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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" | |
4c8722d9 | 20 | RCSID("$OpenBSD: channels.c,v 1.64 2000/07/16 08:27:21 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; | |
5260325f | 247 | debug("channel %d: new [%s]", found, remote_name); |
248 | return found; | |
8efc0c15 | 249 | } |
0fbe8c74 | 250 | /* old interface XXX */ |
6ae2364d | 251 | int |
7368a6c8 | 252 | channel_allocate(int type, int sock, char *remote_name) |
253 | { | |
254 | return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name); | |
255 | } | |
8efc0c15 | 256 | |
0fbe8c74 | 257 | |
258 | /* Close all channel fd/socket. */ | |
259 | ||
260 | void | |
261 | channel_close_fds(Channel *c) | |
262 | { | |
263 | if (c->sock != -1) { | |
264 | close(c->sock); | |
265 | c->sock = -1; | |
266 | } | |
267 | if (c->rfd != -1) { | |
268 | close(c->rfd); | |
269 | c->rfd = -1; | |
270 | } | |
271 | if (c->wfd != -1) { | |
272 | close(c->wfd); | |
273 | c->wfd = -1; | |
274 | } | |
275 | if (c->efd != -1) { | |
276 | close(c->efd); | |
277 | c->efd = -1; | |
278 | } | |
279 | } | |
280 | ||
281 | /* Free the channel and close its fd/socket. */ | |
8efc0c15 | 282 | |
6ae2364d | 283 | void |
7368a6c8 | 284 | channel_free(int id) |
8efc0c15 | 285 | { |
7368a6c8 | 286 | Channel *c = channel_lookup(id); |
287 | if (c == NULL) | |
288 | packet_disconnect("channel free: bad local channel %d", id); | |
289 | debug("channel_free: channel %d: status: %s", id, channel_open_message()); | |
7e7327a1 | 290 | if (c->dettach_user != NULL) { |
291 | debug("channel_free: channel %d: dettaching channel user", id); | |
292 | c->dettach_user(c->self, NULL); | |
293 | } | |
0fbe8c74 | 294 | if (c->sock != -1) |
7368a6c8 | 295 | shutdown(c->sock, SHUT_RDWR); |
0fbe8c74 | 296 | channel_close_fds(c); |
7368a6c8 | 297 | buffer_free(&c->input); |
298 | buffer_free(&c->output); | |
299 | buffer_free(&c->extended); | |
300 | c->type = SSH_CHANNEL_FREE; | |
301 | if (c->remote_name) { | |
302 | xfree(c->remote_name); | |
303 | c->remote_name = NULL; | |
5260325f | 304 | } |
8efc0c15 | 305 | } |
306 | ||
aa3378df | 307 | /* |
7368a6c8 | 308 | * 'channel_pre*' are called just before select() to add any bits relevant to |
309 | * channels in the select bitmasks. | |
aa3378df | 310 | */ |
7368a6c8 | 311 | /* |
312 | * 'channel_post*': perform any appropriate operations for channels which | |
313 | * have events pending. | |
314 | */ | |
315 | typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset); | |
316 | chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE]; | |
317 | chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE]; | |
8efc0c15 | 318 | |
7368a6c8 | 319 | void |
320 | channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
8efc0c15 | 321 | { |
7368a6c8 | 322 | FD_SET(c->sock, readset); |
323 | } | |
5260325f | 324 | |
7368a6c8 | 325 | void |
326 | channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
327 | { | |
328 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
329 | FD_SET(c->sock, readset); | |
330 | if (buffer_len(&c->output) > 0) | |
331 | FD_SET(c->sock, writeset); | |
332 | } | |
5260325f | 333 | |
7368a6c8 | 334 | void |
335 | channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset) | |
336 | { | |
337 | /* test whether sockets are 'alive' for read/write */ | |
338 | if (c->istate == CHAN_INPUT_OPEN) | |
339 | if (buffer_len(&c->input) < packet_get_maxsize()) | |
340 | FD_SET(c->sock, readset); | |
341 | if (c->ostate == CHAN_OUTPUT_OPEN || | |
342 | c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
343 | if (buffer_len(&c->output) > 0) { | |
344 | FD_SET(c->sock, writeset); | |
345 | } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
346 | chan_obuf_empty(c); | |
347 | } | |
348 | } | |
349 | } | |
5260325f | 350 | |
7e7327a1 | 351 | void |
352 | channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset) | |
353 | { | |
354 | if (c->istate == CHAN_INPUT_OPEN && | |
355 | c->remote_window > 0 && | |
356 | buffer_len(&c->input) < c->remote_window) | |
357 | FD_SET(c->rfd, readset); | |
358 | if (c->ostate == CHAN_OUTPUT_OPEN || | |
359 | c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
360 | if (buffer_len(&c->output) > 0) { | |
361 | FD_SET(c->wfd, writeset); | |
362 | } else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) { | |
363 | chan_obuf_empty(c); | |
364 | } | |
365 | } | |
366 | /** XXX check close conditions, too */ | |
367 | if (c->efd != -1) { | |
368 | if (c->extended_usage == CHAN_EXTENDED_WRITE && | |
369 | buffer_len(&c->extended) > 0) | |
370 | FD_SET(c->efd, writeset); | |
371 | else if (c->extended_usage == CHAN_EXTENDED_READ && | |
372 | buffer_len(&c->extended) < c->remote_window) | |
373 | FD_SET(c->efd, readset); | |
374 | } | |
375 | } | |
376 | ||
7368a6c8 | 377 | void |
378 | channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
379 | { | |
380 | if (buffer_len(&c->input) == 0) { | |
381 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
382 | packet_put_int(c->remote_id); | |
383 | packet_send(); | |
384 | c->type = SSH_CHANNEL_CLOSED; | |
385 | debug("Closing channel %d after input drain.", c->self); | |
386 | } | |
387 | } | |
5260325f | 388 | |
7368a6c8 | 389 | void |
390 | channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset) | |
391 | { | |
392 | if (buffer_len(&c->output) == 0) | |
393 | channel_free(c->self); | |
6ae2364d | 394 | else |
7368a6c8 | 395 | FD_SET(c->sock, writeset); |
396 | } | |
5260325f | 397 | |
7368a6c8 | 398 | /* |
399 | * This is a special state for X11 authentication spoofing. An opened X11 | |
400 | * connection (when authentication spoofing is being done) remains in this | |
401 | * state until the first packet has been completely read. The authentication | |
402 | * data in that packet is then substituted by the real data if it matches the | |
403 | * fake data, and the channel is put into normal mode. | |
0b242b12 | 404 | * XXX All this happens at the client side. |
7368a6c8 | 405 | */ |
406 | int | |
407 | x11_open_helper(Channel *c) | |
408 | { | |
409 | unsigned char *ucp; | |
410 | unsigned int proto_len, data_len; | |
5260325f | 411 | |
7368a6c8 | 412 | /* Check if the fixed size part of the packet is in buffer. */ |
413 | if (buffer_len(&c->output) < 12) | |
414 | return 0; | |
415 | ||
416 | /* Parse the lengths of variable-length fields. */ | |
417 | ucp = (unsigned char *) buffer_ptr(&c->output); | |
418 | if (ucp[0] == 0x42) { /* Byte order MSB first. */ | |
419 | proto_len = 256 * ucp[6] + ucp[7]; | |
420 | data_len = 256 * ucp[8] + ucp[9]; | |
421 | } else if (ucp[0] == 0x6c) { /* Byte order LSB first. */ | |
422 | proto_len = ucp[6] + 256 * ucp[7]; | |
423 | data_len = ucp[8] + 256 * ucp[9]; | |
424 | } else { | |
425 | debug("Initial X11 packet contains bad byte order byte: 0x%x", | |
426 | ucp[0]); | |
427 | return -1; | |
428 | } | |
5260325f | 429 | |
7368a6c8 | 430 | /* Check if the whole packet is in buffer. */ |
431 | if (buffer_len(&c->output) < | |
432 | 12 + ((proto_len + 3) & ~3) + ((data_len + 3) & ~3)) | |
433 | return 0; | |
5260325f | 434 | |
7368a6c8 | 435 | /* Check if authentication protocol matches. */ |
436 | if (proto_len != strlen(x11_saved_proto) || | |
437 | memcmp(ucp + 12, x11_saved_proto, proto_len) != 0) { | |
438 | debug("X11 connection uses different authentication protocol."); | |
439 | return -1; | |
440 | } | |
441 | /* Check if authentication data matches our fake data. */ | |
442 | if (data_len != x11_fake_data_len || | |
443 | memcmp(ucp + 12 + ((proto_len + 3) & ~3), | |
444 | x11_fake_data, x11_fake_data_len) != 0) { | |
445 | debug("X11 auth data does not match fake data."); | |
446 | return -1; | |
447 | } | |
448 | /* Check fake data length */ | |
449 | if (x11_fake_data_len != x11_saved_data_len) { | |
450 | error("X11 fake_data_len %d != saved_data_len %d", | |
451 | x11_fake_data_len, x11_saved_data_len); | |
452 | return -1; | |
453 | } | |
454 | /* | |
455 | * Received authentication protocol and data match | |
456 | * our fake data. Substitute the fake data with real | |
457 | * data. | |
458 | */ | |
459 | memcpy(ucp + 12 + ((proto_len + 3) & ~3), | |
460 | x11_saved_data, x11_saved_data_len); | |
461 | return 1; | |
462 | } | |
5260325f | 463 | |
7368a6c8 | 464 | void |
465 | channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset) | |
466 | { | |
467 | int ret = x11_open_helper(c); | |
468 | if (ret == 1) { | |
469 | /* Start normal processing for the channel. */ | |
470 | c->type = SSH_CHANNEL_OPEN; | |
a8be9f80 | 471 | channel_pre_open_13(c, readset, writeset); |
7368a6c8 | 472 | } else if (ret == -1) { |
473 | /* | |
474 | * We have received an X11 connection that has bad | |
475 | * authentication information. | |
476 | */ | |
477 | log("X11 connection rejected because of wrong authentication.\r\n"); | |
478 | buffer_clear(&c->input); | |
479 | buffer_clear(&c->output); | |
480 | close(c->sock); | |
481 | c->sock = -1; | |
482 | c->type = SSH_CHANNEL_CLOSED; | |
483 | packet_start(SSH_MSG_CHANNEL_CLOSE); | |
484 | packet_put_int(c->remote_id); | |
485 | packet_send(); | |
486 | } | |
487 | } | |
5260325f | 488 | |
7368a6c8 | 489 | void |
0b242b12 | 490 | channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset) |
7368a6c8 | 491 | { |
492 | int ret = x11_open_helper(c); | |
493 | if (ret == 1) { | |
494 | c->type = SSH_CHANNEL_OPEN; | |
d0c832f3 | 495 | if (compat20) |
496 | channel_pre_open_20(c, readset, writeset); | |
497 | else | |
498 | channel_pre_open_15(c, readset, writeset); | |
7368a6c8 | 499 | } else if (ret == -1) { |
500 | debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate); | |
0b242b12 | 501 | chan_read_failed(c); /** force close? */ |
7368a6c8 | 502 | chan_write_failed(c); |
503 | debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate); | |
504 | } | |
505 | } | |
