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9108f8d9 | 1 | /* $OpenBSD: serverloop.c,v 1.144 2006/08/03 03:34:42 deraadt 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. */ | |
107 | static int client_alive_timeouts = 0; | |
108 | ||
109 | /* | |
110 | * This SIGCHLD kludge is used to detect when the child exits. The server | |
111 | * will exit after that, as soon as forwarded connections have terminated. | |
112 | */ | |
113 | ||
e9a17296 | 114 | static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */ |
3c0ef626 | 115 | |
2c06c99b | 116 | /* Cleanup on signals (!use_privsep case only) */ |
117 | static volatile sig_atomic_t received_sigterm = 0; | |
118 | ||
3c0ef626 | 119 | /* prototypes */ |
120 | static void server_init_dispatch(void); | |
121 | ||
e9a17296 | 122 | /* |
123 | * we write to this pipe if a SIGCHLD is caught in order to avoid | |
124 | * the race between select() and child_terminated | |
125 | */ | |
126 | static int notify_pipe[2]; | |
127 | static void | |
128 | notify_setup(void) | |
129 | { | |
130 | if (pipe(notify_pipe) < 0) { | |
131 | error("pipe(notify_pipe) failed %s", strerror(errno)); | |
132 | } else if ((fcntl(notify_pipe[0], F_SETFD, 1) == -1) || | |
133 | (fcntl(notify_pipe[1], F_SETFD, 1) == -1)) { | |
134 | error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno)); | |
135 | close(notify_pipe[0]); | |
136 | close(notify_pipe[1]); | |
137 | } else { | |
138 | set_nonblock(notify_pipe[0]); | |
139 | set_nonblock(notify_pipe[1]); | |
140 | return; | |
141 | } | |
142 | notify_pipe[0] = -1; /* read end */ | |
143 | notify_pipe[1] = -1; /* write end */ | |
144 | } | |
145 | static void | |
146 | notify_parent(void) | |
147 | { | |
148 | if (notify_pipe[1] != -1) | |
149 | write(notify_pipe[1], "", 1); | |
150 | } | |
151 | static void | |
152 | notify_prepare(fd_set *readset) | |
153 | { | |
154 | if (notify_pipe[0] != -1) | |
155 | FD_SET(notify_pipe[0], readset); | |
156 | } | |
157 | static void | |
158 | notify_done(fd_set *readset) | |
159 | { | |
160 | char c; | |
161 | ||
162 | if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset)) | |
163 | while (read(notify_pipe[0], &c, 1) != -1) | |
164 | debug2("notify_done: reading"); | |
165 | } | |
166 | ||
9108f8d9 | 167 | /*ARGSUSED*/ |
3c0ef626 | 168 | static void |
169 | sigchld_handler(int sig) | |
170 | { | |
171 | int save_errno = errno; | |
3c0ef626 | 172 | child_terminated = 1; |
41b2f314 | 173 | #ifndef _UNICOS |
3c0ef626 | 174 | mysignal(SIGCHLD, sigchld_handler); |
41b2f314 | 175 | #endif |
e9a17296 | 176 | notify_parent(); |
3c0ef626 | 177 | errno = save_errno; |
178 | } | |
179 | ||
9108f8d9 | 180 | /*ARGSUSED*/ |
2c06c99b | 181 | static void |
182 | sigterm_handler(int sig) | |
183 | { | |
184 | received_sigterm = sig; | |
185 | } | |
186 | ||
3c0ef626 | 187 | /* |
188 | * Make packets from buffered stderr data, and buffer it for sending | |
189 | * to the client. | |
190 | */ | |
191 | static void | |
192 | make_packets_from_stderr_data(void) | |
193 | { | |
0fff78ff | 194 | u_int len; |
3c0ef626 | 195 | |
196 | /* Send buffered stderr data to the client. */ | |
197 | while (buffer_len(&stderr_buffer) > 0 && | |
198 | packet_not_very_much_data_to_write()) { | |
199 | len = buffer_len(&stderr_buffer); | |
200 | if (packet_is_interactive()) { | |
201 | if (len > 512) | |
202 | len = 512; | |
203 | } else { | |
204 | /* Keep the packets at reasonable size. */ | |
205 | if (len > packet_get_maxsize()) | |
206 | len = packet_get_maxsize(); | |
207 | } | |
208 | packet_start(SSH_SMSG_STDERR_DATA); | |
209 | packet_put_string(buffer_ptr(&stderr_buffer), len); | |
210 | packet_send(); | |
211 | buffer_consume(&stderr_buffer, len); | |
212 | stderr_bytes += len; | |
213 | } | |
214 | } | |
215 | ||
216 | /* | |
217 | * Make packets from buffered stdout data, and buffer it for sending to the | |
218 | * client. | |
219 | */ | |
220 | static void | |
221 | make_packets_from_stdout_data(void) | |
222 | { | |
0fff78ff | 223 | u_int len; |
3c0ef626 | 224 | |
225 | /* Send buffered stdout data to the client. */ | |
226 | while (buffer_len(&stdout_buffer) > 0 && | |
227 | packet_not_very_much_data_to_write()) { | |
228 | len = buffer_len(&stdout_buffer); | |
229 | if (packet_is_interactive()) { | |
230 | if (len > 512) | |
231 | len = 512; | |
232 | } else { | |
233 | /* Keep the packets at reasonable size. */ | |
234 | if (len > packet_get_maxsize()) | |
235 | len = packet_get_maxsize(); | |
236 | } | |
237 | packet_start(SSH_SMSG_STDOUT_DATA); | |
238 | packet_put_string(buffer_ptr(&stdout_buffer), len); | |
239 | packet_send(); | |
240 | buffer_consume(&stdout_buffer, len); | |
241 | stdout_bytes += len; | |
242 | } | |
243 | } | |
244 | ||
245 | static void | |
246 | client_alive_check(void) | |
247 | { | |
cdd66111 | 248 | int channel_id; |
e9a17296 | 249 | |
3c0ef626 | 250 | /* timeout, check to see how many we have had */ |
251 | if (++client_alive_timeouts > options.client_alive_count_max) | |
252 | packet_disconnect("Timeout, your session not responding."); | |
253 | ||
3c0ef626 | 254 | /* |
cdd66111 | 255 | * send a bogus global/channel request with "wantreply", |
3c0ef626 | 256 | * we should get back a failure |
