1 /* $Id: server.c,v 1.1.1.1 2011/03/10 09:15:39 jmmv Exp $ */ 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 int server_create_socket(void); 54 void server_loop(void); 55 int server_should_shutdown(void); 56 void server_send_shutdown(void); 57 void server_clean_dead(void); 58 void server_accept_callback(int, short, void *); 59 void server_signal_callback(int, short, void *); 60 void server_child_signal(void); 61 void server_child_exited(pid_t, int); 62 void server_child_stopped(pid_t, int); 63 void server_second_callback(int, short, void *); 64 void server_lock_server(void); 65 void server_lock_sessions(void); 66 67 /* Create server socket. */ 68 int 69 server_create_socket(void) 70 { 71 struct sockaddr_un sa; 72 size_t size; 73 mode_t mask; 74 int fd, mode; 75 76 memset(&sa, 0, sizeof sa); 77 sa.sun_family = AF_UNIX; 78 size = strlcpy(sa.sun_path, socket_path, sizeof sa.sun_path); 79 if (size >= sizeof sa.sun_path) { 80 errno = ENAMETOOLONG; 81 fatal("socket failed"); 82 } 83 unlink(sa.sun_path); 84 85 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) 86 fatal("socket failed"); 87 88 mask = umask(S_IXUSR|S_IXGRP|S_IRWXO); 89 if (bind(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) == -1) 90 fatal("bind failed"); 91 umask(mask); 92 93 if (listen(fd, 16) == -1) 94 fatal("listen failed"); 95 96 if ((mode = fcntl(fd, F_GETFL)) == -1) 97 fatal("fcntl failed"); 98 if (fcntl(fd, F_SETFL, mode|O_NONBLOCK) == -1) 99 fatal("fcntl failed"); 100 101 server_update_socket(); 102 103 return (fd); 104 } 105 106 /* Fork new server. */ 107 int 108 server_start(void) 109 { 110 struct window_pane *wp; 111 int pair[2]; 112 char *cause; 113 struct timeval tv; 114 u_int i; 115 116 /* The first client is special and gets a socketpair; create it. */ 117 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0) 118 fatal("socketpair failed"); 119 120 switch (fork()) { 121 case -1: 122 fatal("fork failed"); 123 case 0: 124 break; 125 default: 126 close(pair[1]); 127 return (pair[0]); 128 } 129 close(pair[0]); 130 131 /* 132 * Must daemonise before loading configuration as the PID changes so 133 * $TMUX would be wrong for sessions created in the config file. 134 */ 135 if (daemon(1, 0) != 0) 136 fatal("daemon failed"); 137 138 /* event_init() was called in our parent, need to reinit. */ 139 if (event_reinit(ev_base) != 0) 140 fatal("event_reinit failed"); 141 clear_signals(0); 142 143 logfile("server"); 144 log_debug("server started, pid %ld", (long) getpid()); 145 146 ARRAY_INIT(&windows); 147 ARRAY_INIT(&clients); 148 ARRAY_INIT(&dead_clients); 149 RB_INIT(&sessions); 150 RB_INIT(&dead_sessions); 151 TAILQ_INIT(&session_groups); 152 mode_key_init_trees(); 153 key_bindings_init(); 154 utf8_build(); 155 156 start_time = time(NULL); 157 log_debug("socket path %s", socket_path); 158 #ifdef HAVE_SETPROCTITLE 159 setproctitle("server (%s)", socket_path); 160 #endif 161 162 server_fd = server_create_socket(); 163 server_client_create(pair[1]); 164 165 if (access(SYSTEM_CFG, R_OK) == 0) 166 load_cfg(SYSTEM_CFG, NULL, &cfg_causes); 167 else if (errno != ENOENT) { 168 cfg_add_cause( 169 &cfg_causes, "%s: %s", strerror(errno), SYSTEM_CFG); 170 } 171 if (cfg_file != NULL) 172 load_cfg(cfg_file, NULL, &cfg_causes); 173 174 /* 175 * If there is a session already, put the current window and pane into 176 * more mode. 177 */ 178 if (!RB_EMPTY(&sessions) && !ARRAY_EMPTY(&cfg_causes)) { 179 wp = RB_MIN(sessions, &sessions)->curw->window->active; 180 window_pane_set_mode(wp, &window_copy_mode); 181 window_copy_init_for_output(wp); 182 for (i = 0; i < ARRAY_LENGTH(&cfg_causes); i++) { 183 cause = ARRAY_ITEM(&cfg_causes, i); 184 window_copy_add(wp, "%s", cause); 185 xfree(cause); 186 } 187 ARRAY_FREE(&cfg_causes); 188 } 189 cfg_finished = 1; 190 191 event_set(&server_ev_accept, 192 server_fd, EV_READ|EV_PERSIST, server_accept_callback, NULL); 193 event_add(&server_ev_accept, NULL); 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 xfree(s->name); 278 xfree(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 xfree(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 /* ARGSUSED */ 330 void 331 server_accept_callback(int fd, short events, unused void *data) 332 { 333 struct sockaddr_storage sa; 334 socklen_t slen = sizeof sa; 335 int newfd; 336 337 