5260325f | 506 | |
7368a6c8 | 507 | /* This is our fake X11 server socket. */ |
508 | void | |
509 | channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
510 | { | |
511 | struct sockaddr addr; | |
512 | int newsock, newch; | |
513 | socklen_t addrlen; | |
514 | char buf[16384], *remote_hostname; | |
0b242b12 | 515 | int remote_port; |
7368a6c8 | 516 | |
517 | if (FD_ISSET(c->sock, readset)) { | |
518 | debug("X11 connection requested."); | |
519 | addrlen = sizeof(addr); | |
520 | newsock = accept(c->sock, &addr, &addrlen); | |
521 | if (newsock < 0) { | |
522 | error("accept: %.100s", strerror(errno)); | |
523 | return; | |
5260325f | 524 | } |
7368a6c8 | 525 | remote_hostname = get_remote_hostname(newsock); |
0b242b12 | 526 | remote_port = get_peer_port(newsock); |
7368a6c8 | 527 | snprintf(buf, sizeof buf, "X11 connection from %.200s port %d", |
0b242b12 | 528 | remote_hostname, remote_port); |
529 | ||
530 | newch = channel_new("x11", | |
531 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
532 | c->local_window_max, c->local_maxpacket, | |
533 | 0, xstrdup(buf)); | |
534 | if (compat20) { | |
535 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
536 | packet_put_cstring("x11"); | |
537 | packet_put_int(newch); | |
538 | packet_put_int(c->local_window_max); | |
539 | packet_put_int(c->local_maxpacket); | |
540 | /* originator host and port */ | |
541 | packet_put_cstring(remote_hostname); | |
d0c832f3 | 542 | if (datafellows & SSH_BUG_X11FWD) { |
543 | debug("ssh2 x11 bug compat mode"); | |
544 | } else { | |
545 | packet_put_int(remote_port); | |
546 | } | |
0b242b12 | 547 | packet_send(); |
548 | } else { | |
549 | packet_start(SSH_SMSG_X11_OPEN); | |
550 | packet_put_int(newch); | |
551 | if (have_hostname_in_open) | |
552 | packet_put_string(buf, strlen(buf)); | |
553 | packet_send(); | |
554 | } | |
7368a6c8 | 555 | xfree(remote_hostname); |
8efc0c15 | 556 | } |
8efc0c15 | 557 | } |
558 | ||
aa3378df | 559 | /* |
7368a6c8 | 560 | * This socket is listening for connections to a forwarded TCP/IP port. |
aa3378df | 561 | */ |
7368a6c8 | 562 | void |
563 | channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
564 | { | |
565 | struct sockaddr addr; | |
566 | int newsock, newch; | |
567 | socklen_t addrlen; | |
568 | char buf[1024], *remote_hostname; | |
569 | int remote_port; | |
570 | ||
571 | if (FD_ISSET(c->sock, readset)) { | |
572 | debug("Connection to port %d forwarding " | |
573 | "to %.100s port %d requested.", | |
574 | c->listening_port, c->path, c->host_port); | |
575 | addrlen = sizeof(addr); | |
576 | newsock = accept(c->sock, &addr, &addrlen); | |
577 | if (newsock < 0) { | |
578 | error("accept: %.100s", strerror(errno)); | |
579 | return; | |
580 | } | |
581 | remote_hostname = get_remote_hostname(newsock); | |
582 | remote_port = get_peer_port(newsock); | |
583 | snprintf(buf, sizeof buf, | |
584 | "listen port %d for %.100s port %d, " | |
585 | "connect from %.200s port %d", | |
586 | c->listening_port, c->path, c->host_port, | |
587 | remote_hostname, remote_port); | |
588 | newch = channel_new("direct-tcpip", | |
589 | SSH_CHANNEL_OPENING, newsock, newsock, -1, | |
590 | c->local_window_max, c->local_maxpacket, | |
591 | 0, xstrdup(buf)); | |
7e7327a1 | 592 | if (compat20) { |
593 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
594 | packet_put_cstring("direct-tcpip"); | |
595 | packet_put_int(newch); | |
596 | packet_put_int(c->local_window_max); | |
597 | packet_put_int(c->local_maxpacket); | |
6ae2364d | 598 | /* target host and port */ |
7e7327a1 | 599 | packet_put_string(c->path, strlen(c->path)); |
600 | packet_put_int(c->host_port); | |
6ae2364d | 601 | /* originator host and port */ |
7e7327a1 | 602 | packet_put_cstring(remote_hostname); |
603 | packet_put_int(remote_port); | |
604 | packet_send(); | |
605 | } else { | |
606 | packet_start(SSH_MSG_PORT_OPEN); | |
607 | packet_put_int(newch); | |
608 | packet_put_string(c->path, strlen(c->path)); | |
609 | packet_put_int(c->host_port); | |
610 | if (have_hostname_in_open) { | |
611 | packet_put_string(buf, strlen(buf)); | |
612 | } | |
613 | packet_send(); | |
7368a6c8 | 614 | } |
7368a6c8 | 615 | xfree(remote_hostname); |
616 | } | |
617 | } | |
8efc0c15 | 618 | |
7368a6c8 | 619 | /* |
620 | * This is the authentication agent socket listening for connections from | |
621 | * clients. | |
622 | */ | |
623 | void | |
624 | channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset) | |
8efc0c15 | 625 | { |
5260325f | 626 | struct sockaddr addr; |
7368a6c8 | 627 | int newsock, newch; |
48e671d5 | 628 | socklen_t addrlen; |
5260325f | 629 | |
7368a6c8 | 630 | if (FD_ISSET(c->sock, readset)) { |
631 | addrlen = sizeof(addr); | |
632 | newsock = accept(c->sock, &addr, &addrlen); | |
633 | if (newsock < 0) { | |
634 | error("accept from auth socket: %.100s", strerror(errno)); | |
635 | return; | |
636 | } | |
637 | newch = channel_allocate(SSH_CHANNEL_OPENING, newsock, | |
638 | xstrdup("accepted auth socket")); | |
639 | packet_start(SSH_SMSG_AGENT_OPEN); | |
640 | packet_put_int(newch); | |
641 | packet_send(); | |
642 | } | |
643 | } | |
5260325f | 644 | |
7368a6c8 | 645 | int |
646 | channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset) | |
647 | { | |
648 | char buf[16*1024]; | |
649 | int len; | |
650 | ||
651 | if (c->rfd != -1 && | |
652 | FD_ISSET(c->rfd, readset)) { | |
653 | len = read(c->rfd, buf, sizeof(buf)); | |
0fbe8c74 | 654 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) |
655 | return 1; | |
7368a6c8 | 656 | if (len <= 0) { |
0b242b12 | 657 | debug("channel %d: read<=0 rfd %d len %d", |
7368a6c8 | 658 | c->self, c->rfd, len); |
659 | if (compat13) { | |
660 | buffer_consume(&c->output, buffer_len(&c->output)); | |
661 | c->type = SSH_CHANNEL_INPUT_DRAINING; | |
662 | debug("Channel %d status set to input draining.", c->self); | |
663 | } else { | |
664 | chan_read_failed(c); | |
5260325f | 665 | } |
7368a6c8 | 666 | return -1; |
667 | } | |
668 | buffer_append(&c->input, buf, len); | |
669 | } | |
670 | return 1; | |
671 | } | |
672 | int | |
673 | channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset) | |
674 | { | |
675 | int len; | |
676 | ||
677 | /* Send buffered output data to the socket. */ | |
678 | if (c->wfd != -1 && | |
679 | FD_ISSET(c->wfd, writeset) && | |
680 | buffer_len(&c->output) > 0) { | |
681 | len = write(c->wfd, buffer_ptr(&c->output), | |
0fbe8c74 | 682 | buffer_len(&c->output)); |
683 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) | |
684 | return 1; | |
7368a6c8 | 685 | if (len <= 0) { |
686 | if (compat13) { | |
687 | buffer_consume(&c->output, buffer_len(&c->output)); | |
688 | debug("Channel %d status set to input draining.", c->self); | |
689 | c->type = SSH_CHANNEL_INPUT_DRAINING; | |
690 | } else { | |
691 | chan_write_failed(c); | |
5260325f | 692 | } |
7368a6c8 | 693 | return -1; |
694 | } | |
695 | buffer_consume(&c->output, len); | |
7e7327a1 | 696 | if (compat20 && len > 0) { |
697 | c->local_consumed += len; | |
698 | } | |
699 | } | |
700 | return 1; | |
701 | } | |
702 | int | |
703 | channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset) | |
704 | { | |
705 | char buf[16*1024]; | |
706 | int len; | |
707 | ||
8ce64345 | 708 | /** XXX handle drain efd, too */ |
7e7327a1 | 709 | if (c->efd != -1) { |
710 | if (c->extended_usage == CHAN_EXTENDED_WRITE && | |
711 | FD_ISSET(c->efd, writeset) && | |
712 | buffer_len(&c->extended) > 0) { | |
713 | len = write(c->efd, buffer_ptr(&c->extended), | |
714 | buffer_len(&c->extended)); | |
715 | debug("channel %d: written %d to efd %d", | |
716 | c->self, len, c->efd); | |
717 | if (len > 0) { | |
718 | buffer_consume(&c->extended, len); | |
719 | c->local_consumed += len; | |
720 | } | |
721 | } else if (c->extended_usage == CHAN_EXTENDED_READ && | |
722 | FD_ISSET(c->efd, readset)) { | |
723 | len = read(c->efd, buf, sizeof(buf)); | |
724 | debug("channel %d: read %d from efd %d", | |
725 | c->self, len, c->efd); | |
8ce64345 | 726 | if (len == 0) { |
727 | debug("channel %d: closing efd %d", | |
728 | c->self, c->efd); | |
729 | close(c->efd); | |
730 | c->efd = -1; | |
731 | } else if (len > 0) | |
7e7327a1 | 732 | buffer_append(&c->extended, buf, len); |
733 | } | |
734 | } | |
735 | return 1; | |
736 | } | |
737 | int | |
738 | channel_check_window(Channel *c, fd_set * readset, fd_set * writeset) | |
739 | { | |
e78a59f5 | 740 | if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) && |
7e7327a1 | 741 | c->local_window < c->local_window_max/2 && |
742 | c->local_consumed > 0) { | |
743 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); | |
744 | packet_put_int(c->remote_id); | |
745 | packet_put_int(c->local_consumed); | |
746 | packet_send(); | |
747 | debug("channel %d: window %d sent adjust %d", | |
748 | c->self, c->local_window, | |
749 | c->local_consumed); | |
750 | c->local_window += c->local_consumed; | |
751 | c->local_consumed = 0; | |
7368a6c8 | 752 | } |
753 | return 1; | |
754 | } | |
5260325f | 755 | |
7368a6c8 | 756 | void |
757 | channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset) | |
758 | { | |
759 | channel_handle_rfd(c, readset, writeset); | |
760 | channel_handle_wfd(c, readset, writeset); | |
761 | } | |
aa3378df | 762 | |
7e7327a1 | 763 | void |
764 | channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset) | |
765 | { | |
766 | channel_handle_rfd(c, readset, writeset); | |
767 | channel_handle_wfd(c, readset, writeset); | |
768 | channel_handle_efd(c, readset, writeset); | |
769 | channel_check_window(c, readset, writeset); | |
770 | } | |
771 | ||
7368a6c8 | 772 | void |
773 | channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset) | |
774 | { | |
775 | int len; | |
776 | /* Send buffered output data to the socket. */ | |
777 | if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) { | |
