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8efc0c15 | 1 | /* |
2 | ||
3 | serverloop.c | |
4 | ||
5 | Author: Tatu Ylonen <ylo@cs.hut.fi> | |
6 | ||
7 | Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
8 | All rights reserved | |
9 | ||
10 | Created: Sun Sep 10 00:30:37 1995 ylo | |
11 | ||
12 | Server main loop for handling the interactive session. | |
13 | ||
14 | */ | |
15 | ||
16 | #include "includes.h" | |
17 | #include "xmalloc.h" | |
18 | #include "ssh.h" | |
19 | #include "packet.h" | |
20 | #include "buffer.h" | |
21 | #include "servconf.h" | |
22 | #include "pty.h" | |
23 | ||
24 | static Buffer stdin_buffer; /* Buffer for stdin data. */ | |
25 | static Buffer stdout_buffer; /* Buffer for stdout data. */ | |
26 | static Buffer stderr_buffer; /* Buffer for stderr data. */ | |
27 | static int fdin; /* Descriptor for stdin (for writing) */ | |
28 | static int fdout; /* Descriptor for stdout (for reading); | |
29 | May be same number as fdin. */ | |
30 | static int fderr; /* Descriptor for stderr. May be -1. */ | |
31 | static long stdin_bytes = 0; /* Number of bytes written to stdin. */ | |
32 | static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */ | |
33 | static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */ | |
34 | static long fdout_bytes = 0; /* Number of stdout bytes read from program. */ | |
35 | static int stdin_eof = 0; /* EOF message received from client. */ | |
36 | static int fdout_eof = 0; /* EOF encountered reading from fdout. */ | |
37 | static int fderr_eof = 0; /* EOF encountered readung from fderr. */ | |
38 | static int connection_in; /* Connection to client (input). */ | |
39 | static int connection_out; /* Connection to client (output). */ | |
40 | static unsigned int buffer_high;/* "Soft" max buffer size. */ | |
41 | static int max_fd; /* Max file descriptor number for select(). */ | |
42 | ||
43 | /* This SIGCHLD kludge is used to detect when the child exits. The server | |
44 | will exit after that, as soon as forwarded connections have terminated. */ | |
45 | ||
46 | static int child_pid; /* Pid of the child. */ | |
47 | static volatile int child_terminated; /* The child has terminated. */ | |
48 | static volatile int child_wait_status; /* Status from wait(). */ | |
49 | ||
50 | void sigchld_handler(int sig) | |
51 | { | |
52 | int save_errno = errno; | |
53 | int wait_pid; | |
54 | debug("Received SIGCHLD."); | |
55 | wait_pid = wait((int *)&child_wait_status); | |
56 | if (wait_pid != -1) | |
57 | { | |
58 | if (wait_pid != child_pid) | |
59 | error("Strange, got SIGCHLD and wait returned pid %d but child is %d", | |
60 | wait_pid, child_pid); | |
61 | if (WIFEXITED(child_wait_status) || | |
62 | WIFSIGNALED(child_wait_status)) | |
63 | child_terminated = 1; | |
64 | } | |
65 | signal(SIGCHLD, sigchld_handler); | |
66 | errno = save_errno; | |
67 | } | |
68 | ||
69 | /* Process any buffered packets that have been received from the client. */ | |
70 | ||
71 | void process_buffered_input_packets() | |
72 | { | |
73 | int type; | |
74 | char *data; | |
75 | unsigned int data_len; | |
76 | int row, col, xpixel, ypixel; | |
77 | int payload_len; | |
78 | ||
79 | /* Process buffered packets from the client. */ | |
80 | while ((type = packet_read_poll(&payload_len)) != SSH_MSG_NONE) | |
81 | { | |
82 | switch (type) | |
83 | { | |
84 | case SSH_CMSG_STDIN_DATA: | |
85 | /* Stdin data from the client. Append it to the buffer. */ | |
86 | if (fdin == -1) | |
87 | break; /* Ignore any data if the client has closed stdin. */ | |
88 | data = packet_get_string(&data_len); | |
89 | packet_integrity_check(payload_len, (4 + data_len), type); | |
90 | buffer_append(&stdin_buffer, data, data_len); | |
91 | memset(data, 0, data_len); | |
92 | xfree(data); | |
93 | break; | |
94 | ||
95 | case SSH_CMSG_EOF: | |
96 | /* Eof from the client. The stdin descriptor to the program | |
