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8efc0c15 | 1 | /* |
5260325f | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5260325f | 5 | * Server main loop for handling the interactive session. |
bcbf86ec | 6 | * |
7 | * As far as I am concerned, the code I have written for this software | |
8 | * can be used freely for any purpose. Any derived versions of this | |
9 | * software must be clearly marked as such, and if the derived work is | |
10 | * incompatible with the protocol description in the RFC file, it must be | |
11 | * called by a name other than "ssh" or "Secure Shell". | |
12 | * | |
e78a59f5 | 13 | * SSH2 support by Markus Friedl. |
a96070d4 | 14 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. |
bcbf86ec | 15 | * |
16 | * Redistribution and use in source and binary forms, with or without | |
17 | * modification, are permitted provided that the following conditions | |
18 | * are met: | |
19 | * 1. Redistributions of source code must retain the above copyright | |
20 | * notice, this list of conditions and the following disclaimer. | |
21 | * 2. Redistributions in binary form must reproduce the above copyright | |
22 | * notice, this list of conditions and the following disclaimer in the | |
23 | * documentation and/or other materials provided with the distribution. | |
24 | * | |
25 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
26 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
27 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
28 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
29 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
30 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
31 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
32 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
33 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
34 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
e78a59f5 | 35 | */ |
8efc0c15 | 36 | |
37 | #include "includes.h" | |
a2b1748a | 38 | RCSID("$OpenBSD: serverloop.c,v 1.124 2005/12/13 15:03:02 reyk Exp $"); |
a22aff1f | 39 | |
8efc0c15 | 40 | #include "xmalloc.h" |
8efc0c15 | 41 | #include "packet.h" |
42 | #include "buffer.h" | |
42f11eb2 | 43 | #include "log.h" |
8efc0c15 | 44 | #include "servconf.h" |
00e842d8 | 45 | #include "canohost.h" |
1729c161 | 46 | #include "sshpty.h" |
a5efa1bb | 47 | #include "channels.h" |
7368a6c8 | 48 | #include "compat.h" |
42f11eb2 | 49 | #include "ssh1.h" |
e78a59f5 | 50 | #include "ssh2.h" |
59c97189 | 51 | #include "auth.h" |
e78a59f5 | 52 | #include "session.h" |
7368a6c8 | 53 | #include "dispatch.h" |
38c295d6 | 54 | #include "auth-options.h" |
42f11eb2 | 55 | #include "serverloop.h" |
56 | #include "misc.h" | |
7a37c112 | 57 | #include "kex.h" |
8efc0c15 | 58 | |
33de75a3 | 59 | extern ServerOptions options; |
60 | ||
7a37c112 | 61 | /* XXX */ |
62 | extern Kex *xxx_kex; | |
2362db19 | 63 | extern Authctxt *the_authctxt; |
0bbbf2a4 | 64 | extern int use_privsep; |
7a37c112 | 65 | |
8efc0c15 | 66 | static Buffer stdin_buffer; /* Buffer for stdin data. */ |
67 | static Buffer stdout_buffer; /* Buffer for stdout data. */ | |
68 | static Buffer stderr_buffer; /* Buffer for stderr data. */ | |
69 | static int fdin; /* Descriptor for stdin (for writing) */ | |
70 | static int fdout; /* Descriptor for stdout (for reading); | |
71 | May be same number as fdin. */ | |
72 | static int fderr; /* Descriptor for stderr. May be -1. */ | |
73 | static long stdin_bytes = 0; /* Number of bytes written to stdin. */ | |
74 | static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */ | |
75 | static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */ | |
76 | static long fdout_bytes = 0; /* Number of stdout bytes read from program. */ | |
77 | static int stdin_eof = 0; /* EOF message received from client. */ | |
78 | static int fdout_eof = 0; /* EOF encountered reading from fdout. */ | |
79 | static int fderr_eof = 0; /* EOF encountered readung from fderr. */ | |
e68225b2 | 80 | static int fdin_is_tty = 0; /* fdin points to a tty. */ |
8efc0c15 | 81 | static int connection_in; /* Connection to client (input). */ |
82 | static int connection_out; /* Connection to client (output). */ | |
cc94bd38 | 83 | static int connection_closed = 0; /* Connection to client closed. */ |
84 | static u_int buffer_high; /* "Soft" max buffer size. */ | |
72176c0e | 85 | static int client_alive_timeouts = 0; |
8efc0c15 | 86 | |
aa3378df | 87 | /* |
88 | * This SIGCHLD kludge is used to detect when the child exits. The server | |
89 | * will exit after that, as soon as forwarded connections have terminated. | |
90 | */ | |
396c147e | 91 | |
7a934d1b | 92 | static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */ |
8efc0c15 | 93 | |
0bbbf2a4 | 94 | /* Cleanup on signals (!use_privsep case only) */ |
95 | static volatile sig_atomic_t received_sigterm = 0; | |
96 | ||
396c147e | 97 | /* prototypes */ |
98 | static void server_init_dispatch(void); | |
7368a6c8 | 99 | |
a10be357 | 100 | /* |
101 | * we write to this pipe if a SIGCHLD is caught in order to avoid | |
102 | * the race between select() and child_terminated | |
103 | */ | |
104 | static int notify_pipe[2]; | |
105 | static void | |
106 | notify_setup(void) | |
107 | { | |
108 | if (pipe(notify_pipe) < 0) { | |
109 | error("pipe(notify_pipe) failed %s", strerror(errno)); | |
110 | } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) || | |
111 | (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) { | |
112 | error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno)); | |
113 | close(notify_pipe[0]); | |
114 | close(notify_pipe[1]); | |
115 | } else { | |
116 | set_nonblock(notify_pipe[0]); | |
117 | set_nonblock(notify_pipe[1]); | |
118 | return; | |
119 | } | |
120 | notify_pipe[0] = -1; /* read end */ | |
121 | notify_pipe[1] = -1; /* write end */ | |
