1/* $OpenBSD: channels.c,v 1.311 2011/06/22 22:08:42 djm Exp $ */
| 1/* $OpenBSD: channels.c,v 1.311 2011/06/22 22:08:42 djm Exp $ */
|
2/* $FreeBSD: head/crypto/openssh/channels.c 226046 2011-10-05 22:08:17Z des $ */
| 2/* $FreeBSD: head/crypto/openssh/channels.c 231584 2012-02-13 11:59:59Z ed $ */
|
3/*
4 * Author: Tatu Ylonen <ylo@cs.hut.fi>
5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * All rights reserved
7 * This file contains functions for generic socket connection forwarding.
8 * There is also code for initiating connection forwarding for X11 connections,
9 * arbitrary tcp/ip connections, and the authentication agent connection.
10 *
11 * As far as I am concerned, the code I have written for this software
12 * can be used freely for any purpose. Any derived versions of this
13 * software must be clearly marked as such, and if the derived work is
14 * incompatible with the protocol description in the RFC file, it must be
15 * called by a name other than "ssh" or "Secure Shell".
16 *
17 * SSH2 support added by Markus Friedl.
18 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
19 * Copyright (c) 1999 Dug Song. All rights reserved.
20 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the above copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
41 */
42
43#include "includes.h"
44
45#include <sys/types.h>
46#include <sys/ioctl.h>
47#include <sys/un.h>
48#include <sys/socket.h>
49#ifdef HAVE_SYS_TIME_H
50# include <sys/time.h>
51#endif
52
53#include <netinet/in.h>
54#include <arpa/inet.h>
55
56#include <errno.h>
57#include <fcntl.h>
58#include <netdb.h>
59#include <stdio.h>
60#include <stdlib.h>
61#include <string.h>
62#include <termios.h>
63#include <unistd.h>
64#include <stdarg.h>
65
66#include "openbsd-compat/sys-queue.h"
67#include "xmalloc.h"
68#include "ssh.h"
69#include "ssh1.h"
70#include "ssh2.h"
71#include "packet.h"
72#include "log.h"
73#include "misc.h"
74#include "buffer.h"
75#include "channels.h"
76#include "compat.h"
77#include "canohost.h"
78#include "key.h"
79#include "authfd.h"
80#include "pathnames.h"
81
82/* -- channel core */
83
84/*
85 * Pointer to an array containing all allocated channels. The array is
86 * dynamically extended as needed.
87 */
88static Channel **channels = NULL;
89
90/*
91 * Size of the channel array. All slots of the array must always be
92 * initialized (at least the type field); unused slots set to NULL
93 */
94static u_int channels_alloc = 0;
95
96/*
97 * Maximum file descriptor value used in any of the channels. This is
98 * updated in channel_new.
99 */
100static int channel_max_fd = 0;
101
102
103/* -- tcp forwarding */
104
105/*
106 * Data structure for storing which hosts are permitted for forward requests.
107 * The local sides of any remote forwards are stored in this array to prevent
108 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
109 * network (which might be behind a firewall).
110 */
111typedef struct {
112 char *host_to_connect; /* Connect to 'host'. */
113 u_short port_to_connect; /* Connect to 'port'. */
114 u_short listen_port; /* Remote side should listen port number. */
115} ForwardPermission;
116
117/* List of all permitted host/port pairs to connect by the user. */
118static ForwardPermission *permitted_opens = NULL;
119
120/* List of all permitted host/port pairs to connect by the admin. */
121static ForwardPermission *permitted_adm_opens = NULL;
122
123/* Number of permitted host/port pairs in the array permitted by the user. */
124static int num_permitted_opens = 0;
125
126/* Number of permitted host/port pair in the array permitted by the admin. */
127static int num_adm_permitted_opens = 0;
128
129/*
130 * If this is true, all opens are permitted. This is the case on the server
131 * on which we have to trust the client anyway, and the user could do
132 * anything after logging in anyway.
133 */
134static int all_opens_permitted = 0;
135
136
137/* -- X11 forwarding */
138
139/* Maximum number of fake X11 displays to try. */
140#define MAX_DISPLAYS 1000
141
142/* Saved X11 local (client) display. */
143static char *x11_saved_display = NULL;
144
145/* Saved X11 authentication protocol name. */
146static char *x11_saved_proto = NULL;
147
148/* Saved X11 authentication data. This is the real data. */
149static char *x11_saved_data = NULL;
150static u_int x11_saved_data_len = 0;
151
152/*
153 * Fake X11 authentication data. This is what the server will be sending us;
154 * we should replace any occurrences of this by the real data.
155 */
156static u_char *x11_fake_data = NULL;
157static u_int x11_fake_data_len;
158
159
160/* -- agent forwarding */
161
162#define NUM_SOCKS 10
163
164/* AF_UNSPEC or AF_INET or AF_INET6 */
165static int IPv4or6 = AF_UNSPEC;
166
167/* helper */
168static void port_open_helper(Channel *c, char *rtype);
169
170/* non-blocking connect helpers */
171static int connect_next(struct channel_connect *);
172static void channel_connect_ctx_free(struct channel_connect *);
173
174/* -- HPN */
175
176static int hpn_disabled = 0;
177static u_int buffer_size = CHAN_HPN_MIN_WINDOW_DEFAULT;
178
179/* -- channel core */
180
181Channel *
182channel_by_id(int id)
183{
184 Channel *c;
185
186 if (id < 0 || (u_int)id >= channels_alloc) {
187 logit("channel_by_id: %d: bad id", id);
188 return NULL;
189 }
190 c = channels[id];
191 if (c == NULL) {
192 logit("channel_by_id: %d: bad id: channel free", id);
193 return NULL;
194 }
195 return c;
196}
197
198/*
199 * Returns the channel if it is allowed to receive protocol messages.
200 * Private channels, like listening sockets, may not receive messages.
201 */
202Channel *
203channel_lookup(int id)
204{
205 Channel *c;
206
207 if ((c = channel_by_id(id)) == NULL)
208 return (NULL);
209
210 switch (c->type) {
211 case SSH_CHANNEL_X11_OPEN:
212 case SSH_CHANNEL_LARVAL:
213 case SSH_CHANNEL_CONNECTING:
214 case SSH_CHANNEL_DYNAMIC:
215 case SSH_CHANNEL_OPENING:
216 case SSH_CHANNEL_OPEN:
217 case SSH_CHANNEL_INPUT_DRAINING:
218 case SSH_CHANNEL_OUTPUT_DRAINING:
219 return (c);
220 }
221 logit("Non-public channel %d, type %d.", id, c->type);
222 return (NULL);
223}
224
225/*
226 * Register filedescriptors for a channel, used when allocating a channel or
227 * when the channel consumer/producer is ready, e.g. shell exec'd
228 */
229static void
230channel_register_fds(Channel *c, int rfd, int wfd, int efd,
231 int extusage, int nonblock, int is_tty)
232{
233 /* Update the maximum file descriptor value. */
234 channel_max_fd = MAX(channel_max_fd, rfd);
235 channel_max_fd = MAX(channel_max_fd, wfd);
236 channel_max_fd = MAX(channel_max_fd, efd);
237
238 if (rfd != -1)
239 fcntl(rfd, F_SETFD, FD_CLOEXEC);
240 if (wfd != -1 && wfd != rfd)
241 fcntl(wfd, F_SETFD, FD_CLOEXEC);
242 if (efd != -1 && efd != rfd && efd != wfd)
243 fcntl(efd, F_SETFD, FD_CLOEXEC);
244
245 c->rfd = rfd;
246 c->wfd = wfd;
247 c->sock = (rfd == wfd) ? rfd : -1;
248 c->efd = efd;
249 c->extended_usage = extusage;
250
251 if ((c->isatty = is_tty) != 0)
252 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
253 c->wfd_isatty = is_tty || isatty(c->wfd);
254
255 /* enable nonblocking mode */
256 if (nonblock) {
257 if (rfd != -1)
258 set_nonblock(rfd);
259 if (wfd != -1)
260 set_nonblock(wfd);
261 if (efd != -1)
262 set_nonblock(efd);
263 }
264}
265
266/*
267 * Allocate a new channel object and set its type and socket. This will cause
268 * remote_name to be freed.
269 */
270Channel *
271channel_new(char *ctype, int type, int rfd, int wfd, int efd,
272 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
273{
274 int found;
275 u_int i;
276 Channel *c;
277
278 /* Do initial allocation if this is the first call. */
279 if (channels_alloc == 0) {
280 channels_alloc = 10;
281 channels = xcalloc(channels_alloc, sizeof(Channel *));
282 for (i = 0; i < channels_alloc; i++)
283 channels[i] = NULL;
284 }
285 /* Try to find a free slot where to put the new channel. */
286 for (found = -1, i = 0; i < channels_alloc; i++)
287 if (channels[i] == NULL) {
288 /* Found a free slot. */
289 found = (int)i;
290 break;
291 }
292 if (found < 0) {
293 /* There are no free slots. Take last+1 slot and expand the array. */
294 found = channels_alloc;
295 if (channels_alloc > 10000)
296 fatal("channel_new: internal error: channels_alloc %d "
297 "too big.", channels_alloc);
298 channels = xrealloc(channels, channels_alloc + 10,
299 sizeof(Channel *));
300 channels_alloc += 10;
301 debug2("channel: expanding %d", channels_alloc);
302 for (i = found; i < channels_alloc; i++)
303 channels[i] = NULL;
304 }
305 /* Initialize and return new channel. */
306 c = channels[found] = xcalloc(1, sizeof(Channel));
307 buffer_init(&c->input);
308 buffer_init(&c->output);
309 buffer_init(&c->extended);
310 c->path = NULL;
311 c->ostate = CHAN_OUTPUT_OPEN;
312 c->istate = CHAN_INPUT_OPEN;
313 c->flags = 0;
314 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
315 c->self = found;
316 c->type = type;
317 c->ctype = ctype;
318 c->dynamic_window = 0;
319 c->local_window = window;
320 c->local_window_max = window;
321 c->local_consumed = 0;
322 c->local_maxpacket = maxpack;
323 c->remote_id = -1;
324 c->remote_name = xstrdup(remote_name);
325 c->remote_window = 0;
326 c->remote_maxpacket = 0;
327 c->force_drain = 0;
328 c->single_connection = 0;
329 c->detach_user = NULL;
330 c->detach_close = 0;
331 c->open_confirm = NULL;
332 c->open_confirm_ctx = NULL;
333 c->input_filter = NULL;
334 c->output_filter = NULL;
335 c->filter_ctx = NULL;
336 c->filter_cleanup = NULL;
337 c->ctl_chan = -1;
338 c->mux_rcb = NULL;
339 c->mux_ctx = NULL;
340 c->mux_pause = 0;
341 c->delayed = 1; /* prevent call to channel_post handler */
342 TAILQ_INIT(&c->status_confirms);
343 debug("channel %d: new [%s]", found, remote_name);
344 return c;
345}
346
347static int
348channel_find_maxfd(void)
349{
350 u_int i;
351 int max = 0;
352 Channel *c;
353
354 for (i = 0; i < channels_alloc; i++) {
355 c = channels[i];
356 if (c != NULL) {
357 max = MAX(max, c->rfd);
358 max = MAX(max, c->wfd);
359 max = MAX(max, c->efd);
360 }
361 }
362 return max;
363}
364
365int
366channel_close_fd(int *fdp)
367{
368 int ret = 0, fd = *fdp;
369
370 if (fd != -1) {
371 ret = close(fd);
372 *fdp = -1;
373 if (fd == channel_max_fd)
374 channel_max_fd = channel_find_maxfd();
375 }
376 return ret;
377}
378
379/* Close all channel fd/socket. */
380static void
381channel_close_fds(Channel *c)
382{
383 channel_close_fd(&c->sock);
384 channel_close_fd(&c->rfd);
385 channel_close_fd(&c->wfd);
386 channel_close_fd(&c->efd);
387}
388
389/* Free the channel and close its fd/socket. */
390void
391channel_free(Channel *c)
392{
393 char *s;
394 u_int i, n;
395 struct channel_confirm *cc;
396
397 for (n = 0, i = 0; i < channels_alloc; i++)
398 if (channels[i])
399 n++;
400 debug("channel %d: free: %s, nchannels %u", c->self,
401 c->remote_name ? c->remote_name : "???", n);
402
403 s = channel_open_message();
404 debug3("channel %d: status: %s", c->self, s);
405 xfree(s);
406
407 if (c->sock != -1)
408 shutdown(c->sock, SHUT_RDWR);
409 channel_close_fds(c);
410 buffer_free(&c->input);
411 buffer_free(&c->output);
412 buffer_free(&c->extended);
413 if (c->remote_name) {
414 xfree(c->remote_name);
415 c->remote_name = NULL;
416 }
417 if (c->path) {
418 xfree(c->path);
419 c->path = NULL;
420 }
421 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
422 if (cc->abandon_cb != NULL)
423 cc->abandon_cb(c, cc->ctx);
424 TAILQ_REMOVE(&c->status_confirms, cc, entry);
425 bzero(cc, sizeof(*cc));
426 xfree(cc);
427 }
428 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
429 c->filter_cleanup(c->self, c->filter_ctx);
430 channels[c->self] = NULL;
431 xfree(c);
432}
433
434void
435channel_free_all(void)
436{
437 u_int i;
438
439 for (i = 0; i < channels_alloc; i++)
440 if (channels[i] != NULL)
441 channel_free(channels[i]);
442}
443
444/*
445 * Closes the sockets/fds of all channels. This is used to close extra file
446 * descriptors after a fork.
447 */
448void
449channel_close_all(void)
450{
451 u_int i;
452
453 for (i = 0; i < channels_alloc; i++)
454 if (channels[i] != NULL)
455 channel_close_fds(channels[i]);
456}
457
458/*
459 * Stop listening to channels.
460 */
461void
462channel_stop_listening(void)
463{
464 u_int i;
465 Channel *c;
466
467 for (i = 0; i < channels_alloc; i++) {
468 c = channels[i];
469 if (c != NULL) {
470 switch (c->type) {
471 case SSH_CHANNEL_AUTH_SOCKET:
472 case SSH_CHANNEL_PORT_LISTENER:
473 case SSH_CHANNEL_RPORT_LISTENER:
474 case SSH_CHANNEL_X11_LISTENER:
475 channel_close_fd(&c->sock);
476 channel_free(c);
477 break;
478 }
479 }
480 }
481}
482
483/*
484 * Returns true if no channel has too much buffered data, and false if one or
485 * more channel is overfull.
486 */
487int
488channel_not_very_much_buffered_data(void)
489{
490 u_int i;
491 Channel *c;
492
493 for (i = 0; i < channels_alloc; i++) {
494 c = channels[i];
495 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
496#if 0
497 if (!compat20 &&
498 buffer_len(&c->input) > packet_get_maxsize()) {
499 debug2("channel %d: big input buffer %d",
500 c->self, buffer_len(&c->input));
501 return 0;
502 }
503#endif
504 if (buffer_len(&c->output) > packet_get_maxsize()) {
505 debug2("channel %d: big output buffer %u > %u",
506 c->self, buffer_len(&c->output),
507 packet_get_maxsize());
508 return 0;
509 }
510 }
511 }
512 return 1;
513}
514
515/* Returns true if any channel is still open. */
516int
517channel_still_open(void)
518{
519 u_int i;
520 Channel *c;
521
522 for (i = 0; i < channels_alloc; i++) {
523 c = channels[i];
524 if (c == NULL)
525 continue;
526 switch (c->type) {
527 case SSH_CHANNEL_X11_LISTENER:
528 case SSH_CHANNEL_PORT_LISTENER:
529 case SSH_CHANNEL_RPORT_LISTENER:
530 case SSH_CHANNEL_MUX_LISTENER:
531 case SSH_CHANNEL_CLOSED:
532 case SSH_CHANNEL_AUTH_SOCKET:
533 case SSH_CHANNEL_DYNAMIC:
534 case SSH_CHANNEL_CONNECTING:
535 case SSH_CHANNEL_ZOMBIE:
536 continue;
537 case SSH_CHANNEL_LARVAL:
538 if (!compat20)
539 fatal("cannot happen: SSH_CHANNEL_LARVAL");
540 continue;
541 case SSH_CHANNEL_OPENING:
542 case SSH_CHANNEL_OPEN:
543 case SSH_CHANNEL_X11_OPEN:
544 case SSH_CHANNEL_MUX_CLIENT:
545 return 1;
546 case SSH_CHANNEL_INPUT_DRAINING:
547 case SSH_CHANNEL_OUTPUT_DRAINING:
548 if (!compat13)
549 fatal("cannot happen: OUT_DRAIN");
550 return 1;
551 default:
552 fatal("channel_still_open: bad channel type %d", c->type);
553 /* NOTREACHED */
554 }
555 }
556 return 0;
557}
558
559/* Returns the id of an open channel suitable for keepaliving */
560int
561channel_find_open(void)
562{
563 u_int i;
564 Channel *c;
565
566 for (i = 0; i < channels_alloc; i++) {
567 c = channels[i];
568 if (c == NULL || c->remote_id < 0)
569 continue;
570 switch (c->type) {
571 case SSH_CHANNEL_CLOSED:
572 case SSH_CHANNEL_DYNAMIC:
573 case SSH_CHANNEL_X11_LISTENER:
574 case SSH_CHANNEL_PORT_LISTENER:
575 case SSH_CHANNEL_RPORT_LISTENER:
576 case SSH_CHANNEL_MUX_LISTENER:
577 case SSH_CHANNEL_MUX_CLIENT:
578 case SSH_CHANNEL_OPENING:
579 case SSH_CHANNEL_CONNECTING:
580 case SSH_CHANNEL_ZOMBIE:
581 continue;
582 case SSH_CHANNEL_LARVAL:
583 case SSH_CHANNEL_AUTH_SOCKET:
584 case SSH_CHANNEL_OPEN:
585 case SSH_CHANNEL_X11_OPEN:
586 return i;
587 case SSH_CHANNEL_INPUT_DRAINING:
588 case SSH_CHANNEL_OUTPUT_DRAINING:
589 if (!compat13)
590 fatal("cannot happen: OUT_DRAIN");
591 return i;
592 default:
593 fatal("channel_find_open: bad channel type %d", c->type);
594 /* NOTREACHED */
595 }
596 }
597 return -1;
598}
599
600
601/*
602 * Returns a message describing the currently open forwarded connections,
603 * suitable for sending to the client. The message contains crlf pairs for
604 * newlines.
605 */
606char *
607channel_open_message(void)
608{
609 Buffer buffer;
610 Channel *c;
611 char buf[1024], *cp;
612 u_int i;
613
614 buffer_init(&buffer);
615 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
616 buffer_append(&buffer, buf, strlen(buf));
617 for (i = 0; i < channels_alloc; i++) {
618 c = channels[i];
619 if (c == NULL)
620 continue;
621 switch (c->type) {
622 case SSH_CHANNEL_X11_LISTENER:
623 case SSH_CHANNEL_PORT_LISTENER:
624 case SSH_CHANNEL_RPORT_LISTENER:
625 case SSH_CHANNEL_CLOSED:
626 case SSH_CHANNEL_AUTH_SOCKET:
627 case SSH_CHANNEL_ZOMBIE:
628 case SSH_CHANNEL_MUX_CLIENT:
629 case SSH_CHANNEL_MUX_LISTENER:
630 continue;
631 case SSH_CHANNEL_LARVAL:
632 case SSH_CHANNEL_OPENING:
633 case SSH_CHANNEL_CONNECTING:
634 case SSH_CHANNEL_DYNAMIC:
635 case SSH_CHANNEL_OPEN:
636 case SSH_CHANNEL_X11_OPEN:
637 case SSH_CHANNEL_INPUT_DRAINING:
638 case SSH_CHANNEL_OUTPUT_DRAINING:
639 snprintf(buf, sizeof buf,
640 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
641 c->self, c->remote_name,
642 c->type, c->remote_id,
643 c->istate, buffer_len(&c->input),
644 c->ostate, buffer_len(&c->output),
645 c->rfd, c->wfd, c->ctl_chan);
646 buffer_append(&buffer, buf, strlen(buf));
647 continue;
648 default:
649 fatal("channel_open_message: bad channel type %d", c->type);
650 /* NOTREACHED */
651 }
652 }
653 buffer_append(&buffer, "\0", 1);
654 cp = xstrdup(buffer_ptr(&buffer));
655 buffer_free(&buffer);
656 return cp;
657}
658
659void
660channel_send_open(int id)
661{
662 Channel *c = channel_lookup(id);
663
664 if (c == NULL) {
665 logit("channel_send_open: %d: bad id", id);
666 return;
667 }
668 debug2("channel %d: send open", id);
669 packet_start(SSH2_MSG_CHANNEL_OPEN);
670 packet_put_cstring(c->ctype);
671 packet_put_int(c->self);
672 packet_put_int(c->local_window);
673 packet_put_int(c->local_maxpacket);
674 packet_send();
675}
676
677void
678channel_request_start(int id, char *service, int wantconfirm)
679{
680 Channel *c = channel_lookup(id);
681
682 if (c == NULL) {
683 logit("channel_request_start: %d: unknown channel id", id);
684 return;
685 }
686 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
687 packet_start(SSH2_MSG_CHANNEL_REQUEST);
688 packet_put_int(c->remote_id);
689 packet_put_cstring(service);
690 packet_put_char(wantconfirm);
691}
692
693void
694channel_register_status_confirm(int id, channel_confirm_cb *cb,
695 channel_confirm_abandon_cb *abandon_cb, void *ctx)
696{
697 struct channel_confirm *cc;
698 Channel *c;
699
700 if ((c = channel_lookup(id)) == NULL)
701 fatal("channel_register_expect: %d: bad id", id);
702
703 cc = xmalloc(sizeof(*cc));
704 cc->cb = cb;
705 cc->abandon_cb = abandon_cb;
706 cc->ctx = ctx;
707 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
708}
709
710void
711channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
712{
713 Channel *c = channel_lookup(id);
714
715 if (c == NULL) {
716 logit("channel_register_open_confirm: %d: bad id", id);
717 return;
718 }
719 c->open_confirm = fn;
720 c->open_confirm_ctx = ctx;
721}
722
723void
724channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
725{
726 Channel *c = channel_by_id(id);
727
728 if (c == NULL) {
729 logit("channel_register_cleanup: %d: bad id", id);
730 return;
731 }
732 c->detach_user = fn;
733 c->detach_close = do_close;
734}
735
736void
737channel_cancel_cleanup(int id)
738{
739 Channel *c = channel_by_id(id);
740
741 if (c == NULL) {
742 logit("channel_cancel_cleanup: %d: bad id", id);
743 return;
744 }
745 c->detach_user = NULL;
746 c->detach_close = 0;
747}
748
749void
750channel_register_filter(int id, channel_infilter_fn *ifn,
751 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
752{
753 Channel *c = channel_lookup(id);
754
755 if (c == NULL) {
756 logit("channel_register_filter: %d: bad id", id);
757 return;
758 }
759 c->input_filter = ifn;
760 c->output_filter = ofn;
761 c->filter_ctx = ctx;
762 c->filter_cleanup = cfn;
763}
764
765void
766channel_set_fds(int id, int rfd, int wfd, int efd,
767 int extusage, int nonblock, int is_tty, u_int window_max)
768{
769 Channel *c = channel_lookup(id);
770
771 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
772 fatal("channel_activate for non-larval channel %d.", id);
773 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
774 c->type = SSH_CHANNEL_OPEN;
775 c->local_window = c->local_window_max = window_max;
776 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
777 packet_put_int(c->remote_id);
778 packet_put_int(c->local_window);
779 packet_send();
780}
781
782/*
783 * 'channel_pre*' are called just before select() to add any bits relevant to
784 * channels in the select bitmasks.
785 */
786/*
787 * 'channel_post*': perform any appropriate operations for channels which
788 * have events pending.
789 */
790typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
791chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
792chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
793
794/* ARGSUSED */
795static void
796channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
797{
798 FD_SET(c->sock, readset);
799}
800
801/* ARGSUSED */
802static void
803channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
804{
805 debug3("channel %d: waiting for connection", c->self);
806 FD_SET(c->sock, writeset);
807}
808
809static void
810channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
811{
812 if (buffer_len(&c->input) < packet_get_maxsize())
813 FD_SET(c->sock, readset);
814 if (buffer_len(&c->output) > 0)
815 FD_SET(c->sock, writeset);
816}
817
818static u_int
819channel_tcpwinsz(void)
820{
821 u_int32_t tcpwinsz;
822 socklen_t optsz;
823 int ret, sd;
824 u_int maxlen;
825
826 /* If we are not on a socket return 128KB. */
| 3/*
4 * Author: Tatu Ylonen <ylo@cs.hut.fi>
5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * All rights reserved
7 * This file contains functions for generic socket connection forwarding.
8 * There is also code for initiating connection forwarding for X11 connections,
9 * arbitrary tcp/ip connections, and the authentication agent connection.
10 *
11 * As far as I am concerned, the code I have written for this software
12 * can be used freely for any purpose. Any derived versions of this
13 * software must be clearly marked as such, and if the derived work is
14 * incompatible with the protocol description in the RFC file, it must be
15 * called by a name other than "ssh" or "Secure Shell".
16 *
17 * SSH2 support added by Markus Friedl.
18 * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved.
19 * Copyright (c) 1999 Dug Song. All rights reserved.
20 * Copyright (c) 1999 Theo de Raadt. All rights reserved.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the above copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
41 */
42
43#include "includes.h"
44
45#include <sys/types.h>
46#include <sys/ioctl.h>
47#include <sys/un.h>
48#include <sys/socket.h>
49#ifdef HAVE_SYS_TIME_H
50# include <sys/time.h>
51#endif
52
53#include <netinet/in.h>
54#include <arpa/inet.h>
55
56#include <errno.h>
57#include <fcntl.h>
58#include <netdb.h>
59#include <stdio.h>
60#include <stdlib.h>
61#include <string.h>
62#include <termios.h>
63#include <unistd.h>
64#include <stdarg.h>
65
66#include "openbsd-compat/sys-queue.h"
67#include "xmalloc.h"
68#include "ssh.h"
69#include "ssh1.h"
70#include "ssh2.h"
71#include "packet.h"
72#include "log.h"
73#include "misc.h"
74#include "buffer.h"
75#include "channels.h"
76#include "compat.h"
77#include "canohost.h"
78#include "key.h"
79#include "authfd.h"
80#include "pathnames.h"
81
82/* -- channel core */
83
84/*
85 * Pointer to an array containing all allocated channels. The array is
86 * dynamically extended as needed.
87 */
88static Channel **channels = NULL;
89
90/*
91 * Size of the channel array. All slots of the array must always be
92 * initialized (at least the type field); unused slots set to NULL
93 */
94static u_int channels_alloc = 0;
95
96/*
97 * Maximum file descriptor value used in any of the channels. This is
98 * updated in channel_new.
99 */
100static int channel_max_fd = 0;
101
102
103/* -- tcp forwarding */
104
105/*
106 * Data structure for storing which hosts are permitted for forward requests.
107 * The local sides of any remote forwards are stored in this array to prevent
108 * a corrupt remote server from accessing arbitrary TCP/IP ports on our local
109 * network (which might be behind a firewall).
110 */
111typedef struct {
112 char *host_to_connect; /* Connect to 'host'. */
113 u_short port_to_connect; /* Connect to 'port'. */
114 u_short listen_port; /* Remote side should listen port number. */
115} ForwardPermission;
116
117/* List of all permitted host/port pairs to connect by the user. */
118static ForwardPermission *permitted_opens = NULL;
119
120/* List of all permitted host/port pairs to connect by the admin. */
121static ForwardPermission *permitted_adm_opens = NULL;
122
123/* Number of permitted host/port pairs in the array permitted by the user. */
124static int num_permitted_opens = 0;
125
126/* Number of permitted host/port pair in the array permitted by the admin. */
127static int num_adm_permitted_opens = 0;
128
129/*
130 * If this is true, all opens are permitted. This is the case on the server
131 * on which we have to trust the client anyway, and the user could do
132 * anything after logging in anyway.
133 */
134static int all_opens_permitted = 0;
135
136
137/* -- X11 forwarding */
138
139/* Maximum number of fake X11 displays to try. */
140#define MAX_DISPLAYS 1000
141
142/* Saved X11 local (client) display. */
143static char *x11_saved_display = NULL;
144
145/* Saved X11 authentication protocol name. */
146static char *x11_saved_proto = NULL;
147
148/* Saved X11 authentication data. This is the real data. */
149static char *x11_saved_data = NULL;
150static u_int x11_saved_data_len = 0;
151
152/*
153 * Fake X11 authentication data. This is what the server will be sending us;
154 * we should replace any occurrences of this by the real data.
