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1 | /* $OpenBSD: channels.c,v 1.268 2007/01/03 03:01:40 stevesk Exp $ */ | |
2 | /* | |
3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
5 | * All rights reserved | |
6 | * This file contains functions for generic socket connection forwarding. | |
7 | * There is also code for initiating connection forwarding for X11 connections, | |
8 | * arbitrary tcp/ip connections, and the authentication agent connection. | |
9 | * | |
10 | * As far as I am concerned, the code I have written for this software | |
11 | * can be used freely for any purpose. Any derived versions of this | |
12 | * software must be clearly marked as such, and if the derived work is | |
13 | * incompatible with the protocol description in the RFC file, it must be | |
14 | * called by a name other than "ssh" or "Secure Shell". | |
15 | * | |
16 | * SSH2 support added by Markus Friedl. | |
17 | * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. | |
18 | * Copyright (c) 1999 Dug Song. All rights reserved. | |
19 | * Copyright (c) 1999 Theo de Raadt. All rights reserved. | |
20 | * | |
21 | * Redistribution and use in source and binary forms, with or without | |
22 | * modification, are permitted provided that the following conditions | |
23 | * are met: | |
24 | * 1. Redistributions of source code must retain the above copyright | |
25 | * notice, this list of conditions and the following disclaimer. | |
26 | * 2. Redistributions in binary form must reproduce the above copyright | |
27 | * notice, this list of conditions and the following disclaimer in the | |
28 | * documentation and/or other materials provided with the distribution. | |
29 | * | |
30 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
31 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
32 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
33 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
34 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
35 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
36 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
37 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
38 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
39 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
40 | */ | |
41 | ||
42 | #include "includes.h" | |
43 | ||
44 | #include <sys/types.h> | |
45 | #include <sys/ioctl.h> | |
46 | #include <sys/un.h> | |
47 | #include <sys/socket.h> | |
48 | #ifdef HAVE_SYS_TIME_H | |
49 | # include <sys/time.h> | |
50 | #endif | |
51 | ||
52 | #include <netinet/in.h> | |
53 | #include <arpa/inet.h> | |
54 | ||
55 | #include <errno.h> | |
56 | #include <netdb.h> | |
57 | #include <stdio.h> | |
58 | #include <stdlib.h> | |
59 | #include <string.h> | |
60 | #include <termios.h> | |
61 | #include <unistd.h> | |
62 | #include <stdarg.h> | |
63 | ||
64 | #include "xmalloc.h" | |
65 | #include "ssh.h" | |
66 | #include "ssh1.h" | |
67 | #include "ssh2.h" | |
68 | #include "packet.h" | |
69 | #include "log.h" | |
70 | #include "misc.h" | |
71 | #include "buffer.h" | |
72 | #include "channels.h" | |
73 | #include "compat.h" | |
74 | #include "canohost.h" | |
75 | #include "key.h" | |
76 | #include "authfd.h" | |
77 | #include "pathnames.h" | |
78 | ||
79 | /* -- channel core */ | |
80 | ||
81 | /* | |
82 | * Pointer to an array containing all allocated channels. The array is | |
83 | * dynamically extended as needed. | |
84 | */ | |
85 | static Channel **channels = NULL; | |
86 | ||
87 | /* | |
88 | * Size of the channel array. All slots of the array must always be | |
89 | * initialized (at least the type field); unused slots set to NULL | |
90 | */ | |
91 | static u_int channels_alloc = 0; | |
92 | ||
93 | /* | |
94 | * Maximum file descriptor value used in any of the channels. This is | |
95 | * updated in channel_new. | |
96 | */ | |
97 | static int channel_max_fd = 0; | |
98 | ||
99 | ||
100 | /* -- tcp forwarding */ | |
101 | ||
102 | /* | |
103 | * Data structure for storing which hosts are permitted for forward requests. | |
104 | * The local sides of any remote forwards are stored in this array to prevent | |
105 | * a corrupt remote server from accessing arbitrary TCP/IP ports on our local | |
106 | * network (which might be behind a firewall). | |
107 | */ | |
108 | typedef struct { | |
109 | char *host_to_connect; /* Connect to 'host'. */ | |
110 | u_short port_to_connect; /* Connect to 'port'. */ | |
111 | u_short listen_port; /* Remote side should listen port number. */ | |
112 | } ForwardPermission; | |
113 | ||
114 | /* List of all permitted host/port pairs to connect by the user. */ | |
115 | static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; | |
116 | ||
117 | /* List of all permitted host/port pairs to connect by the admin. */ | |
118 | static ForwardPermission permitted_adm_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; | |
119 | ||
120 | /* Number of permitted host/port pairs in the array permitted by the user. */ | |
121 | static int num_permitted_opens = 0; | |
122 | ||
123 | /* Number of permitted host/port pair in the array permitted by the admin. */ | |
124 | static int num_adm_permitted_opens = 0; | |
125 | ||
126 | /* | |
127 | * If this is true, all opens are permitted. This is the case on the server | |
128 | * on which we have to trust the client anyway, and the user could do | |
129 | * anything after logging in anyway. | |
130 | */ | |
131 | static int all_opens_permitted = 0; | |
132 | ||
133 | ||
134 | /* -- X11 forwarding */ | |
135 | ||
136 | /* Maximum number of fake X11 displays to try. */ | |
137 | #define MAX_DISPLAYS 1000 | |
138 | ||
139 | /* Saved X11 local (client) display. */ | |
140 | static char *x11_saved_display = NULL; | |
141 | ||
142 | /* Saved X11 authentication protocol name. */ | |
143 | static char *x11_saved_proto = NULL; | |
144 | ||
145 | /* Saved X11 authentication data. This is the real data. */ | |
146 | static char *x11_saved_data = NULL; | |
147 | static u_int x11_saved_data_len = 0; | |
148 | ||
149 | /* | |
150 | * Fake X11 authentication data. This is what the server will be sending us; | |
151 | * we should replace any occurrences of this by the real data. | |
152 | */ | |
153 | static u_char *x11_fake_data = NULL; | |
154 | static u_int x11_fake_data_len; | |
155 | ||
156 | ||
157 | /* -- agent forwarding */ | |
158 | ||
159 | #define NUM_SOCKS 10 | |
160 | ||
161 | /* AF_UNSPEC or AF_INET or AF_INET6 */ | |
162 | static int IPv4or6 = AF_UNSPEC; | |
163 | ||
164 | /* helper */ | |
165 | static void port_open_helper(Channel *c, char *rtype); | |
166 | ||
167 | /* -- channel core */ | |
168 | ||
169 | Channel * | |
170 | channel_by_id(int id) | |
171 | { | |
172 | Channel *c; | |
173 | ||
174 | if (id < 0 || (u_int)id >= channels_alloc) { | |
175 | logit("channel_by_id: %d: bad id", id); | |
176 | return NULL; | |
177 | } | |
178 | c = channels[id]; | |
179 | if (c == NULL) { | |
180 | logit("channel_by_id: %d: bad id: channel free", id); | |
181 | return NULL; | |
182 | } | |
183 | return c; | |
184 | } | |
185 | ||
186 | /* | |
187 | * Returns the channel if it is allowed to receive protocol messages. | |
188 | * Private channels, like listening sockets, may not receive messages. | |
189 | */ | |
190 | Channel * | |
191 | channel_lookup(int id) | |
192 | { | |
193 | Channel *c; | |
194 | ||
195 | if ((c = channel_by_id(id)) == NULL) | |
196 | return (NULL); | |
197 | ||
198 | switch (c->type) { | |
199 | case SSH_CHANNEL_X11_OPEN: | |
200 | case SSH_CHANNEL_LARVAL: | |
201 | case SSH_CHANNEL_CONNECTING: | |
202 | case SSH_CHANNEL_DYNAMIC: | |
203 | case SSH_CHANNEL_OPENING: | |
204 | case SSH_CHANNEL_OPEN: | |
205 | case SSH_CHANNEL_INPUT_DRAINING: | |
206 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
207 | return (c); | |
208 | } | |
209 | logit("Non-public channel %d, type %d.", id, c->type); | |
210 | return (NULL); | |
211 | } | |
212 | ||
213 | /* | |
214 | * Register filedescriptors for a channel, used when allocating a channel or | |
215 | * when the channel consumer/producer is ready, e.g. shell exec'd | |
216 | */ | |
217 | static void | |
218 | channel_register_fds(Channel *c, int rfd, int wfd, int efd, | |
219 | int extusage, int nonblock) | |
220 | { | |
221 | /* Update the maximum file descriptor value. */ | |
222 | channel_max_fd = MAX(channel_max_fd, rfd); | |
223 | channel_max_fd = MAX(channel_max_fd, wfd); | |
224 | channel_max_fd = MAX(channel_max_fd, efd); | |
225 | ||
226 | /* XXX set close-on-exec -markus */ | |
227 | ||
228 | c->rfd = rfd; | |
229 | c->wfd = wfd; | |
230 | c->sock = (rfd == wfd) ? rfd : -1; | |
231 | c->ctl_fd = -1; /* XXX: set elsewhere */ | |
232 | c->efd = efd; | |
233 | c->extended_usage = extusage; | |
234 | ||
235 | /* XXX ugly hack: nonblock is only set by the server */ | |
236 | if (nonblock && isatty(c->rfd)) { | |
237 | debug2("channel %d: rfd %d isatty", c->self, c->rfd); | |
238 | c->isatty = 1; | |
239 | if (!isatty(c->wfd)) { | |
240 | error("channel %d: wfd %d is not a tty?", | |
241 | c->self, c->wfd); | |
242 | } | |
243 | } else { | |
244 | c->isatty = 0; | |
245 | } | |
246 | c->wfd_isatty = isatty(c->wfd); | |
247 | ||
248 | /* enable nonblocking mode */ | |
249 | if (nonblock) { | |
250 | if (rfd != -1) | |
251 | set_nonblock(rfd); | |
252 | if (wfd != -1) | |
253 | set_nonblock(wfd); | |
254 | if (efd != -1) | |
255 | set_nonblock(efd); | |
256 | } | |
257 | } | |
258 | ||
259 | /* | |
260 | * Allocate a new channel object and set its type and socket. This will cause | |
261 | * remote_name to be freed. | |
262 | */ | |
263 | Channel * | |
264 | channel_new(char *ctype, int type, int rfd, int wfd, int efd, | |
265 | u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock) | |
266 | { | |
267 | int found; | |
268 | u_int i; | |
269 | Channel *c; | |
270 | ||
271 | /* Do initial allocation if this is the first call. */ | |
272 | if (channels_alloc == 0) { | |
273 | channels_alloc = 10; | |
274 | channels = xcalloc(channels_alloc, sizeof(Channel *)); | |
275 | for (i = 0; i < channels_alloc; i++) | |
276 | channels[i] = NULL; | |
277 | } | |
278 | /* Try to find a free slot where to put the new channel. */ | |
279 | for (found = -1, i = 0; i < channels_alloc; i++) | |
280 | if (channels[i] == NULL) { | |
281 | /* Found a free slot. */ | |
282 | found = (int)i; | |
283 | break; | |
284 | } | |
285 | if (found < 0) { | |
286 | /* There are no free slots. Take last+1 slot and expand the array. */ | |
287 | found = channels_alloc; | |
288 | if (channels_alloc > 10000) | |
289 | fatal("channel_new: internal error: channels_alloc %d " | |
290 | "too big.", channels_alloc); | |
291 | channels = xrealloc(channels, channels_alloc + 10, | |
292 | sizeof(Channel *)); | |
293 | channels_alloc += 10; | |
294 | debug2("channel: expanding %d", channels_alloc); | |
295 | for (i = found; i < channels_alloc; i++) | |
296 | channels[i] = NULL; | |
297 | } | |
298 | /* Initialize and return new channel. */ | |
299 | c = channels[found] = xcalloc(1, sizeof(Channel)); | |
300 | buffer_init(&c->input); | |
301 | buffer_init(&c->output); | |
302 | buffer_init(&c->extended); | |
303 | c->ostate = CHAN_OUTPUT_OPEN; | |
304 | c->istate = CHAN_INPUT_OPEN; | |
305 | c->flags = 0; | |
306 | channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); | |
307 | c->self = found; | |
308 | c->type = type; | |
309 | c->ctype = ctype; | |
310 | c->local_window = window; | |
311 | c->local_window_max = window; | |
312 | c->local_consumed = 0; | |
313 | c->local_maxpacket = maxpack; | |
314 | c->remote_id = -1; | |
315 | c->remote_name = xstrdup(remote_name); | |
316 | c->remote_window = 0; | |
317 | c->remote_maxpacket = 0; | |
318 | c->force_drain = 0; | |
319 | c->single_connection = 0; | |
320 | c->detach_user = NULL; | |
321 | c->detach_close = 0; | |
322 | c->confirm = NULL; | |
323 | c->confirm_ctx = NULL; | |
324 | c->input_filter = NULL; | |
325 | c->output_filter = NULL; | |
326 | debug("channel %d: new [%s]", found, remote_name); | |
327 | return c; | |
328 | } | |
329 | ||
330 | static int | |
331 | channel_find_maxfd(void) | |
332 | { | |
333 | u_int i; | |
334 | int max = 0; | |
335 | Channel *c; | |
336 | ||
337 | for (i = 0; i < channels_alloc; i++) { | |
338 | c = channels[i]; | |
339 | if (c != NULL) { | |
340 | max = MAX(max, c->rfd); | |
341 | max = MAX(max, c->wfd); | |
342 | max = MAX(max, c->efd); | |
343 | } | |
344 | } | |
345 | return max; | |
346 | } | |
347 | ||
348 | int | |
349 | channel_close_fd(int *fdp) | |
350 | { | |
351 | int ret = 0, fd = *fdp; | |
352 | ||
353 | if (fd != -1) { | |
354 | ret = close(fd); | |
355 | *fdp = -1; | |
356 | if (fd == channel_max_fd) | |
357 | channel_max_fd = channel_find_maxfd(); | |
358 | } | |
359 | return ret; | |
360 | } | |
361 | ||
362 | /* Close all channel fd/socket. */ | |
363 | static void | |
364 | channel_close_fds(Channel *c) | |
365 | { | |
366 | debug3("channel %d: close_fds r %d w %d e %d c %d", | |
367 | c->self, c->rfd, c->wfd, c->efd, c->ctl_fd); | |
368 | ||
369 | channel_close_fd(&c->sock); | |
370 | channel_close_fd(&c->ctl_fd); | |
371 | channel_close_fd(&c->rfd); | |
372 | channel_close_fd(&c->wfd); | |
373 | channel_close_fd(&c->efd); | |
374 | } | |
375 | ||
376 | /* Free the channel and close its fd/socket. */ | |
377 | void | |
378 | channel_free(Channel *c) | |
379 | { | |
380 | char *s; | |
381 | u_int i, n; | |
382 | ||
383 | for (n = 0, i = 0; i < channels_alloc; i++) | |
384 | if (channels[i]) | |
385 | n++; | |
386 | debug("channel %d: free: %s, nchannels %u", c->self, | |
387 | c->remote_name ? c->remote_name : "???", n); | |
388 | ||
389 | s = channel_open_message(); | |
390 | debug3("channel %d: status: %s", c->self, s); | |
391 | xfree(s); | |
392 | ||
393 | if (c->sock != -1) | |
394 | shutdown(c->sock, SHUT_RDWR); | |
395 | if (c->ctl_fd != -1) | |
396 | shutdown(c->ctl_fd, SHUT_RDWR); | |
397 | channel_close_fds(c); | |
398 | buffer_free(&c->input); | |
399 | buffer_free(&c->output); | |
400 | buffer_free(&c->extended); | |
401 | if (c->remote_name) { | |
402 | xfree(c->remote_name); | |
403 | c->remote_name = NULL; | |
404 | } | |
