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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 */
e78a59f5 8/*
9 * SSH2 support by Markus Friedl.
10 * Copyright (c) 2000 Markus Friedl. All rights reserved.
11 */
8efc0c15 12
13#include "includes.h"
14#include "xmalloc.h"
15#include "ssh.h"
16#include "packet.h"
17#include "buffer.h"
18#include "servconf.h"
19#include "pty.h"
7368a6c8 20#include "channels.h"
21
22#include "compat.h"
e78a59f5 23#include "ssh2.h"
24#include "session.h"
7368a6c8 25#include "dispatch.h"
8efc0c15 26
27static Buffer stdin_buffer; /* Buffer for stdin data. */
28static Buffer stdout_buffer; /* Buffer for stdout data. */
29static Buffer stderr_buffer; /* Buffer for stderr data. */
30static int fdin; /* Descriptor for stdin (for writing) */
31static int fdout; /* Descriptor for stdout (for reading);
32 May be same number as fdin. */
33static int fderr; /* Descriptor for stderr. May be -1. */
34static long stdin_bytes = 0; /* Number of bytes written to stdin. */
35static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */
36static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */
37static long fdout_bytes = 0; /* Number of stdout bytes read from program. */
38static int stdin_eof = 0; /* EOF message received from client. */
39static int fdout_eof = 0; /* EOF encountered reading from fdout. */
40static int fderr_eof = 0; /* EOF encountered readung from fderr. */
41static int connection_in; /* Connection to client (input). */
42static int connection_out; /* Connection to client (output). */
43static unsigned int buffer_high;/* "Soft" max buffer size. */
44static int max_fd; /* Max file descriptor number for select(). */
45
aa3378df 46/*
47 * This SIGCHLD kludge is used to detect when the child exits. The server
48 * will exit after that, as soon as forwarded connections have terminated.
691a8a9f 49 *
50 * After SIGCHLD child_has_selected is set to 1 after the first pass
51 * through the wait_until_can_do_something() select(). This ensures
52 * that the child's output gets a chance to drain before it is yanked.
aa3378df 53 */
8efc0c15 54
9da5c3c9 55static pid_t child_pid; /* Pid of the child. */
8efc0c15 56static volatile int child_terminated; /* The child has terminated. */
691a8a9f 57static volatile int child_has_selected; /* Child has had chance to drain. */
8efc0c15 58static volatile int child_wait_status; /* Status from wait(). */
59
7368a6c8 60void server_init_dispatch(void);
61
6ae2364d 62void
5260325f 63sigchld_handler(int sig)
8efc0c15 64{
5260325f 65 int save_errno = errno;
9da5c3c9 66 pid_t wait_pid;
67
5260325f 68 debug("Received SIGCHLD.");
69 wait_pid = wait((int *) &child_wait_status);
70 if (wait_pid != -1) {
71 if (wait_pid != child_pid)
72 error("Strange, got SIGCHLD and wait returned pid %d but child is %d",
73 wait_pid, child_pid);
74 if (WIFEXITED(child_wait_status) ||
75 WIFSIGNALED(child_wait_status))
76 child_terminated = 1;
691a8a9f 77 child_has_selected = 0;
5260325f 78 }
79 signal(SIGCHLD, sigchld_handler);
80 errno = save_errno;
8efc0c15 81}
6ae2364d 82void
e78a59f5 83sigchld_handler2(int sig)
84{
85 int save_errno = errno;
86 debug("Received SIGCHLD.");
87 child_terminated = 1;
88 signal(SIGCHLD, sigchld_handler2);
89 errno = save_errno;
90}
8efc0c15 91
5260325f 92/*
93 * Make packets from buffered stderr data, and buffer it for sending
94 * to the client.
95 */
6ae2364d 96void
5260325f 97make_packets_from_stderr_data()
8efc0c15 98{
5260325f 99 int len;
100
101 /* Send buffered stderr data to the client. */
102 while (buffer_len(&stderr_buffer) > 0 &&
a408af76 103 packet_not_very_much_data_to_write()) {
5260325f 104 len = buffer_len(&stderr_buffer);
105 if (packet_is_interactive()) {
106 if (len > 512)
107 len = 512;
108 } else {
109 /* Keep the packets at reasonable size. */
110 if (len > packet_get_maxsize())
111 len = packet_get_maxsize();
112 }
113 packet_start(SSH_SMSG_STDERR_DATA);
114 packet_put_string(buffer_ptr(&stderr_buffer), len);
115 packet_send();
116 buffer_consume(&stderr_buffer, len);
117 stderr_bytes += len;
8efc0c15 118 }
8efc0c15 119}
120
5260325f 121/*
122 * Make packets from buffered stdout data, and buffer it for sending to the
123 * client.
