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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" | |
680cee3b | 42 | RCSID("$OpenBSD: channels.c,v 1.179 2002/06/26 08:55:02 markus 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" |
3c0ef626 | 57 | |
58 | ||
59 | /* -- channel core */ | |
60 | ||
61 | /* | |
62 | * Pointer to an array containing all allocated channels. The array is | |
63 | * dynamically extended as needed. | |
64 | */ | |
65 | static Channel **channels = NULL; | |
66 | ||
67 | /* | |
68 | * Size of the channel array. All slots of the array must always be | |
69 | * initialized (at least the type field); unused slots set to NULL | |
70 | */ | |
71 | static int channels_alloc = 0; | |
72 | ||
73 | /* | |
74 | * Maximum file descriptor value used in any of the channels. This is | |
75 | * updated in channel_new. | |
76 | */ | |
77 | static int channel_max_fd = 0; | |
78 | ||
79 | ||
80 | /* -- tcp forwarding */ | |
81 | ||
82 | /* | |
83 | * Data structure for storing which hosts are permitted for forward requests. | |
84 | * The local sides of any remote forwards are stored in this array to prevent | |
85 | * a corrupt remote server from accessing arbitrary TCP/IP ports on our local | |
86 | * network (which might be behind a firewall). | |
87 | */ | |
88 | typedef struct { | |
89 | char *host_to_connect; /* Connect to 'host'. */ | |
90 | u_short port_to_connect; /* Connect to 'port'. */ | |
91 | u_short listen_port; /* Remote side should listen port number. */ | |
92 | } ForwardPermission; | |
93 | ||
94 | /* List of all permitted host/port pairs to connect. */ | |
95 | static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; | |
96 | ||
97 | /* Number of permitted host/port pairs in the array. */ | |
98 | static int num_permitted_opens = 0; | |
99 | /* | |
100 | * If this is true, all opens are permitted. This is the case on the server | |
101 | * on which we have to trust the client anyway, and the user could do | |
102 | * anything after logging in anyway. | |
103 | */ | |
104 | static int all_opens_permitted = 0; | |
105 | ||
106 | ||
107 | /* -- X11 forwarding */ | |
108 | ||
109 | /* Maximum number of fake X11 displays to try. */ | |
110 | #define MAX_DISPLAYS 1000 | |
111 | ||
112 | /* Saved X11 authentication protocol name. */ | |
113 | static char *x11_saved_proto = NULL; | |
114 | ||
115 | /* Saved X11 authentication data. This is the real data. */ | |
116 | static char *x11_saved_data = NULL; | |
117 | static u_int x11_saved_data_len = 0; | |
118 | ||
119 | /* | |
120 | * Fake X11 authentication data. This is what the server will be sending us; | |
121 | * we should replace any occurrences of this by the real data. | |
122 | */ | |
123 | static char *x11_fake_data = NULL; | |
124 | static u_int x11_fake_data_len; | |
125 | ||
126 | ||
127 | /* -- agent forwarding */ | |
128 | ||
129 | #define NUM_SOCKS 10 | |
130 | ||
3c0ef626 | 131 | /* AF_UNSPEC or AF_INET or AF_INET6 */ |
132 | static int IPv4or6 = AF_UNSPEC; | |
133 | ||
134 | /* helper */ | |
135 | static void port_open_helper(Channel *c, char *rtype); | |
136 | ||
137 | /* -- channel core */ | |
138 | ||
139 | Channel * | |
140 | channel_lookup(int id) | |
141 | { | |
142 | Channel *c; | |
143 | ||
e9a17296 | 144 | if (id < 0 || id >= channels_alloc) { |
3c0ef626 | 145 | log("channel_lookup: %d: bad id", id); |
146 | return NULL; | |
147 | } | |
148 | c = channels[id]; | |
149 | if (c == NULL) { | |
150 | log("channel_lookup: %d: bad id: channel free", id); | |
151 | return NULL; | |
152 | } | |
153 | return c; | |
154 | } | |
155 | ||
156 | /* | |
157 | * Register filedescriptors for a channel, used when allocating a channel or | |
158 | * when the channel consumer/producer is ready, e.g. shell exec'd | |
159 | */ | |
160 | ||
161 | static void | |
162 | channel_register_fds(Channel *c, int rfd, int wfd, int efd, | |
163 | int extusage, int nonblock) | |
164 | { | |
165 | /* Update the maximum file descriptor value. */ | |
166 | channel_max_fd = MAX(channel_max_fd, rfd); | |
167 | channel_max_fd = MAX(channel_max_fd, wfd); | |
168 | channel_max_fd = MAX(channel_max_fd, efd); | |
169 | ||
170 | /* XXX set close-on-exec -markus */ | |
171 | ||
172 | c->rfd = rfd; | |
173 | c->wfd = wfd; | |
174 | c->sock = (rfd == wfd) ? rfd : -1; | |
175 | c->efd = efd; | |
176 | c->extended_usage = extusage; | |
177 | ||
178 | /* XXX ugly hack: nonblock is only set by the server */ | |
179 | if (nonblock && isatty(c->rfd)) { | |
180 | debug("channel %d: rfd %d isatty", c->self, c->rfd); | |
181 | c->isatty = 1; | |
182 | if (!isatty(c->wfd)) { | |
183 | error("channel %d: wfd %d is not a tty?", | |
184 | c->self, c->wfd); | |
185 | } | |
186 | } else { | |
187 | c->isatty = 0; | |
188 | } | |
189 | ||
190 | /* enable nonblocking mode */ | |
191 | if (nonblock) { | |
192 | if (rfd != -1) | |
193 | set_nonblock(rfd); | |
194 | if (wfd != -1) | |
195 | set_nonblock(wfd); | |
196 | if (efd != -1) | |
197 | set_nonblock(efd); | |
198 | } | |
199 | } | |
200 | ||
201 | /* | |
202 | * Allocate a new channel object and set its type and socket. This will cause | |
203 | * remote_name to be freed. | |
204 | */ | |
205 | ||
206 | Channel * | |
207 | channel_new(char *ctype, int type, int rfd, int wfd, int efd, | |
680cee3b | 208 | u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock) |
3c0ef626 | 209 | { |
210 | int i, found; | |
211 | Channel *c; | |
212 | ||
213 | /* Do initial allocation if this is the first call. */ | |
214 | if (channels_alloc == 0) { | |
3c0ef626 | 215 | channels_alloc = 10; |
216 | channels = xmalloc(channels_alloc * sizeof(Channel *)); | |
217 | for (i = 0; i < channels_alloc; i++) | |
218 | channels[i] = NULL; | |
219 | fatal_add_cleanup((void (*) (void *)) channel_free_all, NULL); | |
220 | } | |
221 | /* Try to find a free slot where to put the new channel. */ | |
222 | for (found = -1, i = 0; i < channels_alloc; i++) | |
223 | if (channels[i] == NULL) { | |
224 | /* Found a free slot. */ | |
225 | found = i; | |
226 | break; | |
227 | } | |
228 | if (found == -1) { | |
229 | /* There are no free slots. Take last+1 slot and expand the array. */ | |
230 | found = channels_alloc; | |
231 | channels_alloc += 10; | |
680cee3b | 232 | if (channels_alloc > 10000) |
233 | fatal("channel_new: internal error: channels_alloc %d " | |
234 | "too big.", channels_alloc); | |
3c0ef626 | 235 | debug2("channel: expanding %d", channels_alloc); |
236 | channels = xrealloc(channels, channels_alloc * sizeof(Channel *)); | |
237 | for (i = found; i < channels_alloc; i++) | |
238 | channels[i] = NULL; | |
239 | } | |
240 | /* Initialize and return new channel. */ | |
241 | c = channels[found] = xmalloc(sizeof(Channel)); | |
242 | memset(c, 0, sizeof(Channel)); | |
243 | buffer_init(&c->input); | |
244 | buffer_init(&c->output); | |
245 | buffer_init(&c->extended); | |
e9a17296 | 246 | c->ostate = CHAN_OUTPUT_OPEN; |
247 | c->istate = CHAN_INPUT_OPEN; | |
248 | c->flags = 0; | |
3c0ef626 | 249 | channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); |
250 | c->self = found; | |
251 | c->type = type; | |
252 | c->ctype = ctype; | |
253 | c->local_window = window; | |
254 | c->local_window_max = window; | |
255 | c->local_consumed = 0; | |
256 | c->local_maxpacket = maxpack; | |
257 | c->remote_id = -1; | |
258 | c->remote_name = remote_name; | |
259 | c->remote_window = 0; | |
260 | c->remote_maxpacket = 0; | |
3c0ef626 | 261 | c->force_drain = 0; |
e9a17296 | 262 | c->single_connection = 0; |
3c0ef626 | 263 | c->detach_user = NULL; |
e9a17296 | 264 | c->confirm = NULL; |
3c0ef626 | 265 | c->input_filter = NULL; |
266 | debug("channel %d: new [%s]", found, remote_name); | |
267 | return c; | |
268 | } | |
269 | ||
270 | static int | |
271 | channel_find_maxfd(void) | |
272 | { | |
273 | int i, max = 0; | |
274 | Channel *c; | |
275 | ||
276 | for (i = 0; i < channels_alloc; i++) { | |
277 | c = channels[i]; | |
278 | if (c != NULL) { | |
279 | max = MAX(max, c->rfd); | |
280 | max = MAX(max, c->wfd); | |
281 | max = MAX(max, c->efd); | |
282 | } | |
283 | } | |
284 | return max; | |
285 | } | |
286 | ||
287 | int | |
288 | channel_close_fd(int *fdp) | |
289 | { | |
290 | int ret = 0, fd = *fdp; | |
291 | ||
292 | if (fd != -1) { | |
293 | ret = close(fd); | |
294 | *fdp = -1; | |
295 | if (fd == channel_max_fd) | |
296 | channel_max_fd = channel_find_maxfd(); | |
297 | } | |
298 | return ret; | |
299 | } | |
300 | ||
301 | /* Close all channel fd/socket. */ | |
302 | ||
303 | static void | |
304 | channel_close_fds(Channel *c) | |
305 | { | |
306 | debug3("channel_close_fds: channel %d: r %d w %d e %d", | |
307 | c->self, c->rfd, c->wfd, c->efd); | |
308 | ||
309 | channel_close_fd(&c->sock); | |
310 | channel_close_fd(&c->rfd); | |
311 | channel_close_fd(&c->wfd); | |
312 | channel_close_fd(&c->efd); | |
313 | } | |
314 | ||
315 | /* Free the channel and close its fd/socket. */ | |
316 | ||
317 | void | |
318 | channel_free(Channel *c) | |
319 | { | |
320 | char *s; | |
321 | int i, n; | |
322 | ||
323 | for (n = 0, i = 0; i < channels_alloc; i++) | |
324 | if (channels[i]) | |
325 | n++; | |
326 | debug("channel_free: channel %d: %s, nchannels %d", c->self, | |
327 | c->remote_name ? c->remote_name : "???", n); | |
328 | ||
329 | s = channel_open_message(); | |
330 | debug3("channel_free: status: %s", s); | |
331 | xfree(s); | |
332 | ||
333 | if (c->sock != -1) | |
334 | shutdown(c->sock, SHUT_RDWR); | |
335 | channel_close_fds(c); | |
336 | buffer_free(&c->input); | |
337 | buffer_free(&c->output); | |
338 | buffer_free(&c->extended); | |
339 | if (c->remote_name) { | |
340 | xfree(c->remote_name); | |
341 | c->remote_name = NULL; | |
342 | } | |
343 | channels[c->self] = NULL; | |
344 | xfree(c); | |
345 | } | |
346 | ||
347 | void | |
348 | channel_free_all(void) | |
349 | { | |
350 | int i; | |
351 | ||
352 | for (i = 0; i < channels_alloc; i++) | |
353 | if (channels[i] != NULL) | |
354 | channel_free(channels[i]); | |
355 | } | |
356 | ||
357 | /* | |
358 | * Closes the sockets/fds of all channels. This is used to close extra file | |
359 | * descriptors after a fork. | |
360 | */ | |
361 | ||
362 | void | |
e9a17296 | 363 | channel_close_all(void) |
3c0ef626 | 364 | { |
365 | int i; | |
366 | ||
367 | for (i = 0; i < channels_alloc; i++) | |
368 | if (channels[i] != NULL) | |
369 | channel_close_fds(channels[i]); | |
370 | } | |
371 | ||
372 | /* | |
373 | * Stop listening to channels. | |
374 | */ | |
375 | ||
376 | void | |
377 | channel_stop_listening(void) | |
378 | { | |
379 | int i; | |
380 | Channel *c; | |
381 | ||
382 | for (i = 0; i < channels_alloc; i++) { | |
383 | c = channels[i]; | |
384 | if (c != NULL) { | |
385 | switch (c->type) { | |
386 | case SSH_CHANNEL_AUTH_SOCKET: | |
387 | case SSH_CHANNEL_PORT_LISTENER: | |
388 | case SSH_CHANNEL_RPORT_LISTENER: | |
389 | case SSH_CHANNEL_X11_LISTENER: | |
390 | channel_close_fd(&c->sock); | |
391 | channel_free(c); | |
392 | break; | |
393 | } | |
394 | } | |
395 | } | |
396 | } | |
397 | ||
398 | /* | |
399 | * Returns true if no channel has too much buffered data, and false if one or | |
400 | * more channel is overfull. | |
401 | */ | |
402 | ||
403 | int | |
e9a17296 | 404 | channel_not_very_much_buffered_data(void) |
3c0ef626 | 405 | { |
406 | u_int i; | |
407 | Channel *c; | |
408 | ||
409 | for (i = 0; i < channels_alloc; i++) { | |
410 | c = channels[i]; | |
411 | if (c != NULL && c->type == SSH_CHANNEL_OPEN) { | |
412 | #if 0 | |
413 | if (!compat20 && | |
414 | buffer_len(&c->input) > packet_get_maxsize()) { | |
415 | debug("channel %d: big input buffer %d", | |
416 | c->self, buffer_len(&c->input)); | |
417 | return 0; | |
418 | } | |
419 | #endif | |
420 | if (buffer_len(&c->output) > packet_get_maxsize()) { | |
421 | debug("channel %d: big output buffer %d > %d", | |
422 | c->self, buffer_len(&c->output), | |
423 | packet_get_maxsize()); | |
424 | return 0; | |
425 | } | |
426 | } | |
427 | } | |
428 | return 1; | |
429 | } | |
430 | ||
431 | /* Returns true if any channel is still open. */ | |
