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3c0ef626 | 1 | /* |
2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5 | * This file contains functions for generic socket connection forwarding. | |
6 | * There is also code for initiating connection forwarding for X11 connections, | |
7 | * arbitrary tcp/ip connections, and the authentication agent connection. | |
8 | * | |
9 | * As far as I am concerned, the code I have written for this software | |
10 | * can be used freely for any purpose. Any derived versions of this | |
11 | * software must be clearly marked as such, and if the derived work is | |
12 | * incompatible with the protocol description in the RFC file, it must be | |
13 | * called by a name other than "ssh" or "Secure Shell". | |
14 | * | |
15 | * SSH2 support added by Markus Friedl. | |
473db5ab | 16 | * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. |
3c0ef626 | 17 | * Copyright (c) 1999 Dug Song. All rights reserved. |
18 | * Copyright (c) 1999 Theo de Raadt. All rights reserved. | |
19 | * | |
20 | * Redistribution and use in source and binary forms, with or without | |
21 | * modification, are permitted provided that the following conditions | |
22 | * are met: | |
23 | * 1. Redistributions of source code must retain the above copyright | |
24 | * notice, this list of conditions and the following disclaimer. | |
25 | * 2. Redistributions in binary form must reproduce the above copyright | |
26 | * notice, this list of conditions and the following disclaimer in the | |
27 | * documentation and/or other materials provided with the distribution. | |
28 | * | |
29 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
30 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
31 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
32 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
33 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
34 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
35 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
36 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
37 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
38 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
39 | */ | |
40 | ||
41 | #include "includes.h" | |
08822d99 | 42 | RCSID("$OpenBSD: channels.c,v 1.232 2006/01/30 12:22:22 reyk Exp $"); |
3c0ef626 | 43 | |
44 | #include "ssh.h" | |
45 | #include "ssh1.h" | |
46 | #include "ssh2.h" | |
47 | #include "packet.h" | |
48 | #include "xmalloc.h" | |
3c0ef626 | 49 | #include "log.h" |
50 | #include "misc.h" | |
51 | #include "channels.h" | |
52 | #include "compat.h" | |
53 | #include "canohost.h" | |
54 | #include "key.h" | |
55 | #include "authfd.h" | |
473db5ab | 56 | #include "pathnames.h" |
57 | #include "bufaux.h" | |
3c0ef626 | 58 | |
59 | /* -- channel core */ | |
60 | ||
61 | /* | |
62 | * Pointer to an array containing all allocated channels. The array is | |
63 | * dynamically extended as needed. | |
64 | */ | |
65 | static Channel **channels = NULL; | |
66 | ||
67 | /* | |
68 | * Size of the channel array. All slots of the array must always be | |
69 | * initialized (at least the type field); unused slots set to NULL | |
70 | */ | |
473db5ab | 71 | static u_int channels_alloc = 0; |
3c0ef626 | 72 | |
73 | /* | |
74 | * Maximum file descriptor value used in any of the channels. This is | |
75 | * updated in channel_new. | |
76 | */ | |
77 | static int channel_max_fd = 0; | |
78 | ||
79 | ||
80 | /* -- tcp forwarding */ | |
81 | ||
82 | /* | |
83 | * Data structure for storing which hosts are permitted for forward requests. | |
84 | * The local sides of any remote forwards are stored in this array to prevent | |
85 | * a corrupt remote server from accessing arbitrary TCP/IP ports on our local | |
86 | * network (which might be behind a firewall). | |
87 | */ | |
88 | typedef struct { | |
89 | char *host_to_connect; /* Connect to 'host'. */ | |
90 | u_short port_to_connect; /* Connect to 'port'. */ | |
91 | u_short listen_port; /* Remote side should listen port number. */ | |
92 | } ForwardPermission; | |
93 | ||
94 | /* List of all permitted host/port pairs to connect. */ | |
95 | static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; | |
96 | ||
97 | /* Number of permitted host/port pairs in the array. */ | |
98 | static int num_permitted_opens = 0; | |
99 | /* | |
100 | * If this is true, all opens are permitted. This is the case on the server | |
101 | * on which we have to trust the client anyway, and the user could do | |
102 | * anything after logging in anyway. | |
103 | */ | |
104 | static int all_opens_permitted = 0; | |
105 | ||
106 | ||
107 | /* -- X11 forwarding */ | |
108 | ||
109 | /* Maximum number of fake X11 displays to try. */ | |
110 | #define MAX_DISPLAYS 1000 | |
111 | ||
473db5ab | 112 | /* Saved X11 local (client) display. */ |
113 | static char *x11_saved_display = NULL; | |
114 | ||
3c0ef626 | 115 | /* Saved X11 authentication protocol name. */ |
116 | static char *x11_saved_proto = NULL; | |
117 | ||
118 | /* Saved X11 authentication data. This is the real data. */ | |
119 | static char *x11_saved_data = NULL; | |
120 | static u_int x11_saved_data_len = 0; | |
121 | ||
122 | /* | |
123 | * Fake X11 authentication data. This is what the server will be sending us; | |
124 | * we should replace any occurrences of this by the real data. | |
125 | */ | |
126 | static char *x11_fake_data = NULL; | |
127 | static u_int x11_fake_data_len; | |
128 | ||
129 | ||
130 | /* -- agent forwarding */ | |
131 | ||
132 | #define NUM_SOCKS 10 | |
133 | ||
3c0ef626 | 134 | /* AF_UNSPEC or AF_INET or AF_INET6 */ |
135 | static int IPv4or6 = AF_UNSPEC; | |
136 | ||
137 | /* helper */ | |
138 | static void port_open_helper(Channel *c, char *rtype); | |
139 | ||
140 | /* -- channel core */ | |
141 | ||
142 | Channel * | |
08822d99 | 143 | channel_by_id(int id) |
3c0ef626 | 144 | { |
145 | Channel *c; | |
146 | ||
473db5ab | 147 | if (id < 0 || (u_int)id >= channels_alloc) { |
08822d99 | 148 | logit("channel_by_id: %d: bad id", id); |
3c0ef626 | 149 | return NULL; |
150 | } | |
151 | c = channels[id]; | |
152 | if (c == NULL) { | |
08822d99 | 153 | logit("channel_by_id: %d: bad id: channel free", id); |
3c0ef626 | 154 | return NULL; |
155 | } | |
156 | return c; | |
157 | } | |
158 | ||
08822d99 | 159 | /* |
160 | * Returns the channel if it is allowed to receive protocol messages. | |
161 | * Private channels, like listening sockets, may not receive messages. | |
162 | */ | |
163 | Channel * | |
164 | channel_lookup(int id) | |
165 | { | |
166 | Channel *c; | |
167 | ||
168 | if ((c = channel_by_id(id)) == NULL) | |
169 | return (NULL); | |
170 | ||
171 | switch(c->type) { | |
172 | case SSH_CHANNEL_X11_OPEN: | |
173 | case SSH_CHANNEL_LARVAL: | |
174 | case SSH_CHANNEL_CONNECTING: | |
175 | case SSH_CHANNEL_DYNAMIC: | |
176 | case SSH_CHANNEL_OPENING: | |
177 | case SSH_CHANNEL_OPEN: | |
178 | case SSH_CHANNEL_INPUT_DRAINING: | |
179 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
180 | return (c); | |
181 | break; | |
182 | } | |
183 | logit("Non-public channel %d, type %d.", id, c->type); | |
184 | return (NULL); | |
185 | } | |
186 | ||
3c0ef626 | 187 | /* |
188 | * Register filedescriptors for a channel, used when allocating a channel or | |
189 | * when the channel consumer/producer is ready, e.g. shell exec'd | |
190 | */ | |
191 | ||
192 | static void | |
193 | channel_register_fds(Channel *c, int rfd, int wfd, int efd, | |
194 | int extusage, int nonblock) | |
195 | { | |
196 | /* Update the maximum file descriptor value. */ | |
197 | channel_max_fd = MAX(channel_max_fd, rfd); | |
198 | channel_max_fd = MAX(channel_max_fd, wfd); | |
199 | channel_max_fd = MAX(channel_max_fd, efd); | |
200 | ||
201 | /* XXX set close-on-exec -markus */ | |
202 | ||
203 | c->rfd = rfd; | |
204 | c->wfd = wfd; | |
205 | c->sock = (rfd == wfd) ? rfd : -1; | |
473db5ab | 206 | c->ctl_fd = -1; /* XXX: set elsewhere */ |
3c0ef626 | 207 | c->efd = efd; |
208 | c->extended_usage = extusage; | |
209 | ||
210 | /* XXX ugly hack: nonblock is only set by the server */ | |
211 | if (nonblock && isatty(c->rfd)) { | |
473db5ab | 212 | debug2("channel %d: rfd %d isatty", c->self, c->rfd); |
3c0ef626 | 213 | c->isatty = 1; |
214 | if (!isatty(c->wfd)) { | |
215 | error("channel %d: wfd %d is not a tty?", | |
216 | c->self, c->wfd); | |
217 | } | |
218 | } else { | |
219 | c->isatty = 0; | |
220 | } | |
473db5ab | 221 | c->wfd_isatty = isatty(c->wfd); |
3c0ef626 | 222 | |
223 | /* enable nonblocking mode */ | |
224 | if (nonblock) { | |
225 | if (rfd != -1) | |
226 | set_nonblock(rfd); | |
227 | if (wfd != -1) | |
228 | set_nonblock(wfd); | |
229 | if (efd != -1) | |
230 | set_nonblock(efd); | |
231 | } | |
232 | } | |
233 | ||
234 | /* | |
235 | * Allocate a new channel object and set its type and socket. This will cause | |
236 | * remote_name to be freed. | |
237 | */ | |
238 | ||
239 | Channel * | |
240 | channel_new(char *ctype, int type, int rfd, int wfd, int efd, | |
473db5ab | 241 | u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock) |
3c0ef626 | 242 | { |
473db5ab | 243 | int found; |
244 | u_int i; | |
3c0ef626 | 245 | Channel *c; |
246 | ||
247 | /* Do initial allocation if this is the first call. */ | |
248 | if (channels_alloc == 0) { | |
3c0ef626 | 249 | channels_alloc = 10; |
250 | channels = xmalloc(channels_alloc * sizeof(Channel *)); | |
251 | for (i = 0; i < channels_alloc; i++) | |
252 | channels[i] = NULL; | |
3c0ef626 | 253 | } |
254 | /* Try to find a free slot where to put the new channel. */ | |
255 | for (found = -1, i = 0; i < channels_alloc; i++) | |
256 | if (channels[i] == NULL) { | |
257 | /* Found a free slot. */ | |
473db5ab | 258 | found = (int)i; |
3c0ef626 | 259 | break; |
260 | } | |
473db5ab | 261 | if (found < 0) { |
3c0ef626 | 262 | /* There are no free slots. Take last+1 slot and expand the array. */ |
263 | found = channels_alloc; | |
473db5ab | 264 | if (channels_alloc > 10000) |
265 | fatal("channel_new: internal error: channels_alloc %d " | |
266 | "too big.", channels_alloc); | |
267 | channels = xrealloc(channels, | |
268 | (channels_alloc + 10) * sizeof(Channel *)); | |
3c0ef626 | 269 | channels_alloc += 10; |
270 | debug2("channel: expanding %d", channels_alloc); | |
3c0ef626 | 271 | for (i = found; i < channels_alloc; i++) |
272 | channels[i] = NULL; | |
273 | } | |
274 | /* Initialize and return new channel. */ | |
275 | c = channels[found] = xmalloc(sizeof(Channel)); | |
276 | memset(c, 0, sizeof(Channel)); | |
277 | buffer_init(&c->input); | |
278 | buffer_init(&c->output); | |
279 | buffer_init(&c->extended); | |
473db5ab | 280 | c->ostate = CHAN_OUTPUT_OPEN; |
281 | c->istate = CHAN_INPUT_OPEN; | |
282 | c->flags = 0; | |
3c0ef626 | 283 | channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); |
284 | c->self = found; | |
285 | c->type = type; | |
286 | c->ctype = ctype; | |
287 | c->local_window = window; | |
288 | c->local_window_max = window; | |
289 | c->local_consumed = 0; | |
290 | c->local_maxpacket = maxpack; | |
473db5ab | 291 | c->dynamic_window = 0; |
3c0ef626 | 292 | c->remote_id = -1; |
473db5ab | 293 | c->remote_name = xstrdup(remote_name); |
3c0ef626 | 294 | c->remote_window = 0; |
295 | c->remote_maxpacket = 0; | |
3c0ef626 | 296 | c->force_drain = 0; |
473db5ab | 297 | c->single_connection = 0; |
3c0ef626 | 298 | c->detach_user = NULL; |
08822d99 | 299 | c->detach_close = 0; |
473db5ab | 300 | c->confirm = NULL; |
301 | c->confirm_ctx = NULL; | |
3c0ef626 | 302 | c->input_filter = NULL; |
08822d99 | 303 | c->output_filter = NULL; |
3c0ef626 | 304 | debug("channel %d: new [%s]", found, remote_name); |
305 | return c; | |
306 | } | |
307 | ||
308 | static int | |
309 | channel_find_maxfd(void) | |
310 | { | |
473db5ab | 311 | u_int i; |
312 | int max = 0; | |
3c0ef626 | 313 | Channel *c; |
314 | ||
315 | for (i = 0; i < channels_alloc; i++) { | |
316 | c = channels[i]; | |
317 | if (c != NULL) { | |
318 | max = MAX(max, c->rfd); | |
319 | max = MAX(max, c->wfd); | |
320 | max = MAX(max, c->efd); | |
321 | } | |
322 | } | |
323 | return max; | |
324 | } | |
325 | ||
326 | int | |
327 | channel_close_fd(int *fdp) | |
328 | { | |
329 | int ret = 0, fd = *fdp; | |
330 | ||
331 | if (fd != -1) { | |
332 | ret = close(fd); | |
333 | *fdp = -1; | |
334 | if (fd == channel_max_fd) | |
335 | channel_max_fd = channel_find_maxfd(); | |
336 | } | |
337 | return ret; | |
338 | } | |
339 | ||
340 | /* Close all channel fd/socket. */ | |
341 | ||
342 | static void | |
343 | channel_close_fds(Channel *c) | |
344 | { | |
473db5ab | 345 | debug3("channel %d: close_fds r %d w %d e %d c %d", |
346 | c->self, c->rfd, c->wfd, c->efd, c->ctl_fd); | |
3c0ef626 | 347 | |
348 | channel_close_fd(&c->sock); | |
473db5ab | 349 | channel_close_fd(&c->ctl_fd); |
3c0ef626 | 350 | channel_close_fd(&c->rfd); |
351 | channel_close_fd(&c->wfd); | |
352 | channel_close_fd(&c->efd); | |
353 | } | |
354 | ||
355 | /* Free the channel and close its fd/socket. */ | |
356 | ||
357 | void | |
358 | channel_free(Channel *c) | |
359 | { | |
360 | char *s; | |
473db5ab | 361 | u_int i, n; |
3c0ef626 | 362 | |
363 | for (n = 0, i = 0; i < channels_alloc; i++) | |
364 | if (channels[i]) | |
365 | n++; | |
473db5ab | 366 | debug("channel %d: free: %s, nchannels %u", c->self, |
3c0ef626 | 367 | c->remote_name ? c->remote_name : "???", n); |
368 | ||
369 | s = channel_open_message(); | |
473db5ab | 370 | debug3("channel %d: status: %s", c->self, s); |
3c0ef626 | 371 | xfree(s); |
372 | ||
373 | if (c->sock != -1) | |
374 | shutdown(c->sock, SHUT_RDWR); | |
473db5ab | 375 | if (c->ctl_fd != -1) |
376 | shutdown(c->ctl_fd, SHUT_RDWR); | |
3c0ef626 | 377 | channel_close_fds(c); |
378 | buffer_free(&c->input); | |
379 | buffer_free(&c->output); | |
380 | buffer_free(&c->extended); | |
381 | if (c->remote_name) { | |
382 | xfree(c->remote_name); | |
383 | c->remote_name = NULL; | |
384 | } | |
385 | channels[c->self] = NULL; | |
386 | xfree(c); | |
387 | } | |
388 | ||
389 | void | |
390 | channel_free_all(void) | |
391 | { | |
473db5ab | 392 | u_int i; |
3c0ef626 | 393 | |
394 | for (i = 0; i < channels_alloc; i++) | |
395 | if (channels[i] != NULL) | |
396 | channel_free(channels[i]); | |
397 | } | |
398 | ||
399 | /* | |
400 | * Closes the sockets/fds of all channels. This is used to close extra file | |
401 | * descriptors after a fork. | |
402 | */ | |
403 | ||