122 | } | |
123 | static void | |
124 | notify_parent(void) | |
125 | { | |
126 | if (notify_pipe[1] != -1) | |
127 | write(notify_pipe[1], "", 1); | |
128 | } | |
129 | static void | |
130 | notify_prepare(fd_set *readset) | |
131 | { | |
132 | if (notify_pipe[0] != -1) | |
133 | FD_SET(notify_pipe[0], readset); | |
134 | } | |
135 | static void | |
136 | notify_done(fd_set *readset) | |
137 | { | |
138 | char c; | |
139 | ||
140 | if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset)) | |
141 | while (read(notify_pipe[0], &c, 1) != -1) | |
142 | debug2("notify_done: reading"); | |
143 | } | |
144 | ||
396c147e | 145 | static void |
5260325f | 146 | sigchld_handler(int sig) |
e78a59f5 | 147 | { |
148 | int save_errno = errno; | |
149 | debug("Received SIGCHLD."); | |
150 | child_terminated = 1; | |
ef51930f | 151 | #ifndef _UNICOS |
c9130033 | 152 | mysignal(SIGCHLD, sigchld_handler); |
ef51930f | 153 | #endif |
a10be357 | 154 | notify_parent(); |
e78a59f5 | 155 | errno = save_errno; |
156 | } | |
8efc0c15 | 157 | |
0bbbf2a4 | 158 | static void |
159 | sigterm_handler(int sig) | |
160 | { | |
161 | received_sigterm = sig; | |
162 | } | |
163 | ||
5260325f | 164 | /* |
165 | * Make packets from buffered stderr data, and buffer it for sending | |
166 | * to the client. | |
167 | */ | |
396c147e | 168 | static void |
5ca51e19 | 169 | make_packets_from_stderr_data(void) |
8efc0c15 | 170 | { |
a27002e5 | 171 | u_int len; |
5260325f | 172 | |
173 | /* Send buffered stderr data to the client. */ | |
174 | while (buffer_len(&stderr_buffer) > 0 && | |
a408af76 | 175 | packet_not_very_much_data_to_write()) { |
5260325f | 176 | len = buffer_len(&stderr_buffer); |
177 | if (packet_is_interactive()) { | |
178 | if (len > 512) | |
179 | len = 512; | |
180 | } else { | |
181 | /* Keep the packets at reasonable size. */ | |
182 | if (len > packet_get_maxsize()) | |
183 | len = packet_get_maxsize(); | |
184 | } | |
185 | packet_start(SSH_SMSG_STDERR_DATA); | |
186 | packet_put_string(buffer_ptr(&stderr_buffer), len); | |
187 | packet_send(); | |
188 | buffer_consume(&stderr_buffer, len); | |
189 | stderr_bytes += len; | |
8efc0c15 | 190 | } |
8efc0c15 | 191 | } |
192 | ||
5260325f | 193 | /* |
194 | * Make packets from buffered stdout data, and buffer it for sending to the | |
195 | * client. | |
196 | */ | |
396c147e | 197 | static void |
5ca51e19 | 198 | make_packets_from_stdout_data(void) |
8efc0c15 | 199 | { |
a27002e5 | 200 | u_int len; |
5260325f | 201 | |
202 | /* Send buffered stdout data to the client. */ | |
203 | while (buffer_len(&stdout_buffer) > 0 && | |
a408af76 | 204 | packet_not_very_much_data_to_write()) { |
5260325f | 205 | len = buffer_len(&stdout_buffer); |
206 | if (packet_is_interactive()) { | |
207 | if (len > 512) | |
208 | len = 512; | |
209 | } else { | |
210 | /* Keep the packets at reasonable size. */ | |
211 | if (len > packet_get_maxsize()) | |
2b87da3b | 212 | len = packet_get_maxsize(); |
5260325f | 213 | } |
214 | packet_start(SSH_SMSG_STDOUT_DATA); | |
215 | packet_put_string(buffer_ptr(&stdout_buffer), len); | |
216 | packet_send(); | |
217 | buffer_consume(&stdout_buffer, len); | |
218 | stdout_bytes += len; | |
8efc0c15 | 219 | } |
8efc0c15 | 220 | } |
221 | ||
72176c0e | 222 | static void |
223 | client_alive_check(void) | |
224 | { | |
95ae2076 | 225 | int channel_id; |
99416ceb | 226 | |
72176c0e | 227 | /* timeout, check to see how many we have had */ |
228 | if (++client_alive_timeouts > options.client_alive_count_max) | |
229 | packet_disconnect("Timeout, your session not responding."); | |
230 | ||
72176c0e | 231 | /* |
95ae2076 | 232 | * send a bogus global/channel request with "wantreply", |
72176c0e | 233 | * we should get back a failure |
234 | */ | |
95ae2076 | 235 | if ((channel_id = channel_find_open()) == -1) { |
236 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
237 | packet_put_cstring("keepalive@openssh.com"); | |
238 | packet_put_char(1); /* boolean: want reply */ | |
239 | } else { | |
240 | channel_request_start(channel_id, "keepalive@openssh.com", 1); | |
241 | } | |
72176c0e | 242 | packet_send(); |
243 | } | |
244 | ||
5260325f | 245 | /* |
246 | * Sleep in select() until we can do something. This will initialize the | |
247 | * select masks. Upon return, the masks will indicate which descriptors | |
248 | * have data or can accept data. Optionally, a maximum time can be specified | |
249 | * for the duration of the wait (0 = infinite). | |
250 | */ | |
396c147e | 251 | static void |
39929cdb | 252 | wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, |
9a995072 | 253 | u_int *nallocp, u_int max_time_milliseconds) |
8efc0c15 | 254 | { |
5260325f | 255 | struct timeval tv, *tvp; |
256 | int ret; | |
3ffc6336 | 257 | int client_alive_scheduled = 0; |
258 | ||
259 | /* | |
184eed6a | 260 | * if using client_alive, set the max timeout accordingly, |
3ffc6336 | 261 | * and indicate that this particular timeout was for client |
262 | * alive by setting the client_alive_scheduled flag. | |
263 | * | |
264 | * this could be randomized somewhat to make traffic | |
184eed6a | 265 | * analysis more difficult, but we're not doing it yet. |
3ffc6336 | 266 | */ |
2c5b1791 | 267 | if (compat20 && |
268 | max_time_milliseconds == 0 && options.client_alive_interval) { | |
39aefe7b | 269 | client_alive_scheduled = 1; |
3ffc6336 | 270 | max_time_milliseconds = options.client_alive_interval * 1000; |
2c5b1791 | 271 | } |
8efc0c15 | 272 | |
39929cdb | 273 | /* Allocate and update select() masks for channel descriptors. */ |
489aa2e9 | 274 | channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0); |
5260325f | 275 | |
e78a59f5 | 276 | if (compat20) { |
0c139bd1 | 277 | #if 0 |
1d1ffb87 | 278 | /* wrong: bad condition XXX */ |
e78a59f5 | 279 | if (channel_not_very_much_buffered_data()) |