97 | will be closed when all buffered data has drained. */ | |
98 | debug("EOF received for stdin."); | |
99 | packet_integrity_check(payload_len, 0, type); | |
100 | stdin_eof = 1; | |
101 | break; | |
102 | ||
103 | case SSH_CMSG_WINDOW_SIZE: | |
104 | debug("Window change received."); | |
105 | packet_integrity_check(payload_len, 4*4, type); | |
106 | row = packet_get_int(); | |
107 | col = packet_get_int(); | |
108 | xpixel = packet_get_int(); | |
109 | ypixel = packet_get_int(); | |
110 | if (fdin != -1) | |
111 | pty_change_window_size(fdin, row, col, xpixel, ypixel); | |
112 | break; | |
113 | ||
114 | case SSH_MSG_PORT_OPEN: | |
115 | debug("Received port open request."); | |
116 | channel_input_port_open(payload_len); | |
117 | break; | |
118 | ||
119 | case SSH_MSG_CHANNEL_OPEN_CONFIRMATION: | |
120 | debug("Received channel open confirmation."); | |
121 | packet_integrity_check(payload_len, 4 + 4, type); | |
122 | channel_input_open_confirmation(); | |
123 | break; | |
124 | ||
125 | case SSH_MSG_CHANNEL_OPEN_FAILURE: | |
126 | debug("Received channel open failure."); | |
127 | packet_integrity_check(payload_len, 4, type); | |
128 | channel_input_open_failure(); | |
129 | break; | |
130 | ||
131 | case SSH_MSG_CHANNEL_DATA: | |
132 | channel_input_data(payload_len); | |
133 | break; | |
134 | ||
135 | case SSH_MSG_CHANNEL_CLOSE: | |
136 | debug("Received channel close."); | |
137 | packet_integrity_check(payload_len, 4, type); | |
138 | channel_input_close(); | |
139 | break; | |
140 | ||
141 | case SSH_MSG_CHANNEL_CLOSE_CONFIRMATION: | |
142 | debug("Received channel close confirmation."); | |
143 | packet_integrity_check(payload_len, 4, type); | |
144 | channel_input_close_confirmation(); | |
145 | break; | |
146 | ||
147 | default: | |
148 | /* In this phase, any unexpected messages cause a protocol | |
149 | error. This is to ease debugging; also, since no | |
150 | confirmations are sent messages, unprocessed unknown | |
151 | messages could cause strange problems. Any compatible | |
152 | protocol extensions must be negotiated before entering the | |
153 | interactive session. */ | |
154 | packet_disconnect("Protocol error during session: type %d", | |
155 | type); | |
156 | } | |
157 | } | |
158 | } | |
159 | ||
160 | /* Make packets from buffered stderr data, and buffer it for sending | |
161 | to the client. */ | |
162 | ||
163 | void make_packets_from_stderr_data() | |
164 | { | |
165 | int len; | |
166 | ||
167 | /* Send buffered stderr data to the client. */ | |
168 | while (buffer_len(&stderr_buffer) > 0 && | |
169 | packet_not_very_much_data_to_write()) | |
170 | { | |
171 | len = buffer_len(&stderr_buffer); | |
172 | if (packet_is_interactive()) | |
173 | { | |
174 | if (len > 512) | |
175 | len = 512; | |
176 | } | |
177 | else | |
178 | { | |
9d6b7add | 179 | if (len > packet_get_maxsize()) |
180 | len = packet_get_maxsize(); /* Keep the packets at reasonable size. */ | |
8efc0c15 | 181 | } |
182 | packet_start(SSH_SMSG_STDERR_DATA); | |
183 | packet_put_string(buffer_ptr(&stderr_buffer), len); | |
184 | packet_send(); | |
185 | buffer_consume(&stderr_buffer, len); | |
186 | stderr_bytes += len; | |
187 | } | |
188 | } | |
189 | ||
190 | /* Make packets from buffered stdout data, and buffer it for sending to the | |
191 | client. */ | |
192 | ||
193 | void make_packets_from_stdout_data() | |
194 | { | |
195 | int len; | |
196 | ||
197 | /* Send buffered stdout data to the client. */ | |
198 | while (buffer_len(&stdout_buffer) > 0 && | |
199 | packet_not_very_much_data_to_write()) | |
200 | { | |
201 | len = buffer_len(&stdout_buffer); | |
202 | if (packet_is_interactive()) | |
203 | { | |
204 | if (len > 512) | |
205 | len = 512; | |
206 | } | |
207 | else | |
208 | { | |
9d6b7add | 209 | if (len > packet_get_maxsize()) |
210 | len = packet_get_maxsize(); /* Keep the packets at reasonable size. */ | |
8efc0c15 | 211 | } |