404 | void | |
473db5ab | 405 | channel_close_all(void) |
3c0ef626 | 406 | { |
473db5ab | 407 | u_int i; |
3c0ef626 | 408 | |
409 | for (i = 0; i < channels_alloc; i++) | |
410 | if (channels[i] != NULL) | |
411 | channel_close_fds(channels[i]); | |
412 | } | |
413 | ||
414 | /* | |
415 | * Stop listening to channels. | |
416 | */ | |
417 | ||
418 | void | |
419 | channel_stop_listening(void) | |
420 | { | |
473db5ab | 421 | u_int i; |
3c0ef626 | 422 | Channel *c; |
423 | ||
424 | for (i = 0; i < channels_alloc; i++) { | |
425 | c = channels[i]; | |
426 | if (c != NULL) { | |
427 | switch (c->type) { | |
428 | case SSH_CHANNEL_AUTH_SOCKET: | |
429 | case SSH_CHANNEL_PORT_LISTENER: | |
430 | case SSH_CHANNEL_RPORT_LISTENER: | |
431 | case SSH_CHANNEL_X11_LISTENER: | |
432 | channel_close_fd(&c->sock); | |
433 | channel_free(c); | |
434 | break; | |
435 | } | |
436 | } | |
437 | } | |
438 | } | |
439 | ||
440 | /* | |
441 | * Returns true if no channel has too much buffered data, and false if one or | |
442 | * more channel is overfull. | |
443 | */ | |
444 | ||
445 | int | |
473db5ab | 446 | channel_not_very_much_buffered_data(void) |
3c0ef626 | 447 | { |
448 | u_int i; | |
449 | Channel *c; | |
450 | ||
451 | for (i = 0; i < channels_alloc; i++) { | |
452 | c = channels[i]; | |
453 | if (c != NULL && c->type == SSH_CHANNEL_OPEN) { | |
454 | #if 0 | |
455 | if (!compat20 && | |
456 | buffer_len(&c->input) > packet_get_maxsize()) { | |
473db5ab | 457 | debug2("channel %d: big input buffer %d", |
3c0ef626 | 458 | c->self, buffer_len(&c->input)); |
459 | return 0; | |
460 | } | |
461 | #endif | |
462 | if (buffer_len(&c->output) > packet_get_maxsize()) { | |
473db5ab | 463 | debug2("channel %d: big output buffer %u > %u", |
3c0ef626 | 464 | c->self, buffer_len(&c->output), |
465 | packet_get_maxsize()); | |
466 | return 0; | |
467 | } | |
468 | } | |
469 | } | |
470 | return 1; | |
471 | } | |
472 | ||
473 | /* Returns true if any channel is still open. */ | |
474 | ||
475 | int | |
473db5ab | 476 | channel_still_open(void) |
3c0ef626 | 477 | { |
473db5ab | 478 | u_int i; |
3c0ef626 | 479 | Channel *c; |
480 | ||
481 | for (i = 0; i < channels_alloc; i++) { | |
482 | c = channels[i]; | |
483 | if (c == NULL) | |
484 | continue; | |
485 | switch (c->type) { | |
486 | case SSH_CHANNEL_X11_LISTENER: | |
487 | case SSH_CHANNEL_PORT_LISTENER: | |
488 | case SSH_CHANNEL_RPORT_LISTENER: | |
489 | case SSH_CHANNEL_CLOSED: | |
490 | case SSH_CHANNEL_AUTH_SOCKET: | |
491 | case SSH_CHANNEL_DYNAMIC: | |
492 | case SSH_CHANNEL_CONNECTING: | |
493 | case SSH_CHANNEL_ZOMBIE: | |
494 | continue; | |
495 | case SSH_CHANNEL_LARVAL: | |
496 | if (!compat20) | |
497 | fatal("cannot happen: SSH_CHANNEL_LARVAL"); | |
498 | continue; | |
499 | case SSH_CHANNEL_OPENING: | |
500 | case SSH_CHANNEL_OPEN: | |
501 | case SSH_CHANNEL_X11_OPEN: | |
502 | return 1; | |
503 | case SSH_CHANNEL_INPUT_DRAINING: | |
504 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
505 | if (!compat13) | |
506 | fatal("cannot happen: OUT_DRAIN"); | |
507 | return 1; | |
508 | default: | |
509 | fatal("channel_still_open: bad channel type %d", c->type); | |
510 | /* NOTREACHED */ | |
511 | } | |
512 | } | |
513 | return 0; | |
514 | } | |
515 | ||
516 | /* Returns the id of an open channel suitable for keepaliving */ | |
517 | ||
518 | int | |
473db5ab | 519 | channel_find_open(void) |
3c0ef626 | 520 | { |
473db5ab | 521 | u_int i; |
3c0ef626 | 522 | Channel *c; |
523 | ||
524 | for (i = 0; i < channels_alloc; i++) { | |
525 | c = channels[i]; | |
473db5ab | 526 | if (c == NULL || c->remote_id < 0) |
3c0ef626 | 527 | continue; |
528 | switch (c->type) { | |
529 | case SSH_CHANNEL_CLOSED: | |
530 | case SSH_CHANNEL_DYNAMIC: | |
531 | case SSH_CHANNEL_X11_LISTENER: | |
532 | case SSH_CHANNEL_PORT_LISTENER: | |
533 | case SSH_CHANNEL_RPORT_LISTENER: | |
534 | case SSH_CHANNEL_OPENING: | |
535 | case SSH_CHANNEL_CONNECTING: | |
536 | case SSH_CHANNEL_ZOMBIE: | |
537 | continue; | |
538 | case SSH_CHANNEL_LARVAL: | |
539 | case SSH_CHANNEL_AUTH_SOCKET: | |
540 | case SSH_CHANNEL_OPEN: | |
541 | case SSH_CHANNEL_X11_OPEN: | |
542 | return i; | |
543 | case SSH_CHANNEL_INPUT_DRAINING: | |
544 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
545 | if (!compat13) | |
546 | fatal("cannot happen: OUT_DRAIN"); | |
547 | return i; | |
548 | default: | |
549 | fatal("channel_find_open: bad channel type %d", c->type); | |
550 | /* NOTREACHED */ | |
551 | } | |
552 | } | |
553 | return -1; | |
554 | } | |
555 | ||
556 | ||
557 | /* | |
558 | * Returns a message describing the currently open forwarded connections, | |
559 | * suitable for sending to the client. The message contains crlf pairs for | |
560 | * newlines. | |
561 | */ | |
562 | ||
563 | char * | |
473db5ab | 564 | channel_open_message(void) |
3c0ef626 | 565 | { |
566 | Buffer buffer; | |
567 | Channel *c; | |
568 | char buf[1024], *cp; | |
473db5ab | 569 | u_int i; |
3c0ef626 | 570 | |
571 | buffer_init(&buffer); | |
572 | snprintf(buf, sizeof buf, "The following connections are open:\r\n"); | |
573 | buffer_append(&buffer, buf, strlen(buf)); | |
574 | for (i = 0; i < channels_alloc; i++) { | |
575 | c = channels[i]; | |
576 | if (c == NULL) | |
577 | continue; | |
578 | switch (c->type) { | |
579 | case SSH_CHANNEL_X11_LISTENER: | |
580 | case SSH_CHANNEL_PORT_LISTENER: | |
581 | case SSH_CHANNEL_RPORT_LISTENER: | |
582 | case SSH_CHANNEL_CLOSED: | |
583 | case SSH_CHANNEL_AUTH_SOCKET: | |
584 | case SSH_CHANNEL_ZOMBIE: | |
585 | continue; | |
586 | case SSH_CHANNEL_LARVAL: | |
587 | case SSH_CHANNEL_OPENING: | |
588 | case SSH_CHANNEL_CONNECTING: | |
589 | case SSH_CHANNEL_DYNAMIC: | |
590 | case SSH_CHANNEL_OPEN: | |
591 | case SSH_CHANNEL_X11_OPEN: | |
592 | case SSH_CHANNEL_INPUT_DRAINING: | |
593 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
473db5ab | 594 | snprintf(buf, sizeof buf, |
595 | " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n", | |
3c0ef626 | 596 | c->self, c->remote_name, |
597 | c->type, c->remote_id, | |
598 | c->istate, buffer_len(&c->input), | |
599 | c->ostate, buffer_len(&c->output), | |
473db5ab | 600 | c->rfd, c->wfd, c->ctl_fd); |
3c0ef626 | 601 | buffer_append(&buffer, buf, strlen(buf)); |
602 | continue; | |
603 | default: | |
604 | fatal("channel_open_message: bad channel type %d", c->type); | |
605 | /* NOTREACHED */ | |
606 | } | |
607 | } | |
608 | buffer_append(&buffer, "\0", 1); | |
609 | cp = xstrdup(buffer_ptr(&buffer)); | |
610 | buffer_free(&buffer); | |
611 | return cp; | |
612 | } | |
613 | ||
614 | void | |
615 | channel_send_open(int id) | |
616 | { | |
617 | Channel *c = channel_lookup(id); | |
473db5ab | 618 | |
3c0ef626 | 619 | if (c == NULL) { |
473db5ab | 620 | logit("channel_send_open: %d: bad id", id); |
3c0ef626 | 621 | return; |
622 | } | |
473db5ab | 623 | debug2("channel %d: send open", id); |
3c0ef626 | 624 | packet_start(SSH2_MSG_CHANNEL_OPEN); |
625 | packet_put_cstring(c->ctype); | |
626 | packet_put_int(c->self); | |
627 | packet_put_int(c->local_window); | |
628 | packet_put_int(c->local_maxpacket); | |
629 | packet_send(); | |
630 | } | |
631 | ||
3c0ef626 | 632 | void |
633 | channel_request_start(int id, char *service, int wantconfirm) | |
634 | { | |
635 | Channel *c = channel_lookup(id); | |
473db5ab | 636 | |
3c0ef626 | 637 | if (c == NULL) { |
473db5ab | 638 | logit("channel_request_start: %d: unknown channel id", id); |
3c0ef626 | 639 | return; |
640 | } | |
473db5ab | 641 | debug2("channel %d: request %s confirm %d", id, service, wantconfirm); |
3c0ef626 | 642 | packet_start(SSH2_MSG_CHANNEL_REQUEST); |
643 | packet_put_int(c->remote_id); | |
644 | packet_put_cstring(service); | |
645 | packet_put_char(wantconfirm); | |
646 | } | |
647 | void | |
473db5ab | 648 | channel_register_confirm(int id, channel_callback_fn *fn, void *ctx) |
3c0ef626 | 649 | { |
650 | Channel *c = channel_lookup(id); | |
473db5ab | 651 | |
3c0ef626 | 652 | if (c == NULL) { |
473db5ab | 653 | logit("channel_register_comfirm: %d: bad id", id); |
3c0ef626 | 654 | return; |
655 | } | |
473db5ab | 656 | c->confirm = fn; |
657 | c->confirm_ctx = ctx; | |
3c0ef626 | 658 | } |
659 | void | |
08822d99 | 660 | channel_register_cleanup(int id, channel_callback_fn *fn, int do_close) |
3c0ef626 | 661 | { |
08822d99 | 662 | Channel *c = channel_by_id(id); |
473db5ab | 663 | |
3c0ef626 | 664 | if (c == NULL) { |
473db5ab | 665 | logit("channel_register_cleanup: %d: bad id", id); |
3c0ef626 | 666 | return; |
667 | } | |
668 | c->detach_user = fn; | |
08822d99 | 669 | c->detach_close = do_close; |
3c0ef626 | 670 | } |
671 | void | |
672 | channel_cancel_cleanup(int id) | |
673 | { | |
08822d99 | 674 | Channel *c = channel_by_id(id); |
473db5ab | 675 | |
3c0ef626 | 676 | if (c == NULL) { |
473db5ab | 677 | logit("channel_cancel_cleanup: %d: bad id", id); |
3c0ef626 | 678 | return; |
679 | } | |
680 | c->detach_user = NULL; | |
08822d99 | 681 | c->detach_close = 0; |
3c0ef626 | 682 | } |
683 | void | |
08822d99 | 684 | channel_register_filter(int id, channel_infilter_fn *ifn, |
685 | channel_outfilter_fn *ofn) | |
3c0ef626 | 686 | { |
687 | Channel *c = channel_lookup(id); | |
473db5ab | 688 | |
3c0ef626 | 689 | if (c == NULL) { |
473db5ab | 690 | logit("channel_register_filter: %d: bad id", id); |
3c0ef626 | 691 | return; |
692 | } | |
08822d99 | 693 | c->input_filter = ifn; |
694 | c->output_filter = ofn; | |
3c0ef626 | 695 | } |
696 | ||
697 | void | |
698 | channel_set_fds(int id, int rfd, int wfd, int efd, | |
473db5ab | 699 | int extusage, int nonblock, u_int window_max) |
3c0ef626 | 700 | { |
701 | Channel *c = channel_lookup(id); | |
473db5ab | 702 | |
3c0ef626 | 703 | if (c == NULL || c->type != SSH_CHANNEL_LARVAL) |
704 | fatal("channel_activate for non-larval channel %d.", id); | |
705 | channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); | |
706 | c->type = SSH_CHANNEL_OPEN; | |
473db5ab | 707 | c->local_window = c->local_window_max = window_max; |
3c0ef626 | 708 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
709 | packet_put_int(c->remote_id); | |
710 | packet_put_int(c->local_window); | |
711 | packet_send(); | |
712 | } | |
713 | ||
714 | /* | |
715 | * 'channel_pre*' are called just before select() to add any bits relevant to | |
716 | * channels in the select bitmasks. | |
717 | */ | |
718 | /* | |
719 | * 'channel_post*': perform any appropriate operations for channels which | |
720 | * have events pending. | |
721 | */ | |
722 | typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset); | |
723 | chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; | |
724 | chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; | |
725 | ||
726 | static void | |
727 | channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
728 | { | |
729 | FD_SET(c->sock, readset); | |
730 | } | |
731 | ||
732 | static void | |
733 | channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset) | |
734 | { | |
735 | debug3("channel %d: waiting for connection", c->self); | |
736 | FD_SET(c->sock, writeset); | |
737 | } | |
738 | ||
739 | static void | |
740 | channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
741 | { | |
742 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
743 | FD_SET(c->sock, readset); | |
744 | if (buffer_len(&c->output) > 0) | |
745 | FD_SET(c->sock, writeset); | |
746 | } | |
747 | ||
748 | static void | |
473db5ab | 749 | channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset) |
3c0ef626 | 750 | { |
473db5ab | 751 | u_int limit = compat20 ? c->remote_window : packet_get_maxsize(); |
3f750d99 | 752 | |
473db5ab | 753 | /* check buffer limits */ |
754 | limit = MIN(limit, (BUFFER_MAX_HPN_LEN - BUFFER_MAX_CHUNK - CHAN_RBUF)); | |
3c0ef626 | 755 | |
3c0ef626 | 756 | if (c->istate == CHAN_INPUT_OPEN && |
473db5ab | 757 | limit > 0 && |
758 | buffer_len(&c->input) < limit) | |
3c0ef626 | 759 | FD_SET(c->rfd, readset); |
760 | if (c->ostate == CHAN_OUTPUT_OPEN || | |
761 | c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
762 | if (buffer_len(&c->output) > 0) { | |
763 | FD_SET(c->wfd, writeset); | |
764 | } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
473db5ab | 765 | if (CHANNEL_EFD_OUTPUT_ACTIVE(c)) |
766 | debug2("channel %d: obuf_empty delayed efd %d/(%d)", | |
767 | c->self, c->efd, buffer_len(&c->extended)); | |
768 | else | |
769 | chan_obuf_empty(c); | |
3c0ef626 | 770 | } |
771 | } | |
772 | /** XXX check close conditions, too */ | |
473db5ab | 773 | if (compat20 && c->efd != -1) { |
3c0ef626 | 774 | if (c->extended_usage == CHAN_EXTENDED_WRITE && |
775 | buffer_len(&c->extended) > 0) | |
776 | FD_SET(c->efd, writeset); | |
473db5ab | 777 | else if (!(c->flags & CHAN_EOF_SENT) && |
778 | c->extended_usage == CHAN_EXTENDED_READ && | |
3c0ef626 | 779 | buffer_len(&c->extended) < c->remote_window) |
780 | FD_SET(c->efd, readset); | |
781 | } | |
473db5ab | 782 | /* XXX: What about efd? races? */ |
783 | if (compat20 && c->ctl_fd != -1 && | |
784 | c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN) | |
785 | FD_SET(c->ctl_fd, readset); | |
3c0ef626 | 786 | } |
787 | ||
788 | static void | |
789 | channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
790 | { | |
791 | if (buffer_len(&c->input) == 0) { | |
792 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
793 | packet_put_int(c->remote_id); | |
794 | packet_send(); | |
795 | c->type = SSH_CHANNEL_CLOSED; | |
473db5ab | 796 | debug2("channel %d: closing after input drain.", c->self); |
3c0ef626 | 797 | } |
798 | } | |
799 | ||
800 | static void | |
801 | channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
802 | { | |
803 | if (buffer_len(&c->output) == 0) | |
804 | chan_mark_dead(c); | |
805 | else | |
806 | FD_SET(c->sock, writeset); | |
807 | } | |
808 | ||
809 | /* | |
810 | * This is a special state for X11 authentication spoofing. An opened X11 | |
811 | * connection (when authentication spoofing is being done) remains in this | |
812 | * state until the first packet has been completely read. The authentication | |
813 | * data in that packet is then substituted by the real data if it matches the | |
814 | * fake data, and the channel is put into normal mode. | |
815 | * XXX All this happens at the client side. | |
816 | * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok | |
817 | */ | |
818 | static int | |
819 | x11_open_helper(Buffer *b) | |
820 | { | |
821 | u_char *ucp; | |
