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8efc0c15 | 1 | /* |
6ae2364d | 2 | * |
5260325f | 3 | * channels.c |
6ae2364d | 4 | * |
5260325f | 5 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
6ae2364d | 6 | * |
5260325f | 7 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
8 | * All rights reserved | |
6ae2364d | 9 | * |
5260325f | 10 | * Created: Fri Mar 24 16:35:24 1995 ylo |
6ae2364d | 11 | * |
5260325f | 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. | |
6ae2364d | 15 | * |
7e7327a1 | 16 | * SSH2 support added by Markus Friedl. |
5260325f | 17 | */ |
8efc0c15 | 18 | |
19 | #include "includes.h" | |
2e73a022 | 20 | RCSID("$OpenBSD: channels.c,v 1.66 2000/08/19 21:55:51 markus Exp $"); |
8efc0c15 | 21 | |
22 | #include "ssh.h" | |
23 | #include "packet.h" | |
24 | #include "xmalloc.h" | |
25 | #include "buffer.h" | |
8efc0c15 | 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 | ||
7e7327a1 | 34 | #include "ssh2.h" |
4c8722d9 | 35 | |
36 | #include <openssl/rsa.h> | |
37 | #include <openssl/dsa.h> | |
38 | #include "key.h" | |
39 | #include "authfd.h" | |
7e7327a1 | 40 | |
8efc0c15 | 41 | /* Maximum number of fake X11 displays to try. */ |
42 | #define MAX_DISPLAYS 1000 | |
43 | ||
44 | /* Max len of agent socket */ | |
45 | #define MAX_SOCKET_NAME 100 | |
46 | ||
0b242b12 | 47 | /* default window/packet sizes for tcp/x11-fwd-channel */ |
48 | #define CHAN_TCP_WINDOW_DEFAULT (8*1024) | |
49 | #define CHAN_TCP_PACKET_DEFAULT (CHAN_TCP_WINDOW_DEFAULT/2) | |
50 | #define CHAN_X11_WINDOW_DEFAULT (4*1024) | |
51 | #define CHAN_X11_PACKET_DEFAULT (CHAN_X11_WINDOW_DEFAULT/2) | |
7368a6c8 | 52 | |
aa3378df | 53 | /* |
54 | * Pointer to an array containing all allocated channels. The array is | |
55 | * dynamically extended as needed. | |
56 | */ | |
8efc0c15 | 57 | static Channel *channels = NULL; |
58 | ||
aa3378df | 59 | /* |
60 | * Size of the channel array. All slots of the array must always be | |
61 | * initialized (at least the type field); unused slots are marked with type | |
62 | * SSH_CHANNEL_FREE. | |
63 | */ | |
8efc0c15 | 64 | static int channels_alloc = 0; |
65 | ||
aa3378df | 66 | /* |
67 | * Maximum file descriptor value used in any of the channels. This is | |
68 | * updated in channel_allocate. | |
69 | */ | |
8efc0c15 | 70 | static int channel_max_fd_value = 0; |
71 | ||
72 | /* Name and directory of socket for authentication agent forwarding. */ | |
73 | static char *channel_forwarded_auth_socket_name = NULL; | |
5260325f | 74 | static char *channel_forwarded_auth_socket_dir = NULL; |
8efc0c15 | 75 | |
76 | /* Saved X11 authentication protocol name. */ | |
77 | char *x11_saved_proto = NULL; | |
78 | ||
79 | /* Saved X11 authentication data. This is the real data. */ | |
80 | char *x11_saved_data = NULL; | |
81 | unsigned int x11_saved_data_len = 0; | |
82 | ||
aa3378df | 83 | /* |
84 | * Fake X11 authentication data. This is what the server will be sending us; | |
85 | * we should replace any occurrences of this by the real data. | |
86 | */ | |
8efc0c15 | 87 | char *x11_fake_data = NULL; |
88 | unsigned int x11_fake_data_len; | |
89 | ||
aa3378df | 90 | /* |
91 | * Data structure for storing which hosts are permitted for forward requests. | |
92 | * The local sides of any remote forwards are stored in this array to prevent | |
93 | * a corrupt remote server from accessing arbitrary TCP/IP ports on our local | |
94 | * network (which might be behind a firewall). | |
95 | */ | |
5260325f | 96 | typedef struct { |
7368a6c8 | 97 | char *host_to_connect; /* Connect to 'host'. */ |
98 | u_short port_to_connect; /* Connect to 'port'. */ | |
99 | u_short listen_port; /* Remote side should listen port number. */ | |
8efc0c15 | 100 | } ForwardPermission; |
101 | ||
102 | /* List of all permitted host/port pairs to connect. */ | |
103 | static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION]; | |
104 | /* Number of permitted host/port pairs in the array. */ | |
105 | static int num_permitted_opens = 0; | |
aa3378df | 106 | /* |
107 | * If this is true, all opens are permitted. This is the case on the server | |
108 | * on which we have to trust the client anyway, and the user could do | |
109 | * anything after logging in anyway. | |
110 | */ | |
8efc0c15 | 111 | static int all_opens_permitted = 0; |
112 | ||
113 | /* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */ | |
114 | static int have_hostname_in_open = 0; | |
115 | ||
116 | /* Sets specific protocol options. */ | |
117 | ||
6ae2364d | 118 | void |
5260325f | 119 | channel_set_options(int hostname_in_open) |
8efc0c15 | 120 | { |
5260325f | 121 | have_hostname_in_open = hostname_in_open; |
8efc0c15 | 122 | } |
123 | ||
aa3378df | 124 | /* |
125 | * Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually | |
126 | * called by the server, because the user could connect to any port anyway, | |
127 | * and the server has no way to know but to trust the client anyway. | |
128 | */ | |
8efc0c15 | 129 | |
6ae2364d | 130 | void |
5260325f | 131 | channel_permit_all_opens() |
8efc0c15 | 132 | { |
5260325f | 133 | all_opens_permitted = 1; |
8efc0c15 | 134 | } |
135 | ||
7368a6c8 | 136 | /* lookup channel by id */ |
137 | ||
138 | Channel * | |
139 | channel_lookup(int id) | |
140 | { | |
141 | Channel *c; | |
3e98362e | 142 | if (id < 0 || id > channels_alloc) { |
7368a6c8 | 143 | log("channel_lookup: %d: bad id", id); |
144 | return NULL; | |
145 | } | |
146 | c = &channels[id]; | |
147 | if (c->type == SSH_CHANNEL_FREE) { | |
148 | log("channel_lookup: %d: bad id: channel free", id); | |
149 | return NULL; | |
150 | } | |
151 | return c; | |
152 | } | |
153 | ||
aa3378df | 154 | /* |
1d1ffb87 | 155 | * Register filedescriptors for a channel, used when allocating a channel or |
0fbe8c74 | 156 | * when the channel consumer/producer is ready, e.g. shell exec'd |
aa3378df | 157 | */ |
8efc0c15 | 158 | |
0fbe8c74 | 159 | void |
160 | channel_register_fds(Channel *c, int rfd, int wfd, int efd, int extusage) | |
8efc0c15 | 161 | { |
5260325f | 162 | /* Update the maximum file descriptor value. */ |
7368a6c8 | 163 | if (rfd > channel_max_fd_value) |
164 | channel_max_fd_value = rfd; | |
165 | if (wfd > channel_max_fd_value) | |
166 | channel_max_fd_value = wfd; | |
167 | if (efd > channel_max_fd_value) | |
168 | channel_max_fd_value = efd; | |
aa3378df | 169 | /* XXX set close-on-exec -markus */ |
1d1ffb87 | 170 | |
0fbe8c74 | 171 | c->rfd = rfd; |
172 | c->wfd = wfd; | |
173 | c->sock = (rfd == wfd) ? rfd : -1; | |
174 | c->efd = efd; | |
175 | c->extended_usage = extusage; | |
1d1ffb87 | 176 | if (rfd != -1) |
177 | set_nonblock(rfd); | |
178 | if (wfd != -1) | |
179 | set_nonblock(wfd); | |
180 | if (efd != -1) | |
181 | set_nonblock(efd); | |
0fbe8c74 | 182 | } |
183 | ||
184 | /* | |
185 | * Allocate a new channel object and set its type and socket. This will cause | |
186 | * remote_name to be freed. | |
187 | */ | |
188 | ||
189 | int | |
190 | channel_new(char *ctype, int type, int rfd, int wfd, int efd, | |
191 | int window, int maxpack, int extusage, char *remote_name) | |
192 | { | |
193 | int i, found; | |
194 | Channel *c; | |
5260325f | 195 | |
196 | /* Do initial allocation if this is the first call. */ | |
197 | if (channels_alloc == 0) { | |
7e7327a1 | 198 | chan_init(); |
5260325f | 199 | channels_alloc = 10; |
200 | channels = xmalloc(channels_alloc * sizeof(Channel)); | |
201 | for (i = 0; i < channels_alloc; i++) | |
202 | channels[i].type = SSH_CHANNEL_FREE; | |
aa3378df | 203 | /* |
204 | * Kludge: arrange a call to channel_stop_listening if we | |
205 | * terminate with fatal(). | |
206 | */ | |
5260325f | 207 | fatal_add_cleanup((void (*) (void *)) channel_stop_listening, NULL); |
208 | } | |
209 | /* Try to find a free slot where to put the new channel. */ | |
210 | for (found = -1, i = 0; i < channels_alloc; i++) | |
211 | if (channels[i].type == SSH_CHANNEL_FREE) { | |
212 | /* Found a free slot. */ | |
213 | found = i; | |
214 | break; | |
215 | } | |
216 | if (found == -1) { | |
aa3378df | 217 | /* There are no free slots. Take last+1 slot and expand the array. */ |
5260325f | 218 | found = channels_alloc; |
219 | channels_alloc += 10; | |
220 | debug("channel: expanding %d", channels_alloc); | |
221 | channels = xrealloc(channels, channels_alloc * sizeof(Channel)); | |
222 | for (i = found; i < channels_alloc; i++) | |
223 | channels[i].type = SSH_CHANNEL_FREE; | |
224 | } | |
225 | /* Initialize and return new channel number. */ | |
226 | c = &channels[found]; | |
227 | buffer_init(&c->input); | |
228 | buffer_init(&c->output); | |
7368a6c8 | 229 | buffer_init(&c->extended); |
5260325f | 230 | chan_init_iostates(c); |
0fbe8c74 | 231 | channel_register_fds(c, rfd, wfd, efd, extusage); |
5260325f | 232 | c->self = found; |
233 | c->type = type; | |
7368a6c8 | 234 | c->ctype = ctype; |
0b242b12 | 235 | c->local_window = window; |
236 | c->local_window_max = window; | |
237 | c->local_consumed = 0; | |
238 | c->local_maxpacket = maxpack; | |
5260325f | 239 | c->remote_id = -1; |
240 | c->remote_name = remote_name; | |
7368a6c8 | 241 | c->remote_window = 0; |
242 | c->remote_maxpacket = 0; | |
243 | c->cb_fn = NULL; | |
244 | c->cb_arg = NULL; | |
245 | c->cb_event = 0; | |
246 | c->dettach_user = NULL; | |
2e73a022 | 247 | c->input_filter = NULL; |
5260325f | 248 | debug("channel %d: new [%s]", found, remote_name); |
249 | return found; | |
8efc0c15 | 250 | } |
0fbe8c74 | 251 | /* old interface XXX */ |
6ae2364d | 252 | int |
7368a6c8 | 253 | channel_allocate(int type, int sock, char *remote_name) |
254 | { | |
255 | return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name); | |
256 | } | |
8efc0c15 | 257 | |
0fbe8c74 | 258 | |
259 | /* Close all channel fd/socket. */ | |
260 | ||
261 | void | |
262 | channel_close_fds(Channel *c) | |
263 | { | |
264 | if (c->sock != -1) { | |
265 | close(c->sock); | |
266 | c->sock = -1; | |
267 | } | |
268 | if (c->rfd != -1) { | |
269 | close(c->rfd); | |
270 | c->rfd = -1; | |
271 | } | |
272 | if (c->wfd != -1) { | |
273 | close(c->wfd); | |
274 | c->wfd = -1; | |
275 | } | |
276 | if (c->efd != -1) { | |
277 | close(c->efd); | |
278 | c->efd = -1; | |
279 | } | |
280 | } | |
281 | ||
282 | /* Free the channel and close its fd/socket. */ | |
8efc0c15 | 283 | |
6ae2364d | 284 | void |
7368a6c8 | 285 | channel_free(int id) |
8efc0c15 | 286 | { |
7368a6c8 | 287 | Channel *c = channel_lookup(id); |
288 | if (c == NULL) | |
289 | packet_disconnect("channel free: bad local channel %d", id); | |
290 | debug("channel_free: channel %d: status: %s", id, channel_open_message()); | |
7e7327a1 | 291 | if (c->dettach_user != NULL) { |
292 | debug("channel_free: channel %d: dettaching channel user", id); | |
293 | c->dettach_user(c->self, NULL); | |
294 | } | |
0fbe8c74 | 295 | if (c->sock != -1) |
7368a6c8 | 296 | shutdown(c->sock, SHUT_RDWR); |
0fbe8c74 | 297 | channel_close_fds(c); |
7368a6c8 | 298 | buffer_free(&c->input); |
299 | buffer_free(&c->output); | |
300 | buffer_free(&c->extended); | |
301 | c->type = SSH_CHANNEL_FREE; | |