405 | channels[c->self] = NULL; | |
406 | xfree(c); | |
407 | } | |
408 | ||
409 | void | |
410 | channel_free_all(void) | |
411 | { | |
412 | u_int i; | |
413 | ||
414 | for (i = 0; i < channels_alloc; i++) | |
415 | if (channels[i] != NULL) | |
416 | channel_free(channels[i]); | |
417 | } | |
418 | ||
419 | /* | |
420 | * Closes the sockets/fds of all channels. This is used to close extra file | |
421 | * descriptors after a fork. | |
422 | */ | |
423 | void | |
424 | channel_close_all(void) | |
425 | { | |
426 | u_int i; | |
427 | ||
428 | for (i = 0; i < channels_alloc; i++) | |
429 | if (channels[i] != NULL) | |
430 | channel_close_fds(channels[i]); | |
431 | } | |
432 | ||
433 | /* | |
434 | * Stop listening to channels. | |
435 | */ | |
436 | void | |
437 | channel_stop_listening(void) | |
438 | { | |
439 | u_int i; | |
440 | Channel *c; | |
441 | ||
442 | for (i = 0; i < channels_alloc; i++) { | |
443 | c = channels[i]; | |
444 | if (c != NULL) { | |
445 | switch (c->type) { | |
446 | case SSH_CHANNEL_AUTH_SOCKET: | |
447 | case SSH_CHANNEL_PORT_LISTENER: | |
448 | case SSH_CHANNEL_RPORT_LISTENER: | |
449 | case SSH_CHANNEL_X11_LISTENER: | |
450 | channel_close_fd(&c->sock); | |
451 | channel_free(c); | |
452 | break; | |
453 | } | |
454 | } | |
455 | } | |
456 | } | |
457 | ||
458 | /* | |
459 | * Returns true if no channel has too much buffered data, and false if one or | |
460 | * more channel is overfull. | |
461 | */ | |
462 | int | |
463 | channel_not_very_much_buffered_data(void) | |
464 | { | |
465 | u_int i; | |
466 | Channel *c; | |
467 | ||
468 | for (i = 0; i < channels_alloc; i++) { | |
469 | c = channels[i]; | |
470 | if (c != NULL && c->type == SSH_CHANNEL_OPEN) { | |
471 | #if 0 | |
472 | if (!compat20 && | |
473 | buffer_len(&c->input) > packet_get_maxsize()) { | |
474 | debug2("channel %d: big input buffer %d", | |
475 | c->self, buffer_len(&c->input)); | |
476 | return 0; | |
477 | } | |
478 | #endif | |
479 | if (buffer_len(&c->output) > packet_get_maxsize()) { | |
480 | debug2("channel %d: big output buffer %u > %u", | |
481 | c->self, buffer_len(&c->output), | |
482 | packet_get_maxsize()); | |
483 | return 0; | |
484 | } | |
485 | } | |
486 | } | |
487 | return 1; | |
488 | } | |
489 | ||
490 | /* Returns true if any channel is still open. */ | |
491 | int | |
492 | channel_still_open(void) | |
493 | { | |
494 | u_int i; | |
495 | Channel *c; | |
496 | ||
497 | for (i = 0; i < channels_alloc; i++) { | |
498 | c = channels[i]; | |
499 | if (c == NULL) | |
500 | continue; | |
501 | switch (c->type) { | |
502 | case SSH_CHANNEL_X11_LISTENER: | |
503 | case SSH_CHANNEL_PORT_LISTENER: | |
504 | case SSH_CHANNEL_RPORT_LISTENER: | |
505 | case SSH_CHANNEL_CLOSED: | |
506 | case SSH_CHANNEL_AUTH_SOCKET: | |
507 | case SSH_CHANNEL_DYNAMIC: | |
508 | case SSH_CHANNEL_CONNECTING: | |
509 | case SSH_CHANNEL_ZOMBIE: | |
510 | continue; | |
511 | case SSH_CHANNEL_LARVAL: | |
512 | if (!compat20) | |
513 | fatal("cannot happen: SSH_CHANNEL_LARVAL"); | |
514 | continue; | |
515 | case SSH_CHANNEL_OPENING: | |
516 | case SSH_CHANNEL_OPEN: | |
517 | case SSH_CHANNEL_X11_OPEN: | |
518 | return 1; | |
519 | case SSH_CHANNEL_INPUT_DRAINING: | |
520 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
521 | if (!compat13) | |
522 | fatal("cannot happen: OUT_DRAIN"); | |
523 | return 1; | |
524 | default: | |
525 | fatal("channel_still_open: bad channel type %d", c->type); | |
526 | /* NOTREACHED */ | |
527 | } | |
528 | } | |
529 | return 0; | |
530 | } | |
531 | ||
532 | /* Returns the id of an open channel suitable for keepaliving */ | |
533 | int | |
534 | channel_find_open(void) | |
535 | { | |
536 | u_int i; | |
537 | Channel *c; | |
538 | ||
539 | for (i = 0; i < channels_alloc; i++) { | |
540 | c = channels[i]; | |
541 | if (c == NULL || c->remote_id < 0) | |
542 | continue; | |
543 | switch (c->type) { | |
544 | case SSH_CHANNEL_CLOSED: | |
545 | case SSH_CHANNEL_DYNAMIC: | |
546 | case SSH_CHANNEL_X11_LISTENER: | |
547 | case SSH_CHANNEL_PORT_LISTENER: | |
548 | case SSH_CHANNEL_RPORT_LISTENER: | |
549 | case SSH_CHANNEL_OPENING: | |
550 | case SSH_CHANNEL_CONNECTING: | |
551 | case SSH_CHANNEL_ZOMBIE: | |
552 | continue; | |
553 | case SSH_CHANNEL_LARVAL: | |
554 | case SSH_CHANNEL_AUTH_SOCKET: | |
555 | case SSH_CHANNEL_OPEN: | |
556 | case SSH_CHANNEL_X11_OPEN: | |
557 | return i; | |
558 | case SSH_CHANNEL_INPUT_DRAINING: | |
559 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
560 | if (!compat13) | |
561 | fatal("cannot happen: OUT_DRAIN"); | |
562 | return i; | |
563 | default: | |
564 | fatal("channel_find_open: bad channel type %d", c->type); | |
565 | /* NOTREACHED */ | |
566 | } | |
567 | } | |
568 | return -1; | |
569 | } | |
570 | ||
571 | ||
572 | /* | |
573 | * Returns a message describing the currently open forwarded connections, | |
574 | * suitable for sending to the client. The message contains crlf pairs for | |
575 | * newlines. | |
576 | */ | |
577 | char * | |
578 | channel_open_message(void) | |
579 | { | |
580 | Buffer buffer; | |
581 | Channel *c; | |
582 | char buf[1024], *cp; | |
583 | u_int i; | |
584 | ||
585 | buffer_init(&buffer); | |
586 | snprintf(buf, sizeof buf, "The following connections are open:\r\n"); | |
587 | buffer_append(&buffer, buf, strlen(buf)); | |
588 | for (i = 0; i < channels_alloc; i++) { | |
589 | c = channels[i]; | |
590 | if (c == NULL) | |
591 | continue; | |
592 | switch (c->type) { | |
593 | case SSH_CHANNEL_X11_LISTENER: | |
594 | case SSH_CHANNEL_PORT_LISTENER: | |
595 | case SSH_CHANNEL_RPORT_LISTENER: | |
596 | case SSH_CHANNEL_CLOSED: | |
597 | case SSH_CHANNEL_AUTH_SOCKET: | |
598 | case SSH_CHANNEL_ZOMBIE: | |
599 | continue; | |
600 | case SSH_CHANNEL_LARVAL: | |
601 | case SSH_CHANNEL_OPENING: | |
602 | case SSH_CHANNEL_CONNECTING: | |
603 | case SSH_CHANNEL_DYNAMIC: | |
604 | case SSH_CHANNEL_OPEN: | |
605 | case SSH_CHANNEL_X11_OPEN: | |
606 | case SSH_CHANNEL_INPUT_DRAINING: | |
607 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
608 | snprintf(buf, sizeof buf, | |
609 | " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d cfd %d)\r\n", | |
610 | c->self, c->remote_name, | |
611 | c->type, c->remote_id, | |
612 | c->istate, buffer_len(&c->input), | |
613 | c->ostate, buffer_len(&c->output), | |
614 | c->rfd, c->wfd, c->ctl_fd); | |
615 | buffer_append(&buffer, buf, strlen(buf)); | |
616 | continue; | |
617 | default: | |
618 | fatal("channel_open_message: bad channel type %d", c->type); | |
619 | /* NOTREACHED */ | |
620 | } | |
621 | } | |
622 | buffer_append(&buffer, "\0", 1); | |
623 | cp = xstrdup(buffer_ptr(&buffer)); | |
624 | buffer_free(&buffer); | |
625 | return cp; | |
626 | } | |
627 | ||
628 | void | |
629 | channel_send_open(int id) | |
630 | { | |
631 | Channel *c = channel_lookup(id); | |
632 | ||
633 | if (c == NULL) { | |
634 | logit("channel_send_open: %d: bad id", id); | |
635 | return; | |
636 | } | |
637 | debug2("channel %d: send open", id); | |
638 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
639 | packet_put_cstring(c->ctype); | |
640 | packet_put_int(c->self); | |
641 | packet_put_int(c->local_window); | |
642 | packet_put_int(c->local_maxpacket); | |
643 | packet_send(); | |
644 | } | |
645 | ||
646 | void | |
647 | channel_request_start(int id, char *service, int wantconfirm) | |
648 | { | |
649 | Channel *c = channel_lookup(id); | |
650 | ||
651 | if (c == NULL) { | |
652 | logit("channel_request_start: %d: unknown channel id", id); | |
653 | return; | |
654 | } | |
655 | debug2("channel %d: request %s confirm %d", id, service, wantconfirm); | |
656 | packet_start(SSH2_MSG_CHANNEL_REQUEST); | |
657 | packet_put_int(c->remote_id); | |
658 | packet_put_cstring(service); | |
659 | packet_put_char(wantconfirm); | |
660 | } | |
661 | ||
662 | void | |
663 | channel_register_confirm(int id, channel_callback_fn *fn, void *ctx) | |
664 | { | |
665 | Channel *c = channel_lookup(id); | |
666 | ||
667 | if (c == NULL) { | |
668 | logit("channel_register_comfirm: %d: bad id", id); | |
669 | return; | |
670 | } | |
671 | c->confirm = fn; | |
672 | c->confirm_ctx = ctx; | |
673 | } | |
674 | ||
675 | void | |
676 | channel_register_cleanup(int id, channel_callback_fn *fn, int do_close) | |
677 | { | |
678 | Channel *c = channel_by_id(id); | |
679 | ||
680 | if (c == NULL) { | |
681 | logit("channel_register_cleanup: %d: bad id", id); | |
682 | return; | |
683 | } | |
684 | c->detach_user = fn; | |
685 | c->detach_close = do_close; | |
686 | } | |
687 | ||
688 | void | |
689 | channel_cancel_cleanup(int id) | |
690 | { | |
691 | Channel *c = channel_by_id(id); | |
692 | ||
693 | if (c == NULL) { | |
694 | logit("channel_cancel_cleanup: %d: bad id", id); | |
695 | return; | |
696 | } | |
697 | c->detach_user = NULL; | |
698 | c->detach_close = 0; | |
699 | } | |
700 | ||
701 | void | |
702 | channel_register_filter(int id, channel_infilter_fn *ifn, | |
703 | channel_outfilter_fn *ofn) | |
704 | { | |
705 | Channel *c = channel_lookup(id); | |
706 | ||
707 | if (c == NULL) { | |
708 | logit("channel_register_filter: %d: bad id", id); | |
709 | return; | |
710 | } | |
711 | c->input_filter = ifn; | |
712 | c->output_filter = ofn; | |
713 | } | |
714 | ||
715 | void | |
716 | channel_set_fds(int id, int rfd, int wfd, int efd, | |
717 | int extusage, int nonblock, u_int window_max) | |
718 | { | |
719 | Channel *c = channel_lookup(id); | |
720 | ||
721 | if (c == NULL || c->type != SSH_CHANNEL_LARVAL) | |
722 | fatal("channel_activate for non-larval channel %d.", id); | |
723 | channel_register_fds(c, rfd, wfd, efd, extusage, nonblock); | |
724 | c->type = SSH_CHANNEL_OPEN; | |
725 | c->local_window = c->local_window_max = window_max; | |
726 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); | |
727 | packet_put_int(c->remote_id); | |
728 | packet_put_int(c->local_window); | |
729 | packet_send(); | |
730 | } | |
731 | ||
732 | /* | |
733 | * 'channel_pre*' are called just before select() to add any bits relevant to | |
734 | * channels in the select bitmasks. | |
735 | */ | |
736 | /* | |
737 | * 'channel_post*': perform any appropriate operations for channels which | |
738 | * have events pending. | |
739 | */ | |
740 | typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset); | |
741 | chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; | |
742 | chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; | |
743 | ||
744 | /* ARGSUSED */ | |
745 | static void | |
746 | channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset) | |
747 | { | |
748 | FD_SET(c->sock, readset); | |
749 | } | |
750 | ||
751 | /* ARGSUSED */ | |
752 | static void | |
753 | channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset) | |
754 | { | |
755 | debug3("channel %d: waiting for connection", c->self); | |
756 | FD_SET(c->sock, writeset); | |
757 | } | |
758 | ||
759 | static void | |
760 | channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset) | |
761 | { | |
762 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
763 | FD_SET(c->sock, readset); | |
764 | if (buffer_len(&c->output) > 0) | |
765 | FD_SET(c->sock, writeset); | |
766 | } | |
767 | ||
768 | static void | |
769 | channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset) | |
770 | { | |
771 | u_int limit = compat20 ? c->remote_window : packet_get_maxsize(); | |
772 | ||
773 | if (c->istate == CHAN_INPUT_OPEN && | |
774 | limit > 0 && | |
775 | buffer_len(&c->input) < limit && | |
776 | buffer_check_alloc(&c->input, CHAN_RBUF)) | |
777 | FD_SET(c->rfd, readset); | |
778 | if (c->ostate == CHAN_OUTPUT_OPEN || | |
779 | c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
780 | if (buffer_len(&c->output) > 0) { | |
781 | FD_SET(c->wfd, writeset); | |
782 | } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
783 | if (CHANNEL_EFD_OUTPUT_ACTIVE(c)) | |
784 | debug2("channel %d: obuf_empty delayed efd %d/(%d)", | |
785 | c->self, c->efd, buffer_len(&c->extended)); | |
786 | else | |
787 | chan_obuf_empty(c); | |
788 | } | |
789 | } | |
790 | /** XXX check close conditions, too */ | |
791 | if (compat20 && c->efd != -1) { | |
792 | if (c->extended_usage == CHAN_EXTENDED_WRITE && | |
793 | buffer_len(&c->extended) > 0) | |
794 | FD_SET(c->efd, writeset); | |
795 | else if (!(c->flags & CHAN_EOF_SENT) && | |
796 | c->extended_usage == CHAN_EXTENDED_READ && | |
797 | buffer_len(&c->extended) < c->remote_window) | |
798 | FD_SET(c->efd, readset); | |
799 | } | |
800 | /* XXX: What about efd? races? */ | |
801 | if (compat20 && c->ctl_fd != -1 && | |
802 | c->istate == CHAN_INPUT_OPEN && c->ostate == CHAN_OUTPUT_OPEN) | |
803 | FD_SET(c->ctl_fd, readset); | |
804 | } | |
805 | ||
806 | /* ARGSUSED */ | |
807 | static void | |
808 | channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset) | |
809 | { | |
810 | if (buffer_len(&c->input) == 0) { | |
811 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
812 | packet_put_int(c->remote_id); | |
813 | packet_send(); | |
814 | c->type = SSH_CHANNEL_CLOSED; | |
815 | debug2("channel %d: closing after input drain.", c->self); | |
816 | } | |
817 | } | |
818 | ||
819 | /* ARGSUSED */ | |
820 | static void | |
821 | channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset) | |
822 | { | |
823 | if (buffer_len(&c->output) == 0) | |
824 | chan_mark_dead(c); | |
825 | else | |
826 | FD_SET(c->sock, writeset); | |
827 | } | |
828 | ||
829 | /* | |
830 | * This is a special state for X11 authentication spoofing. An opened X11 | |
831 | * connection (when authentication spoofing is being done) remains in this | |
832 | * state until the first packet has been completely read. The authentication | |
833 | * data in that packet is then substituted by the real data if it matches the | |
834 | * fake data, and the channel is put into normal mode. | |
835 | * XXX All this happens at the client side. | |
836 | * Returns: 0 = need more data, -1 = wrong cookie, 1 = ok | |
837 | */ | |
838 | static int | |
839 | x11_open_helper(Buffer *b) | |
840 | { | |
841 | u_char *ucp; | |
842 | u_int proto_len, data_len; | |
843 | ||
844 | /* Check if the fixed size part of the packet is in buffer. */ | |
