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We ignore SIGWINCH until ready, so send a MSG_RESIZE immediately when
[tmux-openbsd.git] / server.c
bloba07fa1fd9fae9b0568998464a1a097d62386cee6
1 /* $OpenBSD$ */
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 <paths.h>
30 #include <signal.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <syslog.h>
35 #include <termios.h>
36 #include <time.h>
37 #include <unistd.h>
38
39 #include "tmux.h"
40
41 /*
42 * Main server functions.
43 */
44
45 /* Client list. */
46 struct clients clients;
47 struct clients dead_clients;
48
49 int server_fd;
50 int server_shutdown;
51 struct event server_ev_accept;
52 struct event server_ev_second;
53
54 struct paste_stack global_buffers;
55
56 int server_create_socket(void);
57 void server_loop(void);
58 int server_should_shutdown(void);
59 void server_send_shutdown(void);
60 void server_clean_dead(void);
61 void server_accept_callback(int, short, void *);
62 void server_signal_callback(int, short, void *);
63 void server_child_signal(void);
64 void server_child_exited(pid_t, int);
65 void server_child_stopped(pid_t, int);
66 void server_second_callback(int, short, void *);
67 void server_lock_server(void);
68 void server_lock_sessions(void);
69
70 /* Create server socket. */
71 int
72 server_create_socket(void)
73 {
74 struct sockaddr_un sa;
75 size_t size;
76 mode_t mask;
77 int fd;
78
79 memset(&sa, 0, sizeof sa);
80 sa.sun_family = AF_UNIX;
81 size = strlcpy(sa.sun_path, socket_path, sizeof sa.sun_path);
82 if (size >= sizeof sa.sun_path) {
83 errno = ENAMETOOLONG;
84 fatal("socket failed");
85 }
86 unlink(sa.sun_path);
87
88 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
89 fatal("socket failed");
90
91 mask = umask(S_IXUSR|S_IXGRP|S_IRWXO);
92 if (bind(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) == -1)
93 fatal("bind failed");
94 umask(mask);
95
96 if (listen(fd, 16) == -1)
97 fatal("listen failed");
98 setblocking(fd, 0);
99
100 server_update_socket();
101
102 return (fd);
103 }
104
105 /* Fork new server. */
106 int
107 server_start(int lockfd, char *lockfile)
108 {
109 int pair[2];
110 struct timeval tv;
111 char *cause;
112
113 /* The first client is special and gets a socketpair; create it. */
114 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0)
115 fatal("socketpair failed");
116
117 switch (fork()) {
118 case -1:
119 fatal("fork failed");
120 case 0:
121 break;
122 default:
123 close(pair[1]);
124 return (pair[0]);
125 }
126 close(pair[0]);
127
128 /*
129 * Must daemonise before loading configuration as the PID changes so
130 * $TMUX would be wrong for sessions created in the config file.
131 */
132 if (daemon(1, 0) != 0)
133 fatal("daemon failed");
134
135 /* event_init() was called in our parent, need to reinit. */
136 if (event_reinit(ev_base) != 0)
137 fatal("event_reinit failed");
138 clear_signals(0);
139
140 logfile("server");
141 log_debug("server started, pid %ld", (long) getpid());
142
143 ARRAY_INIT(&windows);
144 RB_INIT(&all_window_panes);
145 ARRAY_INIT(&clients);
146 ARRAY_INIT(&dead_clients);
147 RB_INIT(&sessions);
148 RB_INIT(&dead_sessions);
149 TAILQ_INIT(&session_groups);
150 ARRAY_INIT(&global_buffers);
151 mode_key_init_trees();
152 key_bindings_init();
153 utf8_build();
154
155 start_time = time(NULL);
156 log_debug("socket path %s", socket_path);
157 setproctitle("server (%s)", socket_path);
158
159 server_fd = server_create_socket();
160 server_client_create(pair[1]);
161
162 unlink(lockfile);
163 free(lockfile);
164 close(lockfd);
165
166 cfg_cmd_q = cmdq_new(NULL);
167 cfg_cmd_q->emptyfn = cfg_default_done;
168 cfg_finished = 0;
169 cfg_references = 1;
170 ARRAY_INIT(&cfg_causes);
171
172 if (access(SYSTEM_CFG, R_OK) == 0) {
173 if (load_cfg(SYSTEM_CFG, cfg_cmd_q, &cause) == -1) {
174 xasprintf(&cause, "%s: %s", SYSTEM_CFG, cause);
175 ARRAY_ADD(&cfg_causes, cause);
176 }
177 } else if (errno != ENOENT) {
178 xasprintf(&cause, "%s: %s", SYSTEM_CFG, strerror(errno));
179 ARRAY_ADD(&cfg_causes, cause);
180 }
