1 /* Id */
2
3 /*
4 * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/types.h>
20 #include <sys/ioctl.h>
21 #include <sys/socket.h>
22 #include <sys/stat.h>
23 #include <sys/un.h>
24 #include <sys/wait.h>
25
26 #include <errno.h>
27 #include <event.h>
28 #include <fcntl.h>
29 #include <signal.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <syslog.h>
34 #include <termios.h>
35 #include <time.h>
36 #include <unistd.h>
37
38 #include "tmux.h"
39
40 /*
41 * Main server functions.
42 */
43
44 /* Client list. */
45 struct clients clients;
46 struct clients dead_clients;
47
48 int server_fd;
49 int server_shutdown;
50 struct event server_ev_accept;
51 struct event server_ev_second;
52
53 struct paste_stack global_buffers;
54
55 int server_create_socket(void);
56 void server_loop(void);
57 int server_should_shutdown(void);
58 void server_send_shutdown(void);
59 void server_clean_dead(void);
60 void server_accept_callback(int, short, void *);
61 void server_signal_callback(int, short, void *);
62 void server_child_signal(void);
63 void server_child_exited(pid_t, int);
64 void server_child_stopped(pid_t, int);
65 void server_second_callback(int, short, void *);
66 void server_lock_server(void);
67 void server_lock_sessions(void);
68
69 /* Create server socket. */
70 int
server_create_socket(void)71 server_create_socket(void)
72 {
73 struct sockaddr_un sa;
74 size_t size;
75 mode_t mask;
76 int fd;
77
78 memset(&sa, 0, sizeof sa);
79 sa.sun_family = AF_UNIX;
80 size = strlcpy(sa.sun_path, socket_path, sizeof sa.sun_path);
81 if (size >= sizeof sa.sun_path) {
82 errno = ENAMETOOLONG;
83 fatal("socket failed");
84 }
85 unlink(sa.sun_path);
86
87 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
88 fatal("socket failed");
89
90 mask = umask(S_IXUSR|S_IXGRP|S_IRWXO);
91 if (bind(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) == -1)
92 fatal("bind failed");
93 umask(mask);
94
95 if (listen(fd, 16) == -1)
96 fatal("listen failed");
97 setblocking(fd, 0);
98
99 server_update_socket();
100
101 return (fd);
102 }
103
104 /* Fork new server. */
105 int
server_start(int lockfd,char * lockfile)106 server_start(int lockfd, char *lockfile)
107 {
108 int pair[2];
109 struct timeval tv;
110 char *cause;
111
112 /* The first client is special and gets a socketpair; create it. */
113 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0)
114 fatal("socketpair failed");
115
116 switch (fork()) {
117 case -1:
118 fatal("fork failed");
119 case 0:
120 break;
121 default:
122 close(pair[1]);
123 return (pair[0]);
124 }
125 close(pair[0]);
126
127 /*
128 * Must daemonise before loading configuration as the PID changes so
129 * $TMUX would be wrong for sessions created in the config file.
