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47686178 | 1 | /* $OpenBSD: serverloop.c,v 1.148 2008/02/22 20:44:02 dtucker Exp $ */ |
3c0ef626 | 2 | /* |
3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
5 | * All rights reserved | |
6 | * Server main loop for handling the interactive session. | |
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 | * | |
14 | * SSH2 support by Markus Friedl. | |
15 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. | |
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. | |
36 | */ | |
37 | ||
38 | #include "includes.h" | |
9108f8d9 | 39 | |
40 | #include <sys/types.h> | |
41 | #include <sys/param.h> | |
42 | #include <sys/wait.h> | |
43 | #include <sys/socket.h> | |
44 | #ifdef HAVE_SYS_TIME_H | |
45 | # include <sys/time.h> | |
46 | #endif | |
47 | ||
48 | #include <netinet/in.h> | |
49 | ||
50 | #include <errno.h> | |
51 | #include <fcntl.h> | |
52 | #include <pwd.h> | |
53 | #include <signal.h> | |
54 | #include <string.h> | |
55 | #include <termios.h> | |
56 | #include <unistd.h> | |
57 | #include <stdarg.h> | |
3c0ef626 | 58 | |
59 | #include "xmalloc.h" | |
60 | #include "packet.h" | |
61 | #include "buffer.h" | |
62 | #include "log.h" | |
63 | #include "servconf.h" | |
41b2f314 | 64 | #include "canohost.h" |
3c0ef626 | 65 | #include "sshpty.h" |
66 | #include "channels.h" | |
67 | #include "compat.h" | |
68 | #include "ssh1.h" | |
69 | #include "ssh2.h" | |
9108f8d9 | 70 | #include "key.h" |
71 | #include "cipher.h" | |
72 | #include "kex.h" | |
73 | #include "hostfile.h" | |
3c0ef626 | 74 | #include "auth.h" |
75 | #include "session.h" | |
76 | #include "dispatch.h" | |
77 | #include "auth-options.h" | |
78 | #include "serverloop.h" | |
79 | #include "misc.h" | |
3c0ef626 | 80 | |
81 | extern ServerOptions options; | |
82 | ||
83 | /* XXX */ | |
84 | extern Kex *xxx_kex; | |
cdd66111 | 85 | extern Authctxt *the_authctxt; |
2c06c99b | 86 | extern int use_privsep; |
3c0ef626 | 87 | |
88 | static Buffer stdin_buffer; /* Buffer for stdin data. */ | |
89 | static Buffer stdout_buffer; /* Buffer for stdout data. */ | |
90 | static Buffer stderr_buffer; /* Buffer for stderr data. */ | |
91 | static int fdin; /* Descriptor for stdin (for writing) */ | |
92 | static int fdout; /* Descriptor for stdout (for reading); | |
93 | May be same number as fdin. */ | |
94 | static int fderr; /* Descriptor for stderr. May be -1. */ | |
95 | static long stdin_bytes = 0; /* Number of bytes written to stdin. */ | |
96 | static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */ | |
97 | static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */ | |
98 | static long fdout_bytes = 0; /* Number of stdout bytes read from program. */ | |
99 | static int stdin_eof = 0; /* EOF message received from client. */ | |
100 | static int fdout_eof = 0; /* EOF encountered reading from fdout. */ | |
101 | static int fderr_eof = 0; /* EOF encountered readung from fderr. */ | |
102 | static int fdin_is_tty = 0; /* fdin points to a tty. */ | |
103 | static int connection_in; /* Connection to client (input). */ | |
104 | static int connection_out; /* Connection to client (output). */ | |
105 | static int connection_closed = 0; /* Connection to client closed. */ | |
106 | static u_int buffer_high; /* "Soft" max buffer size. */ | |
3c0ef626 | 107 | |
108 | /* | |
109 | * This SIGCHLD kludge is used to detect when the child exits. The server | |
110 | * will exit after that, as soon as forwarded connections have terminated. | |
111 | */ | |
112 | ||
e9a17296 | 113 | static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */ |
3c0ef626 | 114 | |
2c06c99b | 115 | /* Cleanup on signals (!use_privsep case only) */ |
116 | static volatile sig_atomic_t received_sigterm = 0; | |
117 | ||
3c0ef626 | 118 | /* prototypes */ |
119 | static void server_init_dispatch(void); | |
120 | ||
e9a17296 | 121 | /* |
122 | * we write to this pipe if a SIGCHLD is caught in order to avoid | |
123 | * the race between select() and child_terminated | |
124 | */ | |
125 | static int notify_pipe[2]; | |
126 | static void | |
127 | notify_setup(void) | |
128 | { | |
129 | if (pipe(notify_pipe) < 0) { | |
130 | error("pipe(notify_pipe) failed %s", strerror(errno)); | |
131 | } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) || | |
132 | (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) { | |
133 | error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno)); | |
134 | close(notify_pipe[0]); | |
135 | close(notify_pipe[1]); | |
136 | } else { | |
137 | set_nonblock(notify_pipe[0]); | |
138 | set_nonblock(notify_pipe[1]); | |
139 | return; | |
140 | } | |
141 | notify_pipe[0] = -1; /* read end */ | |
142 | notify_pipe[1] = -1; /* write end */ | |
143 | } | |
144 | static void | |
145 | notify_parent(void) | |
146 | { | |
147 | if (notify_pipe[1] != -1) | |
148 | write(notify_pipe[1], "", 1); | |
149 | } | |
150 | static void | |
151 | notify_prepare(fd_set *readset) | |
152 | { | |
153 | if (notify_pipe[0] != -1) | |
154 | FD_SET(notify_pipe[0], readset); | |
155 | } | |
156 | static void | |
157 | notify_done(fd_set *readset) | |
158 | { | |
159 | char c; | |
160 | ||
161 | if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset)) | |
162 | while (read(notify_pipe[0], &c, 1) != -1) | |
163 | debug2("notify_done: reading"); | |
164 | } | |
165 | ||
9108f8d9 | 166 | /*ARGSUSED*/ |
3c0ef626 | 167 | static void |
168 | sigchld_handler(int sig) | |
169 | { | |
170 | int save_errno = errno; | |
3c0ef626 | 171 | child_terminated = 1; |
41b2f314 | 172 | #ifndef _UNICOS |
