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7ec2b275 | 1 | /* $OpenBSD: serverloop.c,v 1.154 2008/12/02 19:08:59 markus 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) { |
5a0c8771 | 403 | if (errno != EINTR && errno != EAGAIN && |
404 | errno != EWOULDBLOCK) { | |
00e842d8 | 405 | verbose("Read error from remote host " |
406 | "%.100s: %.100s", | |
407 | get_remote_ipaddr(), strerror(errno)); | |
2362db19 | 408 | cleanup_exit(255); |
0e73cc53 | 409 | } |
410 | } else { | |
411 | /* Buffer any received data. */ | |
412 | packet_process_incoming(buf, len); | |
5260325f | 413 | } |
5260325f | 414 | } |
e78a59f5 | 415 | if (compat20) |
416 | return; | |
417 | ||
5260325f | 418 | /* Read and buffer any available stdout data from the program. */ |
419 | if (!fdout_eof && FD_ISSET(fdout, readset)) { | |
ea8c44d9 | 420 | errno = 0; |
5260325f | 421 | len = read(fdout, buf, sizeof(buf)); |
5a0c8771 | 422 | if (len < 0 && (errno == EINTR || ((errno == EAGAIN || |
423 | errno == EWOULDBLOCK) && !child_terminated))) { | |
0e73cc53 | 424 | /* do nothing */ |
24a87055 | 425 | #ifndef PTY_ZEROREAD |
0e73cc53 | 426 | } else if (len <= 0) { |
ea8c44d9 | 427 | #else |
9c04d67d | 428 | } else if ((!isatty(fdout) && len <= 0) || |
429 | (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) { | |
ea8c44d9 | 430 | #endif |
5260325f | 431 | fdout_eof = 1; |
0e73cc53 | 432 | } else { |
5260325f | 433 | buffer_append(&stdout_buffer, buf, len); |
434 | fdout_bytes += len; | |
435 | } | |
436 | } | |
437 | /* Read and buffer any available stderr data from the program. */ | |
438 | if (!fderr_eof && FD_ISSET(fderr, readset)) { | |
ea8c44d9 | 439 | errno = 0; |
5260325f | 440 | len = read(fderr, buf, sizeof(buf)); |
5a0c8771 | 441 | if (len < 0 && (errno == EINTR || ((errno == EAGAIN || |
442 | errno == EWOULDBLOCK) && !child_terminated))) { | |
0e73cc53 | 443 | /* do nothing */ |
24a87055 | 444 | #ifndef PTY_ZEROREAD |
0e73cc53 | 445 | } else if (len <= 0) { |
ea8c44d9 | 446 | #else |
9c04d67d | 447 | } else if ((!isatty(fderr) && len <= 0) || |
448 | (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) { | |
ea8c44d9 | 449 | #endif |
5260325f | 450 | fderr_eof = 1; |
0e73cc53 | 451 | } else { |
5260325f | 452 | buffer_append(&stderr_buffer, buf, len); |
0e73cc53 | 453 | } |
5260325f | 454 | } |
455 | } | |
8efc0c15 | 456 | |
5260325f | 457 | /* |
458 | * Sends data from internal buffers to client program stdin. | |
459 | */ | |
396c147e | 460 | static void |
b476adfa | 461 | process_output(fd_set *writeset) |
8efc0c15 | 462 | { |
4ef922e3 | 463 | struct termios tio; |
780a9951 | 464 | u_char *data; |
465 | u_int dlen; | |
5260325f | 466 | int len; |
467 | ||
468 | /* Write buffered data to program stdin. */ | |
e78a59f5 | 469 | if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) { |
780a9951 | 470 | data = buffer_ptr(&stdin_buffer); |
471 | dlen = buffer_len(&stdin_buffer); | |
472 | len = write(fdin, data, dlen); | |
5a0c8771 | 473 | if (len < 0 && |
474 | (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)) { | |
0e73cc53 | 475 | /* do nothing */ |
476 | } else if (len <= 0) { | |
7368a6c8 | 477 | if (fdin != fdout) |
5260325f | 478 | close(fdin); |
479 | else | |
480 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
5260325f | 481 | fdin = -1; |
482 | } else { | |
4ef922e3 | 483 | /* Successful write. */ |
780a9951 | 484 | if (fdin_is_tty && dlen >= 1 && data[0] != '\r' && |
485 | tcgetattr(fdin, &tio) == 0 && | |
0ae4fe1d | 486 | !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { |
62da27dd | 487 | /* |
488 | * Simulate echo to reduce the impact of | |
489 | * traffic analysis | |
490 | */ | |
95ce5599 | 491 | packet_send_ignore(len); |
4ef922e3 | 492 | packet_send(); |
493 | } | |
494 | /* Consume the data from the buffer. */ | |
5260325f | 495 | buffer_consume(&stdin_buffer, len); |
496 | /* Update the count of bytes written to the program. */ | |
497 | stdin_bytes += len; | |
498 | } | |
8efc0c15 | 499 | } |
5260325f | 500 | /* Send any buffered packet data to the client. */ |
501 | if (FD_ISSET(connection_out, writeset)) | |
502 | packet_write_poll(); | |
8efc0c15 | 503 | } |
504 | ||
