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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 | ||
7368a6c8 | 40 | /* default buffer for tcp-fwd-channel */ |
41 | #define CHAN_WINDOW_DEFAULT (8*1024) | |
42 | #define CHAN_PACKET_DEFAULT (CHAN_WINDOW_DEFAULT/2) | |
43 | ||
aa3378df | 44 | /* |
45 | * Pointer to an array containing all allocated channels. The array is | |
46 | * dynamically extended as needed. | |
47 | */ | |
8efc0c15 | 48 | static Channel *channels = NULL; |
49 | ||
aa3378df | 50 | /* |
51 | * Size of the channel array. All slots of the array must always be | |
52 | * initialized (at least the type field); unused slots are marked with type | |
53 | * SSH_CHANNEL_FREE. | |
54 | */ | |
8efc0c15 | 55 | static int channels_alloc = 0; |
56 | ||
aa3378df | 57 | /* |
58 | * Maximum file descriptor value used in any of the channels. This is | |
59 | * updated in channel_allocate. | |
60 | */ | |
8efc0c15 | 61 | static int channel_max_fd_value = 0; |
62 | ||
63 | /* Name and directory of socket for authentication agent forwarding. */ | |
64 | static char *channel_forwarded_auth_socket_name = NULL; | |
5260325f | 65 | static char *channel_forwarded_auth_socket_dir = NULL; |
8efc0c15 | 66 | |
67 | /* Saved X11 authentication protocol name. */ | |
68 | char *x11_saved_proto = NULL; | |
69 | ||
70 | /* Saved X11 authentication data. This is the real data. */ | |
71 | char *x11_saved_data = NULL; | |
72 | unsigned int x11_saved_data_len = 0; | |
73 | ||
aa3378df | 74 | /* |
75 | * Fake X11 authentication data. This is what the server will be sending us; | |
76 | * we should replace any occurrences of this by the real data. | |
77 | */ | |
8efc0c15 | 78 | char *x11_fake_data = NULL; |
79 | unsigned int x11_fake_data_len; | |
80 | ||
aa3378df | 81 | /* |
82 | * Data structure for storing which hosts are permitted for forward requests. | |
83 | * The local sides of any remote forwards are stored in this array to prevent | |
84 | * a corrupt remote server from accessing arbitrary TCP/IP ports on our local | |
85 | * network (which might be behind a firewall). | |
86 | */ | |
5260325f | 87 | typedef struct { |
7368a6c8 | 88 | char *host_to_connect; /* Connect to 'host'. */ |
89 | u_short port_to_connect; /* Connect to 'port'. */ | |
90 | u_short listen_port; /* Remote side should listen port number. */ | |
8efc0c15 | 91 | } ForwardPermission; |
92 | ||
93 | /* List of all permitted host/port pairs to connect. */ | |
94 | static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; | |
95 | /* Number of permitted host/port pairs in the array. */ | |
96 | static int num_permitted_opens = 0; | |
aa3378df | 97 | /* |
98 | * If this is true, all opens are permitted. This is the case on the server | |
99 | * on which we have to trust the client anyway, and the user could do | |
100 | * anything after logging in anyway. | |
101 | */ | |
8efc0c15 | 102 | static int all_opens_permitted = 0; |
103 | ||
104 | /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */ | |
105 | static int have_hostname_in_open = 0; | |
106 | ||
107 | /* Sets specific protocol options. */ | |
108 | ||
5260325f | 109 | void |
110 | channel_set_options(int hostname_in_open) | |
8efc0c15 | 111 | { |
5260325f | 112 | have_hostname_in_open = hostname_in_open; |
8efc0c15 | 113 | } |
114 | ||
aa3378df | 115 | /* |
116 | * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually | |
117 | * called by the server, because the user could connect to any port anyway, | |
118 | * and the server has no way to know but to trust the client anyway. | |
119 | */ | |
8efc0c15 | 120 | |
5260325f | 121 | void |
122 | channel_permit_all_opens() | |
8efc0c15 | 123 | { |
5260325f | 124 | all_opens_permitted = 1; |
8efc0c15 | 125 | } |
126 | ||
7368a6c8 | 127 | /* lookup channel by id */ |
128 | ||
129 | Channel * | |
130 | channel_lookup(int id) | |
131 | { | |
132 | Channel *c; | |
133 | if (id < 0 && id > channels_alloc) { | |
134 | log("channel_lookup: %d: bad id", id); | |
135 | return NULL; | |
136 | } | |
137 | c = &channels[id]; | |
138 | if (c->type == SSH_CHANNEL_FREE) { | |
139 | log("channel_lookup: %d: bad id: channel free", id); | |
140 | return NULL; | |
141 | } | |
142 | return c; | |
143 | } | |
144 | ||
aa3378df | 145 | /* |
146 | * Allocate a new channel object and set its type and socket. This will cause | |
147 | * remote_name to be freed. | |
148 | */ | |
8efc0c15 | 149 | |
5260325f | 150 | int |
7368a6c8 | 151 | channel_new(char *ctype, int type, int rfd, int wfd, int efd, |
152 | int window, int maxpack, int extended_usage, char *remote_name) | |
8efc0c15 | 153 | { |
5260325f | 154 | int i, found; |
155 | Channel *c; | |
156 | ||
157 | /* Update the maximum file descriptor value. */ | |
7368a6c8 | 158 | if (rfd > channel_max_fd_value) |
159 | channel_max_fd_value = rfd; | |
160 | if (wfd > channel_max_fd_value) | |
161 | channel_max_fd_value = wfd; | |
162 | if (efd > channel_max_fd_value) | |
163 | channel_max_fd_value = efd; | |
aa3378df | 164 | /* XXX set close-on-exec -markus */ |
5260325f | 165 | |
166 | /* Do initial allocation if this is the first call. */ | |
167 | if (channels_alloc == 0) { | |
168 | channels_alloc = 10; | |
169 | channels = xmalloc(channels_alloc * sizeof(Channel)); | |
170 | for (i = 0; i < channels_alloc; i++) | |
171 | channels[i].type = SSH_CHANNEL_FREE; | |
aa3378df | 172 | /* |
173 | * Kludge: arrange a call to channel_stop_listening if we | |
174 | * terminate with fatal(). | |
175 | */ | |
5260325f | 176 | fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL); |
177 | } | |
178 | /* Try to find a free slot where to put the new channel. */ | |
179 | for (found = -1, i = 0; i < channels_alloc; i++) | |
180 | if (channels[i].type == SSH_CHANNEL_FREE) { | |
181 | /* Found a free slot. */ | |
182 | found = i; | |
183 | break; | |
184 | } | |
185 | if (found == -1) { | |
aa3378df | 186 | /* There are no free slots. Take last+1 slot and expand the array. */ |
5260325f | 187 | found = channels_alloc; |
188 | channels_alloc += 10; | |
189 | debug("channel: expanding %d", channels_alloc); | |
190 | channels = xrealloc(channels, channels_alloc * sizeof(Channel)); | |
191 | for (i = found; i < channels_alloc; i++) | |
192 | channels[i].type = SSH_CHANNEL_FREE; | |
193 | } | |
194 | /* Initialize and return new channel number. */ | |
195 | c = &channels[found]; | |
196 | buffer_init(&c->input); | |
197 | buffer_init(&c->output); | |
7368a6c8 | 198 | buffer_init(&c->extended); |
5260325f | 199 | chan_init_iostates(c); |
200 | c->self = found; | |
201 | c->type = type; | |
7368a6c8 | 202 | c->ctype = ctype; |
203 | c->local_window = window; | |
204 | c->local_window_max = window; | |
205 | c->local_consumed = 0; | |
206 | c->local_maxpacket = maxpack; | |
207 | c->remote_window = 0; | |
208 | c->remote_maxpacket = 0; | |
209 | c->rfd = rfd; | |
210 | c->wfd = wfd; | |
211 | c->sock = (rfd == wfd) ? rfd : -1; | |
212 | c->efd = efd; | |
213 | c->extended_usage = extended_usage; | |
5260325f | 214 | c->remote_id = -1; |
215 | c->remote_name = remote_name; | |
7368a6c8 | 216 | c->remote_window = 0; |
217 | c->remote_maxpacket = 0; | |
218 | c->cb_fn = NULL; | |
219 | c->cb_arg = NULL; | |
220 | c->cb_event = 0; | |
221 | c->dettach_user = NULL; | |
5260325f | 222 | debug("channel %d: new [%s]", found, remote_name); |
223 | return found; | |
8efc0c15 | 224 | } |
7368a6c8 | 225 | int |
226 | channel_allocate(int type, int sock, char *remote_name) | |
227 | { | |
228 | return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name); | |
229 | } | |
8efc0c15 | 230 | |
231 | /* Free the channel and close its socket. */ | |
232 | ||
5260325f | 233 | void |
7368a6c8 | 234 | channel_free(int id) |
8efc0c15 | 235 | { |
7368a6c8 | 236 | Channel *c = channel_lookup(id); |
237 | if (c == NULL) | |
238 | packet_disconnect("channel free: bad local channel %d", id); | |
239 | debug("channel_free: channel %d: status: %s", id, channel_open_message()); | |
240 | if (c->sock != -1) { | |
241 | shutdown(c->sock, SHUT_RDWR); | |
242 | close(c->sock); | |
243 | } | |
244 | buffer_free(&c->input); | |
245 | buffer_free(&c->output); | |
246 | buffer_free(&c->extended); | |
247 | c->type = SSH_CHANNEL_FREE; | |
248 | if (c->remote_name) { | |
249 | xfree(c->remote_name); | |
250 | c->remote_name = NULL; | |
5260325f | 251 | } |
8efc0c15 | 252 | } |
253 | ||
aa3378df | 254 | /* |
7368a6c8 | 255 | * 'channel_pre*' are called just before select() to add any bits relevant to |
256 | * channels in the select bitmasks. | |