3c0ef626 | 173 | mysignal(SIGCHLD, sigchld_handler); |
41b2f314 | 174 | #endif |
e9a17296 | 175 | notify_parent(); |
3c0ef626 | 176 | errno = save_errno; |
177 | } | |
178 | ||
9108f8d9 | 179 | /*ARGSUSED*/ |
2c06c99b | 180 | static void |
181 | sigterm_handler(int sig) | |
182 | { | |
183 | received_sigterm = sig; | |
184 | } | |
185 | ||
3c0ef626 | 186 | /* |
187 | * Make packets from buffered stderr data, and buffer it for sending | |
188 | * to the client. | |
189 | */ | |
190 | static void | |
191 | make_packets_from_stderr_data(void) | |
192 | { | |
0fff78ff | 193 | u_int len; |
3c0ef626 | 194 | |
195 | /* Send buffered stderr data to the client. */ | |
196 | while (buffer_len(&stderr_buffer) > 0 && | |
197 | packet_not_very_much_data_to_write()) { | |
198 | len = buffer_len(&stderr_buffer); | |
199 | if (packet_is_interactive()) { | |
200 | if (len > 512) | |
201 | len = 512; | |
202 | } else { | |
203 | /* Keep the packets at reasonable size. */ | |
204 | if (len > packet_get_maxsize()) | |
205 | len = packet_get_maxsize(); | |
206 | } | |
207 | packet_start(SSH_SMSG_STDERR_DATA); | |
208 | packet_put_string(buffer_ptr(&stderr_buffer), len); | |
209 | packet_send(); | |
210 | buffer_consume(&stderr_buffer, len); | |
211 | stderr_bytes += len; | |
212 | } | |
213 | } | |
214 | ||
215 | /* | |
216 | * Make packets from buffered stdout data, and buffer it for sending to the | |
217 | * client. | |
218 | */ | |
219 | static void | |
220 | make_packets_from_stdout_data(void) | |
221 | { | |
0fff78ff | 222 | u_int len; |
3c0ef626 | 223 | |
224 | /* Send buffered stdout data to the client. */ | |
225 | while (buffer_len(&stdout_buffer) > 0 && | |
226 | packet_not_very_much_data_to_write()) { | |
227 | len = buffer_len(&stdout_buffer); | |
228 | if (packet_is_interactive()) { | |
229 | if (len > 512) | |
230 | len = 512; | |
231 | } else { | |
232 | /* Keep the packets at reasonable size. */ | |
233 | if (len > packet_get_maxsize()) | |
234 | len = packet_get_maxsize(); | |
235 | } | |
236 | packet_start(SSH_SMSG_STDOUT_DATA); | |
237 | packet_put_string(buffer_ptr(&stdout_buffer), len); | |
238 | packet_send(); | |
239 | buffer_consume(&stdout_buffer, len); | |
240 | stdout_bytes += len; | |
241 | } | |
242 | } | |
243 | ||
244 | static void | |
245 | client_alive_check(void) | |
246 | { | |
cdd66111 | 247 | int channel_id; |
e9a17296 | 248 | |
3c0ef626 | 249 | /* timeout, check to see how many we have had */ |
47686178 | 250 | if (++keep_alive_timeouts > options.client_alive_count_max) { |
ff7ec503 | 251 | logit("Timeout, client not responding."); |
252 | cleanup_exit(255); | |
253 | } | |
3c0ef626 | 254 | |
3c0ef626 | 255 | /* |
cdd66111 | 256 | * send a bogus global/channel request with "wantreply", |
3c0ef626 | 257 | * we should get back a failure |
258 | */ | |
cdd66111 | 259 | if ((channel_id = channel_find_open()) == -1) { |
260 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
261 | packet_put_cstring("keepalive@openssh.com"); | |
262 | packet_put_char(1); /* boolean: want reply */ | |
263 | } else { | |
264 | channel_request_start(channel_id, "keepalive@openssh.com", 1); | |
265 | } | |
3c0ef626 | 266 | packet_send(); |
267 | } | |
268 | ||
269 | /* | |
270 | * Sleep in select() until we can do something. This will initialize the | |
271 | * select masks. Upon return, the masks will indicate which descriptors | |
272 | * have data or can accept data. Optionally, a maximum time can be specified | |
273 | * for the duration of the wait (0 = infinite). | |
274 | */ | |
275 | static void | |
276 | wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, | |
c9f39d2c | 277 | u_int *nallocp, u_int max_time_milliseconds) |
3c0ef626 | 278 | { |
279 | struct timeval tv, *tvp; | |
280 | int ret; | |
281 | int client_alive_scheduled = 0; | |
799ae497 | 282 | int program_alive_scheduled = 0; |
3c0ef626 | 283 | |
284 | /* | |
e9a17296 | 285 | * if using client_alive, set the max timeout accordingly, |
3c0ef626 | 286 | * and indicate that this particular timeout was for client |
287 | * alive by setting the client_alive_scheduled flag. | |
288 | * | |
289 | * this could be randomized somewhat to make traffic | |
e9a17296 | 290 | * analysis more difficult, but we're not doing it yet. |
3c0ef626 | 291 | */ |
292 | if (compat20 && | |
293 | max_time_milliseconds == 0 && options.client_alive_interval) { | |
294 | client_alive_scheduled = 1; | |
295 | max_time_milliseconds = options.client_alive_interval * 1000; | |
296 | } | |
297 | ||
298 | /* Allocate and update select() masks for channel descriptors. */ | |
299 | channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0); | |
300 | ||
301 | if (compat20) { | |
302 | #if 0 | |
303 | /* wrong: bad condition XXX */ | |
304 | if (channel_not_very_much_buffered_data()) | |
305 | #endif | |
306 | FD_SET(connection_in, *readsetp); | |
307 | } else { | |
308 | /* | |
309 | * Read packets from the client unless we have too much | |
310 | * buffered stdin or channel data. | |
311 | */ | |
312 | if (buffer_len(&stdin_buffer) < buffer_high && | |
313 | channel_not_very_much_buffered_data()) | |
314 | FD_SET(connection_in, *readsetp); | |
315 | /* | |
316 | * If there is not too much data already buffered going to | |
317 | * the client, try to get some more data from the program. | |
318 | */ | |
319 | if (packet_not_very_much_data_to_write()) { | |
799ae497 | 320 | program_alive_scheduled = child_terminated; |
3c0ef626 | 321 | if (!fdout_eof) |
322 | FD_SET(fdout, *readsetp); | |
323 | if (!fderr_eof) | |
324 | FD_SET(fderr, *readsetp); | |
325 | } | |
