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3f0444ca | 1 | /* $OpenBSD: serverloop.c,v 1.152 2008/06/10 22:15:23 djm Exp $ */ |
8efc0c15 | 2 | /* |
5260325f | 3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
5 | * All rights reserved | |
5260325f | 6 | * Server main loop for handling the interactive session. |
bcbf86ec | 7 | * |
8 | * As far as I am concerned, the code I have written for this software | |
9 | * can be used freely for any purpose. Any derived versions of this | |
10 | * software must be clearly marked as such, and if the derived work is | |
11 | * incompatible with the protocol description in the RFC file, it must be | |
12 | * called by a name other than "ssh" or "Secure Shell". | |
13 | * | |
e78a59f5 | 14 | * SSH2 support by Markus Friedl. |
a96070d4 | 15 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. |
bcbf86ec | 16 | * |
17 | * Redistribution and use in source and binary forms, with or without | |
18 | * modification, are permitted provided that the following conditions | |
19 | * are met: | |
20 | * 1. Redistributions of source code must retain the above copyright | |
21 | * notice, this list of conditions and the following disclaimer. | |
22 | * 2. Redistributions in binary form must reproduce the above copyright | |
23 | * notice, this list of conditions and the following disclaimer in the | |
24 | * documentation and/or other materials provided with the distribution. | |
25 | * | |
26 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
27 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
28 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
29 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
30 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
31 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
32 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
33 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
34 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
35 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
e78a59f5 | 36 | */ |
8efc0c15 | 37 | |
38 | #include "includes.h" | |
aa2eae64 | 39 | |
40 | #include <sys/types.h> | |
536c14e8 | 41 | #include <sys/param.h> |
aa2eae64 | 42 | #include <sys/wait.h> |
9794d008 | 43 | #include <sys/socket.h> |
e264ac72 | 44 | #ifdef HAVE_SYS_TIME_H |
45 | # include <sys/time.h> | |
46 | #endif | |
9794d008 | 47 | |
48 | #include <netinet/in.h> | |
1d3e026f | 49 | |
028094f4 | 50 | #include <errno.h> |
d3221cca | 51 | #include <fcntl.h> |
b1842393 | 52 | #include <pwd.h> |
ada68823 | 53 | #include <signal.h> |
00146caa | 54 | #include <string.h> |
1d3e026f | 55 | #include <termios.h> |
67514848 | 56 | #include <unistd.h> |
31652869 | 57 | #include <stdarg.h> |
a22aff1f | 58 | |
3593bdc0 | 59 | #include "openbsd-compat/sys-queue.h" |
8efc0c15 | 60 | #include "xmalloc.h" |
8efc0c15 | 61 | #include "packet.h" |
62 | #include "buffer.h" | |
42f11eb2 | 63 | #include "log.h" |
8efc0c15 | 64 | #include "servconf.h" |
00e842d8 | 65 | #include "canohost.h" |
1729c161 | 66 | #include "sshpty.h" |
a5efa1bb | 67 | #include "channels.h" |
7368a6c8 | 68 | #include "compat.h" |
42f11eb2 | 69 | #include "ssh1.h" |
e78a59f5 | 70 | #include "ssh2.h" |
31652869 | 71 | #include "key.h" |
72 | #include "cipher.h" | |
73 | #include "kex.h" | |
74 | #include "hostfile.h" | |
59c97189 | 75 | #include "auth.h" |
e78a59f5 | 76 | #include "session.h" |
7368a6c8 | 77 | #include "dispatch.h" |
38c295d6 | 78 | #include "auth-options.h" |
42f11eb2 | 79 | #include "serverloop.h" |
80 | #include "misc.h" | |
8efc0c15 | 81 | |
33de75a3 | 82 | extern ServerOptions options; |
83 | ||
7a37c112 | 84 | /* XXX */ |
85 | extern Kex *xxx_kex; | |
2362db19 | 86 | extern Authctxt *the_authctxt; |
0bbbf2a4 | 87 | extern int use_privsep; |
7a37c112 | 88 | |
8efc0c15 | 89 | static Buffer stdin_buffer; /* Buffer for stdin data. */ |
90 | static Buffer stdout_buffer; /* Buffer for stdout data. */ | |
91 | static Buffer stderr_buffer; /* Buffer for stderr data. */ | |
92 | static int fdin; /* Descriptor for stdin (for writing) */ | |
93 | static int fdout; /* Descriptor for stdout (for reading); | |
94 | May be same number as fdin. */ | |
95 | static int fderr; /* Descriptor for stderr. May be -1. */ | |
96 | static long stdin_bytes = 0; /* Number of bytes written to stdin. */ | |
97 | static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */ | |
98 | static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */ | |
99 | static long fdout_bytes = 0; /* Number of stdout bytes read from program. */ | |
100 | static int stdin_eof = 0; /* EOF message received from client. */ | |
101 | static int fdout_eof = 0; /* EOF encountered reading from fdout. */ | |
102 | static int fderr_eof = 0; /* EOF encountered readung from fderr. */ | |
e68225b2 | 103 | static int fdin_is_tty = 0; /* fdin points to a tty. */ |
8efc0c15 | 104 | static int connection_in; /* Connection to client (input). */ |
105 | static int connection_out; /* Connection to client (output). */ | |
cc94bd38 | 106 | static int connection_closed = 0; /* Connection to client closed. */ |
107 | static u_int buffer_high; /* "Soft" max buffer size. */ | |
3f0444ca | 108 | static int no_more_sessions = 0; /* Disallow further sessions. */ |
8efc0c15 | 109 | |
aa3378df | 110 | /* |
111 | * This SIGCHLD kludge is used to detect when the child exits. The server | |
112 | * will exit after that, as soon as forwarded connections have terminated. | |
113 | */ | |
396c147e | 114 | |
7a934d1b | 115 | static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */ |
8efc0c15 | 116 | |
0bbbf2a4 | 117 | /* Cleanup on signals (!use_privsep case only) */ |
118 | static volatile sig_atomic_t received_sigterm = 0; | |
119 | ||
396c147e | 120 | /* prototypes */ |
121 | static void server_init_dispatch(void); | |
7368a6c8 | 122 | |
a10be357 | 123 | /* |
124 | * we write to this pipe if a SIGCHLD is caught in order to avoid | |
125 | * the race between select() and child_terminated | |
126 | */ | |
127 | static int notify_pipe[2]; | |
128 | static void | |
129 | notify_setup(void) | |
130 | { | |
131 | if (pipe(notify_pipe) < 0) { | |
132 | error("pipe(notify_pipe) failed %s", strerror(errno)); | |
