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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 | ||
aa3378df | 36 | /* |
37 | * This SIGCHLD kludge is used to detect when the child exits. The server | |
38 | * will exit after that, as soon as forwarded connections have terminated. | |
39 | */ | |
8efc0c15 | 40 | |
5260325f | 41 | static int child_pid; /* Pid of the child. */ |
8efc0c15 | 42 | static volatile int child_terminated; /* The child has terminated. */ |
43 | static volatile int child_wait_status; /* Status from wait(). */ | |
44 | ||
5260325f | 45 | void |
46 | sigchld_handler(int sig) | |
8efc0c15 | 47 | { |
5260325f | 48 | int save_errno = errno; |
49 | int wait_pid; | |
50 | debug("Received SIGCHLD."); | |
51 | wait_pid = wait((int *) &child_wait_status); | |
52 | if (wait_pid != -1) { | |
53 | if (wait_pid != child_pid) | |
54 | error("Strange, got SIGCHLD and wait returned pid %d but child is %d", | |
55 | wait_pid, child_pid); | |
56 | if (WIFEXITED(child_wait_status) || | |
57 | WIFSIGNALED(child_wait_status)) | |
58 | child_terminated = 1; | |
59 | } | |
60 | signal(SIGCHLD, sigchld_handler); | |
61 | errno = save_errno; | |
8efc0c15 | 62 | } |
63 | ||
5260325f | 64 | /* |
65 | * Process any buffered packets that have been received from the client. | |
66 | */ | |
67 | void | |
68 | process_buffered_input_packets() | |
8efc0c15 | 69 | { |
5260325f | 70 | int type; |
71 | char *data; | |
72 | unsigned int data_len; | |
73 | int row, col, xpixel, ypixel; | |
74 | int payload_len; | |
75 | ||
76 | /* Process buffered packets from the client. */ | |
77 | while ((type = packet_read_poll(&payload_len)) != SSH_MSG_NONE) { | |
78 | switch (type) { | |
79 | case SSH_CMSG_STDIN_DATA: | |
80 | /* Stdin data from the client. Append it to the buffer. */ | |
81 | /* Ignore any data if the client has closed stdin. */ | |
82 | if (fdin == -1) | |
83 | break; | |
84 | data = packet_get_string(&data_len); | |
85 | packet_integrity_check(payload_len, (4 + data_len), type); | |
86 | buffer_append(&stdin_buffer, data, data_len); | |
87 | memset(data, 0, data_len); | |
88 | xfree(data); | |
89 | break; | |
90 | ||
91 | case SSH_CMSG_EOF: | |
aa3378df | 92 | /* |
93 | * Eof from the client. The stdin descriptor to the | |
94 | * program will be closed when all buffered data has | |
95 | * drained. | |
96 | */ | |
5260325f | 97 | debug("EOF received for stdin."); |
98 | packet_integrity_check(payload_len, 0, type); | |
99 | stdin_eof = 1; | |
100 | break; | |
101 | ||
102 | case SSH_CMSG_WINDOW_SIZE: | |
103 | debug("Window change received."); | |
104 | packet_integrity_check(payload_len, 4 * 4, type); | |
105 | row = packet_get_int(); | |
106 | col = packet_get_int(); | |
107 | xpixel = packet_get_int(); | |
108 | ypixel = packet_get_int(); | |
109 | if (fdin != -1) | |
110 | pty_change_window_size(fdin, row, col, xpixel, ypixel); | |
111 | break; | |
112 | ||
113 | case SSH_MSG_PORT_OPEN: | |
114 | debug("Received port open request."); | |
115 | channel_input_port_open(payload_len); | |
116 | break; | |
117 | ||
118 | case SSH_MSG_CHANNEL_OPEN_CONFIRMATION: | |
119 | debug("Received channel open confirmation."); | |
120 | packet_integrity_check(payload_len, 4 + 4, type); | |
121 | channel_input_open_confirmation(); | |
122 | break; | |
123 | ||
124 | case SSH_MSG_CHANNEL_OPEN_FAILURE: | |
125 | debug("Received channel open failure."); | |
126 | packet_integrity_check(payload_len, 4, type); | |
127 | channel_input_open_failure(); | |
128 | break; | |
129 | ||
130 | case SSH_MSG_CHANNEL_DATA: | |
131 | channel_input_data(payload_len); | |
132 | break; | |
133 | ||
134 | case SSH_MSG_CHANNEL_CLOSE: | |
135 | debug("Received channel close."); | |
136 | packet_integrity_check(payload_len, 4, type); | |
137 | channel_input_close(); | |