822 | u_int proto_len, data_len; | |
823 | ||
824 | /* Check if the fixed size part of the packet is in buffer. */ | |
825 | if (buffer_len(b) < 12) | |
826 | return 0; | |
827 | ||
828 | /* Parse the lengths of variable-length fields. */ | |
473db5ab | 829 | ucp = buffer_ptr(b); |
3c0ef626 | 830 | if (ucp[0] == 0x42) { /* Byte order MSB first. */ |
831 | proto_len = 256 * ucp[6] + ucp[7]; | |
832 | data_len = 256 * ucp[8] + ucp[9]; | |
833 | } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ | |
834 | proto_len = ucp[6] + 256 * ucp[7]; | |
835 | data_len = ucp[8] + 256 * ucp[9]; | |
836 | } else { | |
473db5ab | 837 | debug2("Initial X11 packet contains bad byte order byte: 0x%x", |
838 | ucp[0]); | |
3c0ef626 | 839 | return -1; |
840 | } | |
841 | ||
842 | /* Check if the whole packet is in buffer. */ | |
843 | if (buffer_len(b) < | |
844 | 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) | |
845 | return 0; | |
846 | ||
847 | /* Check if authentication protocol matches. */ | |
848 | if (proto_len != strlen(x11_saved_proto) || | |
849 | memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { | |
473db5ab | 850 | debug2("X11 connection uses different authentication protocol."); |
3c0ef626 | 851 | return -1; |
852 | } | |
853 | /* Check if authentication data matches our fake data. */ | |
854 | if (data_len != x11_fake_data_len || | |
855 | memcmp(ucp + 12 + ((proto_len + 3) & ~3), | |
856 | x11_fake_data, x11_fake_data_len) != 0) { | |
473db5ab | 857 | debug2("X11 auth data does not match fake data."); |
3c0ef626 | 858 | return -1; |
859 | } | |
860 | /* Check fake data length */ | |
861 | if (x11_fake_data_len != x11_saved_data_len) { | |
862 | error("X11 fake_data_len %d != saved_data_len %d", | |
863 | x11_fake_data_len, x11_saved_data_len); | |
864 | return -1; | |
865 | } | |
866 | /* | |
867 | * Received authentication protocol and data match | |
868 | * our fake data. Substitute the fake data with real | |
869 | * data. | |
870 | */ | |
871 | memcpy(ucp + 12 + ((proto_len + 3) & ~3), | |
872 | x11_saved_data, x11_saved_data_len); | |
873 | return 1; | |
874 | } | |
875 | ||
876 | static void | |
877 | channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
878 | { | |
879 | int ret = x11_open_helper(&c->output); | |
473db5ab | 880 | |
3c0ef626 | 881 | if (ret == 1) { |
882 | /* Start normal processing for the channel. */ | |
883 | c->type = SSH_CHANNEL_OPEN; | |
884 | channel_pre_open_13(c, readset, writeset); | |
885 | } else if (ret == -1) { | |
886 | /* | |
887 | * We have received an X11 connection that has bad | |
888 | * authentication information. | |
889 | */ | |
473db5ab | 890 | logit("X11 connection rejected because of wrong authentication."); |
3c0ef626 | 891 | buffer_clear(&c->input); |
892 | buffer_clear(&c->output); | |
893 | channel_close_fd(&c->sock); | |
894 | c->sock = -1; | |
895 | c->type = SSH_CHANNEL_CLOSED; | |
896 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
897 | packet_put_int(c->remote_id); | |
898 | packet_send(); | |
899 | } | |
900 | } | |
901 | ||
902 | static void | |
903 | channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset) | |
904 | { | |
905 | int ret = x11_open_helper(&c->output); | |
906 | ||
907 | /* c->force_drain = 1; */ | |
908 | ||
909 | if (ret == 1) { | |
910 | c->type = SSH_CHANNEL_OPEN; | |
473db5ab | 911 | channel_pre_open(c, readset, writeset); |
912 | } else if (ret == -1) { | |
913 | logit("X11 connection rejected because of wrong authentication."); | |
914 | debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); | |
915 | chan_read_failed(c); | |
916 | buffer_clear(&c->input); | |
917 | chan_ibuf_empty(c); | |
918 | buffer_clear(&c->output); | |
919 | /* for proto v1, the peer will send an IEOF */ | |
3c0ef626 | 920 | if (compat20) |
473db5ab | 921 | chan_write_failed(c); |
3c0ef626 | 922 | else |
473db5ab | 923 | c->type = SSH_CHANNEL_OPEN; |
924 | debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); | |
3c0ef626 | 925 | } |
926 | } | |
927 | ||
928 | /* try to decode a socks4 header */ | |
929 | static int | |
930 | channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset) | |
931 | { | |
473db5ab | 932 | char *p, *host; |
933 | u_int len, have, i, found; | |
934 | char username[256]; | |
3c0ef626 | 935 | struct { |
936 | u_int8_t version; | |
937 | u_int8_t command; | |
938 | u_int16_t dest_port; | |
939 | struct in_addr dest_addr; | |
940 | } s4_req, s4_rsp; | |
941 | ||
942 | debug2("channel %d: decode socks4", c->self); | |
943 | ||
944 | have = buffer_len(&c->input); | |
945 | len = sizeof(s4_req); | |
946 | if (have < len) | |
947 | return 0; | |
948 | p = buffer_ptr(&c->input); | |
949 | for (found = 0, i = len; i < have; i++) { | |
950 | if (p[i] == '\0') { | |
951 | found = 1; | |
952 | break; | |
953 | } | |
954 | if (i > 1024) { | |
955 | /* the peer is probably sending garbage */ | |
956 | debug("channel %d: decode socks4: too long", | |
957 | c->self); | |
958 | return -1; | |
959 | } | |
960 | } | |
961 | if (!found) | |
962 | return 0; | |
963 | buffer_get(&c->input, (char *)&s4_req.version, 1); | |
964 | buffer_get(&c->input, (char *)&s4_req.command, 1); | |
965 | buffer_get(&c->input, (char *)&s4_req.dest_port, 2); | |
966 | buffer_get(&c->input, (char *)&s4_req.dest_addr, 4); | |
967 | have = buffer_len(&c->input); | |
968 | p = buffer_ptr(&c->input); | |
969 | len = strlen(p); | |
970 | debug2("channel %d: decode socks4: user %s/%d", c->self, p, len); | |
971 | if (len > have) | |
972 | fatal("channel %d: decode socks4: len %d > have %d", | |
973 | c->self, len, have); | |
974 | strlcpy(username, p, sizeof(username)); | |
975 | buffer_consume(&c->input, len); | |
976 | buffer_consume(&c->input, 1); /* trailing '\0' */ | |
977 | ||
978 | host = inet_ntoa(s4_req.dest_addr); | |
979 | strlcpy(c->path, host, sizeof(c->path)); | |
980 | c->host_port = ntohs(s4_req.dest_port); | |
473db5ab | 981 | |
982 | debug2("channel %d: dynamic request: socks4 host %s port %u command %u", | |
3c0ef626 | 983 | c->self, host, c->host_port, s4_req.command); |
984 | ||
985 | if (s4_req.command != 1) { | |
986 | debug("channel %d: cannot handle: socks4 cn %d", | |
987 | c->self, s4_req.command); | |
988 | return -1; | |
989 | } | |
990 | s4_rsp.version = 0; /* vn: 0 for reply */ | |
991 | s4_rsp.command = 90; /* cd: req granted */ | |
992 | s4_rsp.dest_port = 0; /* ignored */ | |
993 | s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */ | |
994 | buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp)); | |
995 | return 1; | |
996 | } | |
997 | ||
473db5ab | 998 | /* try to decode a socks5 header */ |
999 | #define SSH_SOCKS5_AUTHDONE 0x1000 | |
1000 | #define SSH_SOCKS5_NOAUTH 0x00 | |
1001 | #define SSH_SOCKS5_IPV4 0x01 | |
1002 | #define SSH_SOCKS5_DOMAIN 0x03 | |
1003 | #define SSH_SOCKS5_IPV6 0x04 | |
1004 | #define SSH_SOCKS5_CONNECT 0x01 | |
1005 | #define SSH_SOCKS5_SUCCESS 0x00 | |
1006 | ||
1007 | static int | |
1008 | channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset) | |
1009 | { | |
1010 | struct { | |
1011 | u_int8_t version; | |
1012 | u_int8_t command; | |
1013 | u_int8_t reserved; | |
1014 | u_int8_t atyp; | |
1015 | } s5_req, s5_rsp; | |
1016 | u_int16_t dest_port; | |
1017 | u_char *p, dest_addr[255+1]; | |
1018 | u_int have, i, found, nmethods, addrlen, af; | |
1019 | ||
1020 | debug2("channel %d: decode socks5", c->self); | |
1021 | p = buffer_ptr(&c->input); | |
1022 | if (p[0] != 0x05) | |
1023 | return -1; | |
1024 | have = buffer_len(&c->input); | |
1025 | if (!(c->flags & SSH_SOCKS5_AUTHDONE)) { | |
1026 | /* format: ver | nmethods | methods */ | |
1027 | if (have < 2) | |
1028 | return 0; | |
1029 | nmethods = p[1]; | |
1030 | if (have < nmethods + 2) | |
1031 | return 0; | |
1032 | /* look for method: "NO AUTHENTICATION REQUIRED" */ | |
1033 | for (found = 0, i = 2 ; i < nmethods + 2; i++) { | |
1034 | if (p[i] == SSH_SOCKS5_NOAUTH ) { | |
1035 | found = 1; | |
1036 | break; | |
1037 | } | |
1038 | } | |
1039 | if (!found) { | |
1040 | debug("channel %d: method SSH_SOCKS5_NOAUTH not found", | |
1041 | c->self); | |
1042 | return -1; | |
1043 | } | |
1044 | buffer_consume(&c->input, nmethods + 2); | |
1045 | buffer_put_char(&c->output, 0x05); /* version */ | |
1046 | buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */ | |
1047 | FD_SET(c->sock, writeset); | |
1048 | c->flags |= SSH_SOCKS5_AUTHDONE; | |
1049 | debug2("channel %d: socks5 auth done", c->self); | |
1050 | return 0; /* need more */ | |
1051 | } | |
1052 | debug2("channel %d: socks5 post auth", c->self); | |
1053 | if (have < sizeof(s5_req)+1) | |
1054 | return 0; /* need more */ | |
1055 | memcpy((char *)&s5_req, p, sizeof(s5_req)); | |
1056 | if (s5_req.version != 0x05 || | |
1057 | s5_req.command != SSH_SOCKS5_CONNECT || | |
1058 | s5_req.reserved != 0x00) { | |
1059 | debug2("channel %d: only socks5 connect supported", c->self); | |
1060 | return -1; | |
1061 | } | |
1062 | switch (s5_req.atyp){ | |
1063 | case SSH_SOCKS5_IPV4: | |
1064 | addrlen = 4; | |
1065 | af = AF_INET; | |
1066 | break; | |
1067 | case SSH_SOCKS5_DOMAIN: | |
1068 | addrlen = p[sizeof(s5_req)]; | |
1069 | af = -1; | |
1070 | break; | |
1071 | case SSH_SOCKS5_IPV6: | |
1072 | addrlen = 16; | |
1073 | af = AF_INET6; | |
1074 | break; | |
1075 | default: | |
1076 | debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp); | |
1077 | return -1; | |
1078 | } | |
1079 | if (have < 4 + addrlen + 2) | |
1080 | return 0; | |
1081 | buffer_consume(&c->input, sizeof(s5_req)); | |
1082 | if (s5_req.atyp == SSH_SOCKS5_DOMAIN) | |
1083 | buffer_consume(&c->input, 1); /* host string length */ | |
1084 | buffer_get(&c->input, (char *)&dest_addr, addrlen); | |
1085 | buffer_get(&c->input, (char *)&dest_port, 2); | |
1086 | dest_addr[addrlen] = '\0'; | |
1087 | if (s5_req.atyp == SSH_SOCKS5_DOMAIN) | |
1088 | strlcpy(c->path, (char *)dest_addr, sizeof(c->path)); | |
1089 | else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL) | |
1090 | return -1; | |
1091 | c->host_port = ntohs(dest_port); | |
1092 | ||
1093 | debug2("channel %d: dynamic request: socks5 host %s port %u command %u", | |
1094 | c->self, c->path, c->host_port, s5_req.command); | |
1095 | ||
1096 | s5_rsp.version = 0x05; | |
1097 | s5_rsp.command = SSH_SOCKS5_SUCCESS; | |
1098 | s5_rsp.reserved = 0; /* ignored */ | |
1099 | s5_rsp.atyp = SSH_SOCKS5_IPV4; | |
1100 | ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY; | |
1101 | dest_port = 0; /* ignored */ | |
1102 | ||
1103 | buffer_append(&c->output, (char *)&s5_rsp, sizeof(s5_rsp)); | |
1104 | buffer_append(&c->output, (char *)&dest_addr, sizeof(struct in_addr)); | |
1105 | buffer_append(&c->output, (char *)&dest_port, sizeof(dest_port)); | |
1106 | return 1; | |
1107 | } | |
1108 | ||
3c0ef626 | 1109 | /* dynamic port forwarding */ |
1110 | static void | |
1111 | channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset) | |
1112 | { | |
1113 | u_char *p; | |
473db5ab | 1114 | u_int have; |
1115 | int ret; | |
3c0ef626 | 1116 | |
1117 | have = buffer_len(&c->input); | |
1118 | c->delayed = 0; | |
1119 | debug2("channel %d: pre_dynamic: have %d", c->self, have); | |
1120 | /* buffer_dump(&c->input); */ | |
1121 | /* check if the fixed size part of the packet is in buffer. */ | |
473db5ab | 1122 | if (have < 3) { |
3c0ef626 | 1123 | /* need more */ |
1124 | FD_SET(c->sock, readset); | |
1125 | return; | |
1126 | } | |
1127 | /* try to guess the protocol */ | |
1128 | p = buffer_ptr(&c->input); | |
1129 | switch (p[0]) { | |
1130 | case 0x04: | |
1131 | ret = channel_decode_socks4(c, readset, writeset); | |
1132 | break; | |
473db5ab | 1133 | case 0x05: |
1134 | ret = channel_decode_socks5(c, readset, writeset); | |
1135 | break; | |
3c0ef626 | 1136 | default: |
1137 | ret = -1; | |
1138 | break; | |
1139 | } | |
1140 | if (ret < 0) { | |
1141 | chan_mark_dead(c); | |
1142 | } else if (ret == 0) { | |
1143 | debug2("channel %d: pre_dynamic: need more", c->self); | |
1144 | /* need more */ | |
1145 | FD_SET(c->sock, readset); | |
1146 | } else { | |
1147 | /* switch to the next state */ | |
1148 | c->type = SSH_CHANNEL_OPENING; | |
1149 | port_open_helper(c, "direct-tcpip"); | |
1150 | } | |
1151 | } | |
1152 | ||
1153 | /* This is our fake X11 server socket. */ | |
1154 | static void | |
1155 | channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
1156 | { | |
1157 | Channel *nc; | |
1158 | struct sockaddr addr; | |
1159 | int newsock; | |
1160 | socklen_t addrlen; | |
1161 | char buf[16384], *remote_ipaddr; | |
1162 | int remote_port; | |
1163 | ||
1164 | if (FD_ISSET(c->sock, readset)) { | |
1165 | debug("X11 connection requested."); | |
1166 | addrlen = sizeof(addr); | |
1167 | newsock = accept(c->sock, &addr, &addrlen); | |
473db5ab | 1168 | if (c->single_connection) { |
1169 | debug2("single_connection: closing X11 listener."); | |
1170 | channel_close_fd(&c->sock); | |
1171 | chan_mark_dead(c); | |
1172 | } | |
3c0ef626 | 1173 | if (newsock < 0) { |
1174 | error("accept: %.100s", strerror(errno)); | |
1175 | return; | |
1176 | } | |
473db5ab | 1177 | set_nodelay(newsock); |
3c0ef626 | 1178 | remote_ipaddr = get_peer_ipaddr(newsock); |
1179 | remote_port = get_peer_port(newsock); | |
1180 | snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", | |
1181 | remote_ipaddr, remote_port); | |
1182 | ||
1183 | nc = channel_new("accepted x11 socket", | |
1184 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
473db5ab | 1185 | c->local_window_max, c->local_maxpacket, 0, buf, 1); |
3c0ef626 | 1186 | if (compat20) { |
1187 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1188 | packet_put_cstring("x11"); | |
1189 | packet_put_int(nc->self); | |
473db5ab | 1190 | packet_put_int(nc->local_window_max); |
1191 | packet_put_int(nc->local_maxpacket); | |
3c0ef626 | 1192 | /* originator ipaddr and port */ |
1193 | packet_put_cstring(remote_ipaddr); | |
1194 | if (datafellows & SSH_BUG_X11FWD) { | |
473db5ab | 1195 | debug2("ssh2 x11 bug compat mode"); |
3c0ef626 | 1196 | } else { |
1197 | packet_put_int(remote_port); | |
1198 | } | |
1199 | packet_send(); | |
1200 | } else { | |
1201 | packet_start(SSH_SMSG_X11_OPEN); | |
1202 | packet_put_int(nc->self); | |
1203 | if (packet_get_protocol_flags() & | |
1204 | SSH_PROTOFLAG_HOST_IN_FWD_OPEN) | |
1205 | packet_put_cstring(buf); | |
1206 | packet_send(); | |
1207 | } | |
1208 | xfree(remote_ipaddr); | |
1209 | } | |
1210 | } | |
1211 | ||