133 | } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) || | |
134 | (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) { | |
135 | error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno)); | |
136 | close(notify_pipe[0]); | |
137 | close(notify_pipe[1]); | |
138 | } else { | |
139 | set_nonblock(notify_pipe[0]); | |
140 | set_nonblock(notify_pipe[1]); | |
141 | return; | |
142 | } | |
143 | notify_pipe[0] = -1; /* read end */ | |
144 | notify_pipe[1] = -1; /* write end */ | |
145 | } | |
146 | static void | |
147 | notify_parent(void) | |
148 | { | |
149 | if (notify_pipe[1] != -1) | |
150 | write(notify_pipe[1], "", 1); | |
151 | } | |
152 | static void | |
153 | notify_prepare(fd_set *readset) | |
154 | { | |
155 | if (notify_pipe[0] != -1) | |
156 | FD_SET(notify_pipe[0], readset); | |
157 | } | |
158 | static void | |
159 | notify_done(fd_set *readset) | |
160 | { | |
161 | char c; | |
162 | ||
163 | if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset)) | |
164 | while (read(notify_pipe[0], &c, 1) != -1) | |
165 | debug2("notify_done: reading"); | |
166 | } | |
167 | ||
3efa8ea9 | 168 | /*ARGSUSED*/ |
396c147e | 169 | static void |
5260325f | 170 | sigchld_handler(int sig) |
e78a59f5 | 171 | { |
172 | int save_errno = errno; | |
e78a59f5 | 173 | child_terminated = 1; |
ef51930f | 174 | #ifndef _UNICOS |
c9130033 | 175 | mysignal(SIGCHLD, sigchld_handler); |
ef51930f | 176 | #endif |
a10be357 | 177 | notify_parent(); |
e78a59f5 | 178 | errno = save_errno; |
179 | } | |
8efc0c15 | 180 | |
3efa8ea9 | 181 | /*ARGSUSED*/ |
0bbbf2a4 | 182 | static void |
183 | sigterm_handler(int sig) | |
184 | { | |
185 | received_sigterm = sig; | |
186 | } | |
187 | ||
5260325f | 188 | /* |
189 | * Make packets from buffered stderr data, and buffer it for sending | |
190 | * to the client. | |
191 | */ | |
396c147e | 192 | static void |
5ca51e19 | 193 | make_packets_from_stderr_data(void) |
8efc0c15 | 194 | { |
a27002e5 | 195 | u_int len; |
5260325f | 196 | |
197 | /* Send buffered stderr data to the client. */ | |
198 | while (buffer_len(&stderr_buffer) > 0 && | |
a408af76 | 199 | packet_not_very_much_data_to_write()) { |
5260325f | 200 | len = buffer_len(&stderr_buffer); |
201 | if (packet_is_interactive()) { | |
202 | if (len > 512) | |
203 | len = 512; | |
204 | } else { | |
205 | /* Keep the packets at reasonable size. */ | |
206 | if (len > packet_get_maxsize()) | |
207 | len = packet_get_maxsize(); | |
208 | } | |
209 | packet_start(SSH_SMSG_STDERR_DATA); | |
210 | packet_put_string(buffer_ptr(&stderr_buffer), len); | |
211 | packet_send(); | |
212 | buffer_consume(&stderr_buffer, len); | |
213 | stderr_bytes += len; | |
8efc0c15 | 214 | } |
8efc0c15 | 215 | } |
216 | ||
5260325f | 217 | /* |
218 | * Make packets from buffered stdout data, and buffer it for sending to the | |
219 | * client. | |
220 | */ | |
396c147e | 221 | static void |
5ca51e19 | 222 | make_packets_from_stdout_data(void) |
8efc0c15 | 223 | { |
a27002e5 | 224 | u_int len; |
5260325f | 225 | |
226 | /* Send buffered stdout data to the client. */ | |
227 | while (buffer_len(&stdout_buffer) > 0 && | |
a408af76 | 228 | packet_not_very_much_data_to_write()) { |
5260325f | 229 | len = buffer_len(&stdout_buffer); |
230 | if (packet_is_interactive()) { | |
231 | if (len > 512) | |
232 | len = 512; | |
233 | } else { | |
234 | /* Keep the packets at reasonable size. */ | |
235 | if (len > packet_get_maxsize()) | |
2b87da3b | 236 | len = packet_get_maxsize(); |
5260325f | 237 | } |
238 | packet_start(SSH_SMSG_STDOUT_DATA); | |
239 | packet_put_string(buffer_ptr(&stdout_buffer), len); | |
240 | packet_send(); | |
241 | buffer_consume(&stdout_buffer, len); | |
242 | stdout_bytes += len; | |
8efc0c15 | 243 | } |
8efc0c15 | 244 | } |
245 | ||
72176c0e | 246 | static void |
247 | client_alive_check(void) | |
248 | { | |
95ae2076 | 249 | int channel_id; |
99416ceb | 250 | |
72176c0e | 251 | /* timeout, check to see how many we have had */ |
ac47b626 | 252 | if (++keep_alive_timeouts > options.client_alive_count_max) { |
bd3b2cb2 | 253 | logit("Timeout, client not responding."); |
254 | cleanup_exit(255); | |
255 | } | |
72176c0e | 256 | |
72176c0e | 257 | /* |
95ae2076 | 258 | * send a bogus global/channel request with "wantreply", |
72176c0e | 259 | * we should get back a failure |
260 | */ | |
95ae2076 | 261 | if ((channel_id = channel_find_open()) == -1) { |
262 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
263 | packet_put_cstring("keepalive@openssh.com"); | |
264 | packet_put_char(1); /* boolean: want reply */ | |
265 | } else { | |
266 | channel_request_start(channel_id, "keepalive@openssh.com", 1); | |
267 | } | |
72176c0e | 268 | packet_send(); |
269 | } | |
270 | ||
5260325f | 271 | /* |
272 | * Sleep in select() until we can do something. This will initialize the | |
273 | * select masks. Upon return, the masks will indicate which descriptors | |
274 | * have data or can accept data. Optionally, a maximum time can be specified | |
275 | * for the duration of the wait (0 = infinite). | |
276 | */ | |
396c147e | 277 | static void |
39929cdb | 278 | wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, |
9a995072 | 279 | u_int *nallocp, u_int max_time_milliseconds) |
8efc0c15 | 280 | { |
5260325f | 281 | struct timeval tv, *tvp; |
282 | int ret; | |
3ffc6336 | 283 | int client_alive_scheduled = 0; |
34640ce6 | 284 | int program_alive_scheduled = 0; |
3ffc6336 | 285 | |
286 | /* | |
184eed6a | 287 | * if using client_alive, set the max timeout accordingly, |
3ffc6336 | 288 | * and indicate that this particular timeout was for client |
289 | * alive by setting the client_alive_scheduled flag. | |
290 | * | |
291 | * this could be randomized somewhat to make traffic | |
184eed6a | 292 | * analysis more difficult, but we're not doing it yet. |
3ffc6336 | 293 | */ |
2c5b1791 | 294 | if (compat20 && |
295 | max_time_milliseconds == 0 && options.client_alive_interval) { | |
39aefe7b | 296 | client_alive_scheduled = 1; |
3ffc6336 | 297 | max_time_milliseconds = options.client_alive_interval * 1000; |
2c5b1791 | 298 | } |
8efc0c15 | 299 | |
