server.c

   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_sigterm;
  53 struct event     server_ev_sigusr1;
  54 struct event     server_ev_sigchld;
  55 struct event     server_ev_second;
  56
  57 int              server_create_socket(void);
  58 void             server_loop(void);
  59 int              server_should_shutdown(void);
  60 void             server_send_shutdown(void);
  61 void             server_clean_dead(void);
  62 void             server_accept_callback(int, short, void *);
  63 void             server_signal_callback(int, short, void *);
  64 void             server_child_signal(void);
  65 void             server_child_exited(pid_t, int);
  66 void             server_child_stopped(pid_t, int);
  67 void             server_second_callback(int, short, void *);
  68 void             server_lock_server(void);
  69 void             server_lock_sessions(void);
  70
  71 /* Create server socket. */
  72 int
  73 server_create_socket(void)
  74 {
  75         struct sockaddr_un      sa;
  76         size_t                  size;
  77         mode_t                  mask;
  78         int                     fd, mode;
  79
  80         memset(&sa, 0, sizeof sa);
  81         sa.sun_family = AF_UNIX;
  82         size = strlcpy(sa.sun_path, socket_path, sizeof sa.sun_path);
  83         if (size >= sizeof sa.sun_path) {
  84                 errno = ENAMETOOLONG;
  85                 fatal("socket failed");
  86         }
  87         unlink(sa.sun_path);
  88
  89         if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
  90                 fatal("socket failed");
  91
  92         mask = umask(S_IXUSR|S_IRWXG|S_IRWXO);
  93         if (bind(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) == -1)
  94                 fatal("bind failed");
  95         umask(mask);
  96
  97         if (listen(fd, 16) == -1)
  98                 fatal("listen failed");
  99
 100         if ((mode = fcntl(fd, F_GETFL)) == -1)
 101                 fatal("fcntl failed");
 102         if (fcntl(fd, F_SETFL, mode|O_NONBLOCK) == -1)
 103                 fatal("fcntl failed");
 104         if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
 105                 fatal("fcntl failed");
 106
 107         server_update_socket();
 108
 109         return (fd);
 110 }
 111
 112 /* Fork new server. */
 113 int
 114 server_start(char *path)
 115 {
 116         struct window_pane      *wp;
 117         int                      pair[2];
 118         char                     rpathbuf[MAXPATHLEN], *cause;
 119         struct timeval           tv;
 120         u_int                    i;
 121
 122         /* The first client is special and gets a socketpair; create it. */
 123         if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0)
 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         logfile("server");
 145         log_debug("server started, pid %ld", (long) getpid());
 146
 147         ARRAY_INIT(&windows);
 148         ARRAY_INIT(&clients);
 149         ARRAY_INIT(&dead_clients);
 150         ARRAY_INIT(&sessions);
 151         ARRAY_INIT(&dead_sessions);
 152         TAILQ_INIT(&session_groups);
 153         mode_key_init_trees();
 154         key_bindings_init();
 155         utf8_build();
 156
 157         start_time = time(NULL);
 158         socket_path = path;
 159
 160         if (realpath(socket_path, rpathbuf) == NULL)
 161                 strlcpy(rpathbuf, socket_path, sizeof rpathbuf);
 162         log_debug("socket path %s", socket_path);
 163         setproctitle("server (%s)", rpathbuf);
 164
 165         event_init();
 166
 167         server_fd = server_create_socket();
 168         server_client_create(pair[1]);
 169
 170         if (access(SYSTEM_CFG, R_OK) == 0)
 171                 load_cfg(SYSTEM_CFG, NULL, &cfg_causes);
 172         else if (errno != ENOENT) {
 173                 cfg_add_cause(
 174                     &cfg_causes, "%s: %s", strerror(errno), SYSTEM_CFG);
 175         }
 176         if (cfg_file != NULL)
 177                 load_cfg(cfg_file, NULL, &cfg_causes);
 178
 179         /*
 180          * If there is a session already, put the current window and pane into
 181          * more mode.