212 | packet_start(SSH_SMSG_STDOUT_DATA); | |
213 | packet_put_string(buffer_ptr(&stdout_buffer), len); | |
214 | packet_send(); | |
215 | buffer_consume(&stdout_buffer, len); | |
216 | stdout_bytes += len; | |
217 | } | |
218 | } | |
219 | ||
220 | /* Sleep in select() until we can do something. This will initialize the | |
221 | select masks. Upon return, the masks will indicate which descriptors | |
222 | have data or can accept data. Optionally, a maximum time can be specified | |
223 | for the duration of the wait (0 = infinite). */ | |
224 | ||
225 | void wait_until_can_do_something(fd_set *readset, fd_set *writeset, | |
226 | unsigned int max_time_milliseconds) | |
227 | { | |
228 | struct timeval tv, *tvp; | |
229 | int ret; | |
230 | ||
231 | /* When select fails we restart from here. */ | |
232 | retry_select: | |
233 | ||
234 | /* Initialize select() masks. */ | |
235 | FD_ZERO(readset); | |
236 | ||
237 | /* Read packets from the client unless we have too much buffered stdin | |
238 | or channel data. */ | |
239 | if (buffer_len(&stdin_buffer) < 4096 && | |
240 | channel_not_very_much_buffered_data()) | |
241 | FD_SET(connection_in, readset); | |
242 | ||
243 | /* If there is not too much data already buffered going to the client, | |
244 | try to get some more data from the program. */ | |
245 | if (packet_not_very_much_data_to_write()) | |
246 | { | |
247 | if (!fdout_eof) | |
248 | FD_SET(fdout, readset); | |
249 | if (!fderr_eof) | |
250 | FD_SET(fderr, readset); | |
251 | } | |
252 | ||
253 | FD_ZERO(writeset); | |
254 | ||
255 | /* Set masks for channel descriptors. */ | |
256 | channel_prepare_select(readset, writeset); | |
257 | ||
258 | /* If we have buffered packet data going to the client, mark that | |
259 | descriptor. */ | |
260 | if (packet_have_data_to_write()) | |
261 | FD_SET(connection_out, writeset); | |
262 | ||
263 | /* If we have buffered data, try to write some of that data to the | |
264 | program. */ | |
265 | if (fdin != -1 && buffer_len(&stdin_buffer) > 0) | |
266 | FD_SET(fdin, writeset); | |
267 | ||
268 | /* Update the maximum descriptor number if appropriate. */ | |
269 | if (channel_max_fd() > max_fd) | |
270 | max_fd = channel_max_fd(); | |
271 | ||
f095fcc7 | 272 | /* If child has terminated and there is enough buffer space to read from |
273 | it, then read as much as is available and exit. */ | |
274 | if (child_terminated && packet_not_very_much_data_to_write()) | |
8efc0c15 | 275 | if (max_time_milliseconds == 0) |
276 | max_time_milliseconds = 100; | |
277 | ||
278 | if (max_time_milliseconds == 0) | |
279 | tvp = NULL; | |
280 | else | |
281 | { | |
282 | tv.tv_sec = max_time_milliseconds / 1000; | |
283 | tv.tv_usec = 1000 * (max_time_milliseconds % 1000); | |
284 | tvp = &tv; | |
285 | } | |
286 | ||
287 | /* Wait for something to happen, or the timeout to expire. */ | |
288 | ret = select(max_fd + 1, readset, writeset, NULL, tvp); | |
289 | ||
290 | if (ret < 0) | |
291 | { | |
292 | if (errno != EINTR) | |
293 | error("select: %.100s", strerror(errno)); | |
294 | else | |
295 | goto retry_select; | |
296 | } | |
297 | } | |
298 | ||
299 | /* Processes input from the client and the program. Input data is stored | |
300 | in buffers and processed later. */ | |
301 | ||
302 | void process_input(fd_set *readset) | |
303 | { | |
304 | int len; | |
305 | char buf[16384]; | |
306 | ||
307 | /* Read and buffer any input data from the client. */ | |
308 | if (FD_ISSET(connection_in, readset)) | |
309 | { | |
310 | len = read(connection_in, buf, sizeof(buf)); | |
311 | if (len == 0) | |
312 | fatal("Connection closed by remote host."); | |
313 | ||
314 | /* There is a kernel bug on Solaris that causes select to sometimes | |
315 | wake up even though there is no data available. */ | |
316 | if (len < 0 && errno == EAGAIN) | |
317 | len = 0; | |
318 | ||
319 | if (len < 0) | |