39929cdb | 300 | /* Allocate and update select() masks for channel descriptors. */ |
489aa2e9 | 301 | channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0); |
5260325f | 302 | |
e78a59f5 | 303 | if (compat20) { |
0c139bd1 | 304 | #if 0 |
1d1ffb87 | 305 | /* wrong: bad condition XXX */ |
e78a59f5 | 306 | if (channel_not_very_much_buffered_data()) |
0c139bd1 | 307 | #endif |
308 | FD_SET(connection_in, *readsetp); | |
e78a59f5 | 309 | } else { |
71276795 | 310 | /* |
311 | * Read packets from the client unless we have too much | |
312 | * buffered stdin or channel data. | |
313 | */ | |
314 | if (buffer_len(&stdin_buffer) < buffer_high && | |
e78a59f5 | 315 | channel_not_very_much_buffered_data()) |
39929cdb | 316 | FD_SET(connection_in, *readsetp); |
71276795 | 317 | /* |
318 | * If there is not too much data already buffered going to | |
319 | * the client, try to get some more data from the program. | |
320 | */ | |
321 | if (packet_not_very_much_data_to_write()) { | |
34640ce6 | 322 | program_alive_scheduled = child_terminated; |
71276795 | 323 | if (!fdout_eof) |
39929cdb | 324 | FD_SET(fdout, *readsetp); |
71276795 | 325 | if (!fderr_eof) |
39929cdb | 326 | FD_SET(fderr, *readsetp); |
71276795 | 327 | } |
328 | /* | |
329 | * If we have buffered data, try to write some of that data | |
330 | * to the program. | |
331 | */ | |
332 | if (fdin != -1 && buffer_len(&stdin_buffer) > 0) | |
39929cdb | 333 | FD_SET(fdin, *writesetp); |
e78a59f5 | 334 | } |
a10be357 | 335 | notify_prepare(*readsetp); |
5260325f | 336 | |
aa3378df | 337 | /* |
338 | * If we have buffered packet data going to the client, mark that | |
339 | * descriptor. | |
340 | */ | |
5260325f | 341 | if (packet_have_data_to_write()) |
39929cdb | 342 | FD_SET(connection_out, *writesetp); |
5260325f | 343 | |
aa3378df | 344 | /* |
345 | * If child has terminated and there is enough buffer space to read | |
346 | * from it, then read as much as is available and exit. | |
347 | */ | |
5260325f | 348 | if (child_terminated && packet_not_very_much_data_to_write()) |
3ffc6336 | 349 | if (max_time_milliseconds == 0 || client_alive_scheduled) |
5260325f | 350 | max_time_milliseconds = 100; |
351 | ||
352 | if (max_time_milliseconds == 0) | |
353 | tvp = NULL; | |
354 | else { | |
355 | tv.tv_sec = max_time_milliseconds / 1000; | |
356 | tv.tv_usec = 1000 * (max_time_milliseconds % 1000); | |
357 | tvp = &tv; | |
358 | } | |
8efc0c15 | 359 | |
5260325f | 360 | /* Wait for something to happen, or the timeout to expire. */ |
39929cdb | 361 | ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); |
8efc0c15 | 362 | |
3ffc6336 | 363 | if (ret == -1) { |
b3ad8fe6 | 364 | memset(*readsetp, 0, *nallocp); |
365 | memset(*writesetp, 0, *nallocp); | |
5260325f | 366 | if (errno != EINTR) |
367 | error("select: %.100s", strerror(errno)); | |
34640ce6 | 368 | } else { |
369 | if (ret == 0 && client_alive_scheduled) | |
370 | client_alive_check(); | |
371 | if (!compat20 && program_alive_scheduled && fdin_is_tty) { | |
372 | if (!fdout_eof) | |
373 | FD_SET(fdout, *readsetp); | |
374 | if (!fderr_eof) | |
375 | FD_SET(fderr, *readsetp); | |
376 | } | |
377 | } | |
a10be357 | 378 | |
379 | notify_done(*readsetp); | |
8efc0c15 | 380 | } |
381 | ||
5260325f | 382 | /* |
383 | * Processes input from the client and the program. Input data is stored | |
384 | * in buffers and processed later. | |
385 | */ | |
396c147e | 386 | static void |
b476adfa | 387 | process_input(fd_set *readset) |
5260325f | 388 | { |
389 | int len; | |
390 | char buf[16384]; | |
391 | ||
392 | /* Read and buffer any input data from the client. */ | |
393 | if (FD_ISSET(connection_in, readset)) { | |
394 | len = read(connection_in, buf, sizeof(buf)); | |
395 | if (len == 0) { | |
00e842d8 | 396 | verbose("Connection closed by %.100s", |
397 | get_remote_ipaddr()); | |
cc94bd38 | 398 | connection_closed = 1; |
399 | if (compat20) | |
400 | return; | |
2362db19 | 401 | cleanup_exit(255); |
0e73cc53 | 402 | } else if (len < 0) { |
403 | if (errno != EINTR && errno != EAGAIN) { | |
00e842d8 | 404 | verbose("Read error from remote host " |
405 | "%.100s: %.100s", | |
406 | get_remote_ipaddr(), strerror(errno)); | |
2362db19 | 407 | cleanup_exit(255); |
0e73cc53 | 408 | } |
409 | } else { | |
410 | /* Buffer any received data. */ | |
411 | packet_process_incoming(buf, len); | |
5260325f | 412 | } |
5260325f | 413 | } |
e78a59f5 | 414 | if (compat20) |
415 | return; | |
416 | ||
5260325f | 417 | /* Read and buffer any available stdout data from the program. */ |
418 | if (!fdout_eof && FD_ISSET(fdout, readset)) { | |
ea8c44d9 | 419 | errno = 0; |
5260325f | 420 | len = read(fdout, buf, sizeof(buf)); |
34640ce6 | 421 | if (len < 0 && (errno == EINTR || |
422 | (errno == EAGAIN && !child_terminated))) { | |
0e73cc53 | 423 | /* do nothing */ |
24a87055 | 424 | #ifndef PTY_ZEROREAD |
0e73cc53 | 425 | } else if (len <= 0) { |
ea8c44d9 | 426 | #else |
9c04d67d | 427 | } else if ((!isatty(fdout) && len <= 0) || |
428 | (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) { | |
ea8c44d9 | 429 | #endif |
5260325f | 430 | fdout_eof = 1; |
0e73cc53 | 431 | } else { |
5260325f | 432 | buffer_append(&stdout_buffer, buf, len); |
433 | fdout_bytes += len; | |
434 | } | |
435 | } | |
436 | /* Read and buffer any available stderr data from the program. */ | |
437 | if (!fderr_eof && FD_ISSET(fderr, readset)) { | |
ea8c44d9 | 438 | errno = 0; |
5260325f | 439 | len = read(fderr, buf, sizeof(buf)); |
34640ce6 | 440 | if (len < 0 && (errno == EINTR || |
441 | (errno == EAGAIN && !child_terminated))) { | |
0e73cc53 | 442 | /* do nothing */ |
24a87055 | 443 | #ifndef PTY_ZEROREAD |
0e73cc53 | 444 | } else if (len <= 0) { |
ea8c44d9 | 445 | #else |
9c04d67d | 446 | } else if ((!isatty(fderr) && len <= 0) || |
447 | (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) { | |
ea8c44d9 | 448 | #endif |
5260325f | 449 | fderr_eof = 1; |
0e73cc53 | 450 | } else { |
5260325f | 451 | buffer_append(&stderr_buffer, buf, len); |
0e73cc53 | 452 | } |
5260325f | 453 | } |
454 | } | |
8efc0c15 | 455 | |
5260325f | 456 | /* |
457 | * Sends data from internal buffers to client program stdin. | |
458 | */ | |
