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e74dc197 1/* $OpenBSD: channels.c,v 1.272 2008/01/19 23:02:40 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
64#include "xmalloc.h"
3c0ef626 65#include "ssh.h"
66#include "ssh1.h"
67#include "ssh2.h"
68#include "packet.h"
3c0ef626 69#include "log.h"
70#include "misc.h"
30460aeb 71#include "buffer.h"
3c0ef626 72#include "channels.h"
73#include "compat.h"
74#include "canohost.h"
75#include "key.h"
76#include "authfd.h"
473db5ab 77#include "pathnames.h"
a7213e65 78
3c0ef626 79/* -- channel core */
80
81/*
82 * Pointer to an array containing all allocated channels. The array is
83 * dynamically extended as needed.
84 */
85static Channel **channels = NULL;
86
87/*
88 * Size of the channel array. All slots of the array must always be
89 * initialized (at least the type field); unused slots set to NULL
90 */
473db5ab 91static u_int channels_alloc = 0;
3c0ef626 92
93/*
94 * Maximum file descriptor value used in any of the channels. This is
95 * updated in channel_new.
96 */
97static int channel_max_fd = 0;
98
99
100/* -- tcp forwarding */
101
102/*
103 * Data structure for storing which hosts are permitted for forward requests.
104 * The local sides of any remote forwards are stored in this array to prevent
105 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
106 * network (which might be behind a firewall).
107 */
108typedef struct {
109 char *host_to_connect; /* Connect to 'host'. */
110 u_short port_to_connect; /* Connect to 'port'. */
111 u_short listen_port; /* Remote side should listen port number. */
112} ForwardPermission;
113
30460aeb 114/* List of all permitted host/port pairs to connect by the user. */
3c0ef626 115static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
116
30460aeb 117/* List of all permitted host/port pairs to connect by the admin. */
118static ForwardPermission permitted_adm_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
119
120/* Number of permitted host/port pairs in the array permitted by the user. */
3c0ef626 121static int num_permitted_opens = 0;
30460aeb 122
123/* Number of permitted host/port pair in the array permitted by the admin. */
124static int num_adm_permitted_opens = 0;
125
3c0ef626 126/*
127 * If this is true, all opens are permitted. This is the case on the server
128 * on which we have to trust the client anyway, and the user could do
129 * anything after logging in anyway.
130 */
131static int all_opens_permitted = 0;
132
133
134/* -- X11 forwarding */
135
136/* Maximum number of fake X11 displays to try. */
137#define MAX_DISPLAYS 1000
138
473db5ab 139/* Saved X11 local (client) display. */
140static char *x11_saved_display = NULL;
141
3c0ef626 142/* Saved X11 authentication protocol name. */
143static char *x11_saved_proto = NULL;
144
145/* Saved X11 authentication data. This is the real data. */
146static char *x11_saved_data = NULL;
147static u_int x11_saved_data_len = 0;
148
149/*
150 * Fake X11 authentication data. This is what the server will be sending us;
151 * we should replace any occurrences of this by the real data.
152 */
30460aeb 153static u_char *x11_fake_data = NULL;
3c0ef626 154static u_int x11_fake_data_len;
155
156
157/* -- agent forwarding */
158
159#define NUM_SOCKS 10
160
3c0ef626 161/* AF_UNSPEC or AF_INET or AF_INET6 */
162static int IPv4or6 = AF_UNSPEC;
163
164/* helper */
165static void port_open_helper(Channel *c, char *rtype);
166
167/* -- channel core */
168
169Channel *
08822d99 170channel_by_id(int id)
3c0ef626 171{
172 Channel *c;
173
473db5ab 174 if (id < 0 || (u_int)id >= channels_alloc) {
08822d99 175 logit("channel_by_id: %d: bad id", id);
3c0ef626 176 return NULL;
177 }
178 c = channels[id];
179 if (c == NULL) {
08822d99 180 logit("channel_by_id: %d: bad id: channel free", id);
3c0ef626 181 return NULL;
182 }
183 return c;
184}
185
08822d99 186/*
187 * Returns the channel if it is allowed to receive protocol messages.
188 * Private channels, like listening sockets, may not receive messages.
189 */
190Channel *
191channel_lookup(int id)
192{
193 Channel *c;
194
195 if ((c = channel_by_id(id)) == NULL)
196 return (NULL);
197
30460aeb 198 switch (c->type) {
08822d99 199 case SSH_CHANNEL_X11_OPEN:
200 case SSH_CHANNEL_LARVAL:
201 case SSH_CHANNEL_CONNECTING:
202 case SSH_CHANNEL_DYNAMIC:
203 case SSH_CHANNEL_OPENING:
204 case SSH_CHANNEL_OPEN:
205 case SSH_CHANNEL_INPUT_DRAINING:
206 case SSH_CHANNEL_OUTPUT_DRAINING:
207 return (c);
08822d99 208 }
209 logit("Non-public channel %d, type %d.", id, c->type);
210 return (NULL);
211}
212
3c0ef626 213/*
214 * Register filedescriptors for a channel, used when allocating a channel or
215 * when the channel consumer/producer is ready, e.g. shell exec'd
216 */
3c0ef626 217static void
218channel_register_fds(Channel *c, int rfd, int wfd, int efd,
219 int extusage, int nonblock)
220{
221 /* Update the maximum file descriptor value. */
222 channel_max_fd = MAX(channel_max_fd, rfd);
223 channel_max_fd = MAX(channel_max_fd, wfd);
224 channel_max_fd = MAX(channel_max_fd, efd);
225
226 /* XXX set close-on-exec -markus */
227
228 c->rfd = rfd;
229 c->wfd = wfd;
230 c->sock = (rfd == wfd) ? rfd : -1;
473db5ab 231 c->ctl_fd = -1; /* XXX: set elsewhere */
3c0ef626 232 c->efd = efd;
233 c->extended_usage = extusage;
234
235 /* XXX ugly hack: nonblock is only set by the server */
236 if (nonblock && isatty(c->rfd)) {
473db5ab 237 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
3c0ef626 238 c->isatty = 1;
239 if (!isatty(c->wfd)) {
240 error("channel %d: wfd %d is not a tty?",
241 c->self, c->wfd);
242 }
243 } else {
244 c->isatty = 0;
245 }
473db5ab 246 c->wfd_isatty = isatty(c->wfd);
3c0ef626 247
248 /* enable nonblocking mode */
249 if (nonblock) {
250 if (rfd != -1)
251 set_nonblock(rfd);
252 if (wfd != -1)
253 set_nonblock(wfd);
254 if (efd != -1)
255 set_nonblock(efd);
256 }
257}
258
259/*
260 * Allocate a new channel object and set its type and socket. This will cause
261 * remote_name to be freed.
262 */
3c0ef626 263Channel *
264channel_new(char *ctype, int type, int rfd, int wfd, int efd,
473db5ab 265 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
3c0ef626 266{
473db5ab 267 int found;
268 u_int i;
3c0ef626 269 Channel *c;
270
271 /* Do initial allocation if this is the first call. */
272 if (channels_alloc == 0) {
3c0ef626 273 channels_alloc = 10;
30460aeb 274 channels = xcalloc(channels_alloc, sizeof(Channel *));
3c0ef626 275 for (i = 0; i < channels_alloc; i++)
276 channels[i] = NULL;
3c0ef626 277 }
278 /* Try to find a free slot where to put the new channel. */
279 for (found = -1, i = 0; i < channels_alloc; i++)
280 if (channels[i] == NULL) {
281 /* Found a free slot. */
473db5ab 282 found = (int)i;
3c0ef626 283 break;
284 }
473db5ab 285 if (found < 0) {
3c0ef626 286 /* There are no free slots. Take last+1 slot and expand the array. */
287 found = channels_alloc;
473db5ab 288 if (channels_alloc > 10000)
289 fatal("channel_new: internal error: channels_alloc %d "
290 "too big.", channels_alloc);
30460aeb 291 channels = xrealloc(channels, channels_alloc + 10,
292 sizeof(Channel *));
3c0ef626 293 channels_alloc += 10;
294 debug2("channel: expanding %d", channels_alloc);
3c0ef626 295 for (i = found; i < channels_alloc; i++)
296 channels[i] = NULL;
297 }
298 /* Initialize and return new channel. */
30460aeb 299 c = channels[found] = xcalloc(1, sizeof(Channel));
3c0ef626 300 buffer_init(&c->input);
301 buffer_init(&c->output);
302 buffer_init(&c->extended);
473db5ab 303 c->ostate = CHAN_OUTPUT_OPEN;
304 c->istate = CHAN_INPUT_OPEN;
305 c->flags = 0;
3c0ef626 306 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
307 c->self = found;
308 c->type = type;
309 c->ctype = ctype;
310 c->local_window = window;
311 c->local_window_max = window;
312 c->local_consumed = 0;
313 c->local_maxpacket = maxpack;
473db5ab 314 c->dynamic_window = 0;
3c0ef626 315 c->remote_id = -1;
473db5ab 316 c->remote_name = xstrdup(remote_name);
3c0ef626 317 c->remote_window = 0;
318 c->remote_maxpacket = 0;
3c0ef626 319 c->force_drain = 0;
473db5ab 320 c->single_connection = 0;
3c0ef626 321 c->detach_user = NULL;
08822d99 322 c->detach_close = 0;
473db5ab 323 c->confirm = NULL;
324 c->confirm_ctx = NULL;
3c0ef626 325 c->input_filter = NULL;
08822d99 326 c->output_filter = NULL;
3c0ef626 327 debug("channel %d: new [%s]", found, remote_name);
328 return c;
329}
330
331static int
332channel_find_maxfd(void)
333{
473db5ab 334 u_int i;
335 int max = 0;
3c0ef626 336 Channel *c;
337
338 for (i = 0; i < channels_alloc; i++) {
339 c = channels[i];
340 if (c != NULL) {
341 max = MAX(max, c->rfd);
342 max = MAX(max, c->wfd);
343 max = MAX(max, c->efd);
344 }
345 }
346 return max;
347}
348
349int
350channel_close_fd(int *fdp)
351{
352 int ret = 0, fd = *fdp;
353
354 if (fd != -1) {
355 ret = close(fd);
356 *fdp = -1;
357 if (fd == channel_max_fd)
358 channel_max_fd = channel_find_maxfd();
359 }
360 return ret;
361}
362
363/* Close all channel fd/socket. */
3c0ef626 364static void
365channel_close_fds(Channel *c)
366{
473db5ab 367 debug3("channel %d: close_fds r %d w %d e %d c %d",
368 c->self, c->rfd, c->wfd, c->efd, c->ctl_fd);
3c0ef626 369
370 channel_close_fd(&c->sock);
473db5ab 371 channel_close_fd(&c->ctl_fd);
3c0ef626 372 channel_close_fd(&c->rfd);
373 channel_close_fd(&c->wfd);
374 channel_close_fd(&c->efd);
375}
376
377/* Free the channel and close its fd/socket. */
3c0ef626 378void
379channel_free(Channel *c)
380{
381 char *s;
473db5ab 382 u_int i, n;
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 }
406 channels[c->self] = NULL;
407 xfree(c);
408}
409
410void
411channel_free_all(void)
412{
473db5ab 413 u_int i;
3c0ef626 414
415 for (i = 0; i < channels_alloc; i++)
416 if (channels[i] != NULL)
417 channel_free(channels[i]);
418}
419
420/*
421 * Closes the sockets/fds of all channels. This is used to close extra file
422 * descriptors after a fork.
423 */
3c0ef626 424void
473db5ab 425channel_close_all(void)
3c0ef626 426{
473db5ab 427 u_int i;
3c0ef626 428
429 for (i = 0; i < channels_alloc; i++)
430 if (channels[i] != NULL)
431 channel_close_fds(channels[i]);
432}
433
434/*
435 * Stop listening to channels.
436 */
3c0ef626 437void
438channel_stop_listening(void)
439{
473db5ab 440 u_int i;
3c0ef626 441 Channel *c;
442
443 for (i = 0; i < channels_alloc; i++) {
444 c = channels[i];
445 if (c != NULL) {
446 switch (c->type) {
447 case SSH_CHANNEL_AUTH_SOCKET:
448 case SSH_CHANNEL_PORT_LISTENER:
449 case SSH_CHANNEL_RPORT_LISTENER:
450 case SSH_CHANNEL_X11_LISTENER:
451 channel_close_fd(&c->sock);
452 channel_free(c);
453 break;
454 }
455 }
456 }
457}
458
459/*
460 * Returns true if no channel has too much buffered data, and false if one or
461 * more channel is overfull.