326 | /* | |
327 | * If we have buffered data, try to write some of that data | |
328 | * to the program. | |
329 | */ | |
330 | if (fdin != -1 && buffer_len(&stdin_buffer) > 0) | |
331 | FD_SET(fdin, *writesetp); | |
332 | } | |
e9a17296 | 333 | notify_prepare(*readsetp); |
3c0ef626 | 334 | |
335 | /* | |
336 | * If we have buffered packet data going to the client, mark that | |
337 | * descriptor. | |
338 | */ | |
339 | if (packet_have_data_to_write()) | |
340 | FD_SET(connection_out, *writesetp); | |
341 | ||
342 | /* | |
343 | * If child has terminated and there is enough buffer space to read | |
344 | * from it, then read as much as is available and exit. | |
345 | */ | |
346 | if (child_terminated && packet_not_very_much_data_to_write()) | |
347 | if (max_time_milliseconds == 0 || client_alive_scheduled) | |
348 | max_time_milliseconds = 100; | |
349 | ||
350 | if (max_time_milliseconds == 0) | |
351 | tvp = NULL; | |
352 | else { | |
353 | tv.tv_sec = max_time_milliseconds / 1000; | |
354 | tv.tv_usec = 1000 * (max_time_milliseconds % 1000); | |
355 | tvp = &tv; | |
356 | } | |
3c0ef626 | 357 | |
358 | /* Wait for something to happen, or the timeout to expire. */ | |
359 | ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); | |
360 | ||
361 | if (ret == -1) { | |
362 | memset(*readsetp, 0, *nallocp); | |
363 | memset(*writesetp, 0, *nallocp); | |
364 | if (errno != EINTR) | |
365 | error("select: %.100s", strerror(errno)); | |
799ae497 | 366 | } else { |
367 | if (ret == 0 && client_alive_scheduled) | |
368 | client_alive_check(); | |
369 | if (!compat20 && program_alive_scheduled && fdin_is_tty) { | |
370 | if (!fdout_eof) | |
371 | FD_SET(fdout, *readsetp); | |
372 | if (!fderr_eof) | |
373 | FD_SET(fderr, *readsetp); | |
374 | } | |
375 | } | |
e9a17296 | 376 | |
377 | notify_done(*readsetp); | |
3c0ef626 | 378 | } |
379 | ||
380 | /* | |
381 | * Processes input from the client and the program. Input data is stored | |
382 | * in buffers and processed later. | |
383 | */ | |
384 | static void | |
9108f8d9 | 385 | process_input(fd_set *readset) |
3c0ef626 | 386 | { |
387 | int len; | |
388 | char buf[16384]; | |
389 | ||
390 | /* Read and buffer any input data from the client. */ | |
391 | if (FD_ISSET(connection_in, readset)) { | |
392 | len = read(connection_in, buf, sizeof(buf)); | |
393 | if (len == 0) { | |
41b2f314 | 394 | verbose("Connection closed by %.100s", |
395 | get_remote_ipaddr()); | |
3c0ef626 | 396 | connection_closed = 1; |
397 | if (compat20) | |
398 | return; | |
cdd66111 | 399 | cleanup_exit(255); |
3c0ef626 | 400 | } else if (len < 0) { |
401 | if (errno != EINTR && errno != EAGAIN) { | |
41b2f314 | 402 | verbose("Read error from remote host " |
403 | "%.100s: %.100s", | |
404 | get_remote_ipaddr(), strerror(errno)); | |
cdd66111 | 405 | cleanup_exit(255); |
3c0ef626 | 406 | } |
407 | } else { | |
408 | /* Buffer any received data. */ | |
409 | packet_process_incoming(buf, len); | |
410 | } | |
411 | } | |
412 | if (compat20) | |
413 | return; | |
414 | ||
415 | /* Read and buffer any available stdout data from the program. */ | |
416 | if (!fdout_eof && FD_ISSET(fdout, readset)) { | |
9108f8d9 | 417 | errno = 0; |
3c0ef626 | 418 | len = read(fdout, buf, sizeof(buf)); |
799ae497 | 419 | if (len < 0 && (errno == EINTR || |
420 | (errno == EAGAIN && !child_terminated))) { | |
3c0ef626 | 421 | /* do nothing */ |
9108f8d9 | 422 | #ifndef PTY_ZEROREAD |
3c0ef626 | 423 | } else if (len <= 0) { |
9108f8d9 | 424 | #else |
425 | } else if ((!isatty(fdout) && len <= 0) || | |
426 | (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) { | |
427 | #endif | |
3c0ef626 | 428 | fdout_eof = 1; |
429 | } else { | |
430 | buffer_append(&stdout_buffer, buf, len); | |
431 | fdout_bytes += len; | |
432 | } | |
433 | } | |
434 | /* Read and buffer any available stderr data from the program. */ | |
435 | if (!fderr_eof && FD_ISSET(fderr, readset)) { | |
9108f8d9 | 436 | errno = 0; |
3c0ef626 | 437 | len = read(fderr, buf, sizeof(buf)); |
799ae497 | 438 | if (len < 0 && (errno == EINTR || |
439 | (errno == EAGAIN && !child_terminated))) { | |
3c0ef626 | 440 | /* do nothing */ |
9108f8d9 | 441 | #ifndef PTY_ZEROREAD |
3c0ef626 | 442 | } else if (len <= 0) { |
9108f8d9 | 443 | #else |
444 | } else if ((!isatty(fderr) && len <= 0) || | |
445 | (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) { | |
446 | #endif | |
3c0ef626 | 447 | fderr_eof = 1; |
448 | } else { | |
449 | buffer_append(&stderr_buffer, buf, len); | |
450 | } | |
451 | } | |
452 | } | |
453 | ||
454 | /* | |
455 | * Sends data from internal buffers to client program stdin. | |
456 | */ | |
457 | static void | |
9108f8d9 | 458 | process_output(fd_set *writeset) |
3c0ef626 | 459 | { |
460 | struct termios tio; | |
461 | u_char *data; | |
462 | u_int dlen; | |
463 | int len; | |
464 | ||
465 | /* Write buffered data to program stdin. */ | |
466 | if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) { | |
467 | data = buffer_ptr(&stdin_buffer); | |
468 | dlen = buffer_len(&stdin_buffer); | |
469 | len = write(fdin, data, dlen); | |
470 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) { | |
471 | /* do nothing */ | |
472 | } else if (len <= 0) { | |
3c0ef626 | 473 | if (fdin != fdout) |
474 | close(fdin); | |
475 | else | |
476 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
3c0ef626 | 477 | fdin = -1; |
478 | } else { | |
479 | /* Successful write. */ | |
480 | if (fdin_is_tty && dlen >= 1 && data[0] != '\r' && | |
481 | tcgetattr(fdin, &tio) == 0 && | |
482 | !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { | |
483 | /* | |
484 | * Simulate echo to reduce the impact of | |
485 | * traffic analysis | |
486 | */ | |
487 | packet_send_ignore(len); | |
488 | packet_send(); | |
489 | } | |
490 | /* Consume the data from the buffer. */ | |
491 | buffer_consume(&stdin_buffer, len); | |
492 | /* Update the count of bytes written to the program. */ | |
493 | stdin_bytes += len; | |
494 | } | |
495 | } | |
496 | /* Send any buffered packet data to the client. */ | |
497 | if (FD_ISSET(connection_out, writeset)) | |
498 | packet_write_poll(); | |
499 | } | |
500 | ||
501 | /* | |
502 | * Wait until all buffered output has been sent to the client. | |
503 | * This is used when the program terminates. | |
504 | */ | |
505 | static void | |
506 | drain_output(void) | |
507 | { | |
508 | /* Send any buffered stdout data to the client. */ | |
509 | if (buffer_len(&stdout_buffer) > 0) { | |
510 | packet_start(SSH_SMSG_STDOUT_DATA); | |
511 | packet_put_string(buffer_ptr(&stdout_buffer), | |
512 | buffer_len(&stdout_buffer)); | |
513 | packet_send(); | |
514 | /* Update the count of sent bytes. */ | |
515 | stdout_bytes += buffer_len(&stdout_buffer); | |
516 | } | |
517 | /* Send any buffered stderr data to the client. */ | |
518 | if (buffer_len(&stderr_buffer) > 0) { | |
519 | packet_start(SSH_SMSG_STDERR_DATA); | |
520 | packet_put_string(buffer_ptr(&stderr_buffer), | |
521 | buffer_len(&stderr_buffer)); | |
522 | packet_send(); | |
523 | /* Update the count of sent bytes. */ | |
524 | stderr_bytes += buffer_len(&stderr_buffer); | |
525 | } | |
526 | /* Wait until all buffered data has been written to the client. */ | |
527 | packet_write_wait(); | |
528 | } | |
529 | ||
530 | static void | |
531 | process_buffered_input_packets(void) | |
532 | { | |
533 | dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL); | |
534 | } | |
535 | ||
536 | /* | |
537 | * Performs the interactive session. This handles data transmission between | |
538 | * the client and the program. Note that the notion of stdin, stdout, and | |
539 | * stderr in this function is sort of reversed: this function writes to | |
540 | * stdin (of the child program), and reads from stdout and stderr (of the | |
541 | * child program). | |
542 | */ | |
543 | void | |
544 | server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) | |
545 | { | |
546 | fd_set *readset = NULL, *writeset = NULL; | |
c9f39d2c | 547 | int max_fd = 0; |
548 | u_int nalloc = 0; | |
3c0ef626 | 549 | int wait_status; /* Status returned by wait(). */ |
550 | pid_t wait_pid; /* pid returned by wait(). */ | |
551 | int waiting_termination = 0; /* Have displayed waiting close message. */ | |
552 | u_int max_time_milliseconds; | |
553 | u_int previous_stdout_buffer_bytes; | |
554 | u_int stdout_buffer_bytes; | |
555 | int type; | |
556 | ||
557 | debug("Entering interactive session."); | |
558 | ||
559 | /* Initialize the SIGCHLD kludge. */ | |
560 | child_terminated = 0; | |
561 | mysignal(SIGCHLD, sigchld_handler); | |
562 | ||
2c06c99b | 563 | if (!use_privsep) { |
564 | signal(SIGTERM, sigterm_handler); | |
565 | signal(SIGINT, sigterm_handler); | |
566 | signal(SIGQUIT, sigterm_handler); | |
567 | } | |
568 | ||
3c0ef626 | 569 | /* Initialize our global variables. */ |
570 | fdin = fdin_arg; | |
571 | fdout = fdout_arg; | |
572 | fderr = fderr_arg; | |
573 | ||
574 | /* nonblocking IO */ | |
575 | set_nonblock(fdin); | |
576 | set_nonblock(fdout); | |
577 | /* we don't have stderr for interactive terminal sessions, see below */ | |
578 | if (fderr != -1) | |
579 | set_nonblock(fderr); | |
580 | ||
581 | if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin)) | |
582 | fdin_is_tty = 1; | |
583 | ||
584 | connection_in = packet_get_connection_in(); | |
585 | connection_out = packet_get_connection_out(); | |
586 | ||
e9a17296 | 587 | notify_setup(); |
588 | ||
3c0ef626 | 589 | previous_stdout_buffer_bytes = 0; |
590 | ||
591 | /* Set approximate I/O buffer size. */ | |
592 | if (packet_is_interactive()) | |
593 | buffer_high = 4096; | |
594 | else | |
595 | buffer_high = 64 * 1024; | |
596 | ||
597 | #if 0 | |
598 | /* Initialize max_fd to the maximum of the known file descriptors. */ | |
599 | max_fd = MAX(connection_in, connection_out); | |
600 | max_fd = MAX(max_fd, fdin); | |
601 | max_fd = MAX(max_fd, fdout); | |
602 | if (fderr != -1) | |
603 | max_fd = MAX(max_fd, fderr); | |
604 | #endif | |
605 | ||
606 | /* Initialize Initialize buffers. */ | |
607 | buffer_init(&stdin_buffer); | |
608 | buffer_init(&stdout_buffer); | |
609 | buffer_init(&stderr_buffer); | |
610 | ||
611 | /* | |
612 | * If we have no separate fderr (which is the case when we have a pty | |
613 | * - there we cannot make difference between data sent to stdout and | |
614 | * stderr), indicate that we have seen an EOF from stderr. This way | |
2c06c99b | 615 | * we don't need to check the descriptor everywhere. |
3c0ef626 | 616 | */ |
617 | if (fderr == -1) | |
618 | fderr_eof = 1; | |
619 | ||
620 | server_init_dispatch(); | |
621 | ||
622 | /* Main loop of the server for the interactive session mode. */ | |
623 | for (;;) { | |
624 | ||
625 | /* Process buffered packets from the client. */ | |
626 | process_buffered_input_packets(); | |
627 | ||
628 | /* | |
629 | * If we have received eof, and there is no more pending | |
630 | * input data, cause a real eof by closing fdin. | |
631 | */ | |
632 | if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) { | |
3c0ef626 | 633 | if (fdin != fdout) |
634 | close(fdin); | |
635 | else | |