1212 | static void | |
1213 | port_open_helper(Channel *c, char *rtype) | |
1214 | { | |
1215 | int direct; | |
1216 | char buf[1024]; | |
1217 | char *remote_ipaddr = get_peer_ipaddr(c->sock); | |
473db5ab | 1218 | int remote_port = get_peer_port(c->sock); |
3c0ef626 | 1219 | |
1220 | direct = (strcmp(rtype, "direct-tcpip") == 0); | |
1221 | ||
1222 | snprintf(buf, sizeof buf, | |
1223 | "%s: listening port %d for %.100s port %d, " | |
1224 | "connect from %.200s port %d", | |
1225 | rtype, c->listening_port, c->path, c->host_port, | |
1226 | remote_ipaddr, remote_port); | |
1227 | ||
1228 | xfree(c->remote_name); | |
1229 | c->remote_name = xstrdup(buf); | |
1230 | ||
1231 | if (compat20) { | |
1232 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1233 | packet_put_cstring(rtype); | |
1234 | packet_put_int(c->self); | |
1235 | packet_put_int(c->local_window_max); | |
1236 | packet_put_int(c->local_maxpacket); | |
1237 | if (direct) { | |
1238 | /* target host, port */ | |
1239 | packet_put_cstring(c->path); | |
1240 | packet_put_int(c->host_port); | |
1241 | } else { | |
1242 | /* listen address, port */ | |
1243 | packet_put_cstring(c->path); | |
1244 | packet_put_int(c->listening_port); | |
1245 | } | |
1246 | /* originator host and port */ | |
1247 | packet_put_cstring(remote_ipaddr); | |
473db5ab | 1248 | packet_put_int((u_int)remote_port); |
3c0ef626 | 1249 | packet_send(); |
1250 | } else { | |
1251 | packet_start(SSH_MSG_PORT_OPEN); | |
1252 | packet_put_int(c->self); | |
1253 | packet_put_cstring(c->path); | |
1254 | packet_put_int(c->host_port); | |
1255 | if (packet_get_protocol_flags() & | |
1256 | SSH_PROTOFLAG_HOST_IN_FWD_OPEN) | |
1257 | packet_put_cstring(c->remote_name); | |
1258 | packet_send(); | |
1259 | } | |
1260 | xfree(remote_ipaddr); | |
1261 | } | |
1262 | ||
08822d99 | 1263 | static void |
1264 | channel_set_reuseaddr(int fd) | |
1265 | { | |
1266 | int on = 1; | |
1267 | ||
1268 | /* | |
1269 | * Set socket options. | |
1270 | * Allow local port reuse in TIME_WAIT. | |
1271 | */ | |
1272 | if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) | |
1273 | error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); | |
1274 | } | |
1275 | ||
3c0ef626 | 1276 | /* |
1277 | * This socket is listening for connections to a forwarded TCP/IP port. | |
1278 | */ | |
1279 | static void | |
1280 | channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
1281 | { | |
1282 | Channel *nc; | |
1283 | struct sockaddr addr; | |
1284 | int newsock, nextstate; | |
1285 | socklen_t addrlen; | |
1286 | char *rtype; | |
1287 | ||
1288 | if (FD_ISSET(c->sock, readset)) { | |
1289 | debug("Connection to port %d forwarding " | |
1290 | "to %.100s port %d requested.", | |
1291 | c->listening_port, c->path, c->host_port); | |
1292 | ||
1293 | if (c->type == SSH_CHANNEL_RPORT_LISTENER) { | |
1294 | nextstate = SSH_CHANNEL_OPENING; | |
1295 | rtype = "forwarded-tcpip"; | |
1296 | } else { | |
1297 | if (c->host_port == 0) { | |
1298 | nextstate = SSH_CHANNEL_DYNAMIC; | |
1299 | rtype = "dynamic-tcpip"; | |
1300 | } else { | |
1301 | nextstate = SSH_CHANNEL_OPENING; | |
1302 | rtype = "direct-tcpip"; | |
1303 | } | |
1304 | } | |
1305 | ||
1306 | addrlen = sizeof(addr); | |
1307 | newsock = accept(c->sock, &addr, &addrlen); | |
1308 | if (newsock < 0) { | |
1309 | error("accept: %.100s", strerror(errno)); | |
1310 | return; | |
1311 | } | |
473db5ab | 1312 | set_nodelay(newsock); |
1313 | nc = channel_new(rtype, nextstate, newsock, newsock, -1, | |
1314 | c->local_window_max, c->local_maxpacket, 0, rtype, 1); | |
3c0ef626 | 1315 | nc->listening_port = c->listening_port; |
1316 | nc->host_port = c->host_port; | |
1317 | strlcpy(nc->path, c->path, sizeof(nc->path)); | |
1318 | ||
1319 | if (nextstate == SSH_CHANNEL_DYNAMIC) { | |
1320 | /* | |
1321 | * do not call the channel_post handler until | |
1322 | * this flag has been reset by a pre-handler. | |
1323 | * otherwise the FD_ISSET calls might overflow | |
1324 | */ | |
1325 | nc->delayed = 1; | |
1326 | } else { | |
1327 | port_open_helper(nc, rtype); | |
1328 | } | |
1329 | } | |
1330 | } | |
1331 | ||
1332 | /* | |
1333 | * This is the authentication agent socket listening for connections from | |
1334 | * clients. | |
1335 | */ | |
1336 | static void | |
1337 | channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
1338 | { | |
1339 | Channel *nc; | |
3c0ef626 | 1340 | int newsock; |
1341 | struct sockaddr addr; | |
1342 | socklen_t addrlen; | |
1343 | ||
1344 | if (FD_ISSET(c->sock, readset)) { | |
1345 | addrlen = sizeof(addr); | |
1346 | newsock = accept(c->sock, &addr, &addrlen); | |
1347 | if (newsock < 0) { | |
1348 | error("accept from auth socket: %.100s", strerror(errno)); | |
1349 | return; | |
1350 | } | |
3c0ef626 | 1351 | nc = channel_new("accepted auth socket", |
1352 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
1353 | c->local_window_max, c->local_maxpacket, | |
473db5ab | 1354 | 0, "accepted auth socket", 1); |
3c0ef626 | 1355 | if (compat20) { |
1356 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1357 | packet_put_cstring("auth-agent@openssh.com"); | |
1358 | packet_put_int(nc->self); | |
1359 | packet_put_int(c->local_window_max); | |
1360 | packet_put_int(c->local_maxpacket); | |
1361 | } else { | |
1362 | packet_start(SSH_SMSG_AGENT_OPEN); | |
1363 | packet_put_int(nc->self); | |
1364 | } | |
1365 | packet_send(); | |
1366 | } | |
1367 | } | |
1368 | ||
1369 | static void | |
1370 | channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset) | |
1371 | { | |
1372 | int err = 0; | |
1373 | socklen_t sz = sizeof(err); | |
1374 | ||
1375 | if (FD_ISSET(c->sock, writeset)) { | |
473db5ab | 1376 | if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) { |
3c0ef626 | 1377 | err = errno; |
1378 | error("getsockopt SO_ERROR failed"); | |
1379 | } | |
1380 | if (err == 0) { | |
1381 | debug("channel %d: connected", c->self); | |
1382 | c->type = SSH_CHANNEL_OPEN; | |
1383 | if (compat20) { | |
1384 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1385 | packet_put_int(c->remote_id); | |
1386 | packet_put_int(c->self); | |
1387 | packet_put_int(c->local_window); | |
1388 | packet_put_int(c->local_maxpacket); | |
1389 | } else { | |
1390 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1391 | packet_put_int(c->remote_id); | |
1392 | packet_put_int(c->self); | |
1393 | } | |
1394 | } else { | |
1395 | debug("channel %d: not connected: %s", | |
1396 | c->self, strerror(err)); | |
1397 | if (compat20) { | |
1398 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); | |
1399 | packet_put_int(c->remote_id); | |
1400 | packet_put_int(SSH2_OPEN_CONNECT_FAILED); | |
1401 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
1402 | packet_put_cstring(strerror(err)); | |
1403 | packet_put_cstring(""); | |
1404 | } | |
1405 | } else { | |
1406 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1407 | packet_put_int(c->remote_id); | |
1408 | } | |
1409 | chan_mark_dead(c); | |
1410 | } | |
1411 | packet_send(); | |
1412 | } | |
1413 | } | |
1414 | ||
1415 | static int | |
1416 | channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) | |
1417 | { | |
473db5ab | 1418 | char buf[CHAN_RBUF]; |
3c0ef626 | 1419 | int len; |
1420 | ||
1421 | if (c->rfd != -1 && | |
1422 | FD_ISSET(c->rfd, readset)) { | |
1423 | len = read(c->rfd, buf, sizeof(buf)); | |
1424 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1425 | return 1; | |
1426 | if (len <= 0) { | |
473db5ab | 1427 | debug2("channel %d: read<=0 rfd %d len %d", |
3c0ef626 | 1428 | c->self, c->rfd, len); |
1429 | if (c->type != SSH_CHANNEL_OPEN) { | |
473db5ab | 1430 | debug2("channel %d: not open", c->self); |
3c0ef626 | 1431 | chan_mark_dead(c); |
1432 | return -1; | |
1433 | } else if (compat13) { | |
473db5ab | 1434 | buffer_clear(&c->output); |
3c0ef626 | 1435 | c->type = SSH_CHANNEL_INPUT_DRAINING; |
473db5ab | 1436 | debug2("channel %d: input draining.", c->self); |
3c0ef626 | 1437 | } else { |
1438 | chan_read_failed(c); | |
1439 | } | |
1440 | return -1; | |
1441 | } | |
473db5ab | 1442 | if (c->input_filter != NULL) { |
3c0ef626 | 1443 | if (c->input_filter(c, buf, len) == -1) { |
473db5ab | 1444 | debug2("channel %d: filter stops", c->self); |
3c0ef626 | 1445 | chan_read_failed(c); |
1446 | } | |
08822d99 | 1447 | } else if (c->datagram) { |
1448 | buffer_put_string(&c->input, buf, len); | |
3c0ef626 | 1449 | } else { |
1450 | buffer_append(&c->input, buf, len); | |
1451 | } | |
1452 | } | |
1453 | return 1; | |
1454 | } | |
1455 | static int | |
1456 | channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) | |
1457 | { | |
1458 | struct termios tio; | |
08822d99 | 1459 | u_char *data = NULL, *buf; |
3c0ef626 | 1460 | u_int dlen; |
1461 | int len; | |
1462 | ||
1463 | /* Send buffered output data to the socket. */ | |
1464 | if (c->wfd != -1 && | |
1465 | FD_ISSET(c->wfd, writeset) && | |
1466 | buffer_len(&c->output) > 0) { | |
08822d99 | 1467 | if (c->output_filter != NULL) { |
1468 | if ((buf = c->output_filter(c, &data, &dlen)) == NULL) { | |
1469 | debug2("channel %d: filter stops", c->self); | |
1470 | if (c->type != SSH_CHANNEL_OPEN) | |
1471 | chan_mark_dead(c); | |
1472 | else | |
1473 | chan_write_failed(c); | |
1474 | return -1; | |
1475 | } | |
1476 | } else if (c->datagram) { | |
1477 | buf = data = buffer_get_string(&c->output, &dlen); | |
1478 | } else { | |
1479 | buf = data = buffer_ptr(&c->output); | |
1480 | dlen = buffer_len(&c->output); | |
1481 | } | |
1482 | ||
1483 | if (c->datagram) { | |
1484 | /* ignore truncated writes, datagrams might get lost */ | |
1485 | c->local_consumed += dlen + 4; | |
1486 | len = write(c->wfd, buf, dlen); | |
1487 | xfree(data); | |
1488 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1489 | return 1; | |
1490 | if (len <= 0) { | |
1491 | if (c->type != SSH_CHANNEL_OPEN) | |
1492 | chan_mark_dead(c); | |
1493 | else | |
1494 | chan_write_failed(c); | |
1495 | return -1; | |
1496 | } | |
1497 | return 1; | |
1498 | } | |
473db5ab | 1499 | #ifdef _AIX |
1500 | /* XXX: Later AIX versions can't push as much data to tty */ | |
1501 | if (compat20 && c->wfd_isatty) | |
1502 | dlen = MIN(dlen, 8*1024); | |
1503 | #endif | |
08822d99 | 1504 | |
1505 | len = write(c->wfd, buf, dlen); | |
3c0ef626 | 1506 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) |
1507 | return 1; | |
1508 | if (len <= 0) { | |
1509 | if (c->type != SSH_CHANNEL_OPEN) { | |
473db5ab | 1510 | debug2("channel %d: not open", c->self); |
3c0ef626 | 1511 | chan_mark_dead(c); |
1512 | return -1; | |
1513 | } else if (compat13) { | |
473db5ab | 1514 | buffer_clear(&c->output); |
1515 | debug2("channel %d: input draining.", c->self); | |
3c0ef626 | 1516 | c->type = SSH_CHANNEL_INPUT_DRAINING; |
1517 | } else { | |
1518 | chan_write_failed(c); | |
1519 | } | |
1520 | return -1; | |
1521 | } | |
08822d99 | 1522 | if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') { |
3c0ef626 | 1523 | if (tcgetattr(c->wfd, &tio) == 0 && |
1524 | !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { | |
1525 | /* | |
1526 | * Simulate echo to reduce the impact of | |
1527 | * traffic analysis. We need to match the | |
1528 | * size of a SSH2_MSG_CHANNEL_DATA message | |
08822d99 | 1529 | * (4 byte channel id + buf) |
3c0ef626 | 1530 | */ |
1531 | packet_send_ignore(4 + len); | |
1532 | packet_send(); | |
1533 | } | |
1534 | } | |
1535 | buffer_consume(&c->output, len); | |
1536 | if (compat20 && len > 0) { | |
1537 | c->local_consumed += len; | |
1538 | } | |
1539 | } | |
1540 | return 1; | |
1541 | } | |
1542 | static int | |
1543 | channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) | |
1544 | { | |
473db5ab | 1545 | char buf[CHAN_RBUF]; |
3c0ef626 | 1546 | int len; |
1547 | ||
1548 | /** XXX handle drain efd, too */ | |
1549 | if (c->efd != -1) { | |
1550 | if (c->extended_usage == CHAN_EXTENDED_WRITE && | |
1551 | FD_ISSET(c->efd, writeset) && | |
1552 | buffer_len(&c->extended) > 0) { | |
1553 | len = write(c->efd, buffer_ptr(&c->extended), | |
1554 | buffer_len(&c->extended)); | |
1555 | debug2("channel %d: written %d to efd %d", | |
1556 | c->self, len, c->efd); | |
1557 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1558 | return 1; | |
1559 | if (len <= 0) { | |
1560 | debug2("channel %d: closing write-efd %d", | |
1561 | c->self, c->efd); | |
1562 | channel_close_fd(&c->efd); | |
1563 | } else { | |
1564 | buffer_consume(&c->extended, len); | |
1565 | c->local_consumed += len; | |
1566 | } | |
1567 | } else if (c->extended_usage == CHAN_EXTENDED_READ && | |
1568 | FD_ISSET(c->efd, readset)) { | |
1569 | len = read(c->efd, buf, sizeof(buf)); | |
1570 | debug2("channel %d: read %d from efd %d", | |
473db5ab | 1571 | c->self, len, c->efd); |
3c0ef626 | 1572 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) |
1573 | return 1; | |
1574 | if (len <= 0) { | |
1575 | debug2("channel %d: closing read-efd %d", | |
1576 | c->self, c->efd); | |
1577 | channel_close_fd(&c->efd); | |
1578 | } else { | |
1579 | buffer_append(&c->extended, buf, len); | |
1580 | } | |
1581 | } | |
1582 | } | |
1583 | return 1; | |
1584 | } | |
1585 | static int | |
473db5ab | 1586 | channel_handle_ctl(Channel *c, fd_set * readset, fd_set * writeset) |
1587 | { | |
1588 | char buf[16]; | |
1589 | int len; | |
1590 | ||
1591 | /* Monitor control fd to detect if the slave client exits */ | |
1592 | if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) { | |
1593 | len = read(c->ctl_fd, buf, sizeof(buf)); | |
1594 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1595 | return 1; | |
1596 | if (len <= 0) { | |
1597 | debug2("channel %d: ctl read<=0", c->self); | |
1598 | if (c->type != SSH_CHANNEL_OPEN) { | |
1599 | debug2("channel %d: not open", c->self); | |
1600 | chan_mark_dead(c); | |
1601 | return -1; | |
1602 | } else { | |
1603 | chan_read_failed(c); | |
1604 | chan_write_failed(c); | |
1605 | } | |
1606 | return -1; | |
1607 | } else | |
1608 | fatal("%s: unexpected data on ctl fd", __func__); | |
1609 | } | |
1610 | return 1; | |
1611 | } | |
1612 | static int | |
3c0ef626 | 1613 | channel_check_window(Channel *c) |
1614 | { | |
1615 | if (c->type == SSH_CHANNEL_OPEN && | |
1616 | !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) && | |
1617 | c->local_window < c->local_window_max/2 && | |
1618 | c->local_consumed > 0) { | |
473db5ab | 1619 | u_int32_t tcpwinsz = 0; |
1620 | socklen_t optsz = sizeof(tcpwinsz); | |