5260325f | 505 | /* |
506 | * Wait until all buffered output has been sent to the client. | |
507 | * This is used when the program terminates. | |
508 | */ | |
396c147e | 509 | static void |
5ca51e19 | 510 | drain_output(void) |
8efc0c15 | 511 | { |
5260325f | 512 | /* Send any buffered stdout data to the client. */ |
513 | if (buffer_len(&stdout_buffer) > 0) { | |
514 | packet_start(SSH_SMSG_STDOUT_DATA); | |
515 | packet_put_string(buffer_ptr(&stdout_buffer), | |
516 | buffer_len(&stdout_buffer)); | |
517 | packet_send(); | |
518 | /* Update the count of sent bytes. */ | |
519 | stdout_bytes += buffer_len(&stdout_buffer); | |
520 | } | |
521 | /* Send any buffered stderr data to the client. */ | |
522 | if (buffer_len(&stderr_buffer) > 0) { | |
523 | packet_start(SSH_SMSG_STDERR_DATA); | |
524 | packet_put_string(buffer_ptr(&stderr_buffer), | |
525 | buffer_len(&stderr_buffer)); | |
526 | packet_send(); | |
527 | /* Update the count of sent bytes. */ | |
528 | stderr_bytes += buffer_len(&stderr_buffer); | |
529 | } | |
530 | /* Wait until all buffered data has been written to the client. */ | |
531 | packet_write_wait(); | |
8efc0c15 | 532 | } |
533 | ||
396c147e | 534 | static void |
5ca51e19 | 535 | process_buffered_input_packets(void) |
7368a6c8 | 536 | { |
7a37c112 | 537 | dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL); |
7368a6c8 | 538 | } |
539 | ||
5260325f | 540 | /* |
541 | * Performs the interactive session. This handles data transmission between | |
542 | * the client and the program. Note that the notion of stdin, stdout, and | |
543 | * stderr in this function is sort of reversed: this function writes to | |
544 | * stdin (of the child program), and reads from stdout and stderr (of the | |
545 | * child program). | |
546 | */ | |
6ae2364d | 547 | void |
9da5c3c9 | 548 | server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) |
8efc0c15 | 549 | { |
39929cdb | 550 | fd_set *readset = NULL, *writeset = NULL; |
9a995072 | 551 | int max_fd = 0; |
552 | u_int nalloc = 0; | |
9da5c3c9 | 553 | int wait_status; /* Status returned by wait(). */ |
554 | pid_t wait_pid; /* pid returned by wait(). */ | |
5260325f | 555 | int waiting_termination = 0; /* Have displayed waiting close message. */ |
1e3b8b07 | 556 | u_int max_time_milliseconds; |
557 | u_int previous_stdout_buffer_bytes; | |
558 | u_int stdout_buffer_bytes; | |
5260325f | 559 | int type; |
560 | ||
561 | debug("Entering interactive session."); | |
562 | ||
563 | /* Initialize the SIGCHLD kludge. */ | |
5260325f | 564 | child_terminated = 0; |
42ad0eec | 565 | mysignal(SIGCHLD, sigchld_handler); |
5260325f | 566 | |
0bbbf2a4 | 567 | if (!use_privsep) { |
568 | signal(SIGTERM, sigterm_handler); | |
569 | signal(SIGINT, sigterm_handler); | |
570 | signal(SIGQUIT, sigterm_handler); | |
571 | } | |
572 | ||
5260325f | 573 | /* Initialize our global variables. */ |
574 | fdin = fdin_arg; | |
575 | fdout = fdout_arg; | |
576 | fderr = fderr_arg; | |
0e73cc53 | 577 | |
578 | /* nonblocking IO */ | |
579 | set_nonblock(fdin); | |
580 | set_nonblock(fdout); | |
ff873e98 | 581 | /* we don't have stderr for interactive terminal sessions, see below */ |
582 | if (fderr != -1) | |
583 | set_nonblock(fderr); | |
0e73cc53 | 584 | |
e68225b2 | 585 | if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin)) |
586 | fdin_is_tty = 1; | |
587 | ||
5260325f | 588 | connection_in = packet_get_connection_in(); |
589 | connection_out = packet_get_connection_out(); | |
590 | ||
a10be357 | 591 | notify_setup(); |
592 | ||
5260325f | 593 | previous_stdout_buffer_bytes = 0; |
594 | ||
595 | /* Set approximate I/O buffer size. */ | |
596 | if (packet_is_interactive()) | |
597 | buffer_high = 4096; | |
598 | else | |
599 | buffer_high = 64 * 1024; | |
600 | ||
489aa2e9 | 601 | #if 0 |
5260325f | 602 | /* Initialize max_fd to the maximum of the known file descriptors. */ |
489aa2e9 | 603 | max_fd = MAX(connection_in, connection_out); |
604 | max_fd = MAX(max_fd, fdin); | |
605 | max_fd = MAX(max_fd, fdout); | |
39929cdb | 606 | if (fderr != -1) |
607 | max_fd = MAX(max_fd, fderr); | |
489aa2e9 | 608 | #endif |
5260325f | 609 | |
610 | /* Initialize Initialize buffers. */ | |
