1 /* $OpenBSD$ */
2
3 /*
4 * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
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 <fcntl.h>
28 #include <signal.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <termios.h>
33 #include <time.h>
34 #include <unistd.h>
35
36 #include "tmux.h"
37
38 /*
39 * Main server functions.
40 */
41
42 struct clients clients;
43
44 struct tmuxproc *server_proc;
45 static int server_fd = -1;
46 static uint64_t server_client_flags;
47 static int server_exit;
48 static struct event server_ev_accept;
49 static struct event server_ev_tidy;
50
51 struct cmd_find_state marked_pane;
52
53 static u_int message_next;
54 struct message_list message_log;
55
56 time_t current_time;
57
58 static int server_loop(void);
59 static void server_send_exit(void);
60 static void server_accept(int, short, void *);
61 static void server_signal(int);
62 static void server_child_signal(void);
63 static void server_child_exited(pid_t, int);
64 static void server_child_stopped(pid_t, int);
65
66 /* Set marked pane. */
67 void
server_set_marked(struct session * s,struct winlink * wl,struct window_pane * wp)68 server_set_marked(struct session *s, struct winlink *wl, struct window_pane *wp)
69 {
70 cmd_find_clear_state(&marked_pane, 0);
71 marked_pane.s = s;
72 marked_pane.wl = wl;
73 marked_pane.w = wl->window;
74 marked_pane.wp = wp;
75 }
76
77 /* Clear marked pane. */
78 void
server_clear_marked(void)79 server_clear_marked(void)
80 {
81 cmd_find_clear_state(&marked_pane, 0);
82 }
83
84 /* Is this the marked pane? */
85 int
server_is_marked(struct session * s,struct winlink * wl,struct window_pane * wp)86 server_is_marked(struct session *s, struct winlink *wl, struct window_pane *wp)
87 {
88 if (s == NULL || wl == NULL || wp == NULL)
89 return (0);
90 if (marked_pane.s != s || marked_pane.wl != wl)
91 return (0);
92 if (marked_pane.wp != wp)
93 return (0);
94 return (server_check_marked());
95 }
96
97 /* Check if the marked pane is still valid. */
98 int
server_check_marked(void)99 server_check_marked(void)
100 {
101 return (cmd_find_valid_state(&marked_pane));
102 }
103
104 /* Create server socket. */
105 int
server_create_socket(uint64_t flags,char ** cause)106 server_create_socket(uint64_t flags, char **cause)
107 {
108 struct sockaddr_un sa;
109 size_t size;
110 mode_t mask;
111 int fd, saved_errno;
112
113 memset(&sa, 0, sizeof sa);
114 sa.sun_family = AF_UNIX;
115 size = strlcpy(sa.sun_path, socket_path, sizeof sa.sun_path);
116 if (size >= sizeof sa.sun_path) {
117 errno = ENAMETOOLONG;
118 goto fail;
119 }
120 unlink(sa.sun_path);
121
122 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
123 goto fail;
124
125 if (flags & CLIENT_DEFAULTSOCKET)
126 mask = umask(S_IXUSR|S_IXGRP|S_IRWXO);
127 else
128 mask = umask(S_IXUSR|S_IRWXG|S_IRWXO);
129 if (bind(fd, (struct sockaddr *)&sa, sizeof sa) == -1) {
130 saved_errno = errno;
131 close(fd);
132 errno = saved_errno;
133 goto fail;
134 }
135 umask(mask);
136
137 if (listen(fd, 128) == -1) {
138 saved_errno = errno;
139 close(fd);
140 errno = saved_errno;
141 goto fail;
142 }
143 setblocking(fd, 0);
144
145 return (fd);
146
147 fail:
148 if (cause != NULL) {
149 xasprintf(cause, "error creating %s (%s)", socket_path,
150 strerror(errno));
151 }
152 return (-1);
153 }
154
155 /* Tidy up every hour. */
156 static void
