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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. | |
e9a17296 | 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" | |
665a873d | 42 | RCSID("$OpenBSD: channels.c,v 1.223 2005/07/17 07:17:54 djm 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" | |
e9a17296 | 56 | #include "pathnames.h" |
0fff78ff | 57 | #include "bufaux.h" |
3c0ef626 | 58 | |
59 | /* -- channel core */ | |
60 | ||
dec6d9fe | 61 | #define CHAN_RBUF 16*1024 |
62 | ||
3c0ef626 | 63 | /* |
64 | * Pointer to an array containing all allocated channels. The array is | |
65 | * dynamically extended as needed. | |
66 | */ | |
67 | static Channel **channels = NULL; | |
68 | ||
69 | /* | |
70 | * Size of the channel array. All slots of the array must always be | |
71 | * initialized (at least the type field); unused slots set to NULL | |
72 | */ | |
c9f39d2c | 73 | static u_int channels_alloc = 0; |
3c0ef626 | 74 | |
75 | /* | |
76 | * Maximum file descriptor value used in any of the channels. This is | |
77 | * updated in channel_new. | |
78 | */ | |
79 | static int channel_max_fd = 0; | |
80 | ||
81 | ||
82 | /* -- tcp forwarding */ | |
83 | ||
84 | /* | |
85 | * Data structure for storing which hosts are permitted for forward requests. | |
86 | * The local sides of any remote forwards are stored in this array to prevent | |
87 | * a corrupt remote server from accessing arbitrary TCP/IP ports on our local | |
88 | * network (which might be behind a firewall). | |
89 | */ | |
90 | typedef struct { | |
91 | char *host_to_connect; /* Connect to 'host'. */ | |
92 | u_short port_to_connect; /* Connect to 'port'. */ | |
93 | u_short listen_port; /* Remote side should listen port number. */ | |
94 | } ForwardPermission; | |
95 | ||
96 | /* List of all permitted host/port pairs to connect. */ | |
97 | static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; | |
98 | ||
99 | /* Number of permitted host/port pairs in the array. */ | |
100 | static int num_permitted_opens = 0; | |
101 | /* | |
102 | * If this is true, all opens are permitted. This is the case on the server | |
103 | * on which we have to trust the client anyway, and the user could do | |
104 | * anything after logging in anyway. | |
105 | */ | |
106 | static int all_opens_permitted = 0; | |
107 | ||
108 | ||
109 | /* -- X11 forwarding */ | |
110 | ||
111 | /* Maximum number of fake X11 displays to try. */ | |
112 | #define MAX_DISPLAYS 1000 | |
113 | ||
665a873d | 114 | /* Saved X11 local (client) display. */ |
115 | static char *x11_saved_display = NULL; | |
116 | ||
3c0ef626 | 117 | /* Saved X11 authentication protocol name. */ |
118 | static char *x11_saved_proto = NULL; | |
119 | ||
120 | /* Saved X11 authentication data. This is the real data. */ | |
121 | static char *x11_saved_data = NULL; | |
122 | static u_int x11_saved_data_len = 0; | |
123 | ||
124 | /* | |
125 | * Fake X11 authentication data. This is what the server will be sending us; | |
126 | * we should replace any occurrences of this by the real data. | |
127 | */ | |
128 | static char *x11_fake_data = NULL; | |
129 | static u_int x11_fake_data_len; | |
130 | ||
131 | ||
132 | /* -- agent forwarding */ | |
133 | ||
134 | #define NUM_SOCKS 10 | |
135 | ||
3c0ef626 | 136 | /* AF_UNSPEC or AF_INET or AF_INET6 */ |
137 | static int IPv4or6 = AF_UNSPEC; | |
138 | ||
139 | /* helper */ | |
140 | static void port_open_helper(Channel *c, char *rtype); | |
141 | ||
142 | /* -- channel core */ | |
143 | ||
144 | Channel * | |
145 | channel_lookup(int id) | |
146 | { | |
147 | Channel *c; | |
148 | ||
c9f39d2c | 149 | if (id < 0 || (u_int)id >= channels_alloc) { |
0fff78ff | 150 | logit("channel_lookup: %d: bad id", id); |
3c0ef626 | 151 | return NULL; |
152 | } | |
153 | c = channels[id]; | |
154 | if (c == NULL) { | |
0fff78ff | 155 | logit("channel_lookup: %d: bad id: channel free", id); |
3c0ef626 | 156 | return NULL; |
157 | } | |
158 | return c; | |
159 | } | |
160 | ||
161 | /* | |
162 | * Register filedescriptors for a channel, used when allocating a channel or | |
163 | * when the channel consumer/producer is ready, e.g. shell exec'd | |
164 | */ | |
165 | ||
166 | static void | |
167 | channel_register_fds(Channel *c, int rfd, int wfd, int efd, | |
168 | int extusage, int nonblock) | |
169 | { | |
170 | /* Update the maximum file descriptor value. */ | |
171 | channel_max_fd = MAX(channel_max_fd, rfd); | |
172 | channel_max_fd = MAX(channel_max_fd, wfd); | |
173 | channel_max_fd = MAX(channel_max_fd, efd); | |
174 | ||
175 | /* XXX set close-on-exec -markus */ | |
176 | ||
177 | c->rfd = rfd; | |
178 | c->wfd = wfd; | |
179 | c->sock = (rfd == wfd) ? rfd : -1; | |
c9f39d2c | 180 | c->ctl_fd = -1; /* XXX: set elsewhere */ |
3c0ef626 | 181 | c->efd = efd; |
182 | c->extended_usage = extusage; | |
183 | ||
184 | /* XXX ugly hack: nonblock is only set by the server */ | |
185 | if (nonblock && isatty(c->rfd)) { | |
0fff78ff | 186 | debug2("channel %d: rfd %d isatty", c->self, c->rfd); |
3c0ef626 | 187 | c->isatty = 1; |
188 | if (!isatty(c->wfd)) { | |
189 | error("channel %d: wfd %d is not a tty?", | |
190 | c->self, c->wfd); | |
191 | } | |
192 | } else { | |
193 | c->isatty = 0; | |
194 | } | |
41b2f314 | 195 | c->wfd_isatty = isatty(c->wfd); |
3c0ef626 | 196 | |
197 | /* enable nonblocking mode */ | |
198 | if (nonblock) { | |
199 | if (rfd != -1) | |
200 | set_nonblock(rfd); | |
201 | if (wfd != -1) | |
202 | set_nonblock(wfd); | |
203 | if (efd != -1) | |
204 | set_nonblock(efd); | |
205 | } | |
206 | } | |
207 | ||
208 | /* | |
209 | * Allocate a new channel object and set its type and socket. This will cause | |
210 | * remote_name to be freed. | |
211 | */ | |
212 | ||
213 | Channel * | |
214 | channel_new(char *ctype, int type, int rfd, int wfd, int efd, | |
680cee3b | 215 | u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock) |
3c0ef626 | 216 | { |
c9f39d2c | 217 | int found; |
218 | u_int i; | |
3c0ef626 | 219 | Channel *c; |
220 | ||
221 | /* Do initial allocation if this is the first call. */ | |
222 | if (channels_alloc == 0) { | |
3c0ef626 | 223 | channels_alloc = 10; |
224 | channels = xmalloc(channels_alloc * sizeof(Channel *)); | |
225 | for (i = 0; i < channels_alloc; i++) | |
226 | channels[i] = NULL; | |
3c0ef626 | 227 | } |
228 | /* Try to find a free slot where to put the new channel. */ | |
229 | for (found = -1, i = 0; i < channels_alloc; i++) | |
230 | if (channels[i] == NULL) { | |
231 | /* Found a free slot. */ | |
c9f39d2c | 232 | found = (int)i; |
3c0ef626 | 233 | break; |
234 | } | |
c9f39d2c | 235 | if (found < 0) { |
3c0ef626 | 236 | /* There are no free slots. Take last+1 slot and expand the array. */ |
237 | found = channels_alloc; | |
680cee3b | 238 | if (channels_alloc > 10000) |
239 | fatal("channel_new: internal error: channels_alloc %d " | |
240 | "too big.", channels_alloc); | |
b51b59a5 | 241 | channels = xrealloc(channels, |
242 | (channels_alloc + 10) * sizeof(Channel *)); | |
243 | channels_alloc += 10; | |
3c0ef626 | 244 | debug2("channel: expanding %d", channels_alloc); |
3c0ef626 | 245 | for (i = found; i < channels_alloc; i++) |
246 | channels[i] = NULL; | |
247 | } | |
248 | /* Initialize and return new channel. */ | |
249 | c = channels[found] = xmalloc(sizeof(Channel)); | |
250 | memset(c, 0, sizeof(Channel)); | |
251 | buffer_init(&c->input); | |
252 | buffer_init(&c->output); | |
253 | buffer_init(&c->extended); | |
e9a17296 | 254 | c->ostate = CHAN_OUTPUT_OPEN; |
255 | c->istate = CHAN_INPUT_OPEN; | |
256 | c->flags = 0; | |
3c0ef626 | 257 | channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); |
258 | c->self = found; | |
259 | c->type = type; | |
260 | c->ctype = ctype; | |
261 | c->local_window = window; | |
262 | c->local_window_max = window; | |
263 | c->local_consumed = 0; | |
264 | c->local_maxpacket = maxpack; | |
265 | c->remote_id = -1; | |
0fff78ff | 266 | c->remote_name = xstrdup(remote_name); |
3c0ef626 | 267 | c->remote_window = 0; |
268 | c->remote_maxpacket = 0; | |
3c0ef626 | 269 | c->force_drain = 0; |
e9a17296 | 270 | c->single_connection = 0; |
3c0ef626 | 271 | c->detach_user = NULL; |
e9a17296 | 272 | c->confirm = NULL; |
c9f39d2c | 273 | c->confirm_ctx = NULL; |
3c0ef626 | 274 | c->input_filter = NULL; |
275 | debug("channel %d: new [%s]", found, remote_name); | |
276 | return c; | |
277 | } | |
278 | ||
279 | static int | |
280 | channel_find_maxfd(void) | |
281 | { | |
c9f39d2c | 282 | u_int i; |
283 | int max = 0; | |
3c0ef626 | 284 | Channel *c; |
285 | ||
286 | for (i = 0; i < channels_alloc; i++) { | |
287 | c = channels[i]; | |
288 | if (c != NULL) { | |
289 | max = MAX(max, c->rfd); | |
290 | max = MAX(max, c->wfd); | |
291 | max = MAX(max, c->efd); | |
292 | } | |
293 | } | |
294 | return max; | |
295 | } | |
296 | ||
297 | int | |
298 | channel_close_fd(int *fdp) | |
299 | { | |
300 | int ret = 0, fd = *fdp; | |
301 | ||
302 | if (fd != -1) { | |
303 | ret = close(fd); | |
304 | *fdp = -1; | |
305 | if (fd == channel_max_fd) | |
306 | channel_max_fd = channel_find_maxfd(); | |
307 | } | |
308 | return ret; | |
309 | } | |
310 | ||
311 | /* Close all channel fd/socket. */ | |
312 | ||
313 | static void | |
314 | channel_close_fds(Channel *c) | |
315 | { | |
c9f39d2c | 316 | debug3("channel %d: close_fds r %d w %d e %d c %d", |
317 | c->self, c->rfd, c->wfd, c->efd, c->ctl_fd); | |
3c0ef626 | 318 | |
319 | channel_close_fd(&c->sock); | |
c9f39d2c | 320 | channel_close_fd(&c->ctl_fd); |
3c0ef626 | 321 | channel_close_fd(&c->rfd); |
322 | channel_close_fd(&c->wfd); | |
323 | channel_close_fd(&c->efd); | |
324 | } | |
325 | ||
326 | /* Free the channel and close its fd/socket. */ | |
327 | ||
328 | void | |
329 | channel_free(Channel *c) | |
330 | { | |
331 | char *s; | |
c9f39d2c | 332 | u_int i, n; |
3c0ef626 | 333 | |
334 | for (n = 0, i = 0; i < channels_alloc; i++) | |
335 | if (channels[i]) | |
336 | n++; | |
c9f39d2c | 337 | debug("channel %d: free: %s, nchannels %u", c->self, |
3c0ef626 | 338 | c->remote_name ? c->remote_name : "???", n); |
339 | ||
340 | s = channel_open_message(); | |
0fff78ff | 341 | debug3("channel %d: status: %s", c->self, s); |
3c0ef626 | 342 | xfree(s); |
343 | ||
344 | if (c->sock != -1) | |
345 | shutdown(c->sock, SHUT_RDWR); | |
c9f39d2c | 346 | if (c->ctl_fd != -1) |
347 | shutdown(c->ctl_fd, SHUT_RDWR); | |
3c0ef626 | 348 | channel_close_fds(c); |
349 | buffer_free(&c->input); | |
350 | buffer_free(&c->output); | |
351 | buffer_free(&c->extended); | |
352 | if (c->remote_name) { | |
353 | xfree(c->remote_name); | |
354 | c->remote_name = NULL; | |
355 | } | |
356 | channels[c->self] = NULL; | |
357 | xfree(c); | |
358 | } | |
359 | ||
360 | void | |
361 | channel_free_all(void) | |
362 | { | |
c9f39d2c | 363 | u_int i; |
3c0ef626 | 364 | |
365 | for (i = 0; i < channels_alloc; i++) | |
366 | if (channels[i] != NULL) | |
367 | channel_free(channels[i]); | |
368 | } | |
369 | ||
370 | /* | |
371 | * Closes the sockets/fds of all channels. This is used to close extra file | |
372 | * descriptors after a fork. | |
373 | */ | |
374 | ||
375 | void | |
e9a17296 | 376 | channel_close_all(void) |
3c0ef626 | 377 | { |
c9f39d2c | 378 | u_int i; |
3c0ef626 | 379 | |
380 | for (i = 0; i < channels_alloc; i++) | |
381 | if (channels[i] != NULL) | |
382 | channel_close_fds(channels[i]); | |
383 | } | |
384 | ||
385 | /* | |
386 | * Stop listening to channels. | |
387 | */ | |
388 | ||
389 | void | |
390 | channel_stop_listening(void) | |
391 | { | |
c9f39d2c | 392 | u_int i; |
3c0ef626 | 393 | Channel *c; |
394 | ||
395 | for (i = 0; i < channels_alloc; i++) { | |
396 | c = channels[i]; | |
397 | if (c != NULL) { | |
398 | switch (c->type) { | |
399 | case SSH_CHANNEL_AUTH_SOCKET: | |
400 | case SSH_CHANNEL_PORT_LISTENER: | |
401 | case SSH_CHANNEL_RPORT_LISTENER: | |
402 | case SSH_CHANNEL_X11_LISTENER: | |
403 | channel_close_fd(&c->sock); | |
404 | channel_free(c); | |
405 | break; | |
406 | } | |
407 | } | |
408 | } | |
409 | } | |
410 | ||
411 | /* | |
412 | * Returns true if no channel has too much buffered data, and false if one or | |
413 | * more channel is overfull. | |
414 | */ | |
415 | ||
416 | int | |
e9a17296 | 417 | channel_not_very_much_buffered_data(void) |
3c0ef626 | 418 | { |
419 | u_int i; | |
420 | Channel *c; | |
421 | ||
422 | for (i = 0; i < channels_alloc; i++) { | |
423 | c = channels[i]; | |
424 | if (c != NULL && c->type == SSH_CHANNEL_OPEN) { | |
425 | #if 0 | |
426 | if (!compat20 && | |
427 | buffer_len(&c->input) > packet_get_maxsize()) { | |
6a9b3198 | 428 | debug2("channel %d: big input buffer %d", |
3c0ef626 | 429 | c->self, buffer_len(&c->input)); |
430 | return 0; | |
431 | } | |
432 | #endif | |
433 | if (buffer_len(&c->output) > packet_get_maxsize()) { | |
0fff78ff | 434 | debug2("channel %d: big output buffer %u > %u", |
3c0ef626 | 435 | c->self, buffer_len(&c->output), |
436 | packet_get_maxsize()); | |
437 | return 0; | |
438 | } | |
439 | } | |
440 | } | |
441 | return 1; | |
442 | } | |
443 | ||
444 | /* Returns true if any channel is still open. */ | |
445 | ||
446 | int | |
e9a17296 | 447 | channel_still_open(void) |
3c0ef626 | 448 | { |
c9f39d2c | 449 | u_int i; |
3c0ef626 | 450 | Channel *c; |
451 | ||
452 | for (i = 0; i < channels_alloc; i++) { | |
453 | c = channels[i]; | |
454 | if (c == NULL) | |
455 | continue; | |
456 | switch (c->type) { | |
457 | case SSH_CHANNEL_X11_LISTENER: | |
458 | case SSH_CHANNEL_PORT_LISTENER: | |
459 | case SSH_CHANNEL_RPORT_LISTENER: | |
460 | case SSH_CHANNEL_CLOSED: | |
461 | case SSH_CHANNEL_AUTH_SOCKET: | |
462 | case SSH_CHANNEL_DYNAMIC: | |
463 | case SSH_CHANNEL_CONNECTING: | |
464 | case SSH_CHANNEL_ZOMBIE: | |