611 | buffer_init(&stdin_buffer); | |
612 | buffer_init(&stdout_buffer); | |
613 | buffer_init(&stderr_buffer); | |
614 | ||
aa3378df | 615 | /* |
616 | * If we have no separate fderr (which is the case when we have a pty | |
617 | * - there we cannot make difference between data sent to stdout and | |
618 | * stderr), indicate that we have seen an EOF from stderr. This way | |
7b9b0103 | 619 | * we don't need to check the descriptor everywhere. |
aa3378df | 620 | */ |
5260325f | 621 | if (fderr == -1) |
622 | fderr_eof = 1; | |
623 | ||
7368a6c8 | 624 | server_init_dispatch(); |
625 | ||
5260325f | 626 | /* Main loop of the server for the interactive session mode. */ |
627 | for (;;) { | |
5260325f | 628 | |
629 | /* Process buffered packets from the client. */ | |
630 | process_buffered_input_packets(); | |
631 | ||
aa3378df | 632 | /* |
633 | * If we have received eof, and there is no more pending | |
634 | * input data, cause a real eof by closing fdin. | |
635 | */ | |
5260325f | 636 | if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) { |
7368a6c8 | 637 | if (fdin != fdout) |
5260325f | 638 | close(fdin); |
639 | else | |
640 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
5260325f | 641 | fdin = -1; |
642 | } | |
aa3378df | 643 | /* Make packets from buffered stderr data to send to the client. */ |
5260325f | 644 | make_packets_from_stderr_data(); |
645 | ||
aa3378df | 646 | /* |
647 | * Make packets from buffered stdout data to send to the | |
648 | * client. If there is very little to send, this arranges to | |
649 | * not send them now, but to wait a short while to see if we | |
650 | * are getting more data. This is necessary, as some systems | |
651 | * wake up readers from a pty after each separate character. | |
652 | */ | |
5260325f | 653 | max_time_milliseconds = 0; |
654 | stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
655 | if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && | |
656 | stdout_buffer_bytes != previous_stdout_buffer_bytes) { | |
657 | /* try again after a while */ | |
658 | max_time_milliseconds = 10; | |
659 | } else { | |
660 | /* Send it now. */ | |
661 | make_packets_from_stdout_data(); | |
662 | } | |
663 | previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
664 | ||
665 | /* Send channel data to the client. */ | |
666 | if (packet_not_very_much_data_to_write()) | |
667 | channel_output_poll(); | |
668 | ||
aa3378df | 669 | /* |
670 | * Bail out of the loop if the program has closed its output | |
671 | * descriptors, and we have no more data to send to the | |
672 | * client, and there is no pending buffered data. | |
673 | */ | |
7062c40f | 674 | if (fdout_eof && fderr_eof && !packet_have_data_to_write() && |
675 | buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { | |
5260325f | 676 | if (!channel_still_open()) |
7368a6c8 | 677 | break; |
5260325f | 678 | if (!waiting_termination) { |
679 | const char *s = "Waiting for forwarded connections to terminate...\r\n"; | |
680 | char *cp; | |
681 | waiting_termination = 1; | |
682 | buffer_append(&stderr_buffer, s, strlen(s)); | |
683 | ||
684 | /* Display list of open channels. */ | |
685 | cp = channel_open_message(); | |
686 | buffer_append(&stderr_buffer, cp, strlen(cp)); | |
687 | xfree(cp); | |
688 | } | |
689 | } | |
489aa2e9 | 690 | max_fd = MAX(connection_in, connection_out); |
691 | max_fd = MAX(max_fd, fdin); | |
692 | max_fd = MAX(max_fd, fdout); | |
693 | max_fd = MAX(max_fd, fderr); | |
a10be357 | 694 | max_fd = MAX(max_fd, notify_pipe[0]); |
489aa2e9 | 695 | |
5260325f | 696 | /* Sleep in select() until we can do something. */ |
39929cdb | 697 | wait_until_can_do_something(&readset, &writeset, &max_fd, |
489aa2e9 | 698 | &nalloc, max_time_milliseconds); |
5260325f | 699 | |
0bbbf2a4 | 700 | if (received_sigterm) { |
701 | logit("Exiting on signal %d", received_sigterm); | |
702 | /* Clean up sessions, utmp, etc. */ | |
703 | cleanup_exit(255); | |
704 | } | |
705 | ||
5260325f | 706 | /* Process any channel events. */ |
39929cdb | 707 | channel_after_select(readset, writeset); |
5260325f | 708 | |
709 | /* Process input from the client and from program stdout/stderr. */ | |