124 */
6ae2364d 125void
5260325f 126make_packets_from_stdout_data()
8efc0c15 127{
5260325f 128 int len;
129
130 /* Send buffered stdout data to the client. */
131 while (buffer_len(&stdout_buffer) > 0 &&
a408af76 132 packet_not_very_much_data_to_write()) {
5260325f 133 len = buffer_len(&stdout_buffer);
134 if (packet_is_interactive()) {
135 if (len > 512)
136 len = 512;
137 } else {
138 /* Keep the packets at reasonable size. */
139 if (len > packet_get_maxsize())
140 len = packet_get_maxsize();
141 }
142 packet_start(SSH_SMSG_STDOUT_DATA);
143 packet_put_string(buffer_ptr(&stdout_buffer), len);
144 packet_send();
145 buffer_consume(&stdout_buffer, len);
146 stdout_bytes += len;
8efc0c15 147 }
8efc0c15 148}
149
5260325f 150/*
151 * Sleep in select() until we can do something. This will initialize the
152 * select masks. Upon return, the masks will indicate which descriptors
153 * have data or can accept data. Optionally, a maximum time can be specified
154 * for the duration of the wait (0 = infinite).
155 */
6ae2364d 156void
5260325f 157wait_until_can_do_something(fd_set * readset, fd_set * writeset,
158 unsigned int max_time_milliseconds)
8efc0c15 159{
5260325f 160 struct timeval tv, *tvp;
161 int ret;
8efc0c15 162
5260325f 163 /* When select fails we restart from here. */
8efc0c15 164retry_select:
165
5260325f 166 /* Initialize select() masks. */
167 FD_ZERO(readset);
168
aa3378df 169 /*
170 * Read packets from the client unless we have too much buffered
171 * stdin or channel data.
172 */
e78a59f5 173 if (compat20) {
1d1ffb87 174 /* wrong: bad condition XXX */
e78a59f5 175 if (channel_not_very_much_buffered_data())
176 FD_SET(connection_in, readset);
177 } else {
178 if (buffer_len(&stdin_buffer) < 4096 &&
179 channel_not_very_much_buffered_data())
180 FD_SET(connection_in, readset);
181 }
5260325f 182
aa3378df 183 /*
184 * If there is not too much data already buffered going to the
185 * client, try to get some more data from the program.
186 */
e78a59f5 187 if (!compat20 && packet_not_very_much_data_to_write()) {
5260325f 188 if (!fdout_eof)
189 FD_SET(fdout, readset);
190 if (!fderr_eof)
191 FD_SET(fderr, readset);
192 }
193 FD_ZERO(writeset);
194
195 /* Set masks for channel descriptors. */
196 channel_prepare_select(readset, writeset);
197
aa3378df 198 /*
199 * If we have buffered packet data going to the client, mark that
200 * descriptor.
201 */
5260325f 202 if (packet_have_data_to_write())
203 FD_SET(connection_out, writeset);
204
205 /* If we have buffered data, try to write some of that data to the
206 program. */
e78a59f5 207 if (!compat20 && fdin != -1 && buffer_len(&stdin_buffer) > 0)
5260325f 208 FD_SET(fdin, writeset);
209
210 /* Update the maximum descriptor number if appropriate. */
211 if (channel_max_fd() > max_fd)
212 max_fd = channel_max_fd();
213
aa3378df 214 /*
215 * If child has terminated and there is enough buffer space to read
216 * from it, then read as much as is available and exit.