845 | if (buffer_len(b) < 12) | |
846 | return 0; | |
847 | ||
848 | /* Parse the lengths of variable-length fields. */ | |
849 | ucp = buffer_ptr(b); | |
850 | if (ucp[0] == 0x42) { /* Byte order MSB first. */ | |
851 | proto_len = 256 * ucp[6] + ucp[7]; | |
852 | data_len = 256 * ucp[8] + ucp[9]; | |
853 | } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ | |
854 | proto_len = ucp[6] + 256 * ucp[7]; | |
855 | data_len = ucp[8] + 256 * ucp[9]; | |
856 | } else { | |
857 | debug2("Initial X11 packet contains bad byte order byte: 0x%x", | |
858 | ucp[0]); | |
859 | return -1; | |
860 | } | |
861 | ||
862 | /* Check if the whole packet is in buffer. */ | |
863 | if (buffer_len(b) < | |
864 | 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) | |
865 | return 0; | |
866 | ||
867 | /* Check if authentication protocol matches. */ | |
868 | if (proto_len != strlen(x11_saved_proto) || | |
869 | memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { | |
870 | debug2("X11 connection uses different authentication protocol."); | |
871 | return -1; | |
872 | } | |
873 | /* Check if authentication data matches our fake data. */ | |
874 | if (data_len != x11_fake_data_len || | |
875 | memcmp(ucp + 12 + ((proto_len + 3) & ~3), | |
876 | x11_fake_data, x11_fake_data_len) != 0) { | |
877 | debug2("X11 auth data does not match fake data."); | |
878 | return -1; | |
879 | } | |
880 | /* Check fake data length */ | |
881 | if (x11_fake_data_len != x11_saved_data_len) { | |
882 | error("X11 fake_data_len %d != saved_data_len %d", | |
883 | x11_fake_data_len, x11_saved_data_len); | |
884 | return -1; | |
885 | } | |
886 | /* | |
887 | * Received authentication protocol and data match | |
888 | * our fake data. Substitute the fake data with real | |
889 | * data. | |
890 | */ | |
891 | memcpy(ucp + 12 + ((proto_len + 3) & ~3), | |
892 | x11_saved_data, x11_saved_data_len); | |
893 | return 1; | |
894 | } | |
895 | ||
896 | static void | |
897 | channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset) | |
898 | { | |
899 | int ret = x11_open_helper(&c->output); | |
900 | ||
901 | if (ret == 1) { | |
902 | /* Start normal processing for the channel. */ | |
903 | c->type = SSH_CHANNEL_OPEN; | |
904 | channel_pre_open_13(c, readset, writeset); | |
905 | } else if (ret == -1) { | |
906 | /* | |
907 | * We have received an X11 connection that has bad | |
908 | * authentication information. | |
909 | */ | |
910 | logit("X11 connection rejected because of wrong authentication."); | |
911 | buffer_clear(&c->input); | |
912 | buffer_clear(&c->output); | |
913 | channel_close_fd(&c->sock); | |
914 | c->sock = -1; | |
915 | c->type = SSH_CHANNEL_CLOSED; | |
916 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
917 | packet_put_int(c->remote_id); | |
918 | packet_send(); | |
919 | } | |
920 | } | |
921 | ||
922 | static void | |
923 | channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset) | |
924 | { | |
925 | int ret = x11_open_helper(&c->output); | |
926 | ||
927 | /* c->force_drain = 1; */ | |
928 | ||
929 | if (ret == 1) { | |
930 | c->type = SSH_CHANNEL_OPEN; | |
931 | channel_pre_open(c, readset, writeset); | |
932 | } else if (ret == -1) { | |
933 | logit("X11 connection rejected because of wrong authentication."); | |
934 | debug2("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); | |
935 | chan_read_failed(c); | |
936 | buffer_clear(&c->input); | |
937 | chan_ibuf_empty(c); | |
938 | buffer_clear(&c->output); | |
939 | /* for proto v1, the peer will send an IEOF */ | |
940 | if (compat20) | |
941 | chan_write_failed(c); | |
942 | else | |
943 | c->type = SSH_CHANNEL_OPEN; | |
944 | debug2("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); | |
945 | } | |
946 | } | |
947 | ||
948 | /* try to decode a socks4 header */ | |
949 | /* ARGSUSED */ | |
950 | static int | |
951 | channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset) | |
952 | { | |
953 | char *p, *host; | |
954 | u_int len, have, i, found; | |
955 | char username[256]; | |
956 | struct { | |
957 | u_int8_t version; | |
958 | u_int8_t command; | |
959 | u_int16_t dest_port; | |
960 | struct in_addr dest_addr; | |
961 | } s4_req, s4_rsp; | |
962 | ||
963 | debug2("channel %d: decode socks4", c->self); | |
964 | ||
965 | have = buffer_len(&c->input); | |
966 | len = sizeof(s4_req); | |
967 | if (have < len) | |
968 | return 0; | |
969 | p = buffer_ptr(&c->input); | |
970 | for (found = 0, i = len; i < have; i++) { | |
971 | if (p[i] == '\0') { | |
972 | found = 1; | |
973 | break; | |
974 | } | |
975 | if (i > 1024) { | |
976 | /* the peer is probably sending garbage */ | |
977 | debug("channel %d: decode socks4: too long", | |
978 | c->self); | |
979 | return -1; | |
980 | } | |
981 | } | |
982 | if (!found) | |
983 | return 0; | |
984 | buffer_get(&c->input, (char *)&s4_req.version, 1); | |
985 | buffer_get(&c->input, (char *)&s4_req.command, 1); | |
986 | buffer_get(&c->input, (char *)&s4_req.dest_port, 2); | |
987 | buffer_get(&c->input, (char *)&s4_req.dest_addr, 4); | |
988 | have = buffer_len(&c->input); | |
989 | p = buffer_ptr(&c->input); | |
990 | len = strlen(p); | |
991 | debug2("channel %d: decode socks4: user %s/%d", c->self, p, len); | |
992 | if (len > have) | |
993 | fatal("channel %d: decode socks4: len %d > have %d", | |
994 | c->self, len, have); | |
995 | strlcpy(username, p, sizeof(username)); | |
996 | buffer_consume(&c->input, len); | |
997 | buffer_consume(&c->input, 1); /* trailing '\0' */ | |
998 | ||
999 | host = inet_ntoa(s4_req.dest_addr); | |
1000 | strlcpy(c->path, host, sizeof(c->path)); | |
1001 | c->host_port = ntohs(s4_req.dest_port); | |
1002 | ||
1003 | debug2("channel %d: dynamic request: socks4 host %s port %u command %u", | |
1004 | c->self, host, c->host_port, s4_req.command); | |
1005 | ||
1006 | if (s4_req.command != 1) { | |
1007 | debug("channel %d: cannot handle: socks4 cn %d", | |
1008 | c->self, s4_req.command); | |
1009 | return -1; | |
1010 | } | |
1011 | s4_rsp.version = 0; /* vn: 0 for reply */ | |
1012 | s4_rsp.command = 90; /* cd: req granted */ | |
1013 | s4_rsp.dest_port = 0; /* ignored */ | |
1014 | s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */ | |
1015 | buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp)); | |
1016 | return 1; | |
1017 | } | |
1018 | ||
1019 | /* try to decode a socks5 header */ | |
1020 | #define SSH_SOCKS5_AUTHDONE 0x1000 | |
1021 | #define SSH_SOCKS5_NOAUTH 0x00 | |
1022 | #define SSH_SOCKS5_IPV4 0x01 | |
1023 | #define SSH_SOCKS5_DOMAIN 0x03 | |
1024 | #define SSH_SOCKS5_IPV6 0x04 | |
1025 | #define SSH_SOCKS5_CONNECT 0x01 | |
1026 | #define SSH_SOCKS5_SUCCESS 0x00 | |
1027 | ||
1028 | /* ARGSUSED */ | |
1029 | static int | |
1030 | channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset) | |
1031 | { | |
1032 | struct { | |
1033 | u_int8_t version; | |
1034 | u_int8_t command; | |
1035 | u_int8_t reserved; | |
1036 | u_int8_t atyp; | |
1037 | } s5_req, s5_rsp; | |
1038 | u_int16_t dest_port; | |
1039 | u_char *p, dest_addr[255+1]; | |
1040 | u_int have, need, i, found, nmethods, addrlen, af; | |
1041 | ||
1042 | debug2("channel %d: decode socks5", c->self); | |
1043 | p = buffer_ptr(&c->input); | |
1044 | if (p[0] != 0x05) | |
1045 | return -1; | |
1046 | have = buffer_len(&c->input); | |
1047 | if (!(c->flags & SSH_SOCKS5_AUTHDONE)) { | |
1048 | /* format: ver | nmethods | methods */ | |
1049 | if (have < 2) | |
1050 | return 0; | |
1051 | nmethods = p[1]; | |
1052 | if (have < nmethods + 2) | |
1053 | return 0; | |
1054 | /* look for method: "NO AUTHENTICATION REQUIRED" */ | |
1055 | for (found = 0, i = 2; i < nmethods + 2; i++) { | |
1056 | if (p[i] == SSH_SOCKS5_NOAUTH) { | |
1057 | found = 1; | |
1058 | break; | |
1059 | } | |
1060 | } | |
1061 | if (!found) { | |
1062 | debug("channel %d: method SSH_SOCKS5_NOAUTH not found", | |
1063 | c->self); | |
1064 | return -1; | |
1065 | } | |
1066 | buffer_consume(&c->input, nmethods + 2); | |
1067 | buffer_put_char(&c->output, 0x05); /* version */ | |
1068 | buffer_put_char(&c->output, SSH_SOCKS5_NOAUTH); /* method */ | |
1069 | FD_SET(c->sock, writeset); | |
1070 | c->flags |= SSH_SOCKS5_AUTHDONE; | |
1071 | debug2("channel %d: socks5 auth done", c->self); | |
1072 | return 0; /* need more */ | |
1073 | } | |
1074 | debug2("channel %d: socks5 post auth", c->self); | |
1075 | if (have < sizeof(s5_req)+1) | |
1076 | return 0; /* need more */ | |
1077 | memcpy(&s5_req, p, sizeof(s5_req)); | |
1078 | if (s5_req.version != 0x05 || | |
1079 | s5_req.command != SSH_SOCKS5_CONNECT || | |
1080 | s5_req.reserved != 0x00) { | |
1081 | debug2("channel %d: only socks5 connect supported", c->self); | |
1082 | return -1; | |
1083 | } | |
1084 | switch (s5_req.atyp){ | |
1085 | case SSH_SOCKS5_IPV4: | |
1086 | addrlen = 4; | |
1087 | af = AF_INET; | |
1088 | break; | |
1089 | case SSH_SOCKS5_DOMAIN: | |
1090 | addrlen = p[sizeof(s5_req)]; | |
1091 | af = -1; | |
1092 | break; | |
1093 | case SSH_SOCKS5_IPV6: | |
1094 | addrlen = 16; | |
1095 | af = AF_INET6; | |
1096 | break; | |
1097 | default: | |
1098 | debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp); | |
1099 | return -1; | |
1100 | } | |
1101 | need = sizeof(s5_req) + addrlen + 2; | |
1102 | if (s5_req.atyp == SSH_SOCKS5_DOMAIN) | |
1103 | need++; | |
1104 | if (have < need) | |
1105 | return 0; | |
1106 | buffer_consume(&c->input, sizeof(s5_req)); | |
1107 | if (s5_req.atyp == SSH_SOCKS5_DOMAIN) | |
1108 | buffer_consume(&c->input, 1); /* host string length */ | |
1109 | buffer_get(&c->input, (char *)&dest_addr, addrlen); | |
1110 | buffer_get(&c->input, (char *)&dest_port, 2); | |
1111 | dest_addr[addrlen] = '\0'; | |
1112 | if (s5_req.atyp == SSH_SOCKS5_DOMAIN) | |
1113 | strlcpy(c->path, (char *)dest_addr, sizeof(c->path)); | |
1114 | else if (inet_ntop(af, dest_addr, c->path, sizeof(c->path)) == NULL) | |
1115 | return -1; | |
1116 | c->host_port = ntohs(dest_port); | |
1117 | ||
1118 | debug2("channel %d: dynamic request: socks5 host %s port %u command %u", | |
1119 | c->self, c->path, c->host_port, s5_req.command); | |
1120 | ||
1121 | s5_rsp.version = 0x05; | |
1122 | s5_rsp.command = SSH_SOCKS5_SUCCESS; | |
1123 | s5_rsp.reserved = 0; /* ignored */ | |
1124 | s5_rsp.atyp = SSH_SOCKS5_IPV4; | |
1125 | ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY; | |
1126 | dest_port = 0; /* ignored */ | |
1127 | ||
1128 | buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp)); | |
1129 | buffer_append(&c->output, &dest_addr, sizeof(struct in_addr)); | |
1130 | buffer_append(&c->output, &dest_port, sizeof(dest_port)); | |
1131 | return 1; | |
1132 | } | |
1133 | ||
1134 | /* dynamic port forwarding */ | |
1135 | static void | |
1136 | channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset) | |
1137 | { | |
1138 | u_char *p; | |
1139 | u_int have; | |
1140 | int ret; | |
1141 | ||
1142 | have = buffer_len(&c->input); | |
1143 | c->delayed = 0; | |
1144 | debug2("channel %d: pre_dynamic: have %d", c->self, have); | |
1145 | /* buffer_dump(&c->input); */ | |
1146 | /* check if the fixed size part of the packet is in buffer. */ | |
1147 | if (have < 3) { | |
1148 | /* need more */ | |
1149 | FD_SET(c->sock, readset); | |
1150 | return; | |
1151 | } | |
1152 | /* try to guess the protocol */ | |
1153 | p = buffer_ptr(&c->input); | |
1154 | switch (p[0]) { | |
1155 | case 0x04: | |
1156 | ret = channel_decode_socks4(c, readset, writeset); | |
1157 | break; | |
1158 | case 0x05: | |
1159 | ret = channel_decode_socks5(c, readset, writeset); | |
1160 | break; | |
1161 | default: | |
1162 | ret = -1; | |
1163 | break; | |
1164 | } | |
1165 | if (ret < 0) { | |
1166 | chan_mark_dead(c); | |
1167 | } else if (ret == 0) { | |
1168 | debug2("channel %d: pre_dynamic: need more", c->self); | |
1169 | /* need more */ | |
1170 | FD_SET(c->sock, readset); | |
1171 | } else { | |
1172 | /* switch to the next state */ | |
1173 | c->type = SSH_CHANNEL_OPENING; | |
1174 | port_open_helper(c, "direct-tcpip"); | |
1175 | } | |
1176 | } | |
1177 | ||
1178 | /* This is our fake X11 server socket. */ | |
1179 | /* ARGSUSED */ | |
1180 | static void | |
1181 | channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset) | |
1182 | { | |
1183 | Channel *nc; | |
1184 | struct sockaddr addr; | |
1185 | int newsock; | |
1186 | socklen_t addrlen; | |
1187 | char buf[16384], *remote_ipaddr; | |
1188 | int remote_port; | |
1189 | ||
1190 | if (FD_ISSET(c->sock, readset)) { | |
1191 | debug("X11 connection requested."); | |
1192 | addrlen = sizeof(addr); | |
1193 | newsock = accept(c->sock, &addr, &addrlen); | |
1194 | if (c->single_connection) { | |
1195 | debug2("single_connection: closing X11 listener."); | |
1196 | channel_close_fd(&c->sock); | |
1197 | chan_mark_dead(c); | |
1198 | } | |
1199 | if (newsock < 0) { | |
1200 | error("accept: %.100s", strerror(errno)); | |
1201 | return; | |
1202 | } | |
1203 | set_nodelay(newsock); | |
1204 | remote_ipaddr = get_peer_ipaddr(newsock); | |
1205 | remote_port = get_peer_port(newsock); | |
1206 | snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", | |
1207 | remote_ipaddr, remote_port); | |
1208 | ||
1209 | nc = channel_new("accepted x11 socket", | |
1210 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
1211 | c->local_window_max, c->local_maxpacket, 0, buf, 1); | |
1212 | if (compat20) { | |
1213 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1214 | packet_put_cstring("x11"); | |
1215 | packet_put_int(nc->self); | |
1216 | packet_put_int(nc->local_window_max); | |
1217 | packet_put_int(nc->local_maxpacket); | |
1218 | /* originator ipaddr and port */ | |
1219 | packet_put_cstring(remote_ipaddr); | |
1220 | if (datafellows & SSH_BUG_X11FWD) { | |
1221 | debug2("ssh2 x11 bug compat mode"); | |
1222 | } else { | |
1223 | packet_put_int(remote_port); | |
1224 | } | |
1225 | packet_send(); | |
1226 | } else { | |
1227 | packet_start(SSH_SMSG_X11_OPEN); | |
1228 | packet_put_int(nc->self); | |
1229 | if (packet_get_protocol_flags() & | |
1230 | SSH_PROTOFLAG_HOST_IN_FWD_OPEN) | |
1231 | packet_put_cstring(buf); | |
1232 | packet_send(); | |
1233 | } | |
1234 | xfree(remote_ipaddr); | |