257 | */ | |
cdd66111 | 258 | if ((channel_id = channel_find_open()) == -1) { |
259 | packet_start(SSH2_MSG_GLOBAL_REQUEST); | |
260 | packet_put_cstring("keepalive@openssh.com"); | |
261 | packet_put_char(1); /* boolean: want reply */ | |
262 | } else { | |
263 | channel_request_start(channel_id, "keepalive@openssh.com", 1); | |
264 | } | |
3c0ef626 | 265 | packet_send(); |
266 | } | |
267 | ||
268 | /* | |
269 | * Sleep in select() until we can do something. This will initialize the | |
270 | * select masks. Upon return, the masks will indicate which descriptors | |
271 | * have data or can accept data. Optionally, a maximum time can be specified | |
272 | * for the duration of the wait (0 = infinite). | |
273 | */ | |
274 | static void | |
275 | wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp, | |
c9f39d2c | 276 | u_int *nallocp, u_int max_time_milliseconds) |
3c0ef626 | 277 | { |
278 | struct timeval tv, *tvp; | |
279 | int ret; | |
280 | int client_alive_scheduled = 0; | |
281 | ||
282 | /* | |
e9a17296 | 283 | * if using client_alive, set the max timeout accordingly, |
3c0ef626 | 284 | * and indicate that this particular timeout was for client |
285 | * alive by setting the client_alive_scheduled flag. | |
286 | * | |
287 | * this could be randomized somewhat to make traffic | |
e9a17296 | 288 | * analysis more difficult, but we're not doing it yet. |
3c0ef626 | 289 | */ |
290 | if (compat20 && | |
291 | max_time_milliseconds == 0 && options.client_alive_interval) { | |
292 | client_alive_scheduled = 1; | |
293 | max_time_milliseconds = options.client_alive_interval * 1000; | |
294 | } | |
295 | ||
296 | /* Allocate and update select() masks for channel descriptors. */ | |
297 | channel_prepare_select(readsetp, writesetp, maxfdp, nallocp, 0); | |
298 | ||
299 | if (compat20) { | |
300 | #if 0 | |
301 | /* wrong: bad condition XXX */ | |
302 | if (channel_not_very_much_buffered_data()) | |
303 | #endif | |
304 | FD_SET(connection_in, *readsetp); | |
305 | } else { | |
306 | /* | |
307 | * Read packets from the client unless we have too much | |
308 | * buffered stdin or channel data. | |
309 | */ | |
310 | if (buffer_len(&stdin_buffer) < buffer_high && | |
311 | channel_not_very_much_buffered_data()) | |
312 | FD_SET(connection_in, *readsetp); | |
313 | /* | |
314 | * If there is not too much data already buffered going to | |
315 | * the client, try to get some more data from the program. | |
316 | */ | |
317 | if (packet_not_very_much_data_to_write()) { | |
318 | if (!fdout_eof) | |
319 | FD_SET(fdout, *readsetp); | |
320 | if (!fderr_eof) | |
321 | FD_SET(fderr, *readsetp); | |
322 | } | |
323 | /* | |
324 | * If we have buffered data, try to write some of that data | |
325 | * to the program. | |
326 | */ | |
327 | if (fdin != -1 && buffer_len(&stdin_buffer) > 0) | |
328 | FD_SET(fdin, *writesetp); | |
329 | } | |
e9a17296 | 330 | notify_prepare(*readsetp); |
3c0ef626 | 331 | |
332 | /* | |
333 | * If we have buffered packet data going to the client, mark that | |
334 | * descriptor. | |
335 | */ | |
336 | if (packet_have_data_to_write()) | |
337 | FD_SET(connection_out, *writesetp); | |
338 | ||
339 | /* | |
340 | * If child has terminated and there is enough buffer space to read | |
341 | * from it, then read as much as is available and exit. | |
342 | */ | |
343 | if (child_terminated && packet_not_very_much_data_to_write()) | |
344 | if (max_time_milliseconds == 0 || client_alive_scheduled) | |
345 | max_time_milliseconds = 100; | |
346 | ||
347 | if (max_time_milliseconds == 0) | |
348 | tvp = NULL; | |
349 | else { | |
350 | tv.tv_sec = max_time_milliseconds / 1000; | |
351 | tv.tv_usec = 1000 * (max_time_milliseconds % 1000); | |
352 | tvp = &tv; | |
353 | } | |
3c0ef626 | 354 | |
355 | /* Wait for something to happen, or the timeout to expire. */ | |
356 | ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp); | |
357 | ||
358 | if (ret == -1) { | |
359 | memset(*readsetp, 0, *nallocp); | |
360 | memset(*writesetp, 0, *nallocp); | |
361 | if (errno != EINTR) | |
362 | error("select: %.100s", strerror(errno)); | |
363 | } else if (ret == 0 && client_alive_scheduled) | |
364 | client_alive_check(); | |
e9a17296 | 365 | |
366 | notify_done(*readsetp); | |
3c0ef626 | 367 | } |
368 | ||
369 | /* | |
370 | * Processes input from the client and the program. Input data is stored | |
371 | * in buffers and processed later. | |
372 | */ | |
373 | static void | |
9108f8d9 | 374 | process_input(fd_set *readset) |
3c0ef626 | 375 | { |
376 | int len; | |
377 | char buf[16384]; | |
378 | ||
379 | /* Read and buffer any input data from the client. */ | |
380 | if (FD_ISSET(connection_in, readset)) { | |
381 | len = read(connection_in, buf, sizeof(buf)); | |
382 | if (len == 0) { | |
41b2f314 | 383 | verbose("Connection closed by %.100s", |
384 | get_remote_ipaddr()); | |
3c0ef626 | 385 | connection_closed = 1; |
386 | if (compat20) | |
387 | return; | |
cdd66111 | 388 | cleanup_exit(255); |
3c0ef626 | 389 | } else if (len < 0) { |
390 | if (errno != EINTR && errno != EAGAIN) { | |
41b2f314 | 391 | verbose("Read error from remote host " |
392 | "%.100s: %.100s", | |
393 | get_remote_ipaddr(), strerror(errno)); | |