181 if (cfg_file != NULL) {
182 if (load_cfg(cfg_file, cfg_cmd_q, &cause) == -1) {
183 xasprintf(&cause, "%s: %s", cfg_file, cause);
184 ARRAY_ADD(&cfg_causes, cause);
185 }
186 }
187 cmdq_continue(cfg_cmd_q);
188
189 server_add_accept(0);
190
191 memset(&tv, 0, sizeof tv);
192 tv.tv_sec = 1;
193 evtimer_set(&server_ev_second, server_second_callback, NULL);
194 evtimer_add(&server_ev_second, &tv);
195
196 set_signals(server_signal_callback);
197 server_loop();
198 exit(0);
199 }
200
201 /* Main server loop. */
202 void
203 server_loop(void)
204 {
205 while (!server_should_shutdown()) {
206 event_loop(EVLOOP_ONCE);
207
208 server_window_loop();
209 server_client_loop();
210
211 key_bindings_clean();
212 server_clean_dead();
213 }
214 }
215
216 /* Check if the server should be shutting down (no more clients or sessions). */
217 int
218 server_should_shutdown(void)
219 {
220 u_int i;
221
222 if (!options_get_number(&global_options, "exit-unattached")) {
223 if (!RB_EMPTY(&sessions))
224 return (0);
225 }
226 for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
227 if (ARRAY_ITEM(&clients, i) != NULL)
228 return (0);
229 }
230 return (1);
231 }
232
233 /* Shutdown the server by killing all clients and windows. */
234 void
235 server_send_shutdown(void)
236 {
237 struct client *c;
238 struct session *s, *next_s;
239 u_int i;
240
241 for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
242 c = ARRAY_ITEM(&clients, i);
243 if (c != NULL) {
244 if (c->flags & (CLIENT_BAD|CLIENT_SUSPENDED))
245 server_client_lost(c);
246 else
247 server_write_client(c, MSG_SHUTDOWN, NULL, 0);
248 c->session = NULL;
249 }
250 }
251
252 s = RB_MIN(sessions, &sessions);
253 while (s != NULL) {
254 next_s = RB_NEXT(sessions, &sessions, s);
255 session_destroy(s);
256 s = next_s;
257 }
258 }
259
260 /* Free dead, unreferenced clients and sessions. */
261 void
262 server_clean_dead(void)
263 {
264 struct session *s, *next_s;
265 struct client *c;
266 u_int i;
267
268 s = RB_MIN(sessions, &dead_sessions);
269 while (s != NULL) {
270 next_s = RB_NEXT(sessions, &dead_sessions, s);
271 if (s->references == 0) {
272 RB_REMOVE(sessions, &dead_sessions, s);
273 free(s->name);
274 free(s);
275 }
276 s = next_s;
277 }
278
279 for (i = 0; i < ARRAY_LENGTH(&dead_clients); i++) {
280 c = ARRAY_ITEM(&dead_clients, i);
281 if (c == NULL || c->references != 0)
282 continue;
283 ARRAY_SET(&dead_clients, i, NULL);
284 free(c);
285 }
286 }
287
288 /* Update socket execute permissions based on whether sessions are attached. */
289 void
290 server_update_socket(void)
291 {
292 struct session *s;
293 static int last = -1;
294 int n, mode;
295 struct stat sb;
296
297 n = 0;
298 RB_FOREACH(s, sessions, &sessions) {
299 if (!(s->flags & SESSION_UNATTACHED)) {
300 n++;
301 break;
302 }
303 }
304
305 if (n != last) {
306 last = n;
307
308 if (stat(socket_path, &sb) != 0)
309 return;
310 mode = sb.st_mode;
311 if (n != 0) {
312 if (mode & S_IRUSR)
313 mode |= S_IXUSR;
314 if (mode & S_IRGRP)
315 mode |= S_IXGRP;
316 if (mode & S_IROTH)
317 mode |= S_IXOTH;
318 } else
319 mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH);
320 chmod(socket_path, mode);
321 }
322 }
323
324 /* Callback for server socket. */
325 void
326 server_accept_callback(int fd, short events, unused void *data)
327 {
328 struct sockaddr_storage sa;
329 socklen_t slen = sizeof sa;
330 int newfd;
331
332 server_add_accept(0);
333 if (!(events & EV_READ))
334 return;
335
336 newfd = accept(fd, (struct sockaddr *) &sa, &slen);
337 if (newfd == -1) {
338 if (errno == EAGAIN || errno == EINTR || errno == ECONNABORTED)
339 return;
340 if (errno == ENFILE || errno == EMFILE) {
341 /* Delete and don't try again for 1 second. */
342 server_add_accept(1);
343 return;
344 }
345 fatal("accept failed");
346 }
347 if (server_shutdown) {
348 close(newfd);
349 return;
350 }
351 server_client_create(newfd);
352 }
353
354 /*
355 * Add accept event. If timeout is nonzero, add as a timeout instead of a read
356 * event - used to backoff when running out of file descriptors.