server_tidy_event(__unused int fd,__unused short events,__unused void * data)157 server_tidy_event(__unused int fd, __unused short events, __unused void *data)
158 {
159 struct timeval tv = { .tv_sec = 3600 };
160 uint64_t t = get_timer();
161
162 format_tidy_jobs();
163
164 #ifdef HAVE_MALLOC_TRIM
165 malloc_trim(0);
166 #endif
167
168 log_debug("%s: took %ju milliseconds", __func__, (uintmax_t)get_timer() - t);
169 evtimer_add(&server_ev_tidy, &tv);
170 }
171
172 /* Fork new server. */
173 int
server_start(struct tmuxproc * client,uint64_t flags,struct event_base * base,int lockfd,char * lockfile)174 server_start(struct tmuxproc *client, uint64_t flags, struct event_base *base,
175 int lockfd, char *lockfile)
176 {
177 int fd;
178 sigset_t set, oldset;
179 struct client *c = NULL;
180 char *cause = NULL;
181 struct timeval tv = { .tv_sec = 3600 };
182
183 sigfillset(&set);
184 sigprocmask(SIG_BLOCK, &set, &oldset);
185
186 if (~flags & CLIENT_NOFORK) {
187 if (proc_fork_and_daemon(&fd) != 0) {
188 sigprocmask(SIG_SETMASK, &oldset, NULL);
189 return (fd);
190 }
191 }
192 proc_clear_signals(client, 0);
193 server_client_flags = flags;
194
195 if (event_reinit(base) != 0)
196 fatalx("event_reinit failed");
197 server_proc = proc_start("server");
198
199 proc_set_signals(server_proc, server_signal);
200 sigprocmask(SIG_SETMASK, &oldset, NULL);
201
202 if (log_get_level() > 1)
203 tty_create_log();
204 if (pledge("stdio rpath wpath cpath fattr unix getpw recvfd proc exec "
205 "tty ps", NULL) != 0)
206 fatal("pledge failed");
207
208 input_key_build();
209 RB_INIT(&windows);
210 RB_INIT(&all_window_panes);
211 TAILQ_INIT(&clients);
212 RB_INIT(&sessions);
213 key_bindings_init();
214 TAILQ_INIT(&message_log);
215 gettimeofday(&start_time, NULL);
216
217 #ifdef HAVE_SYSTEMD
218 server_fd = systemd_create_socket(flags, &cause);
219 #else
220 server_fd = server_create_socket(flags, &cause);
221 #endif
222 if (server_fd != -1)
223 server_update_socket();
224 if (~flags & CLIENT_NOFORK)
225 c = server_client_create(fd);
226 else
227 options_set_number(global_options, "exit-empty", 0);
228
229 if (lockfd >= 0) {
230 unlink(lockfile);
231 free(lockfile);
232 close(lockfd);
233 }
234
235 if (cause != NULL) {
236 if (c != NULL) {
237 c->exit_message = cause;
238 c->flags |= CLIENT_EXIT;
239 } else {
240 fprintf(stderr, "%s\n", cause);
241 exit(1);
242 }
243 }
244
245 evtimer_set(&server_ev_tidy, server_tidy_event, NULL);
246 evtimer_add(&server_ev_tidy, &tv);
247
248 server_acl_init();
249
250 server_add_accept(0);
251 proc_loop(server_proc, server_loop);
252
253 job_kill_all();
254 status_prompt_save_history();
255
256 exit(0);
257 }
258
259 /* Server loop callback. */
260 static int
server_loop(void)261 server_loop(void)
262 {
263 struct client *c;
264 u_int items;
265
266 current_time = time(NULL);
267
268 do {
269 items = cmdq_next(NULL);
270 TAILQ_FOREACH(c, &clients, entry) {
271 if (c->flags & CLIENT_IDENTIFIED)
272 items += cmdq_next(c);
273 }
274 } while (items != 0);
275
276 server_client_loop();
277
278 if (!options_get_number(global_options, "exit-empty") && !server_exit)
279 return (0);
280
281 if (!options_get_number(global_options, "exit-unattached")) {
282 if (!RB_EMPTY(&sessions))
283 return (0);
284 }
285
286 TAILQ_FOREACH(c, &clients, entry) {
287 if (c->session != NULL)
288 return (0);
289 }
290
291 /*
292 * No attached clients therefore want to exit - flush any waiting
293 * clients but don't actually exit until they've gone.
