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e07e21ad | 1 | /* $OpenBSD: serverloop.c,v 1.150 2008/05/09 04:55:56 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. */ | |
8efc0c15 | 108 | |
aa3378df | 109 | /* |
110 | * This SIGCHLD kludge is used to detect when the child exits. The server | |
111 | * will exit after that, as soon as forwarded connections have terminated. | |
112 | */ | |
396c147e | 113 | |
7a934d1b | 114 | static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */ |
8efc0c15 | 115 | |
0bbbf2a4 | 116 | /* Cleanup on signals (!use_privsep case only) */ |
117 | static volatile sig_atomic_t received_sigterm = 0; | |
118 | ||
396c147e | 119 | /* prototypes */ |
120 | static void server_init_dispatch(void); | |
7368a6c8 | 121 | |
a10be357 | 122 | /* |
123 | * we write to this pipe if a SIGCHLD is caught in order to avoid | |
124 | * the race between select() and child_terminated | |
125 | */ | |
126 | static int notify_pipe[2]; | |
127 | static void | |
128 | notify_setup(void) | |
129 | { | |
130 | if (pipe(notify_pipe) < 0) { | |
131 | error("pipe(notify_pipe) failed %s", strerror(errno)); | |
132 | } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) || | |
133 | (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) { | |
134 | error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno)); | |
135 | close(notify_pipe[0]); | |
136 | close(notify_pipe[1]); | |
137 | } else { | |
138 | set_nonblock(notify_pipe[0]); | |
139 | set_nonblock(notify_pipe[1]); | |
140 | return; | |
141 | } | |
142 | notify_pipe[0] = -1; /* read end */ | |
143 | notify_pipe[1] = -1; /* write end */ | |
144 | } | |
145 | static void | |
146 | notify_parent(void) | |
147 | { | |
148 | if (notify_pipe[1] != -1) | |
149 | write(notify_pipe[1], "", 1); | |
150 | } | |
151 | static void | |
152 | notify_prepare(fd_set *readset) | |
153 | { | |
154 | if (notify_pipe[0] != -1) | |
155 | FD_SET(notify_pipe[0], readset); | |
156 | } | |
157 | static void | |
158 | notify_done(fd_set *readset) | |
159 | { | |
160 | char c; | |
161 | ||
162 | if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset)) | |
163 | while (read(notify_pipe[0], &c, 1) != -1) | |
164 | debug2("notify_done: reading"); | |
165 | } | |
166 | ||
3efa8ea9 | 167 | /*ARGSUSED*/ |
396c147e | 168 | static void |
5260325f | 169 | sigchld_handler(int sig) |
e78a59f5 | 170 | { |
171 | int save_errno = errno; | |
e78a59f5 | 172 | child_terminated = 1; |
ef51930f | 173 | #ifndef _UNICOS |
c9130033 | 174 | mysignal(SIGCHLD, sigchld_handler); |
ef51930f | 175 | #endif |
a10be357 | 176 | notify_parent(); |
e78a59f5 | 177 | errno = save_errno; |
178 | } | |
8efc0c15 | 179 | |
3efa8ea9 | 180 | /*ARGSUSED*/ |
0bbbf2a4 | 181 | static void |
182 | sigterm_handler(int sig) | |
183 | { | |
184 | received_sigterm = sig; | |
185 | } | |
186 | ||
5260325f | 187 | /* |
188 | * Make packets from buffered stderr data, and buffer it for sending | |
189 | * to the client. | |
190 | */ | |
396c147e | 191 | static void |
5ca51e19 | 192 | make_packets_from_stderr_data(void) |
8efc0c15 | 193 | { |
a27002e5 | 194 | u_int len; |
5260325f | 195 | |
196 | /* Send buffered stderr data to the client. */ | |
197 | while (buffer_len(&stderr_buffer) > 0 && | |
a408af76 | 198 | packet_not_very_much_data_to_write()) { |
5260325f | 199 | len = buffer_len(&stderr_buffer); |
200 | if (packet_is_interactive()) { | |
201 | if (len > 512) | |
202 | len = 512; | |
203 | } else { | |
204 | /* Keep the packets at reasonable size. */ | |
205 | if (len > packet_get_maxsize()) | |
206 | len = packet_get_maxsize(); | |
207 | } | |
208 | packet_start(SSH_SMSG_STDERR_DATA); | |
209 | packet_put_string(buffer_ptr(&stderr_buffer), len); | |
210 | packet_send(); | |
211 | buffer_consume(&stderr_buffer, len); | |
212 | stderr_bytes += len; | |
8efc0c15 | 213 | } |
8efc0c15 | 214 | } |
215 | ||
5260325f | 216 | /* |
217 | * Make packets from buffered stdout data, and buffer it for sending to the | |
218 | * client. | |
219 | */ | |
396c147e | 220 | static void |
5ca51e19 | 221 | make_packets_from_stdout_data(void) |
8efc0c15 | 222 | { |
a27002e5 | 223 | u_int len; |
5260325f | 224 | |
225 | /* Send buffered stdout data to the client. */ | |
226 | while (buffer_len(&stdout_buffer) > 0 && | |
a408af76 | 227 | packet_not_very_much_data_to_write()) { |
5260325f | 228 | len = buffer_len(&stdout_buffer); |
229 | if (packet_is_interactive()) { | |
230 | if (len > 512) | |
231 | len = 512; | |
232 | } else { | |
233 | /* Keep the packets at reasonable size. */ | |
234 | if (len > packet_get_maxsize()) | |
2b87da3b | 235 | len = packet_get_maxsize(); |
5260325f | 236 | } |
237 | packet_start(SSH_SMSG_STDOUT_DATA); | |
238 | packet_put_string(buffer_ptr(&stdout_buffer), len); | |
239 | packet_send(); | |
240 | buffer_consume(&stdout_buffer, len); | |
241 | stdout_bytes += len; | |
8efc0c15 | 242 | } |
8efc0c15 | 243 | } |
244 | ||
72176c0e | 245 | static void |
246 | client_alive_check(void) | |
247 | { | |
95ae2076 | 248 | int channel_id; |
99416ceb | 249 | |
72176c0e | 250 | /* timeout, check to see how many we have had */ |
ac47b626 | 251 | if (++keep_alive_timeouts > options.client_alive_count_max) { |
bd3b2cb2 | 252 | logit("Timeout, client not responding."); |
253 | cleanup_exit(255); | |
254 | } | |
72176c0e | 255 | |
72176c0e | 256 | /* |
95ae2076 | 257 | * send a bogus global/channel request with "wantreply", |
72176c0e | 258 | * we should get back a failure |
259 | */ | |
