1 /* $OpenBSD: clientloop.c,v 1.344 2020/04/24 02:19:40 dtucker 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 * The main loop for the interactive session (client side).
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 *
15 * Copyright (c) 1999 Theo de Raadt. 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 * SSH2 support added by Markus Friedl.
39 * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved.
40 *
41 * Redistribution and use in source and binary forms, with or without
42 * modification, are permitted provided that the following conditions
43 * are met:
44 * 1. Redistributions of source code must retain the above copyright
45 * notice, this list of conditions and the following disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 * notice, this list of conditions and the following disclaimer in the
48 * documentation and/or other materials provided with the distribution.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
51 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
52 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
53 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
54 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
55 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
56 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
57 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
58 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
59 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
60 */
61
62 #include "includes.h"
63
64 #include <sys/types.h>
65 #include <sys/ioctl.h>
66 #ifdef HAVE_SYS_STAT_H
67 # include <sys/stat.h>
68 #endif
69 #ifdef HAVE_SYS_TIME_H
70 # include <sys/time.h>
71 #endif
72 #include <sys/socket.h>
73
74 #include <ctype.h>
75 #include <errno.h>
76 #ifdef HAVE_PATHS_H
77 #include <paths.h>
78 #endif
79 #include <signal.h>
80 #include <stdio.h>
81 #include <stdlib.h>
82 #include <string.h>
83 #include <stdarg.h>
84 #include <termios.h>
85 #include <pwd.h>
86 #include <unistd.h>
87 #include <limits.h>
88
89 #include "openbsd-compat/sys-queue.h"
90 #include "xmalloc.h"
91 #include "ssh.h"
92 #include "ssh2.h"
93 #include "packet.h"
94 #include "sshbuf.h"
95 #include "compat.h"
96 #include "channels.h"
97 #include "dispatch.h"
98 #include "sshkey.h"
99 #include "cipher.h"
100 #include "kex.h"
101 #include "myproposal.h"
102 #include "log.h"
103 #include "misc.h"
104 #include "readconf.h"
105 #include "clientloop.h"
106 #include "sshconnect.h"
107 #include "authfd.h"
108 #include "atomicio.h"
109 #include "sshpty.h"
110 #include "match.h"
111 #include "msg.h"
112 #include "ssherr.h"
113 #include "hostfile.h"
114
115 /* import options */
116 extern Options options;
117
118 /* Flag indicating that stdin should be redirected from /dev/null. */
119 extern int stdin_null_flag;
120
121 /* Flag indicating that no shell has been requested */
122 extern int no_shell_flag;
123
124 /* Flag indicating that ssh should daemonise after authentication is complete */
125 extern int fork_after_authentication_flag;
126
127 /* Control socket */
128 extern int muxserver_sock; /* XXX use mux_client_cleanup() instead */
129
130 /*
131 * Name of the host we are connecting to. This is the name given on the
132 * command line, or the Hostname specified for the user-supplied name in a
133 * configuration file.
134 */
135 extern char *host;
136
137 /*
138 * If this field is not NULL, the ForwardAgent socket is this path and different
139 * instead of SSH_AUTH_SOCK.
140 */
141 extern char *forward_agent_sock_path;
142
143 /*
144 * Flag to indicate that we have received a window change signal which has
145 * not yet been processed. This will cause a message indicating the new
146 * window size to be sent to the server a little later. This is volatile
147 * because this is updated in a signal handler.
148 */
149 static volatile sig_atomic_t received_window_change_signal = 0;
150 static volatile sig_atomic_t received_signal = 0;
151
152 /* Time when backgrounded control master using ControlPersist should exit */
153 static time_t control_persist_exit_time = 0;
154
155 /* Common data for the client loop code. */
156 volatile sig_atomic_t quit_pending; /* Set non-zero to quit the loop. */
157 static int last_was_cr; /* Last character was a newline. */
158 static int exit_status; /* Used to store the command exit status. */
159 static struct sshbuf *stderr_buffer; /* Used for final exit message. */
160 static int connection_in; /* Connection to server (input). */
161 static int connection_out; /* Connection to server (output). */
162 static int need_rekeying; /* Set to non-zero if rekeying is requested. */
163 static int session_closed; /* In SSH2: login session closed. */
164 static u_int x11_refuse_time; /* If >0, refuse x11 opens after this time. */
165
166 static void client_init_dispatch(struct ssh *ssh);
167 int session_ident = -1;
168
169 /* Track escape per proto2 channel */
170 struct escape_filter_ctx {
171 int escape_pending;
172 int escape_char;
173 };
174
175 /* Context for channel confirmation replies */
176 struct channel_reply_ctx {
177 const char *request_type;
178 int id;
179 enum confirm_action action;
180 };
181
182 /* Global request success/failure callbacks */
183 /* XXX move to struct ssh? */
184 struct global_confirm {
185 TAILQ_ENTRY(global_confirm) entry;
186 global_confirm_cb *cb;
187 void *ctx;
188 int ref_count;
189 };
190 TAILQ_HEAD(global_confirms, global_confirm);
191 static struct global_confirms global_confirms =
192 TAILQ_HEAD_INITIALIZER(global_confirms);
193
194 void ssh_process_session2_setup(int, int, int, struct sshbuf *);
195
196 /*
197 * Signal handler for the window change signal (SIGWINCH). This just sets a
198 * flag indicating that the window has changed.
199 */
200 /*ARGSUSED */
201 static void
window_change_handler(int sig)202 window_change_handler(int sig)
203 {
204 received_window_change_signal = 1;
205 }
206
207 /*
208 * Signal handler for signals that cause the program to terminate. These
209 * signals must be trapped to restore terminal modes.
210 */
211 /*ARGSUSED */
212 static void
signal_handler(int sig)213 signal_handler(int sig)
214 {
215 received_signal = sig;
216 quit_pending = 1;
217 }
218
219 /*
220 * Sets control_persist_exit_time to the absolute time when the
221 * backgrounded control master should exit due to expiry of the
222 * ControlPersist timeout. Sets it to 0 if we are not a backgrounded
223 * control master process, or if there is no ControlPersist timeout.
224 */
225 static void
set_control_persist_exit_time(struct ssh * ssh)226 set_control_persist_exit_time(struct ssh *ssh)
227 {
228 if (muxserver_sock == -1 || !options.control_persist
229 || options.control_persist_timeout == 0) {
230 /* not using a ControlPersist timeout */
231 control_persist_exit_time = 0;
232 } else if (channel_still_open(ssh)) {
233 /* some client connections are still open */
234 if (control_persist_exit_time > 0)
235 debug2("%s: cancel scheduled exit", __func__);
236 control_persist_exit_time = 0;
237 } else if (control_persist_exit_time <= 0) {
238 /* a client connection has recently closed */
239 control_persist_exit_time = monotime() +
240 (time_t)options.control_persist_timeout;
241 debug2("%s: schedule exit in %d seconds", __func__,
242 options.control_persist_timeout);
243 }
244 /* else we are already counting down to the timeout */
245 }
246
247 #define SSH_X11_VALID_DISPLAY_CHARS ":/.-_"
248 static int
client_x11_display_valid(const char * display)249 client_x11_display_valid(const char *display)
250 {
251 size_t i, dlen;
252
253 if (display == NULL)
254 return 0;
255
256 dlen = strlen(display);
257 for (i = 0; i < dlen; i++) {
258 if (!isalnum((u_char)display[i]) &&
259 strchr(SSH_X11_VALID_DISPLAY_CHARS, display[i]) == NULL) {
260 debug("Invalid character '%c' in DISPLAY", display[i]);
261 return 0;
262 }
263 }
264 return 1;
265 }
266
267 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
268 #define X11_TIMEOUT_SLACK 60
269 int
client_x11_get_proto(struct ssh * ssh,const char * display,const char * xauth_path,u_int trusted,u_int timeout,char ** _proto,char ** _data)270 client_x11_get_proto(struct ssh *ssh, const char *display,
271 const char *xauth_path, u_int trusted, u_int timeout,
272 char **_proto, char **_data)
273 {
274 char *cmd, line[512], xdisplay[512];
275 char xauthfile[PATH_MAX], xauthdir[PATH_MAX];
276 static char proto[512], data[512];
277 FILE *f;
278 int got_data = 0, generated = 0, do_unlink = 0, r;
279 struct stat st;
280 u_int now, x11_timeout_real;
281
282 *_proto = proto;
283 *_data = data;
284 proto[0] = data[0] = xauthfile[0] = xauthdir[0] = '\0';
285
286 if (!client_x11_display_valid(display)) {
287 if (display != NULL)
288 logit("DISPLAY \"%s\" invalid; disabling X11 forwarding",
289 display);
290 return -1;
291 }
292 if (xauth_path != NULL && stat(xauth_path, &st) == -1) {
293 debug("No xauth program.");
294 xauth_path = NULL;
295 }
296
297 if (xauth_path != NULL) {
298 /*
299 * Handle FamilyLocal case where $DISPLAY does
300 * not match an authorization entry. For this we
301 * just try "xauth list unix:displaynum.screennum".
302 * XXX: "localhost" match to determine FamilyLocal
303 * is not perfect.
304 */
305 if (strncmp(display, "localhost:", 10) == 0) {
306 if ((r = snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
307 display + 10)) < 0 ||
308 (size_t)r >= sizeof(xdisplay)) {
309 error("%s: display name too long", __func__);
310 return -1;
311 }
312 display = xdisplay;
313 }
314 if (trusted == 0) {
315 /*
316 * Generate an untrusted X11 auth cookie.
317 *
318 * The authentication cookie should briefly outlive
319 * ssh's willingness to forward X11 connections to
320 * avoid nasty fail-open behaviour in the X server.
321 */
322 mktemp_proto(xauthdir, sizeof(xauthdir));
323 if (mkdtemp(xauthdir) == NULL) {
324 error("%s: mkdtemp: %s",
325 __func__, strerror(errno));
326 return -1;
327 }
328 do_unlink = 1;
329 if ((r = snprintf(xauthfile, sizeof(xauthfile),
330 "%s/xauthfile", xauthdir)) < 0 ||
331 (size_t)r >= sizeof(xauthfile)) {
332 error("%s: xauthfile path too long", __func__);
333 rmdir(xauthdir);
334 return -1;
335 }
336
337 if (timeout == 0) {
338 /* auth doesn't time out */
339 xasprintf(&cmd, "%s -f %s generate %s %s "
340 "untrusted 2>%s",
341 xauth_path, xauthfile, display,
342 SSH_X11_PROTO, _PATH_DEVNULL);
343 } else {
344 /* Add some slack to requested expiry */
345 if (timeout < UINT_MAX - X11_TIMEOUT_SLACK)
346 x11_timeout_real = timeout +
347 X11_TIMEOUT_SLACK;
348 else {
349 /* Don't overflow on long timeouts */
350 x11_timeout_real = UINT_MAX;
351 }
352 xasprintf(&cmd, "%s -f %s generate %s %s "
353 "untrusted timeout %u 2>%s",
354 xauth_path, xauthfile, display,
355 SSH_X11_PROTO, x11_timeout_real,
356 _PATH_DEVNULL);
357 }
358 debug2("%s: xauth command: %s", __func__, cmd);
359
360 if (timeout != 0 && x11_refuse_time == 0) {
361 now = monotime() + 1;
362 if (UINT_MAX - timeout < now)
363 x11_refuse_time = UINT_MAX;
364 else
365 x11_refuse_time = now + timeout;
366 channel_set_x11_refuse_time(ssh,
367 x11_refuse_time);
368 }
369 if (system(cmd) == 0)
370 generated = 1;
371 free(cmd);
372 }
373
374 /*
375 * When in untrusted mode, we read the cookie only if it was
376 * successfully generated as an untrusted one in the step
377 * above.