1621 | int ret = -1; | |
1622 | u_int32_t addition = 0; | |
1623 | if (c->dynamic_window) { | |
1624 | ret = getsockopt(packet_get_connection_in(), | |
1625 | SOL_SOCKET, SO_RCVBUF, &tcpwinsz, &optsz); | |
1626 | if ((ret == 0) && tcpwinsz > BUFFER_MAX_HPN_LEN) | |
1627 | tcpwinsz = BUFFER_MAX_HPN_LEN; | |
1628 | } | |
1629 | if (c->dynamic_window && (ret == 0) && | |
1630 | (tcpwinsz > c->local_window_max)) { | |
1631 | addition = tcpwinsz - c->local_window_max; | |
1632 | c->local_window_max += addition; | |
1633 | } | |
3c0ef626 | 1634 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
1635 | packet_put_int(c->remote_id); | |
473db5ab | 1636 | packet_put_int(c->local_consumed + addition); |
3c0ef626 | 1637 | packet_send(); |
1638 | debug2("channel %d: window %d sent adjust %d", | |
1639 | c->self, c->local_window, | |
1640 | c->local_consumed); | |
473db5ab | 1641 | c->local_window += c->local_consumed + addition; |
3c0ef626 | 1642 | c->local_consumed = 0; |
1643 | } | |
1644 | return 1; | |
1645 | } | |
1646 | ||
1647 | static void | |
473db5ab | 1648 | channel_post_open(Channel *c, fd_set * readset, fd_set * writeset) |
3c0ef626 | 1649 | { |
1650 | if (c->delayed) | |
1651 | return; | |
1652 | channel_handle_rfd(c, readset, writeset); | |
1653 | channel_handle_wfd(c, readset, writeset); | |
473db5ab | 1654 | if (!compat20) |
3c0ef626 | 1655 | return; |
3c0ef626 | 1656 | channel_handle_efd(c, readset, writeset); |
473db5ab | 1657 | channel_handle_ctl(c, readset, writeset); |
3c0ef626 | 1658 | channel_check_window(c); |
1659 | } | |
1660 | ||
1661 | static void | |
1662 | channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) | |
1663 | { | |
1664 | int len; | |
473db5ab | 1665 | |
3c0ef626 | 1666 | /* Send buffered output data to the socket. */ |
1667 | if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) { | |
1668 | len = write(c->sock, buffer_ptr(&c->output), | |
1669 | buffer_len(&c->output)); | |
1670 | if (len <= 0) | |
473db5ab | 1671 | buffer_clear(&c->output); |
3c0ef626 | 1672 | else |
1673 | buffer_consume(&c->output, len); | |
1674 | } | |
1675 | } | |
1676 | ||
1677 | static void | |
1678 | channel_handler_init_20(void) | |
1679 | { | |
473db5ab | 1680 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; |
3c0ef626 | 1681 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
1682 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1683 | channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener; | |
1684 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
1685 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
1686 | channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; | |
1687 | channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; | |
1688 | ||
473db5ab | 1689 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; |
3c0ef626 | 1690 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; |
1691 | channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener; | |
1692 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
1693 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
1694 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; | |
473db5ab | 1695 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; |
3c0ef626 | 1696 | } |
1697 | ||
1698 | static void | |
1699 | channel_handler_init_13(void) | |
1700 | { | |
1701 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; | |
1702 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13; | |
1703 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
1704 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1705 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
1706 | channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining; | |
1707 | channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining; | |
1708 | channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; | |
1709 | channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; | |
1710 | ||
473db5ab | 1711 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; |
3c0ef626 | 1712 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; |
1713 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
1714 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
1715 | channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; | |
1716 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; | |
473db5ab | 1717 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; |
3c0ef626 | 1718 | } |
1719 | ||
1720 | static void | |
1721 | channel_handler_init_15(void) | |
1722 | { | |
473db5ab | 1723 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; |
3c0ef626 | 1724 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
1725 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
1726 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1727 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
1728 | channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; | |
1729 | channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; | |
1730 | ||
1731 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
1732 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
1733 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
473db5ab | 1734 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; |
3c0ef626 | 1735 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; |
473db5ab | 1736 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; |
3c0ef626 | 1737 | } |
1738 | ||
1739 | static void | |
1740 | channel_handler_init(void) | |
1741 | { | |
1742 | int i; | |
473db5ab | 1743 | |
1744 | for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { | |
3c0ef626 | 1745 | channel_pre[i] = NULL; |
1746 | channel_post[i] = NULL; | |
1747 | } | |
1748 | if (compat20) | |
1749 | channel_handler_init_20(); | |
1750 | else if (compat13) | |
1751 | channel_handler_init_13(); | |
1752 | else | |
1753 | channel_handler_init_15(); | |
1754 | } | |
1755 | ||
1756 | /* gc dead channels */ | |
1757 | static void | |
1758 | channel_garbage_collect(Channel *c) | |
1759 | { | |
1760 | if (c == NULL) | |
1761 | return; | |
1762 | if (c->detach_user != NULL) { | |
08822d99 | 1763 | if (!chan_is_dead(c, c->detach_close)) |
3c0ef626 | 1764 | return; |
473db5ab | 1765 | debug2("channel %d: gc: notify user", c->self); |
3c0ef626 | 1766 | c->detach_user(c->self, NULL); |
1767 | /* if we still have a callback */ | |
1768 | if (c->detach_user != NULL) | |
1769 | return; | |
473db5ab | 1770 | debug2("channel %d: gc: user detached", c->self); |
3c0ef626 | 1771 | } |
1772 | if (!chan_is_dead(c, 1)) | |
1773 | return; | |
473db5ab | 1774 | debug2("channel %d: garbage collecting", c->self); |
3c0ef626 | 1775 | channel_free(c); |
1776 | } | |
1777 | ||
1778 | static void | |
1779 | channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) | |
1780 | { | |
1781 | static int did_init = 0; | |
473db5ab | 1782 | u_int i; |
3c0ef626 | 1783 | Channel *c; |
1784 | ||
1785 | if (!did_init) { | |
1786 | channel_handler_init(); | |
1787 | did_init = 1; | |
1788 | } | |
1789 | for (i = 0; i < channels_alloc; i++) { | |
1790 | c = channels[i]; | |
1791 | if (c == NULL) | |
1792 | continue; | |
1793 | if (ftab[c->type] != NULL) | |
1794 | (*ftab[c->type])(c, readset, writeset); | |
1795 | channel_garbage_collect(c); | |
1796 | } | |
1797 | } | |
1798 | ||
1799 | /* | |
1800 | * Allocate/update select bitmasks and add any bits relevant to channels in | |
1801 | * select bitmasks. | |
1802 | */ | |
1803 | void | |
1804 | channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp, | |
473db5ab | 1805 | u_int *nallocp, int rekeying) |
3c0ef626 | 1806 | { |
473db5ab | 1807 | u_int n, sz; |
3c0ef626 | 1808 | |
1809 | n = MAX(*maxfdp, channel_max_fd); | |
1810 | ||
1811 | sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); | |
1812 | /* perhaps check sz < nalloc/2 and shrink? */ | |
1813 | if (*readsetp == NULL || sz > *nallocp) { | |
1814 | *readsetp = xrealloc(*readsetp, sz); | |
1815 | *writesetp = xrealloc(*writesetp, sz); | |
1816 | *nallocp = sz; | |
1817 | } | |
1818 | *maxfdp = n; | |
1819 | memset(*readsetp, 0, sz); | |
1820 | memset(*writesetp, 0, sz); | |
1821 | ||
1822 | if (!rekeying) | |
1823 | channel_handler(channel_pre, *readsetp, *writesetp); | |
1824 | } | |
1825 | ||
1826 | /* | |
1827 | * After select, perform any appropriate operations for channels which have | |
1828 | * events pending. | |
1829 | */ | |
1830 | void | |
1831 | channel_after_select(fd_set * readset, fd_set * writeset) | |
1832 | { | |
1833 | channel_handler(channel_post, readset, writeset); | |
1834 | } | |
1835 | ||
1836 | ||
1837 | /* If there is data to send to the connection, enqueue some of it now. */ | |
1838 | ||
1839 | void | |
473db5ab | 1840 | channel_output_poll(void) |
3c0ef626 | 1841 | { |
3c0ef626 | 1842 | Channel *c; |
473db5ab | 1843 | u_int i, len; |
3c0ef626 | 1844 | |
1845 | for (i = 0; i < channels_alloc; i++) { | |
1846 | c = channels[i]; | |
1847 | if (c == NULL) | |
1848 | continue; | |
1849 | ||
1850 | /* | |
1851 | * We are only interested in channels that can have buffered | |
1852 | * incoming data. | |
1853 | */ | |
1854 | if (compat13) { | |
1855 | if (c->type != SSH_CHANNEL_OPEN && | |
1856 | c->type != SSH_CHANNEL_INPUT_DRAINING) | |
1857 | continue; | |
1858 | } else { | |
1859 | if (c->type != SSH_CHANNEL_OPEN) | |
1860 | continue; | |
1861 | } | |
1862 | if (compat20 && | |
1863 | (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) { | |
1864 | /* XXX is this true? */ | |
1865 | debug3("channel %d: will not send data after close", c->self); | |
1866 | continue; | |
1867 | } | |
1868 | ||
1869 | /* Get the amount of buffered data for this channel. */ | |
1870 | if ((c->istate == CHAN_INPUT_OPEN || | |
1871 | c->istate == CHAN_INPUT_WAIT_DRAIN) && | |
1872 | (len = buffer_len(&c->input)) > 0) { | |
08822d99 | 1873 | if (c->datagram) { |
1874 | if (len > 0) { | |
1875 | u_char *data; | |
1876 | u_int dlen; | |
1877 | ||
1878 | data = buffer_get_string(&c->input, | |
1879 | &dlen); | |
1880 | packet_start(SSH2_MSG_CHANNEL_DATA); | |
1881 | packet_put_int(c->remote_id); | |
1882 | packet_put_string(data, dlen); | |
1883 | packet_send(); | |
1884 | c->remote_window -= dlen + 4; | |
1885 | xfree(data); | |
1886 | } | |
1887 | continue; | |
1888 | } | |
3c0ef626 | 1889 | /* |
1890 | * Send some data for the other side over the secure | |
1891 | * connection. | |
1892 | */ | |
1893 | if (compat20) { | |
1894 | if (len > c->remote_window) | |
1895 | len = c->remote_window; | |
1896 | if (len > c->remote_maxpacket) | |
1897 | len = c->remote_maxpacket; | |
1898 | } else { | |
1899 | if (packet_is_interactive()) { | |
1900 | if (len > 1024) | |
1901 | len = 512; | |
1902 | } else { | |
1903 | /* Keep the packets at reasonable size. */ | |
1904 | if (len > packet_get_maxsize()/2) | |
1905 | len = packet_get_maxsize()/2; | |
1906 | } | |
1907 | } | |
1908 | if (len > 0) { | |
1909 | packet_start(compat20 ? | |
1910 | SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); | |
1911 | packet_put_int(c->remote_id); | |
1912 | packet_put_string(buffer_ptr(&c->input), len); | |
1913 | packet_send(); | |
1914 | buffer_consume(&c->input, len); | |
1915 | c->remote_window -= len; | |
1916 | } | |
1917 | } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) { | |
1918 | if (compat13) | |
1919 | fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); | |
1920 | /* | |
1921 | * input-buffer is empty and read-socket shutdown: | |
473db5ab | 1922 | * tell peer, that we will not send more data: send IEOF. |
1923 | * hack for extended data: delay EOF if EFD still in use. | |
3c0ef626 | 1924 | */ |
473db5ab | 1925 | if (CHANNEL_EFD_INPUT_ACTIVE(c)) |
1926 | debug2("channel %d: ibuf_empty delayed efd %d/(%d)", | |
1927 | c->self, c->efd, buffer_len(&c->extended)); | |
1928 | else | |
1929 | chan_ibuf_empty(c); | |
3c0ef626 | 1930 | } |
1931 | /* Send extended data, i.e. stderr */ | |
1932 | if (compat20 && | |
473db5ab | 1933 | !(c->flags & CHAN_EOF_SENT) && |
3c0ef626 | 1934 | c->remote_window > 0 && |
1935 | (len = buffer_len(&c->extended)) > 0 && | |
1936 | c->extended_usage == CHAN_EXTENDED_READ) { | |
473db5ab | 1937 | debug2("channel %d: rwin %u elen %u euse %d", |
3c0ef626 | 1938 | c->self, c->remote_window, buffer_len(&c->extended), |
1939 | c->extended_usage); | |
1940 | if (len > c->remote_window) | |
1941 | len = c->remote_window; | |
1942 | if (len > c->remote_maxpacket) | |
1943 | len = c->remote_maxpacket; | |
1944 | packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA); | |
1945 | packet_put_int(c->remote_id); | |
1946 | packet_put_int(SSH2_EXTENDED_DATA_STDERR); | |
1947 | packet_put_string(buffer_ptr(&c->extended), len); | |
1948 | packet_send(); | |
1949 | buffer_consume(&c->extended, len); | |
1950 | c->remote_window -= len; | |
1951 | debug2("channel %d: sent ext data %d", c->self, len); | |
1952 | } | |
1953 | } | |
1954 | } | |
1955 | ||
1956 | ||
1957 | /* -- protocol input */ | |
1958 | ||
1959 | void | |
473db5ab | 1960 | channel_input_data(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1961 | { |
1962 | int id; | |
1963 | char *data; | |
1964 | u_int data_len; | |
1965 | Channel *c; | |
1966 | ||
1967 | /* Get the channel number and verify it. */ | |
1968 | id = packet_get_int(); | |
1969 | c = channel_lookup(id); | |
1970 | if (c == NULL) | |
1971 | packet_disconnect("Received data for nonexistent channel %d.", id); | |
1972 | ||
1973 | /* Ignore any data for non-open channels (might happen on close) */ | |
1974 | if (c->type != SSH_CHANNEL_OPEN && | |
1975 | c->type != SSH_CHANNEL_X11_OPEN) | |
1976 | return; | |
1977 | ||
3c0ef626 | 1978 | /* Get the data. */ |
1979 | data = packet_get_string(&data_len); | |
3c0ef626 | 1980 | |
473db5ab | 1981 | /* |
1982 | * Ignore data for protocol > 1.3 if output end is no longer open. | |
1983 | * For protocol 2 the sending side is reducing its window as it sends | |
1984 | * data, so we must 'fake' consumption of the data in order to ensure | |
1985 | * that window updates are sent back. Otherwise the connection might | |
1986 | * deadlock. | |
1987 | */ | |
1988 | if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) { | |
1989 | if (compat20) { | |
1990 | c->local_window -= data_len; | |
1991 | c->local_consumed += data_len; | |
1992 | } | |
1993 | xfree(data); | |
1994 | return; | |
1995 | } | |
1996 | ||
1997 | if (compat20) { | |
3c0ef626 | 1998 | if (data_len > c->local_maxpacket) { |