432 | ||
433 | int | |
e9a17296 | 434 | channel_still_open(void) |
3c0ef626 | 435 | { |
436 | int i; | |
437 | Channel *c; | |
438 | ||
439 | for (i = 0; i < channels_alloc; i++) { | |
440 | c = channels[i]; | |
441 | if (c == NULL) | |
442 | continue; | |
443 | switch (c->type) { | |
444 | case SSH_CHANNEL_X11_LISTENER: | |
445 | case SSH_CHANNEL_PORT_LISTENER: | |
446 | case SSH_CHANNEL_RPORT_LISTENER: | |
447 | case SSH_CHANNEL_CLOSED: | |
448 | case SSH_CHANNEL_AUTH_SOCKET: | |
449 | case SSH_CHANNEL_DYNAMIC: | |
450 | case SSH_CHANNEL_CONNECTING: | |
451 | case SSH_CHANNEL_ZOMBIE: | |
452 | continue; | |
453 | case SSH_CHANNEL_LARVAL: | |
454 | if (!compat20) | |
455 | fatal("cannot happen: SSH_CHANNEL_LARVAL"); | |
456 | continue; | |
457 | case SSH_CHANNEL_OPENING: | |
458 | case SSH_CHANNEL_OPEN: | |
459 | case SSH_CHANNEL_X11_OPEN: | |
460 | return 1; | |
461 | case SSH_CHANNEL_INPUT_DRAINING: | |
462 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
463 | if (!compat13) | |
464 | fatal("cannot happen: OUT_DRAIN"); | |
465 | return 1; | |
466 | default: | |
467 | fatal("channel_still_open: bad channel type %d", c->type); | |
468 | /* NOTREACHED */ | |
469 | } | |
470 | } | |
471 | return 0; | |
472 | } | |
473 | ||
474 | /* Returns the id of an open channel suitable for keepaliving */ | |
475 | ||
476 | int | |
e9a17296 | 477 | channel_find_open(void) |
3c0ef626 | 478 | { |
479 | int i; | |
480 | Channel *c; | |
481 | ||
482 | for (i = 0; i < channels_alloc; i++) { | |
483 | c = channels[i]; | |
484 | if (c == NULL) | |
485 | continue; | |
486 | switch (c->type) { | |
487 | case SSH_CHANNEL_CLOSED: | |
488 | case SSH_CHANNEL_DYNAMIC: | |
489 | case SSH_CHANNEL_X11_LISTENER: | |
490 | case SSH_CHANNEL_PORT_LISTENER: | |
491 | case SSH_CHANNEL_RPORT_LISTENER: | |
492 | case SSH_CHANNEL_OPENING: | |
493 | case SSH_CHANNEL_CONNECTING: | |
494 | case SSH_CHANNEL_ZOMBIE: | |
495 | continue; | |
496 | case SSH_CHANNEL_LARVAL: | |
497 | case SSH_CHANNEL_AUTH_SOCKET: | |
498 | case SSH_CHANNEL_OPEN: | |
499 | case SSH_CHANNEL_X11_OPEN: | |
500 | return i; | |
501 | case SSH_CHANNEL_INPUT_DRAINING: | |
502 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
503 | if (!compat13) | |
504 | fatal("cannot happen: OUT_DRAIN"); | |
505 | return i; | |
506 | default: | |
507 | fatal("channel_find_open: bad channel type %d", c->type); | |
508 | /* NOTREACHED */ | |
509 | } | |
510 | } | |
511 | return -1; | |
512 | } | |
513 | ||
514 | ||
515 | /* | |
516 | * Returns a message describing the currently open forwarded connections, | |
517 | * suitable for sending to the client. The message contains crlf pairs for | |
518 | * newlines. | |
519 | */ | |
520 | ||
521 | char * | |
e9a17296 | 522 | channel_open_message(void) |
3c0ef626 | 523 | { |
524 | Buffer buffer; | |
525 | Channel *c; | |
526 | char buf[1024], *cp; | |
527 | int i; | |
528 | ||
529 | buffer_init(&buffer); | |
530 | snprintf(buf, sizeof buf, "The following connections are open:\r\n"); | |
531 | buffer_append(&buffer, buf, strlen(buf)); | |
532 | for (i = 0; i < channels_alloc; i++) { | |
533 | c = channels[i]; | |
534 | if (c == NULL) | |
535 | continue; | |
536 | switch (c->type) { | |
537 | case SSH_CHANNEL_X11_LISTENER: | |
538 | case SSH_CHANNEL_PORT_LISTENER: | |
539 | case SSH_CHANNEL_RPORT_LISTENER: | |
540 | case SSH_CHANNEL_CLOSED: | |
541 | case SSH_CHANNEL_AUTH_SOCKET: | |
542 | case SSH_CHANNEL_ZOMBIE: | |
543 | continue; | |
544 | case SSH_CHANNEL_LARVAL: | |
545 | case SSH_CHANNEL_OPENING: | |
546 | case SSH_CHANNEL_CONNECTING: | |
547 | case SSH_CHANNEL_DYNAMIC: | |
548 | case SSH_CHANNEL_OPEN: | |
549 | case SSH_CHANNEL_X11_OPEN: | |
550 | case SSH_CHANNEL_INPUT_DRAINING: | |
551 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
552 | snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n", | |
553 | c->self, c->remote_name, | |
554 | c->type, c->remote_id, | |
555 | c->istate, buffer_len(&c->input), | |
556 | c->ostate, buffer_len(&c->output), | |
557 | c->rfd, c->wfd); | |
558 | buffer_append(&buffer, buf, strlen(buf)); | |
559 | continue; | |
560 | default: | |
561 | fatal("channel_open_message: bad channel type %d", c->type); | |
562 | /* NOTREACHED */ | |
563 | } | |
564 | } | |
565 | buffer_append(&buffer, "\0", 1); | |
566 | cp = xstrdup(buffer_ptr(&buffer)); | |
567 | buffer_free(&buffer); | |
568 | return cp; | |
569 | } | |
570 | ||
571 | void | |
572 | channel_send_open(int id) | |
573 | { | |
574 | Channel *c = channel_lookup(id); | |
575 | if (c == NULL) { | |
576 | log("channel_send_open: %d: bad id", id); | |
577 | return; | |
578 | } | |
579 | debug("send channel open %d", id); | |
580 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
581 | packet_put_cstring(c->ctype); | |
582 | packet_put_int(c->self); | |
583 | packet_put_int(c->local_window); | |
584 | packet_put_int(c->local_maxpacket); | |
585 | packet_send(); | |
586 | } | |
587 | ||
588 | void | |
e9a17296 | 589 | channel_request_start(int local_id, char *service, int wantconfirm) |
3c0ef626 | 590 | { |
e9a17296 | 591 | Channel *c = channel_lookup(local_id); |
3c0ef626 | 592 | if (c == NULL) { |
e9a17296 | 593 | log("channel_request_start: %d: unknown channel id", local_id); |
3c0ef626 | 594 | return; |
595 | } | |
e9a17296 | 596 | debug("channel request %d: %s", local_id, service) ; |
3c0ef626 | 597 | packet_start(SSH2_MSG_CHANNEL_REQUEST); |
598 | packet_put_int(c->remote_id); | |
599 | packet_put_cstring(service); | |
600 | packet_put_char(wantconfirm); | |
601 | } | |
602 | void | |
e9a17296 | 603 | channel_register_confirm(int id, channel_callback_fn *fn) |
3c0ef626 | 604 | { |
605 | Channel *c = channel_lookup(id); | |
606 | if (c == NULL) { | |
e9a17296 | 607 | log("channel_register_comfirm: %d: bad id", id); |
3c0ef626 | 608 | return; |
609 | } | |
e9a17296 | 610 | c->confirm = fn; |
3c0ef626 | 611 | } |
612 | void | |
613 | channel_register_cleanup(int id, channel_callback_fn *fn) | |
614 | { | |
615 | Channel *c = channel_lookup(id); | |
616 | if (c == NULL) { | |
617 | log("channel_register_cleanup: %d: bad id", id); | |
618 | return; | |
619 | } | |
620 | c->detach_user = fn; | |
621 | } | |
622 | void | |
623 | channel_cancel_cleanup(int id) | |
624 | { | |
625 | Channel *c = channel_lookup(id); | |
626 | if (c == NULL) { | |
627 | log("channel_cancel_cleanup: %d: bad id", id); | |
628 | return; | |
629 | } | |
630 | c->detach_user = NULL; | |
631 | } | |
632 | void | |
633 | channel_register_filter(int id, channel_filter_fn *fn) | |
634 | { | |
635 | Channel *c = channel_lookup(id); | |
636 | if (c == NULL) { | |
637 | log("channel_register_filter: %d: bad id", id); | |
638 | return; | |
639 | } | |
640 | c->input_filter = fn; | |
641 | } | |
642 | ||
643 | void | |
644 | channel_set_fds(int id, int rfd, int wfd, int efd, | |
e9a17296 | 645 | int extusage, int nonblock, u_int window_max) |
3c0ef626 | 646 | { |
647 | Channel *c = channel_lookup(id); | |
648 | if (c == NULL || c->type != SSH_CHANNEL_LARVAL) | |
649 | fatal("channel_activate for non-larval channel %d.", id); | |
650 | channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); | |
651 | c->type = SSH_CHANNEL_OPEN; | |
e9a17296 | 652 | c->local_window = c->local_window_max = window_max; |
3c0ef626 | 653 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); |
654 | packet_put_int(c->remote_id); | |
655 | packet_put_int(c->local_window); | |
656 | packet_send(); | |
657 | } | |
658 | ||
659 | /* | |
660 | * 'channel_pre*' are called just before select() to add any bits relevant to | |
661 | * channels in the select bitmasks. | |
662 | */ | |
663 | /* | |
664 | * 'channel_post*': perform any appropriate operations for channels which | |
665 | * have events pending. | |
666 | */ | |
667 | typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset); | |
668 | chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; | |
669 | chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; | |
670 | ||
671 | static void | |
672 | channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
673 | { | |
674 | FD_SET(c->sock, readset); | |
675 | } | |
676 | ||
677 | static void | |
678 | channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset) | |
679 | { | |
680 | debug3("channel %d: waiting for connection", c->self); | |
681 | FD_SET(c->sock, writeset); | |
682 | } | |
683 | ||
684 | static void | |
685 | channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
686 | { | |
687 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
688 | FD_SET(c->sock, readset); | |
689 | if (buffer_len(&c->output) > 0) | |
690 | FD_SET(c->sock, writeset); | |
691 | } | |
692 | ||
693 | static void | |
e9a17296 | 694 | channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset) |
3c0ef626 | 695 | { |
e9a17296 | 696 | u_int limit = compat20 ? c->remote_window : packet_get_maxsize(); |
3c0ef626 | 697 | |
3c0ef626 | 698 | if (c->istate == CHAN_INPUT_OPEN && |
e9a17296 | 699 | limit > 0 && |
700 | buffer_len(&c->input) < limit) | |
3c0ef626 | 701 | FD_SET(c->rfd, readset); |
702 | if (c->ostate == CHAN_OUTPUT_OPEN || | |
703 | c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
704 | if (buffer_len(&c->output) > 0) { | |
705 | FD_SET(c->wfd, writeset); | |
706 | } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
700318f3 | 707 | if (CHANNEL_EFD_OUTPUT_ACTIVE(c)) |
f5799ae1 | 708 | debug2("channel %d: obuf_empty delayed efd %d/(%d)", |
709 | c->self, c->efd, buffer_len(&c->extended)); | |
700318f3 | 710 | else |
711 | chan_obuf_empty(c); | |
3c0ef626 | 712 | } |
713 | } | |
714 | /** XXX check close conditions, too */ | |
e9a17296 | 715 | if (compat20 && c->efd != -1) { |
3c0ef626 | 716 | if (c->extended_usage == CHAN_EXTENDED_WRITE && |
717 | buffer_len(&c->extended) > 0) | |
718 | FD_SET(c->efd, writeset); | |
700318f3 | 719 | else if (!(c->flags & CHAN_EOF_SENT) && |
720 | c->extended_usage == CHAN_EXTENDED_READ && | |
3c0ef626 | 721 | buffer_len(&c->extended) < c->remote_window) |
722 | FD_SET(c->efd, readset); | |
723 | } | |
724 | } | |
725 | ||
726 | static void | |
727 | channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
728 | { | |
729 | if (buffer_len(&c->input) == 0) { | |
730 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
731 | packet_put_int(c->remote_id); | |
732 | packet_send(); | |
733 | c->type = SSH_CHANNEL_CLOSED; | |
734 | debug("channel %d: closing after input drain.", c->self); | |
735 | } | |
736 | } | |
737 | ||
738 | static void | |
739 | channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
740 | { | |
741 | if (buffer_len(&c->output) == 0) | |
742 | chan_mark_dead(c); | |
743 | else | |
744 | FD_SET(c->sock, writeset); | |
745 | } | |
746 | ||
747 | /* | |
748 | * This is a special state for X11 authentication spoofing. An opened X11 | |
749 | * connection (when authentication spoofing is being done) remains in this | |
750 | * state until the first packet has been completely read. The authentication | |
751 | * data in that packet is then substituted by the real data if it matches the | |
752 | * fake data, and the channel is put into normal mode. | |
753 | * XXX All this happens at the client side. | |
754 | * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok | |
755 | */ | |
756 | static int | |
757 | x11_open_helper(Buffer *b) | |
758 | { | |
759 | u_char *ucp; | |
760 | u_int proto_len, data_len; | |
761 | ||
762 | /* Check if the fixed size part of the packet is in buffer. */ | |
763 | if (buffer_len(b) < 12) | |
764 | return 0; | |
765 | ||
766 | /* Parse the lengths of variable-length fields. */ | |
e9a17296 | 767 | ucp = buffer_ptr(b); |
3c0ef626 | 768 | if (ucp[0] == 0x42) { /* Byte order MSB first. */ |
769 | proto_len = 256 * ucp[6] + ucp[7]; | |
770 | data_len = 256 * ucp[8] + ucp[9]; | |
771 | } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ | |
772 | proto_len = ucp[6] + 256 * ucp[7]; | |
773 | data_len = ucp[8] + 256 * ucp[9]; | |
774 | } else { | |
775 | debug("Initial X11 packet contains bad byte order byte: 0x%x", | |