95ae2076 | 260 | if ((channel_id = channel_find_open()) == -1) { |
261 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
262 | packet_put_cstring("keepalive@openssh.com"); | |
263 | packet_put_char(1); /* boolean: want reply */ | |
264 | } else { | |
265 | channel_request_start(channel_id, "keepalive@openssh.com", 1); | |
266 | } | |
72176c0e | 267 | packet_send(); |
268 | } | |
269 | ||
5260325f | 270 | /* |
271 | * Sleep in select() until we can do something. This will initialize the | |
272 | * select masks. Upon return, the masks will indicate which descriptors | |
273 | * have data or can accept data. Optionally, a maximum time can be specified | |
274 | * for the duration of the wait (0 = infinite). | |
275 | */ | |
396c147e | 276 | static void |
39929cdb | 277 | wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, |
9a995072 | 278 | u_int *nallocp, u_int max_time_milliseconds) |
8efc0c15 | 279 | { |
5260325f | 280 | struct timeval tv, *tvp; |
281 | int ret; | |
3ffc6336 | 282 | int client_alive_scheduled = 0; |
34640ce6 | 283 | int program_alive_scheduled = 0; |
3ffc6336 | 284 | |
285 | /* | |
184eed6a | 286 | * if using client_alive, set the max timeout accordingly, |
3ffc6336 | 287 | * and indicate that this particular timeout was for client |
288 | * alive by setting the client_alive_scheduled flag. | |
289 | * | |
290 | * this could be randomized somewhat to make traffic | |
184eed6a | 291 | * analysis more difficult, but we're not doing it yet. |
3ffc6336 | 292 | */ |
2c5b1791 | 293 | if (compat20 && |
294 | max_time_milliseconds == 0 && options.client_alive_interval) { | |
39aefe7b | 295 | client_alive_scheduled = 1; |
3ffc6336 | 296 | max_time_milliseconds = options.client_alive_interval * 1000; |
2c5b1791 | 297 | } |
8efc0c15 | 298 | |
39929cdb | 299 | /* Allocate and update select() masks for channel descriptors. */ |
489aa2e9 | 300 | channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0); |
5260325f | 301 | |
e78a59f5 | 302 | if (compat20) { |
0c139bd1 | 303 | #if 0 |
1d1ffb87 | 304 | /* wrong: bad condition XXX */ |
e78a59f5 | 305 | if (channel_not_very_much_buffered_data()) |
0c139bd1 | 306 | #endif |
307 | FD_SET(connection_in, *readsetp); | |
e78a59f5 | 308 | } else { |
71276795 | 309 | /* |
310 | * Read packets from the client unless we have too much | |
311 | * buffered stdin or channel data. | |
312 | */ | |
313 | if (buffer_len(&stdin_buffer) < buffer_high && | |
e78a59f5 | 314 | channel_not_very_much_buffered_data()) |
39929cdb | 315 | FD_SET(connection_in, *readsetp); |
71276795 | 316 | /* |
317 | * If there is not too much data already buffered going to | |
318 | * the client, try to get some more data from the program. | |
319 | */ | |
320 | if (packet_not_very_much_data_to_write()) { | |
34640ce6 | 321 | program_alive_scheduled = child_terminated; |
71276795 | 322 | if (!fdout_eof) |
39929cdb | 323 | FD_SET(fdout, *readsetp); |
71276795 | 324 | if (!fderr_eof) |
39929cdb | 325 | FD_SET(fderr, *readsetp); |
71276795 | 326 | } |
327 | /* | |
328 | * If we have buffered data, try to write some of that data | |
329 | * to the program. | |
330 | */ | |
331 | if (fdin != -1 && buffer_len(&stdin_buffer) > 0) | |
39929cdb | 332 | FD_SET(fdin, *writesetp); |
e78a59f5 | 333 | } |
a10be357 | 334 | notify_prepare(*readsetp); |
5260325f | 335 | |
aa3378df | 336 | /* |
337 | * If we have buffered packet data going to the client, mark that | |
338 | * descriptor. | |
339 | */ | |
5260325f | 340 | if (packet_have_data_to_write()) |
39929cdb | 341 | FD_SET(connection_out, *writesetp); |
5260325f | 342 | |
aa3378df | 343 | /* |
344 | * If child has terminated and there is enough buffer space to read | |
345 | * from it, then read as much as is available and exit. | |
346 | */ | |
5260325f | 347 | if (child_terminated && packet_not_very_much_data_to_write()) |
3ffc6336 | 348 | if (max_time_milliseconds == 0 || client_alive_scheduled) |
5260325f | 349 | max_time_milliseconds = 100; |
350 | ||
351 | if (max_time_milliseconds == 0) | |
352 | tvp = NULL; | |
353 | else { | |
354 | tv.tv_sec = max_time_milliseconds / 1000; | |
355 | tv.tv_usec = 1000 * (max_time_milliseconds % 1000); | |
356 | tvp = &tv; | |
357 | } | |
8efc0c15 | 358 | |
5260325f | 359 | /* Wait for something to happen, or the timeout to expire. */ |
39929cdb | 360 | ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); |
8efc0c15 | 361 | |
3ffc6336 | 362 | if (ret == -1) { |
b3ad8fe6 | 363 | memset(*readsetp, 0, *nallocp); |
364 | memset(*writesetp, 0, *nallocp); | |
5260325f | 365 | if (errno != EINTR) |
366 | error("select: %.100s", strerror(errno)); | |
34640ce6 | 367 | } else { |
368 | if (ret == 0 && client_alive_scheduled) | |
369 | client_alive_check(); | |
370 | if (!compat20 && program_alive_scheduled && fdin_is_tty) { | |
371 | if (!fdout_eof) | |
372 | FD_SET(fdout, *readsetp); | |
373 | if (!fderr_eof) | |
374 | FD_SET(fderr, *readsetp); | |
375 | } | |
376 | } | |
a10be357 | 377 | |
378 | notify_done(*readsetp); | |
8efc0c15 | 379 | } |
380 | ||
5260325f | 381 | /* |
382 | * Processes input from the client and the program. Input data is stored | |
383 | * in buffers and processed later. | |
384 | */ | |
396c147e | 385 | static void |
b476adfa | 386 | process_input(fd_set *readset) |
5260325f | 387 | { |
388 | int len; | |
389 | char buf[16384]; | |
390 | ||
391 | /* Read and buffer any input data from the client. */ | |
392 | if (FD_ISSET(connection_in, readset)) { | |