217 */
5260325f 218 if (child_terminated && packet_not_very_much_data_to_write())
219 if (max_time_milliseconds == 0)
220 max_time_milliseconds = 100;
221
222 if (max_time_milliseconds == 0)
223 tvp = NULL;
224 else {
225 tv.tv_sec = max_time_milliseconds / 1000;
226 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
227 tvp = &tv;
228 }
e78a59f5 229 if (tvp!=NULL)
230 debug("tvp!=NULL kid %d mili %d", child_terminated, max_time_milliseconds);
8efc0c15 231
5260325f 232 /* Wait for something to happen, or the timeout to expire. */
233 ret = select(max_fd + 1, readset, writeset, NULL, tvp);
8efc0c15 234
5260325f 235 if (ret < 0) {
236 if (errno != EINTR)
237 error("select: %.100s", strerror(errno));
238 else
239 goto retry_select;
8efc0c15 240 }
691a8a9f 241
242 if (child_terminated)
243 child_has_selected = 1;
8efc0c15 244}
245
5260325f 246/*
247 * Processes input from the client and the program. Input data is stored
248 * in buffers and processed later.
249 */
6ae2364d 250void
5260325f 251process_input(fd_set * readset)
252{
253 int len;
254 char buf[16384];
255
256 /* Read and buffer any input data from the client. */
257 if (FD_ISSET(connection_in, readset)) {
258 len = read(connection_in, buf, sizeof(buf));
259 if (len == 0) {
260 verbose("Connection closed by remote host.");
261 fatal_cleanup();
0e73cc53 262 } else if (len < 0) {
263 if (errno != EINTR && errno != EAGAIN) {
264 verbose("Read error from remote host: %.100s", strerror(errno));
265 fatal_cleanup();
266 }
267 } else {
268 /* Buffer any received data. */
269 packet_process_incoming(buf, len);
5260325f 270 }
5260325f 271 }
e78a59f5 272 if (compat20)
273 return;
274
5260325f 275 /* Read and buffer any available stdout data from the program. */
276 if (!fdout_eof && FD_ISSET(fdout, readset)) {
277 len = read(fdout, buf, sizeof(buf));
0e73cc53 278 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
279 /* do nothing */
280 } else if (len <= 0) {
5260325f 281 fdout_eof = 1;
0e73cc53 282 } else {
5260325f 283 buffer_append(&stdout_buffer, buf, len);
284 fdout_bytes += len;
285 }
286 }
287 /* Read and buffer any available stderr data from the program. */
288 if (!fderr_eof && FD_ISSET(fderr, readset)) {
289 len = read(fderr, buf, sizeof(buf));
0e73cc53 290 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
291 /* do nothing */
292 } else if (len <= 0) {
5260325f 293 fderr_eof = 1;
0e73cc53 294 } else {
5260325f 295 buffer_append(&stderr_buffer, buf, len);
0e73cc53 296 }
5260325f 297 }
298}
8efc0c15 299
5260325f 300/*
301 * Sends data from internal buffers to client program stdin.
302 */
6ae2364d 303void
5260325f 304process_output(fd_set * writeset)
8efc0c15 305{
5260325f 306 int len;
307
308 /* Write buffered data to program stdin. */
e78a59f5 309 if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
5260325f 310 len = write(fdin, buffer_ptr(&stdin_buffer),
a408af76 311 buffer_len(&stdin_buffer));
0e73cc53 312 if (len < 0 && (errno == EINTR || errno == EAGAIN)) {
313 /* do nothing */
314 } else if (len <= 0) {
8efc0c15 315#ifdef USE_PIPES
5260325f 316 close(fdin);
8efc0c15 317#else
7368a6c8 318 if (fdin != fdout)
5260325f 319 close(fdin);
320 else
321 shutdown(fdin, SHUT_WR); /* We will no longer send. */
8efc0c15 322#endif
5260325f 323 fdin = -1;
324 } else {
325 /* Successful write. Consume the data from the buffer. */
326 buffer_consume(&stdin_buffer, len);
327 /* Update the count of bytes written to the program. */
328 stdin_bytes += len;
329 }
8efc0c15 330 }
5260325f 331 /* Send any buffered packet data to the client. */
332 if (FD_ISSET(connection_out, writeset))
333 packet_write_poll();
8efc0c15 334}
335
5260325f 336/*
337 * Wait until all buffered output has been sent to the client.
338 * This is used when the program terminates.