302 | if (c->remote_name) { | |
303 | xfree(c->remote_name); | |
304 | c->remote_name = NULL; | |
5260325f | 305 | } |
8efc0c15 | 306 | } |
307 | ||
aa3378df | 308 | /* |
7368a6c8 | 309 | * 'channel_pre*' are called just before select() to add any bits relevant to |
310 | * channels in the select bitmasks. | |
aa3378df | 311 | */ |
7368a6c8 | 312 | /* |
313 | * 'channel_post*': perform any appropriate operations for channels which | |
314 | * have events pending. | |
315 | */ | |
316 | typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset); | |
317 | chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; | |
318 | chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; | |
8efc0c15 | 319 | |
7368a6c8 | 320 | void |
321 | channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
8efc0c15 | 322 | { |
7368a6c8 | 323 | FD_SET(c->sock, readset); |
324 | } | |
5260325f | 325 | |
7368a6c8 | 326 | void |
327 | channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
328 | { | |
329 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
330 | FD_SET(c->sock, readset); | |
331 | if (buffer_len(&c->output) > 0) | |
332 | FD_SET(c->sock, writeset); | |
333 | } | |
5260325f | 334 | |
7368a6c8 | 335 | void |
336 | channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset) | |
337 | { | |
338 | /* test whether sockets are 'alive' for read/write */ | |
339 | if (c->istate == CHAN_INPUT_OPEN) | |
340 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
341 | FD_SET(c->sock, readset); | |
342 | if (c->ostate == CHAN_OUTPUT_OPEN || | |
343 | c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
344 | if (buffer_len(&c->output) > 0) { | |
345 | FD_SET(c->sock, writeset); | |
346 | } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
347 | chan_obuf_empty(c); | |
348 | } | |
349 | } | |
350 | } | |
5260325f | 351 | |
7e7327a1 | 352 | void |
353 | channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset) | |
354 | { | |
355 | if (c->istate == CHAN_INPUT_OPEN && | |
356 | c->remote_window > 0 && | |
357 | buffer_len(&c->input) < c->remote_window) | |
358 | FD_SET(c->rfd, readset); | |
359 | if (c->ostate == CHAN_OUTPUT_OPEN || | |
360 | c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
361 | if (buffer_len(&c->output) > 0) { | |
362 | FD_SET(c->wfd, writeset); | |
363 | } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
364 | chan_obuf_empty(c); | |
365 | } | |
366 | } | |
367 | /** XXX check close conditions, too */ | |
368 | if (c->efd != -1) { | |
369 | if (c->extended_usage == CHAN_EXTENDED_WRITE && | |
370 | buffer_len(&c->extended) > 0) | |
371 | FD_SET(c->efd, writeset); | |
372 | else if (c->extended_usage == CHAN_EXTENDED_READ && | |
373 | buffer_len(&c->extended) < c->remote_window) | |
374 | FD_SET(c->efd, readset); | |
375 | } | |
376 | } | |
377 | ||
7368a6c8 | 378 | void |
379 | channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
380 | { | |
381 | if (buffer_len(&c->input) == 0) { | |
382 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
383 | packet_put_int(c->remote_id); | |
384 | packet_send(); | |
385 | c->type = SSH_CHANNEL_CLOSED; | |
386 | debug("Closing channel %d after input drain.", c->self); | |
387 | } | |
388 | } | |
5260325f | 389 | |
7368a6c8 | 390 | void |
391 | channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
392 | { | |
393 | if (buffer_len(&c->output) == 0) | |
394 | channel_free(c->self); | |
6ae2364d | 395 | else |
7368a6c8 | 396 | FD_SET(c->sock, writeset); |
397 | } | |
5260325f | 398 | |
7368a6c8 | 399 | /* |
400 | * This is a special state for X11 authentication spoofing. An opened X11 | |
401 | * connection (when authentication spoofing is being done) remains in this | |
402 | * state until the first packet has been completely read. The authentication | |
403 | * data in that packet is then substituted by the real data if it matches the | |
404 | * fake data, and the channel is put into normal mode. | |
0b242b12 | 405 | * XXX All this happens at the client side. |
7368a6c8 | 406 | */ |
407 | int | |
408 | x11_open_helper(Channel *c) | |
409 | { | |
410 | unsigned char *ucp; | |
411 | unsigned int proto_len, data_len; | |
5260325f | 412 | |
7368a6c8 | 413 | /* Check if the fixed size part of the packet is in buffer. */ |
414 | if (buffer_len(&c->output) < 12) | |
415 | return 0; | |
416 | ||
417 | /* Parse the lengths of variable-length fields. */ | |
418 | ucp = (unsigned char *) buffer_ptr(&c->output); | |
419 | if (ucp[0] == 0x42) { /* Byte order MSB first. */ | |
420 | proto_len = 256 * ucp[6] + ucp[7]; | |
421 | data_len = 256 * ucp[8] + ucp[9]; | |
422 | } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ | |
423 | proto_len = ucp[6] + 256 * ucp[7]; | |
424 | data_len = ucp[8] + 256 * ucp[9]; | |
425 | } else { | |
426 | debug("Initial X11 packet contains bad byte order byte: 0x%x", | |
427 | ucp[0]); | |
428 | return -1; | |
429 | } | |
5260325f | 430 | |
7368a6c8 | 431 | /* Check if the whole packet is in buffer. */ |
432 | if (buffer_len(&c->output) < | |
433 | 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) | |
434 | return 0; | |
5260325f | 435 | |
7368a6c8 | 436 | /* Check if authentication protocol matches. */ |
437 | if (proto_len != strlen(x11_saved_proto) || | |
438 | memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { | |
439 | debug("X11 connection uses different authentication protocol."); | |
440 | return -1; | |
441 | } | |
442 | /* Check if authentication data matches our fake data. */ | |
443 | if (data_len != x11_fake_data_len || | |
444 | memcmp(ucp + 12 + ((proto_len + 3) & ~3), | |
445 | x11_fake_data, x11_fake_data_len) != 0) { | |
446 | debug("X11 auth data does not match fake data."); | |
447 | return -1; | |
448 | } | |
449 | /* Check fake data length */ | |
450 | if (x11_fake_data_len != x11_saved_data_len) { | |
451 | error("X11 fake_data_len %d != saved_data_len %d", | |
452 | x11_fake_data_len, x11_saved_data_len); | |
453 | return -1; | |
454 | } | |
455 | /* | |
456 | * Received authentication protocol and data match | |
457 | * our fake data. Substitute the fake data with real | |
458 | * data. | |
459 | */ | |
460 | memcpy(ucp + 12 + ((proto_len + 3) & ~3), | |
461 | x11_saved_data, x11_saved_data_len); | |
462 | return 1; | |
463 | } | |
5260325f | 464 | |
7368a6c8 | 465 | void |
466 | channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
467 | { | |
468 | int ret = x11_open_helper(c); | |
469 | if (ret == 1) { | |
470 | /* Start normal processing for the channel. */ | |
471 | c->type = SSH_CHANNEL_OPEN; | |
a8be9f80 | 472 | channel_pre_open_13(c, readset, writeset); |
7368a6c8 | 473 | } else if (ret == -1) { |
474 | /* | |
475 | * We have received an X11 connection that has bad | |
476 | * authentication information. | |
477 | */ | |
478 | log("X11 connection rejected because of wrong authentication.\r\n"); | |
479 | buffer_clear(&c->input); | |
480 | buffer_clear(&c->output); | |
481 | close(c->sock); | |
482 | c->sock = -1; | |
483 | c->type = SSH_CHANNEL_CLOSED; | |
484 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
485 | packet_put_int(c->remote_id); | |
486 | packet_send(); | |
487 | } | |
488 | } | |
5260325f | 489 | |
7368a6c8 | 490 | void |
0b242b12 | 491 | channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset) |
7368a6c8 | 492 | { |
493 | int ret = x11_open_helper(c); | |
494 | if (ret == 1) { | |
495 | c->type = SSH_CHANNEL_OPEN; | |
d0c832f3 | 496 | if (compat20) |
497 | channel_pre_open_20(c, readset, writeset); | |
498 | else | |
499 | channel_pre_open_15(c, readset, writeset); | |
7368a6c8 | 500 | } else if (ret == -1) { |
501 | debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); | |
0b242b12 | 502 | chan_read_failed(c); /** force close? */ |
7368a6c8 | 503 | chan_write_failed(c); |
504 | debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); | |
505 | } | |
506 | } | |
5260325f | 507 | |
7368a6c8 | 508 | /* This is our fake X11 server socket. */ |
509 | void | |
510 | channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
511 | { | |
512 | struct sockaddr addr; | |
513 | int newsock, newch; | |
514 | socklen_t addrlen; | |
515 | char buf[16384], *remote_hostname; | |
0b242b12 | 516 | int remote_port; |
7368a6c8 | 517 | |
518 | if (FD_ISSET(c->sock, readset)) { | |
519 | debug("X11 connection requested."); | |
520 | addrlen = sizeof(addr); | |
521 | newsock = accept(c->sock, &addr, &addrlen); | |
522 | if (newsock < 0) { | |
523 | error("accept: %.100s", strerror(errno)); | |
524 | return; | |
5260325f | 525 | } |
7368a6c8 | 526 | remote_hostname = get_remote_hostname(newsock); |
0b242b12 | 527 | remote_port = get_peer_port(newsock); |
7368a6c8 | 528 | snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", |
0b242b12 | 529 | remote_hostname, remote_port); |
530 | ||
531 | newch = channel_new("x11", | |
532 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
533 | c->local_window_max, c->local_maxpacket, | |
534 | 0, xstrdup(buf)); | |
535 | if (compat20) { | |
536 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
537 | packet_put_cstring("x11"); | |
538 | packet_put_int(newch); | |
539 | packet_put_int(c->local_window_max); | |
540 | packet_put_int(c->local_maxpacket); | |
541 | /* originator host and port */ | |
542 | packet_put_cstring(remote_hostname); | |
d0c832f3 | 543 | if (datafellows & SSH_BUG_X11FWD) { |
544 | debug("ssh2 x11 bug compat mode"); | |
545 | } else { | |
546 | packet_put_int(remote_port); | |
547 | } | |
0b242b12 | 548 | packet_send(); |
549 | } else { | |
550 | packet_start(SSH_SMSG_X11_OPEN); | |
551 | packet_put_int(newch); | |
552 | if (have_hostname_in_open) | |
553 | packet_put_string(buf, strlen(buf)); | |
554 | packet_send(); | |
555 | } | |
7368a6c8 | 556 | xfree(remote_hostname); |
8efc0c15 | 557 | } |
8efc0c15 | 558 | } |
559 | ||
aa3378df | 560 | /* |
7368a6c8 | 561 | * This socket is listening for connections to a forwarded TCP/IP port. |
aa3378df | 562 | */ |
7368a6c8 | 563 | void |
564 | channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
565 | { | |
566 | struct sockaddr addr; | |
567 | int newsock, newch; | |
568 | socklen_t addrlen; | |
569 | char buf[1024], *remote_hostname; | |
570 | int remote_port; | |
571 | ||
572 | if (FD_ISSET(c->sock, readset)) { | |
573 | debug("Connection to port %d forwarding " | |
574 | "to %.100s port %d requested.", | |
575 | c->listening_port, c->path, c->host_port); | |
576 | addrlen = sizeof(addr); | |
577 | newsock = accept(c->sock, &addr, &addrlen); | |
578 | if (newsock < 0) { | |
579 | error("accept: %.100s", strerror(errno)); | |
580 | return; | |
581 | } | |
582 | remote_hostname = get_remote_hostname(newsock); | |
583 | remote_port = get_peer_port(newsock); | |
584 | snprintf(buf, sizeof buf, | |
585 | "listen port %d for %.100s port %d, " | |
586 | "connect from %.200s port %d", | |
587 | c->listening_port, c->path, c->host_port, | |
588 | remote_hostname, remote_port); | |
589 | newch = channel_new("direct-tcpip", | |
590 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
