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1 | /* $OpenBSD: serverloop.c,v 1.157 2009/02/12 03:16:01 djm Exp $ */ | |
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" | |
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> | |
58 | ||
59 | #include "openbsd-compat/sys-queue.h" | |
60 | #include "xmalloc.h" | |
61 | #include "packet.h" | |
62 | #include "buffer.h" | |
63 | #include "log.h" | |
64 | #include "servconf.h" | |
65 | #include "canohost.h" | |
66 | #include "sshpty.h" | |
67 | #include "channels.h" | |
68 | #include "compat.h" | |
69 | #include "ssh1.h" | |
70 | #include "ssh2.h" | |
71 | #include "key.h" | |
72 | #include "cipher.h" | |
73 | #include "kex.h" | |
74 | #include "hostfile.h" | |
75 | #include "auth.h" | |
76 | #include "session.h" | |
77 | #include "dispatch.h" | |
78 | #include "auth-options.h" | |
79 | #include "serverloop.h" | |
80 | #include "misc.h" | |
81 | ||
82 | extern ServerOptions options; | |
83 | ||
84 | /* XXX */ | |
85 | extern Kex *xxx_kex; | |
86 | extern Authctxt *the_authctxt; | |
87 | extern int use_privsep; | |
88 | ||
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 u_long stdin_bytes = 0; /* Number of bytes written to stdin. */ | |
97 | static u_long stdout_bytes = 0; /* Number of stdout bytes sent to client. */ | |
98 | static u_long stderr_bytes = 0; /* Number of stderr bytes sent to client. */ | |
99 | static u_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. */ | |
103 | static int fdin_is_tty = 0; /* fdin points to a tty. */ | |
104 | static int connection_in; /* Connection to client (input). */ | |
105 | static int connection_out; /* Connection to client (output). */ | |
106 | static int connection_closed = 0; /* Connection to client closed. */ | |
107 | static u_int buffer_high; /* "Soft" max buffer size. */ | |
108 | static int no_more_sessions = 0; /* Disallow further sessions. */ | |
109 | ||
110 | /* | |
111 | * This SIGCHLD kludge is used to detect when the child exits. The server | |
112 | * will exit after that, as soon as forwarded connections have terminated. | |
113 | */ | |
114 | ||
115 | static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */ | |
116 | ||
117 | /* Cleanup on signals (!use_privsep case only) */ | |
118 | static volatile sig_atomic_t received_sigterm = 0; | |
119 | ||
120 | /* prototypes */ | |
121 | static void server_init_dispatch(void); | |
122 | ||
123 | /* | |
124 | * Returns current time in seconds from Jan 1, 1970 with the maximum | |
125 | * available resolution. | |
126 | */ | |
127 | ||
128 | static double | |
129 | get_current_time(void) | |
130 | { | |
131 | struct timeval tv; | |
132 | gettimeofday(&tv, NULL); | |
133 | return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0; | |
134 | } | |
135 | ||
136 | ||
137 | /* | |
138 | * we write to this pipe if a SIGCHLD is caught in order to avoid | |
139 | * the race between select() and child_terminated | |
140 | */ | |
141 | static int notify_pipe[2]; | |
142 | static void | |
143 | notify_setup(void) | |
144 | { | |
145 | if (pipe(notify_pipe) < 0) { | |
146 | error("pipe(notify_pipe) failed %s", strerror(errno)); | |
147 | } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) || | |
148 | (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) { | |
149 | error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno)); | |
150 | close(notify_pipe[0]); | |
151 | close(notify_pipe[1]); | |
152 | } else { | |
153 | set_nonblock(notify_pipe[0]); | |
154 | set_nonblock(notify_pipe[1]); | |
155 | return; | |
156 | } | |
157 | notify_pipe[0] = -1; /* read end */ | |
158 | notify_pipe[1] = -1; /* write end */ | |
159 | } | |
160 | static void | |
161 | notify_parent(void) | |
162 | { | |
163 | if (notify_pipe[1] != -1) | |
164 | write(notify_pipe[1], "", 1); | |
165 | } | |
166 | static void | |
167 | notify_prepare(fd_set *readset) | |
168 | { | |
169 | if (notify_pipe[0] != -1) | |
170 | FD_SET(notify_pipe[0], readset); | |
171 | } | |
172 | static void | |
173 | notify_done(fd_set *readset) | |
174 | { | |
175 | char c; | |
176 | ||
177 | if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset)) | |
178 | while (read(notify_pipe[0], &c, 1) != -1) | |
179 | debug2("notify_done: reading"); | |
180 | } | |
181 | ||
182 | /*ARGSUSED*/ | |
183 | static void | |
184 | sigchld_handler(int sig) | |
185 | { | |
186 | int save_errno = errno; | |
187 | child_terminated = 1; | |
188 | #ifndef _UNICOS | |
189 | mysignal(SIGCHLD, sigchld_handler); | |
190 | #endif | |
191 | notify_parent(); | |
192 | errno = save_errno; | |
193 | } | |
194 | ||
195 | /*ARGSUSED*/ | |
196 | static void | |
197 | sigterm_handler(int sig) | |
198 | { | |
199 | received_sigterm = sig; | |
200 | } | |
201 | ||
202 | /* | |
203 | * Make packets from buffered stderr data, and buffer it for sending | |
204 | * to the client. | |
205 | */ | |
206 | static void | |
207 | make_packets_from_stderr_data(void) | |
208 | { | |
209 | u_int len; | |
210 | ||
211 | /* Send buffered stderr data to the client. */ | |
212 | while (buffer_len(&stderr_buffer) > 0 && | |
213 | packet_not_very_much_data_to_write()) { | |
214 | len = buffer_len(&stderr_buffer); | |
215 | if (packet_is_interactive()) { | |
216 | if (len > 512) | |
217 | len = 512; | |
218 | } else { | |
219 | /* Keep the packets at reasonable size. */ | |
220 | if (len > packet_get_maxsize()) | |
221 | len = packet_get_maxsize(); | |