378 */
379 if (trusted || generated) {
380 xasprintf(&cmd,
381 "%s %s%s list %s 2>" _PATH_DEVNULL,
382 xauth_path,
383 generated ? "-f " : "" ,
384 generated ? xauthfile : "",
385 display);
386 debug2("x11_get_proto: %s", cmd);
387 f = popen(cmd, "r");
388 if (f && fgets(line, sizeof(line), f) &&
389 sscanf(line, "%*s %511s %511s", proto, data) == 2)
390 got_data = 1;
391 if (f)
392 pclose(f);
393 free(cmd);
394 }
395 }
396
397 if (do_unlink) {
398 unlink(xauthfile);
399 rmdir(xauthdir);
400 }
401
402 /* Don't fall back to fake X11 data for untrusted forwarding */
403 if (!trusted && !got_data) {
404 error("Warning: untrusted X11 forwarding setup failed: "
405 "xauth key data not generated");
406 return -1;
407 }
408
409 /*
410 * If we didn't get authentication data, just make up some
411 * data. The forwarding code will check the validity of the
412 * response anyway, and substitute this data. The X11
413 * server, however, will ignore this fake data and use
414 * whatever authentication mechanisms it was using otherwise
415 * for the local connection.
416 */
417 if (!got_data) {
418 u_int8_t rnd[16];
419 u_int i;
420
421 logit("Warning: No xauth data; "
422 "using fake authentication data for X11 forwarding.");
423 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
424 arc4random_buf(rnd, sizeof(rnd));
425 for (i = 0; i < sizeof(rnd); i++) {
426 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
427 rnd[i]);
428 }
429 }
430
431 return 0;
432 }
433
434 /*
435 * Checks if the client window has changed, and sends a packet about it to
436 * the server if so. The actual change is detected elsewhere (by a software
437 * interrupt on Unix); this just checks the flag and sends a message if
438 * appropriate.
439 */
440
441 static void
client_check_window_change(struct ssh * ssh)442 client_check_window_change(struct ssh *ssh)
443 {
444 if (!received_window_change_signal)
445 return;
446 received_window_change_signal = 0;
447 debug2("%s: changed", __func__);
448 channel_send_window_changes(ssh);
449 }
450
451 static int
client_global_request_reply(int type,u_int32_t seq,struct ssh * ssh)452 client_global_request_reply(int type, u_int32_t seq, struct ssh *ssh)
453 {
454 struct global_confirm *gc;
455
456 if ((gc = TAILQ_FIRST(&global_confirms)) == NULL)
457 return 0;
458 if (gc->cb != NULL)
459 gc->cb(ssh, type, seq, gc->ctx);
460 if (--gc->ref_count <= 0) {
461 TAILQ_REMOVE(&global_confirms, gc, entry);
462 freezero(gc, sizeof(*gc));
463 }
464
465 ssh_packet_set_alive_timeouts(ssh, 0);
466 return 0;
467 }
468
469 static void
server_alive_check(struct ssh * ssh)470 server_alive_check(struct ssh *ssh)
471 {
472 int r;
473
474 if (ssh_packet_inc_alive_timeouts(ssh) > options.server_alive_count_max) {
475 logit("Timeout, server %s not responding.", host);
476 cleanup_exit(255);
477 }
478 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
479 (r = sshpkt_put_cstring(ssh, "keepalive@openssh.com")) != 0 ||
480 (r = sshpkt_put_u8(ssh, 1)) != 0 || /* boolean: want reply */
481 (r = sshpkt_send(ssh)) != 0)
482 fatal("%s: send packet: %s", __func__, ssh_err(r));
483 /* Insert an empty placeholder to maintain ordering */
484 client_register_global_confirm(NULL, NULL);
485 }
486
487 /*
488 * Waits until the client can do something (some data becomes available on
489 * one of the file descriptors).
490 */
491 static void
client_wait_until_can_do_something(struct ssh * ssh,fd_set ** readsetp,fd_set ** writesetp,int * maxfdp,u_int * nallocp,int rekeying)492 client_wait_until_can_do_something(struct ssh *ssh,
493 fd_set **readsetp, fd_set **writesetp,
494 int *maxfdp, u_int *nallocp, int rekeying)
495 {
496 struct timeval tv, *tvp;
497 int timeout_secs;
498 time_t minwait_secs = 0, server_alive_time = 0, now = monotime();
499 int r, ret;
500
501 /* Add any selections by the channel mechanism. */
502 channel_prepare_select(ssh, readsetp, writesetp, maxfdp,
503 nallocp, &minwait_secs);
504
505 /* channel_prepare_select could have closed the last channel */
506 if (session_closed && !channel_still_open(ssh) &&
507 !ssh_packet_have_data_to_write(ssh)) {
508 /* clear mask since we did not call select() */
509 memset(*readsetp, 0, *nallocp);
510 memset(*writesetp, 0, *nallocp);
511 return;
512 }
513
514 FD_SET(connection_in, *readsetp);
515
516 /* Select server connection if have data to write to the server. */
517 if (ssh_packet_have_data_to_write(ssh))
518 FD_SET(connection_out, *writesetp);
519
520 /*
521 * Wait for something to happen. This will suspend the process until
522 * some selected descriptor can be read, written, or has some other
523 * event pending, or a timeout expires.
524 */
525
526 timeout_secs = INT_MAX; /* we use INT_MAX to mean no timeout */
527 if (options.server_alive_interval > 0) {
528 timeout_secs = options.server_alive_interval;
529 server_alive_time = now + options.server_alive_interval;
530 }
531 if (options.rekey_interval > 0 && !rekeying)
532 timeout_secs = MINIMUM(timeout_secs,
533 ssh_packet_get_rekey_timeout(ssh));
534 set_control_persist_exit_time(ssh);
535 if (control_persist_exit_time > 0) {
536 timeout_secs = MINIMUM(timeout_secs,
537 control_persist_exit_time - now);
538 if (timeout_secs < 0)
539 timeout_secs = 0;
540 }
541 if (minwait_secs != 0)
542 timeout_secs = MINIMUM(timeout_secs, (int)minwait_secs);
543 if (timeout_secs == INT_MAX)
544 tvp = NULL;
545 else {
546 tv.tv_sec = timeout_secs;
547 tv.tv_usec = 0;
548 tvp = &tv;
549 }
550
551 ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
552 if (ret == -1) {
553 /*
554 * We have to clear the select masks, because we return.
555 * We have to return, because the mainloop checks for the flags
556 * set by the signal handlers.
557 */
558 memset(*readsetp, 0, *nallocp);
559 memset(*writesetp, 0, *nallocp);
560
561 if (errno == EINTR)
562 return;
563 /* Note: we might still have data in the buffers. */
564 if ((r = sshbuf_putf(stderr_buffer,
565 "select: %s\r\n", strerror(errno))) != 0)
566 fatal("%s: buffer error: %s", __func__, ssh_err(r));
567 quit_pending = 1;
568 } else if (ret == 0) {
569 /*
570 * Timeout. Could have been either keepalive or rekeying.
571 * Keepalive we check here, rekeying is checked in clientloop.
572 */
573 if (server_alive_time != 0 && server_alive_time <= monotime())
574 server_alive_check(ssh);
575 }
576
577 }
578
579 static void
client_suspend_self(struct sshbuf * bin,struct sshbuf * bout,struct sshbuf * berr)580 client_suspend_self(struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr)
581 {
582 /* Flush stdout and stderr buffers. */
583 if (sshbuf_len(bout) > 0)
584 atomicio(vwrite, fileno(stdout), sshbuf_mutable_ptr(bout),
585 sshbuf_len(bout));
586 if (sshbuf_len(berr) > 0)
587 atomicio(vwrite, fileno(stderr), sshbuf_mutable_ptr(berr),
588 sshbuf_len(berr));
589
590 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
591
592 sshbuf_reset(bin);
593 sshbuf_reset(bout);
594 sshbuf_reset(berr);
595
596 /* Send the suspend signal to the program itself. */
597 kill(getpid(), SIGTSTP);
598
599 /* Reset window sizes in case they have changed */
600 received_window_change_signal = 1;
601
602 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
603 }
604
605 static void
client_process_net_input(struct ssh * ssh,fd_set * readset)606 client_process_net_input(struct ssh *ssh, fd_set *readset)
607 {
608 char buf[SSH_IOBUFSZ];
609 int r, len;
610
611 /*
612 * Read input from the server, and add any such data to the buffer of
613 * the packet subsystem.
614 */
615 if (FD_ISSET(connection_in, readset)) {
616 /* Read as much as possible. */
617 len = read(connection_in, buf, sizeof(buf));
618 if (len == 0) {
619 /*
620 * Received EOF. The remote host has closed the
621 * connection.
622 */
623 if ((r = sshbuf_putf(stderr_buffer,
624 "Connection to %.300s closed by remote host.\r\n",
625 host)) != 0)
626 fatal("%s: buffer error: %s",
627 __func__, ssh_err(r));
628 quit_pending = 1;
629 return;
630 }
631 /*
632 * There is a kernel bug on Solaris that causes select to
633 * sometimes wake up even though there is no data available.
634 */
635 if (len == -1 &&
636 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
637 len = 0;
638
639 if (len == -1) {
640 /*
641 * An error has encountered. Perhaps there is a
642 * network problem.
643 */
644 if ((r = sshbuf_putf(stderr_buffer,
645 "Read from remote host %.300s: %.100s\r\n",
646 host, strerror(errno))) != 0)
647 fatal("%s: buffer error: %s",
648 __func__, ssh_err(r));
649 quit_pending = 1;
650 return;
651 }
652 ssh_packet_process_incoming(ssh, buf, len);
653 }
654 }
655
656 static void
client_status_confirm(struct ssh * ssh,int type,Channel * c,void * ctx)657 client_status_confirm(struct ssh *ssh, int type, Channel *c, void *ctx)
658 {
659 struct channel_reply_ctx *cr = (struct channel_reply_ctx *)ctx;
660 char errmsg[256];
661 int r, tochan;
662
663 /*
664 * If a TTY was explicitly requested, then a failure to allocate
665 * one is fatal.
666 */
667 if (cr->action == CONFIRM_TTY &&
668 (options.request_tty == REQUEST_TTY_FORCE ||
669 options.request_tty == REQUEST_TTY_YES))
670 cr->action = CONFIRM_CLOSE;
671
672 /* XXX suppress on mux _client_ quietmode */
673 tochan = options.log_level >= SYSLOG_LEVEL_ERROR &&
674 c->ctl_chan != -1 && c->extended_usage == CHAN_EXTENDED_WRITE;
675
676 if (type == SSH2_MSG_CHANNEL_SUCCESS) {
677 debug2("%s request accepted on channel %d",
678 cr->request_type, c->self);
679 } else if (type == SSH2_MSG_CHANNEL_FAILURE) {
680 if (tochan) {
681 snprintf(errmsg, sizeof(errmsg),
682 "%s request failed\r\n", cr->request_type);
683 } else {
684 snprintf(errmsg, sizeof(errmsg),
685 "%s request failed on channel %d",
686 cr->request_type, c->self);
687 }
688 /* If error occurred on primary session channel, then exit */
689 if (cr->action == CONFIRM_CLOSE && c->self == session_ident)
690 fatal("%s", errmsg);
691 /*
692 * If error occurred on mux client, append to
693 * their stderr.
