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3bcced4c | 1 | /* $OpenBSD: mux.c,v 1.1 2008/05/09 14:18:44 djm Exp $ */ |
2 | /* | |
3 | * Copyright (c) 2002-2008 Damien Miller <djm@openbsd.org> | |
4 | * | |
5 | * Permission to use, copy, modify, and distribute this software for any | |
6 | * purpose with or without fee is hereby granted, provided that the above | |
7 | * copyright notice and this permission notice appear in all copies. | |
8 | * | |
9 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES | |
10 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF | |
11 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR | |
12 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES | |
13 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN | |
14 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF | |
15 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |
16 | */ | |
17 | ||
18 | /* ssh session multiplexing support */ | |
19 | ||
b3ef88dc | 20 | #include "includes.h" |
21 | ||
3bcced4c | 22 | #include <sys/types.h> |
23 | #include <sys/param.h> | |
24 | #include <sys/stat.h> | |
25 | #include <sys/socket.h> | |
26 | #include <sys/un.h> | |
27 | ||
28 | #include <errno.h> | |
29 | #include <fcntl.h> | |
30 | #include <signal.h> | |
31 | #include <stdarg.h> | |
32 | #include <stddef.h> | |
33 | #include <stdlib.h> | |
34 | #include <stdio.h> | |
35 | #include <string.h> | |
36 | #include <unistd.h> | |
3bcced4c | 37 | #include <paths.h> |
38 | ||
b3ef88dc | 39 | #ifdef HAVE_UTIL_H |
40 | # include <util.h> | |
41 | #endif | |
42 | ||
43 | #ifdef HAVE_LIBUTIL_H | |
44 | # include <libutil.h> | |
45 | #endif | |
46 | ||
3bcced4c | 47 | #include "openbsd-compat/sys-queue.h" |
48 | #include "xmalloc.h" | |
49 | #include "log.h" | |
50 | #include "ssh.h" | |
51 | #include "pathnames.h" | |
52 | #include "misc.h" | |
53 | #include "match.h" | |
54 | #include "buffer.h" | |
55 | #include "channels.h" | |
56 | #include "msg.h" | |
57 | #include "packet.h" | |
58 | #include "monitor_fdpass.h" | |
59 | #include "sshpty.h" | |
60 | #include "key.h" | |
61 | #include "readconf.h" | |
62 | #include "clientloop.h" | |
63 | ||
64 | /* from ssh.c */ | |
65 | extern int tty_flag; | |
66 | extern Options options; | |
67 | extern int stdin_null_flag; | |
68 | extern char *host; | |
69 | int subsystem_flag; | |
70 | extern Buffer command; | |
71 | ||
72 | /* fd to control socket */ | |
73 | int muxserver_sock = -1; | |
74 | ||
75 | /* Multiplexing control command */ | |
76 | u_int muxclient_command = 0; | |
77 | ||
78 | /* Set when signalled. */ | |
79 | static volatile sig_atomic_t muxclient_terminate = 0; | |
80 | ||
81 | /* PID of multiplex server */ | |
82 | static u_int muxserver_pid = 0; | |
83 | ||
84 | ||
85 | /* ** Multiplexing master support */ | |
86 | ||
87 | /* Prepare a mux master to listen on a Unix domain socket. */ | |
88 | void | |
89 | muxserver_listen(void) | |
90 | { | |
91 | struct sockaddr_un addr; | |
92 | mode_t old_umask; | |
93 | int addr_len; | |
94 | ||
95 | if (options.control_path == NULL || | |
96 | options.control_master == SSHCTL_MASTER_NO) | |
97 | return; | |
98 | ||
99 | debug("setting up multiplex master socket"); | |