222 | } | |
223 | packet_start(SSH_SMSG_STDERR_DATA); | |
224 | packet_put_string(buffer_ptr(&stderr_buffer), len); | |
225 | packet_send(); | |
226 | buffer_consume(&stderr_buffer, len); | |
227 | stderr_bytes += len; | |
228 | } | |
229 | } | |
230 | ||
231 | /* | |
232 | * Make packets from buffered stdout data, and buffer it for sending to the | |
233 | * client. | |
234 | */ | |
235 | static void | |
236 | make_packets_from_stdout_data(void) | |
237 | { | |
238 | u_int len; | |
239 | ||
240 | /* Send buffered stdout data to the client. */ | |
241 | while (buffer_len(&stdout_buffer) > 0 && | |
242 | packet_not_very_much_data_to_write()) { | |
243 | len = buffer_len(&stdout_buffer); | |
244 | if (packet_is_interactive()) { | |
245 | if (len > 512) | |
246 | len = 512; | |
247 | } else { | |
248 | /* Keep the packets at reasonable size. */ | |
249 | if (len > packet_get_maxsize()) | |
250 | len = packet_get_maxsize(); | |
251 | } | |
252 | packet_start(SSH_SMSG_STDOUT_DATA); | |
253 | packet_put_string(buffer_ptr(&stdout_buffer), len); | |
254 | packet_send(); | |
255 | buffer_consume(&stdout_buffer, len); | |
256 | stdout_bytes += len; | |
257 | } | |
258 | } | |
259 | ||
260 | static void | |
261 | client_alive_check(void) | |
262 | { | |
263 | int channel_id; | |
264 | ||
265 | /* timeout, check to see how many we have had */ | |
266 | if (++keep_alive_timeouts > options.client_alive_count_max) { | |
267 | logit("Timeout, client not responding."); | |
268 | cleanup_exit(255); | |
269 | } | |
270 | ||
271 | /* | |
272 | * send a bogus global/channel request with "wantreply", | |
273 | * we should get back a failure | |
274 | */ | |
275 | if ((channel_id = channel_find_open()) == -1) { | |
276 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
277 | packet_put_cstring("keepalive@openssh.com"); | |
278 | packet_put_char(1); /* boolean: want reply */ | |
279 | } else { | |
280 | channel_request_start(channel_id, "keepalive@openssh.com", 1); | |
281 | } | |
282 | packet_send(); | |
283 | } | |
284 | ||
285 | /* | |
286 | * Sleep in select() until we can do something. This will initialize the | |
287 | * select masks. Upon return, the masks will indicate which descriptors | |
288 | * have data or can accept data. Optionally, a maximum time can be specified | |
289 | * for the duration of the wait (0 = infinite). | |
290 | */ | |
291 | static void | |
292 | wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, | |
293 | u_int *nallocp, u_int max_time_milliseconds) | |
294 | { | |
295 | struct timeval tv, *tvp; | |
296 | int ret; | |
297 | int client_alive_scheduled = 0; | |
298 | int program_alive_scheduled = 0; | |
299 | ||
300 | /* | |
301 | * if using client_alive, set the max timeout accordingly, | |
302 | * and indicate that this particular timeout was for client | |
303 | * alive by setting the client_alive_scheduled flag. | |
304 | * | |
305 | * this could be randomized somewhat to make traffic | |
306 | * analysis more difficult, but we're not doing it yet. | |
307 | */ | |
308 | if (compat20 && | |
309 | max_time_milliseconds == 0 && options.client_alive_interval) { | |
310 | client_alive_scheduled = 1; | |
311 | max_time_milliseconds = options.client_alive_interval * 1000; | |
312 | } | |
313 | ||
314 | /* Allocate and update select() masks for channel descriptors. */ | |
315 | channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0); | |
316 | ||
317 | if (compat20) { | |
318 | #if 0 | |
319 | /* wrong: bad condition XXX */ | |
320 | if (channel_not_very_much_buffered_data()) | |
321 | #endif | |
322 | FD_SET(connection_in, *readsetp); | |
323 | } else { | |
324 | /* | |
325 | * Read packets from the client unless we have too much | |
326 | * buffered stdin or channel data. | |
327 | */ | |
328 | if (buffer_len(&stdin_buffer) < buffer_high && | |
329 | channel_not_very_much_buffered_data()) | |
330 | FD_SET(connection_in, *readsetp); | |
331 | /* | |
332 | * If there is not too much data already buffered going to | |
333 | * the client, try to get some more data from the program. | |
334 | */ | |
335 | if (packet_not_very_much_data_to_write()) { | |
336 | program_alive_scheduled = child_terminated; | |
337 | if (!fdout_eof) | |
338 | FD_SET(fdout, *readsetp); | |
339 | if (!fderr_eof) | |
340 | FD_SET(fderr, *readsetp); | |
341 | } | |
342 | /* | |
343 | * If we have buffered data, try to write some of that data | |
344 | * to the program. | |
345 | */ | |
346 | if (fdin != -1 && buffer_len(&stdin_buffer) > 0) | |
347 | FD_SET(fdin, *writesetp); | |
348 | } | |
349 | notify_prepare(*readsetp); | |
350 | ||
351 | /* | |
352 | * If we have buffered packet data going to the client, mark that | |
353 | * descriptor. | |
354 | */ | |
355 | if (packet_have_data_to_write()) | |
356 | FD_SET(connection_out, *writesetp); | |
357 | ||
358 | /* | |
359 | * If child has terminated and there is enough buffer space to read | |
360 | * from it, then read as much as is available and exit. | |
361 | */ | |
362 | if (child_terminated && packet_not_very_much_data_to_write()) | |
363 | if (max_time_milliseconds == 0 || client_alive_scheduled) | |
364 | max_time_milliseconds = 100; | |
365 | ||
366 | if (max_time_milliseconds == 0) | |
367 | tvp = NULL; | |
368 | else { | |
369 | tv.tv_sec = max_time_milliseconds / 1000; | |
370 | tv.tv_usec = 1000 * (max_time_milliseconds % 1000); | |
371 | tvp = &tv; | |
372 | } | |
373 | ||