694 */
695 if (tochan) {
696 if ((r = sshbuf_put(c->extended, errmsg,
697 strlen(errmsg))) != 0)
698 fatal("%s: buffer error %s", __func__,
699 ssh_err(r));
700 } else
701 error("%s", errmsg);
702 if (cr->action == CONFIRM_TTY) {
703 /*
704 * If a TTY allocation error occurred, then arrange
705 * for the correct TTY to leave raw mode.
706 */
707 if (c->self == session_ident)
708 leave_raw_mode(0);
709 else
710 mux_tty_alloc_failed(ssh, c);
711 } else if (cr->action == CONFIRM_CLOSE) {
712 chan_read_failed(ssh, c);
713 chan_write_failed(ssh, c);
714 }
715 }
716 free(cr);
717 }
718
719 static void
client_abandon_status_confirm(struct ssh * ssh,Channel * c,void * ctx)720 client_abandon_status_confirm(struct ssh *ssh, Channel *c, void *ctx)
721 {
722 free(ctx);
723 }
724
725 void
client_expect_confirm(struct ssh * ssh,int id,const char * request,enum confirm_action action)726 client_expect_confirm(struct ssh *ssh, int id, const char *request,
727 enum confirm_action action)
728 {
729 struct channel_reply_ctx *cr = xcalloc(1, sizeof(*cr));
730
731 cr->request_type = request;
732 cr->action = action;
733
734 channel_register_status_confirm(ssh, id, client_status_confirm,
735 client_abandon_status_confirm, cr);
736 }
737
738 void
client_register_global_confirm(global_confirm_cb * cb,void * ctx)739 client_register_global_confirm(global_confirm_cb *cb, void *ctx)
740 {
741 struct global_confirm *gc, *last_gc;
742
743 /* Coalesce identical callbacks */
744 last_gc = TAILQ_LAST(&global_confirms, global_confirms);
745 if (last_gc && last_gc->cb == cb && last_gc->ctx == ctx) {
746 if (++last_gc->ref_count >= INT_MAX)
747 fatal("%s: last_gc->ref_count = %d",
748 __func__, last_gc->ref_count);
749 return;
750 }
751
752 gc = xcalloc(1, sizeof(*gc));
753 gc->cb = cb;
754 gc->ctx = ctx;
755 gc->ref_count = 1;
756 TAILQ_INSERT_TAIL(&global_confirms, gc, entry);
757 }
758
759 static void
process_cmdline(struct ssh * ssh)760 process_cmdline(struct ssh *ssh)
761 {
762 void (*handler)(int);
763 char *s, *cmd;
764 int ok, delete = 0, local = 0, remote = 0, dynamic = 0;
765 struct Forward fwd;
766
767 memset(&fwd, 0, sizeof(fwd));
768
769 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
770 handler = ssh_signal(SIGINT, SIG_IGN);
771 cmd = s = read_passphrase("\r\nssh> ", RP_ECHO);
772 if (s == NULL)
773 goto out;
774 while (isspace((u_char)*s))
775 s++;
776 if (*s == '-')
777 s++; /* Skip cmdline '-', if any */
778 if (*s == '\0')
779 goto out;
780
781 if (*s == 'h' || *s == 'H' || *s == '?') {
782 logit("Commands:");
783 logit(" -L[bind_address:]port:host:hostport "
784 "Request local forward");
785 logit(" -R[bind_address:]port:host:hostport "
786 "Request remote forward");
787 logit(" -D[bind_address:]port "
788 "Request dynamic forward");
789 logit(" -KL[bind_address:]port "
790 "Cancel local forward");
791 logit(" -KR[bind_address:]port "
792 "Cancel remote forward");
793 logit(" -KD[bind_address:]port "
794 "Cancel dynamic forward");
795 if (!options.permit_local_command)
796 goto out;
797 logit(" !args "
798 "Execute local command");
799 goto out;
800 }
801
802 if (*s == '!' && options.permit_local_command) {
803 s++;
804 ssh_local_cmd(s);
805 goto out;
806 }
807
808 if (*s == 'K') {
809 delete = 1;
810 s++;
811 }
812 if (*s == 'L')
813 local = 1;
814 else if (*s == 'R')
815 remote = 1;
816 else if (*s == 'D')
817 dynamic = 1;
818 else {
819 logit("Invalid command.");
820 goto out;
821 }
822
823 while (isspace((u_char)*++s))
824 ;
825
826 /* XXX update list of forwards in options */
827 if (delete) {
828 /* We pass 1 for dynamicfwd to restrict to 1 or 2 fields. */
829 if (!parse_forward(&fwd, s, 1, 0)) {
830 logit("Bad forwarding close specification.");
831 goto out;
832 }
833 if (remote)
834 ok = channel_request_rforward_cancel(ssh, &fwd) == 0;
835 else if (dynamic)
836 ok = channel_cancel_lport_listener(ssh, &fwd,
837 0, &options.fwd_opts) > 0;
838 else
839 ok = channel_cancel_lport_listener(ssh, &fwd,
840 CHANNEL_CANCEL_PORT_STATIC,
841 &options.fwd_opts) > 0;
842 if (!ok) {
843 logit("Unknown port forwarding.");
844 goto out;
845 }
846 logit("Canceled forwarding.");
847 } else {
848 if (!parse_forward(&fwd, s, dynamic, remote)) {
849 logit("Bad forwarding specification.");
850 goto out;
851 }
852 if (local || dynamic) {
853 if (!channel_setup_local_fwd_listener(ssh, &fwd,
854 &options.fwd_opts)) {
855 logit("Port forwarding failed.");
856 goto out;
857 }
858 } else {
859 if (channel_request_remote_forwarding(ssh, &fwd) < 0) {
860 logit("Port forwarding failed.");
861 goto out;
862 }
863 }
864 logit("Forwarding port.");
865 }
866
867 out:
868 ssh_signal(SIGINT, handler);
869 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
870 free(cmd);
871 free(fwd.listen_host);
872 free(fwd.listen_path);
873 free(fwd.connect_host);
874 free(fwd.connect_path);
875 }
876
877 /* reasons to suppress output of an escape command in help output */
878 #define SUPPRESS_NEVER 0 /* never suppress, always show */
879 #define SUPPRESS_MUXCLIENT 1 /* don't show in mux client sessions */
880 #define SUPPRESS_MUXMASTER 2 /* don't show in mux master sessions */
881 #define SUPPRESS_SYSLOG 4 /* don't show when logging to syslog */
882 struct escape_help_text {
883 const char *cmd;
884 const char *text;
885 unsigned int flags;
886 };
887 static struct escape_help_text esc_txt[] = {
888 {".", "terminate session", SUPPRESS_MUXMASTER},
889 {".", "terminate connection (and any multiplexed sessions)",
890 SUPPRESS_MUXCLIENT},
891 {"B", "send a BREAK to the remote system", SUPPRESS_NEVER},
892 {"C", "open a command line", SUPPRESS_MUXCLIENT},
893 {"R", "request rekey", SUPPRESS_NEVER},
894 {"V/v", "decrease/increase verbosity (LogLevel)", SUPPRESS_MUXCLIENT},
895 {"^Z", "suspend ssh", SUPPRESS_MUXCLIENT},
896 {"#", "list forwarded connections", SUPPRESS_NEVER},
897 {"&", "background ssh (when waiting for connections to terminate)",
898 SUPPRESS_MUXCLIENT},
899 {"?", "this message", SUPPRESS_NEVER},
900 };
901
902 static void
print_escape_help(struct sshbuf * b,int escape_char,int mux_client,int using_stderr)903 print_escape_help(struct sshbuf *b, int escape_char, int mux_client,
904 int using_stderr)
905 {
906 unsigned int i, suppress_flags;
907 int r;
908
909 if ((r = sshbuf_putf(b,
910 "%c?\r\nSupported escape sequences:\r\n", escape_char)) != 0)
911 fatal("%s: buffer error: %s", __func__, ssh_err(r));
912
913 suppress_flags =
914 (mux_client ? SUPPRESS_MUXCLIENT : 0) |
915 (mux_client ? 0 : SUPPRESS_MUXMASTER) |
916 (using_stderr ? 0 : SUPPRESS_SYSLOG);
917
918 for (i = 0; i < sizeof(esc_txt)/sizeof(esc_txt[0]); i++) {
919 if (esc_txt[i].flags & suppress_flags)
920 continue;
921 if ((r = sshbuf_putf(b, " %c%-3s - %s\r\n",
922 escape_char, esc_txt[i].cmd, esc_txt[i].text)) != 0)
923 fatal("%s: buffer error: %s", __func__, ssh_err(r));
924 }
925
926 if ((r = sshbuf_putf(b,
927 " %c%c - send the escape character by typing it twice\r\n"
928 "(Note that escapes are only recognized immediately after "
929 "newline.)\r\n", escape_char, escape_char)) != 0)
930 fatal("%s: buffer error: %s", __func__, ssh_err(r));
931 }
932
933 /*
934 * Process the characters one by one.
935 */
936 static int
process_escapes(struct ssh * ssh,Channel * c,struct sshbuf * bin,struct sshbuf * bout,struct sshbuf * berr,char * buf,int len)937 process_escapes(struct ssh *ssh, Channel *c,
938 struct sshbuf *bin, struct sshbuf *bout, struct sshbuf *berr,
939 char *buf, int len)
940 {
941 pid_t pid;
942 int r, bytes = 0;
943 u_int i;
944 u_char ch;
945 char *s;
946 struct escape_filter_ctx *efc = c->filter_ctx == NULL ?
947 NULL : (struct escape_filter_ctx *)c->filter_ctx;
948
949 if (c->filter_ctx == NULL)
950 return 0;
951
952 if (len <= 0)
953 return (0);
954
955 for (i = 0; i < (u_int)len; i++) {
956 /* Get one character at a time. */
957 ch = buf[i];
958
959 if (efc->escape_pending) {
960 /* We have previously seen an escape character. */
961 /* Clear the flag now. */
962 efc->escape_pending = 0;
963
964 /* Process the escaped character. */
965 switch (ch) {
966 case '.':
967 /* Terminate the connection. */
968 if ((r = sshbuf_putf(berr, "%c.\r\n",
969 efc->escape_char)) != 0)
970 fatal("%s: buffer error: %s",
971 __func__, ssh_err(r));
972 if (c && c->ctl_chan != -1) {
973 chan_read_failed(ssh, c);
974 chan_write_failed(ssh, c);
975 if (c->detach_user) {
976 c->detach_user(ssh,
977 c->self, NULL);
978 }
979 c->type = SSH_CHANNEL_ABANDONED;
980 sshbuf_reset(c->input);
981 chan_ibuf_empty(ssh, c);
982 return 0;
983 } else
984 quit_pending = 1;
985 return -1;
986
987 case 'Z' - 64:
988 /* XXX support this for mux clients */
989 if (c && c->ctl_chan != -1) {
990 char b[16];
991 noescape:
992 if (ch == 'Z' - 64)
993 snprintf(b, sizeof b, "^Z");
994 else
995 snprintf(b, sizeof b, "%c", ch);
996 if ((r = sshbuf_putf(berr,
997 "%c%s escape not available to "
998 "multiplexed sessions\r\n",
999 efc->escape_char, b)) != 0)
1000 fatal("%s: buffer error: %s",
1001 __func__, ssh_err(r));
1002 continue;
1003 }
1004 /* Suspend the program. Inform the user */
1005 if ((r = sshbuf_putf(berr,
1006 "%c^Z [suspend ssh]\r\n",
1007 efc->escape_char)) != 0)
1008 fatal("%s: buffer error: %s",
1009 __func__, ssh_err(r));
1010
1011 /* Restore terminal modes and suspend. */
1012 client_suspend_self(bin, bout, berr);
1013
1014 /* We have been continued. */
1015 continue;
1016
1017 case 'B':
1018 if ((r = sshbuf_putf(berr,
1019 "%cB\r\n", efc->escape_char)) != 0)
1020 fatal("%s: buffer error: %s",
1021 __func__, ssh_err(r));
1022 channel_request_start(ssh, c->self, "break", 0);
1023 if ((r = sshpkt_put_u32(ssh, 1000)) != 0 ||
1024 (r = sshpkt_send(ssh)) != 0)
1025 fatal("%s: send packet: %s", __func__,
1026 ssh_err(r));
1027 continue;
1028
1029 case 'R':
1030 if (datafellows & SSH_BUG_NOREKEY)
1031 logit("Server does not "
1032 "support re-keying");
1033 else
1034 need_rekeying = 1;
1035 continue;
1036
1037 case 'V':
1038 /* FALLTHROUGH */
1039 case 'v':
1040 if (c && c->ctl_chan != -1)
1041 goto noescape;
1042 if (!log_is_on_stderr()) {
1043 if ((r = sshbuf_putf(berr,
1044 "%c%c [Logging to syslog]\r\n",
1045 efc->escape_char, ch)) != 0)
1046 fatal("%s: buffer error: %s",
1047 __func__, ssh_err(r));
1048 continue;
1049 }
1050 if (ch == 'V' && options.log_level >
1051 SYSLOG_LEVEL_QUIET)
1052 log_change_level(--options.log_level);
1053 if (ch == 'v' && options.log_level <
1054 SYSLOG_LEVEL_DEBUG3)
1055 log_change_level(++options.log_level);
1056 if ((r = sshbuf_putf(berr,
1057 "%c%c [LogLevel %s]\r\n",
1058 efc->escape_char, ch,
1059 log_level_name(options.log_level))) != 0)
1060 fatal("%s: buffer error: %s",
1061 __func__, ssh_err(r));
1062 continue;
1063
1064 case '&':
1065 if (c && c->ctl_chan != -1)
1066 goto noescape;
1067 /*
1068 * Detach the program (continue to serve
1069 * connections, but put in background and no
1070 * more new connections).