0c139bd1 | 280 | #endif |
281 | FD_SET(connection_in, *readsetp); | |
e78a59f5 | 282 | } else { |
71276795 | 283 | /* |
284 | * Read packets from the client unless we have too much | |
285 | * buffered stdin or channel data. | |
286 | */ | |
287 | if (buffer_len(&stdin_buffer) < buffer_high && | |
e78a59f5 | 288 | channel_not_very_much_buffered_data()) |
39929cdb | 289 | FD_SET(connection_in, *readsetp); |
71276795 | 290 | /* |
291 | * If there is not too much data already buffered going to | |
292 | * the client, try to get some more data from the program. | |
293 | */ | |
294 | if (packet_not_very_much_data_to_write()) { | |
295 | if (!fdout_eof) | |
39929cdb | 296 | FD_SET(fdout, *readsetp); |
71276795 | 297 | if (!fderr_eof) |
39929cdb | 298 | FD_SET(fderr, *readsetp); |
71276795 | 299 | } |
300 | /* | |
301 | * If we have buffered data, try to write some of that data | |
302 | * to the program. | |
303 | */ | |
304 | if (fdin != -1 && buffer_len(&stdin_buffer) > 0) | |
39929cdb | 305 | FD_SET(fdin, *writesetp); |
e78a59f5 | 306 | } |
a10be357 | 307 | notify_prepare(*readsetp); |
5260325f | 308 | |
aa3378df | 309 | /* |
310 | * If we have buffered packet data going to the client, mark that | |
311 | * descriptor. | |
312 | */ | |
5260325f | 313 | if (packet_have_data_to_write()) |
39929cdb | 314 | FD_SET(connection_out, *writesetp); |
5260325f | 315 | |
aa3378df | 316 | /* |
317 | * If child has terminated and there is enough buffer space to read | |
318 | * from it, then read as much as is available and exit. | |
319 | */ | |
5260325f | 320 | if (child_terminated && packet_not_very_much_data_to_write()) |
3ffc6336 | 321 | if (max_time_milliseconds == 0 || client_alive_scheduled) |
5260325f | 322 | max_time_milliseconds = 100; |
323 | ||
324 | if (max_time_milliseconds == 0) | |
325 | tvp = NULL; | |
326 | else { | |
327 | tv.tv_sec = max_time_milliseconds / 1000; | |
328 | tv.tv_usec = 1000 * (max_time_milliseconds % 1000); | |
329 | tvp = &tv; | |
330 | } | |
8efc0c15 | 331 | |
5260325f | 332 | /* Wait for something to happen, or the timeout to expire. */ |
39929cdb | 333 | ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); |
8efc0c15 | 334 | |
3ffc6336 | 335 | if (ret == -1) { |
b3ad8fe6 | 336 | memset(*readsetp, 0, *nallocp); |
337 | memset(*writesetp, 0, *nallocp); | |
5260325f | 338 | if (errno != EINTR) |
339 | error("select: %.100s", strerror(errno)); | |
418e724c | 340 | } else if (ret == 0 && client_alive_scheduled) |
72176c0e | 341 | client_alive_check(); |
a10be357 | 342 | |
343 | notify_done(*readsetp); | |
8efc0c15 | 344 | } |
345 | ||
5260325f | 346 | /* |
347 | * Processes input from the client and the program. Input data is stored | |
348 | * in buffers and processed later. | |
349 | */ | |
396c147e | 350 | static void |
5260325f | 351 | process_input(fd_set * readset) |
352 | { | |
353 | int len; | |
354 | char buf[16384]; | |
355 | ||
356 | /* Read and buffer any input data from the client. */ | |
357 | if (FD_ISSET(connection_in, readset)) { | |
358 | len = read(connection_in, buf, sizeof(buf)); | |
359 | if (len == 0) { | |
00e842d8 | 360 | verbose("Connection closed by %.100s", |
361 | get_remote_ipaddr()); | |
cc94bd38 | 362 | connection_closed = 1; |
363 | if (compat20) | |
364 | return; | |
2362db19 | 365 | cleanup_exit(255); |
0e73cc53 | 366 | } else if (len < 0) { |
367 | if (errno != EINTR && errno != EAGAIN) { | |
00e842d8 | 368 | verbose("Read error from remote host " |
369 | "%.100s: %.100s", | |
370 | get_remote_ipaddr(), strerror(errno)); | |
2362db19 | 371 | cleanup_exit(255); |
0e73cc53 | 372 | } |
373 | } else { | |
374 | /* Buffer any received data. */ | |
375 | packet_process_incoming(buf, len); | |
5260325f | 376 | } |
5260325f | 377 | } |
e78a59f5 | 378 | if (compat20) |
379 | return; | |
380 | ||
5260325f | 381 | /* Read and buffer any available stdout data from the program. */ |
382 | if (!fdout_eof && FD_ISSET(fdout, readset)) { | |
383 | len = read(fdout, buf, sizeof(buf)); | |
0e73cc53 | 384 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) { |
385 | /* do nothing */ | |
386 | } else if (len <= 0) { | |
5260325f | 387 | fdout_eof = 1; |
0e73cc53 | 388 | } else { |
5260325f | 389 | buffer_append(&stdout_buffer, buf, len); |
390 | fdout_bytes += len; | |
391 | } | |
392 | } | |
393 | /* Read and buffer any available stderr data from the program. */ | |
394 | if (!fderr_eof && FD_ISSET(fderr, readset)) { | |
395 | len = read(fderr, buf, sizeof(buf)); | |
0e73cc53 | 396 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) { |
397 | /* do nothing */ | |
398 | } else if (len <= 0) { | |
5260325f | 399 | fderr_eof = 1; |
0e73cc53 | 400 | } else { |
5260325f | 401 | buffer_append(&stderr_buffer, buf, len); |
0e73cc53 | 402 | } |
5260325f | 403 | } |
404 | } | |
8efc0c15 | 405 | |
5260325f | 406 | /* |
407 | * Sends data from internal buffers to client program stdin. | |
408 | */ | |
396c147e | 409 | static void |
5260325f | 410 | process_output(fd_set * writeset) |
8efc0c15 | 411 | { |
4ef922e3 | 412 | struct termios tio; |
780a9951 | 413 | u_char *data; |
414 | u_int dlen; | |
5260325f | 415 | int len; |
416 | ||
417 | /* Write buffered data to program stdin. */ | |
e78a59f5 | 418 | if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) { |
780a9951 | 419 | data = buffer_ptr(&stdin_buffer); |
420 | dlen = buffer_len(&stdin_buffer); | |
421 | len = write(fdin, data, dlen); | |
0e73cc53 | 422 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) { |
423 | /* do nothing */ | |
424 | } else if (len <= 0) { | |
7368a6c8 | 425 | if (fdin != fdout) |
5260325f | 426 | close(fdin); |
427 | else | |
428 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
5260325f | 429 | fdin = -1; |
430 | } else { | |
4ef922e3 | 431 | /* Successful write. */ |
780a9951 | 432 | if (fdin_is_tty && dlen >= 1 && data[0] != '\r' && |