130 */
131 if (daemon(1, 0) != 0)
132 fatal("daemon failed");
133
134 /* event_init() was called in our parent, need to reinit. */
135 if (event_reinit(ev_base) != 0)
136 fatal("event_reinit failed");
137 clear_signals(0);
138
139 logfile("server");
140 log_debug("server started, pid %ld", (long) getpid());
141
142 ARRAY_INIT(&windows);
143 RB_INIT(&all_window_panes);
144 ARRAY_INIT(&clients);
145 ARRAY_INIT(&dead_clients);
146 RB_INIT(&sessions);
147 RB_INIT(&dead_sessions);
148 TAILQ_INIT(&session_groups);
149 ARRAY_INIT(&global_buffers);
150 mode_key_init_trees();
151 key_bindings_init();
152 utf8_build();
153
154 start_time = time(NULL);
155 log_debug("socket path %s", socket_path);
156 #ifdef HAVE_SETPROCTITLE
157 setproctitle("server (%s)", socket_path);
158 #endif
159
160 server_fd = server_create_socket();
161 server_client_create(pair[1]);
162
163 unlink(lockfile);
164 free(lockfile);
165 close(lockfd);
166
167 cfg_cmd_q = cmdq_new(NULL);
168 cfg_cmd_q->emptyfn = cfg_default_done;
169 cfg_finished = 0;
170 cfg_references = 1;
171 ARRAY_INIT(&cfg_causes);
172 cfg_client = ARRAY_FIRST(&clients);
173 if (cfg_client != NULL)
174 cfg_client->references++;
175
176 if (access(TMUX_CONF, R_OK) == 0) {
177 if (load_cfg(TMUX_CONF, cfg_cmd_q, &cause) == -1) {
178 xasprintf(&cause, "%s: %s", TMUX_CONF, cause);
179 ARRAY_ADD(&cfg_causes, cause);
180 }
181 } else if (errno != ENOENT) {
182 xasprintf(&cause, "%s: %s", TMUX_CONF, strerror(errno));
183 ARRAY_ADD(&cfg_causes, cause);
184 }
185 if (cfg_file != NULL) {
186 if (load_cfg(cfg_file, cfg_cmd_q, &cause) == -1) {
187 xasprintf(&cause, "%s: %s", cfg_file, cause);
188 ARRAY_ADD(&cfg_causes, cause);
189 }
190 }
191 cmdq_continue(cfg_cmd_q);
192
193 server_add_accept(0);
194
195 memset(&tv, 0, sizeof tv);
196 tv.tv_sec = 1;
197 evtimer_set(&server_ev_second, server_second_callback, NULL);
198 evtimer_add(&server_ev_second, &tv);
199
200 set_signals(server_signal_callback);
201 server_loop();
202 exit(0);
203 }
204
205 /* Main server loop. */
206 void
server_loop(void)207 server_loop(void)
208 {
209 while (!server_should_shutdown()) {
210 event_loop(EVLOOP_ONCE);
211
212 server_window_loop();
213 server_client_loop();
214
215 key_bindings_clean();
216 server_clean_dead();
217 }
218 }
219
220 /* Check if the server should be shutting down (no more clients or sessions). */
221 int
server_should_shutdown(void)222 server_should_shutdown(void)
223 {
224 u_int i;
225
226 if (!options_get_number(&global_options, "exit-unattached")) {
227 if (!RB_EMPTY(&sessions))
228 return (0);
229 }
230 for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
231 if (ARRAY_ITEM(&clients, i) != NULL)
232 return (0);
233 }
234 return (1);
235 }
236
237 /* Shutdown the server by killing all clients and windows. */
238 void
server_send_shutdown(void)239 server_send_shutdown(void)
240 {
241 struct client *c;
242 struct session *s, *next_s;
243 u_int i;
244
245 for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
246 c = ARRAY_ITEM(&clients, i);
247 if (c != NULL) {
248 if (c->flags & (CLIENT_BAD|CLIENT_SUSPENDED))
249 server_client_lost(c);
250 else
251 server_write_client(c, MSG_SHUTDOWN, NULL, 0);
252 c->session = NULL;
253 }
254 }
255
256 s = RB_MIN(sessions, &sessions);
257 while (s != NULL) {
258 next_s = RB_NEXT(sessions, &sessions, s);
259 session_destroy(s);
260 s = next_s;
261 }
262 }
263
264 /* Free dead, unreferenced clients and sessions. */
265 void
