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8efc0c15 | 1 | /* |
5260325f | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5 | * Created: Sun Sep 10 00:30:37 1995 ylo | |
6 | * Server main loop for handling the interactive session. | |
7 | */ | |
8efc0c15 | 8 | |
9 | #include "includes.h" | |
10 | #include "xmalloc.h" | |
11 | #include "ssh.h" | |
12 | #include "packet.h" | |
13 | #include "buffer.h" | |
14 | #include "servconf.h" | |
15 | #include "pty.h" | |
16 | ||
17 | static Buffer stdin_buffer; /* Buffer for stdin data. */ | |
18 | static Buffer stdout_buffer; /* Buffer for stdout data. */ | |
19 | static Buffer stderr_buffer; /* Buffer for stderr data. */ | |
20 | static int fdin; /* Descriptor for stdin (for writing) */ | |
21 | static int fdout; /* Descriptor for stdout (for reading); | |
22 | May be same number as fdin. */ | |
23 | static int fderr; /* Descriptor for stderr. May be -1. */ | |
24 | static long stdin_bytes = 0; /* Number of bytes written to stdin. */ | |
25 | static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */ | |
26 | static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */ | |
27 | static long fdout_bytes = 0; /* Number of stdout bytes read from program. */ | |
28 | static int stdin_eof = 0; /* EOF message received from client. */ | |
29 | static int fdout_eof = 0; /* EOF encountered reading from fdout. */ | |
30 | static int fderr_eof = 0; /* EOF encountered readung from fderr. */ | |
31 | static int connection_in; /* Connection to client (input). */ | |
32 | static int connection_out; /* Connection to client (output). */ | |
33 | static unsigned int buffer_high;/* "Soft" max buffer size. */ | |
34 | static int max_fd; /* Max file descriptor number for select(). */ | |
35 | ||
36 | /* This SIGCHLD kludge is used to detect when the child exits. The server | |
37 | will exit after that, as soon as forwarded connections have terminated. */ | |
38 | ||
5260325f | 39 | static int child_pid; /* Pid of the child. */ |
8efc0c15 | 40 | static volatile int child_terminated; /* The child has terminated. */ |
41 | static volatile int child_wait_status; /* Status from wait(). */ | |
42 | ||
5260325f | 43 | void |
44 | sigchld_handler(int sig) | |
8efc0c15 | 45 | { |
5260325f | 46 | int save_errno = errno; |
47 | int wait_pid; | |
48 | debug("Received SIGCHLD."); | |
49 | wait_pid = wait((int *) &child_wait_status); | |
50 | if (wait_pid != -1) { | |
51 | if (wait_pid != child_pid) | |
52 | error("Strange, got SIGCHLD and wait returned pid %d but child is %d", | |
53 | wait_pid, child_pid); | |
54 | if (WIFEXITED(child_wait_status) || | |
55 | WIFSIGNALED(child_wait_status)) | |
56 | child_terminated = 1; | |
57 | } | |
58 | signal(SIGCHLD, sigchld_handler); | |
59 | errno = save_errno; | |
8efc0c15 | 60 | } |
61 | ||
5260325f | 62 | /* |
63 | * Process any buffered packets that have been received from the client. | |
64 | */ | |
65 | void | |
66 | process_buffered_input_packets() | |
8efc0c15 | 67 | { |
5260325f | 68 | int type; |
69 | char *data; | |
70 | unsigned int data_len; | |
71 | int row, col, xpixel, ypixel; | |
72 | int payload_len; | |
73 | ||
74 | /* Process buffered packets from the client. */ | |
75 | while ((type = packet_read_poll(&payload_len)) != SSH_MSG_NONE) { | |
76 | switch (type) { | |
77 | case SSH_CMSG_STDIN_DATA: | |
78 | /* Stdin data from the client. Append it to the buffer. */ | |