e9a17296 | 776 | ucp[0]); |
3c0ef626 | 777 | return -1; |
778 | } | |
779 | ||
780 | /* Check if the whole packet is in buffer. */ | |
781 | if (buffer_len(b) < | |
782 | 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) | |
783 | return 0; | |
784 | ||
785 | /* Check if authentication protocol matches. */ | |
786 | if (proto_len != strlen(x11_saved_proto) || | |
787 | memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { | |
788 | debug("X11 connection uses different authentication protocol."); | |
789 | return -1; | |
790 | } | |
791 | /* Check if authentication data matches our fake data. */ | |
792 | if (data_len != x11_fake_data_len || | |
793 | memcmp(ucp + 12 + ((proto_len + 3) & ~3), | |
794 | x11_fake_data, x11_fake_data_len) != 0) { | |
795 | debug("X11 auth data does not match fake data."); | |
796 | return -1; | |
797 | } | |
798 | /* Check fake data length */ | |
799 | if (x11_fake_data_len != x11_saved_data_len) { | |
800 | error("X11 fake_data_len %d != saved_data_len %d", | |
801 | x11_fake_data_len, x11_saved_data_len); | |
802 | return -1; | |
803 | } | |
804 | /* | |
805 | * Received authentication protocol and data match | |
806 | * our fake data. Substitute the fake data with real | |
807 | * data. | |
808 | */ | |
809 | memcpy(ucp + 12 + ((proto_len + 3) & ~3), | |
810 | x11_saved_data, x11_saved_data_len); | |
811 | return 1; | |
812 | } | |
813 | ||
814 | static void | |
815 | channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
816 | { | |
817 | int ret = x11_open_helper(&c->output); | |
818 | if (ret == 1) { | |
819 | /* Start normal processing for the channel. */ | |
820 | c->type = SSH_CHANNEL_OPEN; | |
821 | channel_pre_open_13(c, readset, writeset); | |
822 | } else if (ret == -1) { | |
823 | /* | |
824 | * We have received an X11 connection that has bad | |
825 | * authentication information. | |
826 | */ | |
827 | log("X11 connection rejected because of wrong authentication."); | |
828 | buffer_clear(&c->input); | |
829 | buffer_clear(&c->output); | |
830 | channel_close_fd(&c->sock); | |
831 | c->sock = -1; | |
832 | c->type = SSH_CHANNEL_CLOSED; | |
833 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
834 | packet_put_int(c->remote_id); | |
835 | packet_send(); | |
836 | } | |
837 | } | |
838 | ||
839 | static void | |
840 | channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset) | |
841 | { | |
842 | int ret = x11_open_helper(&c->output); | |
843 | ||
844 | /* c->force_drain = 1; */ | |
845 | ||
846 | if (ret == 1) { | |
847 | c->type = SSH_CHANNEL_OPEN; | |
e9a17296 | 848 | channel_pre_open(c, readset, writeset); |
3c0ef626 | 849 | } else if (ret == -1) { |
e9a17296 | 850 | log("X11 connection rejected because of wrong authentication."); |
3c0ef626 | 851 | debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); |
e9a17296 | 852 | chan_read_failed(c); |
853 | buffer_clear(&c->input); | |
854 | chan_ibuf_empty(c); | |
855 | buffer_clear(&c->output); | |
856 | /* for proto v1, the peer will send an IEOF */ | |
857 | if (compat20) | |
858 | chan_write_failed(c); | |
859 | else | |
860 | c->type = SSH_CHANNEL_OPEN; | |
3c0ef626 | 861 | debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); |
862 | } | |
863 | } | |
864 | ||
865 | /* try to decode a socks4 header */ | |
866 | static int | |
867 | channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset) | |
868 | { | |
869 | u_char *p, *host; | |
870 | int len, have, i, found; | |
e9a17296 | 871 | char username[256]; |
3c0ef626 | 872 | struct { |
873 | u_int8_t version; | |
874 | u_int8_t command; | |
875 | u_int16_t dest_port; | |
876 | struct in_addr dest_addr; | |
877 | } s4_req, s4_rsp; | |
878 | ||
879 | debug2("channel %d: decode socks4", c->self); | |
880 | ||
881 | have = buffer_len(&c->input); | |
882 | len = sizeof(s4_req); | |
883 | if (have < len) | |
884 | return 0; | |
885 | p = buffer_ptr(&c->input); | |
886 | for (found = 0, i = len; i < have; i++) { | |
887 | if (p[i] == '\0') { | |
888 | found = 1; | |
889 | break; | |
890 | } | |
891 | if (i > 1024) { | |
892 | /* the peer is probably sending garbage */ | |
893 | debug("channel %d: decode socks4: too long", | |
894 | c->self); | |
895 | return -1; | |
896 | } | |
897 | } | |
898 | if (!found) | |
899 | return 0; | |
900 | buffer_get(&c->input, (char *)&s4_req.version, 1); | |
901 | buffer_get(&c->input, (char *)&s4_req.command, 1); | |
902 | buffer_get(&c->input, (char *)&s4_req.dest_port, 2); | |
903 | buffer_get(&c->input, (char *)&s4_req.dest_addr, 4); | |
904 | have = buffer_len(&c->input); | |
905 | p = buffer_ptr(&c->input); | |
906 | len = strlen(p); | |
907 | debug2("channel %d: decode socks4: user %s/%d", c->self, p, len); | |
908 | if (len > have) | |
909 | fatal("channel %d: decode socks4: len %d > have %d", | |
910 | c->self, len, have); | |
911 | strlcpy(username, p, sizeof(username)); | |
912 | buffer_consume(&c->input, len); | |
913 | buffer_consume(&c->input, 1); /* trailing '\0' */ | |
914 | ||
915 | host = inet_ntoa(s4_req.dest_addr); | |
916 | strlcpy(c->path, host, sizeof(c->path)); | |
917 | c->host_port = ntohs(s4_req.dest_port); | |
e9a17296 | 918 | |
3c0ef626 | 919 | debug("channel %d: dynamic request: socks4 host %s port %u command %u", |
920 | c->self, host, c->host_port, s4_req.command); | |
921 | ||
922 | if (s4_req.command != 1) { | |
923 | debug("channel %d: cannot handle: socks4 cn %d", | |
924 | c->self, s4_req.command); | |
925 | return -1; | |
926 | } | |
927 | s4_rsp.version = 0; /* vn: 0 for reply */ | |
928 | s4_rsp.command = 90; /* cd: req granted */ | |
929 | s4_rsp.dest_port = 0; /* ignored */ | |
930 | s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */ | |
931 | buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp)); | |
932 | return 1; | |
933 | } | |
934 | ||
935 | /* dynamic port forwarding */ | |
936 | static void | |
937 | channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset) | |
938 | { | |
939 | u_char *p; | |
940 | int have, ret; | |
941 | ||
942 | have = buffer_len(&c->input); | |
943 | c->delayed = 0; | |
944 | debug2("channel %d: pre_dynamic: have %d", c->self, have); | |
945 | /* buffer_dump(&c->input); */ | |
946 | /* check if the fixed size part of the packet is in buffer. */ | |
947 | if (have < 4) { | |
948 | /* need more */ | |
949 | FD_SET(c->sock, readset); | |
950 | return; | |
951 | } | |
952 | /* try to guess the protocol */ | |
953 | p = buffer_ptr(&c->input); | |
954 | switch (p[0]) { | |
955 | case 0x04: | |
956 | ret = channel_decode_socks4(c, readset, writeset); | |
957 | break; | |
958 | default: | |
959 | ret = -1; | |
960 | break; | |
961 | } | |
962 | if (ret < 0) { | |
963 | chan_mark_dead(c); | |
964 | } else if (ret == 0) { | |
965 | debug2("channel %d: pre_dynamic: need more", c->self); | |
966 | /* need more */ | |
967 | FD_SET(c->sock, readset); | |
968 | } else { | |
969 | /* switch to the next state */ | |
970 | c->type = SSH_CHANNEL_OPENING; | |
971 | port_open_helper(c, "direct-tcpip"); | |
972 | } | |
973 | } | |
974 | ||
975 | /* This is our fake X11 server socket. */ | |
976 | static void | |
977 | channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
978 | { | |
979 | Channel *nc; | |
980 | struct sockaddr addr; | |
981 | int newsock; | |
982 | socklen_t addrlen; | |
983 | char buf[16384], *remote_ipaddr; | |
984 | int remote_port; | |
985 | ||
986 | if (FD_ISSET(c->sock, readset)) { | |
987 | debug("X11 connection requested."); | |
988 | addrlen = sizeof(addr); | |
989 | newsock = accept(c->sock, &addr, &addrlen); | |
e9a17296 | 990 | if (c->single_connection) { |
991 | debug("single_connection: closing X11 listener."); | |
992 | channel_close_fd(&c->sock); | |
993 | chan_mark_dead(c); | |
994 | } | |
3c0ef626 | 995 | if (newsock < 0) { |
996 | error("accept: %.100s", strerror(errno)); | |
997 | return; | |
998 | } | |
e9a17296 | 999 | set_nodelay(newsock); |
3c0ef626 | 1000 | remote_ipaddr = get_peer_ipaddr(newsock); |
1001 | remote_port = get_peer_port(newsock); | |
1002 | snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", | |
1003 | remote_ipaddr, remote_port); | |
1004 | ||
1005 | nc = channel_new("accepted x11 socket", | |
1006 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
1007 | c->local_window_max, c->local_maxpacket, | |
1008 | 0, xstrdup(buf), 1); | |
3c0ef626 | 1009 | if (compat20) { |
1010 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1011 | packet_put_cstring("x11"); | |
1012 | packet_put_int(nc->self); | |
e9a17296 | 1013 | packet_put_int(nc->local_window_max); |
1014 | packet_put_int(nc->local_maxpacket); | |
3c0ef626 | 1015 | /* originator ipaddr and port */ |
1016 | packet_put_cstring(remote_ipaddr); | |
1017 | if (datafellows & SSH_BUG_X11FWD) { | |
1018 | debug("ssh2 x11 bug compat mode"); | |
1019 | } else { | |
1020 | packet_put_int(remote_port); | |
1021 | } | |
1022 | packet_send(); | |
1023 | } else { | |
1024 | packet_start(SSH_SMSG_X11_OPEN); | |
1025 | packet_put_int(nc->self); | |
1026 | if (packet_get_protocol_flags() & | |
1027 | SSH_PROTOFLAG_HOST_IN_FWD_OPEN) | |
1028 | packet_put_cstring(buf); | |
1029 | packet_send(); | |
1030 | } | |
1031 | xfree(remote_ipaddr); | |
1032 | } | |
1033 | } | |
1034 | ||
1035 | static void | |
1036 | port_open_helper(Channel *c, char *rtype) | |
1037 | { | |
1038 | int direct; | |
1039 | char buf[1024]; | |
1040 | char *remote_ipaddr = get_peer_ipaddr(c->sock); | |
1041 | u_short remote_port = get_peer_port(c->sock); | |
1042 | ||
1043 | direct = (strcmp(rtype, "direct-tcpip") == 0); | |
1044 | ||
1045 | snprintf(buf, sizeof buf, | |
1046 | "%s: listening port %d for %.100s port %d, " | |
1047 | "connect from %.200s port %d", | |
1048 | rtype, c->listening_port, c->path, c->host_port, | |
1049 | remote_ipaddr, remote_port); | |
1050 | ||
1051 | xfree(c->remote_name); | |
1052 | c->remote_name = xstrdup(buf); | |
1053 | ||
1054 | if (compat20) { | |
1055 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1056 | packet_put_cstring(rtype); | |
1057 | packet_put_int(c->self); | |
1058 | packet_put_int(c->local_window_max); | |
1059 | packet_put_int(c->local_maxpacket); | |
1060 | if (direct) { | |
1061 | /* target host, port */ | |
1062 | packet_put_cstring(c->path); | |
1063 | packet_put_int(c->host_port); | |
1064 | } else { | |
1065 | /* listen address, port */ | |
1066 | packet_put_cstring(c->path); | |
1067 | packet_put_int(c->listening_port); | |
1068 | } | |
1069 | /* originator host and port */ | |
1070 | packet_put_cstring(remote_ipaddr); | |
1071 | packet_put_int(remote_port); | |
1072 | packet_send(); | |
1073 | } else { | |
1074 | packet_start(SSH_MSG_PORT_OPEN); | |
1075 | packet_put_int(c->self); | |
1076 | packet_put_cstring(c->path); | |
1077 | packet_put_int(c->host_port); | |
1078 | if (packet_get_protocol_flags() & | |
1079 | SSH_PROTOFLAG_HOST_IN_FWD_OPEN) | |
1080 | packet_put_cstring(c->remote_name); | |
1081 | packet_send(); | |
1082 | } | |
1083 | xfree(remote_ipaddr); | |
1084 | } | |
1085 | ||
1086 | /* | |
1087 | * This socket is listening for connections to a forwarded TCP/IP port. | |
1088 | */ | |
1089 | static void | |
1090 | channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
1091 | { | |
1092 | Channel *nc; | |
1093 | struct sockaddr addr; | |
1094 | int newsock, nextstate; | |
1095 | socklen_t addrlen; | |
1096 | char *rtype; | |
1097 | ||
1098 | if (FD_ISSET(c->sock, readset)) { | |
1099 | debug("Connection to port %d forwarding " | |
1100 | "to %.100s port %d requested.", | |
1101 | c->listening_port, c->path, c->host_port); | |
1102 | ||
1103 | if (c->type == SSH_CHANNEL_RPORT_LISTENER) { | |
1104 | nextstate = SSH_CHANNEL_OPENING; | |
1105 | rtype = "forwarded-tcpip"; | |
1106 | } else { | |
1107 | if (c->host_port == 0) { | |
1108 | nextstate = SSH_CHANNEL_DYNAMIC; | |
1109 | rtype = "dynamic-tcpip"; | |
1110 | } else { | |
1111 | nextstate = SSH_CHANNEL_OPENING; | |
1112 | rtype = "direct-tcpip"; | |
1113 | } | |
1114 | } | |
1115 | ||
1116 | addrlen = sizeof(addr); | |
1117 | newsock = accept(c->sock, &addr, &addrlen); | |