465 | continue; | |
466 | case SSH_CHANNEL_LARVAL: | |
467 | if (!compat20) | |
468 | fatal("cannot happen: SSH_CHANNEL_LARVAL"); | |
469 | continue; | |
470 | case SSH_CHANNEL_OPENING: | |
471 | case SSH_CHANNEL_OPEN: | |
472 | case SSH_CHANNEL_X11_OPEN: | |
473 | return 1; | |
474 | case SSH_CHANNEL_INPUT_DRAINING: | |
475 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
476 | if (!compat13) | |
477 | fatal("cannot happen: OUT_DRAIN"); | |
478 | return 1; | |
479 | default: | |
480 | fatal("channel_still_open: bad channel type %d", c->type); | |
481 | /* NOTREACHED */ | |
482 | } | |
483 | } | |
484 | return 0; | |
485 | } | |
486 | ||
487 | /* Returns the id of an open channel suitable for keepaliving */ | |
488 | ||
489 | int | |
e9a17296 | 490 | channel_find_open(void) |
3c0ef626 | 491 | { |
c9f39d2c | 492 | u_int i; |
3c0ef626 | 493 | Channel *c; |
494 | ||
495 | for (i = 0; i < channels_alloc; i++) { | |
496 | c = channels[i]; | |
c9f39d2c | 497 | if (c == NULL || c->remote_id < 0) |
3c0ef626 | 498 | continue; |
499 | switch (c->type) { | |
500 | case SSH_CHANNEL_CLOSED: | |
501 | case SSH_CHANNEL_DYNAMIC: | |
502 | case SSH_CHANNEL_X11_LISTENER: | |
503 | case SSH_CHANNEL_PORT_LISTENER: | |
504 | case SSH_CHANNEL_RPORT_LISTENER: | |
505 | case SSH_CHANNEL_OPENING: | |
506 | case SSH_CHANNEL_CONNECTING: | |
507 | case SSH_CHANNEL_ZOMBIE: | |
508 | continue; | |
509 | case SSH_CHANNEL_LARVAL: | |
510 | case SSH_CHANNEL_AUTH_SOCKET: | |
511 | case SSH_CHANNEL_OPEN: | |
512 | case SSH_CHANNEL_X11_OPEN: | |
513 | return i; | |
514 | case SSH_CHANNEL_INPUT_DRAINING: | |
515 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
516 | if (!compat13) | |
517 | fatal("cannot happen: OUT_DRAIN"); | |
518 | return i; | |
519 | default: | |
520 | fatal("channel_find_open: bad channel type %d", c->type); | |
521 | /* NOTREACHED */ | |
522 | } | |
523 | } | |
524 | return -1; | |
525 | } | |
526 | ||
527 | ||
528 | /* | |
529 | * Returns a message describing the currently open forwarded connections, | |
530 | * suitable for sending to the client. The message contains crlf pairs for | |
531 | * newlines. | |
532 | */ | |
533 | ||
534 | char * | |
e9a17296 | 535 | channel_open_message(void) |
3c0ef626 | 536 | { |
537 | Buffer buffer; | |
538 | Channel *c; | |
539 | char buf[1024], *cp; | |
c9f39d2c | 540 | u_int i; |
3c0ef626 | 541 | |
542 | buffer_init(&buffer); | |
543 | snprintf(buf, sizeof buf, "The following connections are open:\r\n"); | |
544 | buffer_append(&buffer, buf, strlen(buf)); | |
545 | for (i = 0; i < channels_alloc; i++) { | |
546 | c = channels[i]; | |
547 | if (c == NULL) | |
548 | continue; | |
549 | switch (c->type) { | |
550 | case SSH_CHANNEL_X11_LISTENER: | |
551 | case SSH_CHANNEL_PORT_LISTENER: | |
552 | case SSH_CHANNEL_RPORT_LISTENER: | |
553 | case SSH_CHANNEL_CLOSED: | |
554 | case SSH_CHANNEL_AUTH_SOCKET: | |
555 | case SSH_CHANNEL_ZOMBIE: | |
556 | continue; | |
557 | case SSH_CHANNEL_LARVAL: | |
558 | case SSH_CHANNEL_OPENING: | |
559 | case SSH_CHANNEL_CONNECTING: | |
560 | case SSH_CHANNEL_DYNAMIC: | |
561 | case SSH_CHANNEL_OPEN: | |
562 | case SSH_CHANNEL_X11_OPEN: | |
563 | case SSH_CHANNEL_INPUT_DRAINING: | |
564 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
c9f39d2c | 565 | snprintf(buf, sizeof buf, |
566 | " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n", | |
3c0ef626 | 567 | c->self, c->remote_name, |
568 | c->type, c->remote_id, | |
569 | c->istate, buffer_len(&c->input), | |
570 | c->ostate, buffer_len(&c->output), | |
c9f39d2c | 571 | c->rfd, c->wfd, c->ctl_fd); |
3c0ef626 | 572 | buffer_append(&buffer, buf, strlen(buf)); |
573 | continue; | |
574 | default: | |
575 | fatal("channel_open_message: bad channel type %d", c->type); | |
576 | /* NOTREACHED */ | |
577 | } | |
578 | } | |
579 | buffer_append(&buffer, "\0", 1); | |
580 | cp = xstrdup(buffer_ptr(&buffer)); | |
581 | buffer_free(&buffer); | |
582 | return cp; | |
583 | } | |
584 | ||
585 | void | |
586 | channel_send_open(int id) | |
587 | { | |
588 | Channel *c = channel_lookup(id); | |
41b2f314 | 589 | |
3c0ef626 | 590 | if (c == NULL) { |
0fff78ff | 591 | logit("channel_send_open: %d: bad id", id); |
3c0ef626 | 592 | return; |
593 | } | |
6a9b3198 | 594 | debug2("channel %d: send open", id); |
3c0ef626 | 595 | packet_start(SSH2_MSG_CHANNEL_OPEN); |
596 | packet_put_cstring(c->ctype); | |
597 | packet_put_int(c->self); | |
598 | packet_put_int(c->local_window); | |
599 | packet_put_int(c->local_maxpacket); | |
600 | packet_send(); | |
601 | } | |
602 | ||
603 | void | |
6a9b3198 | 604 | channel_request_start(int id, char *service, int wantconfirm) |
3c0ef626 | 605 | { |
6a9b3198 | 606 | Channel *c = channel_lookup(id); |
41b2f314 | 607 | |
3c0ef626 | 608 | if (c == NULL) { |
0fff78ff | 609 | logit("channel_request_start: %d: unknown channel id", id); |
3c0ef626 | 610 | return; |
611 | } | |
c9f39d2c | 612 | debug2("channel %d: request %s confirm %d", id, service, wantconfirm); |
3c0ef626 | 613 | packet_start(SSH2_MSG_CHANNEL_REQUEST); |
614 | packet_put_int(c->remote_id); | |
615 | packet_put_cstring(service); | |
616 | packet_put_char(wantconfirm); | |
617 | } | |
618 | void | |
c9f39d2c | 619 | channel_register_confirm(int id, channel_callback_fn *fn, void *ctx) |
3c0ef626 | 620 | { |
621 | Channel *c = channel_lookup(id); | |
41b2f314 | 622 | |
3c0ef626 | 623 | if (c == NULL) { |
0fff78ff | 624 | logit("channel_register_comfirm: %d: bad id", id); |
3c0ef626 | 625 | return; |
626 | } | |
e9a17296 | 627 | c->confirm = fn; |
c9f39d2c | 628 | c->confirm_ctx = ctx; |
3c0ef626 | 629 | } |
630 | void | |
631 | channel_register_cleanup(int id, channel_callback_fn *fn) | |
632 | { | |
633 | Channel *c = channel_lookup(id); | |
41b2f314 | 634 | |
3c0ef626 | 635 | if (c == NULL) { |
0fff78ff | 636 | logit("channel_register_cleanup: %d: bad id", id); |
3c0ef626 | 637 | return; |
638 | } | |
639 | c->detach_user = fn; | |
640 | } | |
641 | void | |
642 | channel_cancel_cleanup(int id) | |
643 | { | |
644 | Channel *c = channel_lookup(id); | |
41b2f314 | 645 | |
3c0ef626 | 646 | if (c == NULL) { |
0fff78ff | 647 | logit("channel_cancel_cleanup: %d: bad id", id); |
3c0ef626 | 648 | return; |
649 | } | |
650 | c->detach_user = NULL; | |
651 | } | |
652 | void | |
653 | channel_register_filter(int id, channel_filter_fn *fn) | |
654 | { | |
655 | Channel *c = channel_lookup(id); | |
41b2f314 | 656 | |
3c0ef626 | 657 | if (c == NULL) { |
0fff78ff | 658 | logit("channel_register_filter: %d: bad id", id); |
3c0ef626 | 659 | return; |
660 | } | |
661 | c->input_filter = fn; | |
662 | } | |
663 | ||
664 | void | |
665 | channel_set_fds(int id, int rfd, int wfd, int efd, | |
e9a17296 | 666 | int extusage, int nonblock, u_int window_max) |
3c0ef626 | 667 | { |
668 | Channel *c = channel_lookup(id); | |
41b2f314 | 669 | |
3c0ef626 | 670 | if (c == NULL || c->type != SSH_CHANNEL_LARVAL) |
671 | fatal("channel_activate for non-larval channel %d.", id); | |
672 | channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); | |
673 | c->type = SSH_CHANNEL_OPEN; | |
e9a17296 | 674 | c->local_window = c->local_window_max = window_max; |
3c0ef626 | 675 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
676 | packet_put_int(c->remote_id); | |
677 | packet_put_int(c->local_window); | |
678 | packet_send(); | |
679 | } | |
680 | ||
681 | /* | |
682 | * 'channel_pre*' are called just before select() to add any bits relevant to | |
683 | * channels in the select bitmasks. | |
684 | */ | |
685 | /* | |
686 | * 'channel_post*': perform any appropriate operations for channels which | |
687 | * have events pending. | |
688 | */ | |
689 | typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset); | |
690 | chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; | |
691 | chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; | |
692 | ||
693 | static void | |
694 | channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
695 | { | |
696 | FD_SET(c->sock, readset); | |
697 | } | |
698 | ||
699 | static void | |
700 | channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset) | |
701 | { | |
702 | debug3("channel %d: waiting for connection", c->self); | |
703 | FD_SET(c->sock, writeset); | |
704 | } | |
705 | ||
706 | static void | |
707 | channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
708 | { | |
709 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
710 | FD_SET(c->sock, readset); | |
711 | if (buffer_len(&c->output) > 0) | |
712 | FD_SET(c->sock, writeset); | |
713 | } | |
714 | ||
715 | static void | |
e9a17296 | 716 | channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset) |
3c0ef626 | 717 | { |
e9a17296 | 718 | u_int limit = compat20 ? c->remote_window : packet_get_maxsize(); |
3c0ef626 | 719 | |
dec6d9fe | 720 | /* check buffer limits */ |
721 | limit = MIN(limit, (BUFFER_MAX_LEN - BUFFER_MAX_CHUNK - CHAN_RBUF)); | |
722 | ||
3c0ef626 | 723 | if (c->istate == CHAN_INPUT_OPEN && |
e9a17296 | 724 | limit > 0 && |
725 | buffer_len(&c->input) < limit) | |
3c0ef626 | 726 | FD_SET(c->rfd, readset); |
727 | if (c->ostate == CHAN_OUTPUT_OPEN || | |
728 | c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
729 | if (buffer_len(&c->output) > 0) { | |
730 | FD_SET(c->wfd, writeset); | |
731 | } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
700318f3 | 732 | if (CHANNEL_EFD_OUTPUT_ACTIVE(c)) |
665a873d | 733 | debug2("channel %d: obuf_empty delayed efd %d/(%d)", |
734 | c->self, c->efd, buffer_len(&c->extended)); | |
700318f3 | 735 | else |
736 | chan_obuf_empty(c); | |
3c0ef626 | 737 | } |
738 | } | |
739 | /** XXX check close conditions, too */ | |
e9a17296 | 740 | if (compat20 && c->efd != -1) { |
3c0ef626 | 741 | if (c->extended_usage == CHAN_EXTENDED_WRITE && |
742 | buffer_len(&c->extended) > 0) | |
743 | FD_SET(c->efd, writeset); | |
700318f3 | 744 | else if (!(c->flags & CHAN_EOF_SENT) && |
745 | c->extended_usage == CHAN_EXTENDED_READ && | |
3c0ef626 | 746 | buffer_len(&c->extended) < c->remote_window) |
747 | FD_SET(c->efd, readset); | |
748 | } | |
c9f39d2c | 749 | /* XXX: What about efd? races? */ |
750 | if (compat20 && c->ctl_fd != -1 && | |
751 | c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN) | |
752 | FD_SET(c->ctl_fd, readset); | |
3c0ef626 | 753 | } |
754 | ||
755 | static void | |
756 | channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
757 | { | |
758 | if (buffer_len(&c->input) == 0) { | |
759 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
760 | packet_put_int(c->remote_id); | |
761 | packet_send(); | |
762 | c->type = SSH_CHANNEL_CLOSED; | |
0fff78ff | 763 | debug2("channel %d: closing after input drain.", c->self); |
3c0ef626 | 764 | } |
765 | } | |
766 | ||
767 | static void | |
768 | channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
769 | { | |
770 | if (buffer_len(&c->output) == 0) | |
771 | chan_mark_dead(c); | |
772 | else | |
773 | FD_SET(c->sock, writeset); | |
774 | } | |
775 | ||
776 | /* | |
777 | * This is a special state for X11 authentication spoofing. An opened X11 | |
778 | * connection (when authentication spoofing is being done) remains in this | |
779 | * state until the first packet has been completely read. The authentication | |
780 | * data in that packet is then substituted by the real data if it matches the | |
781 | * fake data, and the channel is put into normal mode. | |
782 | * XXX All this happens at the client side. | |
783 | * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok | |
784 | */ | |
785 | static int | |
786 | x11_open_helper(Buffer *b) | |
787 | { | |
788 | u_char *ucp; | |
789 | u_int proto_len, data_len; | |
790 | ||
791 | /* Check if the fixed size part of the packet is in buffer. */ | |
792 | if (buffer_len(b) < 12) | |
793 | return 0; | |
794 | ||
795 | /* Parse the lengths of variable-length fields. */ | |
e9a17296 | 796 | ucp = buffer_ptr(b); |
3c0ef626 | 797 | if (ucp[0] == 0x42) { /* Byte order MSB first. */ |
798 | proto_len = 256 * ucp[6] + ucp[7]; | |
799 | data_len = 256 * ucp[8] + ucp[9]; | |
800 | } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ | |
801 | proto_len = ucp[6] + 256 * ucp[7]; | |
802 | data_len = ucp[8] + 256 * ucp[9]; | |
803 | } else { | |
0fff78ff | 804 | debug2("Initial X11 packet contains bad byte order byte: 0x%x", |
e9a17296 | 805 | ucp[0]); |
3c0ef626 | 806 | return -1; |
807 | } | |
808 | ||
809 | /* Check if the whole packet is in buffer. */ | |
810 | if (buffer_len(b) < | |
811 | 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) | |
812 | return 0; | |
813 | ||
814 | /* Check if authentication protocol matches. */ | |
815 | if (proto_len != strlen(x11_saved_proto) || | |
816 | memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { | |
0fff78ff | 817 | debug2("X11 connection uses different authentication protocol."); |
3c0ef626 | 818 | return -1; |
819 | } | |
820 | /* Check if authentication data matches our fake data. */ | |
821 | if (data_len != x11_fake_data_len || | |
822 | memcmp(ucp + 12 + ((proto_len + 3) & ~3), | |
823 | x11_fake_data, x11_fake_data_len) != 0) { | |
0fff78ff | 824 | debug2("X11 auth data does not match fake data."); |
3c0ef626 | 825 | return -1; |
826 | } | |
827 | /* Check fake data length */ | |
828 | if (x11_fake_data_len != x11_saved_data_len) { | |
829 | error("X11 fake_data_len %d != saved_data_len %d", | |
830 | x11_fake_data_len, x11_saved_data_len); | |
831 | return -1; | |
832 | } | |
833 | /* | |
834 | * Received authentication protocol and data match | |
835 | * our fake data. Substitute the fake data with real | |
836 | * data. | |
837 | */ | |
838 | memcpy(ucp + 12 + ((proto_len + 3) & ~3), | |
839 | x11_saved_data, x11_saved_data_len); | |
840 | return 1; | |
841 | } | |