462 */
3c0ef626 463int
473db5ab 464channel_not_very_much_buffered_data(void)
3c0ef626 465{
466 u_int i;
467 Channel *c;
468
469 for (i = 0; i < channels_alloc; i++) {
470 c = channels[i];
471 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
472#if 0
473 if (!compat20 &&
474 buffer_len(&c->input) > packet_get_maxsize()) {
473db5ab 475 debug2("channel %d: big input buffer %d",
3c0ef626 476 c->self, buffer_len(&c->input));
477 return 0;
478 }
479#endif
480 if (buffer_len(&c->output) > packet_get_maxsize()) {
473db5ab 481 debug2("channel %d: big output buffer %u > %u",
3c0ef626 482 c->self, buffer_len(&c->output),
483 packet_get_maxsize());
484 return 0;
485 }
486 }
487 }
488 return 1;
489}
490
491/* Returns true if any channel is still open. */
3c0ef626 492int
473db5ab 493channel_still_open(void)
3c0ef626 494{
473db5ab 495 u_int i;
3c0ef626 496 Channel *c;
497
498 for (i = 0; i < channels_alloc; i++) {
499 c = channels[i];
500 if (c == NULL)
501 continue;
502 switch (c->type) {
503 case SSH_CHANNEL_X11_LISTENER:
504 case SSH_CHANNEL_PORT_LISTENER:
505 case SSH_CHANNEL_RPORT_LISTENER:
506 case SSH_CHANNEL_CLOSED:
507 case SSH_CHANNEL_AUTH_SOCKET:
508 case SSH_CHANNEL_DYNAMIC:
509 case SSH_CHANNEL_CONNECTING:
510 case SSH_CHANNEL_ZOMBIE:
511 continue;
512 case SSH_CHANNEL_LARVAL:
513 if (!compat20)
514 fatal("cannot happen: SSH_CHANNEL_LARVAL");
515 continue;
516 case SSH_CHANNEL_OPENING:
517 case SSH_CHANNEL_OPEN:
518 case SSH_CHANNEL_X11_OPEN:
519 return 1;
520 case SSH_CHANNEL_INPUT_DRAINING:
521 case SSH_CHANNEL_OUTPUT_DRAINING:
522 if (!compat13)
523 fatal("cannot happen: OUT_DRAIN");
524 return 1;
525 default:
526 fatal("channel_still_open: bad channel type %d", c->type);
527 /* NOTREACHED */
528 }
529 }
530 return 0;
531}
532
533/* Returns the id of an open channel suitable for keepaliving */
3c0ef626 534int
473db5ab 535channel_find_open(void)
3c0ef626 536{
473db5ab 537 u_int i;
3c0ef626 538 Channel *c;
539
540 for (i = 0; i < channels_alloc; i++) {
541 c = channels[i];
473db5ab 542 if (c == NULL || c->remote_id < 0)
3c0ef626 543 continue;
544 switch (c->type) {
545 case SSH_CHANNEL_CLOSED:
546 case SSH_CHANNEL_DYNAMIC:
547 case SSH_CHANNEL_X11_LISTENER:
548 case SSH_CHANNEL_PORT_LISTENER:
549 case SSH_CHANNEL_RPORT_LISTENER:
550 case SSH_CHANNEL_OPENING:
551 case SSH_CHANNEL_CONNECTING:
552 case SSH_CHANNEL_ZOMBIE:
553 continue;
554 case SSH_CHANNEL_LARVAL:
555 case SSH_CHANNEL_AUTH_SOCKET:
556 case SSH_CHANNEL_OPEN:
557 case SSH_CHANNEL_X11_OPEN:
558 return i;
559 case SSH_CHANNEL_INPUT_DRAINING:
560 case SSH_CHANNEL_OUTPUT_DRAINING:
561 if (!compat13)
562 fatal("cannot happen: OUT_DRAIN");
563 return i;
564 default:
565 fatal("channel_find_open: bad channel type %d", c->type);
566 /* NOTREACHED */
567 }
568 }
569 return -1;
570}
571
572
573/*
574 * Returns a message describing the currently open forwarded connections,
575 * suitable for sending to the client. The message contains crlf pairs for
576 * newlines.
577 */
3c0ef626 578char *
473db5ab 579channel_open_message(void)
3c0ef626 580{
581 Buffer buffer;
582 Channel *c;
583 char buf[1024], *cp;
473db5ab 584 u_int i;
3c0ef626 585
586 buffer_init(&buffer);
587 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
588 buffer_append(&buffer, buf, strlen(buf));
589 for (i = 0; i < channels_alloc; i++) {
590 c = channels[i];
591 if (c == NULL)
592 continue;
593 switch (c->type) {
594 case SSH_CHANNEL_X11_LISTENER:
595 case SSH_CHANNEL_PORT_LISTENER:
596 case SSH_CHANNEL_RPORT_LISTENER:
597 case SSH_CHANNEL_CLOSED:
598 case SSH_CHANNEL_AUTH_SOCKET:
599 case SSH_CHANNEL_ZOMBIE:
600 continue;
601 case SSH_CHANNEL_LARVAL:
602 case SSH_CHANNEL_OPENING:
603 case SSH_CHANNEL_CONNECTING:
604 case SSH_CHANNEL_DYNAMIC:
605 case SSH_CHANNEL_OPEN:
606 case SSH_CHANNEL_X11_OPEN:
607 case SSH_CHANNEL_INPUT_DRAINING:
608 case SSH_CHANNEL_OUTPUT_DRAINING:
473db5ab 609 snprintf(buf, sizeof buf,
610 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n",
3c0ef626 611 c->self, c->remote_name,
612 c->type, c->remote_id,
613 c->istate, buffer_len(&c->input),
614 c->ostate, buffer_len(&c->output),
473db5ab 615 c->rfd, c->wfd, c->ctl_fd);
3c0ef626 616 buffer_append(&buffer, buf, strlen(buf));
617 continue;
618 default:
619 fatal("channel_open_message: bad channel type %d", c->type);
620 /* NOTREACHED */
621 }
622 }
623 buffer_append(&buffer, "\0", 1);
624 cp = xstrdup(buffer_ptr(&buffer));
625 buffer_free(&buffer);
626 return cp;
627}
628
629void
630channel_send_open(int id)
631{
632 Channel *c = channel_lookup(id);
473db5ab 633
3c0ef626 634 if (c == NULL) {
473db5ab 635 logit("channel_send_open: %d: bad id", id);
3c0ef626 636 return;
637 }
473db5ab 638 debug2("channel %d: send open", id);
3c0ef626 639 packet_start(SSH2_MSG_CHANNEL_OPEN);
640 packet_put_cstring(c->ctype);
641 packet_put_int(c->self);
642 packet_put_int(c->local_window);
643 packet_put_int(c->local_maxpacket);
644 packet_send();
645}
646
3c0ef626 647void
648channel_request_start(int id, char *service, int wantconfirm)
649{
650 Channel *c = channel_lookup(id);
473db5ab 651
3c0ef626 652 if (c == NULL) {
473db5ab 653 logit("channel_request_start: %d: unknown channel id", id);
3c0ef626 654 return;
655 }
473db5ab 656 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
3c0ef626 657 packet_start(SSH2_MSG_CHANNEL_REQUEST);
658 packet_put_int(c->remote_id);
659 packet_put_cstring(service);
660 packet_put_char(wantconfirm);
661}
30460aeb 662
3c0ef626 663void
473db5ab 664channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
3c0ef626 665{
666 Channel *c = channel_lookup(id);
473db5ab 667
3c0ef626 668 if (c == NULL) {
473db5ab 669 logit("channel_register_comfirm: %d: bad id", id);
3c0ef626 670 return;
671 }
473db5ab 672 c->confirm = fn;
673 c->confirm_ctx = ctx;
3c0ef626 674}
30460aeb 675
3c0ef626 676void
08822d99 677channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
3c0ef626 678{
08822d99 679 Channel *c = channel_by_id(id);
473db5ab 680
3c0ef626 681 if (c == NULL) {
473db5ab 682 logit("channel_register_cleanup: %d: bad id", id);
3c0ef626 683 return;
684 }
685 c->detach_user = fn;
08822d99 686 c->detach_close = do_close;
3c0ef626 687}
30460aeb 688
3c0ef626 689void
690channel_cancel_cleanup(int id)
691{
08822d99 692 Channel *c = channel_by_id(id);
473db5ab 693
3c0ef626 694 if (c == NULL) {
473db5ab 695 logit("channel_cancel_cleanup: %d: bad id", id);
3c0ef626 696 return;
697 }
698 c->detach_user = NULL;
08822d99 699 c->detach_close = 0;
3c0ef626 700}
30460aeb 701
3c0ef626 702void
08822d99 703channel_register_filter(int id, channel_infilter_fn *ifn,
704 channel_outfilter_fn *ofn)
3c0ef626 705{
706 Channel *c = channel_lookup(id);
473db5ab 707
3c0ef626 708 if (c == NULL) {
473db5ab 709 logit("channel_register_filter: %d: bad id", id);
3c0ef626 710 return;
711 }
08822d99 712 c->input_filter = ifn;
713 c->output_filter = ofn;
3c0ef626 714}
715
716void
717channel_set_fds(int id, int rfd, int wfd, int efd,
473db5ab 718 int extusage, int nonblock, u_int window_max)
3c0ef626 719{
720 Channel *c = channel_lookup(id);
473db5ab 721
3c0ef626 722 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
723 fatal("channel_activate for non-larval channel %d.", id);
724 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
725 c->type = SSH_CHANNEL_OPEN;
473db5ab 726 c->local_window = c->local_window_max = window_max;
3c0ef626 727 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
728 packet_put_int(c->remote_id);
729 packet_put_int(c->local_window);
730 packet_send();
731}
732
733/*
734 * 'channel_pre*' are called just before select() to add any bits relevant to
735 * channels in the select bitmasks.
736 */
737/*
738 * 'channel_post*': perform any appropriate operations for channels which
739 * have events pending.
740 */
30460aeb 741typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
3c0ef626 742chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
743chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
744
30460aeb 745/* ARGSUSED */
3c0ef626 746static void
30460aeb 747channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 748{
749 FD_SET(c->sock, readset);
750}
751
30460aeb 752/* ARGSUSED */
3c0ef626 753static void
30460aeb 754channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 755{
756 debug3("channel %d: waiting for connection", c->self);
757 FD_SET(c->sock, writeset);
758}
759
760static void
30460aeb 761channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 762{
763 if (buffer_len(&c->input) < packet_get_maxsize())
764 FD_SET(c->sock, readset);
765 if (buffer_len(&c->output) > 0)
766 FD_SET(c->sock, writeset);
767}
768
f713db99 769int channel_tcpwinsz () {
770 u_int32_t tcpwinsz = 0;
771 socklen_t optsz = sizeof(tcpwinsz);
772 int ret = -1;
6df46d40 773
774 /* if we aren't on a socket return 128KB*/
f713db99 775 if(!packet_connection_is_on_socket())
6df46d40 776 return(128*1024);
f713db99 777 ret = getsockopt(packet_get_connection_in(),
778 SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz);
6df46d40 779 /* return no more than 64MB */
f713db99 780 if ((ret == 0) && tcpwinsz > BUFFER_MAX_LEN_HPN)
781 tcpwinsz = BUFFER_MAX_LEN_HPN;
782 debug2("tcpwinsz: %d for connection: %d", tcpwinsz,
783 packet_get_connection_in());
784 return(tcpwinsz);
785}
786
3c0ef626 787static void
30460aeb 788channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 789{
473db5ab 790 u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
f472818d 791
f713db99 792 /* check buffer limits */
6df46d40 793 if ((!c->tcpwinsz) || (c->dynamic_window > 0))
f713db99 794 c->tcpwinsz = channel_tcpwinsz();
f713db99 795
796 limit = MIN(limit, 2 * c->tcpwinsz);
797
3c0ef626 798 if (c->istate == CHAN_INPUT_OPEN &&
473db5ab 799 limit > 0 &&
30460aeb 800 buffer_len(&c->input) < limit &&
801 buffer_check_alloc(&c->input, CHAN_RBUF))
3c0ef626 802 FD_SET(c->rfd, readset);
803 if (c->ostate == CHAN_OUTPUT_OPEN ||
804 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
805 if (buffer_len(&c->output) > 0) {
806 FD_SET(c->wfd, writeset);
807 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
473db5ab 808 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
809 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
810 c->self, c->efd, buffer_len(&c->extended));
811 else
812 chan_obuf_empty(c);
3c0ef626 813 }
814 }
815 /** XXX check close conditions, too */
473db5ab 816 if (compat20 && c->efd != -1) {
3c0ef626 817 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
818 buffer_len(&c->extended) > 0)
819 FD_SET(c->efd, writeset);
473db5ab 820 else if (!(c->flags & CHAN_EOF_SENT) &&
821 c->extended_usage == CHAN_EXTENDED_READ &&
3c0ef626 822 buffer_len(&c->extended) < c->remote_window)
823 FD_SET(c->efd, readset);
824 }
473db5ab 825 /* XXX: What about efd? races? */
826 if (compat20 && c->ctl_fd != -1 &&
827 c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN)
828 FD_SET(c->ctl_fd, readset);
3c0ef626 829}
830
30460aeb 831/* ARGSUSED */
3c0ef626 832static void
30460aeb 833channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 834{
835 if (buffer_len(&c->input) == 0) {
836 packet_start(SSH_MSG_CHANNEL_CLOSE);
837 packet_put_int(c->remote_id);
838 packet_send();
839 c->type = SSH_CHANNEL_CLOSED;
473db5ab 840 debug2("channel %d: closing after input drain.", c->self);
3c0ef626 841 }
842}
843
30460aeb 844/* ARGSUSED */
3c0ef626 845static void
30460aeb 846channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 847{
848 if (buffer_len(&c->output) == 0)
849 chan_mark_dead(c);
850 else
851 FD_SET(c->sock, writeset);
852}
853
854/*
855 * This is a special state for X11 authentication spoofing. An opened X11
856 * connection (when authentication spoofing is being done) remains in this
857 * state until the first packet has been completely read. The authentication
858 * data in that packet is then substituted by the real data if it matches the
859 * fake data, and the channel is put into normal mode.
860 * XXX All this happens at the client side.