39929cdb | 710 | process_input(readset); |
5260325f | 711 | |
712 | /* Process output to the client and to program stdin. */ | |
39929cdb | 713 | process_output(writeset); |
8efc0c15 | 714 | } |
39929cdb | 715 | if (readset) |
716 | xfree(readset); | |
717 | if (writeset) | |
718 | xfree(writeset); | |
8efc0c15 | 719 | |
5260325f | 720 | /* Cleanup and termination code. */ |
8efc0c15 | 721 | |
5260325f | 722 | /* Wait until all output has been sent to the client. */ |
723 | drain_output(); | |
8efc0c15 | 724 | |
5260325f | 725 | debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", |
184eed6a | 726 | stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); |
8efc0c15 | 727 | |
5260325f | 728 | /* Free and clear the buffers. */ |
729 | buffer_free(&stdin_buffer); | |
730 | buffer_free(&stdout_buffer); | |
731 | buffer_free(&stderr_buffer); | |
8efc0c15 | 732 | |
5260325f | 733 | /* Close the file descriptors. */ |
734 | if (fdout != -1) | |
735 | close(fdout); | |
736 | fdout = -1; | |
737 | fdout_eof = 1; | |
738 | if (fderr != -1) | |
739 | close(fderr); | |
740 | fderr = -1; | |
741 | fderr_eof = 1; | |
742 | if (fdin != -1) | |
743 | close(fdin); | |
744 | fdin = -1; | |
745 | ||
d6746a0b | 746 | channel_free_all(); |
5260325f | 747 | |
5260325f | 748 | /* We no longer want our SIGCHLD handler to be called. */ |
42ad0eec | 749 | mysignal(SIGCHLD, SIG_DFL); |
5260325f | 750 | |
8c38e88b | 751 | while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0) |
752 | if (errno != EINTR) | |
753 | packet_disconnect("wait: %.100s", strerror(errno)); | |
754 | if (wait_pid != pid) | |
c457707e | 755 | error("Strange, wait returned pid %ld, expected %ld", |
756 | (long)wait_pid, (long)pid); | |
c9130033 | 757 | |
5260325f | 758 | /* Check if it exited normally. */ |
759 | if (WIFEXITED(wait_status)) { | |
760 | /* Yes, normal exit. Get exit status and send it to the client. */ | |
761 | debug("Command exited with status %d.", WEXITSTATUS(wait_status)); | |
762 | packet_start(SSH_SMSG_EXITSTATUS); | |
763 | packet_put_int(WEXITSTATUS(wait_status)); | |
764 | packet_send(); | |
765 | packet_write_wait(); | |
766 | ||
aa3378df | 767 | /* |
768 | * Wait for exit confirmation. Note that there might be | |
769 | * other packets coming before it; however, the program has | |
770 | * already died so we just ignore them. The client is | |
771 | * supposed to respond with the confirmation when it receives | |
772 | * the exit status. | |
773 | */ | |
5260325f | 774 | do { |
54a5250f | 775 | type = packet_read(); |
5260325f | 776 | } |
777 | while (type != SSH_CMSG_EXIT_CONFIRMATION); | |
778 | ||
779 | debug("Received exit confirmation."); | |
780 | return; | |
781 | } | |
782 | /* Check if the program terminated due to a signal. */ | |
783 | if (WIFSIGNALED(wait_status)) | |
784 | packet_disconnect("Command terminated on signal %d.", | |
785 | WTERMSIG(wait_status)); | |
786 | ||
787 | /* Some weird exit cause. Just exit. */ | |
788 | packet_disconnect("wait returned status %04x.", wait_status); | |
789 | /* NOTREACHED */ | |
790 | } | |
7368a6c8 | 791 | |
418e724c | 792 | static void |
793 | collect_children(void) | |
794 | { | |
795 | pid_t pid; | |
796 | sigset_t oset, nset; | |
797 | int status; | |
798 | ||
799 | /* block SIGCHLD while we check for dead children */ | |
800 | sigemptyset(&nset); | |
801 | sigaddset(&nset, SIGCHLD); | |
802 | sigprocmask(SIG_BLOCK, &nset, &oset); | |
803 | if (child_terminated) { | |
140000b4 | 804 | debug("Received SIGCHLD."); |
8c38e88b | 805 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
806 | (pid < 0 && errno == EINTR)) | |
807 | if (pid > 0) | |
808 | session_close_by_pid(pid, status); | |
418e724c | 809 | child_terminated = 0; |
810 | } | |
811 | sigprocmask(SIG_SETMASK, &oset, NULL); | |
812 | } | |
813 | ||
6ae2364d | 814 | void |
57156994 | 815 | server_loop2(Authctxt *authctxt) |
e78a59f5 | 816 | { |
39929cdb | 817 | fd_set *readset = NULL, *writeset = NULL; |
418e724c | 818 | int rekeying = 0, max_fd, nalloc = 0; |
e78a59f5 | 819 | |
820 | debug("Entering interactive session for SSH2."); | |
821 | ||
c9130033 | 822 | mysignal(SIGCHLD, sigchld_handler); |
