1 /* $OpenBSD: serverloop.c,v 1.178 2015/02/20 22:17:21 djm Exp $ */
2 /*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
6 * Server main loop for handling the interactive session.
7 *
8 * As far as I am concerned, the code I have written for this software
9 * can be used freely for any purpose. Any derived versions of this
10 * software must be clearly marked as such, and if the derived work is
11 * incompatible with the protocol description in the RFC file, it must be
12 * called by a name other than "ssh" or "Secure Shell".
13 *
14 * SSH2 support by Markus Friedl.
15 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions
19 * are met:
20 * 1. Redistributions of source code must retain the above copyright
21 * notice, this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright
23 * notice, this list of conditions and the following disclaimer in the
24 * documentation and/or other materials provided with the distribution.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #include "includes.h"
39
40 #include <sys/param.h> /* MIN MAX */
41 #include <sys/types.h>
42 #include <sys/wait.h>
43 #include <sys/socket.h>
44 #ifdef HAVE_SYS_TIME_H
45 # include <sys/time.h>
46 #endif
47
48 #include <netinet/in.h>
49
50 #include <errno.h>
51 #include <fcntl.h>
52 #include <pwd.h>
53 #include <signal.h>
54 #include <string.h>
55 #include <termios.h>
56 #include <unistd.h>
57 #include <stdarg.h>
58
59 #include "openbsd-compat/sys-queue.h"
60 #include "xmalloc.h"
61 #include "packet.h"
62 #include "buffer.h"
63 #include "log.h"
64 #include "misc.h"
65 #include "servconf.h"
66 #include "canohost.h"
67 #include "sshpty.h"
68 #include "channels.h"
69 #include "compat.h"
70 #include "ssh1.h"
71 #include "ssh2.h"
72 #include "key.h"
73 #include "cipher.h"
74 #include "kex.h"
75 #include "hostfile.h"
76 #include "auth.h"
77 #include "session.h"
78 #include "dispatch.h"
79 #include "auth-options.h"
80 #include "serverloop.h"
81 #include "roaming.h"
82 #include "ssherr.h"
83
84 extern ServerOptions options;
85
86 /* XXX */
87 extern Authctxt *the_authctxt;
88 extern int use_privsep;
89
90 static Buffer stdin_buffer; /* Buffer for stdin data. */
91 static Buffer stdout_buffer; /* Buffer for stdout data. */
92 static Buffer stderr_buffer; /* Buffer for stderr data. */
93 static int fdin; /* Descriptor for stdin (for writing) */
94 static int fdout; /* Descriptor for stdout (for reading);
95 May be same number as fdin. */
96 static int fderr; /* Descriptor for stderr. May be -1. */
97 static long stdin_bytes = 0; /* Number of bytes written to stdin. */
98 static long stdout_bytes = 0; /* Number of stdout bytes sent to client. */
99 static long stderr_bytes = 0; /* Number of stderr bytes sent to client. */
100 static long fdout_bytes = 0; /* Number of stdout bytes read from program. */
101 static int stdin_eof = 0; /* EOF message received from client. */
102 static int fdout_eof = 0; /* EOF encountered reading from fdout. */
103 static int fderr_eof = 0; /* EOF encountered readung from fderr. */
104 static int fdin_is_tty = 0; /* fdin points to a tty. */
105 static int connection_in; /* Connection to client (input). */
106 static int connection_out; /* Connection to client (output). */
107 static int connection_closed = 0; /* Connection to client closed. */
108 static u_int buffer_high; /* "Soft" max buffer size. */
109 static int no_more_sessions = 0; /* Disallow further sessions. */
110
111 /*
112 * This SIGCHLD kludge is used to detect when the child exits. The server
113 * will exit after that, as soon as forwarded connections have terminated.
114 */
115
116 static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
117
118 /* Cleanup on signals (!use_privsep case only) */
119 static volatile sig_atomic_t received_sigterm = 0;
120
121 /* prototypes */
122 static void server_init_dispatch(void);
123
124 /*
125 * we write to this pipe if a SIGCHLD is caught in order to avoid
126 * the race between select() and child_terminated
127 */
128 static int notify_pipe[2];
129 static void
notify_setup(void)130 notify_setup(void)
131 {
132 if (pipe(notify_pipe) < 0) {
133 error("pipe(notify_pipe) failed %s", strerror(errno));
134 } else if ((fcntl(notify_pipe[0], F_SETFD, FD_CLOEXEC) == -1) ||
135 (fcntl(notify_pipe[1], F_SETFD, FD_CLOEXEC) == -1)) {
136 error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
137 close(notify_pipe[0]);
138 close(notify_pipe[1]);
139 } else {
140 set_nonblock(notify_pipe[0]);
141 set_nonblock(notify_pipe[1]);
142 return;
143 }
144 notify_pipe[0] = -1; /* read end */
145 notify_pipe[1] = -1; /* write end */
146 }
147 static void
notify_parent(void)148 notify_parent(void)
149 {
150 if (notify_pipe[1] != -1)
151 (void)write(notify_pipe[1], "", 1);
152 }
153 static void
notify_prepare(fd_set * readset)154 notify_prepare(fd_set *readset)
155 {
156 if (notify_pipe[0] != -1)
157 FD_SET(notify_pipe[0], readset);
158 }
159 static void
notify_done(fd_set * readset)160 notify_done(fd_set *readset)
161 {
162 char c;
163
164 if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
165 while (read(notify_pipe[0], &c, 1) != -1)
166 debug2("notify_done: reading");
167 }
168
169 /*ARGSUSED*/
170 static void
sigchld_handler(int sig)171 sigchld_handler(int sig)
172 {
173 int save_errno = errno;
174 child_terminated = 1;
175 #ifndef _UNICOS
176 mysignal(SIGCHLD, sigchld_handler);
177 #endif
178 notify_parent();
179 errno = save_errno;
180 }
181
182 /*ARGSUSED*/
183 static void
sigterm_handler(int sig)184 sigterm_handler(int sig)
185 {
186 received_sigterm = sig;
187 }
188
189 /*
190 * Make packets from buffered stderr data, and buffer it for sending
191 * to the client.