591 | c->local_window_max, c->local_maxpacket, | |
592 | 0, xstrdup(buf)); | |
7e7327a1 | 593 | if (compat20) { |
594 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
595 | packet_put_cstring("direct-tcpip"); | |
596 | packet_put_int(newch); | |
597 | packet_put_int(c->local_window_max); | |
598 | packet_put_int(c->local_maxpacket); | |
6ae2364d | 599 | /* target host and port */ |
7e7327a1 | 600 | packet_put_string(c->path, strlen(c->path)); |
601 | packet_put_int(c->host_port); | |
6ae2364d | 602 | /* originator host and port */ |
7e7327a1 | 603 | packet_put_cstring(remote_hostname); |
604 | packet_put_int(remote_port); | |
605 | packet_send(); | |
606 | } else { | |
607 | packet_start(SSH_MSG_PORT_OPEN); | |
608 | packet_put_int(newch); | |
609 | packet_put_string(c->path, strlen(c->path)); | |
610 | packet_put_int(c->host_port); | |
611 | if (have_hostname_in_open) { | |
612 | packet_put_string(buf, strlen(buf)); | |
613 | } | |
614 | packet_send(); | |
7368a6c8 | 615 | } |
7368a6c8 | 616 | xfree(remote_hostname); |
617 | } | |
618 | } | |
8efc0c15 | 619 | |
7368a6c8 | 620 | /* |
621 | * This is the authentication agent socket listening for connections from | |
622 | * clients. | |
623 | */ | |
624 | void | |
625 | channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
8efc0c15 | 626 | { |
5260325f | 627 | struct sockaddr addr; |
7368a6c8 | 628 | int newsock, newch; |
48e671d5 | 629 | socklen_t addrlen; |
5260325f | 630 | |
7368a6c8 | 631 | if (FD_ISSET(c->sock, readset)) { |
632 | addrlen = sizeof(addr); | |
633 | newsock = accept(c->sock, &addr, &addrlen); | |
634 | if (newsock < 0) { | |
635 | error("accept from auth socket: %.100s", strerror(errno)); | |
636 | return; | |
637 | } | |
638 | newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, | |
639 | xstrdup("accepted auth socket")); | |
640 | packet_start(SSH_SMSG_AGENT_OPEN); | |
641 | packet_put_int(newch); | |
642 | packet_send(); | |
643 | } | |
644 | } | |
5260325f | 645 | |
7368a6c8 | 646 | int |
647 | channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) | |
648 | { | |
649 | char buf[16*1024]; | |
650 | int len; | |
651 | ||
652 | if (c->rfd != -1 && | |
653 | FD_ISSET(c->rfd, readset)) { | |
654 | len = read(c->rfd, buf, sizeof(buf)); | |
0fbe8c74 | 655 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) |
656 | return 1; | |
7368a6c8 | 657 | if (len <= 0) { |
0b242b12 | 658 | debug("channel %d: read<=0 rfd %d len %d", |
7368a6c8 | 659 | c->self, c->rfd, len); |
660 | if (compat13) { | |
661 | buffer_consume(&c->output, buffer_len(&c->output)); | |
662 | c->type = SSH_CHANNEL_INPUT_DRAINING; | |
663 | debug("Channel %d status set to input draining.", c->self); | |
664 | } else { | |
665 | chan_read_failed(c); | |
5260325f | 666 | } |
7368a6c8 | 667 | return -1; |
668 | } | |
2e73a022 | 669 | if(c->input_filter != NULL) { |
670 | if (c->input_filter(c, buf, len) == -1) { | |
671 | debug("filter stops channel %d", c->self); | |
672 | chan_read_failed(c); | |
673 | } | |
674 | } else { | |
675 | buffer_append(&c->input, buf, len); | |
676 | } | |
7368a6c8 | 677 | } |
678 | return 1; | |
679 | } | |
680 | int | |
681 | channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) | |
682 | { | |
683 | int len; | |
684 | ||
685 | /* Send buffered output data to the socket. */ | |
686 | if (c->wfd != -1 && | |
687 | FD_ISSET(c->wfd, writeset) && | |
688 | buffer_len(&c->output) > 0) { | |
689 | len = write(c->wfd, buffer_ptr(&c->output), | |
0fbe8c74 | 690 | buffer_len(&c->output)); |
691 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
692 | return 1; | |
7368a6c8 | 693 | if (len <= 0) { |
694 | if (compat13) { | |
695 | buffer_consume(&c->output, buffer_len(&c->output)); | |
696 | debug("Channel %d status set to input draining.", c->self); | |
697 | c->type = SSH_CHANNEL_INPUT_DRAINING; | |
698 | } else { | |
699 | chan_write_failed(c); | |
5260325f | 700 | } |
7368a6c8 | 701 | return -1; |
702 | } | |
703 | buffer_consume(&c->output, len); | |
7e7327a1 | 704 | if (compat20 && len > 0) { |
705 | c->local_consumed += len; | |
706 | } | |
707 | } | |
708 | return 1; | |
709 | } | |
710 | int | |
711 | channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) | |
712 | { | |
713 | char buf[16*1024]; | |
714 | int len; | |
715 | ||
8ce64345 | 716 | /** XXX handle drain efd, too */ |
7e7327a1 | 717 | if (c->efd != -1) { |
718 | if (c->extended_usage == CHAN_EXTENDED_WRITE && | |
719 | FD_ISSET(c->efd, writeset) && | |
720 | buffer_len(&c->extended) > 0) { | |
721 | len = write(c->efd, buffer_ptr(&c->extended), | |
722 | buffer_len(&c->extended)); | |
723 | debug("channel %d: written %d to efd %d", | |
724 | c->self, len, c->efd); | |
725 | if (len > 0) { | |
726 | buffer_consume(&c->extended, len); | |
727 | c->local_consumed += len; | |
728 | } | |
729 | } else if (c->extended_usage == CHAN_EXTENDED_READ && | |
730 | FD_ISSET(c->efd, readset)) { | |
731 | len = read(c->efd, buf, sizeof(buf)); | |
732 | debug("channel %d: read %d from efd %d", | |
733 | c->self, len, c->efd); | |
8ce64345 | 734 | if (len == 0) { |
735 | debug("channel %d: closing efd %d", | |
736 | c->self, c->efd); | |
737 | close(c->efd); | |
738 | c->efd = -1; | |
739 | } else if (len > 0) | |
7e7327a1 | 740 | buffer_append(&c->extended, buf, len); |
741 | } | |
742 | } | |
743 | return 1; | |
744 | } | |
745 | int | |
746 | channel_check_window(Channel *c, fd_set * readset, fd_set * writeset) | |
747 | { | |
e78a59f5 | 748 | if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) && |
7e7327a1 | 749 | c->local_window < c->local_window_max/2 && |
750 | c->local_consumed > 0) { | |
751 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); | |
752 | packet_put_int(c->remote_id); | |
753 | packet_put_int(c->local_consumed); | |
754 | packet_send(); | |
755 | debug("channel %d: window %d sent adjust %d", | |
756 | c->self, c->local_window, | |
757 | c->local_consumed); | |
758 | c->local_window += c->local_consumed; | |
759 | c->local_consumed = 0; | |
7368a6c8 | 760 | } |
761 | return 1; | |
762 | } | |
5260325f | 763 | |
7368a6c8 | 764 | void |
765 | channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset) | |
766 | { | |
767 | channel_handle_rfd(c, readset, writeset); | |
768 | channel_handle_wfd(c, readset, writeset); | |
769 | } | |
aa3378df | 770 | |
7e7327a1 | 771 | void |
772 | channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset) | |
773 | { | |
774 | channel_handle_rfd(c, readset, writeset); | |
775 | channel_handle_wfd(c, readset, writeset); | |
776 | channel_handle_efd(c, readset, writeset); | |
777 | channel_check_window(c, readset, writeset); | |
778 | } | |
779 | ||
7368a6c8 | 780 | void |
781 | channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) | |
782 | { | |
783 | int len; | |
784 | /* Send buffered output data to the socket. */ | |
785 | if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) { | |
786 | len = write(c->sock, buffer_ptr(&c->output), | |
787 | buffer_len(&c->output)); | |
788 | if (len <= 0) | |
789 | buffer_consume(&c->output, buffer_len(&c->output)); | |
790 | else | |
791 | buffer_consume(&c->output, len); | |
792 | } | |
793 | } | |
5260325f | 794 | |
7e7327a1 | 795 | void |
796 | channel_handler_init_20(void) | |
797 | { | |
798 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20; | |
0b242b12 | 799 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
7e7327a1 | 800 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; |
0b242b12 | 801 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; |
7e7327a1 | 802 | |
803 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2; | |
804 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
0b242b12 | 805 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; |
7e7327a1 | 806 | } |
807 | ||
7368a6c8 | 808 | void |
809 | channel_handler_init_13(void) | |
810 | { | |
811 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; | |
812 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13; | |
813 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
814 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
815 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
816 | channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining; | |
817 | channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining; | |
818 | ||
819 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; | |
820 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
821 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
822 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
823 | channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; | |
824 | } | |
5260325f | 825 | |
7368a6c8 | 826 | void |
827 | channel_handler_init_15(void) | |
828 | { | |
829 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15; | |
0b242b12 | 830 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
7368a6c8 | 831 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; |
832 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
833 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
834 | ||
835 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
836 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
837 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
838 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; | |
839 | } | |
840 | ||
841 | void | |
842 | channel_handler_init(void) | |
843 | { | |
844 | int i; | |
845 | for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { | |
846 | channel_pre[i] = NULL; | |
847 | channel_post[i] = NULL; | |
848 | } | |
7e7327a1 | 849 | if (compat20) |
850 | channel_handler_init_20(); | |
851 | else if (compat13) | |
7368a6c8 | 852 | channel_handler_init_13(); |
853 | else | |
854 | channel_handler_init_15(); | |
855 | } | |
856 | ||
6ae2364d | 857 | void |
7368a6c8 | 858 | channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) |
859 | { | |
860 | static int did_init = 0; | |
861 | int i; | |
862 | Channel *c; | |
863 | ||
864 | if (!did_init) { | |
865 | channel_handler_init(); | |
866 | did_init = 1; | |
867 | } | |
868 | for (i = 0; i < channels_alloc; i++) { | |
869 | c = &channels[i]; | |
870 | if (c->type == SSH_CHANNEL_FREE) | |
5260325f | 871 | continue; |
7368a6c8 | 872 | if (ftab[c->type] == NULL) |
873 | continue; | |
874 | (*ftab[c->type])(c, readset, writeset); | |
7e7327a1 | 875 | chan_delete_if_full_closed(c); |
8efc0c15 | 876 | } |
8efc0c15 | 877 | } |
878 | ||
6ae2364d | 879 | void |
7368a6c8 | 880 | channel_prepare_select(fd_set * readset, fd_set * writeset) |
881 | { | |
882 | channel_handler(channel_pre, readset, writeset); | |
883 | } | |
884 | ||
6ae2364d | 885 | void |
7368a6c8 | 886 | channel_after_select(fd_set * readset, fd_set * writeset) |
887 | { | |
888 | channel_handler(channel_post, readset, writeset); | |
889 | } | |
890 | ||
8efc0c15 | 891 | /* If there is data to send to the connection, send some of it now. */ |
892 | ||
6ae2364d | 893 | void |
5260325f | 894 | channel_output_poll() |
8efc0c15 | 895 | { |
5260325f | 896 | int len, i; |
7368a6c8 | 897 | Channel *c; |
5260325f | 898 | |
