * asked for.
2477 *
2478 * Special-case listen_addrs are:
2479 *
2480 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2481 * "" (empty string), "*" -> wildcard v4/v6
2482 * "localhost" -> loopback v4/v6
2483 */
2484 addr = NULL;
2485 if (listen_addr == NULL) {
2486 /* No address specified: default to gateway_ports setting */
2487 if (gateway_ports)
2488 wildcard = 1;
2489 } else if (gateway_ports || is_client) {
2490 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
e74dc197 2491 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
473db5ab 2492 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2493 (!is_client && gateway_ports == 1))
2494 wildcard = 1;
2495 else if (strcmp(listen_addr, "localhost") != 0)
2496 addr = listen_addr;
2497 }
2498
2499 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2500 type, wildcard, (addr == NULL) ? "NULL" : addr);
2501
3c0ef626 2502 /*
2503 * getaddrinfo returns a loopback address if the hostname is
2504 * set to NULL and hints.ai_flags is not AI_PASSIVE
2505 */
2506 memset(&hints, 0, sizeof(hints));
2507 hints.ai_family = IPv4or6;
473db5ab 2508 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
3c0ef626 2509 hints.ai_socktype = SOCK_STREAM;
2510 snprintf(strport, sizeof strport, "%d", listen_port);
473db5ab 2511 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2512 if (addr == NULL) {
2513 /* This really shouldn't happen */
2514 packet_disconnect("getaddrinfo: fatal error: %s",
e74dc197 2515 ssh_gai_strerror(r));
473db5ab 2516 } else {
2517 error("channel_setup_fwd_listener: "
e74dc197 2518 "getaddrinfo(%.64s): %s", addr,
2519 ssh_gai_strerror(r));
473db5ab 2520 }
2521 return 0;
2522 }
3c0ef626 2523
2524 for (ai = aitop; ai; ai = ai->ai_next) {
2525 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2526 continue;
2527 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2528 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
473db5ab 2529 error("channel_setup_fwd_listener: getnameinfo failed");
3c0ef626 2530 continue;
2531 }
2532 /* Create a port to listen for the host. */
473db5ab 2533 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3c0ef626 2534 if (sock < 0) {
2535 /* this is no error since kernel may not support ipv6 */
2536 verbose("socket: %.100s", strerror(errno));
2537 continue;
2538 }
08822d99 2539
2540 channel_set_reuseaddr(sock);
473db5ab 2541
3c0ef626 2542 debug("Local forwarding listening on %s port %s.", ntop, strport);
2543
2544 /* Bind the socket to the address. */
2545 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2546 /* address can be in use ipv6 address is already bound */
2547 if (!ai->ai_next)
2548 error("bind: %.100s", strerror(errno));
2549 else
2550 verbose("bind: %.100s", strerror(errno));
2551
2552 close(sock);
2553 continue;
2554 }
2555 /* Start listening for connections on the socket. */
473db5ab 2556 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3c0ef626 2557 error("listen: %.100s", strerror(errno));
2558 close(sock);
2559 continue;
2560 }
2561 /* Allocate a channel number for the socket. */
a7213e65 2562 /* explicitly test for hpn disabled option. if true use smaller window size */
2563 if (hpn_disabled)
6df46d40 2564 c = channel_new("port listener", type, sock, sock, -1,
2565 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2566 0, "port listener", 1);
a7213e65 2567 else
2568 c = channel_new("port listener", type, sock, sock, -1,
2569 hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT,
2570 0, "port listener", 1);
3c0ef626 2571 strlcpy(c->path, host, sizeof(c->path));
2572 c->host_port = port_to_connect;
2573 c->listening_port = listen_port;
2574 success = 1;
2575 }
2576 if (success == 0)
473db5ab 2577 error("channel_setup_fwd_listener: cannot listen to port: %d",
3c0ef626 2578 listen_port);
2579 freeaddrinfo(aitop);
2580 return success;
2581}
2582
473db5ab 2583int