aa3378df | 257 | */ |
7368a6c8 | 258 | /* |
259 | * 'channel_post*': perform any appropriate operations for channels which | |
260 | * have events pending. | |
261 | */ | |
262 | typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset); | |
263 | chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; | |
264 | chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; | |
8efc0c15 | 265 | |
7368a6c8 | 266 | void |
267 | channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
8efc0c15 | 268 | { |
7368a6c8 | 269 | FD_SET(c->sock, readset); |
270 | } | |
5260325f | 271 | |
7368a6c8 | 272 | void |
273 | channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
274 | { | |
275 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
276 | FD_SET(c->sock, readset); | |
277 | if (buffer_len(&c->output) > 0) | |
278 | FD_SET(c->sock, writeset); | |
279 | } | |
5260325f | 280 | |
7368a6c8 | 281 | void |
282 | channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset) | |
283 | { | |
284 | /* test whether sockets are 'alive' for read/write */ | |
285 | if (c->istate == CHAN_INPUT_OPEN) | |
286 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
287 | FD_SET(c->sock, readset); | |
288 | if (c->ostate == CHAN_OUTPUT_OPEN || | |
289 | c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
290 | if (buffer_len(&c->output) > 0) { | |
291 | FD_SET(c->sock, writeset); | |
292 | } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
293 | chan_obuf_empty(c); | |
294 | } | |
295 | } | |
296 | } | |
5260325f | 297 | |
7368a6c8 | 298 | void |
299 | channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
300 | { | |
301 | if (buffer_len(&c->input) == 0) { | |
302 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
303 | packet_put_int(c->remote_id); | |
304 | packet_send(); | |
305 | c->type = SSH_CHANNEL_CLOSED; | |
306 | debug("Closing channel %d after input drain.", c->self); | |
307 | } | |
308 | } | |
5260325f | 309 | |
7368a6c8 | 310 | void |
311 | channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
312 | { | |
313 | if (buffer_len(&c->output) == 0) | |
314 | channel_free(c->self); | |
315 | else | |
316 | FD_SET(c->sock, writeset); | |
317 | } | |
5260325f | 318 | |
7368a6c8 | 319 | /* |
320 | * This is a special state for X11 authentication spoofing. An opened X11 | |
321 | * connection (when authentication spoofing is being done) remains in this | |
322 | * state until the first packet has been completely read. The authentication | |
323 | * data in that packet is then substituted by the real data if it matches the | |
324 | * fake data, and the channel is put into normal mode. | |
325 | */ | |
326 | int | |
327 | x11_open_helper(Channel *c) | |
328 | { | |
329 | unsigned char *ucp; | |
330 | unsigned int proto_len, data_len; | |
5260325f | 331 | |
7368a6c8 | 332 | /* Check if the fixed size part of the packet is in buffer. */ |
333 | if (buffer_len(&c->output) < 12) | |
334 | return 0; | |
335 | ||
336 | /* Parse the lengths of variable-length fields. */ | |
337 | ucp = (unsigned char *) buffer_ptr(&c->output); | |
338 | if (ucp[0] == 0x42) { /* Byte order MSB first. */ | |
339 | proto_len = 256 * ucp[6] + ucp[7]; | |
340 | data_len = 256 * ucp[8] + ucp[9]; | |
341 | } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ | |
342 | proto_len = ucp[6] + 256 * ucp[7]; | |
343 | data_len = ucp[8] + 256 * ucp[9]; | |
344 | } else { | |
345 | debug("Initial X11 packet contains bad byte order byte: 0x%x", | |
346 | ucp[0]); | |
347 | return -1; | |
348 | } | |
5260325f | 349 | |
7368a6c8 | 350 | /* Check if the whole packet is in buffer. */ |
351 | if (buffer_len(&c->output) < | |
352 | 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) | |
353 | return 0; | |
5260325f | 354 | |
7368a6c8 | 355 | /* Check if authentication protocol matches. */ |
356 | if (proto_len != strlen(x11_saved_proto) || | |
357 | memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { | |
358 | debug("X11 connection uses different authentication protocol."); | |
359 | return -1; | |
360 | } | |
361 | /* Check if authentication data matches our fake data. */ | |
362 | if (data_len != x11_fake_data_len || | |
363 | memcmp(ucp + 12 + ((proto_len + 3) & ~3), | |
364 | x11_fake_data, x11_fake_data_len) != 0) { | |
365 | debug("X11 auth data does not match fake data."); | |
366 | return -1; | |
367 | } | |
368 | /* Check fake data length */ | |
369 | if (x11_fake_data_len != x11_saved_data_len) { | |
370 | error("X11 fake_data_len %d != saved_data_len %d", | |
371 | x11_fake_data_len, x11_saved_data_len); | |
372 | return -1; | |
373 | } | |
374 | /* | |
375 | * Received authentication protocol and data match | |
376 | * our fake data. Substitute the fake data with real | |
377 | * data. | |
378 | */ | |
379 | memcpy(ucp + 12 + ((proto_len + 3) & ~3), | |
380 | x11_saved_data, x11_saved_data_len); | |
381 | return 1; | |
382 | } | |
5260325f | 383 | |
7368a6c8 | 384 | void |
385 | channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
386 | { | |
387 | int ret = x11_open_helper(c); | |
388 | if (ret == 1) { | |
389 | /* Start normal processing for the channel. */ | |
390 | c->type = SSH_CHANNEL_OPEN; | |
391 | } else if (ret == -1) { | |
392 | /* | |
393 | * We have received an X11 connection that has bad | |
394 | * authentication information. | |
395 | */ | |
396 | log("X11 connection rejected because of wrong authentication.\r\n"); | |
397 | buffer_clear(&c->input); | |
398 | buffer_clear(&c->output); | |
399 | close(c->sock); | |
400 | c->sock = -1; | |
401 | c->type = SSH_CHANNEL_CLOSED; | |
402 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
403 | packet_put_int(c->remote_id); | |
404 | packet_send(); | |
405 | } | |
406 | } | |
5260325f | 407 | |
7368a6c8 | 408 | void |
409 | channel_pre_x11_open_15(Channel *c, fd_set * readset, fd_set * writeset) | |
410 | { | |
411 | int ret = x11_open_helper(c); | |
412 | if (ret == 1) { | |
413 | c->type = SSH_CHANNEL_OPEN; | |
414 | } else if (ret == -1) { | |
415 | debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); | |
416 | chan_read_failed(c); | |
417 | chan_write_failed(c); | |
418 | debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); | |
419 | } | |
420 | } | |
5260325f | 421 | |
7368a6c8 | 422 | /* This is our fake X11 server socket. */ |
423 | void | |
424 | channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
425 | { | |
426 | struct sockaddr addr; | |
427 | int newsock, newch; | |
428 | socklen_t addrlen; | |
429 | char buf[16384], *remote_hostname; | |
430 | ||
431 | if (FD_ISSET(c->sock, readset)) { | |
432 | debug("X11 connection requested."); | |
433 | addrlen = sizeof(addr); | |
434 | newsock = accept(c->sock, &addr, &addrlen); | |
435 | if (newsock < 0) { | |
436 | error("accept: %.100s", strerror(errno)); | |
437 | return; | |
5260325f | 438 | } |
7368a6c8 | 439 | remote_hostname = get_remote_hostname(newsock); |
440 | snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", | |
441 | remote_hostname, get_peer_port(newsock)); | |
442 | xfree(remote_hostname); | |
443 | newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, | |
444 | xstrdup(buf)); | |
445 | packet_start(SSH_SMSG_X11_OPEN); | |
446 | packet_put_int(newch); | |
447 | if (have_hostname_in_open) | |
448 | packet_put_string(buf, strlen(buf)); | |
449 | packet_send(); | |
8efc0c15 | 450 | } |
8efc0c15 | 451 | } |
452 | ||
aa3378df | 453 | /* |
7368a6c8 | 454 | * This socket is listening for connections to a forwarded TCP/IP port. |
aa3378df | 455 | */ |
7368a6c8 | 456 | void |
457 | channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
458 | { | |
459 | struct sockaddr addr; | |
460 | int newsock, newch; | |
461 | socklen_t addrlen; | |
462 | char buf[1024], *remote_hostname; | |
463 | int remote_port; | |
464 | ||
465 | if (FD_ISSET(c->sock, readset)) { | |
466 | debug("Connection to port %d forwarding " | |
467 | "to %.100s port %d requested.", | |
468 | c->listening_port, c->path, c->host_port); | |
469 | addrlen = sizeof(addr); | |
470 | newsock = accept(c->sock, &addr, &addrlen); | |
471 | if (newsock < 0) { | |
472 | error("accept: %.100s", strerror(errno)); | |
473 | return; | |
474 | } | |
475 | remote_hostname = get_remote_hostname(newsock); | |
476 | remote_port = get_peer_port(newsock); | |
477 | snprintf(buf, sizeof buf, | |
478 | "listen port %d for %.100s port %d, " | |
479 | "connect from %.200s port %d", | |
480 | c->listening_port, c->path, c->host_port, | |
481 | remote_hostname, remote_port); | |
482 | newch = channel_new("direct-tcpip", | |