473db5ab | 1999 | logit("channel %d: rcvd big packet %d, maxpack %d", |
3c0ef626 | 2000 | c->self, data_len, c->local_maxpacket); |
2001 | } | |
2002 | if (data_len > c->local_window) { | |
473db5ab | 2003 | logit("channel %d: rcvd too much data %d, win %d", |
3c0ef626 | 2004 | c->self, data_len, c->local_window); |
2005 | xfree(data); | |
2006 | return; | |
2007 | } | |
2008 | c->local_window -= data_len; | |
3c0ef626 | 2009 | } |
473db5ab | 2010 | packet_check_eom(); |
08822d99 | 2011 | if (c->datagram) |
2012 | buffer_put_string(&c->output, data, data_len); | |
2013 | else | |
2014 | buffer_append(&c->output, data, data_len); | |
3c0ef626 | 2015 | xfree(data); |
2016 | } | |
2017 | ||
2018 | void | |
473db5ab | 2019 | channel_input_extended_data(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2020 | { |
2021 | int id; | |
3c0ef626 | 2022 | char *data; |
473db5ab | 2023 | u_int data_len, tcode; |
3c0ef626 | 2024 | Channel *c; |
2025 | ||
2026 | /* Get the channel number and verify it. */ | |
2027 | id = packet_get_int(); | |
2028 | c = channel_lookup(id); | |
2029 | ||
2030 | if (c == NULL) | |
2031 | packet_disconnect("Received extended_data for bad channel %d.", id); | |
2032 | if (c->type != SSH_CHANNEL_OPEN) { | |
473db5ab | 2033 | logit("channel %d: ext data for non open", id); |
3c0ef626 | 2034 | return; |
2035 | } | |
473db5ab | 2036 | if (c->flags & CHAN_EOF_RCVD) { |
2037 | if (datafellows & SSH_BUG_EXTEOF) | |
2038 | debug("channel %d: accepting ext data after eof", id); | |
2039 | else | |
2040 | packet_disconnect("Received extended_data after EOF " | |
2041 | "on channel %d.", id); | |
2042 | } | |
3c0ef626 | 2043 | tcode = packet_get_int(); |
2044 | if (c->efd == -1 || | |
2045 | c->extended_usage != CHAN_EXTENDED_WRITE || | |
2046 | tcode != SSH2_EXTENDED_DATA_STDERR) { | |
473db5ab | 2047 | logit("channel %d: bad ext data", c->self); |
3c0ef626 | 2048 | return; |
2049 | } | |
2050 | data = packet_get_string(&data_len); | |
473db5ab | 2051 | packet_check_eom(); |
3c0ef626 | 2052 | if (data_len > c->local_window) { |
473db5ab | 2053 | logit("channel %d: rcvd too much extended_data %d, win %d", |
3c0ef626 | 2054 | c->self, data_len, c->local_window); |
2055 | xfree(data); | |
2056 | return; | |
2057 | } | |
2058 | debug2("channel %d: rcvd ext data %d", c->self, data_len); | |
2059 | c->local_window -= data_len; | |
2060 | buffer_append(&c->extended, data, data_len); | |
2061 | xfree(data); | |
2062 | } | |
2063 | ||
2064 | void | |
473db5ab | 2065 | channel_input_ieof(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2066 | { |
2067 | int id; | |
2068 | Channel *c; | |
2069 | ||
3c0ef626 | 2070 | id = packet_get_int(); |
473db5ab | 2071 | packet_check_eom(); |
3c0ef626 | 2072 | c = channel_lookup(id); |
2073 | if (c == NULL) | |
2074 | packet_disconnect("Received ieof for nonexistent channel %d.", id); | |
2075 | chan_rcvd_ieof(c); | |
2076 | ||
2077 | /* XXX force input close */ | |
473db5ab | 2078 | if (c->force_drain && c->istate == CHAN_INPUT_OPEN) { |
3c0ef626 | 2079 | debug("channel %d: FORCE input drain", c->self); |
2080 | c->istate = CHAN_INPUT_WAIT_DRAIN; | |
473db5ab | 2081 | if (buffer_len(&c->input) == 0) |
2082 | chan_ibuf_empty(c); | |
3c0ef626 | 2083 | } |
2084 | ||
2085 | } | |
2086 | ||
2087 | void | |
473db5ab | 2088 | channel_input_close(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2089 | { |
2090 | int id; | |
2091 | Channel *c; | |
2092 | ||
3c0ef626 | 2093 | id = packet_get_int(); |
473db5ab | 2094 | packet_check_eom(); |
3c0ef626 | 2095 | c = channel_lookup(id); |
2096 | if (c == NULL) | |
2097 | packet_disconnect("Received close for nonexistent channel %d.", id); | |
2098 | ||
2099 | /* | |
2100 | * Send a confirmation that we have closed the channel and no more | |
2101 | * data is coming for it. | |
2102 | */ | |
2103 | packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); | |
2104 | packet_put_int(c->remote_id); | |
2105 | packet_send(); | |
2106 | ||
2107 | /* | |
2108 | * If the channel is in closed state, we have sent a close request, | |
2109 | * and the other side will eventually respond with a confirmation. | |
2110 | * Thus, we cannot free the channel here, because then there would be | |
2111 | * no-one to receive the confirmation. The channel gets freed when | |
2112 | * the confirmation arrives. | |
2113 | */ | |
2114 | if (c->type != SSH_CHANNEL_CLOSED) { | |
2115 | /* | |
2116 | * Not a closed channel - mark it as draining, which will | |
2117 | * cause it to be freed later. | |
2118 | */ | |
473db5ab | 2119 | buffer_clear(&c->input); |
3c0ef626 | 2120 | c->type = SSH_CHANNEL_OUTPUT_DRAINING; |
2121 | } | |
2122 | } | |
2123 | ||
2124 | /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ | |
2125 | void | |
473db5ab | 2126 | channel_input_oclose(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2127 | { |
2128 | int id = packet_get_int(); | |
2129 | Channel *c = channel_lookup(id); | |
473db5ab | 2130 | |
2131 | packet_check_eom(); | |
3c0ef626 | 2132 | if (c == NULL) |
2133 | packet_disconnect("Received oclose for nonexistent channel %d.", id); | |
2134 | chan_rcvd_oclose(c); | |
2135 | } | |
2136 | ||
2137 | void | |
473db5ab | 2138 | channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2139 | { |
2140 | int id = packet_get_int(); | |
2141 | Channel *c = channel_lookup(id); | |
2142 | ||
473db5ab | 2143 | packet_check_eom(); |
3c0ef626 | 2144 | if (c == NULL) |
2145 | packet_disconnect("Received close confirmation for " | |
2146 | "out-of-range channel %d.", id); | |
2147 | if (c->type != SSH_CHANNEL_CLOSED) | |
2148 | packet_disconnect("Received close confirmation for " | |
2149 | "non-closed channel %d (type %d).", id, c->type); | |
2150 | channel_free(c); | |
2151 | } | |
2152 | ||
2153 | void | |
473db5ab | 2154 | channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2155 | { |
2156 | int id, remote_id; | |
2157 | Channel *c; | |
2158 | ||
3c0ef626 | 2159 | id = packet_get_int(); |
2160 | c = channel_lookup(id); | |
2161 | ||
2162 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
2163 | packet_disconnect("Received open confirmation for " | |
2164 | "non-opening channel %d.", id); | |
2165 | remote_id = packet_get_int(); | |
2166 | /* Record the remote channel number and mark that the channel is now open. */ | |
2167 | c->remote_id = remote_id; | |
2168 | c->type = SSH_CHANNEL_OPEN; | |
2169 | ||
2170 | if (compat20) { | |
2171 | c->remote_window = packet_get_int(); | |
2172 | c->remote_maxpacket = packet_get_int(); | |
473db5ab | 2173 | if (c->confirm) { |
3c0ef626 | 2174 | debug2("callback start"); |
473db5ab | 2175 | c->confirm(c->self, c->confirm_ctx); |
3c0ef626 | 2176 | debug2("callback done"); |
2177 | } | |
473db5ab | 2178 | debug2("channel %d: open confirm rwindow %u rmax %u", c->self, |
3c0ef626 | 2179 | c->remote_window, c->remote_maxpacket); |
2180 | } | |
473db5ab | 2181 | packet_check_eom(); |
3c0ef626 | 2182 | } |
2183 | ||
2184 | static char * | |
2185 | reason2txt(int reason) | |
2186 | { | |
473db5ab | 2187 | switch (reason) { |
3c0ef626 | 2188 | case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED: |
2189 | return "administratively prohibited"; | |
2190 | case SSH2_OPEN_CONNECT_FAILED: | |
2191 | return "connect failed"; | |
2192 | case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE: | |
2193 | return "unknown channel type"; | |
2194 | case SSH2_OPEN_RESOURCE_SHORTAGE: | |
2195 | return "resource shortage"; | |
2196 | } | |
2197 | return "unknown reason"; | |
2198 | } | |
2199 | ||
2200 | void | |
473db5ab | 2201 | channel_input_open_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2202 | { |
2203 | int id, reason; | |
2204 | char *msg = NULL, *lang = NULL; | |
2205 | Channel *c; | |
2206 | ||
3c0ef626 | 2207 | id = packet_get_int(); |
2208 | c = channel_lookup(id); | |
2209 | ||
2210 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
2211 | packet_disconnect("Received open failure for " | |
2212 | "non-opening channel %d.", id); | |
2213 | if (compat20) { | |
2214 | reason = packet_get_int(); | |
2215 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
2216 | msg = packet_get_string(NULL); | |
2217 | lang = packet_get_string(NULL); | |
2218 | } | |
473db5ab | 2219 | logit("channel %d: open failed: %s%s%s", id, |
3c0ef626 | 2220 | reason2txt(reason), msg ? ": ": "", msg ? msg : ""); |
2221 | if (msg != NULL) | |
2222 | xfree(msg); | |
2223 | if (lang != NULL) | |
2224 | xfree(lang); | |
2225 | } | |
473db5ab | 2226 | packet_check_eom(); |
3c0ef626 | 2227 | /* Free the channel. This will also close the socket. */ |
2228 | channel_free(c); | |
2229 | } | |
2230 | ||
2231 | void | |
473db5ab | 2232 | channel_input_window_adjust(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2233 | { |
3c0ef626 | 2234 | Channel *c; |
473db5ab | 2235 | int id; |
2236 | u_int adjust; | |
3c0ef626 | 2237 | |
2238 | if (!compat20) | |
2239 | return; | |
2240 | ||
2241 | /* Get the channel number and verify it. */ | |
2242 | id = packet_get_int(); | |
2243 | c = channel_lookup(id); | |
2244 | ||
08822d99 | 2245 | if (c == NULL) { |
2246 | logit("Received window adjust for non-open channel %d.", id); | |
3c0ef626 | 2247 | return; |
2248 | } | |
2249 | adjust = packet_get_int(); | |
473db5ab | 2250 | packet_check_eom(); |
2251 | debug2("channel %d: rcvd adjust %u", id, adjust); | |
3c0ef626 | 2252 | c->remote_window += adjust; |
2253 | } | |
2254 | ||
2255 | void | |
473db5ab | 2256 | channel_input_port_open(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2257 | { |
2258 | Channel *c = NULL; | |
2259 | u_short host_port; | |
2260 | char *host, *originator_string; | |
2261 | int remote_id, sock = -1; | |
2262 | ||
2263 | remote_id = packet_get_int(); | |
2264 | host = packet_get_string(NULL); | |
2265 | host_port = packet_get_int(); | |
2266 | ||
2267 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { | |
2268 | originator_string = packet_get_string(NULL); | |
2269 | } else { | |
2270 | originator_string = xstrdup("unknown (remote did not supply name)"); | |
2271 | } | |
473db5ab | 2272 | packet_check_eom(); |
3c0ef626 | 2273 | sock = channel_connect_to(host, host_port); |
2274 | if (sock != -1) { | |
2275 | c = channel_new("connected socket", | |
2276 | SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0, | |
2277 | originator_string, 1); | |
473db5ab | 2278 | c->remote_id = remote_id; |
3c0ef626 | 2279 | } |
473db5ab | 2280 | xfree(originator_string); |
3c0ef626 | 2281 | if (c == NULL) { |
2282 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2283 | packet_put_int(remote_id); | |
2284 | packet_send(); | |
2285 | } | |
2286 | xfree(host); | |
2287 | } | |
2288 | ||
2289 | ||
2290 | /* -- tcp forwarding */ | |
2291 | ||
2292 | void | |
2293 | channel_set_af(int af) | |
2294 | { | |
2295 | IPv4or6 = af; | |
2296 | } | |
2297 | ||
473db5ab | 2298 | static int |
2299 | channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port, | |
2300 | const char *host_to_connect, u_short port_to_connect, int gateway_ports) | |
3c0ef626 | 2301 | { |
2302 | Channel *c; | |
08822d99 | 2303 | int sock, r, success = 0, wildcard = 0, is_client; |
3c0ef626 | 2304 | struct addrinfo hints, *ai, *aitop; |
473db5ab | 2305 | const char *host, *addr; |
3c0ef626 | 2306 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
3c0ef626 | 2307 | |
473db5ab | 2308 | host = (type == SSH_CHANNEL_RPORT_LISTENER) ? |
2309 | listen_addr : host_to_connect; | |
2310 | is_client = (type == SSH_CHANNEL_PORT_LISTENER); | |
3c0ef626 | 2311 | |
473db5ab | 2312 | if (host == NULL) { |
2313 | error("No forward host name."); | |
2314 | return 0; | |
3c0ef626 | 2315 | } |
3c0ef626 | 2316 | if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) { |
2317 | error("Forward host name too long."); | |
473db5ab | 2318 | return 0; |
3c0ef626 | 2319 | } |
2320 | ||
473db5ab | 2321 | /* |
2322 | * Determine whether or not a port forward listens to loopback, | |
2323 | * specified address or wildcard. On the client, a specified bind | |
2324 | * address will always override gateway_ports. On the server, a | |
2325 | * gateway_ports of 1 (``yes'') will override the client's | |
2326 | * specification and force a wildcard bind, whereas a value of 2 | |
2327 | * (``clientspecified'') will bind to whatever address the client | |
2328 | * asked for. | |
2329 | * | |
2330 | * Special-case listen_addrs are: | |
2331 | * | |
2332 | * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR | |
2333 | * "" (empty string), "*" -> wildcard v4/v6 | |
2334 | * "localhost" -> loopback v4/v6 | |
2335 | */ | |
2336 | addr = NULL; | |
2337 | if (listen_addr == NULL) { | |
2338 | /* No address specified: default to gateway_ports setting */ | |
2339 | if (gateway_ports) | |
2340 | wildcard = 1; | |
2341 | } else if (gateway_ports || is_client) { | |
2342 | if (((datafellows & SSH_OLD_FORWARD_ADDR) && | |
2343 | strcmp(listen_addr, "0.0.0.0") == 0) || | |
2344 | *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 || | |
2345 | (!is_client && gateway_ports == 1)) | |
2346 | wildcard = 1; | |
2347 | else if (strcmp(listen_addr, "localhost") != 0) | |
2348 | addr = listen_addr; | |
2349 | } | |
2350 | ||
2351 | debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s", | |
2352 | type, wildcard, (addr == NULL) ? "NULL" : addr); | |
2353 | ||
3c0ef626 | 2354 | /* |
2355 | * getaddrinfo returns a loopback address if the hostname is | |
2356 | * set to NULL and hints.ai_flags is not AI_PASSIVE | |
2357 | */ | |
2358 | memset(&hints, 0, sizeof(hints)); | |
2359 | hints.ai_family = IPv4or6; | |
473db5ab | 2360 | hints.ai_flags = wildcard ? AI_PASSIVE : 0; |
3c0ef626 | 2361 | hints.ai_socktype = SOCK_STREAM; |
2362 | snprintf(strport, sizeof strport, "%d", listen_port); | |
473db5ab | 2363 | if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) { |
2364 | if (addr == NULL) { | |
2365 | /* This really shouldn't happen */ | |
2366 | packet_disconnect("getaddrinfo: fatal error: %s", | |
2367 | gai_strerror(r)); | |
2368 | } else { | |
2369 | error("channel_setup_fwd_listener: " | |
2370 | "getaddrinfo(%.64s): %s", addr, gai_strerror(r)); | |
2371 | } | |
2372 | return 0; | |
2373 | } | |
3c0ef626 | 2374 | |
2375 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2376 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2377 | continue; | |
2378 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
