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Commit | Line | Data |
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8efc0c15 | 1 | /* |
5260325f | 2 | * |
3 | * channels.c | |
4 | * | |
5 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
6 | * | |
7 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
8 | * All rights reserved | |
9 | * | |
10 | * Created: Fri Mar 24 16:35:24 1995 ylo | |
11 | * | |
12 | * This file contains functions for generic socket connection forwarding. | |
13 | * There is also code for initiating connection forwarding for X11 connections, | |
14 | * arbitrary tcp/ip connections, and the authentication agent connection. | |
15 | * | |
16 | */ | |
8efc0c15 | 17 | |
18 | #include "includes.h" | |
19 | RCSID("$Id$"); | |
20 | ||
21 | #include "ssh.h" | |
22 | #include "packet.h" | |
23 | #include "xmalloc.h" | |
24 | #include "buffer.h" | |
25 | #include "authfd.h" | |
26 | #include "uidswap.h" | |
6fa724bc | 27 | #include "readconf.h" |
8efc0c15 | 28 | #include "servconf.h" |
29 | ||
30 | #include "channels.h" | |
31 | #include "nchan.h" | |
32 | #include "compat.h" | |
33 | ||
34 | /* Maximum number of fake X11 displays to try. */ | |
35 | #define MAX_DISPLAYS 1000 | |
36 | ||
37 | /* Max len of agent socket */ | |
38 | #define MAX_SOCKET_NAME 100 | |
39 | ||
aa3378df | 40 | /* |
41 | * Pointer to an array containing all allocated channels. The array is | |
42 | * dynamically extended as needed. | |
43 | */ | |
8efc0c15 | 44 | static Channel *channels = NULL; |
45 | ||
aa3378df | 46 | /* |
47 | * Size of the channel array. All slots of the array must always be | |
48 | * initialized (at least the type field); unused slots are marked with type | |
49 | * SSH_CHANNEL_FREE. | |
50 | */ | |
8efc0c15 | 51 | static int channels_alloc = 0; |
52 | ||
aa3378df | 53 | /* |
54 | * Maximum file descriptor value used in any of the channels. This is | |
55 | * updated in channel_allocate. | |
56 | */ | |
8efc0c15 | 57 | static int channel_max_fd_value = 0; |
58 | ||
59 | /* Name and directory of socket for authentication agent forwarding. */ | |
60 | static char *channel_forwarded_auth_socket_name = NULL; | |
5260325f | 61 | static char *channel_forwarded_auth_socket_dir = NULL; |
8efc0c15 | 62 | |
63 | /* Saved X11 authentication protocol name. */ | |
64 | char *x11_saved_proto = NULL; | |
65 | ||
66 | /* Saved X11 authentication data. This is the real data. */ | |
67 | char *x11_saved_data = NULL; | |
68 | unsigned int x11_saved_data_len = 0; | |
69 | ||
aa3378df | 70 | /* |
71 | * Fake X11 authentication data. This is what the server will be sending us; | |
72 | * we should replace any occurrences of this by the real data. | |
73 | */ | |
8efc0c15 | 74 | char *x11_fake_data = NULL; |
75 | unsigned int x11_fake_data_len; | |
76 | ||
aa3378df | 77 | /* |
78 | * Data structure for storing which hosts are permitted for forward requests. | |
79 | * The local sides of any remote forwards are stored in this array to prevent | |
80 | * a corrupt remote server from accessing arbitrary TCP/IP ports on our local | |
81 | * network (which might be behind a firewall). | |
82 | */ | |
5260325f | 83 | typedef struct { |
84 | char *host; /* Host name. */ | |
57112b5a | 85 | u_short port; /* Port number. */ |
8efc0c15 | 86 | } ForwardPermission; |
87 | ||
88 | /* List of all permitted host/port pairs to connect. */ | |
89 | static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; | |
90 | /* Number of permitted host/port pairs in the array. */ | |
91 | static int num_permitted_opens = 0; | |
aa3378df | 92 | /* |
93 | * If this is true, all opens are permitted. This is the case on the server | |
94 | * on which we have to trust the client anyway, and the user could do | |
95 | * anything after logging in anyway. | |
96 | */ | |
8efc0c15 | 97 | static int all_opens_permitted = 0; |
98 | ||
99 | /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */ | |
100 | static int have_hostname_in_open = 0; | |
101 | ||
102 | /* Sets specific protocol options. */ | |
103 | ||
5260325f | 104 | void |
105 | channel_set_options(int hostname_in_open) | |
8efc0c15 | 106 | { |
5260325f | 107 | have_hostname_in_open = hostname_in_open; |
8efc0c15 | 108 | } |
109 | ||
aa3378df | 110 | /* |
111 | * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually | |
112 | * called by the server, because the user could connect to any port anyway, | |
113 | * and the server has no way to know but to trust the client anyway. | |
114 | */ | |
8efc0c15 | 115 | |
5260325f | 116 | void |
117 | channel_permit_all_opens() | |
8efc0c15 | 118 | { |
5260325f | 119 | all_opens_permitted = 1; |
8efc0c15 | 120 | } |
121 | ||
aa3378df | 122 | /* |
123 | * Allocate a new channel object and set its type and socket. This will cause | |
124 | * remote_name to be freed. | |
125 | */ | |
8efc0c15 | 126 | |
5260325f | 127 | int |
128 | channel_allocate(int type, int sock, char *remote_name) | |
8efc0c15 | 129 | { |
5260325f | 130 | int i, found; |
131 | Channel *c; | |
132 | ||
133 | /* Update the maximum file descriptor value. */ | |
134 | if (sock > channel_max_fd_value) | |
135 | channel_max_fd_value = sock; | |
aa3378df | 136 | /* XXX set close-on-exec -markus */ |
5260325f | 137 | |
138 | /* Do initial allocation if this is the first call. */ | |
139 | if (channels_alloc == 0) { | |
140 | channels_alloc = 10; | |
141 | channels = xmalloc(channels_alloc * sizeof(Channel)); | |
142 | for (i = 0; i < channels_alloc; i++) | |
143 | channels[i].type = SSH_CHANNEL_FREE; | |
aa3378df | 144 | /* |
145 | * Kludge: arrange a call to channel_stop_listening if we | |
146 | * terminate with fatal(). | |
147 | */ | |
5260325f | 148 | fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL); |
149 | } | |
150 | /* Try to find a free slot where to put the new channel. */ | |
151 | for (found = -1, i = 0; i < channels_alloc; i++) | |
152 | if (channels[i].type == SSH_CHANNEL_FREE) { | |
153 | /* Found a free slot. */ | |
154 | found = i; | |
155 | break; | |
156 | } | |
157 | if (found == -1) { | |
aa3378df | 158 | /* There are no free slots. Take last+1 slot and expand the array. */ |
5260325f | 159 | found = channels_alloc; |
160 | channels_alloc += 10; | |
161 | debug("channel: expanding %d", channels_alloc); | |
162 | channels = xrealloc(channels, channels_alloc * sizeof(Channel)); | |
163 | for (i = found; i < channels_alloc; i++) | |
164 | channels[i].type = SSH_CHANNEL_FREE; | |
165 | } | |
166 | /* Initialize and return new channel number. */ | |
167 | c = &channels[found]; | |
168 | buffer_init(&c->input); | |
169 | buffer_init(&c->output); | |
170 | chan_init_iostates(c); | |
171 | c->self = found; | |
172 | c->type = type; | |
173 | c->sock = sock; | |
174 | c->remote_id = -1; | |
175 | c->remote_name = remote_name; | |
176 | debug("channel %d: new [%s]", found, remote_name); | |
177 | return found; | |
8efc0c15 | 178 | } |
179 | ||
180 | /* Free the channel and close its socket. */ | |
181 | ||
5260325f | 182 | void |
183 | channel_free(int channel) | |
8efc0c15 | 184 | { |
5260325f | 185 | if (channel < 0 || channel >= channels_alloc || |
186 | channels[channel].type == SSH_CHANNEL_FREE) | |
187 | packet_disconnect("channel free: bad local channel %d", channel); | |
188 | ||
189 | if (compat13) | |
190 | shutdown(channels[channel].sock, SHUT_RDWR); | |
191 | close(channels[channel].sock); | |
192 | buffer_free(&channels[channel].input); | |
193 | buffer_free(&channels[channel].output); | |
194 | channels[channel].type = SSH_CHANNEL_FREE; | |
195 | if (channels[channel].remote_name) { | |
196 | xfree(channels[channel].remote_name); | |
197 | channels[channel].remote_name = NULL; | |
198 | } | |
8efc0c15 | 199 | } |
200 | ||
aa3378df | 201 | /* |
202 | * This is called just before select() to add any bits relevant to channels | |