778 | len = write(c->sock, buffer_ptr(&c->output), | |
779 | buffer_len(&c->output)); | |
780 | if (len <= 0) | |
781 | buffer_consume(&c->output, buffer_len(&c->output)); | |
782 | else | |
783 | buffer_consume(&c->output, len); | |
784 | } | |
785 | } | |
5260325f | 786 | |
7e7327a1 | 787 | void |
788 | channel_handler_init_20(void) | |
789 | { | |
790 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20; | |
0b242b12 | 791 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
7e7327a1 | 792 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; |
0b242b12 | 793 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; |
7e7327a1 | 794 | |
795 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2; | |
796 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
0b242b12 | 797 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; |
7e7327a1 | 798 | } |
799 | ||
7368a6c8 | 800 | void |
801 | channel_handler_init_13(void) | |
802 | { | |
803 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13; | |
804 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13; | |
805 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; | |
806 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
807 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
808 | channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining; | |
809 | channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining; | |
810 | ||
811 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; | |
812 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
813 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
814 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
815 | channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13; | |
816 | } | |
5260325f | 817 | |
7368a6c8 | 818 | void |
819 | channel_handler_init_15(void) | |
820 | { | |
821 | channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15; | |
0b242b12 | 822 | channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open; |
7368a6c8 | 823 | channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener; |
824 | channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener; | |
825 | channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener; | |
826 | ||
827 | channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener; | |
828 | channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener; | |
829 | channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener; | |
830 | channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1; | |
831 | } | |
832 | ||
833 | void | |
834 | channel_handler_init(void) | |
835 | { | |
836 | int i; | |
837 | for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) { | |
838 | channel_pre[i] = NULL; | |
839 | channel_post[i] = NULL; | |
840 | } | |
7e7327a1 | 841 | if (compat20) |
842 | channel_handler_init_20(); | |
843 | else if (compat13) | |
7368a6c8 | 844 | channel_handler_init_13(); |
845 | else | |
846 | channel_handler_init_15(); | |
847 | } | |
848 | ||
6ae2364d | 849 | void |
7368a6c8 | 850 | channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset) |
851 | { | |
852 | static int did_init = 0; | |
853 | int i; | |
854 | Channel *c; | |
855 | ||
856 | if (!did_init) { | |
857 | channel_handler_init(); | |
858 | did_init = 1; | |
859 | } | |
860 | for (i = 0; i < channels_alloc; i++) { | |
861 | c = &channels[i]; | |
862 | if (c->type == SSH_CHANNEL_FREE) | |
5260325f | 863 | continue; |
7368a6c8 | 864 | if (ftab[c->type] == NULL) |
865 | continue; | |
866 | (*ftab[c->type])(c, readset, writeset); | |
7e7327a1 | 867 | chan_delete_if_full_closed(c); |
8efc0c15 | 868 | } |
8efc0c15 | 869 | } |
870 | ||
6ae2364d | 871 | void |
7368a6c8 | 872 | channel_prepare_select(fd_set * readset, fd_set * writeset) |
873 | { | |
874 | channel_handler(channel_pre, readset, writeset); | |
875 | } | |
876 | ||
6ae2364d | 877 | void |
7368a6c8 | 878 | channel_after_select(fd_set * readset, fd_set * writeset) |
879 | { | |
880 | channel_handler(channel_post, readset, writeset); | |
881 | } | |
882 | ||
8efc0c15 | 883 | /* If there is data to send to the connection, send some of it now. */ |
884 | ||
6ae2364d | 885 | void |
5260325f | 886 | channel_output_poll() |
8efc0c15 | 887 | { |
5260325f | 888 | int len, i; |
7368a6c8 | 889 | Channel *c; |
5260325f | 890 | |
891 | for (i = 0; i < channels_alloc; i++) { | |
7368a6c8 | 892 | c = &channels[i]; |
48e671d5 | 893 | |
aa3378df | 894 | /* We are only interested in channels that can have buffered incoming data. */ |
48e671d5 | 895 | if (compat13) { |
7368a6c8 | 896 | if (c->type != SSH_CHANNEL_OPEN && |
897 | c->type != SSH_CHANNEL_INPUT_DRAINING) | |
48e671d5 | 898 | continue; |
899 | } else { | |
7368a6c8 | 900 | if (c->type != SSH_CHANNEL_OPEN) |
48e671d5 | 901 | continue; |
7368a6c8 | 902 | if (c->istate != CHAN_INPUT_OPEN && |
903 | c->istate != CHAN_INPUT_WAIT_DRAIN) | |
48e671d5 | 904 | continue; |
905 | } | |
e78a59f5 | 906 | if (compat20 && |
907 | (c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) { | |
7e7327a1 | 908 | debug("channel: %d: no data after CLOSE", c->self); |
909 | continue; | |
910 | } | |
5260325f | 911 | |
912 | /* Get the amount of buffered data for this channel. */ | |
7368a6c8 | 913 | len = buffer_len(&c->input); |
5260325f | 914 | if (len > 0) { |
aa3378df | 915 | /* Send some data for the other side over the secure connection. */ |
7e7327a1 | 916 | if (compat20) { |
917 | if (len > c->remote_window) | |
918 | len = c->remote_window; | |
919 | if (len > c->remote_maxpacket) | |
920 | len = c->remote_maxpacket; | |
5260325f | 921 | } else { |
7e7327a1 | 922 | if (packet_is_interactive()) { |
923 | if (len > 1024) | |
924 | len = 512; | |
925 | } else { | |
926 | /* Keep the packets at reasonable size. */ | |
927 | if (len > packet_get_maxsize()/2) | |
928 | len = packet_get_maxsize()/2; | |
929 | } | |
5260325f | 930 | } |
7368a6c8 | 931 | if (len > 0) { |
7e7327a1 | 932 | packet_start(compat20 ? |
933 | SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA); | |
7368a6c8 | 934 | packet_put_int(c->remote_id); |
935 | packet_put_string(buffer_ptr(&c->input), len); | |
936 | packet_send(); | |
937 | buffer_consume(&c->input, len); | |
938 | c->remote_window -= len; | |
7368a6c8 | 939 | } |
940 | } else if (c->istate == CHAN_INPUT_WAIT_DRAIN) { | |
5260325f | 941 | if (compat13) |
942 | fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3"); | |
aa3378df | 943 | /* |
944 | * input-buffer is empty and read-socket shutdown: | |
945 | * tell peer, that we will not send more data: send IEOF | |
946 | */ | |
7368a6c8 | 947 | chan_ibuf_empty(c); |
5260325f | 948 | } |
7e7327a1 | 949 | /* Send extended data, i.e. stderr */ |
950 | if (compat20 && | |
951 | c->remote_window > 0 && | |
952 | (len = buffer_len(&c->extended)) > 0 && | |
953 | c->extended_usage == CHAN_EXTENDED_READ) { | |
954 | if (len > c->remote_window) | |
955 | len = c->remote_window; | |
956 | if (len > c->remote_maxpacket) | |
957 | len = c->remote_maxpacket; | |
958 | packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA); | |
959 | packet_put_int(c->remote_id); | |
960 | packet_put_int(SSH2_EXTENDED_DATA_STDERR); | |
961 | packet_put_string(buffer_ptr(&c->extended), len); | |
962 | packet_send(); | |
963 | buffer_consume(&c->extended, len); | |
964 | c->remote_window -= len; | |
965 | } | |
8efc0c15 | 966 | } |
8efc0c15 | 967 | } |
968 | ||
aa3378df | 969 | /* |
970 | * This is called when a packet of type CHANNEL_DATA has just been received. | |
971 | * The message type has already been consumed, but channel number and data is | |
972 | * still there. | |
973 | */ | |
8efc0c15 | 974 | |
6ae2364d | 975 | void |
7368a6c8 | 976 | channel_input_data(int type, int plen) |
8efc0c15 | 977 | { |
48e671d5 | 978 | int id; |
5260325f | 979 | char *data; |
980 | unsigned int data_len; | |
7368a6c8 | 981 | Channel *c; |
5260325f | 982 | |
983 | /* Get the channel number and verify it. */ | |
48e671d5 | 984 | id = packet_get_int(); |
7368a6c8 | 985 | c = channel_lookup(id); |
986 | if (c == NULL) | |
48e671d5 | 987 | packet_disconnect("Received data for nonexistent channel %d.", id); |
5260325f | 988 | |
989 | /* Ignore any data for non-open channels (might happen on close) */ | |
7368a6c8 | 990 | if (c->type != SSH_CHANNEL_OPEN && |
991 | c->type != SSH_CHANNEL_X11_OPEN) | |
48e671d5 | 992 | return; |
993 | ||
994 | /* same for protocol 1.5 if output end is no longer open */ | |
7368a6c8 | 995 | if (!compat13 && c->ostate != CHAN_OUTPUT_OPEN) |
5260325f | 996 | return; |
997 | ||
998 | /* Get the data. */ | |
999 | data = packet_get_string(&data_len); | |
6ae2364d | 1000 | packet_done(); |
7368a6c8 | 1001 | |
7e7327a1 | 1002 | if (compat20){ |
1003 | if (data_len > c->local_maxpacket) { | |
1004 | log("channel %d: rcvd big packet %d, maxpack %d", | |
1005 | c->self, data_len, c->local_maxpacket); | |
1006 | } | |
1007 | if (data_len > c->local_window) { | |
1008 | log("channel %d: rcvd too much data %d, win %d", | |
1009 | c->self, data_len, c->local_window); | |
1010 | xfree(data); | |
1011 | return; | |
1012 | } | |
1013 | c->local_window -= data_len; | |
1014 | }else{ | |
1015 | packet_integrity_check(plen, 4 + 4 + data_len, type); | |
1016 | } | |
7368a6c8 | 1017 | buffer_append(&c->output, data, data_len); |
5260325f | 1018 | xfree(data); |
8efc0c15 | 1019 | } |
6ae2364d | 1020 | void |
7e7327a1 | 1021 | channel_input_extended_data(int type, int plen) |
1022 | { | |
1023 | int id; | |
1024 | int tcode; | |
1025 | char *data; | |
1026 | unsigned int data_len; | |
1027 | Channel *c; | |
1028 | ||
1029 | /* Get the channel number and verify it. */ | |
1030 | id = packet_get_int(); | |
1031 | c = channel_lookup(id); | |
1032 | ||
1033 | if (c == NULL) | |
1034 | packet_disconnect("Received extended_data for bad channel %d.", id); | |
1035 | if (c->type != SSH_CHANNEL_OPEN) { | |
1036 | log("channel %d: ext data for non open", id); | |