861 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
862 */
863static int
864x11_open_helper(Buffer *b)
865{
866 u_char *ucp;
867 u_int proto_len, data_len;
868
869 /* Check if the fixed size part of the packet is in buffer. */
870 if (buffer_len(b) < 12)
871 return 0;
872
873 /* Parse the lengths of variable-length fields. */
473db5ab 874 ucp = buffer_ptr(b);
3c0ef626 875 if (ucp[0] == 0x42) { /* Byte order MSB first. */
876 proto_len = 256 * ucp[6] + ucp[7];
877 data_len = 256 * ucp[8] + ucp[9];
878 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
879 proto_len = ucp[6] + 256 * ucp[7];
880 data_len = ucp[8] + 256 * ucp[9];
881 } else {
473db5ab 882 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
883 ucp[0]);
3c0ef626 884 return -1;
885 }
886
887 /* Check if the whole packet is in buffer. */
888 if (buffer_len(b) <
889 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
890 return 0;
891
892 /* Check if authentication protocol matches. */
893 if (proto_len != strlen(x11_saved_proto) ||
894 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
473db5ab 895 debug2("X11 connection uses different authentication protocol.");
3c0ef626 896 return -1;
897 }
898 /* Check if authentication data matches our fake data. */
899 if (data_len != x11_fake_data_len ||
900 memcmp(ucp + 12 + ((proto_len + 3) & ~3),
901 x11_fake_data, x11_fake_data_len) != 0) {
473db5ab 902 debug2("X11 auth data does not match fake data.");
3c0ef626 903 return -1;
904 }
905 /* Check fake data length */
906 if (x11_fake_data_len != x11_saved_data_len) {
907 error("X11 fake_data_len %d != saved_data_len %d",
908 x11_fake_data_len, x11_saved_data_len);
909 return -1;
910 }
911 /*
912 * Received authentication protocol and data match
913 * our fake data. Substitute the fake data with real
914 * data.
915 */
916 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
917 x11_saved_data, x11_saved_data_len);
918 return 1;
919}
920
921static void
30460aeb 922channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 923{
924 int ret = x11_open_helper(&c->output);
473db5ab 925
3c0ef626 926 if (ret == 1) {
927 /* Start normal processing for the channel. */
928 c->type = SSH_CHANNEL_OPEN;
929 channel_pre_open_13(c, readset, writeset);
930 } else if (ret == -1) {
931 /*
932 * We have received an X11 connection that has bad
933 * authentication information.
934 */
473db5ab 935 logit("X11 connection rejected because of wrong authentication.");
3c0ef626 936 buffer_clear(&c->input);
937 buffer_clear(&c->output);
938 channel_close_fd(&c->sock);
939 c->sock = -1;
940 c->type = SSH_CHANNEL_CLOSED;
941 packet_start(SSH_MSG_CHANNEL_CLOSE);
942 packet_put_int(c->remote_id);
943 packet_send();
944 }
945}
946
947static void
30460aeb 948channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 949{
950 int ret = x11_open_helper(&c->output);
951
952 /* c->force_drain = 1; */
953
954 if (ret == 1) {
955 c->type = SSH_CHANNEL_OPEN;
473db5ab 956 channel_pre_open(c, readset, writeset);
957 } else if (ret == -1) {
958 logit("X11 connection rejected because of wrong authentication.");
959 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
960 chan_read_failed(c);
961 buffer_clear(&c->input);
962 chan_ibuf_empty(c);
963 buffer_clear(&c->output);
964 /* for proto v1, the peer will send an IEOF */
3c0ef626 965 if (compat20)
473db5ab 966 chan_write_failed(c);
3c0ef626 967 else
473db5ab 968 c->type = SSH_CHANNEL_OPEN;
969 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
3c0ef626 970 }
971}
972
973/* try to decode a socks4 header */
30460aeb 974/* ARGSUSED */
3c0ef626 975static int
30460aeb 976channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 977{
473db5ab 978 char *p, *host;
979 u_int len, have, i, found;
980 char username[256];
3c0ef626 981 struct {
982 u_int8_t version;
983 u_int8_t command;
984 u_int16_t dest_port;
985 struct in_addr dest_addr;
986 } s4_req, s4_rsp;
987
988 debug2("channel %d: decode socks4", c->self);
989
990 have = buffer_len(&c->input);
991 len = sizeof(s4_req);
992 if (have < len)
993 return 0;
994 p = buffer_ptr(&c->input);
995 for (found = 0, i = len; i < have; i++) {
996 if (p[i] == '\0') {
997 found = 1;
998 break;
999 }
1000 if (i > 1024) {
1001 /* the peer is probably sending garbage */
1002 debug("channel %d: decode socks4: too long",
1003 c->self);
1004 return -1;
1005 }
1006 }
1007 if (!found)
1008 return 0;
1009 buffer_get(&c->input, (char *)&s4_req.version, 1);
1010 buffer_get(&c->input, (char *)&s4_req.command, 1);
1011 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1012 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1013 have = buffer_len(&c->input);
1014 p = buffer_ptr(&c->input);
1015 len = strlen(p);
1016 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1017 if (len > have)
1018 fatal("channel %d: decode socks4: len %d > have %d",
1019 c->self, len, have);
1020 strlcpy(username, p, sizeof(username));
1021 buffer_consume(&c->input, len);
1022 buffer_consume(&c->input, 1); /* trailing '\0' */
1023
1024 host = inet_ntoa(s4_req.dest_addr);
1025 strlcpy(c->path, host, sizeof(c->path));
1026 c->host_port = ntohs(s4_req.dest_port);
473db5ab 1027
1028 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
3c0ef626 1029 c->self, host, c->host_port, s4_req.command);
1030
1031 if (s4_req.command != 1) {
1032 debug("channel %d: cannot handle: socks4 cn %d",
1033 c->self, s4_req.command);
1034 return -1;
1035 }
1036 s4_rsp.version = 0; /* vn: 0 for reply */
1037 s4_rsp.command = 90; /* cd: req granted */
1038 s4_rsp.dest_port = 0; /* ignored */
1039 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
30460aeb 1040 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
3c0ef626 1041 return 1;
1042}
1043
473db5ab 1044/* try to decode a socks5 header */
1045#define SSH_SOCKS5_AUTHDONE 0x1000
1046#define SSH_SOCKS5_NOAUTH 0x00
1047#define SSH_SOCKS5_IPV4 0x01
1048#define SSH_SOCKS5_DOMAIN 0x03
1049#define SSH_SOCKS5_IPV6 0x04
1050#define SSH_SOCKS5_CONNECT 0x01
1051#define SSH_SOCKS5_SUCCESS 0x00
1052
30460aeb 1053/* ARGSUSED */
473db5ab 1054static int
30460aeb 1055channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
473db5ab 1056{
1057 struct {
1058 u_int8_t version;
1059 u_int8_t command;
1060 u_int8_t reserved;
1061 u_int8_t atyp;
1062 } s5_req, s5_rsp;
1063 u_int16_t dest_port;
1064 u_char *p, dest_addr[255+1];
30460aeb 1065 u_int have, need, i, found, nmethods, addrlen, af;
473db5ab 1066
1067 debug2("channel %d: decode socks5", c->self);
1068 p = buffer_ptr(&c->input);
1069 if (p[0] != 0x05)
1070 return -1;
1071 have = buffer_len(&c->input);
1072 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1073 /* format: ver | nmethods | methods */
1074 if (have < 2)
1075 return 0;
1076 nmethods = p[1];
1077 if (have < nmethods + 2)
1078 return 0;
1079 /* look for method: "NO AUTHENTICATION REQUIRED" */
0b90ac93 1080 for (found = 0, i = 2; i < nmethods + 2; i++) {
30460aeb 1081 if (p[i] == SSH_SOCKS5_NOAUTH) {
473db5ab 1082 found = 1;
1083 break;
1084 }
1085 }
1086 if (!found) {
1087 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1088 c->self);
1089 return -1;
1090 }
1091 buffer_consume(&c->input, nmethods + 2);
1092 buffer_put_char(&c->output, 0x05); /* version */
1093 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1094 FD_SET(c->sock, writeset);
1095 c->flags |= SSH_SOCKS5_AUTHDONE;
1096 debug2("channel %d: socks5 auth done", c->self);
1097 return 0; /* need more */
1098 }
1099 debug2("channel %d: socks5 post auth", c->self);
1100 if (have < sizeof(s5_req)+1)
1101 return 0; /* need more */
30460aeb 1102 memcpy(&s5_req, p, sizeof(s5_req));
473db5ab 1103 if (s5_req.version != 0x05 ||
1104 s5_req.command != SSH_SOCKS5_CONNECT ||
1105 s5_req.reserved != 0x00) {
1106 debug2("channel %d: only socks5 connect supported", c->self);
1107 return -1;
1108 }
1109 switch (s5_req.atyp){
1110 case SSH_SOCKS5_IPV4:
1111 addrlen = 4;
1112 af = AF_INET;
1113 break;
1114 case SSH_SOCKS5_DOMAIN:
1115 addrlen = p[sizeof(s5_req)];
1116 af = -1;
1117 break;
1118 case SSH_SOCKS5_IPV6:
1119 addrlen = 16;
1120 af = AF_INET6;
1121 break;
1122 default:
1123 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1124 return -1;
1125 }
30460aeb 1126 need = sizeof(s5_req) + addrlen + 2;
1127 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1128 need++;
1129 if (have < need)
473db5ab 1130 return 0;
1131 buffer_consume(&c->input, sizeof(s5_req));
1132 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1133 buffer_consume(&c->input, 1); /* host string length */
1134 buffer_get(&c->input, (char *)&dest_addr, addrlen);
1135 buffer_get(&c->input, (char *)&dest_port, 2);
1136 dest_addr[addrlen] = '\0';
1137 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1138 strlcpy(c->path, (char *)dest_addr, sizeof(c->path));
1139 else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL)
1140 return -1;
1141 c->host_port = ntohs(dest_port);
1142
1143 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1144 c->self, c->path, c->host_port, s5_req.command);
1145
1146 s5_rsp.version = 0x05;
1147 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1148 s5_rsp.reserved = 0; /* ignored */
1149 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1150 ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1151 dest_port = 0; /* ignored */
1152
30460aeb 1153 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1154 buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1155 buffer_append(&c->output, &dest_port, sizeof(dest_port));
473db5ab 1156 return 1;
1157}
1158
3c0ef626 1159/* dynamic port forwarding */
1160static void
30460aeb 1161channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1162{
1163 u_char *p;
473db5ab 1164 u_int have;
1165 int ret;
3c0ef626 1166
1167 have = buffer_len(&c->input);
1168 c->delayed = 0;
1169 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1170 /* buffer_dump(&c->input); */
1171 /* check if the fixed size part of the packet is in buffer. */
473db5ab 1172 if (have < 3) {
3c0ef626 1173 /* need more */
1174 FD_SET(c->sock, readset);
1175 return;
1176 }
1177 /* try to guess the protocol */
1178 p = buffer_ptr(&c->input);
1179 switch (p[0]) {
1180 case 0x04:
1181 ret = channel_decode_socks4(c, readset, writeset);
1182 break;
473db5ab 1183 case 0x05:
1184 ret = channel_decode_socks5(c, readset, writeset);
1185 break;
3c0ef626 1186 default:
1187 ret = -1;
1188 break;
1189 }
1190 if (ret < 0) {
1191 chan_mark_dead(c);
1192 } else if (ret == 0) {
1193 debug2("channel %d: pre_dynamic: need more", c->self);
1194 /* need more */
1195 FD_SET(c->sock, readset);
1196 } else {
1197 /* switch to the next state */
1198 c->type = SSH_CHANNEL_OPENING;
1199 port_open_helper(c, "direct-tcpip");
1200 }
1201}
1202
1203/* This is our fake X11 server socket. */
30460aeb 1204/* ARGSUSED */
3c0ef626 1205static void
30460aeb 1206channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1207{
1208 Channel *nc;
1209 struct sockaddr addr;
1210 int newsock;
1211 socklen_t addrlen;
1212 char buf[16384], *remote_ipaddr;
1213 int remote_port;
1214
1215 if (FD_ISSET(c->sock, readset)) {
1216 debug("X11 connection requested.");
1217 addrlen = sizeof(addr);
1218 newsock = accept(c->sock, &addr, &addrlen);
473db5ab 1219 if (c->single_connection) {
1220 debug2("single_connection: closing X11 listener.");
1221 channel_close_fd(&c->sock);
1222 chan_mark_dead(c);
1223 }
3c0ef626 1224 if (newsock < 0) {
1225 error("accept: %.100s", strerror(errno));
1226 return;
1227 }
473db5ab 1228 set_nodelay(newsock);
3c0ef626 1229 remote_ipaddr = get_peer_ipaddr(newsock);
1230 remote_port = get_peer_port(newsock);
1231 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1232 remote_ipaddr, remote_port);
1233
1234 nc = channel_new("accepted x11 socket",
1235 SSH_CHANNEL_OPENING, newsock, newsock, -1,
473db5ab 1236 c->local_window_max, c->local_maxpacket, 0, buf, 1);
3c0ef626 1237 if (compat20) {
1238 packet_start(SSH2_MSG_CHANNEL_OPEN);
1239 packet_put_cstring("x11");
1240 packet_put_int(nc->self);
473db5ab 1241 packet_put_int(nc->local_window_max);
1242 packet_put_int(nc->local_maxpacket);
3c0ef626 1243 /* originator ipaddr and port */
1244 packet_put_cstring(remote_ipaddr);
1245 if (datafellows & SSH_BUG_X11FWD) {
473db5ab 1246 debug2("ssh2 x11 bug compat mode");
3c0ef626 1247 } else {
1248 packet_put_int(remote_port);
1249 }
1250 packet_send();
1251 } else {
1252 packet_start(SSH_SMSG_X11_OPEN);
1253 packet_put_int(nc->self);
1254 if (packet_get_protocol_flags() &
1255 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1256 packet_put_cstring(buf);
1257 packet_send();
1258 }
1259 xfree(remote_ipaddr);
1260 }
1261}
1262
1263static void
1264port_open_helper(Channel *c, char *rtype)
1265{
1266 int direct;
1267 char buf[1024];
1268 char *remote_ipaddr = get_peer_ipaddr(c->sock);
473db5ab 1269 int remote_port = get_peer_port(c->sock);
3c0ef626 1270
1271 direct = (strcmp(rtype, "direct-tcpip") == 0);
1272
1273 snprintf(buf, sizeof buf,
1274 "%s: listening port %d for %.100s port %d, "
1275 "connect from %.200s port %d",
1276 rtype, c->listening_port, c->path, c->host_port,
1277 remote_ipaddr, remote_port);
1278
1279 xfree(c->remote_name);
1280 c->remote_name = xstrdup(buf);
1281
1282 if (compat20) {
1283 packet_start(SSH2_MSG_CHANNEL_OPEN);
1284 packet_put_cstring(rtype);
1285 packet_put_int(c->self);
1286 packet_put_int(c->local_window_max);
1287 packet_put_int(c->local_maxpacket);
1288 if (direct) {
1289 /* target host, port */
1290 packet_put_cstring(c->path);
1291 packet_put_int(c->host_port);
1292 } else {
1293 /* listen address, port */
1294 packet_put_cstring(c->path);
1295 packet_put_int(c->listening_port);
1296 }
1297 /* originator host and port */
1298 packet_put_cstring(remote_ipaddr);
473db5ab 1299 packet_put_int((u_int)remote_port);
3c0ef626 1300 packet_send();
1301 } else {
1302 packet_start(SSH_MSG_PORT_OPEN);
1303 packet_put_int(c->self);
1304 packet_put_cstring(c->path);
1305 packet_put_int(c->host_port);
1306 if (packet_get_protocol_flags() &
1307 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1308 packet_put_cstring(c->remote_name);
1309 packet_send();
1310 }
1311 xfree(remote_ipaddr);
1312}
1313
08822d99 1314static void
1315channel_set_reuseaddr(int fd)
1316{
1317 int on = 1;
1318
1319 /*
1320 * Set socket options.