374 | /* Wait for something to happen, or the timeout to expire. */ | |
375 | ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); | |
376 | ||
377 | if (ret == -1) { | |
378 | memset(*readsetp, 0, *nallocp); | |
379 | memset(*writesetp, 0, *nallocp); | |
380 | if (errno != EINTR) | |
381 | error("select: %.100s", strerror(errno)); | |
382 | } else { | |
383 | if (ret == 0 && client_alive_scheduled) | |
384 | client_alive_check(); | |
385 | if (!compat20 && program_alive_scheduled && fdin_is_tty) { | |
386 | if (!fdout_eof) | |
387 | FD_SET(fdout, *readsetp); | |
388 | if (!fderr_eof) | |
389 | FD_SET(fderr, *readsetp); | |
390 | } | |
391 | } | |
392 | ||
393 | notify_done(*readsetp); | |
394 | } | |
395 | ||
396 | /* | |
397 | * Processes input from the client and the program. Input data is stored | |
398 | * in buffers and processed later. | |
399 | */ | |
400 | static void | |
401 | process_input(fd_set *readset) | |
402 | { | |
403 | int len; | |
404 | char buf[16384]; | |
405 | ||
406 | /* Read and buffer any input data from the client. */ | |
407 | if (FD_ISSET(connection_in, readset)) { | |
408 | len = read(connection_in, buf, sizeof(buf)); | |
409 | if (len == 0) { | |
410 | verbose("Connection closed by %.100s", | |
411 | get_remote_ipaddr()); | |
412 | connection_closed = 1; | |
413 | if (compat20) | |
414 | return; | |
415 | cleanup_exit(255); | |
416 | } else if (len < 0) { | |
417 | if (errno != EINTR && errno != EAGAIN && | |
418 | errno != EWOULDBLOCK) { | |
419 | verbose("Read error from remote host " | |
420 | "%.100s: %.100s", | |
421 | get_remote_ipaddr(), strerror(errno)); | |
422 | cleanup_exit(255); | |
423 | } | |
424 | } else { | |
425 | /* Buffer any received data. */ | |
426 | packet_process_incoming(buf, len); | |
427 | fdout_bytes += len; | |
428 | } | |
429 | } | |
430 | if (compat20) | |
431 | return; | |
432 | ||
433 | /* Read and buffer any available stdout data from the program. */ | |
434 | if (!fdout_eof && FD_ISSET(fdout, readset)) { | |
435 | errno = 0; | |
436 | len = read(fdout, buf, sizeof(buf)); | |
437 | if (len < 0 && (errno == EINTR || ((errno == EAGAIN || | |
438 | errno == EWOULDBLOCK) && !child_terminated))) { | |
439 | /* do nothing */ | |
440 | #ifndef PTY_ZEROREAD | |
441 | } else if (len <= 0) { | |
442 | #else | |
443 | } else if ((!isatty(fdout) && len <= 0) || | |
444 | (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) { | |
445 | #endif | |
446 | fdout_eof = 1; | |
447 | } else { | |
448 | buffer_append(&stdout_buffer, buf, len); | |
449 | fdout_bytes += len; | |
450 | debug ("FD out now: %ld", fdout_bytes); | |
451 | } | |
452 | } | |
453 | /* Read and buffer any available stderr data from the program. */ | |
454 | if (!fderr_eof && FD_ISSET(fderr, readset)) { | |
455 | errno = 0; | |
456 | len = read(fderr, buf, sizeof(buf)); | |
457 | if (len < 0 && (errno == EINTR || ((errno == EAGAIN || | |
458 | errno == EWOULDBLOCK) && !child_terminated))) { | |
459 | /* do nothing */ | |
460 | #ifndef PTY_ZEROREAD | |
461 | } else if (len <= 0) { | |
462 | #else | |
463 | } else if ((!isatty(fderr) && len <= 0) || | |
464 | (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) { | |
465 | #endif | |
466 | fderr_eof = 1; | |
467 | } else { | |
468 | buffer_append(&stderr_buffer, buf, len); | |
469 | } | |
470 | } | |
471 | } | |
472 | ||
473 | /* | |
474 | * Sends data from internal buffers to client program stdin. | |
475 | */ | |
476 | static void | |
477 | process_output(fd_set *writeset) | |
478 | { | |
479 | struct termios tio; | |
480 | u_char *data; | |
481 | u_int dlen; | |
482 | int len; | |
483 | ||
484 | /* Write buffered data to program stdin. */ | |
485 | if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) { | |
486 | data = buffer_ptr(&stdin_buffer); | |
487 | dlen = buffer_len(&stdin_buffer); | |
488 | len = write(fdin, data, dlen); | |
489 | if (len < 0 && | |
490 | (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)) { | |
491 | /* do nothing */ | |
492 | } else if (len <= 0) { | |
493 | if (fdin != fdout) | |
494 | close(fdin); | |
495 | else | |
496 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
497 | fdin = -1; | |
498 | } else { | |
499 | /* Successful write. */ | |
500 | if (fdin_is_tty && dlen >= 1 && data[0] != '\r' && | |
501 | tcgetattr(fdin, &tio) == 0 && | |
502 | !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { | |
503 | /* | |
504 | * Simulate echo to reduce the impact of | |
505 | * traffic analysis | |
506 | */ | |
507 | packet_send_ignore(len); | |
508 | packet_send(); | |
509 | } | |
510 | /* Consume the data from the buffer. */ | |
511 | buffer_consume(&stdin_buffer, len); | |
512 | /* Update the count of bytes written to the program. */ | |
513 | stdin_bytes += len; | |
514 | } | |
515 | } | |
516 | /* Send any buffered packet data to the client. */ | |
517 | if (FD_ISSET(connection_out, writeset)) | |
518 | stdin_bytes += packet_write_poll(); | |
519 | } | |
520 | ||
521 | /* | |
522 | * Wait until all buffered output has been sent to the client. | |
523 | * This is used when the program terminates. | |
524 | */ | |
525 | static void | |
526 | drain_output(void) | |
527 | { | |
528 | /* Send any buffered stdout data to the client. */ | |
529 | if (buffer_len(&stdout_buffer) > 0) { | |
530 | packet_start(SSH_SMSG_STDOUT_DATA); | |
531 | packet_put_string(buffer_ptr(&stdout_buffer), | |
532 | buffer_len(&stdout_buffer)); | |