155 */
156static u_char *x11_fake_data = NULL;
157static u_int x11_fake_data_len;
158
159
160/* -- agent forwarding */
161
162#define NUM_SOCKS 10
163
164/* AF_UNSPEC or AF_INET or AF_INET6 */
165static int IPv4or6 = AF_UNSPEC;
166
167/* helper */
168static void port_open_helper(Channel *c, char *rtype);
169
170/* non-blocking connect helpers */
171static int connect_next(struct channel_connect *);
172static void channel_connect_ctx_free(struct channel_connect *);
173
174/* -- HPN */
175
176static int hpn_disabled = 0;
177static u_int buffer_size = CHAN_HPN_MIN_WINDOW_DEFAULT;
178
179/* -- channel core */
180
181Channel *
182channel_by_id(int id)
183{
184 Channel *c;
185
186 if (id < 0 || (u_int)id >= channels_alloc) {
187 logit("channel_by_id: %d: bad id", id);
188 return NULL;
189 }
190 c = channels[id];
191 if (c == NULL) {
192 logit("channel_by_id: %d: bad id: channel free", id);
193 return NULL;
194 }
195 return c;
196}
197
198/*
199 * Returns the channel if it is allowed to receive protocol messages.
200 * Private channels, like listening sockets, may not receive messages.
201 */
202Channel *
203channel_lookup(int id)
204{
205 Channel *c;
206
207 if ((c = channel_by_id(id)) == NULL)
208 return (NULL);
209
210 switch (c->type) {
211 case SSH_CHANNEL_X11_OPEN:
212 case SSH_CHANNEL_LARVAL:
213 case SSH_CHANNEL_CONNECTING:
214 case SSH_CHANNEL_DYNAMIC:
215 case SSH_CHANNEL_OPENING:
216 case SSH_CHANNEL_OPEN:
217 case SSH_CHANNEL_INPUT_DRAINING:
218 case SSH_CHANNEL_OUTPUT_DRAINING:
219 return (c);
220 }
221 logit("Non-public channel %d, type %d.", id, c->type);
222 return (NULL);
223}
224
225/*
226 * Register filedescriptors for a channel, used when allocating a channel or
227 * when the channel consumer/producer is ready, e.g. shell exec'd
228 */
229static void
230channel_register_fds(Channel *c, int rfd, int wfd, int efd,
231 int extusage, int nonblock, int is_tty)
232{
233 /* Update the maximum file descriptor value. */
234 channel_max_fd = MAX(channel_max_fd, rfd);
235 channel_max_fd = MAX(channel_max_fd, wfd);
236 channel_max_fd = MAX(channel_max_fd, efd);
237
238 if (rfd != -1)
239 fcntl(rfd, F_SETFD, FD_CLOEXEC);
240 if (wfd != -1 && wfd != rfd)
241 fcntl(wfd, F_SETFD, FD_CLOEXEC);
242 if (efd != -1 && efd != rfd && efd != wfd)
243 fcntl(efd, F_SETFD, FD_CLOEXEC);
244
245 c->rfd = rfd;
246 c->wfd = wfd;
247 c->sock = (rfd == wfd) ? rfd : -1;
248 c->efd = efd;
249 c->extended_usage = extusage;
250
251 if ((c->isatty = is_tty) != 0)
252 debug2("channel %d: rfd %d isatty", c->self, c->rfd);
253 c->wfd_isatty = is_tty || isatty(c->wfd);
254
255 /* enable nonblocking mode */
256 if (nonblock) {
257 if (rfd != -1)
258 set_nonblock(rfd);
259 if (wfd != -1)
260 set_nonblock(wfd);
261 if (efd != -1)
262 set_nonblock(efd);
263 }
264}
265
266/*
267 * Allocate a new channel object and set its type and socket. This will cause
268 * remote_name to be freed.
269 */
270Channel *
271channel_new(char *ctype, int type, int rfd, int wfd, int efd,
272 u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
273{
274 int found;
275 u_int i;
276 Channel *c;
277
278 /* Do initial allocation if this is the first call. */
279 if (channels_alloc == 0) {
280 channels_alloc = 10;
281 channels = xcalloc(channels_alloc, sizeof(Channel *));
282 for (i = 0; i < channels_alloc; i++)
283 channels[i] = NULL;
284 }
285 /* Try to find a free slot where to put the new channel. */
286 for (found = -1, i = 0; i < channels_alloc; i++)
287 if (channels[i] == NULL) {
288 /* Found a free slot. */
289 found = (int)i;
290 break;
291 }
292 if (found < 0) {
293 /* There are no free slots. Take last+1 slot and expand the array. */
294 found = channels_alloc;
295 if (channels_alloc > 10000)
296 fatal("channel_new: internal error: channels_alloc %d "
297 "too big.", channels_alloc);
298 channels = xrealloc(channels, channels_alloc + 10,
299 sizeof(Channel *));
300 channels_alloc += 10;
301 debug2("channel: expanding %d", channels_alloc);
302 for (i = found; i < channels_alloc; i++)
303 channels[i] = NULL;
304 }
305 /* Initialize and return new channel. */
306 c = channels[found] = xcalloc(1, sizeof(Channel));
307 buffer_init(&c->input);
308 buffer_init(&c->output);
309 buffer_init(&c->extended);
310 c->path = NULL;
311 c->ostate = CHAN_OUTPUT_OPEN;
312 c->istate = CHAN_INPUT_OPEN;
313 c->flags = 0;
314 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, 0);
315 c->self = found;
316 c->type = type;
317 c->ctype = ctype;
318 c->dynamic_window = 0;
319 c->local_window = window;
320 c->local_window_max = window;
321 c->local_consumed = 0;
322 c->local_maxpacket = maxpack;
323 c->remote_id = -1;
324 c->remote_name = xstrdup(remote_name);
325 c->remote_window = 0;
326 c->remote_maxpacket = 0;
327 c->force_drain = 0;
328 c->single_connection = 0;
329 c->detach_user = NULL;
330 c->detach_close = 0;
331 c->open_confirm = NULL;
332 c->open_confirm_ctx = NULL;
333 c->input_filter = NULL;
334 c->output_filter = NULL;
335 c->filter_ctx = NULL;
336 c->filter_cleanup = NULL;
337 c->ctl_chan = -1;
338 c->mux_rcb = NULL;
339 c->mux_ctx = NULL;
340 c->mux_pause = 0;
341 c->delayed = 1; /* prevent call to channel_post handler */
342 TAILQ_INIT(&c->status_confirms);
343 debug("channel %d: new [%s]", found, remote_name);
344 return c;
345}
346
347static int
348channel_find_maxfd(void)
349{
350 u_int i;
351 int max = 0;
352 Channel *c;
353
354 for (i = 0; i < channels_alloc; i++) {
355 c = channels[i];
356 if (c != NULL) {
357 max = MAX(max, c->rfd);
358 max = MAX(max, c->wfd);
359 max = MAX(max, c->efd);
360 }
361 }
362 return max;
363}
364
365int
366channel_close_fd(int *fdp)
367{
368 int ret = 0, fd = *fdp;
369
370 if (fd != -1) {
371 ret = close(fd);
372 *fdp = -1;
373 if (fd == channel_max_fd)
374 channel_max_fd = channel_find_maxfd();
375 }
376 return ret;
377}
378
379/* Close all channel fd/socket. */
380static void
381channel_close_fds(Channel *c)
382{
383 channel_close_fd(&c->sock);
384 channel_close_fd(&c->rfd);
385 channel_close_fd(&c->wfd);
386 channel_close_fd(&c->efd);
387}
388
389/* Free the channel and close its fd/socket. */
390void
391channel_free(Channel *c)
392{
393 char *s;
394 u_int i, n;
395 struct channel_confirm *cc;
396
397 for (n = 0, i = 0; i < channels_alloc; i++)
398 if (channels[i])
399 n++;
400 debug("channel %d: free: %s, nchannels %u", c->self,
401 c->remote_name ? c->remote_name : "???", n);
402
403 s = channel_open_message();
404 debug3("channel %d: status: %s", c->self, s);
405 xfree(s);
406
407 if (c->sock != -1)
408 shutdown(c->sock, SHUT_RDWR);
409 channel_close_fds(c);
410 buffer_free(&c->input);
411 buffer_free(&c->output);
412 buffer_free(&c->extended);
413 if (c->remote_name) {
414 xfree(c->remote_name);
415 c->remote_name = NULL;
416 }
417 if (c->path) {
418 xfree(c->path);
419 c->path = NULL;
420 }
421 while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) {
422 if (cc->abandon_cb != NULL)
423 cc->abandon_cb(c, cc->ctx);
424 TAILQ_REMOVE(&c->status_confirms, cc, entry);
425 bzero(cc, sizeof(*cc));
426 xfree(cc);
427 }
428 if (c->filter_cleanup != NULL && c->filter_ctx != NULL)
429 c->filter_cleanup(c->self, c->filter_ctx);
430 channels[c->self] = NULL;
431 xfree(c);
432}
433
434void
435channel_free_all(void)
436{
437 u_int i;
438
439 for (i = 0; i < channels_alloc; i++)
440 if (channels[i] != NULL)
441 channel_free(channels[i]);
442}
443
444/*
445 * Closes the sockets/fds of all channels. This is used to close extra file
446 * descriptors after a fork.
447 */
448void
449channel_close_all(void)
450{
451 u_int i;
452
453 for (i = 0; i < channels_alloc; i++)
454 if (channels[i] != NULL)
455 channel_close_fds(channels[i]);
456}
457
458/*
459 * Stop listening to channels.
460 */
461void
462channel_stop_listening(void)
463{
464 u_int i;
465 Channel *c;
466
467 for (i = 0; i < channels_alloc; i++) {
468 c = channels[i];
469 if (c != NULL) {
470 switch (c->type) {
471 case SSH_CHANNEL_AUTH_SOCKET:
472 case SSH_CHANNEL_PORT_LISTENER:
473 case SSH_CHANNEL_RPORT_LISTENER:
474 case SSH_CHANNEL_X11_LISTENER:
475 channel_close_fd(&c->sock);
476 channel_free(c);
477 break;
478 }
479 }
480 }
481}
482
483/*
484 * Returns true if no channel has too much buffered data, and false if one or
485 * more channel is overfull.
486 */
487int
488channel_not_very_much_buffered_data(void)
489{
490 u_int i;
491 Channel *c;
492
493 for (i = 0; i < channels_alloc; i++) {
494 c = channels[i];
495 if (c != NULL && c->type == SSH_CHANNEL_OPEN) {
496#if 0
497 if (!compat20 &&
498 buffer_len(&c->input) > packet_get_maxsize()) {
499 debug2("channel %d: big input buffer %d",
500 c->self, buffer_len(&c->input));
501 return 0;
502 }
503#endif
504 if (buffer_len(&c->output) > packet_get_maxsize()) {
505 debug2("channel %d: big output buffer %u > %u",
506 c->self, buffer_len(&c->output),
507 packet_get_maxsize());
508 return 0;
509 }
510 }
511 }
512 return 1;
513}
514
515/* Returns true if any channel is still open. */
516int
517channel_still_open(void)
518{
519 u_int i;
520 Channel *c;
521
522 for (i = 0; i < channels_alloc; i++) {
523 c = channels[i];
524 if (c == NULL)
525 continue;
526 switch (c->type) {
527 case SSH_CHANNEL_X11_LISTENER:
528 case SSH_CHANNEL_PORT_LISTENER:
529 case SSH_CHANNEL_RPORT_LISTENER:
530 case SSH_CHANNEL_MUX_LISTENER:
531 case SSH_CHANNEL_CLOSED:
532 case SSH_CHANNEL_AUTH_SOCKET:
533 case SSH_CHANNEL_DYNAMIC:
534 case SSH_CHANNEL_CONNECTING:
535 case SSH_CHANNEL_ZOMBIE:
536 continue;
537 case SSH_CHANNEL_LARVAL:
538 if (!compat20)
539 fatal("cannot happen: SSH_CHANNEL_LARVAL");
540 continue;
541 case SSH_CHANNEL_OPENING:
542 case SSH_CHANNEL_OPEN:
543 case SSH_CHANNEL_X11_OPEN:
544 case SSH_CHANNEL_MUX_CLIENT:
545 return 1;
546 case SSH_CHANNEL_INPUT_DRAINING:
547 case SSH_CHANNEL_OUTPUT_DRAINING:
548 if (!compat13)
549 fatal("cannot happen: OUT_DRAIN");
550 return 1;
551 default:
552 fatal("channel_still_open: bad channel type %d", c->type);
553 /* NOTREACHED */
554 }
555 }
556 return 0;
557}
558
559/* Returns the id of an open channel suitable for keepaliving */
560int
561channel_find_open(void)
562{
563 u_int i;
564 Channel *c;
565
566 for (i = 0; i < channels_alloc; i++) {
567 c = channels[i];
568 if (c == NULL || c->remote_id < 0)
569 continue;
570 switch (c->type) {
571 case SSH_CHANNEL_CLOSED:
572 case SSH_CHANNEL_DYNAMIC:
573 case SSH_CHANNEL_X11_LISTENER:
574 case SSH_CHANNEL_PORT_LISTENER:
575 case SSH_CHANNEL_RPORT_LISTENER:
576 case SSH_CHANNEL_MUX_LISTENER:
577 case SSH_CHANNEL_MUX_CLIENT:
578 case SSH_CHANNEL_OPENING:
579 case SSH_CHANNEL_CONNECTING:
580 case SSH_CHANNEL_ZOMBIE:
581 continue;
582 case SSH_CHANNEL_LARVAL:
583 case SSH_CHANNEL_AUTH_SOCKET:
584 case SSH_CHANNEL_OPEN:
585 case SSH_CHANNEL_X11_OPEN:
586 return i;
587 case SSH_CHANNEL_INPUT_DRAINING:
588 case SSH_CHANNEL_OUTPUT_DRAINING:
589 if (!compat13)
590 fatal("cannot happen: OUT_DRAIN");
591 return i;
592 default:
593 fatal("channel_find_open: bad channel type %d", c->type);
594 /* NOTREACHED */
595 }
596 }
597 return -1;
598}
599
600
601/*
602 * Returns a message describing the currently open forwarded connections,
603 * suitable for sending to the client. The message contains crlf pairs for
604 * newlines.
605 */
606char *
607channel_open_message(void)
608{
609 Buffer buffer;
610 Channel *c;
611 char buf[1024], *cp;
612 u_int i;
613
614 buffer_init(&buffer);
615 snprintf(buf, sizeof buf, "The following connections are open:\r\n");
616 buffer_append(&buffer, buf, strlen(buf));
617 for (i = 0; i < channels_alloc; i++) {
618 c = channels[i];
619 if (c == NULL)
620 continue;
621 switch (c->type) {
622 case SSH_CHANNEL_X11_LISTENER:
623 case SSH_CHANNEL_PORT_LISTENER:
624 case SSH_CHANNEL_RPORT_LISTENER:
625 case SSH_CHANNEL_CLOSED:
626 case SSH_CHANNEL_AUTH_SOCKET:
627 case SSH_CHANNEL_ZOMBIE:
628 case SSH_CHANNEL_MUX_CLIENT:
629 case SSH_CHANNEL_MUX_LISTENER:
630 continue;
631 case SSH_CHANNEL_LARVAL:
632 case SSH_CHANNEL_OPENING:
633 case SSH_CHANNEL_CONNECTING:
634 case SSH_CHANNEL_DYNAMIC:
635 case SSH_CHANNEL_OPEN:
636 case SSH_CHANNEL_X11_OPEN:
637 case SSH_CHANNEL_INPUT_DRAINING:
638 case SSH_CHANNEL_OUTPUT_DRAINING:
639 snprintf(buf, sizeof buf,
640 " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cc %d)\r\n",
641 c->self, c->remote_name,
642 c->type, c->remote_id,
643 c->istate, buffer_len(&c->input),
644 c->ostate, buffer_len(&c->output),
645 c->rfd, c->wfd, c->ctl_chan);
646 buffer_append(&buffer, buf, strlen(buf));
647 continue;
648 default:
649 fatal("channel_open_message: bad channel type %d", c->type);
650 /* NOTREACHED */
651 }
652 }
653 buffer_append(&buffer, "\0", 1);
654 cp = xstrdup(buffer_ptr(&buffer));
655 buffer_free(&buffer);
656 return cp;
657}
658
659void
660channel_send_open(int id)
661{
662 Channel *c = channel_lookup(id);
663
664 if (c == NULL) {
665 logit("channel_send_open: %d: bad id", id);
666 return;
667 }
668 debug2("channel %d: send open", id);
669 packet_start(SSH2_MSG_CHANNEL_OPEN);
670 packet_put_cstring(c->ctype);
671 packet_put_int(c->self);
672 packet_put_int(c->local_window);
673 packet_put_int(c->local_maxpacket);
674 packet_send();
675}
676
677void
678channel_request_start(int id, char *service, int wantconfirm)
679{
680 Channel *c = channel_lookup(id);
681
682 if (c == NULL) {
683 logit("channel_request_start: %d: unknown channel id", id);
684 return;
685 }
686 debug2("channel %d: request %s confirm %d", id, service, wantconfirm);
687 packet_start(SSH2_MSG_CHANNEL_REQUEST);
688 packet_put_int(c->remote_id);
689 packet_put_cstring(service);
690 packet_put_char(wantconfirm);
691}
692
693void
694channel_register_status_confirm(int id, channel_confirm_cb *cb,
695 channel_confirm_abandon_cb *abandon_cb, void *ctx)
696{
697 struct channel_confirm *cc;
698 Channel *c;
699
700 if ((c = channel_lookup(id)) == NULL)
701 fatal("channel_register_expect: %d: bad id", id);
702
703 cc = xmalloc(sizeof(*cc));
704 cc->cb = cb;
705 cc->abandon_cb = abandon_cb;
706 cc->ctx = ctx;
707 TAILQ_INSERT_TAIL(&c->status_confirms, cc, entry);
708}
709
710void
711channel_register_open_confirm(int id, channel_open_fn *fn, void *ctx)
712{
713 Channel *c = channel_lookup(id);
714
715 if (c == NULL) {
716 logit("channel_register_open_confirm: %d: bad id", id);
717 return;
718 }
719 c->open_confirm = fn;
720 c->open_confirm_ctx = ctx;
721}
722
723void
724channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
725{
726 Channel *c = channel_by_id(id);
727
728 if (c == NULL) {
729 logit("channel_register_cleanup: %d: bad id", id);
730 return;
731 }
732 c->detach_user = fn;
733 c->detach_close = do_close;
734}
735
736void
737channel_cancel_cleanup(int id)
738{
739 Channel *c = channel_by_id(id);
740
741 if (c == NULL) {
742 logit("channel_cancel_cleanup: %d: bad id", id);
743 return;
744 }
745 c->detach_user = NULL;
746 c->detach_close = 0;
747}
748
749void
750channel_register_filter(int id, channel_infilter_fn *ifn,
751 channel_outfilter_fn *ofn, channel_filter_cleanup_fn *cfn, void *ctx)
752{
753 Channel *c = channel_lookup(id);
754
755 if (c == NULL) {
756 logit("channel_register_filter: %d: bad id", id);
757 return;
758 }
759 c->input_filter = ifn;
760 c->output_filter = ofn;
761 c->filter_ctx = ctx;
762 c->filter_cleanup = cfn;
763}
764
765void
766channel_set_fds(int id, int rfd, int wfd, int efd,
767 int extusage, int nonblock, int is_tty, u_int window_max)
768{
769 Channel *c = channel_lookup(id);
770
771 if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
772 fatal("channel_activate for non-larval channel %d.", id);
773 channel_register_fds(c, rfd, wfd, efd, extusage, nonblock, is_tty);
774 c->type = SSH_CHANNEL_OPEN;
775 c->local_window = c->local_window_max = window_max;
776 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
777 packet_put_int(c->remote_id);
778 packet_put_int(c->local_window);
779 packet_send();
780}
781
782/*
783 * 'channel_pre*' are called just before select() to add any bits relevant to
784 * channels in the select bitmasks.
785 */
786/*
787 * 'channel_post*': perform any appropriate operations for channels which
788 * have events pending.
789 */
790typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
791chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
792chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
793
794/* ARGSUSED */
795static void
796channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
797{
798 FD_SET(c->sock, readset);
799}
800
801/* ARGSUSED */
802static void
803channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
804{
805 debug3("channel %d: waiting for connection", c->self);
806 FD_SET(c->sock, writeset);
807}
808
809static void
810channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
811{
812 if (buffer_len(&c->input) < packet_get_maxsize())
813 FD_SET(c->sock, readset);
814 if (buffer_len(&c->output) > 0)
815 FD_SET(c->sock, writeset);
816}
817
818static u_int
819channel_tcpwinsz(void)
820{
821 u_int32_t tcpwinsz;
822 socklen_t optsz;
823 int ret, sd;
824 u_int maxlen;
825
826 /* If we are not on a socket return 128KB. */
|
827 if (!packet_connection_is_on_socket())
| 827 if (!packet_connection_is_on_socket())
|
828 return (128 * 1024);
829
830 tcpwinsz = 0;
831 optsz = sizeof(tcpwinsz);
832 sd = packet_get_connection_in();
833 ret = getsockopt(sd, SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz);
834
835 /* Return no more than the maximum buffer size. */
836 maxlen = buffer_get_max_len();
837 if ((ret == 0) && tcpwinsz > maxlen)
838 tcpwinsz = maxlen;
839 /* In case getsockopt() failed return a minimum. */
840 if (tcpwinsz == 0)
841 tcpwinsz = CHAN_TCP_WINDOW_DEFAULT;
842 debug2("tcpwinsz: %d for connection: %d", tcpwinsz, sd);
843 return (tcpwinsz);
844}
845
846static void
847channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
848{
849 u_int limit;
850
851 /* Check buffer limits. */
852 if (!c->tcpwinsz || c->dynamic_window > 0)
853 c->tcpwinsz = channel_tcpwinsz();
854
855 limit = MIN(compat20 ? c->remote_window : packet_get_maxsize(),
856 2 * c->tcpwinsz);
| 828 return (128 * 1024);
829
830 tcpwinsz = 0;
831 optsz = sizeof(tcpwinsz);
832 sd = packet_get_connection_in();
833 ret = getsockopt(sd, SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz);
834
835 /* Return no more than the maximum buffer size. */
836 maxlen = buffer_get_max_len();
837 if ((ret == 0) && tcpwinsz > maxlen)
838 tcpwinsz = maxlen;
839 /* In case getsockopt() failed return a minimum. */
840 if (tcpwinsz == 0)
841 tcpwinsz = CHAN_TCP_WINDOW_DEFAULT;
842 debug2("tcpwinsz: %d for connection: %d", tcpwinsz, sd);
843 return (tcpwinsz);
844}
845
846static void
847channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
848{
849 u_int limit;
850
851 /* Check buffer limits. */
852 if (!c->tcpwinsz || c->dynamic_window > 0)
853 c->tcpwinsz = channel_tcpwinsz();
854
855 limit = MIN(compat20 ? c->remote_window : packet_get_maxsize(),
856 2 * c->tcpwinsz);
|
857
| 857
|
858 if (c->istate == CHAN_INPUT_OPEN &&
859 limit > 0 &&
860 buffer_len(&c->input) < limit &&
861 buffer_check_alloc(&c->input, CHAN_RBUF))
862 FD_SET(c->rfd, readset);
863 if (c->ostate == CHAN_OUTPUT_OPEN ||
864 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
865 if (buffer_len(&c->output) > 0) {
866 FD_SET(c->wfd, writeset);
867 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
868 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
869 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
870 c->self, c->efd, buffer_len(&c->extended));
871 else
872 chan_obuf_empty(c);
873 }
874 }
875 /** XXX check close conditions, too */
876 if (compat20 && c->efd != -1 &&
877 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
878 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
879 buffer_len(&c->extended) > 0)
880 FD_SET(c->efd, writeset);
881 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
882 (c->extended_usage == CHAN_EXTENDED_READ ||
883 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
884 buffer_len(&c->extended) < c->remote_window)
885 FD_SET(c->efd, readset);
886 }
887 /* XXX: What about efd? races? */
888}
889
890/* ARGSUSED */
891static void
892channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
893{
894 if (buffer_len(&c->input) == 0) {
895 packet_start(SSH_MSG_CHANNEL_CLOSE);
896 packet_put_int(c->remote_id);
897 packet_send();
898 c->type = SSH_CHANNEL_CLOSED;
899 debug2("channel %d: closing after input drain.", c->self);
900 }
901}
902
903/* ARGSUSED */
904static void
905channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
906{
907 if (buffer_len(&c->output) == 0)
908 chan_mark_dead(c);
909 else
910 FD_SET(c->sock, writeset);
911}
912
913/*
914 * This is a special state for X11 authentication spoofing. An opened X11
915 * connection (when authentication spoofing is being done) remains in this
916 * state until the first packet has been completely read. The authentication
917 * data in that packet is then substituted by the real data if it matches the
918 * fake data, and the channel is put into normal mode.
919 * XXX All this happens at the client side.
920 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
921 */
922static int
923x11_open_helper(Buffer *b)
924{
925 u_char *ucp;
926 u_int proto_len, data_len;
927
928 /* Check if the fixed size part of the packet is in buffer. */
929 if (buffer_len(b) < 12)
930 return 0;
931
932 /* Parse the lengths of variable-length fields. */
933 ucp = buffer_ptr(b);
934 if (ucp[0] == 0x42) { /* Byte order MSB first. */
935 proto_len = 256 * ucp[6] + ucp[7];
936 data_len = 256 * ucp[8] + ucp[9];
937 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
938 proto_len = ucp[6] + 256 * ucp[7];
939 data_len = ucp[8] + 256 * ucp[9];
940 } else {
941 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
942 ucp[0]);
943 return -1;
944 }
945
946 /* Check if the whole packet is in buffer. */
947 if (buffer_len(b) <
948 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
949 return 0;
950
951 /* Check if authentication protocol matches. */
952 if (proto_len != strlen(x11_saved_proto) ||
953 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
954 debug2("X11 connection uses different authentication protocol.");
955 return -1;
956 }
957 /* Check if authentication data matches our fake data. */
958 if (data_len != x11_fake_data_len ||
959 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
960 x11_fake_data, x11_fake_data_len) != 0) {
961 debug2("X11 auth data does not match fake data.");
962 return -1;
963 }
964 /* Check fake data length */
965 if (x11_fake_data_len != x11_saved_data_len) {
966 error("X11 fake_data_len %d != saved_data_len %d",
967 x11_fake_data_len, x11_saved_data_len);
968 return -1;
969 }
970 /*
971 * Received authentication protocol and data match
972 * our fake data. Substitute the fake data with real
973 * data.
974 */
975 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
976 x11_saved_data, x11_saved_data_len);
977 return 1;
978}
979
980static void
981channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
982{
983 int ret = x11_open_helper(&c->output);
984
985 if (ret == 1) {
986 /* Start normal processing for the channel. */
987 c->type = SSH_CHANNEL_OPEN;
988 channel_pre_open_13(c, readset, writeset);
989 } else if (ret == -1) {
990 /*
991 * We have received an X11 connection that has bad
992 * authentication information.