e78a59f5 | 823 | child_terminated = 0; |
824 | connection_in = packet_get_connection_in(); | |
825 | connection_out = packet_get_connection_out(); | |
39929cdb | 826 | |
0bbbf2a4 | 827 | if (!use_privsep) { |
828 | signal(SIGTERM, sigterm_handler); | |
829 | signal(SIGINT, sigterm_handler); | |
830 | signal(SIGQUIT, sigterm_handler); | |
831 | } | |
832 | ||
a10be357 | 833 | notify_setup(); |
834 | ||
39929cdb | 835 | max_fd = MAX(connection_in, connection_out); |
a10be357 | 836 | max_fd = MAX(max_fd, notify_pipe[0]); |
837 | ||
e78a59f5 | 838 | server_init_dispatch(); |
839 | ||
840 | for (;;) { | |
841 | process_buffered_input_packets(); | |
bbb4cc1b | 842 | |
cd332296 | 843 | rekeying = (xxx_kex != NULL && !xxx_kex->done); |
bbb4cc1b | 844 | |
bbb4cc1b | 845 | if (!rekeying && packet_not_very_much_data_to_write()) |
e78a59f5 | 846 | channel_output_poll(); |
bbb4cc1b | 847 | wait_until_can_do_something(&readset, &writeset, &max_fd, |
489aa2e9 | 848 | &nalloc, 0); |
d5f24f94 | 849 | |
0bbbf2a4 | 850 | if (received_sigterm) { |
851 | logit("Exiting on signal %d", received_sigterm); | |
852 | /* Clean up sessions, utmp, etc. */ | |
853 | cleanup_exit(255); | |
854 | } | |
855 | ||
418e724c | 856 | collect_children(); |
ffd7b36b | 857 | if (!rekeying) { |
bbb4cc1b | 858 | channel_after_select(readset, writeset); |
ffd7b36b | 859 | if (packet_need_rekeying()) { |
860 | debug("need rekeying"); | |
861 | xxx_kex->done = 0; | |
862 | kex_send_kexinit(xxx_kex); | |
863 | } | |
864 | } | |
39929cdb | 865 | process_input(readset); |
cc94bd38 | 866 | if (connection_closed) |
867 | break; | |
39929cdb | 868 | process_output(writeset); |
e78a59f5 | 869 | } |
418e724c | 870 | collect_children(); |
871 | ||
39929cdb | 872 | if (readset) |
873 | xfree(readset); | |
874 | if (writeset) | |
875 | xfree(writeset); | |
876 | ||
d5f24f94 | 877 | /* free all channels, no more reads and writes */ |
878 | channel_free_all(); | |
5b5d170c | 879 | |
418e724c | 880 | /* free remaining sessions, e.g. remove wtmp entries */ |
1853d1ef | 881 | session_destroy_all(NULL); |
e78a59f5 | 882 | } |
883 | ||
396c147e | 884 | static void |
95ae2076 | 885 | server_input_keep_alive(int type, u_int32_t seq, void *ctxt) |
3ffc6336 | 886 | { |
95ae2076 | 887 | debug("Got %d/%u for keepalive", type, seq); |
184eed6a | 888 | /* |
39aefe7b | 889 | * reset timeout, since we got a sane answer from the client. |
3ffc6336 | 890 | * even if this was generated by something other than |
891 | * the bogus CHANNEL_REQUEST we send for keepalives. | |
892 | */ | |
ac47b626 | 893 | keep_alive_timeouts = 0; |
3ffc6336 | 894 | } |
895 | ||
396c147e | 896 | static void |
7819b5c3 | 897 | server_input_stdin_data(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 898 | { |
899 | char *data; | |
1e3b8b07 | 900 | u_int data_len; |
7368a6c8 | 901 | |
902 | /* Stdin data from the client. Append it to the buffer. */ | |
903 | /* Ignore any data if the client has closed stdin. */ | |
904 | if (fdin == -1) | |
905 | return; | |
906 | data = packet_get_string(&data_len); | |
95500969 | 907 | packet_check_eom(); |
7368a6c8 | 908 | buffer_append(&stdin_buffer, data, data_len); |
909 | memset(data, 0, data_len); | |
910 | xfree(data); | |
911 | } | |
912 | ||
396c147e | 913 | static void |
7819b5c3 | 914 | server_input_eof(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 915 | { |
916 | /* | |
917 | * Eof from the client. The stdin descriptor to the | |
918 | * program will be closed when all buffered data has | |
919 | * drained. | |
920 | */ | |
921 | debug("EOF received for stdin."); | |
95500969 | 922 | packet_check_eom(); |
7368a6c8 | 923 | stdin_eof = 1; |
924 | } | |
925 | ||
396c147e | 926 | static void |
7819b5c3 | 927 | server_input_window_size(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 928 | { |
148de80c | 929 | u_int row = packet_get_int(); |
930 | u_int col = packet_get_int(); | |
931 | u_int xpixel = packet_get_int(); | |
932 | u_int ypixel = packet_get_int(); | |
7368a6c8 | 933 | |
934 | debug("Window change received."); | |
95500969 | 935 | packet_check_eom(); |
7368a6c8 | 936 | if (fdin != -1) |
937 | pty_change_window_size(fdin, row, col, xpixel, ypixel); | |