320 | fatal("Read error from remote host: %.100s", strerror(errno)); | |
321 | ||
322 | /* Buffer any received data. */ | |
323 | packet_process_incoming(buf, len); | |
324 | } | |
325 | ||
326 | /* Read and buffer any available stdout data from the program. */ | |
327 | if (!fdout_eof && FD_ISSET(fdout, readset)) | |
328 | { | |
329 | len = read(fdout, buf, sizeof(buf)); | |
330 | if (len <= 0) | |
331 | fdout_eof = 1; | |
332 | else | |
333 | { | |
334 | buffer_append(&stdout_buffer, buf, len); | |
335 | fdout_bytes += len; | |
336 | } | |
337 | } | |
338 | ||
339 | /* Read and buffer any available stderr data from the program. */ | |
340 | if (!fderr_eof && FD_ISSET(fderr, readset)) | |
341 | { | |
342 | len = read(fderr, buf, sizeof(buf)); | |
343 | if (len <= 0) | |
344 | fderr_eof = 1; | |
345 | else | |
346 | buffer_append(&stderr_buffer, buf, len); | |
347 | } | |
348 | } | |
349 | ||
350 | /* Sends data from internal buffers to client program stdin. */ | |
351 | ||
352 | void process_output(fd_set *writeset) | |
353 | { | |
354 | int len; | |
355 | ||
356 | /* Write buffered data to program stdin. */ | |
357 | if (fdin != -1 && FD_ISSET(fdin, writeset)) | |
358 | { | |
359 | len = write(fdin, buffer_ptr(&stdin_buffer), | |
360 | buffer_len(&stdin_buffer)); | |
361 | if (len <= 0) | |
362 | { | |
363 | #ifdef USE_PIPES | |
364 | close(fdin); | |
365 | #else | |
366 | if (fdout == -1) | |
367 | close(fdin); | |
368 | else | |
369 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
370 | #endif | |
371 | fdin = -1; | |
372 | } | |
373 | else | |
374 | { | |
375 | /* Successful write. Consume the data from the buffer. */ | |
376 | buffer_consume(&stdin_buffer, len); | |
377 | /* Update the count of bytes written to the program. */ | |
378 | stdin_bytes += len; | |
379 | } | |
380 | } | |
381 | ||
382 | /* Send any buffered packet data to the client. */ | |
383 | if (FD_ISSET(connection_out, writeset)) | |
384 | packet_write_poll(); | |
385 | } | |
386 | ||
387 | /* Wait until all buffered output has been sent to the client. | |
388 | This is used when the program terminates. */ | |
389 | ||
390 | void drain_output() | |
391 | { | |
392 | /* Send any buffered stdout data to the client. */ | |
393 | if (buffer_len(&stdout_buffer) > 0) | |
394 | { | |
395 | packet_start(SSH_SMSG_STDOUT_DATA); | |
396 | packet_put_string(buffer_ptr(&stdout_buffer), | |
397 | buffer_len(&stdout_buffer)); | |
398 | packet_send(); | |
399 | /* Update the count of sent bytes. */ | |
400 | stdout_bytes += buffer_len(&stdout_buffer); | |
401 | } | |
402 | ||
403 | /* Send any buffered stderr data to the client. */ | |
404 | if (buffer_len(&stderr_buffer) > 0) | |
405 | { | |
406 | packet_start(SSH_SMSG_STDERR_DATA); | |
407 | packet_put_string(buffer_ptr(&stderr_buffer), | |
408 | buffer_len(&stderr_buffer)); | |
409 | packet_send(); | |
410 | /* Update the count of sent bytes. */ | |
411 | stderr_bytes += buffer_len(&stderr_buffer); | |
412 | } | |
413 | ||
414 | /* Wait until all buffered data has been written to the client. */ | |
415 | packet_write_wait(); | |
416 | } | |
417 | ||
418 | /* Performs the interactive session. This handles data transmission between | |
419 | the client and the program. Note that the notion of stdin, stdout, and | |
420 | stderr in this function is sort of reversed: this function writes to | |
421 | stdin (of the child program), and reads from stdout and stderr (of the | |
422 | child program). */ | |
423 | ||
424 | void server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) | |
425 | { | |
426 | int wait_status, wait_pid; /* Status and pid returned by wait(). */ | |
427 | int waiting_termination = 0; /* Have displayed waiting close message. */ | |
428 | unsigned int max_time_milliseconds; | |
429 | unsigned int previous_stdout_buffer_bytes; | |
430 | unsigned int stdout_buffer_bytes; | |
431 | int type; | |
432 | ||