192 */
193 static void
make_packets_from_stderr_data(void)194 make_packets_from_stderr_data(void)
195 {
196 u_int len;
197
198 /* Send buffered stderr data to the client. */
199 while (buffer_len(&stderr_buffer) > 0 &&
200 packet_not_very_much_data_to_write()) {
201 len = buffer_len(&stderr_buffer);
202 if (packet_is_interactive()) {
203 if (len > 512)
204 len = 512;
205 } else {
206 /* Keep the packets at reasonable size. */
207 if (len > packet_get_maxsize())
208 len = packet_get_maxsize();
209 }
210 packet_start(SSH_SMSG_STDERR_DATA);
211 packet_put_string(buffer_ptr(&stderr_buffer), len);
212 packet_send();
213 buffer_consume(&stderr_buffer, len);
214 stderr_bytes += len;
215 }
216 }
217
218 /*
219 * Make packets from buffered stdout data, and buffer it for sending to the
220 * client.
221 */
222 static void
make_packets_from_stdout_data(void)223 make_packets_from_stdout_data(void)
224 {
225 u_int len;
226
227 /* Send buffered stdout data to the client. */
228 while (buffer_len(&stdout_buffer) > 0 &&
229 packet_not_very_much_data_to_write()) {
230 len = buffer_len(&stdout_buffer);
231 if (packet_is_interactive()) {
232 if (len > 512)
233 len = 512;
234 } else {
235 /* Keep the packets at reasonable size. */
236 if (len > packet_get_maxsize())
237 len = packet_get_maxsize();
238 }
239 packet_start(SSH_SMSG_STDOUT_DATA);
240 packet_put_string(buffer_ptr(&stdout_buffer), len);
241 packet_send();
242 buffer_consume(&stdout_buffer, len);
243 stdout_bytes += len;
244 }
245 }
246
247 static void
client_alive_check(void)248 client_alive_check(void)
249 {
250 int channel_id;
251
252 /* timeout, check to see how many we have had */
253 if (packet_inc_alive_timeouts() > options.client_alive_count_max) {
254 logit("Timeout, client not responding.");
255 cleanup_exit(255);
256 }
257
258 /*
259 * send a bogus global/channel request with "wantreply",
260 * we should get back a failure
261 */
262 if ((channel_id = channel_find_open()) == -1) {
263 packet_start(SSH2_MSG_GLOBAL_REQUEST);
264 packet_put_cstring("keepalive@openssh.com");
265 packet_put_char(1); /* boolean: want reply */
266 } else {
267 channel_request_start(channel_id, "keepalive@openssh.com", 1);
268 }
269 packet_send();
270 }
271
272 /*
273 * Sleep in select() until we can do something. This will initialize the
274 * select masks. Upon return, the masks will indicate which descriptors
275 * have data or can accept data. Optionally, a maximum time can be specified
276 * for the duration of the wait (0 = infinite).
277 */
278 static void
wait_until_can_do_something(fd_set ** readsetp,fd_set ** writesetp,int * maxfdp,u_int * nallocp,u_int64_t max_time_milliseconds)279 wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
280 u_int *nallocp, u_int64_t max_time_milliseconds)
281 {
282 struct timeval tv, *tvp;
283 int ret;
284 time_t minwait_secs = 0;
285 int client_alive_scheduled = 0;
286 int program_alive_scheduled = 0;
287
288 /* Allocate and update select() masks for channel descriptors. */
289 channel_prepare_select(readsetp, writesetp, maxfdp, nallocp,
290 &minwait_secs, 0);
291
292 if (minwait_secs != 0)
293 max_time_milliseconds = MIN(max_time_milliseconds,
294 (u_int)minwait_secs * 1000);
295
296 /*
297 * if using client_alive, set the max timeout accordingly,
298 * and indicate that this particular timeout was for client
299 * alive by setting the client_alive_scheduled flag.
300 *
301 * this could be randomized somewhat to make traffic
302 * analysis more difficult, but we're not doing it yet.
303 */
304 if (compat20 &&
305 max_time_milliseconds == 0 && options.client_alive_interval) {
306 client_alive_scheduled = 1;
307 max_time_milliseconds =
308 (u_int64_t)options.client_alive_interval * 1000;
309 }
310
311 if (compat20) {
312 #if 0
313 /* wrong: bad condition XXX */
314 if (channel_not_very_much_buffered_data())
315 #endif
316 FD_SET(connection_in, *readsetp);
317 } else {
318 /*
319 * Read packets from the client unless we have too much
320 * buffered stdin or channel data.
321 */
322 if (buffer_len(&stdin_buffer) < buffer_high &&
323 channel_not_very_much_buffered_data())
324 FD_SET(connection_in, *readsetp);
325 /*
326 * If there is not too much data already buffered going to
327 * the client, try to get some more data from the program.
328 */
329 if (packet_not_very_much_data_to_write()) {
330 program_alive_scheduled = child_terminated;
331 if (!fdout_eof)
332 FD_SET(fdout, *readsetp);
333 if (!fderr_eof)
334 FD_SET(fderr, *readsetp);
335 }
336 /*
337 * If we have buffered data, try to write some of that data
338 * to the program.
339 */
340 if (fdin != -1 && buffer_len(&stdin_buffer) > 0)
341 FD_SET(fdin, *writesetp);
342 }
343 notify_prepare(*readsetp);
344
345 /*
346 * If we have buffered packet data going to the client, mark that
347 * descriptor.
348 */
349 if (packet_have_data_to_write())
350 FD_SET(connection_out, *writesetp);
351
352 /*
353 * If child has terminated and there is enough buffer space to read
354 * from it, then read as much as is available and exit.
355 */
356 if (child_terminated && packet_not_very_much_data_to_write())
357 if (max_time_milliseconds == 0 || client_alive_scheduled)
358 max_time_milliseconds = 100;
359
360 if (max_time_milliseconds == 0)
361 tvp = NULL;
362 else {
363 tv.tv_sec = max_time_milliseconds / 1000;
364 tv.tv_usec = 1000 * (max_time_milliseconds % 1000);
365 tvp = &tv;
366 }
367
368 /* Wait for something to happen, or the timeout to expire. */
369 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
370
371 if (ret == -1) {
372 memset(*readsetp, 0, *nallocp);
373 memset(*writesetp, 0, *nallocp);
374 if (errno != EINTR)
375 error("select: %.100s", strerror(errno));
376 } else {
377 if (ret == 0 && client_alive_scheduled)
378 client_alive_check();
379 if (!compat20 && program_alive_scheduled && fdin_is_tty) {
380 if (!fdout_eof)
381 FD_SET(fdout, *readsetp);
382 if (!fderr_eof)
383 FD_SET(fderr, *readsetp);
384 }
385 }
386
387 notify_done(*readsetp);
388 }
389
390 /*
391 * Processes input from the client and the program. Input data is stored
392 * in buffers and processed later.