433 | tcgetattr(fdin, &tio) == 0 && | |
0ae4fe1d | 434 | !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { |
62da27dd | 435 | /* |
436 | * Simulate echo to reduce the impact of | |
437 | * traffic analysis | |
438 | */ | |
95ce5599 | 439 | packet_send_ignore(len); |
4ef922e3 | 440 | packet_send(); |
441 | } | |
442 | /* Consume the data from the buffer. */ | |
5260325f | 443 | buffer_consume(&stdin_buffer, len); |
444 | /* Update the count of bytes written to the program. */ | |
445 | stdin_bytes += len; | |
446 | } | |
8efc0c15 | 447 | } |
5260325f | 448 | /* Send any buffered packet data to the client. */ |
449 | if (FD_ISSET(connection_out, writeset)) | |
450 | packet_write_poll(); | |
8efc0c15 | 451 | } |
452 | ||
5260325f | 453 | /* |
454 | * Wait until all buffered output has been sent to the client. | |
455 | * This is used when the program terminates. | |
456 | */ | |
396c147e | 457 | static void |
5ca51e19 | 458 | drain_output(void) |
8efc0c15 | 459 | { |
5260325f | 460 | /* Send any buffered stdout data to the client. */ |
461 | if (buffer_len(&stdout_buffer) > 0) { | |
462 | packet_start(SSH_SMSG_STDOUT_DATA); | |
463 | packet_put_string(buffer_ptr(&stdout_buffer), | |
464 | buffer_len(&stdout_buffer)); | |
465 | packet_send(); | |
466 | /* Update the count of sent bytes. */ | |
467 | stdout_bytes += buffer_len(&stdout_buffer); | |
468 | } | |
469 | /* Send any buffered stderr data to the client. */ | |
470 | if (buffer_len(&stderr_buffer) > 0) { | |
471 | packet_start(SSH_SMSG_STDERR_DATA); | |
472 | packet_put_string(buffer_ptr(&stderr_buffer), | |
473 | buffer_len(&stderr_buffer)); | |
474 | packet_send(); | |
475 | /* Update the count of sent bytes. */ | |
476 | stderr_bytes += buffer_len(&stderr_buffer); | |
477 | } | |
478 | /* Wait until all buffered data has been written to the client. */ | |
479 | packet_write_wait(); | |
8efc0c15 | 480 | } |
481 | ||
396c147e | 482 | static void |
5ca51e19 | 483 | process_buffered_input_packets(void) |
7368a6c8 | 484 | { |
7a37c112 | 485 | dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL); |
7368a6c8 | 486 | } |
487 | ||
5260325f | 488 | /* |
489 | * Performs the interactive session. This handles data transmission between | |
490 | * the client and the program. Note that the notion of stdin, stdout, and | |
491 | * stderr in this function is sort of reversed: this function writes to | |
492 | * stdin (of the child program), and reads from stdout and stderr (of the | |
493 | * child program). | |
494 | */ | |
6ae2364d | 495 | void |
9da5c3c9 | 496 | server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) |
8efc0c15 | 497 | { |
39929cdb | 498 | fd_set *readset = NULL, *writeset = NULL; |
9a995072 | 499 | int max_fd = 0; |
500 | u_int nalloc = 0; | |
9da5c3c9 | 501 | int wait_status; /* Status returned by wait(). */ |
502 | pid_t wait_pid; /* pid returned by wait(). */ | |
5260325f | 503 | int waiting_termination = 0; /* Have displayed waiting close message. */ |
1e3b8b07 | 504 | u_int max_time_milliseconds; |
505 | u_int previous_stdout_buffer_bytes; | |
506 | u_int stdout_buffer_bytes; | |
5260325f | 507 | int type; |
508 | ||
509 | debug("Entering interactive session."); | |
510 | ||
511 | /* Initialize the SIGCHLD kludge. */ | |
5260325f | 512 | child_terminated = 0; |
42ad0eec | 513 | mysignal(SIGCHLD, sigchld_handler); |
5260325f | 514 | |
0bbbf2a4 | 515 | if (!use_privsep) { |
516 | signal(SIGTERM, sigterm_handler); | |
517 | signal(SIGINT, sigterm_handler); | |
518 | signal(SIGQUIT, sigterm_handler); | |
519 | } | |
520 | ||
5260325f | 521 | /* Initialize our global variables. */ |
522 | fdin = fdin_arg; | |
523 | fdout = fdout_arg; | |
524 | fderr = fderr_arg; | |
0e73cc53 | 525 | |
526 | /* nonblocking IO */ | |
527 | set_nonblock(fdin); | |
528 | set_nonblock(fdout); | |
ff873e98 | 529 | /* we don't have stderr for interactive terminal sessions, see below */ |
530 | if (fderr != -1) | |
531 | set_nonblock(fderr); | |
0e73cc53 | 532 | |
e68225b2 | 533 | if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin)) |
534 | fdin_is_tty = 1; | |
535 | ||
5260325f | 536 | connection_in = packet_get_connection_in(); |
537 | connection_out = packet_get_connection_out(); | |
538 | ||
a10be357 | 539 | notify_setup(); |
540 | ||
5260325f | 541 | previous_stdout_buffer_bytes = 0; |
542 | ||
543 | /* Set approximate I/O buffer size. */ | |
544 | if (packet_is_interactive()) | |
545 | buffer_high = 4096; | |
546 | else | |
547 | buffer_high = 64 * 1024; | |
548 | ||
489aa2e9 | 549 | #if 0 |
5260325f | 550 | /* Initialize max_fd to the maximum of the known file descriptors. */ |
489aa2e9 | 551 | max_fd = MAX(connection_in, connection_out); |
552 | max_fd = MAX(max_fd, fdin); | |
553 | max_fd = MAX(max_fd, fdout); | |
39929cdb | 554 | if (fderr != -1) |
555 | max_fd = MAX(max_fd, fderr); | |
489aa2e9 | 556 | #endif |
5260325f | 557 | |
558 | /* Initialize Initialize buffers. */ | |
559 | buffer_init(&stdin_buffer); | |
560 | buffer_init(&stdout_buffer); | |
561 | buffer_init(&stderr_buffer); | |
562 | ||
aa3378df | 563 | /* |
564 | * If we have no separate fderr (which is the case when we have a pty | |
565 | * - there we cannot make difference between data sent to stdout and | |
566 | * stderr), indicate that we have seen an EOF from stderr. This way | |
7b9b0103 | 567 | * we don't need to check the descriptor everywhere. |
aa3378df | 568 | */ |
5260325f | 569 | if (fderr == -1) |
570 | fderr_eof = 1; | |
571 | ||
7368a6c8 | 572 | server_init_dispatch(); |
573 | ||
5260325f | 574 | /* Main loop of the server for the interactive session mode. */ |
575 | for (;;) { | |
5260325f | 576 | |
577 | /* Process buffered packets from the client. */ | |
578 | process_buffered_input_packets(); | |
579 | ||
aa3378df | 580 | /* |
581 | * If we have received eof, and there is no more pending | |