2584channel_cancel_rport_listener(const char *host, u_short port)
2585{
2586 u_int i;
2587 int found = 0;
2588
2589 for (i = 0; i < channels_alloc; i++) {
2590 Channel *c = channels[i];
2591
2592 if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2593 strncmp(c->path, host, sizeof(c->path)) == 0 &&
2594 c->listening_port == port) {
2595 debug2("%s: close channel %d", __func__, i);
2596 channel_free(c);
2597 found = 1;
2598 }
2599 }
2600
2601 return (found);
2602}
2603
2604/* protocol local port fwd, used by ssh (and sshd in v1) */
2605int
2606channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
a7213e65 2607 const char *host_to_connect, u_short port_to_connect, int gateway_ports,
2608 int hpn_disabled, int hpn_buffer_size)
473db5ab 2609{
2610 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2611 listen_host, listen_port, host_to_connect, port_to_connect,
a7213e65 2612 gateway_ports, hpn_disabled, hpn_buffer_size);
473db5ab 2613}
2614
2615/* protocol v2 remote port fwd, used by sshd */
2616int
2617channel_setup_remote_fwd_listener(const char *listen_address,
a7213e65 2618 u_short listen_port, int gateway_ports, int hpn_disabled, int hpn_buffer_size)
473db5ab 2619{
2620 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
a7213e65 2621 listen_address, listen_port, NULL, 0, gateway_ports,
2622 hpn_disabled, hpn_buffer_size);
473db5ab 2623}
2624
3c0ef626 2625/*
2626 * Initiate forwarding of connections to port "port" on remote host through
2627 * the secure channel to host:port from local side.
2628 */
2629
30460aeb 2630int
473db5ab 2631channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
3c0ef626 2632 const char *host_to_connect, u_short port_to_connect)
2633{
473db5ab 2634 int type, success = 0;
3c0ef626 2635
2636 /* Record locally that connection to this host/port is permitted. */
2637 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2638 fatal("channel_request_remote_forwarding: too many forwards");
2639
2640 /* Send the forward request to the remote side. */
2641 if (compat20) {
473db5ab 2642 const char *address_to_bind;
0b90ac93 2643 if (listen_host == NULL) {
2644 if (datafellows & SSH_BUG_RFWD_ADDR)
2645 address_to_bind = "127.0.0.1";
2646 else
2647 address_to_bind = "localhost";
2648 } else if (*listen_host == '\0' ||
2649 strcmp(listen_host, "*") == 0) {
2650 if (datafellows & SSH_BUG_RFWD_ADDR)
2651 address_to_bind = "0.0.0.0";
2652 else
2653 address_to_bind = "";
2654 } else
473db5ab 2655 address_to_bind = listen_host;
2656
3c0ef626 2657 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2658 packet_put_cstring("tcpip-forward");
473db5ab 2659 packet_put_char(1); /* boolean: want reply */
3c0ef626 2660 packet_put_cstring(address_to_bind);
2661 packet_put_int(listen_port);
2662 packet_send();
2663 packet_write_wait();
2664 /* Assume that server accepts the request */
2665 success = 1;
2666 } else {
2667 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
2668 packet_put_int(listen_port);
2669 packet_put_cstring(host_to_connect);
2670 packet_put_int(port_to_connect);
2671 packet_send();
2672 packet_write_wait();
2673
2674 /* Wait for response from the remote side. */
473db5ab 2675 type = packet_read();
3c0ef626 2676 switch (type) {
2677 case SSH_SMSG_SUCCESS:
2678 success = 1;
2679 break;
2680 case SSH_SMSG_FAILURE:
3c0ef626 2681 break;
2682 default:
2683 /* Unknown packet */
2684 packet_disconnect("Protocol error for port forward request:"
2685 "received packet type %d.", type);
2686 }
2687 }
2688 if (success) {
2689 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2690 permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2691 permitted_opens[num_permitted_opens].listen_port = listen_port;
2692 num_permitted_opens++;
2693 }
30460aeb 2694 return (success ? 0 : -1);
3c0ef626 2695}
2696
473db5ab 2697/*
2698 * Request cancellation of remote forwarding of connection host:port from
2699 * local side.
