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