server_clean_dead(void)266 server_clean_dead(void)
267 {
268 struct session *s, *next_s;
269 struct client *c;
270 u_int i;
271
272 s = RB_MIN(sessions, &dead_sessions);
273 while (s != NULL) {
274 next_s = RB_NEXT(sessions, &dead_sessions, s);
275 if (s->references == 0) {
276 RB_REMOVE(sessions, &dead_sessions, s);
277 free(s->name);
278 free(s);
279 }
280 s = next_s;
281 }
282
283 for (i = 0; i < ARRAY_LENGTH(&dead_clients); i++) {
284 c = ARRAY_ITEM(&dead_clients, i);
285 if (c == NULL || c->references != 0)
286 continue;
287 ARRAY_SET(&dead_clients, i, NULL);
288 free(c);
289 }
290 }
291
292 /* Update socket execute permissions based on whether sessions are attached. */
293 void
server_update_socket(void)294 server_update_socket(void)
295 {
296 struct session *s;
297 static int last = -1;
298 int n, mode;
299 struct stat sb;
300
301 n = 0;
302 RB_FOREACH(s, sessions, &sessions) {
303 if (!(s->flags & SESSION_UNATTACHED)) {
304 n++;
305 break;
306 }
307 }
308
309 if (n != last) {
310 last = n;
311
312 if (stat(socket_path, &sb) != 0)
313 return;
314 mode = sb.st_mode;
315 if (n != 0) {
316 if (mode & S_IRUSR)
317 mode |= S_IXUSR;
318 if (mode & S_IRGRP)
319 mode |= S_IXGRP;
320 if (mode & S_IROTH)
321 mode |= S_IXOTH;
322 } else
323 mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH);
324 chmod(socket_path, mode);
325 }
326 }
327
328 /* Callback for server socket. */
329 void
server_accept_callback(int fd,short events,unused void * data)330 server_accept_callback(int fd, short events, unused void *data)
331 {
332 struct sockaddr_storage sa;
333 socklen_t slen = sizeof sa;
334 int newfd;
335
336 server_add_accept(0);
337 if (!(events & EV_READ))
338 return;
339
340 newfd = accept(fd, (struct sockaddr *) &sa, &slen);
341 if (newfd == -1) {
342 if (errno == EAGAIN || errno == EINTR || errno == ECONNABORTED)
343 return;
344 if (errno == ENFILE || errno == EMFILE) {
345 /* Delete and don't try again for 1 second. */
346 server_add_accept(1);
347 return;
348 }
349 fatal("accept failed");
350 }
351 if (server_shutdown) {
352 close(newfd);
353 return;
354 }
355 server_client_create(newfd);
356 }
357
358 /*
359 * Add accept event. If timeout is nonzero, add as a timeout instead of a read
360 * event - used to backoff when running out of file descriptors.
361 */
362 void
server_add_accept(int timeout)363 server_add_accept(int timeout)
364 {
365 struct timeval tv = { timeout, 0 };
366
367 if (event_initialized(&server_ev_accept))
368 event_del(&server_ev_accept);
369
370 if (timeout == 0) {
371 event_set(&server_ev_accept,
372 server_fd, EV_READ, server_accept_callback, NULL);
373 event_add(&server_ev_accept, NULL);
374 } else {
375 event_set(&server_ev_accept,
376 server_fd, EV_TIMEOUT, server_accept_callback, NULL);
377 event_add(&server_ev_accept, &tv);
378 }
379 }
380
381 /* Signal handler. */
382 void
server_signal_callback(int sig,unused short events,unused void * data)383 server_signal_callback(int sig, unused short events, unused void *data)
384 {
385 switch (sig) {
386 case SIGTERM:
387 server_shutdown = 1;
388 server_send_shutdown();
389 break;
390 case SIGCHLD:
391 server_child_signal();
392 break;
393 case SIGUSR1:
394 event_del(&server_ev_accept);
395 close(server_fd);
396 server_fd = server_create_socket();
397 server_add_accept(0);
398 break;
399 }
400 }
401
402 /* Handle SIGCHLD. */
403 void
server_child_signal(void)404 server_child_signal(void)
405 {
406 int status;
407 pid_t pid;
408
409 for (;;) {