79 | /* Ignore any data if the client has closed stdin. */ | |
80 | if (fdin == -1) | |
81 | break; | |
82 | data = packet_get_string(&data_len); | |
83 | packet_integrity_check(payload_len, (4 + data_len), type); | |
84 | buffer_append(&stdin_buffer, data, data_len); | |
85 | memset(data, 0, data_len); | |
86 | xfree(data); | |
87 | break; | |
88 | ||
89 | case SSH_CMSG_EOF: | |
90 | /* Eof from the client. The stdin descriptor to | |
91 | the program will be closed when all buffered | |
92 | data has drained. */ | |
93 | debug("EOF received for stdin."); | |
94 | packet_integrity_check(payload_len, 0, type); | |
95 | stdin_eof = 1; | |
96 | break; | |
97 | ||
98 | case SSH_CMSG_WINDOW_SIZE: | |
99 | debug("Window change received."); | |
100 | packet_integrity_check(payload_len, 4 * 4, type); | |
101 | row = packet_get_int(); | |
102 | col = packet_get_int(); | |
103 | xpixel = packet_get_int(); | |
104 | ypixel = packet_get_int(); | |
105 | if (fdin != -1) | |
106 | pty_change_window_size(fdin, row, col, xpixel, ypixel); | |
107 | break; | |
108 | ||
109 | case SSH_MSG_PORT_OPEN: | |
110 | debug("Received port open request."); | |
111 | channel_input_port_open(payload_len); | |
112 | break; | |
113 | ||
114 | case SSH_MSG_CHANNEL_OPEN_CONFIRMATION: | |
115 | debug("Received channel open confirmation."); | |
116 | packet_integrity_check(payload_len, 4 + 4, type); | |
117 | channel_input_open_confirmation(); | |
118 | break; | |
119 | ||
120 | case SSH_MSG_CHANNEL_OPEN_FAILURE: | |
121 | debug("Received channel open failure."); | |
122 | packet_integrity_check(payload_len, 4, type); | |
123 | channel_input_open_failure(); | |
124 | break; | |
125 | ||
126 | case SSH_MSG_CHANNEL_DATA: | |
127 | channel_input_data(payload_len); | |
128 | break; | |
129 | ||
130 | case SSH_MSG_CHANNEL_CLOSE: | |
131 | debug("Received channel close."); | |
132 | packet_integrity_check(payload_len, 4, type); | |
133 | channel_input_close(); | |
134 | break; | |
135 | ||
136 | case SSH_MSG_CHANNEL_CLOSE_CONFIRMATION: | |
137 | debug("Received channel close confirmation."); | |
138 | packet_integrity_check(payload_len, 4, type); | |
139 | channel_input_close_confirmation(); | |
140 | break; | |
141 | ||
142 | default: | |
143 | /* In this phase, any unexpected messages cause a | |
144 | protocol error. This is to ease debugging; | |
145 | also, since no confirmations are sent messages, | |
146 | unprocessed unknown messages could cause | |
147 | strange problems. Any compatible protocol | |
148 | extensions must be negotiated before entering | |
149 | the interactive session. */ | |
150 | packet_disconnect("Protocol error during session: type %d", | |
151 | type); | |
152 | } | |
8efc0c15 | 153 | } |
8efc0c15 | 154 | } |
155 | ||
5260325f | 156 | /* |
157 | * Make packets from buffered stderr data, and buffer it for sending | |
158 | * to the client. | |
159 | */ | |
160 | void | |
161 | make_packets_from_stderr_data() | |
8efc0c15 | 162 | { |
5260325f | 163 | int len; |
164 | ||
165 | /* Send buffered stderr data to the client. */ | |
166 | while (buffer_len(&stderr_buffer) > 0 && | |
167 | packet_not_very_much_data_to_write()) { | |
168 | len = buffer_len(&stderr_buffer); | |
169 | if (packet_is_interactive()) { | |
170 | if (len > 512) | |
171 | len = 512; | |
172 | } else { | |
173 | /* Keep the packets at reasonable size. */ | |
174 | if (len > packet_get_maxsize()) | |
175 | len = packet_get_maxsize(); | |