138 | break; | |
139 | ||
140 | case SSH_MSG_CHANNEL_CLOSE_CONFIRMATION: | |
141 | debug("Received channel close confirmation."); | |
142 | packet_integrity_check(payload_len, 4, type); | |
143 | channel_input_close_confirmation(); | |
144 | break; | |
145 | ||
146 | default: | |
aa3378df | 147 | /* |
148 | * In this phase, any unexpected messages cause a | |
149 | * protocol error. This is to ease debugging; also, | |
150 | * since no confirmations are sent messages, | |
151 | * unprocessed unknown messages could cause strange | |
152 | * problems. Any compatible protocol extensions must | |
153 | * be negotiated before entering the interactive | |
154 | * session. | |
155 | */ | |
5260325f | 156 | packet_disconnect("Protocol error during session: type %d", |
157 | type); | |
158 | } | |
8efc0c15 | 159 | } |
8efc0c15 | 160 | } |
161 | ||
5260325f | 162 | /* |
163 | * Make packets from buffered stderr data, and buffer it for sending | |
164 | * to the client. | |
165 | */ | |
166 | void | |
167 | make_packets_from_stderr_data() | |
8efc0c15 | 168 | { |
5260325f | 169 | int len; |
170 | ||
171 | /* Send buffered stderr data to the client. */ | |
172 | while (buffer_len(&stderr_buffer) > 0 && | |
a408af76 | 173 | packet_not_very_much_data_to_write()) { |
5260325f | 174 | len = buffer_len(&stderr_buffer); |
175 | if (packet_is_interactive()) { | |
176 | if (len > 512) | |
177 | len = 512; | |
178 | } else { | |
179 | /* Keep the packets at reasonable size. */ | |
180 | if (len > packet_get_maxsize()) | |
181 | len = packet_get_maxsize(); | |
182 | } | |
183 | packet_start(SSH_SMSG_STDERR_DATA); | |
184 | packet_put_string(buffer_ptr(&stderr_buffer), len); | |
185 | packet_send(); | |
186 | buffer_consume(&stderr_buffer, len); | |
187 | stderr_bytes += len; | |
8efc0c15 | 188 | } |
8efc0c15 | 189 | } |
190 | ||
5260325f | 191 | /* |
192 | * Make packets from buffered stdout data, and buffer it for sending to the | |
193 | * client. | |
194 | */ | |
195 | void | |
196 | make_packets_from_stdout_data() | |
8efc0c15 | 197 | { |
5260325f | 198 | int len; |
199 | ||
200 | /* Send buffered stdout data to the client. */ | |
201 | while (buffer_len(&stdout_buffer) > 0 && | |
a408af76 | 202 | packet_not_very_much_data_to_write()) { |
5260325f | 203 | len = buffer_len(&stdout_buffer); |
204 | if (packet_is_interactive()) { | |
205 | if (len > 512) | |
206 | len = 512; | |
207 | } else { | |
208 | /* Keep the packets at reasonable size. */ | |
209 | if (len > packet_get_maxsize()) | |
210 | len = packet_get_maxsize(); | |
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; | |
8efc0c15 | 217 | } |
8efc0c15 | 218 | } |
219 | ||
5260325f | 220 | /* |
221 | * Sleep in select() until we can do something. This will initialize the | |
222 | * select masks. Upon return, the masks will indicate which descriptors | |
223 | * have data or can accept data. Optionally, a maximum time can be specified | |
224 | * for the duration of the wait (0 = infinite). | |
225 | */ | |
226 | void | |
227 | wait_until_can_do_something(fd_set * readset, fd_set * writeset, | |
228 | unsigned int max_time_milliseconds) | |
8efc0c15 | 229 | { |
5260325f | 230 | struct timeval tv, *tvp; |
231 | int ret; | |
8efc0c15 | 232 | |
5260325f | 233 | /* When select fails we restart from here. */ |
8efc0c15 | 234 | retry_select: |
235 | ||
5260325f | 236 | /* Initialize select() masks. */ |
237 | FD_ZERO(readset); | |
238 | ||
aa3378df | 239 | /* |
240 | * Read packets from the client unless we have too much buffered | |
241 | * stdin or channel data. | |
242 | */ | |
5260325f | 243 | if (buffer_len(&stdin_buffer) < 4096 && |
244 | channel_not_very_much_buffered_data()) | |
245 | FD_SET(connection_in, readset); | |
246 | ||
aa3378df | 247 | /* |