294 */
295 cmd_wait_for_flush();
296 if (!TAILQ_EMPTY(&clients))
297 return (0);
298
299 if (job_still_running())
300 return (0);
301
302 return (1);
303 }
304
305 /* Exit the server by killing all clients and windows. */
306 static void
server_send_exit(void)307 server_send_exit(void)
308 {
309 struct client *c, *c1;
310 struct session *s, *s1;
311
312 cmd_wait_for_flush();
313
314 TAILQ_FOREACH_SAFE(c, &clients, entry, c1) {
315 if (c->flags & CLIENT_SUSPENDED)
316 server_client_lost(c);
317 else {
318 c->flags |= CLIENT_EXIT;
319 c->exit_type = CLIENT_EXIT_SHUTDOWN;
320 }
321 c->session = NULL;
322 }
323
324 RB_FOREACH_SAFE(s, sessions, &sessions, s1)
325 session_destroy(s, 1, __func__);
326 }
327
328 /* Update socket execute permissions based on whether sessions are attached. */
329 void
server_update_socket(void)330 server_update_socket(void)
331 {
332 struct session *s;
333 static int last = -1;
334 int n, mode;
335 struct stat sb;
336
337 n = 0;
338 RB_FOREACH(s, sessions, &sessions) {
339 if (s->attached != 0) {
340 n++;
341 break;
342 }
343 }
344
345 if (n != last) {
346 last = n;
347
348 if (stat(socket_path, &sb) != 0)
349 return;
350 mode = sb.st_mode & ACCESSPERMS;
351 if (n != 0) {
352 if (mode & S_IRUSR)
353 mode |= S_IXUSR;
354 if (mode & S_IRGRP)
355 mode |= S_IXGRP;
356 if (mode & S_IROTH)
357 mode |= S_IXOTH;
358 } else
359 mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH);
360 chmod(socket_path, mode);
361 }
362 }
363
364 /* Callback for server socket. */
365 static void
server_accept(int fd,short events,__unused void * data)366 server_accept(int fd, short events, __unused void *data)
367 {
368 struct sockaddr_storage sa;
369 socklen_t slen = sizeof sa;
370 int newfd;
371 struct client *c;
372
373 server_add_accept(0);
374 if (!(events & EV_READ))
375 return;
376
377 newfd = accept(fd, (struct sockaddr *) &sa, &slen);
378 if (newfd == -1) {
379 if (errno == EAGAIN || errno == EINTR || errno == ECONNABORTED)
380 return;
381 if (errno == ENFILE || errno == EMFILE) {
382 /* Delete and don't try again for 1 second. */
383 server_add_accept(1);
384 return;
385 }
386 fatal("accept failed");
387 }
388
389 if (server_exit) {
390 close(newfd);
391 return;
392 }
393 c = server_client_create(newfd);
394 if (!server_acl_join(c)) {
395 c->exit_message = xstrdup("access not allowed");
396 c->flags |= CLIENT_EXIT;
397 }
398 }
399
400 /*
401 * Add accept event. If timeout is nonzero, add as a timeout instead of a read
402 * event - used to backoff when running out of file descriptors.