1118 | if (newsock < 0) { | |
1119 | error("accept: %.100s", strerror(errno)); | |
1120 | return; | |
1121 | } | |
e9a17296 | 1122 | set_nodelay(newsock); |
3c0ef626 | 1123 | nc = channel_new(rtype, |
1124 | nextstate, newsock, newsock, -1, | |
1125 | c->local_window_max, c->local_maxpacket, | |
1126 | 0, xstrdup(rtype), 1); | |
3c0ef626 | 1127 | nc->listening_port = c->listening_port; |
1128 | nc->host_port = c->host_port; | |
1129 | strlcpy(nc->path, c->path, sizeof(nc->path)); | |
1130 | ||
1131 | if (nextstate == SSH_CHANNEL_DYNAMIC) { | |
1132 | /* | |
1133 | * do not call the channel_post handler until | |
1134 | * this flag has been reset by a pre-handler. | |
1135 | * otherwise the FD_ISSET calls might overflow | |
1136 | */ | |
1137 | nc->delayed = 1; | |
1138 | } else { | |
1139 | port_open_helper(nc, rtype); | |
1140 | } | |
1141 | } | |
1142 | } | |
1143 | ||
1144 | /* | |
1145 | * This is the authentication agent socket listening for connections from | |
1146 | * clients. | |
1147 | */ | |
1148 | static void | |
1149 | channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
1150 | { | |
1151 | Channel *nc; | |
1152 | char *name; | |
1153 | int newsock; | |
1154 | struct sockaddr addr; | |
1155 | socklen_t addrlen; | |
1156 | ||
1157 | if (FD_ISSET(c->sock, readset)) { | |
1158 | addrlen = sizeof(addr); | |
1159 | newsock = accept(c->sock, &addr, &addrlen); | |
1160 | if (newsock < 0) { | |
1161 | error("accept from auth socket: %.100s", strerror(errno)); | |
1162 | return; | |
1163 | } | |
1164 | name = xstrdup("accepted auth socket"); | |
1165 | nc = channel_new("accepted auth socket", | |
1166 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
1167 | c->local_window_max, c->local_maxpacket, | |
1168 | 0, name, 1); | |
3c0ef626 | 1169 | if (compat20) { |
1170 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1171 | packet_put_cstring("auth-agent@openssh.com"); | |
1172 | packet_put_int(nc->self); | |
1173 | packet_put_int(c->local_window_max); | |
1174 | packet_put_int(c->local_maxpacket); | |
1175 | } else { | |
1176 | packet_start(SSH_SMSG_AGENT_OPEN); | |
1177 | packet_put_int(nc->self); | |
1178 | } | |
1179 | packet_send(); | |
1180 | } | |
1181 | } | |
1182 | ||
1183 | static void | |
1184 | channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset) | |
1185 | { | |
1186 | int err = 0; | |
1187 | socklen_t sz = sizeof(err); | |
1188 | ||
1189 | if (FD_ISSET(c->sock, writeset)) { | |
e9a17296 | 1190 | if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) { |
3c0ef626 | 1191 | err = errno; |
1192 | error("getsockopt SO_ERROR failed"); | |
1193 | } | |
1194 | if (err == 0) { | |
1195 | debug("channel %d: connected", c->self); | |
1196 | c->type = SSH_CHANNEL_OPEN; | |
1197 | if (compat20) { | |
1198 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1199 | packet_put_int(c->remote_id); | |
1200 | packet_put_int(c->self); | |
1201 | packet_put_int(c->local_window); | |
1202 | packet_put_int(c->local_maxpacket); | |
1203 | } else { | |
1204 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1205 | packet_put_int(c->remote_id); | |
1206 | packet_put_int(c->self); | |
1207 | } | |
1208 | } else { | |
1209 | debug("channel %d: not connected: %s", | |
1210 | c->self, strerror(err)); | |
1211 | if (compat20) { | |
1212 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); | |
1213 | packet_put_int(c->remote_id); | |
1214 | packet_put_int(SSH2_OPEN_CONNECT_FAILED); | |
1215 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
1216 | packet_put_cstring(strerror(err)); | |
1217 | packet_put_cstring(""); | |
1218 | } | |
1219 | } else { | |
1220 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1221 | packet_put_int(c->remote_id); | |
1222 | } | |
1223 | chan_mark_dead(c); | |
1224 | } | |
1225 | packet_send(); | |
1226 | } | |
1227 | } | |
1228 | ||
1229 | static int | |
1230 | channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) | |
1231 | { | |
1232 | char buf[16*1024]; | |
1233 | int len; | |
1234 | ||
1235 | if (c->rfd != -1 && | |
1236 | FD_ISSET(c->rfd, readset)) { | |
1237 | len = read(c->rfd, buf, sizeof(buf)); | |
1238 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1239 | return 1; | |
1240 | if (len <= 0) { | |
1241 | debug("channel %d: read<=0 rfd %d len %d", | |
1242 | c->self, c->rfd, len); | |
1243 | if (c->type != SSH_CHANNEL_OPEN) { | |
1244 | debug("channel %d: not open", c->self); | |
1245 | chan_mark_dead(c); | |
1246 | return -1; | |
1247 | } else if (compat13) { | |
e9a17296 | 1248 | buffer_clear(&c->output); |
3c0ef626 | 1249 | c->type = SSH_CHANNEL_INPUT_DRAINING; |
1250 | debug("channel %d: input draining.", c->self); | |
1251 | } else { | |
1252 | chan_read_failed(c); | |
1253 | } | |
1254 | return -1; | |
1255 | } | |
e9a17296 | 1256 | if (c->input_filter != NULL) { |
3c0ef626 | 1257 | if (c->input_filter(c, buf, len) == -1) { |
1258 | debug("channel %d: filter stops", c->self); | |
1259 | chan_read_failed(c); | |
1260 | } | |
1261 | } else { | |
1262 | buffer_append(&c->input, buf, len); | |
1263 | } | |
1264 | } | |
1265 | return 1; | |
1266 | } | |
1267 | static int | |
1268 | channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) | |
1269 | { | |
1270 | struct termios tio; | |
1271 | u_char *data; | |
1272 | u_int dlen; | |
1273 | int len; | |
1274 | ||
1275 | /* Send buffered output data to the socket. */ | |
1276 | if (c->wfd != -1 && | |
1277 | FD_ISSET(c->wfd, writeset) && | |
1278 | buffer_len(&c->output) > 0) { | |
1279 | data = buffer_ptr(&c->output); | |
1280 | dlen = buffer_len(&c->output); | |
1281 | len = write(c->wfd, data, dlen); | |
1282 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1283 | return 1; | |
1284 | if (len <= 0) { | |
1285 | if (c->type != SSH_CHANNEL_OPEN) { | |
1286 | debug("channel %d: not open", c->self); | |
1287 | chan_mark_dead(c); | |
1288 | return -1; | |
1289 | } else if (compat13) { | |
e9a17296 | 1290 | buffer_clear(&c->output); |
3c0ef626 | 1291 | debug("channel %d: input draining.", c->self); |
1292 | c->type = SSH_CHANNEL_INPUT_DRAINING; | |
1293 | } else { | |
1294 | chan_write_failed(c); | |
1295 | } | |
1296 | return -1; | |
1297 | } | |
1298 | if (compat20 && c->isatty && dlen >= 1 && data[0] != '\r') { | |
1299 | if (tcgetattr(c->wfd, &tio) == 0 && | |
1300 | !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { | |
1301 | /* | |
1302 | * Simulate echo to reduce the impact of | |
1303 | * traffic analysis. We need to match the | |
1304 | * size of a SSH2_MSG_CHANNEL_DATA message | |
1305 | * (4 byte channel id + data) | |
1306 | */ | |
1307 | packet_send_ignore(4 + len); | |
1308 | packet_send(); | |
1309 | } | |
1310 | } | |
1311 | buffer_consume(&c->output, len); | |
1312 | if (compat20 && len > 0) { | |
1313 | c->local_consumed += len; | |
1314 | } | |
1315 | } | |
1316 | return 1; | |
1317 | } | |
1318 | static int | |
1319 | channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) | |
1320 | { | |
1321 | char buf[16*1024]; | |
1322 | int len; | |
1323 | ||
1324 | /** XXX handle drain efd, too */ | |
1325 | if (c->efd != -1) { | |
1326 | if (c->extended_usage == CHAN_EXTENDED_WRITE && | |
1327 | FD_ISSET(c->efd, writeset) && | |
1328 | buffer_len(&c->extended) > 0) { | |
1329 | len = write(c->efd, buffer_ptr(&c->extended), | |
1330 | buffer_len(&c->extended)); | |
1331 | debug2("channel %d: written %d to efd %d", | |
1332 | c->self, len, c->efd); | |
1333 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1334 | return 1; | |
1335 | if (len <= 0) { | |
1336 | debug2("channel %d: closing write-efd %d", | |
1337 | c->self, c->efd); | |
1338 | channel_close_fd(&c->efd); | |
1339 | } else { | |
1340 | buffer_consume(&c->extended, len); | |
1341 | c->local_consumed += len; | |
1342 | } | |
1343 | } else if (c->extended_usage == CHAN_EXTENDED_READ && | |
1344 | FD_ISSET(c->efd, readset)) { | |
1345 | len = read(c->efd, buf, sizeof(buf)); | |
1346 | debug2("channel %d: read %d from efd %d", | |
e9a17296 | 1347 | c->self, len, c->efd); |
3c0ef626 | 1348 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) |
1349 | return 1; | |
1350 | if (len <= 0) { | |
1351 | debug2("channel %d: closing read-efd %d", | |
1352 | c->self, c->efd); | |
1353 | channel_close_fd(&c->efd); | |
1354 | } else { | |
1355 | buffer_append(&c->extended, buf, len); | |
1356 | } | |
1357 | } | |
1358 | } | |
1359 | return 1; | |
1360 | } | |
1361 | static int | |
1362 | channel_check_window(Channel *c) | |
1363 | { | |
1364 | if (c->type == SSH_CHANNEL_OPEN && | |
1365 | !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) && | |
1366 | c->local_window < c->local_window_max/2 && | |
1367 | c->local_consumed > 0) { | |
1368 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); | |
1369 | packet_put_int(c->remote_id); | |
1370 | packet_put_int(c->local_consumed); | |
1371 | packet_send(); | |
1372 | debug2("channel %d: window %d sent adjust %d", | |
1373 | c->self, c->local_window, | |
1374 | c->local_consumed); | |
1375 | c->local_window += c->local_consumed; | |
1376 | c->local_consumed = 0; | |
1377 | } | |
1378 | return 1; | |
1379 | } | |
1380 | ||
1381 | static void | |
e9a17296 | 1382 | channel_post_open(Channel *c, fd_set * readset, fd_set * writeset) |
3c0ef626 | 1383 | { |
1384 | if (c->delayed) | |
1385 | return; | |
1386 | channel_handle_rfd(c, readset, writeset); | |
1387 | channel_handle_wfd(c, readset, writeset); | |
e9a17296 | 1388 | if (!compat20) |
3c0ef626 | 1389 | return; |
3c0ef626 | 1390 | channel_handle_efd(c, readset, writeset); |
3c0ef626 | 1391 | channel_check_window(c); |
1392 | } | |
1393 | ||
1394 | static void | |
1395 | channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) | |
1396 | { | |
1397 | int len; | |
1398 | /* Send buffered output data to the socket. */ | |
1399 | if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) { | |
1400 | len = write(c->sock, buffer_ptr(&c->output), | |
1401 | buffer_len(&c->output)); | |
1402 | if (len <= 0) | |
e9a17296 | 1403 | buffer_clear(&c->output); |
3c0ef626 | 1404 | else |
1405 | buffer_consume(&c->output, len); | |
1406 | } | |
1407 | } | |
1408 | ||
1409 | static void | |
1410 | channel_handler_init_20(void) | |
1411 | { | |
e9a17296 | 1412 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; |
3c0ef626 | 1413 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
1414 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1415 | channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener; | |
1416 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
1417 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
1418 | channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; | |
1419 | channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; | |
1420 | ||
e9a17296 | 1421 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; |
3c0ef626 | 1422 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; |
1423 | channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener; | |
1424 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
1425 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
1426 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; | |
e9a17296 | 1427 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; |
3c0ef626 | 1428 | } |
1429 | ||
1430 | static void | |
1431 | channel_handler_init_13(void) | |
1432 | { | |
1433 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; | |
1434 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13; | |
1435 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
1436 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1437 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
1438 | channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining; | |
1439 | channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining; | |
1440 | channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; | |
1441 | channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; | |
1442 | ||
e9a17296 | 1443 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; |
3c0ef626 | 1444 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; |