2700 */
2701void
2702channel_request_rforward_cancel(const char *host, u_short port)
2703{
2704 int i;
2705
2706 if (!compat20)
2707 return;
2708
2709 for (i = 0; i < num_permitted_opens; i++) {
2710 if (permitted_opens[i].host_to_connect != NULL &&
2711 permitted_opens[i].listen_port == port)
2712 break;
2713 }
2714 if (i >= num_permitted_opens) {
2715 debug("%s: requested forward not found", __func__);
2716 return;
2717 }
2718 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2719 packet_put_cstring("cancel-tcpip-forward");
2720 packet_put_char(0);
2721 packet_put_cstring(host == NULL ? "" : host);
2722 packet_put_int(port);
2723 packet_send();
2724
2725 permitted_opens[i].listen_port = 0;
2726 permitted_opens[i].port_to_connect = 0;
08822d99 2727 xfree(permitted_opens[i].host_to_connect);
473db5ab 2728 permitted_opens[i].host_to_connect = NULL;
2729}
2730
3c0ef626 2731/*
2732 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2733 * listening for the port, and sends back a success reply (or disconnect
30460aeb 2734 * message if there was an error).
3c0ef626 2735 */
30460aeb 2736int
255d7550 2737channel_input_port_forward_request(int is_root, int gateway_ports,
f713db99 2738 int hpn_disabled, int hpn_buffer_size)
3c0ef626 2739{
2740 u_short port, host_port;
30460aeb 2741 int success = 0;
3c0ef626 2742 char *hostname;
2743
2744 /* Get arguments from the packet. */
2745 port = packet_get_int();
2746 hostname = packet_get_string(NULL);
2747 host_port = packet_get_int();
2748
2749#ifndef HAVE_CYGWIN
2750 /*
2751 * Check that an unprivileged user is not trying to forward a
2752 * privileged port.
2753 */
2754 if (port < IPPORT_RESERVED && !is_root)
473db5ab 2755 packet_disconnect(
2756 "Requested forwarding of port %d but user is not root.",
2757 port);
2758 if (host_port == 0)
2759 packet_disconnect("Dynamic forwarding denied.");
3c0ef626 2760#endif
473db5ab 2761
3c0ef626 2762 /* Initiate forwarding */
30460aeb 2763 success = channel_setup_local_fwd_listener(NULL, port, hostname,
a7213e65 2764 host_port, gateway_ports, hpn_disabled, hpn_buffer_size);
3c0ef626 2765
2766 /* Free the argument string. */
2767 xfree(hostname);
30460aeb 2768
2769 return (success ? 0 : -1);
3c0ef626 2770}
2771
2772/*
2773 * Permits opening to any host/port if permitted_opens[] is empty. This is
2774 * usually called by the server, because the user could connect to any port
2775 * anyway, and the server has no way to know but to trust the client anyway.
2776 */
2777void
473db5ab 2778channel_permit_all_opens(void)
3c0ef626 2779{
2780 if (num_permitted_opens == 0)
2781 all_opens_permitted = 1;
2782}
2783
2784void
2785channel_add_permitted_opens(char *host, int port)
2786{
2787 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
30460aeb 2788 fatal("channel_add_permitted_opens: too many forwards");
3c0ef626 2789 debug("allow port forwarding to host %s port %d", host, port);
2790
2791 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2792 permitted_opens[num_permitted_opens].port_to_connect = port;
2793 num_permitted_opens++;
2794
2795 all_opens_permitted = 0;
2796}
2797
30460aeb 2798int
2799channel_add_adm_permitted_opens(char *host, int port)
2800{
2801 if (num_adm_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2802 fatal("channel_add_adm_permitted_opens: too many forwards");
2803 debug("config allows port forwarding to host %s port %d", host, port);
2804
2805 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