357 */
358 void
359 server_add_accept(int timeout)
360 {
361 struct timeval tv = { timeout, 0 };
362
363 if (event_initialized(&server_ev_accept))
364 event_del(&server_ev_accept);
365
366 if (timeout == 0) {
367 event_set(&server_ev_accept,
368 server_fd, EV_READ, server_accept_callback, NULL);
369 event_add(&server_ev_accept, NULL);
370 } else {
371 event_set(&server_ev_accept,
372 server_fd, EV_TIMEOUT, server_accept_callback, NULL);
373 event_add(&server_ev_accept, &tv);
374 }
375 }
376
377 /* Signal handler. */
378 void
379 server_signal_callback(int sig, unused short events, unused void *data)
380 {
381 switch (sig) {
382 case SIGTERM:
383 server_shutdown = 1;
384 server_send_shutdown();
385 break;
386 case SIGCHLD:
387 server_child_signal();
388 break;
389 case SIGUSR1:
390 event_del(&server_ev_accept);
391 close(server_fd);
392 server_fd = server_create_socket();
393 server_add_accept(0);
394 break;
395 }
396 }
397
398 /* Handle SIGCHLD. */
399 void
400 server_child_signal(void)
401 {
402 int status;
403 pid_t pid;
404
405 for (;;) {
406 switch (pid = waitpid(WAIT_ANY, &status, WNOHANG|WUNTRACED)) {
407 case -1:
408 if (errno == ECHILD)
409 return;
410 fatal("waitpid failed");
411 case 0:
412 return;
413 }
414 if (WIFSTOPPED(status))
415 server_child_stopped(pid, status);
416 else if (WIFEXITED(status) || WIFSIGNALED(status))
417 server_child_exited(pid, status);
418 }
419 }
420
421 /* Handle exited children. */
422 void
423 server_child_exited(pid_t pid, int status)
424 {
425 struct window *w;
426 struct window_pane *wp;
427 struct job *job;
428 u_int i;
429
430 for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
431 if ((w = ARRAY_ITEM(&windows, i)) == NULL)
432 continue;
433 TAILQ_FOREACH(wp, &w->panes, entry) {
434 if (wp->pid == pid) {
435 server_destroy_pane(wp);
436 break;
437 }
438 }
439 }
440
441 LIST_FOREACH(job, &all_jobs, lentry) {
442 if (pid == job->pid) {
443 job_died(job, status); /* might free job */
444 break;
445 }
446 }
447 }
448
449 /* Handle stopped children. */
450 void
451 server_child_stopped(pid_t pid, int status)
452 {
453 struct window *w;
454 struct window_pane *wp;
455 u_int i;
456
457 if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU)
458 return;
459
460 for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
461 if ((w = ARRAY_ITEM(&windows, i)) == NULL)
462 continue;
463 TAILQ_FOREACH(wp, &w->panes, entry) {
464 if (wp->pid == pid) {
465 if (killpg(pid, SIGCONT) != 0)
466 kill(pid, SIGCONT);
467 }
468 }
469 }
470 }
471
472 /* Handle once-per-second timer events. */
473 void
474 server_second_callback(unused int fd, unused short events, unused void *arg)
475 {
476 struct window *w;
477 struct window_pane *wp;
478 struct timeval tv;
479 u_int i;
480
481 if (options_get_number(&global_s_options, "lock-server"))
482 server_lock_server();
483 else
484 server_lock_sessions();
485
486 for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
487 w = ARRAY_ITEM(&windows, i);
488 if (w == NULL)
489 continue;
490
491 TAILQ_FOREACH(wp, &w->panes, entry) {
492 if (wp->mode != NULL && wp->mode->timer != NULL)
493 wp->mode->timer(wp);
494 }
495 }
496
497 server_client_status_timer();
498
499 evtimer_del(&server_ev_second);
500 memset(&tv, 0, sizeof tv);
501 tv.tv_sec = 1;
502 evtimer_add(&server_ev_second, &tv);
503 }
504
505 /* Lock the server if ALL sessions have hit the time limit. */
506 void
507 server_lock_server(void)
508 {
509 struct session *s;
510 int timeout;
511 time_t t;
512
513 t = time(NULL);
514 RB_FOREACH(s, sessions, &sessions) {
515 if (s->flags & SESSION_UNATTACHED)
516 continue;
517 timeout = options_get_number(&s->options, "lock-after-time");
518 if (timeout <= 0 || t <= s->activity_time.tv_sec + timeout)
519 return; /* not timed out */
520 }
521
522 server_lock();
523 recalculate_sizes();
524 }
525
526 /* Lock any sessions which have timed out. */
527 void
528 server_lock_sessions(void)
529 {
530 struct session *s;
531 int timeout;
532 time_t t;
533
534 t = time(NULL);
535 RB_FOREACH(s, sessions, &sessions) {
536 if (s->flags & SESSION_UNATTACHED)
537 continue;
538 timeout = options_get_number(&s->options, "lock-after-time");
539 if (timeout > 0 && t > s->activity_time.tv_sec + timeout) {
540 server_lock_session(s);
541 recalculate_sizes();
542 }
543 }
544 }