582 | * input data, cause a real eof by closing fdin. | |
583 | */ | |
5260325f | 584 | if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) { |
7368a6c8 | 585 | if (fdin != fdout) |
5260325f | 586 | close(fdin); |
587 | else | |
588 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
5260325f | 589 | fdin = -1; |
590 | } | |
aa3378df | 591 | /* Make packets from buffered stderr data to send to the client. */ |
5260325f | 592 | make_packets_from_stderr_data(); |
593 | ||
aa3378df | 594 | /* |
595 | * Make packets from buffered stdout data to send to the | |
596 | * client. If there is very little to send, this arranges to | |
597 | * not send them now, but to wait a short while to see if we | |
598 | * are getting more data. This is necessary, as some systems | |
599 | * wake up readers from a pty after each separate character. | |
600 | */ | |
5260325f | 601 | max_time_milliseconds = 0; |
602 | stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
603 | if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && | |
604 | stdout_buffer_bytes != previous_stdout_buffer_bytes) { | |
605 | /* try again after a while */ | |
606 | max_time_milliseconds = 10; | |
607 | } else { | |
608 | /* Send it now. */ | |
609 | make_packets_from_stdout_data(); | |
610 | } | |
611 | previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
612 | ||
613 | /* Send channel data to the client. */ | |
614 | if (packet_not_very_much_data_to_write()) | |
615 | channel_output_poll(); | |
616 | ||
aa3378df | 617 | /* |
618 | * Bail out of the loop if the program has closed its output | |
619 | * descriptors, and we have no more data to send to the | |
620 | * client, and there is no pending buffered data. | |
621 | */ | |
7062c40f | 622 | if (fdout_eof && fderr_eof && !packet_have_data_to_write() && |
623 | buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { | |
5260325f | 624 | if (!channel_still_open()) |
7368a6c8 | 625 | break; |
5260325f | 626 | if (!waiting_termination) { |
627 | const char *s = "Waiting for forwarded connections to terminate...\r\n"; | |
628 | char *cp; | |
629 | waiting_termination = 1; | |
630 | buffer_append(&stderr_buffer, s, strlen(s)); | |
631 | ||
632 | /* Display list of open channels. */ | |
633 | cp = channel_open_message(); | |
634 | buffer_append(&stderr_buffer, cp, strlen(cp)); | |
635 | xfree(cp); | |
636 | } | |
637 | } | |
489aa2e9 | 638 | max_fd = MAX(connection_in, connection_out); |
639 | max_fd = MAX(max_fd, fdin); | |
640 | max_fd = MAX(max_fd, fdout); | |
641 | max_fd = MAX(max_fd, fderr); | |
a10be357 | 642 | max_fd = MAX(max_fd, notify_pipe[0]); |
489aa2e9 | 643 | |
5260325f | 644 | /* Sleep in select() until we can do something. */ |
39929cdb | 645 | wait_until_can_do_something(&readset, &writeset, &max_fd, |
489aa2e9 | 646 | &nalloc, max_time_milliseconds); |
5260325f | 647 | |
0bbbf2a4 | 648 | if (received_sigterm) { |
649 | logit("Exiting on signal %d", received_sigterm); | |
650 | /* Clean up sessions, utmp, etc. */ | |
651 | cleanup_exit(255); | |
652 | } | |
653 | ||
5260325f | 654 | /* Process any channel events. */ |
39929cdb | 655 | channel_after_select(readset, writeset); |
5260325f | 656 | |
657 | /* Process input from the client and from program stdout/stderr. */ | |
39929cdb | 658 | process_input(readset); |
5260325f | 659 | |
660 | /* Process output to the client and to program stdin. */ | |
39929cdb | 661 | process_output(writeset); |
8efc0c15 | 662 | } |
39929cdb | 663 | if (readset) |
664 | xfree(readset); | |
665 | if (writeset) | |
666 | xfree(writeset); | |
8efc0c15 | 667 | |
5260325f | 668 | /* Cleanup and termination code. */ |
8efc0c15 | 669 | |
5260325f | 670 | /* Wait until all output has been sent to the client. */ |
671 | drain_output(); | |
8efc0c15 | 672 | |
5260325f | 673 | debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", |
184eed6a | 674 | stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); |
8efc0c15 | 675 | |
5260325f | 676 | /* Free and clear the buffers. */ |
677 | buffer_free(&stdin_buffer); | |
678 | buffer_free(&stdout_buffer); | |
679 | buffer_free(&stderr_buffer); | |
8efc0c15 | 680 | |
5260325f | 681 | /* Close the file descriptors. */ |
682 | if (fdout != -1) | |
683 | close(fdout); | |
684 | fdout = -1; | |
685 | fdout_eof = 1; | |
686 | if (fderr != -1) | |
687 | close(fderr); | |
688 | fderr = -1; | |
689 | fderr_eof = 1; | |
690 | if (fdin != -1) | |
691 | close(fdin); | |
692 | fdin = -1; | |
693 | ||
d6746a0b | 694 | channel_free_all(); |
5260325f | 695 | |
5260325f | 696 | /* We no longer want our SIGCHLD handler to be called. */ |
42ad0eec | 697 | mysignal(SIGCHLD, SIG_DFL); |
5260325f | 698 | |
8c38e88b | 699 | while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0) |
700 | if (errno != EINTR) | |
701 | packet_disconnect("wait: %.100s", strerror(errno)); | |
702 | if (wait_pid != pid) | |
c457707e | 703 | error("Strange, wait returned pid %ld, expected %ld", |
704 | (long)wait_pid, (long)pid); | |
c9130033 | 705 | |
5260325f | 706 | /* Check if it exited normally. */ |
707 | if (WIFEXITED(wait_status)) { | |
708 | /* Yes, normal exit. Get exit status and send it to the client. */ | |
709 | debug("Command exited with status %d.", WEXITSTATUS(wait_status)); | |
710 | packet_start(SSH_SMSG_EXITSTATUS); | |
711 | packet_put_int(WEXITSTATUS(wait_status)); | |
712 | packet_send(); | |
713 | packet_write_wait(); | |
714 | ||
aa3378df | 715 | /* |
716 | * Wait for exit confirmation. Note that there might be | |
717 | * other packets coming before it; however, the program has | |
718 | * already died so we just ignore them. The client is | |
719 | * supposed to respond with the confirmation when it receives | |
720 | * the exit status. | |
721 | */ | |
5260325f | 722 | do { |
54a5250f | 723 | type = packet_read(); |
5260325f | 724 | } |