2806 = xstrdup(host);
2807 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
2808 return ++num_adm_permitted_opens;
2809}
2810
3c0ef626 2811void
2812channel_clear_permitted_opens(void)
2813{
2814 int i;
2815
2816 for (i = 0; i < num_permitted_opens; i++)
473db5ab 2817 if (permitted_opens[i].host_to_connect != NULL)
2818 xfree(permitted_opens[i].host_to_connect);
3c0ef626 2819 num_permitted_opens = 0;
3c0ef626 2820}
2821
30460aeb 2822void
2823channel_clear_adm_permitted_opens(void)
2824{
2825 int i;
2826
2827 for (i = 0; i < num_adm_permitted_opens; i++)
2828 if (permitted_adm_opens[i].host_to_connect != NULL)
2829 xfree(permitted_adm_opens[i].host_to_connect);
2830 num_adm_permitted_opens = 0;
2831}
3c0ef626 2832
5156b1a1 2833void
2834channel_print_adm_permitted_opens(void)
2835{
2836 int i;
2837
2838 for (i = 0; i < num_adm_permitted_opens; i++)
2839 if (permitted_adm_opens[i].host_to_connect != NULL)
2840 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
2841 permitted_adm_opens[i].port_to_connect);
2842}
2843
2844/* Try to start non-blocking connect to next host in cctx list */
3c0ef626 2845static int
5156b1a1 2846connect_next(struct channel_connect *cctx)
3c0ef626 2847{
5156b1a1 2848 int sock, saved_errno;
3c0ef626 2849 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3c0ef626 2850
5156b1a1 2851 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
2852 if (cctx->ai->ai_family != AF_INET &&
2853 cctx->ai->ai_family != AF_INET6)
3c0ef626 2854 continue;
5156b1a1 2855 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
2856 ntop, sizeof(ntop), strport, sizeof(strport),
2857 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2858 error("connect_next: getnameinfo failed");
3c0ef626 2859 continue;
2860 }
5156b1a1 2861 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
2862 cctx->ai->ai_protocol)) == -1) {
2863 if (cctx->ai->ai_next == NULL)
473db5ab 2864 error("socket: %.100s", strerror(errno));
2865 else
2866 verbose("socket: %.100s", strerror(errno));
3c0ef626 2867 continue;
2868 }
473db5ab 2869 if (set_nonblock(sock) == -1)
2870 fatal("%s: set_nonblock(%d)", __func__, sock);
5156b1a1 2871 if (connect(sock, cctx->ai->ai_addr,
2872 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
2873 debug("connect_next: host %.100s ([%.100s]:%s): "
2874 "%.100s", cctx->host, ntop, strport,
3c0ef626 2875 strerror(errno));
5156b1a1 2876 saved_errno = errno;
3c0ef626 2877 close(sock);
5156b1a1 2878 errno = saved_errno;
3c0ef626 2879 continue; /* fail -- try next */
2880 }
5156b1a1 2881 debug("connect_next: host %.100s ([%.100s]:%s) "
2882 "in progress, fd=%d", cctx->host, ntop, strport, sock);
2883 cctx->ai = cctx->ai->ai_next;
2884 set_nodelay(sock);
2885 return sock;
2886 }
2887 return -1;
2888}
3c0ef626 2889
5156b1a1 2890static void
2891channel_connect_ctx_free(struct channel_connect *cctx)
2892{
2893 xfree(cctx->host);
2894 if (cctx->aitop)
2895 freeaddrinfo(cctx->aitop);
2896 bzero(cctx, sizeof(*cctx));
2897 cctx->host = NULL;
2898 cctx->ai = cctx->aitop = NULL;
2899}
2900
2901/* Return CONNECTING channel to remote host, port */
2902static Channel *
2903connect_to(const char *host, u_short port, char *ctype, char *rname)
2904{
2905 struct addrinfo hints;
2906 int gaierr;
2907 int sock = -1;
2908 char strport[NI_MAXSERV];
2909 struct channel_connect cctx;
2910 Channel *c;
2911
2912 memset(&cctx, 0, sizeof(cctx));
2913 memset(&hints, 0, sizeof(hints));
2914 hints.ai_family = IPv4or6;