636 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
3c0ef626 | 637 | fdin = -1; |
638 | } | |
639 | /* Make packets from buffered stderr data to send to the client. */ | |
640 | make_packets_from_stderr_data(); | |
641 | ||
642 | /* | |
643 | * Make packets from buffered stdout data to send to the | |
644 | * client. If there is very little to send, this arranges to | |
645 | * not send them now, but to wait a short while to see if we | |
646 | * are getting more data. This is necessary, as some systems | |
647 | * wake up readers from a pty after each separate character. | |
648 | */ | |
649 | max_time_milliseconds = 0; | |
650 | stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
651 | if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && | |
652 | stdout_buffer_bytes != previous_stdout_buffer_bytes) { | |
653 | /* try again after a while */ | |
654 | max_time_milliseconds = 10; | |
655 | } else { | |
656 | /* Send it now. */ | |
657 | make_packets_from_stdout_data(); | |
658 | } | |
659 | previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
660 | ||
661 | /* Send channel data to the client. */ | |
662 | if (packet_not_very_much_data_to_write()) | |
663 | channel_output_poll(); | |
664 | ||
665 | /* | |
666 | * Bail out of the loop if the program has closed its output | |
667 | * descriptors, and we have no more data to send to the | |
668 | * client, and there is no pending buffered data. | |
669 | */ | |
670 | if (fdout_eof && fderr_eof && !packet_have_data_to_write() && | |
671 | buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { | |
672 | if (!channel_still_open()) | |
673 | break; | |
674 | if (!waiting_termination) { | |
675 | const char *s = "Waiting for forwarded connections to terminate...\r\n"; | |
676 | char *cp; | |
677 | waiting_termination = 1; | |
678 | buffer_append(&stderr_buffer, s, strlen(s)); | |
679 | ||
680 | /* Display list of open channels. */ | |
681 | cp = channel_open_message(); | |
682 | buffer_append(&stderr_buffer, cp, strlen(cp)); | |
683 | xfree(cp); | |
684 | } | |
685 | } | |
686 | max_fd = MAX(connection_in, connection_out); | |
687 | max_fd = MAX(max_fd, fdin); | |
688 | max_fd = MAX(max_fd, fdout); | |
689 | max_fd = MAX(max_fd, fderr); | |
e9a17296 | 690 | max_fd = MAX(max_fd, notify_pipe[0]); |
3c0ef626 | 691 | |
692 | /* Sleep in select() until we can do something. */ | |
693 | wait_until_can_do_something(&readset, &writeset, &max_fd, | |
694 | &nalloc, max_time_milliseconds); | |
695 | ||
2c06c99b | 696 | if (received_sigterm) { |
697 | logit("Exiting on signal %d", received_sigterm); | |
698 | /* Clean up sessions, utmp, etc. */ | |
699 | cleanup_exit(255); | |
700 | } | |
701 | ||
3c0ef626 | 702 | /* Process any channel events. */ |
703 | channel_after_select(readset, writeset); | |
704 | ||
705 | /* Process input from the client and from program stdout/stderr. */ | |
706 | process_input(readset); | |
707 | ||
708 | /* Process output to the client and to program stdin. */ | |
709 | process_output(writeset); | |
710 | } | |
711 | if (readset) | |
712 | xfree(readset); | |
713 | if (writeset) | |
714 | xfree(writeset); | |
715 | ||
716 | /* Cleanup and termination code. */ | |
717 | ||
718 | /* Wait until all output has been sent to the client. */ | |
719 | drain_output(); | |
720 | ||
721 | debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", | |
e9a17296 | 722 | stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); |
3c0ef626 | 723 | |
724 | /* Free and clear the buffers. */ | |
725 | buffer_free(&stdin_buffer); | |
726 | buffer_free(&stdout_buffer); | |
727 | buffer_free(&stderr_buffer); | |
728 | ||
729 | /* Close the file descriptors. */ | |
730 | if (fdout != -1) | |
731 | close(fdout); | |
732 | fdout = -1; | |
733 | fdout_eof = 1; | |
734 | if (fderr != -1) | |
735 | close(fderr); | |
736 | fderr = -1; | |
737 | fderr_eof = 1; | |
738 | if (fdin != -1) | |
739 | close(fdin); | |
740 | fdin = -1; | |
741 | ||
742 | channel_free_all(); | |
743 | ||
744 | /* We no longer want our SIGCHLD handler to be called. */ | |
745 | mysignal(SIGCHLD, SIG_DFL); | |
746 | ||
700318f3 | 747 | while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0) |
748 | if (errno != EINTR) | |
749 | packet_disconnect("wait: %.100s", strerror(errno)); | |
750 | if (wait_pid != pid) | |
f5799ae1 | 751 | error("Strange, wait returned pid %ld, expected %ld", |
752 | (long)wait_pid, (long)pid); | |
3c0ef626 | 753 | |
754 | /* Check if it exited normally. */ | |
755 | if (WIFEXITED(wait_status)) { | |
756 | /* Yes, normal exit. Get exit status and send it to the client. */ | |
757 | debug("Command exited with status %d.", WEXITSTATUS(wait_status)); | |
758 | packet_start(SSH_SMSG_EXITSTATUS); | |
759 | packet_put_int(WEXITSTATUS(wait_status)); | |
760 | packet_send(); | |
761 | packet_write_wait(); | |
762 | ||
763 | /* | |
764 | * Wait for exit confirmation. Note that there might be | |
765 | * other packets coming before it; however, the program has | |
766 | * already died so we just ignore them. The client is | |
767 | * supposed to respond with the confirmation when it receives | |
768 | * the exit status. | |
769 | */ | |
770 | do { | |
e9a17296 | 771 | type = packet_read(); |
3c0ef626 | 772 | } |
773 | while (type != SSH_CMSG_EXIT_CONFIRMATION); | |
774 | ||
775 | debug("Received exit confirmation."); | |
776 | return; | |
777 | } | |
778 | /* Check if the program terminated due to a signal. */ | |
779 | if (WIFSIGNALED(wait_status)) | |
780 | packet_disconnect("Command terminated on signal %d.", | |
781 | WTERMSIG(wait_status)); | |
782 | ||