1037 | return; | |
1038 | } | |
1039 | tcode = packet_get_int(); | |
1040 | if (c->efd == -1 || | |
1041 | c->extended_usage != CHAN_EXTENDED_WRITE || | |
1042 | tcode != SSH2_EXTENDED_DATA_STDERR) { | |
1043 | log("channel %d: bad ext data", c->self); | |
1044 | return; | |
1045 | } | |
1046 | data = packet_get_string(&data_len); | |
6ae2364d | 1047 | packet_done(); |
7e7327a1 | 1048 | if (data_len > c->local_window) { |
1049 | log("channel %d: rcvd too much extended_data %d, win %d", | |
1050 | c->self, data_len, c->local_window); | |
1051 | xfree(data); | |
1052 | return; | |
1053 | } | |
1054 | debug("channel %d: rcvd ext data %d", c->self, data_len); | |
1055 | c->local_window -= data_len; | |
1056 | buffer_append(&c->extended, data, data_len); | |
1057 | xfree(data); | |
1058 | } | |
1059 | ||
8efc0c15 | 1060 | |
aa3378df | 1061 | /* |
1062 | * Returns true if no channel has too much buffered data, and false if one or | |
1063 | * more channel is overfull. | |
1064 | */ | |
8efc0c15 | 1065 | |
6ae2364d | 1066 | int |
5260325f | 1067 | channel_not_very_much_buffered_data() |
8efc0c15 | 1068 | { |
5260325f | 1069 | unsigned int i; |
7368a6c8 | 1070 | Channel *c; |
5260325f | 1071 | |
1072 | for (i = 0; i < channels_alloc; i++) { | |
7368a6c8 | 1073 | c = &channels[i]; |
1074 | if (c->type == SSH_CHANNEL_OPEN) { | |
7e7327a1 | 1075 | if (!compat20 && buffer_len(&c->input) > packet_get_maxsize()) { |
7368a6c8 | 1076 | debug("channel %d: big input buffer %d", |
1077 | c->self, buffer_len(&c->input)); | |
5260325f | 1078 | return 0; |
7368a6c8 | 1079 | } |
1080 | if (buffer_len(&c->output) > packet_get_maxsize()) { | |
1081 | debug("channel %d: big output buffer %d", | |
1082 | c->self, buffer_len(&c->output)); | |
5260325f | 1083 | return 0; |
7368a6c8 | 1084 | } |
5260325f | 1085 | } |
8efc0c15 | 1086 | } |
5260325f | 1087 | return 1; |
8efc0c15 | 1088 | } |
1089 | ||
6ae2364d | 1090 | void |
7368a6c8 | 1091 | channel_input_ieof(int type, int plen) |
1092 | { | |
1093 | int id; | |
1094 | Channel *c; | |
1095 | ||
1096 | packet_integrity_check(plen, 4, type); | |
1097 | ||
1098 | id = packet_get_int(); | |
1099 | c = channel_lookup(id); | |
1100 | if (c == NULL) | |
1101 | packet_disconnect("Received ieof for nonexistent channel %d.", id); | |
1102 | chan_rcvd_ieof(c); | |
1103 | } | |
8efc0c15 | 1104 | |
6ae2364d | 1105 | void |
7368a6c8 | 1106 | channel_input_close(int type, int plen) |
8efc0c15 | 1107 | { |
7368a6c8 | 1108 | int id; |
1109 | Channel *c; | |
5260325f | 1110 | |
7368a6c8 | 1111 | packet_integrity_check(plen, 4, type); |
1112 | ||
1113 | id = packet_get_int(); | |
1114 | c = channel_lookup(id); | |
1115 | if (c == NULL) | |
1116 | packet_disconnect("Received close for nonexistent channel %d.", id); | |
aa3378df | 1117 | |
1118 | /* | |
1119 | * Send a confirmation that we have closed the channel and no more | |
1120 | * data is coming for it. | |
1121 | */ | |
5260325f | 1122 | packet_start(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION); |
7368a6c8 | 1123 | packet_put_int(c->remote_id); |
5260325f | 1124 | packet_send(); |
1125 | ||
aa3378df | 1126 | /* |
1127 | * If the channel is in closed state, we have sent a close request, | |
1128 | * and the other side will eventually respond with a confirmation. | |
1129 | * Thus, we cannot free the channel here, because then there would be | |
1130 | * no-one to receive the confirmation. The channel gets freed when | |
1131 | * the confirmation arrives. | |
1132 | */ | |
7368a6c8 | 1133 | if (c->type != SSH_CHANNEL_CLOSED) { |
aa3378df | 1134 | /* |
1135 | * Not a closed channel - mark it as draining, which will | |
1136 | * cause it to be freed later. | |
1137 | */ | |
7368a6c8 | 1138 | buffer_consume(&c->input, buffer_len(&c->input)); |
1139 | c->type = SSH_CHANNEL_OUTPUT_DRAINING; | |
5260325f | 1140 | } |
8efc0c15 | 1141 | } |
1142 | ||
7368a6c8 | 1143 | /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */ |
6ae2364d | 1144 | void |
7368a6c8 | 1145 | channel_input_oclose(int type, int plen) |
8efc0c15 | 1146 | { |
7368a6c8 | 1147 | int id = packet_get_int(); |
1148 | Channel *c = channel_lookup(id); | |
1149 | packet_integrity_check(plen, 4, type); | |
1150 | if (c == NULL) | |
1151 | packet_disconnect("Received oclose for nonexistent channel %d.", id); | |
1152 | chan_rcvd_oclose(c); | |
8efc0c15 | 1153 | } |
1154 | ||
6ae2364d | 1155 | void |
7368a6c8 | 1156 | channel_input_close_confirmation(int type, int plen) |
1157 | { | |
1158 | int id = packet_get_int(); | |
1159 | Channel *c = channel_lookup(id); | |
1160 | ||
6ae2364d | 1161 | packet_done(); |
7368a6c8 | 1162 | if (c == NULL) |
1163 | packet_disconnect("Received close confirmation for " | |
1164 | "out-of-range channel %d.", id); | |
1165 | if (c->type != SSH_CHANNEL_CLOSED) | |
1166 | packet_disconnect("Received close confirmation for " | |
1167 | "non-closed channel %d (type %d).", id, c->type); | |
1168 | channel_free(c->self); | |
1169 | } | |
8efc0c15 | 1170 | |
6ae2364d | 1171 | void |
7368a6c8 | 1172 | channel_input_open_confirmation(int type, int plen) |
8efc0c15 | 1173 | { |
7368a6c8 | 1174 | int id, remote_id; |
1175 | Channel *c; | |
5260325f | 1176 | |
7e7327a1 | 1177 | if (!compat20) |
1178 | packet_integrity_check(plen, 4 + 4, type); | |
5260325f | 1179 | |
7368a6c8 | 1180 | id = packet_get_int(); |
1181 | c = channel_lookup(id); | |
5260325f | 1182 | |
7368a6c8 | 1183 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) |
1184 | packet_disconnect("Received open confirmation for " | |
1185 | "non-opening channel %d.", id); | |
1186 | remote_id = packet_get_int(); | |
aa3378df | 1187 | /* Record the remote channel number and mark that the channel is now open. */ |
7368a6c8 | 1188 | c->remote_id = remote_id; |
1189 | c->type = SSH_CHANNEL_OPEN; | |
7e7327a1 | 1190 | |
1191 | if (compat20) { | |
1192 | c->remote_window = packet_get_int(); | |
1193 | c->remote_maxpacket = packet_get_int(); | |
6ae2364d | 1194 | packet_done(); |
7e7327a1 | 1195 | if (c->cb_fn != NULL && c->cb_event == type) { |
1196 | debug("callback start"); | |
1197 | c->cb_fn(c->self, c->cb_arg); | |
1198 | debug("callback done"); | |
1199 | } | |
1200 | debug("channel %d: open confirm rwindow %d rmax %d", c->self, | |
1201 | c->remote_window, c->remote_maxpacket); | |
1202 | } | |
8efc0c15 | 1203 | } |
1204 | ||
6ae2364d | 1205 | void |
7368a6c8 | 1206 | channel_input_open_failure(int type, int plen) |
8efc0c15 | 1207 | { |
7368a6c8 | 1208 | int id; |
1209 | Channel *c; | |
5260325f | 1210 | |
7e7327a1 | 1211 | if (!compat20) |
1212 | packet_integrity_check(plen, 4, type); | |
7368a6c8 | 1213 | |
1214 | id = packet_get_int(); | |
1215 | c = channel_lookup(id); | |
1216 | ||
1217 | if (c==NULL || c->type != SSH_CHANNEL_OPENING) | |
1218 | packet_disconnect("Received open failure for " | |
1219 | "non-opening channel %d.", id); | |
7e7327a1 | 1220 | if (compat20) { |
1221 | int reason = packet_get_int(); | |
1222 | char *msg = packet_get_string(NULL); | |
6ae2364d | 1223 | char *lang = packet_get_string(NULL); |
7e7327a1 | 1224 | log("channel_open_failure: %d: reason %d: %s", id, reason, msg); |
6ae2364d | 1225 | packet_done(); |
7e7327a1 | 1226 | xfree(msg); |
6ae2364d | 1227 | xfree(lang); |
7e7327a1 | 1228 | } |
5260325f | 1229 | /* Free the channel. This will also close the socket. */ |
7368a6c8 | 1230 | channel_free(id); |
8efc0c15 | 1231 | } |
1232 | ||
7e7327a1 | 1233 | void |
1234 | channel_input_channel_request(int type, int plen) | |
1235 | { | |
1236 | int id; | |
1237 | Channel *c; | |
1238 | ||
1239 | id = packet_get_int(); | |
1240 | c = channel_lookup(id); | |
1241 | ||
1242 | if (c == NULL || | |
1243 | (c->type != SSH_CHANNEL_OPEN && c->type != SSH_CHANNEL_LARVAL)) | |
1244 | packet_disconnect("Received request for " | |
1245 | "non-open channel %d.", id); | |
1246 | if (c->cb_fn != NULL && c->cb_event == type) { | |
1247 | debug("callback start"); | |
1248 | c->cb_fn(c->self, c->cb_arg); | |
1249 | debug("callback done"); | |
1250 | } else { | |
1251 | char *service = packet_get_string(NULL); | |
1252 | debug("channel: %d rcvd request for %s", c->self, service); | |
1253 | debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event); | |
1254 | xfree(service); | |
1255 | } | |
1256 | } | |
1257 | ||
6ae2364d | 1258 | void |
7e7327a1 | 1259 | channel_input_window_adjust(int type, int plen) |
1260 | { | |
1261 | Channel *c; | |
1262 | int id, adjust; | |
1263 | ||
1264 | if (!compat20) | |
1265 | return; | |
1266 | ||
1267 | /* Get the channel number and verify it. */ | |
1268 | id = packet_get_int(); | |
1269 | c = channel_lookup(id); | |
1270 | ||
1271 | if (c == NULL || c->type != SSH_CHANNEL_OPEN) { | |
1272 | log("Received window adjust for " | |
1273 | "non-open channel %d.", id); | |
1274 | return; | |
1275 | } | |
1276 | adjust = packet_get_int(); | |
6ae2364d | 1277 | packet_done(); |
7e7327a1 | 1278 | debug("channel %d: rcvd adjust %d", id, adjust); |
1279 | c->remote_window += adjust; | |
1280 | } | |
1281 | ||
aa3378df | 1282 | /* |
1283 | * Stops listening for channels, and removes any unix domain sockets that we | |
1284 | * might have. | |
1285 | */ | |
8efc0c15 | 1286 | |
6ae2364d | 1287 | void |
5260325f | 1288 | channel_stop_listening() |
8efc0c15 | 1289 | { |
5260325f | 1290 | int i; |
1291 | for (i = 0; i < channels_alloc; i++) { | |
1292 | switch (channels[i].type) { | |
1293 | case SSH_CHANNEL_AUTH_SOCKET: | |
1294 | close(channels[i].sock); | |
1295 | remove(channels[i].path); | |
1296 | channel_free(i); | |
1297 | break; | |
1298 | case SSH_CHANNEL_PORT_LISTENER: | |
1299 | case SSH_CHANNEL_X11_LISTENER: | |
1300 | close(channels[i].sock); | |
1301 | channel_free(i); | |
1302 | break; | |
1303 | default: | |
1304 | break; | |
1305 | } | |
8efc0c15 | 1306 | } |
8efc0c15 | 1307 | } |
1308 | ||
aa3378df | 1309 | /* |