993 */
994 logit("X11 connection rejected because of wrong authentication.");
995 buffer_clear(&c->input);
996 buffer_clear(&c->output);
997 channel_close_fd(&c->sock);
998 c->sock = -1;
999 c->type = SSH_CHANNEL_CLOSED;
1000 packet_start(SSH_MSG_CHANNEL_CLOSE);
1001 packet_put_int(c->remote_id);
1002 packet_send();
1003 }
1004}
1005
1006static void
1007channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1008{
1009 int ret = x11_open_helper(&c->output);
1010
1011 /* c->force_drain = 1; */
1012
1013 if (ret == 1) {
1014 c->type = SSH_CHANNEL_OPEN;
1015 channel_pre_open(c, readset, writeset);
1016 } else if (ret == -1) {
1017 logit("X11 connection rejected because of wrong authentication.");
1018 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1019 chan_read_failed(c);
1020 buffer_clear(&c->input);
1021 chan_ibuf_empty(c);
1022 buffer_clear(&c->output);
1023 /* for proto v1, the peer will send an IEOF */
1024 if (compat20)
1025 chan_write_failed(c);
1026 else
1027 c->type = SSH_CHANNEL_OPEN;
1028 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1029 }
1030}
1031
1032static void
1033channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1034{
1035 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1036 buffer_check_alloc(&c->input, CHAN_RBUF))
1037 FD_SET(c->rfd, readset);
1038 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1039 /* clear buffer immediately (discard any partial packet) */
1040 buffer_clear(&c->input);
1041 chan_ibuf_empty(c);
1042 /* Start output drain. XXX just kill chan? */
1043 chan_rcvd_oclose(c);
1044 }
1045 if (c->ostate == CHAN_OUTPUT_OPEN ||
1046 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1047 if (buffer_len(&c->output) > 0)
1048 FD_SET(c->wfd, writeset);
1049 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1050 chan_obuf_empty(c);
1051 }
1052}
1053
1054/* try to decode a socks4 header */
1055/* ARGSUSED */
1056static int
1057channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1058{
1059 char *p, *host;
1060 u_int len, have, i, found, need;
1061 char username[256];
1062 struct {
1063 u_int8_t version;
1064 u_int8_t command;
1065 u_int16_t dest_port;
1066 struct in_addr dest_addr;
1067 } s4_req, s4_rsp;
1068
1069 debug2("channel %d: decode socks4", c->self);
1070
1071 have = buffer_len(&c->input);
1072 len = sizeof(s4_req);
1073 if (have < len)
1074 return 0;
1075 p = buffer_ptr(&c->input);
1076
1077 need = 1;
1078 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1079 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1080 debug2("channel %d: socks4a request", c->self);
1081 /* ... and needs an extra string (the hostname) */
1082 need = 2;
1083 }
1084 /* Check for terminating NUL on the string(s) */
1085 for (found = 0, i = len; i < have; i++) {
1086 if (p[i] == '\0') {
1087 found++;
1088 if (found == need)
1089 break;
1090 }
1091 if (i > 1024) {
1092 /* the peer is probably sending garbage */
1093 debug("channel %d: decode socks4: too long",
1094 c->self);
1095 return -1;
1096 }
1097 }
1098 if (found < need)
1099 return 0;
1100 buffer_get(&c->input, (char *)&s4_req.version, 1);
1101 buffer_get(&c->input, (char *)&s4_req.command, 1);
1102 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1103 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1104 have = buffer_len(&c->input);
1105 p = buffer_ptr(&c->input);
1106 len = strlen(p);
1107 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1108 len++; /* trailing '\0' */
1109 if (len > have)
1110 fatal("channel %d: decode socks4: len %d > have %d",
1111 c->self, len, have);
1112 strlcpy(username, p, sizeof(username));
1113 buffer_consume(&c->input, len);
1114
1115 if (c->path != NULL) {
1116 xfree(c->path);
1117 c->path = NULL;
1118 }
1119 if (need == 1) { /* SOCKS4: one string */
1120 host = inet_ntoa(s4_req.dest_addr);
1121 c->path = xstrdup(host);
1122 } else { /* SOCKS4A: two strings */
1123 have = buffer_len(&c->input);
1124 p = buffer_ptr(&c->input);
1125 len = strlen(p);
1126 debug2("channel %d: decode socks4a: host %s/%d",
1127 c->self, p, len);
1128 len++; /* trailing '\0' */
1129 if (len > have)
1130 fatal("channel %d: decode socks4a: len %d > have %d",
1131 c->self, len, have);
1132 if (len > NI_MAXHOST) {
1133 error("channel %d: hostname \"%.100s\" too long",
1134 c->self, p);
1135 return -1;
1136 }
1137 c->path = xstrdup(p);
1138 buffer_consume(&c->input, len);
1139 }
1140 c->host_port = ntohs(s4_req.dest_port);
1141
1142 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1143 c->self, c->path, c->host_port, s4_req.command);
1144
1145 if (s4_req.command != 1) {
1146 debug("channel %d: cannot handle: %s cn %d",
1147 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1148 return -1;
1149 }
1150 s4_rsp.version = 0; /* vn: 0 for reply */
1151 s4_rsp.command = 90; /* cd: req granted */
1152 s4_rsp.dest_port = 0; /* ignored */
1153 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1154 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1155 return 1;
1156}
1157
1158/* try to decode a socks5 header */
1159#define SSH_SOCKS5_AUTHDONE 0x1000
1160#define SSH_SOCKS5_NOAUTH 0x00
1161#define SSH_SOCKS5_IPV4 0x01
1162#define SSH_SOCKS5_DOMAIN 0x03
1163#define SSH_SOCKS5_IPV6 0x04
1164#define SSH_SOCKS5_CONNECT 0x01
1165#define SSH_SOCKS5_SUCCESS 0x00
1166
1167/* ARGSUSED */
1168static int
1169channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1170{
1171 struct {
1172 u_int8_t version;
1173 u_int8_t command;
1174 u_int8_t reserved;
1175 u_int8_t atyp;
1176 } s5_req, s5_rsp;
1177 u_int16_t dest_port;
1178 u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1179 u_int have, need, i, found, nmethods, addrlen, af;
1180
1181 debug2("channel %d: decode socks5", c->self);
1182 p = buffer_ptr(&c->input);
1183 if (p[0] != 0x05)
1184 return -1;
1185 have = buffer_len(&c->input);
1186 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1187 /* format: ver | nmethods | methods */
1188 if (have < 2)
1189 return 0;
1190 nmethods = p[1];
1191 if (have < nmethods + 2)
1192 return 0;
1193 /* look for method: "NO AUTHENTICATION REQUIRED" */
1194 for (found = 0, i = 2; i < nmethods + 2; i++) {
1195 if (p[i] == SSH_SOCKS5_NOAUTH) {
1196 found = 1;
1197 break;
1198 }
1199 }
1200 if (!found) {
1201 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1202 c->self);
1203 return -1;
1204 }
1205 buffer_consume(&c->input, nmethods + 2);
1206 buffer_put_char(&c->output, 0x05); /* version */
1207 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1208 FD_SET(c->sock, writeset);
1209 c->flags |= SSH_SOCKS5_AUTHDONE;
1210 debug2("channel %d: socks5 auth done", c->self);
1211 return 0; /* need more */
1212 }
1213 debug2("channel %d: socks5 post auth", c->self);
1214 if (have < sizeof(s5_req)+1)
1215 return 0; /* need more */
1216 memcpy(&s5_req, p, sizeof(s5_req));
1217 if (s5_req.version != 0x05 ||
1218 s5_req.command != SSH_SOCKS5_CONNECT ||
1219 s5_req.reserved != 0x00) {
1220 debug2("channel %d: only socks5 connect supported", c->self);
1221 return -1;
1222 }
1223 switch (s5_req.atyp){
1224 case SSH_SOCKS5_IPV4:
1225 addrlen = 4;
1226 af = AF_INET;
1227 break;
1228 case SSH_SOCKS5_DOMAIN:
1229 addrlen = p[sizeof(s5_req)];
1230 af = -1;
1231 break;
1232 case SSH_SOCKS5_IPV6:
1233 addrlen = 16;
1234 af = AF_INET6;
1235 break;
1236 default:
1237 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1238 return -1;
1239 }
1240 need = sizeof(s5_req) + addrlen + 2;
1241 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1242 need++;
1243 if (have < need)
1244 return 0;
1245 buffer_consume(&c->input, sizeof(s5_req));
1246 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1247 buffer_consume(&c->input, 1); /* host string length */
1248 buffer_get(&c->input, (char *)&dest_addr, addrlen);
1249 buffer_get(&c->input, (char *)&dest_port, 2);
1250 dest_addr[addrlen] = '\0';
1251 if (c->path != NULL) {
1252 xfree(c->path);
1253 c->path = NULL;
1254 }
1255 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1256 if (addrlen >= NI_MAXHOST) {
1257 error("channel %d: dynamic request: socks5 hostname "
1258 "\"%.100s\" too long", c->self, dest_addr);
1259 return -1;
1260 }
1261 c->path = xstrdup(dest_addr);
1262 } else {
1263 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1264 return -1;
1265 c->path = xstrdup(ntop);
1266 }
1267 c->host_port = ntohs(dest_port);
1268
1269 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1270 c->self, c->path, c->host_port, s5_req.command);
1271
1272 s5_rsp.version = 0x05;
1273 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1274 s5_rsp.reserved = 0; /* ignored */
1275 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1276 ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1277 dest_port = 0; /* ignored */
1278
1279 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1280 buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1281 buffer_append(&c->output, &dest_port, sizeof(dest_port));
1282 return 1;
1283}
1284
1285Channel *
1286channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1287 int in, int out)
1288{
1289 Channel *c;
1290
1291 debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1292 port_to_connect);
1293
1294 c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1295 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1296 0, "stdio-forward", /*nonblock*/0);
1297
1298 c->path = xstrdup(host_to_connect);
1299 c->host_port = port_to_connect;
1300 c->listening_port = 0;
1301 c->force_drain = 1;
1302
1303 channel_register_fds(c, in, out, -1, 0, 1, 0);
1304 port_open_helper(c, "direct-tcpip");
1305
1306 return c;
1307}
1308
1309/* dynamic port forwarding */
1310static void
1311channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1312{
1313 u_char *p;
1314 u_int have;
1315 int ret;
1316
1317 have = buffer_len(&c->input);
1318 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1319 /* buffer_dump(&c->input); */
1320 /* check if the fixed size part of the packet is in buffer. */
1321 if (have < 3) {
1322 /* need more */
1323 FD_SET(c->sock, readset);
1324 return;
1325 }
1326 /* try to guess the protocol */
1327 p = buffer_ptr(&c->input);
1328 switch (p[0]) {
1329 case 0x04:
1330 ret = channel_decode_socks4(c, readset, writeset);
1331 break;
1332 case 0x05:
1333 ret = channel_decode_socks5(c, readset, writeset);
1334 break;
1335 default:
1336 ret = -1;
1337 break;
1338 }
1339 if (ret < 0) {
1340 chan_mark_dead(c);
1341 } else if (ret == 0) {
1342 debug2("channel %d: pre_dynamic: need more", c->self);
1343 /* need more */
1344 FD_SET(c->sock, readset);
1345 } else {
1346 /* switch to the next state */
1347 c->type = SSH_CHANNEL_OPENING;
1348 port_open_helper(c, "direct-tcpip");
1349 }
1350}
1351
1352/* This is our fake X11 server socket. */
1353/* ARGSUSED */
1354static void
1355channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1356{
1357 Channel *nc;
1358 struct sockaddr_storage addr;
1359 int newsock;
1360 socklen_t addrlen;
1361 char buf[16384], *remote_ipaddr;
1362 int remote_port;
1363
1364 if (FD_ISSET(c->sock, readset)) {
1365 debug("X11 connection requested.");
1366 addrlen = sizeof(addr);
1367 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1368 if (c->single_connection) {
1369 debug2("single_connection: closing X11 listener.");
1370 channel_close_fd(&c->sock);
1371 chan_mark_dead(c);
1372 }
1373 if (newsock < 0) {
1374 error("accept: %.100s", strerror(errno));
1375 return;
1376 }
1377 set_nodelay(newsock);
1378 remote_ipaddr = get_peer_ipaddr(newsock);
1379 remote_port = get_peer_port(newsock);
1380 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1381 remote_ipaddr, remote_port);
1382
1383 nc = channel_new("accepted x11 socket",
1384 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1385 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1386 if (compat20) {
1387 packet_start(SSH2_MSG_CHANNEL_OPEN);
1388 packet_put_cstring("x11");
1389 packet_put_int(nc->self);
1390 packet_put_int(nc->local_window_max);
1391 packet_put_int(nc->local_maxpacket);
1392 /* originator ipaddr and port */
1393 packet_put_cstring(remote_ipaddr);
1394 if (datafellows & SSH_BUG_X11FWD) {
1395 debug2("ssh2 x11 bug compat mode");
1396 } else {
1397 packet_put_int(remote_port);
1398 }
1399 packet_send();
1400 } else {
1401 packet_start(SSH_SMSG_X11_OPEN);
1402 packet_put_int(nc->self);
1403 if (packet_get_protocol_flags() &
1404 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1405 packet_put_cstring(buf);
1406 packet_send();
1407 }
1408 xfree(remote_ipaddr);
1409 }
1410}
1411
1412static void
1413port_open_helper(Channel *c, char *rtype)
1414{
1415 int direct;
1416 char buf[1024];
1417 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1418 int remote_port = get_peer_port(c->sock);
1419
1420 if (remote_port == -1) {
1421 /* Fake addr/port to appease peers that validate it (Tectia) */
1422 xfree(remote_ipaddr);
1423 remote_ipaddr = xstrdup("127.0.0.1");
1424 remote_port = 65535;
1425 }
1426
1427 direct = (strcmp(rtype, "direct-tcpip") == 0);
1428
1429 snprintf(buf, sizeof buf,
1430 "%s: listening port %d for %.100s port %d, "
1431 "connect from %.200s port %d",
1432 rtype, c->listening_port, c->path, c->host_port,
1433 remote_ipaddr, remote_port);
1434
1435 xfree(c->remote_name);
1436 c->remote_name = xstrdup(buf);
1437
1438 if (compat20) {
1439 packet_start(SSH2_MSG_CHANNEL_OPEN);
1440 packet_put_cstring(rtype);
1441 packet_put_int(c->self);
1442 packet_put_int(c->local_window_max);
1443 packet_put_int(c->local_maxpacket);
1444 if (direct) {
1445 /* target host, port */
1446 packet_put_cstring(c->path);
1447 packet_put_int(c->host_port);
1448 } else {
1449 /* listen address, port */
1450 packet_put_cstring(c->path);
1451 packet_put_int(c->listening_port);
1452 }
1453 /* originator host and port */
1454 packet_put_cstring(remote_ipaddr);
1455 packet_put_int((u_int)remote_port);
1456 packet_send();
1457 } else {
1458 packet_start(SSH_MSG_PORT_OPEN);
1459 packet_put_int(c->self);
1460 packet_put_cstring(c->path);
1461 packet_put_int(c->host_port);
1462 if (packet_get_protocol_flags() &
1463 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1464 packet_put_cstring(c->remote_name);
1465 packet_send();
1466 }
1467 xfree(remote_ipaddr);
1468}
1469
1470static void
1471channel_set_reuseaddr(int fd)
1472{
1473 int on = 1;
1474
1475 /*
1476 * Set socket options.
1477 * Allow local port reuse in TIME_WAIT.
1478 */
1479 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1480 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1481}
1482
1483/*
1484 * This socket is listening for connections to a forwarded TCP/IP port.
1485 */
1486/* ARGSUSED */
1487static void
1488channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1489{
1490 Channel *nc;
1491 struct sockaddr_storage addr;
1492 int newsock, nextstate;
1493 socklen_t addrlen;
1494 char *rtype;
1495
1496 if (FD_ISSET(c->sock, readset)) {
1497 debug("Connection to port %d forwarding "
1498 "to %.100s port %d requested.",
1499 c->listening_port, c->path, c->host_port);
1500
1501 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1502 nextstate = SSH_CHANNEL_OPENING;
1503 rtype = "forwarded-tcpip";
1504 } else {
1505 if (c->host_port == 0) {
1506 nextstate = SSH_CHANNEL_DYNAMIC;
1507 rtype = "dynamic-tcpip";
1508 } else {
1509 nextstate = SSH_CHANNEL_OPENING;
1510 rtype = "direct-tcpip";
1511 }
1512 }
1513
1514 addrlen = sizeof(addr);
1515 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1516 if (newsock < 0) {
1517 error("accept: %.100s", strerror(errno));
1518 return;
1519 }
1520 set_nodelay(newsock);
1521 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1522 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1523 nc->listening_port = c->listening_port;
1524 nc->host_port = c->host_port;
1525 if (c->path != NULL)
1526 nc->path = xstrdup(c->path);
1527
1528 if (nextstate != SSH_CHANNEL_DYNAMIC)
1529 port_open_helper(nc, rtype);
1530 }
1531}
1532
1533/*
1534 * This is the authentication agent socket listening for connections from
1535 * clients.
1536 */
1537/* ARGSUSED */
1538static void
1539channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1540{
1541 Channel *nc;
1542 int newsock;
1543 struct sockaddr_storage addr;
1544 socklen_t addrlen;
1545
1546 if (FD_ISSET(c->sock, readset)) {
1547 addrlen = sizeof(addr);
1548 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1549 if (newsock < 0) {
1550 error("accept from auth socket: %.100s", strerror(errno));
1551 return;
1552 }
1553 nc = channel_new("accepted auth socket",
1554 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1555 c->local_window_max, c->local_maxpacket,
1556 0, "accepted auth socket", 1);
1557 if (compat20) {
1558 packet_start(SSH2_MSG_CHANNEL_OPEN);
1559 packet_put_cstring("auth-agent@openssh.com");
1560 packet_put_int(nc->self);
1561 packet_put_int(c->local_window_max);
1562 packet_put_int(c->local_maxpacket);
1563 } else {
1564 packet_start(SSH_SMSG_AGENT_OPEN);
1565 packet_put_int(nc->self);
1566 }
1567 packet_send();
1568 }
1569}
1570
1571/* ARGSUSED */
1572static void
1573channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1574{
1575 int err = 0, sock;
1576 socklen_t sz = sizeof(err);
1577
1578 if (FD_ISSET(c->sock, writeset)) {
1579 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1580 err = errno;
1581 error("getsockopt SO_ERROR failed");
1582 }
1583 if (err == 0) {
1584 debug("channel %d: connected to %s port %d",
1585 c->self, c->connect_ctx.host, c->connect_ctx.port);
1586 channel_connect_ctx_free(&c->connect_ctx);
1587 c->type = SSH_CHANNEL_OPEN;
1588 if (compat20) {
1589 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1590 packet_put_int(c->remote_id);
1591 packet_put_int(c->self);
1592 packet_put_int(c->local_window);
1593 packet_put_int(c->local_maxpacket);
1594 } else {
1595 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1596 packet_put_int(c->remote_id);
1597 packet_put_int(c->self);
1598 }
1599 } else {
1600 debug("channel %d: connection failed: %s",
1601 c->self, strerror(err));
1602 /* Try next address, if any */
1603 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1604 close(c->sock);
1605 c->sock = c->rfd = c->wfd = sock;
1606 channel_max_fd = channel_find_maxfd();
1607 return;
1608 }
1609 /* Exhausted all addresses */
1610 error("connect_to %.100s port %d: failed.",
1611 c->connect_ctx.host, c->connect_ctx.port);
1612 channel_connect_ctx_free(&c->connect_ctx);
1613 if (compat20) {
1614 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1615 packet_put_int(c->remote_id);
1616 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1617 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1618 packet_put_cstring(strerror(err));
1619 packet_put_cstring("");
1620 }
1621 } else {
1622 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1623 packet_put_int(c->remote_id);
1624 }
1625 chan_mark_dead(c);
1626 }
1627 packet_send();
1628 }
1629}
1630
1631/* ARGSUSED */
1632static int
1633channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1634{
1635 char buf[CHAN_RBUF];
1636 int len, force;
1637
1638 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1639 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
1640 errno = 0;
1641 len = read(c->rfd, buf, sizeof(buf));
1642 if (len < 0 && (errno == EINTR ||
1643 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1644 return 1;
1645#ifndef PTY_ZEROREAD
1646 if (len <= 0) {
1647#else
1648 if ((!c->isatty && len <= 0) ||
1649 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1650#endif
1651 debug2("channel %d: read<=0 rfd %d len %d",
1652 c->self, c->rfd, len);
1653 if (c->type != SSH_CHANNEL_OPEN) {
1654 debug2("channel %d: not open", c->self);
1655 chan_mark_dead(c);
1656 return -1;
1657 } else if (compat13) {
1658 buffer_clear(&c->output);
1659 c->type = SSH_CHANNEL_INPUT_DRAINING;
1660 debug2("channel %d: input draining.", c->self);
1661 } else {
1662 chan_read_failed(c);
1663 }
1664 return -1;
1665 }
1666 if (c->input_filter != NULL) {
1667 if (c->input_filter(c, buf, len) == -1) {
1668 debug2("channel %d: filter stops", c->self);
1669 chan_read_failed(c);
1670 }
1671 } else if (c->datagram) {
1672 buffer_put_string(&c->input, buf, len);
1673 } else {
1674 buffer_append(&c->input, buf, len);
1675 }
1676 }
1677 return 1;
1678}
1679
1680/* ARGSUSED */
1681static int
1682channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1683{
1684 struct termios tio;
1685 u_char *data = NULL, *buf;
1686 u_int dlen, olen = 0;
1687 int len;
1688
1689 /* Send buffered output data to the socket. */
1690 if (c->wfd != -1 &&
1691 FD_ISSET(c->wfd, writeset) &&
1692 buffer_len(&c->output) > 0) {
1693 olen = buffer_len(&c->output);
1694 if (c->output_filter != NULL) {
1695 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1696 debug2("channel %d: filter stops", c->self);
1697 if (c->type != SSH_CHANNEL_OPEN)
1698 chan_mark_dead(c);
1699 else
1700 chan_write_failed(c);
1701 return -1;
1702 }
1703 } else if (c->datagram) {
1704 buf = data = buffer_get_string(&c->output, &dlen);
1705 } else {
1706 buf = data = buffer_ptr(&c->output);
1707 dlen = buffer_len(&c->output);
1708 }
1709
1710 if (c->datagram) {
1711 /* ignore truncated writes, datagrams might get lost */
1712 len = write(c->wfd, buf, dlen);
1713 xfree(data);
1714 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1715 errno == EWOULDBLOCK))
1716 return 1;
1717 if (len <= 0) {
1718 if (c->type != SSH_CHANNEL_OPEN)
1719 chan_mark_dead(c);
1720 else
1721 chan_write_failed(c);
1722 return -1;
1723 }
1724 goto out;
1725 }
1726#ifdef _AIX
1727 /* XXX: Later AIX versions can't push as much data to tty */
1728 if (compat20 && c->wfd_isatty)
1729 dlen = MIN(dlen, 8*1024);
1730#endif
1731
1732 len = write(c->wfd, buf, dlen);
1733 if (len < 0 &&
1734 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
1735 return 1;
1736 if (len <= 0) {
1737 if (c->type != SSH_CHANNEL_OPEN) {
1738 debug2("channel %d: not open", c->self);
1739 chan_mark_dead(c);
1740 return -1;
1741 } else if (compat13) {
1742 buffer_clear(&c->output);
1743 debug2("channel %d: input draining.", c->self);
1744 c->type = SSH_CHANNEL_INPUT_DRAINING;
1745 } else {
1746 chan_write_failed(c);
1747 }
1748 return -1;
1749 }
1750#ifndef BROKEN_TCGETATTR_ICANON
1751 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1752 if (tcgetattr(c->wfd, &tio) == 0 &&
1753 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1754 /*
1755 * Simulate echo to reduce the impact of
1756 * traffic analysis. We need to match the
1757 * size of a SSH2_MSG_CHANNEL_DATA message
1758 * (4 byte channel id + buf)
1759 */
1760 packet_send_ignore(4 + len);
1761 packet_send();
1762 }
1763 }
1764#endif
1765 buffer_consume(&c->output, len);
1766 }
1767 out:
1768 if (compat20 && olen > 0)
1769 c->local_consumed += olen - buffer_len(&c->output);
1770 return 1;
1771}
1772
1773static int
1774channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1775{
1776 char buf[CHAN_RBUF];
1777 int len;
1778
1779/** XXX handle drain efd, too */
1780 if (c->efd != -1) {
1781 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1782 FD_ISSET(c->efd, writeset) &&
1783 buffer_len(&c->extended) > 0) {
1784 len = write(c->efd, buffer_ptr(&c->extended),
1785 buffer_len(&c->extended));
1786 debug2("channel %d: written %d to efd %d",
1787 c->self, len, c->efd);
1788 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1789 errno == EWOULDBLOCK))
1790 return 1;
1791 if (len <= 0) {
1792 debug2("channel %d: closing write-efd %d",
1793 c->self, c->efd);
1794 channel_close_fd(&c->efd);
1795 } else {
1796 buffer_consume(&c->extended, len);
1797 c->local_consumed += len;
1798 }
1799 } else if (c->efd != -1 &&
1800 (c->extended_usage == CHAN_EXTENDED_READ ||
1801 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1802 (c->detach_close || FD_ISSET(c->efd, readset))) {
1803 len = read(c->efd, buf, sizeof(buf));
1804 debug2("channel %d: read %d from efd %d",
1805 c->self, len, c->efd);
1806 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1807 errno == EWOULDBLOCK) && !c->detach_close)))
1808 return 1;
1809 if (len <= 0) {
1810 debug2("channel %d: closing read-efd %d",
1811 c->self, c->efd);
1812 channel_close_fd(&c->efd);
1813 } else {
1814 if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1815 debug3("channel %d: discard efd",
1816 c->self);
1817 } else
1818 buffer_append(&c->extended, buf, len);
1819 }
1820 }
1821 }
1822 return 1;
1823}
1824
1825static int
1826channel_check_window(Channel *c)
1827{
1828 if (c->type == SSH_CHANNEL_OPEN &&
1829 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1830 ((c->local_window_max - c->local_window >
1831 c->local_maxpacket*3) ||
1832 c->local_window < c->local_window_max/2) &&
1833 c->local_consumed > 0) {
1834 u_int addition = 0;
1835
1836 /* Adjust max window size if we are in a dynamic environment. */
1837 if (c->dynamic_window && c->tcpwinsz > c->local_window_max) {
1838 /*
1839 * Grow the window somewhat aggressively to maintain
1840 * pressure.
1841 */
1842 addition = 1.5 * (c->tcpwinsz - c->local_window_max);
1843 c->local_window_max += addition;
1844 }
1845 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1846 packet_put_int(c->remote_id);
1847 packet_put_int(c->local_consumed + addition);
1848 packet_send();
1849 debug2("channel %d: window %d sent adjust %d",
1850 c->self, c->local_window,
1851 c->local_consumed);
1852 c->local_window += c->local_consumed + addition;
1853 c->local_consumed = 0;
1854 }
1855 return 1;
1856}
1857
1858static void
1859channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1860{
1861 channel_handle_rfd(c, readset, writeset);
1862 channel_handle_wfd(c, readset, writeset);
1863 if (!compat20)
1864 return;
1865 channel_handle_efd(c, readset, writeset);
1866 channel_check_window(c);
1867}
1868
1869static u_int
1870read_mux(Channel *c, u_int need)
1871{
1872 char buf[CHAN_RBUF];
1873 int len;
1874 u_int rlen;
1875
1876 if (buffer_len(&c->input) < need) {
1877 rlen = need - buffer_len(&c->input);
1878 len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1879 if (len <= 0) {
1880 if (errno != EINTR && errno != EAGAIN) {
1881 debug2("channel %d: ctl read<=0 rfd %d len %d",
1882 c->self, c->rfd, len);
1883 chan_read_failed(c);
1884 return 0;
1885 }
1886 } else
1887 buffer_append(&c->input, buf, len);
1888 }
1889 return buffer_len(&c->input);
1890}
1891
1892static void
1893channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1894{
1895 u_int need;
1896 ssize_t len;
1897
1898 if (!compat20)
1899 fatal("%s: entered with !compat20", __func__);
1900
1901 if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1902 (c->istate == CHAN_INPUT_OPEN ||
1903 c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1904 /*
1905 * Don't not read past the precise end of packets to
1906 * avoid disrupting fd passing.