100 | ||
101 | memset(&addr, '\0', sizeof(addr)); | |
102 | addr.sun_family = AF_UNIX; | |
103 | addr_len = offsetof(struct sockaddr_un, sun_path) + | |
104 | strlen(options.control_path) + 1; | |
105 | ||
106 | if (strlcpy(addr.sun_path, options.control_path, | |
107 | sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) | |
108 | fatal("ControlPath too long"); | |
109 | ||
110 | if ((muxserver_sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) | |
111 | fatal("%s socket(): %s", __func__, strerror(errno)); | |
112 | ||
113 | old_umask = umask(0177); | |
114 | if (bind(muxserver_sock, (struct sockaddr *)&addr, addr_len) == -1) { | |
115 | muxserver_sock = -1; | |
116 | if (errno == EINVAL || errno == EADDRINUSE) | |
117 | fatal("ControlSocket %s already exists", | |
118 | options.control_path); | |
119 | else | |
120 | fatal("%s bind(): %s", __func__, strerror(errno)); | |
121 | } | |
122 | umask(old_umask); | |
123 | ||
124 | if (listen(muxserver_sock, 64) == -1) | |
125 | fatal("%s listen(): %s", __func__, strerror(errno)); | |
126 | ||
127 | set_nonblock(muxserver_sock); | |
128 | } | |
129 | ||
130 | /* Callback on open confirmation in mux master for a mux client session. */ | |
131 | static void | |
132 | client_extra_session2_setup(int id, void *arg) | |
133 | { | |
134 | struct mux_session_confirm_ctx *cctx = arg; | |
135 | const char *display; | |
136 | Channel *c; | |
137 | int i; | |
138 | ||
139 | if (cctx == NULL) | |
140 | fatal("%s: cctx == NULL", __func__); | |
141 | if ((c = channel_lookup(id)) == NULL) | |
142 | fatal("%s: no channel for id %d", __func__, id); | |
143 | ||
144 | display = getenv("DISPLAY"); | |
145 | if (cctx->want_x_fwd && options.forward_x11 && display != NULL) { | |
146 | char *proto, *data; | |
147 | /* Get reasonable local authentication information. */ | |
148 | client_x11_get_proto(display, options.xauth_location, | |
149 | options.forward_x11_trusted, &proto, &data); | |
150 | /* Request forwarding with authentication spoofing. */ | |
151 | debug("Requesting X11 forwarding with authentication spoofing."); | |
152 | x11_request_forwarding_with_spoofing(id, display, proto, data); | |
153 | /* XXX wait for reply */ | |
154 | } | |
155 | ||
156 | if (cctx->want_agent_fwd && options.forward_agent) { | |
157 | debug("Requesting authentication agent forwarding."); | |
158 | channel_request_start(id, "auth-agent-req@openssh.com", 0); | |
159 | packet_send(); | |
160 | } | |
161 | ||
162 | client_session2_setup(id, cctx->want_tty, cctx->want_subsys, | |
163 | cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env); | |
164 | ||
165 | c->open_confirm_ctx = NULL; | |
166 | buffer_free(&cctx->cmd); | |
167 | xfree(cctx->term); | |
168 | if (cctx->env != NULL) { | |
169 | for (i = 0; cctx->env[i] != NULL; i++) | |
170 | xfree(cctx->env[i]); | |
171 | xfree(cctx->env); | |
172 | } | |
173 | xfree(cctx); | |
174 | } | |
175 | ||
176 | /* | |
177 | * Accept a connection on the mux master socket and process the | |
178 | * client's request. Returns flag indicating whether mux master should | |
179 | * begin graceful close. | |
180 | */ | |
181 | int | |
182 | muxserver_accept_control(void) | |
