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