176 | } | |
177 | packet_start(SSH_SMSG_STDERR_DATA); | |
178 | packet_put_string(buffer_ptr(&stderr_buffer), len); | |
179 | packet_send(); | |
180 | buffer_consume(&stderr_buffer, len); | |
181 | stderr_bytes += len; | |
8efc0c15 | 182 | } |
8efc0c15 | 183 | } |
184 | ||
5260325f | 185 | /* |
186 | * Make packets from buffered stdout data, and buffer it for sending to the | |
187 | * client. | |
188 | */ | |
189 | void | |
190 | make_packets_from_stdout_data() | |
8efc0c15 | 191 | { |
5260325f | 192 | int len; |
193 | ||
194 | /* Send buffered stdout data to the client. */ | |
195 | while (buffer_len(&stdout_buffer) > 0 && | |
196 | packet_not_very_much_data_to_write()) { | |
197 | len = buffer_len(&stdout_buffer); | |
198 | if (packet_is_interactive()) { | |
199 | if (len > 512) | |
200 | len = 512; | |
201 | } else { | |
202 | /* Keep the packets at reasonable size. */ | |
203 | if (len > packet_get_maxsize()) | |
204 | len = packet_get_maxsize(); | |
205 | } | |
206 | packet_start(SSH_SMSG_STDOUT_DATA); | |
207 | packet_put_string(buffer_ptr(&stdout_buffer), len); | |
208 | packet_send(); | |
209 | buffer_consume(&stdout_buffer, len); | |
210 | stdout_bytes += len; | |
8efc0c15 | 211 | } |
8efc0c15 | 212 | } |
213 | ||
5260325f | 214 | /* |
215 | * Sleep in select() until we can do something. This will initialize the | |
216 | * select masks. Upon return, the masks will indicate which descriptors | |
217 | * have data or can accept data. Optionally, a maximum time can be specified | |
218 | * for the duration of the wait (0 = infinite). | |
219 | */ | |
220 | void | |
221 | wait_until_can_do_something(fd_set * readset, fd_set * writeset, | |
222 | unsigned int max_time_milliseconds) | |
8efc0c15 | 223 | { |
5260325f | 224 | struct timeval tv, *tvp; |
225 | int ret; | |
8efc0c15 | 226 | |
5260325f | 227 | /* When select fails we restart from here. */ |
8efc0c15 | 228 | retry_select: |
229 | ||
5260325f | 230 | /* Initialize select() masks. */ |
231 | FD_ZERO(readset); | |
232 | ||
233 | /* Read packets from the client unless we have too much buffered | |
234 | stdin or channel data. */ | |
235 | if (buffer_len(&stdin_buffer) < 4096 && | |
236 | channel_not_very_much_buffered_data()) | |
237 | FD_SET(connection_in, readset); | |
238 | ||
239 | /* If there is not too much data already buffered going to the | |
240 | client, try to get some more data from the program. */ | |
241 | if (packet_not_very_much_data_to_write()) { | |
242 | if (!fdout_eof) | |
243 | FD_SET(fdout, readset); | |
244 | if (!fderr_eof) | |
245 | FD_SET(fderr, readset); | |
246 | } | |
247 | FD_ZERO(writeset); | |
248 | ||
249 | /* Set masks for channel descriptors. */ | |
250 | channel_prepare_select(readset, writeset); | |
251 | ||
252 | /* If we have buffered packet data going to the client, mark that | |
253 | descriptor. */ | |
254 | if (packet_have_data_to_write()) | |
255 | FD_SET(connection_out, writeset); | |
256 | ||
257 | /* If we have buffered data, try to write some of that data to the | |
258 | program. */ | |
259 | if (fdin != -1 && buffer_len(&stdin_buffer) > 0) | |
260 | FD_SET(fdin, writeset); | |
261 | ||
262 | /* Update the maximum descriptor number if appropriate. */ | |
263 | if (channel_max_fd() > max_fd) | |
264 | max_fd = channel_max_fd(); | |
265 | ||
266 | /* If child has terminated and there is enough buffer space to | |