1907 */
1908 if (read_mux(c, 4) < 4) /* read header */
1909 return;
1910 need = get_u32(buffer_ptr(&c->input));
1911#define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1912 if (need > CHANNEL_MUX_MAX_PACKET) {
1913 debug2("channel %d: packet too big %u > %u",
1914 c->self, CHANNEL_MUX_MAX_PACKET, need);
1915 chan_rcvd_oclose(c);
1916 return;
1917 }
1918 if (read_mux(c, need + 4) < need + 4) /* read body */
1919 return;
1920 if (c->mux_rcb(c) != 0) {
1921 debug("channel %d: mux_rcb failed", c->self);
1922 chan_mark_dead(c);
1923 return;
1924 }
1925 }
1926
1927 if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1928 buffer_len(&c->output) > 0) {
1929 len = write(c->wfd, buffer_ptr(&c->output),
1930 buffer_len(&c->output));
1931 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1932 return;
1933 if (len <= 0) {
1934 chan_mark_dead(c);
1935 return;
1936 }
1937 buffer_consume(&c->output, len);
1938 }
1939}
1940
1941static void
1942channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1943{
1944 Channel *nc;
1945 struct sockaddr_storage addr;
1946 socklen_t addrlen;
1947 int newsock;
1948 uid_t euid;
1949 gid_t egid;
1950
1951 if (!FD_ISSET(c->sock, readset))
1952 return;
1953
1954 debug("multiplexing control connection");
1955
1956 /*
1957 * Accept connection on control socket
1958 */
1959 memset(&addr, 0, sizeof(addr));
1960 addrlen = sizeof(addr);
1961 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1962 &addrlen)) == -1) {
1963 error("%s accept: %s", __func__, strerror(errno));
1964 return;
1965 }
1966
1967 if (getpeereid(newsock, &euid, &egid) < 0) {
1968 error("%s getpeereid failed: %s", __func__,
1969 strerror(errno));
1970 close(newsock);
1971 return;
1972 }
1973 if ((euid != 0) && (getuid() != euid)) {
1974 error("multiplex uid mismatch: peer euid %u != uid %u",
1975 (u_int)euid, (u_int)getuid());
1976 close(newsock);
1977 return;
1978 }
1979 nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1980 newsock, newsock, -1, c->local_window_max,
1981 c->local_maxpacket, 0, "mux-control", 1);
1982 nc->mux_rcb = c->mux_rcb;
1983 debug3("%s: new mux channel %d fd %d", __func__,
1984 nc->self, nc->sock);
1985 /* establish state */
1986 nc->mux_rcb(nc);
1987 /* mux state transitions must not elicit protocol messages */
1988 nc->flags |= CHAN_LOCAL;
1989}
1990
1991/* ARGSUSED */
1992static void
1993channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1994{
1995 int len;
1996
1997 /* Send buffered output data to the socket. */
1998 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1999 len = write(c->sock, buffer_ptr(&c->output),
2000 buffer_len(&c->output));
2001 if (len <= 0)
2002 buffer_clear(&c->output);
2003 else
2004 buffer_consume(&c->output, len);
2005 }
2006}
2007
2008static void
2009channel_handler_init_20(void)
2010{
2011 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2012 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2013 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2014 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2015 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2016 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2017 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2018 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2019 channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2020 channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2021
2022 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2023 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2024 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2025 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2026 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2027 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2028 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2029 channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2030 channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2031}
2032
2033static void
2034channel_handler_init_13(void)
2035{
2036 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2037 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
2038 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2039 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2040 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2041 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
2042 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
2043 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2044 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2045
2046 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2047 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2048 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2049 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2050 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
2051 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2052 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2053}
2054
2055static void
2056channel_handler_init_15(void)
2057{
2058 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2059 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2060 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2061 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2062 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2063 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2064 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2065
2066 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2067 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2068 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2069 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2070 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2071 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2072}
2073
2074static void
2075channel_handler_init(void)
2076{
2077 int i;
2078
2079 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
2080 channel_pre[i] = NULL;
2081 channel_post[i] = NULL;
2082 }
2083 if (compat20)
2084 channel_handler_init_20();
2085 else if (compat13)
2086 channel_handler_init_13();
2087 else
2088 channel_handler_init_15();
2089}
2090
2091/* gc dead channels */
2092static void
2093channel_garbage_collect(Channel *c)
2094{
2095 if (c == NULL)
2096 return;
2097 if (c->detach_user != NULL) {
2098 if (!chan_is_dead(c, c->detach_close))
2099 return;
2100 debug2("channel %d: gc: notify user", c->self);
2101 c->detach_user(c->self, NULL);
2102 /* if we still have a callback */
2103 if (c->detach_user != NULL)
2104 return;
2105 debug2("channel %d: gc: user detached", c->self);
2106 }
2107 if (!chan_is_dead(c, 1))
2108 return;
2109 debug2("channel %d: garbage collecting", c->self);
2110 channel_free(c);
2111}
2112
2113static void
2114channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
2115{
2116 static int did_init = 0;
2117 u_int i, oalloc;
2118 Channel *c;
2119
2120 if (!did_init) {
2121 channel_handler_init();
2122 did_init = 1;
2123 }
2124 for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
2125 c = channels[i];
2126 if (c == NULL)
2127 continue;
2128 if (c->delayed) {
2129 if (ftab == channel_pre)
2130 c->delayed = 0;
2131 else
2132 continue;
2133 }
2134 if (ftab[c->type] != NULL)
2135 (*ftab[c->type])(c, readset, writeset);
2136 channel_garbage_collect(c);
2137 }
2138}
2139
2140/*
2141 * Allocate/update select bitmasks and add any bits relevant to channels in
2142 * select bitmasks.
2143 */
2144void
2145channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
2146 u_int *nallocp, int rekeying)
2147{
2148 u_int n, sz, nfdset;
2149
2150 n = MAX(*maxfdp, channel_max_fd);
2151
2152 nfdset = howmany(n+1, NFDBITS);
2153 /* Explicitly test here, because xrealloc isn't always called */
2154 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2155 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2156 sz = nfdset * sizeof(fd_mask);
2157
2158 /* perhaps check sz < nalloc/2 and shrink? */
2159 if (*readsetp == NULL || sz > *nallocp) {
2160 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2161 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
2162 *nallocp = sz;
2163 }
2164 *maxfdp = n;
2165 memset(*readsetp, 0, sz);
2166 memset(*writesetp, 0, sz);
2167
2168 if (!rekeying)
2169 channel_handler(channel_pre, *readsetp, *writesetp);
2170}
2171
2172/*
2173 * After select, perform any appropriate operations for channels which have
2174 * events pending.
2175 */
2176void
2177channel_after_select(fd_set *readset, fd_set *writeset)
2178{
2179 channel_handler(channel_post, readset, writeset);
2180}
2181
2182
2183/* If there is data to send to the connection, enqueue some of it now. */
2184void
2185channel_output_poll(void)
2186{
2187 Channel *c;
2188 u_int i, len;
2189
2190 for (i = 0; i < channels_alloc; i++) {
2191 c = channels[i];
2192 if (c == NULL)
2193 continue;
2194
2195 /*
2196 * We are only interested in channels that can have buffered
2197 * incoming data.
2198 */
2199 if (compat13) {
2200 if (c->type != SSH_CHANNEL_OPEN &&
2201 c->type != SSH_CHANNEL_INPUT_DRAINING)
2202 continue;
2203 } else {
2204 if (c->type != SSH_CHANNEL_OPEN)
2205 continue;
2206 }
2207 if (compat20 &&
2208 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2209 /* XXX is this true? */
2210 debug3("channel %d: will not send data after close", c->self);
2211 continue;
2212 }
2213
2214 /* Get the amount of buffered data for this channel. */
2215 if ((c->istate == CHAN_INPUT_OPEN ||
2216 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2217 (len = buffer_len(&c->input)) > 0) {
2218 if (c->datagram) {
2219 if (len > 0) {
2220 u_char *data;
2221 u_int dlen;
2222
2223 data = buffer_get_string(&c->input,
2224 &dlen);
2225 if (dlen > c->remote_window ||
2226 dlen > c->remote_maxpacket) {
2227 debug("channel %d: datagram "
2228 "too big for channel",
2229 c->self);
2230 xfree(data);
2231 continue;
2232 }
2233 packet_start(SSH2_MSG_CHANNEL_DATA);
2234 packet_put_int(c->remote_id);
2235 packet_put_string(data, dlen);
2236 packet_send();
2237 c->remote_window -= dlen + 4;
2238 xfree(data);
2239 }
2240 continue;
2241 }
2242 /*
2243 * Send some data for the other side over the secure
2244 * connection.
2245 */
2246 if (compat20) {
2247 if (len > c->remote_window)
2248 len = c->remote_window;
2249 if (len > c->remote_maxpacket)
2250 len = c->remote_maxpacket;
2251 } else {
2252 if (packet_is_interactive()) {
2253 if (len > 1024)
2254 len = 512;
2255 } else {
2256 /* Keep the packets at reasonable size. */
2257 if (len > packet_get_maxsize()/2)
2258 len = packet_get_maxsize()/2;
2259 }
2260 }
2261 if (len > 0) {
2262 packet_start(compat20 ?
2263 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2264 packet_put_int(c->remote_id);
2265 packet_put_string(buffer_ptr(&c->input), len);
2266 packet_send();
2267 buffer_consume(&c->input, len);
2268 c->remote_window -= len;
2269 }
2270 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2271 if (compat13)
2272 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2273 /*
2274 * input-buffer is empty and read-socket shutdown:
2275 * tell peer, that we will not send more data: send IEOF.
2276 * hack for extended data: delay EOF if EFD still in use.
2277 */
2278 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2279 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2280 c->self, c->efd, buffer_len(&c->extended));
2281 else
2282 chan_ibuf_empty(c);
2283 }
2284 /* Send extended data, i.e. stderr */
2285 if (compat20 &&
2286 !(c->flags & CHAN_EOF_SENT) &&
2287 c->remote_window > 0 &&
2288 (len = buffer_len(&c->extended)) > 0 &&
2289 c->extended_usage == CHAN_EXTENDED_READ) {
2290 debug2("channel %d: rwin %u elen %u euse %d",
2291 c->self, c->remote_window, buffer_len(&c->extended),
2292 c->extended_usage);
2293 if (len > c->remote_window)
2294 len = c->remote_window;
2295 if (len > c->remote_maxpacket)
2296 len = c->remote_maxpacket;
2297 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2298 packet_put_int(c->remote_id);
2299 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2300 packet_put_string(buffer_ptr(&c->extended), len);
2301 packet_send();
2302 buffer_consume(&c->extended, len);
2303 c->remote_window -= len;
2304 debug2("channel %d: sent ext data %d", c->self, len);
2305 }
2306 }
2307}
2308
2309
2310/* -- protocol input */
2311
2312/* ARGSUSED */
2313void
2314channel_input_data(int type, u_int32_t seq, void *ctxt)
2315{
2316 int id;
2317 char *data;
2318 u_int data_len, win_len;
2319 Channel *c;
2320
2321 /* Get the channel number and verify it. */
2322 id = packet_get_int();
2323 c = channel_lookup(id);
2324 if (c == NULL)
2325 packet_disconnect("Received data for nonexistent channel %d.", id);
2326
2327 /* Ignore any data for non-open channels (might happen on close) */
2328 if (c->type != SSH_CHANNEL_OPEN &&
2329 c->type != SSH_CHANNEL_X11_OPEN)
2330 return;
2331
2332 /* Get the data. */
2333 data = packet_get_string_ptr(&data_len);
2334 win_len = data_len;
2335 if (c->datagram)
2336 win_len += 4; /* string length header */
2337
2338 /*
2339 * Ignore data for protocol > 1.3 if output end is no longer open.
2340 * For protocol 2 the sending side is reducing its window as it sends
2341 * data, so we must 'fake' consumption of the data in order to ensure
2342 * that window updates are sent back. Otherwise the connection might
2343 * deadlock.
2344 */
2345 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2346 if (compat20) {
2347 c->local_window -= win_len;
2348 c->local_consumed += win_len;
2349 }
2350 return;
2351 }
2352
2353 if (compat20) {
2354 if (win_len > c->local_maxpacket) {
2355 logit("channel %d: rcvd big packet %d, maxpack %d",
2356 c->self, win_len, c->local_maxpacket);
2357 }
2358 if (win_len > c->local_window) {
2359 logit("channel %d: rcvd too much data %d, win %d",
2360 c->self, win_len, c->local_window);
2361 return;
2362 }
2363 c->local_window -= win_len;
2364 }
2365 if (c->datagram)
2366 buffer_put_string(&c->output, data, data_len);
2367 else
2368 buffer_append(&c->output, data, data_len);
2369 packet_check_eom();
2370}
2371
2372/* ARGSUSED */
2373void
2374channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
2375{
2376 int id;
2377 char *data;
2378 u_int data_len, tcode;
2379 Channel *c;
2380
2381 /* Get the channel number and verify it. */
2382 id = packet_get_int();
2383 c = channel_lookup(id);
2384
2385 if (c == NULL)
2386 packet_disconnect("Received extended_data for bad channel %d.", id);
2387 if (c->type != SSH_CHANNEL_OPEN) {
2388 logit("channel %d: ext data for non open", id);
2389 return;
2390 }
2391 if (c->flags & CHAN_EOF_RCVD) {
2392 if (datafellows & SSH_BUG_EXTEOF)
2393 debug("channel %d: accepting ext data after eof", id);
2394 else
2395 packet_disconnect("Received extended_data after EOF "
2396 "on channel %d.", id);
2397 }
2398 tcode = packet_get_int();
2399 if (c->efd == -1 ||
2400 c->extended_usage != CHAN_EXTENDED_WRITE ||
2401 tcode != SSH2_EXTENDED_DATA_STDERR) {
2402 logit("channel %d: bad ext data", c->self);
2403 return;
2404 }
2405 data = packet_get_string(&data_len);
2406 packet_check_eom();
2407 if (data_len > c->local_window) {
2408 logit("channel %d: rcvd too much extended_data %d, win %d",
2409 c->self, data_len, c->local_window);
2410 xfree(data);
2411 return;
2412 }
2413 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2414 c->local_window -= data_len;
2415 buffer_append(&c->extended, data, data_len);
2416 xfree(data);
2417}
2418
2419/* ARGSUSED */
2420void
2421channel_input_ieof(int type, u_int32_t seq, void *ctxt)
2422{
2423 int id;
2424 Channel *c;
2425
2426 id = packet_get_int();
2427 packet_check_eom();
2428 c = channel_lookup(id);
2429 if (c == NULL)
2430 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2431 chan_rcvd_ieof(c);
2432
2433 /* XXX force input close */
2434 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
2435 debug("channel %d: FORCE input drain", c->self);
2436 c->istate = CHAN_INPUT_WAIT_DRAIN;
2437 if (buffer_len(&c->input) == 0)
2438 chan_ibuf_empty(c);
2439 }
2440
2441}
2442
2443/* ARGSUSED */
2444void
2445channel_input_close(int type, u_int32_t seq, void *ctxt)
2446{
2447 int id;
2448 Channel *c;
2449
2450 id = packet_get_int();
2451 packet_check_eom();
2452 c = channel_lookup(id);
2453 if (c == NULL)
2454 packet_disconnect("Received close for nonexistent channel %d.", id);
2455
2456 /*
2457 * Send a confirmation that we have closed the channel and no more
2458 * data is coming for it.
2459 */
2460 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2461 packet_put_int(c->remote_id);
2462 packet_send();
2463
2464 /*
2465 * If the channel is in closed state, we have sent a close request,
2466 * and the other side will eventually respond with a confirmation.
2467 * Thus, we cannot free the channel here, because then there would be
2468 * no-one to receive the confirmation. The channel gets freed when
2469 * the confirmation arrives.
2470 */
2471 if (c->type != SSH_CHANNEL_CLOSED) {
2472 /*
2473 * Not a closed channel - mark it as draining, which will
2474 * cause it to be freed later.
2475 */
2476 buffer_clear(&c->input);
2477 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2478 }
2479}
2480
2481/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2482/* ARGSUSED */
2483void
2484channel_input_oclose(int type, u_int32_t seq, void *ctxt)
2485{
2486 int id = packet_get_int();
2487 Channel *c = channel_lookup(id);
2488
2489 packet_check_eom();
2490 if (c == NULL)
2491 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2492 chan_rcvd_oclose(c);
2493}
2494
2495/* ARGSUSED */
2496void
2497channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
2498{
2499 int id = packet_get_int();
2500 Channel *c = channel_lookup(id);
2501
2502 packet_check_eom();
2503 if (c == NULL)
2504 packet_disconnect("Received close confirmation for "
2505 "out-of-range channel %d.", id);
2506 if (c->type != SSH_CHANNEL_CLOSED)
2507 packet_disconnect("Received close confirmation for "
2508 "non-closed channel %d (type %d).", id, c->type);
2509 channel_free(c);
2510}
2511
2512/* ARGSUSED */
2513void
2514channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
2515{
2516 int id, remote_id;
2517 Channel *c;
2518
2519 id = packet_get_int();
2520 c = channel_lookup(id);
2521
2522 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2523 packet_disconnect("Received open confirmation for "
2524 "non-opening channel %d.", id);
2525 remote_id = packet_get_int();
2526 /* Record the remote channel number and mark that the channel is now open. */
2527 c->remote_id = remote_id;
2528 c->type = SSH_CHANNEL_OPEN;
2529
2530 if (compat20) {
2531 c->remote_window = packet_get_int();
2532 c->remote_maxpacket = packet_get_int();
2533 if (c->open_confirm) {
2534 debug2("callback start");
2535 c->open_confirm(c->self, 1, c->open_confirm_ctx);
2536 debug2("callback done");
2537 }
2538 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2539 c->remote_window, c->remote_maxpacket);
2540 }
2541 packet_check_eom();
2542}
2543
2544static char *
2545reason2txt(int reason)
2546{
2547 switch (reason) {
2548 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2549 return "administratively prohibited";
2550 case SSH2_OPEN_CONNECT_FAILED:
2551 return "connect failed";
2552 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2553 return "unknown channel type";
2554 case SSH2_OPEN_RESOURCE_SHORTAGE:
2555 return "resource shortage";
2556 }
2557 return "unknown reason";
2558}
2559
2560/* ARGSUSED */
2561void
2562channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
2563{
2564 int id, reason;
2565 char *msg = NULL, *lang = NULL;
2566 Channel *c;
2567
2568 id = packet_get_int();
2569 c = channel_lookup(id);
2570
2571 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2572 packet_disconnect("Received open failure for "
2573 "non-opening channel %d.", id);
2574 if (compat20) {
2575 reason = packet_get_int();
2576 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2577 msg = packet_get_string(NULL);
2578 lang = packet_get_string(NULL);
2579 }
2580 logit("channel %d: open failed: %s%s%s", id,
2581 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2582 if (msg != NULL)
2583 xfree(msg);
2584 if (lang != NULL)
2585 xfree(lang);
2586 if (c->open_confirm) {
2587 debug2("callback start");
2588 c->open_confirm(c->self, 0, c->open_confirm_ctx);
2589 debug2("callback done");
2590 }
2591 }
2592 packet_check_eom();
2593 /* Schedule the channel for cleanup/deletion. */
2594 chan_mark_dead(c);
2595}
2596
2597/* ARGSUSED */
2598void
2599channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
2600{
2601 Channel *c;
2602 int id;
2603 u_int adjust;
2604
2605 if (!compat20)
2606 return;
2607
2608 /* Get the channel number and verify it. */
2609 id = packet_get_int();
2610 c = channel_lookup(id);
2611
2612 if (c == NULL) {
2613 logit("Received window adjust for non-open channel %d.", id);
2614 return;
2615 }
2616 adjust = packet_get_int();
2617 packet_check_eom();
2618 debug2("channel %d: rcvd adjust %u", id, adjust);
2619 c->remote_window += adjust;
2620}
2621
2622/* ARGSUSED */
2623void
2624channel_input_port_open(int type, u_int32_t seq, void *ctxt)
2625{
2626 Channel *c = NULL;
2627 u_short host_port;
2628 char *host, *originator_string;
2629 int remote_id;
2630
2631 remote_id = packet_get_int();
2632 host = packet_get_string(NULL);
2633 host_port = packet_get_int();
2634
2635 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2636 originator_string = packet_get_string(NULL);
2637 } else {
2638 originator_string = xstrdup("unknown (remote did not supply name)");
2639 }
2640 packet_check_eom();
2641 c = channel_connect_to(host, host_port,
2642 "connected socket", originator_string);
2643 xfree(originator_string);
2644 xfree(host);
2645 if (c == NULL) {
2646 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2647 packet_put_int(remote_id);
2648 packet_send();
2649 } else
2650 c->remote_id = remote_id;
2651}
2652
2653/* ARGSUSED */
2654void
2655channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2656{
2657 Channel *c;
2658 struct channel_confirm *cc;
2659 int id;
2660
2661 /* Reset keepalive timeout */
2662 packet_set_alive_timeouts(0);
2663
2664 id = packet_get_int();
2665 packet_check_eom();
2666
2667 debug2("channel_input_status_confirm: type %d id %d", type, id);
2668
2669 if ((c = channel_lookup(id)) == NULL) {
2670 logit("channel_input_status_confirm: %d: unknown", id);
2671 return;
2672 }
2673 ;
2674 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2675 return;
2676 cc->cb(type, c, cc->ctx);
2677 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2678 bzero(cc, sizeof(*cc));
2679 xfree(cc);
2680}
2681
2682/* -- tcp forwarding */
2683
2684void
2685channel_set_af(int af)
2686{
2687 IPv4or6 = af;
2688}
2689
| 858 if (c->istate == CHAN_INPUT_OPEN &&
859 limit > 0 &&
860 buffer_len(&c->input) < limit &&
861 buffer_check_alloc(&c->input, CHAN_RBUF))
862 FD_SET(c->rfd, readset);
863 if (c->ostate == CHAN_OUTPUT_OPEN ||
864 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
865 if (buffer_len(&c->output) > 0) {
866 FD_SET(c->wfd, writeset);
867 } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
868 if (CHANNEL_EFD_OUTPUT_ACTIVE(c))
869 debug2("channel %d: obuf_empty delayed efd %d/(%d)",
870 c->self, c->efd, buffer_len(&c->extended));
871 else
872 chan_obuf_empty(c);
873 }
874 }
875 /** XXX check close conditions, too */
876 if (compat20 && c->efd != -1 &&
877 !(c->istate == CHAN_INPUT_CLOSED && c->ostate == CHAN_OUTPUT_CLOSED)) {
878 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
879 buffer_len(&c->extended) > 0)
880 FD_SET(c->efd, writeset);
881 else if (c->efd != -1 && !(c->flags & CHAN_EOF_SENT) &&
882 (c->extended_usage == CHAN_EXTENDED_READ ||
883 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
884 buffer_len(&c->extended) < c->remote_window)
885 FD_SET(c->efd, readset);
886 }
887 /* XXX: What about efd? races? */
888}
889
890/* ARGSUSED */
891static void
892channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
893{
894 if (buffer_len(&c->input) == 0) {
895 packet_start(SSH_MSG_CHANNEL_CLOSE);
896 packet_put_int(c->remote_id);
897 packet_send();
898 c->type = SSH_CHANNEL_CLOSED;
899 debug2("channel %d: closing after input drain.", c->self);
900 }
901}
902
903/* ARGSUSED */
904static void
905channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
906{
907 if (buffer_len(&c->output) == 0)
908 chan_mark_dead(c);
909 else
910 FD_SET(c->sock, writeset);
911}
912
913/*
914 * This is a special state for X11 authentication spoofing. An opened X11
915 * connection (when authentication spoofing is being done) remains in this
916 * state until the first packet has been completely read. The authentication
917 * data in that packet is then substituted by the real data if it matches the
918 * fake data, and the channel is put into normal mode.
919 * XXX All this happens at the client side.
920 * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok
921 */
922static int
923x11_open_helper(Buffer *b)
924{
925 u_char *ucp;
926 u_int proto_len, data_len;
927
928 /* Check if the fixed size part of the packet is in buffer. */
929 if (buffer_len(b) < 12)
930 return 0;
931
932 /* Parse the lengths of variable-length fields. */
933 ucp = buffer_ptr(b);
934 if (ucp[0] == 0x42) { /* Byte order MSB first. */
935 proto_len = 256 * ucp[6] + ucp[7];
936 data_len = 256 * ucp[8] + ucp[9];
937 } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */
938 proto_len = ucp[6] + 256 * ucp[7];
939 data_len = ucp[8] + 256 * ucp[9];
940 } else {
941 debug2("Initial X11 packet contains bad byte order byte: 0x%x",
942 ucp[0]);
943 return -1;
944 }
945
946 /* Check if the whole packet is in buffer. */
947 if (buffer_len(b) <
948 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3))
949 return 0;
950
951 /* Check if authentication protocol matches. */
952 if (proto_len != strlen(x11_saved_proto) ||
953 memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) {
954 debug2("X11 connection uses different authentication protocol.");
955 return -1;
956 }
957 /* Check if authentication data matches our fake data. */
958 if (data_len != x11_fake_data_len ||
959 timingsafe_bcmp(ucp + 12 + ((proto_len + 3) & ~3),
960 x11_fake_data, x11_fake_data_len) != 0) {
961 debug2("X11 auth data does not match fake data.");
962 return -1;
963 }
964 /* Check fake data length */
965 if (x11_fake_data_len != x11_saved_data_len) {
966 error("X11 fake_data_len %d != saved_data_len %d",
967 x11_fake_data_len, x11_saved_data_len);
968 return -1;
969 }
970 /*
971 * Received authentication protocol and data match
972 * our fake data. Substitute the fake data with real
973 * data.
974 */
975 memcpy(ucp + 12 + ((proto_len + 3) & ~3),
976 x11_saved_data, x11_saved_data_len);
977 return 1;
978}
979
980static void
981channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
982{
983 int ret = x11_open_helper(&c->output);
984
985 if (ret == 1) {
986 /* Start normal processing for the channel. */
987 c->type = SSH_CHANNEL_OPEN;
988 channel_pre_open_13(c, readset, writeset);
989 } else if (ret == -1) {
990 /*
991 * We have received an X11 connection that has bad
992 * authentication information.