393 */
394 static void
process_input(fd_set * readset)395 process_input(fd_set *readset)
396 {
397 int len;
398 char buf[16384];
399
400 /* Read and buffer any input data from the client. */
401 if (FD_ISSET(connection_in, readset)) {
402 int cont = 0;
403 len = roaming_read(connection_in, buf, sizeof(buf), &cont);
404 if (len == 0) {
405 if (cont)
406 return;
407 verbose("Connection closed by %.100s",
408 get_remote_ipaddr());
409 connection_closed = 1;
410 if (compat20)
411 return;
412 cleanup_exit(255);
413 } else if (len < 0) {
414 if (errno != EINTR && errno != EAGAIN &&
415 errno != EWOULDBLOCK) {
416 verbose("Read error from remote host "
417 "%.100s: %.100s",
418 get_remote_ipaddr(), strerror(errno));
419 cleanup_exit(255);
420 }
421 } else {
422 /* Buffer any received data. */
423 packet_process_incoming(buf, len);
424 }
425 }
426 if (compat20)
427 return;
428
429 /* Read and buffer any available stdout data from the program. */
430 if (!fdout_eof && FD_ISSET(fdout, readset)) {
431 errno = 0;
432 len = read(fdout, buf, sizeof(buf));
433 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
434 errno == EWOULDBLOCK) && !child_terminated))) {
435 /* do nothing */
436 #ifndef PTY_ZEROREAD
437 } else if (len <= 0) {
438 #else
439 } else if ((!isatty(fdout) && len <= 0) ||
440 (isatty(fdout) && (len < 0 || (len == 0 && errno != 0)))) {
441 #endif
442 fdout_eof = 1;
443 } else {
444 buffer_append(&stdout_buffer, buf, len);
445 fdout_bytes += len;
446 }
447 }
448 /* Read and buffer any available stderr data from the program. */
449 if (!fderr_eof && FD_ISSET(fderr, readset)) {
450 errno = 0;
451 len = read(fderr, buf, sizeof(buf));
452 if (len < 0 && (errno == EINTR || ((errno == EAGAIN ||
453 errno == EWOULDBLOCK) && !child_terminated))) {
454 /* do nothing */
455 #ifndef PTY_ZEROREAD
456 } else if (len <= 0) {
457 #else
458 } else if ((!isatty(fderr) && len <= 0) ||
459 (isatty(fderr) && (len < 0 || (len == 0 && errno != 0)))) {
460 #endif
461 fderr_eof = 1;
462 } else {
463 buffer_append(&stderr_buffer, buf, len);
464 }
465 }
466 }
467
468 /*
469 * Sends data from internal buffers to client program stdin.
470 */
471 static void
process_output(fd_set * writeset)472 process_output(fd_set *writeset)
473 {
474 struct termios tio;
475 u_char *data;
476 u_int dlen;
477 int len;
478
479 /* Write buffered data to program stdin. */
480 if (!compat20 && fdin != -1 && FD_ISSET(fdin, writeset)) {
481 data = buffer_ptr(&stdin_buffer);
482 dlen = buffer_len(&stdin_buffer);
483 len = write(fdin, data, dlen);
484 if (len < 0 &&
485 (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)) {
486 /* do nothing */
487 } else if (len <= 0) {
488 if (fdin != fdout)
489 close(fdin);
490 else
491 shutdown(fdin, SHUT_WR); /* We will no longer send. */
492 fdin = -1;
493 } else {
494 /* Successful write. */
495 if (fdin_is_tty && dlen >= 1 && data[0] != '\r' &&
496 tcgetattr(fdin, &tio) == 0 &&
497 !(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
498 /*
499 * Simulate echo to reduce the impact of
500 * traffic analysis
501 */
502 packet_send_ignore(len);
503 packet_send();
504 }
505 /* Consume the data from the buffer. */
506 buffer_consume(&stdin_buffer, len);
507 /* Update the count of bytes written to the program. */
508 stdin_bytes += len;
509 }
510 }
511 /* Send any buffered packet data to the client. */
512 if (FD_ISSET(connection_out, writeset))
513 packet_write_poll();
514 }
515
516 /*
517 * Wait until all buffered output has been sent to the client.
518 * This is used when the program terminates.
519 */
520 static void
drain_output(void)521 drain_output(void)
522 {
523 /* Send any buffered stdout data to the client. */
524 if (buffer_len(&stdout_buffer) > 0) {
525 packet_start(SSH_SMSG_STDOUT_DATA);
526 packet_put_string(buffer_ptr(&stdout_buffer),
527 buffer_len(&stdout_buffer));
528 packet_send();
529 /* Update the count of sent bytes. */
530 stdout_bytes += buffer_len(&stdout_buffer);
531 }
532 /* Send any buffered stderr data to the client. */
533 if (buffer_len(&stderr_buffer) > 0) {
534 packet_start(SSH_SMSG_STDERR_DATA);
535 packet_put_string(buffer_ptr(&stderr_buffer),
536 buffer_len(&stderr_buffer));
537 packet_send();
538 /* Update the count of sent bytes. */
539 stderr_bytes += buffer_len(&stderr_buffer);
540 }
541 /* Wait until all buffered data has been written to the client. */
542 packet_write_wait();
543 }
544
545 static void
process_buffered_input_packets(void)546 process_buffered_input_packets(void)
547 {
548 dispatch_run(DISPATCH_NONBLOCK, NULL, active_state);
549 }
550
551 /*
552 * Performs the interactive session. This handles data transmission between
553 * the client and the program. Note that the notion of stdin, stdout, and
554 * stderr in this function is sort of reversed: this function writes to
555 * stdin (of the child program), and reads from stdout and stderr (of the
556 * child program).