938 | } | |
939 | ||
396c147e | 940 | static Channel * |
43f7a4b8 | 941 | server_request_direct_tcpip(void) |
e78a59f5 | 942 | { |
719fc62f | 943 | Channel *c; |
6ae2364d | 944 | char *target, *originator; |
945 | int target_port, originator_port; | |
e78a59f5 | 946 | |
6ae2364d | 947 | target = packet_get_string(NULL); |
948 | target_port = packet_get_int(); | |
e78a59f5 | 949 | originator = packet_get_string(NULL); |
950 | originator_port = packet_get_int(); | |
95500969 | 951 | packet_check_eom(); |
71276795 | 952 | |
e07e21ad | 953 | debug("server_request_direct_tcpip: originator %s port %d, target %s " |
954 | "port %d", originator, originator_port, target, target_port); | |
38c295d6 | 955 | |
e78a59f5 | 956 | /* XXX check permission */ |
e07e21ad | 957 | c = channel_connect_to(target, target_port, |
958 | "direct-tcpip", "direct-tcpip"); | |
959 | ||
e78a59f5 | 960 | xfree(originator); |
e07e21ad | 961 | xfree(target); |
962 | ||
719fc62f | 963 | return c; |
fa08c86b | 964 | } |
965 | ||
d20f3c9e | 966 | static Channel * |
967 | server_request_tun(void) | |
968 | { | |
969 | Channel *c = NULL; | |
a4f24bf8 | 970 | int mode, tun; |
971 | int sock; | |
d20f3c9e | 972 | |
a4f24bf8 | 973 | mode = packet_get_int(); |
974 | switch (mode) { | |
975 | case SSH_TUNMODE_POINTOPOINT: | |
976 | case SSH_TUNMODE_ETHERNET: | |
977 | break; | |
978 | default: | |
979 | packet_send_debug("Unsupported tunnel device mode."); | |
980 | return NULL; | |
981 | } | |
982 | if ((options.permit_tun & mode) == 0) { | |
983 | packet_send_debug("Server has rejected tunnel device " | |
984 | "forwarding"); | |
d20f3c9e | 985 | return NULL; |
986 | } | |
987 | ||
988 | tun = packet_get_int(); | |
a2b1748a | 989 | if (forced_tun_device != -1) { |
3efa8ea9 | 990 | if (tun != SSH_TUNID_ANY && forced_tun_device != tun) |
d20f3c9e | 991 | goto done; |
992 | tun = forced_tun_device; | |
993 | } | |
a4f24bf8 | 994 | sock = tun_open(tun, mode); |
d20f3c9e | 995 | if (sock < 0) |
996 | goto done; | |
997 | c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1, | |
998 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); | |
999 | c->datagram = 1; | |
e914f53a | 1000 | #if defined(SSH_TUN_FILTER) |
1001 | if (mode == SSH_TUNMODE_POINTOPOINT) | |
1002 | channel_register_filter(c->self, sys_tun_infilter, | |
136d0181 | 1003 | sys_tun_outfilter, NULL, NULL); |
e914f53a | 1004 | #endif |
d20f3c9e | 1005 | |
1006 | done: | |
1007 | if (c == NULL) | |
1008 | packet_send_debug("Failed to open the tunnel device."); | |
1009 | return c; | |
1010 | } | |
1011 | ||
396c147e | 1012 | static Channel * |
43f7a4b8 | 1013 | server_request_session(void) |
fa08c86b | 1014 | { |
719fc62f | 1015 | Channel *c; |
fa08c86b | 1016 | |
1017 | debug("input_session_request"); | |
95500969 | 1018 | packet_check_eom(); |
3f0444ca | 1019 | |
1020 | if (no_more_sessions) { | |
1021 | packet_disconnect("Possible attack: attempt to open a session " | |
1022 | "after additional sessions disabled"); | |
1023 | } | |
1024 | ||
fa08c86b | 1025 | /* |
1026 | * A server session has no fd to read or write until a | |
1027 | * CHANNEL_REQUEST for a shell is made, so we set the type to | |
1028 | * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all | |
1029 | * CHANNEL_REQUEST messages is registered. | |
1030 | */ | |
43f7a4b8 | 1031 | c = channel_new("session", SSH_CHANNEL_LARVAL, |
719fc62f | 1032 | -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT, |
0d942eff | 1033 | 0, "server-session", 1); |
2362db19 | 1034 | if (session_open(the_authctxt, c->self) != 1) { |
719fc62f | 1035 | debug("session open failed, free channel %d", c->self); |
1036 | channel_free(c); | |
1037 | return NULL; | |
fa08c86b | 1038 | } |
8cd0437d | 1039 | channel_register_cleanup(c->self, session_close_by_channel, 0); |
719fc62f | 1040 | return c; |
e78a59f5 | 1041 | } |
1042 | ||
396c147e | 1043 | static void |
7819b5c3 | 1044 | server_input_channel_open(int type, u_int32_t seq, void *ctxt) |
e78a59f5 | 1045 | { |
1046 | Channel *c = NULL; | |
1047 | char *ctype; | |
e78a59f5 | 1048 | int rchan; |
f91d9a89 | 1049 | u_int rmaxpack, rwindow, len; |
e78a59f5 | 1050 | |