533 | packet_send(); | |
534 | /* Update the count of sent bytes. */ | |
535 | stdout_bytes += buffer_len(&stdout_buffer); | |
536 | } | |
537 | /* Send any buffered stderr data to the client. */ | |
538 | if (buffer_len(&stderr_buffer) > 0) { | |
539 | packet_start(SSH_SMSG_STDERR_DATA); | |
540 | packet_put_string(buffer_ptr(&stderr_buffer), | |
541 | buffer_len(&stderr_buffer)); | |
542 | packet_send(); | |
543 | /* Update the count of sent bytes. */ | |
544 | stderr_bytes += buffer_len(&stderr_buffer); | |
545 | } | |
546 | /* Wait until all buffered data has been written to the client. */ | |
547 | packet_write_wait(); | |
548 | } | |
549 | ||
550 | static void | |
551 | process_buffered_input_packets(void) | |
552 | { | |
553 | dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL); | |
554 | } | |
555 | ||
556 | /* | |
557 | * Performs the interactive session. This handles data transmission between | |
558 | * the client and the program. Note that the notion of stdin, stdout, and | |
559 | * stderr in this function is sort of reversed: this function writes to | |
560 | * stdin (of the child program), and reads from stdout and stderr (of the | |
561 | * child program). | |
562 | */ | |
563 | void | |
564 | server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) | |
565 | { | |
566 | fd_set *readset = NULL, *writeset = NULL; | |
567 | int max_fd = 0; | |
568 | u_int nalloc = 0; | |
569 | int wait_status; /* Status returned by wait(). */ | |
570 | pid_t wait_pid; /* pid returned by wait(). */ | |
571 | int waiting_termination = 0; /* Have displayed waiting close message. */ | |
572 | u_int max_time_milliseconds; | |
573 | u_int previous_stdout_buffer_bytes; | |
574 | u_int stdout_buffer_bytes; | |
575 | int type; | |
576 | ||
577 | debug("Entering interactive session."); | |
578 | ||
579 | /* Initialize the SIGCHLD kludge. */ | |
580 | child_terminated = 0; | |
581 | mysignal(SIGCHLD, sigchld_handler); | |
582 | ||
583 | if (!use_privsep) { | |
584 | signal(SIGTERM, sigterm_handler); | |
585 | signal(SIGINT, sigterm_handler); | |
586 | signal(SIGQUIT, sigterm_handler); | |
587 | } | |
588 | ||
589 | /* Initialize our global variables. */ | |
590 | fdin = fdin_arg; | |
591 | fdout = fdout_arg; | |
592 | fderr = fderr_arg; | |
593 | ||
594 | /* nonblocking IO */ | |
595 | set_nonblock(fdin); | |
596 | set_nonblock(fdout); | |
597 | /* we don't have stderr for interactive terminal sessions, see below */ | |
598 | if (fderr != -1) | |
599 | set_nonblock(fderr); | |
600 | ||
601 | if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin)) | |
602 | fdin_is_tty = 1; | |
603 | ||
604 | connection_in = packet_get_connection_in(); | |
605 | connection_out = packet_get_connection_out(); | |
606 | ||
607 | notify_setup(); | |
608 | ||
609 | previous_stdout_buffer_bytes = 0; | |
610 | ||
611 | /* Set approximate I/O buffer size. */ | |
612 | if (packet_is_interactive()) | |
613 | buffer_high = 4096; | |
614 | else | |
615 | buffer_high = 64 * 1024; | |
616 | ||
617 | #if 0 | |
618 | /* Initialize max_fd to the maximum of the known file descriptors. */ | |
619 | max_fd = MAX(connection_in, connection_out); | |
620 | max_fd = MAX(max_fd, fdin); | |
621 | max_fd = MAX(max_fd, fdout); | |
622 | if (fderr != -1) | |
623 | max_fd = MAX(max_fd, fderr); | |
624 | #endif | |
625 | ||
626 | /* Initialize Initialize buffers. */ | |
627 | buffer_init(&stdin_buffer); | |
628 | buffer_init(&stdout_buffer); | |
629 | buffer_init(&stderr_buffer); | |
630 | ||
631 | /* | |
632 | * If we have no separate fderr (which is the case when we have a pty | |
633 | * - there we cannot make difference between data sent to stdout and | |
634 | * stderr), indicate that we have seen an EOF from stderr. This way | |
635 | * we don't need to check the descriptor everywhere. | |
636 | */ | |
637 | if (fderr == -1) | |
638 | fderr_eof = 1; | |
639 | ||
640 | server_init_dispatch(); | |
641 | ||
642 | /* Main loop of the server for the interactive session mode. */ | |
643 | for (;;) { | |
644 | ||
645 | /* Process buffered packets from the client. */ | |
646 | process_buffered_input_packets(); | |
647 | ||
648 | /* | |
649 | * If we have received eof, and there is no more pending | |
650 | * input data, cause a real eof by closing fdin. | |
651 | */ | |
652 | if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) { | |
653 | if (fdin != fdout) | |
654 | close(fdin); | |
655 | else | |
656 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
657 | fdin = -1; | |
658 | } | |
659 | /* Make packets from buffered stderr data to send to the client. */ | |
660 | make_packets_from_stderr_data(); | |
661 | ||
662 | /* | |
663 | * Make packets from buffered stdout data to send to the | |
664 | * client. If there is very little to send, this arranges to | |
665 | * not send them now, but to wait a short while to see if we | |
666 | * are getting more data. This is necessary, as some systems | |
667 | * wake up readers from a pty after each separate character. | |
668 | */ | |
669 | max_time_milliseconds = 0; | |
670 | stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
671 | if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && | |
672 | stdout_buffer_bytes != previous_stdout_buffer_bytes) { | |
673 | /* try again after a while */ | |
674 | max_time_milliseconds = 10; | |
675 | } else { | |
676 | /* Send it now. */ | |
677 | make_packets_from_stdout_data(); | |
678 | } | |