1071 */
1072 /* Restore tty modes. */
1073 leave_raw_mode(
1074 options.request_tty == REQUEST_TTY_FORCE);
1075
1076 /* Stop listening for new connections. */
1077 channel_stop_listening(ssh);
1078
1079 if ((r = sshbuf_putf(berr,
1080 "%c& [backgrounded]\n", efc->escape_char))
1081 != 0)
1082 fatal("%s: buffer error: %s",
1083 __func__, ssh_err(r));
1084
1085 /* Fork into background. */
1086 pid = fork();
1087 if (pid == -1) {
1088 error("fork: %.100s", strerror(errno));
1089 continue;
1090 }
1091 if (pid != 0) { /* This is the parent. */
1092 /* The parent just exits. */
1093 exit(0);
1094 }
1095 /* The child continues serving connections. */
1096 /* fake EOF on stdin */
1097 if ((r = sshbuf_put_u8(bin, 4)) != 0)
1098 fatal("%s: buffer error: %s",
1099 __func__, ssh_err(r));
1100 return -1;
1101 case '?':
1102 print_escape_help(berr, efc->escape_char,
1103 (c && c->ctl_chan != -1),
1104 log_is_on_stderr());
1105 continue;
1106
1107 case '#':
1108 if ((r = sshbuf_putf(berr, "%c#\r\n",
1109 efc->escape_char)) != 0)
1110 fatal("%s: buffer error: %s",
1111 __func__, ssh_err(r));
1112 s = channel_open_message(ssh);
1113 if ((r = sshbuf_put(berr, s, strlen(s))) != 0)
1114 fatal("%s: buffer error: %s",
1115 __func__, ssh_err(r));
1116 free(s);
1117 continue;
1118
1119 case 'C':
1120 if (c && c->ctl_chan != -1)
1121 goto noescape;
1122 process_cmdline(ssh);
1123 continue;
1124
1125 default:
1126 if (ch != efc->escape_char) {
1127 if ((r = sshbuf_put_u8(bin,
1128 efc->escape_char)) != 0)
1129 fatal("%s: buffer error: %s",
1130 __func__, ssh_err(r));
1131 bytes++;
1132 }
1133 /* Escaped characters fall through here */
1134 break;
1135 }
1136 } else {
1137 /*
1138 * The previous character was not an escape char.
1139 * Check if this is an escape.
1140 */
1141 if (last_was_cr && ch == efc->escape_char) {
1142 /*
1143 * It is. Set the flag and continue to
1144 * next character.
1145 */
1146 efc->escape_pending = 1;
1147 continue;
1148 }
1149 }
1150
1151 /*
1152 * Normal character. Record whether it was a newline,
1153 * and append it to the buffer.
1154 */
1155 last_was_cr = (ch == '\r' || ch == '\n');
1156 if ((r = sshbuf_put_u8(bin, ch)) != 0)
1157 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1158 bytes++;
1159 }
1160 return bytes;
1161 }
1162
1163 /*
1164 * Get packets from the connection input buffer, and process them as long as
1165 * there are packets available.
1166 *
1167 * Any unknown packets received during the actual
1168 * session cause the session to terminate. This is
1169 * intended to make debugging easier since no
1170 * confirmations are sent. Any compatible protocol
1171 * extensions must be negotiated during the
1172 * preparatory phase.
1173 */
1174
1175 static void
client_process_buffered_input_packets(struct ssh * ssh)1176 client_process_buffered_input_packets(struct ssh *ssh)
1177 {
1178 ssh_dispatch_run_fatal(ssh, DISPATCH_NONBLOCK, &quit_pending);
1179 }
1180
1181 /* scan buf[] for '~' before sending data to the peer */
1182
1183 /* Helper: allocate a new escape_filter_ctx and fill in its escape char */
1184 void *
client_new_escape_filter_ctx(int escape_char)1185 client_new_escape_filter_ctx(int escape_char)
1186 {
1187 struct escape_filter_ctx *ret;
1188
1189 ret = xcalloc(1, sizeof(*ret));
1190 ret->escape_pending = 0;
1191 ret->escape_char = escape_char;
1192 return (void *)ret;
1193 }
1194
1195 /* Free the escape filter context on channel free */
1196 void
client_filter_cleanup(struct ssh * ssh,int cid,void * ctx)1197 client_filter_cleanup(struct ssh *ssh, int cid, void *ctx)
1198 {
1199 free(ctx);
1200 }
1201
1202 int
client_simple_escape_filter(struct ssh * ssh,Channel * c,char * buf,int len)1203 client_simple_escape_filter(struct ssh *ssh, Channel *c, char *buf, int len)
1204 {
1205 if (c->extended_usage != CHAN_EXTENDED_WRITE)
1206 return 0;
1207
1208 return process_escapes(ssh, c, c->input, c->output, c->extended,
1209 buf, len);
1210 }
1211
1212 static void
client_channel_closed(struct ssh * ssh,int id,void * arg)1213 client_channel_closed(struct ssh *ssh, int id, void *arg)
1214 {
1215 channel_cancel_cleanup(ssh, id);
1216 session_closed = 1;
1217 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1218 }
1219
1220 /*
1221 * Implements the interactive session with the server. This is called after
1222 * the user has been authenticated, and a command has been started on the
1223 * remote host. If escape_char != SSH_ESCAPECHAR_NONE, it is the character
1224 * used as an escape character for terminating or suspending the session.
1225 */
1226 int
client_loop(struct ssh * ssh,int have_pty,int escape_char_arg,int ssh2_chan_id)1227 client_loop(struct ssh *ssh, int have_pty, int escape_char_arg,
1228 int ssh2_chan_id)
1229 {
1230 fd_set *readset = NULL, *writeset = NULL;
1231 double start_time, total_time;
1232 int r, max_fd = 0, max_fd2 = 0, len;
1233 u_int64_t ibytes, obytes;
1234 u_int nalloc = 0;
1235 char buf[100];
1236
1237 debug("Entering interactive session.");
1238
1239 if (options.control_master &&
1240 !option_clear_or_none(options.control_path)) {
1241 debug("pledge: id");
1242 if (pledge("stdio rpath wpath cpath unix inet dns recvfd sendfd proc exec id tty",
1243 NULL) == -1)
1244 fatal("%s pledge(): %s", __func__, strerror(errno));
1245
1246 } else if (options.forward_x11 || options.permit_local_command) {
1247 debug("pledge: exec");
1248 if (pledge("stdio rpath wpath cpath unix inet dns proc exec tty",
1249 NULL) == -1)
1250 fatal("%s pledge(): %s", __func__, strerror(errno));
1251
1252 } else if (options.update_hostkeys) {
1253 debug("pledge: filesystem full");
1254 if (pledge("stdio rpath wpath cpath unix inet dns proc tty",
1255 NULL) == -1)
1256 fatal("%s pledge(): %s", __func__, strerror(errno));
1257
1258 } else if (!option_clear_or_none(options.proxy_command) ||
1259 fork_after_authentication_flag) {
1260 debug("pledge: proc");
1261 if (pledge("stdio cpath unix inet dns proc tty", NULL) == -1)
1262 fatal("%s pledge(): %s", __func__, strerror(errno));
1263
1264 } else {
1265 debug("pledge: network");
1266 if (pledge("stdio unix inet dns proc tty", NULL) == -1)
1267 fatal("%s pledge(): %s", __func__, strerror(errno));
1268 }
1269
1270 start_time = monotime_double();
1271
1272 /* Initialize variables. */
1273 last_was_cr = 1;
1274 exit_status = -1;
1275 connection_in = ssh_packet_get_connection_in(ssh);
1276 connection_out = ssh_packet_get_connection_out(ssh);
1277 max_fd = MAXIMUM(connection_in, connection_out);
1278
1279 quit_pending = 0;
1280
1281 /* Initialize buffer. */
1282 if ((stderr_buffer = sshbuf_new()) == NULL)
1283 fatal("%s: sshbuf_new failed", __func__);
1284
1285 client_init_dispatch(ssh);
1286
1287 /*
1288 * Set signal handlers, (e.g. to restore non-blocking mode)
1289 * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
1290 */
1291 if (ssh_signal(SIGHUP, SIG_IGN) != SIG_IGN)
1292 ssh_signal(SIGHUP, signal_handler);
1293 if (ssh_signal(SIGINT, SIG_IGN) != SIG_IGN)
1294 ssh_signal(SIGINT, signal_handler);
1295 if (ssh_signal(SIGQUIT, SIG_IGN) != SIG_IGN)
1296 ssh_signal(SIGQUIT, signal_handler);
1297 if (ssh_signal(SIGTERM, SIG_IGN) != SIG_IGN)
1298 ssh_signal(SIGTERM, signal_handler);
1299 ssh_signal(SIGWINCH, window_change_handler);
1300
1301 if (have_pty)
1302 enter_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1303
1304 session_ident = ssh2_chan_id;
1305 if (session_ident != -1) {
1306 if (escape_char_arg != SSH_ESCAPECHAR_NONE) {
1307 channel_register_filter(ssh, session_ident,
1308 client_simple_escape_filter, NULL,
1309 client_filter_cleanup,
1310 client_new_escape_filter_ctx(
1311 escape_char_arg));
1312 }
1313 channel_register_cleanup(ssh, session_ident,
1314 client_channel_closed, 0);
1315 }
1316
1317 /* Main loop of the client for the interactive session mode. */
1318 while (!quit_pending) {
1319
1320 /* Process buffered packets sent by the server. */
1321 client_process_buffered_input_packets(ssh);
1322
1323 if (session_closed && !channel_still_open(ssh))
1324 break;
1325
1326 if (ssh_packet_is_rekeying(ssh)) {
1327 debug("rekeying in progress");
1328 } else if (need_rekeying) {
1329 /* manual rekey request */
1330 debug("need rekeying");
1331 if ((r = kex_start_rekex(ssh)) != 0)
1332 fatal("%s: kex_start_rekex: %s", __func__,
1333 ssh_err(r));
1334 need_rekeying = 0;
1335 } else {
1336 /*
1337 * Make packets from buffered channel data, and
1338 * enqueue them for sending to the server.