248 | * If there is not too much data already buffered going to the | |
249 | * client, try to get some more data from the program. | |
250 | */ | |
5260325f | 251 | if (packet_not_very_much_data_to_write()) { |
252 | if (!fdout_eof) | |
253 | FD_SET(fdout, readset); | |
254 | if (!fderr_eof) | |
255 | FD_SET(fderr, readset); | |
256 | } | |
257 | FD_ZERO(writeset); | |
258 | ||
259 | /* Set masks for channel descriptors. */ | |
260 | channel_prepare_select(readset, writeset); | |
261 | ||
aa3378df | 262 | /* |
263 | * If we have buffered packet data going to the client, mark that | |
264 | * descriptor. | |
265 | */ | |
5260325f | 266 | if (packet_have_data_to_write()) |
267 | FD_SET(connection_out, writeset); | |
268 | ||
269 | /* If we have buffered data, try to write some of that data to the | |
270 | program. */ | |
271 | if (fdin != -1 && buffer_len(&stdin_buffer) > 0) | |
272 | FD_SET(fdin, writeset); | |
273 | ||
274 | /* Update the maximum descriptor number if appropriate. */ | |
275 | if (channel_max_fd() > max_fd) | |
276 | max_fd = channel_max_fd(); | |
277 | ||
aa3378df | 278 | /* |
279 | * If child has terminated and there is enough buffer space to read | |
280 | * from it, then read as much as is available and exit. | |
281 | */ | |
5260325f | 282 | if (child_terminated && packet_not_very_much_data_to_write()) |
283 | if (max_time_milliseconds == 0) | |
284 | max_time_milliseconds = 100; | |
285 | ||
286 | if (max_time_milliseconds == 0) | |
287 | tvp = NULL; | |
288 | else { | |
289 | tv.tv_sec = max_time_milliseconds / 1000; | |
290 | tv.tv_usec = 1000 * (max_time_milliseconds % 1000); | |
291 | tvp = &tv; | |
292 | } | |
8efc0c15 | 293 | |
5260325f | 294 | /* Wait for something to happen, or the timeout to expire. */ |
295 | ret = select(max_fd + 1, readset, writeset, NULL, tvp); | |
8efc0c15 | 296 | |
5260325f | 297 | if (ret < 0) { |
298 | if (errno != EINTR) | |
299 | error("select: %.100s", strerror(errno)); | |
300 | else | |
301 | goto retry_select; | |
8efc0c15 | 302 | } |
8efc0c15 | 303 | } |
304 | ||
5260325f | 305 | /* |
306 | * Processes input from the client and the program. Input data is stored | |
307 | * in buffers and processed later. | |
308 | */ | |
309 | void | |
310 | process_input(fd_set * readset) | |
311 | { | |
312 | int len; | |
313 | char buf[16384]; | |
314 | ||
315 | /* Read and buffer any input data from the client. */ | |
316 | if (FD_ISSET(connection_in, readset)) { | |
317 | len = read(connection_in, buf, sizeof(buf)); | |
318 | if (len == 0) { | |
319 | verbose("Connection closed by remote host."); | |
320 | fatal_cleanup(); | |
321 | } | |
aa3378df | 322 | /* |
323 | * There is a kernel bug on Solaris that causes select to | |
324 | * sometimes wake up even though there is no data available. | |
325 | */ | |
5260325f | 326 | if (len < 0 && errno == EAGAIN) |
327 | len = 0; | |
328 | ||
329 | if (len < 0) { | |
330 | verbose("Read error from remote host: %.100s", strerror(errno)); | |
331 | fatal_cleanup(); | |
332 | } | |
333 | /* Buffer any received data. */ | |
334 | packet_process_incoming(buf, len); | |
335 | } | |
336 | /* Read and buffer any available stdout data from the program. */ | |
337 | if (!fdout_eof && FD_ISSET(fdout, readset)) { | |
338 | len = read(fdout, buf, sizeof(buf)); | |
339 | if (len <= 0) | |
340 | fdout_eof = 1; | |
341 | else { | |
342 | buffer_append(&stdout_buffer, buf, len); | |
343 | fdout_bytes += len; | |
344 | } | |
345 | } | |
346 | /* Read and buffer any available stderr data from the program. */ | |
347 | if (!fderr_eof && FD_ISSET(fderr, readset)) { | |
348 | len = read(fderr, buf, sizeof(buf)); | |
349 | if (len <= 0) | |
350 | fderr_eof = 1; | |
351 | else | |
352 | buffer_append(&stderr_buffer, buf, len); | |
353 | } | |
354 | } | |
8efc0c15 | 355 | |
5260325f | 356 | /* |