725 | while (type != SSH_CMSG_EXIT_CONFIRMATION); | |
726 | ||
727 | debug("Received exit confirmation."); | |
728 | return; | |
729 | } | |
730 | /* Check if the program terminated due to a signal. */ | |
731 | if (WIFSIGNALED(wait_status)) | |
732 | packet_disconnect("Command terminated on signal %d.", | |
733 | WTERMSIG(wait_status)); | |
734 | ||
735 | /* Some weird exit cause. Just exit. */ | |
736 | packet_disconnect("wait returned status %04x.", wait_status); | |
737 | /* NOTREACHED */ | |
738 | } | |
7368a6c8 | 739 | |
418e724c | 740 | static void |
741 | collect_children(void) | |
742 | { | |
743 | pid_t pid; | |
744 | sigset_t oset, nset; | |
745 | int status; | |
746 | ||
747 | /* block SIGCHLD while we check for dead children */ | |
748 | sigemptyset(&nset); | |
749 | sigaddset(&nset, SIGCHLD); | |
750 | sigprocmask(SIG_BLOCK, &nset, &oset); | |
751 | if (child_terminated) { | |
8c38e88b | 752 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
753 | (pid < 0 && errno == EINTR)) | |
754 | if (pid > 0) | |
755 | session_close_by_pid(pid, status); | |
418e724c | 756 | child_terminated = 0; |
757 | } | |
758 | sigprocmask(SIG_SETMASK, &oset, NULL); | |
759 | } | |
760 | ||
6ae2364d | 761 | void |
57156994 | 762 | server_loop2(Authctxt *authctxt) |
e78a59f5 | 763 | { |
39929cdb | 764 | fd_set *readset = NULL, *writeset = NULL; |
418e724c | 765 | int rekeying = 0, max_fd, nalloc = 0; |
e78a59f5 | 766 | |
767 | debug("Entering interactive session for SSH2."); | |
768 | ||
c9130033 | 769 | mysignal(SIGCHLD, sigchld_handler); |
e78a59f5 | 770 | child_terminated = 0; |
771 | connection_in = packet_get_connection_in(); | |
772 | connection_out = packet_get_connection_out(); | |
39929cdb | 773 | |
0bbbf2a4 | 774 | if (!use_privsep) { |
775 | signal(SIGTERM, sigterm_handler); | |
776 | signal(SIGINT, sigterm_handler); | |
777 | signal(SIGQUIT, sigterm_handler); | |
778 | } | |
779 | ||
a10be357 | 780 | notify_setup(); |
781 | ||
39929cdb | 782 | max_fd = MAX(connection_in, connection_out); |
a10be357 | 783 | max_fd = MAX(max_fd, notify_pipe[0]); |
784 | ||
e78a59f5 | 785 | server_init_dispatch(); |
786 | ||
787 | for (;;) { | |
788 | process_buffered_input_packets(); | |
bbb4cc1b | 789 | |
cd332296 | 790 | rekeying = (xxx_kex != NULL && !xxx_kex->done); |
bbb4cc1b | 791 | |
bbb4cc1b | 792 | if (!rekeying && packet_not_very_much_data_to_write()) |
e78a59f5 | 793 | channel_output_poll(); |
bbb4cc1b | 794 | wait_until_can_do_something(&readset, &writeset, &max_fd, |
489aa2e9 | 795 | &nalloc, 0); |
d5f24f94 | 796 | |
0bbbf2a4 | 797 | if (received_sigterm) { |
798 | logit("Exiting on signal %d", received_sigterm); | |
799 | /* Clean up sessions, utmp, etc. */ | |
800 | cleanup_exit(255); | |
801 | } | |
802 | ||
418e724c | 803 | collect_children(); |
ffd7b36b | 804 | if (!rekeying) { |
bbb4cc1b | 805 | channel_after_select(readset, writeset); |
ffd7b36b | 806 | if (packet_need_rekeying()) { |
807 | debug("need rekeying"); | |
808 | xxx_kex->done = 0; | |
809 | kex_send_kexinit(xxx_kex); | |
810 | } | |
811 | } | |
39929cdb | 812 | process_input(readset); |
cc94bd38 | 813 | if (connection_closed) |
814 | break; | |
39929cdb | 815 | process_output(writeset); |
e78a59f5 | 816 | } |
418e724c | 817 | collect_children(); |
818 | ||
39929cdb | 819 | if (readset) |
820 | xfree(readset); | |
821 | if (writeset) | |
822 | xfree(writeset); | |
823 | ||
d5f24f94 | 824 | /* free all channels, no more reads and writes */ |
825 | channel_free_all(); | |
5b5d170c | 826 | |
418e724c | 827 | /* free remaining sessions, e.g. remove wtmp entries */ |
1853d1ef | 828 | session_destroy_all(NULL); |
e78a59f5 | 829 | } |
830 | ||
396c147e | 831 | static void |
95ae2076 | 832 | server_input_keep_alive(int type, u_int32_t seq, void *ctxt) |
3ffc6336 | 833 | { |
95ae2076 | 834 | debug("Got %d/%u for keepalive", type, seq); |
184eed6a | 835 | /* |
39aefe7b | 836 | * reset timeout, since we got a sane answer from the client. |
3ffc6336 | 837 | * even if this was generated by something other than |
838 | * the bogus CHANNEL_REQUEST we send for keepalives. | |
839 | */ | |
184eed6a | 840 | client_alive_timeouts = 0; |
3ffc6336 | 841 | } |
842 | ||
396c147e | 843 | static void |
7819b5c3 | 844 | server_input_stdin_data(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 845 | { |
846 | char *data; | |
1e3b8b07 | 847 | u_int data_len; |
7368a6c8 | 848 | |
849 | /* Stdin data from the client. Append it to the buffer. */ | |
850 | /* Ignore any data if the client has closed stdin. */ | |
851 | if (fdin == -1) | |
852 | return; | |
853 | data = packet_get_string(&data_len); | |
95500969 | 854 | packet_check_eom(); |
7368a6c8 | 855 | buffer_append(&stdin_buffer, data, data_len); |
856 | memset(data, 0, data_len); | |
857 | xfree(data); | |
858 | } | |
859 | ||
396c147e | 860 | static void |
7819b5c3 | 861 | server_input_eof(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 862 | { |
863 | /* | |
864 | * Eof from the client. The stdin descriptor to the | |
865 | * program will be closed when all buffered data has | |
866 | * drained. | |
867 | */ | |
868 | debug("EOF received for stdin."); | |
95500969 | 869 | packet_check_eom(); |
7368a6c8 | 870 | stdin_eof = 1; |
871 | } | |
872 | ||
396c147e | 873 | static void |
7819b5c3 | 874 | server_input_window_size(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 875 | { |
876 | int row = packet_get_int(); | |
877 | int col = packet_get_int(); | |
878 | int xpixel = packet_get_int(); | |
879 | int ypixel = packet_get_int(); | |
880 | ||
881 | debug("Window change received."); | |
95500969 | 882 | packet_check_eom(); |
7368a6c8 | 883 | if (fdin != -1) |
884 | pty_change_window_size(fdin, row, col, xpixel, ypixel); | |
885 | } | |
886 | ||
396c147e | 887 | static Channel * |
43f7a4b8 | 888 | server_request_direct_tcpip(void) |
e78a59f5 | 889 | { |