393 | len = read(connection_in, buf, sizeof(buf)); | |
394 | if (len == 0) { | |
00e842d8 | 395 | verbose("Connection closed by %.100s", |
396 | get_remote_ipaddr()); | |
cc94bd38 | 397 | connection_closed = 1; |
398 | if (compat20) | |
399 | return; | |
2362db19 | 400 | cleanup_exit(255); |
0e73cc53 | 401 | } else if (len < 0) { |
402 | if (errno != EINTR && errno != EAGAIN) { | |
00e842d8 | 403 | verbose("Read error from remote host " |
404 | "%.100s: %.100s", | |
405 | get_remote_ipaddr(), strerror(errno)); | |
2362db19 | 406 | cleanup_exit(255); |
0e73cc53 | 407 | } |
408 | } else { | |
409 | /* Buffer any received data. */ | |
410 | packet_process_incoming(buf, len); | |
5260325f | 411 | } |
5260325f | 412 | } |
e78a59f5 | 413 | if (compat20) |
414 | return; | |
415 | ||
5260325f | 416 | /* Read and buffer any available stdout data from the program. */ |
417 | if (!fdout_eof && FD_ISSET(fdout, readset)) { | |
ea8c44d9 | 418 | errno = 0; |
5260325f | 419 | len = read(fdout, buf, sizeof(buf)); |
34640ce6 | 420 | if (len < 0 && (errno == EINTR || |
421 | (errno == EAGAIN && !child_terminated))) { | |
0e73cc53 | 422 | /* do nothing */ |
24a87055 | 423 | #ifndef PTY_ZEROREAD |
0e73cc53 | 424 | } else if (len <= 0) { |
ea8c44d9 | 425 | #else |
9c04d67d | 426 | } else if ((!isatty(fdout) && len <= 0) || |
427 | (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) { | |
ea8c44d9 | 428 | #endif |
5260325f | 429 | fdout_eof = 1; |
0e73cc53 | 430 | } else { |
5260325f | 431 | buffer_append(&stdout_buffer, buf, len); |
432 | fdout_bytes += len; | |
433 | } | |
434 | } | |
435 | /* Read and buffer any available stderr data from the program. */ | |
436 | if (!fderr_eof && FD_ISSET(fderr, readset)) { | |
ea8c44d9 | 437 | errno = 0; |
5260325f | 438 | len = read(fderr, buf, sizeof(buf)); |
34640ce6 | 439 | if (len < 0 && (errno == EINTR || |
440 | (errno == EAGAIN && !child_terminated))) { | |
0e73cc53 | 441 | /* do nothing */ |
24a87055 | 442 | #ifndef PTY_ZEROREAD |
0e73cc53 | 443 | } else if (len <= 0) { |
ea8c44d9 | 444 | #else |
9c04d67d | 445 | } else if ((!isatty(fderr) && len <= 0) || |
446 | (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) { | |
ea8c44d9 | 447 | #endif |
5260325f | 448 | fderr_eof = 1; |
0e73cc53 | 449 | } else { |
5260325f | 450 | buffer_append(&stderr_buffer, buf, len); |
0e73cc53 | 451 | } |
5260325f | 452 | } |
453 | } | |
8efc0c15 | 454 | |
5260325f | 455 | /* |
456 | * Sends data from internal buffers to client program stdin. | |
457 | */ | |
396c147e | 458 | static void |
b476adfa | 459 | process_output(fd_set *writeset) |
8efc0c15 | 460 | { |
4ef922e3 | 461 | struct termios tio; |
780a9951 | 462 | u_char *data; |
463 | u_int dlen; | |
5260325f | 464 | int len; |
465 | ||
466 | /* Write buffered data to program stdin. */ | |
e78a59f5 | 467 | if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) { |
780a9951 | 468 | data = buffer_ptr(&stdin_buffer); |
469 | dlen = buffer_len(&stdin_buffer); | |
470 | len = write(fdin, data, dlen); | |
0e73cc53 | 471 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) { |
472 | /* do nothing */ | |
473 | } else if (len <= 0) { | |
7368a6c8 | 474 | if (fdin != fdout) |
5260325f | 475 | close(fdin); |
476 | else | |
477 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
5260325f | 478 | fdin = -1; |
479 | } else { | |
4ef922e3 | 480 | /* Successful write. */ |
780a9951 | 481 | if (fdin_is_tty && dlen >= 1 && data[0] != '\r' && |
482 | tcgetattr(fdin, &tio) == 0 && | |
0ae4fe1d | 483 | !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { |
62da27dd | 484 | /* |
485 | * Simulate echo to reduce the impact of | |
486 | * traffic analysis | |
487 | */ | |
95ce5599 | 488 | packet_send_ignore(len); |
4ef922e3 | 489 | packet_send(); |
490 | } | |
491 | /* Consume the data from the buffer. */ | |
5260325f | 492 | buffer_consume(&stdin_buffer, len); |
493 | /* Update the count of bytes written to the program. */ | |
494 | stdin_bytes += len; | |
495 | } | |
8efc0c15 | 496 | } |
5260325f | 497 | /* Send any buffered packet data to the client. */ |
498 | if (FD_ISSET(connection_out, writeset)) | |
499 | packet_write_poll(); | |
8efc0c15 | 500 | } |
501 | ||
5260325f | 502 | /* |
503 | * Wait until all buffered output has been sent to the client. | |
504 | * This is used when the program terminates. | |
505 | */ | |
396c147e | 506 | static void |
5ca51e19 | 507 | drain_output(void) |
8efc0c15 | 508 | { |
5260325f | 509 | /* Send any buffered stdout data to the client. */ |
510 | if (buffer_len(&stdout_buffer) > 0) { | |
511 | packet_start(SSH_SMSG_STDOUT_DATA); | |
512 | packet_put_string(buffer_ptr(&stdout_buffer), | |
513 | buffer_len(&stdout_buffer)); | |
514 | packet_send(); | |
515 | /* Update the count of sent bytes. */ | |
516 | stdout_bytes += buffer_len(&stdout_buffer); | |
517 | } | |
518 | /* Send any buffered stderr data to the client. */ | |
519 | if (buffer_len(&stderr_buffer) > 0) { | |
520 | packet_start(SSH_SMSG_STDERR_DATA); | |
521 | packet_put_string(buffer_ptr(&stderr_buffer), | |
522 | buffer_len(&stderr_buffer)); | |
523 | packet_send(); | |
524 | /* Update the count of sent bytes. */ | |
525 | stderr_bytes += buffer_len(&stderr_buffer); | |
526 | } | |
527 | /* Wait until all buffered data has been written to the client. */ | |
528 | packet_write_wait(); | |
8efc0c15 | 529 | } |
530 | ||
396c147e | 531 | static void |
5ca51e19 | 532 | process_buffered_input_packets(void) |
7368a6c8 | 533 | { |