cdd66111 | 394 | cleanup_exit(255); |
3c0ef626 | 395 | } |
396 | } else { | |
397 | /* Buffer any received data. */ | |
398 | packet_process_incoming(buf, len); | |
399 | } | |
400 | } | |
401 | if (compat20) | |
402 | return; | |
403 | ||
404 | /* Read and buffer any available stdout data from the program. */ | |
405 | if (!fdout_eof && FD_ISSET(fdout, readset)) { | |
9108f8d9 | 406 | errno = 0; |
3c0ef626 | 407 | len = read(fdout, buf, sizeof(buf)); |
408 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) { | |
409 | /* do nothing */ | |
9108f8d9 | 410 | #ifndef PTY_ZEROREAD |
3c0ef626 | 411 | } else if (len <= 0) { |
9108f8d9 | 412 | #else |
413 | } else if ((!isatty(fdout) && len <= 0) || | |
414 | (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) { | |
415 | #endif | |
3c0ef626 | 416 | fdout_eof = 1; |
417 | } else { | |
418 | buffer_append(&stdout_buffer, buf, len); | |
419 | fdout_bytes += len; | |
420 | } | |
421 | } | |
422 | /* Read and buffer any available stderr data from the program. */ | |
423 | if (!fderr_eof && FD_ISSET(fderr, readset)) { | |
9108f8d9 | 424 | errno = 0; |
3c0ef626 | 425 | len = read(fderr, buf, sizeof(buf)); |
426 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) { | |
427 | /* do nothing */ | |
9108f8d9 | 428 | #ifndef PTY_ZEROREAD |
3c0ef626 | 429 | } else if (len <= 0) { |
9108f8d9 | 430 | #else |
431 | } else if ((!isatty(fderr) && len <= 0) || | |
432 | (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) { | |
433 | #endif | |
3c0ef626 | 434 | fderr_eof = 1; |
435 | } else { | |
436 | buffer_append(&stderr_buffer, buf, len); | |
437 | } | |
438 | } | |
439 | } | |
440 | ||
441 | /* | |
442 | * Sends data from internal buffers to client program stdin. | |
443 | */ | |
444 | static void | |
9108f8d9 | 445 | process_output(fd_set *writeset) |
3c0ef626 | 446 | { |
447 | struct termios tio; | |
448 | u_char *data; | |
449 | u_int dlen; | |
450 | int len; | |
451 | ||
452 | /* Write buffered data to program stdin. */ | |
453 | if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) { | |
454 | data = buffer_ptr(&stdin_buffer); | |
455 | dlen = buffer_len(&stdin_buffer); | |
456 | len = write(fdin, data, dlen); | |
457 | if (len < 0 && (errno == EINTR || errno == EAGAIN)) { | |
458 | /* do nothing */ | |
459 | } else if (len <= 0) { | |
3c0ef626 | 460 | if (fdin != fdout) |
461 | close(fdin); | |
462 | else | |
463 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
3c0ef626 | 464 | fdin = -1; |
465 | } else { | |
466 | /* Successful write. */ | |
467 | if (fdin_is_tty && dlen >= 1 && data[0] != '\r' && | |
468 | tcgetattr(fdin, &tio) == 0 && | |
469 | !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) { | |
470 | /* | |
471 | * Simulate echo to reduce the impact of | |
472 | * traffic analysis | |
473 | */ | |
474 | packet_send_ignore(len); | |
475 | packet_send(); | |
476 | } | |
477 | /* Consume the data from the buffer. */ | |
478 | buffer_consume(&stdin_buffer, len); | |
479 | /* Update the count of bytes written to the program. */ | |
480 | stdin_bytes += len; | |
481 | } | |
482 | } | |
483 | /* Send any buffered packet data to the client. */ | |
484 | if (FD_ISSET(connection_out, writeset)) | |
485 | packet_write_poll(); | |
486 | } | |
487 | ||
488 | /* | |
489 | * Wait until all buffered output has been sent to the client. | |
490 | * This is used when the program terminates. | |
491 | */ | |
492 | static void | |
493 | drain_output(void) | |
494 | { | |
495 | /* Send any buffered stdout data to the client. */ | |
496 | if (buffer_len(&stdout_buffer) > 0) { | |
497 | packet_start(SSH_SMSG_STDOUT_DATA); | |
498 | packet_put_string(buffer_ptr(&stdout_buffer), | |
499 | buffer_len(&stdout_buffer)); | |
500 | packet_send(); | |
501 | /* Update the count of sent bytes. */ | |
502 | stdout_bytes += buffer_len(&stdout_buffer); | |
503 | } | |
504 | /* Send any buffered stderr data to the client. */ | |
505 | if (buffer_len(&stderr_buffer) > 0) { | |
506 | packet_start(SSH_SMSG_STDERR_DATA); | |
507 | packet_put_string(buffer_ptr(&stderr_buffer), | |
508 | buffer_len(&stderr_buffer)); | |
509 | packet_send(); | |
510 | /* Update the count of sent bytes. */ | |
511 | stderr_bytes += buffer_len(&stderr_buffer); | |
512 | } | |
513 | /* Wait until all buffered data has been written to the client. */ | |
514 | packet_write_wait(); | |
515 | } | |
516 | ||
517 | static void | |
518 | process_buffered_input_packets(void) | |
519 | { | |
520 | dispatch_run(DISPATCH_NONBLOCK, NULL, compat20 ? xxx_kex : NULL); | |
521 | } | |
522 | ||
523 | /* | |
524 | * Performs the interactive session. This handles data transmission between | |
525 | * the client and the program. Note that the notion of stdin, stdout, and | |
526 | * stderr in this function is sort of reversed: this function writes to | |
527 | * stdin (of the child program), and reads from stdout and stderr (of the | |
528 | * child program). | |
529 | */ | |
530 | void | |
531 | server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg) | |
532 | { | |
533 | fd_set *readset = NULL, *writeset = NULL; | |
c9f39d2c | 534 | int max_fd = 0; |
535 | u_int nalloc = 0; | |
3c0ef626 | 536 | int wait_status; /* Status returned by wait(). */ |