183 | { | |
184 | Buffer m; | |
185 | Channel *c; | |
186 | int client_fd, new_fd[3], ver, allowed, window, packetmax; | |
187 | socklen_t addrlen; | |
188 | struct sockaddr_storage addr; | |
189 | struct mux_session_confirm_ctx *cctx; | |
190 | char *cmd; | |
191 | u_int i, j, len, env_len, mux_command, flags; | |
192 | uid_t euid; | |
193 | gid_t egid; | |
194 | int start_close = 0; | |
195 | ||
196 | /* | |
197 | * Accept connection on control socket | |
198 | */ | |
199 | memset(&addr, 0, sizeof(addr)); | |
200 | addrlen = sizeof(addr); | |
201 | if ((client_fd = accept(muxserver_sock, | |
202 | (struct sockaddr*)&addr, &addrlen)) == -1) { | |
203 | error("%s accept: %s", __func__, strerror(errno)); | |
204 | return 0; | |
205 | } | |
206 | ||
207 | if (getpeereid(client_fd, &euid, &egid) < 0) { | |
208 | error("%s getpeereid failed: %s", __func__, strerror(errno)); | |
209 | close(client_fd); | |
210 | return 0; | |
211 | } | |
212 | if ((euid != 0) && (getuid() != euid)) { | |
213 | error("control mode uid mismatch: peer euid %u != uid %u", | |
214 | (u_int) euid, (u_int) getuid()); | |
215 | close(client_fd); | |
216 | return 0; | |
217 | } | |
218 | ||
219 | /* XXX handle asynchronously */ | |
220 | unset_nonblock(client_fd); | |
221 | ||
222 | /* Read command */ | |
223 | buffer_init(&m); | |
224 | if (ssh_msg_recv(client_fd, &m) == -1) { | |
225 | error("%s: client msg_recv failed", __func__); | |
226 | close(client_fd); | |
227 | buffer_free(&m); | |
228 | return 0; | |
229 | } | |
230 | if ((ver = buffer_get_char(&m)) != SSHMUX_VER) { | |
231 | error("%s: wrong client version %d", __func__, ver); | |
232 | buffer_free(&m); | |
233 | close(client_fd); | |
234 | return 0; | |
235 | } | |
236 | ||
237 | allowed = 1; | |
238 | mux_command = buffer_get_int(&m); | |
239 | flags = buffer_get_int(&m); | |
240 | ||
241 | buffer_clear(&m); | |
242 | ||
243 | switch (mux_command) { | |
244 | case SSHMUX_COMMAND_OPEN: | |
245 | if (options.control_master == SSHCTL_MASTER_ASK || | |
246 | options.control_master == SSHCTL_MASTER_AUTO_ASK) | |
247 | allowed = ask_permission("Allow shared connection " | |
248 | "to %s? ", host); | |
249 | /* continue below */ | |
250 | break; | |
251 | case SSHMUX_COMMAND_TERMINATE: | |
252 | if (options.control_master == SSHCTL_MASTER_ASK || | |
253 | options.control_master == SSHCTL_MASTER_AUTO_ASK) | |
254 | allowed = ask_permission("Terminate shared connection " | |
255 | "to %s? ", host); | |
256 | if (allowed) | |
257 | start_close = 1; | |
258 | /* FALLTHROUGH */ | |
259 | case SSHMUX_COMMAND_ALIVE_CHECK: | |
260 | /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */ | |
261 | buffer_clear(&m); | |
262 | buffer_put_int(&m, allowed); | |
263 | buffer_put_int(&m, getpid()); | |
264 | if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { | |
265 | error("%s: client msg_send failed", __func__); | |
266 | close(client_fd); | |
267 | buffer_free(&m); | |
268 | return start_close; | |
269 | } | |
270 | buffer_free(&m); | |
271 | close(client_fd); | |
272 | return start_close; | |
273 | default: | |
274 | error("Unsupported command %d", mux_command); | |
275 | buffer_free(&m); | |
276 | close(client_fd); | |