203 | * in the select bitmasks. | |
204 | */ | |
8efc0c15 | 205 | |
5260325f | 206 | void |
207 | channel_prepare_select(fd_set * readset, fd_set * writeset) | |
8efc0c15 | 208 | { |
5260325f | 209 | int i; |
210 | Channel *ch; | |
211 | unsigned char *ucp; | |
212 | unsigned int proto_len, data_len; | |
213 | ||
214 | for (i = 0; i < channels_alloc; i++) { | |
215 | ch = &channels[i]; | |
216 | redo: | |
217 | switch (ch->type) { | |
218 | case SSH_CHANNEL_X11_LISTENER: | |
219 | case SSH_CHANNEL_PORT_LISTENER: | |
220 | case SSH_CHANNEL_AUTH_SOCKET: | |
221 | FD_SET(ch->sock, readset); | |
222 | break; | |
223 | ||
224 | case SSH_CHANNEL_OPEN: | |
225 | if (compat13) { | |
226 | if (buffer_len(&ch->input) < packet_get_maxsize()) | |
227 | FD_SET(ch->sock, readset); | |
228 | if (buffer_len(&ch->output) > 0) | |
229 | FD_SET(ch->sock, writeset); | |
230 | break; | |
231 | } | |
232 | /* test whether sockets are 'alive' for read/write */ | |
233 | if (ch->istate == CHAN_INPUT_OPEN) | |
234 | if (buffer_len(&ch->input) < packet_get_maxsize()) | |
235 | FD_SET(ch->sock, readset); | |
236 | if (ch->ostate == CHAN_OUTPUT_OPEN || | |
237 | ch->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
238 | if (buffer_len(&ch->output) > 0) { | |
239 | FD_SET(ch->sock, writeset); | |
240 | } else if (ch->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
241 | chan_obuf_empty(ch); | |
242 | } | |
243 | } | |
244 | break; | |
245 | ||
246 | case SSH_CHANNEL_INPUT_DRAINING: | |
247 | if (!compat13) | |
248 | fatal("cannot happen: IN_DRAIN"); | |
249 | if (buffer_len(&ch->input) == 0) { | |
250 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
251 | packet_put_int(ch->remote_id); | |
252 | packet_send(); | |
253 | ch->type = SSH_CHANNEL_CLOSED; | |
00e6dd70 | 254 | debug("Closing channel %d after input drain.", ch->self); |
5260325f | 255 | break; |
256 | } | |
257 | break; | |
258 | ||
259 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
260 | if (!compat13) | |
261 | fatal("cannot happen: OUT_DRAIN"); | |
262 | if (buffer_len(&ch->output) == 0) { | |
263 | channel_free(i); | |
264 | break; | |
265 | } | |
266 | FD_SET(ch->sock, writeset); | |
267 | break; | |
268 | ||
269 | case SSH_CHANNEL_X11_OPEN: | |
aa3378df | 270 | /* |
271 | * This is a special state for X11 authentication | |
272 | * spoofing. An opened X11 connection (when | |
273 | * authentication spoofing is being done) remains in | |
274 | * this state until the first packet has been | |
275 | * completely read. The authentication data in that | |
276 | * packet is then substituted by the real data if it | |
277 | * matches the fake data, and the channel is put into | |
278 | * normal mode. | |
279 | */ | |
5260325f | 280 | /* Check if the fixed size part of the packet is in buffer. */ |
281 | if (buffer_len(&ch->output) < 12) | |
282 | break; | |
283 | ||
284 | /* Parse the lengths of variable-length fields. */ | |
285 | ucp = (unsigned char *) buffer_ptr(&ch->output); | |
286 | if (ucp[0] == 0x42) { /* Byte order MSB first. */ | |
287 | proto_len = 256 * ucp[6] + ucp[7]; | |
288 | data_len = 256 * ucp[8] + ucp[9]; | |
289 | } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ | |
290 | proto_len = ucp[6] + 256 * ucp[7]; | |
291 | data_len = ucp[8] + 256 * ucp[9]; | |
292 | } else { | |
293 | debug("Initial X11 packet contains bad byte order byte: 0x%x", | |
294 | ucp[0]); | |
295 | ch->type = SSH_CHANNEL_OPEN; | |
296 | goto reject; | |
297 | } | |
298 | ||
299 | /* Check if the whole packet is in buffer. */ | |
300 | if (buffer_len(&ch->output) < | |
301 | 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) | |
302 | break; | |
303 | ||
304 | /* Check if authentication protocol matches. */ | |
305 | if (proto_len != strlen(x11_saved_proto) || | |
306 | memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { | |
307 | debug("X11 connection uses different authentication protocol."); | |
308 | ch->type = SSH_CHANNEL_OPEN; | |
309 | goto reject; | |
310 | } | |
311 | /* Check if authentication data matches our fake data. */ | |
312 | if (data_len != x11_fake_data_len || | |
313 | memcmp(ucp + 12 + ((proto_len + 3) & ~3), | |
314 | x11_fake_data, x11_fake_data_len) != 0) { | |
315 | debug("X11 auth data does not match fake data."); | |
316 | ch->type = SSH_CHANNEL_OPEN; | |
317 | goto reject; | |
318 | } | |
319 | /* Check fake data length */ | |
320 | if (x11_fake_data_len != x11_saved_data_len) { | |
321 | error("X11 fake_data_len %d != saved_data_len %d", | |
322 | x11_fake_data_len, x11_saved_data_len); | |
323 | ch->type = SSH_CHANNEL_OPEN; | |
324 | goto reject; | |
325 | } | |
aa3378df | 326 | /* |
327 | * Received authentication protocol and data match | |
328 | * our fake data. Substitute the fake data with real | |
329 | * data. | |
330 | */ | |
5260325f | 331 | memcpy(ucp + 12 + ((proto_len + 3) & ~3), |
332 | x11_saved_data, x11_saved_data_len); | |
333 | ||
334 | /* Start normal processing for the channel. */ | |
335 | ch->type = SSH_CHANNEL_OPEN; | |
336 | goto redo; | |
337 | ||
8efc0c15 | 338 | reject: |
aa3378df | 339 | /* |
340 | * We have received an X11 connection that has bad | |
341 | * authentication information. | |
342 | */ | |
5260325f | 343 | log("X11 connection rejected because of wrong authentication.\r\n"); |
344 | buffer_clear(&ch->input); | |
345 | buffer_clear(&ch->output); | |
346 | if (compat13) { | |
347 | close(ch->sock); | |
348 | ch->sock = -1; | |
349 | ch->type = SSH_CHANNEL_CLOSED; | |
350 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
351 | packet_put_int(ch->remote_id); | |
352 | packet_send(); | |
353 | } else { | |
354 | debug("X11 rejected %d i%d/o%d", ch->self, ch->istate, ch->ostate); | |
355 | chan_read_failed(ch); | |
356 | chan_write_failed(ch); | |
357 | debug("X11 rejected %d i%d/o%d", ch->self, ch->istate, ch->ostate); | |
358 | } | |
359 | break; | |
360 | ||
361 | case SSH_CHANNEL_FREE: | |
362 | default: | |
363 | continue; | |
364 | } | |
8efc0c15 | 365 | } |
8efc0c15 | 366 | } |
367 | ||
aa3378df | 368 | /* |
369 | * After select, perform any appropriate operations for channels which have | |
370 | * events pending. | |
371 | */ | |
8efc0c15 | 372 | |
5260325f | 373 | void |
374 | channel_after_select(fd_set * readset, fd_set * writeset) | |
8efc0c15 | 375 | { |
5260325f | 376 | struct sockaddr addr; |
48e671d5 | 377 | int newsock, i, newch, len; |
378 | socklen_t addrlen; | |
5260325f | 379 | Channel *ch; |
380 | char buf[16384], *remote_hostname; | |
381 | ||
382 | /* Loop over all channels... */ | |
383 | for (i = 0; i < channels_alloc; i++) { | |
384 | ch = &channels[i]; | |
385 | switch (ch->type) { | |
386 | case SSH_CHANNEL_X11_LISTENER: | |
387 | /* This is our fake X11 server socket. */ | |
388 | if (FD_ISSET(ch->sock, readset)) { | |
389 | debug("X11 connection requested."); | |
390 | addrlen = sizeof(addr); | |
391 | newsock = accept(ch->sock, &addr, &addrlen); | |
392 | if (newsock < 0) { | |
393 | error("accept: %.100s", strerror(errno)); | |
394 | break; | |
395 | } | |
396 | remote_hostname = get_remote_hostname(newsock); | |
397 | snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", | |
398 | remote_hostname, get_peer_port(newsock)); | |
399 | xfree(remote_hostname); | |
400 | newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, | |
401 | xstrdup(buf)); | |
402 | packet_start(SSH_SMSG_X11_OPEN); | |
403 | packet_put_int(newch); | |
404 | if (have_hostname_in_open) | |
405 | packet_put_string(buf, strlen(buf)); | |
406 | packet_send(); | |
407 | } | |
408 | break; | |
409 | ||
410 | case SSH_CHANNEL_PORT_LISTENER: | |
aa3378df | 411 | /* |
412 | * This socket is listening for connections to a | |
413 | * forwarded TCP/IP port. | |
414 | */ | |
5260325f | 415 | if (FD_ISSET(ch->sock, readset)) { |
48e671d5 | 416 | debug("Connection to port %d forwarding to %.100s port %d requested.", |