0fbe8c74 | 1310 | * Closes the sockets/fds of all channels. This is used to close extra file |
aa3378df | 1311 | * descriptors after a fork. |
1312 | */ | |
8efc0c15 | 1313 | |
6ae2364d | 1314 | void |
5260325f | 1315 | channel_close_all() |
8efc0c15 | 1316 | { |
5260325f | 1317 | int i; |
0fbe8c74 | 1318 | for (i = 0; i < channels_alloc; i++) |
5260325f | 1319 | if (channels[i].type != SSH_CHANNEL_FREE) |
0fbe8c74 | 1320 | channel_close_fds(&channels[i]); |
8efc0c15 | 1321 | } |
1322 | ||
1323 | /* Returns the maximum file descriptor number used by the channels. */ | |
1324 | ||
6ae2364d | 1325 | int |
5260325f | 1326 | channel_max_fd() |
8efc0c15 | 1327 | { |
5260325f | 1328 | return channel_max_fd_value; |
8efc0c15 | 1329 | } |
1330 | ||
1331 | /* Returns true if any channel is still open. */ | |
1332 | ||
6ae2364d | 1333 | int |
5260325f | 1334 | channel_still_open() |
8efc0c15 | 1335 | { |
5260325f | 1336 | unsigned int i; |
1337 | for (i = 0; i < channels_alloc; i++) | |
1338 | switch (channels[i].type) { | |
1339 | case SSH_CHANNEL_FREE: | |
1340 | case SSH_CHANNEL_X11_LISTENER: | |
1341 | case SSH_CHANNEL_PORT_LISTENER: | |
1342 | case SSH_CHANNEL_CLOSED: | |
1343 | case SSH_CHANNEL_AUTH_SOCKET: | |
1344 | continue; | |
7e7327a1 | 1345 | case SSH_CHANNEL_LARVAL: |
1346 | if (!compat20) | |
1347 | fatal("cannot happen: SSH_CHANNEL_LARVAL"); | |
1348 | continue; | |
5260325f | 1349 | case SSH_CHANNEL_OPENING: |
1350 | case SSH_CHANNEL_OPEN: | |
1351 | case SSH_CHANNEL_X11_OPEN: | |
1352 | return 1; | |
1353 | case SSH_CHANNEL_INPUT_DRAINING: | |
1354 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
1355 | if (!compat13) | |
1356 | fatal("cannot happen: OUT_DRAIN"); | |
1357 | return 1; | |
1358 | default: | |
1359 | fatal("channel_still_open: bad channel type %d", channels[i].type); | |
1360 | /* NOTREACHED */ | |
1361 | } | |
1362 | return 0; | |
8efc0c15 | 1363 | } |
1364 | ||
aa3378df | 1365 | /* |
1366 | * Returns a message describing the currently open forwarded connections, | |
1367 | * suitable for sending to the client. The message contains crlf pairs for | |
1368 | * newlines. | |
1369 | */ | |
8efc0c15 | 1370 | |
5260325f | 1371 | char * |
1372 | channel_open_message() | |
8efc0c15 | 1373 | { |
5260325f | 1374 | Buffer buffer; |
1375 | int i; | |
1376 | char buf[512], *cp; | |
1377 | ||
1378 | buffer_init(&buffer); | |
1379 | snprintf(buf, sizeof buf, "The following connections are open:\r\n"); | |
8efc0c15 | 1380 | buffer_append(&buffer, buf, strlen(buf)); |
5260325f | 1381 | for (i = 0; i < channels_alloc; i++) { |
1382 | Channel *c = &channels[i]; | |
1383 | switch (c->type) { | |
1384 | case SSH_CHANNEL_FREE: | |
1385 | case SSH_CHANNEL_X11_LISTENER: | |
1386 | case SSH_CHANNEL_PORT_LISTENER: | |
1387 | case SSH_CHANNEL_CLOSED: | |
1388 | case SSH_CHANNEL_AUTH_SOCKET: | |
1389 | continue; | |
7e7327a1 | 1390 | case SSH_CHANNEL_LARVAL: |
5260325f | 1391 | case SSH_CHANNEL_OPENING: |
1392 | case SSH_CHANNEL_OPEN: | |
1393 | case SSH_CHANNEL_X11_OPEN: | |
1394 | case SSH_CHANNEL_INPUT_DRAINING: | |
1395 | case SSH_CHANNEL_OUTPUT_DRAINING: | |
7368a6c8 | 1396 | snprintf(buf, sizeof buf, " #%d %.300s (t%d r%d i%d/%d o%d/%d fd %d/%d)\r\n", |
48e671d5 | 1397 | c->self, c->remote_name, |
1398 | c->type, c->remote_id, | |
1399 | c->istate, buffer_len(&c->input), | |
7368a6c8 | 1400 | c->ostate, buffer_len(&c->output), |
1401 | c->rfd, c->wfd); | |
5260325f | 1402 | buffer_append(&buffer, buf, strlen(buf)); |
1403 | continue; | |
1404 | default: | |
7368a6c8 | 1405 | fatal("channel_open_message: bad channel type %d", c->type); |
5260325f | 1406 | /* NOTREACHED */ |
1407 | } | |
1408 | } | |
1409 | buffer_append(&buffer, "\0", 1); | |
1410 | cp = xstrdup(buffer_ptr(&buffer)); | |
1411 | buffer_free(&buffer); | |
1412 | return cp; | |
8efc0c15 | 1413 | } |
1414 | ||
aa3378df | 1415 | /* |
1416 | * Initiate forwarding of connections to local port "port" through the secure | |
1417 | * channel to host:port from remote side. | |
1418 | */ | |
8efc0c15 | 1419 | |
6ae2364d | 1420 | void |
57112b5a | 1421 | channel_request_local_forwarding(u_short port, const char *host, |
95f1eccc | 1422 | u_short host_port, int gateway_ports) |
8efc0c15 | 1423 | { |
48e671d5 | 1424 | int success, ch, sock, on = 1; |
1425 | struct addrinfo hints, *ai, *aitop; | |
1426 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
aa3378df | 1427 | struct linger linger; |
5260325f | 1428 | |
1429 | if (strlen(host) > sizeof(channels[0].path) - 1) | |
1430 | packet_disconnect("Forward host name too long."); | |
1431 | ||
aa3378df | 1432 | /* |
48e671d5 | 1433 | * getaddrinfo returns a loopback address if the hostname is |
1434 | * set to NULL and hints.ai_flags is not AI_PASSIVE | |
aa3378df | 1435 | */ |
48e671d5 | 1436 | memset(&hints, 0, sizeof(hints)); |
1437 | hints.ai_family = IPv4or6; | |
1438 | hints.ai_flags = gateway_ports ? AI_PASSIVE : 0; | |
1439 | hints.ai_socktype = SOCK_STREAM; | |
1440 | snprintf(strport, sizeof strport, "%d", port); | |
1441 | if (getaddrinfo(NULL, strport, &hints, &aitop) != 0) | |
1442 | packet_disconnect("getaddrinfo: fatal error"); | |
1443 | ||
1444 | success = 0; | |
1445 | for (ai = aitop; ai; ai = ai->ai_next) { | |
1446 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1447 | continue; | |
1448 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
1449 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
1450 | error("channel_request_local_forwarding: getnameinfo failed"); | |
1451 | continue; | |
1452 | } | |
1453 | /* Create a port to listen for the host. */ | |
1454 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1455 | if (sock < 0) { | |
1456 | /* this is no error since kernel may not support ipv6 */ | |
1457 | verbose("socket: %.100s", strerror(errno)); | |
1458 | continue; | |
1459 | } | |
1460 | /* | |
1461 | * Set socket options. We would like the socket to disappear | |
1462 | * as soon as it has been closed for whatever reason. | |
1463 | */ | |
1464 | setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); | |
1465 | linger.l_onoff = 1; | |
1466 | linger.l_linger = 5; | |
1467 | setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger)); | |
1468 | debug("Local forwarding listening on %s port %s.", ntop, strport); | |
1469 | ||
1470 | /* Bind the socket to the address. */ | |
1471 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1472 | /* address can be in use ipv6 address is already bound */ | |
16218745 | 1473 | if (!ai->ai_next) |
1474 | error("bind: %.100s", strerror(errno)); | |
1475 | else | |
1476 | verbose("bind: %.100s", strerror(errno)); | |
1477 | ||
48e671d5 | 1478 | close(sock); |
1479 | continue; | |
1480 | } | |
1481 | /* Start listening for connections on the socket. */ | |
1482 | if (listen(sock, 5) < 0) { | |
1483 | error("listen: %.100s", strerror(errno)); | |
1484 | close(sock); | |
1485 | continue; | |
1486 | } | |
1487 | /* Allocate a channel number for the socket. */ | |
7368a6c8 | 1488 | ch = channel_new( |
1489 | "port listener", SSH_CHANNEL_PORT_LISTENER, | |
1490 | sock, sock, -1, | |
0b242b12 | 1491 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, |
7368a6c8 | 1492 | 0, xstrdup("port listener")); |
48e671d5 | 1493 | strlcpy(channels[ch].path, host, sizeof(channels[ch].path)); |
1494 | channels[ch].host_port = host_port; | |
1495 | channels[ch].listening_port = port; | |
1496 | success = 1; | |
1497 | } | |
1498 | if (success == 0) | |
1499 | packet_disconnect("cannot listen port: %d", port); | |
1500 | freeaddrinfo(aitop); | |
5260325f | 1501 | } |
8efc0c15 | 1502 | |
aa3378df | 1503 | /* |
1504 | * Initiate forwarding of connections to port "port" on remote host through | |
1505 | * the secure channel to host:port from local side. | |
1506 | */ | |
8efc0c15 | 1507 | |
6ae2364d | 1508 | void |
7368a6c8 | 1509 | channel_request_remote_forwarding(u_short listen_port, const char *host_to_connect, |
1510 | u_short port_to_connect) | |
8efc0c15 | 1511 | { |
5260325f | 1512 | int payload_len; |
1513 | /* Record locally that connection to this host/port is permitted. */ | |
1514 | if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION) | |
1515 | fatal("channel_request_remote_forwarding: too many forwards"); | |
1516 | ||
7368a6c8 | 1517 | permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect); |
1518 | permitted_opens[num_permitted_opens].port_to_connect = port_to_connect; | |
1519 | permitted_opens[num_permitted_opens].listen_port = listen_port; | |
5260325f | 1520 | num_permitted_opens++; |
1521 | ||
1522 | /* Send the forward request to the remote side. */ | |
7e7327a1 | 1523 | if (compat20) { |
1524 | const char *address_to_bind = "0.0.0.0"; | |
1525 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
1526 | packet_put_cstring("tcpip-forward"); | |
1527 | packet_put_char(0); /* boolean: want reply */ | |
1528 | packet_put_cstring(address_to_bind); | |
1529 | packet_put_int(listen_port); | |
1530 | } else { | |
1531 | packet_start(SSH_CMSG_PORT_FORWARD_REQUEST); | |
7e7327a1 | 1532 | packet_put_int(listen_port); |
d6f24e45 | 1533 | packet_put_cstring(host_to_connect); |
1534 | packet_put_int(port_to_connect); | |
7e7327a1 | 1535 | packet_send(); |
1536 | packet_write_wait(); | |
1537 | /* | |
1538 | * Wait for response from the remote side. It will send a disconnect | |
1539 | * message on failure, and we will never see it here. | |
1540 | */ | |
1541 | packet_read_expect(&payload_len, SSH_SMSG_SUCCESS); | |
1542 | } | |
8efc0c15 | 1543 | } |
1544 | ||
aa3378df | 1545 | /* |
1546 | * This is called after receiving CHANNEL_FORWARDING_REQUEST. This initates | |
1547 | * listening for the port, and sends back a success reply (or disconnect | |
1548 | * message if there was an error). This never returns if there was an error. | |
1549 | */ | |
8efc0c15 | 1550 | |
6ae2364d | 1551 | void |
1d1ffb87 | 1552 | channel_input_port_forward_request(int is_root, int gateway_ports) |