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 fatal("accept failed"); 345 } 346 if (server_shutdown) { 347 close(newfd); 348 return; 349 } 350 server_client_create(newfd); 351 } 352 353 /* Signal handler. */ 354 /* ARGSUSED */ 355 void 356 server_signal_callback(int sig, unused short events, unused void *data) 357 { 358 switch (sig) { 359 case SIGTERM: 360 server_shutdown = 1; 361 server_send_shutdown(); 362 break; 363 case SIGCHLD: 364 server_child_signal(); 365 break; 366 case SIGUSR1: 367 event_del(&server_ev_accept); 368 close(server_fd); 369 server_fd = server_create_socket(); 370 event_set(&server_ev_accept, server_fd, 371 EV_READ|EV_PERSIST, server_accept_callback, NULL); 372 event_add(&server_ev_accept, NULL); 373 break; 374 } 375 } 376 377 /* Handle SIGCHLD. */ 378 void 379 server_child_signal(void) 380 { 381 int status; 382 pid_t pid; 383 384 for (;;) { 385 switch (pid = waitpid(WAIT_ANY, &status, WNOHANG|WUNTRACED)) { 386 case -1: 387 if (errno == ECHILD) 388 return; 389 fatal("waitpid failed"); 390 case 0: 391 return; 392 } 393 if (WIFSTOPPED(status)) 394 server_child_stopped(pid, status); 395 else if (WIFEXITED(status) || WIFSIGNALED(status)) 396 server_child_exited(pid, status); 397 } 398 } 399 400 /* Handle exited children. */ 401 void 402 server_child_exited(pid_t pid, int status) 403 { 404 struct window *w; 405 struct window_pane *wp; 406 struct job *job; 407 u_int i; 408 409 for (i = 0; i < ARRAY_LENGTH(&windows); i++) { 410 if ((w = ARRAY_ITEM(&windows, i)) == NULL) 411 continue; 412 TAILQ_FOREACH(wp, &w->panes, entry) { 413 if (wp->pid == pid) { 414 server_destroy_pane(wp); 415 break; 416 } 417 } 418 } 419 420 SLIST_FOREACH(job, &all_jobs, lentry) { 421 if (pid == job->pid) { 422 job_died(job, status); /* might free job */ 423 break; 424 } 425 } 426 } 427 428 /* Handle stopped children. */ 429 void 430 server_child_stopped(pid_t pid, int status) 431 { 432 struct window *w; 433 struct window_pane *wp; 434 u_int i; 435 436 if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU) 437 return; 438 439 for (i = 0; i < ARRAY_LENGTH(&windows); i++) { 440 if ((w = ARRAY_ITEM(&windows, i)) == NULL) 441 continue; 442 TAILQ_FOREACH(wp, &w->panes, entry) { 443 if (wp->pid == pid) { 444 if (killpg(pid, SIGCONT) != 0) 445 kill(pid, SIGCONT); 446 } 447 } 448 } 449 } 450 451 /* Handle once-per-second timer events. */ 452 /* ARGSUSED */ 453 void 454 server_second_callback(unused int fd, unused short events, unused void *arg) 455 { 456 struct window *w; 457 struct window_pane *wp; 458 struct timeval tv; 459 u_int i; 460 461 if (options_get_number(&global_s_options, "lock-server")) 462 server_lock_server(); 463 else 464 server_lock_sessions(); 465 466 for (i = 0; i < ARRAY_LENGTH(&windows); i++) { 467 w = ARRAY_ITEM(&windows, i); 468 if (w == NULL) 469 continue; 470 471 TAILQ_FOREACH(wp, &w->panes, entry) { 472 if (wp->mode != NULL && wp->mode->timer != NULL) 473 wp->mode->timer(wp); 474 } 475 } 476 477 server_client_status_timer(); 478 479 evtimer_del(&server_ev_second); 480 memset(&tv, 0, sizeof tv); 481 tv.tv_sec = 1; 482 evtimer_add(&server_ev_second, &tv); 483 } 484 485 /* Lock the server if ALL sessions have hit the time limit. */ 486 void 487 server_lock_server(void) 488 { 489 struct session *s; 490 int timeout; 491 time_t t; 492 493 t = time(NULL); 494 RB_FOREACH(s, sessions, &sessions) { 495 if (s->flags & SESSION_UNATTACHED) { 496 if (gettimeofday(&s->activity_time, NULL) != 0) 497 fatal("gettimeofday failed"); 498 continue; 499 } 500 501 timeout = options_get_number(&s->options, "lock-after-time"); 502 if (timeout <= 0 || t <= s->activity_time.tv_sec + timeout) 503 return; /* not timed out */ 504 } 505 506 server_lock(); 507 recalculate_sizes(); 508 } 509 510 /* Lock any sessions which have timed out. */ 511 void 512 server_lock_sessions(void) 513 { 514 struct session *s; 515 int timeout; 516 time_t t; 517 518 t = time(NULL); 519 RB_FOREACH(s, sessions, &sessions) { 520 if (s->flags & SESSION_UNATTACHED) { 521 if (gettimeofday(&s->activity_time, NULL) != 0) 522 fatal("gettimeofday failed"); 523 continue; 524 } 525 526 timeout = options_get_number(&s->options, "lock-after-time"); 527 if (timeout > 0 && t > s->activity_time.tv_sec + timeout) { 528 server_lock_session(s); 529 recalculate_sizes(); 530 } 531 } 532 } 533