5260325f | 417 | ch->listening_port, ch->path, ch->host_port); |
418 | addrlen = sizeof(addr); | |
419 | newsock = accept(ch->sock, &addr, &addrlen); | |
420 | if (newsock < 0) { | |
421 | error("accept: %.100s", strerror(errno)); | |
422 | break; | |
423 | } | |
424 | remote_hostname = get_remote_hostname(newsock); | |
48e671d5 | 425 | snprintf(buf, sizeof buf, "listen port %d for %.100s port %d, connect from %.200s port %d", |
5260325f | 426 | ch->listening_port, ch->path, ch->host_port, |
427 | remote_hostname, get_peer_port(newsock)); | |
428 | xfree(remote_hostname); | |
429 | newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, | |
430 | xstrdup(buf)); | |
431 | packet_start(SSH_MSG_PORT_OPEN); | |
432 | packet_put_int(newch); | |
433 | packet_put_string(ch->path, strlen(ch->path)); | |
434 | packet_put_int(ch->host_port); | |
435 | if (have_hostname_in_open) | |
436 | packet_put_string(buf, strlen(buf)); | |
437 | packet_send(); | |
438 | } | |
439 | break; | |
440 | ||
441 | case SSH_CHANNEL_AUTH_SOCKET: | |
aa3378df | 442 | /* |
443 | * This is the authentication agent socket listening | |
444 | * for connections from clients. | |
445 | */ | |
5260325f | 446 | if (FD_ISSET(ch->sock, readset)) { |
00e6dd70 | 447 | addrlen = sizeof(addr); |
448 | newsock = accept(ch->sock, &addr, &addrlen); | |
5260325f | 449 | if (newsock < 0) { |
450 | error("accept from auth socket: %.100s", strerror(errno)); | |
451 | break; | |
452 | } | |
00e6dd70 | 453 | newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, |
5260325f | 454 | xstrdup("accepted auth socket")); |
455 | packet_start(SSH_SMSG_AGENT_OPEN); | |
00e6dd70 | 456 | packet_put_int(newch); |
5260325f | 457 | packet_send(); |
458 | } | |
459 | break; | |
460 | ||
461 | case SSH_CHANNEL_OPEN: | |
aa3378df | 462 | /* |
463 | * This is an open two-way communication channel. It | |
464 | * is not of interest to us at this point what kind | |
465 | * of data is being transmitted. | |
466 | */ | |
467 | ||
468 | /* | |
469 | * Read available incoming data and append it to | |
470 | * buffer; shutdown socket, if read or write failes | |
471 | */ | |
5260325f | 472 | if (FD_ISSET(ch->sock, readset)) { |
473 | len = read(ch->sock, buf, sizeof(buf)); | |
474 | if (len <= 0) { | |
475 | if (compat13) { | |
476 | buffer_consume(&ch->output, buffer_len(&ch->output)); | |
477 | ch->type = SSH_CHANNEL_INPUT_DRAINING; | |
478 | debug("Channel %d status set to input draining.", i); | |
479 | } else { | |
480 | chan_read_failed(ch); | |
481 | } | |
482 | break; | |
483 | } | |
484 | buffer_append(&ch->input, buf, len); | |
485 | } | |
486 | /* Send buffered output data to the socket. */ | |
487 | if (FD_ISSET(ch->sock, writeset) && buffer_len(&ch->output) > 0) { | |
488 | len = write(ch->sock, buffer_ptr(&ch->output), | |
489 | buffer_len(&ch->output)); | |
490 | if (len <= 0) { | |
491 | if (compat13) { | |
492 | buffer_consume(&ch->output, buffer_len(&ch->output)); | |
493 | debug("Channel %d status set to input draining.", i); | |
494 | ch->type = SSH_CHANNEL_INPUT_DRAINING; | |
495 | } else { | |
496 | chan_write_failed(ch); | |
497 | } | |
498 | break; | |
499 | } | |
500 | buffer_consume(&ch->output, len); | |
501 | } | |
502 | break; | |
503 | ||
504 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
505 | if (!compat13) | |
506 | fatal("cannot happen: OUT_DRAIN"); | |
507 | /* Send buffered output data to the socket. */ | |
508 | if (FD_ISSET(ch->sock, writeset) && buffer_len(&ch->output) > 0) { | |
509 | len = write(ch->sock, buffer_ptr(&ch->output), | |
510 | buffer_len(&ch->output)); | |
511 | if (len <= 0) | |
512 | buffer_consume(&ch->output, buffer_len(&ch->output)); | |
513 | else | |
514 | buffer_consume(&ch->output, len); | |
515 | } | |
516 | break; | |
517 | ||
518 | case SSH_CHANNEL_X11_OPEN: | |
519 | case SSH_CHANNEL_FREE: | |
520 | default: | |
521 | continue; | |
8efc0c15 | 522 | } |
8efc0c15 | 523 | } |
8efc0c15 | 524 | } |
525 | ||
526 | /* If there is data to send to the connection, send some of it now. */ | |
527 | ||
5260325f | 528 | void |
529 | channel_output_poll() | |
8efc0c15 | 530 | { |
5260325f | 531 | int len, i; |
532 | Channel *ch; | |
533 | ||
534 | for (i = 0; i < channels_alloc; i++) { | |
535 | ch = &channels[i]; | |
48e671d5 | 536 | |
aa3378df | 537 | /* We are only interested in channels that can have buffered incoming data. */ |
48e671d5 | 538 | if (compat13) { |
539 | if (ch->type != SSH_CHANNEL_OPEN && | |
540 | ch->type != SSH_CHANNEL_INPUT_DRAINING) | |
541 | continue; | |
542 | } else { | |
543 | if (ch->type != SSH_CHANNEL_OPEN) | |
544 | continue; | |
545 | if (ch->istate != CHAN_INPUT_OPEN && | |
546 | ch->istate != CHAN_INPUT_WAIT_DRAIN) | |
547 | continue; | |
548 | } | |
5260325f | 549 | |
550 | /* Get the amount of buffered data for this channel. */ | |
551 | len = buffer_len(&ch->input); | |
552 | if (len > 0) { | |
aa3378df | 553 | /* Send some data for the other side over the secure connection. */ |
5260325f | 554 | if (packet_is_interactive()) { |
555 | if (len > 1024) | |
556 | len = 512; | |
557 | } else { | |
558 | /* Keep the packets at reasonable size. */ | |
00e6dd70 | 559 | if (len > packet_get_maxsize()/2) |
560 | len = packet_get_maxsize()/2; | |
5260325f | 561 | } |
562 | packet_start(SSH_MSG_CHANNEL_DATA); | |
563 | packet_put_int(ch->remote_id); | |
564 | packet_put_string(buffer_ptr(&ch->input), len); | |
565 | packet_send(); | |
566 | buffer_consume(&ch->input, len); | |
567 | } else if (ch->istate == CHAN_INPUT_WAIT_DRAIN) { | |
568 | if (compat13) | |
569 | fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); | |
aa3378df | 570 | /* |
571 | * input-buffer is empty and read-socket shutdown: | |
572 | * tell peer, that we will not send more data: send IEOF | |
573 | */ | |
5260325f | 574 | chan_ibuf_empty(ch); |
575 | } | |
8efc0c15 | 576 | } |
8efc0c15 | 577 | } |
578 | ||
aa3378df | 579 | /* |
580 | * This is called when a packet of type CHANNEL_DATA has just been received. | |
581 | * The message type has already been consumed, but channel number and data is | |
582 | * still there. | |
583 | */ | |
8efc0c15 | 584 | |
5260325f | 585 | void |
586 | channel_input_data(int payload_len) | |
8efc0c15 | 587 | { |
48e671d5 | 588 | int id; |
5260325f | 589 | char *data; |
590 | unsigned int data_len; | |
48e671d5 | 591 | Channel *ch; |
5260325f | 592 | |
593 | /* Get the channel number and verify it. */ | |
48e671d5 | 594 | id = packet_get_int(); |
595 | if (id < 0 || id >= channels_alloc) | |
596 | packet_disconnect("Received data for nonexistent channel %d.", id); | |
597 | ch = &channels[id]; | |
598 | ||
599 | if (ch->type == SSH_CHANNEL_FREE) | |
600 | packet_disconnect("Received data for free channel %d.", ch->self); | |
5260325f | 601 | |
602 | /* Ignore any data for non-open channels (might happen on close) */ | |
48e671d5 | 603 | if (ch->type != SSH_CHANNEL_OPEN && |
604 | ch->type != SSH_CHANNEL_X11_OPEN) | |
605 | return; | |
606 | ||
607 | /* same for protocol 1.5 if output end is no longer open */ | |
608 | if (!compat13 && ch->ostate != CHAN_OUTPUT_OPEN) | |
5260325f | 609 | return; |
610 | ||
611 | /* Get the data. */ | |
612 | data = packet_get_string(&data_len); | |
613 | packet_integrity_check(payload_len, 4 + 4 + data_len, SSH_MSG_CHANNEL_DATA); | |
48e671d5 | 614 | buffer_append(&ch->output, data, data_len); |
5260325f | 615 | xfree(data); |
8efc0c15 | 616 | } |
617 | ||
aa3378df | 618 | /* |
619 | * Returns true if no channel has too much buffered data, and false if one or | |
620 | * more channel is overfull. | |
621 | */ | |
8efc0c15 | 622 | |
5260325f | 623 | int |
624 | channel_not_very_much_buffered_data() | |
8efc0c15 | 625 | { |
5260325f | 626 | unsigned int i; |
627 | Channel *ch; | |
628 | ||