899 | for (i = 0; i < channels_alloc; i++) { | |
7368a6c8 | 900 | c = &channels[i]; |
48e671d5 | 901 | |
aa3378df | 902 | /* We are only interested in channels that can have buffered incoming data. */ |
48e671d5 | 903 | if (compat13) { |
7368a6c8 | 904 | if (c->type != SSH_CHANNEL_OPEN && |
905 | c->type != SSH_CHANNEL_INPUT_DRAINING) | |
48e671d5 | 906 | continue; |
907 | } else { | |
7368a6c8 | 908 | if (c->type != SSH_CHANNEL_OPEN) |
48e671d5 | 909 | continue; |
7368a6c8 | 910 | if (c->istate != CHAN_INPUT_OPEN && |
911 | c->istate != CHAN_INPUT_WAIT_DRAIN) | |
48e671d5 | 912 | continue; |
913 | } | |
e78a59f5 | 914 | if (compat20 && |
915 | (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) { | |
7e7327a1 | 916 | debug("channel: %d: no data after CLOSE", c->self); |
917 | continue; | |
918 | } | |
5260325f | 919 | |
920 | /* Get the amount of buffered data for this channel. */ | |
7368a6c8 | 921 | len = buffer_len(&c->input); |
5260325f | 922 | if (len > 0) { |
aa3378df | 923 | /* Send some data for the other side over the secure connection. */ |
7e7327a1 | 924 | if (compat20) { |
925 | if (len > c->remote_window) | |
926 | len = c->remote_window; | |
927 | if (len > c->remote_maxpacket) | |
928 | len = c->remote_maxpacket; | |
5260325f | 929 | } else { |
7e7327a1 | 930 | if (packet_is_interactive()) { |
931 | if (len > 1024) | |
932 | len = 512; | |
933 | } else { | |
934 | /* Keep the packets at reasonable size. */ | |
935 | if (len > packet_get_maxsize()/2) | |
936 | len = packet_get_maxsize()/2; | |
937 | } | |
5260325f | 938 | } |
7368a6c8 | 939 | if (len > 0) { |
7e7327a1 | 940 | packet_start(compat20 ? |
941 | SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); | |
7368a6c8 | 942 | packet_put_int(c->remote_id); |
943 | packet_put_string(buffer_ptr(&c->input), len); | |
944 | packet_send(); | |
945 | buffer_consume(&c->input, len); | |
946 | c->remote_window -= len; | |
7368a6c8 | 947 | } |
948 | } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) { | |
5260325f | 949 | if (compat13) |
950 | fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); | |
aa3378df | 951 | /* |
952 | * input-buffer is empty and read-socket shutdown: | |
953 | * tell peer, that we will not send more data: send IEOF | |
954 | */ | |
7368a6c8 | 955 | chan_ibuf_empty(c); |
5260325f | 956 | } |
7e7327a1 | 957 | /* Send extended data, i.e. stderr */ |
958 | if (compat20 && | |
959 | c->remote_window > 0 && | |
960 | (len = buffer_len(&c->extended)) > 0 && | |
961 | c->extended_usage == CHAN_EXTENDED_READ) { | |
962 | if (len > c->remote_window) | |
963 | len = c->remote_window; | |
964 | if (len > c->remote_maxpacket) | |
965 | len = c->remote_maxpacket; | |
966 | packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA); | |
967 | packet_put_int(c->remote_id); | |
968 | packet_put_int(SSH2_EXTENDED_DATA_STDERR); | |
969 | packet_put_string(buffer_ptr(&c->extended), len); | |
970 | packet_send(); | |
971 | buffer_consume(&c->extended, len); | |
972 | c->remote_window -= len; | |
973 | } | |
8efc0c15 | 974 | } |
8efc0c15 | 975 | } |
976 | ||
aa3378df | 977 | /* |
978 | * This is called when a packet of type CHANNEL_DATA has just been received. | |
979 | * The message type has already been consumed, but channel number and data is | |
980 | * still there. | |
981 | */ | |
8efc0c15 | 982 | |
6ae2364d | 983 | void |
7368a6c8 | 984 | channel_input_data(int type, int plen) |
8efc0c15 | 985 | { |
48e671d5 | 986 | int id; |
5260325f | 987 | char *data; |
988 | unsigned int data_len; | |
7368a6c8 | 989 | Channel *c; |
5260325f | 990 | |
991 | /* Get the channel number and verify it. */ | |
48e671d5 | 992 | id = packet_get_int(); |
7368a6c8 | 993 | c = channel_lookup(id); |
994 | if (c == NULL) | |
48e671d5 | 995 | packet_disconnect("Received data for nonexistent channel %d.", id); |
5260325f | 996 | |
997 | /* Ignore any data for non-open channels (might happen on close) */ | |
7368a6c8 | 998 | if (c->type != SSH_CHANNEL_OPEN && |
999 | c->type != SSH_CHANNEL_X11_OPEN) | |
48e671d5 | 1000 | return; |
1001 | ||
1002 | /* same for protocol 1.5 if output end is no longer open */ | |
7368a6c8 | 1003 | if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) |
5260325f | 1004 | return; |
1005 | ||
1006 | /* Get the data. */ | |
1007 | data = packet_get_string(&data_len); | |
6ae2364d | 1008 | packet_done(); |
7368a6c8 | 1009 | |
7e7327a1 | 1010 | if (compat20){ |
1011 | if (data_len > c->local_maxpacket) { | |
1012 | log("channel %d: rcvd big packet %d, maxpack %d", | |
1013 | c->self, data_len, c->local_maxpacket); | |
1014 | } | |
1015 | if (data_len > c->local_window) { | |
1016 | log("channel %d: rcvd too much data %d, win %d", | |
1017 | c->self, data_len, c->local_window); | |
1018 | xfree(data); | |
1019 | return; | |
1020 | } | |
1021 | c->local_window -= data_len; | |
1022 | }else{ | |
1023 | packet_integrity_check(plen, 4 + 4 + data_len, type); | |
1024 | } | |
7368a6c8 | 1025 | buffer_append(&c->output, data, data_len); |
5260325f | 1026 | xfree(data); |
8efc0c15 | 1027 | } |
6ae2364d | 1028 | void |
7e7327a1 | 1029 | channel_input_extended_data(int type, int plen) |
1030 | { | |
1031 | int id; | |
1032 | int tcode; | |
1033 | char *data; | |
1034 | unsigned int data_len; | |
1035 | Channel *c; | |
1036 | ||
1037 | /* Get the channel number and verify it. */ | |
1038 | id = packet_get_int(); | |
1039 | c = channel_lookup(id); | |
1040 | ||
1041 | if (c == NULL) | |
1042 | packet_disconnect("Received extended_data for bad channel %d.", id); | |
1043 | if (c->type != SSH_CHANNEL_OPEN) { | |
1044 | log("channel %d: ext data for non open", id); | |
1045 | return; | |
1046 | } | |
1047 | tcode = packet_get_int(); | |
1048 | if (c->efd == -1 || | |
1049 | c->extended_usage != CHAN_EXTENDED_WRITE || | |
1050 | tcode != SSH2_EXTENDED_DATA_STDERR) { | |
1051 | log("channel %d: bad ext data", c->self); | |
1052 | return; | |
1053 | } | |
1054 | data = packet_get_string(&data_len); | |
6ae2364d | 1055 | packet_done(); |
7e7327a1 | 1056 | if (data_len > c->local_window) { |
1057 | log("channel %d: rcvd too much extended_data %d, win %d", | |
1058 | c->self, data_len, c->local_window); | |
1059 | xfree(data); | |
1060 | return; | |
1061 | } | |
1062 | debug("channel %d: rcvd ext data %d", c->self, data_len); | |
1063 | c->local_window -= data_len; | |
1064 | buffer_append(&c->extended, data, data_len); | |
1065 | xfree(data); | |
1066 | } | |
1067 | ||
8efc0c15 | 1068 | |
aa3378df | 1069 | /* |
1070 | * Returns true if no channel has too much buffered data, and false if one or | |
1071 | * more channel is overfull. | |
1072 | */ | |
8efc0c15 | 1073 | |
6ae2364d | 1074 | int |
5260325f | 1075 | channel_not_very_much_buffered_data() |
8efc0c15 | 1076 | { |
5260325f | 1077 | unsigned int i; |
7368a6c8 | 1078 | Channel *c; |
5260325f | 1079 | |
1080 | for (i = 0; i < channels_alloc; i++) { | |
7368a6c8 | 1081 | c = &channels[i]; |
1082 | if (c->type == SSH_CHANNEL_OPEN) { | |
7e7327a1 | 1083 | if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) { |
7368a6c8 | 1084 | debug("channel %d: big input buffer %d", |
1085 | c->self, buffer_len(&c->input)); | |
5260325f | 1086 | return 0; |
7368a6c8 | 1087 | } |
1088 | if (buffer_len(&c->output) > packet_get_maxsize()) { | |
1089 | debug("channel %d: big output buffer %d", | |
1090 | c->self, buffer_len(&c->output)); | |
5260325f | 1091 | return 0; |
7368a6c8 | 1092 | } |
5260325f | 1093 | } |
8efc0c15 | 1094 | } |
5260325f | 1095 | return 1; |
8efc0c15 | 1096 | } |
1097 | ||
6ae2364d | 1098 | void |
7368a6c8 | 1099 | channel_input_ieof(int type, int plen) |
1100 | { | |
1101 | int id; | |
1102 | Channel *c; | |
1103 | ||
1104 | packet_integrity_check(plen, 4, type); | |
1105 | ||
1106 | id = packet_get_int(); | |
1107 | c = channel_lookup(id); | |
1108 | if (c == NULL) | |
1109 | packet_disconnect("Received ieof for nonexistent channel %d.", id); | |
1110 | chan_rcvd_ieof(c); | |
1111 | } | |
8efc0c15 | 1112 | |
6ae2364d | 1113 | void |
7368a6c8 | 1114 | channel_input_close(int type, int plen) |
8efc0c15 | 1115 | { |
7368a6c8 | 1116 | int id; |
1117 | Channel *c; | |
5260325f | 1118 | |
7368a6c8 | 1119 | packet_integrity_check(plen, 4, type); |
1120 | ||
1121 | id = packet_get_int(); | |
1122 | c = channel_lookup(id); | |
1123 | if (c == NULL) | |
1124 | packet_disconnect("Received close for nonexistent channel %d.", id); | |
aa3378df | 1125 | |
1126 | /* | |
1127 | * Send a confirmation that we have closed the channel and no more | |
1128 | * data is coming for it. | |
1129 | */ | |
5260325f | 1130 | packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); |
7368a6c8 | 1131 | packet_put_int(c->remote_id); |
5260325f | 1132 | packet_send(); |
1133 | ||
aa3378df | 1134 | /* |
1135 | * If the channel is in closed state, we have sent a close request, | |
1136 | * and the other side will eventually respond with a confirmation. | |
1137 | * Thus, we cannot free the channel here, because then there would be | |
1138 | * no-one to receive the confirmation. The channel gets freed when | |
1139 | * the confirmation arrives. | |
1140 | */ | |
7368a6c8 | 1141 | if (c->type != SSH_CHANNEL_CLOSED) { |
aa3378df | 1142 | /* |
1143 | * Not a closed channel - mark it as draining, which will | |
1144 | * cause it to be freed later. | |
1145 | */ | |
7368a6c8 | 1146 | buffer_consume(&c->input, buffer_len(&c->input)); |
1147 | c->type = SSH_CHANNEL_OUTPUT_DRAINING; | |
5260325f | 1148 | } |
8efc0c15 | 1149 | } |
1150 | ||
7368a6c8 | 1151 | /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ |
6ae2364d | 1152 | void |
7368a6c8 | 1153 | channel_input_oclose(int type, int plen) |
8efc0c15 | 1154 | { |
7368a6c8 | 1155 | int id = packet_get_int(); |
1156 | Channel *c = channel_lookup(id); | |
1157 | packet_integrity_check(plen, 4, type); | |
1158 | if (c == NULL) | |
1159 | packet_disconnect("Received oclose for nonexistent channel %d.", id); | |
1160 | chan_rcvd_oclose(c); | |
8efc0c15 | 1161 | } |
1162 | ||
6ae2364d | 1163 | void |
7368a6c8 | 1164 | channel_input_close_confirmation(int type, int plen) |
1165 | { | |
1166 | int id = packet_get_int(); | |
1167 | Channel *c = channel_lookup(id); | |
1168 | ||
6ae2364d | 1169 | packet_done(); |
7368a6c8 | 1170 | if (c == NULL) |
1171 | packet_disconnect("Received close confirmation for " | |
1172 | "out-of-range channel %d.", id); | |
1173 | if (c->type != SSH_CHANNEL_CLOSED) | |
1174 | packet_disconnect("Received close confirmation for " | |
1175 | "non-closed channel %d (type %d).", id, c->type); | |
1176 | channel_free(c->self); | |
1177 | } | |
8efc0c15 | 1178 | |
6ae2364d | 1179 | void |
7368a6c8 | 1180 | channel_input_open_confirmation(int type, int plen) |
8efc0c15 | 1181 | { |
7368a6c8 | 1182 | int id, remote_id; |
1183 | Channel *c; | |
5260325f | 1184 | |
7e7327a1 | 1185 | if (!compat20) |
1186 | packet_integrity_check(plen, 4 + 4, type); | |
5260325f | 1187 | |
7368a6c8 | 1188 | id = packet_get_int(); |
1189 | c = channel_lookup(id); | |
5260325f | 1190 | |
7368a6c8 | 1191 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) |