339 */
6ae2364d 340void
5260325f 341drain_output()
8efc0c15 342{
5260325f 343 /* Send any buffered stdout data to the client. */
344 if (buffer_len(&stdout_buffer) > 0) {
345 packet_start(SSH_SMSG_STDOUT_DATA);
346 packet_put_string(buffer_ptr(&stdout_buffer),
347 buffer_len(&stdout_buffer));
348 packet_send();
349 /* Update the count of sent bytes. */
350 stdout_bytes += buffer_len(&stdout_buffer);
351 }
352 /* Send any buffered stderr data to the client. */
353 if (buffer_len(&stderr_buffer) > 0) {
354 packet_start(SSH_SMSG_STDERR_DATA);
355 packet_put_string(buffer_ptr(&stderr_buffer),
356 buffer_len(&stderr_buffer));
357 packet_send();
358 /* Update the count of sent bytes. */
359 stderr_bytes += buffer_len(&stderr_buffer);
360 }
361 /* Wait until all buffered data has been written to the client. */
362 packet_write_wait();
8efc0c15 363}
364
6ae2364d 365void
7368a6c8 366process_buffered_input_packets()
367{
368 dispatch_run(DISPATCH_NONBLOCK, NULL);
369}
370
5260325f 371/*
372 * Performs the interactive session. This handles data transmission between
373 * the client and the program. Note that the notion of stdin, stdout, and
374 * stderr in this function is sort of reversed: this function writes to
375 * stdin (of the child program), and reads from stdout and stderr (of the
376 * child program).
377 */
6ae2364d 378void
9da5c3c9 379server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
8efc0c15 380{
9da5c3c9 381 int wait_status; /* Status returned by wait(). */
382 pid_t wait_pid; /* pid returned by wait(). */
5260325f 383 int waiting_termination = 0; /* Have displayed waiting close message. */
384 unsigned int max_time_milliseconds;
385 unsigned int previous_stdout_buffer_bytes;
386 unsigned int stdout_buffer_bytes;
387 int type;
388
389 debug("Entering interactive session.");
390
391 /* Initialize the SIGCHLD kludge. */
392 child_pid = pid;
393 child_terminated = 0;
691a8a9f 394 child_has_selected = 0;
5260325f 395 signal(SIGCHLD, sigchld_handler);
396
397 /* Initialize our global variables. */
398 fdin = fdin_arg;
399 fdout = fdout_arg;
400 fderr = fderr_arg;
0e73cc53 401
402 /* nonblocking IO */
403 set_nonblock(fdin);
404 set_nonblock(fdout);
ff873e98 405 /* we don't have stderr for interactive terminal sessions, see below */
406 if (fderr != -1)
407 set_nonblock(fderr);
0e73cc53 408
5260325f 409 connection_in = packet_get_connection_in();
410 connection_out = packet_get_connection_out();
411
412 previous_stdout_buffer_bytes = 0;
413
414 /* Set approximate I/O buffer size. */
415 if (packet_is_interactive())
416 buffer_high = 4096;
417 else
418 buffer_high = 64 * 1024;
419
420 /* Initialize max_fd to the maximum of the known file descriptors. */
421 max_fd = fdin;
422 if (fdout > max_fd)
423 max_fd = fdout;
424 if (fderr != -1 && fderr > max_fd)
425 max_fd = fderr;
426 if (connection_in > max_fd)
427 max_fd = connection_in;
428 if (connection_out > max_fd)
429 max_fd = connection_out;
430
431 /* Initialize Initialize buffers. */
432 buffer_init(&stdin_buffer);
433 buffer_init(&stdout_buffer);
434 buffer_init(&stderr_buffer);
435
aa3378df 436 /*
437 * If we have no separate fderr (which is the case when we have a pty
438 * - there we cannot make difference between data sent to stdout and
439 * stderr), indicate that we have seen an EOF from stderr. This way
440 * we don\'t need to check the descriptor everywhere.
441 */
5260325f 442 if (fderr == -1)
443 fderr_eof = 1;
444
7368a6c8 445 server_init_dispatch();
446
5260325f 447 /* Main loop of the server for the interactive session mode. */
448 for (;;) {
449 fd_set readset, writeset;
450
451 /* Process buffered packets from the client. */
452 process_buffered_input_packets();
453
aa3378df 454 /*
455 * If we have received eof, and there is no more pending
456 * input data, cause a real eof by closing fdin.