396c147e | 459 | static void |
b476adfa | 460 | process_output(fd_set *writeset) |
8efc0c15 | 461 | { |
4ef922e3 | 462 | struct termios tio; |
780a9951 | 463 | u_char *data; |
464 | u_int dlen; | |
5260325f | 465 | int len; |
466 | ||
467 | /* Write buffered data to program stdin. */ | |
e78a59f5 | 468 | if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) { |
780a9951 | 469 | data = buffer_ptr(&stdin_buffer); |
470 | dlen = buffer_len(&stdin_buffer); | |
471 | len = write(fdin, data, dlen); | |
0e73cc53 | 472 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) { |
473 | /* do nothing */ | |
474 | } else if (len <= 0) { | |
7368a6c8 | 475 | if (fdin != fdout) |
5260325f | 476 | close(fdin); |
477 | else | |
478 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
5260325f | 479 | fdin = -1; |
480 | } else { | |
4ef922e3 | 481 | /* Successful write. */ |
780a9951 | 482 | if (fdin_is_tty && dlen >= 1 && data[0] != '\r' && |
483 | tcgetattr(fdin, &tio) == 0 && | |
0ae4fe1d | 484 | !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { |
62da27dd | 485 | /* |
486 | * Simulate echo to reduce the impact of | |
487 | * traffic analysis | |
488 | */ | |
95ce5599 | 489 | packet_send_ignore(len); |
4ef922e3 | 490 | packet_send(); |
491 | } | |
492 | /* Consume the data from the buffer. */ | |
5260325f | 493 | buffer_consume(&stdin_buffer, len); |
494 | /* Update the count of bytes written to the program. */ | |
495 | stdin_bytes += len; | |
496 | } | |
8efc0c15 | 497 | } |
5260325f | 498 | /* Send any buffered packet data to the client. */ |
499 | if (FD_ISSET(connection_out, writeset)) | |
500 | packet_write_poll(); | |
8efc0c15 | 501 | } |
502 | ||
5260325f | 503 | /* |
504 | * Wait until all buffered output has been sent to the client. | |
505 | * This is used when the program terminates. | |
506 | */ | |
396c147e | 507 | static void |
5ca51e19 | 508 | drain_output(void) |
8efc0c15 | 509 | { |
5260325f | 510 | /* Send any buffered stdout data to the client. */ |
511 | if (buffer_len(&stdout_buffer) > 0) { | |
512 | packet_start(SSH_SMSG_STDOUT_DATA); | |
513 | packet_put_string(buffer_ptr(&stdout_buffer), | |
514 | buffer_len(&stdout_buffer)); | |
515 | packet_send(); | |
516 | /* Update the count of sent bytes. */ | |
517 | stdout_bytes += buffer_len(&stdout_buffer); | |
518 | } | |
519 | /* Send any buffered stderr data to the client. */ | |
520 | if (buffer_len(&stderr_buffer) > 0) { | |
521 | packet_start(SSH_SMSG_STDERR_DATA); | |
522 | packet_put_string(buffer_ptr(&stderr_buffer), | |
523 | buffer_len(&stderr_buffer)); | |
524 | packet_send(); | |
525 | /* Update the count of sent bytes. */ | |
526 | stderr_bytes += buffer_len(&stderr_buffer); | |
527 | } | |
528 | /* Wait until all buffered data has been written to the client. */ | |
529 | packet_write_wait(); | |
8efc0c15 | 530 | } |
531 | ||
396c147e | 532 | static void |
5ca51e19 | 533 | process_buffered_input_packets(void) |
7368a6c8 | 534 | { |
7a37c112 | 535 | dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL); |
7368a6c8 | 536 | } |
537 | ||
5260325f | 538 | /* |
539 | * Performs the interactive session. This handles data transmission between | |
540 | * the client and the program. Note that the notion of stdin, stdout, and | |
541 | * stderr in this function is sort of reversed: this function writes to | |
542 | * stdin (of the child program), and reads from stdout and stderr (of the | |
543 | * child program). | |
544 | */ | |
6ae2364d | 545 | void |
9da5c3c9 | 546 | server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) |
8efc0c15 | 547 | { |
39929cdb | 548 | fd_set *readset = NULL, *writeset = NULL; |
9a995072 | 549 | int max_fd = 0; |
550 | u_int nalloc = 0; | |
9da5c3c9 | 551 | int wait_status; /* Status returned by wait(). */ |
552 | pid_t wait_pid; /* pid returned by wait(). */ | |
5260325f | 553 | int waiting_termination = 0; /* Have displayed waiting close message. */ |
1e3b8b07 | 554 | u_int max_time_milliseconds; |
555 | u_int previous_stdout_buffer_bytes; | |
556 | u_int stdout_buffer_bytes; | |
5260325f | 557 | int type; |
558 | ||
559 | debug("Entering interactive session."); | |
560 | ||
561 | /* Initialize the SIGCHLD kludge. */ | |
5260325f | 562 | child_terminated = 0; |
42ad0eec | 563 | mysignal(SIGCHLD, sigchld_handler); |
5260325f | 564 | |
0bbbf2a4 | 565 | if (!use_privsep) { |
566 | signal(SIGTERM, sigterm_handler); | |
567 | signal(SIGINT, sigterm_handler); | |
568 | signal(SIGQUIT, sigterm_handler); | |
569 | } | |
570 | ||
5260325f | 571 | /* Initialize our global variables. */ |
572 | fdin = fdin_arg; | |
573 | fdout = fdout_arg; | |
574 | fderr = fderr_arg; | |
0e73cc53 | 575 | |
576 | /* nonblocking IO */ | |
577 | set_nonblock(fdin); | |
578 | set_nonblock(fdout); | |
ff873e98 | 579 | /* we don't have stderr for interactive terminal sessions, see below */ |
580 | if (fderr != -1) | |
581 | set_nonblock(fderr); | |
0e73cc53 | 582 | |
e68225b2 | 583 | if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin)) |
584 | fdin_is_tty = 1; | |
585 | ||
5260325f | 586 | connection_in = packet_get_connection_in(); |
587 | connection_out = packet_get_connection_out(); | |
588 | ||
a10be357 | 589 | notify_setup(); |
590 | ||
5260325f | 591 | previous_stdout_buffer_bytes = 0; |
592 | ||
593 | /* Set approximate I/O buffer size. */ | |
594 | if (packet_is_interactive()) | |
595 | buffer_high = 4096; | |
596 | else | |
597 | buffer_high = 64 * 1024; | |
598 | ||
489aa2e9 | 599 | #if 0 |
5260325f | 600 | /* Initialize max_fd to the maximum of the known file descriptors. */ |
489aa2e9 | 601 | max_fd = MAX(connection_in, connection_out); |
602 | max_fd = MAX(max_fd, fdin); | |
603 | max_fd = MAX(max_fd, fdout); | |
39929cdb | 604 | if (fderr != -1) |
605 | max_fd = MAX(max_fd, fderr); | |
489aa2e9 | 606 | #endif |
5260325f | 607 | |
608 | /* Initialize Initialize buffers. */ | |
609 | buffer_init(&stdin_buffer); | |
610 | buffer_init(&stdout_buffer); | |
611 | buffer_init(&stderr_buffer); | |
612 | ||
aa3378df | 613 | /* |
614 | * If we have no separate fderr (which is the case when we have a pty | |
615 | * - there we cannot make difference between data sent to stdout and | |