1051 | ctype = packet_get_string(&len); | |
1052 | rchan = packet_get_int(); | |
1053 | rwindow = packet_get_int(); | |
1054 | rmaxpack = packet_get_int(); | |
1055 | ||
188adeb2 | 1056 | debug("server_input_channel_open: ctype %s rchan %d win %d max %d", |
e78a59f5 | 1057 | ctype, rchan, rwindow, rmaxpack); |
1058 | ||
1059 | if (strcmp(ctype, "session") == 0) { | |
43f7a4b8 | 1060 | c = server_request_session(); |
e78a59f5 | 1061 | } else if (strcmp(ctype, "direct-tcpip") == 0) { |
43f7a4b8 | 1062 | c = server_request_direct_tcpip(); |
d20f3c9e | 1063 | } else if (strcmp(ctype, "tun@openssh.com") == 0) { |
1064 | c = server_request_tun(); | |
e78a59f5 | 1065 | } |
1066 | if (c != NULL) { | |
fa08c86b | 1067 | debug("server_input_channel_open: confirm %s", ctype); |
e78a59f5 | 1068 | c->remote_id = rchan; |
1069 | c->remote_window = rwindow; | |
1070 | c->remote_maxpacket = rmaxpack; | |
d18e0850 | 1071 | if (c->type != SSH_CHANNEL_CONNECTING) { |
1072 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1073 | packet_put_int(c->remote_id); | |
1074 | packet_put_int(c->self); | |
1075 | packet_put_int(c->local_window); | |
1076 | packet_put_int(c->local_maxpacket); | |
1077 | packet_send(); | |
1078 | } | |
e78a59f5 | 1079 | } else { |
fa08c86b | 1080 | debug("server_input_channel_open: failure %s", ctype); |
e78a59f5 | 1081 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
1082 | packet_put_int(rchan); | |
1083 | packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); | |
fbe90f7b | 1084 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { |
d18e0850 | 1085 | packet_put_cstring("open failed"); |
fbe90f7b | 1086 | packet_put_cstring(""); |
1087 | } | |
e78a59f5 | 1088 | packet_send(); |
1089 | } | |
1090 | xfree(ctype); | |
1091 | } | |
1092 | ||
396c147e | 1093 | static void |
7819b5c3 | 1094 | server_input_global_request(int type, u_int32_t seq, void *ctxt) |
fa08c86b | 1095 | { |
1096 | char *rtype; | |
1097 | int want_reply; | |
1098 | int success = 0; | |
1099 | ||
1100 | rtype = packet_get_string(NULL); | |
1101 | want_reply = packet_get_char(); | |
1102 | debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply); | |
2b87da3b | 1103 | |
01794848 | 1104 | /* -R style forwarding */ |
fa08c86b | 1105 | if (strcmp(rtype, "tcpip-forward") == 0) { |
1106 | struct passwd *pw; | |
1107 | char *listen_address; | |
1108 | u_short listen_port; | |
1109 | ||
2362db19 | 1110 | pw = the_authctxt->pw; |
95077f48 | 1111 | if (pw == NULL || !the_authctxt->valid) |
fdaef11e | 1112 | fatal("server_input_global_request: no/invalid user"); |
b08a39ff | 1113 | listen_address = packet_get_string(NULL); |
fa08c86b | 1114 | listen_port = (u_short)packet_get_int(); |
1115 | debug("server_input_global_request: tcpip-forward listen %s port %d", | |
1116 | listen_address, listen_port); | |
1117 | ||
1118 | /* check permissions */ | |
1119 | if (!options.allow_tcp_forwarding || | |
e6f15ed1 | 1120 | no_port_forwarding_flag |
1121 | #ifndef NO_IPPORT_RESERVED_CONCEPT | |
1122 | || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0) | |
1123 | #endif | |
98c044d0 | 1124 | ) { |
fa08c86b | 1125 | success = 0; |
1126 | packet_send_debug("Server has disabled port forwarding."); | |
1127 | } else { | |
1128 | /* Start listening on the port */ | |
5641aefa | 1129 | success = channel_setup_remote_fwd_listener( |
1130 | listen_address, listen_port, options.gateway_ports); | |
fa08c86b | 1131 | } |
1132 | xfree(listen_address); | |
d740ec16 | 1133 | } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) { |
1134 | char *cancel_address; | |
1135 | u_short cancel_port; | |
1136 | ||
1137 | cancel_address = packet_get_string(NULL); | |
1138 | cancel_port = (u_short)packet_get_int(); | |
1139 | debug("%s: cancel-tcpip-forward addr %s port %d", __func__, | |
1140 | cancel_address, cancel_port); | |
1141 | ||
1142 | success = channel_cancel_rport_listener(cancel_address, | |
1143 | cancel_port); | |
4113a1d7 | 1144 | xfree(cancel_address); |
3f0444ca | 1145 | } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) { |
1146 | no_more_sessions = 1; | |
1147 | success = 1; | |
fa08c86b | 1148 | } |
1149 | if (want_reply) { | |
1150 | packet_start(success ? | |