1339 */
1340 if (ssh_packet_not_very_much_data_to_write(ssh))
1341 channel_output_poll(ssh);
1342
1343 /*
1344 * Check if the window size has changed, and buffer a
1345 * message about it to the server if so.
1346 */
1347 client_check_window_change(ssh);
1348
1349 if (quit_pending)
1350 break;
1351 }
1352 /*
1353 * Wait until we have something to do (something becomes
1354 * available on one of the descriptors).
1355 */
1356 max_fd2 = max_fd;
1357 client_wait_until_can_do_something(ssh, &readset, &writeset,
1358 &max_fd2, &nalloc, ssh_packet_is_rekeying(ssh));
1359
1360 if (quit_pending)
1361 break;
1362
1363 /* Do channel operations unless rekeying in progress. */
1364 if (!ssh_packet_is_rekeying(ssh))
1365 channel_after_select(ssh, readset, writeset);
1366
1367 /* Buffer input from the connection. */
1368 client_process_net_input(ssh, readset);
1369
1370 if (quit_pending)
1371 break;
1372
1373 /*
1374 * Send as much buffered packet data as possible to the
1375 * sender.
1376 */
1377 if (FD_ISSET(connection_out, writeset)) {
1378 if ((r = ssh_packet_write_poll(ssh)) != 0) {
1379 sshpkt_fatal(ssh, r,
1380 "%s: ssh_packet_write_poll", __func__);
1381 }
1382 }
1383
1384 /*
1385 * If we are a backgrounded control master, and the
1386 * timeout has expired without any active client
1387 * connections, then quit.
1388 */
1389 if (control_persist_exit_time > 0) {
1390 if (monotime() >= control_persist_exit_time) {
1391 debug("ControlPersist timeout expired");
1392 break;
1393 }
1394 }
1395 }
1396 free(readset);
1397 free(writeset);
1398
1399 /* Terminate the session. */
1400
1401 /* Stop watching for window change. */
1402 ssh_signal(SIGWINCH, SIG_DFL);
1403
1404 if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
1405 (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_BY_APPLICATION)) != 0 ||
1406 (r = sshpkt_put_cstring(ssh, "disconnected by user")) != 0 ||
1407 (r = sshpkt_put_cstring(ssh, "")) != 0 || /* language tag */
1408 (r = sshpkt_send(ssh)) != 0 ||
1409 (r = ssh_packet_write_wait(ssh)) != 0)
1410 fatal("%s: send disconnect: %s", __func__, ssh_err(r));
1411
1412 channel_free_all(ssh);
1413
1414 if (have_pty)
1415 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
1416
1417 /* restore blocking io */
1418 if (!isatty(fileno(stdin)))
1419 unset_nonblock(fileno(stdin));
1420 if (!isatty(fileno(stdout)))
1421 unset_nonblock(fileno(stdout));
1422 if (!isatty(fileno(stderr)))
1423 unset_nonblock(fileno(stderr));
1424
1425 /*
1426 * If there was no shell or command requested, there will be no remote
1427 * exit status to be returned. In that case, clear error code if the
1428 * connection was deliberately terminated at this end.
1429 */
1430 if (no_shell_flag && received_signal == SIGTERM) {
1431 received_signal = 0;
1432 exit_status = 0;
1433 }
1434
1435 if (received_signal) {
1436 verbose("Killed by signal %d.", (int) received_signal);
1437 cleanup_exit(0);
1438 }
1439
1440 /*
1441 * In interactive mode (with pseudo tty) display a message indicating
1442 * that the connection has been closed.
1443 */
1444 if (have_pty && options.log_level != SYSLOG_LEVEL_QUIET) {
1445 if ((r = sshbuf_putf(stderr_buffer,
1446 "Connection to %.64s closed.\r\n", host)) != 0)
1447 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1448 }
1449
1450 /* Output any buffered data for stderr. */
1451 if (sshbuf_len(stderr_buffer) > 0) {
1452 len = atomicio(vwrite, fileno(stderr),
1453 (u_char *)sshbuf_ptr(stderr_buffer),
1454 sshbuf_len(stderr_buffer));
1455 if (len < 0 || (u_int)len != sshbuf_len(stderr_buffer))
1456 error("Write failed flushing stderr buffer.");
1457 else if ((r = sshbuf_consume(stderr_buffer, len)) != 0)
1458 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1459 }
1460
1461 /* Clear and free any buffers. */
1462 explicit_bzero(buf, sizeof(buf));
1463 sshbuf_free(stderr_buffer);
1464
1465 /* Report bytes transferred, and transfer rates. */
1466 total_time = monotime_double() - start_time;
1467 ssh_packet_get_bytes(ssh, &ibytes, &obytes);
1468 verbose("Transferred: sent %llu, received %llu bytes, in %.1f seconds",
1469 (unsigned long long)obytes, (unsigned long long)ibytes, total_time);
1470 if (total_time > 0)
1471 verbose("Bytes per second: sent %.1f, received %.1f",
1472 obytes / total_time, ibytes / total_time);
1473 /* Return the exit status of the program. */
1474 debug("Exit status %d", exit_status);
1475 return exit_status;
1476 }
1477
1478 /*********/
1479
1480 static Channel *
client_request_forwarded_tcpip(struct ssh * ssh,const char * request_type,int rchan,u_int rwindow,u_int rmaxpack)1481 client_request_forwarded_tcpip(struct ssh *ssh, const char *request_type,
1482 int rchan, u_int rwindow, u_int rmaxpack)
1483 {
1484 Channel *c = NULL;
1485 struct sshbuf *b = NULL;
1486 char *listen_address, *originator_address;
1487 u_int listen_port, originator_port;
1488 int r;
1489
1490 /* Get rest of the packet */
1491 if ((r = sshpkt_get_cstring(ssh, &listen_address, NULL)) != 0 ||
1492 (r = sshpkt_get_u32(ssh, &listen_port)) != 0 ||
1493 (r = sshpkt_get_cstring(ssh, &originator_address, NULL)) != 0 ||
1494 (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
1495 (r = sshpkt_get_end(ssh)) != 0)
1496 fatal("%s: parse packet: %s", __func__, ssh_err(r));
1497
1498 debug("%s: listen %s port %d, originator %s port %d", __func__,
1499 listen_address, listen_port, originator_address, originator_port);
1500
1501 if (listen_port > 0xffff)
1502 error("%s: invalid listen port", __func__);
1503 else if (originator_port > 0xffff)
1504 error("%s: invalid originator port", __func__);
1505 else {
1506 c = channel_connect_by_listen_address(ssh,
1507 listen_address, listen_port, "forwarded-tcpip",
1508 originator_address);
1509 }
1510
1511 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) {
1512 if ((b = sshbuf_new()) == NULL) {
1513 error("%s: alloc reply", __func__);
1514 goto out;
1515 }
1516 /* reconstruct and send to muxclient */
1517 if ((r = sshbuf_put_u8(b, 0)) != 0 || /* padlen */
1518 (r = sshbuf_put_u8(b, SSH2_MSG_CHANNEL_OPEN)) != 0 ||
1519 (r = sshbuf_put_cstring(b, request_type)) != 0 ||
1520 (r = sshbuf_put_u32(b, rchan)) != 0 ||
1521 (r = sshbuf_put_u32(b, rwindow)) != 0 ||
1522 (r = sshbuf_put_u32(b, rmaxpack)) != 0 ||
1523 (r = sshbuf_put_cstring(b, listen_address)) != 0 ||
1524 (r = sshbuf_put_u32(b, listen_port)) != 0 ||
1525 (r = sshbuf_put_cstring(b, originator_address)) != 0 ||
1526 (r = sshbuf_put_u32(b, originator_port)) != 0 ||
1527 (r = sshbuf_put_stringb(c->output, b)) != 0) {
1528 error("%s: compose for muxclient %s", __func__,
1529 ssh_err(r));
1530 goto out;
1531 }
1532 }
1533
1534 out:
1535 sshbuf_free(b);
1536 free(originator_address);
1537 free(listen_address);
1538 return c;
1539 }
1540
1541 static Channel *
client_request_forwarded_streamlocal(struct ssh * ssh,const char * request_type,int rchan)1542 client_request_forwarded_streamlocal(struct ssh *ssh,
1543 const char *request_type, int rchan)
1544 {
1545 Channel *c = NULL;
1546 char *listen_path;
1547 int r;
1548
1549 /* Get the remote path. */
1550 if ((r = sshpkt_get_cstring(ssh, &listen_path, NULL)) != 0 ||
1551 (r = sshpkt_get_string(ssh, NULL, NULL)) != 0 || /* reserved */
1552 (r = sshpkt_get_end(ssh)) != 0)
1553 fatal("%s: parse packet: %s", __func__, ssh_err(r));
1554
1555 debug("%s: request: %s", __func__, listen_path);
1556
1557 c = channel_connect_by_listen_path(ssh, listen_path,
1558 "forwarded-streamlocal@openssh.com", "forwarded-streamlocal");
1559 free(listen_path);
1560 return c;
1561 }
1562
1563 static Channel *
client_request_x11(struct ssh * ssh,const char * request_type,int rchan)1564 client_request_x11(struct ssh *ssh, const char *request_type, int rchan)
1565 {
1566 Channel *c = NULL;
1567 char *originator;
1568 u_int originator_port;
1569 int r, sock;
1570
1571 if (!options.forward_x11) {
1572 error("Warning: ssh server tried X11 forwarding.");
1573 error("Warning: this is probably a break-in attempt by a "
1574 "malicious server.");
1575 return NULL;
1576 }
1577 if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) {
1578 verbose("Rejected X11 connection after ForwardX11Timeout "
1579 "expired");
1580 return NULL;
1581 }
1582 if ((r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 ||
1583 (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
1584 (r = sshpkt_get_end(ssh)) != 0)
1585 fatal("%s: parse packet: %s", __func__, ssh_err(r));
1586 /* XXX check permission */
1587 /* XXX range check originator port? */
1588 debug("client_request_x11: request from %s %u", originator,
1589 originator_port);
1590 free(originator);
1591 sock = x11_connect_display(ssh);
1592 if (sock < 0)
1593 return NULL;
1594 c = channel_new(ssh, "x11",
1595 SSH_CHANNEL_X11_OPEN, sock, sock, -1,
1596 CHAN_TCP_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, 0, "x11", 1);
1597 c->force_drain = 1;
1598 return c;
1599 }
1600
1601 static Channel *
client_request_agent(struct ssh * ssh,const char * request_type,int rchan)1602 client_request_agent(struct ssh *ssh, const char *request_type, int rchan)
1603 {
1604 Channel *c = NULL;
1605 int r, sock;
1606
1607 if (!options.forward_agent) {
1608 error("Warning: ssh server tried agent forwarding.");
1609 error("Warning: this is probably a break-in attempt by a "
1610 "malicious server.");
1611 return NULL;
1612 }
1613 if (forward_agent_sock_path == NULL) {
1614 r = ssh_get_authentication_socket(&sock);
1615 } else {
1616 r = ssh_get_authentication_socket_path(forward_agent_sock_path, &sock);
1617 }
1618 if (r != 0) {
1619 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1620 debug("%s: ssh_get_authentication_socket: %s",
1621 __func__, ssh_err(r));
1622 return NULL;
1623 }
1624 c = channel_new(ssh, "authentication agent connection",
1625 SSH_CHANNEL_OPEN, sock, sock, -1,
1626 CHAN_X11_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0,
1627 "authentication agent connection", 1);
1628 c->force_drain = 1;
1629 return c;
1630 }
1631
1632 char *
client_request_tun_fwd(struct ssh * ssh,int tun_mode,int local_tun,int remote_tun,channel_open_fn * cb,void * cbctx)1633 client_request_tun_fwd(struct ssh *ssh, int tun_mode,
1634 int local_tun, int remote_tun, channel_open_fn *cb, void *cbctx)
1635 {
1636 Channel *c;
1637 int r, fd;
1638 char *ifname = NULL;
1639
1640 if (tun_mode == SSH_TUNMODE_NO)
1641 return 0;
1642
1643 debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
1644
1645 /* Open local tunnel device */
1646 if ((fd = tun_open(local_tun, tun_mode, &ifname)) == -1) {