483 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
484 | c->local_window_max, c->local_maxpacket, | |
485 | 0, xstrdup(buf)); | |
486 | ||
487 | packet_start(SSH_MSG_PORT_OPEN); | |
488 | packet_put_int(newch); | |
489 | packet_put_string(c->path, strlen(c->path)); | |
490 | packet_put_int(c->host_port); | |
491 | if (have_hostname_in_open) { | |
492 | packet_put_string(buf, strlen(buf)); | |
493 | } | |
494 | packet_send(); | |
495 | xfree(remote_hostname); | |
496 | } | |
497 | } | |
8efc0c15 | 498 | |
7368a6c8 | 499 | /* |
500 | * This is the authentication agent socket listening for connections from | |
501 | * clients. | |
502 | */ | |
503 | void | |
504 | channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
8efc0c15 | 505 | { |
5260325f | 506 | struct sockaddr addr; |
7368a6c8 | 507 | int newsock, newch; |
48e671d5 | 508 | socklen_t addrlen; |
5260325f | 509 | |
7368a6c8 | 510 | if (FD_ISSET(c->sock, readset)) { |
511 | addrlen = sizeof(addr); | |
512 | newsock = accept(c->sock, &addr, &addrlen); | |
513 | if (newsock < 0) { | |
514 | error("accept from auth socket: %.100s", strerror(errno)); | |
515 | return; | |
516 | } | |
517 | newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, | |
518 | xstrdup("accepted auth socket")); | |
519 | packet_start(SSH_SMSG_AGENT_OPEN); | |
520 | packet_put_int(newch); | |
521 | packet_send(); | |
522 | } | |
523 | } | |
5260325f | 524 | |
7368a6c8 | 525 | int |
526 | channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) | |
527 | { | |
528 | char buf[16*1024]; | |
529 | int len; | |
530 | ||
531 | if (c->rfd != -1 && | |
532 | FD_ISSET(c->rfd, readset)) { | |
533 | len = read(c->rfd, buf, sizeof(buf)); | |
534 | if (len <= 0) { | |
535 | debug("channel %d: read<0 rfd %d len %d", | |
536 | c->self, c->rfd, len); | |
537 | if (compat13) { | |
538 | buffer_consume(&c->output, buffer_len(&c->output)); | |
539 | c->type = SSH_CHANNEL_INPUT_DRAINING; | |
540 | debug("Channel %d status set to input draining.", c->self); | |
541 | } else { | |
542 | chan_read_failed(c); | |
5260325f | 543 | } |
7368a6c8 | 544 | return -1; |
545 | } | |
546 | buffer_append(&c->input, buf, len); | |
547 | } | |
548 | return 1; | |
549 | } | |
550 | int | |
551 | channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) | |
552 | { | |
553 | int len; | |
554 | ||
555 | /* Send buffered output data to the socket. */ | |
556 | if (c->wfd != -1 && | |
557 | FD_ISSET(c->wfd, writeset) && | |
558 | buffer_len(&c->output) > 0) { | |
559 | len = write(c->wfd, buffer_ptr(&c->output), | |
560 | buffer_len(&c->output)); | |
561 | if (len <= 0) { | |
562 | if (compat13) { | |
563 | buffer_consume(&c->output, buffer_len(&c->output)); | |
564 | debug("Channel %d status set to input draining.", c->self); | |
565 | c->type = SSH_CHANNEL_INPUT_DRAINING; | |
566 | } else { | |
567 | chan_write_failed(c); | |
5260325f | 568 | } |
7368a6c8 | 569 | return -1; |
570 | } | |
571 | buffer_consume(&c->output, len); | |
572 | } | |
573 | return 1; | |
574 | } | |
5260325f | 575 | |
7368a6c8 | 576 | void |
577 | channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset) | |
578 | { | |
579 | channel_handle_rfd(c, readset, writeset); | |
580 | channel_handle_wfd(c, readset, writeset); | |
581 | } | |
aa3378df | 582 | |
7368a6c8 | 583 | void |
584 | channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) | |
585 | { | |
586 | int len; | |
587 | /* Send buffered output data to the socket. */ | |
588 | if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) { | |
589 | len = write(c->sock, buffer_ptr(&c->output), | |
590 | buffer_len(&c->output)); | |
591 | if (len <= 0) | |
592 | buffer_consume(&c->output, buffer_len(&c->output)); | |
593 | else | |
594 | buffer_consume(&c->output, len); | |
595 | } | |
596 | } | |
5260325f | 597 | |
7368a6c8 | 598 | void |
599 | channel_handler_init_13(void) | |
600 | { | |
601 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; | |
602 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13; | |
603 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
604 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
605 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
606 | channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining; | |
607 | channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining; | |
608 | ||
609 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; | |
610 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
611 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
612 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
613 | channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; | |
614 | } | |
5260325f | 615 | |
7368a6c8 | 616 | void |
617 | channel_handler_init_15(void) | |
618 | { | |
619 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15; | |
620 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_15; | |
621 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
622 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
623 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
624 | ||
625 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
626 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
627 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
628 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; | |
629 | } | |
630 | ||
631 | void | |
632 | channel_handler_init(void) | |
633 | { | |
634 | int i; | |
635 | for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { | |
636 | channel_pre[i] = NULL; | |
637 | channel_post[i] = NULL; | |
638 | } | |
639 | if (compat13) | |
640 | channel_handler_init_13(); | |
641 | else | |
642 | channel_handler_init_15(); | |
643 | } | |
644 | ||
645 | void | |
646 | channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) | |
647 | { | |
648 | static int did_init = 0; | |
649 | int i; | |
650 | Channel *c; | |
651 | ||
652 | if (!did_init) { | |
653 | channel_handler_init(); | |
654 | did_init = 1; | |
655 | } | |
656 | for (i = 0; i < channels_alloc; i++) { | |
657 | c = &channels[i]; | |
658 | if (c->type == SSH_CHANNEL_FREE) | |
5260325f | 659 | continue; |
7368a6c8 | 660 | if (ftab[c->type] == NULL) |
661 | continue; | |
662 | (*ftab[c->type])(c, readset, writeset); | |
663 | if (!compat13) | |
664 | chan_delete_if_full_closed(c); | |
8efc0c15 | 665 | } |
8efc0c15 | 666 | } |
667 | ||
7368a6c8 | 668 | void |
669 | channel_prepare_select(fd_set * readset, fd_set * writeset) | |
670 | { | |
671 | channel_handler(channel_pre, readset, writeset); | |
672 | } | |
673 | ||
674 | void | |
675 | channel_after_select(fd_set * readset, fd_set * writeset) | |
676 | { | |
677 | channel_handler(channel_post, readset, writeset); | |
678 | } | |
679 | ||
8efc0c15 | 680 | /* If there is data to send to the connection, send some of it now. */ |
681 | ||
5260325f | 682 | void |
683 | channel_output_poll() | |
8efc0c15 | 684 | { |
5260325f | 685 | int len, i; |
7368a6c8 | 686 | Channel *c; |
5260325f | 687 | |
688 | for (i = 0; i < channels_alloc; i++) { | |
7368a6c8 | 689 | c = &channels[i]; |
48e671d5 | 690 | |
aa3378df | 691 | /* We are only interested in channels that can have buffered incoming data. */ |
48e671d5 | 692 | if (compat13) { |
7368a6c8 | 693 | if (c->type != SSH_CHANNEL_OPEN && |
694 | c->type != SSH_CHANNEL_INPUT_DRAINING) | |
48e671d5 | 695 | continue; |
696 | } else { | |
7368a6c8 | 697 | if (c->type != SSH_CHANNEL_OPEN) |
48e671d5 | 698 | continue; |
7368a6c8 | 699 | if (c->istate != CHAN_INPUT_OPEN && |
700 | c->istate != CHAN_INPUT_WAIT_DRAIN) | |
48e671d5 | 701 | continue; |
702 | } | |
5260325f | 703 | |
704 | /* Get the amount of buffered data for this channel. */ | |
7368a6c8 | 705 | len = buffer_len(&c->input); |
5260325f | 706 | if (len > 0) { |
aa3378df | 707 | /* Send some data for the other side over the secure connection. */ |
5260325f | 708 | if (packet_is_interactive()) { |
709 | if (len > 1024) | |
710 | len = 512; | |
711 | } else { | |
712 | /* Keep the packets at reasonable size. */ | |
7368a6c8 | 713 | if (len > packet_get_maxsize()) |
00e6dd70 | 714 | len = packet_get_maxsize()/2; |
5260325f | 715 | } |
7368a6c8 | 716 | if (len > 0) { |
717 | packet_start(SSH_MSG_CHANNEL_DATA); | |
718 | packet_put_int(c->remote_id); | |
719 | packet_put_string(buffer_ptr(&c->input), len); | |
720 | packet_send(); | |
721 | buffer_consume(&c->input, len); | |
722 | c->remote_window -= len; | |
723 | debug("channel %d: send data len %d", c->self, len); | |
724 | } | |
725 | } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) { | |