1192 | packet_disconnect("Received open confirmation for " | |
1193 | "non-opening channel %d.", id); | |
1194 | remote_id = packet_get_int(); | |
aa3378df | 1195 | /* Record the remote channel number and mark that the channel is now open. */ |
7368a6c8 | 1196 | c->remote_id = remote_id; |
1197 | c->type = SSH_CHANNEL_OPEN; | |
7e7327a1 | 1198 | |
1199 | if (compat20) { | |
1200 | c->remote_window = packet_get_int(); | |
1201 | c->remote_maxpacket = packet_get_int(); | |
6ae2364d | 1202 | packet_done(); |
7e7327a1 | 1203 | if (c->cb_fn != NULL && c->cb_event == type) { |
1204 | debug("callback start"); | |
1205 | c->cb_fn(c->self, c->cb_arg); | |
1206 | debug("callback done"); | |
1207 | } | |
1208 | debug("channel %d: open confirm rwindow %d rmax %d", c->self, | |
1209 | c->remote_window, c->remote_maxpacket); | |
1210 | } | |
8efc0c15 | 1211 | } |
1212 | ||
6ae2364d | 1213 | void |
7368a6c8 | 1214 | channel_input_open_failure(int type, int plen) |
8efc0c15 | 1215 | { |
7368a6c8 | 1216 | int id; |
1217 | Channel *c; | |
5260325f | 1218 | |
7e7327a1 | 1219 | if (!compat20) |
1220 | packet_integrity_check(plen, 4, type); | |
7368a6c8 | 1221 | |
1222 | id = packet_get_int(); | |
1223 | c = channel_lookup(id); | |
1224 | ||
1225 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
1226 | packet_disconnect("Received open failure for " | |
1227 | "non-opening channel %d.", id); | |
7e7327a1 | 1228 | if (compat20) { |
1229 | int reason = packet_get_int(); | |
1230 | char *msg = packet_get_string(NULL); | |
6ae2364d | 1231 | char *lang = packet_get_string(NULL); |
7e7327a1 | 1232 | log("channel_open_failure: %d: reason %d: %s", id, reason, msg); |
6ae2364d | 1233 | packet_done(); |
7e7327a1 | 1234 | xfree(msg); |
6ae2364d | 1235 | xfree(lang); |
7e7327a1 | 1236 | } |
5260325f | 1237 | /* Free the channel. This will also close the socket. */ |
7368a6c8 | 1238 | channel_free(id); |
8efc0c15 | 1239 | } |
1240 | ||
7e7327a1 | 1241 | void |
1242 | channel_input_channel_request(int type, int plen) | |
1243 | { | |
1244 | int id; | |
1245 | Channel *c; | |
1246 | ||
1247 | id = packet_get_int(); | |
1248 | c = channel_lookup(id); | |
1249 | ||
1250 | if (c == NULL || | |
1251 | (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL)) | |
1252 | packet_disconnect("Received request for " | |
1253 | "non-open channel %d.", id); | |
1254 | if (c->cb_fn != NULL && c->cb_event == type) { | |
1255 | debug("callback start"); | |
1256 | c->cb_fn(c->self, c->cb_arg); | |
1257 | debug("callback done"); | |
1258 | } else { | |
1259 | char *service = packet_get_string(NULL); | |
1260 | debug("channel: %d rcvd request for %s", c->self, service); | |
1261 | debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event); | |
1262 | xfree(service); | |
1263 | } | |
1264 | } | |
1265 | ||
6ae2364d | 1266 | void |
7e7327a1 | 1267 | channel_input_window_adjust(int type, int plen) |
1268 | { | |
1269 | Channel *c; | |
1270 | int id, adjust; | |
1271 | ||
1272 | if (!compat20) | |
1273 | return; | |
1274 | ||
1275 | /* Get the channel number and verify it. */ | |
1276 | id = packet_get_int(); | |
1277 | c = channel_lookup(id); | |
1278 | ||
1279 | if (c == NULL || c->type != SSH_CHANNEL_OPEN) { | |
1280 | log("Received window adjust for " | |
1281 | "non-open channel %d.", id); | |
1282 | return; | |
1283 | } | |
1284 | adjust = packet_get_int(); | |
6ae2364d | 1285 | packet_done(); |
7e7327a1 | 1286 | debug("channel %d: rcvd adjust %d", id, adjust); |
1287 | c->remote_window += adjust; | |
1288 | } | |
1289 | ||
aa3378df | 1290 | /* |
1291 | * Stops listening for channels, and removes any unix domain sockets that we | |
1292 | * might have. | |
1293 | */ | |
8efc0c15 | 1294 | |
6ae2364d | 1295 | void |
5260325f | 1296 | channel_stop_listening() |
8efc0c15 | 1297 | { |
5260325f | 1298 | int i; |
1299 | for (i = 0; i < channels_alloc; i++) { | |
1300 | switch (channels[i].type) { | |
1301 | case SSH_CHANNEL_AUTH_SOCKET: | |
1302 | close(channels[i].sock); | |
1303 | remove(channels[i].path); | |
1304 | channel_free(i); | |
1305 | break; | |
1306 | case SSH_CHANNEL_PORT_LISTENER: | |
1307 | case SSH_CHANNEL_X11_LISTENER: | |
1308 | close(channels[i].sock); | |
1309 | channel_free(i); | |
1310 | break; | |
1311 | default: | |
1312 | break; | |
1313 | } | |
8efc0c15 | 1314 | } |
8efc0c15 | 1315 | } |
1316 | ||
aa3378df | 1317 | /* |
0fbe8c74 | 1318 | * Closes the sockets/fds of all channels. This is used to close extra file |
aa3378df | 1319 | * descriptors after a fork. |
1320 | */ | |
8efc0c15 | 1321 | |
6ae2364d | 1322 | void |
5260325f | 1323 | channel_close_all() |
8efc0c15 | 1324 | { |
5260325f | 1325 | int i; |
0fbe8c74 | 1326 | for (i = 0; i < channels_alloc; i++) |
5260325f | 1327 | if (channels[i].type != SSH_CHANNEL_FREE) |
0fbe8c74 | 1328 | channel_close_fds(&channels[i]); |
8efc0c15 | 1329 | } |
1330 | ||
1331 | /* Returns the maximum file descriptor number used by the channels. */ | |
1332 | ||
6ae2364d | 1333 | int |
5260325f | 1334 | channel_max_fd() |
8efc0c15 | 1335 | { |
5260325f | 1336 | return channel_max_fd_value; |
8efc0c15 | 1337 | } |
1338 | ||
1339 | /* Returns true if any channel is still open. */ | |
1340 | ||
6ae2364d | 1341 | int |
5260325f | 1342 | channel_still_open() |
8efc0c15 | 1343 | { |
5260325f | 1344 | unsigned int i; |
1345 | for (i = 0; i < channels_alloc; i++) | |
1346 | switch (channels[i].type) { | |
1347 | case SSH_CHANNEL_FREE: | |
1348 | case SSH_CHANNEL_X11_LISTENER: | |
1349 | case SSH_CHANNEL_PORT_LISTENER: | |
1350 | case SSH_CHANNEL_CLOSED: | |
1351 | case SSH_CHANNEL_AUTH_SOCKET: | |
1352 | continue; | |
7e7327a1 | 1353 | case SSH_CHANNEL_LARVAL: |
1354 | if (!compat20) | |
1355 | fatal("cannot happen: SSH_CHANNEL_LARVAL"); | |
1356 | continue; | |
5260325f | 1357 | case SSH_CHANNEL_OPENING: |
1358 | case SSH_CHANNEL_OPEN: | |
1359 | case SSH_CHANNEL_X11_OPEN: | |
1360 | return 1; | |
1361 | case SSH_CHANNEL_INPUT_DRAINING: | |
1362 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
1363 | if (!compat13) | |
1364 | fatal("cannot happen: OUT_DRAIN"); | |
1365 | return 1; | |
1366 | default: | |
1367 | fatal("channel_still_open: bad channel type %d", channels[i].type); | |
1368 | /* NOTREACHED */ | |
1369 | } | |
1370 | return 0; | |
8efc0c15 | 1371 | } |
1372 | ||
aa3378df | 1373 | /* |
1374 | * Returns a message describing the currently open forwarded connections, | |
1375 | * suitable for sending to the client. The message contains crlf pairs for | |
1376 | * newlines. | |
1377 | */ | |
8efc0c15 | 1378 | |
5260325f | 1379 | char * |
1380 | channel_open_message() | |
8efc0c15 | 1381 | { |
5260325f | 1382 | Buffer buffer; |
1383 | int i; | |
1384 | char buf[512], *cp; | |
1385 | ||
1386 | buffer_init(&buffer); | |
1387 | snprintf(buf, sizeof buf, "The following connections are open:\r\n"); | |
8efc0c15 | 1388 | buffer_append(&buffer, buf, strlen(buf)); |
5260325f | 1389 | for (i = 0; i < channels_alloc; i++) { |
1390 | Channel *c = &channels[i]; | |
1391 | switch (c->type) { | |
1392 | case SSH_CHANNEL_FREE: | |
1393 | case SSH_CHANNEL_X11_LISTENER: | |
1394 | case SSH_CHANNEL_PORT_LISTENER: | |
1395 | case SSH_CHANNEL_CLOSED: | |
1396 | case SSH_CHANNEL_AUTH_SOCKET: | |
1397 | continue; | |
7e7327a1 | 1398 | case SSH_CHANNEL_LARVAL: |
5260325f | 1399 | case SSH_CHANNEL_OPENING: |
1400 | case SSH_CHANNEL_OPEN: | |
1401 | case SSH_CHANNEL_X11_OPEN: | |
1402 | case SSH_CHANNEL_INPUT_DRAINING: | |
1403 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
7368a6c8 | 1404 | snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n", |
48e671d5 | 1405 | c->self, c->remote_name, |
1406 | c->type, c->remote_id, | |
1407 | c->istate, buffer_len(&c->input), | |
7368a6c8 | 1408 | c->ostate, buffer_len(&c->output), |
1409 | c->rfd, c->wfd); | |
5260325f | 1410 | buffer_append(&buffer, buf, strlen(buf)); |
1411 | continue; | |
1412 | default: | |
7368a6c8 | 1413 | fatal("channel_open_message: bad channel type %d", c->type); |
5260325f | 1414 | /* NOTREACHED */ |
1415 | } | |
1416 | } | |
1417 | buffer_append(&buffer, "\0", 1); | |
1418 | cp = xstrdup(buffer_ptr(&buffer)); | |
1419 | buffer_free(&buffer); | |
1420 | return cp; | |
8efc0c15 | 1421 | } |
1422 | ||
aa3378df | 1423 | /* |
1424 | * Initiate forwarding of connections to local port "port" through the secure | |
1425 | * channel to host:port from remote side. | |
1426 | */ | |
8efc0c15 | 1427 | |
6ae2364d | 1428 | void |
57112b5a | 1429 | channel_request_local_forwarding(u_short port, const char *host, |
95f1eccc | 1430 | u_short host_port, int gateway_ports) |
8efc0c15 | 1431 | { |
48e671d5 | 1432 | int success, ch, sock, on = 1; |
1433 | struct addrinfo hints, *ai, *aitop; | |
1434 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
aa3378df | 1435 | struct linger linger; |
5260325f | 1436 | |
1437 | if (strlen(host) > sizeof(channels[0].path) - 1) | |
1438 | packet_disconnect("Forward host name too long."); | |
1439 | ||
aa3378df | 1440 | /* |
48e671d5 | 1441 | * getaddrinfo returns a loopback address if the hostname is |
1442 | * set to NULL and hints.ai_flags is not AI_PASSIVE | |
aa3378df | 1443 | */ |
48e671d5 | 1444 | memset(&hints, 0, sizeof(hints)); |
1445 | hints.ai_family = IPv4or6; | |
1446 | hints.ai_flags = gateway_ports ? AI_PASSIVE : 0; | |
1447 | hints.ai_socktype = SOCK_STREAM; | |
1448 | snprintf(strport, sizeof strport, "%d", port); | |
1449 | if (getaddrinfo(NULL, strport, &hints, &aitop) != 0) | |
1450 | packet_disconnect("getaddrinfo: fatal error"); | |
1451 | ||
1452 | success = 0; | |
1453 | for (ai = aitop; ai; ai = ai->ai_next) { | |
1454 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1455 | continue; | |
1456 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
1457 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
1458 | error("channel_request_local_forwarding: getnameinfo failed"); | |
1459 | continue; | |
1460 | } | |
1461 | /* Create a port to listen for the host. */ | |
1462 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1463 | if (sock < 0) { | |
1464 | /* this is no error since kernel may not support ipv6 */ | |
1465 | verbose("socket: %.100s", strerror(errno)); | |
1466 | continue; | |
1467 | } | |
1468 | /* | |
1469 | * Set socket options. We would like the socket to disappear | |
1470 | * as soon as it has been closed for whatever reason. | |
1471 | */ | |
1472 | setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); | |
1473 | linger.l_onoff = 1; | |
1474 | linger.l_linger = 5; | |
1475 | setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger)); | |
1476 | debug("Local forwarding listening on %s port %s.", ntop, strport); | |
1477 | ||
1478 | /* Bind the socket to the address. */ | |
1479 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1480 | /* address can be in use ipv6 address is already bound */ | |
16218745 | 1481 | if (!ai->ai_next) |
1482 | error("bind: %.100s", strerror(errno)); | |
1483 | else | |
1484 | verbose("bind: %.100s", strerror(errno)); | |
1485 | ||
48e671d5 | 1486 | close(sock); |