1647 error("Tunnel device open failed.");
1648 return NULL;
1649 }
1650 debug("Tunnel forwarding using interface %s", ifname);
1651
1652 c = channel_new(ssh, "tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1653 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
1654 c->datagram = 1;
1655
1656 #if defined(SSH_TUN_FILTER)
1657 if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1658 channel_register_filter(ssh, c->self, sys_tun_infilter,
1659 sys_tun_outfilter, NULL, NULL);
1660 #endif
1661
1662 if (cb != NULL)
1663 channel_register_open_confirm(ssh, c->self, cb, cbctx);
1664
1665 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN)) != 0 ||
1666 (r = sshpkt_put_cstring(ssh, "tun@openssh.com")) != 0 ||
1667 (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
1668 (r = sshpkt_put_u32(ssh, c->local_window_max)) != 0 ||
1669 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
1670 (r = sshpkt_put_u32(ssh, tun_mode)) != 0 ||
1671 (r = sshpkt_put_u32(ssh, remote_tun)) != 0 ||
1672 (r = sshpkt_send(ssh)) != 0)
1673 sshpkt_fatal(ssh, r, "%s: send reply", __func__);
1674
1675 return ifname;
1676 }
1677
1678 /* XXXX move to generic input handler */
1679 static int
client_input_channel_open(int type,u_int32_t seq,struct ssh * ssh)1680 client_input_channel_open(int type, u_int32_t seq, struct ssh *ssh)
1681 {
1682 Channel *c = NULL;
1683 char *ctype = NULL;
1684 int r;
1685 u_int rchan;
1686 size_t len;
1687 u_int rmaxpack, rwindow;
1688
1689 if ((r = sshpkt_get_cstring(ssh, &ctype, &len)) != 0 ||
1690 (r = sshpkt_get_u32(ssh, &rchan)) != 0 ||
1691 (r = sshpkt_get_u32(ssh, &rwindow)) != 0 ||
1692 (r = sshpkt_get_u32(ssh, &rmaxpack)) != 0)
1693 goto out;
1694
1695 debug("client_input_channel_open: ctype %s rchan %d win %d max %d",
1696 ctype, rchan, rwindow, rmaxpack);
1697
1698 if (strcmp(ctype, "forwarded-tcpip") == 0) {
1699 c = client_request_forwarded_tcpip(ssh, ctype, rchan, rwindow,
1700 rmaxpack);
1701 } else if (strcmp(ctype, "forwarded-streamlocal@openssh.com") == 0) {
1702 c = client_request_forwarded_streamlocal(ssh, ctype, rchan);
1703 } else if (strcmp(ctype, "x11") == 0) {
1704 c = client_request_x11(ssh, ctype, rchan);
1705 } else if (strcmp(ctype, "auth-agent@openssh.com") == 0) {
1706 c = client_request_agent(ssh, ctype, rchan);
1707 }
1708 if (c != NULL && c->type == SSH_CHANNEL_MUX_CLIENT) {
1709 debug3("proxied to downstream: %s", ctype);
1710 } else if (c != NULL) {
1711 debug("confirm %s", ctype);
1712 c->remote_id = rchan;
1713 c->have_remote_id = 1;
1714 c->remote_window = rwindow;
1715 c->remote_maxpacket = rmaxpack;
1716 if (c->type != SSH_CHANNEL_CONNECTING) {
1717 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
1718 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1719 (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
1720 (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
1721 (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
1722 (r = sshpkt_send(ssh)) != 0)
1723 sshpkt_fatal(ssh, r, "%s: send reply", __func__);
1724 }
1725 } else {
1726 debug("failure %s", ctype);
1727 if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
1728 (r = sshpkt_put_u32(ssh, rchan)) != 0 ||
1729 (r = sshpkt_put_u32(ssh, SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED)) != 0 ||
1730 (r = sshpkt_put_cstring(ssh, "open failed")) != 0 ||
1731 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1732 (r = sshpkt_send(ssh)) != 0)
1733 sshpkt_fatal(ssh, r, "%s: send failure", __func__);
1734 }
1735 r = 0;
1736 out:
1737 free(ctype);
1738 return r;
1739 }
1740
1741 static int
client_input_channel_req(int type,u_int32_t seq,struct ssh * ssh)1742 client_input_channel_req(int type, u_int32_t seq, struct ssh *ssh)
1743 {
1744 Channel *c = NULL;
1745 char *rtype = NULL;
1746 u_char reply;
1747 u_int id, exitval;
1748 int r, success = 0;
1749
1750 if ((r = sshpkt_get_u32(ssh, &id)) != 0)
1751 return r;
1752 if (id <= INT_MAX)
1753 c = channel_lookup(ssh, id);
1754 if (channel_proxy_upstream(c, type, seq, ssh))
1755 return 0;
1756 if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
1757 (r = sshpkt_get_u8(ssh, &reply)) != 0)
1758 goto out;
1759
1760 debug("client_input_channel_req: channel %u rtype %s reply %d",
1761 id, rtype, reply);
1762
1763 if (c == NULL) {
1764 error("client_input_channel_req: channel %d: "
1765 "unknown channel", id);
1766 } else if (strcmp(rtype, "eow@openssh.com") == 0) {
1767 if ((r = sshpkt_get_end(ssh)) != 0)
1768 goto out;
1769 chan_rcvd_eow(ssh, c);
1770 } else if (strcmp(rtype, "exit-status") == 0) {
1771 if ((r = sshpkt_get_u32(ssh, &exitval)) != 0)
1772 goto out;
1773 if (c->ctl_chan != -1) {
1774 mux_exit_message(ssh, c, exitval);
1775 success = 1;
1776 } else if ((int)id == session_ident) {
1777 /* Record exit value of local session */
1778 success = 1;
1779 exit_status = exitval;
1780 } else {
1781 /* Probably for a mux channel that has already closed */
1782 debug("%s: no sink for exit-status on channel %d",
1783 __func__, id);
1784 }
1785 if ((r = sshpkt_get_end(ssh)) != 0)
1786 goto out;
1787 }
1788 if (reply && c != NULL && !(c->flags & CHAN_CLOSE_SENT)) {
1789 if (!c->have_remote_id)
1790 fatal("%s: channel %d: no remote_id",
1791 __func__, c->self);
1792 if ((r = sshpkt_start(ssh, success ?
1793 SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE)) != 0 ||
1794 (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
1795 (r = sshpkt_send(ssh)) != 0)
1796 sshpkt_fatal(ssh, r, "%s: send failure", __func__);
1797 }
1798 r = 0;
1799 out:
1800 free(rtype);
1801 return r;
1802 }
1803
1804 struct hostkeys_update_ctx {
1805 /* The hostname and (optionally) IP address string for the server */
1806 char *host_str, *ip_str;
1807
1808 /*
1809 * Keys received from the server and a flag for each indicating
1810 * whether they already exist in known_hosts.
1811 * keys_seen is filled in by hostkeys_find() and later (for new
1812 * keys) by client_global_hostkeys_private_confirm().
1813 */
1814 struct sshkey **keys;
1815 int *keys_seen;
1816 size_t nkeys, nnew;
1817
1818 /*
1819 * Keys that are in known_hosts, but were not present in the update
1820 * from the server (i.e. scheduled to be deleted).
1821 * Filled in by hostkeys_find().
1822 */
1823 struct sshkey **old_keys;
1824 size_t nold;
1825 };
1826
1827 static void
hostkeys_update_ctx_free(struct hostkeys_update_ctx * ctx)1828 hostkeys_update_ctx_free(struct hostkeys_update_ctx *ctx)
1829 {
1830 size_t i;
1831
1832 if (ctx == NULL)
1833 return;
1834 for (i = 0; i < ctx->nkeys; i++)
1835 sshkey_free(ctx->keys[i]);
1836 free(ctx->keys);
1837 free(ctx->keys_seen);
1838 for (i = 0; i < ctx->nold; i++)
1839 sshkey_free(ctx->old_keys[i]);
1840 free(ctx->old_keys);
1841 free(ctx->host_str);
1842 free(ctx->ip_str);
1843 free(ctx);
1844 }
1845
1846 static int
hostkeys_find(struct hostkey_foreach_line * l,void * _ctx)1847 hostkeys_find(struct hostkey_foreach_line *l, void *_ctx)
1848 {
1849 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx;
1850 size_t i;
1851 struct sshkey **tmp;
1852
1853 if (l->status != HKF_STATUS_MATCHED || l->key == NULL)
1854 return 0;
1855
1856 /* Mark off keys we've already seen for this host */
1857 for (i = 0; i < ctx->nkeys; i++) {
1858 if (sshkey_equal(l->key, ctx->keys[i])) {
1859 debug3("%s: found %s key at %s:%ld", __func__,
1860 sshkey_ssh_name(ctx->keys[i]), l->path, l->linenum);
1861 ctx->keys_seen[i] = 1;
1862 return 0;
1863 }
1864 }
1865 /* This line contained a key that not offered by the server */
1866 debug3("%s: deprecated %s key at %s:%ld", __func__,
1867 sshkey_ssh_name(l->key), l->path, l->linenum);
1868 if ((tmp = recallocarray(ctx->old_keys, ctx->nold, ctx->nold + 1,
1869 sizeof(*ctx->old_keys))) == NULL)
1870 fatal("%s: recallocarray failed nold = %zu",
1871 __func__, ctx->nold);
1872 ctx->old_keys = tmp;
1873 ctx->old_keys[ctx->nold++] = l->key;
1874 l->key = NULL;
1875
1876 return 0;
1877 }
1878
1879 static void
hostkey_change_preamble(LogLevel loglevel)1880 hostkey_change_preamble(LogLevel loglevel)
1881 {
1882 do_log2(loglevel, "The server has updated its host keys.");
1883 do_log2(loglevel, "These changes were verified by the server's "
1884 "existing trusted key.");
1885 }
1886
1887 static void
update_known_hosts(struct hostkeys_update_ctx * ctx)1888 update_known_hosts(struct hostkeys_update_ctx *ctx)
1889 {
1890 int r, was_raw = 0, first = 1;
1891 int asking = options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK;
1892 LogLevel loglevel = asking ? SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_VERBOSE;
1893 char *fp, *response;
1894 size_t i;
1895 struct stat sb;
1896
1897 for (i = 0; i < ctx->nkeys; i++) {
1898 if (ctx->keys_seen[i] != 2)
1899 continue;
1900 if ((fp = sshkey_fingerprint(ctx->keys[i],
1901 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
1902 fatal("%s: sshkey_fingerprint failed", __func__);
1903 if (first && asking)
1904 hostkey_change_preamble(loglevel);
1905 do_log2(loglevel, "Learned new hostkey: %s %s",
1906 sshkey_type(ctx->keys[i]), fp);
1907 first = 0;
1908 free(fp);
1909 }
1910 for (i = 0; i < ctx->nold; i++) {
1911 if ((fp = sshkey_fingerprint(ctx->old_keys[i],
1912 options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
1913 fatal("%s: sshkey_fingerprint failed", __func__);
1914 if (first && asking)
1915 hostkey_change_preamble(loglevel);
1916 do_log2(loglevel, "Deprecating obsolete hostkey: %s %s",
1917 sshkey_type(ctx->old_keys[i]), fp);
1918 first = 0;
1919 free(fp);
1920 }
1921 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {
1922 if (get_saved_tio() != NULL) {
1923 leave_raw_mode(1);
1924 was_raw = 1;
1925 }
1926 response = NULL;
1927 for (i = 0; !quit_pending && i < 3; i++) {
1928 free(response);
1929 response = read_passphrase("Accept updated hostkeys? "
1930 "(yes/no): ", RP_ECHO);
1931 if (strcasecmp(response, "yes") == 0)
1932 break;
1933 else if (quit_pending || response == NULL ||
1934 strcasecmp(response, "no") == 0) {
1935 options.update_hostkeys = 0;
1936 break;
1937 } else {
1938 do_log2(loglevel, "Please enter "
1939 "\"yes\" or \"no\"");
1940 }
1941 }
1942 if (quit_pending || i >= 3 || response == NULL)
1943 options.update_hostkeys = 0;
1944 free(response);
1945 if (was_raw)
1946 enter_raw_mode(1);
1947 }
1948 if (options.update_hostkeys == 0)
1949 return;
1950 /*
1951 * Now that all the keys are verified, we can go ahead and replace
1952 * them in known_hosts (assuming SSH_UPDATE_HOSTKEYS_ASK didn't
1953 * cancel the operation).