 182          */
 183         if (!ARRAY_EMPTY(&sessions) && !ARRAY_EMPTY(&cfg_causes)) {
 184                 wp = ARRAY_FIRST(&sessions)->curw->window->active;
 185                 window_pane_set_mode(wp, &window_copy_mode);
 186                 window_copy_init_for_output(wp);
 187                 for (i = 0; i < ARRAY_LENGTH(&cfg_causes); i++) {
 188                         cause = ARRAY_ITEM(&cfg_causes, i);
 189                         window_copy_add(wp, "%s", cause);
 190                         xfree(cause);
 191                 }
 192                 ARRAY_FREE(&cfg_causes);
 193         }
 194         cfg_finished = 1;
 195
 196         event_set(&server_ev_accept,
 197             server_fd, EV_READ|EV_PERSIST, server_accept_callback, NULL);
 198         event_add(&server_ev_accept, NULL);
 199
 200         memset(&tv, 0, sizeof tv);
 201         tv.tv_sec = 1;
 202         evtimer_set(&server_ev_second, server_second_callback, NULL);
 203         evtimer_add(&server_ev_second, &tv);
 204
 205         server_signal_set();
 206         server_loop();
 207         exit(0);
 208 }
 209
 210 /* Main server loop. */
 211 void
 212 server_loop(void)
 213 {
 214         while (!server_should_shutdown()) {
 215                 event_loop(EVLOOP_ONCE);
 216
 217                 server_window_loop();
 218                 server_client_loop();
 219
 220                 key_bindings_clean();
 221                 server_clean_dead();
 222         }
 223 }
 224
 225 /* Check if the server should be shutting down (no more clients or windows). */
 226 int
 227 server_should_shutdown(void)
 228 {
 229         u_int   i;
 230
 231         for (i = 0; i < ARRAY_LENGTH(&sessions); i++) {
 232                 if (ARRAY_ITEM(&sessions, i) != NULL)
 233                         return (0);
 234         }
 235         for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
 236                 if (ARRAY_ITEM(&clients, i) != NULL)
 237                         return (0);
 238         }
 239         return (1);
 240 }
 241
 242 /* Shutdown the server by killing all clients and windows. */
 243 void
 244 server_send_shutdown(void)
 245 {
 246         struct client   *c;
 247         struct session  *s;
 248         u_int            i;
 249
 250         for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
 251                 c = ARRAY_ITEM(&clients, i);
 252                 if (c != NULL) {
 253                         if (c->flags & (CLIENT_BAD|CLIENT_SUSPENDED))
 254                                 server_client_lost(c);
 255                         else
 256                                 server_write_client(c, MSG_SHUTDOWN, NULL, 0);
 257                         c->session = NULL;
 258                 }
 259         }
 260
 261         for (i = 0; i < ARRAY_LENGTH(&sessions); i++) {
 262                 if ((s = ARRAY_ITEM(&sessions, i)) != NULL)
 263                         session_destroy(s);
 264         }
 265 }
 266
 267 /* Free dead, unreferenced clients and sessions. */
 268 void
 269 server_clean_dead(void)
 270 {
 271         struct session  *s;
 272         struct client   *c;
 273         u_int            i;
 274
 275         for (i = 0; i < ARRAY_LENGTH(&dead_sessions); i++) {
 276                 s = ARRAY_ITEM(&dead_sessions, i);
 277                 if (s == NULL || s->references != 0)
 278                         continue;
 279                 ARRAY_SET(&dead_sessions, i, NULL);
 280                 xfree(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         u_int            i;
 298         static int       last = -1;
 299         int              n;
 300
 301         n = 0;
 302         for (i = 0; i < ARRAY_LENGTH(&sessions); i++) {
 303                 s = ARRAY_ITEM(&sessions, i);
 304                 if (s != NULL && !(s->flags & SESSION_UNATTACHED)) {
 305                         n++;
 306                         break;
 307                 }
 308         }
 309
 310         if (n != last) {
 311                 last = n;
 312                 if (n != 0)
 313                         chmod(socket_path, S_IRWXU);
 314                 else
 315                         chmod(socket_path, S_IRUSR|S_IWUSR);
 316         }
 317 }
 318
 319 /* Callback for server socket. */
 320 /* ARGSUSED */
 321 void
 322 server_accept_callback(int fd, short events, unused void *data)
 323 {
 324         struct sockaddr_storage sa;
 325         socklen_t               slen = sizeof sa;
 326         int                     newfd;
 327
 328         if (!(events & EV_READ))
 329                 return;
 330
 331         newfd = accept(fd, (struct sockaddr *) &sa, &slen);