2915 hints.ai_socktype = SOCK_STREAM;
2916 snprintf(strport, sizeof strport, "%d", port);
2917 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
2918 error("connect_to %.100s: unknown host (%s)", host,
2919 ssh_gai_strerror(gaierr));
2920 return NULL;
3c0ef626 2921 }
5156b1a1 2922
2923 cctx.host = xstrdup(host);
2924 cctx.port = port;
2925 cctx.ai = cctx.aitop;
2926
2927 if ((sock = connect_next(&cctx)) == -1) {
2928 error("connect to %.100s port %d failed: %s",
2929 host, port, strerror(errno));
2930 channel_connect_ctx_free(&cctx);
2931 return NULL;
3c0ef626 2932 }
5156b1a1 2933 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
2934 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
2935 c->connect_ctx = cctx;
2936 return c;
3c0ef626 2937}
2938
5156b1a1 2939Channel *
2940channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
3c0ef626 2941{
2942 int i;
2943
5156b1a1 2944 for (i = 0; i < num_permitted_opens; i++) {
473db5ab 2945 if (permitted_opens[i].host_to_connect != NULL &&
5156b1a1 2946 permitted_opens[i].listen_port == listen_port) {
3c0ef626 2947 return connect_to(
2948 permitted_opens[i].host_to_connect,
5156b1a1 2949 permitted_opens[i].port_to_connect, ctype, rname);
2950 }
2951 }
3c0ef626 2952 error("WARNING: Server requests forwarding for unknown listen_port %d",
2953 listen_port);
5156b1a1 2954 return NULL;
3c0ef626 2955}
2956
2957/* Check if connecting to that port is permitted and connect. */
5156b1a1 2958Channel *
2959channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
3c0ef626 2960{
30460aeb 2961 int i, permit, permit_adm = 1;
3c0ef626 2962
2963 permit = all_opens_permitted;
2964 if (!permit) {
2965 for (i = 0; i < num_permitted_opens; i++)
473db5ab 2966 if (permitted_opens[i].host_to_connect != NULL &&
2967 permitted_opens[i].port_to_connect == port &&
3c0ef626 2968 strcmp(permitted_opens[i].host_to_connect, host) == 0)
2969 permit = 1;
30460aeb 2970 }
3c0ef626 2971
30460aeb 2972 if (num_adm_permitted_opens > 0) {
2973 permit_adm = 0;
2974 for (i = 0; i < num_adm_permitted_opens; i++)
2975 if (permitted_adm_opens[i].host_to_connect != NULL &&
2976 permitted_adm_opens[i].port_to_connect == port &&
2977 strcmp(permitted_adm_opens[i].host_to_connect, host)
2978 == 0)
2979 permit_adm = 1;
3c0ef626 2980 }
30460aeb 2981
2982 if (!permit || !permit_adm) {
473db5ab 2983 logit("Received request to connect to host %.100s port %d, "
3c0ef626 2984 "but the request was denied.", host, port);
5156b1a1 2985 return NULL;
3c0ef626 2986 }
5156b1a1 2987 return connect_to(host, port, ctype, rname);
3c0ef626 2988}
2989
473db5ab 2990void
2991channel_send_window_changes(void)
2992{
2993 u_int i;
2994 struct winsize ws;
2995
2996 for (i = 0; i < channels_alloc; i++) {
2997 if (channels[i] == NULL || !channels[i]->client_tty ||
2998 channels[i]->type != SSH_CHANNEL_OPEN)
2999 continue;
3000 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3001 continue;
3002 channel_request_start(i, "window-change", 0);
30460aeb 3003 packet_put_int((u_int)ws.ws_col);
3004 packet_put_int((u_int)ws.ws_row);
3005 packet_put_int((u_int)ws.ws_xpixel);
3006 packet_put_int((u_int)ws.ws_ypixel);
473db5ab 3007 packet_send();
3008 }
3009}
3010
3c0ef626 3011/* -- X11 forwarding */
3012
3013/*
3014 * Creates an internet domain socket for listening for X11 connections.
473db5ab 3015 * Returns 0 and a suitable display number for the DISPLAY variable
3016 * stored in display_numberp , or -1 if an error occurs.