1235 | } | |
1236 | } | |
1237 | ||
1238 | static void | |
1239 | port_open_helper(Channel *c, char *rtype) | |
1240 | { | |
1241 | int direct; | |
1242 | char buf[1024]; | |
1243 | char *remote_ipaddr = get_peer_ipaddr(c->sock); | |
1244 | int remote_port = get_peer_port(c->sock); | |
1245 | ||
1246 | direct = (strcmp(rtype, "direct-tcpip") == 0); | |
1247 | ||
1248 | snprintf(buf, sizeof buf, | |
1249 | "%s: listening port %d for %.100s port %d, " | |
1250 | "connect from %.200s port %d", | |
1251 | rtype, c->listening_port, c->path, c->host_port, | |
1252 | remote_ipaddr, remote_port); | |
1253 | ||
1254 | xfree(c->remote_name); | |
1255 | c->remote_name = xstrdup(buf); | |
1256 | ||
1257 | if (compat20) { | |
1258 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1259 | packet_put_cstring(rtype); | |
1260 | packet_put_int(c->self); | |
1261 | packet_put_int(c->local_window_max); | |
1262 | packet_put_int(c->local_maxpacket); | |
1263 | if (direct) { | |
1264 | /* target host, port */ | |
1265 | packet_put_cstring(c->path); | |
1266 | packet_put_int(c->host_port); | |
1267 | } else { | |
1268 | /* listen address, port */ | |
1269 | packet_put_cstring(c->path); | |
1270 | packet_put_int(c->listening_port); | |
1271 | } | |
1272 | /* originator host and port */ | |
1273 | packet_put_cstring(remote_ipaddr); | |
1274 | packet_put_int((u_int)remote_port); | |
1275 | packet_send(); | |
1276 | } else { | |
1277 | packet_start(SSH_MSG_PORT_OPEN); | |
1278 | packet_put_int(c->self); | |
1279 | packet_put_cstring(c->path); | |
1280 | packet_put_int(c->host_port); | |
1281 | if (packet_get_protocol_flags() & | |
1282 | SSH_PROTOFLAG_HOST_IN_FWD_OPEN) | |
1283 | packet_put_cstring(c->remote_name); | |
1284 | packet_send(); | |
1285 | } | |
1286 | xfree(remote_ipaddr); | |
1287 | } | |
1288 | ||
1289 | static void | |
1290 | channel_set_reuseaddr(int fd) | |
1291 | { | |
1292 | int on = 1; | |
1293 | ||
1294 | /* | |
1295 | * Set socket options. | |
1296 | * Allow local port reuse in TIME_WAIT. | |
1297 | */ | |
1298 | if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) | |
1299 | error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); | |
1300 | } | |
1301 | ||
1302 | /* | |
1303 | * This socket is listening for connections to a forwarded TCP/IP port. | |
1304 | */ | |
1305 | /* ARGSUSED */ | |
1306 | static void | |
1307 | channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset) | |
1308 | { | |
1309 | Channel *nc; | |
1310 | struct sockaddr addr; | |
1311 | int newsock, nextstate; | |
1312 | socklen_t addrlen; | |
1313 | char *rtype; | |
1314 | ||
1315 | if (FD_ISSET(c->sock, readset)) { | |
1316 | debug("Connection to port %d forwarding " | |
1317 | "to %.100s port %d requested.", | |
1318 | c->listening_port, c->path, c->host_port); | |
1319 | ||
1320 | if (c->type == SSH_CHANNEL_RPORT_LISTENER) { | |
1321 | nextstate = SSH_CHANNEL_OPENING; | |
1322 | rtype = "forwarded-tcpip"; | |
1323 | } else { | |
1324 | if (c->host_port == 0) { | |
1325 | nextstate = SSH_CHANNEL_DYNAMIC; | |
1326 | rtype = "dynamic-tcpip"; | |
1327 | } else { | |
1328 | nextstate = SSH_CHANNEL_OPENING; | |
1329 | rtype = "direct-tcpip"; | |
1330 | } | |
1331 | } | |
1332 | ||
1333 | addrlen = sizeof(addr); | |
1334 | newsock = accept(c->sock, &addr, &addrlen); | |
1335 | if (newsock < 0) { | |
1336 | error("accept: %.100s", strerror(errno)); | |
1337 | return; | |
1338 | } | |
1339 | set_nodelay(newsock); | |
1340 | nc = channel_new(rtype, nextstate, newsock, newsock, -1, | |
1341 | c->local_window_max, c->local_maxpacket, 0, rtype, 1); | |
1342 | nc->listening_port = c->listening_port; | |
1343 | nc->host_port = c->host_port; | |
1344 | strlcpy(nc->path, c->path, sizeof(nc->path)); | |
1345 | ||
1346 | if (nextstate == SSH_CHANNEL_DYNAMIC) { | |
1347 | /* | |
1348 | * do not call the channel_post handler until | |
1349 | * this flag has been reset by a pre-handler. | |
1350 | * otherwise the FD_ISSET calls might overflow | |
1351 | */ | |
1352 | nc->delayed = 1; | |
1353 | } else { | |
1354 | port_open_helper(nc, rtype); | |
1355 | } | |
1356 | } | |
1357 | } | |
1358 | ||
1359 | /* | |
1360 | * This is the authentication agent socket listening for connections from | |
1361 | * clients. | |
1362 | */ | |
1363 | /* ARGSUSED */ | |
1364 | static void | |
1365 | channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset) | |
1366 | { | |
1367 | Channel *nc; | |
1368 | int newsock; | |
1369 | struct sockaddr addr; | |
1370 | socklen_t addrlen; | |
1371 | ||
1372 | if (FD_ISSET(c->sock, readset)) { | |
1373 | addrlen = sizeof(addr); | |
1374 | newsock = accept(c->sock, &addr, &addrlen); | |
1375 | if (newsock < 0) { | |
1376 | error("accept from auth socket: %.100s", strerror(errno)); | |
1377 | return; | |
1378 | } | |
1379 | nc = channel_new("accepted auth socket", | |
1380 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
1381 | c->local_window_max, c->local_maxpacket, | |
1382 | 0, "accepted auth socket", 1); | |
1383 | if (compat20) { | |
1384 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1385 | packet_put_cstring("auth-agent@openssh.com"); | |
1386 | packet_put_int(nc->self); | |
1387 | packet_put_int(c->local_window_max); | |
1388 | packet_put_int(c->local_maxpacket); | |
1389 | } else { | |
1390 | packet_start(SSH_SMSG_AGENT_OPEN); | |
1391 | packet_put_int(nc->self); | |
1392 | } | |
1393 | packet_send(); | |
1394 | } | |
1395 | } | |
1396 | ||
1397 | /* ARGSUSED */ | |
1398 | static void | |
1399 | channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset) | |
1400 | { | |
1401 | int err = 0; | |
1402 | socklen_t sz = sizeof(err); | |
1403 | ||
1404 | if (FD_ISSET(c->sock, writeset)) { | |
1405 | if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, &err, &sz) < 0) { | |
1406 | err = errno; | |
1407 | error("getsockopt SO_ERROR failed"); | |
1408 | } | |
1409 | if (err == 0) { | |
1410 | debug("channel %d: connected", c->self); | |
1411 | c->type = SSH_CHANNEL_OPEN; | |
1412 | if (compat20) { | |
1413 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1414 | packet_put_int(c->remote_id); | |
1415 | packet_put_int(c->self); | |
1416 | packet_put_int(c->local_window); | |
1417 | packet_put_int(c->local_maxpacket); | |
1418 | } else { | |
1419 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1420 | packet_put_int(c->remote_id); | |
1421 | packet_put_int(c->self); | |
1422 | } | |
1423 | } else { | |
1424 | debug("channel %d: not connected: %s", | |
1425 | c->self, strerror(err)); | |
1426 | if (compat20) { | |
1427 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); | |
1428 | packet_put_int(c->remote_id); | |
1429 | packet_put_int(SSH2_OPEN_CONNECT_FAILED); | |
1430 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
1431 | packet_put_cstring(strerror(err)); | |
1432 | packet_put_cstring(""); | |
1433 | } | |
1434 | } else { | |
1435 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1436 | packet_put_int(c->remote_id); | |
1437 | } | |
1438 | chan_mark_dead(c); | |
1439 | } | |
1440 | packet_send(); | |
1441 | } | |
1442 | } | |
1443 | ||
1444 | /* ARGSUSED */ | |
1445 | static int | |
1446 | channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset) | |
1447 | { | |
1448 | char buf[CHAN_RBUF]; | |
1449 | int len; | |
1450 | ||
1451 | if (c->rfd != -1 && | |
1452 | (c->detach_close || FD_ISSET(c->rfd, readset))) { | |
1453 | errno = 0; | |
1454 | len = read(c->rfd, buf, sizeof(buf)); | |
1455 | if (len < 0 && (errno == EINTR || | |
1456 | (errno == EAGAIN && !(c->isatty && c->detach_close)))) | |
1457 | return 1; | |
1458 | #ifndef PTY_ZEROREAD | |
1459 | if (len <= 0) { | |
1460 | #else | |
1461 | if ((!c->isatty && len <= 0) || | |
1462 | (c->isatty && (len < 0 || (len == 0 && errno != 0)))) { | |
1463 | #endif | |
1464 | debug2("channel %d: read<=0 rfd %d len %d", | |
1465 | c->self, c->rfd, len); | |
1466 | if (c->type != SSH_CHANNEL_OPEN) { | |
1467 | debug2("channel %d: not open", c->self); | |
1468 | chan_mark_dead(c); | |
1469 | return -1; | |
1470 | } else if (compat13) { | |
1471 | buffer_clear(&c->output); | |
1472 | c->type = SSH_CHANNEL_INPUT_DRAINING; | |
1473 | debug2("channel %d: input draining.", c->self); | |
1474 | } else { | |
1475 | chan_read_failed(c); | |
1476 | } | |
1477 | return -1; | |
1478 | } | |
1479 | if (c->input_filter != NULL) { | |
1480 | if (c->input_filter(c, buf, len) == -1) { | |
1481 | debug2("channel %d: filter stops", c->self); | |
1482 | chan_read_failed(c); | |
1483 | } | |
1484 | } else if (c->datagram) { | |
1485 | buffer_put_string(&c->input, buf, len); | |
1486 | } else { | |
1487 | buffer_append(&c->input, buf, len); | |
1488 | } | |
1489 | } | |
1490 | return 1; | |
1491 | } | |
1492 | ||
1493 | /* ARGSUSED */ | |
1494 | static int | |
1495 | channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset) | |
1496 | { | |
1497 | struct termios tio; | |
1498 | u_char *data = NULL, *buf; | |
1499 | u_int dlen; | |
1500 | int len; | |
1501 | ||
1502 | /* Send buffered output data to the socket. */ | |
1503 | if (c->wfd != -1 && | |
1504 | FD_ISSET(c->wfd, writeset) && | |
1505 | buffer_len(&c->output) > 0) { | |
1506 | if (c->output_filter != NULL) { | |
1507 | if ((buf = c->output_filter(c, &data, &dlen)) == NULL) { | |
1508 | debug2("channel %d: filter stops", c->self); | |
1509 | if (c->type != SSH_CHANNEL_OPEN) | |
1510 | chan_mark_dead(c); | |
1511 | else | |
1512 | chan_write_failed(c); | |
1513 | return -1; | |
1514 | } | |
1515 | } else if (c->datagram) { | |
1516 | buf = data = buffer_get_string(&c->output, &dlen); | |
1517 | } else { | |
1518 | buf = data = buffer_ptr(&c->output); | |
1519 | dlen = buffer_len(&c->output); | |
1520 | } | |
1521 | ||
1522 | if (c->datagram) { | |
1523 | /* ignore truncated writes, datagrams might get lost */ | |
1524 | c->local_consumed += dlen + 4; | |
1525 | len = write(c->wfd, buf, dlen); | |
1526 | xfree(data); | |
1527 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1528 | return 1; | |
1529 | if (len <= 0) { | |
1530 | if (c->type != SSH_CHANNEL_OPEN) | |
1531 | chan_mark_dead(c); | |
1532 | else | |
1533 | chan_write_failed(c); | |
1534 | return -1; | |
1535 | } | |
1536 | return 1; | |
1537 | } | |
1538 | #ifdef _AIX | |
1539 | /* XXX: Later AIX versions can't push as much data to tty */ | |
1540 | if (compat20 && c->wfd_isatty) | |
1541 | dlen = MIN(dlen, 8*1024); | |
1542 | #endif | |
1543 | ||
1544 | len = write(c->wfd, buf, dlen); | |
1545 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1546 | return 1; | |
1547 | if (len <= 0) { | |
1548 | if (c->type != SSH_CHANNEL_OPEN) { | |
1549 | debug2("channel %d: not open", c->self); | |
1550 | chan_mark_dead(c); | |
1551 | return -1; | |
1552 | } else if (compat13) { | |
1553 | buffer_clear(&c->output); | |
1554 | debug2("channel %d: input draining.", c->self); | |
1555 | c->type = SSH_CHANNEL_INPUT_DRAINING; | |
1556 | } else { | |
1557 | chan_write_failed(c); | |
1558 | } | |
1559 | return -1; | |
1560 | } | |
1561 | if (compat20 && c->isatty && dlen >= 1 && buf[0] != '\r') { | |
1562 | if (tcgetattr(c->wfd, &tio) == 0 && | |
1563 | !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { | |
1564 | /* | |
1565 | * Simulate echo to reduce the impact of | |
1566 | * traffic analysis. We need to match the | |
1567 | * size of a SSH2_MSG_CHANNEL_DATA message | |
1568 | * (4 byte channel id + buf) | |
1569 | */ | |
1570 | packet_send_ignore(4 + len); | |
1571 | packet_send(); | |
1572 | } | |
1573 | } | |
1574 | buffer_consume(&c->output, len); | |
1575 | if (compat20 && len > 0) { | |
1576 | c->local_consumed += len; | |
1577 | } | |
1578 | } | |
1579 | return 1; | |
1580 | } | |
1581 | ||
1582 | static int | |
1583 | channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset) | |
1584 | { | |
1585 | char buf[CHAN_RBUF]; | |
1586 | int len; | |
1587 | ||
1588 | /** XXX handle drain efd, too */ | |
1589 | if (c->efd != -1) { | |
1590 | if (c->extended_usage == CHAN_EXTENDED_WRITE && | |
1591 | FD_ISSET(c->efd, writeset) && | |
1592 | buffer_len(&c->extended) > 0) { | |
1593 | len = write(c->efd, buffer_ptr(&c->extended), | |
1594 | buffer_len(&c->extended)); | |
1595 | debug2("channel %d: written %d to efd %d", | |
1596 | c->self, len, c->efd); | |
1597 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1598 | return 1; | |
1599 | if (len <= 0) { | |
1600 | debug2("channel %d: closing write-efd %d", | |
1601 | c->self, c->efd); | |
1602 | channel_close_fd(&c->efd); | |
1603 | } else { | |
1604 | buffer_consume(&c->extended, len); | |
1605 | c->local_consumed += len; | |
1606 | } | |
1607 | } else if (c->extended_usage == CHAN_EXTENDED_READ && | |
1608 | (c->detach_close || FD_ISSET(c->efd, readset))) { | |
1609 | len = read(c->efd, buf, sizeof(buf)); | |
1610 | debug2("channel %d: read %d from efd %d", | |
1611 | c->self, len, c->efd); | |
1612 | if (len < 0 && (errno == EINTR || | |
1613 | (errno == EAGAIN && !c->detach_close))) | |
1614 | return 1; | |
1615 | if (len <= 0) { | |
1616 | debug2("channel %d: closing read-efd %d", | |
1617 | c->self, c->efd); | |
1618 | channel_close_fd(&c->efd); | |
1619 | } else { | |
1620 | buffer_append(&c->extended, buf, len); | |
1621 | } | |
1622 | } | |
1623 | } | |
1624 | return 1; | |
1625 | } | |
1626 | ||
1627 | /* ARGSUSED */ | |
1628 | static int | |
1629 | channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset) | |
1630 | { | |
1631 | char buf[16]; | |
1632 | int len; | |
1633 | ||
1634 | /* Monitor control fd to detect if the slave client exits */ | |
1635 | if (c->ctl_fd != -1 && FD_ISSET(c->ctl_fd, readset)) { | |
1636 | len = read(c->ctl_fd, buf, sizeof(buf)); | |
1637 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
1638 | return 1; | |
1639 | if (len <= 0) { | |
1640 | debug2("channel %d: ctl read<=0", c->self); | |
1641 | if (c->type != SSH_CHANNEL_OPEN) { | |
1642 | debug2("channel %d: not open", c->self); | |
1643 | chan_mark_dead(c); | |
1644 | return -1; | |
1645 | } else { | |
1646 | chan_read_failed(c); | |
1647 | chan_write_failed(c); | |
1648 | } | |
1649 | return -1; | |
1650 | } else | |
1651 | fatal("%s: unexpected data on ctl fd", __func__); | |