8efc0c15 | 1553 | { |
57112b5a | 1554 | u_short port, host_port; |
5260325f | 1555 | char *hostname; |
1556 | ||
1557 | /* Get arguments from the packet. */ | |
1558 | port = packet_get_int(); | |
1559 | hostname = packet_get_string(NULL); | |
1560 | host_port = packet_get_int(); | |
1561 | ||
aa3378df | 1562 | /* |
1563 | * Check that an unprivileged user is not trying to forward a | |
1564 | * privileged port. | |
1565 | */ | |
5260325f | 1566 | if (port < IPPORT_RESERVED && !is_root) |
1567 | packet_disconnect("Requested forwarding of port %d but user is not root.", | |
1568 | port); | |
95f1eccc | 1569 | /* |
1570 | * Initiate forwarding, | |
95f1eccc | 1571 | */ |
1d1ffb87 | 1572 | channel_request_local_forwarding(port, hostname, host_port, gateway_ports); |
5260325f | 1573 | |
1574 | /* Free the argument string. */ | |
1575 | xfree(hostname); | |
8efc0c15 | 1576 | } |
1577 | ||
7368a6c8 | 1578 | /* XXX move to aux.c */ |
1579 | int | |
1580 | channel_connect_to(const char *host, u_short host_port) | |
8efc0c15 | 1581 | { |
48e671d5 | 1582 | struct addrinfo hints, *ai, *aitop; |
1583 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
1584 | int gaierr; | |
7368a6c8 | 1585 | int sock = -1; |
48e671d5 | 1586 | |
1587 | memset(&hints, 0, sizeof(hints)); | |
1588 | hints.ai_family = IPv4or6; | |
1589 | hints.ai_socktype = SOCK_STREAM; | |
1590 | snprintf(strport, sizeof strport, "%d", host_port); | |
1591 | if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) { | |
1592 | error("%.100s: unknown host (%s)", host, gai_strerror(gaierr)); | |
7368a6c8 | 1593 | return -1; |
48e671d5 | 1594 | } |
48e671d5 | 1595 | for (ai = aitop; ai; ai = ai->ai_next) { |
1596 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1597 | continue; | |
1598 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop), | |
1599 | strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
7368a6c8 | 1600 | error("channel_connect_to: getnameinfo failed"); |
48e671d5 | 1601 | continue; |
5260325f | 1602 | } |
48e671d5 | 1603 | /* Create the socket. */ |
1604 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1605 | if (sock < 0) { | |
1606 | error("socket: %.100s", strerror(errno)); | |
1607 | continue; | |
5260325f | 1608 | } |
48e671d5 | 1609 | /* Connect to the host/port. */ |
1610 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1611 | error("connect %.100s port %s: %.100s", ntop, strport, | |
1612 | strerror(errno)); | |
1613 | close(sock); | |
1614 | continue; /* fail -- try next */ | |
1615 | } | |
1616 | break; /* success */ | |
5260325f | 1617 | |
5260325f | 1618 | } |
48e671d5 | 1619 | freeaddrinfo(aitop); |
48e671d5 | 1620 | if (!ai) { |
1621 | error("connect %.100s port %d: failed.", host, host_port); | |
7368a6c8 | 1622 | return -1; |
8efc0c15 | 1623 | } |
7368a6c8 | 1624 | /* success */ |
1625 | return sock; | |
1626 | } | |
48e671d5 | 1627 | |
7368a6c8 | 1628 | /* |
1629 | * This is called after receiving PORT_OPEN message. This attempts to | |
1630 | * connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION | |
1631 | * or CHANNEL_OPEN_FAILURE. | |
1632 | */ | |
5260325f | 1633 | |
6ae2364d | 1634 | void |
7368a6c8 | 1635 | channel_input_port_open(int type, int plen) |
1636 | { | |
1637 | u_short host_port; | |
1638 | char *host, *originator_string; | |
1639 | int remote_channel, sock = -1, newch, i, denied; | |
1640 | unsigned int host_len, originator_len; | |
5260325f | 1641 | |
7368a6c8 | 1642 | /* Get remote channel number. */ |
1643 | remote_channel = packet_get_int(); | |
5260325f | 1644 | |
7368a6c8 | 1645 | /* Get host name to connect to. */ |
1646 | host = packet_get_string(&host_len); | |
5260325f | 1647 | |
7368a6c8 | 1648 | /* Get port to connect to. */ |
1649 | host_port = packet_get_int(); | |
5260325f | 1650 | |
7368a6c8 | 1651 | /* Get remote originator name. */ |
1652 | if (have_hostname_in_open) { | |
1653 | originator_string = packet_get_string(&originator_len); | |
1654 | originator_len += 4; /* size of packet_int */ | |
1655 | } else { | |
1656 | originator_string = xstrdup("unknown (remote did not supply name)"); | |
1657 | originator_len = 0; /* no originator supplied */ | |
1658 | } | |
5260325f | 1659 | |
7368a6c8 | 1660 | packet_integrity_check(plen, |
1661 | 4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN); | |
1662 | ||
1663 | /* Check if opening that port is permitted. */ | |
1664 | denied = 0; | |
1665 | if (!all_opens_permitted) { | |
1666 | /* Go trough all permitted ports. */ | |
1667 | for (i = 0; i < num_permitted_opens; i++) | |
1668 | if (permitted_opens[i].port_to_connect == host_port && | |
1669 | strcmp(permitted_opens[i].host_to_connect, host) == 0) | |
1670 | break; | |
1671 | ||
1672 | /* Check if we found the requested port among those permitted. */ | |
1673 | if (i >= num_permitted_opens) { | |
1674 | /* The port is not permitted. */ | |
1675 | log("Received request to connect to %.100s:%d, but the request was denied.", | |
1676 | host, host_port); | |
1677 | denied = 1; | |
1678 | } | |
1679 | } | |
1680 | sock = denied ? -1 : channel_connect_to(host, host_port); | |
1681 | if (sock > 0) { | |
1682 | /* Allocate a channel for this connection. */ | |
1683 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string); | |
1684 | channels[newch].remote_id = remote_channel; | |
1685 | ||
1686 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1687 | packet_put_int(remote_channel); | |
1688 | packet_put_int(newch); | |
1689 | packet_send(); | |
1690 | } else { | |
1691 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
1692 | packet_put_int(remote_channel); | |
1693 | packet_send(); | |
1694 | } | |
1695 | xfree(host); | |
8efc0c15 | 1696 | } |
1697 | ||
aa3378df | 1698 | /* |
1699 | * Creates an internet domain socket for listening for X11 connections. | |
1700 | * Returns a suitable value for the DISPLAY variable, or NULL if an error | |
1701 | * occurs. | |
1702 | */ | |
8efc0c15 | 1703 | |
48e671d5 | 1704 | #define NUM_SOCKS 10 |
1705 | ||
5260325f | 1706 | char * |
95f1eccc | 1707 | x11_create_display_inet(int screen_number, int x11_display_offset) |
8efc0c15 | 1708 | { |
57112b5a | 1709 | int display_number, sock; |
1710 | u_short port; | |
48e671d5 | 1711 | struct addrinfo hints, *ai, *aitop; |
1712 | char strport[NI_MAXSERV]; | |
1713 | int gaierr, n, num_socks = 0, socks[NUM_SOCKS]; | |
1714 | char display[512]; | |
5260325f | 1715 | char hostname[MAXHOSTNAMELEN]; |
1716 | ||
95f1eccc | 1717 | for (display_number = x11_display_offset; |
5260325f | 1718 | display_number < MAX_DISPLAYS; |
1719 | display_number++) { | |
1720 | port = 6000 + display_number; | |
48e671d5 | 1721 | memset(&hints, 0, sizeof(hints)); |
1722 | hints.ai_family = IPv4or6; | |
1723 | hints.ai_flags = AI_PASSIVE; /* XXX loopback only ? */ | |
1724 | hints.ai_socktype = SOCK_STREAM; | |
1725 | snprintf(strport, sizeof strport, "%d", port); | |
1726 | if ((gaierr = getaddrinfo(NULL, strport, &hints, &aitop)) != 0) { | |
1727 | error("getaddrinfo: %.100s", gai_strerror(gaierr)); | |
5260325f | 1728 | return NULL; |
1729 | } | |
48e671d5 | 1730 | for (ai = aitop; ai; ai = ai->ai_next) { |
1731 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1732 | continue; | |
1733 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1734 | if (sock < 0) { | |
80a44451 | 1735 | if (errno != EINVAL) { |
1736 | error("socket: %.100s", strerror(errno)); | |
1737 | return NULL; | |
1738 | } else { | |
1739 | debug("Socket family %d not supported [X11 disp create]", ai->ai_family); | |
1740 | continue; | |
1741 | } | |
48e671d5 | 1742 | } |
1743 | if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1744 | debug("bind port %d: %.100s", port, strerror(errno)); | |
1745 | shutdown(sock, SHUT_RDWR); | |
1746 | close(sock); | |
16218745 | 1747 | |
1748 | if (ai->ai_next) | |
1749 | continue; | |
1750 | ||
48e671d5 | 1751 | for (n = 0; n < num_socks; n++) { |
1752 | shutdown(socks[n], SHUT_RDWR); | |
1753 | close(socks[n]); | |
1754 | } | |
1755 | num_socks = 0; | |
1756 | break; | |
1757 | } | |
1758 | socks[num_socks++] = sock; | |
80faa19f | 1759 | #ifndef DONT_TRY_OTHER_AF |
48e671d5 | 1760 | if (num_socks == NUM_SOCKS) |
1761 | break; | |
80faa19f | 1762 | #else |
1763 | break; | |
1764 | #endif | |
5260325f | 1765 | } |
48e671d5 | 1766 | if (num_socks > 0) |
1767 | break; | |
5260325f | 1768 | } |
1769 | if (display_number >= MAX_DISPLAYS) { | |
1770 | error("Failed to allocate internet-domain X11 display socket."); | |
1771 | return NULL; | |
8efc0c15 | 1772 | } |
5260325f | 1773 | /* Start listening for connections on the socket. */ |
48e671d5 | 1774 | for (n = 0; n < num_socks; n++) { |
1775 | sock = socks[n]; | |
1776 | if (listen(sock, 5) < 0) { | |
1777 | error("listen: %.100s", strerror(errno)); | |
1778 | shutdown(sock, SHUT_RDWR); | |
1779 | close(sock); | |
1780 | return NULL; | |
1781 | } | |
8efc0c15 | 1782 | } |
48e671d5 | 1783 | |
5260325f | 1784 | /* Set up a suitable value for the DISPLAY variable. */ |
a7effaac | 1785 | |
5260325f | 1786 | if (gethostname(hostname, sizeof(hostname)) < 0) |
1787 | fatal("gethostname: %.100s", strerror(errno)); | |
a7effaac | 1788 | |
1789 | #ifdef IPADDR_IN_DISPLAY | |
1790 | /* | |
1791 | * HPUX detects the local hostname in the DISPLAY variable and tries | |
1792 | * to set up a shared memory connection to the server, which it | |
1793 | * incorrectly supposes to be local. | |
1794 | * | |
1795 | * The workaround - as used in later $$H and other programs - is | |
1796 | * is to set display to the host's IP address. | |
1797 | */ | |
1798 | { | |
1799 | struct hostent *he; | |
1800 | struct in_addr my_addr; | |
1801 | ||
1802 | he = gethostbyname(hostname); | |
1803 | if (he == NULL) { | |
1804 | error("[X11-broken-fwd-hostname-workaround] Could not get " | |
1805 | "IP address for hostname %s.", hostname); | |
1806 | ||