457 */
5260325f 458 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
8efc0c15 459#ifdef USE_PIPES
5260325f 460 close(fdin);
8efc0c15 461#else
7368a6c8 462 if (fdin != fdout)
5260325f 463 close(fdin);
464 else
465 shutdown(fdin, SHUT_WR); /* We will no longer send. */
8efc0c15 466#endif
5260325f 467 fdin = -1;
468 }
aa3378df 469 /* Make packets from buffered stderr data to send to the client. */
5260325f 470 make_packets_from_stderr_data();
471
aa3378df 472 /*
473 * Make packets from buffered stdout data to send to the
474 * client. If there is very little to send, this arranges to
475 * not send them now, but to wait a short while to see if we
476 * are getting more data. This is necessary, as some systems
477 * wake up readers from a pty after each separate character.
478 */
5260325f 479 max_time_milliseconds = 0;
480 stdout_buffer_bytes = buffer_len(&stdout_buffer);
481 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
482 stdout_buffer_bytes != previous_stdout_buffer_bytes) {
483 /* try again after a while */
484 max_time_milliseconds = 10;
485 } else {
486 /* Send it now. */
487 make_packets_from_stdout_data();
488 }
489 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
490
491 /* Send channel data to the client. */
492 if (packet_not_very_much_data_to_write())
493 channel_output_poll();
494
aa3378df 495 /*
496 * Bail out of the loop if the program has closed its output
497 * descriptors, and we have no more data to send to the
498 * client, and there is no pending buffered data.
499 */
691a8a9f 500 if (((fdout_eof && fderr_eof) ||
501 (child_terminated && child_has_selected)) &&
502 !packet_have_data_to_write() &&
503 (buffer_len(&stdout_buffer) == 0) &&
504 (buffer_len(&stderr_buffer) == 0)) {
5260325f 505 if (!channel_still_open())
7368a6c8 506 break;
5260325f 507 if (!waiting_termination) {
508 const char *s = "Waiting for forwarded connections to terminate...\r\n";
509 char *cp;
510 waiting_termination = 1;
511 buffer_append(&stderr_buffer, s, strlen(s));
512
513 /* Display list of open channels. */
514 cp = channel_open_message();
515 buffer_append(&stderr_buffer, cp, strlen(cp));
516 xfree(cp);
517 }
518 }
519 /* Sleep in select() until we can do something. */
520 wait_until_can_do_something(&readset, &writeset,
521 max_time_milliseconds);
522
523 /* Process any channel events. */
524 channel_after_select(&readset, &writeset);
525
526 /* Process input from the client and from program stdout/stderr. */
527 process_input(&readset);
528
529 /* Process output to the client and to program stdin. */
530 process_output(&writeset);
8efc0c15 531 }
532
5260325f 533 /* Cleanup and termination code. */
8efc0c15 534
5260325f 535 /* Wait until all output has been sent to the client. */
536 drain_output();
8efc0c15 537
5260325f 538 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
539 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
8efc0c15 540
5260325f 541 /* Free and clear the buffers. */
542 buffer_free(&stdin_buffer);
543 buffer_free(&stdout_buffer);
544 buffer_free(&stderr_buffer);
8efc0c15 545
5260325f 546 /* Close the file descriptors. */
547 if (fdout != -1)
548 close(fdout);
549 fdout = -1;
550 fdout_eof = 1;
551 if (fderr != -1)
552 close(fderr);
553 fderr = -1;
554 fderr_eof = 1;
555 if (fdin != -1)
556 close(fdin);
557 fdin = -1;
558
559 /* Stop listening for channels; this removes unix domain sockets. */
560 channel_stop_listening();
561
562 /* Wait for the child to exit. Get its exit status. */
563 wait_pid = wait(&wait_status);
564 if (wait_pid < 0) {
565 /*
566 * It is possible that the wait was handled by SIGCHLD
567 * handler. This may result in either: this call
568 * returning with EINTR, or: this call returning ECHILD.