1652 | } | |
1653 | return 1; | |
1654 | } | |
1655 | ||
1656 | static int | |
1657 | channel_check_window(Channel *c) | |
1658 | { | |
1659 | if (c->type == SSH_CHANNEL_OPEN && | |
1660 | !(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) && | |
1661 | c->local_window < c->local_window_max/2 && | |
1662 | c->local_consumed > 0) { | |
1663 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); | |
1664 | packet_put_int(c->remote_id); | |
1665 | packet_put_int(c->local_consumed); | |
1666 | packet_send(); | |
1667 | debug2("channel %d: window %d sent adjust %d", | |
1668 | c->self, c->local_window, | |
1669 | c->local_consumed); | |
1670 | c->local_window += c->local_consumed; | |
1671 | c->local_consumed = 0; | |
1672 | } | |
1673 | return 1; | |
1674 | } | |
1675 | ||
1676 | static void | |
1677 | channel_post_open(Channel *c, fd_set *readset, fd_set *writeset) | |
1678 | { | |
1679 | if (c->delayed) | |
1680 | return; | |
1681 | channel_handle_rfd(c, readset, writeset); | |
1682 | channel_handle_wfd(c, readset, writeset); | |
1683 | if (!compat20) | |
1684 | return; | |
1685 | channel_handle_efd(c, readset, writeset); | |
1686 | channel_handle_ctl(c, readset, writeset); | |
1687 | channel_check_window(c); | |
1688 | } | |
1689 | ||
1690 | /* ARGSUSED */ | |
1691 | static void | |
1692 | channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset) | |
1693 | { | |
1694 | int len; | |
1695 | ||
1696 | /* Send buffered output data to the socket. */ | |
1697 | if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) { | |
1698 | len = write(c->sock, buffer_ptr(&c->output), | |
1699 | buffer_len(&c->output)); | |
1700 | if (len <= 0) | |
1701 | buffer_clear(&c->output); | |
1702 | else | |
1703 | buffer_consume(&c->output, len); | |
1704 | } | |
1705 | } | |
1706 | ||
1707 | static void | |
1708 | channel_handler_init_20(void) | |
1709 | { | |
1710 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; | |
1711 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; | |
1712 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1713 | channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener; | |
1714 | channel_pre[SSH_CHANNEL_X11_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_OPEN] = &channel_post_open; | |
1720 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
1721 | channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener; | |
1722 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
1723 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
1724 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; | |
1725 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; | |
1726 | } | |
1727 | ||
1728 | static void | |
1729 | channel_handler_init_13(void) | |
1730 | { | |
1731 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; | |
1732 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13; | |
1733 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
1734 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1735 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
1736 | channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining; | |
1737 | channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining; | |
1738 | channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; | |
1739 | channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; | |
1740 | ||
1741 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; | |
1742 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
1743 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
1744 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
1745 | channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; | |
1746 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; | |
1747 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; | |
1748 | } | |
1749 | ||
1750 | static void | |
1751 | channel_handler_init_15(void) | |
1752 | { | |
1753 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open; | |
1754 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; | |
1755 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
1756 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
1757 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
1758 | channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting; | |
1759 | channel_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic; | |
1760 | ||
1761 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
1762 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
1763 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
1764 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open; | |
1765 | channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting; | |
1766 | channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open; | |
1767 | } | |
1768 | ||
1769 | static void | |
1770 | channel_handler_init(void) | |
1771 | { | |
1772 | int i; | |
1773 | ||
1774 | for (i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { | |
1775 | channel_pre[i] = NULL; | |
1776 | channel_post[i] = NULL; | |
1777 | } | |
1778 | if (compat20) | |
1779 | channel_handler_init_20(); | |
1780 | else if (compat13) | |
1781 | channel_handler_init_13(); | |
1782 | else | |
1783 | channel_handler_init_15(); | |
1784 | } | |
1785 | ||
1786 | /* gc dead channels */ | |
1787 | static void | |
1788 | channel_garbage_collect(Channel *c) | |
1789 | { | |
1790 | if (c == NULL) | |
1791 | return; | |
1792 | if (c->detach_user != NULL) { | |
1793 | if (!chan_is_dead(c, c->detach_close)) | |
1794 | return; | |
1795 | debug2("channel %d: gc: notify user", c->self); | |
1796 | c->detach_user(c->self, NULL); | |
1797 | /* if we still have a callback */ | |
1798 | if (c->detach_user != NULL) | |
1799 | return; | |
1800 | debug2("channel %d: gc: user detached", c->self); | |
1801 | } | |
1802 | if (!chan_is_dead(c, 1)) | |
1803 | return; | |
1804 | debug2("channel %d: garbage collecting", c->self); | |
1805 | channel_free(c); | |
1806 | } | |
1807 | ||
1808 | static void | |
1809 | channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset) | |
1810 | { | |
1811 | static int did_init = 0; | |
1812 | u_int i; | |
1813 | Channel *c; | |
1814 | ||
1815 | if (!did_init) { | |
1816 | channel_handler_init(); | |
1817 | did_init = 1; | |
1818 | } | |
1819 | for (i = 0; i < channels_alloc; i++) { | |
1820 | c = channels[i]; | |
1821 | if (c == NULL) | |
1822 | continue; | |
1823 | if (ftab[c->type] != NULL) | |
1824 | (*ftab[c->type])(c, readset, writeset); | |
1825 | channel_garbage_collect(c); | |
1826 | } | |
1827 | } | |
1828 | ||
1829 | /* | |
1830 | * Allocate/update select bitmasks and add any bits relevant to channels in | |
1831 | * select bitmasks. | |
1832 | */ | |
1833 | void | |
1834 | channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp, | |
1835 | u_int *nallocp, int rekeying) | |
1836 | { | |
1837 | u_int n, sz, nfdset; | |
1838 | ||
1839 | n = MAX(*maxfdp, channel_max_fd); | |
1840 | ||
1841 | nfdset = howmany(n+1, NFDBITS); | |
1842 | /* Explicitly test here, because xrealloc isn't always called */ | |
1843 | if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask)) | |
1844 | fatal("channel_prepare_select: max_fd (%d) is too large", n); | |
1845 | sz = nfdset * sizeof(fd_mask); | |
1846 | ||
1847 | /* perhaps check sz < nalloc/2 and shrink? */ | |
1848 | if (*readsetp == NULL || sz > *nallocp) { | |
1849 | *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask)); | |
1850 | *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask)); | |
1851 | *nallocp = sz; | |
1852 | } | |
1853 | *maxfdp = n; | |
1854 | memset(*readsetp, 0, sz); | |
1855 | memset(*writesetp, 0, sz); | |
1856 | ||
1857 | if (!rekeying) | |
1858 | channel_handler(channel_pre, *readsetp, *writesetp); | |
1859 | } | |
1860 | ||
1861 | /* | |
1862 | * After select, perform any appropriate operations for channels which have | |
1863 | * events pending. | |
1864 | */ | |
1865 | void | |
1866 | channel_after_select(fd_set *readset, fd_set *writeset) | |
1867 | { | |
1868 | channel_handler(channel_post, readset, writeset); | |
1869 | } | |
1870 | ||
1871 | ||
1872 | /* If there is data to send to the connection, enqueue some of it now. */ | |
1873 | void | |
1874 | channel_output_poll(void) | |
1875 | { | |
1876 | Channel *c; | |
1877 | u_int i, len; | |
1878 | ||
1879 | for (i = 0; i < channels_alloc; i++) { | |
1880 | c = channels[i]; | |
1881 | if (c == NULL) | |
1882 | continue; | |
1883 | ||
1884 | /* | |
1885 | * We are only interested in channels that can have buffered | |
1886 | * incoming data. | |
1887 | */ | |
1888 | if (compat13) { | |
1889 | if (c->type != SSH_CHANNEL_OPEN && | |
1890 | c->type != SSH_CHANNEL_INPUT_DRAINING) | |
1891 | continue; | |
1892 | } else { | |
1893 | if (c->type != SSH_CHANNEL_OPEN) | |
1894 | continue; | |
1895 | } | |
1896 | if (compat20 && | |
1897 | (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) { | |
1898 | /* XXX is this true? */ | |
1899 | debug3("channel %d: will not send data after close", c->self); | |
1900 | continue; | |
1901 | } | |
1902 | ||
1903 | /* Get the amount of buffered data for this channel. */ | |
1904 | if ((c->istate == CHAN_INPUT_OPEN || | |
1905 | c->istate == CHAN_INPUT_WAIT_DRAIN) && | |
1906 | (len = buffer_len(&c->input)) > 0) { | |
1907 | if (c->datagram) { | |
1908 | if (len > 0) { | |
1909 | u_char *data; | |
1910 | u_int dlen; | |
1911 | ||
1912 | data = buffer_get_string(&c->input, | |
1913 | &dlen); | |
1914 | packet_start(SSH2_MSG_CHANNEL_DATA); | |
1915 | packet_put_int(c->remote_id); | |
1916 | packet_put_string(data, dlen); | |
1917 | packet_send(); | |
1918 | c->remote_window -= dlen + 4; | |
1919 | xfree(data); | |
1920 | } | |
1921 | continue; | |
1922 | } | |
1923 | /* | |
1924 | * Send some data for the other side over the secure | |
1925 | * connection. | |
1926 | */ | |
1927 | if (compat20) { | |
1928 | if (len > c->remote_window) | |
1929 | len = c->remote_window; | |
1930 | if (len > c->remote_maxpacket) | |
1931 | len = c->remote_maxpacket; | |
1932 | } else { | |
1933 | if (packet_is_interactive()) { | |
1934 | if (len > 1024) | |
1935 | len = 512; | |
1936 | } else { | |
1937 | /* Keep the packets at reasonable size. */ | |
1938 | if (len > packet_get_maxsize()/2) | |
1939 | len = packet_get_maxsize()/2; | |
1940 | } | |
1941 | } | |
1942 | if (len > 0) { | |
1943 | packet_start(compat20 ? | |
1944 | SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); | |
1945 | packet_put_int(c->remote_id); | |
1946 | packet_put_string(buffer_ptr(&c->input), len); | |
1947 | packet_send(); | |
1948 | buffer_consume(&c->input, len); | |
1949 | c->remote_window -= len; | |
1950 | } | |
1951 | } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) { | |
1952 | if (compat13) | |
1953 | fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); | |
1954 | /* | |
1955 | * input-buffer is empty and read-socket shutdown: | |
1956 | * tell peer, that we will not send more data: send IEOF. | |
1957 | * hack for extended data: delay EOF if EFD still in use. | |
1958 | */ | |
1959 | if (CHANNEL_EFD_INPUT_ACTIVE(c)) | |
1960 | debug2("channel %d: ibuf_empty delayed efd %d/(%d)", | |
1961 | c->self, c->efd, buffer_len(&c->extended)); | |
1962 | else | |
1963 | chan_ibuf_empty(c); | |
1964 | } | |
1965 | /* Send extended data, i.e. stderr */ | |
1966 | if (compat20 && | |
1967 | !(c->flags & CHAN_EOF_SENT) && | |
1968 | c->remote_window > 0 && | |
1969 | (len = buffer_len(&c->extended)) > 0 && | |
1970 | c->extended_usage == CHAN_EXTENDED_READ) { | |
1971 | debug2("channel %d: rwin %u elen %u euse %d", | |
1972 | c->self, c->remote_window, buffer_len(&c->extended), | |
1973 | c->extended_usage); | |
1974 | if (len > c->remote_window) | |
1975 | len = c->remote_window; | |
1976 | if (len > c->remote_maxpacket) | |
1977 | len = c->remote_maxpacket; | |
1978 | packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA); | |
1979 | packet_put_int(c->remote_id); | |
1980 | packet_put_int(SSH2_EXTENDED_DATA_STDERR); | |
1981 | packet_put_string(buffer_ptr(&c->extended), len); | |
1982 | packet_send(); | |
1983 | buffer_consume(&c->extended, len); | |
1984 | c->remote_window -= len; | |
1985 | debug2("channel %d: sent ext data %d", c->self, len); | |
1986 | } | |
1987 | } | |
1988 | } | |
1989 | ||
1990 | ||
1991 | /* -- protocol input */ | |
1992 | ||
1993 | /* ARGSUSED */ | |
1994 | void | |
1995 | channel_input_data(int type, u_int32_t seq, void *ctxt) | |
1996 | { | |
1997 | int id; | |
1998 | char *data; | |
1999 | u_int data_len; | |
2000 | Channel *c; | |
2001 | ||
2002 | /* Get the channel number and verify it. */ | |
2003 | id = packet_get_int(); | |
2004 | c = channel_lookup(id); | |
2005 | if (c == NULL) | |
2006 | packet_disconnect("Received data for nonexistent channel %d.", id); | |
2007 | ||
2008 | /* Ignore any data for non-open channels (might happen on close) */ | |
2009 | if (c->type != SSH_CHANNEL_OPEN && | |
2010 | c->type != SSH_CHANNEL_X11_OPEN) | |
2011 | return; | |
2012 | ||
2013 | /* Get the data. */ | |
2014 | data = packet_get_string(&data_len); | |
2015 | ||
2016 | /* | |
2017 | * Ignore data for protocol > 1.3 if output end is no longer open. | |
2018 | * For protocol 2 the sending side is reducing its window as it sends | |
2019 | * data, so we must 'fake' consumption of the data in order to ensure | |
2020 | * that window updates are sent back. Otherwise the connection might | |
2021 | * deadlock. | |
2022 | */ | |
2023 | if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) { | |
2024 | if (compat20) { | |
2025 | c->local_window -= data_len; | |
2026 | c->local_consumed += data_len; | |
2027 | } | |
2028 | xfree(data); | |
2029 | return; | |
2030 | } | |
2031 | ||
2032 | if (compat20) { | |
2033 | if (data_len > c->local_maxpacket) { | |
2034 | logit("channel %d: rcvd big packet %d, maxpack %d", | |
2035 | c->self, data_len, c->local_maxpacket); | |
2036 | } | |
2037 | if (data_len > c->local_window) { | |
2038 | logit("channel %d: rcvd too much data %d, win %d", | |
2039 | c->self, data_len, c->local_window); | |
2040 | xfree(data); | |
2041 | return; | |
2042 | } | |
2043 | c->local_window -= data_len; | |