783 | /* Some weird exit cause. Just exit. */ | |
784 | packet_disconnect("wait returned status %04x.", wait_status); | |
785 | /* NOTREACHED */ | |
786 | } | |
787 | ||
788 | static void | |
789 | collect_children(void) | |
790 | { | |
791 | pid_t pid; | |
792 | sigset_t oset, nset; | |
793 | int status; | |
794 | ||
795 | /* block SIGCHLD while we check for dead children */ | |
796 | sigemptyset(&nset); | |
797 | sigaddset(&nset, SIGCHLD); | |
798 | sigprocmask(SIG_BLOCK, &nset, &oset); | |
799 | if (child_terminated) { | |
9108f8d9 | 800 | debug("Received SIGCHLD."); |
700318f3 | 801 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
802 | (pid < 0 && errno == EINTR)) | |
803 | if (pid > 0) | |
804 | session_close_by_pid(pid, status); | |
3c0ef626 | 805 | child_terminated = 0; |
806 | } | |
807 | sigprocmask(SIG_SETMASK, &oset, NULL); | |
808 | } | |
809 | ||
810 | void | |
811 | server_loop2(Authctxt *authctxt) | |
812 | { | |
813 | fd_set *readset = NULL, *writeset = NULL; | |
814 | int rekeying = 0, max_fd, nalloc = 0; | |
815 | ||
816 | debug("Entering interactive session for SSH2."); | |
817 | ||
818 | mysignal(SIGCHLD, sigchld_handler); | |
819 | child_terminated = 0; | |
820 | connection_in = packet_get_connection_in(); | |
821 | connection_out = packet_get_connection_out(); | |
822 | ||
2c06c99b | 823 | if (!use_privsep) { |
824 | signal(SIGTERM, sigterm_handler); | |
825 | signal(SIGINT, sigterm_handler); | |
826 | signal(SIGQUIT, sigterm_handler); | |
827 | } | |
828 | ||
e9a17296 | 829 | notify_setup(); |
830 | ||
3c0ef626 | 831 | max_fd = MAX(connection_in, connection_out); |
e9a17296 | 832 | max_fd = MAX(max_fd, notify_pipe[0]); |
833 | ||
3c0ef626 | 834 | server_init_dispatch(); |
835 | ||
836 | for (;;) { | |
837 | process_buffered_input_packets(); | |
838 | ||
839 | rekeying = (xxx_kex != NULL && !xxx_kex->done); | |
840 | ||
841 | if (!rekeying && packet_not_very_much_data_to_write()) | |
842 | channel_output_poll(); | |
843 | wait_until_can_do_something(&readset, &writeset, &max_fd, | |
844 | &nalloc, 0); | |
845 | ||
2c06c99b | 846 | if (received_sigterm) { |
847 | logit("Exiting on signal %d", received_sigterm); | |
848 | /* Clean up sessions, utmp, etc. */ | |
849 | cleanup_exit(255); | |
850 | } | |
851 | ||
3c0ef626 | 852 | collect_children(); |
0fff78ff | 853 | if (!rekeying) { |
3c0ef626 | 854 | channel_after_select(readset, writeset); |
0fff78ff | 855 | if (packet_need_rekeying()) { |
856 | debug("need rekeying"); | |
857 | xxx_kex->done = 0; | |
858 | kex_send_kexinit(xxx_kex); | |
859 | } | |
860 | } | |
3c0ef626 | 861 | process_input(readset); |
862 | if (connection_closed) | |
863 | break; | |
864 | process_output(writeset); | |
865 | } | |
866 | collect_children(); | |
867 | ||
868 | if (readset) | |
869 | xfree(readset); | |
870 | if (writeset) | |
871 | xfree(writeset); | |
872 | ||
873 | /* free all channels, no more reads and writes */ | |
874 | channel_free_all(); | |
875 | ||
876 | /* free remaining sessions, e.g. remove wtmp entries */ | |
700318f3 | 877 | session_destroy_all(NULL); |
3c0ef626 | 878 | } |
879 | ||
880 | static void | |
cdd66111 | 881 | server_input_keep_alive(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 882 | { |
cdd66111 | 883 | debug("Got %d/%u for keepalive", type, seq); |
e9a17296 | 884 | /* |
3c0ef626 | 885 | * reset timeout, since we got a sane answer from the client. |
886 | * even if this was generated by something other than | |
887 | * the bogus CHANNEL_REQUEST we send for keepalives. | |
888 | */ | |
47686178 | 889 | keep_alive_timeouts = 0; |
3c0ef626 | 890 | } |
891 | ||
3c0ef626 | 892 | static void |
e9a17296 | 893 | server_input_stdin_data(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 894 | { |
895 | char *data; | |
896 | u_int data_len; | |
897 | ||
898 | /* Stdin data from the client. Append it to the buffer. */ | |
899 | /* Ignore any data if the client has closed stdin. */ | |
900 | if (fdin == -1) | |
901 | return; | |
902 | data = packet_get_string(&data_len); | |
e9a17296 | 903 | packet_check_eom(); |
3c0ef626 | 904 | buffer_append(&stdin_buffer, data, data_len); |
905 | memset(data, 0, data_len); | |
906 | xfree(data); | |
907 | } | |
908 | ||
909 | static void | |
e9a17296 | 910 | server_input_eof(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 911 | { |
912 | /* | |
913 | * Eof from the client. The stdin descriptor to the | |
914 | * program will be closed when all buffered data has | |
915 | * drained. | |
916 | */ | |
917 | debug("EOF received for stdin."); | |
e9a17296 | 918 | packet_check_eom(); |
3c0ef626 | 919 | stdin_eof = 1; |
920 | } | |
921 | ||
922 | static void | |
e9a17296 | 923 | server_input_window_size(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 924 | { |
9108f8d9 | 925 | u_int row = packet_get_int(); |
926 | u_int col = packet_get_int(); | |
927 | u_int xpixel = packet_get_int(); | |
928 | u_int ypixel = packet_get_int(); | |
3c0ef626 | 929 | |
930 | debug("Window change received."); | |
e9a17296 | 931 | packet_check_eom(); |
3c0ef626 | 932 | if (fdin != -1) |
933 | pty_change_window_size(fdin, row, col, xpixel, ypixel); | |
934 | } | |
935 | ||
936 | static Channel * | |
cdd66111 | 937 | server_request_direct_tcpip(void) |
3c0ef626 | 938 | { |
939 | Channel *c; | |
940 | int sock; | |
941 | char *target, *originator; | |
942 | int target_port, originator_port; | |
943 | ||
944 | target = packet_get_string(NULL); | |
945 | target_port = packet_get_int(); | |
946 | originator = packet_get_string(NULL); | |
947 | originator_port = packet_get_int(); | |