842 | ||
843 | static void | |
844 | channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
845 | { | |
846 | int ret = x11_open_helper(&c->output); | |
41b2f314 | 847 | |
3c0ef626 | 848 | if (ret == 1) { |
849 | /* Start normal processing for the channel. */ | |
850 | c->type = SSH_CHANNEL_OPEN; | |
851 | channel_pre_open_13(c, readset, writeset); | |
852 | } else if (ret == -1) { | |
853 | /* | |
854 | * We have received an X11 connection that has bad | |
855 | * authentication information. | |
856 | */ | |
0fff78ff | 857 | logit("X11 connection rejected because of wrong authentication."); |
3c0ef626 | 858 | buffer_clear(&c->input); |
859 | buffer_clear(&c->output); | |
860 | channel_close_fd(&c->sock); | |
861 | c->sock = -1; | |
862 | c->type = SSH_CHANNEL_CLOSED; | |
863 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
864 | packet_put_int(c->remote_id); | |
865 | packet_send(); | |
866 | } | |
867 | } | |
868 | ||
869 | static void | |
870 | channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset) | |
871 | { | |
872 | int ret = x11_open_helper(&c->output); | |
873 | ||
874 | /* c->force_drain = 1; */ | |
875 | ||
876 | if (ret == 1) { | |
877 | c->type = SSH_CHANNEL_OPEN; | |
e9a17296 | 878 | channel_pre_open(c, readset, writeset); |
3c0ef626 | 879 | } else if (ret == -1) { |
0fff78ff | 880 | logit("X11 connection rejected because of wrong authentication."); |
881 | debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); | |
e9a17296 | 882 | chan_read_failed(c); |
883 | buffer_clear(&c->input); | |
884 | chan_ibuf_empty(c); | |
885 | buffer_clear(&c->output); | |
886 | /* for proto v1, the peer will send an IEOF */ | |
887 | if (compat20) | |
888 | chan_write_failed(c); | |
889 | else | |
890 | c->type = SSH_CHANNEL_OPEN; | |
0fff78ff | 891 | debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); |
3c0ef626 | 892 | } |
893 | } | |
894 | ||
895 | /* try to decode a socks4 header */ | |
896 | static int | |
897 | channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset) | |
898 | { | |
41b2f314 | 899 | char *p, *host; |
665a873d | 900 | u_int len, have, i, found; |
e9a17296 | 901 | char username[256]; |
3c0ef626 | 902 | struct { |
903 | u_int8_t version; | |
904 | u_int8_t command; | |
905 | u_int16_t dest_port; | |
906 | struct in_addr dest_addr; | |
907 | } s4_req, s4_rsp; | |
908 | ||
909 | debug2("channel %d: decode socks4", c->self); | |
910 | ||
911 | have = buffer_len(&c->input); | |
912 | len = sizeof(s4_req); | |
913 | if (have < len) | |
914 | return 0; | |
915 | p = buffer_ptr(&c->input); | |
916 | for (found = 0, i = len; i < have; i++) { | |
917 | if (p[i] == '\0') { | |
918 | found = 1; | |
919 | break; | |
920 | } | |
921 | if (i > 1024) { | |
922 | /* the peer is probably sending garbage */ | |
923 | debug("channel %d: decode socks4: too long", | |
924 | c->self); | |
925 | return -1; | |
926 | } | |
927 | } | |
928 | if (!found) | |
929 | return 0; | |
930 | buffer_get(&c->input, (char *)&s4_req.version, 1); | |
931 | buffer_get(&c->input, (char *)&s4_req.command, 1); | |
932 | buffer_get(&c->input, (char *)&s4_req.dest_port, 2); | |
933 | buffer_get(&c->input, (char *)&s4_req.dest_addr, 4); | |
934 | have = buffer_len(&c->input); | |
935 | p = buffer_ptr(&c->input); | |
936 | len = strlen(p); | |
937 | debug2("channel %d: decode socks4: user %s/%d", c->self, p, len); | |
938 | if (len > have) | |
939 | fatal("channel %d: decode socks4: len %d > have %d", | |
940 | c->self, len, have); | |
941 | strlcpy(username, p, sizeof(username)); | |
942 | buffer_consume(&c->input, len); | |
943 | buffer_consume(&c->input, 1); /* trailing '\0' */ | |
944 | ||
945 | host = inet_ntoa(s4_req.dest_addr); | |
946 | strlcpy(c->path, host, sizeof(c->path)); | |
947 | c->host_port = ntohs(s4_req.dest_port); | |
e9a17296 | 948 | |
0fff78ff | 949 | debug2("channel %d: dynamic request: socks4 host %s port %u command %u", |
3c0ef626 | 950 | c->self, host, c->host_port, s4_req.command); |
951 | ||
952 | if (s4_req.command != 1) { | |
953 | debug("channel %d: cannot handle: socks4 cn %d", | |
954 | c->self, s4_req.command); | |
955 | return -1; | |
956 | } | |
957 | s4_rsp.version = 0; /* vn: 0 for reply */ | |
958 | s4_rsp.command = 90; /* cd: req granted */ | |
959 | s4_rsp.dest_port = 0; /* ignored */ | |
960 | s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */ | |
961 | buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp)); | |
962 | return 1; | |
963 | } | |
964 | ||
0fff78ff | 965 | /* try to decode a socks5 header */ |
966 | #define SSH_SOCKS5_AUTHDONE 0x1000 | |
967 | #define SSH_SOCKS5_NOAUTH 0x00 | |
968 | #define SSH_SOCKS5_IPV4 0x01 | |
969 | #define SSH_SOCKS5_DOMAIN 0x03 | |
970 | #define SSH_SOCKS5_IPV6 0x04 | |
971 | #define SSH_SOCKS5_CONNECT 0x01 | |
972 | #define SSH_SOCKS5_SUCCESS 0x00 | |
973 | ||
974 | static int | |
975 | channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset) | |
976 | { | |
977 | struct { | |
978 | u_int8_t version; | |
979 | u_int8_t command; | |
980 | u_int8_t reserved; | |
981 | u_int8_t atyp; | |
982 | } s5_req, s5_rsp; | |
983 | u_int16_t dest_port; | |
984 | u_char *p, dest_addr[255+1]; | |
665a873d | 985 | u_int have, i, found, nmethods, addrlen, af; |
0fff78ff | 986 | |
987 | debug2("channel %d: decode socks5", c->self); | |
988 | p = buffer_ptr(&c->input); | |
989 | if (p[0] != 0x05) | |
990 | return -1; | |
991 | have = buffer_len(&c->input); | |
992 | if (!(c->flags & SSH_SOCKS5_AUTHDONE)) { | |
993 | /* format: ver | nmethods | methods */ | |
cdd66111 | 994 | if (have < 2) |
0fff78ff | 995 | return 0; |
996 | nmethods = p[1]; | |
997 | if (have < nmethods + 2) | |
998 | return 0; | |
999 | /* look for method: "NO AUTHENTICATION REQUIRED" */ | |
1000 | for (found = 0, i = 2 ; i < nmethods + 2; i++) { | |
1001 | if (p[i] == SSH_SOCKS5_NOAUTH ) { | |
1002 | found = 1; | |
1003 | break; | |
1004 | } | |
1005 | } | |
1006 | if (!found) { | |
1007 | debug("channel %d: method SSH_SOCKS5_NOAUTH not found", | |
1008 | c->self); | |
1009 | return -1; | |
1010 | } | |
1011 | buffer_consume(&c->input, nmethods + 2); | |
1012 | buffer_put_char(&c->output, 0x05); /* version */ | |
1013 | buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */ | |
1014 | FD_SET(c->sock, writeset); | |
1015 | c->flags |= SSH_SOCKS5_AUTHDONE; | |
1016 | debug2("channel %d: socks5 auth done", c->self); | |
1017 | return 0; /* need more */ | |
1018 | } | |
1019 | debug2("channel %d: socks5 post auth", c->self); | |
1020 | if (have < sizeof(s5_req)+1) | |
1021 | return 0; /* need more */ | |
1022 | memcpy((char *)&s5_req, p, sizeof(s5_req)); | |
1023 | if (s5_req.version != 0x05 || | |
1024 | s5_req.command != SSH_SOCKS5_CONNECT || | |
1025 | s5_req.reserved != 0x00) { | |
1026 | debug2("channel %d: only socks5 connect supported", c->self); | |
1027 | return -1; | |
1028 | } | |
dec6d9fe | 1029 | switch (s5_req.atyp){ |
0fff78ff | 1030 | case SSH_SOCKS5_IPV4: |
1031 | addrlen = 4; | |
1032 | af = AF_INET; | |
1033 | break; | |
1034 | case SSH_SOCKS5_DOMAIN: | |
1035 | addrlen = p[sizeof(s5_req)]; | |
1036 | af = -1; | |
1037 | break; | |
1038 | case SSH_SOCKS5_IPV6: | |
1039 | addrlen = 16; | |
1040 | af = AF_INET6; | |
1041 | break; | |
1042 | default: | |
1043 | debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp); | |
1044 | return -1; | |
1045 | } | |
1046 | if (have < 4 + addrlen + 2) | |
1047 | return 0; | |
1048 | buffer_consume(&c->input, sizeof(s5_req)); | |
1049 | if (s5_req.atyp == SSH_SOCKS5_DOMAIN) | |
1050 | buffer_consume(&c->input, 1); /* host string length */ | |
1051 | buffer_get(&c->input, (char *)&dest_addr, addrlen); | |
1052 | buffer_get(&c->input, (char *)&dest_port, 2); | |
1053 | dest_addr[addrlen] = '\0'; | |
1054 | if (s5_req.atyp == SSH_SOCKS5_DOMAIN) | |
c9f39d2c | 1055 | strlcpy(c->path, (char *)dest_addr, sizeof(c->path)); |
0fff78ff | 1056 | else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL) |
1057 | return -1; | |
1058 | c->host_port = ntohs(dest_port); | |
cdd66111 | 1059 | |
0fff78ff | 1060 | debug2("channel %d: dynamic request: socks5 host %s port %u command %u", |
1061 | c->self, c->path, c->host_port, s5_req.command); | |
1062 | ||
1063 | s5_rsp.version = 0x05; | |
1064 | s5_rsp.command = SSH_SOCKS5_SUCCESS; | |
1065 | s5_rsp.reserved = 0; /* ignored */ | |
1066 | s5_rsp.atyp = SSH_SOCKS5_IPV4; | |
1067 | ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY; | |
1068 | dest_port = 0; /* ignored */ | |
1069 | ||
1070 | buffer_append(&c->output, (char *)&s5_rsp, sizeof(s5_rsp)); | |
1071 | buffer_append(&c->output, (char *)&dest_addr, sizeof(struct in_addr)); | |
1072 | buffer_append(&c->output, (char *)&dest_port, sizeof(dest_port)); | |
1073 | return 1; | |
1074 | } | |
1075 | ||
3c0ef626 | 1076 | /* dynamic port forwarding */ |
1077 | static void | |
1078 | channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset) | |
1079 | { | |
1080 | u_char *p; | |
665a873d | 1081 | u_int have; |
1082 | int ret; | |
3c0ef626 | 1083 | |
1084 | have = buffer_len(&c->input); | |
1085 | c->delayed = 0; | |
1086 | debug2("channel %d: pre_dynamic: have %d", c->self, have); | |
1087 | /* buffer_dump(&c->input); */ | |
1088 | /* check if the fixed size part of the packet is in buffer. */ | |
0fff78ff | 1089 | if (have < 3) { |
3c0ef626 | 1090 | /* need more */ |
1091 | FD_SET(c->sock, readset); | |
1092 | return; | |
1093 | } | |
1094 | /* try to guess the protocol */ | |
1095 | p = buffer_ptr(&c->input); | |
1096 | switch (p[0]) { | |
1097 | case 0x04: | |
1098 | ret = channel_decode_socks4(c, readset, writeset); | |
1099 | break; | |
0fff78ff | 1100 | case 0x05: |
1101 | ret = channel_decode_socks5(c, readset, writeset); | |
1102 | break; | |
3c0ef626 | 1103 | default: |
1104 | ret = -1; | |
1105 | break; | |
1106 | } | |
1107 | if (ret < 0) { | |
1108 | chan_mark_dead(c); | |
1109 | } else if (ret == 0) { | |
1110 | debug2("channel %d: pre_dynamic: need more", c->self); | |
1111 | /* need more */ | |
1112 | FD_SET(c->sock, readset); | |
1113 | } else { | |
1114 | /* switch to the next state */ | |
1115 | c->type = SSH_CHANNEL_OPENING; | |
1116 | port_open_helper(c, "direct-tcpip"); | |
1117 | } | |
1118 | } | |
1119 | ||
1120 | /* This is our fake X11 server socket. */ | |
1121 | static void | |
1122 | channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
1123 | { | |
1124 | Channel *nc; | |
1125 | struct sockaddr addr; | |
1126 | int newsock; | |
1127 | socklen_t addrlen; | |
1128 | char buf[16384], *remote_ipaddr; | |
1129 | int remote_port; | |
1130 | ||
1131 | if (FD_ISSET(c->sock, readset)) { | |
1132 | debug("X11 connection requested."); | |
1133 | addrlen = sizeof(addr); | |
1134 | newsock = accept(c->sock, &addr, &addrlen); | |
e9a17296 | 1135 | if (c->single_connection) { |
0fff78ff | 1136 | debug2("single_connection: closing X11 listener."); |
e9a17296 | 1137 | channel_close_fd(&c->sock); |
1138 | chan_mark_dead(c); | |
1139 | } | |
3c0ef626 | 1140 | if (newsock < 0) { |
1141 | error("accept: %.100s", strerror(errno)); | |
1142 | return; | |
1143 | } | |
e9a17296 | 1144 | set_nodelay(newsock); |
3c0ef626 | 1145 | remote_ipaddr = get_peer_ipaddr(newsock); |
1146 | remote_port = get_peer_port(newsock); | |
1147 | snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", | |
1148 | remote_ipaddr, remote_port); | |
1149 | ||
1150 | nc = channel_new("accepted x11 socket", | |
1151 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
0fff78ff | 1152 | c->local_window_max, c->local_maxpacket, 0, buf, 1); |
3c0ef626 | 1153 | if (compat20) { |
1154 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1155 | packet_put_cstring("x11"); | |
1156 | packet_put_int(nc->self); | |
e9a17296 | 1157 | packet_put_int(nc->local_window_max); |
1158 | packet_put_int(nc->local_maxpacket); | |
3c0ef626 | 1159 | /* originator ipaddr and port */ |
1160 | packet_put_cstring(remote_ipaddr); | |
1161 | if (datafellows & SSH_BUG_X11FWD) { | |
0fff78ff | 1162 | debug2("ssh2 x11 bug compat mode"); |
3c0ef626 | 1163 | } else { |
1164 | packet_put_int(remote_port); | |
1165 | } | |
1166 | packet_send(); | |
1167 | } else { | |
1168 | packet_start(SSH_SMSG_X11_OPEN); | |
1169 | packet_put_int(nc->self); | |
1170 | if (packet_get_protocol_flags() & | |
1171 | SSH_PROTOFLAG_HOST_IN_FWD_OPEN) | |
1172 | packet_put_cstring(buf); | |
1173 | packet_send(); | |
1174 | } | |
1175 | xfree(remote_ipaddr); | |
1176 | } | |
1177 | } | |
1178 | ||
1179 | static void | |
1180 | port_open_helper(Channel *c, char *rtype) | |
1181 | { | |
1182 | int direct; | |
1183 | char buf[1024]; | |
1184 | char *remote_ipaddr = get_peer_ipaddr(c->sock); | |
665a873d | 1185 | int remote_port = get_peer_port(c->sock); |
3c0ef626 | 1186 | |
1187 | direct = (strcmp(rtype, "direct-tcpip") == 0); | |
1188 | ||
1189 | snprintf(buf, sizeof buf, | |
1190 | "%s: listening port %d for %.100s port %d, " | |
1191 | "connect from %.200s port %d", | |
1192 | rtype, c->listening_port, c->path, c->host_port, | |
1193 | remote_ipaddr, remote_port); | |
1194 | ||
1195 | xfree(c->remote_name); | |
1196 | c->remote_name = xstrdup(buf); | |
1197 | ||
1198 | if (compat20) { | |
1199 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1200 | packet_put_cstring(rtype); | |
1201 | packet_put_int(c->self); | |
1202 | packet_put_int(c->local_window_max); | |
1203 | packet_put_int(c->local_maxpacket); | |
1204 | if (direct) { | |
1205 | /* target host, port */ | |
1206 | packet_put_cstring(c->path); | |
1207 | packet_put_int(c->host_port); | |
1208 | } else { | |
1209 | /* listen address, port */ | |
1210 | packet_put_cstring(c->path); | |
1211 | packet_put_int(c->listening_port); | |
1212 | } | |
1213 | /* originator host and port */ | |