629 | for (i = 0; i < channels_alloc; i++) { | |
630 | ch = &channels[i]; | |
48e671d5 | 631 | if (ch->type == SSH_CHANNEL_OPEN) { |
5260325f | 632 | if (buffer_len(&ch->input) > packet_get_maxsize()) |
633 | return 0; | |
634 | if (buffer_len(&ch->output) > packet_get_maxsize()) | |
635 | return 0; | |
5260325f | 636 | } |
8efc0c15 | 637 | } |
5260325f | 638 | return 1; |
8efc0c15 | 639 | } |
640 | ||
641 | /* This is called after receiving CHANNEL_CLOSE/IEOF. */ | |
642 | ||
5260325f | 643 | void |
644 | channel_input_close() | |
8efc0c15 | 645 | { |
5260325f | 646 | int channel; |
647 | ||
648 | /* Get the channel number and verify it. */ | |
649 | channel = packet_get_int(); | |
650 | if (channel < 0 || channel >= channels_alloc || | |
651 | channels[channel].type == SSH_CHANNEL_FREE) | |
652 | packet_disconnect("Received data for nonexistent channel %d.", channel); | |
653 | ||
654 | if (!compat13) { | |
655 | /* proto version 1.5 overloads CLOSE with IEOF */ | |
656 | chan_rcvd_ieof(&channels[channel]); | |
657 | return; | |
658 | } | |
aa3378df | 659 | |
660 | /* | |
661 | * Send a confirmation that we have closed the channel and no more | |
662 | * data is coming for it. | |
663 | */ | |
5260325f | 664 | packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); |
665 | packet_put_int(channels[channel].remote_id); | |
666 | packet_send(); | |
667 | ||
aa3378df | 668 | /* |
669 | * If the channel is in closed state, we have sent a close request, | |
670 | * and the other side will eventually respond with a confirmation. | |
671 | * Thus, we cannot free the channel here, because then there would be | |
672 | * no-one to receive the confirmation. The channel gets freed when | |
673 | * the confirmation arrives. | |
674 | */ | |
5260325f | 675 | if (channels[channel].type != SSH_CHANNEL_CLOSED) { |
aa3378df | 676 | /* |
677 | * Not a closed channel - mark it as draining, which will | |
678 | * cause it to be freed later. | |
679 | */ | |
5260325f | 680 | buffer_consume(&channels[channel].input, |
681 | buffer_len(&channels[channel].input)); | |
682 | channels[channel].type = SSH_CHANNEL_OUTPUT_DRAINING; | |
683 | } | |
8efc0c15 | 684 | } |
685 | ||
686 | /* This is called after receiving CHANNEL_CLOSE_CONFIRMATION/OCLOSE. */ | |
687 | ||
5260325f | 688 | void |
689 | channel_input_close_confirmation() | |
8efc0c15 | 690 | { |
5260325f | 691 | int channel; |
692 | ||
693 | /* Get the channel number and verify it. */ | |
694 | channel = packet_get_int(); | |
695 | if (channel < 0 || channel >= channels_alloc) | |
696 | packet_disconnect("Received close confirmation for out-of-range channel %d.", | |
697 | channel); | |
698 | ||
699 | if (!compat13) { | |
700 | /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ | |
701 | chan_rcvd_oclose(&channels[channel]); | |
702 | return; | |
703 | } | |
704 | if (channels[channel].type != SSH_CHANNEL_CLOSED) | |
705 | packet_disconnect("Received close confirmation for non-closed channel %d (type %d).", | |
706 | channel, channels[channel].type); | |
707 | ||
708 | /* Free the channel. */ | |
709 | channel_free(channel); | |
8efc0c15 | 710 | } |
711 | ||
712 | /* This is called after receiving CHANNEL_OPEN_CONFIRMATION. */ | |
713 | ||
5260325f | 714 | void |
715 | channel_input_open_confirmation() | |
8efc0c15 | 716 | { |
5260325f | 717 | int channel, remote_channel; |
718 | ||
719 | /* Get the channel number and verify it. */ | |
720 | channel = packet_get_int(); | |
721 | if (channel < 0 || channel >= channels_alloc || | |
722 | channels[channel].type != SSH_CHANNEL_OPENING) | |
723 | packet_disconnect("Received open confirmation for non-opening channel %d.", | |
724 | channel); | |
725 | ||
726 | /* Get remote side's id for this channel. */ | |
727 | remote_channel = packet_get_int(); | |
728 | ||
aa3378df | 729 | /* Record the remote channel number and mark that the channel is now open. */ |
5260325f | 730 | channels[channel].remote_id = remote_channel; |
731 | channels[channel].type = SSH_CHANNEL_OPEN; | |
8efc0c15 | 732 | } |
733 | ||
734 | /* This is called after receiving CHANNEL_OPEN_FAILURE from the other side. */ | |
735 | ||
5260325f | 736 | void |
737 | channel_input_open_failure() | |
8efc0c15 | 738 | { |
5260325f | 739 | int channel; |
740 | ||
741 | /* Get the channel number and verify it. */ | |
742 | channel = packet_get_int(); | |
743 | if (channel < 0 || channel >= channels_alloc || | |
744 | channels[channel].type != SSH_CHANNEL_OPENING) | |
745 | packet_disconnect("Received open failure for non-opening channel %d.", | |
746 | channel); | |
747 | ||
748 | /* Free the channel. This will also close the socket. */ | |
749 | channel_free(channel); | |
8efc0c15 | 750 | } |
751 | ||
aa3378df | 752 | /* |
753 | * Stops listening for channels, and removes any unix domain sockets that we | |
754 | * might have. | |
755 | */ | |
8efc0c15 | 756 | |
5260325f | 757 | void |
758 | channel_stop_listening() | |
8efc0c15 | 759 | { |
5260325f | 760 | int i; |
761 | for (i = 0; i < channels_alloc; i++) { | |
762 | switch (channels[i].type) { | |
763 | case SSH_CHANNEL_AUTH_SOCKET: | |
764 | close(channels[i].sock); | |
765 | remove(channels[i].path); | |
766 | channel_free(i); | |
767 | break; | |
768 | case SSH_CHANNEL_PORT_LISTENER: | |
769 | case SSH_CHANNEL_X11_LISTENER: | |
770 | close(channels[i].sock); | |
771 | channel_free(i); | |
772 | break; | |
773 | default: | |
774 | break; | |
775 | } | |
8efc0c15 | 776 | } |
8efc0c15 | 777 | } |
778 | ||
aa3378df | 779 | /* |
780 | * Closes the sockets of all channels. This is used to close extra file | |
781 | * descriptors after a fork. | |
782 | */ | |
8efc0c15 | 783 | |
5260325f | 784 | void |
785 | channel_close_all() | |
8efc0c15 | 786 | { |
5260325f | 787 | int i; |
788 | for (i = 0; i < channels_alloc; i++) { | |
789 | if (channels[i].type != SSH_CHANNEL_FREE) | |
790 | close(channels[i].sock); | |
791 | } | |
8efc0c15 | 792 | } |
793 | ||
794 | /* Returns the maximum file descriptor number used by the channels. */ | |
795 | ||
5260325f | 796 | int |
797 | channel_max_fd() | |
8efc0c15 | 798 | { |
5260325f | 799 | return channel_max_fd_value; |
8efc0c15 | 800 | } |
801 | ||
802 | /* Returns true if any channel is still open. */ | |
803 | ||
5260325f | 804 | int |
805 | channel_still_open() | |
8efc0c15 | 806 | { |
5260325f | 807 | unsigned int i; |
808 | for (i = 0; i < channels_alloc; i++) | |
809 | switch (channels[i].type) { | |
810 | case SSH_CHANNEL_FREE: | |
811 | case SSH_CHANNEL_X11_LISTENER: | |
812 | case SSH_CHANNEL_PORT_LISTENER: | |
813 | case SSH_CHANNEL_CLOSED: | |
814 | case SSH_CHANNEL_AUTH_SOCKET: | |
815 | continue; | |
816 | case SSH_CHANNEL_OPENING: | |
817 | case SSH_CHANNEL_OPEN: | |
818 | case SSH_CHANNEL_X11_OPEN: | |
819 | return 1; | |
820 | case SSH_CHANNEL_INPUT_DRAINING: | |
821 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
822 | if (!compat13) | |
823 | fatal("cannot happen: OUT_DRAIN"); | |
824 | return 1; | |
825 | default: | |
826 | fatal("channel_still_open: bad channel type %d", channels[i].type); | |
827 | /* NOTREACHED */ | |
828 | } | |
829 | return 0; | |
8efc0c15 | 830 | } |
831 | ||
aa3378df | 832 | /* |
833 | * Returns a message describing the currently open forwarded connections, | |
834 | * suitable for sending to the client. The message contains crlf pairs for | |
835 | * newlines. | |
836 | */ | |
8efc0c15 | 837 | |
5260325f | 838 | char * |
839 | channel_open_message() | |
8efc0c15 | 840 | { |
5260325f | 841 | Buffer buffer; |
842 | int i; | |
843 | char buf[512], *cp; | |
844 | ||
845 | buffer_init(&buffer); | |
846 | snprintf(buf, sizeof buf, "The following connections are open:\r\n"); | |
8efc0c15 | 847 | buffer_append(&buffer, buf, strlen(buf)); |
5260325f | 848 | for (i = 0; i < channels_alloc; i++) { |
849 | Channel *c = &channels[i]; | |
850 | switch (c->type) { | |