267 | read from it, then read as much as is available and exit. */ | |
268 | if (child_terminated && packet_not_very_much_data_to_write()) | |
269 | if (max_time_milliseconds == 0) | |
270 | max_time_milliseconds = 100; | |
271 | ||
272 | if (max_time_milliseconds == 0) | |
273 | tvp = NULL; | |
274 | else { | |
275 | tv.tv_sec = max_time_milliseconds / 1000; | |
276 | tv.tv_usec = 1000 * (max_time_milliseconds % 1000); | |
277 | tvp = &tv; | |
278 | } | |
8efc0c15 | 279 | |
5260325f | 280 | /* Wait for something to happen, or the timeout to expire. */ |
281 | ret = select(max_fd + 1, readset, writeset, NULL, tvp); | |
8efc0c15 | 282 | |
5260325f | 283 | if (ret < 0) { |
284 | if (errno != EINTR) | |
285 | error("select: %.100s", strerror(errno)); | |
286 | else | |
287 | goto retry_select; | |
8efc0c15 | 288 | } |
8efc0c15 | 289 | } |
290 | ||
5260325f | 291 | /* |
292 | * Processes input from the client and the program. Input data is stored | |
293 | * in buffers and processed later. | |
294 | */ | |
295 | void | |
296 | process_input(fd_set * readset) | |
297 | { | |
298 | int len; | |
299 | char buf[16384]; | |
300 | ||
301 | /* Read and buffer any input data from the client. */ | |
302 | if (FD_ISSET(connection_in, readset)) { | |
303 | len = read(connection_in, buf, sizeof(buf)); | |
304 | if (len == 0) { | |
305 | verbose("Connection closed by remote host."); | |
306 | fatal_cleanup(); | |
307 | } | |
308 | /* There is a kernel bug on Solaris that causes select to | |
309 | sometimes wake up even though there is no data | |
310 | available. */ | |
311 | if (len < 0 && errno == EAGAIN) | |
312 | len = 0; | |
313 | ||
314 | if (len < 0) { | |
315 | verbose("Read error from remote host: %.100s", strerror(errno)); | |
316 | fatal_cleanup(); | |
317 | } | |
318 | /* Buffer any received data. */ | |
319 | packet_process_incoming(buf, len); | |
320 | } | |
321 | /* Read and buffer any available stdout data from the program. */ | |
322 | if (!fdout_eof && FD_ISSET(fdout, readset)) { | |
323 | len = read(fdout, buf, sizeof(buf)); | |
324 | if (len <= 0) | |
325 | fdout_eof = 1; | |
326 | else { | |
327 | buffer_append(&stdout_buffer, buf, len); | |
328 | fdout_bytes += len; | |
329 | } | |
330 | } | |
331 | /* Read and buffer any available stderr data from the program. */ | |
332 | if (!fderr_eof && FD_ISSET(fderr, readset)) { | |
333 | len = read(fderr, buf, sizeof(buf)); | |
334 | if (len <= 0) | |
335 | fderr_eof = 1; | |
336 | else | |
337 | buffer_append(&stderr_buffer, buf, len); | |
338 | } | |
339 | } | |
8efc0c15 | 340 | |
5260325f | 341 | /* |
342 | * Sends data from internal buffers to client program stdin. | |
343 | */ | |
344 | void | |
345 | process_output(fd_set * writeset) | |
8efc0c15 | 346 | { |
5260325f | 347 | int len; |
348 | ||
349 | /* Write buffered data to program stdin. */ | |
350 | if (fdin != -1 && FD_ISSET(fdin, writeset)) { | |
351 | len = write(fdin, buffer_ptr(&stdin_buffer), | |
352 | buffer_len(&stdin_buffer)); | |
353 | if (len <= 0) { | |
8efc0c15 | 354 | #ifdef USE_PIPES |
5260325f | 355 | close(fdin); |
8efc0c15 | 356 | #else |
5260325f | 357 | if (fdout == -1) |
358 | close(fdin); | |
359 | else | |
360 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
8efc0c15 | 361 | #endif |
5260325f | 362 | fdin = -1; |
363 | } else { | |
364 | /* Successful write. Consume the data from the buffer. */ | |
365 | buffer_consume(&stdin_buffer, len); | |