2044 | } | |
2045 | packet_check_eom(); | |
2046 | if (c->datagram) | |
2047 | buffer_put_string(&c->output, data, data_len); | |
2048 | else | |
2049 | buffer_append(&c->output, data, data_len); | |
2050 | xfree(data); | |
2051 | } | |
2052 | ||
2053 | /* ARGSUSED */ | |
2054 | void | |
2055 | channel_input_extended_data(int type, u_int32_t seq, void *ctxt) | |
2056 | { | |
2057 | int id; | |
2058 | char *data; | |
2059 | u_int data_len, tcode; | |
2060 | Channel *c; | |
2061 | ||
2062 | /* Get the channel number and verify it. */ | |
2063 | id = packet_get_int(); | |
2064 | c = channel_lookup(id); | |
2065 | ||
2066 | if (c == NULL) | |
2067 | packet_disconnect("Received extended_data for bad channel %d.", id); | |
2068 | if (c->type != SSH_CHANNEL_OPEN) { | |
2069 | logit("channel %d: ext data for non open", id); | |
2070 | return; | |
2071 | } | |
2072 | if (c->flags & CHAN_EOF_RCVD) { | |
2073 | if (datafellows & SSH_BUG_EXTEOF) | |
2074 | debug("channel %d: accepting ext data after eof", id); | |
2075 | else | |
2076 | packet_disconnect("Received extended_data after EOF " | |
2077 | "on channel %d.", id); | |
2078 | } | |
2079 | tcode = packet_get_int(); | |
2080 | if (c->efd == -1 || | |
2081 | c->extended_usage != CHAN_EXTENDED_WRITE || | |
2082 | tcode != SSH2_EXTENDED_DATA_STDERR) { | |
2083 | logit("channel %d: bad ext data", c->self); | |
2084 | return; | |
2085 | } | |
2086 | data = packet_get_string(&data_len); | |
2087 | packet_check_eom(); | |
2088 | if (data_len > c->local_window) { | |
2089 | logit("channel %d: rcvd too much extended_data %d, win %d", | |
2090 | c->self, data_len, c->local_window); | |
2091 | xfree(data); | |
2092 | return; | |
2093 | } | |
2094 | debug2("channel %d: rcvd ext data %d", c->self, data_len); | |
2095 | c->local_window -= data_len; | |
2096 | buffer_append(&c->extended, data, data_len); | |
2097 | xfree(data); | |
2098 | } | |
2099 | ||
2100 | /* ARGSUSED */ | |
2101 | void | |
2102 | channel_input_ieof(int type, u_int32_t seq, void *ctxt) | |
2103 | { | |
2104 | int id; | |
2105 | Channel *c; | |
2106 | ||
2107 | id = packet_get_int(); | |
2108 | packet_check_eom(); | |
2109 | c = channel_lookup(id); | |
2110 | if (c == NULL) | |
2111 | packet_disconnect("Received ieof for nonexistent channel %d.", id); | |
2112 | chan_rcvd_ieof(c); | |
2113 | ||
2114 | /* XXX force input close */ | |
2115 | if (c->force_drain && c->istate == CHAN_INPUT_OPEN) { | |
2116 | debug("channel %d: FORCE input drain", c->self); | |
2117 | c->istate = CHAN_INPUT_WAIT_DRAIN; | |
2118 | if (buffer_len(&c->input) == 0) | |
2119 | chan_ibuf_empty(c); | |
2120 | } | |
2121 | ||
2122 | } | |
2123 | ||
2124 | /* ARGSUSED */ | |
2125 | void | |
2126 | channel_input_close(int type, u_int32_t seq, void *ctxt) | |
2127 | { | |
2128 | int id; | |
2129 | Channel *c; | |
2130 | ||
2131 | id = packet_get_int(); | |
2132 | packet_check_eom(); | |
2133 | c = channel_lookup(id); | |
2134 | if (c == NULL) | |
2135 | packet_disconnect("Received close for nonexistent channel %d.", id); | |
2136 | ||
2137 | /* | |
2138 | * Send a confirmation that we have closed the channel and no more | |
2139 | * data is coming for it. | |
2140 | */ | |
2141 | packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); | |
2142 | packet_put_int(c->remote_id); | |
2143 | packet_send(); | |
2144 | ||
2145 | /* | |
2146 | * If the channel is in closed state, we have sent a close request, | |
2147 | * and the other side will eventually respond with a confirmation. | |
2148 | * Thus, we cannot free the channel here, because then there would be | |
2149 | * no-one to receive the confirmation. The channel gets freed when | |
2150 | * the confirmation arrives. | |
2151 | */ | |
2152 | if (c->type != SSH_CHANNEL_CLOSED) { | |
2153 | /* | |
2154 | * Not a closed channel - mark it as draining, which will | |
2155 | * cause it to be freed later. | |
2156 | */ | |
2157 | buffer_clear(&c->input); | |
2158 | c->type = SSH_CHANNEL_OUTPUT_DRAINING; | |
2159 | } | |
2160 | } | |
2161 | ||
2162 | /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ | |
2163 | /* ARGSUSED */ | |
2164 | void | |
2165 | channel_input_oclose(int type, u_int32_t seq, void *ctxt) | |
2166 | { | |
2167 | int id = packet_get_int(); | |
2168 | Channel *c = channel_lookup(id); | |
2169 | ||
2170 | packet_check_eom(); | |
2171 | if (c == NULL) | |
2172 | packet_disconnect("Received oclose for nonexistent channel %d.", id); | |
2173 | chan_rcvd_oclose(c); | |
2174 | } | |
2175 | ||
2176 | /* ARGSUSED */ | |
2177 | void | |
2178 | channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt) | |
2179 | { | |
2180 | int id = packet_get_int(); | |
2181 | Channel *c = channel_lookup(id); | |
2182 | ||
2183 | packet_check_eom(); | |
2184 | if (c == NULL) | |
2185 | packet_disconnect("Received close confirmation for " | |
2186 | "out-of-range channel %d.", id); | |
2187 | if (c->type != SSH_CHANNEL_CLOSED) | |
2188 | packet_disconnect("Received close confirmation for " | |
2189 | "non-closed channel %d (type %d).", id, c->type); | |
2190 | channel_free(c); | |
2191 | } | |
2192 | ||
2193 | /* ARGSUSED */ | |
2194 | void | |
2195 | channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt) | |
2196 | { | |
2197 | int id, remote_id; | |
2198 | Channel *c; | |
2199 | ||
2200 | id = packet_get_int(); | |
2201 | c = channel_lookup(id); | |
2202 | ||
2203 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
2204 | packet_disconnect("Received open confirmation for " | |
2205 | "non-opening channel %d.", id); | |
2206 | remote_id = packet_get_int(); | |
2207 | /* Record the remote channel number and mark that the channel is now open. */ | |
2208 | c->remote_id = remote_id; | |
2209 | c->type = SSH_CHANNEL_OPEN; | |
2210 | ||
2211 | if (compat20) { | |
2212 | c->remote_window = packet_get_int(); | |
2213 | c->remote_maxpacket = packet_get_int(); | |
2214 | if (c->confirm) { | |
2215 | debug2("callback start"); | |
2216 | c->confirm(c->self, c->confirm_ctx); | |
2217 | debug2("callback done"); | |
2218 | } | |
2219 | debug2("channel %d: open confirm rwindow %u rmax %u", c->self, | |
2220 | c->remote_window, c->remote_maxpacket); | |
2221 | } | |
2222 | packet_check_eom(); | |
2223 | } | |
2224 | ||
2225 | static char * | |
2226 | reason2txt(int reason) | |
2227 | { | |
2228 | switch (reason) { | |
2229 | case SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED: | |
2230 | return "administratively prohibited"; | |
2231 | case SSH2_OPEN_CONNECT_FAILED: | |
2232 | return "connect failed"; | |
2233 | case SSH2_OPEN_UNKNOWN_CHANNEL_TYPE: | |
2234 | return "unknown channel type"; | |
2235 | case SSH2_OPEN_RESOURCE_SHORTAGE: | |
2236 | return "resource shortage"; | |
2237 | } | |
2238 | return "unknown reason"; | |
2239 | } | |
2240 | ||
2241 | /* ARGSUSED */ | |
2242 | void | |
2243 | channel_input_open_failure(int type, u_int32_t seq, void *ctxt) | |
2244 | { | |
2245 | int id, reason; | |
2246 | char *msg = NULL, *lang = NULL; | |
2247 | Channel *c; | |
2248 | ||
2249 | id = packet_get_int(); | |
2250 | c = channel_lookup(id); | |
2251 | ||
2252 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
2253 | packet_disconnect("Received open failure for " | |
2254 | "non-opening channel %d.", id); | |
2255 | if (compat20) { | |
2256 | reason = packet_get_int(); | |
2257 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
2258 | msg = packet_get_string(NULL); | |
2259 | lang = packet_get_string(NULL); | |
2260 | } | |
2261 | logit("channel %d: open failed: %s%s%s", id, | |
2262 | reason2txt(reason), msg ? ": ": "", msg ? msg : ""); | |
2263 | if (msg != NULL) | |
2264 | xfree(msg); | |
2265 | if (lang != NULL) | |
2266 | xfree(lang); | |
2267 | } | |
2268 | packet_check_eom(); | |
2269 | /* Free the channel. This will also close the socket. */ | |
2270 | channel_free(c); | |
2271 | } | |
2272 | ||
2273 | /* ARGSUSED */ | |
2274 | void | |
2275 | channel_input_window_adjust(int type, u_int32_t seq, void *ctxt) | |
2276 | { | |
2277 | Channel *c; | |
2278 | int id; | |
2279 | u_int adjust; | |
2280 | ||
2281 | if (!compat20) | |
2282 | return; | |
2283 | ||
2284 | /* Get the channel number and verify it. */ | |
2285 | id = packet_get_int(); | |
2286 | c = channel_lookup(id); | |
2287 | ||
2288 | if (c == NULL) { | |
2289 | logit("Received window adjust for non-open channel %d.", id); | |
2290 | return; | |
2291 | } | |
2292 | adjust = packet_get_int(); | |
2293 | packet_check_eom(); | |
2294 | debug2("channel %d: rcvd adjust %u", id, adjust); | |
2295 | c->remote_window += adjust; | |
2296 | } | |
2297 | ||
2298 | /* ARGSUSED */ | |
2299 | void | |
2300 | channel_input_port_open(int type, u_int32_t seq, void *ctxt) | |
2301 | { | |
2302 | Channel *c = NULL; | |
2303 | u_short host_port; | |
2304 | char *host, *originator_string; | |
2305 | int remote_id, sock = -1; | |
2306 | ||
2307 | remote_id = packet_get_int(); | |
2308 | host = packet_get_string(NULL); | |
2309 | host_port = packet_get_int(); | |
2310 | ||
2311 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { | |
2312 | originator_string = packet_get_string(NULL); | |
2313 | } else { | |
2314 | originator_string = xstrdup("unknown (remote did not supply name)"); | |
2315 | } | |
2316 | packet_check_eom(); | |
2317 | sock = channel_connect_to(host, host_port); | |
2318 | if (sock != -1) { | |
2319 | c = channel_new("connected socket", | |
2320 | SSH_CHANNEL_CONNECTING, sock, sock, -1, 0, 0, 0, | |
2321 | originator_string, 1); | |
2322 | c->remote_id = remote_id; | |
2323 | } | |
2324 | xfree(originator_string); | |
2325 | if (c == NULL) { | |
2326 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2327 | packet_put_int(remote_id); | |
2328 | packet_send(); | |
2329 | } | |
2330 | xfree(host); | |
2331 | } | |
2332 | ||
2333 | ||
2334 | /* -- tcp forwarding */ | |
2335 | ||
2336 | void | |
2337 | channel_set_af(int af) | |
2338 | { | |
2339 | IPv4or6 = af; | |
2340 | } | |
2341 | ||
2342 | static int | |
2343 | channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port, | |
2344 | const char *host_to_connect, u_short port_to_connect, int gateway_ports) | |
2345 | { | |
2346 | Channel *c; | |
2347 | int sock, r, success = 0, wildcard = 0, is_client; | |
2348 | struct addrinfo hints, *ai, *aitop; | |
2349 | const char *host, *addr; | |
2350 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
2351 | ||
2352 | host = (type == SSH_CHANNEL_RPORT_LISTENER) ? | |
2353 | listen_addr : host_to_connect; | |
2354 | is_client = (type == SSH_CHANNEL_PORT_LISTENER); | |
2355 | ||
2356 | if (host == NULL) { | |
2357 | error("No forward host name."); | |
2358 | return 0; | |
2359 | } | |
2360 | if (strlen(host) > SSH_CHANNEL_PATH_LEN - 1) { | |
2361 | error("Forward host name too long."); | |
2362 | return 0; | |
2363 | } | |
2364 | ||
2365 | /* | |
2366 | * Determine whether or not a port forward listens to loopback, | |
2367 | * specified address or wildcard. On the client, a specified bind | |
2368 | * address will always override gateway_ports. On the server, a | |
2369 | * gateway_ports of 1 (``yes'') will override the client's | |
2370 | * specification and force a wildcard bind, whereas a value of 2 | |
2371 | * (``clientspecified'') will bind to whatever address the client | |
2372 | * asked for. | |
2373 | * | |
2374 | * Special-case listen_addrs are: | |
2375 | * | |
2376 | * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR | |
2377 | * "" (empty string), "*" -> wildcard v4/v6 | |
2378 | * "localhost" -> loopback v4/v6 | |
2379 | */ | |
2380 | addr = NULL; | |
2381 | if (listen_addr == NULL) { | |
2382 | /* No address specified: default to gateway_ports setting */ | |
2383 | if (gateway_ports) | |
2384 | wildcard = 1; | |
2385 | } else if (gateway_ports || is_client) { | |
2386 | if (((datafellows & SSH_OLD_FORWARD_ADDR) && | |
2387 | strcmp(listen_addr, "0.0.0.0") == 0) || | |
2388 | *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 || | |
2389 | (!is_client && gateway_ports == 1)) | |
2390 | wildcard = 1; | |
2391 | else if (strcmp(listen_addr, "localhost") != 0) | |
2392 | addr = listen_addr; | |
2393 | } | |
2394 | ||
2395 | debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s", | |
2396 | type, wildcard, (addr == NULL) ? "NULL" : addr); | |
2397 | ||
2398 | /* | |
2399 | * getaddrinfo returns a loopback address if the hostname is | |
2400 | * set to NULL and hints.ai_flags is not AI_PASSIVE | |
2401 | */ | |
2402 | memset(&hints, 0, sizeof(hints)); | |
2403 | hints.ai_family = IPv4or6; | |
2404 | hints.ai_flags = wildcard ? AI_PASSIVE : 0; | |
2405 | hints.ai_socktype = SOCK_STREAM; | |
2406 | snprintf(strport, sizeof strport, "%d", listen_port); | |
2407 | if ((r = getaddrinfo(addr, strport, &hints, &aitop)) != 0) { | |
2408 | if (addr == NULL) { | |
2409 | /* This really shouldn't happen */ | |
2410 | packet_disconnect("getaddrinfo: fatal error: %s", | |
2411 | gai_strerror(r)); | |
2412 | } else { | |
2413 | error("channel_setup_fwd_listener: " | |
2414 | "getaddrinfo(%.64s): %s", addr, gai_strerror(r)); | |
2415 | } | |
2416 | return 0; | |
2417 | } | |
2418 | ||
2419 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2420 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2421 | continue; | |
2422 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
2423 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
2424 | error("channel_setup_fwd_listener: getnameinfo failed"); | |
2425 | continue; | |
2426 | } | |
2427 | /* Create a port to listen for the host. */ | |
2428 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); | |
2429 | if (sock < 0) { | |
2430 | /* this is no error since kernel may not support ipv6 */ | |
2431 | verbose("socket: %.100s", strerror(errno)); | |
2432 | continue; | |
2433 | } | |
2434 | ||
2435 | channel_set_reuseaddr(sock); | |
2436 | ||
2437 | debug("Local forwarding listening on %s port %s.", ntop, strport); | |
2438 | ||
2439 | /* Bind the socket to the address. */ | |
2440 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
2441 | /* address can be in use ipv6 address is already bound */ | |
2442 | if (!ai->ai_next) | |
2443 | error("bind: %.100s", strerror(errno)); | |