851 | case SSH_CHANNEL_FREE: | |
852 | case SSH_CHANNEL_X11_LISTENER: | |
853 | case SSH_CHANNEL_PORT_LISTENER: | |
854 | case SSH_CHANNEL_CLOSED: | |
855 | case SSH_CHANNEL_AUTH_SOCKET: | |
856 | continue; | |
857 | case SSH_CHANNEL_OPENING: | |
858 | case SSH_CHANNEL_OPEN: | |
859 | case SSH_CHANNEL_X11_OPEN: | |
860 | case SSH_CHANNEL_INPUT_DRAINING: | |
861 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
48e671d5 | 862 | snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d)\r\n", |
863 | c->self, c->remote_name, | |
864 | c->type, c->remote_id, | |
865 | c->istate, buffer_len(&c->input), | |
866 | c->ostate, buffer_len(&c->output)); | |
5260325f | 867 | buffer_append(&buffer, buf, strlen(buf)); |
868 | continue; | |
869 | default: | |
870 | fatal("channel_still_open: bad channel type %d", c->type); | |
871 | /* NOTREACHED */ | |
872 | } | |
873 | } | |
874 | buffer_append(&buffer, "\0", 1); | |
875 | cp = xstrdup(buffer_ptr(&buffer)); | |
876 | buffer_free(&buffer); | |
877 | return cp; | |
8efc0c15 | 878 | } |
879 | ||
aa3378df | 880 | /* |
881 | * Initiate forwarding of connections to local port "port" through the secure | |
882 | * channel to host:port from remote side. | |
883 | */ | |
8efc0c15 | 884 | |
5260325f | 885 | void |
57112b5a | 886 | channel_request_local_forwarding(u_short port, const char *host, |
95f1eccc | 887 | u_short host_port, int gateway_ports) |
8efc0c15 | 888 | { |
48e671d5 | 889 | int success, ch, sock, on = 1; |
890 | struct addrinfo hints, *ai, *aitop; | |
891 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
aa3378df | 892 | struct linger linger; |
5260325f | 893 | |
894 | if (strlen(host) > sizeof(channels[0].path) - 1) | |
895 | packet_disconnect("Forward host name too long."); | |
896 | ||
aa3378df | 897 | /* |
48e671d5 | 898 | * getaddrinfo returns a loopback address if the hostname is |
899 | * set to NULL and hints.ai_flags is not AI_PASSIVE | |
aa3378df | 900 | */ |
48e671d5 | 901 | memset(&hints, 0, sizeof(hints)); |
902 | hints.ai_family = IPv4or6; | |
903 | hints.ai_flags = gateway_ports ? AI_PASSIVE : 0; | |
904 | hints.ai_socktype = SOCK_STREAM; | |
905 | snprintf(strport, sizeof strport, "%d", port); | |
906 | if (getaddrinfo(NULL, strport, &hints, &aitop) != 0) | |
907 | packet_disconnect("getaddrinfo: fatal error"); | |
908 | ||
909 | success = 0; | |
910 | for (ai = aitop; ai; ai = ai->ai_next) { | |
911 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
912 | continue; | |
913 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
914 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
915 | error("channel_request_local_forwarding: getnameinfo failed"); | |
916 | continue; | |
917 | } | |
918 | /* Create a port to listen for the host. */ | |
919 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
920 | if (sock < 0) { | |
921 | /* this is no error since kernel may not support ipv6 */ | |
922 | verbose("socket: %.100s", strerror(errno)); | |
923 | continue; | |
924 | } | |
925 | /* | |
926 | * Set socket options. We would like the socket to disappear | |
927 | * as soon as it has been closed for whatever reason. | |
928 | */ | |
929 | setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); | |
930 | linger.l_onoff = 1; | |
931 | linger.l_linger = 5; | |
932 | setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger)); | |
933 | debug("Local forwarding listening on %s port %s.", ntop, strport); | |
934 | ||
935 | /* Bind the socket to the address. */ | |
936 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
937 | /* address can be in use ipv6 address is already bound */ | |
938 | verbose("bind: %.100s", strerror(errno)); | |
939 | close(sock); | |
940 | continue; | |
941 | } | |
942 | /* Start listening for connections on the socket. */ | |
943 | if (listen(sock, 5) < 0) { | |
944 | error("listen: %.100s", strerror(errno)); | |
945 | close(sock); | |
946 | continue; | |
947 | } | |
948 | /* Allocate a channel number for the socket. */ | |
949 | ch = channel_allocate(SSH_CHANNEL_PORT_LISTENER, sock, | |
950 | xstrdup("port listener")); | |
951 | strlcpy(channels[ch].path, host, sizeof(channels[ch].path)); | |
952 | channels[ch].host_port = host_port; | |
953 | channels[ch].listening_port = port; | |
954 | success = 1; | |
955 | } | |
956 | if (success == 0) | |
957 | packet_disconnect("cannot listen port: %d", port); | |
958 | freeaddrinfo(aitop); | |
5260325f | 959 | } |
8efc0c15 | 960 | |
aa3378df | 961 | /* |
962 | * Initiate forwarding of connections to port "port" on remote host through | |
963 | * the secure channel to host:port from local side. | |
964 | */ | |
8efc0c15 | 965 | |
5260325f | 966 | void |
57112b5a | 967 | channel_request_remote_forwarding(u_short port, const char *host, |
968 | u_short remote_port) | |
8efc0c15 | 969 | { |
5260325f | 970 | int payload_len; |
971 | /* Record locally that connection to this host/port is permitted. */ | |
972 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
973 | fatal("channel_request_remote_forwarding: too many forwards"); | |
974 | ||
975 | permitted_opens[num_permitted_opens].host = xstrdup(host); | |
976 | permitted_opens[num_permitted_opens].port = remote_port; | |
977 | num_permitted_opens++; | |
978 | ||
979 | /* Send the forward request to the remote side. */ | |
980 | packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); | |
981 | packet_put_int(port); | |
982 | packet_put_string(host, strlen(host)); | |
983 | packet_put_int(remote_port); | |
984 | packet_send(); | |
985 | packet_write_wait(); | |
986 | ||
aa3378df | 987 | /* |
988 | * Wait for response from the remote side. It will send a disconnect | |
989 | * message on failure, and we will never see it here. | |
990 | */ | |
5260325f | 991 | packet_read_expect(&payload_len, SSH_SMSG_SUCCESS); |
8efc0c15 | 992 | } |
993 | ||
aa3378df | 994 | /* |
995 | * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates | |
996 | * listening for the port, and sends back a success reply (or disconnect | |
997 | * message if there was an error). This never returns if there was an error. | |
998 | */ | |
8efc0c15 | 999 | |
5260325f | 1000 | void |
1001 | channel_input_port_forward_request(int is_root) | |
8efc0c15 | 1002 | { |
57112b5a | 1003 | u_short port, host_port; |
5260325f | 1004 | char *hostname; |
1005 | ||
1006 | /* Get arguments from the packet. */ | |
1007 | port = packet_get_int(); | |
1008 | hostname = packet_get_string(NULL); | |
1009 | host_port = packet_get_int(); | |
1010 | ||
aa3378df | 1011 | /* |
1012 | * Check that an unprivileged user is not trying to forward a | |
1013 | * privileged port. | |
1014 | */ | |
5260325f | 1015 | if (port < IPPORT_RESERVED && !is_root) |
1016 | packet_disconnect("Requested forwarding of port %d but user is not root.", | |
1017 | port); | |
95f1eccc | 1018 | /* |
1019 | * Initiate forwarding, | |
1020 | * bind port to localhost only (gateway ports == 0). | |
1021 | */ | |
1022 | channel_request_local_forwarding(port, hostname, host_port, 0); | |
5260325f | 1023 | |
1024 | /* Free the argument string. */ | |
1025 | xfree(hostname); | |
8efc0c15 | 1026 | } |
1027 | ||
aa3378df | 1028 | /* |
1029 | * This is called after receiving PORT_OPEN message. This attempts to | |
1030 | * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION | |
1031 | * or CHANNEL_OPEN_FAILURE. | |
1032 | */ | |
8efc0c15 | 1033 | |
5260325f | 1034 | void |
1035 | channel_input_port_open(int payload_len) | |
8efc0c15 | 1036 | { |
48e671d5 | 1037 | int remote_channel, sock = 0, newch, i; |
57112b5a | 1038 | u_short host_port; |
5260325f | 1039 | char *host, *originator_string; |
5260325f | 1040 | int host_len, originator_len; |
48e671d5 | 1041 | struct addrinfo hints, *ai, *aitop; |
1042 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
1043 | int gaierr; | |
5260325f | 1044 | |