7a37c112 | 534 | dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL); |
7368a6c8 | 535 | } |
536 | ||
5260325f | 537 | /* |
538 | * Performs the interactive session. This handles data transmission between | |
539 | * the client and the program. Note that the notion of stdin, stdout, and | |
540 | * stderr in this function is sort of reversed: this function writes to | |
541 | * stdin (of the child program), and reads from stdout and stderr (of the | |
542 | * child program). | |
543 | */ | |
6ae2364d | 544 | void |
9da5c3c9 | 545 | server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) |
8efc0c15 | 546 | { |
39929cdb | 547 | fd_set *readset = NULL, *writeset = NULL; |
9a995072 | 548 | int max_fd = 0; |
549 | u_int nalloc = 0; | |
9da5c3c9 | 550 | int wait_status; /* Status returned by wait(). */ |
551 | pid_t wait_pid; /* pid returned by wait(). */ | |
5260325f | 552 | int waiting_termination = 0; /* Have displayed waiting close message. */ |
1e3b8b07 | 553 | u_int max_time_milliseconds; |
554 | u_int previous_stdout_buffer_bytes; | |
555 | u_int stdout_buffer_bytes; | |
5260325f | 556 | int type; |
557 | ||
558 | debug("Entering interactive session."); | |
559 | ||
560 | /* Initialize the SIGCHLD kludge. */ | |
5260325f | 561 | child_terminated = 0; |
42ad0eec | 562 | mysignal(SIGCHLD, sigchld_handler); |
5260325f | 563 | |
0bbbf2a4 | 564 | if (!use_privsep) { |
565 | signal(SIGTERM, sigterm_handler); | |
566 | signal(SIGINT, sigterm_handler); | |
567 | signal(SIGQUIT, sigterm_handler); | |
568 | } | |
569 | ||
5260325f | 570 | /* Initialize our global variables. */ |
571 | fdin = fdin_arg; | |
572 | fdout = fdout_arg; | |
573 | fderr = fderr_arg; | |
0e73cc53 | 574 | |
575 | /* nonblocking IO */ | |
576 | set_nonblock(fdin); | |
577 | set_nonblock(fdout); | |
ff873e98 | 578 | /* we don't have stderr for interactive terminal sessions, see below */ |
579 | if (fderr != -1) | |
580 | set_nonblock(fderr); | |
0e73cc53 | 581 | |
e68225b2 | 582 | if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin)) |
583 | fdin_is_tty = 1; | |
584 | ||
5260325f | 585 | connection_in = packet_get_connection_in(); |
586 | connection_out = packet_get_connection_out(); | |
587 | ||
a10be357 | 588 | notify_setup(); |
589 | ||
5260325f | 590 | previous_stdout_buffer_bytes = 0; |
591 | ||
592 | /* Set approximate I/O buffer size. */ | |
593 | if (packet_is_interactive()) | |
594 | buffer_high = 4096; | |
595 | else | |
596 | buffer_high = 64 * 1024; | |
597 | ||
489aa2e9 | 598 | #if 0 |
5260325f | 599 | /* Initialize max_fd to the maximum of the known file descriptors. */ |
489aa2e9 | 600 | max_fd = MAX(connection_in, connection_out); |
601 | max_fd = MAX(max_fd, fdin); | |
602 | max_fd = MAX(max_fd, fdout); | |
39929cdb | 603 | if (fderr != -1) |
604 | max_fd = MAX(max_fd, fderr); | |
489aa2e9 | 605 | #endif |
5260325f | 606 | |
607 | /* Initialize Initialize buffers. */ | |
608 | buffer_init(&stdin_buffer); | |
609 | buffer_init(&stdout_buffer); | |
610 | buffer_init(&stderr_buffer); | |
611 | ||
aa3378df | 612 | /* |
613 | * If we have no separate fderr (which is the case when we have a pty | |
614 | * - there we cannot make difference between data sent to stdout and | |
615 | * stderr), indicate that we have seen an EOF from stderr. This way | |
7b9b0103 | 616 | * we don't need to check the descriptor everywhere. |
aa3378df | 617 | */ |
5260325f | 618 | if (fderr == -1) |
619 | fderr_eof = 1; | |
620 | ||
7368a6c8 | 621 | server_init_dispatch(); |
622 | ||
5260325f | 623 | /* Main loop of the server for the interactive session mode. */ |
624 | for (;;) { | |
5260325f | 625 | |
626 | /* Process buffered packets from the client. */ | |
627 | process_buffered_input_packets(); | |
628 | ||
aa3378df | 629 | /* |
630 | * If we have received eof, and there is no more pending | |
631 | * input data, cause a real eof by closing fdin. | |
632 | */ | |
5260325f | 633 | if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) { |
7368a6c8 | 634 | if (fdin != fdout) |
5260325f | 635 | close(fdin); |
636 | else | |
637 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
5260325f | 638 | fdin = -1; |
639 | } | |
aa3378df | 640 | /* Make packets from buffered stderr data to send to the client. */ |
5260325f | 641 | make_packets_from_stderr_data(); |
642 | ||
aa3378df | 643 | /* |
644 | * Make packets from buffered stdout data to send to the | |
645 | * client. If there is very little to send, this arranges to | |
646 | * not send them now, but to wait a short while to see if we | |
647 | * are getting more data. This is necessary, as some systems | |
648 | * wake up readers from a pty after each separate character. | |
649 | */ | |
5260325f | 650 | max_time_milliseconds = 0; |
651 | stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
652 | if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && | |
653 | stdout_buffer_bytes != previous_stdout_buffer_bytes) { | |
654 | /* try again after a while */ | |
655 | max_time_milliseconds = 10; | |
656 | } else { | |
657 | /* Send it now. */ | |
658 | make_packets_from_stdout_data(); | |
659 | } | |
660 | previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
661 | ||
662 | /* Send channel data to the client. */ | |
663 | if (packet_not_very_much_data_to_write()) | |
664 | channel_output_poll(); | |
665 | ||
aa3378df | 666 | /* |
667 | * Bail out of the loop if the program has closed its output | |
668 | * descriptors, and we have no more data to send to the | |