2379 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
473db5ab | 2380 | error("channel_setup_fwd_listener: getnameinfo failed"); |
3c0ef626 | 2381 | continue; |
2382 | } | |
2383 | /* Create a port to listen for the host. */ | |
473db5ab | 2384 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3c0ef626 | 2385 | if (sock < 0) { |
2386 | /* this is no error since kernel may not support ipv6 */ | |
2387 | verbose("socket: %.100s", strerror(errno)); | |
2388 | continue; | |
2389 | } | |
08822d99 | 2390 | |
2391 | channel_set_reuseaddr(sock); | |
473db5ab | 2392 | |
3c0ef626 | 2393 | debug("Local forwarding listening on %s port %s.", ntop, strport); |
2394 | ||
2395 | /* Bind the socket to the address. */ | |
2396 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
2397 | /* address can be in use ipv6 address is already bound */ | |
2398 | if (!ai->ai_next) | |
2399 | error("bind: %.100s", strerror(errno)); | |
2400 | else | |
2401 | verbose("bind: %.100s", strerror(errno)); | |
2402 | ||
2403 | close(sock); | |
2404 | continue; | |
2405 | } | |
2406 | /* Start listening for connections on the socket. */ | |
473db5ab | 2407 | if (listen(sock, SSH_LISTEN_BACKLOG) < 0) { |
3c0ef626 | 2408 | error("listen: %.100s", strerror(errno)); |
2409 | close(sock); | |
2410 | continue; | |
2411 | } | |
2412 | /* Allocate a channel number for the socket. */ | |
2413 | c = channel_new("port listener", type, sock, sock, -1, | |
2414 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, | |
473db5ab | 2415 | 0, "port listener", 1); |
3c0ef626 | 2416 | strlcpy(c->path, host, sizeof(c->path)); |
2417 | c->host_port = port_to_connect; | |
2418 | c->listening_port = listen_port; | |
2419 | success = 1; | |
2420 | } | |
2421 | if (success == 0) | |
473db5ab | 2422 | error("channel_setup_fwd_listener: cannot listen to port: %d", |
3c0ef626 | 2423 | listen_port); |
2424 | freeaddrinfo(aitop); | |
2425 | return success; | |
2426 | } | |
2427 | ||
473db5ab | 2428 | int |
2429 | channel_cancel_rport_listener(const char *host, u_short port) | |
2430 | { | |
2431 | u_int i; | |
2432 | int found = 0; | |
2433 | ||
2434 | for (i = 0; i < channels_alloc; i++) { | |
2435 | Channel *c = channels[i]; | |
2436 | ||
2437 | if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER && | |
2438 | strncmp(c->path, host, sizeof(c->path)) == 0 && | |
2439 | c->listening_port == port) { | |
2440 | debug2("%s: close channel %d", __func__, i); | |
2441 | channel_free(c); | |
2442 | found = 1; | |
2443 | } | |
2444 | } | |
2445 | ||
2446 | return (found); | |
2447 | } | |
2448 | ||
2449 | /* protocol local port fwd, used by ssh (and sshd in v1) */ | |
2450 | int | |
2451 | channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port, | |
2452 | const char *host_to_connect, u_short port_to_connect, int gateway_ports) | |
2453 | { | |
2454 | return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER, | |
2455 | listen_host, listen_port, host_to_connect, port_to_connect, | |
2456 | gateway_ports); | |
2457 | } | |
2458 | ||
2459 | /* protocol v2 remote port fwd, used by sshd */ | |
2460 | int | |
2461 | channel_setup_remote_fwd_listener(const char *listen_address, | |
2462 | u_short listen_port, int gateway_ports) | |
2463 | { | |
2464 | return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER, | |
2465 | listen_address, listen_port, NULL, 0, gateway_ports); | |
2466 | } | |
2467 | ||
3c0ef626 | 2468 | /* |
2469 | * Initiate forwarding of connections to port "port" on remote host through | |
2470 | * the secure channel to host:port from local side. | |
2471 | */ | |
2472 | ||
2473 | void | |
473db5ab | 2474 | channel_request_remote_forwarding(const char *listen_host, u_short listen_port, |
3c0ef626 | 2475 | const char *host_to_connect, u_short port_to_connect) |
2476 | { | |
473db5ab | 2477 | int type, success = 0; |
3c0ef626 | 2478 | |
2479 | /* Record locally that connection to this host/port is permitted. */ | |
2480 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
2481 | fatal("channel_request_remote_forwarding: too many forwards"); | |
2482 | ||
2483 | /* Send the forward request to the remote side. */ | |
2484 | if (compat20) { | |
473db5ab | 2485 | const char *address_to_bind; |
2486 | if (listen_host == NULL) | |
2487 | address_to_bind = "localhost"; | |
2488 | else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) | |
2489 | address_to_bind = ""; | |
2490 | else | |
2491 | address_to_bind = listen_host; | |
2492 | ||
3c0ef626 | 2493 | packet_start(SSH2_MSG_GLOBAL_REQUEST); |
2494 | packet_put_cstring("tcpip-forward"); | |
473db5ab | 2495 | packet_put_char(1); /* boolean: want reply */ |
3c0ef626 | 2496 | packet_put_cstring(address_to_bind); |
2497 | packet_put_int(listen_port); | |
2498 | packet_send(); | |
2499 | packet_write_wait(); | |
2500 | /* Assume that server accepts the request */ | |
2501 | success = 1; | |
2502 | } else { | |
2503 | packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); | |
2504 | packet_put_int(listen_port); | |
2505 | packet_put_cstring(host_to_connect); | |
2506 | packet_put_int(port_to_connect); | |
2507 | packet_send(); | |
2508 | packet_write_wait(); | |
2509 | ||
2510 | /* Wait for response from the remote side. */ | |
473db5ab | 2511 | type = packet_read(); |
3c0ef626 | 2512 | switch (type) { |
2513 | case SSH_SMSG_SUCCESS: | |
2514 | success = 1; | |
2515 | break; | |
2516 | case SSH_SMSG_FAILURE: | |
473db5ab | 2517 | logit("Warning: Server denied remote port forwarding."); |
3c0ef626 | 2518 | break; |
2519 | default: | |
2520 | /* Unknown packet */ | |
2521 | packet_disconnect("Protocol error for port forward request:" | |
2522 | "received packet type %d.", type); | |
2523 | } | |
2524 | } | |
2525 | if (success) { | |
2526 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect); | |
2527 | permitted_opens[num_permitted_opens].port_to_connect = port_to_connect; | |
2528 | permitted_opens[num_permitted_opens].listen_port = listen_port; | |
2529 | num_permitted_opens++; | |
2530 | } | |
2531 | } | |
2532 | ||
473db5ab | 2533 | /* |
2534 | * Request cancellation of remote forwarding of connection host:port from | |
2535 | * local side. | |
2536 | */ | |
2537 | void | |
2538 | channel_request_rforward_cancel(const char *host, u_short port) | |
2539 | { | |
2540 | int i; | |
2541 | ||
2542 | if (!compat20) | |
2543 | return; | |
2544 | ||
2545 | for (i = 0; i < num_permitted_opens; i++) { | |
2546 | if (permitted_opens[i].host_to_connect != NULL && | |
2547 | permitted_opens[i].listen_port == port) | |
2548 | break; | |
2549 | } | |
2550 | if (i >= num_permitted_opens) { | |
2551 | debug("%s: requested forward not found", __func__); | |
2552 | return; | |
2553 | } | |
2554 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
2555 | packet_put_cstring("cancel-tcpip-forward"); | |
2556 | packet_put_char(0); | |
2557 | packet_put_cstring(host == NULL ? "" : host); | |
2558 | packet_put_int(port); | |
2559 | packet_send(); | |
2560 | ||
2561 | permitted_opens[i].listen_port = 0; | |
2562 | permitted_opens[i].port_to_connect = 0; | |
08822d99 | 2563 | xfree(permitted_opens[i].host_to_connect); |
473db5ab | 2564 | permitted_opens[i].host_to_connect = NULL; |
2565 | } | |
2566 | ||
3c0ef626 | 2567 | /* |
2568 | * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates | |
2569 | * listening for the port, and sends back a success reply (or disconnect | |
2570 | * message if there was an error). This never returns if there was an error. | |
2571 | */ | |
2572 | ||
2573 | void | |
2574 | channel_input_port_forward_request(int is_root, int gateway_ports) | |
2575 | { | |
2576 | u_short port, host_port; | |
2577 | char *hostname; | |
2578 | ||
2579 | /* Get arguments from the packet. */ | |
2580 | port = packet_get_int(); | |
2581 | hostname = packet_get_string(NULL); | |
2582 | host_port = packet_get_int(); | |
2583 | ||
2584 | #ifndef HAVE_CYGWIN | |
2585 | /* | |
2586 | * Check that an unprivileged user is not trying to forward a | |
2587 | * privileged port. | |
2588 | */ | |
2589 | if (port < IPPORT_RESERVED && !is_root) | |
473db5ab | 2590 | packet_disconnect( |
2591 | "Requested forwarding of port %d but user is not root.", | |
2592 | port); | |
2593 | if (host_port == 0) | |
2594 | packet_disconnect("Dynamic forwarding denied."); | |
3c0ef626 | 2595 | #endif |
473db5ab | 2596 | |
3c0ef626 | 2597 | /* Initiate forwarding */ |
473db5ab | 2598 | channel_setup_local_fwd_listener(NULL, port, hostname, |
2599 | host_port, gateway_ports); | |
3c0ef626 | 2600 | |
2601 | /* Free the argument string. */ | |
2602 | xfree(hostname); | |
2603 | } | |
2604 | ||
2605 | /* | |
2606 | * Permits opening to any host/port if permitted_opens[] is empty. This is | |
2607 | * usually called by the server, because the user could connect to any port | |
2608 | * anyway, and the server has no way to know but to trust the client anyway. | |
2609 | */ | |
2610 | void | |
473db5ab | 2611 | channel_permit_all_opens(void) |
3c0ef626 | 2612 | { |
2613 | if (num_permitted_opens == 0) | |
2614 | all_opens_permitted = 1; | |
2615 | } | |
2616 | ||
2617 | void | |
2618 | channel_add_permitted_opens(char *host, int port) | |
2619 | { | |
2620 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
2621 | fatal("channel_request_remote_forwarding: too many forwards"); | |
2622 | debug("allow port forwarding to host %s port %d", host, port); | |
2623 | ||
2624 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host); | |
2625 | permitted_opens[num_permitted_opens].port_to_connect = port; | |
2626 | num_permitted_opens++; | |
2627 | ||
2628 | all_opens_permitted = 0; | |
2629 | } | |
2630 | ||
2631 | void | |
2632 | channel_clear_permitted_opens(void) | |
2633 | { | |
2634 | int i; | |
2635 | ||
2636 | for (i = 0; i < num_permitted_opens; i++) | |
473db5ab | 2637 | if (permitted_opens[i].host_to_connect != NULL) |
2638 | xfree(permitted_opens[i].host_to_connect); | |
3c0ef626 | 2639 | num_permitted_opens = 0; |
2640 | ||
2641 | } | |
2642 | ||
2643 | ||
2644 | /* return socket to remote host, port */ | |
2645 | static int | |
2646 | connect_to(const char *host, u_short port) | |
2647 | { | |
2648 | struct addrinfo hints, *ai, *aitop; | |
2649 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
2650 | int gaierr; | |
2651 | int sock = -1; | |
2652 | ||
2653 | memset(&hints, 0, sizeof(hints)); | |
2654 | hints.ai_family = IPv4or6; | |
2655 | hints.ai_socktype = SOCK_STREAM; | |
2656 | snprintf(strport, sizeof strport, "%d", port); | |
2657 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { | |
2658 | error("connect_to %.100s: unknown host (%s)", host, | |
2659 | gai_strerror(gaierr)); | |
2660 | return -1; | |
2661 | } | |
2662 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2663 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2664 | continue; | |
2665 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
2666 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
2667 | error("connect_to: getnameinfo failed"); | |
2668 | continue; | |
2669 | } | |
473db5ab | 2670 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3c0ef626 | 2671 | if (sock < 0) { |
473db5ab | 2672 | if (ai->ai_next == NULL) |
2673 | error("socket: %.100s", strerror(errno)); | |
2674 | else | |
2675 | verbose("socket: %.100s", strerror(errno)); | |
3c0ef626 | 2676 | continue; |
2677 | } | |
473db5ab | 2678 | if (set_nonblock(sock) == -1) |
2679 | fatal("%s: set_nonblock(%d)", __func__, sock); | |
3c0ef626 | 2680 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 && |
2681 | errno != EINPROGRESS) { | |
2682 | error("connect_to %.100s port %s: %.100s", ntop, strport, | |
2683 | strerror(errno)); | |
2684 | close(sock); | |
2685 | continue; /* fail -- try next */ | |
2686 | } | |
2687 | break; /* success */ | |
2688 | ||
2689 | } | |
2690 | freeaddrinfo(aitop); | |
2691 | if (!ai) { | |
2692 | error("connect_to %.100s port %d: failed.", host, port); | |
2693 | return -1; | |
2694 | } | |
2695 | /* success */ | |
473db5ab | 2696 | set_nodelay(sock); |
3c0ef626 | 2697 | return sock; |
2698 | } | |
2699 | ||
2700 | int | |
2701 | channel_connect_by_listen_address(u_short listen_port) | |
2702 | { | |
2703 | int i; | |
2704 | ||
2705 | for (i = 0; i < num_permitted_opens; i++) | |
473db5ab | 2706 | if (permitted_opens[i].host_to_connect != NULL && |
2707 | permitted_opens[i].listen_port == listen_port) | |
3c0ef626 | 2708 | return connect_to( |
2709 | permitted_opens[i].host_to_connect, | |
2710 | permitted_opens[i].port_to_connect); | |
2711 | error("WARNING: Server requests forwarding for unknown listen_port %d", | |
2712 | listen_port); | |
2713 | return -1; | |
2714 | } | |
2715 | ||
2716 | /* Check if connecting to that port is permitted and connect. */ | |
2717 | int | |
2718 | channel_connect_to(const char *host, u_short port) | |
2719 | { | |
2720 | int i, permit; | |
2721 | ||
2722 | permit = all_opens_permitted; | |
2723 | if (!permit) { | |
2724 | for (i = 0; i < num_permitted_opens; i++) | |
473db5ab | 2725 | if (permitted_opens[i].host_to_connect != NULL && |
2726 | permitted_opens[i].port_to_connect == port && | |
3c0ef626 | 2727 | strcmp(permitted_opens[i].host_to_connect, host) == 0) |
2728 | permit = 1; | |
2729 | ||
2730 | } | |
2731 | if (!permit) { | |
473db5ab | 2732 | logit("Received request to connect to host %.100s port %d, " |
3c0ef626 | 2733 | "but the request was denied.", host, port); |
2734 | return -1; | |
2735 | } | |
2736 | return connect_to(host, port); | |
2737 | } | |
2738 | ||
473db5ab | 2739 | void |
2740 | channel_send_window_changes(void) | |
2741 | { | |
2742 | u_int i; | |
2743 | struct winsize ws; | |
2744 | ||
2745 | for (i = 0; i < channels_alloc; i++) { | |
2746 | if (channels[i] == NULL || !channels[i]->client_tty || | |
2747 | channels[i]->type != SSH_CHANNEL_OPEN) | |
2748 | continue; | |
2749 | if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0) | |
2750 | continue; | |
2751 | channel_request_start(i, "window-change", 0); | |
2752 | packet_put_int(ws.ws_col); | |
2753 | packet_put_int(ws.ws_row); | |
2754 | packet_put_int(ws.ws_xpixel); | |
2755 | packet_put_int(ws.ws_ypixel); | |
2756 | packet_send(); | |
2757 | } | |
2758 | } | |
2759 | ||
3c0ef626 | 2760 | /* -- X11 forwarding */ |
2761 | ||
2762 | /* | |
2763 | * Creates an internet domain socket for listening for X11 connections. | |
473db5ab | 2764 | * Returns 0 and a suitable display number for the DISPLAY variable |