1807 | packet_send_debug("[X11-broken-fwd-hostname-workaround]" | |
1808 | "Could not get IP address for hostname %s.", hostname); | |
1809 | ||
1810 | shutdown(sock, SHUT_RDWR); | |
1811 | close(sock); | |
1812 | ||
1813 | return NULL; | |
1814 | } | |
1815 | ||
1816 | memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); | |
1817 | ||
1818 | /* Set DISPLAY to <ip address>:screen.display */ | |
48e671d5 | 1819 | snprintf(display, sizeof(display), "%.50s:%d.%d", inet_ntoa(my_addr), |
a7effaac | 1820 | display_number, screen_number); |
1821 | } | |
1822 | #else /* IPADDR_IN_DISPLAY */ | |
1823 | /* Just set DISPLAY to hostname:screen.display */ | |
48e671d5 | 1824 | snprintf(display, sizeof display, "%.400s:%d.%d", hostname, |
a7effaac | 1825 | display_number, screen_number); |
1826 | #endif /* IPADDR_IN_DISPLAY */ | |
5260325f | 1827 | |
48e671d5 | 1828 | /* Allocate a channel for each socket. */ |
1829 | for (n = 0; n < num_socks; n++) { | |
1830 | sock = socks[n]; | |
0b242b12 | 1831 | (void) channel_new("x11 listener", |
1832 | SSH_CHANNEL_X11_LISTENER, sock, sock, -1, | |
1833 | CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, | |
1834 | 0, xstrdup("X11 inet listener")); | |
48e671d5 | 1835 | } |
5260325f | 1836 | |
1837 | /* Return a suitable value for the DISPLAY environment variable. */ | |
48e671d5 | 1838 | return xstrdup(display); |
8efc0c15 | 1839 | } |
1840 | ||
1841 | #ifndef X_UNIX_PATH | |
1842 | #define X_UNIX_PATH "/tmp/.X11-unix/X" | |
1843 | #endif | |
1844 | ||
1845 | static | |
1846 | int | |
2f450969 | 1847 | connect_local_xsocket(unsigned int dnr) |
8efc0c15 | 1848 | { |
5260325f | 1849 | static const char *const x_sockets[] = { |
1850 | X_UNIX_PATH "%u", | |
1851 | "/var/X/.X11-unix/X" "%u", | |
1852 | "/usr/spool/sockets/X11/" "%u", | |
1853 | NULL | |
1854 | }; | |
1855 | int sock; | |
1856 | struct sockaddr_un addr; | |
1857 | const char *const * path; | |
1858 | ||
1859 | for (path = x_sockets; *path; ++path) { | |
1860 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
1861 | if (sock < 0) | |
1862 | error("socket: %.100s", strerror(errno)); | |
1863 | memset(&addr, 0, sizeof(addr)); | |
1864 | addr.sun_family = AF_UNIX; | |
1865 | snprintf(addr.sun_path, sizeof addr.sun_path, *path, dnr); | |
1866 | if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0) | |
1867 | return sock; | |
1868 | close(sock); | |
1869 | } | |
1870 | error("connect %.100s: %.100s", addr.sun_path, strerror(errno)); | |
1871 | return -1; | |
8efc0c15 | 1872 | } |
1873 | ||
0b242b12 | 1874 | int |
1875 | x11_connect_display(void) | |
8efc0c15 | 1876 | { |
0b242b12 | 1877 | int display_number, sock = 0; |
5260325f | 1878 | const char *display; |
0b242b12 | 1879 | char buf[1024], *cp; |
48e671d5 | 1880 | struct addrinfo hints, *ai, *aitop; |
1881 | char strport[NI_MAXSERV]; | |
1882 | int gaierr; | |
5260325f | 1883 | |
5260325f | 1884 | /* Try to open a socket for the local X server. */ |
1885 | display = getenv("DISPLAY"); | |
1886 | if (!display) { | |
1887 | error("DISPLAY not set."); | |
0b242b12 | 1888 | return -1; |
5260325f | 1889 | } |
aa3378df | 1890 | /* |
1891 | * Now we decode the value of the DISPLAY variable and make a | |
1892 | * connection to the real X server. | |
1893 | */ | |
1894 | ||
1895 | /* | |
1896 | * Check if it is a unix domain socket. Unix domain displays are in | |
1897 | * one of the following formats: unix:d[.s], :d[.s], ::d[.s] | |
1898 | */ | |
5260325f | 1899 | if (strncmp(display, "unix:", 5) == 0 || |
1900 | display[0] == ':') { | |
1901 | /* Connect to the unix domain socket. */ | |
1902 | if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) { | |
1903 | error("Could not parse display number from DISPLAY: %.100s", | |
1904 | display); | |
0b242b12 | 1905 | return -1; |
5260325f | 1906 | } |
1907 | /* Create a socket. */ | |
1908 | sock = connect_local_xsocket(display_number); | |
1909 | if (sock < 0) | |
0b242b12 | 1910 | return -1; |
5260325f | 1911 | |
1912 | /* OK, we now have a connection to the display. */ | |
0b242b12 | 1913 | return sock; |
5260325f | 1914 | } |
aa3378df | 1915 | /* |
1916 | * Connect to an inet socket. The DISPLAY value is supposedly | |
1917 | * hostname:d[.s], where hostname may also be numeric IP address. | |
1918 | */ | |
5260325f | 1919 | strncpy(buf, display, sizeof(buf)); |
1920 | buf[sizeof(buf) - 1] = 0; | |
1921 | cp = strchr(buf, ':'); | |
1922 | if (!cp) { | |
1923 | error("Could not find ':' in DISPLAY: %.100s", display); | |
0b242b12 | 1924 | return -1; |
5260325f | 1925 | } |
1926 | *cp = 0; | |
aa3378df | 1927 | /* buf now contains the host name. But first we parse the display number. */ |
5260325f | 1928 | if (sscanf(cp + 1, "%d", &display_number) != 1) { |
1929 | error("Could not parse display number from DISPLAY: %.100s", | |
1930 | display); | |
0b242b12 | 1931 | return -1; |
5260325f | 1932 | } |
5260325f | 1933 | |
48e671d5 | 1934 | /* Look up the host address */ |
1935 | memset(&hints, 0, sizeof(hints)); | |
1936 | hints.ai_family = IPv4or6; | |
1937 | hints.ai_socktype = SOCK_STREAM; | |
1938 | snprintf(strport, sizeof strport, "%d", 6000 + display_number); | |
1939 | if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) { | |
1940 | error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr)); | |
0b242b12 | 1941 | return -1; |
8efc0c15 | 1942 | } |
48e671d5 | 1943 | for (ai = aitop; ai; ai = ai->ai_next) { |
1944 | /* Create a socket. */ | |
1945 | sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
1946 | if (sock < 0) { | |
1947 | debug("socket: %.100s", strerror(errno)); | |
7368a6c8 | 1948 | continue; |
1949 | } | |
1950 | /* Connect it to the display. */ | |
1951 | if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) { | |
1952 | debug("connect %.100s port %d: %.100s", buf, | |
1953 | 6000 + display_number, strerror(errno)); | |
1954 | close(sock); | |
1955 | continue; | |
1956 | } | |
1957 | /* Success */ | |
1958 | break; | |
48e671d5 | 1959 | } |
48e671d5 | 1960 | freeaddrinfo(aitop); |
1961 | if (!ai) { | |
6ae2364d | 1962 | error("connect %.100s port %d: %.100s", buf, 6000 + display_number, |
48e671d5 | 1963 | strerror(errno)); |
0b242b12 | 1964 | return -1; |
8efc0c15 | 1965 | } |
0b242b12 | 1966 | return sock; |
1967 | } | |
5260325f | 1968 | |
0b242b12 | 1969 | /* |
1970 | * This is called when SSH_SMSG_X11_OPEN is received. The packet contains | |
1971 | * the remote channel number. We should do whatever we want, and respond | |
1972 | * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE. | |
1973 | */ | |
5260325f | 1974 | |
0b242b12 | 1975 | void |
1976 | x11_input_open(int type, int plen) | |
1977 | { | |
1978 | int remote_channel, sock = 0, newch; | |
1979 | char *remote_host; | |
1980 | unsigned int remote_len; | |
5260325f | 1981 | |
0b242b12 | 1982 | /* Get remote channel number. */ |
1983 | remote_channel = packet_get_int(); | |
5260325f | 1984 | |
0b242b12 | 1985 | /* Get remote originator name. */ |
1986 | if (have_hostname_in_open) { | |
1987 | remote_host = packet_get_string(&remote_len); | |
1988 | remote_len += 4; | |
1989 | } else { | |
1990 | remote_host = xstrdup("unknown (remote did not supply name)"); | |
1991 | remote_len = 0; | |
1992 | } | |
1993 | ||
1994 | debug("Received X11 open request."); | |
1995 | packet_integrity_check(plen, 4 + remote_len, SSH_SMSG_X11_OPEN); | |
1996 | ||
1997 | /* Obtain a connection to the real X display. */ | |
1998 | sock = x11_connect_display(); | |
1999 | if (sock == -1) { | |
2000 | /* Send refusal to the remote host. */ | |
2001 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2002 | packet_put_int(remote_channel); | |
2003 | packet_send(); | |
2004 | } else { | |
2005 | /* Allocate a channel for this connection. */ | |
2006 | newch = channel_allocate( | |
2007 | (x11_saved_proto == NULL) ? | |
2008 | SSH_CHANNEL_OPEN : SSH_CHANNEL_X11_OPEN, | |
2009 | sock, remote_host); | |
2010 | channels[newch].remote_id = remote_channel; | |
2011 | ||
2012 | /* Send a confirmation to the remote host. */ | |
2013 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
2014 | packet_put_int(remote_channel); | |
2015 | packet_put_int(newch); | |
2016 | packet_send(); | |
2017 | } | |
8efc0c15 | 2018 | } |
2019 | ||
aa3378df | 2020 | /* |
2021 | * Requests forwarding of X11 connections, generates fake authentication | |
2022 | * data, and enables authentication spoofing. | |
2023 | */ | |
8efc0c15 | 2024 | |
6ae2364d | 2025 | void |
0b242b12 | 2026 | x11_request_forwarding_with_spoofing(int client_session_id, |
2027 | const char *proto, const char *data) | |
8efc0c15 | 2028 | { |
5260325f | 2029 | unsigned int data_len = (unsigned int) strlen(data) / 2; |
2030 | unsigned int i, value; | |
2031 | char *new_data; | |
2032 | int screen_number; | |
2033 | const char *cp; | |
2034 | u_int32_t rand = 0; | |
2035 | ||
2036 | cp = getenv("DISPLAY"); | |
2037 | if (cp) | |
2038 | cp = strchr(cp, ':'); | |
2039 | if (cp) | |
2040 | cp = strchr(cp, '.'); | |
2041 | if (cp) | |
2042 | screen_number = atoi(cp + 1); | |
2043 | else | |
2044 | screen_number = 0; | |
2045 | ||
2046 | /* Save protocol name. */ | |
2047 | x11_saved_proto = xstrdup(proto); | |
2048 | ||
aa3378df | 2049 | /* |
2050 | * Extract real authentication data and generate fake data of the | |
2051 | * same length. | |
2052 | */ | |
5260325f | 2053 | x11_saved_data = xmalloc(data_len); |
2054 | x11_fake_data = xmalloc(data_len); | |
2055 | for (i = 0; i < data_len; i++) { | |
2056 | if (sscanf(data + 2 * i, "%2x", &value) != 1) | |
2057 | fatal("x11_request_forwarding: bad authentication data: %.100s", data); | |
2058 | if (i % 4 == 0) | |
2059 | rand = arc4random(); | |
2060 | x11_saved_data[i] = value; | |
2061 | x11_fake_data[i] = rand & 0xff; | |
2062 | rand >>= 8; | |
2063 | } | |
2064 | x11_saved_data_len = data_len; | |
2065 | x11_fake_data_len = data_len; | |
2066 | ||
2067 | /* Convert the fake data into hex. */ | |