1445 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
1446 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
1447 | channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; | |
1448 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; | |
e9a17296 | 1449 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; |
3c0ef626 | 1450 | } |
1451 | ||
1452 | static void | |
1453 | channel_handler_init_15(void) | |
1454 | { | |
e9a17296 | 1455 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; |
3c0ef626 | 1456 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
1457 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
1458 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1459 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
1460 | channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; | |
1461 | channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; | |
1462 | ||
1463 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
1464 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
1465 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
e9a17296 | 1466 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; |
3c0ef626 | 1467 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; |
e9a17296 | 1468 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; |
3c0ef626 | 1469 | } |
1470 | ||
1471 | static void | |
1472 | channel_handler_init(void) | |
1473 | { | |
1474 | int i; | |
e9a17296 | 1475 | for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { |
3c0ef626 | 1476 | channel_pre[i] = NULL; |
1477 | channel_post[i] = NULL; | |
1478 | } | |
1479 | if (compat20) | |
1480 | channel_handler_init_20(); | |
1481 | else if (compat13) | |
1482 | channel_handler_init_13(); | |
1483 | else | |
1484 | channel_handler_init_15(); | |
1485 | } | |
1486 | ||
1487 | /* gc dead channels */ | |
1488 | static void | |
1489 | channel_garbage_collect(Channel *c) | |
1490 | { | |
1491 | if (c == NULL) | |
1492 | return; | |
1493 | if (c->detach_user != NULL) { | |
1494 | if (!chan_is_dead(c, 0)) | |
1495 | return; | |
1496 | debug("channel %d: gc: notify user", c->self); | |
1497 | c->detach_user(c->self, NULL); | |
1498 | /* if we still have a callback */ | |
1499 | if (c->detach_user != NULL) | |
1500 | return; | |
1501 | debug("channel %d: gc: user detached", c->self); | |
1502 | } | |
1503 | if (!chan_is_dead(c, 1)) | |
1504 | return; | |
1505 | debug("channel %d: garbage collecting", c->self); | |
1506 | channel_free(c); | |
1507 | } | |
1508 | ||
1509 | static void | |
1510 | channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) | |
1511 | { | |
1512 | static int did_init = 0; | |
1513 | int i; | |
1514 | Channel *c; | |
1515 | ||
1516 | if (!did_init) { | |
1517 | channel_handler_init(); | |
1518 | did_init = 1; | |
1519 | } | |
1520 | for (i = 0; i < channels_alloc; i++) { | |
1521 | c = channels[i]; | |
1522 | if (c == NULL) | |
1523 | continue; | |
1524 | if (ftab[c->type] != NULL) | |
1525 | (*ftab[c->type])(c, readset, writeset); | |
1526 | channel_garbage_collect(c); | |
1527 | } | |
1528 | } | |
1529 | ||
1530 | /* | |
1531 | * Allocate/update select bitmasks and add any bits relevant to channels in | |
1532 | * select bitmasks. | |
1533 | */ | |
1534 | void | |
1535 | channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp, | |
1536 | int *nallocp, int rekeying) | |
1537 | { | |
1538 | int n; | |
1539 | u_int sz; | |
1540 | ||
1541 | n = MAX(*maxfdp, channel_max_fd); | |
1542 | ||
1543 | sz = howmany(n+1, NFDBITS) * sizeof(fd_mask); | |
1544 | /* perhaps check sz < nalloc/2 and shrink? */ | |
1545 | if (*readsetp == NULL || sz > *nallocp) { | |
1546 | *readsetp = xrealloc(*readsetp, sz); | |
1547 | *writesetp = xrealloc(*writesetp, sz); | |
1548 | *nallocp = sz; | |
1549 | } | |
1550 | *maxfdp = n; | |
1551 | memset(*readsetp, 0, sz); | |
1552 | memset(*writesetp, 0, sz); | |
1553 | ||
1554 | if (!rekeying) | |
1555 | channel_handler(channel_pre, *readsetp, *writesetp); | |
1556 | } | |
1557 | ||
1558 | /* | |
1559 | * After select, perform any appropriate operations for channels which have | |
1560 | * events pending. | |
1561 | */ | |
1562 | void | |
1563 | channel_after_select(fd_set * readset, fd_set * writeset) | |
1564 | { | |
1565 | channel_handler(channel_post, readset, writeset); | |
1566 | } | |
1567 | ||
1568 | ||
1569 | /* If there is data to send to the connection, enqueue some of it now. */ | |
1570 | ||
1571 | void | |
e9a17296 | 1572 | channel_output_poll(void) |
3c0ef626 | 1573 | { |
3c0ef626 | 1574 | Channel *c; |
680cee3b | 1575 | int i; |
1576 | u_int len; | |
3c0ef626 | 1577 | |
1578 | for (i = 0; i < channels_alloc; i++) { | |
1579 | c = channels[i]; | |
1580 | if (c == NULL) | |
1581 | continue; | |
1582 | ||
1583 | /* | |
1584 | * We are only interested in channels that can have buffered | |
1585 | * incoming data. | |
1586 | */ | |
1587 | if (compat13) { | |
1588 | if (c->type != SSH_CHANNEL_OPEN && | |
1589 | c->type != SSH_CHANNEL_INPUT_DRAINING) | |
1590 | continue; | |
1591 | } else { | |
1592 | if (c->type != SSH_CHANNEL_OPEN) | |
1593 | continue; | |
1594 | } | |
1595 | if (compat20 && | |
1596 | (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) { | |
1597 | /* XXX is this true? */ | |
1598 | debug3("channel %d: will not send data after close", c->self); | |
1599 | continue; | |
1600 | } | |
1601 | ||
1602 | /* Get the amount of buffered data for this channel. */ | |
1603 | if ((c->istate == CHAN_INPUT_OPEN || | |
1604 | c->istate == CHAN_INPUT_WAIT_DRAIN) && | |
1605 | (len = buffer_len(&c->input)) > 0) { | |
1606 | /* | |
1607 | * Send some data for the other side over the secure | |
1608 | * connection. | |
1609 | */ | |
1610 | if (compat20) { | |
1611 | if (len > c->remote_window) | |
1612 | len = c->remote_window; | |
1613 | if (len > c->remote_maxpacket) | |
1614 | len = c->remote_maxpacket; | |
1615 | } else { | |
1616 | if (packet_is_interactive()) { | |
1617 | if (len > 1024) | |
1618 | len = 512; | |
1619 | } else { | |
1620 | /* Keep the packets at reasonable size. */ | |
1621 | if (len > packet_get_maxsize()/2) | |
1622 | len = packet_get_maxsize()/2; | |
1623 | } | |
1624 | } | |
1625 | if (len > 0) { | |
1626 | packet_start(compat20 ? | |
1627 | SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); | |
1628 | packet_put_int(c->remote_id); | |
1629 | packet_put_string(buffer_ptr(&c->input), len); | |
1630 | packet_send(); | |
1631 | buffer_consume(&c->input, len); | |
1632 | c->remote_window -= len; | |
1633 | } | |
1634 | } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) { | |
1635 | if (compat13) | |
1636 | fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); | |
1637 | /* | |
1638 | * input-buffer is empty and read-socket shutdown: | |
700318f3 | 1639 | * tell peer, that we will not send more data: send IEOF. |
1640 | * hack for extended data: delay EOF if EFD still in use. | |
3c0ef626 | 1641 | */ |
700318f3 | 1642 | if (CHANNEL_EFD_INPUT_ACTIVE(c)) |
f5799ae1 | 1643 | debug2("channel %d: ibuf_empty delayed efd %d/(%d)", |
1644 | c->self, c->efd, buffer_len(&c->extended)); | |
700318f3 | 1645 | else |
1646 | chan_ibuf_empty(c); | |
3c0ef626 | 1647 | } |
1648 | /* Send extended data, i.e. stderr */ | |
1649 | if (compat20 && | |
700318f3 | 1650 | !(c->flags & CHAN_EOF_SENT) && |
3c0ef626 | 1651 | c->remote_window > 0 && |
1652 | (len = buffer_len(&c->extended)) > 0 && | |
1653 | c->extended_usage == CHAN_EXTENDED_READ) { | |
680cee3b | 1654 | debug2("channel %d: rwin %u elen %u euse %d", |
3c0ef626 | 1655 | c->self, c->remote_window, buffer_len(&c->extended), |
1656 | c->extended_usage); | |
1657 | if (len > c->remote_window) | |
1658 | len = c->remote_window; | |
1659 | if (len > c->remote_maxpacket) | |
1660 | len = c->remote_maxpacket; | |
1661 | packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA); | |
1662 | packet_put_int(c->remote_id); | |
1663 | packet_put_int(SSH2_EXTENDED_DATA_STDERR); | |
1664 | packet_put_string(buffer_ptr(&c->extended), len); | |
1665 | packet_send(); | |
1666 | buffer_consume(&c->extended, len); | |
1667 | c->remote_window -= len; | |
1668 | debug2("channel %d: sent ext data %d", c->self, len); | |
1669 | } | |
1670 | } | |
1671 | } | |
1672 | ||
1673 | ||
1674 | /* -- protocol input */ | |
1675 | ||
1676 | void | |
e9a17296 | 1677 | channel_input_data(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1678 | { |
1679 | int id; | |
1680 | char *data; | |
1681 | u_int data_len; | |
1682 | Channel *c; | |
1683 | ||
1684 | /* Get the channel number and verify it. */ | |
1685 | id = packet_get_int(); | |
1686 | c = channel_lookup(id); | |
1687 | if (c == NULL) | |
1688 | packet_disconnect("Received data for nonexistent channel %d.", id); | |
1689 | ||
1690 | /* Ignore any data for non-open channels (might happen on close) */ | |
1691 | if (c->type != SSH_CHANNEL_OPEN && | |
1692 | c->type != SSH_CHANNEL_X11_OPEN) | |
1693 | return; | |
1694 | ||
1695 | /* same for protocol 1.5 if output end is no longer open */ | |
1696 | if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) | |
1697 | return; | |
1698 | ||
1699 | /* Get the data. */ | |
1700 | data = packet_get_string(&data_len); | |
3c0ef626 | 1701 | |
e9a17296 | 1702 | if (compat20) { |
3c0ef626 | 1703 | if (data_len > c->local_maxpacket) { |
1704 | log("channel %d: rcvd big packet %d, maxpack %d", | |
1705 | c->self, data_len, c->local_maxpacket); | |
1706 | } | |
1707 | if (data_len > c->local_window) { | |
1708 | log("channel %d: rcvd too much data %d, win %d", | |
1709 | c->self, data_len, c->local_window); | |
1710 | xfree(data); | |
1711 | return; | |
1712 | } | |
1713 | c->local_window -= data_len; | |
3c0ef626 | 1714 | } |
e9a17296 | 1715 | packet_check_eom(); |
3c0ef626 | 1716 | buffer_append(&c->output, data, data_len); |
1717 | xfree(data); | |
1718 | } | |
1719 | ||
1720 | void | |
e9a17296 | 1721 | channel_input_extended_data(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1722 | { |
1723 | int id; | |
3c0ef626 | 1724 | char *data; |
680cee3b | 1725 | u_int data_len, tcode; |
3c0ef626 | 1726 | Channel *c; |
1727 | ||
1728 | /* Get the channel number and verify it. */ | |
1729 | id = packet_get_int(); | |
1730 | c = channel_lookup(id); | |
1731 | ||
1732 | if (c == NULL) | |
1733 | packet_disconnect("Received extended_data for bad channel %d.", id); | |
1734 | if (c->type != SSH_CHANNEL_OPEN) { | |
1735 | log("channel %d: ext data for non open", id); | |
1736 | return; | |
1737 | } | |
700318f3 | 1738 | if (c->flags & CHAN_EOF_RCVD) { |
1739 | if (datafellows & SSH_BUG_EXTEOF) | |
1740 | debug("channel %d: accepting ext data after eof", id); | |
1741 | else | |
1742 | packet_disconnect("Received extended_data after EOF " | |
1743 | "on channel %d.", id); | |
1744 | } | |
3c0ef626 | 1745 | tcode = packet_get_int(); |
1746 | if (c->efd == -1 || | |
1747 | c->extended_usage != CHAN_EXTENDED_WRITE || | |
1748 | tcode != SSH2_EXTENDED_DATA_STDERR) { | |
1749 | log("channel %d: bad ext data", c->self); | |
1750 | return; | |
1751 | } | |
1752 | data = packet_get_string(&data_len); | |
e9a17296 | 1753 | packet_check_eom(); |
3c0ef626 | 1754 | if (data_len > c->local_window) { |
1755 | log("channel %d: rcvd too much extended_data %d, win %d", | |
1756 | c->self, data_len, c->local_window); | |
1757 | xfree(data); | |
1758 | return; | |
1759 | } | |
1760 | debug2("channel %d: rcvd ext data %d", c->self, data_len); | |
1761 | c->local_window -= data_len; | |
1762 | buffer_append(&c->extended, data, data_len); | |
1763 | xfree(data); | |
1764 | } | |
1765 | ||
1766 | void | |
e9a17296 | 1767 | channel_input_ieof(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1768 | { |
1769 | int id; | |
1770 | Channel *c; | |
1771 | ||
3c0ef626 | 1772 | id = packet_get_int(); |
e9a17296 | 1773 | packet_check_eom(); |
3c0ef626 | 1774 | c = channel_lookup(id); |
1775 | if (c == NULL) | |
1776 | packet_disconnect("Received ieof for nonexistent channel %d.", id); | |
1777 | chan_rcvd_ieof(c); | |
1778 | ||
1779 | /* XXX force input close */ | |