1321 * Allow local port reuse in TIME_WAIT.
1322 */
1323 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1324 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1325}
1326
3c0ef626 1327/*
1328 * This socket is listening for connections to a forwarded TCP/IP port.
1329 */
30460aeb 1330/* ARGSUSED */
3c0ef626 1331static void
30460aeb 1332channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1333{
1334 Channel *nc;
1335 struct sockaddr addr;
1336 int newsock, nextstate;
1337 socklen_t addrlen;
1338 char *rtype;
1339
1340 if (FD_ISSET(c->sock, readset)) {
1341 debug("Connection to port %d forwarding "
1342 "to %.100s port %d requested.",
1343 c->listening_port, c->path, c->host_port);
1344
1345 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1346 nextstate = SSH_CHANNEL_OPENING;
1347 rtype = "forwarded-tcpip";
1348 } else {
1349 if (c->host_port == 0) {
1350 nextstate = SSH_CHANNEL_DYNAMIC;
1351 rtype = "dynamic-tcpip";
1352 } else {
1353 nextstate = SSH_CHANNEL_OPENING;
1354 rtype = "direct-tcpip";
1355 }
1356 }
1357
1358 addrlen = sizeof(addr);
1359 newsock = accept(c->sock, &addr, &addrlen);
1360 if (newsock < 0) {
1361 error("accept: %.100s", strerror(errno));
1362 return;
1363 }
473db5ab 1364 set_nodelay(newsock);
1365 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1366 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
3c0ef626 1367 nc->listening_port = c->listening_port;
1368 nc->host_port = c->host_port;
1369 strlcpy(nc->path, c->path, sizeof(nc->path));
1370
1371 if (nextstate == SSH_CHANNEL_DYNAMIC) {
1372 /*
1373 * do not call the channel_post handler until
1374 * this flag has been reset by a pre-handler.
1375 * otherwise the FD_ISSET calls might overflow
1376 */
1377 nc->delayed = 1;
1378 } else {
1379 port_open_helper(nc, rtype);
1380 }
1381 }
1382}
1383
1384/*
1385 * This is the authentication agent socket listening for connections from
1386 * clients.
1387 */
30460aeb 1388/* ARGSUSED */
3c0ef626 1389static void
30460aeb 1390channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1391{
1392 Channel *nc;
3c0ef626 1393 int newsock;
1394 struct sockaddr addr;
1395 socklen_t addrlen;
1396
1397 if (FD_ISSET(c->sock, readset)) {
1398 addrlen = sizeof(addr);
1399 newsock = accept(c->sock, &addr, &addrlen);
1400 if (newsock < 0) {
1401 error("accept from auth socket: %.100s", strerror(errno));
1402 return;
1403 }
3c0ef626 1404 nc = channel_new("accepted auth socket",
1405 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1406 c->local_window_max, c->local_maxpacket,
473db5ab 1407 0, "accepted auth socket", 1);
3c0ef626 1408 if (compat20) {
1409 packet_start(SSH2_MSG_CHANNEL_OPEN);
1410 packet_put_cstring("auth-agent@openssh.com");
1411 packet_put_int(nc->self);
1412 packet_put_int(c->local_window_max);
1413 packet_put_int(c->local_maxpacket);
1414 } else {
1415 packet_start(SSH_SMSG_AGENT_OPEN);
1416 packet_put_int(nc->self);
1417 }
1418 packet_send();
1419 }
1420}
1421
30460aeb 1422/* ARGSUSED */
3c0ef626 1423static void
30460aeb 1424channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1425{
1426 int err = 0;
1427 socklen_t sz = sizeof(err);
1428
1429 if (FD_ISSET(c->sock, writeset)) {
473db5ab 1430 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
3c0ef626 1431 err = errno;
1432 error("getsockopt SO_ERROR failed");
1433 }
1434 if (err == 0) {
1435 debug("channel %d: connected", c->self);
1436 c->type = SSH_CHANNEL_OPEN;
1437 if (compat20) {
1438 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1439 packet_put_int(c->remote_id);
1440 packet_put_int(c->self);
1441 packet_put_int(c->local_window);
1442 packet_put_int(c->local_maxpacket);
1443 } else {
1444 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1445 packet_put_int(c->remote_id);
1446 packet_put_int(c->self);
1447 }
1448 } else {
1449 debug("channel %d: not connected: %s",
1450 c->self, strerror(err));
1451 if (compat20) {
1452 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1453 packet_put_int(c->remote_id);
1454 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1455 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1456 packet_put_cstring(strerror(err));
1457 packet_put_cstring("");
1458 }
1459 } else {
1460 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1461 packet_put_int(c->remote_id);
1462 }
1463 chan_mark_dead(c);
1464 }
1465 packet_send();
1466 }
1467}
1468
30460aeb 1469/* ARGSUSED */
3c0ef626 1470static int
30460aeb 1471channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1472{
473db5ab 1473 char buf[CHAN_RBUF];
fa0f0f45 1474 int len, force;
3c0ef626 1475
fa0f0f45 1476 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1477 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
30460aeb 1478 errno = 0;
3c0ef626 1479 len = read(c->rfd, buf, sizeof(buf));
fa0f0f45 1480 if (len < 0 && (errno == EINTR || (errno == EAGAIN && !force)))
3c0ef626 1481 return 1;
30460aeb 1482#ifndef PTY_ZEROREAD
3c0ef626 1483 if (len <= 0) {
30460aeb 1484#else
1485 if ((!c->isatty && len <= 0) ||
1486 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1487#endif
473db5ab 1488 debug2("channel %d: read<=0 rfd %d len %d",
3c0ef626 1489 c->self, c->rfd, len);
1490 if (c->type != SSH_CHANNEL_OPEN) {
473db5ab 1491 debug2("channel %d: not open", c->self);
3c0ef626 1492 chan_mark_dead(c);
1493 return -1;
1494 } else if (compat13) {
473db5ab 1495 buffer_clear(&c->output);
3c0ef626 1496 c->type = SSH_CHANNEL_INPUT_DRAINING;
473db5ab 1497 debug2("channel %d: input draining.", c->self);
3c0ef626 1498 } else {
1499 chan_read_failed(c);
1500 }
1501 return -1;
1502 }
473db5ab 1503 if (c->input_filter != NULL) {
3c0ef626 1504 if (c->input_filter(c, buf, len) == -1) {
473db5ab 1505 debug2("channel %d: filter stops", c->self);
3c0ef626 1506 chan_read_failed(c);
1507 }
08822d99 1508 } else if (c->datagram) {
1509 buffer_put_string(&c->input, buf, len);
3c0ef626 1510 } else {
1511 buffer_append(&c->input, buf, len);
1512 }
1513 }
1514 return 1;
1515}
30460aeb 1516
1517/* ARGSUSED */
3c0ef626 1518static int
30460aeb 1519channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1520{
1521 struct termios tio;
08822d99 1522 u_char *data = NULL, *buf;
3c0ef626 1523 u_int dlen;
1524 int len;
1525
1526 /* Send buffered output data to the socket. */
1527 if (c->wfd != -1 &&
1528 FD_ISSET(c->wfd, writeset) &&
1529 buffer_len(&c->output) > 0) {
08822d99 1530 if (c->output_filter != NULL) {
1531 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1532 debug2("channel %d: filter stops", c->self);
1533 if (c->type != SSH_CHANNEL_OPEN)
1534 chan_mark_dead(c);
1535 else
1536 chan_write_failed(c);
1537 return -1;
1538 }
1539 } else if (c->datagram) {
1540 buf = data = buffer_get_string(&c->output, &dlen);
1541 } else {
1542 buf = data = buffer_ptr(&c->output);
1543 dlen = buffer_len(&c->output);
1544 }
1545
1546 if (c->datagram) {
1547 /* ignore truncated writes, datagrams might get lost */
1548 c->local_consumed += dlen + 4;
1549 len = write(c->wfd, buf, dlen);
1550 xfree(data);
1551 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1552 return 1;
1553 if (len <= 0) {
1554 if (c->type != SSH_CHANNEL_OPEN)
1555 chan_mark_dead(c);
1556 else
1557 chan_write_failed(c);
1558 return -1;
1559 }
1560 return 1;
1561 }
473db5ab 1562#ifdef _AIX
1563 /* XXX: Later AIX versions can't push as much data to tty */
1564 if (compat20 && c->wfd_isatty)
1565 dlen = MIN(dlen, 8*1024);
1566#endif
08822d99 1567
1568 len = write(c->wfd, buf, dlen);
3c0ef626 1569 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1570 return 1;
1571 if (len <= 0) {
1572 if (c->type != SSH_CHANNEL_OPEN) {
473db5ab 1573 debug2("channel %d: not open", c->self);
3c0ef626 1574 chan_mark_dead(c);
1575 return -1;
1576 } else if (compat13) {
473db5ab 1577 buffer_clear(&c->output);
1578 debug2("channel %d: input draining.", c->self);
3c0ef626 1579 c->type = SSH_CHANNEL_INPUT_DRAINING;
1580 } else {
1581 chan_write_failed(c);
1582 }
1583 return -1;
1584 }
08822d99 1585 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
3c0ef626 1586 if (tcgetattr(c->wfd, &tio) == 0 &&
1587 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1588 /*
1589 * Simulate echo to reduce the impact of
1590 * traffic analysis. We need to match the
1591 * size of a SSH2_MSG_CHANNEL_DATA message
08822d99 1592 * (4 byte channel id + buf)
3c0ef626 1593 */
1594 packet_send_ignore(4 + len);
1595 packet_send();
1596 }
1597 }
1598 buffer_consume(&c->output, len);
1599 if (compat20 && len > 0) {
1600 c->local_consumed += len;
1601 }
1602 }
1603 return 1;
1604}
30460aeb 1605
3c0ef626 1606static int
30460aeb 1607channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1608{
473db5ab 1609 char buf[CHAN_RBUF];
3c0ef626 1610 int len;
1611
1612/** XXX handle drain efd, too */
1613 if (c->efd != -1) {
1614 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1615 FD_ISSET(c->efd, writeset) &&
1616 buffer_len(&c->extended) > 0) {
1617 len = write(c->efd, buffer_ptr(&c->extended),
1618 buffer_len(&c->extended));
1619 debug2("channel %d: written %d to efd %d",
1620 c->self, len, c->efd);
1621 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1622 return 1;
1623 if (len <= 0) {
1624 debug2("channel %d: closing write-efd %d",
1625 c->self, c->efd);
1626 channel_close_fd(&c->efd);
1627 } else {
1628 buffer_consume(&c->extended, len);
1629 c->local_consumed += len;
1630 }
1631 } else if (c->extended_usage == CHAN_EXTENDED_READ &&
0b90ac93 1632 (c->detach_close || FD_ISSET(c->efd, readset))) {
3c0ef626 1633 len = read(c->efd, buf, sizeof(buf));
1634 debug2("channel %d: read %d from efd %d",
473db5ab 1635 c->self, len, c->efd);
0b90ac93 1636 if (len < 0 && (errno == EINTR ||
1637 (errno == EAGAIN && !c->detach_close)))
3c0ef626 1638 return 1;
1639 if (len <= 0) {
1640 debug2("channel %d: closing read-efd %d",
1641 c->self, c->efd);
1642 channel_close_fd(&c->efd);
1643 } else {
1644 buffer_append(&c->extended, buf, len);
1645 }
1646 }
1647 }
1648 return 1;
1649}
30460aeb 1650
1651/* ARGSUSED */
3c0ef626 1652static int
30460aeb 1653channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset)
473db5ab 1654{
1655 char buf[16];
1656 int len;
1657
1658 /* Monitor control fd to detect if the slave client exits */
1659 if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) {
1660 len = read(c->ctl_fd, buf, sizeof(buf));
1661 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1662 return 1;
1663 if (len <= 0) {
1664 debug2("channel %d: ctl read<=0", c->self);
1665 if (c->type != SSH_CHANNEL_OPEN) {
1666 debug2("channel %d: not open", c->self);
1667 chan_mark_dead(c);
1668 return -1;
1669 } else {
1670 chan_read_failed(c);
1671 chan_write_failed(c);
1672 }
1673 return -1;
1674 } else
1675 fatal("%s: unexpected data on ctl fd", __func__);
1676 }
1677 return 1;
1678}
30460aeb 1679
473db5ab 1680static int
3c0ef626 1681channel_check_window(Channel *c)
1682{
1683 if (c->type == SSH_CHANNEL_OPEN &&
1684 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
fa0f0f45 1685 ((c->local_window_max - c->local_window >
1686 c->local_maxpacket*3) ||
1687 c->local_window < c->local_window_max/2) &&
3c0ef626 1688 c->local_consumed > 0) {
a7213e65 1689 u_int addition = 0;
1690 /* adjust max window size if we are in a dynamic environment */
1691 if (c->dynamic_window && (c->tcpwinsz > c->local_window_max)) {
6df46d40 1692 /* grow the window somewhat aggressively to maintain pressure */
1693 addition = 1.5*(c->tcpwinsz - c->local_window_max);
473db5ab 1694 c->local_window_max += addition;
1695 }
3c0ef626 1696 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1697 packet_put_int(c->remote_id);
473db5ab 1698 packet_put_int(c->local_consumed + addition);
3c0ef626 1699 packet_send();
1700 debug2("channel %d: window %d sent adjust %d",
1701 c->self, c->local_window,