3c0ef626 3017 */
473db5ab 3018int
3019x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
a7213e65 3020 int single_connection, u_int *display_numberp, int **chanids,
3021 int hpn_disabled, int hpn_buffer_size)
3c0ef626 3022{
473db5ab 3023 Channel *nc = NULL;
3c0ef626 3024 int display_number, sock;
3025 u_short port;
3026 struct addrinfo hints, *ai, *aitop;
3027 char strport[NI_MAXSERV];
3028 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3c0ef626 3029
08822d99 3030 if (chanids == NULL)
3031 return -1;
3032
3c0ef626 3033 for (display_number = x11_display_offset;
473db5ab 3034 display_number < MAX_DISPLAYS;
3035 display_number++) {
3c0ef626 3036 port = 6000 + display_number;
3037 memset(&hints, 0, sizeof(hints));
3038 hints.ai_family = IPv4or6;
473db5ab 3039 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3c0ef626 3040 hints.ai_socktype = SOCK_STREAM;
3041 snprintf(strport, sizeof strport, "%d", port);
3042 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
e74dc197 3043 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
473db5ab 3044 return -1;
3c0ef626 3045 }
3046 for (ai = aitop; ai; ai = ai->ai_next) {
3047 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3048 continue;
473db5ab 3049 sock = socket(ai->ai_family, ai->ai_socktype,
3050 ai->ai_protocol);
3c0ef626 3051 if (sock < 0) {
3052 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) {
3053 error("socket: %.100s", strerror(errno));
473db5ab 3054 freeaddrinfo(aitop);
3055 return -1;
3c0ef626 3056 } else {
3057 debug("x11_create_display_inet: Socket family %d not supported",
3058 ai->ai_family);
3059 continue;
3060 }
3061 }
473db5ab 3062#ifdef IPV6_V6ONLY
3063 if (ai->ai_family == AF_INET6) {
3064 int on = 1;
3065 if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0)
3066 error("setsockopt IPV6_V6ONLY: %.100s", strerror(errno));
3067 }
3068#endif
5156b1a1 3069 if (x11_use_localhost)
3070 channel_set_reuseaddr(sock);
3c0ef626 3071 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
473db5ab 3072 debug2("bind port %d: %.100s", port, strerror(errno));
3c0ef626 3073 close(sock);
3074
3c0ef626 3075 for (n = 0; n < num_socks; n++) {
3c0ef626 3076 close(socks[n]);
3077 }
3078 num_socks = 0;
3079 break;
3080 }
3081 socks[num_socks++] = sock;
3c0ef626 3082 if (num_socks == NUM_SOCKS)
3083 break;
3c0ef626 3084 }
3085 freeaddrinfo(aitop);
3086 if (num_socks > 0)
3087 break;
3088 }
3089 if (display_number >= MAX_DISPLAYS) {
3090 error("Failed to allocate internet-domain X11 display socket.");
473db5ab 3091 return -1;
3c0ef626 3092 }
3093 /* Start listening for connections on the socket. */
3094 for (n = 0; n < num_socks; n++) {
3095 sock = socks[n];
473db5ab 3096 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3c0ef626 3097 error("listen: %.100s", strerror(errno));
3c0ef626 3098 close(sock);
473db5ab 3099 return -1;
3c0ef626 3100 }
3c0ef626 3101 }
3c0ef626 3102
3103 /* Allocate a channel for each socket. */
30460aeb 3104 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3c0ef626 3105 for (n = 0; n < num_socks; n++) {
3106 sock = socks[n];
6df46d40 3107 /* Is this really necassary? */
a7213e65 3108 if (hpn_disabled)
6df46d40 3109 nc = channel_new("x11 listener",
3110 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3111 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3112 0, "X11 inet listener", 1);
a7213e65 3113 else
3114 nc = channel_new("x11 listener",
3115 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3116 hpn_buffer_size, CHAN_X11_PACKET_DEFAULT,
3117 0, "X11 inet listener", 1);
473db5ab 3118 nc->single_connection = single_connection;
08822d99 3119 (*chanids)[n] = nc->self;
3c0ef626 3120 }
08822d99 3121 (*chanids)[n] = -1;
3c0ef626 3122
473db5ab 3123 /* Return the display number for the DISPLAY environment variable. */
3124 *display_numberp = display_number;
3125 return (0);
3c0ef626 3126}
3127
3c0ef626 3128static int
3129connect_local_xsocket(u_int dnr)
3130{
3c0ef626 3131 int sock;
3132 struct sockaddr_un addr;
3c0ef626 3133
473db5ab 3134 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3135 if (sock < 0)
3136 error("socket: %.100s", strerror(errno));
3137 memset(&addr, 0, sizeof(addr));
3138 addr.sun_family = AF_UNIX;
3139 snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
30460aeb 3140 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
473db5ab 3141 return sock;
3142 close(sock);
3c0ef626 3143 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3144 return -1;
3145}
3146
3147int
3148x11_connect_display(void)
3149{
30460aeb 3150 u_int display_number;
3c0ef626 3151 const char *display;
3152 char buf[1024], *cp;
3153 struct addrinfo hints, *ai, *aitop;
3154 char strport[NI_MAXSERV];
30460aeb 3155 int gaierr, sock = 0;
3c0ef626 3156
3157 /* Try to open a socket for the local X server. */
3158 display = getenv("DISPLAY");
3159 if (!display) {
3160 error("DISPLAY not set.");
3161 return -1;
3162 }
3163 /*
3164 * Now we decode the value of the DISPLAY variable and make a
3165 * connection to the real X server.
