1 /* $Id: server.c,v 1.1.1.2 2011/08/17 18:40:05 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 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 #ifndef __minix 88 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) 89 #else 90 if ((fd = socket(AF_UNIX, SOCK_SEQPACKET, 0)) == -1) 91 #endif 92 fatal("socket failed"); 93 94 mask = umask(S_IXUSR|S_IXGRP|S_IRWXO); 95 if (bind(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) == -1) 96 fatal("bind failed"); 97 umask(mask); 98 99 if (listen(fd, 16) == -1) 100 fatal("listen failed"); 101 setblocking(fd, 0); 102 103 server_update_socket(); 104 105 return (fd); 106 } 107 108 /* Fork new server. */ 109 int 110 server_start(void) 111 { 112 struct window_pane *wp; 113 int pair[2]; 114 char *cause; 115 struct timeval tv; 116 u_int i; 117 118 /* The first client is special and gets a socketpair; create it. */ 119 #ifndef __minix 120 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0) 121 #else 122 if (socketpair(AF_UNIX, SOCK_SEQPACKET, PF_UNSPEC, pair) != 0) 123 #endif 124 fatal("socketpair failed"); 125 126 switch (fork()) { 127 case -1: 128 fatal("fork failed"); 129 case 0: 130 break; 131 default: 132 close(pair[1]); 133 return (pair[0]); 134 } 135 close(pair[0]); 136 137 /* 138 * Must daemonise before loading configuration as the PID changes so 139 * $TMUX would be wrong for sessions created in the config file. 140 */ 141 if (daemon(1, 0) != 0) 142 fatal("daemon failed"); 143 144 /* event_init() was called in our parent, need to reinit. */ 145 if (event_reinit(ev_base) != 0) 146 fatal("event_reinit failed"); 147 clear_signals(0); 148 149 logfile("server"); 150 log_debug("server started, pid %ld", (long) getpid()); 151 152 ARRAY_INIT(&windows); 153 RB_INIT(&all_window_panes); 154 ARRAY_INIT(&clients); 155 ARRAY_INIT(&dead_clients); 156 RB_INIT(&sessions); 157 RB_INIT(&dead_sessions); 158 TAILQ_INIT(&session_groups); 159 ARRAY_INIT(&global_buffers); 160 mode_key_init_trees(); 161 key_bindings_init(); 162 utf8_build(); 163 164 start_time = time(NULL); 165 log_debug("socket path %s", socket_path); 166 #ifdef HAVE_SETPROCTITLE 167 setproctitle("server (%s)", socket_path); 168 #endif 169 170 server_fd = server_create_socket(); 171 server_client_create(pair[1]); 172 173 if (access(SYSTEM_CFG, R_OK) == 0) 174 load_cfg(SYSTEM_CFG, NULL, &cfg_causes); 175 else if (errno != ENOENT) { 176 cfg_add_cause( 177 &cfg_causes, "%s: %s", strerror(errno), SYSTEM_CFG); 178 } 179 if (cfg_file != NULL) 180 load_cfg(cfg_file, NULL, &cfg_causes); 181 182 /* 183 * If there is a session already, put the current window and pane into 184 * more mode. 185 */ 186 if (!RB_EMPTY(&sessions) && !ARRAY_EMPTY(&cfg_causes)) { 187 wp = RB_MIN(sessions, &sessions)->curw->window->active; 188 window_pane_set_mode(wp, &window_copy_mode); 189 window_copy_init_for_output(wp); 190 for (i = 0; i < ARRAY_LENGTH(&cfg_causes); i++) { 191 cause = ARRAY_ITEM(&cfg_causes, i); 192 window_copy_add(wp, "%s", cause); 193 xfree(cause); 194 } 195 ARRAY_FREE(&cfg_causes); 196 } 197 cfg_finished = 1; 198 199 event_set(&server_ev_accept, 200 server_fd, EV_READ|EV_PERSIST, server_accept_callback, NULL); 201 event_add(&server_ev_accept, NULL); 202 203 memset(&tv, 0, sizeof tv); 204 tv.tv_sec = 1; 205 evtimer_set(&server_ev_second, server_second_callback, NULL); 206 evtimer_add(&server_ev_second, &tv); 207 208 set_signals(server_signal_callback); 209 server_loop(); 210 exit(0); 211 } 212 213 /* Main server loop. */ 214 void 215 