1214 | packet_put_cstring(remote_ipaddr); | |
665a873d | 1215 | packet_put_int((u_int)remote_port); |
3c0ef626 | 1216 | packet_send(); |
1217 | } else { | |
1218 | packet_start(SSH_MSG_PORT_OPEN); | |
1219 | packet_put_int(c->self); | |
1220 | packet_put_cstring(c->path); | |
1221 | packet_put_int(c->host_port); | |
1222 | if (packet_get_protocol_flags() & | |
1223 | SSH_PROTOFLAG_HOST_IN_FWD_OPEN) | |
1224 | packet_put_cstring(c->remote_name); | |
1225 | packet_send(); | |
1226 | } | |
1227 | xfree(remote_ipaddr); | |
1228 | } | |
1229 | ||
1230 | /* | |
1231 | * This socket is listening for connections to a forwarded TCP/IP port. | |
1232 | */ | |
1233 | static void | |
1234 | channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
1235 | { | |
1236 | Channel *nc; | |
1237 | struct sockaddr addr; | |
1238 | int newsock, nextstate; | |
1239 | socklen_t addrlen; | |
1240 | char *rtype; | |
1241 | ||
1242 | if (FD_ISSET(c->sock, readset)) { | |
1243 | debug("Connection to port %d forwarding " | |
1244 | "to %.100s port %d requested.", | |
1245 | c->listening_port, c->path, c->host_port); | |
1246 | ||
1247 | if (c->type == SSH_CHANNEL_RPORT_LISTENER) { | |
1248 | nextstate = SSH_CHANNEL_OPENING; | |
1249 | rtype = "forwarded-tcpip"; | |
1250 | } else { | |
1251 | if (c->host_port == 0) { | |
1252 | nextstate = SSH_CHANNEL_DYNAMIC; | |
1253 | rtype = "dynamic-tcpip"; | |
1254 | } else { | |
1255 | nextstate = SSH_CHANNEL_OPENING; | |
1256 | rtype = "direct-tcpip"; | |
1257 | } | |
1258 | } | |
1259 | ||
1260 | addrlen = sizeof(addr); | |
1261 | newsock = accept(c->sock, &addr, &addrlen); | |
1262 | if (newsock < 0) { | |
1263 | error("accept: %.100s", strerror(errno)); | |
1264 | return; | |
1265 | } | |
e9a17296 | 1266 | set_nodelay(newsock); |
0fff78ff | 1267 | nc = channel_new(rtype, nextstate, newsock, newsock, -1, |
1268 | c->local_window_max, c->local_maxpacket, 0, rtype, 1); | |
3c0ef626 | 1269 | nc->listening_port = c->listening_port; |
1270 | nc->host_port = c->host_port; | |
1271 | strlcpy(nc->path, c->path, sizeof(nc->path)); | |
1272 | ||
1273 | if (nextstate == SSH_CHANNEL_DYNAMIC) { | |
1274 | /* | |
1275 | * do not call the channel_post handler until | |
1276 | * this flag has been reset by a pre-handler. | |
1277 | * otherwise the FD_ISSET calls might overflow | |
1278 | */ | |
1279 | nc->delayed = 1; | |
1280 | } else { | |
1281 | port_open_helper(nc, rtype); | |
1282 | } | |
1283 | } | |
1284 | } | |
1285 | ||
1286 | /* | |
1287 | * This is the authentication agent socket listening for connections from | |
1288 | * clients. | |
1289 | */ | |
1290 | static void | |
1291 | channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
1292 | { | |
1293 | Channel *nc; | |
3c0ef626 | 1294 | int newsock; |
1295 | struct sockaddr addr; | |
1296 | socklen_t addrlen; | |
1297 | ||
1298 | if (FD_ISSET(c->sock, readset)) { | |
1299 | addrlen = sizeof(addr); | |
1300 | newsock = accept(c->sock, &addr, &addrlen); | |
1301 | if (newsock < 0) { | |
1302 | error("accept from auth socket: %.100s", strerror(errno)); | |
1303 | return; | |
1304 | } | |
3c0ef626 | 1305 | nc = channel_new("accepted auth socket", |
1306 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
1307 | c->local_window_max, c->local_maxpacket, | |
0fff78ff | 1308 | 0, "accepted auth socket", 1); |
3c0ef626 | 1309 | if (compat20) { |
1310 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1311 | packet_put_cstring("auth-agent@openssh.com"); | |
1312 | packet_put_int(nc->self); | |
1313 | packet_put_int(c->local_window_max); | |
1314 | packet_put_int(c->local_maxpacket); | |
1315 | } else { | |
1316 | packet_start(SSH_SMSG_AGENT_OPEN); | |
1317 | packet_put_int(nc->self); | |
1318 | } | |
1319 | packet_send(); | |
1320 | } | |
1321 | } | |
1322 | ||
1323 | static void | |
1324 | channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset) | |
1325 | { | |
1326 | int err = 0; | |
1327 | socklen_t sz = sizeof(err); | |
1328 | ||
1329 | if (FD_ISSET(c->sock, writeset)) { | |
e9a17296 | 1330 | if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) { |
3c0ef626 | 1331 | err = errno; |
1332 | error("getsockopt SO_ERROR failed"); | |
1333 | } | |
1334 | if (err == 0) { | |
1335 | debug("channel %d: connected", c->self); | |
1336 | c->type = SSH_CHANNEL_OPEN; | |
1337 | if (compat20) { | |
1338 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1339 | packet_put_int(c->remote_id); | |
1340 | packet_put_int(c->self); | |
1341 | packet_put_int(c->local_window); | |
1342 | packet_put_int(c->local_maxpacket); | |
1343 | } else { | |
1344 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1345 | packet_put_int(c->remote_id); | |
1346 | packet_put_int(c->self); | |
1347 | } | |
1348 | } else { | |
1349 | debug("channel %d: not connected: %s", | |
1350 | c->self, strerror(err)); | |
1351 | if (compat20) { | |
1352 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); | |
1353 | packet_put_int(c->remote_id); | |
1354 | packet_put_int(SSH2_OPEN_CONNECT_FAILED); | |
1355 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
1356 | packet_put_cstring(strerror(err)); | |
1357 | packet_put_cstring(""); | |
1358 | } | |
1359 | } else { | |
1360 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1361 | packet_put_int(c->remote_id); | |
1362 | } | |
1363 | chan_mark_dead(c); | |
1364 | } | |
1365 | packet_send(); | |
1366 | } | |
1367 | } | |
1368 | ||
1369 | static int | |
1370 | channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) | |
1371 | { | |
dec6d9fe | 1372 | char buf[CHAN_RBUF]; |
3c0ef626 | 1373 | int len; |
1374 | ||
1375 | if (c->rfd != -1 && | |
1376 | FD_ISSET(c->rfd, readset)) { | |
1377 | len = read(c->rfd, buf, sizeof(buf)); | |
1378 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1379 | return 1; | |
1380 | if (len <= 0) { | |
0fff78ff | 1381 | debug2("channel %d: read<=0 rfd %d len %d", |
3c0ef626 | 1382 | c->self, c->rfd, len); |
1383 | if (c->type != SSH_CHANNEL_OPEN) { | |
0fff78ff | 1384 | debug2("channel %d: not open", c->self); |
3c0ef626 | 1385 | chan_mark_dead(c); |
1386 | return -1; | |
1387 | } else if (compat13) { | |
e9a17296 | 1388 | buffer_clear(&c->output); |
3c0ef626 | 1389 | c->type = SSH_CHANNEL_INPUT_DRAINING; |
0fff78ff | 1390 | debug2("channel %d: input draining.", c->self); |
3c0ef626 | 1391 | } else { |
1392 | chan_read_failed(c); | |
1393 | } | |
1394 | return -1; | |
1395 | } | |
e9a17296 | 1396 | if (c->input_filter != NULL) { |
3c0ef626 | 1397 | if (c->input_filter(c, buf, len) == -1) { |
0fff78ff | 1398 | debug2("channel %d: filter stops", c->self); |
3c0ef626 | 1399 | chan_read_failed(c); |
1400 | } | |
1401 | } else { | |
1402 | buffer_append(&c->input, buf, len); | |
1403 | } | |
1404 | } | |
1405 | return 1; | |
1406 | } | |
1407 | static int | |
1408 | channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) | |
1409 | { | |
1410 | struct termios tio; | |
1411 | u_char *data; | |
1412 | u_int dlen; | |
1413 | int len; | |
1414 | ||
1415 | /* Send buffered output data to the socket. */ | |
1416 | if (c->wfd != -1 && | |
1417 | FD_ISSET(c->wfd, writeset) && | |
1418 | buffer_len(&c->output) > 0) { | |
1419 | data = buffer_ptr(&c->output); | |
1420 | dlen = buffer_len(&c->output); | |
41b2f314 | 1421 | #ifdef _AIX |
cdd66111 | 1422 | /* XXX: Later AIX versions can't push as much data to tty */ |
1423 | if (compat20 && c->wfd_isatty) | |
1424 | dlen = MIN(dlen, 8*1024); | |
41b2f314 | 1425 | #endif |
3c0ef626 | 1426 | len = write(c->wfd, data, dlen); |
1427 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1428 | return 1; | |
1429 | if (len <= 0) { | |
1430 | if (c->type != SSH_CHANNEL_OPEN) { | |
0fff78ff | 1431 | debug2("channel %d: not open", c->self); |
3c0ef626 | 1432 | chan_mark_dead(c); |
1433 | return -1; | |
1434 | } else if (compat13) { | |
e9a17296 | 1435 | buffer_clear(&c->output); |
0fff78ff | 1436 | debug2("channel %d: input draining.", c->self); |
3c0ef626 | 1437 | c->type = SSH_CHANNEL_INPUT_DRAINING; |
1438 | } else { | |
1439 | chan_write_failed(c); | |
1440 | } | |
1441 | return -1; | |
1442 | } | |
1443 | if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') { | |
1444 | if (tcgetattr(c->wfd, &tio) == 0 && | |
1445 | !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { | |
1446 | /* | |
1447 | * Simulate echo to reduce the impact of | |
1448 | * traffic analysis. We need to match the | |
1449 | * size of a SSH2_MSG_CHANNEL_DATA message | |
1450 | * (4 byte channel id + data) | |
1451 | */ | |
1452 | packet_send_ignore(4 + len); | |
1453 | packet_send(); | |
1454 | } | |
1455 | } | |
1456 | buffer_consume(&c->output, len); | |
1457 | if (compat20 && len > 0) { | |
1458 | c->local_consumed += len; | |
1459 | } | |
1460 | } | |
1461 | return 1; | |
1462 | } | |
1463 | static int | |
1464 | channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) | |
1465 | { | |
dec6d9fe | 1466 | char buf[CHAN_RBUF]; |
3c0ef626 | 1467 | int len; |
1468 | ||
1469 | /** XXX handle drain efd, too */ | |
1470 | if (c->efd != -1) { | |
1471 | if (c->extended_usage == CHAN_EXTENDED_WRITE && | |
1472 | FD_ISSET(c->efd, writeset) && | |
1473 | buffer_len(&c->extended) > 0) { | |
1474 | len = write(c->efd, buffer_ptr(&c->extended), | |
1475 | buffer_len(&c->extended)); | |
1476 | debug2("channel %d: written %d to efd %d", | |
1477 | c->self, len, c->efd); | |
1478 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1479 | return 1; | |
1480 | if (len <= 0) { | |
1481 | debug2("channel %d: closing write-efd %d", | |
1482 | c->self, c->efd); | |
1483 | channel_close_fd(&c->efd); | |
1484 | } else { | |
1485 | buffer_consume(&c->extended, len); | |
1486 | c->local_consumed += len; | |
1487 | } | |
1488 | } else if (c->extended_usage == CHAN_EXTENDED_READ && | |
1489 | FD_ISSET(c->efd, readset)) { | |
1490 | len = read(c->efd, buf, sizeof(buf)); | |
1491 | debug2("channel %d: read %d from efd %d", | |
e9a17296 | 1492 | c->self, len, c->efd); |
3c0ef626 | 1493 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) |
1494 | return 1; | |
1495 | if (len <= 0) { | |
1496 | debug2("channel %d: closing read-efd %d", | |
1497 | c->self, c->efd); | |
1498 | channel_close_fd(&c->efd); | |
1499 | } else { | |
1500 | buffer_append(&c->extended, buf, len); | |
1501 | } | |
1502 | } | |
1503 | } | |
1504 | return 1; | |
1505 | } | |
1506 | static int | |
c9f39d2c | 1507 | channel_handle_ctl(Channel *c, fd_set * readset, fd_set * writeset) |
1508 | { | |
1509 | char buf[16]; | |
1510 | int len; | |
1511 | ||
1512 | /* Monitor control fd to detect if the slave client exits */ | |
1513 | if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) { | |
1514 | len = read(c->ctl_fd, buf, sizeof(buf)); | |
1515 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1516 | return 1; | |
1517 | if (len <= 0) { | |
1518 | debug2("channel %d: ctl read<=0", c->self); | |
1519 | if (c->type != SSH_CHANNEL_OPEN) { | |
1520 | debug2("channel %d: not open", c->self); | |
1521 | chan_mark_dead(c); | |
1522 | return -1; | |
1523 | } else { | |
1524 | chan_read_failed(c); | |
1525 | chan_write_failed(c); | |
1526 | } | |
1527 | return -1; | |
1528 | } else | |
1529 | fatal("%s: unexpected data on ctl fd", __func__); | |
1530 | } | |
1531 | return 1; | |
1532 | } | |
1533 | static int | |
3c0ef626 | 1534 | channel_check_window(Channel *c) |
1535 | { | |
1536 | if (c->type == SSH_CHANNEL_OPEN && | |
1537 | !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) && | |
1538 | c->local_window < c->local_window_max/2 && | |
1539 | c->local_consumed > 0) { | |
1540 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); | |
1541 | packet_put_int(c->remote_id); | |
1542 | packet_put_int(c->local_consumed); | |
1543 | packet_send(); | |
1544 | debug2("channel %d: window %d sent adjust %d", | |
1545 | c->self, c->local_window, | |
1546 | c->local_consumed); | |
1547 | c->local_window += c->local_consumed; | |
1548 | c->local_consumed = 0; | |
1549 | } | |
1550 | return 1; | |
1551 | } | |
1552 | ||
1553 | static void | |
e9a17296 | 1554 | channel_post_open(Channel *c, fd_set * readset, fd_set * writeset) |
3c0ef626 | 1555 | { |
1556 | if (c->delayed) | |
1557 | return; | |
1558 | channel_handle_rfd(c, readset, writeset); | |
1559 | channel_handle_wfd(c, readset, writeset); | |
e9a17296 | 1560 | if (!compat20) |
3c0ef626 | 1561 | return; |
3c0ef626 | 1562 | channel_handle_efd(c, readset, writeset); |
c9f39d2c | 1563 | channel_handle_ctl(c, readset, writeset); |
3c0ef626 | 1564 | channel_check_window(c); |
1565 | } | |
1566 | ||
1567 | static void | |
1568 | channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) | |
1569 | { | |
1570 | int len; | |
41b2f314 | 1571 | |
3c0ef626 | 1572 | /* Send buffered output data to the socket. */ |
1573 | if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) { | |
1574 | len = write(c->sock, buffer_ptr(&c->output), | |
1575 | buffer_len(&c->output)); | |
1576 | if (len <= 0) | |
e9a17296 | 1577 | buffer_clear(&c->output); |
3c0ef626 | 1578 | else |
1579 | buffer_consume(&c->output, len); | |
1580 | } | |
1581 | } | |
1582 | ||
1583 | static void | |
1584 | channel_handler_init_20(void) | |
1585 | { | |
e9a17296 | 1586 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; |
3c0ef626 | 1587 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
1588 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1589 | channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener; | |
1590 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
1591 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
1592 | channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; | |
1593 | channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; | |
1594 | ||