5260325f | 726 | if (compat13) |
727 | fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); | |
aa3378df | 728 | /* |
729 | * input-buffer is empty and read-socket shutdown: | |
730 | * tell peer, that we will not send more data: send IEOF | |
731 | */ | |
7368a6c8 | 732 | chan_ibuf_empty(c); |
5260325f | 733 | } |
8efc0c15 | 734 | } |
8efc0c15 | 735 | } |
736 | ||
aa3378df | 737 | /* |
738 | * This is called when a packet of type CHANNEL_DATA has just been received. | |
739 | * The message type has already been consumed, but channel number and data is | |
740 | * still there. | |
741 | */ | |
8efc0c15 | 742 | |
5260325f | 743 | void |
7368a6c8 | 744 | channel_input_data(int type, int plen) |
8efc0c15 | 745 | { |
48e671d5 | 746 | int id; |
5260325f | 747 | char *data; |
748 | unsigned int data_len; | |
7368a6c8 | 749 | Channel *c; |
5260325f | 750 | |
751 | /* Get the channel number and verify it. */ | |
48e671d5 | 752 | id = packet_get_int(); |
7368a6c8 | 753 | c = channel_lookup(id); |
754 | if (c == NULL) | |
48e671d5 | 755 | packet_disconnect("Received data for nonexistent channel %d.", id); |
5260325f | 756 | |
757 | /* Ignore any data for non-open channels (might happen on close) */ | |
7368a6c8 | 758 | if (c->type != SSH_CHANNEL_OPEN && |
759 | c->type != SSH_CHANNEL_X11_OPEN) | |
48e671d5 | 760 | return; |
761 | ||
762 | /* same for protocol 1.5 if output end is no longer open */ | |
7368a6c8 | 763 | if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) |
5260325f | 764 | return; |
765 | ||
766 | /* Get the data. */ | |
767 | data = packet_get_string(&data_len); | |
7368a6c8 | 768 | |
769 | packet_integrity_check(plen, 4 + 4 + data_len, SSH_MSG_CHANNEL_DATA); | |
770 | buffer_append(&c->output, data, data_len); | |
5260325f | 771 | xfree(data); |
8efc0c15 | 772 | } |
773 | ||
aa3378df | 774 | /* |
775 | * Returns true if no channel has too much buffered data, and false if one or | |
776 | * more channel is overfull. | |
777 | */ | |
8efc0c15 | 778 | |
5260325f | 779 | int |
780 | channel_not_very_much_buffered_data() | |
8efc0c15 | 781 | { |
5260325f | 782 | unsigned int i; |
7368a6c8 | 783 | Channel *c; |
5260325f | 784 | |
785 | for (i = 0; i < channels_alloc; i++) { | |
7368a6c8 | 786 | c = &channels[i]; |
787 | if (c->type == SSH_CHANNEL_OPEN) { | |
788 | if (buffer_len(&c->input) > packet_get_maxsize()) { | |
789 | debug("channel %d: big input buffer %d", | |
790 | c->self, buffer_len(&c->input)); | |
5260325f | 791 | return 0; |
7368a6c8 | 792 | } |
793 | if (buffer_len(&c->output) > packet_get_maxsize()) { | |
794 | debug("channel %d: big output buffer %d", | |
795 | c->self, buffer_len(&c->output)); | |
5260325f | 796 | return 0; |
7368a6c8 | 797 | } |
5260325f | 798 | } |
8efc0c15 | 799 | } |
5260325f | 800 | return 1; |
8efc0c15 | 801 | } |
802 | ||
7368a6c8 | 803 | void |
804 | channel_input_ieof(int type, int plen) | |
805 | { | |
806 | int id; | |
807 | Channel *c; | |
808 | ||
809 | packet_integrity_check(plen, 4, type); | |
810 | ||
811 | id = packet_get_int(); | |
812 | c = channel_lookup(id); | |
813 | if (c == NULL) | |
814 | packet_disconnect("Received ieof for nonexistent channel %d.", id); | |
815 | chan_rcvd_ieof(c); | |
816 | } | |
8efc0c15 | 817 | |
5260325f | 818 | void |
7368a6c8 | 819 | channel_input_close(int type, int plen) |
8efc0c15 | 820 | { |
7368a6c8 | 821 | int id; |
822 | Channel *c; | |
5260325f | 823 | |
7368a6c8 | 824 | packet_integrity_check(plen, 4, type); |
825 | ||
826 | id = packet_get_int(); | |
827 | c = channel_lookup(id); | |
828 | if (c == NULL) | |
829 | packet_disconnect("Received close for nonexistent channel %d.", id); | |
aa3378df | 830 | |
831 | /* | |
832 | * Send a confirmation that we have closed the channel and no more | |
833 | * data is coming for it. | |
834 | */ | |
5260325f | 835 | packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); |
7368a6c8 | 836 | packet_put_int(c->remote_id); |
5260325f | 837 | packet_send(); |
838 | ||
aa3378df | 839 | /* |
840 | * If the channel is in closed state, we have sent a close request, | |
841 | * and the other side will eventually respond with a confirmation. | |
842 | * Thus, we cannot free the channel here, because then there would be | |
843 | * no-one to receive the confirmation. The channel gets freed when | |
844 | * the confirmation arrives. | |
845 | */ | |
7368a6c8 | 846 | if (c->type != SSH_CHANNEL_CLOSED) { |
aa3378df | 847 | /* |
848 | * Not a closed channel - mark it as draining, which will | |
849 | * cause it to be freed later. | |
850 | */ | |
7368a6c8 | 851 | buffer_consume(&c->input, buffer_len(&c->input)); |
852 | c->type = SSH_CHANNEL_OUTPUT_DRAINING; | |
5260325f | 853 | } |
8efc0c15 | 854 | } |
855 | ||
7368a6c8 | 856 | /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ |
5260325f | 857 | void |
7368a6c8 | 858 | channel_input_oclose(int type, int plen) |
8efc0c15 | 859 | { |
7368a6c8 | 860 | int id = packet_get_int(); |
861 | Channel *c = channel_lookup(id); | |
862 | packet_integrity_check(plen, 4, type); | |
863 | if (c == NULL) | |
864 | packet_disconnect("Received oclose for nonexistent channel %d.", id); | |
865 | chan_rcvd_oclose(c); | |
8efc0c15 | 866 | } |
867 | ||
7368a6c8 | 868 | void |
869 | channel_input_close_confirmation(int type, int plen) | |
870 | { | |
871 | int id = packet_get_int(); | |
872 | Channel *c = channel_lookup(id); | |
873 | ||
874 | if (c == NULL) | |
875 | packet_disconnect("Received close confirmation for " | |
876 | "out-of-range channel %d.", id); | |
877 | if (c->type != SSH_CHANNEL_CLOSED) | |
878 | packet_disconnect("Received close confirmation for " | |
879 | "non-closed channel %d (type %d).", id, c->type); | |
880 | channel_free(c->self); | |
881 | } | |
8efc0c15 | 882 | |
5260325f | 883 | void |
7368a6c8 | 884 | channel_input_open_confirmation(int type, int plen) |
8efc0c15 | 885 | { |
7368a6c8 | 886 | int id, remote_id; |
887 | Channel *c; | |
5260325f | 888 | |
7368a6c8 | 889 | packet_integrity_check(plen, 4 + 4, type); |
5260325f | 890 | |
7368a6c8 | 891 | id = packet_get_int(); |
892 | c = channel_lookup(id); | |
5260325f | 893 | |
7368a6c8 | 894 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) |
895 | packet_disconnect("Received open confirmation for " | |
896 | "non-opening channel %d.", id); | |
897 | remote_id = packet_get_int(); | |
aa3378df | 898 | /* Record the remote channel number and mark that the channel is now open. */ |
7368a6c8 | 899 | c->remote_id = remote_id; |
900 | c->type = SSH_CHANNEL_OPEN; | |
8efc0c15 | 901 | } |
902 | ||
5260325f | 903 | void |
7368a6c8 | 904 | channel_input_open_failure(int type, int plen) |
8efc0c15 | 905 | { |
7368a6c8 | 906 | int id; |
907 | Channel *c; | |
5260325f | 908 | |
7368a6c8 | 909 | packet_integrity_check(plen, 4, type); |
910 | ||
911 | id = packet_get_int(); | |
912 | c = channel_lookup(id); | |
913 | ||
914 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
915 | packet_disconnect("Received open failure for " | |
916 | "non-opening channel %d.", id); | |
5260325f | 917 | |
918 | /* Free the channel. This will also close the socket. */ | |
7368a6c8 | 919 | channel_free(id); |
8efc0c15 | 920 | } |
921 | ||
aa3378df | 922 | /* |
923 | * Stops listening for channels, and removes any unix domain sockets that we | |
924 | * might have. | |
925 | */ | |
8efc0c15 | 926 | |
5260325f | 927 | void |
928 | channel_stop_listening() | |
8efc0c15 | 929 | { |
5260325f | 930 | int i; |
931 | for (i = 0; i < channels_alloc; i++) { | |
932 | switch (channels[i].type) { | |
933 | case SSH_CHANNEL_AUTH_SOCKET: | |
934 | close(channels[i].sock); | |
935 | remove(channels[i].path); | |
936 | channel_free(i); | |
937 | break; | |
938 | case SSH_CHANNEL_PORT_LISTENER: | |
939 | case SSH_CHANNEL_X11_LISTENER: | |
940 | close(channels[i].sock); | |
941 | channel_free(i); | |
942 | break; | |
943 | default: | |
944 | break; | |
945 | } | |
8efc0c15 | 946 | } |
8efc0c15 | 947 | } |
948 | ||
aa3378df | 949 | /* |
950 | * Closes the sockets of all channels. This is used to close extra file | |
951 | * descriptors after a fork. | |
952 | */ | |
8efc0c15 | 953 | |
5260325f | 954 | void |
955 | channel_close_all() | |
8efc0c15 | 956 | { |
5260325f | 957 | int i; |
958 | for (i = 0; i < channels_alloc; i++) { | |
959 | if (channels[i].type != SSH_CHANNEL_FREE) | |
960 | close(channels[i].sock); | |
961 | } | |
8efc0c15 | 962 | } |
963 | ||
964 | /* Returns the maximum file descriptor number used by the channels. */ | |
965 | ||
5260325f | 966 | int |
967 | channel_max_fd() | |