616 | * stderr), indicate that we have seen an EOF from stderr. This way | |
7b9b0103 | 617 | * we don't need to check the descriptor everywhere. |
aa3378df | 618 | */ |
5260325f | 619 | if (fderr == -1) |
620 | fderr_eof = 1; | |
621 | ||
7368a6c8 | 622 | server_init_dispatch(); |
623 | ||
5260325f | 624 | /* Main loop of the server for the interactive session mode. */ |
625 | for (;;) { | |
5260325f | 626 | |
627 | /* Process buffered packets from the client. */ | |
628 | process_buffered_input_packets(); | |
629 | ||
aa3378df | 630 | /* |
631 | * If we have received eof, and there is no more pending | |
632 | * input data, cause a real eof by closing fdin. | |
633 | */ | |
5260325f | 634 | if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) { |
7368a6c8 | 635 | if (fdin != fdout) |
5260325f | 636 | close(fdin); |
637 | else | |
638 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
5260325f | 639 | fdin = -1; |
640 | } | |
aa3378df | 641 | /* Make packets from buffered stderr data to send to the client. */ |
5260325f | 642 | make_packets_from_stderr_data(); |
643 | ||
aa3378df | 644 | /* |
645 | * Make packets from buffered stdout data to send to the | |
646 | * client. If there is very little to send, this arranges to | |
647 | * not send them now, but to wait a short while to see if we | |
648 | * are getting more data. This is necessary, as some systems | |
649 | * wake up readers from a pty after each separate character. | |
650 | */ | |
5260325f | 651 | max_time_milliseconds = 0; |
652 | stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
653 | if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && | |
654 | stdout_buffer_bytes != previous_stdout_buffer_bytes) { | |
655 | /* try again after a while */ | |
656 | max_time_milliseconds = 10; | |
657 | } else { | |
658 | /* Send it now. */ | |
659 | make_packets_from_stdout_data(); | |
660 | } | |
661 | previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
662 | ||
663 | /* Send channel data to the client. */ | |
664 | if (packet_not_very_much_data_to_write()) | |
665 | channel_output_poll(); | |
666 | ||
aa3378df | 667 | /* |
668 | * Bail out of the loop if the program has closed its output | |
669 | * descriptors, and we have no more data to send to the | |
670 | * client, and there is no pending buffered data. | |
671 | */ | |
7062c40f | 672 | if (fdout_eof && fderr_eof && !packet_have_data_to_write() && |
673 | buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { | |
5260325f | 674 | if (!channel_still_open()) |
7368a6c8 | 675 | break; |
5260325f | 676 | if (!waiting_termination) { |
677 | const char *s = "Waiting for forwarded connections to terminate...\r\n"; | |
678 | char *cp; | |
679 | waiting_termination = 1; | |
680 | buffer_append(&stderr_buffer, s, strlen(s)); | |
681 | ||
682 | /* Display list of open channels. */ | |
683 | cp = channel_open_message(); | |
684 | buffer_append(&stderr_buffer, cp, strlen(cp)); | |
685 | xfree(cp); | |
686 | } | |
687 | } | |
489aa2e9 | 688 | max_fd = MAX(connection_in, connection_out); |
689 | max_fd = MAX(max_fd, fdin); | |
690 | max_fd = MAX(max_fd, fdout); | |
691 | max_fd = MAX(max_fd, fderr); | |
a10be357 | 692 | max_fd = MAX(max_fd, notify_pipe[0]); |
489aa2e9 | 693 | |
5260325f | 694 | /* Sleep in select() until we can do something. */ |
39929cdb | 695 | wait_until_can_do_something(&readset, &writeset, &max_fd, |
489aa2e9 | 696 | &nalloc, max_time_milliseconds); |
5260325f | 697 | |
0bbbf2a4 | 698 | if (received_sigterm) { |
699 | logit("Exiting on signal %d", received_sigterm); | |
700 | /* Clean up sessions, utmp, etc. */ | |
701 | cleanup_exit(255); | |
702 | } | |
703 | ||
5260325f | 704 | /* Process any channel events. */ |
39929cdb | 705 | channel_after_select(readset, writeset); |
5260325f | 706 | |
707 | /* Process input from the client and from program stdout/stderr. */ | |
39929cdb | 708 | process_input(readset); |
5260325f | 709 | |
710 | /* Process output to the client and to program stdin. */ | |
39929cdb | 711 | process_output(writeset); |
8efc0c15 | 712 | } |
39929cdb | 713 | if (readset) |
714 | xfree(readset); | |
715 | if (writeset) | |
716 | xfree(writeset); | |
8efc0c15 | 717 | |
5260325f | 718 | /* Cleanup and termination code. */ |
8efc0c15 | 719 | |
5260325f | 720 | /* Wait until all output has been sent to the client. */ |
721 | drain_output(); | |
8efc0c15 | 722 | |
5260325f | 723 | debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", |
184eed6a | 724 | stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); |
8efc0c15 | 725 | |
5260325f | 726 | /* Free and clear the buffers. */ |
727 | buffer_free(&stdin_buffer); | |
728 | buffer_free(&stdout_buffer); | |
729 | buffer_free(&stderr_buffer); | |
8efc0c15 | 730 | |
5260325f | 731 | /* Close the file descriptors. */ |
732 | if (fdout != -1) | |
733 | close(fdout); | |
734 | fdout = -1; | |
735 | fdout_eof = 1; | |
736 | if (fderr != -1) | |
737 | close(fderr); | |
738 | fderr = -1; | |
739 | fderr_eof = 1; | |
740 | if (fdin != -1) | |
741 | close(fdin); | |
742 | fdin = -1; | |
743 | ||
d6746a0b | 744 | channel_free_all(); |
5260325f | 745 | |
5260325f | 746 | /* We no longer want our SIGCHLD handler to be called. */ |
42ad0eec | 747 | mysignal(SIGCHLD, SIG_DFL); |
5260325f | 748 | |
8c38e88b | 749 | while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0) |
750 | if (errno != EINTR) | |
751 | packet_disconnect("wait: %.100s", strerror(errno)); | |
752 | if (wait_pid != pid) | |
c457707e | 753 | error("Strange, wait returned pid %ld, expected %ld", |
754 | (long)wait_pid, (long)pid); | |
c9130033 | 755 | |
5260325f | 756 | /* Check if it exited normally. */ |
757 | if (WIFEXITED(wait_status)) { | |
758 | /* Yes, normal exit. Get exit status and send it to the client. */ | |
759 | debug("Command exited with status %d.", WEXITSTATUS(wait_status)); | |
760 | packet_start(SSH_SMSG_EXITSTATUS); | |
761 | packet_put_int(WEXITSTATUS(wait_status)); | |
762 | packet_send(); | |
763 | packet_write_wait(); | |
764 | ||
aa3378df | 765 | /* |
766 | * Wait for exit confirmation. Note that there might be | |
767 | * other packets coming before it; however, the program has | |