2765 | * stored in display_numberp , or -1 if an error occurs. | |
3c0ef626 | 2766 | */ |
473db5ab | 2767 | int |
2768 | x11_create_display_inet(int x11_display_offset, int x11_use_localhost, | |
2769 | int single_connection, u_int *display_numberp, int **chanids) | |
3c0ef626 | 2770 | { |
473db5ab | 2771 | Channel *nc = NULL; |
3c0ef626 | 2772 | int display_number, sock; |
2773 | u_short port; | |
2774 | struct addrinfo hints, *ai, *aitop; | |
2775 | char strport[NI_MAXSERV]; | |
2776 | int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; | |
3c0ef626 | 2777 | |
08822d99 | 2778 | if (chanids == NULL) |
2779 | return -1; | |
2780 | ||
3c0ef626 | 2781 | for (display_number = x11_display_offset; |
473db5ab | 2782 | display_number < MAX_DISPLAYS; |
2783 | display_number++) { | |
3c0ef626 | 2784 | port = 6000 + display_number; |
2785 | memset(&hints, 0, sizeof(hints)); | |
2786 | hints.ai_family = IPv4or6; | |
473db5ab | 2787 | hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE; |
3c0ef626 | 2788 | hints.ai_socktype = SOCK_STREAM; |
2789 | snprintf(strport, sizeof strport, "%d", port); | |
2790 | if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { | |
2791 | error("getaddrinfo: %.100s", gai_strerror(gaierr)); | |
473db5ab | 2792 | return -1; |
3c0ef626 | 2793 | } |
2794 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2795 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2796 | continue; | |
473db5ab | 2797 | sock = socket(ai->ai_family, ai->ai_socktype, |
2798 | ai->ai_protocol); | |
3c0ef626 | 2799 | if (sock < 0) { |
2800 | if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) { | |
2801 | error("socket: %.100s", strerror(errno)); | |
473db5ab | 2802 | freeaddrinfo(aitop); |
2803 | return -1; | |
3c0ef626 | 2804 | } else { |
2805 | debug("x11_create_display_inet: Socket family %d not supported", | |
2806 | ai->ai_family); | |
2807 | continue; | |
2808 | } | |
2809 | } | |
473db5ab | 2810 | #ifdef IPV6_V6ONLY |
2811 | if (ai->ai_family == AF_INET6) { | |
2812 | int on = 1; | |
2813 | if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) | |
2814 | error("setsockopt IPV6_V6ONLY: %.100s", strerror(errno)); | |
2815 | } | |
2816 | #endif | |
08822d99 | 2817 | channel_set_reuseaddr(sock); |
3c0ef626 | 2818 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { |
473db5ab | 2819 | debug2("bind port %d: %.100s", port, strerror(errno)); |
3c0ef626 | 2820 | close(sock); |
2821 | ||
2822 | if (ai->ai_next) | |
2823 | continue; | |
2824 | ||
2825 | for (n = 0; n < num_socks; n++) { | |
3c0ef626 | 2826 | close(socks[n]); |
2827 | } | |
2828 | num_socks = 0; | |
2829 | break; | |
2830 | } | |
2831 | socks[num_socks++] = sock; | |
2832 | #ifndef DONT_TRY_OTHER_AF | |
2833 | if (num_socks == NUM_SOCKS) | |
2834 | break; | |
2835 | #else | |
473db5ab | 2836 | if (x11_use_localhost) { |
2837 | if (num_socks == NUM_SOCKS) | |
2838 | break; | |
2839 | } else { | |
2840 | break; | |
2841 | } | |
3c0ef626 | 2842 | #endif |
2843 | } | |
2844 | freeaddrinfo(aitop); | |
2845 | if (num_socks > 0) | |
2846 | break; | |
2847 | } | |
2848 | if (display_number >= MAX_DISPLAYS) { | |
2849 | error("Failed to allocate internet-domain X11 display socket."); | |
473db5ab | 2850 | return -1; |
3c0ef626 | 2851 | } |
2852 | /* Start listening for connections on the socket. */ | |
2853 | for (n = 0; n < num_socks; n++) { | |
2854 | sock = socks[n]; | |
473db5ab | 2855 | if (listen(sock, SSH_LISTEN_BACKLOG) < 0) { |
3c0ef626 | 2856 | error("listen: %.100s", strerror(errno)); |
3c0ef626 | 2857 | close(sock); |
473db5ab | 2858 | return -1; |
3c0ef626 | 2859 | } |
3c0ef626 | 2860 | } |
3c0ef626 | 2861 | |
2862 | /* Allocate a channel for each socket. */ | |
08822d99 | 2863 | *chanids = xmalloc(sizeof(**chanids) * (num_socks + 1)); |
3c0ef626 | 2864 | for (n = 0; n < num_socks; n++) { |
2865 | sock = socks[n]; | |
473db5ab | 2866 | nc = channel_new("x11 listener", |
3c0ef626 | 2867 | SSH_CHANNEL_X11_LISTENER, sock, sock, -1, |
2868 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
473db5ab | 2869 | 0, "X11 inet listener", 1); |
2870 | nc->single_connection = single_connection; | |
08822d99 | 2871 | (*chanids)[n] = nc->self; |
3c0ef626 | 2872 | } |
08822d99 | 2873 | (*chanids)[n] = -1; |
3c0ef626 | 2874 | |
473db5ab | 2875 | /* Return the display number for the DISPLAY environment variable. */ |
2876 | *display_numberp = display_number; | |
2877 | return (0); | |
3c0ef626 | 2878 | } |
2879 | ||
3c0ef626 | 2880 | static int |
2881 | connect_local_xsocket(u_int dnr) | |
2882 | { | |
3c0ef626 | 2883 | int sock; |
2884 | struct sockaddr_un addr; | |
3c0ef626 | 2885 | |
473db5ab | 2886 | sock = socket(AF_UNIX, SOCK_STREAM, 0); |
2887 | if (sock < 0) | |
2888 | error("socket: %.100s", strerror(errno)); | |
2889 | memset(&addr, 0, sizeof(addr)); | |
2890 | addr.sun_family = AF_UNIX; | |
2891 | snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr); | |
2892 | if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0) | |
2893 | return sock; | |
2894 | close(sock); | |
3c0ef626 | 2895 | error("connect %.100s: %.100s", addr.sun_path, strerror(errno)); |
2896 | return -1; | |
2897 | } | |
2898 | ||
2899 | int | |
2900 | x11_connect_display(void) | |
2901 | { | |
2902 | int display_number, sock = 0; | |
2903 | const char *display; | |
2904 | char buf[1024], *cp; | |
2905 | struct addrinfo hints, *ai, *aitop; | |
2906 | char strport[NI_MAXSERV]; | |
2907 | int gaierr; | |
2908 | ||
2909 | /* Try to open a socket for the local X server. */ | |
2910 | display = getenv("DISPLAY"); | |
2911 | if (!display) { | |
2912 | error("DISPLAY not set."); | |
2913 | return -1; | |
2914 | } | |
2915 | /* | |
2916 | * Now we decode the value of the DISPLAY variable and make a | |
2917 | * connection to the real X server. | |
2918 | */ | |
2919 | ||
2920 | /* | |
2921 | * Check if it is a unix domain socket. Unix domain displays are in | |
2922 | * one of the following formats: unix:d[.s], :d[.s], ::d[.s] | |
2923 | */ | |
2924 | if (strncmp(display, "unix:", 5) == 0 || | |
2925 | display[0] == ':') { | |
2926 | /* Connect to the unix domain socket. */ | |
2927 | if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) { | |
2928 | error("Could not parse display number from DISPLAY: %.100s", | |
473db5ab | 2929 | display); |
3c0ef626 | 2930 | return -1; |
2931 | } | |
2932 | /* Create a socket. */ | |
2933 | sock = connect_local_xsocket(display_number); | |
2934 | if (sock < 0) | |
2935 | return -1; | |
2936 | ||
2937 | /* OK, we now have a connection to the display. */ | |
2938 | return sock; | |
2939 | } | |
2940 | /* | |
2941 | * Connect to an inet socket. The DISPLAY value is supposedly | |
2942 | * hostname:d[.s], where hostname may also be numeric IP address. | |
2943 | */ | |
473db5ab | 2944 | strlcpy(buf, display, sizeof(buf)); |
3c0ef626 | 2945 | cp = strchr(buf, ':'); |
2946 | if (!cp) { | |
2947 | error("Could not find ':' in DISPLAY: %.100s", display); | |
2948 | return -1; | |
2949 | } | |
2950 | *cp = 0; | |
2951 | /* buf now contains the host name. But first we parse the display number. */ | |
2952 | if (sscanf(cp + 1, "%d", &display_number) != 1) { | |
2953 | error("Could not parse display number from DISPLAY: %.100s", | |
473db5ab | 2954 | display); |
3c0ef626 | 2955 | return -1; |
2956 | } | |
2957 | ||
2958 | /* Look up the host address */ | |
2959 | memset(&hints, 0, sizeof(hints)); | |
2960 | hints.ai_family = IPv4or6; | |
2961 | hints.ai_socktype = SOCK_STREAM; | |
2962 | snprintf(strport, sizeof strport, "%d", 6000 + display_number); | |
2963 | if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { | |
2964 | error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr)); | |
2965 | return -1; | |
2966 | } | |
2967 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2968 | /* Create a socket. */ | |
473db5ab | 2969 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3c0ef626 | 2970 | if (sock < 0) { |
473db5ab | 2971 | debug2("socket: %.100s", strerror(errno)); |
3c0ef626 | 2972 | continue; |
2973 | } | |
2974 | /* Connect it to the display. */ | |
2975 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
473db5ab | 2976 | debug2("connect %.100s port %d: %.100s", buf, |
3c0ef626 | 2977 | 6000 + display_number, strerror(errno)); |
2978 | close(sock); | |
2979 | continue; | |
2980 | } | |
2981 | /* Success */ | |
2982 | break; | |
2983 | } | |
2984 | freeaddrinfo(aitop); | |
2985 | if (!ai) { | |
2986 | error("connect %.100s port %d: %.100s", buf, 6000 + display_number, | |
2987 | strerror(errno)); | |
2988 | return -1; | |
2989 | } | |
473db5ab | 2990 | set_nodelay(sock); |
3c0ef626 | 2991 | return sock; |
2992 | } | |
2993 | ||
2994 | /* | |
2995 | * This is called when SSH_SMSG_X11_OPEN is received. The packet contains | |
2996 | * the remote channel number. We should do whatever we want, and respond | |
2997 | * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. | |
2998 | */ | |
2999 | ||
3000 | void | |
473db5ab | 3001 | x11_input_open(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 3002 | { |
3003 | Channel *c = NULL; | |
3004 | int remote_id, sock = 0; | |
3005 | char *remote_host; | |
3006 | ||
3007 | debug("Received X11 open request."); | |
3008 | ||
3009 | remote_id = packet_get_int(); | |
3010 | ||
3011 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { | |
3012 | remote_host = packet_get_string(NULL); | |
3013 | } else { | |
3014 | remote_host = xstrdup("unknown (remote did not supply name)"); | |
3015 | } | |
473db5ab | 3016 | packet_check_eom(); |
3c0ef626 | 3017 | |
3018 | /* Obtain a connection to the real X display. */ | |
3019 | sock = x11_connect_display(); | |
3020 | if (sock != -1) { | |
3021 | /* Allocate a channel for this connection. */ | |
3022 | c = channel_new("connected x11 socket", | |
3023 | SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0, | |
3024 | remote_host, 1); | |
473db5ab | 3025 | c->remote_id = remote_id; |
3026 | c->force_drain = 1; | |
3c0ef626 | 3027 | } |
473db5ab | 3028 | xfree(remote_host); |
3c0ef626 | 3029 | if (c == NULL) { |
3030 | /* Send refusal to the remote host. */ | |
3031 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
3032 | packet_put_int(remote_id); | |
3033 | } else { | |
3034 | /* Send a confirmation to the remote host. */ | |
3035 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
3036 | packet_put_int(remote_id); | |
3037 | packet_put_int(c->self); | |
3038 | } | |
3039 | packet_send(); | |
3040 | } | |
3041 | ||
3042 | /* dummy protocol handler that denies SSH-1 requests (agent/x11) */ | |
3043 | void | |
473db5ab | 3044 | deny_input_open(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 3045 | { |
3046 | int rchan = packet_get_int(); | |
473db5ab | 3047 | |
3048 | switch (type) { | |
3c0ef626 | 3049 | case SSH_SMSG_AGENT_OPEN: |
3050 | error("Warning: ssh server tried agent forwarding."); | |
3051 | break; | |
3052 | case SSH_SMSG_X11_OPEN: | |
3053 | error("Warning: ssh server tried X11 forwarding."); | |
3054 | break; | |
3055 | default: | |
473db5ab | 3056 | error("deny_input_open: type %d", type); |
3c0ef626 | 3057 | break; |
3058 | } | |
08822d99 | 3059 | error("Warning: this is probably a break-in attempt by a malicious server."); |
3c0ef626 | 3060 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); |
3061 | packet_put_int(rchan); | |
3062 | packet_send(); | |
3063 | } | |
3064 | ||
3065 | /* | |
3066 | * Requests forwarding of X11 connections, generates fake authentication | |
3067 | * data, and enables authentication spoofing. | |
3068 | * This should be called in the client only. | |
3069 | */ | |
3070 | void | |
473db5ab | 3071 | x11_request_forwarding_with_spoofing(int client_session_id, const char *disp, |
3c0ef626 | 3072 | const char *proto, const char *data) |
3073 | { | |
3074 | u_int data_len = (u_int) strlen(data) / 2; | |
473db5ab | 3075 | u_int i, value; |
3c0ef626 | 3076 | char *new_data; |
3077 | int screen_number; | |
3078 | const char *cp; | |
473db5ab | 3079 | u_int32_t rnd = 0; |
3c0ef626 | 3080 | |
473db5ab | 3081 | if (x11_saved_display == NULL) |
3082 | x11_saved_display = xstrdup(disp); | |
3083 | else if (strcmp(disp, x11_saved_display) != 0) { | |
3084 | error("x11_request_forwarding_with_spoofing: different " | |
3085 | "$DISPLAY already forwarded"); | |
3086 | return; | |
3087 | } | |
3088 | ||
3089 | cp = disp; | |
3090 | if (disp) | |
3091 | cp = strchr(disp, ':'); | |
3c0ef626 | 3092 | if (cp) |
3093 | cp = strchr(cp, '.'); | |
3094 | if (cp) | |
3095 | screen_number = atoi(cp + 1); | |
3096 | else | |
3097 | screen_number = 0; | |
3098 | ||
473db5ab | 3099 | if (x11_saved_proto == NULL) { |
3100 | /* Save protocol name. */ | |
3101 | x11_saved_proto = xstrdup(proto); | |
3102 | /* | |
3103 | * Extract real authentication data and generate fake data | |
3104 | * of the same length. | |
3105 | */ | |
3106 | x11_saved_data = xmalloc(data_len); | |
3107 | x11_fake_data = xmalloc(data_len); | |
3108 | for (i = 0; i < data_len; i++) { | |
3109 | if (sscanf(data + 2 * i, "%2x", &value) != 1) | |
3110 | fatal("x11_request_forwarding: bad " | |
3111 | "authentication data: %.100s", data); | |
3112 | if (i % 4 == 0) | |
3113 | rnd = arc4random(); | |
3114 | x11_saved_data[i] = value; | |
3115 | x11_fake_data[i] = rnd & 0xff; | |
3116 | rnd >>= 8; | |
3117 | } | |
3118 | x11_saved_data_len = data_len; | |
3119 | x11_fake_data_len = data_len; | |
3120 | } | |
3c0ef626 | 3121 | |
3122 | /* Convert the fake data into hex. */ | |
473db5ab | 3123 | new_data = tohex(x11_fake_data, data_len); |
3c0ef626 | 3124 | |
3125 | /* Send the request packet. */ | |
3126 | if (compat20) { | |
3127 | channel_request_start(client_session_id, "x11-req", 0); | |
3128 | packet_put_char(0); /* XXX bool single connection */ | |
3129 | } else { | |
3130 | packet_start(SSH_CMSG_X11_REQUEST_FORWARDING); | |
3131 | } | |
3132 | packet_put_cstring(proto); | |
3133 | packet_put_cstring(new_data); | |
3134 | packet_put_int(screen_number); | |
3135 | packet_send(); | |
3136 | packet_write_wait(); | |
3137 | xfree(new_data); | |
3138 | } | |
3139 | ||
3140 | ||
3141 | /* -- agent forwarding */ | |
3142 | ||
3143 | /* Sends a message to the server to request authentication fd forwarding. */ | |
3144 | ||
3145 | void | |
473db5ab | 3146 | auth_request_forwarding(void) |
3c0ef626 | 3147 | { |
3148 | packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); | |
3149 | packet_send(); | |
3150 | packet_write_wait(); | |
3151 | } |