8efc0c15 | 968 | { |
5260325f | 969 | return channel_max_fd_value; |
8efc0c15 | 970 | } |
971 | ||
972 | /* Returns true if any channel is still open. */ | |
973 | ||
5260325f | 974 | int |
975 | channel_still_open() | |
8efc0c15 | 976 | { |
5260325f | 977 | unsigned int i; |
978 | for (i = 0; i < channels_alloc; i++) | |
979 | switch (channels[i].type) { | |
980 | case SSH_CHANNEL_FREE: | |
981 | case SSH_CHANNEL_X11_LISTENER: | |
982 | case SSH_CHANNEL_PORT_LISTENER: | |
983 | case SSH_CHANNEL_CLOSED: | |
984 | case SSH_CHANNEL_AUTH_SOCKET: | |
985 | continue; | |
986 | case SSH_CHANNEL_OPENING: | |
987 | case SSH_CHANNEL_OPEN: | |
988 | case SSH_CHANNEL_X11_OPEN: | |
989 | return 1; | |
990 | case SSH_CHANNEL_INPUT_DRAINING: | |
991 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
992 | if (!compat13) | |
993 | fatal("cannot happen: OUT_DRAIN"); | |
994 | return 1; | |
995 | default: | |
996 | fatal("channel_still_open: bad channel type %d", channels[i].type); | |
997 | /* NOTREACHED */ | |
998 | } | |
999 | return 0; | |
8efc0c15 | 1000 | } |
1001 | ||
aa3378df | 1002 | /* |
1003 | * Returns a message describing the currently open forwarded connections, | |
1004 | * suitable for sending to the client. The message contains crlf pairs for | |
1005 | * newlines. | |
1006 | */ | |
8efc0c15 | 1007 | |
5260325f | 1008 | char * |
1009 | channel_open_message() | |
8efc0c15 | 1010 | { |
5260325f | 1011 | Buffer buffer; |
1012 | int i; | |
1013 | char buf[512], *cp; | |
1014 | ||
1015 | buffer_init(&buffer); | |
1016 | snprintf(buf, sizeof buf, "The following connections are open:\r\n"); | |
8efc0c15 | 1017 | buffer_append(&buffer, buf, strlen(buf)); |
5260325f | 1018 | for (i = 0; i < channels_alloc; i++) { |
1019 | Channel *c = &channels[i]; | |
1020 | switch (c->type) { | |
1021 | case SSH_CHANNEL_FREE: | |
1022 | case SSH_CHANNEL_X11_LISTENER: | |
1023 | case SSH_CHANNEL_PORT_LISTENER: | |
1024 | case SSH_CHANNEL_CLOSED: | |
1025 | case SSH_CHANNEL_AUTH_SOCKET: | |
1026 | continue; | |
1027 | case SSH_CHANNEL_OPENING: | |
1028 | case SSH_CHANNEL_OPEN: | |
1029 | case SSH_CHANNEL_X11_OPEN: | |
1030 | case SSH_CHANNEL_INPUT_DRAINING: | |
1031 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
7368a6c8 | 1032 | snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n", |
48e671d5 | 1033 | c->self, c->remote_name, |
1034 | c->type, c->remote_id, | |
1035 | c->istate, buffer_len(&c->input), | |
7368a6c8 | 1036 | c->ostate, buffer_len(&c->output), |
1037 | c->rfd, c->wfd); | |
5260325f | 1038 | buffer_append(&buffer, buf, strlen(buf)); |
1039 | continue; | |
1040 | default: | |
7368a6c8 | 1041 | fatal("channel_open_message: bad channel type %d", c->type); |
5260325f | 1042 | /* NOTREACHED */ |
1043 | } | |
1044 | } | |
1045 | buffer_append(&buffer, "\0", 1); | |
1046 | cp = xstrdup(buffer_ptr(&buffer)); | |
1047 | buffer_free(&buffer); | |
1048 | return cp; | |
8efc0c15 | 1049 | } |
1050 | ||
aa3378df | 1051 | /* |
1052 | * Initiate forwarding of connections to local port "port" through the secure | |
1053 | * channel to host:port from remote side. | |
1054 | */ | |
8efc0c15 | 1055 | |
5260325f | 1056 | void |
57112b5a | 1057 | channel_request_local_forwarding(u_short port, const char *host, |
95f1eccc | 1058 | u_short host_port, int gateway_ports) |
8efc0c15 | 1059 | { |
48e671d5 | 1060 | int success, ch, sock, on = 1; |
1061 | struct addrinfo hints, *ai, *aitop; | |
1062 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
aa3378df | 1063 | struct linger linger; |
5260325f | 1064 | |
1065 | if (strlen(host) > sizeof(channels[0].path) - 1) | |
1066 | packet_disconnect("Forward host name too long."); | |
1067 | ||
aa3378df | 1068 | /* |
48e671d5 | 1069 | * getaddrinfo returns a loopback address if the hostname is |
1070 | * set to NULL and hints.ai_flags is not AI_PASSIVE | |
aa3378df | 1071 | */ |
48e671d5 | 1072 | memset(&hints, 0, sizeof(hints)); |
1073 | hints.ai_family = IPv4or6; | |
1074 | hints.ai_flags = gateway_ports ? AI_PASSIVE : 0; | |
1075 | hints.ai_socktype = SOCK_STREAM; | |
1076 | snprintf(strport, sizeof strport, "%d", port); | |
1077 | if (getaddrinfo(NULL, strport, &hints, &aitop) != 0) | |
1078 | packet_disconnect("getaddrinfo: fatal error"); | |
1079 | ||
1080 | success = 0; | |
1081 | for (ai = aitop; ai; ai = ai->ai_next) { | |
1082 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1083 | continue; | |
1084 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
1085 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
1086 | error("channel_request_local_forwarding: getnameinfo failed"); | |
1087 | continue; | |
1088 | } | |
1089 | /* Create a port to listen for the host. */ | |
1090 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1091 | if (sock < 0) { | |
1092 | /* this is no error since kernel may not support ipv6 */ | |
1093 | verbose("socket: %.100s", strerror(errno)); | |
1094 | continue; | |
1095 | } | |
1096 | /* | |
1097 | * Set socket options. We would like the socket to disappear | |
1098 | * as soon as it has been closed for whatever reason. | |
1099 | */ | |
1100 | setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); | |
1101 | linger.l_onoff = 1; | |
1102 | linger.l_linger = 5; | |
1103 | setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger)); | |
1104 | debug("Local forwarding listening on %s port %s.", ntop, strport); | |
1105 | ||
1106 | /* Bind the socket to the address. */ | |
1107 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1108 | /* address can be in use ipv6 address is already bound */ | |
16218745 | 1109 | if (!ai->ai_next) |
1110 | error("bind: %.100s", strerror(errno)); | |
1111 | else | |
1112 | verbose("bind: %.100s", strerror(errno)); | |
1113 | ||
48e671d5 | 1114 | close(sock); |
1115 | continue; | |
1116 | } | |
1117 | /* Start listening for connections on the socket. */ | |
1118 | if (listen(sock, 5) < 0) { | |
1119 | error("listen: %.100s", strerror(errno)); | |
1120 | close(sock); | |
1121 | continue; | |
1122 | } | |
1123 | /* Allocate a channel number for the socket. */ | |
7368a6c8 | 1124 | ch = channel_new( |
1125 | "port listener", SSH_CHANNEL_PORT_LISTENER, | |
1126 | sock, sock, -1, | |
1127 | CHAN_WINDOW_DEFAULT, CHAN_PACKET_DEFAULT, | |
1128 | 0, xstrdup("port listener")); | |
48e671d5 | 1129 | strlcpy(channels[ch].path, host, sizeof(channels[ch].path)); |
1130 | channels[ch].host_port = host_port; | |
1131 | channels[ch].listening_port = port; | |
1132 | success = 1; | |
1133 | } | |
1134 | if (success == 0) | |
1135 | packet_disconnect("cannot listen port: %d", port); | |
1136 | freeaddrinfo(aitop); | |
5260325f | 1137 | } |
8efc0c15 | 1138 | |
aa3378df | 1139 | /* |
1140 | * Initiate forwarding of connections to port "port" on remote host through | |
1141 | * the secure channel to host:port from local side. | |
1142 | */ | |
8efc0c15 | 1143 | |
5260325f | 1144 | void |
7368a6c8 | 1145 | channel_request_remote_forwarding(u_short listen_port, const char *host_to_connect, |
1146 | u_short port_to_connect) | |
8efc0c15 | 1147 | { |
5260325f | 1148 | int payload_len; |
1149 | /* Record locally that connection to this host/port is permitted. */ | |
1150 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
1151 | fatal("channel_request_remote_forwarding: too many forwards"); | |
1152 | ||
7368a6c8 | 1153 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect); |
1154 | permitted_opens[num_permitted_opens].port_to_connect = port_to_connect; | |
1155 | permitted_opens[num_permitted_opens].listen_port = listen_port; | |
5260325f | 1156 | num_permitted_opens++; |
1157 | ||
1158 | /* Send the forward request to the remote side. */ | |
1159 | packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); | |
7368a6c8 | 1160 | packet_put_int(port_to_connect); |
1161 | packet_put_string(host_to_connect, strlen(host_to_connect)); | |
1162 | packet_put_int(listen_port); | |
5260325f | 1163 | packet_send(); |
1164 | packet_write_wait(); | |
aa3378df | 1165 | /* |
1166 | * Wait for response from the remote side. It will send a disconnect | |
1167 | * message on failure, and we will never see it here. | |
1168 | */ | |
5260325f | 1169 | packet_read_expect(&payload_len, SSH_SMSG_SUCCESS); |
8efc0c15 | 1170 | } |
1171 | ||
aa3378df | 1172 | /* |
1173 | * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates | |
1174 | * listening for the port, and sends back a success reply (or disconnect | |
1175 | * message if there was an error). This never returns if there was an error. | |
1176 | */ | |
8efc0c15 | 1177 | |