357 | * Sends data from internal buffers to client program stdin. | |
358 | */ | |
359 | void | |
360 | process_output(fd_set * writeset) | |
8efc0c15 | 361 | { |
5260325f | 362 | int len; |
363 | ||
364 | /* Write buffered data to program stdin. */ | |
365 | if (fdin != -1 && FD_ISSET(fdin, writeset)) { | |
366 | len = write(fdin, buffer_ptr(&stdin_buffer), | |
a408af76 | 367 | buffer_len(&stdin_buffer)); |
5260325f | 368 | if (len <= 0) { |
8efc0c15 | 369 | #ifdef USE_PIPES |
5260325f | 370 | close(fdin); |
8efc0c15 | 371 | #else |
5260325f | 372 | if (fdout == -1) |
373 | close(fdin); | |
374 | else | |
375 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
8efc0c15 | 376 | #endif |
5260325f | 377 | fdin = -1; |
378 | } else { | |
379 | /* Successful write. Consume the data from the buffer. */ | |
380 | buffer_consume(&stdin_buffer, len); | |
381 | /* Update the count of bytes written to the program. */ | |
382 | stdin_bytes += len; | |
383 | } | |
8efc0c15 | 384 | } |
5260325f | 385 | /* Send any buffered packet data to the client. */ |
386 | if (FD_ISSET(connection_out, writeset)) | |
387 | packet_write_poll(); | |
8efc0c15 | 388 | } |
389 | ||
5260325f | 390 | /* |
391 | * Wait until all buffered output has been sent to the client. | |
392 | * This is used when the program terminates. | |
393 | */ | |
394 | void | |
395 | drain_output() | |
8efc0c15 | 396 | { |
5260325f | 397 | /* Send any buffered stdout data to the client. */ |
398 | if (buffer_len(&stdout_buffer) > 0) { | |
399 | packet_start(SSH_SMSG_STDOUT_DATA); | |
400 | packet_put_string(buffer_ptr(&stdout_buffer), | |
401 | buffer_len(&stdout_buffer)); | |
402 | packet_send(); | |
403 | /* Update the count of sent bytes. */ | |
404 | stdout_bytes += buffer_len(&stdout_buffer); | |
405 | } | |
406 | /* Send any buffered stderr data to the client. */ | |
407 | if (buffer_len(&stderr_buffer) > 0) { | |
408 | packet_start(SSH_SMSG_STDERR_DATA); | |
409 | packet_put_string(buffer_ptr(&stderr_buffer), | |
410 | buffer_len(&stderr_buffer)); | |
411 | packet_send(); | |
412 | /* Update the count of sent bytes. */ | |
413 | stderr_bytes += buffer_len(&stderr_buffer); | |
414 | } | |
415 | /* Wait until all buffered data has been written to the client. */ | |
416 | packet_write_wait(); | |
8efc0c15 | 417 | } |
418 | ||
5260325f | 419 | /* |
420 | * Performs the interactive session. This handles data transmission between | |
421 | * the client and the program. Note that the notion of stdin, stdout, and | |
422 | * stderr in this function is sort of reversed: this function writes to | |
423 | * stdin (of the child program), and reads from stdout and stderr (of the | |
424 | * child program). | |
425 | */ | |
426 | void | |
427 | server_loop(int pid, int fdin_arg, int fdout_arg, int fderr_arg) | |
8efc0c15 | 428 | { |
5260325f | 429 | int wait_status, wait_pid; /* Status and pid returned by wait(). */ |
430 | int waiting_termination = 0; /* Have displayed waiting close message. */ | |
431 | unsigned int max_time_milliseconds; | |
432 | unsigned int previous_stdout_buffer_bytes; | |
433 | unsigned int stdout_buffer_bytes; | |
434 | int type; | |
435 | ||
436 | debug("Entering interactive session."); | |
437 | ||
438 | /* Initialize the SIGCHLD kludge. */ | |
439 | child_pid = pid; | |
440 | child_terminated = 0; | |
441 | signal(SIGCHLD, sigchld_handler); | |
442 | ||
443 | /* Initialize our global variables. */ | |
444 | fdin = fdin_arg; | |
445 | fdout = fdout_arg; | |
446 | fderr = fderr_arg; | |
447 | connection_in = packet_get_connection_in(); | |
448 | connection_out = packet_get_connection_out(); | |
449 | ||
450 | previous_stdout_buffer_bytes = 0; | |
451 | ||
452 | /* Set approximate I/O buffer size. */ | |
453 | if (packet_is_interactive()) | |
454 | buffer_high = 4096; | |