433 | debug("Entering interactive session."); | |
434 | ||
435 | /* Initialize the SIGCHLD kludge. */ | |
436 | child_pid = pid; | |
437 | child_terminated = 0; | |
438 | signal(SIGCHLD, sigchld_handler); | |
439 | ||
440 | /* Initialize our global variables. */ | |
441 | fdin = fdin_arg; | |
442 | fdout = fdout_arg; | |
443 | fderr = fderr_arg; | |
444 | connection_in = packet_get_connection_in(); | |
445 | connection_out = packet_get_connection_out(); | |
446 | ||
447 | previous_stdout_buffer_bytes = 0; | |
448 | ||
449 | /* Set approximate I/O buffer size. */ | |
450 | if (packet_is_interactive()) | |
451 | buffer_high = 4096; | |
452 | else | |
453 | buffer_high = 64 * 1024; | |
454 | ||
455 | /* Initialize max_fd to the maximum of the known file descriptors. */ | |
456 | max_fd = fdin; | |
457 | if (fdout > max_fd) | |
458 | max_fd = fdout; | |
459 | if (fderr != -1 && fderr > max_fd) | |
460 | max_fd = fderr; | |
461 | if (connection_in > max_fd) | |
462 | max_fd = connection_in; | |
463 | if (connection_out > max_fd) | |
464 | max_fd = connection_out; | |
465 | ||
466 | /* Initialize Initialize buffers. */ | |
467 | buffer_init(&stdin_buffer); | |
468 | buffer_init(&stdout_buffer); | |
469 | buffer_init(&stderr_buffer); | |
470 | ||
471 | /* If we have no separate fderr (which is the case when we have a pty - there | |
472 | we cannot make difference between data sent to stdout and stderr), | |
473 | indicate that we have seen an EOF from stderr. This way we don\'t | |
474 | need to check the descriptor everywhere. */ | |
475 | if (fderr == -1) | |
476 | fderr_eof = 1; | |
477 | ||
478 | /* Main loop of the server for the interactive session mode. */ | |
479 | for (;;) | |
480 | { | |
481 | fd_set readset, writeset; | |
482 | ||
483 | /* Process buffered packets from the client. */ | |
484 | process_buffered_input_packets(); | |
485 | ||
486 | /* If we have received eof, and there is no more pending input data, | |
487 | cause a real eof by closing fdin. */ | |
488 | if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) | |
489 | { | |
490 | #ifdef USE_PIPES | |
491 | close(fdin); | |
492 | #else | |
493 | if (fdout == -1) | |
494 | close(fdin); | |
495 | else | |
496 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
497 | #endif | |
498 | fdin = -1; | |
499 | } | |
500 | ||
501 | /* Make packets from buffered stderr data to send to the client. */ | |
502 | make_packets_from_stderr_data(); | |
503 | ||
504 | /* Make packets from buffered stdout data to send to the client. | |
505 | If there is very little to send, this arranges to not send them | |
506 | now, but to wait a short while to see if we are getting more data. | |
507 | This is necessary, as some systems wake up readers from a pty after | |
508 | each separate character. */ | |
509 | max_time_milliseconds = 0; | |
510 | stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
511 | if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && | |
512 | stdout_buffer_bytes != previous_stdout_buffer_bytes) | |
513 | max_time_milliseconds = 10; /* try again after a while */ | |
514 | else | |
515 | make_packets_from_stdout_data(); /* Send it now. */ | |
516 | previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
517 | ||
518 | /* Send channel data to the client. */ | |
519 | if (packet_not_very_much_data_to_write()) | |
520 | channel_output_poll(); | |
521 | ||
522 | /* Bail out of the loop if the program has closed its output descriptors, | |
523 | and we have no more data to send to the client, and there is no | |
524 | pending buffered data. */ | |
525 | if (fdout_eof && fderr_eof && !packet_have_data_to_write() && | |
526 | buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) | |
527 | { | |
528 | if (!channel_still_open()) | |
529 | goto quit; | |
530 | if (!waiting_termination) | |
531 | { | |
532 | const char *s = | |
533 | "Waiting for forwarded connections to terminate...\r\n"; | |