993 */
994 logit("X11 connection rejected because of wrong authentication.");
995 buffer_clear(&c->input);
996 buffer_clear(&c->output);
997 channel_close_fd(&c->sock);
998 c->sock = -1;
999 c->type = SSH_CHANNEL_CLOSED;
1000 packet_start(SSH_MSG_CHANNEL_CLOSE);
1001 packet_put_int(c->remote_id);
1002 packet_send();
1003 }
1004}
1005
1006static void
1007channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
1008{
1009 int ret = x11_open_helper(&c->output);
1010
1011 /* c->force_drain = 1; */
1012
1013 if (ret == 1) {
1014 c->type = SSH_CHANNEL_OPEN;
1015 channel_pre_open(c, readset, writeset);
1016 } else if (ret == -1) {
1017 logit("X11 connection rejected because of wrong authentication.");
1018 debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
1019 chan_read_failed(c);
1020 buffer_clear(&c->input);
1021 chan_ibuf_empty(c);
1022 buffer_clear(&c->output);
1023 /* for proto v1, the peer will send an IEOF */
1024 if (compat20)
1025 chan_write_failed(c);
1026 else
1027 c->type = SSH_CHANNEL_OPEN;
1028 debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
1029 }
1030}
1031
1032static void
1033channel_pre_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1034{
1035 if (c->istate == CHAN_INPUT_OPEN && !c->mux_pause &&
1036 buffer_check_alloc(&c->input, CHAN_RBUF))
1037 FD_SET(c->rfd, readset);
1038 if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
1039 /* clear buffer immediately (discard any partial packet) */
1040 buffer_clear(&c->input);
1041 chan_ibuf_empty(c);
1042 /* Start output drain. XXX just kill chan? */
1043 chan_rcvd_oclose(c);
1044 }
1045 if (c->ostate == CHAN_OUTPUT_OPEN ||
1046 c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
1047 if (buffer_len(&c->output) > 0)
1048 FD_SET(c->wfd, writeset);
1049 else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN)
1050 chan_obuf_empty(c);
1051 }
1052}
1053
1054/* try to decode a socks4 header */
1055/* ARGSUSED */
1056static int
1057channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
1058{
1059 char *p, *host;
1060 u_int len, have, i, found, need;
1061 char username[256];
1062 struct {
1063 u_int8_t version;
1064 u_int8_t command;
1065 u_int16_t dest_port;
1066 struct in_addr dest_addr;
1067 } s4_req, s4_rsp;
1068
1069 debug2("channel %d: decode socks4", c->self);
1070
1071 have = buffer_len(&c->input);
1072 len = sizeof(s4_req);
1073 if (have < len)
1074 return 0;
1075 p = buffer_ptr(&c->input);
1076
1077 need = 1;
1078 /* SOCKS4A uses an invalid IP address 0.0.0.x */
1079 if (p[4] == 0 && p[5] == 0 && p[6] == 0 && p[7] != 0) {
1080 debug2("channel %d: socks4a request", c->self);
1081 /* ... and needs an extra string (the hostname) */
1082 need = 2;
1083 }
1084 /* Check for terminating NUL on the string(s) */
1085 for (found = 0, i = len; i < have; i++) {
1086 if (p[i] == '\0') {
1087 found++;
1088 if (found == need)
1089 break;
1090 }
1091 if (i > 1024) {
1092 /* the peer is probably sending garbage */
1093 debug("channel %d: decode socks4: too long",
1094 c->self);
1095 return -1;
1096 }
1097 }
1098 if (found < need)
1099 return 0;
1100 buffer_get(&c->input, (char *)&s4_req.version, 1);
1101 buffer_get(&c->input, (char *)&s4_req.command, 1);
1102 buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
1103 buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
1104 have = buffer_len(&c->input);
1105 p = buffer_ptr(&c->input);
1106 len = strlen(p);
1107 debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
1108 len++; /* trailing '\0' */
1109 if (len > have)
1110 fatal("channel %d: decode socks4: len %d > have %d",
1111 c->self, len, have);
1112 strlcpy(username, p, sizeof(username));
1113 buffer_consume(&c->input, len);
1114
1115 if (c->path != NULL) {
1116 xfree(c->path);
1117 c->path = NULL;
1118 }
1119 if (need == 1) { /* SOCKS4: one string */
1120 host = inet_ntoa(s4_req.dest_addr);
1121 c->path = xstrdup(host);
1122 } else { /* SOCKS4A: two strings */
1123 have = buffer_len(&c->input);
1124 p = buffer_ptr(&c->input);
1125 len = strlen(p);
1126 debug2("channel %d: decode socks4a: host %s/%d",
1127 c->self, p, len);
1128 len++; /* trailing '\0' */
1129 if (len > have)
1130 fatal("channel %d: decode socks4a: len %d > have %d",
1131 c->self, len, have);
1132 if (len > NI_MAXHOST) {
1133 error("channel %d: hostname \"%.100s\" too long",
1134 c->self, p);
1135 return -1;
1136 }
1137 c->path = xstrdup(p);
1138 buffer_consume(&c->input, len);
1139 }
1140 c->host_port = ntohs(s4_req.dest_port);
1141
1142 debug2("channel %d: dynamic request: socks4 host %s port %u command %u",
1143 c->self, c->path, c->host_port, s4_req.command);
1144
1145 if (s4_req.command != 1) {
1146 debug("channel %d: cannot handle: %s cn %d",
1147 c->self, need == 1 ? "SOCKS4" : "SOCKS4A", s4_req.command);
1148 return -1;
1149 }
1150 s4_rsp.version = 0; /* vn: 0 for reply */
1151 s4_rsp.command = 90; /* cd: req granted */
1152 s4_rsp.dest_port = 0; /* ignored */
1153 s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
1154 buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
1155 return 1;
1156}
1157
1158/* try to decode a socks5 header */
1159#define SSH_SOCKS5_AUTHDONE 0x1000
1160#define SSH_SOCKS5_NOAUTH 0x00
1161#define SSH_SOCKS5_IPV4 0x01
1162#define SSH_SOCKS5_DOMAIN 0x03
1163#define SSH_SOCKS5_IPV6 0x04
1164#define SSH_SOCKS5_CONNECT 0x01
1165#define SSH_SOCKS5_SUCCESS 0x00
1166
1167/* ARGSUSED */
1168static int
1169channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
1170{
1171 struct {
1172 u_int8_t version;
1173 u_int8_t command;
1174 u_int8_t reserved;
1175 u_int8_t atyp;
1176 } s5_req, s5_rsp;
1177 u_int16_t dest_port;
1178 u_char *p, dest_addr[255+1], ntop[INET6_ADDRSTRLEN];
1179 u_int have, need, i, found, nmethods, addrlen, af;
1180
1181 debug2("channel %d: decode socks5", c->self);
1182 p = buffer_ptr(&c->input);
1183 if (p[0] != 0x05)
1184 return -1;
1185 have = buffer_len(&c->input);
1186 if (!(c->flags & SSH_SOCKS5_AUTHDONE)) {
1187 /* format: ver | nmethods | methods */
1188 if (have < 2)
1189 return 0;
1190 nmethods = p[1];
1191 if (have < nmethods + 2)
1192 return 0;
1193 /* look for method: "NO AUTHENTICATION REQUIRED" */
1194 for (found = 0, i = 2; i < nmethods + 2; i++) {
1195 if (p[i] == SSH_SOCKS5_NOAUTH) {
1196 found = 1;
1197 break;
1198 }
1199 }
1200 if (!found) {
1201 debug("channel %d: method SSH_SOCKS5_NOAUTH not found",
1202 c->self);
1203 return -1;
1204 }
1205 buffer_consume(&c->input, nmethods + 2);
1206 buffer_put_char(&c->output, 0x05); /* version */
1207 buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */
1208 FD_SET(c->sock, writeset);
1209 c->flags |= SSH_SOCKS5_AUTHDONE;
1210 debug2("channel %d: socks5 auth done", c->self);
1211 return 0; /* need more */
1212 }
1213 debug2("channel %d: socks5 post auth", c->self);
1214 if (have < sizeof(s5_req)+1)
1215 return 0; /* need more */
1216 memcpy(&s5_req, p, sizeof(s5_req));
1217 if (s5_req.version != 0x05 ||
1218 s5_req.command != SSH_SOCKS5_CONNECT ||
1219 s5_req.reserved != 0x00) {
1220 debug2("channel %d: only socks5 connect supported", c->self);
1221 return -1;
1222 }
1223 switch (s5_req.atyp){
1224 case SSH_SOCKS5_IPV4:
1225 addrlen = 4;
1226 af = AF_INET;
1227 break;
1228 case SSH_SOCKS5_DOMAIN:
1229 addrlen = p[sizeof(s5_req)];
1230 af = -1;
1231 break;
1232 case SSH_SOCKS5_IPV6:
1233 addrlen = 16;
1234 af = AF_INET6;
1235 break;
1236 default:
1237 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
1238 return -1;
1239 }
1240 need = sizeof(s5_req) + addrlen + 2;
1241 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1242 need++;
1243 if (have < need)
1244 return 0;
1245 buffer_consume(&c->input, sizeof(s5_req));
1246 if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
1247 buffer_consume(&c->input, 1); /* host string length */
1248 buffer_get(&c->input, (char *)&dest_addr, addrlen);
1249 buffer_get(&c->input, (char *)&dest_port, 2);
1250 dest_addr[addrlen] = '\0';
1251 if (c->path != NULL) {
1252 xfree(c->path);
1253 c->path = NULL;
1254 }
1255 if (s5_req.atyp == SSH_SOCKS5_DOMAIN) {
1256 if (addrlen >= NI_MAXHOST) {
1257 error("channel %d: dynamic request: socks5 hostname "
1258 "\"%.100s\" too long", c->self, dest_addr);
1259 return -1;
1260 }
1261 c->path = xstrdup(dest_addr);
1262 } else {
1263 if (inet_ntop(af, dest_addr, ntop, sizeof(ntop)) == NULL)
1264 return -1;
1265 c->path = xstrdup(ntop);
1266 }
1267 c->host_port = ntohs(dest_port);
1268
1269 debug2("channel %d: dynamic request: socks5 host %s port %u command %u",
1270 c->self, c->path, c->host_port, s5_req.command);
1271
1272 s5_rsp.version = 0x05;
1273 s5_rsp.command = SSH_SOCKS5_SUCCESS;
1274 s5_rsp.reserved = 0; /* ignored */
1275 s5_rsp.atyp = SSH_SOCKS5_IPV4;
1276 ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
1277 dest_port = 0; /* ignored */
1278
1279 buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
1280 buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
1281 buffer_append(&c->output, &dest_port, sizeof(dest_port));
1282 return 1;
1283}
1284
1285Channel *
1286channel_connect_stdio_fwd(const char *host_to_connect, u_short port_to_connect,
1287 int in, int out)
1288{
1289 Channel *c;
1290
1291 debug("channel_connect_stdio_fwd %s:%d", host_to_connect,
1292 port_to_connect);
1293
1294 c = channel_new("stdio-forward", SSH_CHANNEL_OPENING, in, out,
1295 -1, CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1296 0, "stdio-forward", /*nonblock*/0);
1297
1298 c->path = xstrdup(host_to_connect);
1299 c->host_port = port_to_connect;
1300 c->listening_port = 0;
1301 c->force_drain = 1;
1302
1303 channel_register_fds(c, in, out, -1, 0, 1, 0);
1304 port_open_helper(c, "direct-tcpip");
1305
1306 return c;
1307}
1308
1309/* dynamic port forwarding */
1310static void
1311channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
1312{
1313 u_char *p;
1314 u_int have;
1315 int ret;
1316
1317 have = buffer_len(&c->input);
1318 debug2("channel %d: pre_dynamic: have %d", c->self, have);
1319 /* buffer_dump(&c->input); */
1320 /* check if the fixed size part of the packet is in buffer. */
1321 if (have < 3) {
1322 /* need more */
1323 FD_SET(c->sock, readset);
1324 return;
1325 }
1326 /* try to guess the protocol */
1327 p = buffer_ptr(&c->input);
1328 switch (p[0]) {
1329 case 0x04:
1330 ret = channel_decode_socks4(c, readset, writeset);
1331 break;
1332 case 0x05:
1333 ret = channel_decode_socks5(c, readset, writeset);
1334 break;
1335 default:
1336 ret = -1;
1337 break;
1338 }
1339 if (ret < 0) {
1340 chan_mark_dead(c);
1341 } else if (ret == 0) {
1342 debug2("channel %d: pre_dynamic: need more", c->self);
1343 /* need more */
1344 FD_SET(c->sock, readset);
1345 } else {
1346 /* switch to the next state */
1347 c->type = SSH_CHANNEL_OPENING;
1348 port_open_helper(c, "direct-tcpip");
1349 }
1350}
1351
1352/* This is our fake X11 server socket. */
1353/* ARGSUSED */
1354static void
1355channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
1356{
1357 Channel *nc;
1358 struct sockaddr_storage addr;
1359 int newsock;
1360 socklen_t addrlen;
1361 char buf[16384], *remote_ipaddr;
1362 int remote_port;
1363
1364 if (FD_ISSET(c->sock, readset)) {
1365 debug("X11 connection requested.");
1366 addrlen = sizeof(addr);
1367 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1368 if (c->single_connection) {
1369 debug2("single_connection: closing X11 listener.");
1370 channel_close_fd(&c->sock);
1371 chan_mark_dead(c);
1372 }
1373 if (newsock < 0) {
1374 error("accept: %.100s", strerror(errno));
1375 return;
1376 }
1377 set_nodelay(newsock);
1378 remote_ipaddr = get_peer_ipaddr(newsock);
1379 remote_port = get_peer_port(newsock);
1380 snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
1381 remote_ipaddr, remote_port);
1382
1383 nc = channel_new("accepted x11 socket",
1384 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1385 c->local_window_max, c->local_maxpacket, 0, buf, 1);
1386 if (compat20) {
1387 packet_start(SSH2_MSG_CHANNEL_OPEN);
1388 packet_put_cstring("x11");
1389 packet_put_int(nc->self);
1390 packet_put_int(nc->local_window_max);
1391 packet_put_int(nc->local_maxpacket);
1392 /* originator ipaddr and port */
1393 packet_put_cstring(remote_ipaddr);
1394 if (datafellows & SSH_BUG_X11FWD) {
1395 debug2("ssh2 x11 bug compat mode");
1396 } else {
1397 packet_put_int(remote_port);
1398 }
1399 packet_send();
1400 } else {
1401 packet_start(SSH_SMSG_X11_OPEN);
1402 packet_put_int(nc->self);
1403 if (packet_get_protocol_flags() &
1404 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1405 packet_put_cstring(buf);
1406 packet_send();
1407 }
1408 xfree(remote_ipaddr);
1409 }
1410}
1411
1412static void
1413port_open_helper(Channel *c, char *rtype)
1414{
1415 int direct;
1416 char buf[1024];
1417 char *remote_ipaddr = get_peer_ipaddr(c->sock);
1418 int remote_port = get_peer_port(c->sock);
1419
1420 if (remote_port == -1) {
1421 /* Fake addr/port to appease peers that validate it (Tectia) */
1422 xfree(remote_ipaddr);
1423 remote_ipaddr = xstrdup("127.0.0.1");
1424 remote_port = 65535;
1425 }
1426
1427 direct = (strcmp(rtype, "direct-tcpip") == 0);
1428
1429 snprintf(buf, sizeof buf,
1430 "%s: listening port %d for %.100s port %d, "
1431 "connect from %.200s port %d",
1432 rtype, c->listening_port, c->path, c->host_port,
1433 remote_ipaddr, remote_port);
1434
1435 xfree(c->remote_name);
1436 c->remote_name = xstrdup(buf);
1437
1438 if (compat20) {
1439 packet_start(SSH2_MSG_CHANNEL_OPEN);
1440 packet_put_cstring(rtype);
1441 packet_put_int(c->self);
1442 packet_put_int(c->local_window_max);
1443 packet_put_int(c->local_maxpacket);
1444 if (direct) {
1445 /* target host, port */
1446 packet_put_cstring(c->path);
1447 packet_put_int(c->host_port);
1448 } else {
1449 /* listen address, port */
1450 packet_put_cstring(c->path);
1451 packet_put_int(c->listening_port);
1452 }
1453 /* originator host and port */
1454 packet_put_cstring(remote_ipaddr);
1455 packet_put_int((u_int)remote_port);
1456 packet_send();
1457 } else {
1458 packet_start(SSH_MSG_PORT_OPEN);
1459 packet_put_int(c->self);
1460 packet_put_cstring(c->path);
1461 packet_put_int(c->host_port);
1462 if (packet_get_protocol_flags() &
1463 SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
1464 packet_put_cstring(c->remote_name);
1465 packet_send();
1466 }
1467 xfree(remote_ipaddr);
1468}
1469
1470static void
1471channel_set_reuseaddr(int fd)
1472{
1473 int on = 1;
1474
1475 /*
1476 * Set socket options.
1477 * Allow local port reuse in TIME_WAIT.
1478 */
1479 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1)
1480 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));
1481}
1482
1483/*
1484 * This socket is listening for connections to a forwarded TCP/IP port.
1485 */
1486/* ARGSUSED */
1487static void
1488channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
1489{
1490 Channel *nc;
1491 struct sockaddr_storage addr;
1492 int newsock, nextstate;
1493 socklen_t addrlen;
1494 char *rtype;
1495
1496 if (FD_ISSET(c->sock, readset)) {
1497 debug("Connection to port %d forwarding "
1498 "to %.100s port %d requested.",
1499 c->listening_port, c->path, c->host_port);
1500
1501 if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
1502 nextstate = SSH_CHANNEL_OPENING;
1503 rtype = "forwarded-tcpip";
1504 } else {
1505 if (c->host_port == 0) {
1506 nextstate = SSH_CHANNEL_DYNAMIC;
1507 rtype = "dynamic-tcpip";
1508 } else {
1509 nextstate = SSH_CHANNEL_OPENING;
1510 rtype = "direct-tcpip";
1511 }
1512 }
1513
1514 addrlen = sizeof(addr);
1515 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1516 if (newsock < 0) {
1517 error("accept: %.100s", strerror(errno));
1518 return;
1519 }
1520 set_nodelay(newsock);
1521 nc = channel_new(rtype, nextstate, newsock, newsock, -1,
1522 c->local_window_max, c->local_maxpacket, 0, rtype, 1);
1523 nc->listening_port = c->listening_port;
1524 nc->host_port = c->host_port;
1525 if (c->path != NULL)
1526 nc->path = xstrdup(c->path);
1527
1528 if (nextstate != SSH_CHANNEL_DYNAMIC)
1529 port_open_helper(nc, rtype);
1530 }
1531}
1532
1533/*
1534 * This is the authentication agent socket listening for connections from
1535 * clients.
1536 */
1537/* ARGSUSED */
1538static void
1539channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
1540{
1541 Channel *nc;
1542 int newsock;
1543 struct sockaddr_storage addr;
1544 socklen_t addrlen;
1545
1546 if (FD_ISSET(c->sock, readset)) {
1547 addrlen = sizeof(addr);
1548 newsock = accept(c->sock, (struct sockaddr *)&addr, &addrlen);
1549 if (newsock < 0) {
1550 error("accept from auth socket: %.100s", strerror(errno));
1551 return;
1552 }
1553 nc = channel_new("accepted auth socket",
1554 SSH_CHANNEL_OPENING, newsock, newsock, -1,
1555 c->local_window_max, c->local_maxpacket,
1556 0, "accepted auth socket", 1);
1557 if (compat20) {
1558 packet_start(SSH2_MSG_CHANNEL_OPEN);
1559 packet_put_cstring("auth-agent@openssh.com");
1560 packet_put_int(nc->self);
1561 packet_put_int(c->local_window_max);
1562 packet_put_int(c->local_maxpacket);
1563 } else {
1564 packet_start(SSH_SMSG_AGENT_OPEN);
1565 packet_put_int(nc->self);
1566 }
1567 packet_send();
1568 }
1569}
1570
1571/* ARGSUSED */
1572static void
1573channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
1574{
1575 int err = 0, sock;
1576 socklen_t sz = sizeof(err);
1577
1578 if (FD_ISSET(c->sock, writeset)) {
1579 if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) {
1580 err = errno;
1581 error("getsockopt SO_ERROR failed");
1582 }
1583 if (err == 0) {
1584 debug("channel %d: connected to %s port %d",
1585 c->self, c->connect_ctx.host, c->connect_ctx.port);
1586 channel_connect_ctx_free(&c->connect_ctx);
1587 c->type = SSH_CHANNEL_OPEN;
1588 if (compat20) {
1589 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1590 packet_put_int(c->remote_id);
1591 packet_put_int(c->self);
1592 packet_put_int(c->local_window);
1593 packet_put_int(c->local_maxpacket);
1594 } else {
1595 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
1596 packet_put_int(c->remote_id);
1597 packet_put_int(c->self);
1598 }
1599 } else {
1600 debug("channel %d: connection failed: %s",
1601 c->self, strerror(err));
1602 /* Try next address, if any */
1603 if ((sock = connect_next(&c->connect_ctx)) > 0) {
1604 close(c->sock);
1605 c->sock = c->rfd = c->wfd = sock;
1606 channel_max_fd = channel_find_maxfd();
1607 return;
1608 }
1609 /* Exhausted all addresses */
1610 error("connect_to %.100s port %d: failed.",
1611 c->connect_ctx.host, c->connect_ctx.port);
1612 channel_connect_ctx_free(&c->connect_ctx);
1613 if (compat20) {
1614 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1615 packet_put_int(c->remote_id);
1616 packet_put_int(SSH2_OPEN_CONNECT_FAILED);
1617 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1618 packet_put_cstring(strerror(err));
1619 packet_put_cstring("");
1620 }
1621 } else {
1622 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
1623 packet_put_int(c->remote_id);
1624 }
1625 chan_mark_dead(c);
1626 }
1627 packet_send();
1628 }
1629}
1630
1631/* ARGSUSED */
1632static int
1633channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
1634{
1635 char buf[CHAN_RBUF];
1636 int len, force;
1637
1638 force = c->isatty && c->detach_close && c->istate != CHAN_INPUT_CLOSED;
1639 if (c->rfd != -1 && (force || FD_ISSET(c->rfd, readset))) {
1640 errno = 0;
1641 len = read(c->rfd, buf, sizeof(buf));
1642 if (len < 0 && (errno == EINTR ||
1643 ((errno == EAGAIN || errno == EWOULDBLOCK) && !force)))
1644 return 1;
1645#ifndef PTY_ZEROREAD
1646 if (len <= 0) {
1647#else
1648 if ((!c->isatty && len <= 0) ||
1649 (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
1650#endif
1651 debug2("channel %d: read<=0 rfd %d len %d",
1652 c->self, c->rfd, len);
1653 if (c->type != SSH_CHANNEL_OPEN) {
1654 debug2("channel %d: not open", c->self);
1655 chan_mark_dead(c);
1656 return -1;
1657 } else if (compat13) {
1658 buffer_clear(&c->output);
1659 c->type = SSH_CHANNEL_INPUT_DRAINING;
1660 debug2("channel %d: input draining.", c->self);
1661 } else {
1662 chan_read_failed(c);
1663 }
1664 return -1;
1665 }
1666 if (c->input_filter != NULL) {
1667 if (c->input_filter(c, buf, len) == -1) {
1668 debug2("channel %d: filter stops", c->self);
1669 chan_read_failed(c);
1670 }
1671 } else if (c->datagram) {
1672 buffer_put_string(&c->input, buf, len);
1673 } else {
1674 buffer_append(&c->input, buf, len);
1675 }
1676 }
1677 return 1;
1678}
1679
1680/* ARGSUSED */
1681static int
1682channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
1683{
1684 struct termios tio;
1685 u_char *data = NULL, *buf;
1686 u_int dlen, olen = 0;
1687 int len;
1688
1689 /* Send buffered output data to the socket. */
1690 if (c->wfd != -1 &&
1691 FD_ISSET(c->wfd, writeset) &&
1692 buffer_len(&c->output) > 0) {
1693 olen = buffer_len(&c->output);
1694 if (c->output_filter != NULL) {
1695 if ((buf = c->output_filter(c, &data, &dlen)) == NULL) {
1696 debug2("channel %d: filter stops", c->self);
1697 if (c->type != SSH_CHANNEL_OPEN)
1698 chan_mark_dead(c);
1699 else
1700 chan_write_failed(c);
1701 return -1;
1702 }
1703 } else if (c->datagram) {
1704 buf = data = buffer_get_string(&c->output, &dlen);
1705 } else {
1706 buf = data = buffer_ptr(&c->output);
1707 dlen = buffer_len(&c->output);
1708 }
1709
1710 if (c->datagram) {
1711 /* ignore truncated writes, datagrams might get lost */
1712 len = write(c->wfd, buf, dlen);
1713 xfree(data);
1714 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1715 errno == EWOULDBLOCK))
1716 return 1;
1717 if (len <= 0) {
1718 if (c->type != SSH_CHANNEL_OPEN)
1719 chan_mark_dead(c);
1720 else
1721 chan_write_failed(c);
1722 return -1;
1723 }
1724 goto out;
1725 }
1726#ifdef _AIX
1727 /* XXX: Later AIX versions can't push as much data to tty */
1728 if (compat20 && c->wfd_isatty)
1729 dlen = MIN(dlen, 8*1024);
1730#endif
1731
1732 len = write(c->wfd, buf, dlen);
1733 if (len < 0 &&
1734 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK))
1735 return 1;
1736 if (len <= 0) {
1737 if (c->type != SSH_CHANNEL_OPEN) {
1738 debug2("channel %d: not open", c->self);
1739 chan_mark_dead(c);
1740 return -1;
1741 } else if (compat13) {
1742 buffer_clear(&c->output);
1743 debug2("channel %d: input draining.", c->self);
1744 c->type = SSH_CHANNEL_INPUT_DRAINING;
1745 } else {
1746 chan_write_failed(c);
1747 }
1748 return -1;
1749 }
1750#ifndef BROKEN_TCGETATTR_ICANON
1751 if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') {
1752 if (tcgetattr(c->wfd, &tio) == 0 &&
1753 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
1754 /*
1755 * Simulate echo to reduce the impact of
1756 * traffic analysis. We need to match the
1757 * size of a SSH2_MSG_CHANNEL_DATA message
1758 * (4 byte channel id + buf)
1759 */
1760 packet_send_ignore(4 + len);
1761 packet_send();
1762 }
1763 }
1764#endif
1765 buffer_consume(&c->output, len);
1766 }
1767 out:
1768 if (compat20 && olen > 0)
1769 c->local_consumed += olen - buffer_len(&c->output);
1770 return 1;
1771}
1772
1773static int
1774channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
1775{
1776 char buf[CHAN_RBUF];
1777 int len;
1778
1779/** XXX handle drain efd, too */
1780 if (c->efd != -1) {
1781 if (c->extended_usage == CHAN_EXTENDED_WRITE &&
1782 FD_ISSET(c->efd, writeset) &&
1783 buffer_len(&c->extended) > 0) {
1784 len = write(c->efd, buffer_ptr(&c->extended),
1785 buffer_len(&c->extended));
1786 debug2("channel %d: written %d to efd %d",
1787 c->self, len, c->efd);
1788 if (len < 0 && (errno == EINTR || errno == EAGAIN ||
1789 errno == EWOULDBLOCK))
1790 return 1;
1791 if (len <= 0) {
1792 debug2("channel %d: closing write-efd %d",
1793 c->self, c->efd);
1794 channel_close_fd(&c->efd);
1795 } else {
1796 buffer_consume(&c->extended, len);
1797 c->local_consumed += len;
1798 }
1799 } else if (c->efd != -1 &&
1800 (c->extended_usage == CHAN_EXTENDED_READ ||
1801 c->extended_usage == CHAN_EXTENDED_IGNORE) &&
1802 (c->detach_close || FD_ISSET(c->efd, readset))) {
1803 len = read(c->efd, buf, sizeof(buf));
1804 debug2("channel %d: read %d from efd %d",
1805 c->self, len, c->efd);
1806 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
1807 errno == EWOULDBLOCK) && !c->detach_close)))
1808 return 1;
1809 if (len <= 0) {
1810 debug2("channel %d: closing read-efd %d",
1811 c->self, c->efd);
1812 channel_close_fd(&c->efd);
1813 } else {
1814 if (c->extended_usage == CHAN_EXTENDED_IGNORE) {
1815 debug3("channel %d: discard efd",
1816 c->self);
1817 } else
1818 buffer_append(&c->extended, buf, len);
1819 }
1820 }
1821 }
1822 return 1;
1823}
1824
1825static int
1826channel_check_window(Channel *c)
1827{
1828 if (c->type == SSH_CHANNEL_OPEN &&
1829 !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
1830 ((c->local_window_max - c->local_window >
1831 c->local_maxpacket*3) ||
1832 c->local_window < c->local_window_max/2) &&
1833 c->local_consumed > 0) {
1834 u_int addition = 0;
1835
1836 /* Adjust max window size if we are in a dynamic environment. */
1837 if (c->dynamic_window && c->tcpwinsz > c->local_window_max) {
1838 /*
1839 * Grow the window somewhat aggressively to maintain
1840 * pressure.
1841 */
1842 addition = 1.5 * (c->tcpwinsz - c->local_window_max);
1843 c->local_window_max += addition;
1844 }
1845 packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
1846 packet_put_int(c->remote_id);
1847 packet_put_int(c->local_consumed + addition);
1848 packet_send();
1849 debug2("channel %d: window %d sent adjust %d",
1850 c->self, c->local_window,
1851 c->local_consumed);
1852 c->local_window += c->local_consumed + addition;
1853 c->local_consumed = 0;
1854 }
1855 return 1;
1856}
1857
1858static void
1859channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
1860{
1861 channel_handle_rfd(c, readset, writeset);
1862 channel_handle_wfd(c, readset, writeset);
1863 if (!compat20)
1864 return;
1865 channel_handle_efd(c, readset, writeset);
1866 channel_check_window(c);
1867}
1868
1869static u_int
1870read_mux(Channel *c, u_int need)
1871{
1872 char buf[CHAN_RBUF];
1873 int len;
1874 u_int rlen;
1875
1876 if (buffer_len(&c->input) < need) {
1877 rlen = need - buffer_len(&c->input);
1878 len = read(c->rfd, buf, MIN(rlen, CHAN_RBUF));
1879 if (len <= 0) {
1880 if (errno != EINTR && errno != EAGAIN) {
1881 debug2("channel %d: ctl read<=0 rfd %d len %d",
1882 c->self, c->rfd, len);
1883 chan_read_failed(c);
1884 return 0;
1885 }
1886 } else
1887 buffer_append(&c->input, buf, len);
1888 }
1889 return buffer_len(&c->input);
1890}
1891
1892static void
1893channel_post_mux_client(Channel *c, fd_set *readset, fd_set *writeset)
1894{
1895 u_int need;
1896 ssize_t len;
1897
1898 if (!compat20)
1899 fatal("%s: entered with !compat20", __func__);
1900
1901 if (c->rfd != -1 && !c->mux_pause && FD_ISSET(c->rfd, readset) &&
1902 (c->istate == CHAN_INPUT_OPEN ||
1903 c->istate == CHAN_INPUT_WAIT_DRAIN)) {
1904 /*
1905 * Don't not read past the precise end of packets to
1906 * avoid disrupting fd passing.