679 | previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
680 | ||
681 | /* Send channel data to the client. */ | |
682 | if (packet_not_very_much_data_to_write()) | |
683 | channel_output_poll(); | |
684 | ||
685 | /* | |
686 | * Bail out of the loop if the program has closed its output | |
687 | * descriptors, and we have no more data to send to the | |
688 | * client, and there is no pending buffered data. | |
689 | */ | |
690 | if (fdout_eof && fderr_eof && !packet_have_data_to_write() && | |
691 | buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { | |
692 | if (!channel_still_open()) | |
693 | break; | |
694 | if (!waiting_termination) { | |
695 | const char *s = "Waiting for forwarded connections to terminate...\r\n"; | |
696 | char *cp; | |
697 | waiting_termination = 1; | |
698 | buffer_append(&stderr_buffer, s, strlen(s)); | |
699 | ||
700 | /* Display list of open channels. */ | |
701 | cp = channel_open_message(); | |
702 | buffer_append(&stderr_buffer, cp, strlen(cp)); | |
703 | xfree(cp); | |
704 | } | |
705 | } | |
706 | max_fd = MAX(connection_in, connection_out); | |
707 | max_fd = MAX(max_fd, fdin); | |
708 | max_fd = MAX(max_fd, fdout); | |
709 | max_fd = MAX(max_fd, fderr); | |
710 | max_fd = MAX(max_fd, notify_pipe[0]); | |
711 | ||
712 | /* Sleep in select() until we can do something. */ | |
713 | wait_until_can_do_something(&readset, &writeset, &max_fd, | |
714 | &nalloc, max_time_milliseconds); | |
715 | ||
716 | if (received_sigterm) { | |
717 | logit("Exiting on signal %d", received_sigterm); | |
718 | /* Clean up sessions, utmp, etc. */ | |
719 | cleanup_exit(255); | |
720 | } | |
721 | ||
722 | /* Process any channel events. */ | |
723 | channel_after_select(readset, writeset); | |
724 | ||
725 | /* Process input from the client and from program stdout/stderr. */ | |
726 | process_input(readset); | |
727 | ||
728 | /* Process output to the client and to program stdin. */ | |
729 | process_output(writeset); | |
730 | } | |
731 | if (readset) | |
732 | xfree(readset); | |
733 | if (writeset) | |
734 | xfree(writeset); | |
735 | ||
736 | /* Cleanup and termination code. */ | |
737 | ||
738 | /* Wait until all output has been sent to the client. */ | |
739 | drain_output(); | |
740 | ||
741 | debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", | |
742 | stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); | |
743 | ||
744 | /* Free and clear the buffers. */ | |
745 | buffer_free(&stdin_buffer); | |
746 | buffer_free(&stdout_buffer); | |
747 | buffer_free(&stderr_buffer); | |
748 | ||
749 | /* Close the file descriptors. */ | |
750 | if (fdout != -1) | |
751 | close(fdout); | |
752 | fdout = -1; | |
753 | fdout_eof = 1; | |
754 | if (fderr != -1) | |
755 | close(fderr); | |
756 | fderr = -1; | |
757 | fderr_eof = 1; | |
758 | if (fdin != -1) | |
759 | close(fdin); | |
760 | fdin = -1; | |
761 | ||
762 | channel_free_all(); | |
763 | ||
764 | /* We no longer want our SIGCHLD handler to be called. */ | |
765 | mysignal(SIGCHLD, SIG_DFL); | |
766 | ||
767 | while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0) | |
768 | if (errno != EINTR) | |
769 | packet_disconnect("wait: %.100s", strerror(errno)); | |
770 | if (wait_pid != pid) | |
771 | error("Strange, wait returned pid %ld, expected %ld", | |
772 | (long)wait_pid, (long)pid); | |
773 | ||
774 | /* Check if it exited normally. */ | |
775 | if (WIFEXITED(wait_status)) { | |
776 | /* Yes, normal exit. Get exit status and send it to the client. */ | |
777 | debug("Command exited with status %d.", WEXITSTATUS(wait_status)); | |
778 | packet_start(SSH_SMSG_EXITSTATUS); | |
779 | packet_put_int(WEXITSTATUS(wait_status)); | |
780 | packet_send(); | |
781 | packet_write_wait(); | |
782 | ||
783 | /* | |
784 | * Wait for exit confirmation. Note that there might be | |
785 | * other packets coming before it; however, the program has | |
786 | * already died so we just ignore them. The client is | |
787 | * supposed to respond with the confirmation when it receives | |
788 | * the exit status. | |
789 | */ | |
790 | do { | |
791 | type = packet_read(); | |
792 | } | |
793 | while (type != SSH_CMSG_EXIT_CONFIRMATION); | |
794 | ||
795 | debug("Received exit confirmation."); | |
796 | return; | |
797 | } | |
798 | /* Check if the program terminated due to a signal. */ | |
799 | if (WIFSIGNALED(wait_status)) | |
800 | packet_disconnect("Command terminated on signal %d.", | |
801 | WTERMSIG(wait_status)); | |
802 | ||
803 | /* Some weird exit cause. Just exit. */ | |
804 | packet_disconnect("wait returned status %04x.", wait_status); | |
805 | /* NOTREACHED */ | |
806 | } | |
807 | ||
808 | static void | |
809 | collect_children(void) | |
810 | { | |
811 | pid_t pid; | |
812 | sigset_t oset, nset; | |
813 | int status; | |
814 | ||
815 | /* block SIGCHLD while we check for dead children */ | |
816 | sigemptyset(&nset); | |
817 | sigaddset(&nset, SIGCHLD); | |
818 | sigprocmask(SIG_BLOCK, &nset, &oset); | |
819 | if (child_terminated) { | |
820 | debug("Received SIGCHLD."); | |
821 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || | |
822 | (pid < 0 && errno == EINTR)) | |
823 | if (pid > 0) | |
824 | session_close_by_pid(pid, status); | |
825 | child_terminated = 0; | |
826 | } | |
827 | sigprocmask(SIG_SETMASK, &oset, NULL); | |
828 | } | |
829 | ||
830 | void | |
831 | server_loop2(Authctxt *authctxt) | |
832 | { | |