537 | pid_t wait_pid; /* pid returned by wait(). */ | |
538 | int waiting_termination = 0; /* Have displayed waiting close message. */ | |
539 | u_int max_time_milliseconds; | |
540 | u_int previous_stdout_buffer_bytes; | |
541 | u_int stdout_buffer_bytes; | |
542 | int type; | |
543 | ||
544 | debug("Entering interactive session."); | |
545 | ||
546 | /* Initialize the SIGCHLD kludge. */ | |
547 | child_terminated = 0; | |
548 | mysignal(SIGCHLD, sigchld_handler); | |
549 | ||
2c06c99b | 550 | if (!use_privsep) { |
551 | signal(SIGTERM, sigterm_handler); | |
552 | signal(SIGINT, sigterm_handler); | |
553 | signal(SIGQUIT, sigterm_handler); | |
554 | } | |
555 | ||
3c0ef626 | 556 | /* Initialize our global variables. */ |
557 | fdin = fdin_arg; | |
558 | fdout = fdout_arg; | |
559 | fderr = fderr_arg; | |
560 | ||
561 | /* nonblocking IO */ | |
562 | set_nonblock(fdin); | |
563 | set_nonblock(fdout); | |
564 | /* we don't have stderr for interactive terminal sessions, see below */ | |
565 | if (fderr != -1) | |
566 | set_nonblock(fderr); | |
567 | ||
568 | if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin)) | |
569 | fdin_is_tty = 1; | |
570 | ||
571 | connection_in = packet_get_connection_in(); | |
572 | connection_out = packet_get_connection_out(); | |
573 | ||
e9a17296 | 574 | notify_setup(); |
575 | ||
3c0ef626 | 576 | previous_stdout_buffer_bytes = 0; |
577 | ||
578 | /* Set approximate I/O buffer size. */ | |
579 | if (packet_is_interactive()) | |
580 | buffer_high = 4096; | |
581 | else | |
582 | buffer_high = 64 * 1024; | |
583 | ||
584 | #if 0 | |
585 | /* Initialize max_fd to the maximum of the known file descriptors. */ | |
586 | max_fd = MAX(connection_in, connection_out); | |
587 | max_fd = MAX(max_fd, fdin); | |
588 | max_fd = MAX(max_fd, fdout); | |
589 | if (fderr != -1) | |
590 | max_fd = MAX(max_fd, fderr); | |
591 | #endif | |
592 | ||
593 | /* Initialize Initialize buffers. */ | |
594 | buffer_init(&stdin_buffer); | |
595 | buffer_init(&stdout_buffer); | |
596 | buffer_init(&stderr_buffer); | |
597 | ||
598 | /* | |
599 | * If we have no separate fderr (which is the case when we have a pty | |
600 | * - there we cannot make difference between data sent to stdout and | |
601 | * stderr), indicate that we have seen an EOF from stderr. This way | |
2c06c99b | 602 | * we don't need to check the descriptor everywhere. |
3c0ef626 | 603 | */ |
604 | if (fderr == -1) | |
605 | fderr_eof = 1; | |
606 | ||
607 | server_init_dispatch(); | |
608 | ||
609 | /* Main loop of the server for the interactive session mode. */ | |
610 | for (;;) { | |
611 | ||
612 | /* Process buffered packets from the client. */ | |
613 | process_buffered_input_packets(); | |
614 | ||
615 | /* | |
616 | * If we have received eof, and there is no more pending | |
617 | * input data, cause a real eof by closing fdin. | |
618 | */ | |
619 | if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) { | |
3c0ef626 | 620 | if (fdin != fdout) |
621 | close(fdin); | |
622 | else | |
623 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
3c0ef626 | 624 | fdin = -1; |
625 | } | |
626 | /* Make packets from buffered stderr data to send to the client. */ | |
627 | make_packets_from_stderr_data(); | |
628 | ||
629 | /* | |
630 | * Make packets from buffered stdout data to send to the | |
631 | * client. If there is very little to send, this arranges to | |
632 | * not send them now, but to wait a short while to see if we | |
633 | * are getting more data. This is necessary, as some systems | |
634 | * wake up readers from a pty after each separate character. | |
635 | */ | |
636 | max_time_milliseconds = 0; | |
637 | stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
638 | if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && | |
639 | stdout_buffer_bytes != previous_stdout_buffer_bytes) { | |
640 | /* try again after a while */ | |
641 | max_time_milliseconds = 10; | |
642 | } else { | |
643 | /* Send it now. */ | |
644 | make_packets_from_stdout_data(); | |
645 | } | |
646 | previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
647 | ||
648 | /* Send channel data to the client. */ | |
649 | if (packet_not_very_much_data_to_write()) | |
650 | channel_output_poll(); | |
651 | ||
652 | /* | |
653 | * Bail out of the loop if the program has closed its output | |
654 | * descriptors, and we have no more data to send to the | |
655 | * client, and there is no pending buffered data. | |
656 | */ | |
657 | if (fdout_eof && fderr_eof && !packet_have_data_to_write() && | |
658 | buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { | |
659 | if (!channel_still_open()) | |
660 | break; | |
661 | if (!waiting_termination) { | |
662 | const char *s = "Waiting for forwarded connections to terminate...\r\n"; | |
663 | char *cp; | |
664 | waiting_termination = 1; | |
665 | buffer_append(&stderr_buffer, s, strlen(s)); | |
666 | ||
667 | /* Display list of open channels. */ | |
668 | cp = channel_open_message(); | |
669 | buffer_append(&stderr_buffer, cp, strlen(cp)); | |
670 | xfree(cp); | |
671 | } | |
672 | } | |
673 | max_fd = MAX(connection_in, connection_out); | |
674 | max_fd = MAX(max_fd, fdin); | |