768 | * already died so we just ignore them. The client is | |
769 | * supposed to respond with the confirmation when it receives | |
770 | * the exit status. | |
771 | */ | |
5260325f | 772 | do { |
54a5250f | 773 | type = packet_read(); |
5260325f | 774 | } |
775 | while (type != SSH_CMSG_EXIT_CONFIRMATION); | |
776 | ||
777 | debug("Received exit confirmation."); | |
778 | return; | |
779 | } | |
780 | /* Check if the program terminated due to a signal. */ | |
781 | if (WIFSIGNALED(wait_status)) | |
782 | packet_disconnect("Command terminated on signal %d.", | |
783 | WTERMSIG(wait_status)); | |
784 | ||
785 | /* Some weird exit cause. Just exit. */ | |
786 | packet_disconnect("wait returned status %04x.", wait_status); | |
787 | /* NOTREACHED */ | |
788 | } | |
7368a6c8 | 789 | |
418e724c | 790 | static void |
791 | collect_children(void) | |
792 | { | |
793 | pid_t pid; | |
794 | sigset_t oset, nset; | |
795 | int status; | |
796 | ||
797 | /* block SIGCHLD while we check for dead children */ | |
798 | sigemptyset(&nset); | |
799 | sigaddset(&nset, SIGCHLD); | |
800 | sigprocmask(SIG_BLOCK, &nset, &oset); | |
801 | if (child_terminated) { | |
140000b4 | 802 | debug("Received SIGCHLD."); |
8c38e88b | 803 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
804 | (pid < 0 && errno == EINTR)) | |
805 | if (pid > 0) | |
806 | session_close_by_pid(pid, status); | |
418e724c | 807 | child_terminated = 0; |
808 | } | |
809 | sigprocmask(SIG_SETMASK, &oset, NULL); | |
810 | } | |
811 | ||
6ae2364d | 812 | void |
57156994 | 813 | server_loop2(Authctxt *authctxt) |
e78a59f5 | 814 | { |
39929cdb | 815 | fd_set *readset = NULL, *writeset = NULL; |
418e724c | 816 | int rekeying = 0, max_fd, nalloc = 0; |
e78a59f5 | 817 | |
818 | debug("Entering interactive session for SSH2."); | |
819 | ||
c9130033 | 820 | mysignal(SIGCHLD, sigchld_handler); |
e78a59f5 | 821 | child_terminated = 0; |
822 | connection_in = packet_get_connection_in(); | |
823 | connection_out = packet_get_connection_out(); | |
39929cdb | 824 | |
0bbbf2a4 | 825 | if (!use_privsep) { |
826 | signal(SIGTERM, sigterm_handler); | |
827 | signal(SIGINT, sigterm_handler); | |
828 | signal(SIGQUIT, sigterm_handler); | |
829 | } | |
830 | ||
a10be357 | 831 | notify_setup(); |
832 | ||
39929cdb | 833 | max_fd = MAX(connection_in, connection_out); |
a10be357 | 834 | max_fd = MAX(max_fd, notify_pipe[0]); |
835 | ||
e78a59f5 | 836 | server_init_dispatch(); |
837 | ||
838 | for (;;) { | |
839 | process_buffered_input_packets(); | |
bbb4cc1b | 840 | |
cd332296 | 841 | rekeying = (xxx_kex != NULL && !xxx_kex->done); |
bbb4cc1b | 842 | |
bbb4cc1b | 843 | if (!rekeying && packet_not_very_much_data_to_write()) |
e78a59f5 | 844 | channel_output_poll(); |
bbb4cc1b | 845 | wait_until_can_do_something(&readset, &writeset, &max_fd, |
489aa2e9 | 846 | &nalloc, 0); |
d5f24f94 | 847 | |
0bbbf2a4 | 848 | if (received_sigterm) { |
849 | logit("Exiting on signal %d", received_sigterm); | |
850 | /* Clean up sessions, utmp, etc. */ | |
851 | cleanup_exit(255); | |
852 | } | |
853 | ||
418e724c | 854 | collect_children(); |
ffd7b36b | 855 | if (!rekeying) { |
bbb4cc1b | 856 | channel_after_select(readset, writeset); |
ffd7b36b | 857 | if (packet_need_rekeying()) { |
858 | debug("need rekeying"); | |
859 | xxx_kex->done = 0; | |
860 | kex_send_kexinit(xxx_kex); | |
861 | } | |
862 | } | |
39929cdb | 863 | process_input(readset); |
cc94bd38 | 864 | if (connection_closed) |
865 | break; | |
39929cdb | 866 | process_output(writeset); |
e78a59f5 | 867 | } |
418e724c | 868 | collect_children(); |
869 | ||
39929cdb | 870 | if (readset) |
871 | xfree(readset); | |
872 | if (writeset) | |
873 | xfree(writeset); | |
874 | ||
d5f24f94 | 875 | /* free all channels, no more reads and writes */ |
876 | channel_free_all(); | |
5b5d170c | 877 | |
418e724c | 878 | /* free remaining sessions, e.g. remove wtmp entries */ |
1853d1ef | 879 | session_destroy_all(NULL); |
e78a59f5 | 880 | } |
881 | ||
396c147e | 882 | static void |
95ae2076 | 883 | server_input_keep_alive(int type, u_int32_t seq, void *ctxt) |
3ffc6336 | 884 | { |
95ae2076 | 885 | debug("Got %d/%u for keepalive", type, seq); |
184eed6a | 886 | /* |
39aefe7b | 887 | * reset timeout, since we got a sane answer from the client. |
3ffc6336 | 888 | * even if this was generated by something other than |
889 | * the bogus CHANNEL_REQUEST we send for keepalives. | |
890 | */ | |
ac47b626 | 891 | keep_alive_timeouts = 0; |
3ffc6336 | 892 | } |
893 | ||
396c147e | 894 | static void |
7819b5c3 | 895 | server_input_stdin_data(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 896 | { |
897 | char *data; | |
1e3b8b07 | 898 | u_int data_len; |
7368a6c8 | 899 | |
900 | /* Stdin data from the client. Append it to the buffer. */ | |
901 | /* Ignore any data if the client has closed stdin. */ | |
902 | if (fdin == -1) | |
903 | return; | |
904 | data = packet_get_string(&data_len); | |
95500969 | 905 | packet_check_eom(); |
7368a6c8 | 906 | buffer_append(&stdin_buffer, data, data_len); |
907 | memset(data, 0, data_len); | |
908 | xfree(data); | |
909 | } | |
910 | ||
396c147e | 911 | static void |
7819b5c3 | 912 | server_input_eof(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 913 | { |
914 | /* | |
915 | * Eof from the client. The stdin descriptor to the | |
916 | * program will be closed when all buffered data has | |
917 | * drained. | |
918 | */ | |
919 | debug("EOF received for stdin."); | |
95500969 | 920 | packet_check_eom(); |
7368a6c8 | 921 | stdin_eof = 1; |
922 | } | |
923 | ||
396c147e | 924 | static void |
7819b5c3 | 925 | server_input_window_size(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 926 | { |
148de80c | 927 | u_int row = packet_get_int(); |
928 | u_int col = packet_get_int(); | |
929 | u_int xpixel = packet_get_int(); | |
930 | u_int ypixel = packet_get_int(); | |
7368a6c8 | 931 | |
932 | debug("Window change received."); | |
95500969 | 933 | packet_check_eom(); |
7368a6c8 | 934 | if (fdin != -1) |
935 | pty_change_window_size(fdin, row, col, xpixel, ypixel); | |
936 | } | |
937 | ||
396c147e | 938 | static Channel * |
43f7a4b8 | 939 | server_request_direct_tcpip(void) |