719fc62f | 890 | Channel *c; |
891 | int sock; | |
6ae2364d | 892 | char *target, *originator; |
893 | int target_port, originator_port; | |
e78a59f5 | 894 | |
6ae2364d | 895 | target = packet_get_string(NULL); |
896 | target_port = packet_get_int(); | |
e78a59f5 | 897 | originator = packet_get_string(NULL); |
898 | originator_port = packet_get_int(); | |
95500969 | 899 | packet_check_eom(); |
71276795 | 900 | |
fa08c86b | 901 | debug("server_request_direct_tcpip: originator %s port %d, target %s port %d", |
4e2e5cfd | 902 | originator, originator_port, target, target_port); |
38c295d6 | 903 | |
e78a59f5 | 904 | /* XXX check permission */ |
6ae2364d | 905 | sock = channel_connect_to(target, target_port); |
906 | xfree(target); | |
e78a59f5 | 907 | xfree(originator); |
908 | if (sock < 0) | |
fa08c86b | 909 | return NULL; |
43f7a4b8 | 910 | c = channel_new("direct-tcpip", SSH_CHANNEL_CONNECTING, |
bcbf86ec | 911 | sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT, |
0d942eff | 912 | CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1); |
719fc62f | 913 | return c; |
fa08c86b | 914 | } |
915 | ||
d20f3c9e | 916 | static Channel * |
917 | server_request_tun(void) | |
918 | { | |
919 | Channel *c = NULL; | |
a4f24bf8 | 920 | int mode, tun; |
921 | int sock; | |
d20f3c9e | 922 | |
a4f24bf8 | 923 | mode = packet_get_int(); |
924 | switch (mode) { | |
925 | case SSH_TUNMODE_POINTOPOINT: | |
926 | case SSH_TUNMODE_ETHERNET: | |
927 | break; | |
928 | default: | |
929 | packet_send_debug("Unsupported tunnel device mode."); | |
930 | return NULL; | |
931 | } | |
932 | if ((options.permit_tun & mode) == 0) { | |
933 | packet_send_debug("Server has rejected tunnel device " | |
934 | "forwarding"); | |
d20f3c9e | 935 | return NULL; |
936 | } | |
937 | ||
938 | tun = packet_get_int(); | |
a2b1748a | 939 | if (forced_tun_device != -1) { |
a4f24bf8 | 940 | if (tun != SSH_TUNID_ANY && forced_tun_device != tun) |
d20f3c9e | 941 | goto done; |
942 | tun = forced_tun_device; | |
943 | } | |
a4f24bf8 | 944 | sock = tun_open(tun, mode); |
d20f3c9e | 945 | if (sock < 0) |
946 | goto done; | |
947 | c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1, | |
948 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); | |
949 | c->datagram = 1; | |
950 | ||
951 | done: | |
952 | if (c == NULL) | |
953 | packet_send_debug("Failed to open the tunnel device."); | |
954 | return c; | |
955 | } | |
956 | ||
396c147e | 957 | static Channel * |
43f7a4b8 | 958 | server_request_session(void) |
fa08c86b | 959 | { |
719fc62f | 960 | Channel *c; |
fa08c86b | 961 | |
962 | debug("input_session_request"); | |
95500969 | 963 | packet_check_eom(); |
fa08c86b | 964 | /* |
965 | * A server session has no fd to read or write until a | |
966 | * CHANNEL_REQUEST for a shell is made, so we set the type to | |
967 | * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all | |
968 | * CHANNEL_REQUEST messages is registered. | |
969 | */ | |
43f7a4b8 | 970 | c = channel_new("session", SSH_CHANNEL_LARVAL, |
719fc62f | 971 | -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT, |
0d942eff | 972 | 0, "server-session", 1); |
2362db19 | 973 | if (session_open(the_authctxt, c->self) != 1) { |
719fc62f | 974 | debug("session open failed, free channel %d", c->self); |
975 | channel_free(c); | |
976 | return NULL; | |
fa08c86b | 977 | } |
8cd0437d | 978 | channel_register_cleanup(c->self, session_close_by_channel, 0); |
719fc62f | 979 | return c; |
e78a59f5 | 980 | } |
981 | ||
396c147e | 982 | static void |
7819b5c3 | 983 | server_input_channel_open(int type, u_int32_t seq, void *ctxt) |
e78a59f5 | 984 | { |
985 | Channel *c = NULL; | |
986 | char *ctype; | |
e78a59f5 | 987 | int rchan; |
f91d9a89 | 988 | u_int rmaxpack, rwindow, len; |
e78a59f5 | 989 | |
990 | ctype = packet_get_string(&len); | |
991 | rchan = packet_get_int(); | |
992 | rwindow = packet_get_int(); | |
993 | rmaxpack = packet_get_int(); | |
994 | ||
188adeb2 | 995 | debug("server_input_channel_open: ctype %s rchan %d win %d max %d", |
e78a59f5 | 996 | ctype, rchan, rwindow, rmaxpack); |
997 | ||
998 | if (strcmp(ctype, "session") == 0) { | |
43f7a4b8 | 999 | c = server_request_session(); |
e78a59f5 | 1000 | } else if (strcmp(ctype, "direct-tcpip") == 0) { |
43f7a4b8 | 1001 | c = server_request_direct_tcpip(); |
d20f3c9e | 1002 | } else if (strcmp(ctype, "tun@openssh.com") == 0) { |
1003 | c = server_request_tun(); | |
e78a59f5 | 1004 | } |
1005 | if (c != NULL) { | |
fa08c86b | 1006 | debug("server_input_channel_open: confirm %s", ctype); |
e78a59f5 | 1007 | c->remote_id = rchan; |
1008 | c->remote_window = rwindow; | |
1009 | c->remote_maxpacket = rmaxpack; | |
d18e0850 | 1010 | if (c->type != SSH_CHANNEL_CONNECTING) { |
1011 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1012 | packet_put_int(c->remote_id); | |
1013 | packet_put_int(c->self); | |
1014 | packet_put_int(c->local_window); | |
1015 | packet_put_int(c->local_maxpacket); | |
1016 | packet_send(); | |
1017 | } | |
e78a59f5 | 1018 | } else { |
fa08c86b | 1019 | debug("server_input_channel_open: failure %s", ctype); |
e78a59f5 | 1020 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
1021 | packet_put_int(rchan); | |
1022 | packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); | |
fbe90f7b | 1023 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { |
d18e0850 | 1024 | packet_put_cstring("open failed"); |
fbe90f7b | 1025 | packet_put_cstring(""); |
1026 | } | |
e78a59f5 | 1027 | packet_send(); |
1028 | } | |
1029 | xfree(ctype); | |
1030 | } | |
1031 | ||
396c147e | 1032 | static void |
7819b5c3 | 1033 | server_input_global_request(int type, u_int32_t seq, void *ctxt) |
fa08c86b | 1034 | { |
1035 | char *rtype; | |
1036 | int want_reply; | |
1037 | int success = 0; | |
1038 | ||
1039 | rtype = packet_get_string(NULL); | |