e9a17296 | 1595 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; |
3c0ef626 | 1596 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; |
1597 | channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener; | |
1598 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
1599 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
1600 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; | |
e9a17296 | 1601 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; |
3c0ef626 | 1602 | } |
1603 | ||
1604 | static void | |
1605 | channel_handler_init_13(void) | |
1606 | { | |
1607 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; | |
1608 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13; | |
1609 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
1610 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1611 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
1612 | channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining; | |
1613 | channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining; | |
1614 | channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; | |
1615 | channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; | |
1616 | ||
e9a17296 | 1617 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; |
3c0ef626 | 1618 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; |
1619 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
1620 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
1621 | channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; | |
1622 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; | |
e9a17296 | 1623 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; |
3c0ef626 | 1624 | } |
1625 | ||
1626 | static void | |
1627 | channel_handler_init_15(void) | |
1628 | { | |
e9a17296 | 1629 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; |
3c0ef626 | 1630 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
1631 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
1632 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1633 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
1634 | channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; | |
1635 | channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; | |
1636 | ||
1637 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
1638 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
1639 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
e9a17296 | 1640 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; |
3c0ef626 | 1641 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; |
e9a17296 | 1642 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; |
3c0ef626 | 1643 | } |
1644 | ||
1645 | static void | |
1646 | channel_handler_init(void) | |
1647 | { | |
1648 | int i; | |
41b2f314 | 1649 | |
e9a17296 | 1650 | for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { |
3c0ef626 | 1651 | channel_pre[i] = NULL; |
1652 | channel_post[i] = NULL; | |
1653 | } | |
1654 | if (compat20) | |
1655 | channel_handler_init_20(); | |
1656 | else if (compat13) | |
1657 | channel_handler_init_13(); | |
1658 | else | |
1659 | channel_handler_init_15(); | |
1660 | } | |
1661 | ||
1662 | /* gc dead channels */ | |
1663 | static void | |
1664 | channel_garbage_collect(Channel *c) | |
1665 | { | |
1666 | if (c == NULL) | |
1667 | return; | |
1668 | if (c->detach_user != NULL) { | |
1669 | if (!chan_is_dead(c, 0)) | |
1670 | return; | |
0fff78ff | 1671 | debug2("channel %d: gc: notify user", c->self); |
3c0ef626 | 1672 | c->detach_user(c->self, NULL); |
1673 | /* if we still have a callback */ | |
1674 | if (c->detach_user != NULL) | |
1675 | return; | |
0fff78ff | 1676 | debug2("channel %d: gc: user detached", c->self); |
3c0ef626 | 1677 | } |
1678 | if (!chan_is_dead(c, 1)) | |
1679 | return; | |
0fff78ff | 1680 | debug2("channel %d: garbage collecting", c->self); |
3c0ef626 | 1681 | channel_free(c); |
1682 | } | |
1683 | ||
1684 | static void | |
1685 | channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) | |
1686 | { | |
1687 | static int did_init = 0; | |
c9f39d2c | 1688 | u_int i; |
3c0ef626 | 1689 | Channel *c; |
1690 | ||
1691 | if (!did_init) { | |
1692 | channel_handler_init(); | |
1693 | did_init = 1; | |
1694 | } | |
1695 | for (i = 0; i < channels_alloc; i++) { | |
1696 | c = channels[i]; | |
1697 | if (c == NULL) | |
1698 | continue; | |
1699 | if (ftab[c->type] != NULL) | |
1700 | (*ftab[c->type])(c, readset, writeset); | |
1701 | channel_garbage_collect(c); | |
1702 | } | |
1703 | } | |
1704 | ||
1705 | /* | |
1706 | * Allocate/update select bitmasks and add any bits relevant to channels in | |
1707 | * select bitmasks. | |
1708 | */ | |
1709 | void | |
1710 | channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp, | |
c9f39d2c | 1711 | u_int *nallocp, int rekeying) |
3c0ef626 | 1712 | { |
c9f39d2c | 1713 | u_int n, sz; |
3c0ef626 | 1714 | |
1715 | n = MAX(*maxfdp, channel_max_fd); | |
1716 | ||
1717 | sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); | |
1718 | /* perhaps check sz < nalloc/2 and shrink? */ | |
1719 | if (*readsetp == NULL || sz > *nallocp) { | |
1720 | *readsetp = xrealloc(*readsetp, sz); | |
1721 | *writesetp = xrealloc(*writesetp, sz); | |
1722 | *nallocp = sz; | |
1723 | } | |
1724 | *maxfdp = n; | |
1725 | memset(*readsetp, 0, sz); | |
1726 | memset(*writesetp, 0, sz); | |
1727 | ||
1728 | if (!rekeying) | |
1729 | channel_handler(channel_pre, *readsetp, *writesetp); | |
1730 | } | |
1731 | ||
1732 | /* | |
1733 | * After select, perform any appropriate operations for channels which have | |
1734 | * events pending. | |
1735 | */ | |
1736 | void | |
1737 | channel_after_select(fd_set * readset, fd_set * writeset) | |
1738 | { | |
1739 | channel_handler(channel_post, readset, writeset); | |
1740 | } | |
1741 | ||
1742 | ||
1743 | /* If there is data to send to the connection, enqueue some of it now. */ | |
1744 | ||
1745 | void | |
e9a17296 | 1746 | channel_output_poll(void) |
3c0ef626 | 1747 | { |
3c0ef626 | 1748 | Channel *c; |
c9f39d2c | 1749 | u_int i, len; |
3c0ef626 | 1750 | |
1751 | for (i = 0; i < channels_alloc; i++) { | |
1752 | c = channels[i]; | |
1753 | if (c == NULL) | |
1754 | continue; | |
1755 | ||
1756 | /* | |
1757 | * We are only interested in channels that can have buffered | |
1758 | * incoming data. | |
1759 | */ | |
1760 | if (compat13) { | |
1761 | if (c->type != SSH_CHANNEL_OPEN && | |
1762 | c->type != SSH_CHANNEL_INPUT_DRAINING) | |
1763 | continue; | |
1764 | } else { | |
1765 | if (c->type != SSH_CHANNEL_OPEN) | |
1766 | continue; | |
1767 | } | |
1768 | if (compat20 && | |
1769 | (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) { | |
1770 | /* XXX is this true? */ | |
1771 | debug3("channel %d: will not send data after close", c->self); | |
1772 | continue; | |
1773 | } | |
1774 | ||
1775 | /* Get the amount of buffered data for this channel. */ | |
1776 | if ((c->istate == CHAN_INPUT_OPEN || | |
1777 | c->istate == CHAN_INPUT_WAIT_DRAIN) && | |
1778 | (len = buffer_len(&c->input)) > 0) { | |
1779 | /* | |
1780 | * Send some data for the other side over the secure | |
1781 | * connection. | |
1782 | */ | |
1783 | if (compat20) { | |
1784 | if (len > c->remote_window) | |
1785 | len = c->remote_window; | |
1786 | if (len > c->remote_maxpacket) | |
1787 | len = c->remote_maxpacket; | |
1788 | } else { | |
1789 | if (packet_is_interactive()) { | |
1790 | if (len > 1024) | |
1791 | len = 512; | |
1792 | } else { | |
1793 | /* Keep the packets at reasonable size. */ | |
1794 | if (len > packet_get_maxsize()/2) | |
1795 | len = packet_get_maxsize()/2; | |
1796 | } | |
1797 | } | |
1798 | if (len > 0) { | |
1799 | packet_start(compat20 ? | |
1800 | SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); | |
1801 | packet_put_int(c->remote_id); | |
1802 | packet_put_string(buffer_ptr(&c->input), len); | |
1803 | packet_send(); | |
1804 | buffer_consume(&c->input, len); | |
1805 | c->remote_window -= len; | |
1806 | } | |
1807 | } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) { | |
1808 | if (compat13) | |
1809 | fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); | |
1810 | /* | |
1811 | * input-buffer is empty and read-socket shutdown: | |
700318f3 | 1812 | * tell peer, that we will not send more data: send IEOF. |
1813 | * hack for extended data: delay EOF if EFD still in use. | |
3c0ef626 | 1814 | */ |
700318f3 | 1815 | if (CHANNEL_EFD_INPUT_ACTIVE(c)) |
665a873d | 1816 | debug2("channel %d: ibuf_empty delayed efd %d/(%d)", |
1817 | c->self, c->efd, buffer_len(&c->extended)); | |
700318f3 | 1818 | else |
1819 | chan_ibuf_empty(c); | |
3c0ef626 | 1820 | } |
1821 | /* Send extended data, i.e. stderr */ | |
1822 | if (compat20 && | |
700318f3 | 1823 | !(c->flags & CHAN_EOF_SENT) && |
3c0ef626 | 1824 | c->remote_window > 0 && |
1825 | (len = buffer_len(&c->extended)) > 0 && | |
1826 | c->extended_usage == CHAN_EXTENDED_READ) { | |
680cee3b | 1827 | debug2("channel %d: rwin %u elen %u euse %d", |
3c0ef626 | 1828 | c->self, c->remote_window, buffer_len(&c->extended), |
1829 | c->extended_usage); | |
1830 | if (len > c->remote_window) | |
1831 | len = c->remote_window; | |
1832 | if (len > c->remote_maxpacket) | |
1833 | len = c->remote_maxpacket; | |
1834 | packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA); | |
1835 | packet_put_int(c->remote_id); | |
1836 | packet_put_int(SSH2_EXTENDED_DATA_STDERR); | |
1837 | packet_put_string(buffer_ptr(&c->extended), len); | |
1838 | packet_send(); | |
1839 | buffer_consume(&c->extended, len); | |
1840 | c->remote_window -= len; | |
1841 | debug2("channel %d: sent ext data %d", c->self, len); | |
1842 | } | |
1843 | } | |
1844 | } | |
1845 | ||
1846 | ||
1847 | /* -- protocol input */ | |
1848 | ||
1849 | void | |
e9a17296 | 1850 | channel_input_data(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1851 | { |
1852 | int id; | |
1853 | char *data; | |
1854 | u_int data_len; | |
1855 | Channel *c; | |
1856 | ||
1857 | /* Get the channel number and verify it. */ | |
1858 | id = packet_get_int(); | |
1859 | c = channel_lookup(id); | |
1860 | if (c == NULL) | |
1861 | packet_disconnect("Received data for nonexistent channel %d.", id); | |
1862 | ||
1863 | /* Ignore any data for non-open channels (might happen on close) */ | |
1864 | if (c->type != SSH_CHANNEL_OPEN && | |
1865 | c->type != SSH_CHANNEL_X11_OPEN) | |
1866 | return; | |
1867 | ||
3c0ef626 | 1868 | /* Get the data. */ |
1869 | data = packet_get_string(&data_len); | |
3c0ef626 | 1870 | |
cdd66111 | 1871 | /* |
1872 | * Ignore data for protocol > 1.3 if output end is no longer open. | |
1873 | * For protocol 2 the sending side is reducing its window as it sends | |
1874 | * data, so we must 'fake' consumption of the data in order to ensure | |
1875 | * that window updates are sent back. Otherwise the connection might | |
1876 | * deadlock. | |
1877 | */ | |
1878 | if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) { | |
1879 | if (compat20) { | |
1880 | c->local_window -= data_len; | |
1881 | c->local_consumed += data_len; | |
1882 | } | |
1883 | xfree(data); | |
1884 | return; | |
1885 | } | |
1886 | ||
e9a17296 | 1887 | if (compat20) { |
3c0ef626 | 1888 | if (data_len > c->local_maxpacket) { |
0fff78ff | 1889 | logit("channel %d: rcvd big packet %d, maxpack %d", |
3c0ef626 | 1890 | c->self, data_len, c->local_maxpacket); |
1891 | } | |
1892 | if (data_len > c->local_window) { | |
0fff78ff | 1893 | logit("channel %d: rcvd too much data %d, win %d", |
3c0ef626 | 1894 | c->self, data_len, c->local_window); |
1895 | xfree(data); | |
1896 | return; | |
1897 | } | |
1898 | c->local_window -= data_len; | |
3c0ef626 | 1899 | } |
e9a17296 | 1900 | packet_check_eom(); |
3c0ef626 | 1901 | buffer_append(&c->output, data, data_len); |
1902 | xfree(data); | |
1903 | } | |
1904 | ||
1905 | void | |
e9a17296 | 1906 | channel_input_extended_data(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1907 | { |
1908 | int id; | |
3c0ef626 | 1909 | char *data; |
680cee3b | 1910 | u_int data_len, tcode; |
3c0ef626 | 1911 | Channel *c; |
1912 | ||
1913 | /* Get the channel number and verify it. */ | |
1914 | id = packet_get_int(); | |
1915 | c = channel_lookup(id); | |
1916 | ||
1917 | if (c == NULL) | |
1918 | packet_disconnect("Received extended_data for bad channel %d.", id); | |
1919 | if (c->type != SSH_CHANNEL_OPEN) { | |
0fff78ff | 1920 | logit("channel %d: ext data for non open", id); |
3c0ef626 | 1921 | return; |
1922 | } | |
700318f3 | 1923 | if (c->flags & CHAN_EOF_RCVD) { |
1924 | if (datafellows & SSH_BUG_EXTEOF) | |
1925 | debug("channel %d: accepting ext data after eof", id); | |
1926 | else | |
1927 | packet_disconnect("Received extended_data after EOF " | |
1928 | "on channel %d.", id); | |
1929 | } | |
3c0ef626 | 1930 | tcode = packet_get_int(); |
1931 | if (c->efd == -1 || | |
1932 | c->extended_usage != CHAN_EXTENDED_WRITE || | |
1933 | tcode != SSH2_EXTENDED_DATA_STDERR) { | |
0fff78ff | 1934 | logit("channel %d: bad ext data", c->self); |
3c0ef626 | 1935 | return; |
1936 | } | |
1937 | data = packet_get_string(&data_len); | |
e9a17296 | 1938 | packet_check_eom(); |
3c0ef626 | 1939 | if (data_len > c->local_window) { |
0fff78ff | 1940 | logit("channel %d: rcvd too much extended_data %d, win %d", |
3c0ef626 | 1941 | c->self, data_len, c->local_window); |
1942 | xfree(data); | |
1943 | return; | |
1944 | } | |
1945 | debug2("channel %d: rcvd ext data %d", c->self, data_len); | |
1946 | c->local_window -= data_len; | |
1947 | buffer_append(&c->extended, data, data_len); | |
1948 | xfree(data); | |
1949 | } | |
1950 | ||
1951 | void | |
e9a17296 | 1952 | channel_input_ieof(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1953 | { |
1954 | int id; | |
1955 | Channel *c; | |