534 | char *cp; | |
535 | waiting_termination = 1; | |
536 | buffer_append(&stderr_buffer, s, strlen(s)); | |
537 | ||
538 | /* Display list of open channels. */ | |
539 | cp = channel_open_message(); | |
540 | buffer_append(&stderr_buffer, cp, strlen(cp)); | |
541 | xfree(cp); | |
542 | } | |
543 | } | |
544 | ||
545 | /* Sleep in select() until we can do something. */ | |
546 | wait_until_can_do_something(&readset, &writeset, | |
547 | max_time_milliseconds); | |
548 | ||
549 | /* Process any channel events. */ | |
550 | channel_after_select(&readset, &writeset); | |
551 | ||
552 | /* Process input from the client and from program stdout/stderr. */ | |
553 | process_input(&readset); | |
554 | ||
555 | /* Process output to the client and to program stdin. */ | |
556 | process_output(&writeset); | |
557 | } | |
558 | ||
559 | quit: | |
560 | /* Cleanup and termination code. */ | |
561 | ||
562 | /* Wait until all output has been sent to the client. */ | |
563 | drain_output(); | |
564 | ||
565 | debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", | |
566 | stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); | |
567 | ||
568 | /* Free and clear the buffers. */ | |
569 | buffer_free(&stdin_buffer); | |
570 | buffer_free(&stdout_buffer); | |
571 | buffer_free(&stderr_buffer); | |
572 | ||
573 | /* Close the file descriptors. */ | |
574 | if (fdout != -1) | |
575 | close(fdout); | |
576 | fdout = -1; | |
577 | fdout_eof = 1; | |
578 | if (fderr != -1) | |
579 | close(fderr); | |
580 | fderr = -1; | |
581 | fderr_eof = 1; | |
582 | if (fdin != -1) | |
583 | close(fdin); | |
584 | fdin = -1; | |
585 | ||
586 | /* Stop listening for channels; this removes unix domain sockets. */ | |
587 | channel_stop_listening(); | |
588 | ||
589 | /* Wait for the child to exit. Get its exit status. */ | |
590 | wait_pid = wait(&wait_status); | |
591 | if (wait_pid < 0) | |
592 | { | |
593 | /* It is possible that the wait was handled by SIGCHLD handler. This | |
594 | may result in either: this call returning with EINTR, or: this | |
595 | call returning ECHILD. */ | |
596 | if (child_terminated) | |
597 | wait_status = child_wait_status; | |
598 | else | |
599 | packet_disconnect("wait: %.100s", strerror(errno)); | |
600 | } | |
601 | else | |
602 | { | |
603 | /* Check if it matches the process we forked. */ | |
604 | if (wait_pid != pid) | |
605 | error("Strange, wait returned pid %d, expected %d", wait_pid, pid); | |
606 | } | |
607 | ||
608 | /* We no longer want our SIGCHLD handler to be called. */ | |
609 | signal(SIGCHLD, SIG_DFL); | |
610 | ||
611 | /* Check if it exited normally. */ | |
612 | if (WIFEXITED(wait_status)) | |
613 | { | |
614 | /* Yes, normal exit. Get exit status and send it to the client. */ | |
615 | debug("Command exited with status %d.", WEXITSTATUS(wait_status)); | |
616 | packet_start(SSH_SMSG_EXITSTATUS); | |
617 | packet_put_int(WEXITSTATUS(wait_status)); | |
618 | packet_send(); | |
619 | packet_write_wait(); | |
620 | ||
621 | /* Wait for exit confirmation. Note that there might be other | |
622 | packets coming before it; however, the program has already died | |
623 | so we just ignore them. The client is supposed to respond with | |
624 | the confirmation when it receives the exit status. */ | |
625 | do | |
626 | { | |
627 | int plen; | |
628 | type = packet_read(&plen); | |
629 | } | |
630 | while (type != SSH_CMSG_EXIT_CONFIRMATION); | |
631 | ||
632 | debug("Received exit confirmation."); | |
633 | return; | |
634 | } | |
635 | ||
636 | /* Check if the program terminated due to a signal. */ | |
637 | if (WIFSIGNALED(wait_status)) | |
638 | packet_disconnect("Command terminated on signal %d.", | |
639 | WTERMSIG(wait_status)); | |
640 | ||
641 | /* Some weird exit cause. Just exit. */ | |
642 | packet_disconnect("wait returned status %04x.", wait_status); | |
643 | /*NOTREACHED*/ | |
644 | } | |
645 |