1487 | continue; | |
1488 | } | |
1489 | /* Start listening for connections on the socket. */ | |
1490 | if (listen(sock, 5) < 0) { | |
1491 | error("listen: %.100s", strerror(errno)); | |
1492 | close(sock); | |
1493 | continue; | |
1494 | } | |
1495 | /* Allocate a channel number for the socket. */ | |
7368a6c8 | 1496 | ch = channel_new( |
1497 | "port listener", SSH_CHANNEL_PORT_LISTENER, | |
1498 | sock, sock, -1, | |
0b242b12 | 1499 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, |
7368a6c8 | 1500 | 0, xstrdup("port listener")); |
48e671d5 | 1501 | strlcpy(channels[ch].path, host, sizeof(channels[ch].path)); |
1502 | channels[ch].host_port = host_port; | |
1503 | channels[ch].listening_port = port; | |
1504 | success = 1; | |
1505 | } | |
1506 | if (success == 0) | |
1507 | packet_disconnect("cannot listen port: %d", port); | |
1508 | freeaddrinfo(aitop); | |
5260325f | 1509 | } |
8efc0c15 | 1510 | |
aa3378df | 1511 | /* |
1512 | * Initiate forwarding of connections to port "port" on remote host through | |
1513 | * the secure channel to host:port from local side. | |
1514 | */ | |
8efc0c15 | 1515 | |
6ae2364d | 1516 | void |
7368a6c8 | 1517 | channel_request_remote_forwarding(u_short listen_port, const char *host_to_connect, |
1518 | u_short port_to_connect) | |
8efc0c15 | 1519 | { |
5260325f | 1520 | int payload_len; |
1521 | /* Record locally that connection to this host/port is permitted. */ | |
1522 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
1523 | fatal("channel_request_remote_forwarding: too many forwards"); | |
1524 | ||
7368a6c8 | 1525 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect); |
1526 | permitted_opens[num_permitted_opens].port_to_connect = port_to_connect; | |
1527 | permitted_opens[num_permitted_opens].listen_port = listen_port; | |
5260325f | 1528 | num_permitted_opens++; |
1529 | ||
1530 | /* Send the forward request to the remote side. */ | |
7e7327a1 | 1531 | if (compat20) { |
1532 | const char *address_to_bind = "0.0.0.0"; | |
1533 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
1534 | packet_put_cstring("tcpip-forward"); | |
1535 | packet_put_char(0); /* boolean: want reply */ | |
1536 | packet_put_cstring(address_to_bind); | |
1537 | packet_put_int(listen_port); | |
1538 | } else { | |
1539 | packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); | |
7e7327a1 | 1540 | packet_put_int(listen_port); |
d6f24e45 | 1541 | packet_put_cstring(host_to_connect); |
1542 | packet_put_int(port_to_connect); | |
7e7327a1 | 1543 | packet_send(); |
1544 | packet_write_wait(); | |
1545 | /* | |
1546 | * Wait for response from the remote side. It will send a disconnect | |
1547 | * message on failure, and we will never see it here. | |
1548 | */ | |
1549 | packet_read_expect(&payload_len, SSH_SMSG_SUCCESS); | |
1550 | } | |
8efc0c15 | 1551 | } |
1552 | ||
aa3378df | 1553 | /* |
1554 | * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates | |
1555 | * listening for the port, and sends back a success reply (or disconnect | |
1556 | * message if there was an error). This never returns if there was an error. | |
1557 | */ | |
8efc0c15 | 1558 | |
6ae2364d | 1559 | void |
1d1ffb87 | 1560 | channel_input_port_forward_request(int is_root, int gateway_ports) |
8efc0c15 | 1561 | { |
57112b5a | 1562 | u_short port, host_port; |
5260325f | 1563 | char *hostname; |
1564 | ||
1565 | /* Get arguments from the packet. */ | |
1566 | port = packet_get_int(); | |
1567 | hostname = packet_get_string(NULL); | |
1568 | host_port = packet_get_int(); | |
1569 | ||
3c62e7eb | 1570 | #ifndef HAVE_CYGWIN |
aa3378df | 1571 | /* |
1572 | * Check that an unprivileged user is not trying to forward a | |
1573 | * privileged port. | |
1574 | */ | |
5260325f | 1575 | if (port < IPPORT_RESERVED && !is_root) |
1576 | packet_disconnect("Requested forwarding of port %d but user is not root.", | |
1577 | port); | |
3c62e7eb | 1578 | #endif |
95f1eccc | 1579 | /* |
1580 | * Initiate forwarding, | |
95f1eccc | 1581 | */ |
1d1ffb87 | 1582 | channel_request_local_forwarding(port, hostname, host_port, gateway_ports); |
5260325f | 1583 | |
1584 | /* Free the argument string. */ | |
1585 | xfree(hostname); | |
8efc0c15 | 1586 | } |
1587 | ||
7368a6c8 | 1588 | /* XXX move to aux.c */ |
1589 | int | |
1590 | channel_connect_to(const char *host, u_short host_port) | |
8efc0c15 | 1591 | { |
48e671d5 | 1592 | struct addrinfo hints, *ai, *aitop; |
1593 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
1594 | int gaierr; | |
7368a6c8 | 1595 | int sock = -1; |
48e671d5 | 1596 | |
1597 | memset(&hints, 0, sizeof(hints)); | |
1598 | hints.ai_family = IPv4or6; | |
1599 | hints.ai_socktype = SOCK_STREAM; | |
1600 | snprintf(strport, sizeof strport, "%d", host_port); | |
1601 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { | |
1602 | error("%.100s: unknown host (%s)", host, gai_strerror(gaierr)); | |
7368a6c8 | 1603 | return -1; |
48e671d5 | 1604 | } |
48e671d5 | 1605 | for (ai = aitop; ai; ai = ai->ai_next) { |
1606 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1607 | continue; | |
1608 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
1609 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
7368a6c8 | 1610 | error("channel_connect_to: getnameinfo failed"); |
48e671d5 | 1611 | continue; |
5260325f | 1612 | } |
48e671d5 | 1613 | /* Create the socket. */ |
1614 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1615 | if (sock < 0) { | |
1616 | error("socket: %.100s", strerror(errno)); | |
1617 | continue; | |
5260325f | 1618 | } |
48e671d5 | 1619 | /* Connect to the host/port. */ |
1620 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1621 | error("connect %.100s port %s: %.100s", ntop, strport, | |
1622 | strerror(errno)); | |
1623 | close(sock); | |
1624 | continue; /* fail -- try next */ | |
1625 | } | |
1626 | break; /* success */ | |
5260325f | 1627 | |
5260325f | 1628 | } |
48e671d5 | 1629 | freeaddrinfo(aitop); |
48e671d5 | 1630 | if (!ai) { |
1631 | error("connect %.100s port %d: failed.", host, host_port); | |
7368a6c8 | 1632 | return -1; |
8efc0c15 | 1633 | } |
7368a6c8 | 1634 | /* success */ |
1635 | return sock; | |
1636 | } | |
48e671d5 | 1637 | |
7368a6c8 | 1638 | /* |
1639 | * This is called after receiving PORT_OPEN message. This attempts to | |
1640 | * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION | |
1641 | * or CHANNEL_OPEN_FAILURE. | |
1642 | */ | |
5260325f | 1643 | |
6ae2364d | 1644 | void |
7368a6c8 | 1645 | channel_input_port_open(int type, int plen) |
1646 | { | |
1647 | u_short host_port; | |
1648 | char *host, *originator_string; | |
1649 | int remote_channel, sock = -1, newch, i, denied; | |
1650 | unsigned int host_len, originator_len; | |
5260325f | 1651 | |
7368a6c8 | 1652 | /* Get remote channel number. */ |
1653 | remote_channel = packet_get_int(); | |
5260325f | 1654 | |
7368a6c8 | 1655 | /* Get host name to connect to. */ |
1656 | host = packet_get_string(&host_len); | |
5260325f | 1657 | |
7368a6c8 | 1658 | /* Get port to connect to. */ |
1659 | host_port = packet_get_int(); | |
5260325f | 1660 | |
7368a6c8 | 1661 | /* Get remote originator name. */ |
1662 | if (have_hostname_in_open) { | |
1663 | originator_string = packet_get_string(&originator_len); | |
1664 | originator_len += 4; /* size of packet_int */ | |
1665 | } else { | |
1666 | originator_string = xstrdup("unknown (remote did not supply name)"); | |
1667 | originator_len = 0; /* no originator supplied */ | |
1668 | } | |
5260325f | 1669 | |
7368a6c8 | 1670 | packet_integrity_check(plen, |
1671 | 4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN); | |
1672 | ||
1673 | /* Check if opening that port is permitted. */ | |
1674 | denied = 0; | |
1675 | if (!all_opens_permitted) { | |
1676 | /* Go trough all permitted ports. */ | |
1677 | for (i = 0; i < num_permitted_opens; i++) | |
1678 | if (permitted_opens[i].port_to_connect == host_port && | |
1679 | strcmp(permitted_opens[i].host_to_connect, host) == 0) | |
1680 | break; | |
1681 | ||
1682 | /* Check if we found the requested port among those permitted. */ | |
1683 | if (i >= num_permitted_opens) { | |
1684 | /* The port is not permitted. */ | |
1685 | log("Received request to connect to %.100s:%d, but the request was denied.", | |
1686 | host, host_port); | |
1687 | denied = 1; | |
1688 | } | |
1689 | } | |
1690 | sock = denied ? -1 : channel_connect_to(host, host_port); | |
1691 | if (sock > 0) { | |
1692 | /* Allocate a channel for this connection. */ | |
1693 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string); | |
1694 | channels[newch].remote_id = remote_channel; | |
1695 | ||
1696 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1697 | packet_put_int(remote_channel); | |
1698 | packet_put_int(newch); | |
1699 | packet_send(); | |
1700 | } else { | |
1701 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1702 | packet_put_int(remote_channel); | |
1703 | packet_send(); | |
1704 | } | |
1705 | xfree(host); | |
8efc0c15 | 1706 | } |
1707 | ||
aa3378df | 1708 | /* |
1709 | * Creates an internet domain socket for listening for X11 connections. | |
1710 | * Returns a suitable value for the DISPLAY variable, or NULL if an error | |
1711 | * occurs. | |
1712 | */ | |
8efc0c15 | 1713 | |
48e671d5 | 1714 | #define NUM_SOCKS 10 |
1715 | ||
5260325f | 1716 | char * |
95f1eccc | 1717 | x11_create_display_inet(int screen_number, int x11_display_offset) |
8efc0c15 | 1718 | { |
57112b5a | 1719 | int display_number, sock; |
1720 | u_short port; | |
48e671d5 | 1721 | struct addrinfo hints, *ai, *aitop; |
1722 | char strport[NI_MAXSERV]; | |
1723 | int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; | |
1724 | char display[512]; | |
5260325f | 1725 | char hostname[MAXHOSTNAMELEN]; |
1726 | ||
95f1eccc | 1727 | for (display_number = x11_display_offset; |
5260325f | 1728 | display_number < MAX_DISPLAYS; |
1729 | display_number++) { | |
1730 | port = 6000 + display_number; | |
48e671d5 | 1731 | memset(&hints, 0, sizeof(hints)); |
1732 | hints.ai_family = IPv4or6; | |
1733 | hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */ | |
1734 | hints.ai_socktype = SOCK_STREAM; | |
1735 | snprintf(strport, sizeof strport, "%d", port); | |
1736 | if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { | |
1737 | error("getaddrinfo: %.100s", gai_strerror(gaierr)); | |
5260325f | 1738 | return NULL; |
1739 | } | |
48e671d5 | 1740 | for (ai = aitop; ai; ai = ai->ai_next) { |
1741 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1742 | continue; | |
1743 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1744 | if (sock < 0) { | |
80a44451 | 1745 | if (errno != EINVAL) { |
1746 | error("socket: %.100s", strerror(errno)); | |
1747 | return NULL; | |
1748 | } else { | |
1749 | debug("Socket family %d not supported [X11 disp create]", ai->ai_family); | |
1750 | continue; | |
1751 | } | |
48e671d5 | 1752 | } |
1753 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1754 | debug("bind port %d: %.100s", port, strerror(errno)); | |
1755 | shutdown(sock, SHUT_RDWR); | |
1756 | close(sock); | |