3166 */
3167
3168 /*
3169 * Check if it is a unix domain socket. Unix domain displays are in
3170 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3171 */
3172 if (strncmp(display, "unix:", 5) == 0 ||
3173 display[0] == ':') {
3174 /* Connect to the unix domain socket. */
30460aeb 3175 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
3c0ef626 3176 error("Could not parse display number from DISPLAY: %.100s",
473db5ab 3177 display);
3c0ef626 3178 return -1;
3179 }
3180 /* Create a socket. */
3181 sock = connect_local_xsocket(display_number);
3182 if (sock < 0)
3183 return -1;
3184
3185 /* OK, we now have a connection to the display. */
3186 return sock;
3187 }
3188 /*
3189 * Connect to an inet socket. The DISPLAY value is supposedly
3190 * hostname:d[.s], where hostname may also be numeric IP address.
3191 */
473db5ab 3192 strlcpy(buf, display, sizeof(buf));
3c0ef626 3193 cp = strchr(buf, ':');
3194 if (!cp) {
3195 error("Could not find ':' in DISPLAY: %.100s", display);
3196 return -1;
3197 }
3198 *cp = 0;
3199 /* buf now contains the host name. But first we parse the display number. */
30460aeb 3200 if (sscanf(cp + 1, "%u", &display_number) != 1) {
3c0ef626 3201 error("Could not parse display number from DISPLAY: %.100s",
473db5ab 3202 display);
3c0ef626 3203 return -1;
3204 }
3205
3206 /* Look up the host address */
3207 memset(&hints, 0, sizeof(hints));
3208 hints.ai_family = IPv4or6;
3209 hints.ai_socktype = SOCK_STREAM;
30460aeb 3210 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
3c0ef626 3211 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
e74dc197 3212 error("%.100s: unknown host. (%s)", buf,
3213 ssh_gai_strerror(gaierr));
3c0ef626 3214 return -1;
3215 }
3216 for (ai = aitop; ai; ai = ai->ai_next) {
3217 /* Create a socket. */
473db5ab 3218 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3c0ef626 3219 if (sock < 0) {
473db5ab 3220 debug2("socket: %.100s", strerror(errno));
3c0ef626 3221 continue;
3222 }
3223 /* Connect it to the display. */
3224 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
30460aeb 3225 debug2("connect %.100s port %u: %.100s", buf,
3c0ef626 3226 6000 + display_number, strerror(errno));
3227 close(sock);
3228 continue;
3229 }
3230 /* Success */
3231 break;
3232 }
3233 freeaddrinfo(aitop);
3234 if (!ai) {
30460aeb 3235 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
3c0ef626 3236 strerror(errno));
3237 return -1;
3238 }
473db5ab 3239 set_nodelay(sock);
3c0ef626 3240 return sock;
3241}
3242
3243/*
3244 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3245 * the remote channel number. We should do whatever we want, and respond
3246 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3247 */
3248
30460aeb 3249/* ARGSUSED */
3c0ef626 3250void
473db5ab 3251x11_input_open(int type, u_int32_t seq, void *ctxt)
3c0ef626 3252{
3253 Channel *c = NULL;
3254 int remote_id, sock = 0;
3255 char *remote_host;
3256
3257 debug("Received X11 open request.");
3258
3259 remote_id = packet_get_int();
3260
3261 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3262 remote_host = packet_get_string(NULL);
3263 } else {
3264 remote_host = xstrdup("unknown (remote did not supply name)");
3265 }
473db5ab 3266 packet_check_eom();
3c0ef626 3267
3268 /* Obtain a connection to the real X display. */
3269 sock = x11_connect_display();
3270 if (sock != -1) {
3271 /* Allocate a channel for this connection. */
3272 c = channel_new("connected x11 socket",
3273 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3274 remote_host, 1);
473db5ab 3275 c->remote_id = remote_id;
3276 c->force_drain = 1;
3c0ef626 3277 }
473db5ab 3278 xfree(remote_host);
3c0ef626 3279 if (c == NULL) {
3280 /* Send refusal to the remote host. */