669 | * client, and there is no pending buffered data. | |
670 | */ | |
7062c40f | 671 | if (fdout_eof && fderr_eof && !packet_have_data_to_write() && |
672 | buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { | |
5260325f | 673 | if (!channel_still_open()) |
7368a6c8 | 674 | break; |
5260325f | 675 | if (!waiting_termination) { |
676 | const char *s = "Waiting for forwarded connections to terminate...\r\n"; | |
677 | char *cp; | |
678 | waiting_termination = 1; | |
679 | buffer_append(&stderr_buffer, s, strlen(s)); | |
680 | ||
681 | /* Display list of open channels. */ | |
682 | cp = channel_open_message(); | |
683 | buffer_append(&stderr_buffer, cp, strlen(cp)); | |
684 | xfree(cp); | |
685 | } | |
686 | } | |
489aa2e9 | 687 | max_fd = MAX(connection_in, connection_out); |
688 | max_fd = MAX(max_fd, fdin); | |
689 | max_fd = MAX(max_fd, fdout); | |
690 | max_fd = MAX(max_fd, fderr); | |
a10be357 | 691 | max_fd = MAX(max_fd, notify_pipe[0]); |
489aa2e9 | 692 | |
5260325f | 693 | /* Sleep in select() until we can do something. */ |
39929cdb | 694 | wait_until_can_do_something(&readset, &writeset, &max_fd, |
489aa2e9 | 695 | &nalloc, max_time_milliseconds); |
5260325f | 696 | |
0bbbf2a4 | 697 | if (received_sigterm) { |
698 | logit("Exiting on signal %d", received_sigterm); | |
699 | /* Clean up sessions, utmp, etc. */ | |
700 | cleanup_exit(255); | |
701 | } | |
702 | ||
5260325f | 703 | /* Process any channel events. */ |
39929cdb | 704 | channel_after_select(readset, writeset); |
5260325f | 705 | |
706 | /* Process input from the client and from program stdout/stderr. */ | |
39929cdb | 707 | process_input(readset); |
5260325f | 708 | |
709 | /* Process output to the client and to program stdin. */ | |
39929cdb | 710 | process_output(writeset); |
8efc0c15 | 711 | } |
39929cdb | 712 | if (readset) |
713 | xfree(readset); | |
714 | if (writeset) | |
715 | xfree(writeset); | |
8efc0c15 | 716 | |
5260325f | 717 | /* Cleanup and termination code. */ |
8efc0c15 | 718 | |
5260325f | 719 | /* Wait until all output has been sent to the client. */ |
720 | drain_output(); | |
8efc0c15 | 721 | |
5260325f | 722 | debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", |
184eed6a | 723 | stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); |
8efc0c15 | 724 | |
5260325f | 725 | /* Free and clear the buffers. */ |
726 | buffer_free(&stdin_buffer); | |
727 | buffer_free(&stdout_buffer); | |
728 | buffer_free(&stderr_buffer); | |
8efc0c15 | 729 | |
5260325f | 730 | /* Close the file descriptors. */ |
731 | if (fdout != -1) | |
732 | close(fdout); | |
733 | fdout = -1; | |
734 | fdout_eof = 1; | |
735 | if (fderr != -1) | |
736 | close(fderr); | |
737 | fderr = -1; | |
738 | fderr_eof = 1; | |
739 | if (fdin != -1) | |
740 | close(fdin); | |
741 | fdin = -1; | |
742 | ||
d6746a0b | 743 | channel_free_all(); |
5260325f | 744 | |
5260325f | 745 | /* We no longer want our SIGCHLD handler to be called. */ |
42ad0eec | 746 | mysignal(SIGCHLD, SIG_DFL); |
5260325f | 747 | |
8c38e88b | 748 | while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0) |
749 | if (errno != EINTR) | |
750 | packet_disconnect("wait: %.100s", strerror(errno)); | |
751 | if (wait_pid != pid) | |
c457707e | 752 | error("Strange, wait returned pid %ld, expected %ld", |
753 | (long)wait_pid, (long)pid); | |
c9130033 | 754 | |
5260325f | 755 | /* Check if it exited normally. */ |
756 | if (WIFEXITED(wait_status)) { | |
757 | /* Yes, normal exit. Get exit status and send it to the client. */ | |
758 | debug("Command exited with status %d.", WEXITSTATUS(wait_status)); | |
759 | packet_start(SSH_SMSG_EXITSTATUS); | |
760 | packet_put_int(WEXITSTATUS(wait_status)); | |
761 | packet_send(); | |
762 | packet_write_wait(); | |
763 | ||
aa3378df | 764 | /* |
765 | * Wait for exit confirmation. Note that there might be | |
766 | * other packets coming before it; however, the program has | |
767 | * already died so we just ignore them. The client is | |
768 | * supposed to respond with the confirmation when it receives | |
769 | * the exit status. | |
770 | */ | |
5260325f | 771 | do { |
54a5250f | 772 | type = packet_read(); |
5260325f | 773 | } |
774 | while (type != SSH_CMSG_EXIT_CONFIRMATION); | |
775 | ||
776 | debug("Received exit confirmation."); | |
777 | return; | |
778 | } | |
779 | /* Check if the program terminated due to a signal. */ | |
780 | if (WIFSIGNALED(wait_status)) | |
781 | packet_disconnect("Command terminated on signal %d.", | |
782 | WTERMSIG(wait_status)); | |
783 | ||
784 | /* Some weird exit cause. Just exit. */ | |
785 | packet_disconnect("wait returned status %04x.", wait_status); | |
786 | /* NOTREACHED */ | |
787 | } | |
7368a6c8 | 788 | |
418e724c | 789 | static void |
790 | collect_children(void) | |
791 | { | |
792 | pid_t pid; | |
793 | sigset_t oset, nset; | |
794 | int status; | |
795 | ||
796 | /* block SIGCHLD while we check for dead children */ | |
797 | sigemptyset(&nset); | |
798 | sigaddset(&nset, SIGCHLD); | |
799 | sigprocmask(SIG_BLOCK, &nset, &oset); | |
800 | if (child_terminated) { | |
140000b4 | 801 | debug("Received SIGCHLD."); |
8c38e88b | 802 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
803 | (pid < 0 && errno == EINTR)) | |
804 | if (pid > 0) | |
805 | session_close_by_pid(pid, status); | |
418e724c | 806 | child_terminated = 0; |
807 | } | |
808 | sigprocmask(SIG_SETMASK, &oset, NULL); | |
809 | } | |
810 | ||
6ae2364d | 811 | void |
57156994 | 812 | server_loop2(Authctxt *authctxt) |