1702 c->local_consumed);
473db5ab 1703 c->local_window += c->local_consumed + addition;
3c0ef626 1704 c->local_consumed = 0;
1705 }
1706 return 1;
1707}
1708
1709static void
30460aeb 1710channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1711{
1712 if (c->delayed)
1713 return;
1714 channel_handle_rfd(c, readset, writeset);
1715 channel_handle_wfd(c, readset, writeset);
473db5ab 1716 if (!compat20)
3c0ef626 1717 return;
3c0ef626 1718 channel_handle_efd(c, readset, writeset);
473db5ab 1719 channel_handle_ctl(c, readset, writeset);
3c0ef626 1720 channel_check_window(c);
1721}
1722
30460aeb 1723/* ARGSUSED */
3c0ef626 1724static void
30460aeb 1725channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
3c0ef626 1726{
1727 int len;
473db5ab 1728
3c0ef626 1729 /* Send buffered output data to the socket. */
1730 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1731 len = write(c->sock, buffer_ptr(&c->output),
1732 buffer_len(&c->output));
1733 if (len <= 0)
473db5ab 1734 buffer_clear(&c->output);
3c0ef626 1735 else
1736 buffer_consume(&c->output, len);
1737 }
1738}
1739
1740static void
1741channel_handler_init_20(void)
1742{
473db5ab 1743 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
3c0ef626 1744 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1745 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1746 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
1747 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1748 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1749 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1750 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1751
473db5ab 1752 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
3c0ef626 1753 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1754 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
1755 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1756 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1757 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
473db5ab 1758 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
3c0ef626 1759}
1760
1761static void
1762channel_handler_init_13(void)
1763{
1764 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
1765 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
1766 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1767 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1768 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1769 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
1770 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
1771 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1772 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1773
473db5ab 1774 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
3c0ef626 1775 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1776 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1777 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
1778 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
1779 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
473db5ab 1780 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
3c0ef626 1781}
1782
1783static void
1784channel_handler_init_15(void)
1785{
473db5ab 1786 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
3c0ef626 1787 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
1788 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
1789 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
1790 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
1791 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
1792 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
1793
1794 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
1795 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
1796 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
473db5ab 1797 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
3c0ef626 1798 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
473db5ab 1799 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
3c0ef626 1800}
1801
1802static void
1803channel_handler_init(void)
1804{
1805 int i;
473db5ab 1806
1807 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
3c0ef626 1808 channel_pre[i] = NULL;
1809 channel_post[i] = NULL;
1810 }
1811 if (compat20)
1812 channel_handler_init_20();
1813 else if (compat13)
1814 channel_handler_init_13();
1815 else
1816 channel_handler_init_15();
1817}
1818
1819/* gc dead channels */
1820static void
1821channel_garbage_collect(Channel *c)
1822{
1823 if (c == NULL)
1824 return;
1825 if (c->detach_user != NULL) {
08822d99 1826 if (!chan_is_dead(c, c->detach_close))
3c0ef626 1827 return;
473db5ab 1828 debug2("channel %d: gc: notify user", c->self);
3c0ef626 1829 c->detach_user(c->self, NULL);
1830 /* if we still have a callback */
1831 if (c->detach_user != NULL)
1832 return;
473db5ab 1833 debug2("channel %d: gc: user detached", c->self);
3c0ef626 1834 }
1835 if (!chan_is_dead(c, 1))
1836 return;
473db5ab 1837 debug2("channel %d: garbage collecting", c->self);
3c0ef626 1838 channel_free(c);
1839}
1840
1841static void
30460aeb 1842channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
3c0ef626 1843{
1844 static int did_init = 0;
473db5ab 1845 u_int i;
3c0ef626 1846 Channel *c;
1847
1848 if (!did_init) {
1849 channel_handler_init();
1850 did_init = 1;
1851 }
1852 for (i = 0; i < channels_alloc; i++) {
1853 c = channels[i];
1854 if (c == NULL)
1855 continue;
1856 if (ftab[c->type] != NULL)
1857 (*ftab[c->type])(c, readset, writeset);
1858 channel_garbage_collect(c);
1859 }
1860}
1861
1862/*
1863 * Allocate/update select bitmasks and add any bits relevant to channels in
1864 * select bitmasks.
1865 */
1866void
1867channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
473db5ab 1868 u_int *nallocp, int rekeying)
3c0ef626 1869{
30460aeb 1870 u_int n, sz, nfdset;
3c0ef626 1871
1872 n = MAX(*maxfdp, channel_max_fd);
1873
30460aeb 1874 nfdset = howmany(n+1, NFDBITS);
1875 /* Explicitly test here, because xrealloc isn't always called */
1876 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
1877 fatal("channel_prepare_select: max_fd (%d) is too large", n);
1878 sz = nfdset * sizeof(fd_mask);
1879
3c0ef626 1880 /* perhaps check sz < nalloc/2 and shrink? */
1881 if (*readsetp == NULL || sz > *nallocp) {
30460aeb 1882 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
1883 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
3c0ef626 1884 *nallocp = sz;
1885 }
1886 *maxfdp = n;
1887 memset(*readsetp, 0, sz);
1888 memset(*writesetp, 0, sz);
1889
1890 if (!rekeying)
1891 channel_handler(channel_pre, *readsetp, *writesetp);
1892}
1893
1894/*
1895 * After select, perform any appropriate operations for channels which have
1896 * events pending.
1897 */
1898void
30460aeb 1899channel_after_select(fd_set *readset, fd_set *writeset)
3c0ef626 1900{
1901 channel_handler(channel_post, readset, writeset);
1902}
1903
1904
1905/* If there is data to send to the connection, enqueue some of it now. */
fa7499cc 1906int
473db5ab 1907channel_output_poll(void)
3c0ef626 1908{
3c0ef626 1909 Channel *c;
473db5ab 1910 u_int i, len;
fa7499cc 1911 int packet_length = 0;
3c0ef626 1912
1913 for (i = 0; i < channels_alloc; i++) {
1914 c = channels[i];
1915 if (c == NULL)
1916 continue;
1917
1918 /*
1919 * We are only interested in channels that can have buffered
1920 * incoming data.
1921 */
1922 if (compat13) {
1923 if (c->type != SSH_CHANNEL_OPEN &&
1924 c->type != SSH_CHANNEL_INPUT_DRAINING)
1925 continue;
1926 } else {
1927 if (c->type != SSH_CHANNEL_OPEN)
1928 continue;
1929 }
1930 if (compat20 &&
1931 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
1932 /* XXX is this true? */
1933 debug3("channel %d: will not send data after close", c->self);
1934 continue;
1935 }
1936
1937 /* Get the amount of buffered data for this channel. */
1938 if ((c->istate == CHAN_INPUT_OPEN ||
1939 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
1940 (len = buffer_len(&c->input)) > 0) {
08822d99 1941 if (c->datagram) {
1942 if (len > 0) {
1943 u_char *data;
1944 u_int dlen;
1945
1946 data = buffer_get_string(&c->input,
1947 &dlen);
1948 packet_start(SSH2_MSG_CHANNEL_DATA);
1949 packet_put_int(c->remote_id);
1950 packet_put_string(data, dlen);
fa7499cc 1951 packet_length = packet_send();
08822d99 1952 c->remote_window -= dlen + 4;
1953 xfree(data);
1954 }
1955 continue;
1956 }
3c0ef626 1957 /*
1958 * Send some data for the other side over the secure
1959 * connection.
1960 */
1961 if (compat20) {
1962 if (len > c->remote_window)
1963 len = c->remote_window;
1964 if (len > c->remote_maxpacket)
1965 len = c->remote_maxpacket;
1966 } else {
1967 if (packet_is_interactive()) {
1968 if (len > 1024)
1969 len = 512;
1970 } else {
1971 /* Keep the packets at reasonable size. */
1972 if (len > packet_get_maxsize()/2)
1973 len = packet_get_maxsize()/2;
1974 }
1975 }
1976 if (len > 0) {
1977 packet_start(compat20 ?
1978 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
1979 packet_put_int(c->remote_id);
1980 packet_put_string(buffer_ptr(&c->input), len);
fa7499cc 1981 packet_length = packet_send();
3c0ef626 1982 buffer_consume(&c->input, len);
1983 c->remote_window -= len;
1984 }
1985 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1986 if (compat13)
1987 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
1988 /*
1989 * input-buffer is empty and read-socket shutdown:
473db5ab 1990 * tell peer, that we will not send more data: send IEOF.
1991 * hack for extended data: delay EOF if EFD still in use.
3c0ef626 1992 */
473db5ab 1993 if (CHANNEL_EFD_INPUT_ACTIVE(c))
1994 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
1995 c->self, c->efd, buffer_len(&c->extended));
1996 else
1997 chan_ibuf_empty(c);
3c0ef626 1998 }
1999 /* Send extended data, i.e. stderr */
2000 if (compat20 &&
473db5ab 2001 !(c->flags & CHAN_EOF_SENT) &&
3c0ef626 2002 c->remote_window > 0 &&
2003 (len = buffer_len(&c->extended)) > 0 &&
2004 c->extended_usage == CHAN_EXTENDED_READ) {
473db5ab 2005 debug2("channel %d: rwin %u elen %u euse %d",
3c0ef626 2006 c->self, c->remote_window, buffer_len(&c->extended),
2007 c->extended_usage);
2008 if (len > c->remote_window)
2009 len = c->remote_window;
2010 if (len > c->remote_maxpacket)
2011 len = c->remote_maxpacket;
2012 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2013 packet_put_int(c->remote_id);
2014 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2015 packet_put_string(buffer_ptr(&c->extended), len);
fa7499cc 2016 packet_length = packet_send();
3c0ef626 2017 buffer_consume(&c->extended, len);
2018 c->remote_window -= len;
2019 debug2("channel %d: sent ext data %d", c->self, len);
2020 }
2021 }
fa7499cc 2022 return (packet_length);
3c0ef626 2023}
2024
2025
2026/* -- protocol input */
2027
30460aeb 2028/* ARGSUSED */
3c0ef626 2029void
473db5ab 2030channel_input_data(int type, u_int32_t seq, void *ctxt)
3c0ef626 2031{
2032 int id;
2033 char *data;
2034 u_int data_len;
2035 Channel *c;
2036
2037 /* Get the channel number and verify it. */
2038 id = packet_get_int();
2039 c = channel_lookup(id);
2040 if (c == NULL)
2041 packet_disconnect("Received data for nonexistent channel %d.", id);
2042
2043 /* Ignore any data for non-open channels (might happen on close) */
2044 if (c->type != SSH_CHANNEL_OPEN &&
2045 c->type != SSH_CHANNEL_X11_OPEN)
2046 return;
2047
3c0ef626 2048 /* Get the data. */
2049 data = packet_get_string(&data_len);
3c0ef626 2050
473db5ab 2051 /*
2052 * Ignore data for protocol > 1.3 if output end is no longer open.
2053 * For protocol 2 the sending side is reducing its window as it sends
2054 * data, so we must 'fake' consumption of the data in order to ensure
2055 * that window updates are sent back. Otherwise the connection might
2056 * deadlock.