e78a59f5 | 940 | { |
719fc62f | 941 | Channel *c; |
6ae2364d | 942 | char *target, *originator; |
943 | int target_port, originator_port; | |
e78a59f5 | 944 | |
6ae2364d | 945 | target = packet_get_string(NULL); |
946 | target_port = packet_get_int(); | |
e78a59f5 | 947 | originator = packet_get_string(NULL); |
948 | originator_port = packet_get_int(); | |
95500969 | 949 | packet_check_eom(); |
71276795 | 950 | |
e07e21ad | 951 | debug("server_request_direct_tcpip: originator %s port %d, target %s " |
952 | "port %d", originator, originator_port, target, target_port); | |
38c295d6 | 953 | |
e78a59f5 | 954 | /* XXX check permission */ |
e07e21ad | 955 | c = channel_connect_to(target, target_port, |
956 | "direct-tcpip", "direct-tcpip"); | |
957 | ||
e78a59f5 | 958 | xfree(originator); |
e07e21ad | 959 | xfree(target); |
960 | ||
719fc62f | 961 | return c; |
fa08c86b | 962 | } |
963 | ||
d20f3c9e | 964 | static Channel * |
965 | server_request_tun(void) | |
966 | { | |
967 | Channel *c = NULL; | |
a4f24bf8 | 968 | int mode, tun; |
969 | int sock; | |
d20f3c9e | 970 | |
a4f24bf8 | 971 | mode = packet_get_int(); |
972 | switch (mode) { | |
973 | case SSH_TUNMODE_POINTOPOINT: | |
974 | case SSH_TUNMODE_ETHERNET: | |
975 | break; | |
976 | default: | |
977 | packet_send_debug("Unsupported tunnel device mode."); | |
978 | return NULL; | |
979 | } | |
980 | if ((options.permit_tun & mode) == 0) { | |
981 | packet_send_debug("Server has rejected tunnel device " | |
982 | "forwarding"); | |
d20f3c9e | 983 | return NULL; |
984 | } | |
985 | ||
986 | tun = packet_get_int(); | |
a2b1748a | 987 | if (forced_tun_device != -1) { |
3efa8ea9 | 988 | if (tun != SSH_TUNID_ANY && forced_tun_device != tun) |
d20f3c9e | 989 | goto done; |
990 | tun = forced_tun_device; | |
991 | } | |
a4f24bf8 | 992 | sock = tun_open(tun, mode); |
d20f3c9e | 993 | if (sock < 0) |
994 | goto done; | |
995 | c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1, | |
996 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); | |
997 | c->datagram = 1; | |
e914f53a | 998 | #if defined(SSH_TUN_FILTER) |
999 | if (mode == SSH_TUNMODE_POINTOPOINT) | |
1000 | channel_register_filter(c->self, sys_tun_infilter, | |
1001 | sys_tun_outfilter); | |
1002 | #endif | |
d20f3c9e | 1003 | |
1004 | done: | |
1005 | if (c == NULL) | |
1006 | packet_send_debug("Failed to open the tunnel device."); | |
1007 | return c; | |
1008 | } | |
1009 | ||
396c147e | 1010 | static Channel * |
43f7a4b8 | 1011 | server_request_session(void) |
fa08c86b | 1012 | { |
719fc62f | 1013 | Channel *c; |
fa08c86b | 1014 | |
1015 | debug("input_session_request"); | |
95500969 | 1016 | packet_check_eom(); |
3f0444ca | 1017 | |
1018 | if (no_more_sessions) { | |
1019 | packet_disconnect("Possible attack: attempt to open a session " | |
1020 | "after additional sessions disabled"); | |
1021 | } | |
1022 | ||
fa08c86b | 1023 | /* |
1024 | * A server session has no fd to read or write until a | |
1025 | * CHANNEL_REQUEST for a shell is made, so we set the type to | |
1026 | * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all | |
1027 | * CHANNEL_REQUEST messages is registered. | |
1028 | */ | |
43f7a4b8 | 1029 | c = channel_new("session", SSH_CHANNEL_LARVAL, |
719fc62f | 1030 | -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT, |
0d942eff | 1031 | 0, "server-session", 1); |
2362db19 | 1032 | if (session_open(the_authctxt, c->self) != 1) { |
719fc62f | 1033 | debug("session open failed, free channel %d", c->self); |
1034 | channel_free(c); | |
1035 | return NULL; | |
fa08c86b | 1036 | } |
8cd0437d | 1037 | channel_register_cleanup(c->self, session_close_by_channel, 0); |
719fc62f | 1038 | return c; |
e78a59f5 | 1039 | } |
1040 | ||
396c147e | 1041 | static void |
7819b5c3 | 1042 | server_input_channel_open(int type, u_int32_t seq, void *ctxt) |
e78a59f5 | 1043 | { |
1044 | Channel *c = NULL; | |
1045 | char *ctype; | |
e78a59f5 | 1046 | int rchan; |
f91d9a89 | 1047 | u_int rmaxpack, rwindow, len; |
e78a59f5 | 1048 | |
1049 | ctype = packet_get_string(&len); | |
1050 | rchan = packet_get_int(); | |
1051 | rwindow = packet_get_int(); | |
1052 | rmaxpack = packet_get_int(); | |
1053 | ||
188adeb2 | 1054 | debug("server_input_channel_open: ctype %s rchan %d win %d max %d", |
e78a59f5 | 1055 | ctype, rchan, rwindow, rmaxpack); |
1056 | ||
1057 | if (strcmp(ctype, "session") == 0) { | |
43f7a4b8 | 1058 | c = server_request_session(); |
e78a59f5 | 1059 | } else if (strcmp(ctype, "direct-tcpip") == 0) { |
43f7a4b8 | 1060 | c = server_request_direct_tcpip(); |
d20f3c9e | 1061 | } else if (strcmp(ctype, "tun@openssh.com") == 0) { |
1062 | c = server_request_tun(); | |
e78a59f5 | 1063 | } |
1064 | if (c != NULL) { | |
fa08c86b | 1065 | debug("server_input_channel_open: confirm %s", ctype); |
e78a59f5 | 1066 | c->remote_id = rchan; |
1067 | c->remote_window = rwindow; | |
1068 | c->remote_maxpacket = rmaxpack; | |
d18e0850 | 1069 | if (c->type != SSH_CHANNEL_CONNECTING) { |
1070 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1071 | packet_put_int(c->remote_id); | |
1072 | packet_put_int(c->self); | |
1073 | packet_put_int(c->local_window); | |
1074 | packet_put_int(c->local_maxpacket); | |
1075 | packet_send(); | |
1076 | } | |
e78a59f5 | 1077 | } else { |
fa08c86b | 1078 | debug("server_input_channel_open: failure %s", ctype); |
e78a59f5 | 1079 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
1080 | packet_put_int(rchan); | |
1081 | packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); | |
fbe90f7b | 1082 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { |
d18e0850 | 1083 | packet_put_cstring("open failed"); |
fbe90f7b | 1084 | packet_put_cstring(""); |
1085 | } | |
e78a59f5 | 1086 | packet_send(); |
1087 | } | |
1088 | xfree(ctype); | |
1089 | } | |
1090 | ||
396c147e | 1091 | static void |
7819b5c3 | 1092 | server_input_global_request(int type, u_int32_t seq, void *ctxt) |
fa08c86b | 1093 | { |
1094 | char *rtype; | |
1095 | int want_reply; | |
1096 | int success = 0; | |
1097 | ||
1098 | rtype = packet_get_string(NULL); | |
1099 | want_reply = packet_get_char(); | |
1100 | debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply); | |