1956 | ||
3c0ef626 | 1957 | id = packet_get_int(); |
e9a17296 | 1958 | packet_check_eom(); |
3c0ef626 | 1959 | c = channel_lookup(id); |
1960 | if (c == NULL) | |
1961 | packet_disconnect("Received ieof for nonexistent channel %d.", id); | |
1962 | chan_rcvd_ieof(c); | |
1963 | ||
1964 | /* XXX force input close */ | |
e9a17296 | 1965 | if (c->force_drain && c->istate == CHAN_INPUT_OPEN) { |
3c0ef626 | 1966 | debug("channel %d: FORCE input drain", c->self); |
1967 | c->istate = CHAN_INPUT_WAIT_DRAIN; | |
e9a17296 | 1968 | if (buffer_len(&c->input) == 0) |
1969 | chan_ibuf_empty(c); | |
3c0ef626 | 1970 | } |
1971 | ||
1972 | } | |
1973 | ||
1974 | void | |
e9a17296 | 1975 | channel_input_close(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1976 | { |
1977 | int id; | |
1978 | Channel *c; | |
1979 | ||
3c0ef626 | 1980 | id = packet_get_int(); |
e9a17296 | 1981 | packet_check_eom(); |
3c0ef626 | 1982 | c = channel_lookup(id); |
1983 | if (c == NULL) | |
1984 | packet_disconnect("Received close for nonexistent channel %d.", id); | |
1985 | ||
1986 | /* | |
1987 | * Send a confirmation that we have closed the channel and no more | |
1988 | * data is coming for it. | |
1989 | */ | |
1990 | packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); | |
1991 | packet_put_int(c->remote_id); | |
1992 | packet_send(); | |
1993 | ||
1994 | /* | |
1995 | * If the channel is in closed state, we have sent a close request, | |
1996 | * and the other side will eventually respond with a confirmation. | |
1997 | * Thus, we cannot free the channel here, because then there would be | |
1998 | * no-one to receive the confirmation. The channel gets freed when | |
1999 | * the confirmation arrives. | |
2000 | */ | |
2001 | if (c->type != SSH_CHANNEL_CLOSED) { | |
2002 | /* | |
2003 | * Not a closed channel - mark it as draining, which will | |
2004 | * cause it to be freed later. | |
2005 | */ | |
e9a17296 | 2006 | buffer_clear(&c->input); |
3c0ef626 | 2007 | c->type = SSH_CHANNEL_OUTPUT_DRAINING; |
2008 | } | |
2009 | } | |
2010 | ||
2011 | /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ | |
2012 | void | |
e9a17296 | 2013 | channel_input_oclose(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2014 | { |
2015 | int id = packet_get_int(); | |
2016 | Channel *c = channel_lookup(id); | |
e9a17296 | 2017 | |
2018 | packet_check_eom(); | |
3c0ef626 | 2019 | if (c == NULL) |
2020 | packet_disconnect("Received oclose for nonexistent channel %d.", id); | |
2021 | chan_rcvd_oclose(c); | |
2022 | } | |
2023 | ||
2024 | void | |
e9a17296 | 2025 | channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2026 | { |
2027 | int id = packet_get_int(); | |
2028 | Channel *c = channel_lookup(id); | |
2029 | ||
e9a17296 | 2030 | packet_check_eom(); |
3c0ef626 | 2031 | if (c == NULL) |
2032 | packet_disconnect("Received close confirmation for " | |
2033 | "out-of-range channel %d.", id); | |
2034 | if (c->type != SSH_CHANNEL_CLOSED) | |
2035 | packet_disconnect("Received close confirmation for " | |
2036 | "non-closed channel %d (type %d).", id, c->type); | |
2037 | channel_free(c); | |
2038 | } | |
2039 | ||
2040 | void | |
e9a17296 | 2041 | channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2042 | { |
2043 | int id, remote_id; | |
2044 | Channel *c; | |
2045 | ||
3c0ef626 | 2046 | id = packet_get_int(); |
2047 | c = channel_lookup(id); | |
2048 | ||
2049 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
2050 | packet_disconnect("Received open confirmation for " | |
2051 | "non-opening channel %d.", id); | |
2052 | remote_id = packet_get_int(); | |
2053 | /* Record the remote channel number and mark that the channel is now open. */ | |
2054 | c->remote_id = remote_id; | |
2055 | c->type = SSH_CHANNEL_OPEN; | |
2056 | ||
2057 | if (compat20) { | |
2058 | c->remote_window = packet_get_int(); | |
2059 | c->remote_maxpacket = packet_get_int(); | |
e9a17296 | 2060 | if (c->confirm) { |
3c0ef626 | 2061 | debug2("callback start"); |
c9f39d2c | 2062 | c->confirm(c->self, c->confirm_ctx); |
3c0ef626 | 2063 | debug2("callback done"); |
2064 | } | |
0fff78ff | 2065 | debug2("channel %d: open confirm rwindow %u rmax %u", c->self, |
3c0ef626 | 2066 | c->remote_window, c->remote_maxpacket); |
2067 | } | |
e9a17296 | 2068 | packet_check_eom(); |
3c0ef626 | 2069 | } |
2070 | ||
2071 | static char * | |
2072 | reason2txt(int reason) | |
2073 | { | |
e9a17296 | 2074 | switch (reason) { |
3c0ef626 | 2075 | case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED: |
2076 | return "administratively prohibited"; | |
2077 | case SSH2_OPEN_CONNECT_FAILED: | |
2078 | return "connect failed"; | |
2079 | case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE: | |
2080 | return "unknown channel type"; | |
2081 | case SSH2_OPEN_RESOURCE_SHORTAGE: | |
2082 | return "resource shortage"; | |
2083 | } | |
2084 | return "unknown reason"; | |
2085 | } | |
2086 | ||
2087 | void | |
e9a17296 | 2088 | channel_input_open_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2089 | { |
2090 | int id, reason; | |
2091 | char *msg = NULL, *lang = NULL; | |
2092 | Channel *c; | |
2093 | ||
3c0ef626 | 2094 | id = packet_get_int(); |
2095 | c = channel_lookup(id); | |
2096 | ||
2097 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
2098 | packet_disconnect("Received open failure for " | |
2099 | "non-opening channel %d.", id); | |
2100 | if (compat20) { | |
2101 | reason = packet_get_int(); | |
2102 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
2103 | msg = packet_get_string(NULL); | |
2104 | lang = packet_get_string(NULL); | |
2105 | } | |
0fff78ff | 2106 | logit("channel %d: open failed: %s%s%s", id, |
3c0ef626 | 2107 | reason2txt(reason), msg ? ": ": "", msg ? msg : ""); |
2108 | if (msg != NULL) | |
2109 | xfree(msg); | |
2110 | if (lang != NULL) | |
2111 | xfree(lang); | |
2112 | } | |
e9a17296 | 2113 | packet_check_eom(); |
3c0ef626 | 2114 | /* Free the channel. This will also close the socket. */ |
2115 | channel_free(c); | |
2116 | } | |
2117 | ||
2118 | void | |
e9a17296 | 2119 | channel_input_window_adjust(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2120 | { |
2121 | Channel *c; | |
680cee3b | 2122 | int id; |
2123 | u_int adjust; | |
3c0ef626 | 2124 | |
2125 | if (!compat20) | |
2126 | return; | |
2127 | ||
2128 | /* Get the channel number and verify it. */ | |
2129 | id = packet_get_int(); | |
2130 | c = channel_lookup(id); | |
2131 | ||
2132 | if (c == NULL || c->type != SSH_CHANNEL_OPEN) { | |
0fff78ff | 2133 | logit("Received window adjust for " |
3c0ef626 | 2134 | "non-open channel %d.", id); |
2135 | return; | |
2136 | } | |
2137 | adjust = packet_get_int(); | |
e9a17296 | 2138 | packet_check_eom(); |
680cee3b | 2139 | debug2("channel %d: rcvd adjust %u", id, adjust); |
3c0ef626 | 2140 | c->remote_window += adjust; |
2141 | } | |
2142 | ||
2143 | void | |
e9a17296 | 2144 | channel_input_port_open(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2145 | { |
2146 | Channel *c = NULL; | |
2147 | u_short host_port; | |
2148 | char *host, *originator_string; | |
2149 | int remote_id, sock = -1; | |
2150 | ||
2151 | remote_id = packet_get_int(); | |
2152 | host = packet_get_string(NULL); | |
2153 | host_port = packet_get_int(); | |
2154 | ||
2155 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { | |
2156 | originator_string = packet_get_string(NULL); | |
2157 | } else { | |
2158 | originator_string = xstrdup("unknown (remote did not supply name)"); | |
2159 | } | |
e9a17296 | 2160 | packet_check_eom(); |
3c0ef626 | 2161 | sock = channel_connect_to(host, host_port); |
2162 | if (sock != -1) { | |
2163 | c = channel_new("connected socket", | |
2164 | SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0, | |
2165 | originator_string, 1); | |
e9a17296 | 2166 | c->remote_id = remote_id; |
3c0ef626 | 2167 | } |
0fff78ff | 2168 | xfree(originator_string); |
3c0ef626 | 2169 | if (c == NULL) { |
2170 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2171 | packet_put_int(remote_id); | |
2172 | packet_send(); | |
2173 | } | |
2174 | xfree(host); | |
2175 | } | |
2176 | ||
2177 | ||
2178 | /* -- tcp forwarding */ | |
2179 | ||
2180 | void | |
2181 | channel_set_af(int af) | |
2182 | { | |
2183 | IPv4or6 = af; | |
2184 | } | |
2185 | ||
e9a17296 | 2186 | static int |
2187 | channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port, | |
2188 | const char *host_to_connect, u_short port_to_connect, int gateway_ports) | |
3c0ef626 | 2189 | { |
2190 | Channel *c; | |
996d5e62 | 2191 | int sock, r, success = 0, on = 1, wildcard = 0, is_client; |
3c0ef626 | 2192 | struct addrinfo hints, *ai, *aitop; |
996d5e62 | 2193 | const char *host, *addr; |
e9a17296 | 2194 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
3c0ef626 | 2195 | |
e9a17296 | 2196 | host = (type == SSH_CHANNEL_RPORT_LISTENER) ? |
2197 | listen_addr : host_to_connect; | |
996d5e62 | 2198 | is_client = (type == SSH_CHANNEL_PORT_LISTENER); |
3c0ef626 | 2199 | |
e9a17296 | 2200 | if (host == NULL) { |
2201 | error("No forward host name."); | |
665a873d | 2202 | return 0; |
3c0ef626 | 2203 | } |
3c0ef626 | 2204 | if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) { |
2205 | error("Forward host name too long."); | |
665a873d | 2206 | return 0; |
3c0ef626 | 2207 | } |
2208 | ||
996d5e62 | 2209 | /* |
2210 | * Determine whether or not a port forward listens to loopback, | |
dec6d9fe | 2211 | * specified address or wildcard. On the client, a specified bind |
2212 | * address will always override gateway_ports. On the server, a | |
2213 | * gateway_ports of 1 (``yes'') will override the client's | |
2214 | * specification and force a wildcard bind, whereas a value of 2 | |
2215 | * (``clientspecified'') will bind to whatever address the client | |
996d5e62 | 2216 | * asked for. |
2217 | * | |
2218 | * Special-case listen_addrs are: | |
2219 | * | |
2220 | * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR | |
2221 | * "" (empty string), "*" -> wildcard v4/v6 | |
2222 | * "localhost" -> loopback v4/v6 | |
2223 | */ | |
2224 | addr = NULL; | |
2225 | if (listen_addr == NULL) { | |
2226 | /* No address specified: default to gateway_ports setting */ | |
2227 | if (gateway_ports) | |
2228 | wildcard = 1; | |
2229 | } else if (gateway_ports || is_client) { | |
2230 | if (((datafellows & SSH_OLD_FORWARD_ADDR) && | |
2231 | strcmp(listen_addr, "0.0.0.0") == 0) || | |
2232 | *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 || | |
2233 | (!is_client && gateway_ports == 1)) | |
2234 | wildcard = 1; | |
2235 | else if (strcmp(listen_addr, "localhost") != 0) | |
2236 | addr = listen_addr; | |
2237 | } | |
2238 | ||
2239 | debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s", | |
2240 | type, wildcard, (addr == NULL) ? "NULL" : addr); | |
2241 | ||
3c0ef626 | 2242 | /* |
2243 | * getaddrinfo returns a loopback address if the hostname is | |
2244 | * set to NULL and hints.ai_flags is not AI_PASSIVE | |
2245 | */ | |
2246 | memset(&hints, 0, sizeof(hints)); | |
2247 | hints.ai_family = IPv4or6; | |
996d5e62 | 2248 | hints.ai_flags = wildcard ? AI_PASSIVE : 0; |
3c0ef626 | 2249 | hints.ai_socktype = SOCK_STREAM; |
2250 | snprintf(strport, sizeof strport, "%d", listen_port); | |
996d5e62 | 2251 | if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) { |
2252 | if (addr == NULL) { | |
2253 | /* This really shouldn't happen */ | |
2254 | packet_disconnect("getaddrinfo: fatal error: %s", | |
2255 | gai_strerror(r)); | |
2256 | } else { | |
665a873d | 2257 | error("channel_setup_fwd_listener: " |
996d5e62 | 2258 | "getaddrinfo(%.64s): %s", addr, gai_strerror(r)); |
2259 | } | |
665a873d | 2260 | return 0; |
996d5e62 | 2261 | } |
3c0ef626 | 2262 | |
2263 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2264 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2265 | continue; | |
2266 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
2267 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
e9a17296 | 2268 | error("channel_setup_fwd_listener: getnameinfo failed"); |
3c0ef626 | 2269 | continue; |
2270 | } | |
2271 | /* Create a port to listen for the host. */ | |
0fff78ff | 2272 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3c0ef626 | 2273 | if (sock < 0) { |
2274 | /* this is no error since kernel may not support ipv6 */ | |
2275 | verbose("socket: %.100s", strerror(errno)); | |
2276 | continue; | |
2277 | } | |
2278 | /* | |
41b2f314 | 2279 | * Set socket options. |
2280 | * Allow local port reuse in TIME_WAIT. | |
3c0ef626 | 2281 | */ |
41b2f314 | 2282 | if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, |
2283 | sizeof(on)) == -1) | |
2284 | error("setsockopt SO_REUSEADDR: %s", strerror(errno)); | |
2285 | ||
3c0ef626 | 2286 | debug("Local forwarding listening on %s port %s.", ntop, strport); |
2287 | ||
2288 | /* Bind the socket to the address. */ | |
2289 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
2290 | /* address can be in use ipv6 address is already bound */ | |
2291 | if (!ai->ai_next) | |
2292 | error("bind: %.100s", strerror(errno)); | |
2293 | else | |
2294 | verbose("bind: %.100s", strerror(errno)); | |
2295 | ||
2296 | close(sock); | |
2297 | continue; | |
2298 | } | |
2299 | /* Start listening for connections on the socket. */ | |
cdd66111 | 2300 | if (listen(sock, SSH_LISTEN_BACKLOG) < 0) { |
3c0ef626 | 2301 | error("listen: %.100s", strerror(errno)); |
2302 | close(sock); | |
2303 | continue; | |
2304 | } | |
2305 | /* Allocate a channel number for the socket. */ | |
2306 | c = channel_new("port listener", type, sock, sock, -1, | |
2307 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, | |
0fff78ff | 2308 | 0, "port listener", 1); |
3c0ef626 | 2309 | strlcpy(c->path, host, sizeof(c->path)); |