5260325f | 1178 | void |
1179 | channel_input_port_forward_request(int is_root) | |
8efc0c15 | 1180 | { |
57112b5a | 1181 | u_short port, host_port; |
5260325f | 1182 | char *hostname; |
1183 | ||
1184 | /* Get arguments from the packet. */ | |
1185 | port = packet_get_int(); | |
1186 | hostname = packet_get_string(NULL); | |
1187 | host_port = packet_get_int(); | |
1188 | ||
aa3378df | 1189 | /* |
1190 | * Check that an unprivileged user is not trying to forward a | |
1191 | * privileged port. | |
1192 | */ | |
5260325f | 1193 | if (port < IPPORT_RESERVED && !is_root) |
1194 | packet_disconnect("Requested forwarding of port %d but user is not root.", | |
1195 | port); | |
95f1eccc | 1196 | /* |
1197 | * Initiate forwarding, | |
1198 | * bind port to localhost only (gateway ports == 0). | |
1199 | */ | |
1200 | channel_request_local_forwarding(port, hostname, host_port, 0); | |
5260325f | 1201 | |
1202 | /* Free the argument string. */ | |
1203 | xfree(hostname); | |
8efc0c15 | 1204 | } |
1205 | ||
7368a6c8 | 1206 | /* XXX move to aux.c */ |
1207 | int | |
1208 | channel_connect_to(const char *host, u_short host_port) | |
8efc0c15 | 1209 | { |
48e671d5 | 1210 | struct addrinfo hints, *ai, *aitop; |
1211 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
1212 | int gaierr; | |
7368a6c8 | 1213 | int sock = -1; |
48e671d5 | 1214 | |
1215 | memset(&hints, 0, sizeof(hints)); | |
1216 | hints.ai_family = IPv4or6; | |
1217 | hints.ai_socktype = SOCK_STREAM; | |
1218 | snprintf(strport, sizeof strport, "%d", host_port); | |
1219 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { | |
1220 | error("%.100s: unknown host (%s)", host, gai_strerror(gaierr)); | |
7368a6c8 | 1221 | return -1; |
48e671d5 | 1222 | } |
48e671d5 | 1223 | for (ai = aitop; ai; ai = ai->ai_next) { |
1224 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1225 | continue; | |
1226 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
1227 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
7368a6c8 | 1228 | error("channel_connect_to: getnameinfo failed"); |
48e671d5 | 1229 | continue; |
5260325f | 1230 | } |
48e671d5 | 1231 | /* Create the socket. */ |
1232 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1233 | if (sock < 0) { | |
1234 | error("socket: %.100s", strerror(errno)); | |
1235 | continue; | |
5260325f | 1236 | } |
48e671d5 | 1237 | /* Connect to the host/port. */ |
1238 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1239 | error("connect %.100s port %s: %.100s", ntop, strport, | |
1240 | strerror(errno)); | |
1241 | close(sock); | |
1242 | continue; /* fail -- try next */ | |
1243 | } | |
1244 | break; /* success */ | |
5260325f | 1245 | |
5260325f | 1246 | } |
48e671d5 | 1247 | freeaddrinfo(aitop); |
48e671d5 | 1248 | if (!ai) { |
1249 | error("connect %.100s port %d: failed.", host, host_port); | |
7368a6c8 | 1250 | return -1; |
8efc0c15 | 1251 | } |
7368a6c8 | 1252 | /* success */ |
1253 | return sock; | |
1254 | } | |
48e671d5 | 1255 | |
7368a6c8 | 1256 | /* |
1257 | * This is called after receiving PORT_OPEN message. This attempts to | |
1258 | * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION | |
1259 | * or CHANNEL_OPEN_FAILURE. | |
1260 | */ | |
5260325f | 1261 | |
7368a6c8 | 1262 | void |
1263 | channel_input_port_open(int type, int plen) | |
1264 | { | |
1265 | u_short host_port; | |
1266 | char *host, *originator_string; | |
1267 | int remote_channel, sock = -1, newch, i, denied; | |
1268 | unsigned int host_len, originator_len; | |
5260325f | 1269 | |
7368a6c8 | 1270 | /* Get remote channel number. */ |
1271 | remote_channel = packet_get_int(); | |
5260325f | 1272 | |
7368a6c8 | 1273 | /* Get host name to connect to. */ |
1274 | host = packet_get_string(&host_len); | |
5260325f | 1275 | |
7368a6c8 | 1276 | /* Get port to connect to. */ |
1277 | host_port = packet_get_int(); | |
5260325f | 1278 | |
7368a6c8 | 1279 | /* Get remote originator name. */ |
1280 | if (have_hostname_in_open) { | |
1281 | originator_string = packet_get_string(&originator_len); | |
1282 | originator_len += 4; /* size of packet_int */ | |
1283 | } else { | |
1284 | originator_string = xstrdup("unknown (remote did not supply name)"); | |
1285 | originator_len = 0; /* no originator supplied */ | |
1286 | } | |
5260325f | 1287 | |
7368a6c8 | 1288 | packet_integrity_check(plen, |
1289 | 4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN); | |
1290 | ||
1291 | /* Check if opening that port is permitted. */ | |
1292 | denied = 0; | |
1293 | if (!all_opens_permitted) { | |
1294 | /* Go trough all permitted ports. */ | |
1295 | for (i = 0; i < num_permitted_opens; i++) | |
1296 | if (permitted_opens[i].port_to_connect == host_port && | |
1297 | strcmp(permitted_opens[i].host_to_connect, host) == 0) | |
1298 | break; | |
1299 | ||
1300 | /* Check if we found the requested port among those permitted. */ | |
1301 | if (i >= num_permitted_opens) { | |
1302 | /* The port is not permitted. */ | |
1303 | log("Received request to connect to %.100s:%d, but the request was denied.", | |
1304 | host, host_port); | |
1305 | denied = 1; | |
1306 | } | |
1307 | } | |
1308 | sock = denied ? -1 : channel_connect_to(host, host_port); | |
1309 | if (sock > 0) { | |
1310 | /* Allocate a channel for this connection. */ | |
1311 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string); | |
1312 | channels[newch].remote_id = remote_channel; | |
1313 | ||
1314 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1315 | packet_put_int(remote_channel); | |
1316 | packet_put_int(newch); | |
1317 | packet_send(); | |
1318 | } else { | |
1319 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1320 | packet_put_int(remote_channel); | |
1321 | packet_send(); | |
1322 | } | |
1323 | xfree(host); | |
8efc0c15 | 1324 | } |
1325 | ||
aa3378df | 1326 | /* |
1327 | * Creates an internet domain socket for listening for X11 connections. | |
1328 | * Returns a suitable value for the DISPLAY variable, or NULL if an error | |
1329 | * occurs. | |
1330 | */ | |
8efc0c15 | 1331 | |
48e671d5 | 1332 | #define NUM_SOCKS 10 |
1333 | ||
5260325f | 1334 | char * |
95f1eccc | 1335 | x11_create_display_inet(int screen_number, int x11_display_offset) |
8efc0c15 | 1336 | { |
57112b5a | 1337 | int display_number, sock; |
1338 | u_short port; | |
48e671d5 | 1339 | struct addrinfo hints, *ai, *aitop; |
1340 | char strport[NI_MAXSERV]; | |
1341 | int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; | |
1342 | char display[512]; | |
5260325f | 1343 | char hostname[MAXHOSTNAMELEN]; |
1344 | ||
95f1eccc | 1345 | for (display_number = x11_display_offset; |
5260325f | 1346 | display_number < MAX_DISPLAYS; |
1347 | display_number++) { | |
1348 | port = 6000 + display_number; | |
48e671d5 | 1349 | memset(&hints, 0, sizeof(hints)); |
1350 | hints.ai_family = IPv4or6; | |
1351 | hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */ | |
1352 | hints.ai_socktype = SOCK_STREAM; | |
1353 | snprintf(strport, sizeof strport, "%d", port); | |
1354 | if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { | |
1355 | error("getaddrinfo: %.100s", gai_strerror(gaierr)); | |
5260325f | 1356 | return NULL; |
1357 | } | |
48e671d5 | 1358 | for (ai = aitop; ai; ai = ai->ai_next) { |
1359 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1360 | continue; | |
1361 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1362 | if (sock < 0) { | |
80a44451 | 1363 | if (errno != EINVAL) { |
1364 | error("socket: %.100s", strerror(errno)); | |
1365 | return NULL; | |
1366 | } else { | |
1367 | debug("Socket family %d not supported [X11 disp create]", ai->ai_family); | |
1368 | continue; | |
1369 | } | |
48e671d5 | 1370 | } |
1371 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1372 | debug("bind port %d: %.100s", port, strerror(errno)); | |
1373 | shutdown(sock, SHUT_RDWR); | |
1374 | close(sock); | |
16218745 | 1375 | |
1376 | if (ai->ai_next) | |
1377 | continue; | |
1378 | ||
48e671d5 | 1379 | for (n = 0; n < num_socks; n++) { |
1380 | shutdown(socks[n], SHUT_RDWR); | |
1381 | close(socks[n]); | |
1382 | } | |
1383 | num_socks = 0; | |
1384 | break; | |
1385 | } | |
1386 | socks[num_socks++] = sock; | |
80faa19f | 1387 | #ifndef DONT_TRY_OTHER_AF |
48e671d5 | 1388 | if (num_socks == NUM_SOCKS) |
1389 | break; | |
80faa19f | 1390 | #else |
1391 | break; | |
1392 | #endif | |
5260325f | 1393 | } |
48e671d5 | 1394 | if (num_socks > 0) |
1395 | break; | |
5260325f | 1396 | } |
1397 | if (display_number >= MAX_DISPLAYS) { | |
1398 | error("Failed to allocate internet-domain X11 display socket."); | |