3281 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3282 packet_put_int(remote_id);
3283 } else {
3284 /* Send a confirmation to the remote host. */
3285 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
3286 packet_put_int(remote_id);
3287 packet_put_int(c->self);
3288 }
3289 packet_send();
3290}
3291
3292/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
30460aeb 3293/* ARGSUSED */
3c0ef626 3294void
473db5ab 3295deny_input_open(int type, u_int32_t seq, void *ctxt)
3c0ef626 3296{
3297 int rchan = packet_get_int();
473db5ab 3298
3299 switch (type) {
3c0ef626 3300 case SSH_SMSG_AGENT_OPEN:
3301 error("Warning: ssh server tried agent forwarding.");
3302 break;
3303 case SSH_SMSG_X11_OPEN:
3304 error("Warning: ssh server tried X11 forwarding.");
3305 break;
3306 default:
473db5ab 3307 error("deny_input_open: type %d", type);
3c0ef626 3308 break;
3309 }
08822d99 3310 error("Warning: this is probably a break-in attempt by a malicious server.");
3c0ef626 3311 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3312 packet_put_int(rchan);
3313 packet_send();
3314}
3315
3316/*
3317 * Requests forwarding of X11 connections, generates fake authentication
3318 * data, and enables authentication spoofing.
3319 * This should be called in the client only.
3320 */
3321void
473db5ab 3322x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
3c0ef626 3323 const char *proto, const char *data)
3324{
3325 u_int data_len = (u_int) strlen(data) / 2;
473db5ab 3326 u_int i, value;
3c0ef626 3327 char *new_data;
3328 int screen_number;
3329 const char *cp;
473db5ab 3330 u_int32_t rnd = 0;
3c0ef626 3331
473db5ab 3332 if (x11_saved_display == NULL)
3333 x11_saved_display = xstrdup(disp);
3334 else if (strcmp(disp, x11_saved_display) != 0) {
3335 error("x11_request_forwarding_with_spoofing: different "
3336 "$DISPLAY already forwarded");
3337 return;
3338 }
3339
30460aeb 3340 cp = strchr(disp, ':');
3c0ef626 3341 if (cp)
3342 cp = strchr(cp, '.');
3343 if (cp)
30460aeb 3344 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
3c0ef626 3345 else
3346 screen_number = 0;
3347
473db5ab 3348 if (x11_saved_proto == NULL) {
3349 /* Save protocol name. */
3350 x11_saved_proto = xstrdup(proto);
3351 /*
3352 * Extract real authentication data and generate fake data
3353 * of the same length.
3354 */
3355 x11_saved_data = xmalloc(data_len);
3356 x11_fake_data = xmalloc(data_len);
3357 for (i = 0; i < data_len; i++) {
3358 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3359 fatal("x11_request_forwarding: bad "
3360 "authentication data: %.100s", data);
3361 if (i % 4 == 0)
3362 rnd = arc4random();
3363 x11_saved_data[i] = value;
3364 x11_fake_data[i] = rnd & 0xff;
3365 rnd >>= 8;
3366 }
3367 x11_saved_data_len = data_len;
3368 x11_fake_data_len = data_len;
3369 }
3c0ef626 3370
3371 /* Convert the fake data into hex. */
473db5ab 3372 new_data = tohex(x11_fake_data, data_len);
3c0ef626 3373
3374 /* Send the request packet. */
3375 if (compat20) {
3376 channel_request_start(client_session_id, "x11-req", 0);
3377 packet_put_char(0); /* XXX bool single connection */
3378 } else {
3379 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3380 }
3381 packet_put_cstring(proto);
3382 packet_put_cstring(new_data);
3383 packet_put_int(screen_number);
3384 packet_send();
3385 packet_write_wait();
3386 xfree(new_data);
3387}
3388
3389
3390/* -- agent forwarding */
3391
3392/* Sends a message to the server to request authentication fd forwarding. */
3393
3394void
473db5ab 3395auth_request_forwarding(void)
3c0ef626 3396{
3397 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3398 packet_send();
3399 packet_write_wait();
3400}
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