455 | else | |
456 | buffer_high = 64 * 1024; | |
457 | ||
458 | /* Initialize max_fd to the maximum of the known file descriptors. */ | |
459 | max_fd = fdin; | |
460 | if (fdout > max_fd) | |
461 | max_fd = fdout; | |
462 | if (fderr != -1 && fderr > max_fd) | |
463 | max_fd = fderr; | |
464 | if (connection_in > max_fd) | |
465 | max_fd = connection_in; | |
466 | if (connection_out > max_fd) | |
467 | max_fd = connection_out; | |
468 | ||
469 | /* Initialize Initialize buffers. */ | |
470 | buffer_init(&stdin_buffer); | |
471 | buffer_init(&stdout_buffer); | |
472 | buffer_init(&stderr_buffer); | |
473 | ||
aa3378df | 474 | /* |
475 | * If we have no separate fderr (which is the case when we have a pty | |
476 | * - there we cannot make difference between data sent to stdout and | |
477 | * stderr), indicate that we have seen an EOF from stderr. This way | |
478 | * we don\'t need to check the descriptor everywhere. | |
479 | */ | |
5260325f | 480 | if (fderr == -1) |
481 | fderr_eof = 1; | |
482 | ||
483 | /* Main loop of the server for the interactive session mode. */ | |
484 | for (;;) { | |
485 | fd_set readset, writeset; | |
486 | ||
487 | /* Process buffered packets from the client. */ | |
488 | process_buffered_input_packets(); | |
489 | ||
aa3378df | 490 | /* |
491 | * If we have received eof, and there is no more pending | |
492 | * input data, cause a real eof by closing fdin. | |
493 | */ | |
5260325f | 494 | if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) { |
8efc0c15 | 495 | #ifdef USE_PIPES |
5260325f | 496 | close(fdin); |
8efc0c15 | 497 | #else |
5260325f | 498 | if (fdout == -1) |
499 | close(fdin); | |
500 | else | |
501 | shutdown(fdin, SHUT_WR); /* We will no longer send. */ | |
8efc0c15 | 502 | #endif |
5260325f | 503 | fdin = -1; |
504 | } | |
aa3378df | 505 | /* Make packets from buffered stderr data to send to the client. */ |
5260325f | 506 | make_packets_from_stderr_data(); |
507 | ||
aa3378df | 508 | /* |
509 | * Make packets from buffered stdout data to send to the | |
510 | * client. If there is very little to send, this arranges to | |
511 | * not send them now, but to wait a short while to see if we | |
512 | * are getting more data. This is necessary, as some systems | |
513 | * wake up readers from a pty after each separate character. | |
514 | */ | |
5260325f | 515 | max_time_milliseconds = 0; |
516 | stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
517 | if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 && | |
518 | stdout_buffer_bytes != previous_stdout_buffer_bytes) { | |
519 | /* try again after a while */ | |
520 | max_time_milliseconds = 10; | |
521 | } else { | |
522 | /* Send it now. */ | |
523 | make_packets_from_stdout_data(); | |
524 | } | |
525 | previous_stdout_buffer_bytes = buffer_len(&stdout_buffer); | |
526 | ||
527 | /* Send channel data to the client. */ | |
528 | if (packet_not_very_much_data_to_write()) | |
529 | channel_output_poll(); | |
530 | ||
aa3378df | 531 | /* |
532 | * Bail out of the loop if the program has closed its output | |
533 | * descriptors, and we have no more data to send to the | |
534 | * client, and there is no pending buffered data. | |
535 | */ | |
5260325f | 536 | if (fdout_eof && fderr_eof && !packet_have_data_to_write() && |
537 | buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) { | |
538 | if (!channel_still_open()) | |
539 | goto quit; | |
540 | if (!waiting_termination) { | |
541 | const char *s = "Waiting for forwarded connections to terminate...\r\n"; | |
542 | char *cp; | |
543 | waiting_termination = 1; | |
544 | buffer_append(&stderr_buffer, s, strlen(s)); | |
545 | ||
546 | /* Display list of open channels. */ | |
547 | cp = channel_open_message(); | |
548 | buffer_append(&stderr_buffer, cp, strlen(cp)); | |