410 switch (pid = waitpid(WAIT_ANY, &status, WNOHANG|WUNTRACED)) {
411 case -1:
412 if (errno == ECHILD)
413 return;
414 fatal("waitpid failed");
415 case 0:
416 return;
417 }
418 if (WIFSTOPPED(status))
419 server_child_stopped(pid, status);
420 else if (WIFEXITED(status) || WIFSIGNALED(status))
421 server_child_exited(pid, status);
422 }
423 }
424
425 /* Handle exited children. */
426 void
server_child_exited(pid_t pid,int status)427 server_child_exited(pid_t pid, int status)
428 {
429 struct window *w;
430 struct window_pane *wp;
431 struct job *job;
432 u_int i;
433
434 for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
435 if ((w = ARRAY_ITEM(&windows, i)) == NULL)
436 continue;
437 TAILQ_FOREACH(wp, &w->panes, entry) {
438 if (wp->pid == pid) {
439 server_destroy_pane(wp);
440 break;
441 }
442 }
443 }
444
445 LIST_FOREACH(job, &all_jobs, lentry) {
446 if (pid == job->pid) {
447 job_died(job, status); /* might free job */
448 break;
449 }
450 }
451 }
452
453 /* Handle stopped children. */
454 void
server_child_stopped(pid_t pid,int status)455 server_child_stopped(pid_t pid, int status)
456 {
457 struct window *w;
458 struct window_pane *wp;
459 u_int i;
460
461 if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU)
462 return;
463
464 for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
465 if ((w = ARRAY_ITEM(&windows, i)) == NULL)
466 continue;
467 TAILQ_FOREACH(wp, &w->panes, entry) {
468 if (wp->pid == pid) {
469 if (killpg(pid, SIGCONT) != 0)
470 kill(pid, SIGCONT);
471 }
472 }
473 }
474 }
475
476 /* Handle once-per-second timer events. */
477 void
server_second_callback(unused int fd,unused short events,unused void * arg)478 server_second_callback(unused int fd, unused short events, unused void *arg)
479 {
480 struct window *w;
481 struct window_pane *wp;
482 struct timeval tv;
483 u_int i;
484
485 if (options_get_number(&global_s_options, "lock-server"))
486 server_lock_server();
487 else
488 server_lock_sessions();
489
490 for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
491 w = ARRAY_ITEM(&windows, i);
492 if (w == NULL)
493 continue;
494
495 TAILQ_FOREACH(wp, &w->panes, entry) {
496 if (wp->mode != NULL && wp->mode->timer != NULL)
497 wp->mode->timer(wp);
498 }
499 }
500
501 server_client_status_timer();
502
503 evtimer_del(&server_ev_second);
504 memset(&tv, 0, sizeof tv);
505 tv.tv_sec = 1;
506 evtimer_add(&server_ev_second, &tv);
507 }
508
509 /* Lock the server if ALL sessions have hit the time limit. */
510 void
server_lock_server(void)511 server_lock_server(void)
512 {
513 struct session *s;
514 int timeout;
515 time_t t;
516
517 t = time(NULL);
518 RB_FOREACH(s, sessions, &sessions) {
519 if (s->flags & SESSION_UNATTACHED)
520 continue;
521 timeout = options_get_number(&s->options, "lock-after-time");
522 if (timeout <= 0 || t <= s->activity_time.tv_sec + timeout)
523 return; /* not timed out */
524 }
525
526 server_lock();
527 recalculate_sizes();
528 }
529
530 /* Lock any sessions which have timed out. */
531 void
server_lock_sessions(void)532 server_lock_sessions(void)
533 {
534 struct session *s;
535 int timeout;
536 time_t t;
537
538 t = time(NULL);
539 RB_FOREACH(s, sessions, &sessions) {
540 if (s->flags & SESSION_UNATTACHED)
541 continue;
542 timeout = options_get_number(&s->options, "lock-after-time");
543 if (timeout > 0 && t > s->activity_time.tv_sec + timeout) {
544 server_lock_session(s);
545 recalculate_sizes();
546 }
547 }
548 }
549