e9a17296 | 948 | packet_check_eom(); |
3c0ef626 | 949 | |
950 | debug("server_request_direct_tcpip: originator %s port %d, target %s port %d", | |
665a873d | 951 | originator, originator_port, target, target_port); |
3c0ef626 | 952 | |
953 | /* XXX check permission */ | |
954 | sock = channel_connect_to(target, target_port); | |
955 | xfree(target); | |
956 | xfree(originator); | |
957 | if (sock < 0) | |
958 | return NULL; | |
cdd66111 | 959 | c = channel_new("direct-tcpip", SSH_CHANNEL_CONNECTING, |
3c0ef626 | 960 | sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT, |
0fff78ff | 961 | CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1); |
3c0ef626 | 962 | return c; |
963 | } | |
964 | ||
2c06c99b | 965 | static Channel * |
966 | server_request_tun(void) | |
967 | { | |
968 | Channel *c = NULL; | |
969 | int mode, tun; | |
970 | int sock; | |
971 | ||
972 | mode = packet_get_int(); | |
973 | switch (mode) { | |
974 | case SSH_TUNMODE_POINTOPOINT: | |
975 | case SSH_TUNMODE_ETHERNET: | |
976 | break; | |
977 | default: | |
978 | packet_send_debug("Unsupported tunnel device mode."); | |
979 | return NULL; | |
980 | } | |
981 | if ((options.permit_tun & mode) == 0) { | |
982 | packet_send_debug("Server has rejected tunnel device " | |
983 | "forwarding"); | |
984 | return NULL; | |
985 | } | |
986 | ||
987 | tun = packet_get_int(); | |
988 | if (forced_tun_device != -1) { | |
9108f8d9 | 989 | if (tun != SSH_TUNID_ANY && forced_tun_device != tun) |
2c06c99b | 990 | goto done; |
991 | tun = forced_tun_device; | |
992 | } | |
993 | sock = tun_open(tun, mode); | |
994 | if (sock < 0) | |
995 | goto done; | |
996 | c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1, | |
997 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); | |
998 | c->datagram = 1; | |
999 | #if defined(SSH_TUN_FILTER) | |
1000 | if (mode == SSH_TUNMODE_POINTOPOINT) | |
1001 | channel_register_filter(c->self, sys_tun_infilter, | |
1002 | sys_tun_outfilter); | |
1003 | #endif | |
1004 | ||
1005 | done: | |
1006 | if (c == NULL) | |
1007 | packet_send_debug("Failed to open the tunnel device."); | |
1008 | return c; | |
1009 | } | |
1010 | ||
3c0ef626 | 1011 | static Channel * |
cdd66111 | 1012 | server_request_session(void) |
3c0ef626 | 1013 | { |
1014 | Channel *c; | |
1015 | ||
1016 | debug("input_session_request"); | |
e9a17296 | 1017 | packet_check_eom(); |
3c0ef626 | 1018 | /* |
1019 | * A server session has no fd to read or write until a | |
1020 | * CHANNEL_REQUEST for a shell is made, so we set the type to | |
1021 | * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all | |
1022 | * CHANNEL_REQUEST messages is registered. | |
1023 | */ | |
cdd66111 | 1024 | c = channel_new("session", SSH_CHANNEL_LARVAL, |
3c0ef626 | 1025 | -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT, |
0fff78ff | 1026 | 0, "server-session", 1); |
cdd66111 | 1027 | if (session_open(the_authctxt, c->self) != 1) { |
3c0ef626 | 1028 | debug("session open failed, free channel %d", c->self); |
1029 | channel_free(c); | |
1030 | return NULL; | |
1031 | } | |
2c06c99b | 1032 | channel_register_cleanup(c->self, session_close_by_channel, 0); |
3c0ef626 | 1033 | return c; |
1034 | } | |
1035 | ||
1036 | static void | |
e9a17296 | 1037 | server_input_channel_open(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1038 | { |
1039 | Channel *c = NULL; | |
1040 | char *ctype; | |
3c0ef626 | 1041 | int rchan; |
680cee3b | 1042 | u_int rmaxpack, rwindow, len; |
3c0ef626 | 1043 | |
1044 | ctype = packet_get_string(&len); | |
1045 | rchan = packet_get_int(); | |
1046 | rwindow = packet_get_int(); | |
1047 | rmaxpack = packet_get_int(); | |
1048 | ||
1049 | debug("server_input_channel_open: ctype %s rchan %d win %d max %d", | |
1050 | ctype, rchan, rwindow, rmaxpack); | |
1051 | ||
1052 | if (strcmp(ctype, "session") == 0) { | |
cdd66111 | 1053 | c = server_request_session(); |
3c0ef626 | 1054 | } else if (strcmp(ctype, "direct-tcpip") == 0) { |
cdd66111 | 1055 | c = server_request_direct_tcpip(); |
2c06c99b | 1056 | } else if (strcmp(ctype, "tun@openssh.com") == 0) { |
1057 | c = server_request_tun(); | |
3c0ef626 | 1058 | } |
1059 | if (c != NULL) { | |
1060 | debug("server_input_channel_open: confirm %s", ctype); | |
1061 | c->remote_id = rchan; | |
1062 | c->remote_window = rwindow; | |
1063 | c->remote_maxpacket = rmaxpack; | |
1064 | if (c->type != SSH_CHANNEL_CONNECTING) { | |
1065 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1066 | packet_put_int(c->remote_id); | |
1067 | packet_put_int(c->self); | |
1068 | packet_put_int(c->local_window); | |
1069 | packet_put_int(c->local_maxpacket); | |
1070 | packet_send(); | |
1071 | } | |
1072 | } else { | |
1073 | debug("server_input_channel_open: failure %s", ctype); | |
1074 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); | |
1075 | packet_put_int(rchan); | |
1076 | packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); | |
1077 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
1078 | packet_put_cstring("open failed"); | |
1079 | packet_put_cstring(""); | |
1080 | } | |
1081 | packet_send(); | |
1082 | } | |
1083 | xfree(ctype); | |
1084 | } | |
1085 | ||
1086 | static void | |
e9a17296 | 1087 | server_input_global_request(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1088 | { |
1089 | char *rtype; | |
1090 | int want_reply; | |
1091 | int success = 0; | |
1092 | ||
1093 | rtype = packet_get_string(NULL); | |
1094 | want_reply = packet_get_char(); | |
1095 | debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply); | |
1096 | ||