2b87da3b | 1101 | |
01794848 | 1102 | /* -R style forwarding */ |
fa08c86b | 1103 | if (strcmp(rtype, "tcpip-forward") == 0) { |
1104 | struct passwd *pw; | |
1105 | char *listen_address; | |
1106 | u_short listen_port; | |
1107 | ||
2362db19 | 1108 | pw = the_authctxt->pw; |
95077f48 | 1109 | if (pw == NULL || !the_authctxt->valid) |
fdaef11e | 1110 | fatal("server_input_global_request: no/invalid user"); |
b08a39ff | 1111 | listen_address = packet_get_string(NULL); |
fa08c86b | 1112 | listen_port = (u_short)packet_get_int(); |
1113 | debug("server_input_global_request: tcpip-forward listen %s port %d", | |
1114 | listen_address, listen_port); | |
1115 | ||
1116 | /* check permissions */ | |
1117 | if (!options.allow_tcp_forwarding || | |
e6f15ed1 | 1118 | no_port_forwarding_flag |
1119 | #ifndef NO_IPPORT_RESERVED_CONCEPT | |
1120 | || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0) | |
1121 | #endif | |
98c044d0 | 1122 | ) { |
fa08c86b | 1123 | success = 0; |
1124 | packet_send_debug("Server has disabled port forwarding."); | |
1125 | } else { | |
1126 | /* Start listening on the port */ | |
5641aefa | 1127 | success = channel_setup_remote_fwd_listener( |
1128 | listen_address, listen_port, options.gateway_ports); | |
fa08c86b | 1129 | } |
1130 | xfree(listen_address); | |
d740ec16 | 1131 | } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) { |
1132 | char *cancel_address; | |
1133 | u_short cancel_port; | |
1134 | ||
1135 | cancel_address = packet_get_string(NULL); | |
1136 | cancel_port = (u_short)packet_get_int(); | |
1137 | debug("%s: cancel-tcpip-forward addr %s port %d", __func__, | |
1138 | cancel_address, cancel_port); | |
1139 | ||
1140 | success = channel_cancel_rport_listener(cancel_address, | |
1141 | cancel_port); | |
4113a1d7 | 1142 | xfree(cancel_address); |
3f0444ca | 1143 | } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) { |
1144 | no_more_sessions = 1; | |
1145 | success = 1; | |
fa08c86b | 1146 | } |
1147 | if (want_reply) { | |
1148 | packet_start(success ? | |
1149 | SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); | |
1150 | packet_send(); | |
1151 | packet_write_wait(); | |
1152 | } | |
1153 | xfree(rtype); | |
1154 | } | |
a7137f6b | 1155 | |
7899c98f | 1156 | static void |
1157 | server_input_channel_req(int type, u_int32_t seq, void *ctxt) | |
1158 | { | |
1159 | Channel *c; | |
1160 | int id, reply, success = 0; | |
1161 | char *rtype; | |
1162 | ||
1163 | id = packet_get_int(); | |
1164 | rtype = packet_get_string(NULL); | |
1165 | reply = packet_get_char(); | |
1166 | ||
1167 | debug("server_input_channel_req: channel %d request %s reply %d", | |
1168 | id, rtype, reply); | |
1169 | ||
1170 | if ((c = channel_lookup(id)) == NULL) | |
1171 | packet_disconnect("server_input_channel_req: " | |
1172 | "unknown channel %d", id); | |
50c96367 | 1173 | if (!strcmp(rtype, "eow@openssh.com")) { |
1174 | packet_check_eom(); | |
1175 | chan_rcvd_eow(c); | |
1176 | } else if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN) | |
7899c98f | 1177 | success = session_input_channel_req(c, rtype); |
1178 | if (reply) { | |
1179 | packet_start(success ? | |
1180 | SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); | |
1181 | packet_put_int(c->remote_id); | |
1182 | packet_send(); | |
1183 | } | |
1184 | xfree(rtype); | |
1185 | } | |
fa08c86b | 1186 | |
396c147e | 1187 | static void |
5ca51e19 | 1188 | server_init_dispatch_20(void) |
e78a59f5 | 1189 | { |
1190 | debug("server_init_dispatch_20"); | |
1191 | dispatch_init(&dispatch_protocol_error); | |
1192 | dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); | |
1193 | dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); | |
1194 | dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); | |
1195 | dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); | |
1196 | dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open); | |
1197 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1198 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
7899c98f | 1199 | dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req); |
e78a59f5 | 1200 | dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); |
fa08c86b | 1201 | dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request); |
3593bdc0 | 1202 | dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); |
1203 | dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); | |
3ffc6336 | 1204 | /* client_alive */ |
95ae2076 | 1205 | dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive); |
1206 | dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive); | |
7a37c112 | 1207 | /* rekeying */ |
1208 | dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); | |
e78a59f5 | 1209 | } |
396c147e | 1210 | static void |
5ca51e19 | 1211 | server_init_dispatch_13(void) |
7368a6c8 | 1212 | { |
1213 | debug("server_init_dispatch_13"); | |
1214 | dispatch_init(NULL); | |
1215 | dispatch_set(SSH_CMSG_EOF, &server_input_eof); | |
1216 | dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data); | |
1217 | dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size); | |
1218 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); | |
1219 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); | |
1220 | dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); | |
1221 | dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1222 | dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
1223 | dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); | |
1224 | } | |
396c147e | 1225 | static void |
5ca51e19 | 1226 | server_init_dispatch_15(void) |
7368a6c8 | 1227 | { |
1228 | server_init_dispatch_13(); | |
1229 | debug("server_init_dispatch_15"); | |
1230 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); | |
1231 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose); | |
1232 | } | |
396c147e | 1233 | static void |
5ca51e19 | 1234 | server_init_dispatch(void) |
7368a6c8 | 1235 | { |
e78a59f5 | 1236 | if (compat20) |
1237 | server_init_dispatch_20(); | |
1238 | else if (compat13) | |
7368a6c8 | 1239 | server_init_dispatch_13(); |
1240 | else | |
1241 | server_init_dispatch_15(); | |
1242 | } |