366 | /* Update the count of bytes written to the program. */ | |
367 | stdin_bytes += len; | |
368 | } | |
8efc0c15 | 369 | } |
5260325f | 370 | /* Send any buffered packet data to the client. */ |
371 | if (FD_ISSET(connection_out, writeset)) | |
372 | packet_write_poll(); | |
8efc0c15 | 373 | } |
374 | ||
5260325f | 375 | /* |
376 | * Wait until all buffered output has been sent to the client. | |
377 | * This is used when the program terminates. | |
378 | */ | |
379 | void | |
380 | drain_output() | |
8efc0c15 | 381 | { |
5260325f | 382 | /* Send any buffered stdout data to the client. */ |
383 | if (buffer_len(&stdout_buffer) > 0) { | |
384 | packet_start(SSH_SMSG_STDOUT_DATA); | |
385 | packet_put_string(buffer_ptr(&stdout_buffer), | |
386 | buffer_len(&stdout_buffer)); | |
387 | packet_send(); | |
388 | /* Update the count of sent bytes. */ | |
389 | stdout_bytes += buffer_len(&stdout_buffer); | |
390 | } | |
391 | /* Send any buffered stderr data to the client. */ | |
392 | if (buffer_len(&stderr_buffer) > 0) { | |
393 | packet_start(SSH_SMSG_STDERR_DATA); | |
394 | packet_put_string(buffer_ptr(&stderr_buffer), | |
395 | buffer_len(&stderr_buffer)); | |
396 | packet_send(); | |
397 | /* Update the count of sent bytes. */ | |
398 | stderr_bytes += buffer_len(&stderr_buffer); | |
399 | } | |
400 | /* Wait until all buffered data has been written to the client. */ | |
401 | packet_write_wait(); | |
8efc0c15 | 402 | } |
403 | ||
5260325f | 404 | /* |
405 | * Performs the interactive session. This handles data transmission between | |
406 | * the client and the program. Note that the notion of stdin, stdout, and | |
407 | * stderr in this function is sort of reversed: this function writes to | |
408 | * stdin (of the child program), and reads from stdout and stderr (of the | |
409 | * child program). | |
410 | */ | |
411 | void | |
412 | server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) | |
8efc0c15 | 413 | { |
5260325f | 414 | int wait_status, wait_pid; /* Status and pid returned by wait(). */ |
415 | int waiting_termination = 0; /* Have displayed waiting close message. */ | |
416 | unsigned int max_time_milliseconds; | |
417 | unsigned int previous_stdout_buffer_bytes; | |
418 | unsigned int stdout_buffer_bytes; | |
419 | int type; | |
420 | ||
421 | debug("Entering interactive session."); | |
422 | ||
423 | /* Initialize the SIGCHLD kludge. */ | |
424 | child_pid = pid; | |
425 | child_terminated = 0; | |
426 | signal(SIGCHLD, sigchld_handler); | |
427 | ||
428 | /* Initialize our global variables. */ | |
429 | fdin = fdin_arg; | |
430 | fdout = fdout_arg; | |
431 | fderr = fderr_arg; | |
432 | connection_in = packet_get_connection_in(); | |
433 | connection_out = packet_get_connection_out(); | |
434 | ||
435 | previous_stdout_buffer_bytes = 0; | |
436 | ||
437 | /* Set approximate I/O buffer size. */ | |
438 | if (packet_is_interactive()) | |
439 | buffer_high = 4096; | |
440 | else | |
441 | buffer_high = 64 * 1024; | |
442 | ||
443 | /* Initialize max_fd to the maximum of the known file descriptors. */ | |
444 | max_fd = fdin; | |
445 | if (fdout > max_fd) | |
446 | max_fd = fdout; | |
447 | if (fderr != -1 && fderr > max_fd) | |
448 | max_fd = fderr; | |
449 | if (connection_in > max_fd) | |
450 | max_fd = connection_in; | |
451 | if (connection_out > max_fd) | |
452 | max_fd = connection_out; | |
453 | ||
454 | /* Initialize Initialize buffers. */ | |