2057 */
2058 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2059 if (compat20) {
2060 c->local_window -= data_len;
2061 c->local_consumed += data_len;
2062 }
2063 xfree(data);
2064 return;
2065 }
2066
2067 if (compat20) {
3c0ef626 2068 if (data_len > c->local_maxpacket) {
473db5ab 2069 logit("channel %d: rcvd big packet %d, maxpack %d",
3c0ef626 2070 c->self, data_len, c->local_maxpacket);
2071 }
2072 if (data_len > c->local_window) {
473db5ab 2073 logit("channel %d: rcvd too much data %d, win %d",
3c0ef626 2074 c->self, data_len, c->local_window);
2075 xfree(data);
2076 return;
2077 }
2078 c->local_window -= data_len;
3c0ef626 2079 }
473db5ab 2080 packet_check_eom();
08822d99 2081 if (c->datagram)
2082 buffer_put_string(&c->output, data, data_len);
2083 else
2084 buffer_append(&c->output, data, data_len);
3c0ef626 2085 xfree(data);
2086}
2087
30460aeb 2088/* ARGSUSED */
3c0ef626 2089void
473db5ab 2090channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
3c0ef626 2091{
2092 int id;
3c0ef626 2093 char *data;
473db5ab 2094 u_int data_len, tcode;
3c0ef626 2095 Channel *c;
2096
2097 /* Get the channel number and verify it. */
2098 id = packet_get_int();
2099 c = channel_lookup(id);
2100
2101 if (c == NULL)
2102 packet_disconnect("Received extended_data for bad channel %d.", id);
2103 if (c->type != SSH_CHANNEL_OPEN) {
473db5ab 2104 logit("channel %d: ext data for non open", id);
3c0ef626 2105 return;
2106 }
473db5ab 2107 if (c->flags & CHAN_EOF_RCVD) {
2108 if (datafellows & SSH_BUG_EXTEOF)
2109 debug("channel %d: accepting ext data after eof", id);
2110 else
2111 packet_disconnect("Received extended_data after EOF "
2112 "on channel %d.", id);
2113 }
3c0ef626 2114 tcode = packet_get_int();
2115 if (c->efd == -1 ||
2116 c->extended_usage != CHAN_EXTENDED_WRITE ||
2117 tcode != SSH2_EXTENDED_DATA_STDERR) {
473db5ab 2118 logit("channel %d: bad ext data", c->self);
3c0ef626 2119 return;
2120 }
2121 data = packet_get_string(&data_len);
473db5ab 2122 packet_check_eom();
3c0ef626 2123 if (data_len > c->local_window) {
473db5ab 2124 logit("channel %d: rcvd too much extended_data %d, win %d",
3c0ef626 2125 c->self, data_len, c->local_window);
2126 xfree(data);
2127 return;
2128 }
2129 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2130 c->local_window -= data_len;
2131 buffer_append(&c->extended, data, data_len);
2132 xfree(data);
2133}
2134
30460aeb 2135/* ARGSUSED */
3c0ef626 2136void
473db5ab 2137channel_input_ieof(int type, u_int32_t seq, void *ctxt)
3c0ef626 2138{
2139 int id;
2140 Channel *c;
2141
3c0ef626 2142 id = packet_get_int();
473db5ab 2143 packet_check_eom();
3c0ef626 2144 c = channel_lookup(id);
2145 if (c == NULL)
2146 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2147 chan_rcvd_ieof(c);
2148
2149 /* XXX force input close */
473db5ab 2150 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
3c0ef626 2151 debug("channel %d: FORCE input drain", c->self);
2152 c->istate = CHAN_INPUT_WAIT_DRAIN;
473db5ab 2153 if (buffer_len(&c->input) == 0)
2154 chan_ibuf_empty(c);
3c0ef626 2155 }
2156
2157}
2158
30460aeb 2159/* ARGSUSED */
3c0ef626 2160void
473db5ab 2161channel_input_close(int type, u_int32_t seq, void *ctxt)
3c0ef626 2162{
2163 int id;
2164 Channel *c;
2165
3c0ef626 2166 id = packet_get_int();
473db5ab 2167 packet_check_eom();
3c0ef626 2168 c = channel_lookup(id);
2169 if (c == NULL)
2170 packet_disconnect("Received close for nonexistent channel %d.", id);
2171
2172 /*
2173 * Send a confirmation that we have closed the channel and no more
2174 * data is coming for it.
2175 */
2176 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2177 packet_put_int(c->remote_id);
2178 packet_send();
2179
2180 /*
2181 * If the channel is in closed state, we have sent a close request,
2182 * and the other side will eventually respond with a confirmation.
2183 * Thus, we cannot free the channel here, because then there would be
2184 * no-one to receive the confirmation. The channel gets freed when
2185 * the confirmation arrives.
2186 */
2187 if (c->type != SSH_CHANNEL_CLOSED) {
2188 /*
2189 * Not a closed channel - mark it as draining, which will
2190 * cause it to be freed later.
2191 */
473db5ab 2192 buffer_clear(&c->input);
3c0ef626 2193 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2194 }
2195}
2196
2197/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
30460aeb 2198/* ARGSUSED */
3c0ef626 2199void
473db5ab 2200channel_input_oclose(int type, u_int32_t seq, void *ctxt)
3c0ef626 2201{
2202 int id = packet_get_int();
2203 Channel *c = channel_lookup(id);
473db5ab 2204
2205 packet_check_eom();
3c0ef626 2206 if (c == NULL)
2207 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2208 chan_rcvd_oclose(c);
2209}
2210
30460aeb 2211/* ARGSUSED */
3c0ef626 2212void
473db5ab 2213channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
3c0ef626 2214{
2215 int id = packet_get_int();
2216 Channel *c = channel_lookup(id);
2217
473db5ab 2218 packet_check_eom();
3c0ef626 2219 if (c == NULL)
2220 packet_disconnect("Received close confirmation for "
2221 "out-of-range channel %d.", id);
2222 if (c->type != SSH_CHANNEL_CLOSED)
2223 packet_disconnect("Received close confirmation for "
2224 "non-closed channel %d (type %d).", id, c->type);
2225 channel_free(c);
2226}
2227
30460aeb 2228/* ARGSUSED */
3c0ef626 2229void
473db5ab 2230channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
3c0ef626 2231{
2232 int id, remote_id;
2233 Channel *c;
2234
3c0ef626 2235 id = packet_get_int();
2236 c = channel_lookup(id);
2237
2238 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2239 packet_disconnect("Received open confirmation for "
2240 "non-opening channel %d.", id);
2241 remote_id = packet_get_int();
2242 /* Record the remote channel number and mark that the channel is now open. */
2243 c->remote_id = remote_id;
2244 c->type = SSH_CHANNEL_OPEN;
2245
2246 if (compat20) {
2247 c->remote_window = packet_get_int();
2248 c->remote_maxpacket = packet_get_int();
473db5ab 2249 if (c->confirm) {
3c0ef626 2250 debug2("callback start");
473db5ab 2251 c->confirm(c->self, c->confirm_ctx);
3c0ef626 2252 debug2("callback done");
2253 }
473db5ab 2254 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
3c0ef626 2255 c->remote_window, c->remote_maxpacket);
2256 }
473db5ab 2257 packet_check_eom();
3c0ef626 2258}
2259
2260static char *
2261reason2txt(int reason)
2262{
473db5ab 2263 switch (reason) {
3c0ef626 2264 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2265 return "administratively prohibited";
2266 case SSH2_OPEN_CONNECT_FAILED:
2267 return "connect failed";
2268 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2269 return "unknown channel type";
2270 case SSH2_OPEN_RESOURCE_SHORTAGE:
2271 return "resource shortage";
2272 }
2273 return "unknown reason";
2274}
2275
30460aeb 2276/* ARGSUSED */
3c0ef626 2277void
473db5ab 2278channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
3c0ef626 2279{
2280 int id, reason;
2281 char *msg = NULL, *lang = NULL;
2282 Channel *c;
2283
3c0ef626 2284 id = packet_get_int();
2285 c = channel_lookup(id);
2286
2287 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2288 packet_disconnect("Received open failure for "
2289 "non-opening channel %d.", id);
2290 if (compat20) {
2291 reason = packet_get_int();
2292 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2293 msg = packet_get_string(NULL);
2294 lang = packet_get_string(NULL);
2295 }
473db5ab 2296 logit("channel %d: open failed: %s%s%s", id,
3c0ef626 2297 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2298 if (msg != NULL)
2299 xfree(msg);
2300 if (lang != NULL)
2301 xfree(lang);
2302 }
473db5ab 2303 packet_check_eom();
3c0ef626 2304 /* Free the channel. This will also close the socket. */
2305 channel_free(c);
2306}
2307
30460aeb 2308/* ARGSUSED */
3c0ef626 2309void
473db5ab 2310channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
3c0ef626 2311{
3c0ef626 2312 Channel *c;
473db5ab 2313 int id;
2314 u_int adjust;
3c0ef626 2315
2316 if (!compat20)
2317 return;
2318
2319 /* Get the channel number and verify it. */
2320 id = packet_get_int();
2321 c = channel_lookup(id);
2322
08822d99 2323 if (c == NULL) {
2324 logit("Received window adjust for non-open channel %d.", id);
3c0ef626 2325 return;
2326 }
2327 adjust = packet_get_int();
473db5ab 2328 packet_check_eom();
2329 debug2("channel %d: rcvd adjust %u", id, adjust);
3c0ef626 2330 c->remote_window += adjust;
2331}
2332
30460aeb 2333/* ARGSUSED */
3c0ef626 2334void
473db5ab 2335channel_input_port_open(int type, u_int32_t seq, void *ctxt)
3c0ef626 2336{
2337 Channel *c = NULL;
2338 u_short host_port;
2339 char *host, *originator_string;
2340 int remote_id, sock = -1;
2341
2342 remote_id = packet_get_int();
2343 host = packet_get_string(NULL);
2344 host_port = packet_get_int();
2345
2346 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2347 originator_string = packet_get_string(NULL);
2348 } else {
2349 originator_string = xstrdup("unknown (remote did not supply name)");
2350 }
473db5ab 2351 packet_check_eom();
3c0ef626 2352 sock = channel_connect_to(host, host_port);
2353 if (sock != -1) {
2354 c = channel_new("connected socket",
2355 SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0,
2356 originator_string, 1);
473db5ab 2357 c->remote_id = remote_id;
3c0ef626 2358 }
473db5ab 2359 xfree(originator_string);
3c0ef626 2360 if (c == NULL) {
2361 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2362 packet_put_int(remote_id);
2363 packet_send();
2364 }
2365 xfree(host);
2366}
2367
2368
2369/* -- tcp forwarding */
2370
2371void
2372channel_set_af(int af)
2373{
2374 IPv4or6 = af;
2375}
2376
473db5ab 2377static int
2378channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port,
a7213e65 2379 const char *host_to_connect, u_short port_to_connect, int gateway_ports,
2380 int hpn_disabled, int hpn_buffer_size)
3c0ef626 2381{
2382 Channel *c;
08822d99 2383 int sock, r, success = 0, wildcard = 0, is_client;
3c0ef626 2384 struct addrinfo hints, *ai, *aitop;
473db5ab 2385 const char *host, *addr;
3c0ef626 2386 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3c0ef626 2387
473db5ab 2388 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2389 listen_addr : host_to_connect;
2390 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
3c0ef626 2391
473db5ab 2392 if (host == NULL) {
2393 error("No forward host name.");
2394 return 0;
3c0ef626 2395 }
3c0ef626 2396 if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) {
2397 error("Forward host name too long.");
473db5ab 2398 return 0;
3c0ef626 2399 }
2400
473db5ab 2401 /*
2402 * Determine whether or not a port forward listens to loopback,
2403 * specified address or wildcard. On the client, a specified bind
2404 * address will always override gateway_ports. On the server, a
2405 * gateway_ports of 1 (``yes'') will override the client's
2406 * specification and force a wildcard bind, whereas a value of 2
2407 * (``clientspecified'') will bind to whatever address the client
2408 * asked for.
2409 *
2410 * Special-case listen_addrs are:
2411 *
2412 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2413 * "" (empty string), "*" -> wildcard v4/v6
2414 * "localhost" -> loopback v4/v6
2415 */
2416 addr = NULL;
2417 if (listen_addr == NULL) {
2418 /* No address specified: default to gateway_ports setting */
2419 if (gateway_ports)
2420 wildcard = 1;
2421 } else if (gateway_ports || is_client) {
2422 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
e74dc197 2423 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
473db5ab 2424 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2425 (!is_client && gateway_ports == 1))
2426 wildcard = 1;
2427 else if (strcmp(listen_addr, "localhost") != 0)
2428 addr = listen_addr;
2429 }
2430
2431 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2432 type, wildcard, (addr == NULL) ? "NULL" : addr);
2433
3c0ef626 2434 /*
2435 * getaddrinfo returns a loopback address if the hostname is
2436 * set to NULL and hints.ai_flags is not AI_PASSIVE
2437 */
2438 memset(&hints, 0, sizeof(hints));
2439 hints.ai_family = IPv4or6;
473db5ab 2440 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
3c0ef626 2441 hints.ai_socktype = SOCK_STREAM;
2442 snprintf(strport, sizeof strport, "%d", listen_port);
473db5ab 2443 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2444 if (addr == NULL) {
2445 /* This really shouldn't happen */
2446 packet_disconnect("getaddrinfo: fatal error: %s",
e74dc197 2447 ssh_gai_strerror(r));
473db5ab 2448 } else {
2449 error("channel_setup_fwd_listener: "
e74dc197 2450 "getaddrinfo(%.64s): %s", addr,
2451 ssh_gai_strerror(r));
473db5ab 2452 }
2453 return 0;
2454 }
3c0ef626 2455
2456 for (ai = aitop; ai; ai = ai->ai_next) {
2457 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2458 continue;
2459 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2460 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
473db5ab 2461 error("channel_setup_fwd_listener: getnameinfo failed");
3c0ef626 2462 continue;
2463 }
2464 /* Create a port to listen for the host. */
473db5ab 2465 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3c0ef626 2466 if (sock < 0) {
2467 /* this is no error since kernel may not support ipv6 */
2468 verbose("socket: %.100s", strerror(errno));
2469 continue;
2470 }
08822d99 2471
2472 channel_set_reuseaddr(sock);
473db5ab 2473
3c0ef626 2474 debug("Local forwarding listening on %s port %s.", ntop, strport);
2475
2476 /* Bind the socket to the address. */
2477 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2478 /* address can be in use ipv6 address is already bound */
2479 if (!ai->ai_next)
2480 error("bind: %.100s", strerror(errno));
2481 else
2482 verbose("bind: %.100s", strerror(errno));
2483
2484 close(sock);
2485 continue;
2486 }
2487 /* Start listening for connections on the socket. */
473db5ab 2488 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3c0ef626 2489 error("listen: %.100s", strerror(errno));
2490 close(sock);
2491 continue;
2492 }
2493 /* Allocate a channel number for the socket. */
a7213e65 2494 /* explicitly test for hpn disabled option. if true use smaller window size */
2495 if (hpn_disabled)
6df46d40 2496 c = channel_new("port listener", type, sock, sock, -1,
2497 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2498 0, "port listener", 1);
a7213e65 2499 else
2500 c = channel_new("port listener", type, sock, sock, -1,
2501 hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT,
2502 0, "port listener", 1);
3c0ef626 2503 strlcpy(c->path, host, sizeof(c->path));
2504 c->host_port = port_to_connect;
2505 c->listening_port = listen_port;
2506 success = 1;
2507 }
2508 if (success == 0)
473db5ab 2509 error("channel_setup_fwd_listener: cannot listen to port: %d",
3c0ef626 2510 listen_port);
2511 freeaddrinfo(aitop);
2512 return success;
2513}
2514
473db5ab 2515int
2516channel_cancel_rport_listener(const char *host, u_short port)
2517{
2518 u_int i;
2519 int found = 0;
2520
2521 for (i = 0; i < channels_alloc; i++) {
2522 Channel *c = channels[i];
2523
2524 if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2525 strncmp(c->path, host, sizeof(c->path)) == 0 &&
2526 c->listening_port == port) {
2527 debug2("%s: close channel %d", __func__, i);
2528 channel_free(c);
2529 found = 1;
2530 }
2531 }
2532
2533 return (found);
2534}
2535
2536/* protocol local port fwd, used by ssh (and sshd in v1) */
2537int
2538channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
a7213e65 2539 const char *host_to_connect, u_short port_to_connect, int gateway_ports,
2540 int hpn_disabled, int hpn_buffer_size)
473db5ab 2541{
2542 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2543 listen_host, listen_port, host_to_connect, port_to_connect,
a7213e65 2544 gateway_ports, hpn_disabled, hpn_buffer_size);
473db5ab 2545}
2546
2547/* protocol v2 remote port fwd, used by sshd */
2548int
2549channel_setup_remote_fwd_listener(const char *listen_address,
a7213e65 2550 u_short listen_port, int gateway_ports, int hpn_disabled, int hpn_buffer_size)
473db5ab 2551{
2552 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
a7213e65 2553 listen_address, listen_port, NULL, 0, gateway_ports,
2554 hpn_disabled, hpn_buffer_size);
473db5ab 2555}
2556
3c0ef626 2557/*
2558 * Initiate forwarding of connections to port "port" on remote host through
2559 * the secure channel to host:port from local side.