e9a17296 | 1780 | if (c->force_drain && c->istate == CHAN_INPUT_OPEN) { |
3c0ef626 | 1781 | debug("channel %d: FORCE input drain", c->self); |
1782 | c->istate = CHAN_INPUT_WAIT_DRAIN; | |
e9a17296 | 1783 | if (buffer_len(&c->input) == 0) |
1784 | chan_ibuf_empty(c); | |
3c0ef626 | 1785 | } |
1786 | ||
1787 | } | |
1788 | ||
1789 | void | |
e9a17296 | 1790 | channel_input_close(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1791 | { |
1792 | int id; | |
1793 | Channel *c; | |
1794 | ||
3c0ef626 | 1795 | id = packet_get_int(); |
e9a17296 | 1796 | packet_check_eom(); |
3c0ef626 | 1797 | c = channel_lookup(id); |
1798 | if (c == NULL) | |
1799 | packet_disconnect("Received close for nonexistent channel %d.", id); | |
1800 | ||
1801 | /* | |
1802 | * Send a confirmation that we have closed the channel and no more | |
1803 | * data is coming for it. | |
1804 | */ | |
1805 | packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); | |
1806 | packet_put_int(c->remote_id); | |
1807 | packet_send(); | |
1808 | ||
1809 | /* | |
1810 | * If the channel is in closed state, we have sent a close request, | |
1811 | * and the other side will eventually respond with a confirmation. | |
1812 | * Thus, we cannot free the channel here, because then there would be | |
1813 | * no-one to receive the confirmation. The channel gets freed when | |
1814 | * the confirmation arrives. | |
1815 | */ | |
1816 | if (c->type != SSH_CHANNEL_CLOSED) { | |
1817 | /* | |
1818 | * Not a closed channel - mark it as draining, which will | |
1819 | * cause it to be freed later. | |
1820 | */ | |
e9a17296 | 1821 | buffer_clear(&c->input); |
3c0ef626 | 1822 | c->type = SSH_CHANNEL_OUTPUT_DRAINING; |
1823 | } | |
1824 | } | |
1825 | ||
1826 | /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ | |
1827 | void | |
e9a17296 | 1828 | channel_input_oclose(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1829 | { |
1830 | int id = packet_get_int(); | |
1831 | Channel *c = channel_lookup(id); | |
e9a17296 | 1832 | |
1833 | packet_check_eom(); | |
3c0ef626 | 1834 | if (c == NULL) |
1835 | packet_disconnect("Received oclose for nonexistent channel %d.", id); | |
1836 | chan_rcvd_oclose(c); | |
1837 | } | |
1838 | ||
1839 | void | |
e9a17296 | 1840 | channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1841 | { |
1842 | int id = packet_get_int(); | |
1843 | Channel *c = channel_lookup(id); | |
1844 | ||
e9a17296 | 1845 | packet_check_eom(); |
3c0ef626 | 1846 | if (c == NULL) |
1847 | packet_disconnect("Received close confirmation for " | |
1848 | "out-of-range channel %d.", id); | |
1849 | if (c->type != SSH_CHANNEL_CLOSED) | |
1850 | packet_disconnect("Received close confirmation for " | |
1851 | "non-closed channel %d (type %d).", id, c->type); | |
1852 | channel_free(c); | |
1853 | } | |
1854 | ||
1855 | void | |
e9a17296 | 1856 | channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1857 | { |
1858 | int id, remote_id; | |
1859 | Channel *c; | |
1860 | ||
3c0ef626 | 1861 | id = packet_get_int(); |
1862 | c = channel_lookup(id); | |
1863 | ||
1864 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
1865 | packet_disconnect("Received open confirmation for " | |
1866 | "non-opening channel %d.", id); | |
1867 | remote_id = packet_get_int(); | |
1868 | /* Record the remote channel number and mark that the channel is now open. */ | |
1869 | c->remote_id = remote_id; | |
1870 | c->type = SSH_CHANNEL_OPEN; | |
1871 | ||
1872 | if (compat20) { | |
1873 | c->remote_window = packet_get_int(); | |
1874 | c->remote_maxpacket = packet_get_int(); | |
e9a17296 | 1875 | if (c->confirm) { |
3c0ef626 | 1876 | debug2("callback start"); |
e9a17296 | 1877 | c->confirm(c->self, NULL); |
3c0ef626 | 1878 | debug2("callback done"); |
1879 | } | |
680cee3b | 1880 | debug("channel %d: open confirm rwindow %u rmax %u", c->self, |
3c0ef626 | 1881 | c->remote_window, c->remote_maxpacket); |
1882 | } | |
e9a17296 | 1883 | packet_check_eom(); |
3c0ef626 | 1884 | } |
1885 | ||
1886 | static char * | |
1887 | reason2txt(int reason) | |
1888 | { | |
e9a17296 | 1889 | switch (reason) { |
3c0ef626 | 1890 | case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED: |
1891 | return "administratively prohibited"; | |
1892 | case SSH2_OPEN_CONNECT_FAILED: | |
1893 | return "connect failed"; | |
1894 | case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE: | |
1895 | return "unknown channel type"; | |
1896 | case SSH2_OPEN_RESOURCE_SHORTAGE: | |
1897 | return "resource shortage"; | |
1898 | } | |
1899 | return "unknown reason"; | |
1900 | } | |
1901 | ||
1902 | void | |
e9a17296 | 1903 | channel_input_open_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1904 | { |
1905 | int id, reason; | |
1906 | char *msg = NULL, *lang = NULL; | |
1907 | Channel *c; | |
1908 | ||
3c0ef626 | 1909 | id = packet_get_int(); |
1910 | c = channel_lookup(id); | |
1911 | ||
1912 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
1913 | packet_disconnect("Received open failure for " | |
1914 | "non-opening channel %d.", id); | |
1915 | if (compat20) { | |
1916 | reason = packet_get_int(); | |
1917 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
1918 | msg = packet_get_string(NULL); | |
1919 | lang = packet_get_string(NULL); | |
1920 | } | |
3c0ef626 | 1921 | log("channel %d: open failed: %s%s%s", id, |
1922 | reason2txt(reason), msg ? ": ": "", msg ? msg : ""); | |
1923 | if (msg != NULL) | |
1924 | xfree(msg); | |
1925 | if (lang != NULL) | |
1926 | xfree(lang); | |
1927 | } | |
e9a17296 | 1928 | packet_check_eom(); |
3c0ef626 | 1929 | /* Free the channel. This will also close the socket. */ |
1930 | channel_free(c); | |
1931 | } | |
1932 | ||
1933 | void | |
e9a17296 | 1934 | channel_input_window_adjust(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1935 | { |
1936 | Channel *c; | |
680cee3b | 1937 | int id; |
1938 | u_int adjust; | |
3c0ef626 | 1939 | |
1940 | if (!compat20) | |
1941 | return; | |
1942 | ||
1943 | /* Get the channel number and verify it. */ | |
1944 | id = packet_get_int(); | |
1945 | c = channel_lookup(id); | |
1946 | ||
1947 | if (c == NULL || c->type != SSH_CHANNEL_OPEN) { | |
1948 | log("Received window adjust for " | |
1949 | "non-open channel %d.", id); | |
1950 | return; | |
1951 | } | |
1952 | adjust = packet_get_int(); | |
e9a17296 | 1953 | packet_check_eom(); |
680cee3b | 1954 | debug2("channel %d: rcvd adjust %u", id, adjust); |
3c0ef626 | 1955 | c->remote_window += adjust; |
1956 | } | |
1957 | ||
1958 | void | |
e9a17296 | 1959 | channel_input_port_open(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1960 | { |
1961 | Channel *c = NULL; | |
1962 | u_short host_port; | |
1963 | char *host, *originator_string; | |
1964 | int remote_id, sock = -1; | |
1965 | ||
1966 | remote_id = packet_get_int(); | |
1967 | host = packet_get_string(NULL); | |
1968 | host_port = packet_get_int(); | |
1969 | ||
1970 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { | |
1971 | originator_string = packet_get_string(NULL); | |
1972 | } else { | |
1973 | originator_string = xstrdup("unknown (remote did not supply name)"); | |
1974 | } | |
e9a17296 | 1975 | packet_check_eom(); |
3c0ef626 | 1976 | sock = channel_connect_to(host, host_port); |
1977 | if (sock != -1) { | |
1978 | c = channel_new("connected socket", | |
1979 | SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0, | |
1980 | originator_string, 1); | |
e9a17296 | 1981 | c->remote_id = remote_id; |
3c0ef626 | 1982 | } |
1983 | if (c == NULL) { | |
1984 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1985 | packet_put_int(remote_id); | |
1986 | packet_send(); | |
1987 | } | |
1988 | xfree(host); | |
1989 | } | |
1990 | ||
1991 | ||
1992 | /* -- tcp forwarding */ | |
1993 | ||
1994 | void | |
1995 | channel_set_af(int af) | |
1996 | { | |
1997 | IPv4or6 = af; | |
1998 | } | |
1999 | ||
e9a17296 | 2000 | static int |
2001 | channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port, | |
2002 | const char *host_to_connect, u_short port_to_connect, int gateway_ports) | |
3c0ef626 | 2003 | { |
2004 | Channel *c; | |
e9a17296 | 2005 | int success, sock, on = 1; |
3c0ef626 | 2006 | struct addrinfo hints, *ai, *aitop; |
3c0ef626 | 2007 | const char *host; |
e9a17296 | 2008 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
3c0ef626 | 2009 | struct linger linger; |
2010 | ||
2011 | success = 0; | |
e9a17296 | 2012 | host = (type == SSH_CHANNEL_RPORT_LISTENER) ? |
2013 | listen_addr : host_to_connect; | |
3c0ef626 | 2014 | |
e9a17296 | 2015 | if (host == NULL) { |
2016 | error("No forward host name."); | |
2017 | return success; | |
3c0ef626 | 2018 | } |
3c0ef626 | 2019 | if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) { |
2020 | error("Forward host name too long."); | |
2021 | return success; | |
2022 | } | |
2023 | ||
3c0ef626 | 2024 | /* |
2025 | * getaddrinfo returns a loopback address if the hostname is | |
2026 | * set to NULL and hints.ai_flags is not AI_PASSIVE | |
2027 | */ | |
2028 | memset(&hints, 0, sizeof(hints)); | |
2029 | hints.ai_family = IPv4or6; | |
2030 | hints.ai_flags = gateway_ports ? AI_PASSIVE : 0; | |
2031 | hints.ai_socktype = SOCK_STREAM; | |
2032 | snprintf(strport, sizeof strport, "%d", listen_port); | |
2033 | if (getaddrinfo(NULL, strport, &hints, &aitop) != 0) | |
2034 | packet_disconnect("getaddrinfo: fatal error"); | |
2035 | ||
2036 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2037 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2038 | continue; | |
2039 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
2040 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
e9a17296 | 2041 | error("channel_setup_fwd_listener: getnameinfo failed"); |
3c0ef626 | 2042 | continue; |
2043 | } | |
2044 | /* Create a port to listen for the host. */ | |
2045 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
2046 | if (sock < 0) { | |
2047 | /* this is no error since kernel may not support ipv6 */ | |
2048 | verbose("socket: %.100s", strerror(errno)); | |
2049 | continue; | |
2050 | } | |
2051 | /* | |
2052 | * Set socket options. We would like the socket to disappear | |
2053 | * as soon as it has been closed for whatever reason. | |
2054 | */ | |
e9a17296 | 2055 | setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); |
3c0ef626 | 2056 | linger.l_onoff = 1; |
2057 | linger.l_linger = 5; | |
e9a17296 | 2058 | setsockopt(sock, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger)); |
3c0ef626 | 2059 | debug("Local forwarding listening on %s port %s.", ntop, strport); |
2060 | ||
2061 | /* Bind the socket to the address. */ | |
2062 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
2063 | /* address can be in use ipv6 address is already bound */ | |
2064 | if (!ai->ai_next) | |
2065 | error("bind: %.100s", strerror(errno)); | |
2066 | else | |
2067 | verbose("bind: %.100s", strerror(errno)); | |
2068 | ||
2069 | close(sock); | |
2070 | continue; | |
2071 | } | |
2072 | /* Start listening for connections on the socket. */ | |
2073 | if (listen(sock, 5) < 0) { | |
2074 | error("listen: %.100s", strerror(errno)); | |
2075 | close(sock); | |
2076 | continue; | |
2077 | } | |
2078 | /* Allocate a channel number for the socket. */ | |
2079 | c = channel_new("port listener", type, sock, sock, -1, | |
2080 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, | |
2081 | 0, xstrdup("port listener"), 1); | |
3c0ef626 | 2082 | strlcpy(c->path, host, sizeof(c->path)); |
2083 | c->host_port = port_to_connect; | |
2084 | c->listening_port = listen_port; | |
2085 | success = 1; | |
2086 | } | |
2087 | if (success == 0) | |
e9a17296 | 2088 | error("channel_setup_fwd_listener: cannot listen to port: %d", |
3c0ef626 | 2089 | listen_port); |
2090 | freeaddrinfo(aitop); | |
2091 | return success; | |
2092 | } | |
2093 | ||
e9a17296 | 2094 | /* protocol local port fwd, used by ssh (and sshd in v1) */ |
2095 | int | |
2096 | channel_setup_local_fwd_listener(u_short listen_port, | |
2097 | const char *host_to_connect, u_short port_to_connect, int gateway_ports) | |
2098 | { | |