455 | buffer_init(&stdin_buffer); | |
456 | buffer_init(&stdout_buffer); | |
457 | buffer_init(&stderr_buffer); | |
458 | ||
459 | /* If we have no separate fderr (which is the case when we have a | |
460 | pty - there we cannot make difference between data sent to | |
461 | stdout and stderr), indicate that we have seen an EOF from | |
462 | stderr. This way we don\'t need to check the descriptor | |
463 | everywhere. */ | |
464 | if (fderr == -1) | |
465 | fderr_eof = 1; | |
466 | ||
467 | /* Main loop of the server for the interactive session mode. */ | |
468 | for (;;) { | |
469 | fd_set readset, writeset; | |
470 | ||
471 | /* Process buffered packets from the client. */ | |
472 | process_buffered_input_packets(); | |
473 | ||
474 | /* If we have received eof, and there is no more pending | |
475 | input data, cause a real eof by closing fdin. */ | |
476 | if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) { | |
8efc0c15 | 477 | #ifdef USE_PIPES |
5260325f | 478 | close(fdin); |
8efc0c15 | 479 | #else |
5260325f | 480 | if (fdout == -1) |
481 | close(fdin); | |
482 | else | |
483 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
8efc0c15 | 484 | #endif |
5260325f | 485 | fdin = -1; |
486 | } | |
487 | /* Make packets from buffered stderr data to send to the | |
488 | client. */ | |
489 | make_packets_from_stderr_data(); | |
490 | ||
491 | /* Make packets from buffered stdout data to send to the | |
492 | client. If there is very little to send, this arranges | |
493 | to not send them now, but to wait a short while to see | |
494 | if we are getting more data. This is necessary, as some | |
495 | systems wake up readers from a pty after each separate | |
496 | character. */ | |
497 | max_time_milliseconds = 0; | |
498 | stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
499 | if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && | |
500 | stdout_buffer_bytes != previous_stdout_buffer_bytes) { | |
501 | /* try again after a while */ | |
502 | max_time_milliseconds = 10; | |
503 | } else { | |
504 | /* Send it now. */ | |
505 | make_packets_from_stdout_data(); | |
506 | } | |
507 | previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
508 | ||
509 | /* Send channel data to the client. */ | |
510 | if (packet_not_very_much_data_to_write()) | |
511 | channel_output_poll(); | |
512 | ||
513 | /* Bail out of the loop if the program has closed its | |
514 | output descriptors, and we have no more data to send to | |
515 | the client, and there is no pending buffered data. */ | |
516 | if (fdout_eof && fderr_eof && !packet_have_data_to_write() && | |
517 | buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { | |
518 | if (!channel_still_open()) | |
519 | goto quit; | |
520 | if (!waiting_termination) { | |
521 | const char *s = "Waiting for forwarded connections to terminate...\r\n"; | |
522 | char *cp; | |
523 | waiting_termination = 1; | |
524 | buffer_append(&stderr_buffer, s, strlen(s)); | |
525 | ||
526 | /* Display list of open channels. */ | |
527 | cp = channel_open_message(); | |
528 | buffer_append(&stderr_buffer, cp, strlen(cp)); | |
529 | xfree(cp); | |
530 | } | |
531 | } | |
532 | /* Sleep in select() until we can do something. */ | |
533 | wait_until_can_do_something(&readset, &writeset, | |
534 | max_time_milliseconds); | |
535 | ||
536 | /* Process any channel events. */ | |
537 | channel_after_select(&readset, &writeset); | |