675 | max_fd = MAX(max_fd, fdout); | |
676 | max_fd = MAX(max_fd, fderr); | |
e9a17296 | 677 | max_fd = MAX(max_fd, notify_pipe[0]); |
3c0ef626 | 678 | |
679 | /* Sleep in select() until we can do something. */ | |
680 | wait_until_can_do_something(&readset, &writeset, &max_fd, | |
681 | &nalloc, max_time_milliseconds); | |
682 | ||
2c06c99b | 683 | if (received_sigterm) { |
684 | logit("Exiting on signal %d", received_sigterm); | |
685 | /* Clean up sessions, utmp, etc. */ | |
686 | cleanup_exit(255); | |
687 | } | |
688 | ||
3c0ef626 | 689 | /* Process any channel events. */ |
690 | channel_after_select(readset, writeset); | |
691 | ||
692 | /* Process input from the client and from program stdout/stderr. */ | |
693 | process_input(readset); | |
694 | ||
695 | /* Process output to the client and to program stdin. */ | |
696 | process_output(writeset); | |
697 | } | |
698 | if (readset) | |
699 | xfree(readset); | |
700 | if (writeset) | |
701 | xfree(writeset); | |
702 | ||
703 | /* Cleanup and termination code. */ | |
704 | ||
705 | /* Wait until all output has been sent to the client. */ | |
706 | drain_output(); | |
707 | ||
708 | debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", | |
e9a17296 | 709 | stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); |
3c0ef626 | 710 | |
711 | /* Free and clear the buffers. */ | |
712 | buffer_free(&stdin_buffer); | |
713 | buffer_free(&stdout_buffer); | |
714 | buffer_free(&stderr_buffer); | |
715 | ||
716 | /* Close the file descriptors. */ | |
717 | if (fdout != -1) | |
718 | close(fdout); | |
719 | fdout = -1; | |
720 | fdout_eof = 1; | |
721 | if (fderr != -1) | |
722 | close(fderr); | |
723 | fderr = -1; | |
724 | fderr_eof = 1; | |
725 | if (fdin != -1) | |
726 | close(fdin); | |
727 | fdin = -1; | |
728 | ||
729 | channel_free_all(); | |
730 | ||
731 | /* We no longer want our SIGCHLD handler to be called. */ | |
732 | mysignal(SIGCHLD, SIG_DFL); | |
733 | ||
700318f3 | 734 | while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0) |
735 | if (errno != EINTR) | |
736 | packet_disconnect("wait: %.100s", strerror(errno)); | |
737 | if (wait_pid != pid) | |
f5799ae1 | 738 | error("Strange, wait returned pid %ld, expected %ld", |
739 | (long)wait_pid, (long)pid); | |
3c0ef626 | 740 | |
741 | /* Check if it exited normally. */ | |
742 | if (WIFEXITED(wait_status)) { | |
743 | /* Yes, normal exit. Get exit status and send it to the client. */ | |
744 | debug("Command exited with status %d.", WEXITSTATUS(wait_status)); | |
745 | packet_start(SSH_SMSG_EXITSTATUS); | |
746 | packet_put_int(WEXITSTATUS(wait_status)); | |
747 | packet_send(); | |
748 | packet_write_wait(); | |
749 | ||
750 | /* | |
751 | * Wait for exit confirmation. Note that there might be | |
752 | * other packets coming before it; however, the program has | |
753 | * already died so we just ignore them. The client is | |
754 | * supposed to respond with the confirmation when it receives | |
755 | * the exit status. | |
756 | */ | |
757 | do { | |
e9a17296 | 758 | type = packet_read(); |
3c0ef626 | 759 | } |
760 | while (type != SSH_CMSG_EXIT_CONFIRMATION); | |
761 | ||
762 | debug("Received exit confirmation."); | |
763 | return; | |
764 | } | |
765 | /* Check if the program terminated due to a signal. */ | |
766 | if (WIFSIGNALED(wait_status)) | |
767 | packet_disconnect("Command terminated on signal %d.", | |
768 | WTERMSIG(wait_status)); | |
769 | ||
770 | /* Some weird exit cause. Just exit. */ | |
771 | packet_disconnect("wait returned status %04x.", wait_status); | |
772 | /* NOTREACHED */ | |
773 | } | |
774 | ||
775 | static void | |
776 | collect_children(void) | |
777 | { | |
778 | pid_t pid; | |
779 | sigset_t oset, nset; | |
780 | int status; | |
781 | ||
782 | /* block SIGCHLD while we check for dead children */ | |
783 | sigemptyset(&nset); | |
784 | sigaddset(&nset, SIGCHLD); | |
785 | sigprocmask(SIG_BLOCK, &nset, &oset); | |
786 | if (child_terminated) { | |
9108f8d9 | 787 | debug("Received SIGCHLD."); |
700318f3 | 788 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
789 | (pid < 0 && errno == EINTR)) | |
790 | if (pid > 0) | |
791 | session_close_by_pid(pid, status); | |
3c0ef626 | 792 | child_terminated = 0; |
793 | } | |
794 | sigprocmask(SIG_SETMASK, &oset, NULL); | |
795 | } | |
796 | ||
797 | void | |
798 | server_loop2(Authctxt *authctxt) | |
799 | { | |
800 | fd_set *readset = NULL, *writeset = NULL; | |
801 | int rekeying = 0, max_fd, nalloc = 0; | |
802 | ||
803 | debug("Entering interactive session for SSH2."); | |
804 | ||
805 | mysignal(SIGCHLD, sigchld_handler); | |
806 | child_terminated = 0; | |
807 | connection_in = packet_get_connection_in(); | |
808 | connection_out = packet_get_connection_out(); | |
809 | ||
2c06c99b | 810 | if (!use_privsep) { |
811 | signal(SIGTERM, sigterm_handler); | |
812 | signal(SIGINT, sigterm_handler); | |
813 | signal(SIGQUIT, sigterm_handler); | |
814 | } | |
815 | ||
e9a17296 | 816 | notify_setup(); |
817 | ||
3c0ef626 | 818 | max_fd = MAX(connection_in, connection_out); |
e9a17296 | 819 | max_fd = MAX(max_fd, notify_pipe[0]); |
820 | ||
3c0ef626 | 821 | server_init_dispatch(); |
822 | ||
823 | for (;;) { | |