1399 | return NULL; | |
8efc0c15 | 1400 | } |
5260325f | 1401 | /* Start listening for connections on the socket. */ |
48e671d5 | 1402 | for (n = 0; n < num_socks; n++) { |
1403 | sock = socks[n]; | |
1404 | if (listen(sock, 5) < 0) { | |
1405 | error("listen: %.100s", strerror(errno)); | |
1406 | shutdown(sock, SHUT_RDWR); | |
1407 | close(sock); | |
1408 | return NULL; | |
1409 | } | |
8efc0c15 | 1410 | } |
48e671d5 | 1411 | |
5260325f | 1412 | /* Set up a suitable value for the DISPLAY variable. */ |
a7effaac | 1413 | |
5260325f | 1414 | if (gethostname(hostname, sizeof(hostname)) < 0) |
1415 | fatal("gethostname: %.100s", strerror(errno)); | |
a7effaac | 1416 | |
1417 | #ifdef IPADDR_IN_DISPLAY | |
1418 | /* | |
1419 | * HPUX detects the local hostname in the DISPLAY variable and tries | |
1420 | * to set up a shared memory connection to the server, which it | |
1421 | * incorrectly supposes to be local. | |
1422 | * | |
1423 | * The workaround - as used in later $$H and other programs - is | |
1424 | * is to set display to the host's IP address. | |
1425 | */ | |
1426 | { | |
1427 | struct hostent *he; | |
1428 | struct in_addr my_addr; | |
1429 | ||
1430 | he = gethostbyname(hostname); | |
1431 | if (he == NULL) { | |
1432 | error("[X11-broken-fwd-hostname-workaround] Could not get " | |
1433 | "IP address for hostname %s.", hostname); | |
1434 | ||
1435 | packet_send_debug("[X11-broken-fwd-hostname-workaround]" | |
1436 | "Could not get IP address for hostname %s.", hostname); | |
1437 | ||
1438 | shutdown(sock, SHUT_RDWR); | |
1439 | close(sock); | |
1440 | ||
1441 | return NULL; | |
1442 | } | |
1443 | ||
1444 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
1445 | ||
1446 | /* Set DISPLAY to <ip address>:screen.display */ | |
48e671d5 | 1447 | snprintf(display, sizeof(display), "%.50s:%d.%d", inet_ntoa(my_addr), |
a7effaac | 1448 | display_number, screen_number); |
1449 | } | |
1450 | #else /* IPADDR_IN_DISPLAY */ | |
1451 | /* Just set DISPLAY to hostname:screen.display */ | |
48e671d5 | 1452 | snprintf(display, sizeof display, "%.400s:%d.%d", hostname, |
a7effaac | 1453 | display_number, screen_number); |
1454 | #endif /* IPADDR_IN_DISPLAY */ | |
5260325f | 1455 | |
48e671d5 | 1456 | /* Allocate a channel for each socket. */ |
1457 | for (n = 0; n < num_socks; n++) { | |
1458 | sock = socks[n]; | |
1459 | (void) channel_allocate(SSH_CHANNEL_X11_LISTENER, sock, | |
1460 | xstrdup("X11 inet listener")); | |
1461 | } | |
5260325f | 1462 | |
1463 | /* Return a suitable value for the DISPLAY environment variable. */ | |
48e671d5 | 1464 | return xstrdup(display); |
8efc0c15 | 1465 | } |
1466 | ||
1467 | #ifndef X_UNIX_PATH | |
1468 | #define X_UNIX_PATH "/tmp/.X11-unix/X" | |
1469 | #endif | |
1470 | ||
1471 | static | |
1472 | int | |
2f450969 | 1473 | connect_local_xsocket(unsigned int dnr) |
8efc0c15 | 1474 | { |
5260325f | 1475 | static const char *const x_sockets[] = { |
1476 | X_UNIX_PATH "%u", | |
1477 | "/var/X/.X11-unix/X" "%u", | |
1478 | "/usr/spool/sockets/X11/" "%u", | |
1479 | NULL | |
1480 | }; | |
1481 | int sock; | |
1482 | struct sockaddr_un addr; | |
1483 | const char *const * path; | |
1484 | ||
1485 | for (path = x_sockets; *path; ++path) { | |
1486 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
1487 | if (sock < 0) | |
1488 | error("socket: %.100s", strerror(errno)); | |
1489 | memset(&addr, 0, sizeof(addr)); | |
1490 | addr.sun_family = AF_UNIX; | |
1491 | snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr); | |
1492 | if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0) | |
1493 | return sock; | |
1494 | close(sock); | |
1495 | } | |
1496 | error("connect %.100s: %.100s", addr.sun_path, strerror(errno)); | |
1497 | return -1; | |
8efc0c15 | 1498 | } |
1499 | ||
1500 | ||
aa3378df | 1501 | /* |
1502 | * This is called when SSH_SMSG_X11_OPEN is received. The packet contains | |
1503 | * the remote channel number. We should do whatever we want, and respond | |
1504 | * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. | |
1505 | */ | |
8efc0c15 | 1506 | |
5260325f | 1507 | void |
7368a6c8 | 1508 | x11_input_open(int type, int plen) |
8efc0c15 | 1509 | { |
48e671d5 | 1510 | int remote_channel, display_number, sock = 0, newch; |
5260325f | 1511 | const char *display; |
5260325f | 1512 | char buf[1024], *cp, *remote_host; |
610cd5c6 | 1513 | unsigned int remote_len; |
48e671d5 | 1514 | struct addrinfo hints, *ai, *aitop; |
1515 | char strport[NI_MAXSERV]; | |
1516 | int gaierr; | |
5260325f | 1517 | |
1518 | /* Get remote channel number. */ | |
1519 | remote_channel = packet_get_int(); | |
1520 | ||
1521 | /* Get remote originator name. */ | |
aa3378df | 1522 | if (have_hostname_in_open) { |
5260325f | 1523 | remote_host = packet_get_string(&remote_len); |
aa3378df | 1524 | remote_len += 4; |
1525 | } else { | |
5260325f | 1526 | remote_host = xstrdup("unknown (remote did not supply name)"); |
aa3378df | 1527 | remote_len = 0; |
1528 | } | |
5260325f | 1529 | |
1530 | debug("Received X11 open request."); | |
7368a6c8 | 1531 | packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN); |
5260325f | 1532 | |
1533 | /* Try to open a socket for the local X server. */ | |
1534 | display = getenv("DISPLAY"); | |
1535 | if (!display) { | |
1536 | error("DISPLAY not set."); | |
1537 | goto fail; | |
1538 | } | |
aa3378df | 1539 | /* |
1540 | * Now we decode the value of the DISPLAY variable and make a | |
1541 | * connection to the real X server. | |
1542 | */ | |
1543 | ||
1544 | /* | |
1545 | * Check if it is a unix domain socket. Unix domain displays are in | |
1546 | * one of the following formats: unix:d[.s], :d[.s], ::d[.s] | |
1547 | */ | |
5260325f | 1548 | if (strncmp(display, "unix:", 5) == 0 || |
1549 | display[0] == ':') { | |
1550 | /* Connect to the unix domain socket. */ | |
1551 | if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) { | |
1552 | error("Could not parse display number from DISPLAY: %.100s", | |
1553 | display); | |
1554 | goto fail; | |
1555 | } | |
1556 | /* Create a socket. */ | |
1557 | sock = connect_local_xsocket(display_number); | |
1558 | if (sock < 0) | |
1559 | goto fail; | |
1560 | ||
1561 | /* OK, we now have a connection to the display. */ | |
1562 | goto success; | |
1563 | } | |
aa3378df | 1564 | /* |
1565 | * Connect to an inet socket. The DISPLAY value is supposedly | |
1566 | * hostname:d[.s], where hostname may also be numeric IP address. | |
1567 | */ | |
5260325f | 1568 | strncpy(buf, display, sizeof(buf)); |
1569 | buf[sizeof(buf) - 1] = 0; | |
1570 | cp = strchr(buf, ':'); | |
1571 | if (!cp) { | |
1572 | error("Could not find ':' in DISPLAY: %.100s", display); | |
1573 | goto fail; | |
1574 | } | |
1575 | *cp = 0; | |
aa3378df | 1576 | /* buf now contains the host name. But first we parse the display number. */ |
5260325f | 1577 | if (sscanf(cp + 1, "%d", &display_number) != 1) { |
1578 | error("Could not parse display number from DISPLAY: %.100s", | |
1579 | display); | |
1580 | goto fail; | |
1581 | } | |
5260325f | 1582 | |
48e671d5 | 1583 | /* Look up the host address */ |
1584 | memset(&hints, 0, sizeof(hints)); | |
1585 | hints.ai_family = IPv4or6; | |
1586 | hints.ai_socktype = SOCK_STREAM; | |
1587 | snprintf(strport, sizeof strport, "%d", 6000 + display_number); | |
1588 | if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { | |
1589 | error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr)); | |
5260325f | 1590 | goto fail; |
8efc0c15 | 1591 | } |
48e671d5 | 1592 | for (ai = aitop; ai; ai = ai->ai_next) { |
1593 | /* Create a socket. */ | |
1594 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1595 | if (sock < 0) { | |
1596 | debug("socket: %.100s", strerror(errno)); | |
7368a6c8 | 1597 | continue; |
1598 | } | |
1599 | /* Connect it to the display. */ | |
1600 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1601 | debug("connect %.100s port %d: %.100s", buf, | |
1602 | 6000 + display_number, strerror(errno)); | |
1603 | close(sock); | |
1604 | continue; | |
1605 | } | |
1606 | /* Success */ | |
1607 | break; | |
48e671d5 | 1608 | } |
48e671d5 | 1609 | freeaddrinfo(aitop); |
1610 | if (!ai) { | |
1611 | error("connect %.100s port %d: %.100s", buf, 6000 + display_number, | |
1612 | strerror(errno)); | |
5260325f | 1613 | goto fail; |
8efc0c15 | 1614 | } |
5260325f | 1615 | success: |
1616 | /* We have successfully obtained a connection to the real X display. */ | |
1617 | ||
1618 | /* Allocate a channel for this connection. */ | |