1045 | /* Get remote channel number. */ | |
1046 | remote_channel = packet_get_int(); | |
1047 | ||
1048 | /* Get host name to connect to. */ | |
1049 | host = packet_get_string(&host_len); | |
1050 | ||
1051 | /* Get port to connect to. */ | |
1052 | host_port = packet_get_int(); | |
1053 | ||
1054 | /* Get remote originator name. */ | |
aa3378df | 1055 | if (have_hostname_in_open) { |
5260325f | 1056 | originator_string = packet_get_string(&originator_len); |
aa3378df | 1057 | originator_len += 4; /* size of packet_int */ |
1058 | } else { | |
5260325f | 1059 | originator_string = xstrdup("unknown (remote did not supply name)"); |
aa3378df | 1060 | originator_len = 0; /* no originator supplied */ |
1061 | } | |
5260325f | 1062 | |
1063 | packet_integrity_check(payload_len, | |
aa3378df | 1064 | 4 + 4 + host_len + 4 + originator_len, |
5260325f | 1065 | SSH_MSG_PORT_OPEN); |
1066 | ||
1067 | /* Check if opening that port is permitted. */ | |
1068 | if (!all_opens_permitted) { | |
1069 | /* Go trough all permitted ports. */ | |
1070 | for (i = 0; i < num_permitted_opens; i++) | |
1071 | if (permitted_opens[i].port == host_port && | |
1072 | strcmp(permitted_opens[i].host, host) == 0) | |
1073 | break; | |
1074 | ||
1075 | /* Check if we found the requested port among those permitted. */ | |
1076 | if (i >= num_permitted_opens) { | |
1077 | /* The port is not permitted. */ | |
1078 | log("Received request to connect to %.100s:%d, but the request was denied.", | |
1079 | host, host_port); | |
1080 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1081 | packet_put_int(remote_channel); | |
1082 | packet_send(); | |
1083 | } | |
8efc0c15 | 1084 | } |
48e671d5 | 1085 | |
1086 | memset(&hints, 0, sizeof(hints)); | |
1087 | hints.ai_family = IPv4or6; | |
1088 | hints.ai_socktype = SOCK_STREAM; | |
1089 | snprintf(strport, sizeof strport, "%d", host_port); | |
1090 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { | |
1091 | error("%.100s: unknown host (%s)", host, gai_strerror(gaierr)); | |
1092 | goto fail; | |
1093 | } | |
1094 | ||
1095 | for (ai = aitop; ai; ai = ai->ai_next) { | |
1096 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1097 | continue; | |
1098 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
1099 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
1100 | error("channel_input_port_open: getnameinfo failed"); | |
1101 | continue; | |
5260325f | 1102 | } |
48e671d5 | 1103 | /* Create the socket. */ |
1104 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1105 | if (sock < 0) { | |
1106 | error("socket: %.100s", strerror(errno)); | |
1107 | continue; | |
5260325f | 1108 | } |
48e671d5 | 1109 | /* Connect to the host/port. */ |
1110 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1111 | error("connect %.100s port %s: %.100s", ntop, strport, | |
1112 | strerror(errno)); | |
1113 | close(sock); | |
1114 | continue; /* fail -- try next */ | |
1115 | } | |
1116 | break; /* success */ | |
5260325f | 1117 | |
5260325f | 1118 | } |
48e671d5 | 1119 | freeaddrinfo(aitop); |
1120 | ||
1121 | if (!ai) { | |
1122 | error("connect %.100s port %d: failed.", host, host_port); | |
5260325f | 1123 | goto fail; |
8efc0c15 | 1124 | } |
48e671d5 | 1125 | |
5260325f | 1126 | /* Successful connection. */ |
1127 | ||
1128 | /* Allocate a channel for this connection. */ | |
1129 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string); | |
1130 | channels[newch].remote_id = remote_channel; | |
1131 | ||
1132 | /* Send a confirmation to the remote host. */ | |
1133 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1134 | packet_put_int(remote_channel); | |
1135 | packet_put_int(newch); | |
1136 | packet_send(); | |
1137 | ||
1138 | /* Free the argument string. */ | |
1139 | xfree(host); | |
1140 | ||
1141 | return; | |
1142 | ||
1143 | fail: | |
1144 | /* Free the argument string. */ | |
1145 | xfree(host); | |
1146 | ||
1147 | /* Send refusal to the remote host. */ | |
1148 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1149 | packet_put_int(remote_channel); | |
1150 | packet_send(); | |
8efc0c15 | 1151 | } |
1152 | ||
aa3378df | 1153 | /* |
1154 | * Creates an internet domain socket for listening for X11 connections. | |
1155 | * Returns a suitable value for the DISPLAY variable, or NULL if an error | |
1156 | * occurs. | |
1157 | */ | |
8efc0c15 | 1158 | |
48e671d5 | 1159 | #define NUM_SOCKS 10 |
1160 | ||
5260325f | 1161 | char * |
95f1eccc | 1162 | x11_create_display_inet(int screen_number, int x11_display_offset) |
8efc0c15 | 1163 | { |
57112b5a | 1164 | int display_number, sock; |
1165 | u_short port; | |
48e671d5 | 1166 | struct addrinfo hints, *ai, *aitop; |
1167 | char strport[NI_MAXSERV]; | |
1168 | int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; | |
1169 | char display[512]; | |
5260325f | 1170 | char hostname[MAXHOSTNAMELEN]; |
1171 | ||
95f1eccc | 1172 | for (display_number = x11_display_offset; |
5260325f | 1173 | display_number < MAX_DISPLAYS; |
1174 | display_number++) { | |
1175 | port = 6000 + display_number; | |
48e671d5 | 1176 | memset(&hints, 0, sizeof(hints)); |
1177 | hints.ai_family = IPv4or6; | |
1178 | hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */ | |
1179 | hints.ai_socktype = SOCK_STREAM; | |
1180 | snprintf(strport, sizeof strport, "%d", port); | |
1181 | if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { | |
1182 | error("getaddrinfo: %.100s", gai_strerror(gaierr)); | |
5260325f | 1183 | return NULL; |
1184 | } | |
48e671d5 | 1185 | for (ai = aitop; ai; ai = ai->ai_next) { |
1186 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1187 | continue; | |
1188 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1189 | if (sock < 0) { | |
1190 | error("socket: %.100s", strerror(errno)); | |
1191 | return NULL; | |
1192 | } | |
1193 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1194 | debug("bind port %d: %.100s", port, strerror(errno)); | |
1195 | shutdown(sock, SHUT_RDWR); | |
1196 | close(sock); | |
1197 | for (n = 0; n < num_socks; n++) { | |
1198 | shutdown(socks[n], SHUT_RDWR); | |
1199 | close(socks[n]); | |
1200 | } | |
1201 | num_socks = 0; | |
1202 | break; | |
1203 | } | |
1204 | socks[num_socks++] = sock; | |
1205 | if (num_socks == NUM_SOCKS) | |
1206 | break; | |
5260325f | 1207 | } |
48e671d5 | 1208 | if (num_socks > 0) |
1209 | break; | |
5260325f | 1210 | } |
1211 | if (display_number >= MAX_DISPLAYS) { | |
1212 | error("Failed to allocate internet-domain X11 display socket."); | |
1213 | return NULL; | |
8efc0c15 | 1214 | } |
5260325f | 1215 | /* Start listening for connections on the socket. */ |
48e671d5 | 1216 | for (n = 0; n < num_socks; n++) { |
1217 | sock = socks[n]; | |
1218 | if (listen(sock, 5) < 0) { | |
1219 | error("listen: %.100s", strerror(errno)); | |
1220 | shutdown(sock, SHUT_RDWR); | |
1221 | close(sock); | |
1222 | return NULL; | |
1223 | } | |
8efc0c15 | 1224 | } |
48e671d5 | 1225 | |
5260325f | 1226 | /* Set up a suitable value for the DISPLAY variable. */ |
a7effaac | 1227 | |
5260325f | 1228 | if (gethostname(hostname, sizeof(hostname)) < 0) |
1229 | fatal("gethostname: %.100s", strerror(errno)); | |
a7effaac | 1230 | |
1231 | #ifdef IPADDR_IN_DISPLAY | |
1232 | /* | |
1233 | * HPUX detects the local hostname in the DISPLAY variable and tries | |
1234 | * to set up a shared memory connection to the server, which it | |
1235 | * incorrectly supposes to be local. | |
1236 | * | |
1237 | * The workaround - as used in later $$H and other programs - is | |
1238 | * is to set display to the host's IP address. | |
1239 | */ | |
1240 | { | |
1241 | struct hostent *he; | |
1242 | struct in_addr my_addr; | |
1243 | ||
1244 | he = gethostbyname(hostname); | |
1245 | if (he == NULL) { | |
1246 | error("[X11-broken-fwd-hostname-workaround] Could not get " | |