e78a59f5 | 813 | { |
39929cdb | 814 | fd_set *readset = NULL, *writeset = NULL; |
418e724c | 815 | int rekeying = 0, max_fd, nalloc = 0; |
e78a59f5 | 816 | |
817 | debug("Entering interactive session for SSH2."); | |
818 | ||
c9130033 | 819 | mysignal(SIGCHLD, sigchld_handler); |
e78a59f5 | 820 | child_terminated = 0; |
821 | connection_in = packet_get_connection_in(); | |
822 | connection_out = packet_get_connection_out(); | |
39929cdb | 823 | |
0bbbf2a4 | 824 | if (!use_privsep) { |
825 | signal(SIGTERM, sigterm_handler); | |
826 | signal(SIGINT, sigterm_handler); | |
827 | signal(SIGQUIT, sigterm_handler); | |
828 | } | |
829 | ||
a10be357 | 830 | notify_setup(); |
831 | ||
39929cdb | 832 | max_fd = MAX(connection_in, connection_out); |
a10be357 | 833 | max_fd = MAX(max_fd, notify_pipe[0]); |
834 | ||
e78a59f5 | 835 | server_init_dispatch(); |
836 | ||
837 | for (;;) { | |
838 | process_buffered_input_packets(); | |
bbb4cc1b | 839 | |
cd332296 | 840 | rekeying = (xxx_kex != NULL && !xxx_kex->done); |
bbb4cc1b | 841 | |
bbb4cc1b | 842 | if (!rekeying && packet_not_very_much_data_to_write()) |
e78a59f5 | 843 | channel_output_poll(); |
bbb4cc1b | 844 | wait_until_can_do_something(&readset, &writeset, &max_fd, |
489aa2e9 | 845 | &nalloc, 0); |
d5f24f94 | 846 | |
0bbbf2a4 | 847 | if (received_sigterm) { |
848 | logit("Exiting on signal %d", received_sigterm); | |
849 | /* Clean up sessions, utmp, etc. */ | |
850 | cleanup_exit(255); | |
851 | } | |
852 | ||
418e724c | 853 | collect_children(); |
ffd7b36b | 854 | if (!rekeying) { |
bbb4cc1b | 855 | channel_after_select(readset, writeset); |
ffd7b36b | 856 | if (packet_need_rekeying()) { |
857 | debug("need rekeying"); | |
858 | xxx_kex->done = 0; | |
859 | kex_send_kexinit(xxx_kex); | |
860 | } | |
861 | } | |
39929cdb | 862 | process_input(readset); |
cc94bd38 | 863 | if (connection_closed) |
864 | break; | |
39929cdb | 865 | process_output(writeset); |
e78a59f5 | 866 | } |
418e724c | 867 | collect_children(); |
868 | ||
39929cdb | 869 | if (readset) |
870 | xfree(readset); | |
871 | if (writeset) | |
872 | xfree(writeset); | |
873 | ||
d5f24f94 | 874 | /* free all channels, no more reads and writes */ |
875 | channel_free_all(); | |
5b5d170c | 876 | |
418e724c | 877 | /* free remaining sessions, e.g. remove wtmp entries */ |
1853d1ef | 878 | session_destroy_all(NULL); |
e78a59f5 | 879 | } |
880 | ||
396c147e | 881 | static void |
95ae2076 | 882 | server_input_keep_alive(int type, u_int32_t seq, void *ctxt) |
3ffc6336 | 883 | { |
95ae2076 | 884 | debug("Got %d/%u for keepalive", type, seq); |
184eed6a | 885 | /* |
39aefe7b | 886 | * reset timeout, since we got a sane answer from the client. |
3ffc6336 | 887 | * even if this was generated by something other than |
888 | * the bogus CHANNEL_REQUEST we send for keepalives. | |
889 | */ | |
ac47b626 | 890 | keep_alive_timeouts = 0; |
3ffc6336 | 891 | } |
892 | ||
396c147e | 893 | static void |
7819b5c3 | 894 | server_input_stdin_data(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 895 | { |
896 | char *data; | |
1e3b8b07 | 897 | u_int data_len; |
7368a6c8 | 898 | |
899 | /* Stdin data from the client. Append it to the buffer. */ | |
900 | /* Ignore any data if the client has closed stdin. */ | |
901 | if (fdin == -1) | |
902 | return; | |
903 | data = packet_get_string(&data_len); | |
95500969 | 904 | packet_check_eom(); |
7368a6c8 | 905 | buffer_append(&stdin_buffer, data, data_len); |
906 | memset(data, 0, data_len); | |
907 | xfree(data); | |
908 | } | |
909 | ||
396c147e | 910 | static void |
7819b5c3 | 911 | server_input_eof(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 912 | { |
913 | /* | |
914 | * Eof from the client. The stdin descriptor to the | |
915 | * program will be closed when all buffered data has | |
916 | * drained. | |
917 | */ | |
918 | debug("EOF received for stdin."); | |
95500969 | 919 | packet_check_eom(); |
7368a6c8 | 920 | stdin_eof = 1; |
921 | } | |
922 | ||
396c147e | 923 | static void |
7819b5c3 | 924 | server_input_window_size(int type, u_int32_t seq, void *ctxt) |
7368a6c8 | 925 | { |
148de80c | 926 | u_int row = packet_get_int(); |
927 | u_int col = packet_get_int(); | |
928 | u_int xpixel = packet_get_int(); | |
929 | u_int ypixel = packet_get_int(); | |
7368a6c8 | 930 | |
931 | debug("Window change received."); | |
95500969 | 932 | packet_check_eom(); |
7368a6c8 | 933 | if (fdin != -1) |
934 | pty_change_window_size(fdin, row, col, xpixel, ypixel); | |
935 | } | |
936 | ||
396c147e | 937 | static Channel * |
43f7a4b8 | 938 | server_request_direct_tcpip(void) |
e78a59f5 | 939 | { |
719fc62f | 940 | Channel *c; |
6ae2364d | 941 | char *target, *originator; |
942 | int target_port, originator_port; | |
e78a59f5 | 943 | |
6ae2364d | 944 | target = packet_get_string(NULL); |
945 | target_port = packet_get_int(); | |
e78a59f5 | 946 | originator = packet_get_string(NULL); |
947 | originator_port = packet_get_int(); | |
95500969 | 948 | packet_check_eom(); |
71276795 | 949 | |
e07e21ad | 950 | debug("server_request_direct_tcpip: originator %s port %d, target %s " |
951 | "port %d", originator, originator_port, target, target_port); | |
38c295d6 | 952 | |
e78a59f5 | 953 | /* XXX check permission */ |
e07e21ad | 954 | c = channel_connect_to(target, target_port, |
955 | "direct-tcpip", "direct-tcpip"); | |
956 | ||
e78a59f5 | 957 | xfree(originator); |
e07e21ad | 958 | xfree(target); |
959 | ||
719fc62f | 960 | return c; |
fa08c86b | 961 | } |
962 | ||