2310 | c->host_port = port_to_connect; | |
2311 | c->listening_port = listen_port; | |
2312 | success = 1; | |
2313 | } | |
2314 | if (success == 0) | |
e9a17296 | 2315 | error("channel_setup_fwd_listener: cannot listen to port: %d", |
3c0ef626 | 2316 | listen_port); |
2317 | freeaddrinfo(aitop); | |
2318 | return success; | |
2319 | } | |
2320 | ||
c9f39d2c | 2321 | int |
2322 | channel_cancel_rport_listener(const char *host, u_short port) | |
2323 | { | |
2324 | u_int i; | |
2325 | int found = 0; | |
2326 | ||
dec6d9fe | 2327 | for (i = 0; i < channels_alloc; i++) { |
c9f39d2c | 2328 | Channel *c = channels[i]; |
2329 | ||
2330 | if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER && | |
2331 | strncmp(c->path, host, sizeof(c->path)) == 0 && | |
2332 | c->listening_port == port) { | |
996d5e62 | 2333 | debug2("%s: close channel %d", __func__, i); |
c9f39d2c | 2334 | channel_free(c); |
2335 | found = 1; | |
2336 | } | |
2337 | } | |
2338 | ||
2339 | return (found); | |
2340 | } | |
2341 | ||
e9a17296 | 2342 | /* protocol local port fwd, used by ssh (and sshd in v1) */ |
2343 | int | |
996d5e62 | 2344 | channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port, |
e9a17296 | 2345 | const char *host_to_connect, u_short port_to_connect, int gateway_ports) |
2346 | { | |
2347 | return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER, | |
996d5e62 | 2348 | listen_host, listen_port, host_to_connect, port_to_connect, |
2349 | gateway_ports); | |
e9a17296 | 2350 | } |
2351 | ||
2352 | /* protocol v2 remote port fwd, used by sshd */ | |
2353 | int | |
2354 | channel_setup_remote_fwd_listener(const char *listen_address, | |
2355 | u_short listen_port, int gateway_ports) | |
2356 | { | |
2357 | return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER, | |
2358 | listen_address, listen_port, NULL, 0, gateway_ports); | |
2359 | } | |
2360 | ||
3c0ef626 | 2361 | /* |
2362 | * Initiate forwarding of connections to port "port" on remote host through | |
2363 | * the secure channel to host:port from local side. | |
2364 | */ | |
2365 | ||
2366 | void | |
996d5e62 | 2367 | channel_request_remote_forwarding(const char *listen_host, u_short listen_port, |
3c0ef626 | 2368 | const char *host_to_connect, u_short port_to_connect) |
2369 | { | |
e9a17296 | 2370 | int type, success = 0; |
3c0ef626 | 2371 | |
2372 | /* Record locally that connection to this host/port is permitted. */ | |
2373 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
2374 | fatal("channel_request_remote_forwarding: too many forwards"); | |
2375 | ||
2376 | /* Send the forward request to the remote side. */ | |
2377 | if (compat20) { | |
996d5e62 | 2378 | const char *address_to_bind; |
2379 | if (listen_host == NULL) | |
2380 | address_to_bind = "localhost"; | |
2381 | else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) | |
2382 | address_to_bind = ""; | |
2383 | else | |
2384 | address_to_bind = listen_host; | |
2385 | ||
3c0ef626 | 2386 | packet_start(SSH2_MSG_GLOBAL_REQUEST); |
2387 | packet_put_cstring("tcpip-forward"); | |
700318f3 | 2388 | packet_put_char(1); /* boolean: want reply */ |
3c0ef626 | 2389 | packet_put_cstring(address_to_bind); |
2390 | packet_put_int(listen_port); | |
2391 | packet_send(); | |
2392 | packet_write_wait(); | |
2393 | /* Assume that server accepts the request */ | |
2394 | success = 1; | |
2395 | } else { | |
2396 | packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); | |
2397 | packet_put_int(listen_port); | |
2398 | packet_put_cstring(host_to_connect); | |
2399 | packet_put_int(port_to_connect); | |
2400 | packet_send(); | |
2401 | packet_write_wait(); | |
2402 | ||
2403 | /* Wait for response from the remote side. */ | |
e9a17296 | 2404 | type = packet_read(); |
3c0ef626 | 2405 | switch (type) { |
2406 | case SSH_SMSG_SUCCESS: | |
2407 | success = 1; | |
2408 | break; | |
2409 | case SSH_SMSG_FAILURE: | |
0fff78ff | 2410 | logit("Warning: Server denied remote port forwarding."); |
3c0ef626 | 2411 | break; |
2412 | default: | |
2413 | /* Unknown packet */ | |
2414 | packet_disconnect("Protocol error for port forward request:" | |
2415 | "received packet type %d.", type); | |
2416 | } | |
2417 | } | |
2418 | if (success) { | |
2419 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect); | |
2420 | permitted_opens[num_permitted_opens].port_to_connect = port_to_connect; | |
2421 | permitted_opens[num_permitted_opens].listen_port = listen_port; | |
2422 | num_permitted_opens++; | |
2423 | } | |
2424 | } | |
2425 | ||
c9f39d2c | 2426 | /* |
2427 | * Request cancellation of remote forwarding of connection host:port from | |
2428 | * local side. | |
2429 | */ | |
2430 | void | |
996d5e62 | 2431 | channel_request_rforward_cancel(const char *host, u_short port) |
c9f39d2c | 2432 | { |
2433 | int i; | |
c9f39d2c | 2434 | |
2435 | if (!compat20) | |
2436 | return; | |
2437 | ||
2438 | for (i = 0; i < num_permitted_opens; i++) { | |
2439 | if (permitted_opens[i].host_to_connect != NULL && | |
2440 | permitted_opens[i].listen_port == port) | |
2441 | break; | |
2442 | } | |
2443 | if (i >= num_permitted_opens) { | |
2444 | debug("%s: requested forward not found", __func__); | |
2445 | return; | |
2446 | } | |
2447 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
2448 | packet_put_cstring("cancel-tcpip-forward"); | |
2449 | packet_put_char(0); | |
996d5e62 | 2450 | packet_put_cstring(host == NULL ? "" : host); |
c9f39d2c | 2451 | packet_put_int(port); |
2452 | packet_send(); | |
2453 | ||
2454 | permitted_opens[i].listen_port = 0; | |
2455 | permitted_opens[i].port_to_connect = 0; | |
2456 | free(permitted_opens[i].host_to_connect); | |
2457 | permitted_opens[i].host_to_connect = NULL; | |
2458 | } | |
2459 | ||
3c0ef626 | 2460 | /* |
2461 | * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates | |
2462 | * listening for the port, and sends back a success reply (or disconnect | |
2463 | * message if there was an error). This never returns if there was an error. | |
2464 | */ | |
2465 | ||
2466 | void | |
2467 | channel_input_port_forward_request(int is_root, int gateway_ports) | |
2468 | { | |
2469 | u_short port, host_port; | |
2470 | char *hostname; | |
2471 | ||
2472 | /* Get arguments from the packet. */ | |
2473 | port = packet_get_int(); | |
2474 | hostname = packet_get_string(NULL); | |
2475 | host_port = packet_get_int(); | |
2476 | ||
2477 | #ifndef HAVE_CYGWIN | |
2478 | /* | |
2479 | * Check that an unprivileged user is not trying to forward a | |
2480 | * privileged port. | |
2481 | */ | |
2482 | if (port < IPPORT_RESERVED && !is_root) | |
0fff78ff | 2483 | packet_disconnect( |
2484 | "Requested forwarding of port %d but user is not root.", | |
2485 | port); | |
2486 | if (host_port == 0) | |
2487 | packet_disconnect("Dynamic forwarding denied."); | |
3c0ef626 | 2488 | #endif |
0fff78ff | 2489 | |
3c0ef626 | 2490 | /* Initiate forwarding */ |
996d5e62 | 2491 | channel_setup_local_fwd_listener(NULL, port, hostname, |
2492 | host_port, gateway_ports); | |
3c0ef626 | 2493 | |
2494 | /* Free the argument string. */ | |
2495 | xfree(hostname); | |
2496 | } | |
2497 | ||
2498 | /* | |
2499 | * Permits opening to any host/port if permitted_opens[] is empty. This is | |
2500 | * usually called by the server, because the user could connect to any port | |
2501 | * anyway, and the server has no way to know but to trust the client anyway. | |
2502 | */ | |
2503 | void | |
e9a17296 | 2504 | channel_permit_all_opens(void) |
3c0ef626 | 2505 | { |
2506 | if (num_permitted_opens == 0) | |
2507 | all_opens_permitted = 1; | |
2508 | } | |
2509 | ||
2510 | void | |
2511 | channel_add_permitted_opens(char *host, int port) | |
2512 | { | |
2513 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
2514 | fatal("channel_request_remote_forwarding: too many forwards"); | |
2515 | debug("allow port forwarding to host %s port %d", host, port); | |
2516 | ||
2517 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host); | |
2518 | permitted_opens[num_permitted_opens].port_to_connect = port; | |
2519 | num_permitted_opens++; | |
2520 | ||
2521 | all_opens_permitted = 0; | |
2522 | } | |
2523 | ||
2524 | void | |
2525 | channel_clear_permitted_opens(void) | |
2526 | { | |
2527 | int i; | |
2528 | ||
2529 | for (i = 0; i < num_permitted_opens; i++) | |
c9f39d2c | 2530 | if (permitted_opens[i].host_to_connect != NULL) |
2531 | xfree(permitted_opens[i].host_to_connect); | |
3c0ef626 | 2532 | num_permitted_opens = 0; |
2533 | ||
2534 | } | |
2535 | ||
2536 | ||
2537 | /* return socket to remote host, port */ | |
2538 | static int | |
2539 | connect_to(const char *host, u_short port) | |
2540 | { | |
2541 | struct addrinfo hints, *ai, *aitop; | |
2542 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
2543 | int gaierr; | |
2544 | int sock = -1; | |
2545 | ||
2546 | memset(&hints, 0, sizeof(hints)); | |
2547 | hints.ai_family = IPv4or6; | |
2548 | hints.ai_socktype = SOCK_STREAM; | |
2549 | snprintf(strport, sizeof strport, "%d", port); | |
2550 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { | |
2551 | error("connect_to %.100s: unknown host (%s)", host, | |
2552 | gai_strerror(gaierr)); | |
2553 | return -1; | |
2554 | } | |
2555 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2556 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2557 | continue; | |
2558 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
2559 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
2560 | error("connect_to: getnameinfo failed"); | |
2561 | continue; | |
2562 | } | |
0fff78ff | 2563 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3c0ef626 | 2564 | if (sock < 0) { |
6a9b3198 | 2565 | if (ai->ai_next == NULL) |
2566 | error("socket: %.100s", strerror(errno)); | |
2567 | else | |
2568 | verbose("socket: %.100s", strerror(errno)); | |
3c0ef626 | 2569 | continue; |
2570 | } | |
c9f39d2c | 2571 | if (set_nonblock(sock) == -1) |
2572 | fatal("%s: set_nonblock(%d)", __func__, sock); | |
3c0ef626 | 2573 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 && |
2574 | errno != EINPROGRESS) { | |
2575 | error("connect_to %.100s port %s: %.100s", ntop, strport, | |
2576 | strerror(errno)); | |
2577 | close(sock); | |
2578 | continue; /* fail -- try next */ | |
2579 | } | |
2580 | break; /* success */ | |
2581 | ||
2582 | } | |
2583 | freeaddrinfo(aitop); | |
2584 | if (!ai) { | |
2585 | error("connect_to %.100s port %d: failed.", host, port); | |
2586 | return -1; | |
2587 | } | |
2588 | /* success */ | |
e9a17296 | 2589 | set_nodelay(sock); |
3c0ef626 | 2590 | return sock; |
2591 | } | |
2592 | ||
2593 | int | |
2594 | channel_connect_by_listen_address(u_short listen_port) | |
2595 | { | |
2596 | int i; | |
2597 | ||
2598 | for (i = 0; i < num_permitted_opens; i++) | |
c9f39d2c | 2599 | if (permitted_opens[i].host_to_connect != NULL && |
2600 | permitted_opens[i].listen_port == listen_port) | |
3c0ef626 | 2601 | return connect_to( |
2602 | permitted_opens[i].host_to_connect, | |
2603 | permitted_opens[i].port_to_connect); | |
2604 | error("WARNING: Server requests forwarding for unknown listen_port %d", | |
2605 | listen_port); | |
2606 | return -1; | |
2607 | } | |
2608 | ||
2609 | /* Check if connecting to that port is permitted and connect. */ | |
2610 | int | |
2611 | channel_connect_to(const char *host, u_short port) | |
2612 | { | |
2613 | int i, permit; | |
2614 | ||
2615 | permit = all_opens_permitted; | |
2616 | if (!permit) { | |
2617 | for (i = 0; i < num_permitted_opens; i++) | |
c9f39d2c | 2618 | if (permitted_opens[i].host_to_connect != NULL && |
2619 | permitted_opens[i].port_to_connect == port && | |
3c0ef626 | 2620 | strcmp(permitted_opens[i].host_to_connect, host) == 0) |
2621 | permit = 1; | |
2622 | ||
2623 | } | |
2624 | if (!permit) { | |
0fff78ff | 2625 | logit("Received request to connect to host %.100s port %d, " |
3c0ef626 | 2626 | "but the request was denied.", host, port); |
2627 | return -1; | |
2628 | } | |
2629 | return connect_to(host, port); | |
2630 | } | |
2631 | ||
c9f39d2c | 2632 | void |
2633 | channel_send_window_changes(void) | |
2634 | { | |
2635 | u_int i; | |
2636 | struct winsize ws; | |
2637 | ||
2638 | for (i = 0; i < channels_alloc; i++) { | |
dec6d9fe | 2639 | if (channels[i] == NULL || !channels[i]->client_tty || |
c9f39d2c | 2640 | channels[i]->type != SSH_CHANNEL_OPEN) |
2641 | continue; | |
2642 | if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0) | |
2643 | continue; | |
2644 | channel_request_start(i, "window-change", 0); | |
2645 | packet_put_int(ws.ws_col); | |
2646 | packet_put_int(ws.ws_row); | |
2647 | packet_put_int(ws.ws_xpixel); | |
2648 | packet_put_int(ws.ws_ypixel); | |
2649 | packet_send(); | |
2650 | } | |
2651 | } | |
2652 | ||
3c0ef626 | 2653 | /* -- X11 forwarding */ |
2654 | ||
2655 | /* | |
2656 | * Creates an internet domain socket for listening for X11 connections. | |
680cee3b | 2657 | * Returns 0 and a suitable display number for the DISPLAY variable |
2658 | * stored in display_numberp , or -1 if an error occurs. | |
3c0ef626 | 2659 | */ |
e9a17296 | 2660 | int |
2661 | x11_create_display_inet(int x11_display_offset, int x11_use_localhost, | |
665a873d | 2662 | int single_connection, u_int *display_numberp, int **chanids) |
3c0ef626 | 2663 | { |
e9a17296 | 2664 | Channel *nc = NULL; |
3c0ef626 | 2665 | int display_number, sock; |
2666 | u_short port; | |
2667 | struct addrinfo hints, *ai, *aitop; | |
2668 | char strport[NI_MAXSERV]; | |
2669 | int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; | |
3c0ef626 | 2670 | |
2671 | for (display_number = x11_display_offset; | |
e9a17296 | 2672 | display_number < MAX_DISPLAYS; |
2673 | display_number++) { | |