1247 | "IP address for hostname %s.", hostname); | |
1248 | ||
1249 | packet_send_debug("[X11-broken-fwd-hostname-workaround]" | |
1250 | "Could not get IP address for hostname %s.", hostname); | |
1251 | ||
1252 | shutdown(sock, SHUT_RDWR); | |
1253 | close(sock); | |
1254 | ||
1255 | return NULL; | |
1256 | } | |
1257 | ||
1258 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
1259 | ||
1260 | /* Set DISPLAY to <ip address>:screen.display */ | |
48e671d5 | 1261 | snprintf(display, sizeof(display), "%.50s:%d.%d", inet_ntoa(my_addr), |
a7effaac | 1262 | display_number, screen_number); |
1263 | } | |
1264 | #else /* IPADDR_IN_DISPLAY */ | |
1265 | /* Just set DISPLAY to hostname:screen.display */ | |
48e671d5 | 1266 | snprintf(display, sizeof display, "%.400s:%d.%d", hostname, |
a7effaac | 1267 | display_number, screen_number); |
1268 | #endif /* IPADDR_IN_DISPLAY */ | |
5260325f | 1269 | |
48e671d5 | 1270 | /* Allocate a channel for each socket. */ |
1271 | for (n = 0; n < num_socks; n++) { | |
1272 | sock = socks[n]; | |
1273 | (void) channel_allocate(SSH_CHANNEL_X11_LISTENER, sock, | |
1274 | xstrdup("X11 inet listener")); | |
1275 | } | |
5260325f | 1276 | |
1277 | /* Return a suitable value for the DISPLAY environment variable. */ | |
48e671d5 | 1278 | return xstrdup(display); |
8efc0c15 | 1279 | } |
1280 | ||
1281 | #ifndef X_UNIX_PATH | |
1282 | #define X_UNIX_PATH "/tmp/.X11-unix/X" | |
1283 | #endif | |
1284 | ||
1285 | static | |
1286 | int | |
2f450969 | 1287 | connect_local_xsocket(unsigned int dnr) |
8efc0c15 | 1288 | { |
5260325f | 1289 | static const char *const x_sockets[] = { |
1290 | X_UNIX_PATH "%u", | |
1291 | "/var/X/.X11-unix/X" "%u", | |
1292 | "/usr/spool/sockets/X11/" "%u", | |
1293 | NULL | |
1294 | }; | |
1295 | int sock; | |
1296 | struct sockaddr_un addr; | |
1297 | const char *const * path; | |
1298 | ||
1299 | for (path = x_sockets; *path; ++path) { | |
1300 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
1301 | if (sock < 0) | |
1302 | error("socket: %.100s", strerror(errno)); | |
1303 | memset(&addr, 0, sizeof(addr)); | |
1304 | addr.sun_family = AF_UNIX; | |
1305 | snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr); | |
1306 | if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0) | |
1307 | return sock; | |
1308 | close(sock); | |
1309 | } | |
1310 | error("connect %.100s: %.100s", addr.sun_path, strerror(errno)); | |
1311 | return -1; | |
8efc0c15 | 1312 | } |
1313 | ||
1314 | ||
aa3378df | 1315 | /* |
1316 | * This is called when SSH_SMSG_X11_OPEN is received. The packet contains | |
1317 | * the remote channel number. We should do whatever we want, and respond | |
1318 | * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. | |
1319 | */ | |
8efc0c15 | 1320 | |
5260325f | 1321 | void |
1322 | x11_input_open(int payload_len) | |
8efc0c15 | 1323 | { |
48e671d5 | 1324 | int remote_channel, display_number, sock = 0, newch; |
5260325f | 1325 | const char *display; |
5260325f | 1326 | char buf[1024], *cp, *remote_host; |
5260325f | 1327 | int remote_len; |
48e671d5 | 1328 | struct addrinfo hints, *ai, *aitop; |
1329 | char strport[NI_MAXSERV]; | |
1330 | int gaierr; | |
5260325f | 1331 | |
1332 | /* Get remote channel number. */ | |
1333 | remote_channel = packet_get_int(); | |
1334 | ||
1335 | /* Get remote originator name. */ | |
aa3378df | 1336 | if (have_hostname_in_open) { |
5260325f | 1337 | remote_host = packet_get_string(&remote_len); |
aa3378df | 1338 | remote_len += 4; |
1339 | } else { | |
5260325f | 1340 | remote_host = xstrdup("unknown (remote did not supply name)"); |
aa3378df | 1341 | remote_len = 0; |
1342 | } | |
5260325f | 1343 | |
1344 | debug("Received X11 open request."); | |
aa3378df | 1345 | packet_integrity_check(payload_len, 4 + remote_len, SSH_SMSG_X11_OPEN); |
5260325f | 1346 | |
1347 | /* Try to open a socket for the local X server. */ | |
1348 | display = getenv("DISPLAY"); | |
1349 | if (!display) { | |
1350 | error("DISPLAY not set."); | |
1351 | goto fail; | |
1352 | } | |
aa3378df | 1353 | /* |
1354 | * Now we decode the value of the DISPLAY variable and make a | |
1355 | * connection to the real X server. | |
1356 | */ | |
1357 | ||
1358 | /* | |
1359 | * Check if it is a unix domain socket. Unix domain displays are in | |
1360 | * one of the following formats: unix:d[.s], :d[.s], ::d[.s] | |
1361 | */ | |
5260325f | 1362 | if (strncmp(display, "unix:", 5) == 0 || |
1363 | display[0] == ':') { | |
1364 | /* Connect to the unix domain socket. */ | |
1365 | if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) { | |
1366 | error("Could not parse display number from DISPLAY: %.100s", | |
1367 | display); | |
1368 | goto fail; | |
1369 | } | |
1370 | /* Create a socket. */ | |
1371 | sock = connect_local_xsocket(display_number); | |
1372 | if (sock < 0) | |
1373 | goto fail; | |
1374 | ||
1375 | /* OK, we now have a connection to the display. */ | |
1376 | goto success; | |
1377 | } | |
aa3378df | 1378 | /* |
1379 | * Connect to an inet socket. The DISPLAY value is supposedly | |
1380 | * hostname:d[.s], where hostname may also be numeric IP address. | |
1381 | */ | |
5260325f | 1382 | strncpy(buf, display, sizeof(buf)); |
1383 | buf[sizeof(buf) - 1] = 0; | |
1384 | cp = strchr(buf, ':'); | |
1385 | if (!cp) { | |
1386 | error("Could not find ':' in DISPLAY: %.100s", display); | |
1387 | goto fail; | |
1388 | } | |
1389 | *cp = 0; | |
aa3378df | 1390 | /* buf now contains the host name. But first we parse the display number. */ |
5260325f | 1391 | if (sscanf(cp + 1, "%d", &display_number) != 1) { |
1392 | error("Could not parse display number from DISPLAY: %.100s", | |
1393 | display); | |
1394 | goto fail; | |
1395 | } | |
5260325f | 1396 | |
48e671d5 | 1397 | /* Look up the host address */ |
1398 | memset(&hints, 0, sizeof(hints)); | |
1399 | hints.ai_family = IPv4or6; | |
1400 | hints.ai_socktype = SOCK_STREAM; | |
1401 | snprintf(strport, sizeof strport, "%d", 6000 + display_number); | |
1402 | if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { | |
1403 | error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr)); | |
5260325f | 1404 | goto fail; |
8efc0c15 | 1405 | } |
48e671d5 | 1406 | for (ai = aitop; ai; ai = ai->ai_next) { |
1407 | /* Create a socket. */ | |
1408 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1409 | if (sock < 0) { | |
1410 | debug("socket: %.100s", strerror(errno)); | |
1411 | continue; | |
1412 | } | |
5260325f | 1413 | /* Connect it to the display. */ |
48e671d5 | 1414 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { |
1415 | debug("connect %.100s port %d: %.100s", buf, 6000 + display_number, | |
1416 | strerror(errno)); | |
5260325f | 1417 | close(sock); |
48e671d5 | 1418 | continue; |
1419 | } | |
1420 | /* Success */ | |
1421 | break; | |
1422 | ||
1423 | } /* (ai = aitop, ai; ai = ai->ai_next) */ | |
1424 | freeaddrinfo(aitop); | |
1425 | if (!ai) { | |
1426 | error("connect %.100s port %d: %.100s", buf, 6000 + display_number, | |
1427 | strerror(errno)); | |
5260325f | 1428 | goto fail; |
8efc0c15 | 1429 | } |
5260325f | 1430 | success: |
1431 | /* We have successfully obtained a connection to the real X display. */ | |
1432 | ||
1433 | /* Allocate a channel for this connection. */ | |
1434 | if (x11_saved_proto == NULL) | |
1435 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, remote_host); | |
1436 | else | |
1437 | newch = channel_allocate(SSH_CHANNEL_X11_OPEN, sock, remote_host); | |
1438 | channels[newch].remote_id = remote_channel; | |
1439 | ||
1440 | /* Send a confirmation to the remote host. */ | |
1441 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1442 | packet_put_int(remote_channel); | |
1443 | packet_put_int(newch); | |
1444 | packet_send(); | |
1445 | ||
1446 | return; | |
1447 | ||
1448 | fail: | |
1449 | /* Send refusal to the remote host. */ | |