d20f3c9e | 963 | static Channel * |
964 | server_request_tun(void) | |
965 | { | |
966 | Channel *c = NULL; | |
a4f24bf8 | 967 | int mode, tun; |
968 | int sock; | |
d20f3c9e | 969 | |
a4f24bf8 | 970 | mode = packet_get_int(); |
971 | switch (mode) { | |
972 | case SSH_TUNMODE_POINTOPOINT: | |
973 | case SSH_TUNMODE_ETHERNET: | |
974 | break; | |
975 | default: | |
976 | packet_send_debug("Unsupported tunnel device mode."); | |
977 | return NULL; | |
978 | } | |
979 | if ((options.permit_tun & mode) == 0) { | |
980 | packet_send_debug("Server has rejected tunnel device " | |
981 | "forwarding"); | |
d20f3c9e | 982 | return NULL; |
983 | } | |
984 | ||
985 | tun = packet_get_int(); | |
a2b1748a | 986 | if (forced_tun_device != -1) { |
3efa8ea9 | 987 | if (tun != SSH_TUNID_ANY && forced_tun_device != tun) |
d20f3c9e | 988 | goto done; |
989 | tun = forced_tun_device; | |
990 | } | |
a4f24bf8 | 991 | sock = tun_open(tun, mode); |
d20f3c9e | 992 | if (sock < 0) |
993 | goto done; | |
994 | c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1, | |
995 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); | |
996 | c->datagram = 1; | |
e914f53a | 997 | #if defined(SSH_TUN_FILTER) |
998 | if (mode == SSH_TUNMODE_POINTOPOINT) | |
999 | channel_register_filter(c->self, sys_tun_infilter, | |
1000 | sys_tun_outfilter); | |
1001 | #endif | |
d20f3c9e | 1002 | |
1003 | done: | |
1004 | if (c == NULL) | |
1005 | packet_send_debug("Failed to open the tunnel device."); | |
1006 | return c; | |
1007 | } | |
1008 | ||
396c147e | 1009 | static Channel * |
43f7a4b8 | 1010 | server_request_session(void) |
fa08c86b | 1011 | { |
719fc62f | 1012 | Channel *c; |
fa08c86b | 1013 | |
1014 | debug("input_session_request"); | |
95500969 | 1015 | packet_check_eom(); |
fa08c86b | 1016 | /* |
1017 | * A server session has no fd to read or write until a | |
1018 | * CHANNEL_REQUEST for a shell is made, so we set the type to | |
1019 | * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all | |
1020 | * CHANNEL_REQUEST messages is registered. | |
1021 | */ | |
43f7a4b8 | 1022 | c = channel_new("session", SSH_CHANNEL_LARVAL, |
719fc62f | 1023 | -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT, |
0d942eff | 1024 | 0, "server-session", 1); |
2362db19 | 1025 | if (session_open(the_authctxt, c->self) != 1) { |
719fc62f | 1026 | debug("session open failed, free channel %d", c->self); |
1027 | channel_free(c); | |
1028 | return NULL; | |
fa08c86b | 1029 | } |
8cd0437d | 1030 | channel_register_cleanup(c->self, session_close_by_channel, 0); |
719fc62f | 1031 | return c; |
e78a59f5 | 1032 | } |
1033 | ||
396c147e | 1034 | static void |
7819b5c3 | 1035 | server_input_channel_open(int type, u_int32_t seq, void *ctxt) |
e78a59f5 | 1036 | { |
1037 | Channel *c = NULL; | |
1038 | char *ctype; | |
e78a59f5 | 1039 | int rchan; |
f91d9a89 | 1040 | u_int rmaxpack, rwindow, len; |
e78a59f5 | 1041 | |
1042 | ctype = packet_get_string(&len); | |
1043 | rchan = packet_get_int(); | |
1044 | rwindow = packet_get_int(); | |
1045 | rmaxpack = packet_get_int(); | |
1046 | ||
188adeb2 | 1047 | debug("server_input_channel_open: ctype %s rchan %d win %d max %d", |
e78a59f5 | 1048 | ctype, rchan, rwindow, rmaxpack); |
1049 | ||
1050 | if (strcmp(ctype, "session") == 0) { | |
43f7a4b8 | 1051 | c = server_request_session(); |
e78a59f5 | 1052 | } else if (strcmp(ctype, "direct-tcpip") == 0) { |
43f7a4b8 | 1053 | c = server_request_direct_tcpip(); |
d20f3c9e | 1054 | } else if (strcmp(ctype, "tun@openssh.com") == 0) { |
1055 | c = server_request_tun(); | |
e78a59f5 | 1056 | } |
1057 | if (c != NULL) { | |
fa08c86b | 1058 | debug("server_input_channel_open: confirm %s", ctype); |
e78a59f5 | 1059 | c->remote_id = rchan; |
1060 | c->remote_window = rwindow; | |
1061 | c->remote_maxpacket = rmaxpack; | |
d18e0850 | 1062 | if (c->type != SSH_CHANNEL_CONNECTING) { |
1063 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1064 | packet_put_int(c->remote_id); | |
1065 | packet_put_int(c->self); | |
1066 | packet_put_int(c->local_window); | |
1067 | packet_put_int(c->local_maxpacket); | |
1068 | packet_send(); | |
1069 | } | |
e78a59f5 | 1070 | } else { |
fa08c86b | 1071 | debug("server_input_channel_open: failure %s", ctype); |
e78a59f5 | 1072 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); |
1073 | packet_put_int(rchan); | |
1074 | packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); | |
fbe90f7b | 1075 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { |
d18e0850 | 1076 | packet_put_cstring("open failed"); |
fbe90f7b | 1077 | packet_put_cstring(""); |
1078 | } | |
e78a59f5 | 1079 | packet_send(); |
1080 | } | |
1081 | xfree(ctype); | |
1082 | } | |
1083 | ||
396c147e | 1084 | static void |
7819b5c3 | 1085 | server_input_global_request(int type, u_int32_t seq, void *ctxt) |
fa08c86b | 1086 | { |
1087 | char *rtype; | |
1088 | int want_reply; | |
1089 | int success = 0; | |
1090 | ||
1091 | rtype = packet_get_string(NULL); | |
1092 | want_reply = packet_get_char(); | |
1093 | debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply); | |
2b87da3b | 1094 | |
01794848 | 1095 | /* -R style forwarding */ |
fa08c86b | 1096 | if (strcmp(rtype, "tcpip-forward") == 0) { |
1097 | struct passwd *pw; | |
1098 | char *listen_address; | |
1099 | u_short listen_port; | |
1100 | ||
2362db19 | 1101 | pw = the_authctxt->pw; |
95077f48 | 1102 | if (pw == NULL || !the_authctxt->valid) |
fdaef11e | 1103 | fatal("server_input_global_request: no/invalid user"); |