557 */
558 void
server_loop(pid_t pid,int fdin_arg,int fdout_arg,int fderr_arg)559 server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
560 {
561 fd_set *readset = NULL, *writeset = NULL;
562 int max_fd = 0;
563 u_int nalloc = 0;
564 int wait_status; /* Status returned by wait(). */
565 pid_t wait_pid; /* pid returned by wait(). */
566 int waiting_termination = 0; /* Have displayed waiting close message. */
567 u_int64_t max_time_milliseconds;
568 u_int previous_stdout_buffer_bytes;
569 u_int stdout_buffer_bytes;
570 int type;
571
572 debug("Entering interactive session.");
573
574 /* Initialize the SIGCHLD kludge. */
575 child_terminated = 0;
576 mysignal(SIGCHLD, sigchld_handler);
577
578 if (!use_privsep) {
579 signal(SIGTERM, sigterm_handler);
580 signal(SIGINT, sigterm_handler);
581 signal(SIGQUIT, sigterm_handler);
582 }
583
584 /* Initialize our global variables. */
585 fdin = fdin_arg;
586 fdout = fdout_arg;
587 fderr = fderr_arg;
588
589 /* nonblocking IO */
590 set_nonblock(fdin);
591 set_nonblock(fdout);
592 /* we don't have stderr for interactive terminal sessions, see below */
593 if (fderr != -1)
594 set_nonblock(fderr);
595
596 if (!(datafellows & SSH_BUG_IGNOREMSG) && isatty(fdin))
597 fdin_is_tty = 1;
598
599 connection_in = packet_get_connection_in();
600 connection_out = packet_get_connection_out();
601
602 notify_setup();
603
604 previous_stdout_buffer_bytes = 0;
605
606 /* Set approximate I/O buffer size. */
607 if (packet_is_interactive())
608 buffer_high = 4096;
609 else
610 buffer_high = 64 * 1024;
611
612 #if 0
613 /* Initialize max_fd to the maximum of the known file descriptors. */
614 max_fd = MAX(connection_in, connection_out);
615 max_fd = MAX(max_fd, fdin);
616 max_fd = MAX(max_fd, fdout);
617 if (fderr != -1)
618 max_fd = MAX(max_fd, fderr);
619 #endif
620
621 /* Initialize Initialize buffers. */
622 buffer_init(&stdin_buffer);
623 buffer_init(&stdout_buffer);
624 buffer_init(&stderr_buffer);
625
626 /*
627 * If we have no separate fderr (which is the case when we have a pty
628 * - there we cannot make difference between data sent to stdout and
629 * stderr), indicate that we have seen an EOF from stderr. This way
630 * we don't need to check the descriptor everywhere.
631 */
632 if (fderr == -1)
633 fderr_eof = 1;
634
635 server_init_dispatch();
636
637 /* Main loop of the server for the interactive session mode. */
638 for (;;) {
639
640 /* Process buffered packets from the client. */
641 process_buffered_input_packets();
642
643 /*
644 * If we have received eof, and there is no more pending
645 * input data, cause a real eof by closing fdin.
646 */
647 if (stdin_eof && fdin != -1 && buffer_len(&stdin_buffer) == 0) {
648 if (fdin != fdout)
649 close(fdin);
650 else
651 shutdown(fdin, SHUT_WR); /* We will no longer send. */
652 fdin = -1;
653 }
654 /* Make packets from buffered stderr data to send to the client. */
655 make_packets_from_stderr_data();
656
657 /*
658 * Make packets from buffered stdout data to send to the
659 * client. If there is very little to send, this arranges to
660 * not send them now, but to wait a short while to see if we
661 * are getting more data. This is necessary, as some systems
662 * wake up readers from a pty after each separate character.
663 */
664 max_time_milliseconds = 0;
665 stdout_buffer_bytes = buffer_len(&stdout_buffer);
666 if (stdout_buffer_bytes != 0 && stdout_buffer_bytes < 256 &&
667 stdout_buffer_bytes != previous_stdout_buffer_bytes) {
668 /* try again after a while */
669 max_time_milliseconds = 10;
670 } else {
671 /* Send it now. */
672 make_packets_from_stdout_data();
673 }
674 previous_stdout_buffer_bytes = buffer_len(&stdout_buffer);
675
676 /* Send channel data to the client. */
677 if (packet_not_very_much_data_to_write())
678 channel_output_poll();
679
680 /*
681 * Bail out of the loop if the program has closed its output
682 * descriptors, and we have no more data to send to the
683 * client, and there is no pending buffered data.