1040 | want_reply = packet_get_char(); | |
1041 | debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply); | |
2b87da3b | 1042 | |
01794848 | 1043 | /* -R style forwarding */ |
fa08c86b | 1044 | if (strcmp(rtype, "tcpip-forward") == 0) { |
1045 | struct passwd *pw; | |
1046 | char *listen_address; | |
1047 | u_short listen_port; | |
1048 | ||
2362db19 | 1049 | pw = the_authctxt->pw; |
95077f48 | 1050 | if (pw == NULL || !the_authctxt->valid) |
fdaef11e | 1051 | fatal("server_input_global_request: no/invalid user"); |
b08a39ff | 1052 | listen_address = packet_get_string(NULL); |
fa08c86b | 1053 | listen_port = (u_short)packet_get_int(); |
1054 | debug("server_input_global_request: tcpip-forward listen %s port %d", | |
1055 | listen_address, listen_port); | |
1056 | ||
1057 | /* check permissions */ | |
1058 | if (!options.allow_tcp_forwarding || | |
e6f15ed1 | 1059 | no_port_forwarding_flag |
1060 | #ifndef NO_IPPORT_RESERVED_CONCEPT | |
1061 | || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0) | |
1062 | #endif | |
98c044d0 | 1063 | ) { |
fa08c86b | 1064 | success = 0; |
1065 | packet_send_debug("Server has disabled port forwarding."); | |
1066 | } else { | |
1067 | /* Start listening on the port */ | |
5641aefa | 1068 | success = channel_setup_remote_fwd_listener( |
1069 | listen_address, listen_port, options.gateway_ports); | |
fa08c86b | 1070 | } |
1071 | xfree(listen_address); | |
d740ec16 | 1072 | } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) { |
1073 | char *cancel_address; | |
1074 | u_short cancel_port; | |
1075 | ||
1076 | cancel_address = packet_get_string(NULL); | |
1077 | cancel_port = (u_short)packet_get_int(); | |
1078 | debug("%s: cancel-tcpip-forward addr %s port %d", __func__, | |
1079 | cancel_address, cancel_port); | |
1080 | ||
1081 | success = channel_cancel_rport_listener(cancel_address, | |
1082 | cancel_port); | |
fa08c86b | 1083 | } |
1084 | if (want_reply) { | |
1085 | packet_start(success ? | |
1086 | SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); | |
1087 | packet_send(); | |
1088 | packet_write_wait(); | |
1089 | } | |
1090 | xfree(rtype); | |
1091 | } | |
7899c98f | 1092 | static void |
1093 | server_input_channel_req(int type, u_int32_t seq, void *ctxt) | |
1094 | { | |
1095 | Channel *c; | |
1096 | int id, reply, success = 0; | |
1097 | char *rtype; | |
1098 | ||
1099 | id = packet_get_int(); | |
1100 | rtype = packet_get_string(NULL); | |
1101 | reply = packet_get_char(); | |
1102 | ||
1103 | debug("server_input_channel_req: channel %d request %s reply %d", | |
1104 | id, rtype, reply); | |
1105 | ||
1106 | if ((c = channel_lookup(id)) == NULL) | |
1107 | packet_disconnect("server_input_channel_req: " | |
1108 | "unknown channel %d", id); | |
1109 | if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN) | |
1110 | success = session_input_channel_req(c, rtype); | |
1111 | if (reply) { | |
1112 | packet_start(success ? | |
1113 | SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); | |
1114 | packet_put_int(c->remote_id); | |
1115 | packet_send(); | |
1116 | } | |
1117 | xfree(rtype); | |
1118 | } | |
fa08c86b | 1119 | |
396c147e | 1120 | static void |
5ca51e19 | 1121 | server_init_dispatch_20(void) |
e78a59f5 | 1122 | { |
1123 | debug("server_init_dispatch_20"); | |
1124 | dispatch_init(&dispatch_protocol_error); | |
1125 | dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); | |
1126 | dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); | |
1127 | dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); | |
1128 | dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); | |
1129 | dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open); | |
1130 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1131 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
7899c98f | 1132 | dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req); |
e78a59f5 | 1133 | dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); |
fa08c86b | 1134 | dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request); |
3ffc6336 | 1135 | /* client_alive */ |
95ae2076 | 1136 | dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive); |
1137 | dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive); | |
1138 | dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive); | |
7a37c112 | 1139 | /* rekeying */ |
1140 | dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); | |
e78a59f5 | 1141 | } |
396c147e | 1142 | static void |
5ca51e19 | 1143 | server_init_dispatch_13(void) |
7368a6c8 | 1144 | { |
1145 | debug("server_init_dispatch_13"); | |
1146 | dispatch_init(NULL); | |
1147 | dispatch_set(SSH_CMSG_EOF, &server_input_eof); | |
1148 | dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data); | |
1149 | dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size); | |
1150 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); | |
1151 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); | |
1152 | dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); | |
1153 | dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1154 | dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
1155 | dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); | |
1156 | } | |
396c147e | 1157 | static void |
5ca51e19 | 1158 | server_init_dispatch_15(void) |
7368a6c8 | 1159 | { |
1160 | server_init_dispatch_13(); | |
1161 | debug("server_init_dispatch_15"); | |
1162 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); | |
1163 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose); | |
1164 | } | |
396c147e | 1165 | static void |
5ca51e19 | 1166 | server_init_dispatch(void) |
7368a6c8 | 1167 | { |
e78a59f5 | 1168 | if (compat20) |
1169 | server_init_dispatch_20(); | |
1170 | else if (compat13) | |
7368a6c8 | 1171 | server_init_dispatch_13(); |
1172 | else | |
1173 | server_init_dispatch_15(); | |
1174 | } |