2560 */
2561
30460aeb 2562int
473db5ab 2563channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
3c0ef626 2564 const char *host_to_connect, u_short port_to_connect)
2565{
473db5ab 2566 int type, success = 0;
3c0ef626 2567
2568 /* Record locally that connection to this host/port is permitted. */
2569 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2570 fatal("channel_request_remote_forwarding: too many forwards");
2571
2572 /* Send the forward request to the remote side. */
2573 if (compat20) {
473db5ab 2574 const char *address_to_bind;
0b90ac93 2575 if (listen_host == NULL) {
2576 if (datafellows & SSH_BUG_RFWD_ADDR)
2577 address_to_bind = "127.0.0.1";
2578 else
2579 address_to_bind = "localhost";
2580 } else if (*listen_host == '\0' ||
2581 strcmp(listen_host, "*") == 0) {
2582 if (datafellows & SSH_BUG_RFWD_ADDR)
2583 address_to_bind = "0.0.0.0";
2584 else
2585 address_to_bind = "";
2586 } else
473db5ab 2587 address_to_bind = listen_host;
2588
3c0ef626 2589 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2590 packet_put_cstring("tcpip-forward");
473db5ab 2591 packet_put_char(1); /* boolean: want reply */
3c0ef626 2592 packet_put_cstring(address_to_bind);
2593 packet_put_int(listen_port);
2594 packet_send();
2595 packet_write_wait();
2596 /* Assume that server accepts the request */
2597 success = 1;
2598 } else {
2599 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
2600 packet_put_int(listen_port);
2601 packet_put_cstring(host_to_connect);
2602 packet_put_int(port_to_connect);
2603 packet_send();
2604 packet_write_wait();
2605
2606 /* Wait for response from the remote side. */
473db5ab 2607 type = packet_read();
3c0ef626 2608 switch (type) {
2609 case SSH_SMSG_SUCCESS:
2610 success = 1;
2611 break;
2612 case SSH_SMSG_FAILURE:
3c0ef626 2613 break;
2614 default:
2615 /* Unknown packet */
2616 packet_disconnect("Protocol error for port forward request:"
2617 "received packet type %d.", type);
2618 }
2619 }
2620 if (success) {
2621 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2622 permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2623 permitted_opens[num_permitted_opens].listen_port = listen_port;
2624 num_permitted_opens++;
2625 }
30460aeb 2626 return (success ? 0 : -1);
3c0ef626 2627}
2628
473db5ab 2629/*
2630 * Request cancellation of remote forwarding of connection host:port from
2631 * local side.
2632 */
2633void
2634channel_request_rforward_cancel(const char *host, u_short port)
2635{
2636 int i;
2637
2638 if (!compat20)
2639 return;
2640
2641 for (i = 0; i < num_permitted_opens; i++) {
2642 if (permitted_opens[i].host_to_connect != NULL &&
2643 permitted_opens[i].listen_port == port)
2644 break;
2645 }
2646 if (i >= num_permitted_opens) {
2647 debug("%s: requested forward not found", __func__);
2648 return;
2649 }
2650 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2651 packet_put_cstring("cancel-tcpip-forward");
2652 packet_put_char(0);
2653 packet_put_cstring(host == NULL ? "" : host);
2654 packet_put_int(port);
2655 packet_send();
2656
2657 permitted_opens[i].listen_port = 0;
2658 permitted_opens[i].port_to_connect = 0;
08822d99 2659 xfree(permitted_opens[i].host_to_connect);
473db5ab 2660 permitted_opens[i].host_to_connect = NULL;
2661}
2662
3c0ef626 2663/*
2664 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
2665 * listening for the port, and sends back a success reply (or disconnect
30460aeb 2666 * message if there was an error).
3c0ef626 2667 */
30460aeb 2668int
255d7550 2669channel_input_port_forward_request(int is_root, int gateway_ports,
f713db99 2670 int hpn_disabled, int hpn_buffer_size)
3c0ef626 2671{
2672 u_short port, host_port;
30460aeb 2673 int success = 0;
3c0ef626 2674 char *hostname;
2675
2676 /* Get arguments from the packet. */
2677 port = packet_get_int();
2678 hostname = packet_get_string(NULL);
2679 host_port = packet_get_int();
2680
2681#ifndef HAVE_CYGWIN
2682 /*
2683 * Check that an unprivileged user is not trying to forward a
2684 * privileged port.
2685 */
2686 if (port < IPPORT_RESERVED && !is_root)
473db5ab 2687 packet_disconnect(
2688 "Requested forwarding of port %d but user is not root.",
2689 port);
2690 if (host_port == 0)
2691 packet_disconnect("Dynamic forwarding denied.");
3c0ef626 2692#endif
473db5ab 2693
3c0ef626 2694 /* Initiate forwarding */
30460aeb 2695 success = channel_setup_local_fwd_listener(NULL, port, hostname,
a7213e65 2696 host_port, gateway_ports, hpn_disabled, hpn_buffer_size);
3c0ef626 2697
2698 /* Free the argument string. */
2699 xfree(hostname);
30460aeb 2700
2701 return (success ? 0 : -1);
3c0ef626 2702}
2703
2704/*
2705 * Permits opening to any host/port if permitted_opens[] is empty. This is
2706 * usually called by the server, because the user could connect to any port
2707 * anyway, and the server has no way to know but to trust the client anyway.
2708 */
2709void
473db5ab 2710channel_permit_all_opens(void)
3c0ef626 2711{
2712 if (num_permitted_opens == 0)
2713 all_opens_permitted = 1;
2714}
2715
2716void
2717channel_add_permitted_opens(char *host, int port)
2718{
2719 if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
30460aeb 2720 fatal("channel_add_permitted_opens: too many forwards");
3c0ef626 2721 debug("allow port forwarding to host %s port %d", host, port);
2722
2723 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
2724 permitted_opens[num_permitted_opens].port_to_connect = port;
2725 num_permitted_opens++;
2726
2727 all_opens_permitted = 0;
2728}
2729
30460aeb 2730int
2731channel_add_adm_permitted_opens(char *host, int port)
2732{
2733 if (num_adm_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
2734 fatal("channel_add_adm_permitted_opens: too many forwards");
2735 debug("config allows port forwarding to host %s port %d", host, port);
2736
2737 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
2738 = xstrdup(host);
2739 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
2740 return ++num_adm_permitted_opens;
2741}
2742
3c0ef626 2743void
2744channel_clear_permitted_opens(void)
2745{
2746 int i;
2747
2748 for (i = 0; i < num_permitted_opens; i++)
473db5ab 2749 if (permitted_opens[i].host_to_connect != NULL)
2750 xfree(permitted_opens[i].host_to_connect);
3c0ef626 2751 num_permitted_opens = 0;
3c0ef626 2752}
2753
30460aeb 2754void
2755channel_clear_adm_permitted_opens(void)
2756{
2757 int i;
2758
2759 for (i = 0; i < num_adm_permitted_opens; i++)
2760 if (permitted_adm_opens[i].host_to_connect != NULL)
2761 xfree(permitted_adm_opens[i].host_to_connect);
2762 num_adm_permitted_opens = 0;
2763}
3c0ef626 2764
2765/* return socket to remote host, port */
2766static int
2767connect_to(const char *host, u_short port)
2768{
2769 struct addrinfo hints, *ai, *aitop;
2770 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2771 int gaierr;
2772 int sock = -1;
2773
2774 memset(&hints, 0, sizeof(hints));
2775 hints.ai_family = IPv4or6;
2776 hints.ai_socktype = SOCK_STREAM;
2777 snprintf(strport, sizeof strport, "%d", port);
2778 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
2779 error("connect_to %.100s: unknown host (%s)", host,
e74dc197 2780 ssh_gai_strerror(gaierr));
3c0ef626 2781 return -1;
2782 }
2783 for (ai = aitop; ai; ai = ai->ai_next) {
2784 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2785 continue;
2786 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2787 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2788 error("connect_to: getnameinfo failed");
2789 continue;
2790 }
473db5ab 2791 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3c0ef626 2792 if (sock < 0) {
473db5ab 2793 if (ai->ai_next == NULL)
2794 error("socket: %.100s", strerror(errno));
2795 else
2796 verbose("socket: %.100s", strerror(errno));
3c0ef626 2797 continue;
2798 }
473db5ab 2799 if (set_nonblock(sock) == -1)
2800 fatal("%s: set_nonblock(%d)", __func__, sock);
3c0ef626 2801 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
2802 errno != EINPROGRESS) {
2803 error("connect_to %.100s port %s: %.100s", ntop, strport,
2804 strerror(errno));
2805 close(sock);
2806 continue; /* fail -- try next */
2807 }
2808 break; /* success */
2809
2810 }
2811 freeaddrinfo(aitop);
2812 if (!ai) {
2813 error("connect_to %.100s port %d: failed.", host, port);
2814 return -1;
2815 }
2816 /* success */
473db5ab 2817 set_nodelay(sock);
3c0ef626 2818 return sock;
2819}
2820
2821int
2822channel_connect_by_listen_address(u_short listen_port)
2823{
2824 int i;
2825
2826 for (i = 0; i < num_permitted_opens; i++)
473db5ab 2827 if (permitted_opens[i].host_to_connect != NULL &&
2828 permitted_opens[i].listen_port == listen_port)
3c0ef626 2829 return connect_to(
2830 permitted_opens[i].host_to_connect,
2831 permitted_opens[i].port_to_connect);
2832 error("WARNING: Server requests forwarding for unknown listen_port %d",
2833 listen_port);
2834 return -1;
2835}
2836
2837/* Check if connecting to that port is permitted and connect. */
2838int
2839channel_connect_to(const char *host, u_short port)
2840{
30460aeb 2841 int i, permit, permit_adm = 1;
3c0ef626 2842
2843 permit = all_opens_permitted;
2844 if (!permit) {
2845 for (i = 0; i < num_permitted_opens; i++)
473db5ab 2846 if (permitted_opens[i].host_to_connect != NULL &&
2847 permitted_opens[i].port_to_connect == port &&
3c0ef626 2848 strcmp(permitted_opens[i].host_to_connect, host) == 0)
2849 permit = 1;
30460aeb 2850 }
3c0ef626 2851
30460aeb 2852 if (num_adm_permitted_opens > 0) {
2853 permit_adm = 0;
2854 for (i = 0; i < num_adm_permitted_opens; i++)
2855 if (permitted_adm_opens[i].host_to_connect != NULL &&
2856 permitted_adm_opens[i].port_to_connect == port &&
2857 strcmp(permitted_adm_opens[i].host_to_connect, host)
2858 == 0)
2859 permit_adm = 1;
3c0ef626 2860 }
30460aeb 2861
2862 if (!permit || !permit_adm) {
473db5ab 2863 logit("Received request to connect to host %.100s port %d, "
3c0ef626 2864 "but the request was denied.", host, port);
2865 return -1;
2866 }
2867 return connect_to(host, port);
2868}
2869
473db5ab 2870void
2871channel_send_window_changes(void)
2872{
2873 u_int i;
2874 struct winsize ws;
2875
2876 for (i = 0; i < channels_alloc; i++) {
2877 if (channels[i] == NULL || !channels[i]->client_tty ||
2878 channels[i]->type != SSH_CHANNEL_OPEN)
2879 continue;
2880 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
2881 continue;
2882 channel_request_start(i, "window-change", 0);
30460aeb 2883 packet_put_int((u_int)ws.ws_col);
2884 packet_put_int((u_int)ws.ws_row);
2885 packet_put_int((u_int)ws.ws_xpixel);
2886 packet_put_int((u_int)ws.ws_ypixel);
473db5ab 2887 packet_send();
2888 }
2889}
2890
3c0ef626 2891/* -- X11 forwarding */
2892
2893/*
2894 * Creates an internet domain socket for listening for X11 connections.