824 | process_buffered_input_packets(); | |
825 | ||
826 | rekeying = (xxx_kex != NULL && !xxx_kex->done); | |
827 | ||
828 | if (!rekeying && packet_not_very_much_data_to_write()) | |
829 | channel_output_poll(); | |
830 | wait_until_can_do_something(&readset, &writeset, &max_fd, | |
831 | &nalloc, 0); | |
832 | ||
2c06c99b | 833 | if (received_sigterm) { |
834 | logit("Exiting on signal %d", received_sigterm); | |
835 | /* Clean up sessions, utmp, etc. */ | |
836 | cleanup_exit(255); | |
837 | } | |
838 | ||
3c0ef626 | 839 | collect_children(); |
0fff78ff | 840 | if (!rekeying) { |
3c0ef626 | 841 | channel_after_select(readset, writeset); |
0fff78ff | 842 | if (packet_need_rekeying()) { |
843 | debug("need rekeying"); | |
844 | xxx_kex->done = 0; | |
845 | kex_send_kexinit(xxx_kex); | |
846 | } | |
847 | } | |
3c0ef626 | 848 | process_input(readset); |
849 | if (connection_closed) | |
850 | break; | |
851 | process_output(writeset); | |
852 | } | |
853 | collect_children(); | |
854 | ||
855 | if (readset) | |
856 | xfree(readset); | |
857 | if (writeset) | |
858 | xfree(writeset); | |
859 | ||
860 | /* free all channels, no more reads and writes */ | |
861 | channel_free_all(); | |
862 | ||
863 | /* free remaining sessions, e.g. remove wtmp entries */ | |
700318f3 | 864 | session_destroy_all(NULL); |
3c0ef626 | 865 | } |
866 | ||
867 | static void | |
cdd66111 | 868 | server_input_keep_alive(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 869 | { |
cdd66111 | 870 | debug("Got %d/%u for keepalive", type, seq); |
e9a17296 | 871 | /* |
3c0ef626 | 872 | * reset timeout, since we got a sane answer from the client. |
873 | * even if this was generated by something other than | |
874 | * the bogus CHANNEL_REQUEST we send for keepalives. | |
875 | */ | |
e9a17296 | 876 | client_alive_timeouts = 0; |
3c0ef626 | 877 | } |
878 | ||
3c0ef626 | 879 | static void |
e9a17296 | 880 | server_input_stdin_data(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 881 | { |
882 | char *data; | |
883 | u_int data_len; | |
884 | ||
885 | /* Stdin data from the client. Append it to the buffer. */ | |
886 | /* Ignore any data if the client has closed stdin. */ | |
887 | if (fdin == -1) | |
888 | return; | |
889 | data = packet_get_string(&data_len); | |
e9a17296 | 890 | packet_check_eom(); |
3c0ef626 | 891 | buffer_append(&stdin_buffer, data, data_len); |
892 | memset(data, 0, data_len); | |
893 | xfree(data); | |
894 | } | |
895 | ||
896 | static void | |
e9a17296 | 897 | server_input_eof(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 898 | { |
899 | /* | |
900 | * Eof from the client. The stdin descriptor to the | |
901 | * program will be closed when all buffered data has | |
902 | * drained. | |
903 | */ | |
904 | debug("EOF received for stdin."); | |
e9a17296 | 905 | packet_check_eom(); |
3c0ef626 | 906 | stdin_eof = 1; |
907 | } | |
908 | ||
909 | static void | |
e9a17296 | 910 | server_input_window_size(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 911 | { |
9108f8d9 | 912 | u_int row = packet_get_int(); |
913 | u_int col = packet_get_int(); | |
914 | u_int xpixel = packet_get_int(); | |
915 | u_int ypixel = packet_get_int(); | |
3c0ef626 | 916 | |
917 | debug("Window change received."); | |
e9a17296 | 918 | packet_check_eom(); |
3c0ef626 | 919 | if (fdin != -1) |
920 | pty_change_window_size(fdin, row, col, xpixel, ypixel); | |
921 | } | |
922 | ||
923 | static Channel * | |
cdd66111 | 924 | server_request_direct_tcpip(void) |
3c0ef626 | 925 | { |
926 | Channel *c; | |
927 | int sock; | |
928 | char *target, *originator; | |
929 | int target_port, originator_port; | |
930 | ||
931 | target = packet_get_string(NULL); | |
932 | target_port = packet_get_int(); | |
933 | originator = packet_get_string(NULL); | |
934 | originator_port = packet_get_int(); | |
e9a17296 | 935 | packet_check_eom(); |
3c0ef626 | 936 | |
937 | debug("server_request_direct_tcpip: originator %s port %d, target %s port %d", | |
665a873d | 938 | originator, originator_port, target, target_port); |
3c0ef626 | 939 | |
940 | /* XXX check permission */ | |
941 | sock = channel_connect_to(target, target_port); | |
942 | xfree(target); | |
943 | xfree(originator); | |
944 | if (sock < 0) | |
945 | return NULL; | |
bed7ee6f | 946 | if (options.hpn_disabled) |
947 | c = channel_new("direct-tcpip", SSH_CHANNEL_CONNECTING, | |
948 | sock, sock, -1, CHAN_TCP_WINDOW_DEFAULT, | |
949 | CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1); | |
950 | else | |
951 | c = channel_new("direct-tcpip", SSH_CHANNEL_CONNECTING, | |
952 | sock, sock, -1, options.hpn_buffer_size, | |
953 | CHAN_TCP_PACKET_DEFAULT, 0, "direct-tcpip", 1); | |
3c0ef626 | 954 | return c; |
955 | } | |
956 | ||
2c06c99b | 957 | static Channel * |
958 | server_request_tun(void) | |
959 | { | |
960 | Channel *c = NULL; | |
961 | int mode, tun; | |
962 | int sock; | |
963 | ||
964 | mode = packet_get_int(); | |
965 | switch (mode) { | |
966 | case SSH_TUNMODE_POINTOPOINT: | |
967 | case SSH_TUNMODE_ETHERNET: | |
968 | break; | |
969 | default: | |
970 | packet_send_debug("Unsupported tunnel device mode."); | |
971 | return NULL; | |
972 | } | |
973 | if ((options.permit_tun & mode) == 0) { | |