684 */
685 if (fdout_eof && fderr_eof && !packet_have_data_to_write() &&
686 buffer_len(&stdout_buffer) == 0 && buffer_len(&stderr_buffer) == 0) {
687 if (!channel_still_open())
688 break;
689 if (!waiting_termination) {
690 const char *s = "Waiting for forwarded connections to terminate...\r\n";
691 char *cp;
692 waiting_termination = 1;
693 buffer_append(&stderr_buffer, s, strlen(s));
694
695 /* Display list of open channels. */
696 cp = channel_open_message();
697 buffer_append(&stderr_buffer, cp, strlen(cp));
698 free(cp);
699 }
700 }
701 max_fd = MAX(connection_in, connection_out);
702 max_fd = MAX(max_fd, fdin);
703 max_fd = MAX(max_fd, fdout);
704 max_fd = MAX(max_fd, fderr);
705 max_fd = MAX(max_fd, notify_pipe[0]);
706
707 /* Sleep in select() until we can do something. */
708 wait_until_can_do_something(&readset, &writeset, &max_fd,
709 &nalloc, max_time_milliseconds);
710
711 if (received_sigterm) {
712 logit("Exiting on signal %d", (int)received_sigterm);
713 /* Clean up sessions, utmp, etc. */
714 cleanup_exit(255);
715 }
716
717 /* Process any channel events. */
718 channel_after_select(readset, writeset);
719
720 /* Process input from the client and from program stdout/stderr. */
721 process_input(readset);
722
723 /* Process output to the client and to program stdin. */
724 process_output(writeset);
725 }
726 free(readset);
727 free(writeset);
728
729 /* Cleanup and termination code. */
730
731 /* Wait until all output has been sent to the client. */
732 drain_output();
733
734 debug("End of interactive session; stdin %ld, stdout (read %ld, sent %ld), stderr %ld bytes.",
735 stdin_bytes, fdout_bytes, stdout_bytes, stderr_bytes);
736
737 /* Free and clear the buffers. */
738 buffer_free(&stdin_buffer);
739 buffer_free(&stdout_buffer);
740 buffer_free(&stderr_buffer);
741
742 /* Close the file descriptors. */
743 if (fdout != -1)
744 close(fdout);
745 fdout = -1;
746 fdout_eof = 1;
747 if (fderr != -1)
748 close(fderr);
749 fderr = -1;
750 fderr_eof = 1;
751 if (fdin != -1)
752 close(fdin);
753 fdin = -1;
754
755 channel_free_all();
756
757 /* We no longer want our SIGCHLD handler to be called. */
758 mysignal(SIGCHLD, SIG_DFL);
759
760 while ((wait_pid = waitpid(-1, &wait_status, 0)) < 0)
761 if (errno != EINTR)
762 packet_disconnect("wait: %.100s", strerror(errno));
763 if (wait_pid != pid)
764 error("Strange, wait returned pid %ld, expected %ld",
765 (long)wait_pid, (long)pid);
766
767 /* Check if it exited normally. */
768 if (WIFEXITED(wait_status)) {
769 /* Yes, normal exit. Get exit status and send it to the client. */
770 debug("Command exited with status %d.", WEXITSTATUS(wait_status));
771 packet_start(SSH_SMSG_EXITSTATUS);
772 packet_put_int(WEXITSTATUS(wait_status));
773 packet_send();
774 packet_write_wait();
775
776 /*
777 * Wait for exit confirmation. Note that there might be
778 * other packets coming before it; however, the program has
779 * already died so we just ignore them. The client is
780 * supposed to respond with the confirmation when it receives
781 * the exit status.
782 */
783 do {
784 type = packet_read();
785 }
786 while (type != SSH_CMSG_EXIT_CONFIRMATION);
787
788 debug("Received exit confirmation.");
789 return;
790 }
791 /* Check if the program terminated due to a signal. */
792 if (WIFSIGNALED(wait_status))
793 packet_disconnect("Command terminated on signal %d.",
794 WTERMSIG(wait_status));
795
796 /* Some weird exit cause. Just exit. */
797 packet_disconnect("wait returned status %04x.", wait_status);
798 /* NOTREACHED */
799 }
800
801 static void
collect_children(void)802 collect_children(void)
803 {
804 pid_t pid;
805 sigset_t oset, nset;
806 int status;
807
808 /* block SIGCHLD while we check for dead children */
809 sigemptyset(&nset);
810 sigaddset(&nset, SIGCHLD);
811 sigprocmask(SIG_BLOCK, &nset, &oset);
812 if (child_terminated) {
813 debug("Received SIGCHLD.");
814 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
815 (pid < 0 && errno == EINTR))
816 if (pid > 0)
817 session_close_by_pid(pid, status);
818 child_terminated = 0;
819 }
820 sigprocmask(SIG_SETMASK, &oset, NULL);
821 }
822
823 void
server_loop2(Authctxt * authctxt)824 server_loop2(Authctxt *authctxt)
825 {
826 fd_set *readset = NULL, *writeset = NULL;
827 int rekeying = 0, max_fd;
828 u_int nalloc = 0;
829 u_int64_t rekey_timeout_ms = 0;
830
831 debug("Entering interactive session for SSH2.");
832
833 mysignal(SIGCHLD, sigchld_handler);
834 child_terminated = 0;
835 connection_in = packet_get_connection_in();
836 connection_out = packet_get_connection_out();
837
838 if (!use_privsep) {
839 signal(SIGTERM, sigterm_handler);
840 signal(SIGINT, sigterm_handler);
841 signal(SIGQUIT, sigterm_handler);
842 }
843
844 notify_setup();
845
846 max_fd = MAX(connection_in, connection_out);
847 max_fd = MAX(max_fd, notify_pipe[0]);
848
849 server_init_dispatch();
850
851 for (;;) {
852 process_buffered_input_packets();
853
854 rekeying = (active_state->kex != NULL && !active_state->kex->done);
855
856 if (!rekeying && packet_not_very_much_data_to_write())
857 channel_output_poll();
858 if (options.rekey_interval > 0 && compat20 && !rekeying)
859 rekey_timeout_ms = packet_get_rekey_timeout() * 1000;
860 else
861 rekey_timeout_ms = 0;
862
863 wait_until_can_do_something(&readset, &writeset, &max_fd,
864 &nalloc, rekey_timeout_ms);
865
866 if (received_sigterm) {
867 logit("Exiting on signal %d", (int)received_sigterm);
868 /* Clean up sessions, utmp, etc. */
869 cleanup_exit(255);
870 }
871
872 collect_children();
873 if (!rekeying) {
874 channel_after_select(readset, writeset);
875 if (packet_need_rekeying()) {
876 debug("need rekeying");
877 active_state->kex->done = 0;
878 kex_send_kexinit(active_state);
879 }
880 }
881 process_input(readset);
882 if (connection_closed)
883 break;
884 process_output(writeset);
885 }
886 collect_children();
887
888 free(readset);
889 free(writeset);
890
891 /* free all channels, no more reads and writes */
892 channel_free_all();
893
894 /* free remaining sessions, e.g. remove wtmp entries */
895 session_destroy_all(NULL);
896 }
897
898 static int
server_input_keep_alive(int type,u_int32_t seq,void * ctxt)899 server_input_keep_alive(int type, u_int32_t seq, void *ctxt)
900 {
901 debug("Got %d/%u for keepalive", type, seq);
902 /*
903 * reset timeout, since we got a sane answer from the client.
904 * even if this was generated by something other than
905 * the bogus CHANNEL_REQUEST we send for keepalives.