1954 */
1955 for (i = 0; i < options.num_user_hostfiles; i++) {
1956 /*
1957 * NB. keys are only added to hostfiles[0], for the rest we
1958 * just delete the hostname entries.
1959 */
1960 if (stat(options.user_hostfiles[i], &sb) != 0) {
1961 if (errno == ENOENT) {
1962 debug("%s: known hosts file %s does not exist",
1963 __func__, strerror(errno));
1964 } else {
1965 error("%s: known hosts file %s inaccessible",
1966 __func__, strerror(errno));
1967 }
1968 continue;
1969 }
1970 if ((r = hostfile_replace_entries(options.user_hostfiles[i],
1971 ctx->host_str, ctx->ip_str,
1972 i == 0 ? ctx->keys : NULL, i == 0 ? ctx->nkeys : 0,
1973 options.hash_known_hosts, 0,
1974 options.fingerprint_hash)) != 0) {
1975 error("%s: hostfile_replace_entries failed for %s: %s",
1976 __func__, options.user_hostfiles[i], ssh_err(r));
1977 }
1978 }
1979 }
1980
1981 static void
client_global_hostkeys_private_confirm(struct ssh * ssh,int type,u_int32_t seq,void * _ctx)1982 client_global_hostkeys_private_confirm(struct ssh *ssh, int type,
1983 u_int32_t seq, void *_ctx)
1984 {
1985 struct hostkeys_update_ctx *ctx = (struct hostkeys_update_ctx *)_ctx;
1986 size_t i, ndone;
1987 struct sshbuf *signdata;
1988 int r, kexsigtype, use_kexsigtype;
1989 const u_char *sig;
1990 size_t siglen;
1991
1992 if (ctx->nnew == 0)
1993 fatal("%s: ctx->nnew == 0", __func__); /* sanity */
1994 if (type != SSH2_MSG_REQUEST_SUCCESS) {
1995 error("Server failed to confirm ownership of "
1996 "private host keys");
1997 hostkeys_update_ctx_free(ctx);
1998 return;
1999 }
2000 kexsigtype = sshkey_type_plain(
2001 sshkey_type_from_name(ssh->kex->hostkey_alg));
2002
2003 if ((signdata = sshbuf_new()) == NULL)
2004 fatal("%s: sshbuf_new failed", __func__);
2005 /* Don't want to accidentally accept an unbound signature */
2006 if (ssh->kex->session_id_len == 0)
2007 fatal("%s: ssh->kex->session_id_len == 0", __func__);
2008 /*
2009 * Expect a signature for each of the ctx->nnew private keys we
2010 * haven't seen before. They will be in the same order as the
2011 * ctx->keys where the corresponding ctx->keys_seen[i] == 0.
2012 */
2013 for (ndone = i = 0; i < ctx->nkeys; i++) {
2014 if (ctx->keys_seen[i])
2015 continue;
2016 /* Prepare data to be signed: session ID, unique string, key */
2017 sshbuf_reset(signdata);
2018 if ( (r = sshbuf_put_cstring(signdata,
2019 "hostkeys-prove-00@openssh.com")) != 0 ||
2020 (r = sshbuf_put_string(signdata, ssh->kex->session_id,
2021 ssh->kex->session_id_len)) != 0 ||
2022 (r = sshkey_puts(ctx->keys[i], signdata)) != 0)
2023 fatal("%s: failed to prepare signature: %s",
2024 __func__, ssh_err(r));
2025 /* Extract and verify signature */
2026 if ((r = sshpkt_get_string_direct(ssh, &sig, &siglen)) != 0) {
2027 error("%s: couldn't parse message: %s",
2028 __func__, ssh_err(r));
2029 goto out;
2030 }
2031 /*
2032 * For RSA keys, prefer to use the signature type negotiated
2033 * during KEX to the default (SHA1).
2034 */
2035 use_kexsigtype = kexsigtype == KEY_RSA &&
2036 sshkey_type_plain(ctx->keys[i]->type) == KEY_RSA;
2037 if ((r = sshkey_verify(ctx->keys[i], sig, siglen,
2038 sshbuf_ptr(signdata), sshbuf_len(signdata),
2039 use_kexsigtype ? ssh->kex->hostkey_alg : NULL, 0,
2040 NULL)) != 0) {
2041 error("%s: server gave bad signature for %s key %zu",
2042 __func__, sshkey_type(ctx->keys[i]), i);
2043 goto out;
2044 }
2045 /* Key is good. Mark it as 'seen' */
2046 ctx->keys_seen[i] = 2;
2047 ndone++;
2048 }
2049 if (ndone != ctx->nnew)
2050 fatal("%s: ndone != ctx->nnew (%zu / %zu)", __func__,
2051 ndone, ctx->nnew); /* Shouldn't happen */
2052 if ((r = sshpkt_get_end(ssh)) != 0) {
2053 error("%s: protocol error", __func__);
2054 goto out;
2055 }
2056
2057 /* Make the edits to known_hosts */
2058 update_known_hosts(ctx);
2059 out:
2060 hostkeys_update_ctx_free(ctx);
2061 }
2062
2063 /*
2064 * Returns non-zero if the key is accepted by HostkeyAlgorithms.
2065 * Made slightly less trivial by the multiple RSA signature algorithm names.
2066 */
2067 static int
key_accepted_by_hostkeyalgs(const struct sshkey * key)2068 key_accepted_by_hostkeyalgs(const struct sshkey *key)
2069 {
2070 const char *ktype = sshkey_ssh_name(key);
2071 const char *hostkeyalgs = options.hostkeyalgorithms;
2072
2073 if (key == NULL || key->type == KEY_UNSPEC)
2074 return 0;
2075 if (key->type == KEY_RSA &&
2076 (match_pattern_list("rsa-sha2-256", hostkeyalgs, 0) == 1 ||
2077 match_pattern_list("rsa-sha2-512", hostkeyalgs, 0) == 1))
2078 return 1;
2079 return match_pattern_list(ktype, hostkeyalgs, 0) == 1;
2080 }
2081
2082 /*
2083 * Handle hostkeys-00@openssh.com global request to inform the client of all
2084 * the server's hostkeys. The keys are checked against the user's
2085 * HostkeyAlgorithms preference before they are accepted.
2086 */
2087 static int
client_input_hostkeys(struct ssh * ssh)2088 client_input_hostkeys(struct ssh *ssh)
2089 {
2090 const u_char *blob = NULL;
2091 size_t i, len = 0;
2092 struct sshbuf *buf = NULL;
2093 struct sshkey *key = NULL, **tmp;
2094 int r;
2095 char *fp;
2096 static int hostkeys_seen = 0; /* XXX use struct ssh */
2097 extern struct sockaddr_storage hostaddr; /* XXX from ssh.c */
2098 struct hostkeys_update_ctx *ctx = NULL;
2099
2100 if (hostkeys_seen)
2101 fatal("%s: server already sent hostkeys", __func__);
2102 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK &&
2103 options.batch_mode)
2104 return 1; /* won't ask in batchmode, so don't even try */
2105 if (!options.update_hostkeys || options.num_user_hostfiles <= 0)
2106 return 1;
2107
2108 ctx = xcalloc(1, sizeof(*ctx));
2109 while (ssh_packet_remaining(ssh) > 0) {
2110 sshkey_free(key);
2111 key = NULL;
2112 if ((r = sshpkt_get_string_direct(ssh, &blob, &len)) != 0) {
2113 error("%s: couldn't parse message: %s",
2114 __func__, ssh_err(r));
2115 goto out;
2116 }
2117 if ((r = sshkey_from_blob(blob, len, &key)) != 0) {
2118 do_log2(r == SSH_ERR_KEY_TYPE_UNKNOWN ?
2119 SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_ERROR,
2120 "%s: parse key: %s", __func__, ssh_err(r));
2121 continue;
2122 }
2123 fp = sshkey_fingerprint(key, options.fingerprint_hash,
2124 SSH_FP_DEFAULT);
2125 debug3("%s: received %s key %s", __func__,
2126 sshkey_type(key), fp);
2127 free(fp);
2128
2129 if (!key_accepted_by_hostkeyalgs(key)) {
2130 debug3("%s: %s key not permitted by HostkeyAlgorithms",
2131 __func__, sshkey_ssh_name(key));
2132 continue;
2133 }
2134 /* Skip certs */
2135 if (sshkey_is_cert(key)) {
2136 debug3("%s: %s key is a certificate; skipping",
2137 __func__, sshkey_ssh_name(key));
2138 continue;
2139 }
2140 /* Ensure keys are unique */
2141 for (i = 0; i < ctx->nkeys; i++) {
2142 if (sshkey_equal(key, ctx->keys[i])) {
2143 error("%s: received duplicated %s host key",
2144 __func__, sshkey_ssh_name(key));
2145 goto out;
2146 }
2147 }
2148 /* Key is good, record it */
2149 if ((tmp = recallocarray(ctx->keys, ctx->nkeys, ctx->nkeys + 1,
2150 sizeof(*ctx->keys))) == NULL)
2151 fatal("%s: recallocarray failed nkeys = %zu",
2152 __func__, ctx->nkeys);
2153 ctx->keys = tmp;
2154 ctx->keys[ctx->nkeys++] = key;
2155 key = NULL;
2156 }
2157
2158 if (ctx->nkeys == 0) {
2159 debug("%s: server sent no hostkeys", __func__);
2160 goto out;
2161 }
2162
2163 if ((ctx->keys_seen = calloc(ctx->nkeys,
2164 sizeof(*ctx->keys_seen))) == NULL)
2165 fatal("%s: calloc failed", __func__);
2166
2167 get_hostfile_hostname_ipaddr(host,
2168 options.check_host_ip ? (struct sockaddr *)&hostaddr : NULL,
2169 options.port, &ctx->host_str,
2170 options.check_host_ip ? &ctx->ip_str : NULL);
2171
2172 /* Find which keys we already know about. */
2173 for (i = 0; i < options.num_user_hostfiles; i++) {
2174 debug("%s: searching %s for %s / %s", __func__,
2175 options.user_hostfiles[i], ctx->host_str,
2176 ctx->ip_str ? ctx->ip_str : "(none)");
2177 if ((r = hostkeys_foreach(options.user_hostfiles[i],
2178 hostkeys_find, ctx, ctx->host_str, ctx->ip_str,
2179 HKF_WANT_PARSE_KEY|HKF_WANT_MATCH)) != 0) {
2180 if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) {
2181 debug("%s: hostkeys file %s does not exist",
2182 __func__, options.user_hostfiles[i]);
2183 continue;
2184 }
2185 error("%s: hostkeys_foreach failed for %s: %s",
2186 __func__, options.user_hostfiles[i], ssh_err(r));
2187 goto out;
2188 }
2189 }
2190
2191 /* Figure out if we have any new keys to add */
2192 ctx->nnew = 0;
2193 for (i = 0; i < ctx->nkeys; i++) {
2194 if (!ctx->keys_seen[i])
2195 ctx->nnew++;
2196 }
2197
2198 debug3("%s: %zu keys from server: %zu new, %zu retained. %zu to remove",
2199 __func__, ctx->nkeys, ctx->nnew, ctx->nkeys - ctx->nnew, ctx->nold);
2200
2201 if (ctx->nnew == 0 && ctx->nold != 0) {
2202 /* We have some keys to remove. Just do it. */
2203 update_known_hosts(ctx);
2204 } else if (ctx->nnew != 0) {
2205 /*
2206 * We have received hitherto-unseen keys from the server.