974 | packet_send_debug("Server has rejected tunnel device " | |
975 | "forwarding"); | |
976 | return NULL; | |
977 | } | |
978 | ||
979 | tun = packet_get_int(); | |
980 | if (forced_tun_device != -1) { | |
9108f8d9 | 981 | if (tun != SSH_TUNID_ANY && forced_tun_device != tun) |
2c06c99b | 982 | goto done; |
983 | tun = forced_tun_device; | |
984 | } | |
985 | sock = tun_open(tun, mode); | |
986 | if (sock < 0) | |
987 | goto done; | |
bed7ee6f | 988 | if (options.hpn_disabled) |
989 | c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1, | |
990 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); | |
991 | else | |
992 | c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1, | |
993 | options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1); | |
2c06c99b | 994 | c->datagram = 1; |
995 | #if defined(SSH_TUN_FILTER) | |
996 | if (mode == SSH_TUNMODE_POINTOPOINT) | |
997 | channel_register_filter(c->self, sys_tun_infilter, | |
998 | sys_tun_outfilter); | |
999 | #endif | |
1000 | ||
1001 | done: | |
1002 | if (c == NULL) | |
1003 | packet_send_debug("Failed to open the tunnel device."); | |
1004 | return c; | |
1005 | } | |
1006 | ||
3c0ef626 | 1007 | static Channel * |
cdd66111 | 1008 | server_request_session(void) |
3c0ef626 | 1009 | { |
1010 | Channel *c; | |
1011 | ||
1012 | debug("input_session_request"); | |
e9a17296 | 1013 | packet_check_eom(); |
3c0ef626 | 1014 | /* |
1015 | * A server session has no fd to read or write until a | |
1016 | * CHANNEL_REQUEST for a shell is made, so we set the type to | |
1017 | * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all | |
1018 | * CHANNEL_REQUEST messages is registered. | |
1019 | */ | |
cdd66111 | 1020 | c = channel_new("session", SSH_CHANNEL_LARVAL, |
3c0ef626 | 1021 | -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT, |
0fff78ff | 1022 | 0, "server-session", 1); |
bed7ee6f | 1023 | if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) |
1024 | c->dynamic_window = 1; | |
cdd66111 | 1025 | if (session_open(the_authctxt, c->self) != 1) { |
3c0ef626 | 1026 | debug("session open failed, free channel %d", c->self); |
1027 | channel_free(c); | |
1028 | return NULL; | |
1029 | } | |
2c06c99b | 1030 | channel_register_cleanup(c->self, session_close_by_channel, 0); |
3c0ef626 | 1031 | return c; |
1032 | } | |
1033 | ||
1034 | static void | |
e9a17296 | 1035 | server_input_channel_open(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1036 | { |
1037 | Channel *c = NULL; | |
1038 | char *ctype; | |
3c0ef626 | 1039 | int rchan; |
680cee3b | 1040 | u_int rmaxpack, rwindow, len; |
3c0ef626 | 1041 | |
1042 | ctype = packet_get_string(&len); | |
1043 | rchan = packet_get_int(); | |
1044 | rwindow = packet_get_int(); | |
1045 | rmaxpack = packet_get_int(); | |
1046 | ||
1047 | debug("server_input_channel_open: ctype %s rchan %d win %d max %d", | |
1048 | ctype, rchan, rwindow, rmaxpack); | |
1049 | ||
1050 | if (strcmp(ctype, "session") == 0) { | |
cdd66111 | 1051 | c = server_request_session(); |
3c0ef626 | 1052 | } else if (strcmp(ctype, "direct-tcpip") == 0) { |
cdd66111 | 1053 | c = server_request_direct_tcpip(); |
2c06c99b | 1054 | } else if (strcmp(ctype, "tun@openssh.com") == 0) { |
1055 | c = server_request_tun(); | |
3c0ef626 | 1056 | } |
1057 | if (c != NULL) { | |
1058 | debug("server_input_channel_open: confirm %s", ctype); | |
1059 | c->remote_id = rchan; | |
1060 | c->remote_window = rwindow; | |
1061 | c->remote_maxpacket = rmaxpack; | |
1062 | if (c->type != SSH_CHANNEL_CONNECTING) { | |
1063 | packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION); | |
1064 | packet_put_int(c->remote_id); | |
1065 | packet_put_int(c->self); | |
1066 | packet_put_int(c->local_window); | |
1067 | packet_put_int(c->local_maxpacket); | |
1068 | packet_send(); | |
1069 | } | |
1070 | } else { | |
1071 | debug("server_input_channel_open: failure %s", ctype); | |
1072 | packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE); | |
1073 | packet_put_int(rchan); | |
1074 | packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED); | |
1075 | if (!(datafellows & SSH_BUG_OPENFAILURE)) { | |
1076 | packet_put_cstring("open failed"); | |
1077 | packet_put_cstring(""); | |
1078 | } | |
1079 | packet_send(); | |
1080 | } | |
1081 | xfree(ctype); | |
1082 | } | |
1083 | ||
1084 | static void | |
e9a17296 | 1085 | server_input_global_request(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1086 | { |
1087 | char *rtype; | |
1088 | int want_reply; | |
1089 | int success = 0; | |
1090 | ||
1091 | rtype = packet_get_string(NULL); | |
1092 | want_reply = packet_get_char(); | |
1093 | debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply); | |
1094 | ||
1095 | /* -R style forwarding */ | |
1096 | if (strcmp(rtype, "tcpip-forward") == 0) { | |
1097 | struct passwd *pw; | |
1098 | char *listen_address; | |
1099 | u_short listen_port; | |
1100 | ||
cdd66111 | 1101 | pw = the_authctxt->pw; |
1102 | if (pw == NULL || !the_authctxt->valid) | |
1103 | fatal("server_input_global_request: no/invalid user"); | |
0fff78ff | 1104 | listen_address = packet_get_string(NULL); |
3c0ef626 | 1105 | listen_port = (u_short)packet_get_int(); |
1106 | debug("server_input_global_request: tcpip-forward listen %s port %d", | |