1907 */
1908 if (read_mux(c, 4) < 4) /* read header */
1909 return;
1910 need = get_u32(buffer_ptr(&c->input));
1911#define CHANNEL_MUX_MAX_PACKET (256 * 1024)
1912 if (need > CHANNEL_MUX_MAX_PACKET) {
1913 debug2("channel %d: packet too big %u > %u",
1914 c->self, CHANNEL_MUX_MAX_PACKET, need);
1915 chan_rcvd_oclose(c);
1916 return;
1917 }
1918 if (read_mux(c, need + 4) < need + 4) /* read body */
1919 return;
1920 if (c->mux_rcb(c) != 0) {
1921 debug("channel %d: mux_rcb failed", c->self);
1922 chan_mark_dead(c);
1923 return;
1924 }
1925 }
1926
1927 if (c->wfd != -1 && FD_ISSET(c->wfd, writeset) &&
1928 buffer_len(&c->output) > 0) {
1929 len = write(c->wfd, buffer_ptr(&c->output),
1930 buffer_len(&c->output));
1931 if (len < 0 && (errno == EINTR || errno == EAGAIN))
1932 return;
1933 if (len <= 0) {
1934 chan_mark_dead(c);
1935 return;
1936 }
1937 buffer_consume(&c->output, len);
1938 }
1939}
1940
1941static void
1942channel_post_mux_listener(Channel *c, fd_set *readset, fd_set *writeset)
1943{
1944 Channel *nc;
1945 struct sockaddr_storage addr;
1946 socklen_t addrlen;
1947 int newsock;
1948 uid_t euid;
1949 gid_t egid;
1950
1951 if (!FD_ISSET(c->sock, readset))
1952 return;
1953
1954 debug("multiplexing control connection");
1955
1956 /*
1957 * Accept connection on control socket
1958 */
1959 memset(&addr, 0, sizeof(addr));
1960 addrlen = sizeof(addr);
1961 if ((newsock = accept(c->sock, (struct sockaddr*)&addr,
1962 &addrlen)) == -1) {
1963 error("%s accept: %s", __func__, strerror(errno));
1964 return;
1965 }
1966
1967 if (getpeereid(newsock, &euid, &egid) < 0) {
1968 error("%s getpeereid failed: %s", __func__,
1969 strerror(errno));
1970 close(newsock);
1971 return;
1972 }
1973 if ((euid != 0) && (getuid() != euid)) {
1974 error("multiplex uid mismatch: peer euid %u != uid %u",
1975 (u_int)euid, (u_int)getuid());
1976 close(newsock);
1977 return;
1978 }
1979 nc = channel_new("multiplex client", SSH_CHANNEL_MUX_CLIENT,
1980 newsock, newsock, -1, c->local_window_max,
1981 c->local_maxpacket, 0, "mux-control", 1);
1982 nc->mux_rcb = c->mux_rcb;
1983 debug3("%s: new mux channel %d fd %d", __func__,
1984 nc->self, nc->sock);
1985 /* establish state */
1986 nc->mux_rcb(nc);
1987 /* mux state transitions must not elicit protocol messages */
1988 nc->flags |= CHAN_LOCAL;
1989}
1990
1991/* ARGSUSED */
1992static void
1993channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
1994{
1995 int len;
1996
1997 /* Send buffered output data to the socket. */
1998 if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
1999 len = write(c->sock, buffer_ptr(&c->output),
2000 buffer_len(&c->output));
2001 if (len <= 0)
2002 buffer_clear(&c->output);
2003 else
2004 buffer_consume(&c->output, len);
2005 }
2006}
2007
2008static void
2009channel_handler_init_20(void)
2010{
2011 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2012 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2013 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2014 channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
2015 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2016 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2017 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2018 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2019 channel_pre[SSH_CHANNEL_MUX_LISTENER] = &channel_pre_listener;
2020 channel_pre[SSH_CHANNEL_MUX_CLIENT] = &channel_pre_mux_client;
2021
2022 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2023 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2024 channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
2025 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2026 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2027 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2028 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2029 channel_post[SSH_CHANNEL_MUX_LISTENER] = &channel_post_mux_listener;
2030 channel_post[SSH_CHANNEL_MUX_CLIENT] = &channel_post_mux_client;
2031}
2032
2033static void
2034channel_handler_init_13(void)
2035{
2036 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
2037 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
2038 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2039 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2040 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2041 channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
2042 channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
2043 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2044 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2045
2046 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2047 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2048 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2049 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2050 channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
2051 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2052 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2053}
2054
2055static void
2056channel_handler_init_15(void)
2057{
2058 channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open;
2059 channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
2060 channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
2061 channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
2062 channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
2063 channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
2064 channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
2065
2066 channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
2067 channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
2068 channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
2069 channel_post[SSH_CHANNEL_OPEN] = &channel_post_open;
2070 channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
2071 channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open;
2072}
2073
2074static void
2075channel_handler_init(void)
2076{
2077 int i;
2078
2079 for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
2080 channel_pre[i] = NULL;
2081 channel_post[i] = NULL;
2082 }
2083 if (compat20)
2084 channel_handler_init_20();
2085 else if (compat13)
2086 channel_handler_init_13();
2087 else
2088 channel_handler_init_15();
2089}
2090
2091/* gc dead channels */
2092static void
2093channel_garbage_collect(Channel *c)
2094{
2095 if (c == NULL)
2096 return;
2097 if (c->detach_user != NULL) {
2098 if (!chan_is_dead(c, c->detach_close))
2099 return;
2100 debug2("channel %d: gc: notify user", c->self);
2101 c->detach_user(c->self, NULL);
2102 /* if we still have a callback */
2103 if (c->detach_user != NULL)
2104 return;
2105 debug2("channel %d: gc: user detached", c->self);
2106 }
2107 if (!chan_is_dead(c, 1))
2108 return;
2109 debug2("channel %d: garbage collecting", c->self);
2110 channel_free(c);
2111}
2112
2113static void
2114channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
2115{
2116 static int did_init = 0;
2117 u_int i, oalloc;
2118 Channel *c;
2119
2120 if (!did_init) {
2121 channel_handler_init();
2122 did_init = 1;
2123 }
2124 for (i = 0, oalloc = channels_alloc; i < oalloc; i++) {
2125 c = channels[i];
2126 if (c == NULL)
2127 continue;
2128 if (c->delayed) {
2129 if (ftab == channel_pre)
2130 c->delayed = 0;
2131 else
2132 continue;
2133 }
2134 if (ftab[c->type] != NULL)
2135 (*ftab[c->type])(c, readset, writeset);
2136 channel_garbage_collect(c);
2137 }
2138}
2139
2140/*
2141 * Allocate/update select bitmasks and add any bits relevant to channels in
2142 * select bitmasks.
2143 */
2144void
2145channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
2146 u_int *nallocp, int rekeying)
2147{
2148 u_int n, sz, nfdset;
2149
2150 n = MAX(*maxfdp, channel_max_fd);
2151
2152 nfdset = howmany(n+1, NFDBITS);
2153 /* Explicitly test here, because xrealloc isn't always called */
2154 if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
2155 fatal("channel_prepare_select: max_fd (%d) is too large", n);
2156 sz = nfdset * sizeof(fd_mask);
2157
2158 /* perhaps check sz < nalloc/2 and shrink? */
2159 if (*readsetp == NULL || sz > *nallocp) {
2160 *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
2161 *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
2162 *nallocp = sz;
2163 }
2164 *maxfdp = n;
2165 memset(*readsetp, 0, sz);
2166 memset(*writesetp, 0, sz);
2167
2168 if (!rekeying)
2169 channel_handler(channel_pre, *readsetp, *writesetp);
2170}
2171
2172/*
2173 * After select, perform any appropriate operations for channels which have
2174 * events pending.
2175 */
2176void
2177channel_after_select(fd_set *readset, fd_set *writeset)
2178{
2179 channel_handler(channel_post, readset, writeset);
2180}
2181
2182
2183/* If there is data to send to the connection, enqueue some of it now. */
2184void
2185channel_output_poll(void)
2186{
2187 Channel *c;
2188 u_int i, len;
2189
2190 for (i = 0; i < channels_alloc; i++) {
2191 c = channels[i];
2192 if (c == NULL)
2193 continue;
2194
2195 /*
2196 * We are only interested in channels that can have buffered
2197 * incoming data.
2198 */
2199 if (compat13) {
2200 if (c->type != SSH_CHANNEL_OPEN &&
2201 c->type != SSH_CHANNEL_INPUT_DRAINING)
2202 continue;
2203 } else {
2204 if (c->type != SSH_CHANNEL_OPEN)
2205 continue;
2206 }
2207 if (compat20 &&
2208 (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
2209 /* XXX is this true? */
2210 debug3("channel %d: will not send data after close", c->self);
2211 continue;
2212 }
2213
2214 /* Get the amount of buffered data for this channel. */
2215 if ((c->istate == CHAN_INPUT_OPEN ||
2216 c->istate == CHAN_INPUT_WAIT_DRAIN) &&
2217 (len = buffer_len(&c->input)) > 0) {
2218 if (c->datagram) {
2219 if (len > 0) {
2220 u_char *data;
2221 u_int dlen;
2222
2223 data = buffer_get_string(&c->input,
2224 &dlen);
2225 if (dlen > c->remote_window ||
2226 dlen > c->remote_maxpacket) {
2227 debug("channel %d: datagram "
2228 "too big for channel",
2229 c->self);
2230 xfree(data);
2231 continue;
2232 }
2233 packet_start(SSH2_MSG_CHANNEL_DATA);
2234 packet_put_int(c->remote_id);
2235 packet_put_string(data, dlen);
2236 packet_send();
2237 c->remote_window -= dlen + 4;
2238 xfree(data);
2239 }
2240 continue;
2241 }
2242 /*
2243 * Send some data for the other side over the secure
2244 * connection.
2245 */
2246 if (compat20) {
2247 if (len > c->remote_window)
2248 len = c->remote_window;
2249 if (len > c->remote_maxpacket)
2250 len = c->remote_maxpacket;
2251 } else {
2252 if (packet_is_interactive()) {
2253 if (len > 1024)
2254 len = 512;
2255 } else {
2256 /* Keep the packets at reasonable size. */
2257 if (len > packet_get_maxsize()/2)
2258 len = packet_get_maxsize()/2;
2259 }
2260 }
2261 if (len > 0) {
2262 packet_start(compat20 ?
2263 SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
2264 packet_put_int(c->remote_id);
2265 packet_put_string(buffer_ptr(&c->input), len);
2266 packet_send();
2267 buffer_consume(&c->input, len);
2268 c->remote_window -= len;
2269 }
2270 } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
2271 if (compat13)
2272 fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
2273 /*
2274 * input-buffer is empty and read-socket shutdown:
2275 * tell peer, that we will not send more data: send IEOF.
2276 * hack for extended data: delay EOF if EFD still in use.
2277 */
2278 if (CHANNEL_EFD_INPUT_ACTIVE(c))
2279 debug2("channel %d: ibuf_empty delayed efd %d/(%d)",
2280 c->self, c->efd, buffer_len(&c->extended));
2281 else
2282 chan_ibuf_empty(c);
2283 }
2284 /* Send extended data, i.e. stderr */
2285 if (compat20 &&
2286 !(c->flags & CHAN_EOF_SENT) &&
2287 c->remote_window > 0 &&
2288 (len = buffer_len(&c->extended)) > 0 &&
2289 c->extended_usage == CHAN_EXTENDED_READ) {
2290 debug2("channel %d: rwin %u elen %u euse %d",
2291 c->self, c->remote_window, buffer_len(&c->extended),
2292 c->extended_usage);
2293 if (len > c->remote_window)
2294 len = c->remote_window;
2295 if (len > c->remote_maxpacket)
2296 len = c->remote_maxpacket;
2297 packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
2298 packet_put_int(c->remote_id);
2299 packet_put_int(SSH2_EXTENDED_DATA_STDERR);
2300 packet_put_string(buffer_ptr(&c->extended), len);
2301 packet_send();
2302 buffer_consume(&c->extended, len);
2303 c->remote_window -= len;
2304 debug2("channel %d: sent ext data %d", c->self, len);
2305 }
2306 }
2307}
2308
2309
2310/* -- protocol input */
2311
2312/* ARGSUSED */
2313void
2314channel_input_data(int type, u_int32_t seq, void *ctxt)
2315{
2316 int id;
2317 char *data;
2318 u_int data_len, win_len;
2319 Channel *c;
2320
2321 /* Get the channel number and verify it. */
2322 id = packet_get_int();
2323 c = channel_lookup(id);
2324 if (c == NULL)
2325 packet_disconnect("Received data for nonexistent channel %d.", id);
2326
2327 /* Ignore any data for non-open channels (might happen on close) */
2328 if (c->type != SSH_CHANNEL_OPEN &&
2329 c->type != SSH_CHANNEL_X11_OPEN)
2330 return;
2331
2332 /* Get the data. */
2333 data = packet_get_string_ptr(&data_len);
2334 win_len = data_len;
2335 if (c->datagram)
2336 win_len += 4; /* string length header */
2337
2338 /*
2339 * Ignore data for protocol > 1.3 if output end is no longer open.
2340 * For protocol 2 the sending side is reducing its window as it sends
2341 * data, so we must 'fake' consumption of the data in order to ensure
2342 * that window updates are sent back. Otherwise the connection might
2343 * deadlock.
2344 */
2345 if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) {
2346 if (compat20) {
2347 c->local_window -= win_len;
2348 c->local_consumed += win_len;
2349 }
2350 return;
2351 }
2352
2353 if (compat20) {
2354 if (win_len > c->local_maxpacket) {
2355 logit("channel %d: rcvd big packet %d, maxpack %d",
2356 c->self, win_len, c->local_maxpacket);
2357 }
2358 if (win_len > c->local_window) {
2359 logit("channel %d: rcvd too much data %d, win %d",
2360 c->self, win_len, c->local_window);
2361 return;
2362 }
2363 c->local_window -= win_len;
2364 }
2365 if (c->datagram)
2366 buffer_put_string(&c->output, data, data_len);
2367 else
2368 buffer_append(&c->output, data, data_len);
2369 packet_check_eom();
2370}
2371
2372/* ARGSUSED */
2373void
2374channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
2375{
2376 int id;
2377 char *data;
2378 u_int data_len, tcode;
2379 Channel *c;
2380
2381 /* Get the channel number and verify it. */
2382 id = packet_get_int();
2383 c = channel_lookup(id);
2384
2385 if (c == NULL)
2386 packet_disconnect("Received extended_data for bad channel %d.", id);
2387 if (c->type != SSH_CHANNEL_OPEN) {
2388 logit("channel %d: ext data for non open", id);
2389 return;
2390 }
2391 if (c->flags & CHAN_EOF_RCVD) {
2392 if (datafellows & SSH_BUG_EXTEOF)
2393 debug("channel %d: accepting ext data after eof", id);
2394 else
2395 packet_disconnect("Received extended_data after EOF "
2396 "on channel %d.", id);
2397 }
2398 tcode = packet_get_int();
2399 if (c->efd == -1 ||
2400 c->extended_usage != CHAN_EXTENDED_WRITE ||
2401 tcode != SSH2_EXTENDED_DATA_STDERR) {
2402 logit("channel %d: bad ext data", c->self);
2403 return;
2404 }
2405 data = packet_get_string(&data_len);
2406 packet_check_eom();
2407 if (data_len > c->local_window) {
2408 logit("channel %d: rcvd too much extended_data %d, win %d",
2409 c->self, data_len, c->local_window);
2410 xfree(data);
2411 return;
2412 }
2413 debug2("channel %d: rcvd ext data %d", c->self, data_len);
2414 c->local_window -= data_len;
2415 buffer_append(&c->extended, data, data_len);
2416 xfree(data);
2417}
2418
2419/* ARGSUSED */
2420void
2421channel_input_ieof(int type, u_int32_t seq, void *ctxt)
2422{
2423 int id;
2424 Channel *c;
2425
2426 id = packet_get_int();
2427 packet_check_eom();
2428 c = channel_lookup(id);
2429 if (c == NULL)
2430 packet_disconnect("Received ieof for nonexistent channel %d.", id);
2431 chan_rcvd_ieof(c);
2432
2433 /* XXX force input close */
2434 if (c->force_drain && c->istate == CHAN_INPUT_OPEN) {
2435 debug("channel %d: FORCE input drain", c->self);
2436 c->istate = CHAN_INPUT_WAIT_DRAIN;
2437 if (buffer_len(&c->input) == 0)
2438 chan_ibuf_empty(c);
2439 }
2440
2441}
2442
2443/* ARGSUSED */
2444void
2445channel_input_close(int type, u_int32_t seq, void *ctxt)
2446{
2447 int id;
2448 Channel *c;
2449
2450 id = packet_get_int();
2451 packet_check_eom();
2452 c = channel_lookup(id);
2453 if (c == NULL)
2454 packet_disconnect("Received close for nonexistent channel %d.", id);
2455
2456 /*
2457 * Send a confirmation that we have closed the channel and no more
2458 * data is coming for it.
2459 */
2460 packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION);
2461 packet_put_int(c->remote_id);
2462 packet_send();
2463
2464 /*
2465 * If the channel is in closed state, we have sent a close request,
2466 * and the other side will eventually respond with a confirmation.
2467 * Thus, we cannot free the channel here, because then there would be
2468 * no-one to receive the confirmation. The channel gets freed when
2469 * the confirmation arrives.
2470 */
2471 if (c->type != SSH_CHANNEL_CLOSED) {
2472 /*
2473 * Not a closed channel - mark it as draining, which will
2474 * cause it to be freed later.
2475 */
2476 buffer_clear(&c->input);
2477 c->type = SSH_CHANNEL_OUTPUT_DRAINING;
2478 }
2479}
2480
2481/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
2482/* ARGSUSED */
2483void
2484channel_input_oclose(int type, u_int32_t seq, void *ctxt)
2485{
2486 int id = packet_get_int();
2487 Channel *c = channel_lookup(id);
2488
2489 packet_check_eom();
2490 if (c == NULL)
2491 packet_disconnect("Received oclose for nonexistent channel %d.", id);
2492 chan_rcvd_oclose(c);
2493}
2494
2495/* ARGSUSED */
2496void
2497channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
2498{
2499 int id = packet_get_int();
2500 Channel *c = channel_lookup(id);
2501
2502 packet_check_eom();
2503 if (c == NULL)
2504 packet_disconnect("Received close confirmation for "
2505 "out-of-range channel %d.", id);
2506 if (c->type != SSH_CHANNEL_CLOSED)
2507 packet_disconnect("Received close confirmation for "
2508 "non-closed channel %d (type %d).", id, c->type);
2509 channel_free(c);
2510}
2511
2512/* ARGSUSED */
2513void
2514channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
2515{
2516 int id, remote_id;
2517 Channel *c;
2518
2519 id = packet_get_int();
2520 c = channel_lookup(id);
2521
2522 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2523 packet_disconnect("Received open confirmation for "
2524 "non-opening channel %d.", id);
2525 remote_id = packet_get_int();
2526 /* Record the remote channel number and mark that the channel is now open. */
2527 c->remote_id = remote_id;
2528 c->type = SSH_CHANNEL_OPEN;
2529
2530 if (compat20) {
2531 c->remote_window = packet_get_int();
2532 c->remote_maxpacket = packet_get_int();
2533 if (c->open_confirm) {
2534 debug2("callback start");
2535 c->open_confirm(c->self, 1, c->open_confirm_ctx);
2536 debug2("callback done");
2537 }
2538 debug2("channel %d: open confirm rwindow %u rmax %u", c->self,
2539 c->remote_window, c->remote_maxpacket);
2540 }
2541 packet_check_eom();
2542}
2543
2544static char *
2545reason2txt(int reason)
2546{
2547 switch (reason) {
2548 case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED:
2549 return "administratively prohibited";
2550 case SSH2_OPEN_CONNECT_FAILED:
2551 return "connect failed";
2552 case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE:
2553 return "unknown channel type";
2554 case SSH2_OPEN_RESOURCE_SHORTAGE:
2555 return "resource shortage";
2556 }
2557 return "unknown reason";
2558}
2559
2560/* ARGSUSED */
2561void
2562channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
2563{
2564 int id, reason;
2565 char *msg = NULL, *lang = NULL;
2566 Channel *c;
2567
2568 id = packet_get_int();
2569 c = channel_lookup(id);
2570
2571 if (c==NULL || c->type != SSH_CHANNEL_OPENING)
2572 packet_disconnect("Received open failure for "
2573 "non-opening channel %d.", id);
2574 if (compat20) {
2575 reason = packet_get_int();
2576 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
2577 msg = packet_get_string(NULL);
2578 lang = packet_get_string(NULL);
2579 }
2580 logit("channel %d: open failed: %s%s%s", id,
2581 reason2txt(reason), msg ? ": ": "", msg ? msg : "");
2582 if (msg != NULL)
2583 xfree(msg);
2584 if (lang != NULL)
2585 xfree(lang);
2586 if (c->open_confirm) {
2587 debug2("callback start");
2588 c->open_confirm(c->self, 0, c->open_confirm_ctx);
2589 debug2("callback done");
2590 }
2591 }
2592 packet_check_eom();
2593 /* Schedule the channel for cleanup/deletion. */
2594 chan_mark_dead(c);
2595}
2596
2597/* ARGSUSED */
2598void
2599channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
2600{
2601 Channel *c;
2602 int id;
2603 u_int adjust;
2604
2605 if (!compat20)
2606 return;
2607
2608 /* Get the channel number and verify it. */
2609 id = packet_get_int();
2610 c = channel_lookup(id);
2611
2612 if (c == NULL) {
2613 logit("Received window adjust for non-open channel %d.", id);
2614 return;
2615 }
2616 adjust = packet_get_int();
2617 packet_check_eom();
2618 debug2("channel %d: rcvd adjust %u", id, adjust);
2619 c->remote_window += adjust;
2620}
2621
2622/* ARGSUSED */
2623void
2624channel_input_port_open(int type, u_int32_t seq, void *ctxt)
2625{
2626 Channel *c = NULL;
2627 u_short host_port;
2628 char *host, *originator_string;
2629 int remote_id;
2630
2631 remote_id = packet_get_int();
2632 host = packet_get_string(NULL);
2633 host_port = packet_get_int();
2634
2635 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
2636 originator_string = packet_get_string(NULL);
2637 } else {
2638 originator_string = xstrdup("unknown (remote did not supply name)");
2639 }
2640 packet_check_eom();
2641 c = channel_connect_to(host, host_port,
2642 "connected socket", originator_string);
2643 xfree(originator_string);
2644 xfree(host);
2645 if (c == NULL) {
2646 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
2647 packet_put_int(remote_id);
2648 packet_send();
2649 } else
2650 c->remote_id = remote_id;
2651}
2652
2653/* ARGSUSED */
2654void
2655channel_input_status_confirm(int type, u_int32_t seq, void *ctxt)
2656{
2657 Channel *c;
2658 struct channel_confirm *cc;
2659 int id;
2660
2661 /* Reset keepalive timeout */
2662 packet_set_alive_timeouts(0);
2663
2664 id = packet_get_int();
2665 packet_check_eom();
2666
2667 debug2("channel_input_status_confirm: type %d id %d", type, id);
2668
2669 if ((c = channel_lookup(id)) == NULL) {
2670 logit("channel_input_status_confirm: %d: unknown", id);
2671 return;
2672 }
2673 ;
2674 if ((cc = TAILQ_FIRST(&c->status_confirms)) == NULL)
2675 return;
2676 cc->cb(type, c, cc->ctx);
2677 TAILQ_REMOVE(&c->status_confirms, cc, entry);
2678 bzero(cc, sizeof(*cc));
2679 xfree(cc);
2680}
2681
2682/* -- tcp forwarding */
2683
2684void
2685channel_set_af(int af)
2686{
2687 IPv4or6 = af;
2688}
2689
|
2690void
| 2690void
|
2691channel_set_hpn(int disabled, u_int buf_size)
2692{
| 2691channel_set_hpn(int disabled, u_int buf_size)
2692{
|
2693 hpn_disabled = disabled;
| 2693 hpn_disabled = disabled;
|
2694 buffer_size = buf_size;
2695 debug("HPN Disabled: %d, HPN Buffer Size: %d",
2696 hpn_disabled, buffer_size);
2697}
2698
2699static int
2700channel_setup_fwd_listener(int type, const char *listen_addr,
2701 u_short listen_port, int *allocated_listen_port,
2702 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2703{
2704 Channel *c;
2705 int sock, r, success = 0, wildcard = 0, is_client;
2706 struct addrinfo hints, *ai, *aitop;
2707 const char *host, *addr;
2708 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2709 in_port_t *lport_p;
2710
2711 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2712 listen_addr : host_to_connect;
2713 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
2714
2715 if (host == NULL) {
2716 error("No forward host name.");
2717 return 0;
2718 }
2719 if (strlen(host) >= NI_MAXHOST) {
2720 error("Forward host name too long.");
2721 return 0;
2722 }
2723
2724 /*
2725 * Determine whether or not a port forward listens to loopback,
2726 * specified address or wildcard. On the client, a specified bind
2727 * address will always override gateway_ports. On the server, a
2728 * gateway_ports of 1 (``yes'') will override the client's
2729 * specification and force a wildcard bind, whereas a value of 2
2730 * (``clientspecified'') will bind to whatever address the client
2731 * asked for.
2732 *
2733 * Special-case listen_addrs are:
2734 *
2735 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2736 * "" (empty string), "*" -> wildcard v4/v6
2737 * "localhost" -> loopback v4/v6
2738 */
2739 addr = NULL;
2740 if (listen_addr == NULL) {
2741 /* No address specified: default to gateway_ports setting */
2742 if (gateway_ports)
2743 wildcard = 1;
2744 } else if (gateway_ports || is_client) {
2745 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2746 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2747 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2748 (!is_client && gateway_ports == 1))
2749 wildcard = 1;
2750 else if (strcmp(listen_addr, "localhost") != 0)
2751 addr = listen_addr;
2752 }
2753
2754 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2755 type, wildcard, (addr == NULL) ? "NULL" : addr);
2756
2757 /*
2758 * getaddrinfo returns a loopback address if the hostname is
2759 * set to NULL and hints.ai_flags is not AI_PASSIVE
2760 */
2761 memset(&hints, 0, sizeof(hints));
2762 hints.ai_family = IPv4or6;
2763 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
2764 hints.ai_socktype = SOCK_STREAM;
2765 snprintf(strport, sizeof strport, "%d", listen_port);
2766 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2767 if (addr == NULL) {
2768 /* This really shouldn't happen */
2769 packet_disconnect("getaddrinfo: fatal error: %s",
2770 ssh_gai_strerror(r));
2771 } else {
2772 error("channel_setup_fwd_listener: "
2773 "getaddrinfo(%.64s): %s", addr,
2774 ssh_gai_strerror(r));
2775 }
2776 return 0;
2777 }
2778 if (allocated_listen_port != NULL)
2779 *allocated_listen_port = 0;
2780 for (ai = aitop; ai; ai = ai->ai_next) {
2781 switch (ai->ai_family) {
2782 case AF_INET:
2783 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2784 sin_port;
2785 break;
2786 case AF_INET6:
2787 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2788 sin6_port;
2789 break;
2790 default:
2791 continue;
2792 }
2793 /*
2794 * If allocating a port for -R forwards, then use the
2795 * same port for all address families.
2796 */
2797 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2798 allocated_listen_port != NULL && *allocated_listen_port > 0)
2799 *lport_p = htons(*allocated_listen_port);
2800
2801 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2802 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2803 error("channel_setup_fwd_listener: getnameinfo failed");
2804 continue;
2805 }
2806 /* Create a port to listen for the host. */
2807 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
2808 if (sock < 0) {
2809 /* this is no error since kernel may not support ipv6 */
2810 verbose("socket: %.100s", strerror(errno));
2811 continue;
2812 }
2813
2814 channel_set_reuseaddr(sock);
2815 if (ai->ai_family == AF_INET6)
2816 sock_set_v6only(sock);
2817
2818 debug("Local forwarding listening on %s port %s.",
2819 ntop, strport);
2820
2821 /* Bind the socket to the address. */
2822 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2823 /* address can be in use ipv6 address is already bound */
2824 if (!ai->ai_next)
2825 error("bind: %.100s", strerror(errno));
2826 else
2827 verbose("bind: %.100s", strerror(errno));
2828
2829 close(sock);
2830 continue;
2831 }
2832 /* Start listening for connections on the socket. */
2833 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
2834 error("listen: %.100s", strerror(errno));
2835 close(sock);
2836 continue;
2837 }
2838
2839 /*
2840 * listen_port == 0 requests a dynamically allocated port -
2841 * record what we got.
2842 */
2843 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2844 allocated_listen_port != NULL &&
2845 *allocated_listen_port == 0) {
2846 *allocated_listen_port = get_sock_port(sock, 1);
2847 debug("Allocated listen port %d",
2848 *allocated_listen_port);
2849 }
2850
2851 /*
2852 * Allocate a channel number for the socket. Explicitly test
2853 * for hpn disabled option. If true use smaller window size.
2854 */
2855 if (hpn_disabled)
2856 c = channel_new("port listener", type, sock, sock, -1,
2857 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2858 0, "port listener", 1);
| 2694 buffer_size = buf_size;
2695 debug("HPN Disabled: %d, HPN Buffer Size: %d",
2696 hpn_disabled, buffer_size);
2697}
2698
2699static int
2700channel_setup_fwd_listener(int type, const char *listen_addr,
2701 u_short listen_port, int *allocated_listen_port,
2702 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2703{
2704 Channel *c;
2705 int sock, r, success = 0, wildcard = 0, is_client;
2706 struct addrinfo hints, *ai, *aitop;
2707 const char *host, *addr;
2708 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
2709 in_port_t *lport_p;
2710
2711 host = (type == SSH_CHANNEL_RPORT_LISTENER) ?
2712 listen_addr : host_to_connect;
2713 is_client = (type == SSH_CHANNEL_PORT_LISTENER);
2714
2715 if (host == NULL) {
2716 error("No forward host name.");
2717 return 0;
2718 }
2719 if (strlen(host) >= NI_MAXHOST) {
2720 error("Forward host name too long.");
2721 return 0;
2722 }
2723
2724 /*
2725 * Determine whether or not a port forward listens to loopback,
2726 * specified address or wildcard. On the client, a specified bind
2727 * address will always override gateway_ports. On the server, a
2728 * gateway_ports of 1 (``yes'') will override the client's
2729 * specification and force a wildcard bind, whereas a value of 2
2730 * (``clientspecified'') will bind to whatever address the client
2731 * asked for.