2207 * Ask the server to confirm ownership of the private halves.
2208 */
2209 debug3("%s: asking server to prove ownership for %zu keys",
2210 __func__, ctx->nnew);
2211 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
2212 (r = sshpkt_put_cstring(ssh,
2213 "hostkeys-prove-00@openssh.com")) != 0 ||
2214 (r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */
2215 fatal("%s: cannot prepare packet: %s",
2216 __func__, ssh_err(r));
2217 if ((buf = sshbuf_new()) == NULL)
2218 fatal("%s: sshbuf_new", __func__);
2219 for (i = 0; i < ctx->nkeys; i++) {
2220 if (ctx->keys_seen[i])
2221 continue;
2222 sshbuf_reset(buf);
2223 if ((r = sshkey_putb(ctx->keys[i], buf)) != 0)
2224 fatal("%s: sshkey_putb: %s",
2225 __func__, ssh_err(r));
2226 if ((r = sshpkt_put_stringb(ssh, buf)) != 0)
2227 fatal("%s: sshpkt_put_string: %s",
2228 __func__, ssh_err(r));
2229 }
2230 if ((r = sshpkt_send(ssh)) != 0)
2231 fatal("%s: sshpkt_send: %s", __func__, ssh_err(r));
2232 client_register_global_confirm(
2233 client_global_hostkeys_private_confirm, ctx);
2234 ctx = NULL; /* will be freed in callback */
2235 }
2236
2237 /* Success */
2238 out:
2239 hostkeys_update_ctx_free(ctx);
2240 sshkey_free(key);
2241 sshbuf_free(buf);
2242 /*
2243 * NB. Return success for all cases. The server doesn't need to know
2244 * what the client does with its hosts file.
2245 */
2246 return 1;
2247 }
2248
2249 static int
client_input_global_request(int type,u_int32_t seq,struct ssh * ssh)2250 client_input_global_request(int type, u_int32_t seq, struct ssh *ssh)
2251 {
2252 char *rtype;
2253 u_char want_reply;
2254 int r, success = 0;
2255
2256 if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
2257 (r = sshpkt_get_u8(ssh, &want_reply)) != 0)
2258 goto out;
2259 debug("client_input_global_request: rtype %s want_reply %d",
2260 rtype, want_reply);
2261 if (strcmp(rtype, "hostkeys-00@openssh.com") == 0)
2262 success = client_input_hostkeys(ssh);
2263 if (want_reply) {
2264 if ((r = sshpkt_start(ssh, success ? SSH2_MSG_REQUEST_SUCCESS :
2265 SSH2_MSG_REQUEST_FAILURE)) != 0 ||
2266 (r = sshpkt_send(ssh)) != 0 ||
2267 (r = ssh_packet_write_wait(ssh)) != 0)
2268 goto out;
2269 }
2270 r = 0;
2271 out:
2272 free(rtype);
2273 return r;
2274 }
2275
2276 void
client_session2_setup(struct ssh * ssh,int id,int want_tty,int want_subsystem,const char * term,struct termios * tiop,int in_fd,struct sshbuf * cmd,char ** env)2277 client_session2_setup(struct ssh *ssh, int id, int want_tty, int want_subsystem,
2278 const char *term, struct termios *tiop, int in_fd, struct sshbuf *cmd,
2279 char **env)
2280 {
2281 int i, j, matched, len, r;
2282 char *name, *val;
2283 Channel *c = NULL;
2284
2285 debug2("%s: id %d", __func__, id);
2286
2287 if ((c = channel_lookup(ssh, id)) == NULL)
2288 fatal("%s: channel %d: unknown channel", __func__, id);
2289
2290 ssh_packet_set_interactive(ssh, want_tty,
2291 options.ip_qos_interactive, options.ip_qos_bulk);
2292
2293 if (want_tty) {
2294 struct winsize ws;
2295
2296 /* Store window size in the packet. */
2297 if (ioctl(in_fd, TIOCGWINSZ, &ws) == -1)
2298 memset(&ws, 0, sizeof(ws));
2299
2300 channel_request_start(ssh, id, "pty-req", 1);
2301 client_expect_confirm(ssh, id, "PTY allocation", CONFIRM_TTY);
2302 if ((r = sshpkt_put_cstring(ssh, term != NULL ? term : ""))
2303 != 0 ||
2304 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_col)) != 0 ||
2305 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_row)) != 0 ||
2306 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_xpixel)) != 0 ||
2307 (r = sshpkt_put_u32(ssh, (u_int)ws.ws_ypixel)) != 0)
2308 fatal("%s: build packet: %s", __func__, ssh_err(r));
2309 if (tiop == NULL)
2310 tiop = get_saved_tio();
2311 ssh_tty_make_modes(ssh, -1, tiop);
2312 if ((r = sshpkt_send(ssh)) != 0)
2313 fatal("%s: send packet: %s", __func__, ssh_err(r));
2314 /* XXX wait for reply */
2315 c->client_tty = 1;
2316 }
2317
2318 /* Transfer any environment variables from client to server */
2319 if (options.num_send_env != 0 && env != NULL) {
2320 debug("Sending environment.");
2321 for (i = 0; env[i] != NULL; i++) {
2322 /* Split */
2323 name = xstrdup(env[i]);
2324 if ((val = strchr(name, '=')) == NULL) {
2325 free(name);
2326 continue;
2327 }
2328 *val++ = '\0';
2329
2330 matched = 0;
2331 for (j = 0; j < options.num_send_env; j++) {
2332 if (match_pattern(name, options.send_env[j])) {
2333 matched = 1;
2334 break;
2335 }
2336 }
2337 if (!matched) {
2338 debug3("Ignored env %s", name);
2339 free(name);
2340 continue;
2341 }
2342
2343 debug("Sending env %s = %s", name, val);
2344 channel_request_start(ssh, id, "env", 0);
2345 if ((r = sshpkt_put_cstring(ssh, name)) != 0 ||
2346 (r = sshpkt_put_cstring(ssh, val)) != 0 ||
2347 (r = sshpkt_send(ssh)) != 0) {
2348 fatal("%s: send packet: %s",
2349 __func__, ssh_err(r));
2350 }
2351 free(name);
2352 }
2353 }
2354 for (i = 0; i < options.num_setenv; i++) {
2355 /* Split */
2356 name = xstrdup(options.setenv[i]);
2357 if ((val = strchr(name, '=')) == NULL) {
2358 free(name);
2359 continue;
2360 }
2361 *val++ = '\0';
2362
2363 debug("Setting env %s = %s", name, val);
2364 channel_request_start(ssh, id, "env", 0);
2365 if ((r = sshpkt_put_cstring(ssh, name)) != 0 ||
2366 (r = sshpkt_put_cstring(ssh, val)) != 0 ||
2367 (r = sshpkt_send(ssh)) != 0)
2368 fatal("%s: send packet: %s", __func__, ssh_err(r));
2369 free(name);
2370 }
2371
2372 len = sshbuf_len(cmd);
2373 if (len > 0) {
2374 if (len > 900)
2375 len = 900;
2376 if (want_subsystem) {
2377 debug("Sending subsystem: %.*s",
2378 len, (const u_char*)sshbuf_ptr(cmd));
2379 channel_request_start(ssh, id, "subsystem", 1);
2380 client_expect_confirm(ssh, id, "subsystem",
2381 CONFIRM_CLOSE);
2382 } else {
2383 debug("Sending command: %.*s",
2384 len, (const u_char*)sshbuf_ptr(cmd));
2385 channel_request_start(ssh, id, "exec", 1);
2386 client_expect_confirm(ssh, id, "exec", CONFIRM_CLOSE);
2387 }
2388 if ((r = sshpkt_put_stringb(ssh, cmd)) != 0 ||
2389 (r = sshpkt_send(ssh)) != 0)
2390 fatal("%s: send command: %s", __func__, ssh_err(r));
2391 } else {
2392 channel_request_start(ssh, id, "shell", 1);
2393 client_expect_confirm(ssh, id, "shell", CONFIRM_CLOSE);
2394 if ((r = sshpkt_send(ssh)) != 0) {
2395 fatal("%s: send shell request: %s",
2396 __func__, ssh_err(r));
2397 }
2398 }
2399 }
2400
2401 static void
client_init_dispatch(struct ssh * ssh)2402 client_init_dispatch(struct ssh *ssh)
2403 {
2404 ssh_dispatch_init(ssh, &dispatch_protocol_error);
2405
2406 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
2407 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_DATA, &channel_input_data);
2408 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
2409 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
2410 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN, &client_input_channel_open);
2411 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
2412 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
2413 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_REQUEST, &client_input_channel_req);
2414 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
2415 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_SUCCESS, &channel_input_status_confirm);
2416 ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_FAILURE, &channel_input_status_confirm);
2417 ssh_dispatch_set(ssh, SSH2_MSG_GLOBAL_REQUEST, &client_input_global_request);
2418
2419 /* rekeying */
2420 ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit);
2421
2422 /* global request reply messages */
2423 ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_FAILURE, &client_global_request_reply);
2424 ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_SUCCESS, &client_global_request_reply);
2425 }
2426
2427 void
client_stop_mux(void)2428 client_stop_mux(void)
2429 {
2430 if (options.control_path != NULL && muxserver_sock != -1)
2431 unlink(options.control_path);
2432 /*
2433 * If we are in persist mode, or don't have a shell, signal that we
2434 * should close when all active channels are closed.
2435 */
2436 if (options.control_persist || no_shell_flag) {
2437 session_closed = 1;
2438 setproctitle("[stopped mux]");
2439 }
2440 }
2441
2442 /* client specific fatal cleanup */
2443 void
cleanup_exit(int i)2444 cleanup_exit(int i)
2445 {
2446 leave_raw_mode(options.request_tty == REQUEST_TTY_FORCE);
2447 if (options.control_path != NULL && muxserver_sock != -1)
2448 unlink(options.control_path);
2449 ssh_kill_proxy_command();
2450 _exit(i);
2451 }
2452