277 | return 0; | |
278 | } | |
279 | ||
280 | /* Reply for SSHMUX_COMMAND_OPEN */ | |
281 | buffer_clear(&m); | |
282 | buffer_put_int(&m, allowed); | |
283 | buffer_put_int(&m, getpid()); | |
284 | if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { | |
285 | error("%s: client msg_send failed", __func__); | |
286 | close(client_fd); | |
287 | buffer_free(&m); | |
288 | return 0; | |
289 | } | |
290 | ||
291 | if (!allowed) { | |
292 | error("Refused control connection"); | |
293 | close(client_fd); | |
294 | buffer_free(&m); | |
295 | return 0; | |
296 | } | |
297 | ||
298 | buffer_clear(&m); | |
299 | if (ssh_msg_recv(client_fd, &m) == -1) { | |
300 | error("%s: client msg_recv failed", __func__); | |
301 | close(client_fd); | |
302 | buffer_free(&m); | |
303 | return 0; | |
304 | } | |
305 | if ((ver = buffer_get_char(&m)) != SSHMUX_VER) { | |
306 | error("%s: wrong client version %d", __func__, ver); | |
307 | buffer_free(&m); | |
308 | close(client_fd); | |
309 | return 0; | |
310 | } | |
311 | ||
312 | cctx = xcalloc(1, sizeof(*cctx)); | |
313 | cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0; | |
314 | cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0; | |
315 | cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0; | |
316 | cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0; | |
317 | cctx->term = buffer_get_string(&m, &len); | |
318 | ||
319 | cmd = buffer_get_string(&m, &len); | |
320 | buffer_init(&cctx->cmd); | |
321 | buffer_append(&cctx->cmd, cmd, strlen(cmd)); | |
322 | ||
323 | env_len = buffer_get_int(&m); | |
324 | env_len = MIN(env_len, 4096); | |
325 | debug3("%s: receiving %d env vars", __func__, env_len); | |
326 | if (env_len != 0) { | |
327 | cctx->env = xcalloc(env_len + 1, sizeof(*cctx->env)); | |
328 | for (i = 0; i < env_len; i++) | |
329 | cctx->env[i] = buffer_get_string(&m, &len); | |
330 | cctx->env[i] = NULL; | |
331 | } | |
332 | ||
333 | debug2("%s: accepted tty %d, subsys %d, cmd %s", __func__, | |
334 | cctx->want_tty, cctx->want_subsys, cmd); | |
335 | xfree(cmd); | |
336 | ||
337 | /* Gather fds from client */ | |
338 | for(i = 0; i < 3; i++) { | |
339 | if ((new_fd[i] = mm_receive_fd(client_fd)) == -1) { | |
340 | error("%s: failed to receive fd %d from slave", | |
341 | __func__, i); | |
342 | for (j = 0; j < i; j++) | |
343 | close(new_fd[j]); | |
344 | for (j = 0; j < env_len; j++) | |
345 | xfree(cctx->env[j]); | |
346 | if (env_len > 0) | |
347 | xfree(cctx->env); | |
348 | xfree(cctx->term); | |
349 | buffer_free(&cctx->cmd); | |
350 | close(client_fd); | |
351 | xfree(cctx); | |
352 | return 0; | |
353 | } | |
354 | } | |
355 | ||
356 | debug2("%s: got fds stdin %d, stdout %d, stderr %d", __func__, | |
357 | new_fd[0], new_fd[1], new_fd[2]); | |
358 | ||
359 | /* Try to pick up ttymodes from client before it goes raw */ | |
360 | if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1) | |
361 | error("%s: tcgetattr: %s", __func__, strerror(errno)); | |
362 | ||
363 | /* This roundtrip is just for synchronisation of ttymodes */ | |
364 | buffer_clear(&m); | |
365 | if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) { | |
366 | error("%s: client msg_send failed", __func__); | |