2099 | return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER, | |
2100 | NULL, listen_port, host_to_connect, port_to_connect, gateway_ports); | |
2101 | } | |
2102 | ||
2103 | /* protocol v2 remote port fwd, used by sshd */ | |
2104 | int | |
2105 | channel_setup_remote_fwd_listener(const char *listen_address, | |
2106 | u_short listen_port, int gateway_ports) | |
2107 | { | |
2108 | return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER, | |
2109 | listen_address, listen_port, NULL, 0, gateway_ports); | |
2110 | } | |
2111 | ||
3c0ef626 | 2112 | /* |
2113 | * Initiate forwarding of connections to port "port" on remote host through | |
2114 | * the secure channel to host:port from local side. | |
2115 | */ | |
2116 | ||
2117 | void | |
2118 | channel_request_remote_forwarding(u_short listen_port, | |
2119 | const char *host_to_connect, u_short port_to_connect) | |
2120 | { | |
e9a17296 | 2121 | int type, success = 0; |
3c0ef626 | 2122 | |
2123 | /* Record locally that connection to this host/port is permitted. */ | |
2124 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
2125 | fatal("channel_request_remote_forwarding: too many forwards"); | |
2126 | ||
2127 | /* Send the forward request to the remote side. */ | |
2128 | if (compat20) { | |
2129 | const char *address_to_bind = "0.0.0.0"; | |
2130 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
2131 | packet_put_cstring("tcpip-forward"); | |
700318f3 | 2132 | packet_put_char(1); /* boolean: want reply */ |
3c0ef626 | 2133 | packet_put_cstring(address_to_bind); |
2134 | packet_put_int(listen_port); | |
2135 | packet_send(); | |
2136 | packet_write_wait(); | |
2137 | /* Assume that server accepts the request */ | |
2138 | success = 1; | |
2139 | } else { | |
2140 | packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); | |
2141 | packet_put_int(listen_port); | |
2142 | packet_put_cstring(host_to_connect); | |
2143 | packet_put_int(port_to_connect); | |
2144 | packet_send(); | |
2145 | packet_write_wait(); | |
2146 | ||
2147 | /* Wait for response from the remote side. */ | |
e9a17296 | 2148 | type = packet_read(); |
3c0ef626 | 2149 | switch (type) { |
2150 | case SSH_SMSG_SUCCESS: | |
2151 | success = 1; | |
2152 | break; | |
2153 | case SSH_SMSG_FAILURE: | |
2154 | log("Warning: Server denied remote port forwarding."); | |
2155 | break; | |
2156 | default: | |
2157 | /* Unknown packet */ | |
2158 | packet_disconnect("Protocol error for port forward request:" | |
2159 | "received packet type %d.", type); | |
2160 | } | |
2161 | } | |
2162 | if (success) { | |
2163 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect); | |
2164 | permitted_opens[num_permitted_opens].port_to_connect = port_to_connect; | |
2165 | permitted_opens[num_permitted_opens].listen_port = listen_port; | |
2166 | num_permitted_opens++; | |
2167 | } | |
2168 | } | |
2169 | ||
2170 | /* | |
2171 | * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates | |
2172 | * listening for the port, and sends back a success reply (or disconnect | |
2173 | * message if there was an error). This never returns if there was an error. | |
2174 | */ | |
2175 | ||
2176 | void | |
2177 | channel_input_port_forward_request(int is_root, int gateway_ports) | |
2178 | { | |
2179 | u_short port, host_port; | |
2180 | char *hostname; | |
2181 | ||
2182 | /* Get arguments from the packet. */ | |
2183 | port = packet_get_int(); | |
2184 | hostname = packet_get_string(NULL); | |
2185 | host_port = packet_get_int(); | |
2186 | ||
2187 | #ifndef HAVE_CYGWIN | |
2188 | /* | |
2189 | * Check that an unprivileged user is not trying to forward a | |
2190 | * privileged port. | |
2191 | */ | |
2192 | if (port < IPPORT_RESERVED && !is_root) | |
2193 | packet_disconnect("Requested forwarding of port %d but user is not root.", | |
2194 | port); | |
2195 | #endif | |
2196 | /* Initiate forwarding */ | |
e9a17296 | 2197 | channel_setup_local_fwd_listener(port, hostname, host_port, gateway_ports); |
3c0ef626 | 2198 | |
2199 | /* Free the argument string. */ | |
2200 | xfree(hostname); | |
2201 | } | |
2202 | ||
2203 | /* | |
2204 | * Permits opening to any host/port if permitted_opens[] is empty. This is | |
2205 | * usually called by the server, because the user could connect to any port | |
2206 | * anyway, and the server has no way to know but to trust the client anyway. | |
2207 | */ | |
2208 | void | |
e9a17296 | 2209 | channel_permit_all_opens(void) |
3c0ef626 | 2210 | { |
2211 | if (num_permitted_opens == 0) | |
2212 | all_opens_permitted = 1; | |
2213 | } | |
2214 | ||
2215 | void | |
2216 | channel_add_permitted_opens(char *host, int port) | |
2217 | { | |
2218 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
2219 | fatal("channel_request_remote_forwarding: too many forwards"); | |
2220 | debug("allow port forwarding to host %s port %d", host, port); | |
2221 | ||
2222 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host); | |
2223 | permitted_opens[num_permitted_opens].port_to_connect = port; | |
2224 | num_permitted_opens++; | |
2225 | ||
2226 | all_opens_permitted = 0; | |
2227 | } | |
2228 | ||
2229 | void | |
2230 | channel_clear_permitted_opens(void) | |
2231 | { | |
2232 | int i; | |
2233 | ||
2234 | for (i = 0; i < num_permitted_opens; i++) | |
2235 | xfree(permitted_opens[i].host_to_connect); | |
2236 | num_permitted_opens = 0; | |
2237 | ||
2238 | } | |
2239 | ||
2240 | ||
2241 | /* return socket to remote host, port */ | |
2242 | static int | |
2243 | connect_to(const char *host, u_short port) | |
2244 | { | |
2245 | struct addrinfo hints, *ai, *aitop; | |
2246 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
2247 | int gaierr; | |
2248 | int sock = -1; | |
2249 | ||
2250 | memset(&hints, 0, sizeof(hints)); | |
2251 | hints.ai_family = IPv4or6; | |
2252 | hints.ai_socktype = SOCK_STREAM; | |
2253 | snprintf(strport, sizeof strport, "%d", port); | |
2254 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { | |
2255 | error("connect_to %.100s: unknown host (%s)", host, | |
2256 | gai_strerror(gaierr)); | |
2257 | return -1; | |
2258 | } | |
2259 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2260 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2261 | continue; | |
2262 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
2263 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
2264 | error("connect_to: getnameinfo failed"); | |
2265 | continue; | |
2266 | } | |
2267 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
2268 | if (sock < 0) { | |
2269 | error("socket: %.100s", strerror(errno)); | |
2270 | continue; | |
2271 | } | |
2272 | if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) | |
2273 | fatal("connect_to: F_SETFL: %s", strerror(errno)); | |
2274 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 && | |
2275 | errno != EINPROGRESS) { | |
2276 | error("connect_to %.100s port %s: %.100s", ntop, strport, | |
2277 | strerror(errno)); | |
2278 | close(sock); | |
2279 | continue; /* fail -- try next */ | |
2280 | } | |
2281 | break; /* success */ | |
2282 | ||
2283 | } | |
2284 | freeaddrinfo(aitop); | |
2285 | if (!ai) { | |
2286 | error("connect_to %.100s port %d: failed.", host, port); | |
2287 | return -1; | |
2288 | } | |
2289 | /* success */ | |
e9a17296 | 2290 | set_nodelay(sock); |
3c0ef626 | 2291 | return sock; |
2292 | } | |
2293 | ||
2294 | int | |
2295 | channel_connect_by_listen_address(u_short listen_port) | |
2296 | { | |
2297 | int i; | |
2298 | ||
2299 | for (i = 0; i < num_permitted_opens; i++) | |
2300 | if (permitted_opens[i].listen_port == listen_port) | |
2301 | return connect_to( | |
2302 | permitted_opens[i].host_to_connect, | |
2303 | permitted_opens[i].port_to_connect); | |
2304 | error("WARNING: Server requests forwarding for unknown listen_port %d", | |
2305 | listen_port); | |
2306 | return -1; | |
2307 | } | |
2308 | ||
2309 | /* Check if connecting to that port is permitted and connect. */ | |
2310 | int | |
2311 | channel_connect_to(const char *host, u_short port) | |
2312 | { | |
2313 | int i, permit; | |
2314 | ||
2315 | permit = all_opens_permitted; | |
2316 | if (!permit) { | |
2317 | for (i = 0; i < num_permitted_opens; i++) | |
2318 | if (permitted_opens[i].port_to_connect == port && | |
2319 | strcmp(permitted_opens[i].host_to_connect, host) == 0) | |
2320 | permit = 1; | |
2321 | ||
2322 | } | |
2323 | if (!permit) { | |
2324 | log("Received request to connect to host %.100s port %d, " | |
2325 | "but the request was denied.", host, port); | |
2326 | return -1; | |
2327 | } | |
2328 | return connect_to(host, port); | |
2329 | } | |
2330 | ||
2331 | /* -- X11 forwarding */ | |
2332 | ||
2333 | /* | |
2334 | * Creates an internet domain socket for listening for X11 connections. | |
680cee3b | 2335 | * Returns 0 and a suitable display number for the DISPLAY variable |
2336 | * stored in display_numberp , or -1 if an error occurs. | |
3c0ef626 | 2337 | */ |
e9a17296 | 2338 | int |
2339 | x11_create_display_inet(int x11_display_offset, int x11_use_localhost, | |
680cee3b | 2340 | int single_connection, u_int *display_numberp) |
3c0ef626 | 2341 | { |
e9a17296 | 2342 | Channel *nc = NULL; |
3c0ef626 | 2343 | int display_number, sock; |
2344 | u_short port; | |
2345 | struct addrinfo hints, *ai, *aitop; | |
2346 | char strport[NI_MAXSERV]; | |
2347 | int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; | |
3c0ef626 | 2348 | |
2349 | for (display_number = x11_display_offset; | |
e9a17296 | 2350 | display_number < MAX_DISPLAYS; |
2351 | display_number++) { | |
3c0ef626 | 2352 | port = 6000 + display_number; |
2353 | memset(&hints, 0, sizeof(hints)); | |
2354 | hints.ai_family = IPv4or6; | |
e9a17296 | 2355 | hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE; |
3c0ef626 | 2356 | hints.ai_socktype = SOCK_STREAM; |
2357 | snprintf(strport, sizeof strport, "%d", port); | |
2358 | if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { | |
2359 | error("getaddrinfo: %.100s", gai_strerror(gaierr)); | |
e9a17296 | 2360 | return -1; |
3c0ef626 | 2361 | } |
2362 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2363 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2364 | continue; | |
2365 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
2366 | if (sock < 0) { | |
2367 | if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) { | |
2368 | error("socket: %.100s", strerror(errno)); | |
e9a17296 | 2369 | return -1; |
3c0ef626 | 2370 | } else { |
2371 | debug("x11_create_display_inet: Socket family %d not supported", | |
2372 | ai->ai_family); | |
2373 | continue; | |
2374 | } | |
2375 | } | |
f5799ae1 | 2376 | #ifdef IPV6_V6ONLY |
2377 | if (ai->ai_family == AF_INET6) { | |
2378 | int on = 1; | |
2379 | if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) | |
2380 | error("setsockopt IPV6_V6ONLY: %.100s", strerror(errno)); | |
2381 | } | |
2382 | #endif | |
3c0ef626 | 2383 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { |
2384 | debug("bind port %d: %.100s", port, strerror(errno)); | |
3c0ef626 | 2385 | close(sock); |
2386 | ||
2387 | if (ai->ai_next) | |
2388 | continue; | |
2389 | ||
2390 | for (n = 0; n < num_socks; n++) { | |
3c0ef626 | 2391 | close(socks[n]); |
2392 | } | |
2393 | num_socks = 0; | |
2394 | break; | |
2395 | } | |
2396 | socks[num_socks++] = sock; | |
2397 | #ifndef DONT_TRY_OTHER_AF | |
2398 | if (num_socks == NUM_SOCKS) | |
2399 | break; | |
2400 | #else | |
f5799ae1 | 2401 | if (x11_use_localhost) { |
2402 | if (num_socks == NUM_SOCKS) | |
2403 | break; | |
2404 | } else { | |
2405 | break; | |
2406 | } | |
3c0ef626 | 2407 | #endif |
2408 | } | |
2409 | freeaddrinfo(aitop); | |
2410 | if (num_socks > 0) | |
2411 | break; | |
2412 | } | |
2413 | if (display_number >= MAX_DISPLAYS) { | |
2414 | error("Failed to allocate internet-domain X11 display socket."); | |
e9a17296 | 2415 | return -1; |
3c0ef626 | 2416 | } |
2417 | /* Start listening for connections on the socket. */ | |
2418 | for (n = 0; n < num_socks; n++) { | |
2419 | sock = socks[n]; | |
2420 | if (listen(sock, 5) < 0) { | |