906 */
907 packet_set_alive_timeouts(0);
908 return 0;
909 }
910
911 static int
server_input_stdin_data(int type,u_int32_t seq,void * ctxt)912 server_input_stdin_data(int type, u_int32_t seq, void *ctxt)
913 {
914 char *data;
915 u_int data_len;
916
917 /* Stdin data from the client. Append it to the buffer. */
918 /* Ignore any data if the client has closed stdin. */
919 if (fdin == -1)
920 return 0;
921 data = packet_get_string(&data_len);
922 packet_check_eom();
923 buffer_append(&stdin_buffer, data, data_len);
924 explicit_bzero(data, data_len);
925 free(data);
926 return 0;
927 }
928
929 static int
server_input_eof(int type,u_int32_t seq,void * ctxt)930 server_input_eof(int type, u_int32_t seq, void *ctxt)
931 {
932 /*
933 * Eof from the client. The stdin descriptor to the
934 * program will be closed when all buffered data has
935 * drained.
936 */
937 debug("EOF received for stdin.");
938 packet_check_eom();
939 stdin_eof = 1;
940 return 0;
941 }
942
943 static int
server_input_window_size(int type,u_int32_t seq,void * ctxt)944 server_input_window_size(int type, u_int32_t seq, void *ctxt)
945 {
946 u_int row = packet_get_int();
947 u_int col = packet_get_int();
948 u_int xpixel = packet_get_int();
949 u_int ypixel = packet_get_int();
950
951 debug("Window change received.");
952 packet_check_eom();
953 if (fdin != -1)
954 pty_change_window_size(fdin, row, col, xpixel, ypixel);
955 return 0;
956 }
957
958 static Channel *
server_request_direct_tcpip(void)959 server_request_direct_tcpip(void)
960 {
961 Channel *c = NULL;
962 char *target, *originator;
963 u_short target_port, originator_port;
964
965 target = packet_get_string(NULL);
966 target_port = packet_get_int();
967 originator = packet_get_string(NULL);
968 originator_port = packet_get_int();
969 packet_check_eom();
970
971 debug("server_request_direct_tcpip: originator %s port %d, target %s "
972 "port %d", originator, originator_port, target, target_port);
973
974 /* XXX fine grained permissions */
975 if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0 &&
976 !no_port_forwarding_flag) {
977 c = channel_connect_to_port(target, target_port,
978 "direct-tcpip", "direct-tcpip");
979 } else {
980 logit("refused local port forward: "
981 "originator %s port %d, target %s port %d",
982 originator, originator_port, target, target_port);
983 }
984
985 free(originator);
986 free(target);
987
988 return c;
989 }
990
991 static Channel *
server_request_direct_streamlocal(void)992 server_request_direct_streamlocal(void)
993 {
994 Channel *c = NULL;
995 char *target, *originator;
996 u_short originator_port;
997
998 target = packet_get_string(NULL);
999 originator = packet_get_string(NULL);
1000 originator_port = packet_get_int();
1001 packet_check_eom();
1002
1003 debug("server_request_direct_streamlocal: originator %s port %d, target %s",
1004 originator, originator_port, target);
1005
1006 /* XXX fine grained permissions */
1007 if ((options.allow_streamlocal_forwarding & FORWARD_LOCAL) != 0 &&
1008 !no_port_forwarding_flag) {
1009 c = channel_connect_to_path(target,
1010 "direct-streamlocal@openssh.com", "direct-streamlocal");
1011 } else {
1012 logit("refused streamlocal port forward: "
1013 "originator %s port %d, target %s",
1014 originator, originator_port, target);
1015 }
1016
1017 free(originator);
1018 free(target);
1019
1020 return c;
1021 }
1022
1023 static Channel *
server_request_tun(void)1024 server_request_tun(void)
1025 {
1026 Channel *c = NULL;
1027 int mode, tun;
1028 int sock;
1029
1030 mode = packet_get_int();
1031 switch (mode) {
1032 case SSH_TUNMODE_POINTOPOINT:
1033 case SSH_TUNMODE_ETHERNET:
1034 break;
1035 default:
1036 packet_send_debug("Unsupported tunnel device mode.");
1037 return NULL;
1038 }
1039 if ((options.permit_tun & mode) == 0) {
1040 packet_send_debug("Server has rejected tunnel device "
1041 "forwarding");
1042 return NULL;
1043 }
1044
1045 tun = packet_get_int();
1046 if (forced_tun_device != -1) {
1047 if (tun != SSH_TUNID_ANY && forced_tun_device != tun)
1048 goto done;
1049 tun = forced_tun_device;
1050 }
1051 sock = tun_open(tun, mode);
1052 if (sock < 0)
1053 goto done;
1054 c = channel_new("tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1055 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1056 c->datagram = 1;
1057 #if defined(SSH_TUN_FILTER)
1058 if (mode == SSH_TUNMODE_POINTOPOINT)
1059 channel_register_filter(c->self, sys_tun_infilter,
1060 sys_tun_outfilter, NULL, NULL);
1061 #endif
1062
1063 done:
1064 if (c == NULL)
1065 packet_send_debug("Failed to open the tunnel device.");
1066 return c;
1067 }
1068
1069 static Channel *
server_request_session(void)1070 server_request_session(void)
1071 {
1072 Channel *c;
1073
1074 debug("input_session_request");
1075 packet_check_eom();
1076
1077 if (no_more_sessions) {
1078 packet_disconnect("Possible attack: attempt to open a session "
1079 "after additional sessions disabled");
1080 }
1081
1082 /*
1083 * A server session has no fd to read or write until a
1084 * CHANNEL_REQUEST for a shell is made, so we set the type to
1085 * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
1086 * CHANNEL_REQUEST messages is registered.