2444 | else | |
2445 | verbose("bind: %.100s", strerror(errno)); | |
2446 | ||
2447 | close(sock); | |
2448 | continue; | |
2449 | } | |
2450 | /* Start listening for connections on the socket. */ | |
2451 | if (listen(sock, SSH_LISTEN_BACKLOG) < 0) { | |
2452 | error("listen: %.100s", strerror(errno)); | |
2453 | close(sock); | |
2454 | continue; | |
2455 | } | |
2456 | /* Allocate a channel number for the socket. */ | |
2457 | c = channel_new("port listener", type, sock, sock, -1, | |
2458 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, | |
2459 | 0, "port listener", 1); | |
2460 | strlcpy(c->path, host, sizeof(c->path)); | |
2461 | c->host_port = port_to_connect; | |
2462 | c->listening_port = listen_port; | |
2463 | success = 1; | |
2464 | } | |
2465 | if (success == 0) | |
2466 | error("channel_setup_fwd_listener: cannot listen to port: %d", | |
2467 | listen_port); | |
2468 | freeaddrinfo(aitop); | |
2469 | return success; | |
2470 | } | |
2471 | ||
2472 | int | |
2473 | channel_cancel_rport_listener(const char *host, u_short port) | |
2474 | { | |
2475 | u_int i; | |
2476 | int found = 0; | |
2477 | ||
2478 | for (i = 0; i < channels_alloc; i++) { | |
2479 | Channel *c = channels[i]; | |
2480 | ||
2481 | if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER && | |
2482 | strncmp(c->path, host, sizeof(c->path)) == 0 && | |
2483 | c->listening_port == port) { | |
2484 | debug2("%s: close channel %d", __func__, i); | |
2485 | channel_free(c); | |
2486 | found = 1; | |
2487 | } | |
2488 | } | |
2489 | ||
2490 | return (found); | |
2491 | } | |
2492 | ||
2493 | /* protocol local port fwd, used by ssh (and sshd in v1) */ | |
2494 | int | |
2495 | channel_setup_local_fwd_listener(const char *listen_host, u_short listen_port, | |
2496 | const char *host_to_connect, u_short port_to_connect, int gateway_ports) | |
2497 | { | |
2498 | return channel_setup_fwd_listener(SSH_CHANNEL_PORT_LISTENER, | |
2499 | listen_host, listen_port, host_to_connect, port_to_connect, | |
2500 | gateway_ports); | |
2501 | } | |
2502 | ||
2503 | /* protocol v2 remote port fwd, used by sshd */ | |
2504 | int | |
2505 | channel_setup_remote_fwd_listener(const char *listen_address, | |
2506 | u_short listen_port, int gateway_ports) | |
2507 | { | |
2508 | return channel_setup_fwd_listener(SSH_CHANNEL_RPORT_LISTENER, | |
2509 | listen_address, listen_port, NULL, 0, gateway_ports); | |
2510 | } | |
2511 | ||
2512 | /* | |
2513 | * Initiate forwarding of connections to port "port" on remote host through | |
2514 | * the secure channel to host:port from local side. | |
2515 | */ | |
2516 | ||
2517 | int | |
2518 | channel_request_remote_forwarding(const char *listen_host, u_short listen_port, | |
2519 | const char *host_to_connect, u_short port_to_connect) | |
2520 | { | |
2521 | int type, success = 0; | |
2522 | ||
2523 | /* Record locally that connection to this host/port is permitted. */ | |
2524 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
2525 | fatal("channel_request_remote_forwarding: too many forwards"); | |
2526 | ||
2527 | /* Send the forward request to the remote side. */ | |
2528 | if (compat20) { | |
2529 | const char *address_to_bind; | |
2530 | if (listen_host == NULL) { | |
2531 | if (datafellows & SSH_BUG_RFWD_ADDR) | |
2532 | address_to_bind = "127.0.0.1"; | |
2533 | else | |
2534 | address_to_bind = "localhost"; | |
2535 | } else if (*listen_host == '\0' || | |
2536 | strcmp(listen_host, "*") == 0) { | |
2537 | if (datafellows & SSH_BUG_RFWD_ADDR) | |
2538 | address_to_bind = "0.0.0.0"; | |
2539 | else | |
2540 | address_to_bind = ""; | |
2541 | } else | |
2542 | address_to_bind = listen_host; | |
2543 | ||
2544 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
2545 | packet_put_cstring("tcpip-forward"); | |
2546 | packet_put_char(1); /* boolean: want reply */ | |
2547 | packet_put_cstring(address_to_bind); | |
2548 | packet_put_int(listen_port); | |
2549 | packet_send(); | |
2550 | packet_write_wait(); | |
2551 | /* Assume that server accepts the request */ | |
2552 | success = 1; | |
2553 | } else { | |
2554 | packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); | |
2555 | packet_put_int(listen_port); | |
2556 | packet_put_cstring(host_to_connect); | |
2557 | packet_put_int(port_to_connect); | |
2558 | packet_send(); | |
2559 | packet_write_wait(); | |
2560 | ||
2561 | /* Wait for response from the remote side. */ | |
2562 | type = packet_read(); | |
2563 | switch (type) { | |
2564 | case SSH_SMSG_SUCCESS: | |
2565 | success = 1; | |
2566 | break; | |
2567 | case SSH_SMSG_FAILURE: | |
2568 | break; | |
2569 | default: | |
2570 | /* Unknown packet */ | |
2571 | packet_disconnect("Protocol error for port forward request:" | |
2572 | "received packet type %d.", type); | |
2573 | } | |
2574 | } | |
2575 | if (success) { | |
2576 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect); | |
2577 | permitted_opens[num_permitted_opens].port_to_connect = port_to_connect; | |
2578 | permitted_opens[num_permitted_opens].listen_port = listen_port; | |
2579 | num_permitted_opens++; | |
2580 | } | |
2581 | return (success ? 0 : -1); | |
2582 | } | |
2583 | ||
2584 | /* | |
2585 | * Request cancellation of remote forwarding of connection host:port from | |
2586 | * local side. | |
2587 | */ | |
2588 | void | |
2589 | channel_request_rforward_cancel(const char *host, u_short port) | |
2590 | { | |
2591 | int i; | |
2592 | ||
2593 | if (!compat20) | |
2594 | return; | |
2595 | ||
2596 | for (i = 0; i < num_permitted_opens; i++) { | |
2597 | if (permitted_opens[i].host_to_connect != NULL && | |
2598 | permitted_opens[i].listen_port == port) | |
2599 | break; | |
2600 | } | |
2601 | if (i >= num_permitted_opens) { | |
2602 | debug("%s: requested forward not found", __func__); | |
2603 | return; | |
2604 | } | |
2605 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
2606 | packet_put_cstring("cancel-tcpip-forward"); | |
2607 | packet_put_char(0); | |
2608 | packet_put_cstring(host == NULL ? "" : host); | |
2609 | packet_put_int(port); | |
2610 | packet_send(); | |
2611 | ||
2612 | permitted_opens[i].listen_port = 0; | |
2613 | permitted_opens[i].port_to_connect = 0; | |
2614 | xfree(permitted_opens[i].host_to_connect); | |
2615 | permitted_opens[i].host_to_connect = NULL; | |
2616 | } | |
2617 | ||
2618 | /* | |
2619 | * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates | |
2620 | * listening for the port, and sends back a success reply (or disconnect | |
2621 | * message if there was an error). | |
2622 | */ | |
2623 | int | |
2624 | channel_input_port_forward_request(int is_root, int gateway_ports) | |
2625 | { | |
2626 | u_short port, host_port; | |
2627 | int success = 0; | |
2628 | char *hostname; | |
2629 | ||
2630 | /* Get arguments from the packet. */ | |
2631 | port = packet_get_int(); | |
2632 | hostname = packet_get_string(NULL); | |
2633 | host_port = packet_get_int(); | |
2634 | ||
2635 | #ifndef HAVE_CYGWIN | |
2636 | /* | |
2637 | * Check that an unprivileged user is not trying to forward a | |
2638 | * privileged port. | |
2639 | */ | |
2640 | if (port < IPPORT_RESERVED && !is_root) | |
2641 | packet_disconnect( | |
2642 | "Requested forwarding of port %d but user is not root.", | |
2643 | port); | |
2644 | if (host_port == 0) | |
2645 | packet_disconnect("Dynamic forwarding denied."); | |
2646 | #endif | |
2647 | ||
2648 | /* Initiate forwarding */ | |
2649 | success = channel_setup_local_fwd_listener(NULL, port, hostname, | |
2650 | host_port, gateway_ports); | |
2651 | ||
2652 | /* Free the argument string. */ | |
2653 | xfree(hostname); | |
2654 | ||
2655 | return (success ? 0 : -1); | |
2656 | } | |
2657 | ||
2658 | /* | |
2659 | * Permits opening to any host/port if permitted_opens[] is empty. This is | |
2660 | * usually called by the server, because the user could connect to any port | |
2661 | * anyway, and the server has no way to know but to trust the client anyway. | |
2662 | */ | |
2663 | void | |
2664 | channel_permit_all_opens(void) | |
2665 | { | |
2666 | if (num_permitted_opens == 0) | |
2667 | all_opens_permitted = 1; | |
2668 | } | |
2669 | ||
2670 | void | |
2671 | channel_add_permitted_opens(char *host, int port) | |
2672 | { | |
2673 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
2674 | fatal("channel_add_permitted_opens: too many forwards"); | |
2675 | debug("allow port forwarding to host %s port %d", host, port); | |
2676 | ||
2677 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host); | |
2678 | permitted_opens[num_permitted_opens].port_to_connect = port; | |
2679 | num_permitted_opens++; | |
2680 | ||
2681 | all_opens_permitted = 0; | |
2682 | } | |
2683 | ||
2684 | int | |
2685 | channel_add_adm_permitted_opens(char *host, int port) | |
2686 | { | |
2687 | if (num_adm_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
2688 | fatal("channel_add_adm_permitted_opens: too many forwards"); | |
2689 | debug("config allows port forwarding to host %s port %d", host, port); | |
2690 | ||
2691 | permitted_adm_opens[num_adm_permitted_opens].host_to_connect | |
2692 | = xstrdup(host); | |
2693 | permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port; | |
2694 | return ++num_adm_permitted_opens; | |
2695 | } | |
2696 | ||
2697 | void | |
2698 | channel_clear_permitted_opens(void) | |
2699 | { | |
2700 | int i; | |
2701 | ||
2702 | for (i = 0; i < num_permitted_opens; i++) | |
2703 | if (permitted_opens[i].host_to_connect != NULL) | |
2704 | xfree(permitted_opens[i].host_to_connect); | |
2705 | num_permitted_opens = 0; | |
2706 | } | |
2707 | ||
2708 | void | |
2709 | channel_clear_adm_permitted_opens(void) | |
2710 | { | |
2711 | int i; | |
2712 | ||
2713 | for (i = 0; i < num_adm_permitted_opens; i++) | |
2714 | if (permitted_adm_opens[i].host_to_connect != NULL) | |
2715 | xfree(permitted_adm_opens[i].host_to_connect); | |
2716 | num_adm_permitted_opens = 0; | |
2717 | } | |
2718 | ||
2719 | /* return socket to remote host, port */ | |
2720 | static int | |
2721 | connect_to(const char *host, u_short port) | |
2722 | { | |
2723 | struct addrinfo hints, *ai, *aitop; | |
2724 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
2725 | int gaierr; | |
2726 | int sock = -1; | |
2727 | ||
2728 | memset(&hints, 0, sizeof(hints)); | |
2729 | hints.ai_family = IPv4or6; | |
2730 | hints.ai_socktype = SOCK_STREAM; | |
2731 | snprintf(strport, sizeof strport, "%d", port); | |
2732 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { | |
2733 | error("connect_to %.100s: unknown host (%s)", host, | |
2734 | gai_strerror(gaierr)); | |
2735 | return -1; | |
2736 | } | |
2737 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2738 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2739 | continue; | |
2740 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
2741 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
2742 | error("connect_to: getnameinfo failed"); | |
2743 | continue; | |
2744 | } | |
2745 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); | |
2746 | if (sock < 0) { | |
2747 | if (ai->ai_next == NULL) | |
2748 | error("socket: %.100s", strerror(errno)); | |
2749 | else | |
2750 | verbose("socket: %.100s", strerror(errno)); | |
2751 | continue; | |
2752 | } | |
2753 | if (set_nonblock(sock) == -1) | |
2754 | fatal("%s: set_nonblock(%d)", __func__, sock); | |
2755 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 && | |
2756 | errno != EINPROGRESS) { | |
2757 | error("connect_to %.100s port %s: %.100s", ntop, strport, | |
2758 | strerror(errno)); | |
2759 | close(sock); | |
2760 | continue; /* fail -- try next */ | |
2761 | } | |
2762 | break; /* success */ | |
2763 | ||
2764 | } | |
2765 | freeaddrinfo(aitop); | |
2766 | if (!ai) { | |
2767 | error("connect_to %.100s port %d: failed.", host, port); | |
2768 | return -1; | |
2769 | } | |
2770 | /* success */ | |
2771 | set_nodelay(sock); | |
2772 | return sock; | |
2773 | } | |
2774 | ||
2775 | int | |
2776 | channel_connect_by_listen_address(u_short listen_port) | |
2777 | { | |
2778 | int i; | |
2779 | ||
2780 | for (i = 0; i < num_permitted_opens; i++) | |
2781 | if (permitted_opens[i].host_to_connect != NULL && | |
2782 | permitted_opens[i].listen_port == listen_port) | |
2783 | return connect_to( | |
2784 | permitted_opens[i].host_to_connect, | |
2785 | permitted_opens[i].port_to_connect); | |
2786 | error("WARNING: Server requests forwarding for unknown listen_port %d", | |
2787 | listen_port); | |
2788 | return -1; | |
2789 | } | |
2790 | ||
2791 | /* Check if connecting to that port is permitted and connect. */ | |
2792 | int | |
2793 | channel_connect_to(const char *host, u_short port) | |
2794 | { | |
2795 | int i, permit, permit_adm = 1; | |
2796 | ||
2797 | permit = all_opens_permitted; | |
2798 | if (!permit) { | |
2799 | for (i = 0; i < num_permitted_opens; i++) | |
2800 | if (permitted_opens[i].host_to_connect != NULL && | |
2801 | permitted_opens[i].port_to_connect == port && | |
2802 | strcmp(permitted_opens[i].host_to_connect, host) == 0) | |
2803 | permit = 1; | |
2804 | } | |
2805 | ||
2806 | if (num_adm_permitted_opens > 0) { | |
2807 | permit_adm = 0; | |
2808 | for (i = 0; i < num_adm_permitted_opens; i++) | |
2809 | if (permitted_adm_opens[i].host_to_connect != NULL && | |
2810 | permitted_adm_opens[i].port_to_connect == port && | |
2811 | strcmp(permitted_adm_opens[i].host_to_connect, host) | |
2812 | == 0) | |
2813 | permit_adm = 1; | |
2814 | } | |
2815 | ||
2816 | if (!permit || !permit_adm) { | |
2817 | logit("Received request to connect to host %.100s port %d, " | |
2818 | "but the request was denied.", host, port); | |
2819 | return -1; | |
2820 | } | |
2821 | return connect_to(host, port); | |
2822 | } | |
2823 | ||
2824 | void | |
2825 | channel_send_window_changes(void) | |
2826 | { | |
2827 | u_int i; | |
2828 | struct winsize ws; | |
2829 | ||
2830 | for (i = 0; i < channels_alloc; i++) { | |
2831 | if (channels[i] == NULL || !channels[i]->client_tty || | |
2832 | channels[i]->type != SSH_CHANNEL_OPEN) | |
2833 | continue; | |
2834 | if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0) | |
2835 | continue; | |