 332         if (newfd == -1) {
 333                 if (errno == EAGAIN || errno == EINTR || errno == ECONNABORTED)
 334                         return;
 335                 fatal("accept failed");
 336         }
 337         if (server_shutdown) {
 338                 close(newfd);
 339                 return;
 340         }
 341         server_client_create(newfd);
 342 }
 343
 344 /* Set up server signal handling. */
 345 void
 346 server_signal_set(void)
 347 {
 348         struct sigaction         sigact;
 349
 350         memset(&sigact, 0, sizeof sigact);
 351         sigemptyset(&sigact.sa_mask);
 352         sigact.sa_flags = SA_RESTART;
 353         sigact.sa_handler = SIG_IGN;
 354         if (sigaction(SIGINT, &sigact, NULL) != 0)
 355                 fatal("sigaction failed");
 356         if (sigaction(SIGPIPE, &sigact, NULL) != 0)
 357                 fatal("sigaction failed");
 358         if (sigaction(SIGUSR2, &sigact, NULL) != 0)
 359                 fatal("sigaction failed");
 360         if (sigaction(SIGTSTP, &sigact, NULL) != 0)
 361                 fatal("sigaction failed");
 362         if (sigaction(SIGHUP, &sigact, NULL) != 0)
 363                 fatal("sigaction failed");
 364
 365         signal_set(&server_ev_sigchld, SIGCHLD, server_signal_callback, NULL);
 366         signal_add(&server_ev_sigchld, NULL);
 367         signal_set(&server_ev_sigterm, SIGTERM, server_signal_callback, NULL);
 368         signal_add(&server_ev_sigterm, NULL);
 369         signal_set(&server_ev_sigusr1, SIGUSR1, server_signal_callback, NULL);
 370         signal_add(&server_ev_sigusr1, NULL);
 371 }
 372
 373 /* Destroy server signal events. */
 374 void
 375 server_signal_clear(void)
 376 {
 377         struct sigaction         sigact;
 378
 379         memset(&sigact, 0, sizeof sigact);
 380         sigemptyset(&sigact.sa_mask);
 381         sigact.sa_flags = SA_RESTART;
 382         sigact.sa_handler = SIG_DFL;
 383         if (sigaction(SIGINT, &sigact, NULL) != 0)
 384                 fatal("sigaction failed");
 385         if (sigaction(SIGPIPE, &sigact, NULL) != 0)
 386                 fatal("sigaction failed");
 387         if (sigaction(SIGUSR2, &sigact, NULL) != 0)
 388                 fatal("sigaction failed");
 389         if (sigaction(SIGTSTP, &sigact, NULL) != 0)
 390                 fatal("sigaction failed");
 391         if (sigaction(SIGHUP, &sigact, NULL) != 0)
 392                 fatal("sigaction failed");
 393
 394         signal_del(&server_ev_sigchld);
 395         signal_del(&server_ev_sigterm);
 396         signal_del(&server_ev_sigusr1);
 397 }
 398
 399 /* Signal handler. */
 400 /* ARGSUSED */
 401 void
 402 server_signal_callback(int sig, unused short events, unused void *data)
 403 {
 404         switch (sig) {
 405         case SIGTERM:
 406                 server_shutdown = 1;
 407                 server_send_shutdown();
 408                 break;
 409         case SIGCHLD:
 410                 server_child_signal();
 411                 break;
 412         case SIGUSR1:
 413                 event_del(&server_ev_accept);
 414                 close(server_fd);
 415                 server_fd = server_create_socket();
 416                 event_set(&server_ev_accept, server_fd,
 417                     EV_READ|EV_PERSIST, server_accept_callback, NULL);
 418                 event_add(&server_ev_accept, NULL);
 419                 break;
 420         }
 421 }
 422
 423 /* Handle SIGCHLD. */
 424 void
 425 server_child_signal(void)
 426 {
 427         int      status;
 428         pid_t    pid;
 429
 430         for (;;) {
 431                 switch (pid = waitpid(WAIT_ANY, &status, WNOHANG|WUNTRACED)) {
 432                 case -1:
 433                         if (errno == ECHILD)
 434                                 return;
 435                         fatal("waitpid failed");
 436                 case 0:
 437                         return;
 438                 }
 439                 if (WIFSTOPPED(status))
 440                         server_child_stopped(pid, status);
 441                 else if (WIFEXITED(status) || WIFSIGNALED(status))
 442                         server_child_exited(pid, status);
 443         }
 444 }
 445
 446 /* Handle exited children. */
 447 void
 448 server_child_exited(pid_t pid, int status)
 449 {
 450         struct window           *w;
 451         struct window_pane      *wp;
 452         struct job              *job;
 453         u_int                    i;
 454
 455         for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
 456                 if ((w = ARRAY_ITEM(&windows, i)) == NULL)