2421 | error("listen: %.100s", strerror(errno)); | |
3c0ef626 | 2422 | close(sock); |
e9a17296 | 2423 | return -1; |
3c0ef626 | 2424 | } |
3c0ef626 | 2425 | } |
3c0ef626 | 2426 | |
2427 | /* Allocate a channel for each socket. */ | |
2428 | for (n = 0; n < num_socks; n++) { | |
2429 | sock = socks[n]; | |
e9a17296 | 2430 | nc = channel_new("x11 listener", |
3c0ef626 | 2431 | SSH_CHANNEL_X11_LISTENER, sock, sock, -1, |
2432 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
2433 | 0, xstrdup("X11 inet listener"), 1); | |
e9a17296 | 2434 | nc->single_connection = single_connection; |
3c0ef626 | 2435 | } |
2436 | ||
e9a17296 | 2437 | /* Return the display number for the DISPLAY environment variable. */ |
680cee3b | 2438 | *display_numberp = display_number; |
2439 | return (0); | |
3c0ef626 | 2440 | } |
2441 | ||
3c0ef626 | 2442 | static int |
2443 | connect_local_xsocket(u_int dnr) | |
2444 | { | |
3c0ef626 | 2445 | int sock; |
2446 | struct sockaddr_un addr; | |
3c0ef626 | 2447 | |
e9a17296 | 2448 | sock = socket(AF_UNIX, SOCK_STREAM, 0); |
2449 | if (sock < 0) | |
2450 | error("socket: %.100s", strerror(errno)); | |
2451 | memset(&addr, 0, sizeof(addr)); | |
2452 | addr.sun_family = AF_UNIX; | |
2453 | snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr); | |
2454 | if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0) | |
2455 | return sock; | |
2456 | close(sock); | |
3c0ef626 | 2457 | error("connect %.100s: %.100s", addr.sun_path, strerror(errno)); |
2458 | return -1; | |
2459 | } | |
2460 | ||
2461 | int | |
2462 | x11_connect_display(void) | |
2463 | { | |
2464 | int display_number, sock = 0; | |
2465 | const char *display; | |
2466 | char buf[1024], *cp; | |
2467 | struct addrinfo hints, *ai, *aitop; | |
2468 | char strport[NI_MAXSERV]; | |
2469 | int gaierr; | |
2470 | ||
2471 | /* Try to open a socket for the local X server. */ | |
2472 | display = getenv("DISPLAY"); | |
2473 | if (!display) { | |
2474 | error("DISPLAY not set."); | |
2475 | return -1; | |
2476 | } | |
2477 | /* | |
2478 | * Now we decode the value of the DISPLAY variable and make a | |
2479 | * connection to the real X server. | |
2480 | */ | |
2481 | ||
2482 | /* | |
2483 | * Check if it is a unix domain socket. Unix domain displays are in | |
2484 | * one of the following formats: unix:d[.s], :d[.s], ::d[.s] | |
2485 | */ | |
2486 | if (strncmp(display, "unix:", 5) == 0 || | |
2487 | display[0] == ':') { | |
2488 | /* Connect to the unix domain socket. */ | |
2489 | if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) { | |
2490 | error("Could not parse display number from DISPLAY: %.100s", | |
e9a17296 | 2491 | display); |
3c0ef626 | 2492 | return -1; |
2493 | } | |
2494 | /* Create a socket. */ | |
2495 | sock = connect_local_xsocket(display_number); | |
2496 | if (sock < 0) | |
2497 | return -1; | |
2498 | ||
2499 | /* OK, we now have a connection to the display. */ | |
2500 | return sock; | |
2501 | } | |
2502 | /* | |
2503 | * Connect to an inet socket. The DISPLAY value is supposedly | |
2504 | * hostname:d[.s], where hostname may also be numeric IP address. | |
2505 | */ | |
e9a17296 | 2506 | strlcpy(buf, display, sizeof(buf)); |
3c0ef626 | 2507 | cp = strchr(buf, ':'); |
2508 | if (!cp) { | |
2509 | error("Could not find ':' in DISPLAY: %.100s", display); | |
2510 | return -1; | |
2511 | } | |
2512 | *cp = 0; | |
2513 | /* buf now contains the host name. But first we parse the display number. */ | |
2514 | if (sscanf(cp + 1, "%d", &display_number) != 1) { | |
2515 | error("Could not parse display number from DISPLAY: %.100s", | |
e9a17296 | 2516 | display); |
3c0ef626 | 2517 | return -1; |
2518 | } | |
2519 | ||
2520 | /* Look up the host address */ | |
2521 | memset(&hints, 0, sizeof(hints)); | |
2522 | hints.ai_family = IPv4or6; | |
2523 | hints.ai_socktype = SOCK_STREAM; | |
2524 | snprintf(strport, sizeof strport, "%d", 6000 + display_number); | |
2525 | if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { | |
2526 | error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr)); | |
2527 | return -1; | |
2528 | } | |
2529 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2530 | /* Create a socket. */ | |
2531 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
2532 | if (sock < 0) { | |
2533 | debug("socket: %.100s", strerror(errno)); | |
2534 | continue; | |
2535 | } | |
2536 | /* Connect it to the display. */ | |
2537 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
2538 | debug("connect %.100s port %d: %.100s", buf, | |
2539 | 6000 + display_number, strerror(errno)); | |
2540 | close(sock); | |
2541 | continue; | |
2542 | } | |
2543 | /* Success */ | |
2544 | break; | |
2545 | } | |
2546 | freeaddrinfo(aitop); | |
2547 | if (!ai) { | |
2548 | error("connect %.100s port %d: %.100s", buf, 6000 + display_number, | |
2549 | strerror(errno)); | |
2550 | return -1; | |
2551 | } | |
e9a17296 | 2552 | set_nodelay(sock); |
3c0ef626 | 2553 | return sock; |
2554 | } | |
2555 | ||
2556 | /* | |
2557 | * This is called when SSH_SMSG_X11_OPEN is received. The packet contains | |
2558 | * the remote channel number. We should do whatever we want, and respond | |
2559 | * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. | |
2560 | */ | |
2561 | ||
2562 | void | |
e9a17296 | 2563 | x11_input_open(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2564 | { |
2565 | Channel *c = NULL; | |
2566 | int remote_id, sock = 0; | |
2567 | char *remote_host; | |
2568 | ||
2569 | debug("Received X11 open request."); | |
2570 | ||
2571 | remote_id = packet_get_int(); | |
2572 | ||
2573 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { | |
2574 | remote_host = packet_get_string(NULL); | |
2575 | } else { | |
2576 | remote_host = xstrdup("unknown (remote did not supply name)"); | |
2577 | } | |
e9a17296 | 2578 | packet_check_eom(); |
3c0ef626 | 2579 | |
2580 | /* Obtain a connection to the real X display. */ | |
2581 | sock = x11_connect_display(); | |
2582 | if (sock != -1) { | |
2583 | /* Allocate a channel for this connection. */ | |
2584 | c = channel_new("connected x11 socket", | |
2585 | SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0, | |
2586 | remote_host, 1); | |
e9a17296 | 2587 | c->remote_id = remote_id; |
2588 | c->force_drain = 1; | |
3c0ef626 | 2589 | } |
2590 | if (c == NULL) { | |
2591 | /* Send refusal to the remote host. */ | |
2592 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2593 | packet_put_int(remote_id); | |
2594 | } else { | |
2595 | /* Send a confirmation to the remote host. */ | |
2596 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
2597 | packet_put_int(remote_id); | |
2598 | packet_put_int(c->self); | |
2599 | } | |
2600 | packet_send(); | |
2601 | } | |
2602 | ||
2603 | /* dummy protocol handler that denies SSH-1 requests (agent/x11) */ | |
2604 | void | |
e9a17296 | 2605 | deny_input_open(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2606 | { |
2607 | int rchan = packet_get_int(); | |
e9a17296 | 2608 | switch (type) { |
3c0ef626 | 2609 | case SSH_SMSG_AGENT_OPEN: |
2610 | error("Warning: ssh server tried agent forwarding."); | |
2611 | break; | |
2612 | case SSH_SMSG_X11_OPEN: | |
2613 | error("Warning: ssh server tried X11 forwarding."); | |
2614 | break; | |
2615 | default: | |
e9a17296 | 2616 | error("deny_input_open: type %d", type); |
3c0ef626 | 2617 | break; |
2618 | } | |
2619 | error("Warning: this is probably a break in attempt by a malicious server."); | |
2620 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2621 | packet_put_int(rchan); | |
2622 | packet_send(); | |
2623 | } | |
2624 | ||
2625 | /* | |
2626 | * Requests forwarding of X11 connections, generates fake authentication | |
2627 | * data, and enables authentication spoofing. | |
2628 | * This should be called in the client only. | |
2629 | */ | |
2630 | void | |
2631 | x11_request_forwarding_with_spoofing(int client_session_id, | |
2632 | const char *proto, const char *data) | |
2633 | { | |
2634 | u_int data_len = (u_int) strlen(data) / 2; | |
2635 | u_int i, value, len; | |
2636 | char *new_data; | |
2637 | int screen_number; | |
2638 | const char *cp; | |
2639 | u_int32_t rand = 0; | |
2640 | ||
2641 | cp = getenv("DISPLAY"); | |
2642 | if (cp) | |
2643 | cp = strchr(cp, ':'); | |
2644 | if (cp) | |
2645 | cp = strchr(cp, '.'); | |
2646 | if (cp) | |
2647 | screen_number = atoi(cp + 1); | |
2648 | else | |
2649 | screen_number = 0; | |
2650 | ||
2651 | /* Save protocol name. */ | |
2652 | x11_saved_proto = xstrdup(proto); | |
2653 | ||
2654 | /* | |
2655 | * Extract real authentication data and generate fake data of the | |
2656 | * same length. | |
2657 | */ | |
2658 | x11_saved_data = xmalloc(data_len); | |
2659 | x11_fake_data = xmalloc(data_len); | |
2660 | for (i = 0; i < data_len; i++) { | |
2661 | if (sscanf(data + 2 * i, "%2x", &value) != 1) | |
2662 | fatal("x11_request_forwarding: bad authentication data: %.100s", data); | |
2663 | if (i % 4 == 0) | |
2664 | rand = arc4random(); | |
2665 | x11_saved_data[i] = value; | |
2666 | x11_fake_data[i] = rand & 0xff; | |
2667 | rand >>= 8; | |
2668 | } | |
2669 | x11_saved_data_len = data_len; | |
2670 | x11_fake_data_len = data_len; | |
2671 | ||
2672 | /* Convert the fake data into hex. */ | |
2673 | len = 2 * data_len + 1; | |
2674 | new_data = xmalloc(len); | |
2675 | for (i = 0; i < data_len; i++) | |
2676 | snprintf(new_data + 2 * i, len - 2 * i, | |
2677 | "%02x", (u_char) x11_fake_data[i]); | |
2678 | ||
2679 | /* Send the request packet. */ | |
2680 | if (compat20) { | |
2681 | channel_request_start(client_session_id, "x11-req", 0); | |
2682 | packet_put_char(0); /* XXX bool single connection */ | |
2683 | } else { | |
2684 | packet_start(SSH_CMSG_X11_REQUEST_FORWARDING); | |
2685 | } | |
2686 | packet_put_cstring(proto); | |
2687 | packet_put_cstring(new_data); | |
2688 | packet_put_int(screen_number); | |
2689 | packet_send(); | |
2690 | packet_write_wait(); | |
2691 | xfree(new_data); | |
2692 | } | |
2693 | ||
2694 | ||
2695 | /* -- agent forwarding */ | |
2696 | ||
2697 | /* Sends a message to the server to request authentication fd forwarding. */ | |
2698 | ||
2699 | void | |
e9a17296 | 2700 | auth_request_forwarding(void) |
3c0ef626 | 2701 | { |
2702 | packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); | |
2703 | packet_send(); | |
2704 | packet_write_wait(); | |
2705 | } | |
2706 | ||
3c0ef626 | 2707 | /* This is called to process an SSH_SMSG_AGENT_OPEN message. */ |
2708 | ||
2709 | void | |
e9a17296 | 2710 | auth_input_open_request(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 2711 | { |
2712 | Channel *c = NULL; | |
2713 | int remote_id, sock; | |
2714 | char *name; | |
2715 | ||
3c0ef626 | 2716 | /* Read the remote channel number from the message. */ |
2717 | remote_id = packet_get_int(); | |
e9a17296 | 2718 | packet_check_eom(); |
3c0ef626 | 2719 | |
2720 | /* | |
2721 | * Get a connection to the local authentication agent (this may again | |
2722 | * get forwarded). | |
2723 | */ | |
2724 | sock = ssh_get_authentication_socket(); | |
2725 | ||
2726 | /* | |
2727 | * If we could not connect the agent, send an error message back to | |
2728 | * the server. This should never happen unless the agent dies, | |
2729 | * because authentication forwarding is only enabled if we have an | |
2730 | * agent. | |
2731 | */ | |
2732 | if (sock >= 0) { | |
2733 | name = xstrdup("authentication agent connection"); | |
2734 | c = channel_new("", SSH_CHANNEL_OPEN, sock, sock, | |
2735 | -1, 0, 0, 0, name, 1); | |
e9a17296 | 2736 | c->remote_id = remote_id; |
2737 | c->force_drain = 1; | |
3c0ef626 | 2738 | } |
2739 | if (c == NULL) { | |
2740 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2741 | packet_put_int(remote_id); | |
2742 | } else { | |
2743 | /* Send a confirmation to the remote host. */ | |
2744 | debug("Forwarding authentication connection."); | |
2745 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
2746 | packet_put_int(remote_id); | |
2747 | packet_put_int(c->self); | |
2748 | } | |
2749 | packet_send(); | |
2750 | } |