2836 | channel_request_start(i, "window-change", 0); | |
2837 | packet_put_int((u_int)ws.ws_col); | |
2838 | packet_put_int((u_int)ws.ws_row); | |
2839 | packet_put_int((u_int)ws.ws_xpixel); | |
2840 | packet_put_int((u_int)ws.ws_ypixel); | |
2841 | packet_send(); | |
2842 | } | |
2843 | } | |
2844 | ||
2845 | /* -- X11 forwarding */ | |
2846 | ||
2847 | /* | |
2848 | * Creates an internet domain socket for listening for X11 connections. | |
2849 | * Returns 0 and a suitable display number for the DISPLAY variable | |
2850 | * stored in display_numberp , or -1 if an error occurs. | |
2851 | */ | |
2852 | int | |
2853 | x11_create_display_inet(int x11_display_offset, int x11_use_localhost, | |
2854 | int single_connection, u_int *display_numberp, int **chanids) | |
2855 | { | |
2856 | Channel *nc = NULL; | |
2857 | int display_number, sock; | |
2858 | u_short port; | |
2859 | struct addrinfo hints, *ai, *aitop; | |
2860 | char strport[NI_MAXSERV]; | |
2861 | int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; | |
2862 | ||
2863 | if (chanids == NULL) | |
2864 | return -1; | |
2865 | ||
2866 | for (display_number = x11_display_offset; | |
2867 | display_number < MAX_DISPLAYS; | |
2868 | display_number++) { | |
2869 | port = 6000 + display_number; | |
2870 | memset(&hints, 0, sizeof(hints)); | |
2871 | hints.ai_family = IPv4or6; | |
2872 | hints.ai_flags = x11_use_localhost ? 0: AI_PASSIVE; | |
2873 | hints.ai_socktype = SOCK_STREAM; | |
2874 | snprintf(strport, sizeof strport, "%d", port); | |
2875 | if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { | |
2876 | error("getaddrinfo: %.100s", gai_strerror(gaierr)); | |
2877 | return -1; | |
2878 | } | |
2879 | for (ai = aitop; ai; ai = ai->ai_next) { | |
2880 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
2881 | continue; | |
2882 | sock = socket(ai->ai_family, ai->ai_socktype, | |
2883 | ai->ai_protocol); | |
2884 | if (sock < 0) { | |
2885 | if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) { | |
2886 | error("socket: %.100s", strerror(errno)); | |
2887 | freeaddrinfo(aitop); | |
2888 | return -1; | |
2889 | } else { | |
2890 | debug("x11_create_display_inet: Socket family %d not supported", | |
2891 | ai->ai_family); | |
2892 | continue; | |
2893 | } | |
2894 | } | |
2895 | #ifdef IPV6_V6ONLY | |
2896 | if (ai->ai_family == AF_INET6) { | |
2897 | int on = 1; | |
2898 | if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) | |
2899 | error("setsockopt IPV6_V6ONLY: %.100s", strerror(errno)); | |
2900 | } | |
2901 | #endif | |
2902 | channel_set_reuseaddr(sock); | |
2903 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
2904 | debug2("bind port %d: %.100s", port, strerror(errno)); | |
2905 | close(sock); | |
2906 | ||
2907 | if (ai->ai_next) | |
2908 | continue; | |
2909 | ||
2910 | for (n = 0; n < num_socks; n++) { | |
2911 | close(socks[n]); | |
2912 | } | |
2913 | num_socks = 0; | |
2914 | break; | |
2915 | } | |
2916 | socks[num_socks++] = sock; | |
2917 | #ifndef DONT_TRY_OTHER_AF | |
2918 | if (num_socks == NUM_SOCKS) | |
2919 | break; | |
2920 | #else | |
2921 | if (x11_use_localhost) { | |
2922 | if (num_socks == NUM_SOCKS) | |
2923 | break; | |
2924 | } else { | |
2925 | break; | |
2926 | } | |
2927 | #endif | |
2928 | } | |
2929 | freeaddrinfo(aitop); | |
2930 | if (num_socks > 0) | |
2931 | break; | |
2932 | } | |
2933 | if (display_number >= MAX_DISPLAYS) { | |
2934 | error("Failed to allocate internet-domain X11 display socket."); | |
2935 | return -1; | |
2936 | } | |
2937 | /* Start listening for connections on the socket. */ | |
2938 | for (n = 0; n < num_socks; n++) { | |
2939 | sock = socks[n]; | |
2940 | if (listen(sock, SSH_LISTEN_BACKLOG) < 0) { | |
2941 | error("listen: %.100s", strerror(errno)); | |
2942 | close(sock); | |
2943 | return -1; | |
2944 | } | |
2945 | } | |
2946 | ||
2947 | /* Allocate a channel for each socket. */ | |
2948 | *chanids = xcalloc(num_socks + 1, sizeof(**chanids)); | |
2949 | for (n = 0; n < num_socks; n++) { | |
2950 | sock = socks[n]; | |
2951 | nc = channel_new("x11 listener", | |
2952 | SSH_CHANNEL_X11_LISTENER, sock, sock, -1, | |
2953 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
2954 | 0, "X11 inet listener", 1); | |
2955 | nc->single_connection = single_connection; | |
2956 | (*chanids)[n] = nc->self; | |
2957 | } | |
2958 | (*chanids)[n] = -1; | |
2959 | ||
2960 | /* Return the display number for the DISPLAY environment variable. */ | |
2961 | *display_numberp = display_number; | |
2962 | return (0); | |
2963 | } | |
2964 | ||
2965 | static int | |
2966 | connect_local_xsocket(u_int dnr) | |
2967 | { | |
2968 | int sock; | |
2969 | struct sockaddr_un addr; | |
2970 | ||
2971 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
2972 | if (sock < 0) | |
2973 | error("socket: %.100s", strerror(errno)); | |
2974 | memset(&addr, 0, sizeof(addr)); | |
2975 | addr.sun_family = AF_UNIX; | |
2976 | snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr); | |
2977 | if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0) | |
2978 | return sock; | |
2979 | close(sock); | |
2980 | error("connect %.100s: %.100s", addr.sun_path, strerror(errno)); | |
2981 | return -1; | |
2982 | } | |
2983 | ||
2984 | int | |
2985 | x11_connect_display(void) | |
2986 | { | |
2987 | u_int display_number; | |
2988 | const char *display; | |
2989 | char buf[1024], *cp; | |
2990 | struct addrinfo hints, *ai, *aitop; | |
2991 | char strport[NI_MAXSERV]; | |
2992 | int gaierr, sock = 0; | |
2993 | ||
2994 | /* Try to open a socket for the local X server. */ | |
2995 | display = getenv("DISPLAY"); | |
2996 | if (!display) { | |
2997 | error("DISPLAY not set."); | |
2998 | return -1; | |
2999 | } | |
3000 | /* | |
3001 | * Now we decode the value of the DISPLAY variable and make a | |
3002 | * connection to the real X server. | |
3003 | */ | |
3004 | ||
3005 | /* | |
3006 | * Check if it is a unix domain socket. Unix domain displays are in | |
3007 | * one of the following formats: unix:d[.s], :d[.s], ::d[.s] | |
3008 | */ | |
3009 | if (strncmp(display, "unix:", 5) == 0 || | |
3010 | display[0] == ':') { | |
3011 | /* Connect to the unix domain socket. */ | |
3012 | if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) { | |
3013 | error("Could not parse display number from DISPLAY: %.100s", | |
3014 | display); | |
3015 | return -1; | |
3016 | } | |
3017 | /* Create a socket. */ | |
3018 | sock = connect_local_xsocket(display_number); | |
3019 | if (sock < 0) | |
3020 | return -1; | |
3021 | ||
3022 | /* OK, we now have a connection to the display. */ | |
3023 | return sock; | |
3024 | } | |
3025 | /* | |
3026 | * Connect to an inet socket. The DISPLAY value is supposedly | |
3027 | * hostname:d[.s], where hostname may also be numeric IP address. | |
3028 | */ | |
3029 | strlcpy(buf, display, sizeof(buf)); | |
3030 | cp = strchr(buf, ':'); | |
3031 | if (!cp) { | |
3032 | error("Could not find ':' in DISPLAY: %.100s", display); | |
3033 | return -1; | |
3034 | } | |
3035 | *cp = 0; | |
3036 | /* buf now contains the host name. But first we parse the display number. */ | |
3037 | if (sscanf(cp + 1, "%u", &display_number) != 1) { | |
3038 | error("Could not parse display number from DISPLAY: %.100s", | |
3039 | display); | |
3040 | return -1; | |
3041 | } | |
3042 | ||
3043 | /* Look up the host address */ | |
3044 | memset(&hints, 0, sizeof(hints)); | |
3045 | hints.ai_family = IPv4or6; | |
3046 | hints.ai_socktype = SOCK_STREAM; | |
3047 | snprintf(strport, sizeof strport, "%u", 6000 + display_number); | |
3048 | if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { | |
3049 | error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr)); | |
3050 | return -1; | |
3051 | } | |
3052 | for (ai = aitop; ai; ai = ai->ai_next) { | |
3053 | /* Create a socket. */ | |
3054 | sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); | |
3055 | if (sock < 0) { | |
3056 | debug2("socket: %.100s", strerror(errno)); | |
3057 | continue; | |
3058 | } | |
3059 | /* Connect it to the display. */ | |
3060 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
3061 | debug2("connect %.100s port %u: %.100s", buf, | |
3062 | 6000 + display_number, strerror(errno)); | |
3063 | close(sock); | |
3064 | continue; | |
3065 | } | |
3066 | /* Success */ | |
3067 | break; | |
3068 | } | |
3069 | freeaddrinfo(aitop); | |
3070 | if (!ai) { | |
3071 | error("connect %.100s port %u: %.100s", buf, 6000 + display_number, | |
3072 | strerror(errno)); | |
3073 | return -1; | |
3074 | } | |
3075 | set_nodelay(sock); | |
3076 | return sock; | |
3077 | } | |
3078 | ||
3079 | /* | |
3080 | * This is called when SSH_SMSG_X11_OPEN is received. The packet contains | |
3081 | * the remote channel number. We should do whatever we want, and respond | |
3082 | * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. | |
3083 | */ | |
3084 | ||
3085 | /* ARGSUSED */ | |
3086 | void | |
3087 | x11_input_open(int type, u_int32_t seq, void *ctxt) | |
3088 | { | |
3089 | Channel *c = NULL; | |
3090 | int remote_id, sock = 0; | |
3091 | char *remote_host; | |
3092 | ||
3093 | debug("Received X11 open request."); | |
3094 | ||
3095 | remote_id = packet_get_int(); | |
3096 | ||
3097 | if (packet_get_protocol_flags() & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) { | |
3098 | remote_host = packet_get_string(NULL); | |
3099 | } else { | |
3100 | remote_host = xstrdup("unknown (remote did not supply name)"); | |
3101 | } | |
3102 | packet_check_eom(); | |
3103 | ||
3104 | /* Obtain a connection to the real X display. */ | |
3105 | sock = x11_connect_display(); | |
3106 | if (sock != -1) { | |
3107 | /* Allocate a channel for this connection. */ | |
3108 | c = channel_new("connected x11 socket", | |
3109 | SSH_CHANNEL_X11_OPEN, sock, sock, -1, 0, 0, 0, | |
3110 | remote_host, 1); | |
3111 | c->remote_id = remote_id; | |
3112 | c->force_drain = 1; | |
3113 | } | |
3114 | xfree(remote_host); | |
3115 | if (c == NULL) { | |
3116 | /* Send refusal to the remote host. */ | |
3117 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
3118 | packet_put_int(remote_id); | |
3119 | } else { | |
3120 | /* Send a confirmation to the remote host. */ | |
3121 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
3122 | packet_put_int(remote_id); | |
3123 | packet_put_int(c->self); | |
3124 | } | |
3125 | packet_send(); | |
3126 | } | |
3127 | ||
3128 | /* dummy protocol handler that denies SSH-1 requests (agent/x11) */ | |
3129 | /* ARGSUSED */ | |
3130 | void | |
3131 | deny_input_open(int type, u_int32_t seq, void *ctxt) | |
3132 | { | |
3133 | int rchan = packet_get_int(); | |
3134 | ||
3135 | switch (type) { | |
3136 | case SSH_SMSG_AGENT_OPEN: | |
3137 | error("Warning: ssh server tried agent forwarding."); | |
3138 | break; | |
3139 | case SSH_SMSG_X11_OPEN: | |
3140 | error("Warning: ssh server tried X11 forwarding."); | |
3141 | break; | |
3142 | default: | |
3143 | error("deny_input_open: type %d", type); | |
3144 | break; | |
3145 | } | |
3146 | error("Warning: this is probably a break-in attempt by a malicious server."); | |
3147 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
3148 | packet_put_int(rchan); | |
3149 | packet_send(); | |
3150 | } | |
3151 | ||
3152 | /* | |
3153 | * Requests forwarding of X11 connections, generates fake authentication | |
3154 | * data, and enables authentication spoofing. | |
3155 | * This should be called in the client only. | |
3156 | */ | |
3157 | void | |
3158 | x11_request_forwarding_with_spoofing(int client_session_id, const char *disp, | |
3159 | const char *proto, const char *data) | |
3160 | { | |
3161 | u_int data_len = (u_int) strlen(data) / 2; | |
3162 | u_int i, value; | |
3163 | char *new_data; | |
3164 | int screen_number; | |
3165 | const char *cp; | |
3166 | u_int32_t rnd = 0; | |
3167 | ||
3168 | if (x11_saved_display == NULL) | |
3169 | x11_saved_display = xstrdup(disp); | |
3170 | else if (strcmp(disp, x11_saved_display) != 0) { | |
3171 | error("x11_request_forwarding_with_spoofing: different " | |
3172 | "$DISPLAY already forwarded"); | |
3173 | return; | |
3174 | } | |
3175 | ||
3176 | cp = strchr(disp, ':'); | |
3177 | if (cp) | |
3178 | cp = strchr(cp, '.'); | |
3179 | if (cp) | |
3180 | screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL); | |
3181 | else | |
3182 | screen_number = 0; | |
3183 | ||
3184 | if (x11_saved_proto == NULL) { | |
3185 | /* Save protocol name. */ | |
3186 | x11_saved_proto = xstrdup(proto); | |
3187 | /* | |
3188 | * Extract real authentication data and generate fake data | |
3189 | * of the same length. | |
3190 | */ | |
3191 | x11_saved_data = xmalloc(data_len); | |
3192 | x11_fake_data = xmalloc(data_len); | |
3193 | for (i = 0; i < data_len; i++) { | |
3194 | if (sscanf(data + 2 * i, "%2x", &value) != 1) | |
3195 | fatal("x11_request_forwarding: bad " | |
3196 | "authentication data: %.100s", data); | |
3197 | if (i % 4 == 0) | |
3198 | rnd = arc4random(); | |
3199 | x11_saved_data[i] = value; | |
3200 | x11_fake_data[i] = rnd & 0xff; | |
3201 | rnd >>= 8; | |
3202 | } | |
3203 | x11_saved_data_len = data_len; | |
3204 | x11_fake_data_len = data_len; | |
3205 | } | |
3206 | ||
3207 | /* Convert the fake data into hex. */ | |
3208 | new_data = tohex(x11_fake_data, data_len); | |
3209 | ||
3210 | /* Send the request packet. */ | |
3211 | if (compat20) { | |
3212 | channel_request_start(client_session_id, "x11-req", 0); | |
3213 | packet_put_char(0); /* XXX bool single connection */ | |
3214 | } else { | |
3215 | packet_start(SSH_CMSG_X11_REQUEST_FORWARDING); | |
3216 | } | |
3217 | packet_put_cstring(proto); | |
3218 | packet_put_cstring(new_data); | |
3219 | packet_put_int(screen_number); | |
3220 | packet_send(); | |
3221 | packet_write_wait(); | |
3222 | xfree(new_data); | |
3223 | } | |
3224 | ||
3225 | ||
3226 | /* -- agent forwarding */ | |
3227 | ||
3228 | /* Sends a message to the server to request authentication fd forwarding. */ | |
3229 | ||
3230 | void | |
3231 | auth_request_forwarding(void) | |
3232 | { | |
3233 | packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); | |
3234 | packet_send(); | |
3235 | packet_write_wait(); | |
3236 | } |