833 | fd_set *readset = NULL, *writeset = NULL; | |
834 | int rekeying = 0, max_fd, nalloc = 0; | |
835 | double start_time, total_time; | |
836 | ||
837 | debug("Entering interactive session for SSH2."); | |
838 | start_time = get_current_time(); | |
839 | ||
840 | mysignal(SIGCHLD, sigchld_handler); | |
841 | child_terminated = 0; | |
842 | connection_in = packet_get_connection_in(); | |
843 | connection_out = packet_get_connection_out(); | |
844 | ||
845 | if (!use_privsep) { | |
846 | signal(SIGTERM, sigterm_handler); | |
847 | signal(SIGINT, sigterm_handler); | |
848 | signal(SIGQUIT, sigterm_handler); | |
849 | } | |
850 | ||
851 | notify_setup(); | |
852 | ||
853 | max_fd = MAX(connection_in, connection_out); | |
854 | max_fd = MAX(max_fd, notify_pipe[0]); | |
855 | ||
856 | server_init_dispatch(); | |
857 | ||
858 | for (;;) { | |
859 | process_buffered_input_packets(); | |
860 | ||
861 | rekeying = (xxx_kex != NULL && !xxx_kex->done); | |
862 | ||
863 | if (!rekeying && packet_not_very_much_data_to_write()) | |
864 | channel_output_poll(); | |
865 | wait_until_can_do_something(&readset, &writeset, &max_fd, | |
866 | &nalloc, 0); | |
867 | ||
868 | if (received_sigterm) { | |
869 | logit("Exiting on signal %d", received_sigterm); | |
870 | /* Clean up sessions, utmp, etc. */ | |
871 | cleanup_exit(255); | |
872 | } | |
873 | ||
874 | collect_children(); | |
875 | if (!rekeying) { | |
876 | channel_after_select(readset, writeset); | |
877 | if (packet_need_rekeying()) { | |
878 | debug("need rekeying"); | |
879 | xxx_kex->done = 0; | |
880 | kex_send_kexinit(xxx_kex); | |
881 | } | |
882 | } | |
883 | process_input(readset); | |
884 | if (connection_closed) | |
885 | break; | |
886 | process_output(writeset); | |
887 | } | |
888 | collect_children(); | |
889 | ||
890 | if (readset) | |
891 | xfree(readset); | |
892 | if (writeset) | |
893 | xfree(writeset); | |
894 | ||
895 | /* free all channels, no more reads and writes */ | |
896 | channel_free_all(); | |
897 | ||
898 | /* free remaining sessions, e.g. remove wtmp entries */ | |
899 | session_destroy_all(NULL); | |
900 | total_time = get_current_time() - start_time; | |
901 | logit("SSH: Server;LType: Throughput;Remote: %s-%d;IN: %lu;OUT: %lu;Duration: %.1f;tPut_in: %.1f;tPut_out: %.1f", | |
902 | get_remote_ipaddr(), get_remote_port(), | |
903 | stdin_bytes, fdout_bytes, total_time, stdin_bytes / total_time, | |
904 | fdout_bytes / total_time); | |
905 | } | |
906 | ||
907 | static void | |
908 | server_input_keep_alive(int type, u_int32_t seq, void *ctxt) | |
909 | { | |
910 | debug("Got %d/%u for keepalive", type, seq); | |
911 | /* | |
912 | * reset timeout, since we got a sane answer from the client. | |
913 | * even if this was generated by something other than | |
914 | * the bogus CHANNEL_REQUEST we send for keepalives. | |
915 | */ | |
916 | keep_alive_timeouts = 0; | |
917 | } | |
918 | ||
919 | static void | |
920 | server_input_stdin_data(int type, u_int32_t seq, void *ctxt) | |
921 | { | |
922 | char *data; | |
923 | u_int data_len; | |
924 | ||
925 | /* Stdin data from the client. Append it to the buffer. */ | |
926 | /* Ignore any data if the client has closed stdin. */ | |
927 | if (fdin == -1) | |
928 | return; | |
929 | data = packet_get_string(&data_len); | |
930 | packet_check_eom(); | |
931 | buffer_append(&stdin_buffer, data, data_len); | |
932 | memset(data, 0, data_len); | |
933 | xfree(data); | |
934 | } | |
935 | ||
936 | static void | |
937 | server_input_eof(int type, u_int32_t seq, void *ctxt) | |
938 | { | |
939 | /* | |
940 | * Eof from the client. The stdin descriptor to the | |
941 | * program will be closed when all buffered data has | |
942 | * drained. | |
943 | */ | |
944 | debug("EOF received for stdin."); | |
945 | packet_check_eom(); | |
946 | stdin_eof = 1; | |
947 | } | |
948 | ||
949 | static void | |
950 | server_input_window_size(int type, u_int32_t seq, void *ctxt) | |
951 | { | |
952 | u_int row = packet_get_int(); | |
953 | u_int col = packet_get_int(); | |
954 | u_int xpixel = packet_get_int(); | |
955 | u_int ypixel = packet_get_int(); | |
956 | ||
957 | debug("Window change received."); | |
958 | packet_check_eom(); | |
959 | if (fdin != -1) | |
960 | pty_change_window_size(fdin, row, col, xpixel, ypixel); | |
961 | } | |
962 | ||
963 | static Channel * | |
964 | server_request_direct_tcpip(void) | |
965 | { | |
966 | Channel *c; | |
967 | char *target, *originator; | |
968 | u_short target_port, originator_port; | |
969 | ||
970 | target = packet_get_string(NULL); | |
971 | target_port = packet_get_int(); | |
972 | originator = packet_get_string(NULL); | |
973 | originator_port = packet_get_int(); | |
974 | packet_check_eom(); | |
975 | ||
976 | debug("server_request_direct_tcpip: originator %s port %d, target %s " | |
977 | "port %d", originator, originator_port, target, target_port); | |
978 | ||
979 | /* XXX check permission */ | |
980 | c = channel_connect_to(target, target_port, | |
981 | "direct-tcpip", "direct-tcpip"); | |
982 | ||
983 | xfree(originator); | |
984 | xfree(target); | |
985 | ||
986 | return c; | |
987 | } | |
988 | ||
989 | static Channel * | |
990 | server_request_tun(void) | |
991 | { | |
992 | Channel *c = NULL; | |
993 | int mode, tun; | |
994 | int sock; | |
995 | ||
996 | mode = packet_get_int(); | |
997 | switch (mode) { | |
998 | case SSH_TUNMODE_POINTOPOINT: | |
999 | case SSH_TUNMODE_ETHERNET: | |