1619 | if (x11_saved_proto == NULL) | |
1620 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, remote_host); | |
1621 | else | |
1622 | newch = channel_allocate(SSH_CHANNEL_X11_OPEN, sock, remote_host); | |
1623 | channels[newch].remote_id = remote_channel; | |
1624 | ||
1625 | /* Send a confirmation to the remote host. */ | |
1626 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1627 | packet_put_int(remote_channel); | |
1628 | packet_put_int(newch); | |
1629 | packet_send(); | |
1630 | ||
1631 | return; | |
1632 | ||
1633 | fail: | |
1634 | /* Send refusal to the remote host. */ | |
1635 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1636 | packet_put_int(remote_channel); | |
1637 | packet_send(); | |
8efc0c15 | 1638 | } |
1639 | ||
aa3378df | 1640 | /* |
1641 | * Requests forwarding of X11 connections, generates fake authentication | |
1642 | * data, and enables authentication spoofing. | |
1643 | */ | |
8efc0c15 | 1644 | |
5260325f | 1645 | void |
1646 | x11_request_forwarding_with_spoofing(const char *proto, const char *data) | |
8efc0c15 | 1647 | { |
5260325f | 1648 | unsigned int data_len = (unsigned int) strlen(data) / 2; |
1649 | unsigned int i, value; | |
1650 | char *new_data; | |
1651 | int screen_number; | |
1652 | const char *cp; | |
1653 | u_int32_t rand = 0; | |
1654 | ||
1655 | cp = getenv("DISPLAY"); | |
1656 | if (cp) | |
1657 | cp = strchr(cp, ':'); | |
1658 | if (cp) | |
1659 | cp = strchr(cp, '.'); | |
1660 | if (cp) | |
1661 | screen_number = atoi(cp + 1); | |
1662 | else | |
1663 | screen_number = 0; | |
1664 | ||
1665 | /* Save protocol name. */ | |
1666 | x11_saved_proto = xstrdup(proto); | |
1667 | ||
aa3378df | 1668 | /* |
1669 | * Extract real authentication data and generate fake data of the | |
1670 | * same length. | |
1671 | */ | |
5260325f | 1672 | x11_saved_data = xmalloc(data_len); |
1673 | x11_fake_data = xmalloc(data_len); | |
1674 | for (i = 0; i < data_len; i++) { | |
1675 | if (sscanf(data + 2 * i, "%2x", &value) != 1) | |
1676 | fatal("x11_request_forwarding: bad authentication data: %.100s", data); | |
1677 | if (i % 4 == 0) | |
1678 | rand = arc4random(); | |
1679 | x11_saved_data[i] = value; | |
1680 | x11_fake_data[i] = rand & 0xff; | |
1681 | rand >>= 8; | |
1682 | } | |
1683 | x11_saved_data_len = data_len; | |
1684 | x11_fake_data_len = data_len; | |
1685 | ||
1686 | /* Convert the fake data into hex. */ | |
1687 | new_data = xmalloc(2 * data_len + 1); | |
1688 | for (i = 0; i < data_len; i++) | |
1689 | sprintf(new_data + 2 * i, "%02x", (unsigned char) x11_fake_data[i]); | |
1690 | ||
1691 | /* Send the request packet. */ | |
1692 | packet_start(SSH_CMSG_X11_REQUEST_FORWARDING); | |
1693 | packet_put_string(proto, strlen(proto)); | |
1694 | packet_put_string(new_data, strlen(new_data)); | |
1695 | packet_put_int(screen_number); | |
1696 | packet_send(); | |
1697 | packet_write_wait(); | |
1698 | xfree(new_data); | |
8efc0c15 | 1699 | } |
1700 | ||
1701 | /* Sends a message to the server to request authentication fd forwarding. */ | |
1702 | ||
5260325f | 1703 | void |
1704 | auth_request_forwarding() | |
8efc0c15 | 1705 | { |
5260325f | 1706 | packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); |
1707 | packet_send(); | |
1708 | packet_write_wait(); | |
8efc0c15 | 1709 | } |
1710 | ||
aa3378df | 1711 | /* |
1712 | * Returns the name of the forwarded authentication socket. Returns NULL if | |
1713 | * there is no forwarded authentication socket. The returned value points to | |
1714 | * a static buffer. | |
1715 | */ | |
8efc0c15 | 1716 | |
5260325f | 1717 | char * |
1718 | auth_get_socket_name() | |
8efc0c15 | 1719 | { |
5260325f | 1720 | return channel_forwarded_auth_socket_name; |
8efc0c15 | 1721 | } |
1722 | ||
1723 | /* removes the agent forwarding socket */ | |
1724 | ||
5260325f | 1725 | void |
1726 | cleanup_socket(void) | |
1727 | { | |
1728 | remove(channel_forwarded_auth_socket_name); | |
1729 | rmdir(channel_forwarded_auth_socket_dir); | |
8efc0c15 | 1730 | } |
1731 | ||
aa3378df | 1732 | /* |
1733 | * This if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. | |
1734 | * This starts forwarding authentication requests. | |
1735 | */ | |
8efc0c15 | 1736 | |
5260325f | 1737 | void |
1738 | auth_input_request_forwarding(struct passwd * pw) | |
8efc0c15 | 1739 | { |
5260325f | 1740 | int sock, newch; |
1741 | struct sockaddr_un sunaddr; | |
1742 | ||
1743 | if (auth_get_socket_name() != NULL) | |
1744 | fatal("Protocol error: authentication forwarding requested twice."); | |
1745 | ||
1746 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
1747 | temporarily_use_uid(pw->pw_uid); | |
1748 | ||
1749 | /* Allocate a buffer for the socket name, and format the name. */ | |
1750 | channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME); | |
1751 | channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME); | |
1752 | strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME); | |
1753 | ||
1754 | /* Create private directory for socket */ | |
1755 | if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) | |
1756 | packet_disconnect("mkdtemp: %.100s", strerror(errno)); | |
1757 | snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d", | |
1758 | channel_forwarded_auth_socket_dir, (int) getpid()); | |
1759 | ||
1760 | if (atexit(cleanup_socket) < 0) { | |
1761 | int saved = errno; | |
1762 | cleanup_socket(); | |
1763 | packet_disconnect("socket: %.100s", strerror(saved)); | |
1764 | } | |
1765 | /* Create the socket. */ | |
1766 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
1767 | if (sock < 0) | |
1768 | packet_disconnect("socket: %.100s", strerror(errno)); | |
1769 | ||
1770 | /* Bind it to the name. */ | |
1771 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
1772 | sunaddr.sun_family = AF_UNIX; | |
1773 | strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name, | |
1774 | sizeof(sunaddr.sun_path)); | |
1775 | ||
1776 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) | |
1777 | packet_disconnect("bind: %.100s", strerror(errno)); | |
1778 | ||
1779 | /* Restore the privileged uid. */ | |
1780 | restore_uid(); | |
1781 | ||
1782 | /* Start listening on the socket. */ | |
1783 | if (listen(sock, 5) < 0) | |
1784 | packet_disconnect("listen: %.100s", strerror(errno)); | |
1785 | ||
1786 | /* Allocate a channel for the authentication agent socket. */ | |
1787 | newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock, | |
1788 | xstrdup("auth socket")); | |
a408af76 | 1789 | strlcpy(channels[newch].path, channel_forwarded_auth_socket_name, |
1790 | sizeof(channels[newch].path)); | |
8efc0c15 | 1791 | } |
1792 | ||
1793 | /* This is called to process an SSH_SMSG_AGENT_OPEN message. */ | |
1794 | ||
5260325f | 1795 | void |
7368a6c8 | 1796 | auth_input_open_request(int type, int plen) |
8efc0c15 | 1797 | { |
5260325f | 1798 | int remch, sock, newch; |
1799 | char *dummyname; | |
1800 | ||
7368a6c8 | 1801 | packet_integrity_check(plen, 4, type); |
1802 | ||
5260325f | 1803 | /* Read the remote channel number from the message. */ |
1804 | remch = packet_get_int(); | |
1805 | ||
aa3378df | 1806 | /* |
1807 | * Get a connection to the local authentication agent (this may again | |
1808 | * get forwarded). | |
1809 | */ | |
5260325f | 1810 | sock = ssh_get_authentication_socket(); |
1811 | ||
aa3378df | 1812 | /* |
1813 | * If we could not connect the agent, send an error message back to | |
1814 | * the server. This should never happen unless the agent dies, | |
1815 | * because authentication forwarding is only enabled if we have an | |
1816 | * agent. | |
1817 | */ | |
5260325f | 1818 | if (sock < 0) { |
1819 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1820 | packet_put_int(remch); | |
1821 | packet_send(); | |
1822 | return; | |
1823 | } | |
1824 | debug("Forwarding authentication connection."); | |
1825 | ||
aa3378df | 1826 | /* |
1827 | * Dummy host name. This will be freed when the channel is freed; it | |
1828 | * will still be valid in the packet_put_string below since the | |
1829 | * channel cannot yet be freed at that point. | |
1830 | */ | |
5260325f | 1831 | dummyname = xstrdup("authentication agent connection"); |
1832 | ||
1833 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname); | |
1834 | channels[newch].remote_id = remch; | |
1835 | ||
1836 | /* Send a confirmation to the remote host. */ | |
1837 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1838 | packet_put_int(remch); | |
1839 | packet_put_int(newch); | |
1840 | packet_send(); | |
8efc0c15 | 1841 | } |