16218745 | 1757 | |
1758 | if (ai->ai_next) | |
1759 | continue; | |
1760 | ||
48e671d5 | 1761 | for (n = 0; n < num_socks; n++) { |
1762 | shutdown(socks[n], SHUT_RDWR); | |
1763 | close(socks[n]); | |
1764 | } | |
1765 | num_socks = 0; | |
1766 | break; | |
1767 | } | |
1768 | socks[num_socks++] = sock; | |
80faa19f | 1769 | #ifndef DONT_TRY_OTHER_AF |
48e671d5 | 1770 | if (num_socks == NUM_SOCKS) |
1771 | break; | |
80faa19f | 1772 | #else |
1773 | break; | |
1774 | #endif | |
5260325f | 1775 | } |
48e671d5 | 1776 | if (num_socks > 0) |
1777 | break; | |
5260325f | 1778 | } |
1779 | if (display_number >= MAX_DISPLAYS) { | |
1780 | error("Failed to allocate internet-domain X11 display socket."); | |
1781 | return NULL; | |
8efc0c15 | 1782 | } |
5260325f | 1783 | /* Start listening for connections on the socket. */ |
48e671d5 | 1784 | for (n = 0; n < num_socks; n++) { |
1785 | sock = socks[n]; | |
1786 | if (listen(sock, 5) < 0) { | |
1787 | error("listen: %.100s", strerror(errno)); | |
1788 | shutdown(sock, SHUT_RDWR); | |
1789 | close(sock); | |
1790 | return NULL; | |
1791 | } | |
8efc0c15 | 1792 | } |
48e671d5 | 1793 | |
5260325f | 1794 | /* Set up a suitable value for the DISPLAY variable. */ |
a7effaac | 1795 | |
5260325f | 1796 | if (gethostname(hostname, sizeof(hostname)) < 0) |
1797 | fatal("gethostname: %.100s", strerror(errno)); | |
a7effaac | 1798 | |
1799 | #ifdef IPADDR_IN_DISPLAY | |
1800 | /* | |
1801 | * HPUX detects the local hostname in the DISPLAY variable and tries | |
1802 | * to set up a shared memory connection to the server, which it | |
1803 | * incorrectly supposes to be local. | |
1804 | * | |
1805 | * The workaround - as used in later $$H and other programs - is | |
1806 | * is to set display to the host's IP address. | |
1807 | */ | |
1808 | { | |
1809 | struct hostent *he; | |
1810 | struct in_addr my_addr; | |
1811 | ||
1812 | he = gethostbyname(hostname); | |
1813 | if (he == NULL) { | |
1814 | error("[X11-broken-fwd-hostname-workaround] Could not get " | |
1815 | "IP address for hostname %s.", hostname); | |
1816 | ||
1817 | packet_send_debug("[X11-broken-fwd-hostname-workaround]" | |
1818 | "Could not get IP address for hostname %s.", hostname); | |
1819 | ||
1820 | shutdown(sock, SHUT_RDWR); | |
1821 | close(sock); | |
1822 | ||
1823 | return NULL; | |
1824 | } | |
1825 | ||
1826 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
1827 | ||
1828 | /* Set DISPLAY to <ip address>:screen.display */ | |
48e671d5 | 1829 | snprintf(display, sizeof(display), "%.50s:%d.%d", inet_ntoa(my_addr), |
a7effaac | 1830 | display_number, screen_number); |
1831 | } | |
1832 | #else /* IPADDR_IN_DISPLAY */ | |
1833 | /* Just set DISPLAY to hostname:screen.display */ | |
48e671d5 | 1834 | snprintf(display, sizeof display, "%.400s:%d.%d", hostname, |
a7effaac | 1835 | display_number, screen_number); |
1836 | #endif /* IPADDR_IN_DISPLAY */ | |
5260325f | 1837 | |
48e671d5 | 1838 | /* Allocate a channel for each socket. */ |
1839 | for (n = 0; n < num_socks; n++) { | |
1840 | sock = socks[n]; | |
0b242b12 | 1841 | (void) channel_new("x11 listener", |
1842 | SSH_CHANNEL_X11_LISTENER, sock, sock, -1, | |
1843 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
1844 | 0, xstrdup("X11 inet listener")); | |
48e671d5 | 1845 | } |
5260325f | 1846 | |
1847 | /* Return a suitable value for the DISPLAY environment variable. */ | |
48e671d5 | 1848 | return xstrdup(display); |
8efc0c15 | 1849 | } |
1850 | ||
1851 | #ifndef X_UNIX_PATH | |
1852 | #define X_UNIX_PATH "/tmp/.X11-unix/X" | |
1853 | #endif | |
1854 | ||
1855 | static | |
1856 | int | |
2f450969 | 1857 | connect_local_xsocket(unsigned int dnr) |
8efc0c15 | 1858 | { |
5260325f | 1859 | static const char *const x_sockets[] = { |
1860 | X_UNIX_PATH "%u", | |
1861 | "/var/X/.X11-unix/X" "%u", | |
1862 | "/usr/spool/sockets/X11/" "%u", | |
1863 | NULL | |
1864 | }; | |
1865 | int sock; | |
1866 | struct sockaddr_un addr; | |
1867 | const char *const * path; | |
1868 | ||
1869 | for (path = x_sockets; *path; ++path) { | |
1870 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
1871 | if (sock < 0) | |
1872 | error("socket: %.100s", strerror(errno)); | |
1873 | memset(&addr, 0, sizeof(addr)); | |
1874 | addr.sun_family = AF_UNIX; | |
1875 | snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr); | |
1876 | if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0) | |
1877 | return sock; | |
1878 | close(sock); | |
1879 | } | |
1880 | error("connect %.100s: %.100s", addr.sun_path, strerror(errno)); | |
1881 | return -1; | |
8efc0c15 | 1882 | } |
1883 | ||
0b242b12 | 1884 | int |
1885 | x11_connect_display(void) | |
8efc0c15 | 1886 | { |
0b242b12 | 1887 | int display_number, sock = 0; |
5260325f | 1888 | const char *display; |
0b242b12 | 1889 | char buf[1024], *cp; |
48e671d5 | 1890 | struct addrinfo hints, *ai, *aitop; |
1891 | char strport[NI_MAXSERV]; | |
1892 | int gaierr; | |
5260325f | 1893 | |
5260325f | 1894 | /* Try to open a socket for the local X server. */ |
1895 | display = getenv("DISPLAY"); | |
1896 | if (!display) { | |
1897 | error("DISPLAY not set."); | |
0b242b12 | 1898 | return -1; |
5260325f | 1899 | } |
aa3378df | 1900 | /* |
1901 | * Now we decode the value of the DISPLAY variable and make a | |
1902 | * connection to the real X server. | |
1903 | */ | |
1904 | ||
1905 | /* | |
1906 | * Check if it is a unix domain socket. Unix domain displays are in | |
1907 | * one of the following formats: unix:d[.s], :d[.s], ::d[.s] | |
1908 | */ | |
5260325f | 1909 | if (strncmp(display, "unix:", 5) == 0 || |
1910 | display[0] == ':') { | |
1911 | /* Connect to the unix domain socket. */ | |
1912 | if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) { | |
1913 | error("Could not parse display number from DISPLAY: %.100s", | |
1914 | display); | |
0b242b12 | 1915 | return -1; |
5260325f | 1916 | } |
1917 | /* Create a socket. */ | |
1918 | sock = connect_local_xsocket(display_number); | |
1919 | if (sock < 0) | |
0b242b12 | 1920 | return -1; |
5260325f | 1921 | |
1922 | /* OK, we now have a connection to the display. */ | |
0b242b12 | 1923 | return sock; |
5260325f | 1924 | } |
aa3378df | 1925 | /* |
1926 | * Connect to an inet socket. The DISPLAY value is supposedly | |
1927 | * hostname:d[.s], where hostname may also be numeric IP address. | |
1928 | */ | |
5260325f | 1929 | strncpy(buf, display, sizeof(buf)); |
1930 | buf[sizeof(buf) - 1] = 0; | |
1931 | cp = strchr(buf, ':'); | |
1932 | if (!cp) { | |
1933 | error("Could not find ':' in DISPLAY: %.100s", display); | |
0b242b12 | 1934 | return -1; |
5260325f | 1935 | } |
1936 | *cp = 0; | |
aa3378df | 1937 | /* buf now contains the host name. But first we parse the display number. */ |
5260325f | 1938 | if (sscanf(cp + 1, "%d", &display_number) != 1) { |
1939 | error("Could not parse display number from DISPLAY: %.100s", | |
1940 | display); | |
0b242b12 | 1941 | return -1; |
5260325f | 1942 | } |
5260325f | 1943 | |
48e671d5 | 1944 | /* Look up the host address */ |
1945 | memset(&hints, 0, sizeof(hints)); | |
1946 | hints.ai_family = IPv4or6; | |
1947 | hints.ai_socktype = SOCK_STREAM; | |
1948 | snprintf(strport, sizeof strport, "%d", 6000 + display_number); | |
1949 | if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { | |
1950 | error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr)); | |
0b242b12 | 1951 | return -1; |
8efc0c15 | 1952 | } |
48e671d5 | 1953 | for (ai = aitop; ai; ai = ai->ai_next) { |
1954 | /* Create a socket. */ | |
1955 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1956 | if (sock < 0) { | |
1957 | debug("socket: %.100s", strerror(errno)); | |
7368a6c8 | 1958 | continue; |
1959 | } | |
1960 | /* Connect it to the display. */ | |
1961 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1962 | debug("connect %.100s port %d: %.100s", buf, | |
1963 | 6000 + display_number, strerror(errno)); | |
1964 | close(sock); | |
1965 | continue; | |
1966 | } | |
1967 | /* Success */ | |
1968 | break; | |
48e671d5 | 1969 | } |
48e671d5 | 1970 | freeaddrinfo(aitop); |
1971 | if (!ai) { | |
6ae2364d | 1972 | error("connect %.100s port %d: %.100s", buf, 6000 + display_number, |
48e671d5 | 1973 | strerror(errno)); |
0b242b12 | 1974 | return -1; |
8efc0c15 | 1975 | } |
0b242b12 | 1976 | return sock; |
1977 | } | |
5260325f | 1978 | |
0b242b12 | 1979 | /* |
1980 | * This is called when SSH_SMSG_X11_OPEN is received. The packet contains | |
1981 | * the remote channel number. We should do whatever we want, and respond | |
1982 | * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. | |
1983 | */ | |
5260325f | 1984 | |
0b242b12 | 1985 | void |
1986 | x11_input_open(int type, int plen) | |
1987 | { | |
1988 | int remote_channel, sock = 0, newch; | |
1989 | char *remote_host; | |
1990 | unsigned int remote_len; | |
5260325f | 1991 | |
0b242b12 | 1992 | /* Get remote channel number. */ |
1993 | remote_channel = packet_get_int(); | |
5260325f | 1994 | |
0b242b12 | 1995 | /* Get remote originator name. */ |
1996 | if (have_hostname_in_open) { | |
1997 | remote_host = packet_get_string(&remote_len); | |
1998 | remote_len += 4; | |
1999 | } else { | |
2000 | remote_host = xstrdup("unknown (remote did not supply name)"); | |
2001 | remote_len = 0; | |
2002 | } | |
2003 | ||
2004 | debug("Received X11 open request."); | |
2005 | packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN); | |
2006 | ||
2007 | /* Obtain a connection to the real X display. */ | |
2008 | sock = x11_connect_display(); | |
2009 | if (sock == -1) { | |
2010 | /* Send refusal to the remote host. */ | |
2011 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2012 | packet_put_int(remote_channel); | |
2013 | packet_send(); | |
2014 | } else { | |
2015 | /* Allocate a channel for this connection. */ | |
2016 | newch = channel_allocate( | |
2017 | (x11_saved_proto == NULL) ? | |
2018 | SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN, | |
2019 | sock, remote_host); | |
2020 | channels[newch].remote_id = remote_channel; | |
2021 | ||
2022 | /* Send a confirmation to the remote host. */ | |
2023 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
2024 | packet_put_int(remote_channel); | |
2025 | packet_put_int(newch); | |
2026 | packet_send(); | |
2027 | } | |
8efc0c15 | 2028 | } |
2029 | ||
aa3378df | 2030 | /* |
2031 | * Requests forwarding of X11 connections, generates fake authentication | |
2032 | * data, and enables authentication spoofing. | |
2033 | */ | |
8efc0c15 | 2034 | |
6ae2364d | 2035 | void |
0b242b12 | 2036 | x11_request_forwarding_with_spoofing(int client_session_id, |
2037 | const char *proto, const char *data) | |
8efc0c15 | 2038 | { |
5260325f | 2039 | unsigned int data_len = (unsigned int) strlen(data) / 2; |
2040 | unsigned int i, value; | |
2041 | char *new_data; | |
2042 | int screen_number; | |
2043 | const char *cp; | |
2044 | u_int32_t rand = 0; | |
2045 | ||
2046 | cp = getenv("DISPLAY"); | |
2047 | if (cp) | |
2048 | cp = strchr(cp, ':'); | |
2049 | if (cp) | |
2050 | cp = strchr(cp, '.'); | |
2051 | if (cp) | |