367 | close(client_fd); | |
368 | close(new_fd[0]); | |
369 | close(new_fd[1]); | |
370 | close(new_fd[2]); | |
371 | buffer_free(&m); | |
372 | xfree(cctx->term); | |
373 | if (env_len != 0) { | |
374 | for (i = 0; i < env_len; i++) | |
375 | xfree(cctx->env[i]); | |
376 | xfree(cctx->env); | |
377 | } | |
378 | return 0; | |
379 | } | |
380 | buffer_free(&m); | |
381 | ||
382 | /* enable nonblocking unless tty */ | |
383 | if (!isatty(new_fd[0])) | |
384 | set_nonblock(new_fd[0]); | |
385 | if (!isatty(new_fd[1])) | |
386 | set_nonblock(new_fd[1]); | |
387 | if (!isatty(new_fd[2])) | |
388 | set_nonblock(new_fd[2]); | |
389 | ||
390 | set_nonblock(client_fd); | |
391 | ||
392 | window = CHAN_SES_WINDOW_DEFAULT; | |
393 | packetmax = CHAN_SES_PACKET_DEFAULT; | |
394 | if (cctx->want_tty) { | |
395 | window >>= 1; | |
396 | packetmax >>= 1; | |
397 | } | |
398 | ||
399 | c = channel_new("session", SSH_CHANNEL_OPENING, | |
400 | new_fd[0], new_fd[1], new_fd[2], window, packetmax, | |
401 | CHAN_EXTENDED_WRITE, "client-session", /*nonblock*/0); | |
402 | ||
403 | /* XXX */ | |
404 | c->ctl_fd = client_fd; | |
405 | ||
406 | debug3("%s: channel_new: %d", __func__, c->self); | |
407 | ||
408 | channel_send_open(c->self); | |
409 | channel_register_open_confirm(c->self, | |
410 | client_extra_session2_setup, cctx); | |
411 | return 0; | |
412 | } | |
413 | ||
414 | /* ** Multiplexing client support */ | |
415 | ||
416 | /* Exit signal handler */ | |
417 | static void | |
418 | control_client_sighandler(int signo) | |
419 | { | |
420 | muxclient_terminate = signo; | |
421 | } | |
422 | ||
423 | /* | |
424 | * Relay signal handler - used to pass some signals from mux client to | |
425 | * mux master. | |
426 | */ | |
427 | static void | |
428 | control_client_sigrelay(int signo) | |
429 | { | |
430 | int save_errno = errno; | |
431 | ||
432 | if (muxserver_pid > 1) | |
433 | kill(muxserver_pid, signo); | |
434 | ||
435 | errno = save_errno; | |
436 | } | |
437 | ||
438 | /* Check mux client environment variables before passing them to mux master. */ | |
439 | static int | |
440 | env_permitted(char *env) | |
441 | { | |
442 | int i, ret; | |
443 | char name[1024], *cp; | |
444 | ||
445 | if ((cp = strchr(env, '=')) == NULL || cp == env) | |
446 | return (0); | |
447 | ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env); | |
448 | if (ret <= 0 || (size_t)ret >= sizeof(name)) | |
449 | fatal("env_permitted: name '%.100s...' too long", env); | |
450 | ||
451 | for (i = 0; i < options.num_send_env; i++) | |
452 | if (match_pattern(name, options.send_env[i])) | |
453 | return (1); | |
454 | ||
455 | return (0); | |
456 | } | |
457 | ||
458 | /* Multiplex client main loop. */ | |
459 | void | |
460 | muxclient(const char *path) | |
461 | { | |
462 | struct sockaddr_un addr; | |
463 | int i, r, fd, sock, exitval[2], num_env, addr_len; | |
464 | Buffer m; | |
465 | char *term; | |
466 | extern char **environ; | |
467 | u_int flags; | |
468 | ||
469 | if (muxclient_command == 0) | |
470 | muxclient_command = SSHMUX_COMMAND_OPEN; | |
471 | ||
472 | switch (options.control_master) { | |
473 | case SSHCTL_MASTER_AUTO: | |
474 | case SSHCTL_MASTER_AUTO_ASK: | |