 457                         continue;
 458                 TAILQ_FOREACH(wp, &w->panes, entry) {
 459                         if (wp->pid == pid) {
 460                                 server_destroy_pane(wp);
 461                                 break;
 462                         }
 463                 }
 464         }
 465
 466         SLIST_FOREACH(job, &all_jobs, lentry) {
 467                 if (pid == job->pid) {
 468                         job_died(job, status);  /* might free job */
 469                         break;
 470                 }
 471         }
 472 }
 473
 474 /* Handle stopped children. */
 475 void
 476 server_child_stopped(pid_t pid, int status)
 477 {
 478         struct window           *w;
 479         struct window_pane      *wp;
 480         u_int                    i;
 481
 482         if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU)
 483                 return;
 484
 485         for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
 486                 if ((w = ARRAY_ITEM(&windows, i)) == NULL)
 487                         continue;
 488                 TAILQ_FOREACH(wp, &w->panes, entry) {
 489                         if (wp->pid == pid) {
 490                                 if (killpg(pid, SIGCONT) != 0)
 491                                         kill(pid, SIGCONT);
 492                         }
 493                 }
 494         }
 495 }
 496
 497 /* Handle once-per-second timer events. */
 498 /* ARGSUSED */
 499 void
 500 server_second_callback(unused int fd, unused short events, unused void *arg)
 501 {
 502         struct window           *w;
 503         struct window_pane      *wp;
 504         struct timeval           tv;
 505         u_int                    i;
 506
 507         if (options_get_number(&global_s_options, "lock-server"))
 508                 server_lock_server();
 509         else
 510                 server_lock_sessions();
 511
 512         for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
 513                 w = ARRAY_ITEM(&windows, i);
 514                 if (w == NULL)
 515                         continue;
 516
 517                 TAILQ_FOREACH(wp, &w->panes, entry) {
 518                         if (wp->mode != NULL && wp->mode->timer != NULL)
 519                                 wp->mode->timer(wp);
 520                 }
 521         }
 522
 523         server_client_status_timer();
 524
 525         evtimer_del(&server_ev_second);
 526         memset(&tv, 0, sizeof tv);
 527         tv.tv_sec = 1;
 528         evtimer_add(&server_ev_second, &tv);
 529 }
 530
 531 /* Lock the server if ALL sessions have hit the time limit. */
 532 void
 533 server_lock_server(void)
 534 {
 535         struct session  *s;
 536         u_int            i;
 537         int              timeout;
 538         time_t           t;
 539
 540         t = time(NULL);
 541         for (i = 0; i < ARRAY_LENGTH(&sessions); i++) {
 542                 if ((s = ARRAY_ITEM(&sessions, i)) == NULL)
 543                         continue;
 544
 545                 if (s->flags & SESSION_UNATTACHED) {
 546                         if (gettimeofday(&s->activity_time, NULL) != 0)
 547                                 fatal("gettimeofday failed");
 548                         continue;
 549                 }
 550
 551                 timeout = options_get_number(&s->options, "lock-after-time");
 552                 if (timeout <= 0 || t <= s->activity_time.tv_sec + timeout)
 553                         return; /* not timed out */
 554         }
 555
 556         server_lock();
 557         recalculate_sizes();
 558 }
 559
 560 /* Lock any sessions which have timed out. */
 561 void
 562 server_lock_sessions(void)
 563 {
 564         struct session  *s;
 565         u_int            i;
 566         int              timeout;
 567         time_t           t;
 568
 569         t = time(NULL);
 570         for (i = 0; i < ARRAY_LENGTH(&sessions); i++) {
 571                 if ((s = ARRAY_ITEM(&sessions, i)) == NULL)
 572                         continue;
 573
 574                 if (s->flags & SESSION_UNATTACHED) {
 575                         if (gettimeofday(&s->activity_time, NULL) != 0)
 576                                 fatal("gettimeofday failed");
 577                         continue;
 578                 }
 579
 580                 timeout = options_get_number(&s->options, "lock-after-time");
 581                 if (timeout > 0 && t > s->activity_time.tv_sec + timeout) {
 582                         server_lock_session(s);
 583                         recalculate_sizes();
 584                 }
 585         }
 586 }