1087 */
1088 c = channel_new("session", SSH_CHANNEL_LARVAL,
1089 -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
1090 0, "server-session", 1);
1091 if (session_open(the_authctxt, c->self) != 1) {
1092 debug("session open failed, free channel %d", c->self);
1093 channel_free(c);
1094 return NULL;
1095 }
1096 channel_register_cleanup(c->self, session_close_by_channel, 0);
1097 return c;
1098 }
1099
1100 static int
server_input_channel_open(int type,u_int32_t seq,void * ctxt)1101 server_input_channel_open(int type, u_int32_t seq, void *ctxt)
1102 {
1103 Channel *c = NULL;
1104 char *ctype;
1105 int rchan;
1106 u_int rmaxpack, rwindow, len;
1107
1108 ctype = packet_get_string(&len);
1109 rchan = packet_get_int();
1110 rwindow = packet_get_int();
1111 rmaxpack = packet_get_int();
1112
1113 debug("server_input_channel_open: ctype %s rchan %d win %d max %d",
1114 ctype, rchan, rwindow, rmaxpack);
1115
1116 if (strcmp(ctype, "session") == 0) {
1117 c = server_request_session();
1118 } else if (strcmp(ctype, "direct-tcpip") == 0) {
1119 c = server_request_direct_tcpip();
1120 } else if (strcmp(ctype, "direct-streamlocal@openssh.com") == 0) {
1121 c = server_request_direct_streamlocal();
1122 } else if (strcmp(ctype, "tun@openssh.com") == 0) {
1123 c = server_request_tun();
1124 }
1125 if (c != NULL) {
1126 debug("server_input_channel_open: confirm %s", ctype);
1127 c->remote_id = rchan;
1128 c->remote_window = rwindow;
1129 c->remote_maxpacket = rmaxpack;
1130 if (c->type != SSH_CHANNEL_CONNECTING) {
1131 packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
1132 packet_put_int(c->remote_id);
1133 packet_put_int(c->self);
1134 packet_put_int(c->local_window);
1135 packet_put_int(c->local_maxpacket);
1136 packet_send();
1137 }
1138 } else {
1139 debug("server_input_channel_open: failure %s", ctype);
1140 packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
1141 packet_put_int(rchan);
1142 packet_put_int(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED);
1143 if (!(datafellows & SSH_BUG_OPENFAILURE)) {
1144 packet_put_cstring("open failed");
1145 packet_put_cstring("");
1146 }
1147 packet_send();
1148 }
1149 free(ctype);
1150 return 0;
1151 }
1152
1153 static int
server_input_hostkeys_prove(struct sshbuf ** respp)1154 server_input_hostkeys_prove(struct sshbuf **respp)
1155 {
1156 struct ssh *ssh = active_state; /* XXX */
1157 struct sshbuf *resp = NULL;
1158 struct sshbuf *sigbuf = NULL;
1159 struct sshkey *key = NULL, *key_pub = NULL, *key_prv = NULL;
1160 int r, ndx, success = 0;
1161 const u_char *blob;
1162 u_char *sig = 0;
1163 size_t blen, slen;
1164
1165 if ((resp = sshbuf_new()) == NULL || (sigbuf = sshbuf_new()) == NULL)
1166 fatal("%s: sshbuf_new", __func__);
1167
1168 while (ssh_packet_remaining(ssh) > 0) {
1169 sshkey_free(key);
1170 key = NULL;
1171 if ((r = sshpkt_get_string_direct(ssh, &blob, &blen)) != 0 ||
1172 (r = sshkey_from_blob(blob, blen, &key)) != 0) {
1173 error("%s: couldn't parse key: %s",
1174 __func__, ssh_err(r));
1175 goto out;
1176 }
1177 /*
1178 * Better check that this is actually one of our hostkeys
1179 * before attempting to sign anything with it.
1180 */
1181 if ((ndx = ssh->kex->host_key_index(key, 1, ssh)) == -1) {
1182 error("%s: unknown host %s key",
1183 __func__, sshkey_type(key));
1184 goto out;
1185 }
1186 /*
1187 * XXX refactor: make kex->sign just use an index rather
1188 * than passing in public and private keys
1189 */
1190 if ((key_prv = get_hostkey_by_index(ndx)) == NULL &&
1191 (key_pub = get_hostkey_public_by_index(ndx, ssh)) == NULL) {
1192 error("%s: can't retrieve hostkey %d", __func__, ndx);
1193 goto out;
1194 }
1195 sshbuf_reset(sigbuf);
1196 free(sig);
1197 sig = NULL;
1198 if ((r = sshbuf_put_cstring(sigbuf,
1199 "hostkeys-prove-00@openssh.com")) != 0 ||
1200 (r = sshbuf_put_string(sigbuf,
1201 ssh->kex->session_id, ssh->kex->session_id_len)) != 0 ||
1202 (r = sshkey_puts(key, sigbuf)) != 0 ||
1203 (r = ssh->kex->sign(key_prv, key_pub, &sig, &slen,
1204 sshbuf_ptr(sigbuf), sshbuf_len(sigbuf), 0)) != 0 ||
1205 (r = sshbuf_put_string(resp, sig, slen)) != 0) {
1206 error("%s: couldn't prepare signature: %s",
1207 __func__, ssh_err(r));
1208 goto out;
1209 }
1210 }
1211 /* Success */
1212 *respp = resp;
1213 resp = NULL; /* don't free it */
1214 success = 1;
1215 out:
1216 free(sig);
1217 sshbuf_free(resp);
1218 sshbuf_free(sigbuf);
1219 sshkey_free(key);
1220 return success;
1221 }
1222
1223 static int
server_input_global_request(int type,u_int32_t seq,void * ctxt)1224 server_input_global_request(int type, u_int32_t seq, void *ctxt)
1225 {
1226 char *rtype;
1227 int want_reply;
1228 int r, success = 0, allocated_listen_port = 0;
1229 struct sshbuf *resp = NULL;
1230
1231 rtype = packet_get_string(NULL);
1232 want_reply = packet_get_char();
1233 debug("server_input_global_request: rtype %s want_reply %d", rtype, want_reply);
1234
1235 /* -R style forwarding */
1236 if (strcmp(rtype, "tcpip-forward") == 0) {
1237 struct passwd *pw;
1238 struct Forward fwd;
1239
1240 pw = the_authctxt->pw;
1241 if (pw == NULL || !the_authctxt->valid)
1242 fatal("server_input_global_request: no/invalid user");
1243 memset(&fwd, 0, sizeof(fwd));
1244 fwd.listen_host = packet_get_string(NULL);
1245 fwd.listen_port = (u_short)packet_get_int();
1246 debug("server_input_global_request: tcpip-forward listen %s port %d",
1247 fwd.listen_host, fwd.listen_port);
1248
1249 /* check permissions */
1250 if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
1251 no_port_forwarding_flag ||
1252 (!want_reply && fwd.listen_port == 0)
1253 #ifndef NO_IPPORT_RESERVED_CONCEPT
1254 || (fwd.listen_port != 0 && fwd.listen_port < IPPORT_RESERVED &&
1255 pw->pw_uid != 0)
1256 #endif
1257 ) {
1258 success = 0;
1259 packet_send_debug("Server has disabled port forwarding.");
1260 } else {
1261 /* Start listening on the port */