475 | debug("auto-mux: Trying existing master"); | |
476 | /* FALLTHROUGH */ | |
477 | case SSHCTL_MASTER_NO: | |
478 | break; | |
479 | default: | |
480 | return; | |
481 | } | |
482 | ||
483 | memset(&addr, '\0', sizeof(addr)); | |
484 | addr.sun_family = AF_UNIX; | |
485 | addr_len = offsetof(struct sockaddr_un, sun_path) + | |
486 | strlen(path) + 1; | |
487 | ||
488 | if (strlcpy(addr.sun_path, path, | |
489 | sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) | |
490 | fatal("ControlPath too long"); | |
491 | ||
492 | if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) | |
493 | fatal("%s socket(): %s", __func__, strerror(errno)); | |
494 | ||
495 | if (connect(sock, (struct sockaddr *)&addr, addr_len) == -1) { | |
496 | if (muxclient_command != SSHMUX_COMMAND_OPEN) { | |
497 | fatal("Control socket connect(%.100s): %s", path, | |
498 | strerror(errno)); | |
499 | } | |
500 | if (errno == ENOENT) | |
501 | debug("Control socket \"%.100s\" does not exist", path); | |
502 | else { | |
503 | error("Control socket connect(%.100s): %s", path, | |
504 | strerror(errno)); | |
505 | } | |
506 | close(sock); | |
507 | return; | |
508 | } | |
509 | ||
510 | if (stdin_null_flag) { | |
511 | if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1) | |
512 | fatal("open(/dev/null): %s", strerror(errno)); | |
513 | if (dup2(fd, STDIN_FILENO) == -1) | |
514 | fatal("dup2: %s", strerror(errno)); | |
515 | if (fd > STDERR_FILENO) | |
516 | close(fd); | |
517 | } | |
518 | ||
519 | term = getenv("TERM"); | |
520 | ||
521 | flags = 0; | |
522 | if (tty_flag) | |
523 | flags |= SSHMUX_FLAG_TTY; | |
524 | if (subsystem_flag) | |
525 | flags |= SSHMUX_FLAG_SUBSYS; | |
526 | if (options.forward_x11) | |
527 | flags |= SSHMUX_FLAG_X11_FWD; | |
528 | if (options.forward_agent) | |
529 | flags |= SSHMUX_FLAG_AGENT_FWD; | |
530 | ||
531 | signal(SIGPIPE, SIG_IGN); | |
532 | ||
533 | buffer_init(&m); | |
534 | ||
535 | /* Send our command to server */ | |
536 | buffer_put_int(&m, muxclient_command); | |
537 | buffer_put_int(&m, flags); | |
538 | if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) | |
539 | fatal("%s: msg_send", __func__); | |
540 | buffer_clear(&m); | |
541 | ||
542 | /* Get authorisation status and PID of controlee */ | |
543 | if (ssh_msg_recv(sock, &m) == -1) | |
544 | fatal("%s: msg_recv", __func__); | |
545 | if (buffer_get_char(&m) != SSHMUX_VER) | |
546 | fatal("%s: wrong version", __func__); | |
547 | if (buffer_get_int(&m) != 1) | |
548 | fatal("Connection to master denied"); | |
549 | muxserver_pid = buffer_get_int(&m); | |
550 | ||
551 | buffer_clear(&m); | |
552 | ||
553 | switch (muxclient_command) { | |
554 | case SSHMUX_COMMAND_ALIVE_CHECK: | |
555 | fprintf(stderr, "Master running (pid=%d)\r\n", | |
556 | muxserver_pid); | |
557 | exit(0); | |
558 | case SSHMUX_COMMAND_TERMINATE: | |
559 | fprintf(stderr, "Exit request sent.\r\n"); | |
560 | exit(0); | |
561 | case SSHMUX_COMMAND_OPEN: | |
562 | /* continue below */ | |
563 | break; | |
564 | default: | |
565 | fatal("silly muxclient_command %d", muxclient_command); | |
566 | } | |
567 | ||
568 | /* SSHMUX_COMMAND_OPEN */ | |