2052 | screen_number = atoi(cp + 1); | |
2053 | else | |
2054 | screen_number = 0; | |
2055 | ||
2056 | /* Save protocol name. */ | |
2057 | x11_saved_proto = xstrdup(proto); | |
2058 | ||
aa3378df | 2059 | /* |
2060 | * Extract real authentication data and generate fake data of the | |
2061 | * same length. | |
2062 | */ | |
5260325f | 2063 | x11_saved_data = xmalloc(data_len); |
2064 | x11_fake_data = xmalloc(data_len); | |
2065 | for (i = 0; i < data_len; i++) { | |
2066 | if (sscanf(data + 2 * i, "%2x", &value) != 1) | |
2067 | fatal("x11_request_forwarding: bad authentication data: %.100s", data); | |
2068 | if (i % 4 == 0) | |
2069 | rand = arc4random(); | |
2070 | x11_saved_data[i] = value; | |
2071 | x11_fake_data[i] = rand & 0xff; | |
2072 | rand >>= 8; | |
2073 | } | |
2074 | x11_saved_data_len = data_len; | |
2075 | x11_fake_data_len = data_len; | |
2076 | ||
2077 | /* Convert the fake data into hex. */ | |
2078 | new_data = xmalloc(2 * data_len + 1); | |
2079 | for (i = 0; i < data_len; i++) | |
2080 | sprintf(new_data + 2 * i, "%02x", (unsigned char) x11_fake_data[i]); | |
2081 | ||
2082 | /* Send the request packet. */ | |
0b242b12 | 2083 | if (compat20) { |
2084 | channel_request_start(client_session_id, "x11-req", 0); | |
2085 | packet_put_char(0); /* XXX bool single connection */ | |
2086 | } else { | |
2087 | packet_start(SSH_CMSG_X11_REQUEST_FORWARDING); | |
2088 | } | |
2089 | packet_put_cstring(proto); | |
2090 | packet_put_cstring(new_data); | |
5260325f | 2091 | packet_put_int(screen_number); |
2092 | packet_send(); | |
2093 | packet_write_wait(); | |
2094 | xfree(new_data); | |
8efc0c15 | 2095 | } |
2096 | ||
2097 | /* Sends a message to the server to request authentication fd forwarding. */ | |
2098 | ||
6ae2364d | 2099 | void |
5260325f | 2100 | auth_request_forwarding() |
8efc0c15 | 2101 | { |
5260325f | 2102 | packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); |
2103 | packet_send(); | |
2104 | packet_write_wait(); | |
8efc0c15 | 2105 | } |
2106 | ||
aa3378df | 2107 | /* |
2108 | * Returns the name of the forwarded authentication socket. Returns NULL if | |
2109 | * there is no forwarded authentication socket. The returned value points to | |
2110 | * a static buffer. | |
2111 | */ | |
8efc0c15 | 2112 | |
5260325f | 2113 | char * |
2114 | auth_get_socket_name() | |
8efc0c15 | 2115 | { |
5260325f | 2116 | return channel_forwarded_auth_socket_name; |
8efc0c15 | 2117 | } |
2118 | ||
2119 | /* removes the agent forwarding socket */ | |
2120 | ||
6ae2364d | 2121 | void |
5260325f | 2122 | cleanup_socket(void) |
2123 | { | |
2124 | remove(channel_forwarded_auth_socket_name); | |
2125 | rmdir(channel_forwarded_auth_socket_dir); | |
8efc0c15 | 2126 | } |
2127 | ||
aa3378df | 2128 | /* |
fa649821 | 2129 | * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. |
aa3378df | 2130 | * This starts forwarding authentication requests. |
2131 | */ | |
8efc0c15 | 2132 | |
fa649821 | 2133 | int |
5260325f | 2134 | auth_input_request_forwarding(struct passwd * pw) |
8efc0c15 | 2135 | { |
5260325f | 2136 | int sock, newch; |
2137 | struct sockaddr_un sunaddr; | |
2138 | ||
2139 | if (auth_get_socket_name() != NULL) | |
2140 | fatal("Protocol error: authentication forwarding requested twice."); | |
2141 | ||
2142 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
2143 | temporarily_use_uid(pw->pw_uid); | |
2144 | ||
2145 | /* Allocate a buffer for the socket name, and format the name. */ | |
2146 | channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME); | |
2147 | channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME); | |
2148 | strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME); | |
2149 | ||
2150 | /* Create private directory for socket */ | |
fa649821 | 2151 | if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) { |
2152 | packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s", | |
2153 | strerror(errno)); | |
2154 | restore_uid(); | |
2155 | xfree(channel_forwarded_auth_socket_name); | |
2156 | xfree(channel_forwarded_auth_socket_dir); | |
2157 | channel_forwarded_auth_socket_name = NULL; | |
2158 | channel_forwarded_auth_socket_dir = NULL; | |
2159 | return 0; | |
2160 | } | |
5260325f | 2161 | snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d", |
2162 | channel_forwarded_auth_socket_dir, (int) getpid()); | |
2163 | ||
2164 | if (atexit(cleanup_socket) < 0) { | |
2165 | int saved = errno; | |
2166 | cleanup_socket(); | |
2167 | packet_disconnect("socket: %.100s", strerror(saved)); | |
2168 | } | |
2169 | /* Create the socket. */ | |
2170 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
2171 | if (sock < 0) | |
2172 | packet_disconnect("socket: %.100s", strerror(errno)); | |
2173 | ||
2174 | /* Bind it to the name. */ | |
2175 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
2176 | sunaddr.sun_family = AF_UNIX; | |
2177 | strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name, | |
2178 | sizeof(sunaddr.sun_path)); | |
2179 | ||
2180 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) | |
2181 | packet_disconnect("bind: %.100s", strerror(errno)); | |
2182 | ||
2183 | /* Restore the privileged uid. */ | |
2184 | restore_uid(); | |
2185 | ||
2186 | /* Start listening on the socket. */ | |
2187 | if (listen(sock, 5) < 0) | |
2188 | packet_disconnect("listen: %.100s", strerror(errno)); | |
2189 | ||
2190 | /* Allocate a channel for the authentication agent socket. */ | |
2191 | newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock, | |
2192 | xstrdup("auth socket")); | |
a408af76 | 2193 | strlcpy(channels[newch].path, channel_forwarded_auth_socket_name, |
2194 | sizeof(channels[newch].path)); | |
fa649821 | 2195 | return 1; |
8efc0c15 | 2196 | } |
2197 | ||
2198 | /* This is called to process an SSH_SMSG_AGENT_OPEN message. */ | |
2199 | ||
6ae2364d | 2200 | void |
7368a6c8 | 2201 | auth_input_open_request(int type, int plen) |
8efc0c15 | 2202 | { |
5260325f | 2203 | int remch, sock, newch; |
2204 | char *dummyname; | |
2205 | ||
7368a6c8 | 2206 | packet_integrity_check(plen, 4, type); |
2207 | ||
5260325f | 2208 | /* Read the remote channel number from the message. */ |
2209 | remch = packet_get_int(); | |
2210 | ||
aa3378df | 2211 | /* |
2212 | * Get a connection to the local authentication agent (this may again | |
2213 | * get forwarded). | |
2214 | */ | |
5260325f | 2215 | sock = ssh_get_authentication_socket(); |
2216 | ||
aa3378df | 2217 | /* |
2218 | * If we could not connect the agent, send an error message back to | |
2219 | * the server. This should never happen unless the agent dies, | |
2220 | * because authentication forwarding is only enabled if we have an | |
2221 | * agent. | |
2222 | */ | |
5260325f | 2223 | if (sock < 0) { |
2224 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2225 | packet_put_int(remch); | |
2226 | packet_send(); | |
2227 | return; | |
2228 | } | |
2229 | debug("Forwarding authentication connection."); | |
2230 | ||
aa3378df | 2231 | /* |
2232 | * Dummy host name. This will be freed when the channel is freed; it | |
2233 | * will still be valid in the packet_put_string below since the | |
2234 | * channel cannot yet be freed at that point. | |
2235 | */ | |
5260325f | 2236 | dummyname = xstrdup("authentication agent connection"); |
2237 | ||
2238 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname); | |
2239 | channels[newch].remote_id = remch; | |
2240 | ||
2241 | /* Send a confirmation to the remote host. */ | |
2242 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
2243 | packet_put_int(remch); | |
2244 | packet_put_int(newch); | |
2245 | packet_send(); | |
8efc0c15 | 2246 | } |
7e7327a1 | 2247 | |
2248 | void | |
0b242b12 | 2249 | channel_start_open(int id) |
7e7327a1 | 2250 | { |
2251 | Channel *c = channel_lookup(id); | |
2252 | if (c == NULL) { | |
2253 | log("channel_open: %d: bad id", id); | |
2254 | return; | |
2255 | } | |
0b242b12 | 2256 | debug("send channel open %d", id); |
7e7327a1 | 2257 | packet_start(SSH2_MSG_CHANNEL_OPEN); |
2258 | packet_put_cstring(c->ctype); | |
2259 | packet_put_int(c->self); | |
2260 | packet_put_int(c->local_window); | |
2261 | packet_put_int(c->local_maxpacket); | |
0b242b12 | 2262 | } |
2263 | void | |
2264 | channel_open(int id) | |
2265 | { | |
2266 | /* XXX REMOVE ME */ | |
2267 | channel_start_open(id); | |
7e7327a1 | 2268 | packet_send(); |
7e7327a1 | 2269 | } |
2270 | void | |
2271 | channel_request(int id, char *service, int wantconfirm) | |
2272 | { | |
2273 | channel_request_start(id, service, wantconfirm); | |
2274 | packet_send(); | |
2275 | debug("channel request %d: %s", id, service) ; | |
2276 | } | |
2277 | void | |
2278 | channel_request_start(int id, char *service, int wantconfirm) | |
2279 | { | |
2280 | Channel *c = channel_lookup(id); | |
2281 | if (c == NULL) { | |
2282 | log("channel_request: %d: bad id", id); | |
2283 | return; | |
2284 | } | |
2285 | packet_start(SSH2_MSG_CHANNEL_REQUEST); | |
2286 | packet_put_int(c->remote_id); | |
2287 | packet_put_cstring(service); | |
2288 | packet_put_char(wantconfirm); | |
2289 | } | |
2290 | void | |
2291 | channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg) | |
2292 | { | |
2293 | Channel *c = channel_lookup(id); | |
2294 | if (c == NULL) { | |
2295 | log("channel_register_callback: %d: bad id", id); | |
2296 | return; | |
2297 | } | |
2298 | c->cb_event = mtype; | |
2299 | c->cb_fn = fn; | |
2300 | c->cb_arg = arg; | |
2301 | } | |
2302 | void | |
2303 | channel_register_cleanup(int id, channel_callback_fn *fn) | |
2304 | { | |
2305 | Channel *c = channel_lookup(id); | |
2306 | if (c == NULL) { | |
2307 | log("channel_register_cleanup: %d: bad id", id); | |
2308 | return; | |
2309 | } | |
2310 | c->dettach_user = fn; | |
2311 | } | |
2312 | void | |
2313 | channel_cancel_cleanup(int id) | |
2314 | { | |
2315 | Channel *c = channel_lookup(id); | |
2316 | if (c == NULL) { | |
2317 | log("channel_cancel_cleanup: %d: bad id", id); | |
2318 | return; | |
2319 | } | |
2320 | c->dettach_user = NULL; | |
2321 | } | |
2e73a022 | 2322 | void |
2323 | channel_register_filter(int id, channel_filter_fn *fn) | |
2324 | { | |
2325 | Channel *c = channel_lookup(id); | |
2326 | if (c == NULL) { | |
2327 | log("channel_register_filter: %d: bad id", id); | |
2328 | return; | |
2329 | } | |
2330 | c->input_filter = fn; | |
2331 | } | |
7e7327a1 | 2332 | |
2333 | void | |
2334 | channel_set_fds(int id, int rfd, int wfd, int efd, int extusage) | |
2335 | { | |
2336 | Channel *c = channel_lookup(id); | |
2337 | if (c == NULL || c->type != SSH_CHANNEL_LARVAL) | |
2338 | fatal("channel_activate for non-larval channel %d.", id); | |
0fbe8c74 | 2339 | |
2340 | channel_register_fds(c, rfd, wfd, efd, extusage); | |
7e7327a1 | 2341 | c->type = SSH_CHANNEL_OPEN; |
7e7327a1 | 2342 | /* XXX window size? */ |
2343 | c->local_window = c->local_window_max = c->local_maxpacket/2; | |
2344 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); | |
2345 | packet_put_int(c->remote_id); | |
2346 | packet_put_int(c->local_window); | |
2347 | packet_send(); | |
2348 | } |