2732 *
2733 * Special-case listen_addrs are:
2734 *
2735 * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR
2736 * "" (empty string), "*" -> wildcard v4/v6
2737 * "localhost" -> loopback v4/v6
2738 */
2739 addr = NULL;
2740 if (listen_addr == NULL) {
2741 /* No address specified: default to gateway_ports setting */
2742 if (gateway_ports)
2743 wildcard = 1;
2744 } else if (gateway_ports || is_client) {
2745 if (((datafellows & SSH_OLD_FORWARD_ADDR) &&
2746 strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) ||
2747 *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 ||
2748 (!is_client && gateway_ports == 1))
2749 wildcard = 1;
2750 else if (strcmp(listen_addr, "localhost") != 0)
2751 addr = listen_addr;
2752 }
2753
2754 debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s",
2755 type, wildcard, (addr == NULL) ? "NULL" : addr);
2756
2757 /*
2758 * getaddrinfo returns a loopback address if the hostname is
2759 * set to NULL and hints.ai_flags is not AI_PASSIVE
2760 */
2761 memset(&hints, 0, sizeof(hints));
2762 hints.ai_family = IPv4or6;
2763 hints.ai_flags = wildcard ? AI_PASSIVE : 0;
2764 hints.ai_socktype = SOCK_STREAM;
2765 snprintf(strport, sizeof strport, "%d", listen_port);
2766 if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) {
2767 if (addr == NULL) {
2768 /* This really shouldn't happen */
2769 packet_disconnect("getaddrinfo: fatal error: %s",
2770 ssh_gai_strerror(r));
2771 } else {
2772 error("channel_setup_fwd_listener: "
2773 "getaddrinfo(%.64s): %s", addr,
2774 ssh_gai_strerror(r));
2775 }
2776 return 0;
2777 }
2778 if (allocated_listen_port != NULL)
2779 *allocated_listen_port = 0;
2780 for (ai = aitop; ai; ai = ai->ai_next) {
2781 switch (ai->ai_family) {
2782 case AF_INET:
2783 lport_p = &((struct sockaddr_in *)ai->ai_addr)->
2784 sin_port;
2785 break;
2786 case AF_INET6:
2787 lport_p = &((struct sockaddr_in6 *)ai->ai_addr)->
2788 sin6_port;
2789 break;
2790 default:
2791 continue;
2792 }
2793 /*
2794 * If allocating a port for -R forwards, then use the
2795 * same port for all address families.
2796 */
2797 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2798 allocated_listen_port != NULL && *allocated_listen_port > 0)
2799 *lport_p = htons(*allocated_listen_port);
2800
2801 if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
2802 strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
2803 error("channel_setup_fwd_listener: getnameinfo failed");
2804 continue;
2805 }
2806 /* Create a port to listen for the host. */
2807 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
2808 if (sock < 0) {
2809 /* this is no error since kernel may not support ipv6 */
2810 verbose("socket: %.100s", strerror(errno));
2811 continue;
2812 }
2813
2814 channel_set_reuseaddr(sock);
2815 if (ai->ai_family == AF_INET6)
2816 sock_set_v6only(sock);
2817
2818 debug("Local forwarding listening on %s port %s.",
2819 ntop, strport);
2820
2821 /* Bind the socket to the address. */
2822 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
2823 /* address can be in use ipv6 address is already bound */
2824 if (!ai->ai_next)
2825 error("bind: %.100s", strerror(errno));
2826 else
2827 verbose("bind: %.100s", strerror(errno));
2828
2829 close(sock);
2830 continue;
2831 }
2832 /* Start listening for connections on the socket. */
2833 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
2834 error("listen: %.100s", strerror(errno));
2835 close(sock);
2836 continue;
2837 }
2838
2839 /*
2840 * listen_port == 0 requests a dynamically allocated port -
2841 * record what we got.
2842 */
2843 if (type == SSH_CHANNEL_RPORT_LISTENER && listen_port == 0 &&
2844 allocated_listen_port != NULL &&
2845 *allocated_listen_port == 0) {
2846 *allocated_listen_port = get_sock_port(sock, 1);
2847 debug("Allocated listen port %d",
2848 *allocated_listen_port);
2849 }
2850
2851 /*
2852 * Allocate a channel number for the socket. Explicitly test
2853 * for hpn disabled option. If true use smaller window size.
2854 */
2855 if (hpn_disabled)
2856 c = channel_new("port listener", type, sock, sock, -1,
2857 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
2858 0, "port listener", 1);
|
2859 else
2860 c = channel_new("port listener", type, sock, sock, -1,
2861 buffer_size, CHAN_TCP_PACKET_DEFAULT,
2862 0, "port listener", 1);
| 2859 else
2860 c = channel_new("port listener", type, sock, sock, -1,
2861 buffer_size, CHAN_TCP_PACKET_DEFAULT,
2862 0, "port listener", 1);
|
2863 c->path = xstrdup(host);
2864 c->host_port = port_to_connect;
2865 c->listening_port = listen_port;
2866 success = 1;
2867 }
2868 if (success == 0)
2869 error("channel_setup_fwd_listener: cannot listen to port: %d",
2870 listen_port);
2871 freeaddrinfo(aitop);
2872 return success;
2873}
2874
2875int
2876channel_cancel_rport_listener(const char *host, u_short port)
2877{
2878 u_int i;
2879 int found = 0;
2880
2881 for (i = 0; i < channels_alloc; i++) {
2882 Channel *c = channels[i];
2883
2884 if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2885 strcmp(c->path, host) == 0 && c->listening_port == port) {
2886 debug2("%s: close channel %d", __func__, i);
2887 channel_free(c);
2888 found = 1;
2889 }
2890 }
2891
2892 return (found);
2893}
2894
2895/* protocol local port fwd, used by ssh (and sshd in v1) */
2896int
2897channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
2898 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2899{
2900 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2901 listen_host, listen_port, NULL, host_to_connect, port_to_connect,
2902 gateway_ports);
2903}
2904
2905/* protocol v2 remote port fwd, used by sshd */
2906int
2907channel_setup_remote_fwd_listener(const char *listen_address,
2908 u_short listen_port, int *allocated_listen_port, int gateway_ports)
2909{
2910 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2911 listen_address, listen_port, allocated_listen_port,
2912 NULL, 0, gateway_ports);
2913}
2914
2915/*
2916 * Initiate forwarding of connections to port "port" on remote host through
2917 * the secure channel to host:port from local side.
2918 */
2919
2920int
2921channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
2922 const char *host_to_connect, u_short port_to_connect)
2923{
2924 int type, success = 0;
2925
2926 /* Send the forward request to the remote side. */
2927 if (compat20) {
2928 const char *address_to_bind;
2929 if (listen_host == NULL) {
2930 if (datafellows & SSH_BUG_RFWD_ADDR)
2931 address_to_bind = "127.0.0.1";
2932 else
2933 address_to_bind = "localhost";
2934 } else if (*listen_host == '\0' ||
2935 strcmp(listen_host, "*") == 0) {
2936 if (datafellows & SSH_BUG_RFWD_ADDR)
2937 address_to_bind = "0.0.0.0";
2938 else
2939 address_to_bind = "";
2940 } else
2941 address_to_bind = listen_host;
2942
2943 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2944 packet_put_cstring("tcpip-forward");
2945 packet_put_char(1); /* boolean: want reply */
2946 packet_put_cstring(address_to_bind);
2947 packet_put_int(listen_port);
2948 packet_send();
2949 packet_write_wait();
2950 /* Assume that server accepts the request */
2951 success = 1;
2952 } else {
2953 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
2954 packet_put_int(listen_port);
2955 packet_put_cstring(host_to_connect);
2956 packet_put_int(port_to_connect);
2957 packet_send();
2958 packet_write_wait();
2959
2960 /* Wait for response from the remote side. */
2961 type = packet_read();
2962 switch (type) {
2963 case SSH_SMSG_SUCCESS:
2964 success = 1;
2965 break;
2966 case SSH_SMSG_FAILURE:
2967 break;
2968 default:
2969 /* Unknown packet */
2970 packet_disconnect("Protocol error for port forward request:"
2971 "received packet type %d.", type);
2972 }
2973 }
2974 if (success) {
2975 /* Record that connection to this host/port is permitted. */
2976 permitted_opens = xrealloc(permitted_opens,
2977 num_permitted_opens + 1, sizeof(*permitted_opens));
2978 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2979 permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2980 permitted_opens[num_permitted_opens].listen_port = listen_port;
2981 num_permitted_opens++;
2982 }
2983 return (success ? 0 : -1);
2984}
2985
2986/*
2987 * Request cancellation of remote forwarding of connection host:port from
2988 * local side.
2989 */
2990void
2991channel_request_rforward_cancel(const char *host, u_short port)
2992{
2993 int i;
2994
2995 if (!compat20)
2996 return;
2997
2998 for (i = 0; i < num_permitted_opens; i++) {
2999 if (permitted_opens[i].host_to_connect != NULL &&
3000 permitted_opens[i].listen_port == port)
3001 break;
3002 }
3003 if (i >= num_permitted_opens) {
3004 debug("%s: requested forward not found", __func__);
3005 return;
3006 }
3007 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3008 packet_put_cstring("cancel-tcpip-forward");
3009 packet_put_char(0);
3010 packet_put_cstring(host == NULL ? "" : host);
3011 packet_put_int(port);
3012 packet_send();
3013
3014 permitted_opens[i].listen_port = 0;
3015 permitted_opens[i].port_to_connect = 0;
3016 xfree(permitted_opens[i].host_to_connect);
3017 permitted_opens[i].host_to_connect = NULL;
3018}
3019
3020/*
3021 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3022 * listening for the port, and sends back a success reply (or disconnect
3023 * message if there was an error).
3024 */
3025int
3026channel_input_port_forward_request(int is_root, int gateway_ports)
3027{
3028 u_short port, host_port;
3029 int success = 0;
3030 char *hostname;
3031
3032 /* Get arguments from the packet. */
3033 port = packet_get_int();
3034 hostname = packet_get_string(NULL);
3035 host_port = packet_get_int();
3036
3037#ifndef HAVE_CYGWIN
3038 /*
3039 * Check that an unprivileged user is not trying to forward a
3040 * privileged port.
3041 */
3042 if (port < IPPORT_RESERVED && !is_root)
3043 packet_disconnect(
3044 "Requested forwarding of port %d but user is not root.",
3045 port);
3046 if (host_port == 0)
3047 packet_disconnect("Dynamic forwarding denied.");
3048#endif
3049
3050 /* Initiate forwarding */
3051 success = channel_setup_local_fwd_listener(NULL, port, hostname,
3052 host_port, gateway_ports);
3053
3054 /* Free the argument string. */
3055 xfree(hostname);
3056
3057 return (success ? 0 : -1);
3058}
3059
3060/*
3061 * Permits opening to any host/port if permitted_opens[] is empty. This is
3062 * usually called by the server, because the user could connect to any port
3063 * anyway, and the server has no way to know but to trust the client anyway.
3064 */
3065void
3066channel_permit_all_opens(void)
3067{
3068 if (num_permitted_opens == 0)
3069 all_opens_permitted = 1;
3070}
3071
3072void
3073channel_add_permitted_opens(char *host, int port)
3074{
3075 debug("allow port forwarding to host %s port %d", host, port);
3076
3077 permitted_opens = xrealloc(permitted_opens,
3078 num_permitted_opens + 1, sizeof(*permitted_opens));
3079 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3080 permitted_opens[num_permitted_opens].port_to_connect = port;
3081 num_permitted_opens++;
3082
3083 all_opens_permitted = 0;
3084}
3085
3086int
3087channel_add_adm_permitted_opens(char *host, int port)
3088{
3089 debug("config allows port forwarding to host %s port %d", host, port);
3090
3091 permitted_adm_opens = xrealloc(permitted_adm_opens,
3092 num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
3093 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3094 = xstrdup(host);
3095 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
3096 return ++num_adm_permitted_opens;
3097}
3098
3099void
3100channel_clear_permitted_opens(void)
3101{
3102 int i;
3103
3104 for (i = 0; i < num_permitted_opens; i++)
3105 if (permitted_opens[i].host_to_connect != NULL)
3106 xfree(permitted_opens[i].host_to_connect);
3107 if (num_permitted_opens > 0) {
3108 xfree(permitted_opens);
3109 permitted_opens = NULL;
3110 }
3111 num_permitted_opens = 0;
3112}
3113
3114void
3115channel_clear_adm_permitted_opens(void)
3116{
3117 int i;
3118
3119 for (i = 0; i < num_adm_permitted_opens; i++)
3120 if (permitted_adm_opens[i].host_to_connect != NULL)
3121 xfree(permitted_adm_opens[i].host_to_connect);
3122 if (num_adm_permitted_opens > 0) {
3123 xfree(permitted_adm_opens);
3124 permitted_adm_opens = NULL;
3125 }
3126 num_adm_permitted_opens = 0;
3127}
3128
3129void
3130channel_print_adm_permitted_opens(void)
3131{
3132 int i;
3133
3134 printf("permitopen");
3135 if (num_adm_permitted_opens == 0) {
3136 printf(" any\n");
3137 return;
3138 }
3139 for (i = 0; i < num_adm_permitted_opens; i++)
3140 if (permitted_adm_opens[i].host_to_connect != NULL)
3141 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3142 permitted_adm_opens[i].port_to_connect);
3143 printf("\n");
3144}
3145
3146/* Try to start non-blocking connect to next host in cctx list */
3147static int
3148connect_next(struct channel_connect *cctx)
3149{
3150 int sock, saved_errno;
3151 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3152
3153 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3154 if (cctx->ai->ai_family != AF_INET &&
3155 cctx->ai->ai_family != AF_INET6)
3156 continue;
3157 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3158 ntop, sizeof(ntop), strport, sizeof(strport),
3159 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3160 error("connect_next: getnameinfo failed");
3161 continue;
3162 }
3163 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3164 cctx->ai->ai_protocol)) == -1) {
3165 if (cctx->ai->ai_next == NULL)
3166 error("socket: %.100s", strerror(errno));
3167 else
3168 verbose("socket: %.100s", strerror(errno));
3169 continue;
3170 }
3171 if (set_nonblock(sock) == -1)
3172 fatal("%s: set_nonblock(%d)", __func__, sock);
3173 if (connect(sock, cctx->ai->ai_addr,
3174 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3175 debug("connect_next: host %.100s ([%.100s]:%s): "
3176 "%.100s", cctx->host, ntop, strport,
3177 strerror(errno));
3178 saved_errno = errno;
3179 close(sock);
3180 errno = saved_errno;
3181 continue; /* fail -- try next */
3182 }
3183 debug("connect_next: host %.100s ([%.100s]:%s) "
3184 "in progress, fd=%d", cctx->host, ntop, strport, sock);
3185 cctx->ai = cctx->ai->ai_next;
3186 set_nodelay(sock);
3187 return sock;
3188 }
3189 return -1;
3190}
3191
3192static void
3193channel_connect_ctx_free(struct channel_connect *cctx)
3194{
3195 xfree(cctx->host);
3196 if (cctx->aitop)
3197 freeaddrinfo(cctx->aitop);
3198 bzero(cctx, sizeof(*cctx));
3199 cctx->host = NULL;
3200 cctx->ai = cctx->aitop = NULL;
3201}
3202
3203/* Return CONNECTING channel to remote host, port */
3204static Channel *
3205connect_to(const char *host, u_short port, char *ctype, char *rname)
3206{
3207 struct addrinfo hints;
3208 int gaierr;
3209 int sock = -1;
3210 char strport[NI_MAXSERV];
3211 struct channel_connect cctx;
3212 Channel *c;
3213
3214 memset(&cctx, 0, sizeof(cctx));
3215 memset(&hints, 0, sizeof(hints));
3216 hints.ai_family = IPv4or6;
3217 hints.ai_socktype = SOCK_STREAM;
3218 snprintf(strport, sizeof strport, "%d", port);
3219 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3220 error("connect_to %.100s: unknown host (%s)", host,
3221 ssh_gai_strerror(gaierr));
3222 return NULL;
3223 }
3224
3225 cctx.host = xstrdup(host);
3226 cctx.port = port;
3227 cctx.ai = cctx.aitop;
3228
3229 if ((sock = connect_next(&cctx)) == -1) {
3230 error("connect to %.100s port %d failed: %s",
3231 host, port, strerror(errno));
3232 channel_connect_ctx_free(&cctx);
3233 return NULL;
3234 }
3235 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3236 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3237 c->connect_ctx = cctx;
3238 return c;
3239}
3240
3241Channel *
3242channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
3243{
3244 int i;
3245
3246 for (i = 0; i < num_permitted_opens; i++) {
3247 if (permitted_opens[i].host_to_connect != NULL &&
3248 permitted_opens[i].listen_port == listen_port) {
3249 return connect_to(
3250 permitted_opens[i].host_to_connect,
3251 permitted_opens[i].port_to_connect, ctype, rname);
3252 }
3253 }
3254 error("WARNING: Server requests forwarding for unknown listen_port %d",
3255 listen_port);
3256 return NULL;
3257}
3258
3259/* Check if connecting to that port is permitted and connect. */
3260Channel *
3261channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
3262{
3263 int i, permit, permit_adm = 1;
3264
3265 permit = all_opens_permitted;
3266 if (!permit) {
3267 for (i = 0; i < num_permitted_opens; i++)
3268 if (permitted_opens[i].host_to_connect != NULL &&
3269 permitted_opens[i].port_to_connect == port &&
3270 strcmp(permitted_opens[i].host_to_connect, host) == 0)
3271 permit = 1;
3272 }
3273
3274 if (num_adm_permitted_opens > 0) {
3275 permit_adm = 0;
3276 for (i = 0; i < num_adm_permitted_opens; i++)
3277 if (permitted_adm_opens[i].host_to_connect != NULL &&
3278 permitted_adm_opens[i].port_to_connect == port &&
3279 strcmp(permitted_adm_opens[i].host_to_connect, host)
3280 == 0)
3281 permit_adm = 1;
3282 }
3283
3284 if (!permit || !permit_adm) {
3285 logit("Received request to connect to host %.100s port %d, "
3286 "but the request was denied.", host, port);
3287 return NULL;
3288 }
3289 return connect_to(host, port, ctype, rname);
3290}
3291
3292void
3293channel_send_window_changes(void)
3294{
3295 u_int i;
3296 struct winsize ws;
3297
3298 for (i = 0; i < channels_alloc; i++) {
3299 if (channels[i] == NULL || !channels[i]->client_tty ||
3300 channels[i]->type != SSH_CHANNEL_OPEN)
3301 continue;
3302 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3303 continue;
3304 channel_request_start(i, "window-change", 0);
3305 packet_put_int((u_int)ws.ws_col);
3306 packet_put_int((u_int)ws.ws_row);
3307 packet_put_int((u_int)ws.ws_xpixel);
3308 packet_put_int((u_int)ws.ws_ypixel);
3309 packet_send();
3310 }
3311}
3312
3313/* -- X11 forwarding */
3314
3315/*
3316 * Creates an internet domain socket for listening for X11 connections.
3317 * Returns 0 and a suitable display number for the DISPLAY variable
3318 * stored in display_numberp , or -1 if an error occurs.
3319 */
3320int
3321x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
3322 int single_connection, u_int *display_numberp, int **chanids)
3323{
3324 Channel *nc = NULL;
3325 int display_number, sock;
3326 u_short port;
3327 struct addrinfo hints, *ai, *aitop;
3328 char strport[NI_MAXSERV];
3329 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3330
3331 if (chanids == NULL)
3332 return -1;
3333
3334 for (display_number = x11_display_offset;
3335 display_number < MAX_DISPLAYS;
3336 display_number++) {
3337 port = 6000 + display_number;
3338 memset(&hints, 0, sizeof(hints));
3339 hints.ai_family = IPv4or6;
3340 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3341 hints.ai_socktype = SOCK_STREAM;
3342 snprintf(strport, sizeof strport, "%d", port);
3343 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
3344 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
3345 return -1;
3346 }
3347 for (ai = aitop; ai; ai = ai->ai_next) {
3348 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3349 continue;
3350 sock = socket(ai->ai_family, ai->ai_socktype,
3351 ai->ai_protocol);
3352 if (sock < 0) {
3353 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
3354#ifdef EPFNOSUPPORT
3355 && (errno != EPFNOSUPPORT)
3356#endif
3357 ) {
3358 error("socket: %.100s", strerror(errno));
3359 freeaddrinfo(aitop);
3360 return -1;
3361 } else {
3362 debug("x11_create_display_inet: Socket family %d not supported",
3363 ai->ai_family);
3364 continue;
3365 }
3366 }
3367 if (ai->ai_family == AF_INET6)
3368 sock_set_v6only(sock);
3369 if (x11_use_localhost)
3370 channel_set_reuseaddr(sock);
3371 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3372 debug2("bind port %d: %.100s", port, strerror(errno));
3373 close(sock);
3374
3375 for (n = 0; n < num_socks; n++) {
3376 close(socks[n]);
3377 }
3378 num_socks = 0;
3379 break;
3380 }
3381 socks[num_socks++] = sock;
3382 if (num_socks == NUM_SOCKS)
3383 break;
3384 }
3385 freeaddrinfo(aitop);
3386 if (num_socks > 0)
3387 break;
3388 }
3389 if (display_number >= MAX_DISPLAYS) {
3390 error("Failed to allocate internet-domain X11 display socket.");
3391 return -1;
3392 }
3393 /* Start listening for connections on the socket. */
3394 for (n = 0; n < num_socks; n++) {
3395 sock = socks[n];
3396 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3397 error("listen: %.100s", strerror(errno));
3398 close(sock);
3399 return -1;
3400 }
3401 }
3402
3403 /* Allocate a channel for each socket. */
3404 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3405 for (n = 0; n < num_socks; n++) {
3406 sock = socks[n];
3407 if (hpn_disabled)
3408 nc = channel_new("x11 listener",
3409 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3410 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3411 0, "X11 inet listener", 1);
3412 else
3413 nc = channel_new("x11 listener",
3414 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3415 buffer_size, CHAN_X11_PACKET_DEFAULT,
3416 0, "X11 inet listener", 1);
3417 nc->single_connection = single_connection;
3418 (*chanids)[n] = nc->self;
3419 }
3420 (*chanids)[n] = -1;
3421
3422 /* Return the display number for the DISPLAY environment variable. */
3423 *display_numberp = display_number;
3424 return (0);
3425}
3426
3427static int
3428connect_local_xsocket_path(const char *pathname)
3429{
3430 int sock;
3431 struct sockaddr_un addr;
3432
3433 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3434 if (sock < 0)
3435 error("socket: %.100s", strerror(errno));
3436 memset(&addr, 0, sizeof(addr));
3437 addr.sun_family = AF_UNIX;
3438 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
3439 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
3440 return sock;
3441 close(sock);
3442 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3443 return -1;
3444}
3445
3446static int
3447connect_local_xsocket(u_int dnr)
3448{
3449 char buf[1024];
3450 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
3451 return connect_local_xsocket_path(buf);
3452}
3453
3454int
3455x11_connect_display(void)
3456{
3457 u_int display_number;
3458 const char *display;
3459 char buf[1024], *cp;
3460 struct addrinfo hints, *ai, *aitop;
3461 char strport[NI_MAXSERV];
3462 int gaierr, sock = 0;
3463
3464 /* Try to open a socket for the local X server. */
3465 display = getenv("DISPLAY");
3466 if (!display) {
3467 error("DISPLAY not set.");
3468 return -1;
3469 }
3470 /*
3471 * Now we decode the value of the DISPLAY variable and make a
3472 * connection to the real X server.
3473 */
3474
3475 /* Check if the display is from launchd. */
3476#ifdef __APPLE__
3477 if (strncmp(display, "/tmp/launch", 11) == 0) {
3478 sock = connect_local_xsocket_path(display);
3479 if (sock < 0)
3480 return -1;
3481
3482 /* OK, we now have a connection to the display. */
3483 return sock;
3484 }
3485#endif
3486 /*
3487 * Check if it is a unix domain socket. Unix domain displays are in
3488 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3489 */
3490 if (strncmp(display, "unix:", 5) == 0 ||
3491 display[0] == ':') {
3492 /* Connect to the unix domain socket. */
3493 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
3494 error("Could not parse display number from DISPLAY: %.100s",
3495 display);
3496 return -1;
3497 }
3498 /* Create a socket. */
3499 sock = connect_local_xsocket(display_number);
3500 if (sock < 0)
3501 return -1;
3502
3503 /* OK, we now have a connection to the display. */
3504 return sock;
3505 }
3506 /*
3507 * Connect to an inet socket. The DISPLAY value is supposedly
3508 * hostname:d[.s], where hostname may also be numeric IP address.
3509 */
3510 strlcpy(buf, display, sizeof(buf));
3511 cp = strchr(buf, ':');
3512 if (!cp) {
3513 error("Could not find ':' in DISPLAY: %.100s", display);
3514 return -1;
3515 }
3516 *cp = 0;
3517 /* buf now contains the host name. But first we parse the display number. */
3518 if (sscanf(cp + 1, "%u", &display_number) != 1) {
3519 error("Could not parse display number from DISPLAY: %.100s",
3520 display);
3521 return -1;
3522 }
3523
3524 /* Look up the host address */
3525 memset(&hints, 0, sizeof(hints));
3526 hints.ai_family = IPv4or6;
3527 hints.ai_socktype = SOCK_STREAM;
3528 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
3529 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
3530 error("%.100s: unknown host. (%s)", buf,
3531 ssh_gai_strerror(gaierr));
3532 return -1;
3533 }
3534 for (ai = aitop; ai; ai = ai->ai_next) {
3535 /* Create a socket. */
3536 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3537 if (sock < 0) {
3538 debug2("socket: %.100s", strerror(errno));
3539 continue;
3540 }
3541 /* Connect it to the display. */
3542 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3543 debug2("connect %.100s port %u: %.100s", buf,
3544 6000 + display_number, strerror(errno));
3545 close(sock);
3546 continue;
3547 }
3548 /* Success */
3549 break;
3550 }
3551 freeaddrinfo(aitop);
3552 if (!ai) {
3553 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
3554 strerror(errno));
3555 return -1;
3556 }
3557 set_nodelay(sock);
3558 return sock;
3559}
3560
3561/*
3562 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3563 * the remote channel number. We should do whatever we want, and respond
3564 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3565 */
3566
3567/* ARGSUSED */
3568void
3569x11_input_open(int type, u_int32_t seq, void *ctxt)
3570{
3571 Channel *c = NULL;
3572 int remote_id, sock = 0;
3573 char *remote_host;
3574
3575 debug("Received X11 open request.");
3576
3577 remote_id = packet_get_int();
3578
3579 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3580 remote_host = packet_get_string(NULL);
3581 } else {
3582 remote_host = xstrdup("unknown (remote did not supply name)");
3583 }
3584 packet_check_eom();
3585
3586 /* Obtain a connection to the real X display. */
3587 sock = x11_connect_display();
3588 if (sock != -1) {
3589 /* Allocate a channel for this connection. */
3590 c = channel_new("connected x11 socket",
3591 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3592 remote_host, 1);
3593 c->remote_id = remote_id;
3594 c->force_drain = 1;
3595 }
3596 xfree(remote_host);
3597 if (c == NULL) {
3598 /* Send refusal to the remote host. */
3599 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3600 packet_put_int(remote_id);
3601 } else {
3602 /* Send a confirmation to the remote host. */
3603 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
3604 packet_put_int(remote_id);
3605 packet_put_int(c->self);
3606 }
3607 packet_send();
3608}
3609
3610/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3611/* ARGSUSED */
3612void
3613deny_input_open(int type, u_int32_t seq, void *ctxt)
3614{
3615 int rchan = packet_get_int();
3616
3617 switch (type) {
3618 case SSH_SMSG_AGENT_OPEN:
3619 error("Warning: ssh server tried agent forwarding.");
3620 break;
3621 case SSH_SMSG_X11_OPEN:
3622 error("Warning: ssh server tried X11 forwarding.");
3623 break;
3624 default:
3625 error("deny_input_open: type %d", type);
3626 break;
3627 }
3628 error("Warning: this is probably a break-in attempt by a malicious server.");
3629 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3630 packet_put_int(rchan);
3631 packet_send();
3632}
3633
3634/*
3635 * Requests forwarding of X11 connections, generates fake authentication
3636 * data, and enables authentication spoofing.
3637 * This should be called in the client only.
3638 */
3639void
3640x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
3641 const char *proto, const char *data, int want_reply)
3642{
3643 u_int data_len = (u_int) strlen(data) / 2;
3644 u_int i, value;
3645 char *new_data;
3646 int screen_number;
3647 const char *cp;
3648 u_int32_t rnd = 0;
3649
3650 if (x11_saved_display == NULL)
3651 x11_saved_display = xstrdup(disp);
3652 else if (strcmp(disp, x11_saved_display) != 0) {
3653 error("x11_request_forwarding_with_spoofing: different "
3654 "$DISPLAY already forwarded");
3655 return;
3656 }
3657
3658 cp = strchr(disp, ':');
3659 if (cp)
3660 cp = strchr(cp, '.');
3661 if (cp)
3662 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
3663 else
3664 screen_number = 0;
3665
3666 if (x11_saved_proto == NULL) {
3667 /* Save protocol name. */
3668 x11_saved_proto = xstrdup(proto);
3669 /*
3670 * Extract real authentication data and generate fake data
3671 * of the same length.