569 | buffer_put_cstring(&m, term ? term : ""); | |
570 | buffer_append(&command, "\0", 1); | |
571 | buffer_put_cstring(&m, buffer_ptr(&command)); | |
572 | ||
573 | if (options.num_send_env == 0 || environ == NULL) { | |
574 | buffer_put_int(&m, 0); | |
575 | } else { | |
576 | /* Pass environment */ | |
577 | num_env = 0; | |
578 | for (i = 0; environ[i] != NULL; i++) | |
579 | if (env_permitted(environ[i])) | |
580 | num_env++; /* Count */ | |
581 | ||
582 | buffer_put_int(&m, num_env); | |
583 | ||
584 | for (i = 0; environ[i] != NULL && num_env >= 0; i++) | |
585 | if (env_permitted(environ[i])) { | |
586 | num_env--; | |
587 | buffer_put_cstring(&m, environ[i]); | |
588 | } | |
589 | } | |
590 | ||
591 | if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) | |
592 | fatal("%s: msg_send", __func__); | |
593 | ||
594 | if (mm_send_fd(sock, STDIN_FILENO) == -1 || | |
595 | mm_send_fd(sock, STDOUT_FILENO) == -1 || | |
596 | mm_send_fd(sock, STDERR_FILENO) == -1) | |
597 | fatal("%s: send fds failed", __func__); | |
598 | ||
599 | /* Wait for reply, so master has a chance to gather ttymodes */ | |
600 | buffer_clear(&m); | |
601 | if (ssh_msg_recv(sock, &m) == -1) | |
602 | fatal("%s: msg_recv", __func__); | |
603 | if (buffer_get_char(&m) != SSHMUX_VER) | |
604 | fatal("%s: wrong version", __func__); | |
605 | buffer_free(&m); | |
606 | ||
607 | signal(SIGHUP, control_client_sighandler); | |
608 | signal(SIGINT, control_client_sighandler); | |
609 | signal(SIGTERM, control_client_sighandler); | |
610 | signal(SIGWINCH, control_client_sigrelay); | |
611 | ||
612 | if (tty_flag) | |
613 | enter_raw_mode(); | |
614 | ||
615 | /* | |
616 | * Stick around until the controlee closes the client_fd. | |
617 | * Before it does, it is expected to write this process' exit | |
618 | * value (one int). This process must read the value and wait for | |
619 | * the closure of the client_fd; if this one closes early, the | |
620 | * multiplex master will terminate early too (possibly losing data). | |
621 | */ | |
622 | exitval[0] = 0; | |
623 | for (i = 0; !muxclient_terminate && i < (int)sizeof(exitval);) { | |
624 | r = read(sock, (char *)exitval + i, sizeof(exitval) - i); | |
625 | if (r == 0) { | |
626 | debug2("Received EOF from master"); | |
627 | break; | |
628 | } | |
629 | if (r == -1) { | |
630 | if (errno == EINTR) | |
631 | continue; | |
632 | fatal("%s: read %s", __func__, strerror(errno)); | |
633 | } | |
634 | i += r; | |
635 | } | |
636 | ||
637 | close(sock); | |
638 | leave_raw_mode(); | |
639 | if (i > (int)sizeof(int)) | |
640 | fatal("%s: master returned too much data (%d > %lu)", | |
641 | __func__, i, sizeof(int)); | |
642 | if (muxclient_terminate) { | |
643 | debug2("Exiting on signal %d", muxclient_terminate); | |
644 | exitval[0] = 255; | |
645 | } else if (i < (int)sizeof(int)) { | |
646 | debug2("Control master terminated unexpectedly"); | |
647 | exitval[0] = 255; | |
648 | } else | |
649 | debug2("Received exit status from master %d", exitval[0]); | |
650 | ||
651 | if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET) | |
652 | fprintf(stderr, "Shared connection to %s closed.\r\n", host); | |
653 | ||
654 | exit(exitval[0]); | |
655 | } |