569 */
570 if (child_terminated)
571 wait_status = child_wait_status;
572 else
573 packet_disconnect("wait: %.100s", strerror(errno));
574 } else {
575 /* Check if it matches the process we forked. */
576 if (wait_pid != pid)
577 error("Strange, wait returned pid %d, expected %d",
57112b5a 578 wait_pid, pid);
5260325f 579 }
8efc0c15 580
5260325f 581 /* We no longer want our SIGCHLD handler to be called. */
582 signal(SIGCHLD, SIG_DFL);
583
584 /* Check if it exited normally. */
585 if (WIFEXITED(wait_status)) {
586 /* Yes, normal exit. Get exit status and send it to the client. */
587 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
588 packet_start(SSH_SMSG_EXITSTATUS);
589 packet_put_int(WEXITSTATUS(wait_status));
590 packet_send();
591 packet_write_wait();
592
aa3378df 593 /*
594 * Wait for exit confirmation. Note that there might be
595 * other packets coming before it; however, the program has
596 * already died so we just ignore them. The client is
597 * supposed to respond with the confirmation when it receives
598 * the exit status.
599 */
5260325f 600 do {
601 int plen;
602 type = packet_read(&plen);
603 }
604 while (type != SSH_CMSG_EXIT_CONFIRMATION);
605
606 debug("Received exit confirmation.");
607 return;
608 }
609 /* Check if the program terminated due to a signal. */
610 if (WIFSIGNALED(wait_status))
611 packet_disconnect("Command terminated on signal %d.",
612 WTERMSIG(wait_status));
613
614 /* Some weird exit cause. Just exit. */
615 packet_disconnect("wait returned status %04x.", wait_status);
616 /* NOTREACHED */
617}
7368a6c8 618
6ae2364d 619void
e78a59f5 620server_loop2(void)
621{
622 fd_set readset, writeset;
623 int had_channel = 0;
624 int status;
625 pid_t pid;
626
627 debug("Entering interactive session for SSH2.");
628
629 signal(SIGCHLD, sigchld_handler2);
630 child_terminated = 0;
631 connection_in = packet_get_connection_in();
632 connection_out = packet_get_connection_out();
633 max_fd = connection_in;
634 if (connection_out > max_fd)
635 max_fd = connection_out;
636 server_init_dispatch();
637
638 for (;;) {
639 process_buffered_input_packets();
640 if (!had_channel && channel_still_open())
641 had_channel = 1;
642 if (had_channel && !channel_still_open()) {
643 debug("!channel_still_open.");
644 break;
645 }
646 if (packet_not_very_much_data_to_write())
647 channel_output_poll();
648 wait_until_can_do_something(&readset, &writeset, 0);
649 if (child_terminated) {
650 while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
651 session_close_by_pid(pid, status);
652 child_terminated = 0;
653 }
654 channel_after_select(&readset, &writeset);
655 process_input(&readset);
656 process_output(&writeset);
657 }
658 signal(SIGCHLD, SIG_DFL);
659 while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
660 session_close_by_pid(pid, status);
661 channel_stop_listening();
662}
663
7368a6c8 664void
665server_input_stdin_data(int type, int plen)
666{
667 char *data;
668 unsigned int data_len;
669
670 /* Stdin data from the client. Append it to the buffer. */
671 /* Ignore any data if the client has closed stdin. */
672 if (fdin == -1)
673 return;
674 data = packet_get_string(&data_len);
675 packet_integrity_check(plen, (4 + data_len), type);
676 buffer_append(&stdin_buffer, data, data_len);
677 memset(data, 0, data_len);
678 xfree(data);
679}
680
681void
682server_input_eof(int type, int plen)
683{
684 /*
685 * Eof from the client. The stdin descriptor to the
686 * program will be closed when all buffered data has
687 * drained.