1000 | break; | |
1001 | default: | |
1002 | packet_send_debug("Unsupported tunnel device mode."); | |
1003 | return NULL; | |
1004 | } | |
1005 | if ((options.permit_tun & mode) == 0) { | |
1006 | packet_send_debug("Server has rejected tunnel device " | |
1007 | "forwarding"); | |
1008 | return NULL; | |
1009 | } | |
1010 | ||
1011 | tun = packet_get_int(); | |
1012 | if (forced_tun_device != -1) { | |
1013 | if (tun != SSH_TUNID_ANY && forced_tun_device != tun) | |
1014 | goto done; | |
1015 | tun = forced_tun_device; | |
1016 | } | |
1017 | sock = tun_open(tun, mode); | |
1018 | if (sock < 0) | |
1019 | goto done; | |
1020 | if (options.hpn_disabled) | |
1021 | c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1, | |
1022 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); | |
1023 | else | |
1024 | c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1, | |
1025 | options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); | |
1026 | c->datagram = 1; | |
1027 | #if defined(SSH_TUN_FILTER) | |
1028 | if (mode == SSH_TUNMODE_POINTOPOINT) | |
1029 | channel_register_filter(c->self, sys_tun_infilter, | |
1030 | sys_tun_outfilter, NULL, NULL); | |
1031 | #endif | |
1032 | ||
1033 | done: | |
1034 | if (c == NULL) | |
1035 | packet_send_debug("Failed to open the tunnel device."); | |
1036 | return c; | |
1037 | } | |
1038 | ||
1039 | static Channel * | |
1040 | server_request_session(void) | |
1041 | { | |
1042 | Channel *c; | |
1043 | ||
1044 | debug("input_session_request"); | |
1045 | packet_check_eom(); | |
1046 | ||
1047 | if (no_more_sessions) { | |
1048 | packet_disconnect("Possible attack: attempt to open a session " | |
1049 | "after additional sessions disabled"); | |
1050 | } | |
1051 | ||
1052 | /* | |
1053 | * A server session has no fd to read or write until a | |
1054 | * CHANNEL_REQUEST for a shell is made, so we set the type to | |
1055 | * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all | |
1056 | * CHANNEL_REQUEST messages is registered. | |
1057 | */ | |
1058 | c = channel_new("session", SSH_CHANNEL_LARVAL, | |
1059 | -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT, | |
1060 | 0, "server-session", 1); | |
1061 | if ((options.tcp_rcv_buf_poll) && (!options.hpn_disabled)) | |
1062 | c->dynamic_window = 1; | |
1063 | if (session_open(the_authctxt, c->self) != 1) { | |
1064 | debug("session open failed, free channel %d", c->self); | |
1065 | channel_free(c); | |
1066 | return NULL; | |
1067 | } | |
1068 | channel_register_cleanup(c->self, session_close_by_channel, 0); | |
1069 | return c; | |
1070 | } | |
1071 | ||
1072 | static void | |
1073 | server_input_channel_open(int type, u_int32_t seq, void *ctxt) | |
1074 | { | |
1075 | Channel *c = NULL; | |
1076 | char *ctype; | |
1077 | int rchan; | |
1078 | u_int rmaxpack, rwindow, len; | |
1079 | ||
1080 | ctype = packet_get_string(&len); | |
1081 | rchan = packet_get_int(); | |
1082 | rwindow = packet_get_int(); | |
1083 | rmaxpack = packet_get_int(); | |
1084 | ||
1085 | debug("server_input_channel_open: ctype %s rchan %d win %d max %d", | |
1086 | ctype, rchan, rwindow, rmaxpack); | |
1087 | ||
1088 | if (strcmp(ctype, "session") == 0) { | |
1089 | c = server_request_session(); | |
1090 | } else if (strcmp(ctype, "direct-tcpip") == 0) { | |
1091 | c = server_request_direct_tcpip(); | |
1092 | } else if (strcmp(ctype, "tun@openssh.com") == 0) { | |
1093 | c = server_request_tun(); | |
1094 | } | |
1095 | if (c != NULL) { | |
1096 | debug("server_input_channel_open: confirm %s", ctype); | |
1097 | c->remote_id = rchan; | |
1098 | c->remote_window = rwindow; | |
1099 | c->remote_maxpacket = rmaxpack; | |
1100 | if (c->type != SSH_CHANNEL_CONNECTING) { | |
1101 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1102 | packet_put_int(c->remote_id); | |
1103 | packet_put_int(c->self); | |
1104 | packet_put_int(c->local_window); | |
1105 | packet_put_int(c->local_maxpacket); | |
1106 | packet_send(); | |
1107 | } | |
1108 | } else { | |
1109 | debug("server_input_channel_open: failure %s", ctype); | |
1110 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); | |
1111 | packet_put_int(rchan); | |
1112 | packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); | |
1113 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
1114 | packet_put_cstring("open failed"); | |
1115 | packet_put_cstring(""); | |
1116 | } | |
1117 | packet_send(); | |
1118 | } | |
1119 | xfree(ctype); | |
1120 | } | |
1121 | ||
1122 | static void | |
1123 | server_input_global_request(int type, u_int32_t seq, void *ctxt) | |
1124 | { | |
1125 | char *rtype; | |
1126 | int want_reply; | |
1127 | int success = 0, allocated_listen_port = 0; | |
1128 | ||
1129 | rtype = packet_get_string(NULL); | |
1130 | want_reply = packet_get_char(); | |
1131 | debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply); | |
1132 | ||
1133 | /* -R style forwarding */ | |
1134 | if (strcmp(rtype, "tcpip-forward") == 0) { | |
1135 | struct passwd *pw; | |
1136 | char *listen_address; | |
1137 | u_short listen_port; | |
1138 | ||
1139 | pw = the_authctxt->pw; | |
1140 | if (pw == NULL || !the_authctxt->valid) | |
1141 | fatal("server_input_global_request: no/invalid user"); | |
1142 | listen_address = packet_get_string(NULL); | |
1143 | listen_port = (u_short)packet_get_int(); | |
1144 | debug("server_input_global_request: tcpip-forward listen %s port %d", | |
1145 | listen_address, listen_port); | |