1151 | SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); | |
1152 | packet_send(); | |
1153 | packet_write_wait(); | |
1154 | } | |
1155 | xfree(rtype); | |
1156 | } | |
a7137f6b | 1157 | |
7899c98f | 1158 | static void |
1159 | server_input_channel_req(int type, u_int32_t seq, void *ctxt) | |
1160 | { | |
1161 | Channel *c; | |
1162 | int id, reply, success = 0; | |
1163 | char *rtype; | |
1164 | ||
1165 | id = packet_get_int(); | |
1166 | rtype = packet_get_string(NULL); | |
1167 | reply = packet_get_char(); | |
1168 | ||
1169 | debug("server_input_channel_req: channel %d request %s reply %d", | |
1170 | id, rtype, reply); | |
1171 | ||
1172 | if ((c = channel_lookup(id)) == NULL) | |
1173 | packet_disconnect("server_input_channel_req: " | |
1174 | "unknown channel %d", id); | |
50c96367 | 1175 | if (!strcmp(rtype, "eow@openssh.com")) { |
1176 | packet_check_eom(); | |
1177 | chan_rcvd_eow(c); | |
fb5582f7 | 1178 | } else if ((c->type == SSH_CHANNEL_LARVAL || |
1179 | c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0) | |
7899c98f | 1180 | success = session_input_channel_req(c, rtype); |
1181 | if (reply) { | |
1182 | packet_start(success ? | |
1183 | SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); | |
1184 | packet_put_int(c->remote_id); | |
1185 | packet_send(); | |
1186 | } | |
1187 | xfree(rtype); | |
1188 | } | |
fa08c86b | 1189 | |
396c147e | 1190 | static void |
5ca51e19 | 1191 | server_init_dispatch_20(void) |
e78a59f5 | 1192 | { |
1193 | debug("server_init_dispatch_20"); | |
1194 | dispatch_init(&dispatch_protocol_error); | |
1195 | dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); | |
1196 | dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); | |
1197 | dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); | |
1198 | dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); | |
1199 | dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open); | |
1200 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1201 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
7899c98f | 1202 | dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req); |
e78a59f5 | 1203 | dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); |
fa08c86b | 1204 | dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request); |
3ffc6336 | 1205 | /* client_alive */ |
7ec2b275 | 1206 | dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive); |
1207 | dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive); | |
95ae2076 | 1208 | dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive); |
1209 | dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive); | |
7a37c112 | 1210 | /* rekeying */ |
1211 | dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); | |
e78a59f5 | 1212 | } |
396c147e | 1213 | static void |
5ca51e19 | 1214 | server_init_dispatch_13(void) |
7368a6c8 | 1215 | { |
1216 | debug("server_init_dispatch_13"); | |
1217 | dispatch_init(NULL); | |
1218 | dispatch_set(SSH_CMSG_EOF, &server_input_eof); | |
1219 | dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data); | |
1220 | dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size); | |
1221 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); | |
1222 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); | |
1223 | dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); | |
1224 | dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1225 | dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
1226 | dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); | |
1227 | } | |
396c147e | 1228 | static void |
5ca51e19 | 1229 | server_init_dispatch_15(void) |
7368a6c8 | 1230 | { |
1231 | server_init_dispatch_13(); | |
1232 | debug("server_init_dispatch_15"); | |
1233 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); | |
1234 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose); | |
1235 | } | |
396c147e | 1236 | static void |
5ca51e19 | 1237 | server_init_dispatch(void) |
7368a6c8 | 1238 | { |
e78a59f5 | 1239 | if (compat20) |
1240 | server_init_dispatch_20(); | |
1241 | else if (compat13) | |
7368a6c8 | 1242 | server_init_dispatch_13(); |
1243 | else | |
1244 | server_init_dispatch_15(); | |
1245 | } |