1107 | listen_address, listen_port); | |
1108 | ||
1109 | /* check permissions */ | |
1110 | if (!options.allow_tcp_forwarding || | |
41b2f314 | 1111 | no_port_forwarding_flag |
1112 | #ifndef NO_IPPORT_RESERVED_CONCEPT | |
1113 | || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0) | |
1114 | #endif | |
665a873d | 1115 | ) { |
3c0ef626 | 1116 | success = 0; |
1117 | packet_send_debug("Server has disabled port forwarding."); | |
1118 | } else { | |
1119 | /* Start listening on the port */ | |
e9a17296 | 1120 | success = channel_setup_remote_fwd_listener( |
bed7ee6f | 1121 | listen_address, listen_port, options.gateway_ports, |
1122 | options.hpn_disabled, options.hpn_buffer_size); | |
3c0ef626 | 1123 | } |
1124 | xfree(listen_address); | |
c9f39d2c | 1125 | } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) { |
1126 | char *cancel_address; | |
1127 | u_short cancel_port; | |
1128 | ||
1129 | cancel_address = packet_get_string(NULL); | |
1130 | cancel_port = (u_short)packet_get_int(); | |
1131 | debug("%s: cancel-tcpip-forward addr %s port %d", __func__, | |
1132 | cancel_address, cancel_port); | |
1133 | ||
1134 | success = channel_cancel_rport_listener(cancel_address, | |
1135 | cancel_port); | |
9108f8d9 | 1136 | xfree(cancel_address); |
3c0ef626 | 1137 | } |
1138 | if (want_reply) { | |
1139 | packet_start(success ? | |
1140 | SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE); | |
1141 | packet_send(); | |
1142 | packet_write_wait(); | |
1143 | } | |
1144 | xfree(rtype); | |
1145 | } | |
9108f8d9 | 1146 | |
e9a17296 | 1147 | static void |
1148 | server_input_channel_req(int type, u_int32_t seq, void *ctxt) | |
1149 | { | |
1150 | Channel *c; | |
1151 | int id, reply, success = 0; | |
1152 | char *rtype; | |
1153 | ||
1154 | id = packet_get_int(); | |
1155 | rtype = packet_get_string(NULL); | |
1156 | reply = packet_get_char(); | |
1157 | ||
1158 | debug("server_input_channel_req: channel %d request %s reply %d", | |
1159 | id, rtype, reply); | |
1160 | ||
1161 | if ((c = channel_lookup(id)) == NULL) | |
1162 | packet_disconnect("server_input_channel_req: " | |
1163 | "unknown channel %d", id); | |
1164 | if (c->type == SSH_CHANNEL_LARVAL || c->type == SSH_CHANNEL_OPEN) | |
1165 | success = session_input_channel_req(c, rtype); | |
1166 | if (reply) { | |
1167 | packet_start(success ? | |
1168 | SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); | |
1169 | packet_put_int(c->remote_id); | |
1170 | packet_send(); | |
1171 | } | |
1172 | xfree(rtype); | |
1173 | } | |
3c0ef626 | 1174 | |
1175 | static void | |
1176 | server_init_dispatch_20(void) | |
1177 | { | |
1178 | debug("server_init_dispatch_20"); | |
1179 | dispatch_init(&dispatch_protocol_error); | |
1180 | dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose); | |
1181 | dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data); | |
1182 | dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof); | |
1183 | dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data); | |
1184 | dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open); | |
1185 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1186 | dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
e9a17296 | 1187 | dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req); |
3c0ef626 | 1188 | dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust); |
1189 | dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request); | |
1190 | /* client_alive */ | |
cdd66111 | 1191 | dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive); |
1192 | dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive); | |
1193 | dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive); | |
3c0ef626 | 1194 | /* rekeying */ |
1195 | dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit); | |
1196 | } | |
1197 | static void | |
1198 | server_init_dispatch_13(void) | |
1199 | { | |
1200 | debug("server_init_dispatch_13"); | |
1201 | dispatch_init(NULL); | |
1202 | dispatch_set(SSH_CMSG_EOF, &server_input_eof); | |
1203 | dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data); | |
1204 | dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size); | |
1205 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close); | |
1206 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation); | |
1207 | dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data); | |
1208 | dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation); | |
1209 | dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure); | |
1210 | dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open); | |
1211 | } | |
1212 | static void | |
1213 | server_init_dispatch_15(void) | |
1214 | { | |
1215 | server_init_dispatch_13(); | |
1216 | debug("server_init_dispatch_15"); | |
1217 | dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof); | |
1218 | dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose); | |
1219 | } | |
1220 | static void | |
1221 | server_init_dispatch(void) | |
1222 | { | |
1223 | if (compat20) | |
1224 | server_init_dispatch_20(); | |
1225 | else if (compat13) | |
1226 | server_init_dispatch_13(); | |
1227 | else | |
1228 | server_init_dispatch_15(); | |
1229 | } |