1146 | ||
1147 | /* check permissions */ | |
1148 | if (!options.allow_tcp_forwarding || | |
1149 | no_port_forwarding_flag || | |
1150 | (!want_reply && listen_port == 0) | |
1151 | #ifndef NO_IPPORT_RESERVED_CONCEPT | |
1152 | || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0) | |
1153 | #endif | |
1154 | ) { | |
1155 | success = 0; | |
1156 | packet_send_debug("Server has disabled port forwarding."); | |
1157 | } else { | |
1158 | /* Start listening on the port */ | |
1159 | success = channel_setup_remote_fwd_listener( | |
1160 | listen_address, listen_port, | |
1161 | &allocated_listen_port, options.gateway_ports); | |
1162 | } | |
1163 | xfree(listen_address); | |
1164 | } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) { | |
1165 | char *cancel_address; | |
1166 | u_short cancel_port; | |
1167 | ||
1168 | cancel_address = packet_get_string(NULL); | |
1169 | cancel_port = (u_short)packet_get_int(); | |
1170 | debug("%s: cancel-tcpip-forward addr %s port %d", __func__, | |
1171 | cancel_address, cancel_port); | |
1172 | ||
1173 | success = channel_cancel_rport_listener(cancel_address, | |
1174 | cancel_port); | |
1175 | xfree(cancel_address); | |
1176 | } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) { | |
1177 | no_more_sessions = 1; | |
1178 | success = 1; | |
1179 | } | |
1180 | if (want_reply) { | |
1181 | packet_start(success ? | |
1182 | SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); | |
1183 | if (success && allocated_listen_port > 0) | |
1184 | packet_put_int(allocated_listen_port); | |
1185 | packet_send(); | |
1186 | packet_write_wait(); | |
1187 | } | |
1188 | xfree(rtype); | |
1189 | } | |
1190 | ||
1191 | static void | |
1192 | server_input_channel_req(int type, u_int32_t seq, void *ctxt) | |
1193 | { | |
1194 | Channel *c; | |
1195 | int id, reply, success = 0; | |
1196 | char *rtype; | |
1197 | ||
1198 | id = packet_get_int(); | |
1199 | rtype = packet_get_string(NULL); | |
1200 | reply = packet_get_char(); | |
1201 | ||
1202 | debug("server_input_channel_req: channel %d request %s reply %d", | |
1203 | id, rtype, reply); | |
1204 | ||
1205 | if ((c = channel_lookup(id)) == NULL) | |
1206 | packet_disconnect("server_input_channel_req: " | |
1207 | "unknown channel %d", id); | |
1208 | if (!strcmp(rtype, "eow@openssh.com")) { | |
1209 | packet_check_eom(); | |
1210 | chan_rcvd_eow(c); | |
1211 | } else if ((c->type == SSH_CHANNEL_LARVAL || | |
1212 | c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0) | |
1213 | success = session_input_channel_req(c, rtype); | |
1214 | if (reply) { | |
1215 | packet_start(success ? | |
1216 | SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); | |
1217 | packet_put_int(c->remote_id); | |
1218 | packet_send(); | |
1219 | } | |
1220 | xfree(rtype); | |
1221 | } | |
1222 | ||
1223 | static void | |
1224 | server_init_dispatch_20(void) | |
1225 | { | |
1226 | debug("server_init_dispatch_20"); | |
1227 | dispatch_init(&dispatch_protocol_error); | |
1228 | dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); | |
1229 | dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); | |
1230 | dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); | |
1231 | dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); | |
1232 | dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open); | |
1233 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1234 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
1235 | dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req); | |
1236 | dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); | |
1237 | dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request); | |
1238 | /* client_alive */ | |
1239 | dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive); | |
1240 | dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive); | |
1241 | dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive); | |
1242 | dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive); | |
1243 | /* rekeying */ | |
1244 | dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); | |
1245 | } | |
1246 | static void | |
1247 | server_init_dispatch_13(void) | |
1248 | { | |
1249 | debug("server_init_dispatch_13"); | |
1250 | dispatch_init(NULL); | |
1251 | dispatch_set(SSH_CMSG_EOF, &server_input_eof); | |
1252 | dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data); | |
1253 | dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size); | |
1254 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); | |
1255 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); | |
1256 | dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); | |
1257 | dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1258 | dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
1259 | dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); | |
1260 | } | |
1261 | static void | |
1262 | server_init_dispatch_15(void) | |
1263 | { | |
1264 | server_init_dispatch_13(); | |
1265 | debug("server_init_dispatch_15"); | |
1266 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); | |
1267 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose); | |
1268 | } | |
1269 | static void | |
1270 | server_init_dispatch(void) | |
1271 | { | |
1272 | if (compat20) | |
1273 | server_init_dispatch_20(); | |
1274 | else if (compat13) | |
1275 | server_init_dispatch_13(); | |
1276 | else | |
1277 | server_init_dispatch_15(); | |
1278 | } |