server_loop(void) 216 { 217 while (!server_should_shutdown()) { 218 event_loop(EVLOOP_ONCE); 219 220 server_window_loop(); 221 server_client_loop(); 222 223 key_bindings_clean(); 224 server_clean_dead(); 225 } 226 } 227 228 /* Check if the server should be shutting down (no more clients or sessions). */ 229 int 230 server_should_shutdown(void) 231 { 232 u_int i; 233 234 if (!options_get_number(&global_options, "exit-unattached")) { 235 if (!RB_EMPTY(&sessions)) 236 return (0); 237 } 238 for (i = 0; i < ARRAY_LENGTH(&clients); i++) { 239 if (ARRAY_ITEM(&clients, i) != NULL) 240 return (0); 241 } 242 return (1); 243 } 244 245 /* Shutdown the server by killing all clients and windows. */ 246 void 247 server_send_shutdown(void) 248 { 249 struct client *c; 250 struct session *s, *next_s; 251 u_int i; 252 253 for (i = 0; i < ARRAY_LENGTH(&clients); i++) { 254 c = ARRAY_ITEM(&clients, i); 255 if (c != NULL) { 256 if (c->flags & (CLIENT_BAD|CLIENT_SUSPENDED)) 257 server_client_lost(c); 258 else 259 server_write_client(c, MSG_SHUTDOWN, NULL, 0); 260 c->session = NULL; 261 } 262 } 263 264 s = RB_MIN(sessions, &sessions); 265 while (s != NULL) { 266 next_s = RB_NEXT(sessions, &sessions, s); 267 session_destroy(s); 268 s = next_s; 269 } 270 } 271 272 /* Free dead, unreferenced clients and sessions. */ 273 void 274 server_clean_dead(void) 275 { 276 struct session *s, *next_s; 277 struct client *c; 278 u_int i; 279 280 s = RB_MIN(sessions, &dead_sessions); 281 while (s != NULL) { 282 next_s = RB_NEXT(sessions, &dead_sessions, s); 283 if (s->references == 0) { 284 RB_REMOVE(sessions, &dead_sessions, s); 285 xfree(s->name); 286 xfree(s); 287 } 288 s = next_s; 289 } 290 291 for (i = 0; i < ARRAY_LENGTH(&dead_clients); i++) { 292 c = ARRAY_ITEM(&dead_clients, i); 293 if (c == NULL || c->references != 0) 294 continue; 295 ARRAY_SET(&dead_clients, i, NULL); 296 xfree(c); 297 } 298 } 299 300 /* Update socket execute permissions based on whether sessions are attached. */ 301 void 302 server_update_socket(void) 303 { 304 struct session *s; 305 static int last = -1; 306 int n, mode; 307 struct stat sb; 308 309 n = 0; 310 RB_FOREACH(s, sessions, &sessions) { 311 if (!(s->flags & SESSION_UNATTACHED)) { 312 n++; 313 break; 314 } 315 } 316 317 if (n != last) { 318 last = n; 319 320 if (stat(socket_path, &sb) != 0) 321 return; 322 mode = sb.st_mode; 323 if (n != 0) { 324 if (mode & S_IRUSR) 325 mode |= S_IXUSR; 326 if (mode & S_IRGRP) 327 mode |= S_IXGRP; 328 if (mode & S_IROTH) 329 mode |= S_IXOTH; 330 } else 331 mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH); 332 chmod(socket_path, mode); 333 } 334 } 335 336 /* Callback for server socket. */ 337 /* ARGSUSED */ 338 void 339 server_accept_callback(int fd, short events, unused void *data) 340 { 341 struct sockaddr_storage sa; 342 socklen_t slen = sizeof sa; 343 int newfd; 344 345 if (!(events & EV_READ)) 346 return; 347 348 newfd = accept(fd, (struct sockaddr *) &sa, &slen); 349 if (newfd == -1) { 350 if (errno == EAGAIN || errno == EINTR || errno == ECONNABORTED) 351 return; 352 fatal("accept failed"); 353 } 354 if (server_shutdown) { 355 close(newfd); 356 return; 357 } 358 server_client_create(newfd); 359 } 360 361 /* Signal handler. */ 362 /* ARGSUSED */ 363 void 364 server_signal_callback(int sig, unused short events, unused void *data) 365 { 366 switch (sig) { 367 case SIGTERM: 368 server_shutdown = 1; 369 server_send_shutdown(); 370 break; 371 case SIGCHLD: 372 server_child_signal(); 373 