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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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