403 */
404 void
server_add_accept(int timeout)405 server_add_accept(int timeout)
406 {
407 struct timeval tv = { timeout, 0 };
408
409 if (server_fd == -1)
410 return;
411
412 if (event_initialized(&server_ev_accept))
413 event_del(&server_ev_accept);
414
415 if (timeout == 0) {
416 event_set(&server_ev_accept, server_fd, EV_READ, server_accept,
417 NULL);
418 event_add(&server_ev_accept, NULL);
419 } else {
420 event_set(&server_ev_accept, server_fd, EV_TIMEOUT,
421 server_accept, NULL);
422 event_add(&server_ev_accept, &tv);
423 }
424 }
425
426 /* Signal handler. */
427 static void
server_signal(int sig)428 server_signal(int sig)
429 {
430 int fd;
431
432 log_debug("%s: %s", __func__, strsignal(sig));
433 switch (sig) {
434 case SIGINT:
435 case SIGTERM:
436 server_exit = 1;
437 server_send_exit();
438 break;
439 case SIGCHLD:
440 server_child_signal();
441 break;
442 case SIGUSR1:
443 event_del(&server_ev_accept);
444 fd = server_create_socket(server_client_flags, NULL);
445 if (fd != -1) {
446 close(server_fd);
447 server_fd = fd;
448 server_update_socket();
449 }
450 server_add_accept(0);
451 break;
452 case SIGUSR2:
453 proc_toggle_log(server_proc);
454 break;
455 }
456 }
457
458 /* Handle SIGCHLD. */
459 static void
server_child_signal(void)460 server_child_signal(void)
461 {
462 int status;
463 pid_t pid;
464
465 for (;;) {
466 switch (pid = waitpid(WAIT_ANY, &status, WNOHANG|WUNTRACED)) {
467 case -1:
468 if (errno == ECHILD)
469 return;
470 fatal("waitpid failed");
471 case 0:
472 return;
473 }
474 if (WIFSTOPPED(status))
475 server_child_stopped(pid, status);
476 else if (WIFEXITED(status) || WIFSIGNALED(status))
477 server_child_exited(pid, status);
478 }
479 }
480
481 /* Handle exited children. */
482 static void
server_child_exited(pid_t pid,int status)483 server_child_exited(pid_t pid, int status)
484 {
485 struct window *w, *w1;
486 struct window_pane *wp;
487
488 RB_FOREACH_SAFE(w, windows, &windows, w1) {
489 TAILQ_FOREACH(wp, &w->panes, entry) {
490 if (wp->pid == pid) {
491 wp->status = status;
492 wp->flags |= PANE_STATUSREADY;
493
494 log_debug("%%%u exited", wp->id);
495 wp->flags |= PANE_EXITED;
496
497 if (window_pane_destroy_ready(wp))
498 server_destroy_pane(wp, 1);
499 break;
500 }
501 }
502 }
503 job_check_died(pid, status);
504 }
505
506 /* Handle stopped children. */
507 static void
server_child_stopped(pid_t pid,int status)508 server_child_stopped(pid_t pid, int status)
509 {
510 struct window *w;
511 struct window_pane *wp;
512
513 if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU)
514 return;
515
516 RB_FOREACH(w, windows, &windows) {
517 TAILQ_FOREACH(wp, &w->panes, entry) {
518 if (wp->pid == pid) {
519 if (killpg(pid, SIGCONT) != 0)
520 kill(pid, SIGCONT);
521 }
522 }
523 }
524 job_check_died(pid, status);
525 }
526
527 /* Add to message log. */
528 void
server_add_message(const char * fmt,...)529 server_add_message(const char *fmt, ...)
530 {
531 struct message_entry *msg, *msg1;
532 char *s;
533 va_list ap;
534 u_int limit;
535
536 va_start(ap, fmt);
537 xvasprintf(&s, fmt, ap);
538 va_end(ap);
539
540 log_debug("message: %s", s);
541
542 msg = xcalloc(1, sizeof *msg);
543 gettimeofday(&msg->msg_time, NULL);
544 msg->msg_num = message_next++;
545 msg->msg = s;
546 TAILQ_INSERT_TAIL(&message_log, msg, entry);
547
548 limit = options_get_number(global_options, "message-limit");
549 TAILQ_FOREACH_SAFE(msg, &message_log, entry, msg1) {
550 if (msg->msg_num + limit >= message_next)
551 break;
552 free(msg->msg);
553 TAILQ_REMOVE(&message_log, msg, entry);
554 free(msg);
555 }
556 }
557