688 */
689 debug("EOF received for stdin.");
690 packet_integrity_check(plen, 0, type);
691 stdin_eof = 1;
692}
693
694void
695server_input_window_size(int type, int plen)
696{
697 int row = packet_get_int();
698 int col = packet_get_int();
699 int xpixel = packet_get_int();
700 int ypixel = packet_get_int();
701
702 debug("Window change received.");
703 packet_integrity_check(plen, 4 * 4, type);
704 if (fdin != -1)
705 pty_change_window_size(fdin, row, col, xpixel, ypixel);
706}
707
e78a59f5 708int
709input_direct_tcpip(void)
710{
711 int sock;
6ae2364d 712 char *target, *originator;
713 int target_port, originator_port;
e78a59f5 714
6ae2364d 715 target = packet_get_string(NULL);
716 target_port = packet_get_int();
e78a59f5 717 originator = packet_get_string(NULL);
718 originator_port = packet_get_int();
6ae2364d 719 packet_done();
e78a59f5 720 /* XXX check permission */
6ae2364d 721 sock = channel_connect_to(target, target_port);
722 xfree(target);
e78a59f5 723 xfree(originator);
724 if (sock < 0)
725 return -1;
726 return channel_new("direct-tcpip", SSH_CHANNEL_OPEN,
727 sock, sock, -1, 4*1024, 32*1024, 0, xstrdup("direct-tcpip"));
728}
729
6ae2364d 730void
e78a59f5 731server_input_channel_open(int type, int plen)
732{
733 Channel *c = NULL;
734 char *ctype;
735 int id;
736 unsigned int len;
737 int rchan;
738 int rmaxpack;
739 int rwindow;
740
741 ctype = packet_get_string(&len);
742 rchan = packet_get_int();
743 rwindow = packet_get_int();
744 rmaxpack = packet_get_int();
745
a306f2dd 746 debug("channel_input_open: ctype %s rchan %d win %d max %d",
e78a59f5 747 ctype, rchan, rwindow, rmaxpack);
748
749 if (strcmp(ctype, "session") == 0) {
750 debug("open session");
6ae2364d 751 packet_done();
e78a59f5 752 /*
753 * A server session has no fd to read or write
754 * until a CHANNEL_REQUEST for a shell is made,
755 * so we set the type to SSH_CHANNEL_LARVAL.
756 * Additionally, a callback for handling all
757 * CHANNEL_REQUEST messages is registered.
758 */
759 id = channel_new(ctype, SSH_CHANNEL_LARVAL,
760 -1, -1, -1, 0, 32*1024, 0, xstrdup("server-session"));
761 if (session_open(id) == 1) {
762 channel_register_callback(id, SSH2_MSG_CHANNEL_REQUEST,
763 session_input_channel_req, (void *)0);
764 channel_register_cleanup(id, session_close_by_channel);
765 c = channel_lookup(id);
766 } else {
767 debug("session open failed, free channel %d", id);
768 channel_free(id);
769 }
770 } else if (strcmp(ctype, "direct-tcpip") == 0) {
771 debug("open direct-tcpip");
772 id = input_direct_tcpip();
773 if (id >= 0)
774 c = channel_lookup(id);
775 }
776 if (c != NULL) {
777 debug("confirm %s", ctype);
778 c->remote_id = rchan;
779 c->remote_window = rwindow;
780 c->remote_maxpacket = rmaxpack;
781
782 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
783 packet_put_int(c->remote_id);
784 packet_put_int(c->self);
785 packet_put_int(c->local_window);
786 packet_put_int(c->local_maxpacket);
787 packet_send();
788 } else {
789 debug("failure %s", ctype);
790 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
791 packet_put_int(rchan);
792 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
793 packet_put_cstring("bla bla");
794 packet_put_cstring("");
795 packet_send();
796 }
797 xfree(ctype);
798}
799
6ae2364d 800void
e78a59f5 801server_init_dispatch_20()
802{
803 debug("server_init_dispatch_20");
804 dispatch_init(&dispatch_protocol_error);
805 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
806 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
807 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
808 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
809 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
810 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
811 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
812 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &channel_input_channel_request);
813 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
814}
6ae2364d 815void
7368a6c8 816server_init_dispatch_13()
817{
818 debug("server_init_dispatch_13");
819 dispatch_init(NULL);
820 dispatch_set(SSH_CMSG_EOF, &server_input_eof);
821 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
822 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
823 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
824 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
825 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
826 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
827 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
828 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
829}
6ae2364d 830void
7368a6c8 831server_init_dispatch_15()
832{
833 server_init_dispatch_13();
834 debug("server_init_dispatch_15");
835 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
836 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
837}
6ae2364d 838void
7368a6c8 839server_init_dispatch()
840{
e78a59f5 841 if (compat20)
842 server_init_dispatch_20();
843 else if (compat13)
7368a6c8 844 server_init_dispatch_13();
845 else
846 server_init_dispatch_15();
847}
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