1097 | /* -R style forwarding */ | |
1098 | if (strcmp(rtype, "tcpip-forward") == 0) { | |
1099 | struct passwd *pw; | |
1100 | char *listen_address; | |
1101 | u_short listen_port; | |
1102 | ||
cdd66111 | 1103 | pw = the_authctxt->pw; |
1104 | if (pw == NULL || !the_authctxt->valid) | |
1105 | fatal("server_input_global_request: no/invalid user"); | |
0fff78ff | 1106 | listen_address = packet_get_string(NULL); |
3c0ef626 | 1107 | listen_port = (u_short)packet_get_int(); |
1108 | debug("server_input_global_request: tcpip-forward listen %s port %d", | |
1109 | listen_address, listen_port); | |
1110 | ||
1111 | /* check permissions */ | |
1112 | if (!options.allow_tcp_forwarding || | |
41b2f314 | 1113 | no_port_forwarding_flag |
1114 | #ifndef NO_IPPORT_RESERVED_CONCEPT | |
1115 | || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0) | |
1116 | #endif | |
665a873d | 1117 | ) { |
3c0ef626 | 1118 | success = 0; |
1119 | packet_send_debug("Server has disabled port forwarding."); | |
1120 | } else { | |
1121 | /* Start listening on the port */ | |
e9a17296 | 1122 | success = channel_setup_remote_fwd_listener( |
1123 | listen_address, listen_port, options.gateway_ports); | |
3c0ef626 | 1124 | } |
1125 | xfree(listen_address); | |
c9f39d2c | 1126 | } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) { |
1127 | char *cancel_address; | |
1128 | u_short cancel_port; | |
1129 | ||
1130 | cancel_address = packet_get_string(NULL); | |
1131 | cancel_port = (u_short)packet_get_int(); | |
1132 | debug("%s: cancel-tcpip-forward addr %s port %d", __func__, | |
1133 | cancel_address, cancel_port); | |
1134 | ||
1135 | success = channel_cancel_rport_listener(cancel_address, | |
1136 | cancel_port); | |
9108f8d9 | 1137 | xfree(cancel_address); |
3c0ef626 | 1138 | } |
1139 | if (want_reply) { | |
1140 | packet_start(success ? | |
1141 | SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); | |
1142 | packet_send(); | |
1143 | packet_write_wait(); | |
1144 | } | |
1145 | xfree(rtype); | |
1146 | } | |
9108f8d9 | 1147 | |
e9a17296 | 1148 | static void |
1149 | server_input_channel_req(int type, u_int32_t seq, void *ctxt) | |
1150 | { | |
1151 | Channel *c; | |
1152 | int id, reply, success = 0; | |
1153 | char *rtype; | |
1154 | ||
1155 | id = packet_get_int(); | |
1156 | rtype = packet_get_string(NULL); | |
1157 | reply = packet_get_char(); | |
1158 | ||
1159 | debug("server_input_channel_req: channel %d request %s reply %d", | |
1160 | id, rtype, reply); | |
1161 | ||
1162 | if ((c = channel_lookup(id)) == NULL) | |
1163 | packet_disconnect("server_input_channel_req: " | |
1164 | "unknown channel %d", id); | |
1165 | if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN) | |
1166 | success = session_input_channel_req(c, rtype); | |
1167 | if (reply) { | |
1168 | packet_start(success ? | |
1169 | SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); | |
1170 | packet_put_int(c->remote_id); | |
1171 | packet_send(); | |
1172 | } | |
1173 | xfree(rtype); | |
1174 | } | |
3c0ef626 | 1175 | |
1176 | static void | |
1177 | server_init_dispatch_20(void) | |
1178 | { | |
1179 | debug("server_init_dispatch_20"); | |
1180 | dispatch_init(&dispatch_protocol_error); | |
1181 | dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); | |
1182 | dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); | |
1183 | dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); | |
1184 | dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); | |
1185 | dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open); | |
1186 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1187 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
e9a17296 | 1188 | dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req); |
3c0ef626 | 1189 | dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); |
1190 | dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request); | |
1191 | /* client_alive */ | |
cdd66111 | 1192 | dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive); |
1193 | dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive); | |
1194 | dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive); | |
3c0ef626 | 1195 | /* rekeying */ |
1196 | dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); | |
1197 | } | |
1198 | static void | |
1199 | server_init_dispatch_13(void) | |
1200 | { | |
1201 | debug("server_init_dispatch_13"); | |
1202 | dispatch_init(NULL); | |
1203 | dispatch_set(SSH_CMSG_EOF, &server_input_eof); | |
1204 | dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data); | |
1205 | dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size); | |
1206 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); | |
1207 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); | |
1208 | dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); | |
1209 | dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1210 | dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
1211 | dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); | |
1212 | } | |
1213 | static void | |
1214 | server_init_dispatch_15(void) | |
1215 | { | |
1216 | server_init_dispatch_13(); | |
1217 | debug("server_init_dispatch_15"); | |
1218 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); | |
1219 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose); | |
1220 | } | |
1221 | static void | |
1222 | server_init_dispatch(void) | |
1223 | { | |
1224 | if (compat20) | |
1225 | server_init_dispatch_20(); | |
1226 | else if (compat13) | |
1227 | server_init_dispatch_13(); | |
1228 | else | |
1229 | server_init_dispatch_15(); | |
1230 | } |