3672 */
3673 x11_saved_data = xmalloc(data_len);
3674 x11_fake_data = xmalloc(data_len);
3675 for (i = 0; i < data_len; i++) {
3676 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3677 fatal("x11_request_forwarding: bad "
3678 "authentication data: %.100s", data);
3679 if (i % 4 == 0)
3680 rnd = arc4random();
3681 x11_saved_data[i] = value;
3682 x11_fake_data[i] = rnd & 0xff;
3683 rnd >>= 8;
3684 }
3685 x11_saved_data_len = data_len;
3686 x11_fake_data_len = data_len;
3687 }
3688
3689 /* Convert the fake data into hex. */
3690 new_data = tohex(x11_fake_data, data_len);
3691
3692 /* Send the request packet. */
3693 if (compat20) {
3694 channel_request_start(client_session_id, "x11-req", want_reply);
3695 packet_put_char(0); /* XXX bool single connection */
3696 } else {
3697 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3698 }
3699 packet_put_cstring(proto);
3700 packet_put_cstring(new_data);
3701 packet_put_int(screen_number);
3702 packet_send();
3703 packet_write_wait();
3704 xfree(new_data);
3705}
3706
3707
3708/* -- agent forwarding */
3709
3710/* Sends a message to the server to request authentication fd forwarding. */
3711
3712void
3713auth_request_forwarding(void)
3714{
3715 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3716 packet_send();
3717 packet_write_wait();
3718}
| 2863 c->path = xstrdup(host);
2864 c->host_port = port_to_connect;
2865 c->listening_port = listen_port;
2866 success = 1;
2867 }
2868 if (success == 0)
2869 error("channel_setup_fwd_listener: cannot listen to port: %d",
2870 listen_port);
2871 freeaddrinfo(aitop);
2872 return success;
2873}
2874
2875int
2876channel_cancel_rport_listener(const char *host, u_short port)
2877{
2878 u_int i;
2879 int found = 0;
2880
2881 for (i = 0; i < channels_alloc; i++) {
2882 Channel *c = channels[i];
2883
2884 if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER &&
2885 strcmp(c->path, host) == 0 && c->listening_port == port) {
2886 debug2("%s: close channel %d", __func__, i);
2887 channel_free(c);
2888 found = 1;
2889 }
2890 }
2891
2892 return (found);
2893}
2894
2895/* protocol local port fwd, used by ssh (and sshd in v1) */
2896int
2897channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port,
2898 const char *host_to_connect, u_short port_to_connect, int gateway_ports)
2899{
2900 return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER,
2901 listen_host, listen_port, NULL, host_to_connect, port_to_connect,
2902 gateway_ports);
2903}
2904
2905/* protocol v2 remote port fwd, used by sshd */
2906int
2907channel_setup_remote_fwd_listener(const char *listen_address,
2908 u_short listen_port, int *allocated_listen_port, int gateway_ports)
2909{
2910 return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER,
2911 listen_address, listen_port, allocated_listen_port,
2912 NULL, 0, gateway_ports);
2913}
2914
2915/*
2916 * Initiate forwarding of connections to port "port" on remote host through
2917 * the secure channel to host:port from local side.
2918 */
2919
2920int
2921channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
2922 const char *host_to_connect, u_short port_to_connect)
2923{
2924 int type, success = 0;
2925
2926 /* Send the forward request to the remote side. */
2927 if (compat20) {
2928 const char *address_to_bind;
2929 if (listen_host == NULL) {
2930 if (datafellows & SSH_BUG_RFWD_ADDR)
2931 address_to_bind = "127.0.0.1";
2932 else
2933 address_to_bind = "localhost";
2934 } else if (*listen_host == '\0' ||
2935 strcmp(listen_host, "*") == 0) {
2936 if (datafellows & SSH_BUG_RFWD_ADDR)
2937 address_to_bind = "0.0.0.0";
2938 else
2939 address_to_bind = "";
2940 } else
2941 address_to_bind = listen_host;
2942
2943 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2944 packet_put_cstring("tcpip-forward");
2945 packet_put_char(1); /* boolean: want reply */
2946 packet_put_cstring(address_to_bind);
2947 packet_put_int(listen_port);
2948 packet_send();
2949 packet_write_wait();
2950 /* Assume that server accepts the request */
2951 success = 1;
2952 } else {
2953 packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
2954 packet_put_int(listen_port);
2955 packet_put_cstring(host_to_connect);
2956 packet_put_int(port_to_connect);
2957 packet_send();
2958 packet_write_wait();
2959
2960 /* Wait for response from the remote side. */
2961 type = packet_read();
2962 switch (type) {
2963 case SSH_SMSG_SUCCESS:
2964 success = 1;
2965 break;
2966 case SSH_SMSG_FAILURE:
2967 break;
2968 default:
2969 /* Unknown packet */
2970 packet_disconnect("Protocol error for port forward request:"
2971 "received packet type %d.", type);
2972 }
2973 }
2974 if (success) {
2975 /* Record that connection to this host/port is permitted. */
2976 permitted_opens = xrealloc(permitted_opens,
2977 num_permitted_opens + 1, sizeof(*permitted_opens));
2978 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
2979 permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
2980 permitted_opens[num_permitted_opens].listen_port = listen_port;
2981 num_permitted_opens++;
2982 }
2983 return (success ? 0 : -1);
2984}
2985
2986/*
2987 * Request cancellation of remote forwarding of connection host:port from
2988 * local side.
2989 */
2990void
2991channel_request_rforward_cancel(const char *host, u_short port)
2992{
2993 int i;
2994
2995 if (!compat20)
2996 return;
2997
2998 for (i = 0; i < num_permitted_opens; i++) {
2999 if (permitted_opens[i].host_to_connect != NULL &&
3000 permitted_opens[i].listen_port == port)
3001 break;
3002 }
3003 if (i >= num_permitted_opens) {
3004 debug("%s: requested forward not found", __func__);
3005 return;
3006 }
3007 packet_start(SSH2_MSG_GLOBAL_REQUEST);
3008 packet_put_cstring("cancel-tcpip-forward");
3009 packet_put_char(0);
3010 packet_put_cstring(host == NULL ? "" : host);
3011 packet_put_int(port);
3012 packet_send();
3013
3014 permitted_opens[i].listen_port = 0;
3015 permitted_opens[i].port_to_connect = 0;
3016 xfree(permitted_opens[i].host_to_connect);
3017 permitted_opens[i].host_to_connect = NULL;
3018}
3019
3020/*
3021 * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates
3022 * listening for the port, and sends back a success reply (or disconnect
3023 * message if there was an error).
3024 */
3025int
3026channel_input_port_forward_request(int is_root, int gateway_ports)
3027{
3028 u_short port, host_port;
3029 int success = 0;
3030 char *hostname;
3031
3032 /* Get arguments from the packet. */
3033 port = packet_get_int();
3034 hostname = packet_get_string(NULL);
3035 host_port = packet_get_int();
3036
3037#ifndef HAVE_CYGWIN
3038 /*
3039 * Check that an unprivileged user is not trying to forward a
3040 * privileged port.
3041 */
3042 if (port < IPPORT_RESERVED && !is_root)
3043 packet_disconnect(
3044 "Requested forwarding of port %d but user is not root.",
3045 port);
3046 if (host_port == 0)
3047 packet_disconnect("Dynamic forwarding denied.");
3048#endif
3049
3050 /* Initiate forwarding */
3051 success = channel_setup_local_fwd_listener(NULL, port, hostname,
3052 host_port, gateway_ports);
3053
3054 /* Free the argument string. */
3055 xfree(hostname);
3056
3057 return (success ? 0 : -1);
3058}
3059
3060/*
3061 * Permits opening to any host/port if permitted_opens[] is empty. This is
3062 * usually called by the server, because the user could connect to any port
3063 * anyway, and the server has no way to know but to trust the client anyway.
3064 */
3065void
3066channel_permit_all_opens(void)
3067{
3068 if (num_permitted_opens == 0)
3069 all_opens_permitted = 1;
3070}
3071
3072void
3073channel_add_permitted_opens(char *host, int port)
3074{
3075 debug("allow port forwarding to host %s port %d", host, port);
3076
3077 permitted_opens = xrealloc(permitted_opens,
3078 num_permitted_opens + 1, sizeof(*permitted_opens));
3079 permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
3080 permitted_opens[num_permitted_opens].port_to_connect = port;
3081 num_permitted_opens++;
3082
3083 all_opens_permitted = 0;
3084}
3085
3086int
3087channel_add_adm_permitted_opens(char *host, int port)
3088{
3089 debug("config allows port forwarding to host %s port %d", host, port);
3090
3091 permitted_adm_opens = xrealloc(permitted_adm_opens,
3092 num_adm_permitted_opens + 1, sizeof(*permitted_adm_opens));
3093 permitted_adm_opens[num_adm_permitted_opens].host_to_connect
3094 = xstrdup(host);
3095 permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
3096 return ++num_adm_permitted_opens;
3097}
3098
3099void
3100channel_clear_permitted_opens(void)
3101{
3102 int i;
3103
3104 for (i = 0; i < num_permitted_opens; i++)
3105 if (permitted_opens[i].host_to_connect != NULL)
3106 xfree(permitted_opens[i].host_to_connect);
3107 if (num_permitted_opens > 0) {
3108 xfree(permitted_opens);
3109 permitted_opens = NULL;
3110 }
3111 num_permitted_opens = 0;
3112}
3113
3114void
3115channel_clear_adm_permitted_opens(void)
3116{
3117 int i;
3118
3119 for (i = 0; i < num_adm_permitted_opens; i++)
3120 if (permitted_adm_opens[i].host_to_connect != NULL)
3121 xfree(permitted_adm_opens[i].host_to_connect);
3122 if (num_adm_permitted_opens > 0) {
3123 xfree(permitted_adm_opens);
3124 permitted_adm_opens = NULL;
3125 }
3126 num_adm_permitted_opens = 0;
3127}
3128
3129void
3130channel_print_adm_permitted_opens(void)
3131{
3132 int i;
3133
3134 printf("permitopen");
3135 if (num_adm_permitted_opens == 0) {
3136 printf(" any\n");
3137 return;
3138 }
3139 for (i = 0; i < num_adm_permitted_opens; i++)
3140 if (permitted_adm_opens[i].host_to_connect != NULL)
3141 printf(" %s:%d", permitted_adm_opens[i].host_to_connect,
3142 permitted_adm_opens[i].port_to_connect);
3143 printf("\n");
3144}
3145
3146/* Try to start non-blocking connect to next host in cctx list */
3147static int
3148connect_next(struct channel_connect *cctx)
3149{
3150 int sock, saved_errno;
3151 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
3152
3153 for (; cctx->ai; cctx->ai = cctx->ai->ai_next) {
3154 if (cctx->ai->ai_family != AF_INET &&
3155 cctx->ai->ai_family != AF_INET6)
3156 continue;
3157 if (getnameinfo(cctx->ai->ai_addr, cctx->ai->ai_addrlen,
3158 ntop, sizeof(ntop), strport, sizeof(strport),
3159 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
3160 error("connect_next: getnameinfo failed");
3161 continue;
3162 }
3163 if ((sock = socket(cctx->ai->ai_family, cctx->ai->ai_socktype,
3164 cctx->ai->ai_protocol)) == -1) {
3165 if (cctx->ai->ai_next == NULL)
3166 error("socket: %.100s", strerror(errno));
3167 else
3168 verbose("socket: %.100s", strerror(errno));
3169 continue;
3170 }
3171 if (set_nonblock(sock) == -1)
3172 fatal("%s: set_nonblock(%d)", __func__, sock);
3173 if (connect(sock, cctx->ai->ai_addr,
3174 cctx->ai->ai_addrlen) == -1 && errno != EINPROGRESS) {
3175 debug("connect_next: host %.100s ([%.100s]:%s): "
3176 "%.100s", cctx->host, ntop, strport,
3177 strerror(errno));
3178 saved_errno = errno;
3179 close(sock);
3180 errno = saved_errno;
3181 continue; /* fail -- try next */
3182 }
3183 debug("connect_next: host %.100s ([%.100s]:%s) "
3184 "in progress, fd=%d", cctx->host, ntop, strport, sock);
3185 cctx->ai = cctx->ai->ai_next;
3186 set_nodelay(sock);
3187 return sock;
3188 }
3189 return -1;
3190}
3191
3192static void
3193channel_connect_ctx_free(struct channel_connect *cctx)
3194{
3195 xfree(cctx->host);
3196 if (cctx->aitop)
3197 freeaddrinfo(cctx->aitop);
3198 bzero(cctx, sizeof(*cctx));
3199 cctx->host = NULL;
3200 cctx->ai = cctx->aitop = NULL;
3201}
3202
3203/* Return CONNECTING channel to remote host, port */
3204static Channel *
3205connect_to(const char *host, u_short port, char *ctype, char *rname)
3206{
3207 struct addrinfo hints;
3208 int gaierr;
3209 int sock = -1;
3210 char strport[NI_MAXSERV];
3211 struct channel_connect cctx;
3212 Channel *c;
3213
3214 memset(&cctx, 0, sizeof(cctx));
3215 memset(&hints, 0, sizeof(hints));
3216 hints.ai_family = IPv4or6;
3217 hints.ai_socktype = SOCK_STREAM;
3218 snprintf(strport, sizeof strport, "%d", port);
3219 if ((gaierr = getaddrinfo(host, strport, &hints, &cctx.aitop)) != 0) {
3220 error("connect_to %.100s: unknown host (%s)", host,
3221 ssh_gai_strerror(gaierr));
3222 return NULL;
3223 }
3224
3225 cctx.host = xstrdup(host);
3226 cctx.port = port;
3227 cctx.ai = cctx.aitop;
3228
3229 if ((sock = connect_next(&cctx)) == -1) {
3230 error("connect to %.100s port %d failed: %s",
3231 host, port, strerror(errno));
3232 channel_connect_ctx_free(&cctx);
3233 return NULL;
3234 }
3235 c = channel_new(ctype, SSH_CHANNEL_CONNECTING, sock, sock, -1,
3236 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, rname, 1);
3237 c->connect_ctx = cctx;
3238 return c;
3239}
3240
3241Channel *
3242channel_connect_by_listen_address(u_short listen_port, char *ctype, char *rname)
3243{
3244 int i;
3245
3246 for (i = 0; i < num_permitted_opens; i++) {
3247 if (permitted_opens[i].host_to_connect != NULL &&
3248 permitted_opens[i].listen_port == listen_port) {
3249 return connect_to(
3250 permitted_opens[i].host_to_connect,
3251 permitted_opens[i].port_to_connect, ctype, rname);
3252 }
3253 }
3254 error("WARNING: Server requests forwarding for unknown listen_port %d",
3255 listen_port);
3256 return NULL;
3257}
3258
3259/* Check if connecting to that port is permitted and connect. */
3260Channel *
3261channel_connect_to(const char *host, u_short port, char *ctype, char *rname)
3262{
3263 int i, permit, permit_adm = 1;
3264
3265 permit = all_opens_permitted;
3266 if (!permit) {
3267 for (i = 0; i < num_permitted_opens; i++)
3268 if (permitted_opens[i].host_to_connect != NULL &&
3269 permitted_opens[i].port_to_connect == port &&
3270 strcmp(permitted_opens[i].host_to_connect, host) == 0)
3271 permit = 1;
3272 }
3273
3274 if (num_adm_permitted_opens > 0) {
3275 permit_adm = 0;
3276 for (i = 0; i < num_adm_permitted_opens; i++)
3277 if (permitted_adm_opens[i].host_to_connect != NULL &&
3278 permitted_adm_opens[i].port_to_connect == port &&
3279 strcmp(permitted_adm_opens[i].host_to_connect, host)
3280 == 0)
3281 permit_adm = 1;
3282 }
3283
3284 if (!permit || !permit_adm) {
3285 logit("Received request to connect to host %.100s port %d, "
3286 "but the request was denied.", host, port);
3287 return NULL;
3288 }
3289 return connect_to(host, port, ctype, rname);
3290}
3291
3292void
3293channel_send_window_changes(void)
3294{
3295 u_int i;
3296 struct winsize ws;
3297
3298 for (i = 0; i < channels_alloc; i++) {
3299 if (channels[i] == NULL || !channels[i]->client_tty ||
3300 channels[i]->type != SSH_CHANNEL_OPEN)
3301 continue;
3302 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
3303 continue;
3304 channel_request_start(i, "window-change", 0);
3305 packet_put_int((u_int)ws.ws_col);
3306 packet_put_int((u_int)ws.ws_row);
3307 packet_put_int((u_int)ws.ws_xpixel);
3308 packet_put_int((u_int)ws.ws_ypixel);
3309 packet_send();
3310 }
3311}
3312
3313/* -- X11 forwarding */
3314
3315/*
3316 * Creates an internet domain socket for listening for X11 connections.
3317 * Returns 0 and a suitable display number for the DISPLAY variable
3318 * stored in display_numberp , or -1 if an error occurs.
3319 */
3320int
3321x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
3322 int single_connection, u_int *display_numberp, int **chanids)
3323{
3324 Channel *nc = NULL;
3325 int display_number, sock;
3326 u_short port;
3327 struct addrinfo hints, *ai, *aitop;
3328 char strport[NI_MAXSERV];
3329 int gaierr, n, num_socks = 0, socks[NUM_SOCKS];
3330
3331 if (chanids == NULL)
3332 return -1;
3333
3334 for (display_number = x11_display_offset;
3335 display_number < MAX_DISPLAYS;
3336 display_number++) {
3337 port = 6000 + display_number;
3338 memset(&hints, 0, sizeof(hints));
3339 hints.ai_family = IPv4or6;
3340 hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE;
3341 hints.ai_socktype = SOCK_STREAM;
3342 snprintf(strport, sizeof strport, "%d", port);
3343 if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) {
3344 error("getaddrinfo: %.100s", ssh_gai_strerror(gaierr));
3345 return -1;
3346 }
3347 for (ai = aitop; ai; ai = ai->ai_next) {
3348 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
3349 continue;
3350 sock = socket(ai->ai_family, ai->ai_socktype,
3351 ai->ai_protocol);
3352 if (sock < 0) {
3353 if ((errno != EINVAL) && (errno != EAFNOSUPPORT)
3354#ifdef EPFNOSUPPORT
3355 && (errno != EPFNOSUPPORT)
3356#endif
3357 ) {
3358 error("socket: %.100s", strerror(errno));
3359 freeaddrinfo(aitop);
3360 return -1;
3361 } else {
3362 debug("x11_create_display_inet: Socket family %d not supported",
3363 ai->ai_family);
3364 continue;
3365 }
3366 }
3367 if (ai->ai_family == AF_INET6)
3368 sock_set_v6only(sock);
3369 if (x11_use_localhost)
3370 channel_set_reuseaddr(sock);
3371 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3372 debug2("bind port %d: %.100s", port, strerror(errno));
3373 close(sock);
3374
3375 for (n = 0; n < num_socks; n++) {
3376 close(socks[n]);
3377 }
3378 num_socks = 0;
3379 break;
3380 }
3381 socks[num_socks++] = sock;
3382 if (num_socks == NUM_SOCKS)
3383 break;
3384 }
3385 freeaddrinfo(aitop);
3386 if (num_socks > 0)
3387 break;
3388 }
3389 if (display_number >= MAX_DISPLAYS) {
3390 error("Failed to allocate internet-domain X11 display socket.");
3391 return -1;
3392 }
3393 /* Start listening for connections on the socket. */
3394 for (n = 0; n < num_socks; n++) {
3395 sock = socks[n];
3396 if (listen(sock, SSH_LISTEN_BACKLOG) < 0) {
3397 error("listen: %.100s", strerror(errno));
3398 close(sock);
3399 return -1;
3400 }
3401 }
3402
3403 /* Allocate a channel for each socket. */
3404 *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
3405 for (n = 0; n < num_socks; n++) {
3406 sock = socks[n];
3407 if (hpn_disabled)
3408 nc = channel_new("x11 listener",
3409 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3410 CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
3411 0, "X11 inet listener", 1);
3412 else
3413 nc = channel_new("x11 listener",
3414 SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
3415 buffer_size, CHAN_X11_PACKET_DEFAULT,
3416 0, "X11 inet listener", 1);
3417 nc->single_connection = single_connection;
3418 (*chanids)[n] = nc->self;
3419 }
3420 (*chanids)[n] = -1;
3421
3422 /* Return the display number for the DISPLAY environment variable. */
3423 *display_numberp = display_number;
3424 return (0);
3425}
3426
3427static int
3428connect_local_xsocket_path(const char *pathname)
3429{
3430 int sock;
3431 struct sockaddr_un addr;
3432
3433 sock = socket(AF_UNIX, SOCK_STREAM, 0);
3434 if (sock < 0)
3435 error("socket: %.100s", strerror(errno));
3436 memset(&addr, 0, sizeof(addr));
3437 addr.sun_family = AF_UNIX;
3438 strlcpy(addr.sun_path, pathname, sizeof addr.sun_path);
3439 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
3440 return sock;
3441 close(sock);
3442 error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
3443 return -1;
3444}
3445
3446static int
3447connect_local_xsocket(u_int dnr)
3448{
3449 char buf[1024];
3450 snprintf(buf, sizeof buf, _PATH_UNIX_X, dnr);
3451 return connect_local_xsocket_path(buf);
3452}
3453
3454int
3455x11_connect_display(void)
3456{
3457 u_int display_number;
3458 const char *display;
3459 char buf[1024], *cp;
3460 struct addrinfo hints, *ai, *aitop;
3461 char strport[NI_MAXSERV];
3462 int gaierr, sock = 0;
3463
3464 /* Try to open a socket for the local X server. */
3465 display = getenv("DISPLAY");
3466 if (!display) {
3467 error("DISPLAY not set.");
3468 return -1;
3469 }
3470 /*
3471 * Now we decode the value of the DISPLAY variable and make a
3472 * connection to the real X server.
3473 */
3474
3475 /* Check if the display is from launchd. */
3476#ifdef __APPLE__
3477 if (strncmp(display, "/tmp/launch", 11) == 0) {
3478 sock = connect_local_xsocket_path(display);
3479 if (sock < 0)
3480 return -1;
3481
3482 /* OK, we now have a connection to the display. */
3483 return sock;
3484 }
3485#endif
3486 /*
3487 * Check if it is a unix domain socket. Unix domain displays are in
3488 * one of the following formats: unix:d[.s], :d[.s], ::d[.s]
3489 */
3490 if (strncmp(display, "unix:", 5) == 0 ||
3491 display[0] == ':') {
3492 /* Connect to the unix domain socket. */
3493 if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
3494 error("Could not parse display number from DISPLAY: %.100s",
3495 display);
3496 return -1;
3497 }
3498 /* Create a socket. */
3499 sock = connect_local_xsocket(display_number);
3500 if (sock < 0)
3501 return -1;
3502
3503 /* OK, we now have a connection to the display. */
3504 return sock;
3505 }
3506 /*
3507 * Connect to an inet socket. The DISPLAY value is supposedly
3508 * hostname:d[.s], where hostname may also be numeric IP address.
3509 */
3510 strlcpy(buf, display, sizeof(buf));
3511 cp = strchr(buf, ':');
3512 if (!cp) {
3513 error("Could not find ':' in DISPLAY: %.100s", display);
3514 return -1;
3515 }
3516 *cp = 0;
3517 /* buf now contains the host name. But first we parse the display number. */
3518 if (sscanf(cp + 1, "%u", &display_number) != 1) {
3519 error("Could not parse display number from DISPLAY: %.100s",
3520 display);
3521 return -1;
3522 }
3523
3524 /* Look up the host address */
3525 memset(&hints, 0, sizeof(hints));
3526 hints.ai_family = IPv4or6;
3527 hints.ai_socktype = SOCK_STREAM;
3528 snprintf(strport, sizeof strport, "%u", 6000 + display_number);
3529 if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
3530 error("%.100s: unknown host. (%s)", buf,
3531 ssh_gai_strerror(gaierr));
3532 return -1;
3533 }
3534 for (ai = aitop; ai; ai = ai->ai_next) {
3535 /* Create a socket. */
3536 sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
3537 if (sock < 0) {
3538 debug2("socket: %.100s", strerror(errno));
3539 continue;
3540 }
3541 /* Connect it to the display. */
3542 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
3543 debug2("connect %.100s port %u: %.100s", buf,
3544 6000 + display_number, strerror(errno));
3545 close(sock);
3546 continue;
3547 }
3548 /* Success */
3549 break;
3550 }
3551 freeaddrinfo(aitop);
3552 if (!ai) {
3553 error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
3554 strerror(errno));
3555 return -1;
3556 }
3557 set_nodelay(sock);
3558 return sock;
3559}
3560
3561/*
3562 * This is called when SSH_SMSG_X11_OPEN is received. The packet contains
3563 * the remote channel number. We should do whatever we want, and respond
3564 * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
3565 */
3566
3567/* ARGSUSED */
3568void
3569x11_input_open(int type, u_int32_t seq, void *ctxt)
3570{
3571 Channel *c = NULL;
3572 int remote_id, sock = 0;
3573 char *remote_host;
3574
3575 debug("Received X11 open request.");
3576
3577 remote_id = packet_get_int();
3578
3579 if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) {
3580 remote_host = packet_get_string(NULL);
3581 } else {
3582 remote_host = xstrdup("unknown (remote did not supply name)");
3583 }
3584 packet_check_eom();
3585
3586 /* Obtain a connection to the real X display. */
3587 sock = x11_connect_display();
3588 if (sock != -1) {
3589 /* Allocate a channel for this connection. */
3590 c = channel_new("connected x11 socket",
3591 SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0,
3592 remote_host, 1);
3593 c->remote_id = remote_id;
3594 c->force_drain = 1;
3595 }
3596 xfree(remote_host);
3597 if (c == NULL) {
3598 /* Send refusal to the remote host. */
3599 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3600 packet_put_int(remote_id);
3601 } else {
3602 /* Send a confirmation to the remote host. */
3603 packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
3604 packet_put_int(remote_id);
3605 packet_put_int(c->self);
3606 }
3607 packet_send();
3608}
3609
3610/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
3611/* ARGSUSED */
3612void
3613deny_input_open(int type, u_int32_t seq, void *ctxt)
3614{
3615 int rchan = packet_get_int();
3616
3617 switch (type) {
3618 case SSH_SMSG_AGENT_OPEN:
3619 error("Warning: ssh server tried agent forwarding.");
3620 break;
3621 case SSH_SMSG_X11_OPEN:
3622 error("Warning: ssh server tried X11 forwarding.");
3623 break;
3624 default:
3625 error("deny_input_open: type %d", type);
3626 break;
3627 }
3628 error("Warning: this is probably a break-in attempt by a malicious server.");
3629 packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
3630 packet_put_int(rchan);
3631 packet_send();
3632}
3633
3634/*
3635 * Requests forwarding of X11 connections, generates fake authentication
3636 * data, and enables authentication spoofing.
3637 * This should be called in the client only.
3638 */
3639void
3640x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
3641 const char *proto, const char *data, int want_reply)
3642{
3643 u_int data_len = (u_int) strlen(data) / 2;
3644 u_int i, value;
3645 char *new_data;
3646 int screen_number;
3647 const char *cp;
3648 u_int32_t rnd = 0;
3649
3650 if (x11_saved_display == NULL)
3651 x11_saved_display = xstrdup(disp);
3652 else if (strcmp(disp, x11_saved_display) != 0) {
3653 error("x11_request_forwarding_with_spoofing: different "
3654 "$DISPLAY already forwarded");
3655 return;
3656 }
3657
3658 cp = strchr(disp, ':');
3659 if (cp)
3660 cp = strchr(cp, '.');
3661 if (cp)
3662 screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
3663 else
3664 screen_number = 0;
3665
3666 if (x11_saved_proto == NULL) {
3667 /* Save protocol name. */
3668 x11_saved_proto = xstrdup(proto);
3669 /*
3670 * Extract real authentication data and generate fake data
3671 * of the same length.
3672 */
3673 x11_saved_data = xmalloc(data_len);
3674 x11_fake_data = xmalloc(data_len);
3675 for (i = 0; i < data_len; i++) {
3676 if (sscanf(data + 2 * i, "%2x", &value) != 1)
3677 fatal("x11_request_forwarding: bad "
3678 "authentication data: %.100s", data);
3679 if (i % 4 == 0)
3680 rnd = arc4random();
3681 x11_saved_data[i] = value;
3682 x11_fake_data[i] = rnd & 0xff;
3683 rnd >>= 8;
3684 }
3685 x11_saved_data_len = data_len;
3686 x11_fake_data_len = data_len;
3687 }
3688
3689 /* Convert the fake data into hex. */
3690 new_data = tohex(x11_fake_data, data_len);
3691
3692 /* Send the request packet. */
3693 if (compat20) {
3694 channel_request_start(client_session_id, "x11-req", want_reply);
3695 packet_put_char(0); /* XXX bool single connection */
3696 } else {
3697 packet_start(SSH_CMSG_X11_REQUEST_FORWARDING);
3698 }
3699 packet_put_cstring(proto);
3700 packet_put_cstring(new_data);
3701 packet_put_int(screen_number);
3702 packet_send();
3703 packet_write_wait();
3704 xfree(new_data);
3705}
3706
3707
3708/* -- agent forwarding */
3709
3710/* Sends a message to the server to request authentication fd forwarding. */
3711
3712void
3713auth_request_forwarding(void)
3714{
3715 packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING);
3716 packet_send();
3717 packet_write_wait();
3718}
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