2068 | new_data = xmalloc(2 * data_len + 1); | |
2069 | for (i = 0; i < data_len; i++) | |
2070 | sprintf(new_data + 2 * i, "%02x", (unsigned char) x11_fake_data[i]); | |
2071 | ||
2072 | /* Send the request packet. */ | |
0b242b12 | 2073 | if (compat20) { |
2074 | channel_request_start(client_session_id, "x11-req", 0); | |
2075 | packet_put_char(0); /* XXX bool single connection */ | |
2076 | } else { | |
2077 | packet_start(SSH_CMSG_X11_REQUEST_FORWARDING); | |
2078 | } | |
2079 | packet_put_cstring(proto); | |
2080 | packet_put_cstring(new_data); | |
5260325f | 2081 | packet_put_int(screen_number); |
2082 | packet_send(); | |
2083 | packet_write_wait(); | |
2084 | xfree(new_data); | |
8efc0c15 | 2085 | } |
2086 | ||
2087 | /* Sends a message to the server to request authentication fd forwarding. */ | |
2088 | ||
6ae2364d | 2089 | void |
5260325f | 2090 | auth_request_forwarding() |
8efc0c15 | 2091 | { |
5260325f | 2092 | packet_start(SSH_CMSG_AGENT_REQUEST_FORWARDING); |
2093 | packet_send(); | |
2094 | packet_write_wait(); | |
8efc0c15 | 2095 | } |
2096 | ||
aa3378df | 2097 | /* |
2098 | * Returns the name of the forwarded authentication socket. Returns NULL if | |
2099 | * there is no forwarded authentication socket. The returned value points to | |
2100 | * a static buffer. | |
2101 | */ | |
8efc0c15 | 2102 | |
5260325f | 2103 | char * |
2104 | auth_get_socket_name() | |
8efc0c15 | 2105 | { |
5260325f | 2106 | return channel_forwarded_auth_socket_name; |
8efc0c15 | 2107 | } |
2108 | ||
2109 | /* removes the agent forwarding socket */ | |
2110 | ||
6ae2364d | 2111 | void |
5260325f | 2112 | cleanup_socket(void) |
2113 | { | |
2114 | remove(channel_forwarded_auth_socket_name); | |
2115 | rmdir(channel_forwarded_auth_socket_dir); | |
8efc0c15 | 2116 | } |
2117 | ||
aa3378df | 2118 | /* |
fa649821 | 2119 | * This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server. |
aa3378df | 2120 | * This starts forwarding authentication requests. |
2121 | */ | |
8efc0c15 | 2122 | |
fa649821 | 2123 | int |
5260325f | 2124 | auth_input_request_forwarding(struct passwd * pw) |
8efc0c15 | 2125 | { |
5260325f | 2126 | int sock, newch; |
2127 | struct sockaddr_un sunaddr; | |
2128 | ||
2129 | if (auth_get_socket_name() != NULL) | |
2130 | fatal("Protocol error: authentication forwarding requested twice."); | |
2131 | ||
2132 | /* Temporarily drop privileged uid for mkdir/bind. */ | |
2133 | temporarily_use_uid(pw->pw_uid); | |
2134 | ||
2135 | /* Allocate a buffer for the socket name, and format the name. */ | |
2136 | channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME); | |
2137 | channel_forwarded_auth_socket_dir = xmalloc(MAX_SOCKET_NAME); | |
2138 | strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME); | |
2139 | ||
2140 | /* Create private directory for socket */ | |
fa649821 | 2141 | if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) { |
2142 | packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s", | |
2143 | strerror(errno)); | |
2144 | restore_uid(); | |
2145 | xfree(channel_forwarded_auth_socket_name); | |
2146 | xfree(channel_forwarded_auth_socket_dir); | |
2147 | channel_forwarded_auth_socket_name = NULL; | |
2148 | channel_forwarded_auth_socket_dir = NULL; | |
2149 | return 0; | |
2150 | } | |
5260325f | 2151 | snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d", |
2152 | channel_forwarded_auth_socket_dir, (int) getpid()); | |
2153 | ||
2154 | if (atexit(cleanup_socket) < 0) { | |
2155 | int saved = errno; | |
2156 | cleanup_socket(); | |
2157 | packet_disconnect("socket: %.100s", strerror(saved)); | |
2158 | } | |
2159 | /* Create the socket. */ | |
2160 | sock = socket(AF_UNIX, SOCK_STREAM, 0); | |
2161 | if (sock < 0) | |
2162 | packet_disconnect("socket: %.100s", strerror(errno)); | |
2163 | ||
2164 | /* Bind it to the name. */ | |
2165 | memset(&sunaddr, 0, sizeof(sunaddr)); | |
2166 | sunaddr.sun_family = AF_UNIX; | |
2167 | strncpy(sunaddr.sun_path, channel_forwarded_auth_socket_name, | |
2168 | sizeof(sunaddr.sun_path)); | |
2169 | ||
2170 | if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0) | |
2171 | packet_disconnect("bind: %.100s", strerror(errno)); | |
2172 | ||
2173 | /* Restore the privileged uid. */ | |
2174 | restore_uid(); | |
2175 | ||
2176 | /* Start listening on the socket. */ | |
2177 | if (listen(sock, 5) < 0) | |
2178 | packet_disconnect("listen: %.100s", strerror(errno)); | |
2179 | ||
2180 | /* Allocate a channel for the authentication agent socket. */ | |
2181 | newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock, | |
2182 | xstrdup("auth socket")); | |
a408af76 | 2183 | strlcpy(channels[newch].path, channel_forwarded_auth_socket_name, |
2184 | sizeof(channels[newch].path)); | |
fa649821 | 2185 | return 1; |
8efc0c15 | 2186 | } |
2187 | ||
2188 | /* This is called to process an SSH_SMSG_AGENT_OPEN message. */ | |
2189 | ||
6ae2364d | 2190 | void |
7368a6c8 | 2191 | auth_input_open_request(int type, int plen) |
8efc0c15 | 2192 | { |
5260325f | 2193 | int remch, sock, newch; |
2194 | char *dummyname; | |
2195 | ||
7368a6c8 | 2196 | packet_integrity_check(plen, 4, type); |
2197 | ||
5260325f | 2198 | /* Read the remote channel number from the message. */ |
2199 | remch = packet_get_int(); | |
2200 | ||
aa3378df | 2201 | /* |
2202 | * Get a connection to the local authentication agent (this may again | |
2203 | * get forwarded). | |
2204 | */ | |
5260325f | 2205 | sock = ssh_get_authentication_socket(); |
2206 | ||
aa3378df | 2207 | /* |
2208 | * If we could not connect the agent, send an error message back to | |
2209 | * the server. This should never happen unless the agent dies, | |
2210 | * because authentication forwarding is only enabled if we have an | |
2211 | * agent. | |
2212 | */ | |
5260325f | 2213 | if (sock < 0) { |
2214 | packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE); | |
2215 | packet_put_int(remch); | |
2216 | packet_send(); | |
2217 | return; | |
2218 | } | |
2219 | debug("Forwarding authentication connection."); | |
2220 | ||
aa3378df | 2221 | /* |
2222 | * Dummy host name. This will be freed when the channel is freed; it | |
2223 | * will still be valid in the packet_put_string below since the | |
2224 | * channel cannot yet be freed at that point. | |
2225 | */ | |
5260325f | 2226 | dummyname = xstrdup("authentication agent connection"); |
2227 | ||
2228 | newch = channel_allocate(SSH_CHANNEL_OPEN, sock, dummyname); | |
2229 | channels[newch].remote_id = remch; | |
2230 | ||
2231 | /* Send a confirmation to the remote host. */ | |
2232 | packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION); | |
2233 | packet_put_int(remch); | |
2234 | packet_put_int(newch); | |
2235 | packet_send(); | |
8efc0c15 | 2236 | } |
7e7327a1 | 2237 | |
2238 | void | |
0b242b12 | 2239 | channel_start_open(int id) |
7e7327a1 | 2240 | { |
2241 | Channel *c = channel_lookup(id); | |
2242 | if (c == NULL) { | |
2243 | log("channel_open: %d: bad id", id); | |
2244 | return; | |
2245 | } | |
0b242b12 | 2246 | debug("send channel open %d", id); |
7e7327a1 | 2247 | packet_start(SSH2_MSG_CHANNEL_OPEN); |
2248 | packet_put_cstring(c->ctype); | |
2249 | packet_put_int(c->self); | |
2250 | packet_put_int(c->local_window); | |
2251 | packet_put_int(c->local_maxpacket); | |
0b242b12 | 2252 | } |
2253 | void | |
2254 | channel_open(int id) | |
2255 | { | |
2256 | /* XXX REMOVE ME */ | |
2257 | channel_start_open(id); | |
7e7327a1 | 2258 | packet_send(); |
7e7327a1 | 2259 | } |
2260 | void | |
2261 | channel_request(int id, char *service, int wantconfirm) | |
2262 | { | |
2263 | channel_request_start(id, service, wantconfirm); | |
2264 | packet_send(); | |
2265 | debug("channel request %d: %s", id, service) ; | |
2266 | } | |
2267 | void | |
2268 | channel_request_start(int id, char *service, int wantconfirm) | |
2269 | { | |
2270 | Channel *c = channel_lookup(id); | |
2271 | if (c == NULL) { | |
2272 | log("channel_request: %d: bad id", id); | |
2273 | return; | |
2274 | } | |
2275 | packet_start(SSH2_MSG_CHANNEL_REQUEST); | |
2276 | packet_put_int(c->remote_id); | |
2277 | packet_put_cstring(service); | |
2278 | packet_put_char(wantconfirm); | |
2279 | } | |
2280 | void | |
2281 | channel_register_callback(int id, int mtype, channel_callback_fn *fn, void *arg) | |
2282 | { | |
2283 | Channel *c = channel_lookup(id); | |
2284 | if (c == NULL) { | |
2285 | log("channel_register_callback: %d: bad id", id); | |
2286 | return; | |
2287 | } | |
2288 | c->cb_event = mtype; | |
2289 | c->cb_fn = fn; | |
2290 | c->cb_arg = arg; | |
2291 | } | |
2292 | void | |
2293 | channel_register_cleanup(int id, channel_callback_fn *fn) | |
2294 | { | |
2295 | Channel *c = channel_lookup(id); | |
2296 | if (c == NULL) { | |
2297 | log("channel_register_cleanup: %d: bad id", id); | |
2298 | return; | |
2299 | } | |
2300 | c->dettach_user = fn; | |
2301 | } | |
2302 | void | |
2303 | channel_cancel_cleanup(int id) | |
2304 | { | |
2305 | Channel *c = channel_lookup(id); | |
2306 | if (c == NULL) { | |
2307 | log("channel_cancel_cleanup: %d: bad id", id); | |
2308 | return; | |
2309 | } | |
2310 | c->dettach_user = NULL; | |
2311 | } | |
2312 | ||
2313 | void | |
2314 | channel_set_fds(int id, int rfd, int wfd, int efd, int extusage) | |
2315 | { | |
2316 | Channel *c = channel_lookup(id); | |
2317 | if (c == NULL || c->type != SSH_CHANNEL_LARVAL) | |
2318 | fatal("channel_activate for non-larval channel %d.", id); | |
0fbe8c74 | 2319 | |
2320 | channel_register_fds(c, rfd, wfd, efd, extusage); | |
7e7327a1 | 2321 | c->type = SSH_CHANNEL_OPEN; |
7e7327a1 | 2322 | /* XXX window size? */ |
2323 | c->local_window = c->local_window_max = c->local_maxpacket/2; | |
2324 | packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST); | |
2325 | packet_put_int(c->remote_id); | |
2326 | packet_put_int(c->local_window); | |
2327 | packet_send(); | |
2328 | } |