473db5ab 2895 * Returns 0 and a suitable display number for the DISPLAY variable
2896 * stored in display_numberp , or -1 if an error occurs.
3c0ef626 2897 */
473db5ab 2898int
2899x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
a7213e65 2900 int single_connection, u_int *display_numberp, int **chanids,
2901 int hpn_disabled, int hpn_buffer_size)
3c0ef626 2902{
473db5ab 2903 Channel *nc = NULL;
3c0ef626 2904 int display_number, sock;
2905 u_short port;
2906 struct addrinfo hints, *ai, *aitop;
2907 char strport[NI_MAXSERV];
2908 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3c0ef626 2909
08822d99 2910 if (chanids == NULL)
2911 return -1;
2912
3c0ef626 2913 for (display_number = x11_display_offset;
473db5ab 2914 display_number < MAX_DISPLAYS;
2915 display_number++) {
3c0ef626 2916 port = 6000 + display_number;
2917 memset(&hints, 0, sizeof(hints));
2918 hints.ai_family = IPv4or6;
473db5ab 2919 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3c0ef626 2920 hints.ai_socktype = SOCK_STREAM;
2921 snprintf(strport, sizeof strport, "%d", port);
2922 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
e74dc197 2923 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
473db5ab 2924 return -1;
3c0ef626 2925 }
2926 for (ai = aitop; ai; ai = ai->ai_next) {
2927 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
2928 continue;
473db5ab 2929 sock = socket(ai->ai_family, ai->ai_socktype,
2930 ai->ai_protocol);
3c0ef626 2931 if (sock < 0) {
2932 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) {
2933 error("socket: %.100s", strerror(errno));
473db5ab 2934 freeaddrinfo(aitop);
2935 return -1;
3c0ef626 2936 } else {
2937 debug("x11_create_display_inet: Socket family %d not supported",
2938 ai->ai_family);
2939 continue;
2940 }
2941 }
473db5ab 2942#ifdef IPV6_V6ONLY
2943 if (ai->ai_family == AF_INET6) {
2944 int on = 1;
2945 if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0)
2946 error("setsockopt IPV6_V6ONLY: %.100s", strerror(errno));
2947 }
2948#endif
08822d99 2949 channel_set_reuseaddr(sock);
3c0ef626 2950 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
473db5ab 2951 debug2("bind port %d: %.100s", port, strerror(errno));
3c0ef626 2952 close(sock);
2953
2954 if (ai->ai_next)
2955 continue;
2956
2957 for (n = 0; n < num_socks; n++) {
3c0ef626 2958 close(socks[n]);
2959 }
2960 num_socks = 0;
2961 break;
2962 }
2963 socks[num_socks++] = sock;
2964#ifndef DONT_TRY_OTHER_AF
2965 if (num_socks == NUM_SOCKS)
2966 break;
2967#else
473db5ab 2968 if (x11_use_localhost) {
2969 if (num_socks == NUM_SOCKS)
2970 break;
2971 } else {
2972 break;
2973 }
3c0ef626 2974#endif
2975 }
2976 freeaddrinfo(aitop);
2977 if (num_socks > 0)
2978 break;
2979 }
2980 if (display_number >= MAX_DISPLAYS) {
2981 error("Failed to allocate internet-domain X11 display socket.");
473db5ab 2982 return -1;
3c0ef626 2983 }
2984 /* Start listening for connections on the socket. */
2985 for (n = 0; n < num_socks; n++) {
2986 sock = socks[n];
473db5ab 2987 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3c0ef626 2988 error("listen: %.100s", strerror(errno));
3c0ef626 2989 close(sock);
473db5ab 2990 return -1;
3c0ef626 2991 }
3c0ef626 2992 }
3c0ef626 2993
2994 /* Allocate a channel for each socket. */
30460aeb 2995 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3c0ef626 2996 for (n = 0; n < num_socks; n++) {
2997 sock = socks[n];
6df46d40 2998 /* Is this really necassary? */
a7213e65 2999 if (hpn_disabled)
6df46d40 3000 nc = channel_new("x11 listener",
3001 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3002 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3003 0, "X11 inet listener", 1);
a7213e65 3004 else
3005 nc = channel_new("x11 listener",
3006 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3007 hpn_buffer_size, CHAN_X11_PACKET_DEFAULT,
3008 0, "X11 inet listener", 1);
473db5ab 3009 nc->single_connection = single_connection;
08822d99 3010 (*chanids)[n] = nc->self;
3c0ef626 3011 }
08822d99 3012 (*chanids)[n] = -1;
3c0ef626 3013
473db5ab 3014 /* Return the display number for the DISPLAY environment variable. */
3015 *display_numberp = display_number;
3016 return (0);
3c0ef626 3017}
3018
3c0ef626 3019static int
3020connect_local_xsocket(u_int dnr)
3021{
3c0ef626 3022 int sock;
3023 struct sockaddr_un addr;
3c0ef626 3024
473db5ab 3025 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3026 if (sock < 0)
3027 error("socket: %.100s", strerror(errno));
3028 memset(&addr, 0, sizeof(addr));
3029 addr.sun_family = AF_UNIX;
3030 snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
30460aeb 3031 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
473db5ab 3032 return sock;
3033 close(sock);
3c0ef626 3034 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3035 return -1;
3036}
3037
3038int
3039x11_connect_display(void)
3040{
30460aeb 3041 u_int display_number;
3c0ef626 3042 const char *display;
3043 char buf[1024], *cp;
3044 struct addrinfo hints, *ai, *aitop;
3045 char strport[NI_MAXSERV];
30460aeb 3046 int gaierr, sock = 0;
3c0ef626 3047
3048 /* Try to open a socket for the local X server. */
3049 display = getenv("DISPLAY");
3050 if (!display) {
3051 error("DISPLAY not set.");
3052 return -1;
3053 }
3054 /*
3055 * Now we decode the value of the DISPLAY variable and make a
3056 * connection to the real X server.
3057 */
3058
3059 /*
3060 * Check if it is a unix domain socket. Unix domain displays are in
3061 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3062 */
3063 if (strncmp(display, "unix:", 5) == 0 ||
3064 display[0] == ':') {
3065 /* Connect to the unix domain socket. */
30460aeb 3066 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
3c0ef626 3067 error("Could not parse display number from DISPLAY: %.100s",
473db5ab 3068 display);
3c0ef626 3069 return -1;
3070 }
3071 /* Create a socket. */
3072 sock = connect_local_xsocket(display_number);
3073 if (sock < 0)
3074 return -1;
3075
3076 /* OK, we now have a connection to the display. */
3077 return sock;
3078 }
3079 /*
3080 * Connect to an inet socket. The DISPLAY value is supposedly
3081 * hostname:d[.s], where hostname may also be numeric IP address.
3082 */
473db5ab 3083 strlcpy(buf, display, sizeof(buf));
3c0ef626 3084 cp = strchr(buf, ':');
3085 if (!cp) {
3086 error("Could not find ':' in DISPLAY: %.100s", display);
3087 return -1;
3088 }
3089 *cp = 0;
3090 /* buf now contains the host name. But first we parse the display number. */
30460aeb 3091 if (sscanf(cp + 1, "%u", &display_number) != 1) {
3c0ef626 3092 error("Could not parse display number from DISPLAY: %.100s",
473db5ab 3093 display);
3c0ef626 3094 return -1;
3095 }
3096
3097 /* Look up the host address */
3098 memset(&hints, 0, sizeof(hints));
3099 hints.ai_family = IPv4or6;
3100 hints.ai_socktype = SOCK_STREAM;
30460aeb 3101 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
3c0ef626 3102 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
e74dc197 3103 error("%.100s: unknown host. (%s)", buf,
3104 ssh_gai_strerror(gaierr));
3c0ef626 3105 return -1;
3106 }
3107 for (ai = aitop; ai; ai = ai->ai_next) {
3108 /* Create a socket. */
473db5ab 3109 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3c0ef626 3110 if (sock < 0) {
473db5ab 3111 debug2("socket: %.100s", strerror(errno));
3c0ef626 3112 continue;
3113 }
3114 /* Connect it to the display. */
3115 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
30460aeb 3116 debug2("connect %.100s port %u: %.100s", buf,
3c0ef626 3117 6000 + display_number, strerror(errno));
3118 close(sock);
3119 continue;
3120 }
3121 /* Success */
3122 break;
3123 }
3124 freeaddrinfo(aitop);
3125 if (!ai) {
30460aeb 3126 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
3c0ef626 3127 strerror(errno));
3128 return -1;
3129 }
473db5ab 3130 set_nodelay(sock);
3c0ef626 3131 return sock;
3132}
3133
3134/*
3135 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3136 * the remote channel number. We should do whatever we want, and respond
3137 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3138 */
3139
30460aeb 3140/* ARGSUSED */
3c0ef626 3141void
473db5ab 3142x11_input_open(int type, u_int32_t seq, void *ctxt)
3c0ef626 3143{
3144 Channel *c = NULL;
3145 int remote_id, sock = 0;
3146 char *remote_host;
3147
3148 debug("Received X11 open request.");
3149
3150 remote_id = packet_get_int();
3151
3152 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3153 remote_host = packet_get_string(NULL);
3154 } else {
3155 remote_host = xstrdup("unknown (remote did not supply name)");
3156 }
473db5ab 3157 packet_check_eom();
3c0ef626 3158
3159 /* Obtain a connection to the real X display. */
3160 sock = x11_connect_display();
3161 if (sock != -1) {
3162 /* Allocate a channel for this connection. */
3163 c = channel_new("connected x11 socket",
3164 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3165 remote_host, 1);
473db5ab 3166 c->remote_id = remote_id;
3167 c->force_drain = 1;
3c0ef626 3168 }
473db5ab 3169 xfree(remote_host);
3c0ef626 3170 if (c == NULL) {
3171 /* Send refusal to the remote host. */
3172 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3173 packet_put_int(remote_id);
3174 } else {
3175 /* Send a confirmation to the remote host. */
3176 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
3177 packet_put_int(remote_id);
3178 packet_put_int(c->self);
3179 }
3180 packet_send();
3181}
3182
3183/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
30460aeb 3184/* ARGSUSED */
3c0ef626 3185void
473db5ab 3186deny_input_open(int type, u_int32_t seq, void *ctxt)
3c0ef626 3187{
3188 int rchan = packet_get_int();
473db5ab 3189
3190 switch (type) {
3c0ef626 3191 case SSH_SMSG_AGENT_OPEN:
3192 error("Warning: ssh server tried agent forwarding.");
3193 break;
3194 case SSH_SMSG_X11_OPEN:
3195 error("Warning: ssh server tried X11 forwarding.");
3196 break;
3197 default:
473db5ab 3198 error("deny_input_open: type %d", type);
3c0ef626 3199 break;
3200 }
08822d99 3201 error("Warning: this is probably a break-in attempt by a malicious server.");
3c0ef626 3202 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3203 packet_put_int(rchan);
3204 packet_send();
3205}
3206
3207/*
3208 * Requests forwarding of X11 connections, generates fake authentication
3209 * data, and enables authentication spoofing.
3210 * This should be called in the client only.
3211 */
3212void
473db5ab 3213x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
3c0ef626 3214 const char *proto, const char *data)
3215{
3216 u_int data_len = (u_int) strlen(data) / 2;
473db5ab 3217 u_int i, value;
3c0ef626 3218 char *new_data;
3219 int screen_number;
3220 const char *cp;
473db5ab 3221 u_int32_t rnd = 0;
3c0ef626 3222
473db5ab 3223 if (x11_saved_display == NULL)
3224 x11_saved_display = xstrdup(disp);
3225 else if (strcmp(disp, x11_saved_display) != 0) {
3226 error("x11_request_forwarding_with_spoofing: different "
3227 "$DISPLAY already forwarded");
3228 return;
3229 }
3230
30460aeb 3231 cp = strchr(disp, ':');
3c0ef626 3232 if (cp)
3233 cp = strchr(cp, '.');
3234 if (cp)
30460aeb 3235 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
3c0ef626 3236 else
3237 screen_number = 0;
3238
473db5ab 3239 if (x11_saved_proto == NULL) {
3240 /* Save protocol name. */
3241 x11_saved_proto = xstrdup(proto);
3242 /*
3243 * Extract real authentication data and generate fake data
3244 * of the same length.
3245 */
3246 x11_saved_data = xmalloc(data_len);
3247 x11_fake_data = xmalloc(data_len);
3248 for (i = 0; i < data_len; i++) {
3249 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3250 fatal("x11_request_forwarding: bad "
3251 "authentication data: %.100s", data);
3252 if (i % 4 == 0)
3253 rnd = arc4random();
3254 x11_saved_data[i] = value;
3255 x11_fake_data[i] = rnd & 0xff;
3256 rnd >>= 8;
3257 }
3258 x11_saved_data_len = data_len;
3259 x11_fake_data_len = data_len;
3260 }
3c0ef626 3261
3262 /* Convert the fake data into hex. */
473db5ab 3263 new_data = tohex(x11_fake_data, data_len);
3c0ef626 3264
3265 /* Send the request packet. */
3266 if (compat20) {
3267 channel_request_start(client_session_id, "x11-req", 0);
3268 packet_put_char(0); /* XXX bool single connection */
3269 } else {
3270 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3271 }
3272 packet_put_cstring(proto);
3273 packet_put_cstring(new_data);
3274 packet_put_int(screen_number);
3275 packet_send();
3276 packet_write_wait();
3277 xfree(new_data);
3278}
3279
3280
3281/* -- agent forwarding */
3282
3283/* Sends a message to the server to request authentication fd forwarding. */
3284
3285void
473db5ab 3286auth_request_forwarding(void)
3c0ef626 3287{
3288 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3289 packet_send();
3290 packet_write_wait();
3291}
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