3c0ef626 | 2674 | port = 6000 + display_number; |
2675 | memset(&hints, 0, sizeof(hints)); | |
2676 | hints.ai_family = IPv4or6; | |
e9a17296 | 2677 | hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE; |
3c0ef626 | 2678 | hints.ai_socktype = SOCK_STREAM; |
2679 | snprintf(strport, sizeof strport, "%d", port); | |
2680 | if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { | |
2681 | error("getaddrinfo: %.100s", gai_strerror(gaierr)); | |
e9a17296 | 2682 | return -1; |
3c0ef626 | 2683 | } |
2684 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2685 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2686 | continue; | |
0fff78ff | 2687 | sock = socket(ai->ai_family, ai->ai_socktype, |
2688 | ai->ai_protocol); | |
3c0ef626 | 2689 | if (sock < 0) { |
2690 | if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) { | |
2691 | error("socket: %.100s", strerror(errno)); | |
c9f39d2c | 2692 | freeaddrinfo(aitop); |
e9a17296 | 2693 | return -1; |
3c0ef626 | 2694 | } else { |
2695 | debug("x11_create_display_inet: Socket family %d not supported", | |
2696 | ai->ai_family); | |
2697 | continue; | |
2698 | } | |
2699 | } | |
f5799ae1 | 2700 | #ifdef IPV6_V6ONLY |
2701 | if (ai->ai_family == AF_INET6) { | |
2702 | int on = 1; | |
2703 | if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) | |
2704 | error("setsockopt IPV6_V6ONLY: %.100s", strerror(errno)); | |
2705 | } | |
2706 | #endif | |
3c0ef626 | 2707 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { |
0fff78ff | 2708 | debug2("bind port %d: %.100s", port, strerror(errno)); |
3c0ef626 | 2709 | close(sock); |
2710 | ||
2711 | if (ai->ai_next) | |
2712 | continue; | |
2713 | ||
2714 | for (n = 0; n < num_socks; n++) { | |
3c0ef626 | 2715 | close(socks[n]); |
2716 | } | |
2717 | num_socks = 0; | |
2718 | break; | |
2719 | } | |
2720 | socks[num_socks++] = sock; | |
2721 | #ifndef DONT_TRY_OTHER_AF | |
2722 | if (num_socks == NUM_SOCKS) | |
2723 | break; | |
2724 | #else | |
f5799ae1 | 2725 | if (x11_use_localhost) { |
2726 | if (num_socks == NUM_SOCKS) | |
2727 | break; | |
2728 | } else { | |
2729 | break; | |
2730 | } | |
3c0ef626 | 2731 | #endif |
2732 | } | |
2733 | freeaddrinfo(aitop); | |
2734 | if (num_socks > 0) | |
2735 | break; | |
2736 | } | |
2737 | if (display_number >= MAX_DISPLAYS) { | |
2738 | error("Failed to allocate internet-domain X11 display socket."); | |
e9a17296 | 2739 | return -1; |
3c0ef626 | 2740 | } |
2741 | /* Start listening for connections on the socket. */ | |
2742 | for (n = 0; n < num_socks; n++) { | |
2743 | sock = socks[n]; | |
cdd66111 | 2744 | if (listen(sock, SSH_LISTEN_BACKLOG) < 0) { |
3c0ef626 | 2745 | error("listen: %.100s", strerror(errno)); |
3c0ef626 | 2746 | close(sock); |
e9a17296 | 2747 | return -1; |
3c0ef626 | 2748 | } |
3c0ef626 | 2749 | } |
3c0ef626 | 2750 | |
2751 | /* Allocate a channel for each socket. */ | |
665a873d | 2752 | if (chanids != NULL) |
2753 | *chanids = xmalloc(sizeof(**chanids) * (num_socks + 1)); | |
3c0ef626 | 2754 | for (n = 0; n < num_socks; n++) { |
2755 | sock = socks[n]; | |
e9a17296 | 2756 | nc = channel_new("x11 listener", |
3c0ef626 | 2757 | SSH_CHANNEL_X11_LISTENER, sock, sock, -1, |
2758 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
0fff78ff | 2759 | 0, "X11 inet listener", 1); |
e9a17296 | 2760 | nc->single_connection = single_connection; |
665a873d | 2761 | if (*chanids != NULL) |
2762 | (*chanids)[n] = nc->self; | |
3c0ef626 | 2763 | } |
665a873d | 2764 | if (*chanids != NULL) |
2765 | (*chanids)[n] = -1; | |
3c0ef626 | 2766 | |
e9a17296 | 2767 | /* Return the display number for the DISPLAY environment variable. */ |
680cee3b | 2768 | *display_numberp = display_number; |
2769 | return (0); | |
3c0ef626 | 2770 | } |
2771 | ||
3c0ef626 | 2772 | static int |
2773 | connect_local_xsocket(u_int dnr) | |
2774 | { | |
3c0ef626 | 2775 | int sock; |
2776 | struct sockaddr_un addr; | |
3c0ef626 | 2777 | |
e9a17296 | 2778 | sock = socket(AF_UNIX, SOCK_STREAM, 0); |
2779 | if (sock < 0) | |
2780 | error("socket: %.100s", strerror(errno)); | |
2781 | memset(&addr, 0, sizeof(addr)); | |
2782 | addr.sun_family = AF_UNIX; | |
2783 | snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr); | |
2784 | if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0) | |
2785 | return sock; | |
2786 | close(sock); | |
3c0ef626 | 2787 | error("connect %.100s: %.100s", addr.sun_path, strerror(errno)); |
2788 | return -1; | |
2789 | } | |
2790 | ||
2791 | int | |
2792 | x11_connect_display(void) | |
2793 | { | |
2794 | int display_number, sock = 0; | |
2795 | const char *display; | |
2796 | char buf[1024], *cp; | |
2797 | struct addrinfo hints, *ai, *aitop; | |
2798 | char strport[NI_MAXSERV]; | |
2799 | int gaierr; | |
2800 | ||
2801 | /* Try to open a socket for the local X server. */ | |
2802 | display = getenv("DISPLAY"); | |
2803 | if (!display) { | |
2804 | error("DISPLAY not set."); | |
2805 | return -1; | |
2806 | } | |
2807 | /* | |
2808 | * Now we decode the value of the DISPLAY variable and make a | |
2809 | * connection to the real X server. | |
2810 | */ | |
2811 | ||
2812 | /* | |
2813 | * Check if it is a unix domain socket. Unix domain displays are in | |
2814 | * one of the following formats: unix:d[.s], :d[.s], ::d[.s] | |
2815 | */ | |
2816 | if (strncmp(display, "unix:", 5) == 0 || | |
2817 | display[0] == ':') { | |
2818 | /* Connect to the unix domain socket. */ | |
2819 | if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) { | |
2820 | error("Could not parse display number from DISPLAY: %.100s", | |
e9a17296 | 2821 | display); |
3c0ef626 | 2822 | return -1; |
2823 | } | |
2824 | /* Create a socket. */ | |
2825 | sock = connect_local_xsocket(display_number); | |
2826 | if (sock < 0) | |
2827 | return -1; | |
2828 | ||
2829 | /* OK, we now have a connection to the display. */ | |
2830 | return sock; | |
2831 | } | |
2832 | /* | |
2833 | * Connect to an inet socket. The DISPLAY value is supposedly | |
2834 | * hostname:d[.s], where hostname may also be numeric IP address. | |
2835 | */ | |
e9a17296 | 2836 | strlcpy(buf, display, sizeof(buf)); |
3c0ef626 | 2837 | cp = strchr(buf, ':'); |
2838 | if (!cp) { | |
2839 | error("Could not find ':' in DISPLAY: %.100s", display); | |
2840 | return -1; | |
2841 | } | |
2842 | *cp = 0; | |
2843 | /* buf now contains the host name. But first we parse the display number. */ | |
2844 | if (sscanf(cp + 1, "%d", &display_number) != 1) { | |
2845 | error("Could not parse display number from DISPLAY: %.100s", | |
e9a17296 | 2846 | display); |
3c0ef626 | 2847 | return -1; |
2848 | } | |
2849 | ||
2850 | /* Look up the host address */ | |
2851 | memset(&hints, 0, sizeof(hints)); | |
2852 | hints.ai_family = IPv4or6; | |
2853 | hints.ai_socktype = SOCK_STREAM; | |
2854 | snprintf(strport, sizeof strport, "%d", 6000 + display_number); | |
2855 | if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { | |
2856 | error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr)); | |
2857 | return -1; | |
2858 | } | |
2859 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2860 | /* Create a socket. */ | |
0fff78ff | 2861 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); |
3c0ef626 | 2862 | if (sock < 0) { |
0fff78ff | 2863 | debug2("socket: %.100s", strerror(errno)); |
3c0ef626 | 2864 | continue; |
2865 | } | |
2866 | /* Connect it to the display. */ | |
2867 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
0fff78ff | 2868 | debug2("connect %.100s port %d: %.100s", buf, |
3c0ef626 | 2869 | 6000 + display_number, strerror(errno)); |
2870 | close(sock); | |
2871 | continue; | |
2872 | } | |
2873 | /* Success */ | |
2874 | break; | |
2875 | } | |
2876 | freeaddrinfo(aitop); | |
2877 | if (!ai) { | |
2878 | error("connect %.100s port %d: %.100s", buf, 6000 + display_number, | |
2879 | strerror(errno)); | |
2880 | return -1; | |
2881 | } | |
e9a17296 | 2882 | set_nodelay(sock); |
3c0ef626 | 2883 | return sock; |
2884 | } | |
2885 | ||
2886 | /* | |
2887 | * This is called when SSH_SMSG_X11_OPEN is received. The packet contains | |
2888 | * the remote channel number. We should do whatever we want, and respond | |
2889 | * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. | |
2890 | */ | |
2891 | ||
2892 | void | |
e9a17296 | 2893 | x11_input_open(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2894 | { |
2895 | Channel *c = NULL; | |
2896 | int remote_id, sock = 0; | |
2897 | char *remote_host; | |
2898 | ||
2899 | debug("Received X11 open request."); | |
2900 | ||
2901 | remote_id = packet_get_int(); | |
2902 | ||
2903 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { | |
2904 | remote_host = packet_get_string(NULL); | |
2905 | } else { | |
2906 | remote_host = xstrdup("unknown (remote did not supply name)"); | |
2907 | } | |
e9a17296 | 2908 | packet_check_eom(); |
3c0ef626 | 2909 | |
2910 | /* Obtain a connection to the real X display. */ | |
2911 | sock = x11_connect_display(); | |
2912 | if (sock != -1) { | |
2913 | /* Allocate a channel for this connection. */ | |
2914 | c = channel_new("connected x11 socket", | |
2915 | SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0, | |
2916 | remote_host, 1); | |
e9a17296 | 2917 | c->remote_id = remote_id; |
2918 | c->force_drain = 1; | |
3c0ef626 | 2919 | } |
0fff78ff | 2920 | xfree(remote_host); |
3c0ef626 | 2921 | if (c == NULL) { |
2922 | /* Send refusal to the remote host. */ | |
2923 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2924 | packet_put_int(remote_id); | |
2925 | } else { | |
2926 | /* Send a confirmation to the remote host. */ | |
2927 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
2928 | packet_put_int(remote_id); | |
2929 | packet_put_int(c->self); | |
2930 | } | |
2931 | packet_send(); | |
2932 | } | |
2933 | ||
2934 | /* dummy protocol handler that denies SSH-1 requests (agent/x11) */ | |
2935 | void | |
e9a17296 | 2936 | deny_input_open(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2937 | { |
2938 | int rchan = packet_get_int(); | |
41b2f314 | 2939 | |
e9a17296 | 2940 | switch (type) { |
3c0ef626 | 2941 | case SSH_SMSG_AGENT_OPEN: |
2942 | error("Warning: ssh server tried agent forwarding."); | |
2943 | break; | |
2944 | case SSH_SMSG_X11_OPEN: | |
2945 | error("Warning: ssh server tried X11 forwarding."); | |
2946 | break; | |
2947 | default: | |
e9a17296 | 2948 | error("deny_input_open: type %d", type); |
3c0ef626 | 2949 | break; |
2950 | } | |
2951 | error("Warning: this is probably a break in attempt by a malicious server."); | |
2952 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2953 | packet_put_int(rchan); | |
2954 | packet_send(); | |
2955 | } | |
2956 | ||
2957 | /* | |
2958 | * Requests forwarding of X11 connections, generates fake authentication | |
2959 | * data, and enables authentication spoofing. | |
2960 | * This should be called in the client only. | |
2961 | */ | |
2962 | void | |
665a873d | 2963 | x11_request_forwarding_with_spoofing(int client_session_id, const char *disp, |
3c0ef626 | 2964 | const char *proto, const char *data) |
2965 | { | |
2966 | u_int data_len = (u_int) strlen(data) / 2; | |
665a873d | 2967 | u_int i, value; |
3c0ef626 | 2968 | char *new_data; |
2969 | int screen_number; | |
2970 | const char *cp; | |
c9f39d2c | 2971 | u_int32_t rnd = 0; |
3c0ef626 | 2972 | |
665a873d | 2973 | if (x11_saved_display == NULL) |
2974 | x11_saved_display = xstrdup(disp); | |
2975 | else if (strcmp(disp, x11_saved_display) != 0) { | |
2976 | error("x11_request_forwarding_with_spoofing: different " | |
2977 | "$DISPLAY already forwarded"); | |
2978 | return; | |
2979 | } | |
2980 | ||
2981 | cp = disp; | |
2982 | if (disp) | |
2983 | cp = strchr(disp, ':'); | |
3c0ef626 | 2984 | if (cp) |
2985 | cp = strchr(cp, '.'); | |
2986 | if (cp) | |
2987 | screen_number = atoi(cp + 1); | |
2988 | else | |
2989 | screen_number = 0; | |
2990 | ||
665a873d | 2991 | if (x11_saved_proto == NULL) { |
2992 | /* Save protocol name. */ | |
2993 | x11_saved_proto = xstrdup(proto); | |
2994 | /* | |
2995 | * Extract real authentication data and generate fake data | |
2996 | * of the same length. | |
2997 | */ | |
2998 | x11_saved_data = xmalloc(data_len); | |
2999 | x11_fake_data = xmalloc(data_len); | |
3000 | for (i = 0; i < data_len; i++) { | |
3001 | if (sscanf(data + 2 * i, "%2x", &value) != 1) | |
3002 | fatal("x11_request_forwarding: bad " | |
3003 | "authentication data: %.100s", data); | |
3004 | if (i % 4 == 0) | |
3005 | rnd = arc4random(); | |
3006 | x11_saved_data[i] = value; | |
3007 | x11_fake_data[i] = rnd & 0xff; | |
3008 | rnd >>= 8; | |
3009 | } | |
3010 | x11_saved_data_len = data_len; | |
3011 | x11_fake_data_len = data_len; | |
3012 | } | |
3c0ef626 | 3013 | |
3014 | /* Convert the fake data into hex. */ | |
665a873d | 3015 | new_data = tohex(x11_fake_data, data_len); |
3c0ef626 | 3016 | |
3017 | /* Send the request packet. */ | |
3018 | if (compat20) { | |
3019 | channel_request_start(client_session_id, "x11-req", 0); | |
3020 | packet_put_char(0); /* XXX bool single connection */ | |
3021 | } else { | |
3022 | packet_start(SSH_CMSG_X11_REQUEST_FORWARDING); | |
3023 | } | |
3024 | packet_put_cstring(proto); | |
3025 | packet_put_cstring(new_data); | |
3026 | packet_put_int(screen_number); | |
3027 | packet_send(); | |
3028 | packet_write_wait(); | |
3029 | xfree(new_data); | |
3030 | } | |
3031 | ||
3032 | ||
3033 | /* -- agent forwarding */ | |
3034 | ||
3035 | /* Sends a message to the server to request authentication fd forwarding. */ | |
3036 | ||
3037 | void | |
e9a17296 | 3038 | auth_request_forwarding(void) |
3c0ef626 | 3039 | { |
3040 | packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); | |
3041 | packet_send(); | |
3042 | packet_write_wait(); | |
3043 | } |