538 | ||
539 | /* Process input from the client and from program stdout/stderr. */ | |
540 | process_input(&readset); | |
541 | ||
542 | /* Process output to the client and to program stdin. */ | |
543 | process_output(&writeset); | |
8efc0c15 | 544 | } |
545 | ||
5260325f | 546 | quit: |
547 | /* Cleanup and termination code. */ | |
8efc0c15 | 548 | |
5260325f | 549 | /* Wait until all output has been sent to the client. */ |
550 | drain_output(); | |
8efc0c15 | 551 | |
5260325f | 552 | debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", |
553 | stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); | |
8efc0c15 | 554 | |
5260325f | 555 | /* Free and clear the buffers. */ |
556 | buffer_free(&stdin_buffer); | |
557 | buffer_free(&stdout_buffer); | |
558 | buffer_free(&stderr_buffer); | |
8efc0c15 | 559 | |
5260325f | 560 | /* Close the file descriptors. */ |
561 | if (fdout != -1) | |
562 | close(fdout); | |
563 | fdout = -1; | |
564 | fdout_eof = 1; | |
565 | if (fderr != -1) | |
566 | close(fderr); | |
567 | fderr = -1; | |
568 | fderr_eof = 1; | |
569 | if (fdin != -1) | |
570 | close(fdin); | |
571 | fdin = -1; | |
572 | ||
573 | /* Stop listening for channels; this removes unix domain sockets. */ | |
574 | channel_stop_listening(); | |
575 | ||
576 | /* Wait for the child to exit. Get its exit status. */ | |
577 | wait_pid = wait(&wait_status); | |
578 | if (wait_pid < 0) { | |
579 | /* | |
580 | * It is possible that the wait was handled by SIGCHLD | |
581 | * handler. This may result in either: this call | |
582 | * returning with EINTR, or: this call returning ECHILD. | |
583 | */ | |
584 | if (child_terminated) | |
585 | wait_status = child_wait_status; | |
586 | else | |
587 | packet_disconnect("wait: %.100s", strerror(errno)); | |
588 | } else { | |
589 | /* Check if it matches the process we forked. */ | |
590 | if (wait_pid != pid) | |
591 | error("Strange, wait returned pid %d, expected %d", | |
592 | wait_pid, pid); | |
593 | } | |
8efc0c15 | 594 | |
5260325f | 595 | /* We no longer want our SIGCHLD handler to be called. */ |
596 | signal(SIGCHLD, SIG_DFL); | |
597 | ||
598 | /* Check if it exited normally. */ | |
599 | if (WIFEXITED(wait_status)) { | |
600 | /* Yes, normal exit. Get exit status and send it to the client. */ | |
601 | debug("Command exited with status %d.", WEXITSTATUS(wait_status)); | |
602 | packet_start(SSH_SMSG_EXITSTATUS); | |
603 | packet_put_int(WEXITSTATUS(wait_status)); | |
604 | packet_send(); | |
605 | packet_write_wait(); | |
606 | ||
607 | /* Wait for exit confirmation. Note that there might be | |
608 | other packets coming before it; however, the program | |
609 | has already died so we just ignore them. The client is | |
610 | supposed to respond with the confirmation when it | |
611 | receives the exit status. */ | |
612 | do { | |
613 | int plen; | |
614 | type = packet_read(&plen); | |
615 | } | |
616 | while (type != SSH_CMSG_EXIT_CONFIRMATION); | |
617 | ||
618 | debug("Received exit confirmation."); | |
619 | return; | |
620 | } | |
621 | /* Check if the program terminated due to a signal. */ | |
622 | if (WIFSIGNALED(wait_status)) | |
623 | packet_disconnect("Command terminated on signal %d.", | |
624 | WTERMSIG(wait_status)); | |
625 | ||
626 | /* Some weird exit cause. Just exit. */ | |
627 | packet_disconnect("wait returned status %04x.", wait_status); | |
628 | /* NOTREACHED */ | |
629 | } |