break; 374 case SIGUSR1: 375 event_del(&server_ev_accept); 376 close(server_fd); 377 server_fd = server_create_socket(); 378 event_set(&server_ev_accept, server_fd, 379 EV_READ|EV_PERSIST, server_accept_callback, NULL); 380 event_add(&server_ev_accept, NULL); 381 break; 382 } 383 } 384 385 /* Handle SIGCHLD. */ 386 void 387 server_child_signal(void) 388 { 389 int status; 390 pid_t pid; 391 392 for (;;) { 393 switch (pid = waitpid(WAIT_ANY, &status, WNOHANG|WUNTRACED)) { 394 case -1: 395 if (errno == ECHILD) 396 return; 397 fatal("waitpid failed"); 398 case 0: 399 return; 400 } 401 if (WIFSTOPPED(status)) 402 server_child_stopped(pid, status); 403 else if (WIFEXITED(status) || WIFSIGNALED(status)) 404 server_child_exited(pid, status); 405 } 406 } 407 408 /* Handle exited children. */ 409 void 410 server_child_exited(pid_t pid, int status) 411 { 412 struct window *w; 413 struct window_pane *wp; 414 struct job *job; 415 u_int i; 416 417 for (i = 0; i < ARRAY_LENGTH(&windows); i++) { 418 if ((w = ARRAY_ITEM(&windows, i)) == NULL) 419 continue; 420 TAILQ_FOREACH(wp, &w->panes, entry) { 421 if (wp->pid == pid) { 422 server_destroy_pane(wp); 423 break; 424 } 425 } 426 } 427 428 LIST_FOREACH(job, &all_jobs, lentry) { 429 if (pid == job->pid) { 430 job_died(job, status); /* might free job */ 431 break; 432 } 433 } 434 } 435 436 /* Handle stopped children. */ 437 void 438 server_child_stopped(pid_t pid, int status) 439 { 440 struct window *w; 441 struct window_pane *wp; 442 u_int i; 443 444 if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU) 445 return; 446 447 for (i = 0; i < ARRAY_LENGTH(&windows); i++) { 448 if ((w = ARRAY_ITEM(&windows, i)) == NULL) 449 continue; 450 TAILQ_FOREACH(wp, &w->panes, entry) { 451 if (wp->pid == pid) { 452 if (killpg(pid, SIGCONT) != 0) 453 kill(pid, SIGCONT); 454 } 455 } 456 } 457 } 458 459 /* Handle once-per-second timer events. */ 460 /* ARGSUSED */ 461 void 462 server_second_callback(unused int fd, unused short events, unused void *arg) 463 { 464 struct window *w; 465 struct window_pane *wp; 466 struct timeval tv; 467 u_int i; 468 469 if (options_get_number(&global_s_options, "lock-server")) 470 server_lock_server(); 471 else 472 server_lock_sessions(); 473 474 for (i = 0; i < ARRAY_LENGTH(&windows); i++) { 475 w = ARRAY_ITEM(&windows, i); 476 if (w == NULL) 477 continue; 478 479 TAILQ_FOREACH(wp, &w->panes, entry) { 480 if (wp->mode != NULL && wp->mode->timer != NULL) 481 wp->mode->timer(wp); 482 } 483 } 484 485 server_client_status_timer(); 486 487 evtimer_del(&server_ev_second); 488 memset(&tv, 0, sizeof tv); 489 tv.tv_sec = 1; 490 evtimer_add(&server_ev_second, &tv); 491 } 492 493 /* Lock the server if ALL sessions have hit the time limit. */ 494 void 495 server_lock_server(void) 496 { 497 struct session *s; 498 int timeout; 499 time_t t; 500 501 t = time(NULL); 502 RB_FOREACH(s, sessions, &sessions) { 503 if (s->flags & SESSION_UNATTACHED) 504 continue; 505 timeout = options_get_number(&s->options, "lock-after-time"); 506 if (timeout <= 0 || t <= s->activity_time.tv_sec + timeout) 507 return; /* not timed out */ 508 } 509 510 server_lock(); 511 recalculate_sizes(); 512 } 513 514 /* Lock any sessions which have timed out. */ 515 void 516 server_lock_sessions(void) 517 { 518 struct session *s; 519 int timeout; 520 time_t t; 521 522 t = time(NULL); 523 RB_FOREACH(s, sessions, &sessions) { 524 if (s->flags & SESSION_UNATTACHED) 525 continue; 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