b08a39ff | 1104 | listen_address = packet_get_string(NULL); |
fa08c86b | 1105 | listen_port = (u_short)packet_get_int(); |
1106 | debug("server_input_global_request: tcpip-forward listen %s port %d", | |
1107 | listen_address, listen_port); | |
1108 | ||
1109 | /* check permissions */ | |
1110 | if (!options.allow_tcp_forwarding || | |
e6f15ed1 | 1111 | no_port_forwarding_flag |
1112 | #ifndef NO_IPPORT_RESERVED_CONCEPT | |
1113 | || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0) | |
1114 | #endif | |
98c044d0 | 1115 | ) { |
fa08c86b | 1116 | success = 0; |
1117 | packet_send_debug("Server has disabled port forwarding."); | |
1118 | } else { | |
1119 | /* Start listening on the port */ | |
5641aefa | 1120 | success = channel_setup_remote_fwd_listener( |
1121 | listen_address, listen_port, options.gateway_ports); | |
fa08c86b | 1122 | } |
1123 | xfree(listen_address); | |
d740ec16 | 1124 | } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) { |
1125 | char *cancel_address; | |
1126 | u_short cancel_port; | |
1127 | ||
1128 | cancel_address = packet_get_string(NULL); | |
1129 | cancel_port = (u_short)packet_get_int(); | |
1130 | debug("%s: cancel-tcpip-forward addr %s port %d", __func__, | |
1131 | cancel_address, cancel_port); | |
1132 | ||
1133 | success = channel_cancel_rport_listener(cancel_address, | |
1134 | cancel_port); | |
4113a1d7 | 1135 | xfree(cancel_address); |
fa08c86b | 1136 | } |
1137 | if (want_reply) { | |
1138 | packet_start(success ? | |
1139 | SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); | |
1140 | packet_send(); | |
1141 | packet_write_wait(); | |
1142 | } | |
1143 | xfree(rtype); | |
1144 | } | |
a7137f6b | 1145 | |
7899c98f | 1146 | static void |
1147 | server_input_channel_req(int type, u_int32_t seq, void *ctxt) | |
1148 | { | |
1149 | Channel *c; | |
1150 | int id, reply, success = 0; | |
1151 | char *rtype; | |
1152 | ||
1153 | id = packet_get_int(); | |
1154 | rtype = packet_get_string(NULL); | |
1155 | reply = packet_get_char(); | |
1156 | ||
1157 | debug("server_input_channel_req: channel %d request %s reply %d", | |
1158 | id, rtype, reply); | |
1159 | ||
1160 | if ((c = channel_lookup(id)) == NULL) | |
1161 | packet_disconnect("server_input_channel_req: " | |
1162 | "unknown channel %d", id); | |
1163 | if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN) | |
1164 | success = session_input_channel_req(c, rtype); | |
1165 | if (reply) { | |
1166 | packet_start(success ? | |
1167 | SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); | |
1168 | packet_put_int(c->remote_id); | |
1169 | packet_send(); | |
1170 | } | |
1171 | xfree(rtype); | |
1172 | } | |
fa08c86b | 1173 | |
396c147e | 1174 | static void |
5ca51e19 | 1175 | server_init_dispatch_20(void) |
e78a59f5 | 1176 | { |
1177 | debug("server_init_dispatch_20"); | |
1178 | dispatch_init(&dispatch_protocol_error); | |
1179 | dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); | |
1180 | dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); | |
1181 | dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); | |
1182 | dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); | |
1183 | dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open); | |
1184 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1185 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
7899c98f | 1186 | dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req); |
e78a59f5 | 1187 | dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); |
fa08c86b | 1188 | dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request); |
3593bdc0 | 1189 | dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm); |
1190 | dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm); | |
3ffc6336 | 1191 | /* client_alive */ |
95ae2076 | 1192 | dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive); |
1193 | dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive); | |
7a37c112 | 1194 | /* rekeying */ |
1195 | dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); | |
e78a59f5 | 1196 | } |
396c147e | 1197 | static void |
5ca51e19 | 1198 | server_init_dispatch_13(void) |
7368a6c8 | 1199 | { |
1200 | debug("server_init_dispatch_13"); | |
1201 | dispatch_init(NULL); | |
1202 | dispatch_set(SSH_CMSG_EOF, &server_input_eof); | |
1203 | dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data); | |
1204 | dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size); | |
1205 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); | |
1206 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); | |
1207 | dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); | |
1208 | dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1209 | dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
1210 | dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); | |
1211 | } | |
396c147e | 1212 | static void |
5ca51e19 | 1213 | server_init_dispatch_15(void) |
7368a6c8 | 1214 | { |
1215 | server_init_dispatch_13(); | |
1216 | debug("server_init_dispatch_15"); | |
1217 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); | |
1218 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose); | |
1219 | } | |
396c147e | 1220 | static void |
5ca51e19 | 1221 | server_init_dispatch(void) |
7368a6c8 | 1222 | { |
e78a59f5 | 1223 | if (compat20) |
1224 | server_init_dispatch_20(); | |
1225 | else if (compat13) | |
7368a6c8 | 1226 | server_init_dispatch_13(); |
1227 | else | |
1228 | server_init_dispatch_15(); | |
1229 | } |