1262 success = channel_setup_remote_fwd_listener(&fwd,
1263 &allocated_listen_port, &options.fwd_opts);
1264 }
1265 free(fwd.listen_host);
1266 if ((resp = sshbuf_new()) == NULL)
1267 fatal("%s: sshbuf_new", __func__);
1268 if ((r = sshbuf_put_u32(resp, allocated_listen_port)) != 0)
1269 fatal("%s: sshbuf_put_u32: %s", __func__, ssh_err(r));
1270 } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
1271 struct Forward fwd;
1272
1273 memset(&fwd, 0, sizeof(fwd));
1274 fwd.listen_host = packet_get_string(NULL);
1275 fwd.listen_port = (u_short)packet_get_int();
1276 debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
1277 fwd.listen_host, fwd.listen_port);
1278
1279 success = channel_cancel_rport_listener(&fwd);
1280 free(fwd.listen_host);
1281 } else if (strcmp(rtype, "streamlocal-forward@openssh.com") == 0) {
1282 struct Forward fwd;
1283
1284 memset(&fwd, 0, sizeof(fwd));
1285 fwd.listen_path = packet_get_string(NULL);
1286 debug("server_input_global_request: streamlocal-forward listen path %s",
1287 fwd.listen_path);
1288
1289 /* check permissions */
1290 if ((options.allow_streamlocal_forwarding & FORWARD_REMOTE) == 0
1291 || no_port_forwarding_flag) {
1292 success = 0;
1293 packet_send_debug("Server has disabled port forwarding.");
1294 } else {
1295 /* Start listening on the socket */
1296 success = channel_setup_remote_fwd_listener(
1297 &fwd, NULL, &options.fwd_opts);
1298 }
1299 free(fwd.listen_path);
1300 } else if (strcmp(rtype, "cancel-streamlocal-forward@openssh.com") == 0) {
1301 struct Forward fwd;
1302
1303 memset(&fwd, 0, sizeof(fwd));
1304 fwd.listen_path = packet_get_string(NULL);
1305 debug("%s: cancel-streamlocal-forward path %s", __func__,
1306 fwd.listen_path);
1307
1308 success = channel_cancel_rport_listener(&fwd);
1309 free(fwd.listen_path);
1310 } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {
1311 no_more_sessions = 1;
1312 success = 1;
1313 } else if (strcmp(rtype, "hostkeys-prove-00@openssh.com") == 0) {
1314 success = server_input_hostkeys_prove(&resp);
1315 }
1316 if (want_reply) {
1317 packet_start(success ?
1318 SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
1319 if (success && resp != NULL)
1320 ssh_packet_put_raw(active_state, sshbuf_ptr(resp),
1321 sshbuf_len(resp));
1322 packet_send();
1323 packet_write_wait();
1324 }
1325 free(rtype);
1326 sshbuf_free(resp);
1327 return 0;
1328 }
1329
1330 static int
server_input_channel_req(int type,u_int32_t seq,void * ctxt)1331 server_input_channel_req(int type, u_int32_t seq, void *ctxt)
1332 {
1333 Channel *c;
1334 int id, reply, success = 0;
1335 char *rtype;
1336
1337 id = packet_get_int();
1338 rtype = packet_get_string(NULL);
1339 reply = packet_get_char();
1340
1341 debug("server_input_channel_req: channel %d request %s reply %d",
1342 id, rtype, reply);
1343
1344 if ((c = channel_lookup(id)) == NULL)
1345 packet_disconnect("server_input_channel_req: "
1346 "unknown channel %d", id);
1347 if (!strcmp(rtype, "eow@openssh.com")) {
1348 packet_check_eom();
1349 chan_rcvd_eow(c);
1350 } else if ((c->type == SSH_CHANNEL_LARVAL ||
1351 c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
1352 success = session_input_channel_req(c, rtype);
1353 if (reply && !(c->flags & CHAN_CLOSE_SENT)) {
1354 packet_start(success ?
1355 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
1356 packet_put_int(c->remote_id);
1357 packet_send();
1358 }
1359 free(rtype);
1360 return 0;
1361 }
1362
1363 static void
server_init_dispatch_20(void)1364 server_init_dispatch_20(void)
1365 {
1366 debug("server_init_dispatch_20");
1367 dispatch_init(&dispatch_protocol_error);
1368 dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
1369 dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
1370 dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
1371 dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
1372 dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
1373 dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1374 dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1375 dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
1376 dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
1377 dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1378 /* client_alive */
1379 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
1380 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
1381 dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
1382 dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
1383 /* rekeying */
1384 dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
1385 }
1386 static void
server_init_dispatch_13(void)1387 server_init_dispatch_13(void)
1388 {
1389 debug("server_init_dispatch_13");
1390 dispatch_init(NULL);
1391 dispatch_set(SSH_CMSG_EOF, &server_input_eof);
1392 dispatch_set(SSH_CMSG_STDIN_DATA, &server_input_stdin_data);
1393 dispatch_set(SSH_CMSG_WINDOW_SIZE, &server_input_window_size);
1394 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_close);
1395 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_close_confirmation);
1396 dispatch_set(SSH_MSG_CHANNEL_DATA, &channel_input_data);
1397 dispatch_set(SSH_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
1398 dispatch_set(SSH_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
1399 dispatch_set(SSH_MSG_PORT_OPEN, &channel_input_port_open);
1400 }
1401 static void
server_init_dispatch_15(void)1402 server_init_dispatch_15(void)
1403 {
1404 server_init_dispatch_13();
1405 debug("server_init_dispatch_15");
1406 dispatch_set(SSH_MSG_CHANNEL_CLOSE, &channel_input_ieof);
1407 dispatch_set(SSH_MSG_CHANNEL_CLOSE_CONFIRMATION, &channel_input_oclose);
1408 }
1409 static void
server_init_dispatch(void)1410 server_init_dispatch(void)
1411 {
1412 if (compat20)
1413 server_init_dispatch_20();
1414 else if (compat13)
1415 server_init_dispatch_13();
1416 else
1417 server_init_dispatch_15();
1418 }
1419