549 | xfree(cp); | |
550 | } | |
551 | } | |
552 | /* Sleep in select() until we can do something. */ | |
553 | wait_until_can_do_something(&readset, &writeset, | |
554 | max_time_milliseconds); | |
555 | ||
556 | /* Process any channel events. */ | |
557 | channel_after_select(&readset, &writeset); | |
558 | ||
559 | /* Process input from the client and from program stdout/stderr. */ | |
560 | process_input(&readset); | |
561 | ||
562 | /* Process output to the client and to program stdin. */ | |
563 | process_output(&writeset); | |
8efc0c15 | 564 | } |
565 | ||
5260325f | 566 | quit: |
567 | /* Cleanup and termination code. */ | |
8efc0c15 | 568 | |
5260325f | 569 | /* Wait until all output has been sent to the client. */ |
570 | drain_output(); | |
8efc0c15 | 571 | |
5260325f | 572 | debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.", |
573 | stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes); | |
8efc0c15 | 574 | |
5260325f | 575 | /* Free and clear the buffers. */ |
576 | buffer_free(&stdin_buffer); | |
577 | buffer_free(&stdout_buffer); | |
578 | buffer_free(&stderr_buffer); | |
8efc0c15 | 579 | |
5260325f | 580 | /* Close the file descriptors. */ |
581 | if (fdout != -1) | |
582 | close(fdout); | |
583 | fdout = -1; | |
584 | fdout_eof = 1; | |
585 | if (fderr != -1) | |
586 | close(fderr); | |
587 | fderr = -1; | |
588 | fderr_eof = 1; | |
589 | if (fdin != -1) | |
590 | close(fdin); | |
591 | fdin = -1; | |
592 | ||
593 | /* Stop listening for channels; this removes unix domain sockets. */ | |
594 | channel_stop_listening(); | |
595 | ||
596 | /* Wait for the child to exit. Get its exit status. */ | |
597 | wait_pid = wait(&wait_status); | |
598 | if (wait_pid < 0) { | |
599 | /* | |
600 | * It is possible that the wait was handled by SIGCHLD | |
601 | * handler. This may result in either: this call | |
602 | * returning with EINTR, or: this call returning ECHILD. | |
603 | */ | |
604 | if (child_terminated) | |
605 | wait_status = child_wait_status; | |
606 | else | |
607 | packet_disconnect("wait: %.100s", strerror(errno)); | |
608 | } else { | |
609 | /* Check if it matches the process we forked. */ | |
610 | if (wait_pid != pid) | |
611 | error("Strange, wait returned pid %d, expected %d", | |
57112b5a | 612 | wait_pid, pid); |
5260325f | 613 | } |
8efc0c15 | 614 | |
5260325f | 615 | /* We no longer want our SIGCHLD handler to be called. */ |
616 | signal(SIGCHLD, SIG_DFL); | |
617 | ||
618 | /* Check if it exited normally. */ | |
619 | if (WIFEXITED(wait_status)) { | |
620 | /* Yes, normal exit. Get exit status and send it to the client. */ | |
621 | debug("Command exited with status %d.", WEXITSTATUS(wait_status)); | |
622 | packet_start(SSH_SMSG_EXITSTATUS); | |
623 | packet_put_int(WEXITSTATUS(wait_status)); | |
624 | packet_send(); | |
625 | packet_write_wait(); | |
626 | ||
aa3378df | 627 | /* |
628 | * Wait for exit confirmation. Note that there might be | |
629 | * other packets coming before it; however, the program has | |
630 | * already died so we just ignore them. The client is | |
631 | * supposed to respond with the confirmation when it receives | |
632 | * the exit status. | |
633 | */ | |
5260325f | 634 | do { |
635 | int plen; | |
636 | type = packet_read(&plen); | |
637 | } | |
638 | while (type != SSH_CMSG_EXIT_CONFIRMATION); | |
639 | ||
640 | debug("Received exit confirmation."); | |
641 | return; | |
642 | } | |
643 | /* Check if the program terminated due to a signal. */ | |
644 | if (WIFSIGNALED(wait_status)) | |
645 | packet_disconnect("Command terminated on signal %d.", | |
646 | WTERMSIG(wait_status)); | |
647 | ||
648 | /* Some weird exit cause. Just exit. */ | |
649 | packet_disconnect("wait returned status %04x.", wait_status); | |
650 | /* NOTREACHED */ | |
651 | } |