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