1450 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1451 | packet_put_int(remote_channel); | |
1452 | packet_send(); | |
8efc0c15 | 1453 | } |
1454 | ||
aa3378df | 1455 | /* |
1456 | * Requests forwarding of X11 connections, generates fake authentication | |
1457 | * data, and enables authentication spoofing. | |
1458 | */ | |
8efc0c15 | 1459 | |
5260325f | 1460 | void |
1461 | x11_request_forwarding_with_spoofing(const char *proto, const char *data) | |
8efc0c15 | 1462 | { |
5260325f | 1463 | unsigned int data_len = (unsigned int) strlen(data) / 2; |
1464 | unsigned int i, value; | |
1465 | char *new_data; | |
1466 | int screen_number; | |
1467 | const char *cp; | |
1468 | u_int32_t rand = 0; | |
1469 | ||
1470 | cp = getenv("DISPLAY"); | |
1471 | if (cp) | |
1472 | cp = strchr(cp, ':'); | |
1473 | if (cp) | |
1474 | cp = strchr(cp, '.'); | |
1475 | if (cp) | |
1476 | screen_number = atoi(cp + 1); | |
1477 | else | |
1478 | screen_number = 0; | |
1479 | ||
1480 | /* Save protocol name. */ | |
1481 | x11_saved_proto = xstrdup(proto); | |
1482 | ||
aa3378df | 1483 | /* |
1484 | * Extract real authentication data and generate fake data of the | |
1485 | * same length. | |
1486 | */ | |
5260325f | 1487 | x11_saved_data = xmalloc(data_len); |
1488 | x11_fake_data = xmalloc(data_len); | |
1489 | for (i = 0; i < data_len; i++) { | |
1490 | if (sscanf(data + 2 * i, "%2x", &value) != 1) | |
1491 | fatal("x11_request_forwarding: bad authentication data: %.100s", data); | |
1492 | if (i % 4 == 0) | |
1493 | rand = arc4random(); | |
1494 | x11_saved_data[i] = value; | |
1495 | x11_fake_data[i] = rand & 0xff; | |
1496 | rand >>= 8; | |
1497 | } | |
1498 | x11_saved_data_len = data_len; | |
1499 | x11_fake_data_len = data_len; | |
1500 | ||
1501 | /* Convert the fake data into hex. */ | |
1502 | new_data = xmalloc(2 * data_len + 1); | |
1503 | for (i = 0; i < data_len; i++) | |
1504 | sprintf(new_data + 2 * i, "%02x", (unsigned char) x11_fake_data[i]); | |
1505 | ||
1506 | /* Send the request packet. */ | |
1507 | packet_start(SSH_CMSG_X11_REQUEST_FORWARDING); | |
1508 | packet_put_string(proto, strlen(proto)); | |
1509 | packet_put_string(new_data, strlen(new_data)); | |
1510 | packet_put_int(screen_number); | |
1511 | packet_send(); | |
1512 | packet_write_wait(); | |
1513 | xfree(new_data); | |
8efc0c15 | 1514 | } |
1515 | ||
1516 | /* Sends a message to the server to request authentication fd forwarding. */ | |
1517 | ||
5260325f | 1518 | void |
1519 | auth_request_forwarding() | |
8efc0c15 | 1520 | { |
5260325f | 1521 | packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); |
1522 | packet_send(); | |
1523 | packet_write_wait(); | |
8efc0c15 | 1524 | } |
1525 | ||
aa3378df | 1526 | /* |
1527 | * Returns the name of the forwarded authentication socket. Returns NULL if | |
1528 | * there is no forwarded authentication socket. The returned value points to | |
1529 | * a static buffer. | |
1530 | */ | |
8efc0c15 | 1531 | |
5260325f | 1532 | char * |
1533 | auth_get_socket_name() | |
8efc0c15 | 1534 | { |
5260325f | 1535 | return channel_forwarded_auth_socket_name; |
8efc0c15 | 1536 | } |
1537 | ||
1538 | /* removes the agent forwarding socket */ | |
1539 | ||
5260325f | 1540 | void |
1541 | cleanup_socket(void) | |
1542 | { | |
1543 | remove(channel_forwarded_auth_socket_name); | |
1544 | rmdir(channel_forwarded_auth_socket_dir); | |
8efc0c15 | 1545 | } |
1546 | ||
aa3378df | 1547 | /* |
1548 | * This if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. | |
1549 | * This starts forwarding authentication requests. | |
1550 | */ | |
8efc0c15 | 1551 | |
5260325f | 1552 | void |
1553 | auth_input_request_forwarding(struct passwd * pw) | |
8efc0c15 | 1554 | { |
5260325f | 1555 | int sock, newch; |
1556 | struct sockaddr_un sunaddr; | |
1557 | ||
1558 | if (auth_get_socket_name() != NULL) | |
1559 | fatal("Protocol error: authentication forwarding requested twice."); | |
1560 | ||
1561 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
1562 | temporarily_use_uid(pw->pw_uid); | |
1563 | ||
1564 | /* Allocate a buffer for the socket name, and format the name. */ | |
1565 | channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME); | |
1566 | channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME); | |
1567 | strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME); | |
1568 | ||
1569 | /* Create private directory for socket */ | |
1570 | if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) | |
1571 | packet_disconnect("mkdtemp: %.100s", strerror(errno)); | |
1572 | snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d", | |
1573 | channel_forwarded_auth_socket_dir, (int) getpid()); | |
1574 | ||
1575 | if (atexit(cleanup_socket) < 0) { | |
1576 | int saved = errno; | |
1577 | cleanup_socket(); | |
1578 | packet_disconnect("socket: %.100s", strerror(saved)); | |
1579 | } | |
1580 | /* Create the socket. */ | |
1581 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
1582 | if (sock < 0) | |
1583 | packet_disconnect("socket: %.100s", strerror(errno)); | |
1584 | ||
1585 | /* Bind it to the name. */ | |
1586 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
1587 | sunaddr.sun_family = AF_UNIX; | |
1588 | strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name, | |
1589 | sizeof(sunaddr.sun_path)); | |
1590 | ||
1591 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) | |
1592 | packet_disconnect("bind: %.100s", strerror(errno)); | |
1593 | ||
1594 | /* Restore the privileged uid. */ | |
1595 | restore_uid(); | |
1596 | ||
1597 | /* Start listening on the socket. */ | |
1598 | if (listen(sock, 5) < 0) | |
1599 | packet_disconnect("listen: %.100s", strerror(errno)); | |
1600 | ||
1601 | /* Allocate a channel for the authentication agent socket. */ | |
1602 | newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock, | |
1603 | xstrdup("auth socket")); | |
a408af76 | 1604 | strlcpy(channels[newch].path, channel_forwarded_auth_socket_name, |
1605 | sizeof(channels[newch].path)); | |
8efc0c15 | 1606 | } |
1607 | ||
1608 | /* This is called to process an SSH_SMSG_AGENT_OPEN message. */ | |
1609 | ||
5260325f | 1610 | void |
1611 | auth_input_open_request() | |
8efc0c15 | 1612 | { |
5260325f | 1613 | int remch, sock, newch; |
1614 | char *dummyname; | |
1615 | ||
1616 | /* Read the remote channel number from the message. */ | |
1617 | remch = packet_get_int(); | |
1618 | ||
aa3378df | 1619 | /* |
1620 | * Get a connection to the local authentication agent (this may again | |
1621 | * get forwarded). | |
1622 | */ | |
5260325f | 1623 | sock = ssh_get_authentication_socket(); |
1624 | ||
aa3378df | 1625 | /* |
1626 | * If we could not connect the agent, send an error message back to | |
1627 | * the server. This should never happen unless the agent dies, | |
1628 | * because authentication forwarding is only enabled if we have an | |
1629 | * agent. | |
1630 | */ | |
5260325f | 1631 | if (sock < 0) { |
1632 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1633 | packet_put_int(remch); | |
1634 | packet_send(); | |
1635 | return; | |
1636 | } | |
1637 | debug("Forwarding authentication connection."); | |
1638 | ||
aa3378df | 1639 | /* |
1640 | * Dummy host name. This will be freed when the channel is freed; it | |
1641 | * will still be valid in the packet_put_string below since the | |
1642 | * channel cannot yet be freed at that point. | |
1643 | */ | |
5260325f | 1644 | dummyname = xstrdup("authentication agent connection"); |
1645 | ||
1646 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname); | |
1647 | channels[newch].remote_id = remch; | |
1648 | ||
1649 | /* Send a confirmation to the remote host. */ | |
1650 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1651 | packet_put_int(remch); | |
1652 | packet_put_int(newch); | |
1653 | packet_send(); | |
8efc0c15 | 1654 | } |