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 time_t current_time; 57 58 static int server_loop(void); 59 static void server_send_exit(void); 60 static void server_accept(int, short, void *); 61 static void server_signal(int); 62 static void server_child_signal(void); 63 static void server_child_exited(pid_t, int); 64 static void server_child_stopped(pid_t, int); 65 66 /* Set marked pane. */ 67 void 68 server_set_marked(struct session *s, struct winlink *wl, struct window_pane *wp) 69 { 70 cmd_find_clear_state(&marked_pane, 0); 71 marked_pane.s = s; 72 marked_pane.wl = wl; 73 marked_pane.w = wl->window; 74 marked_pane.wp = wp; 75 } 76 77 /* Clear marked pane. */ 78 void 79 server_clear_marked(void) 80 { 81 cmd_find_clear_state(&marked_pane, 0); 82 } 83 84 /* Is this the marked pane? */ 85 int 86 server_is_marked(struct session *s, struct winlink *wl, struct window_pane *wp) 87 { 88 if (s == NULL || wl == NULL || wp == NULL) 89 return (0); 90 if (marked_pane.s != s || marked_pane.wl != wl) 91 return (0); 92 if (marked_pane.wp != wp) 93 return (0); 94 return (server_check_marked()); 95 } 96 97 /* Check if the marked pane is still valid. */ 98 int 99 server_check_marked(void) 100 { 101 return (cmd_find_valid_state(&marked_pane)); 102 } 103 104 /* Create server socket. */ 105 int 106 server_create_socket(uint64_t flags, char **cause) 107 { 108 struct sockaddr_un sa; 109 size_t size; 110 mode_t mask; 111 int fd, saved_errno; 112 113 memset(&sa, 0, sizeof sa); 114 sa.sun_family = AF_UNIX; 115 size = strlcpy(sa.sun_path, socket_path, sizeof sa.sun_path); 116 if (size >= sizeof sa.sun_path) { 117 errno = ENAMETOOLONG; 118 goto fail; 119 } 120 unlink(sa.sun_path); 121 122 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) 123 goto fail; 124 125 if (flags & CLIENT_DEFAULTSOCKET) 126 mask = umask(S_IXUSR|S_IXGRP|S_IRWXO); 127 else 128 mask = umask(S_IXUSR|S_IRWXG|S_IRWXO); 129 if (bind(fd, (struct sockaddr *)&sa, sizeof sa) == -1) { 130 saved_errno = errno; 131 close(fd); 132 errno = saved_errno; 133 goto fail; 134 } 135 umask(mask); 136 137 if (listen(fd, 128) == -1) { 138 saved_errno = errno; 139 close(fd); 140 errno = saved_errno; 141 goto fail; 142 } 143 setblocking(fd, 0); 144 145 return (fd); 146 147 fail: 148 if (cause != NULL) { 149 xasprintf(cause, "error creating %s (%s)", socket_path, 150 strerror(errno)); 151 } 152 return (-1); 153 } 154 155 /* Tidy up every hour. */ 156 static void 157 server_tidy_event(__unused int fd, __unused short events, __unused void *data) 158 { 159 struct timeval tv = { .tv_sec = 3600 }; 160 uint64_t t = get_timer(); 161 162 format_tidy_jobs(); 163 164 #ifdef HAVE_MALLOC_TRIM 165 malloc_trim(0); 166 #endif 167 168 log_debug("%s: took %ju milliseconds", __func__, (uintmax_t)get_timer() - t); 169 evtimer_add(&server_ev_tidy, &tv); 170 } 171 172 /* Fork new server. */ 173 int 174 server_start(struct tmuxproc *client, uint64_t flags, struct event_base *base, 175 int lockfd, char *lockfile) 176 { 177 int fd; 178 sigset_t set, oldset; 179 struct client *c = NULL; 180 char *cause = NULL; 181 struct timeval tv = { .tv_sec = 3600 }; 182 183 sigfillset(&set); 184 sigprocmask(SIG_BLOCK, &set, &oldset); 185 186 if (~flags & CLIENT_NOFORK) { 187 if (proc_fork_and_daemon(&fd) != 0) { 188 sigprocmask(SIG_SETMASK, &oldset, NULL); 189 return (fd); 190 } 191 } 192 proc_clear_signals(client, 0); 193 server_client_flags = flags; 194 195 if (event_reinit(base) != 0) 196 fatalx("event_reinit failed"); 197 server_proc = proc_start("server"); 198 199 proc_set_signals(server_proc, server_signal); 200 sigprocmask(SIG_SETMASK, &oldset, NULL); 201 202 if (log_get_level() > 1) 203 tty_create_log(); 204 if (pledge("stdio rpath wpath cpath fattr unix getpw recvfd proc exec " 205 "tty ps", NULL) != 0) 206 fatal("pledge failed"); 207 208 input_key_build(); 209 RB_INIT(&windows); 210 RB_INIT(&all_window_panes); 211 TAILQ_INIT(&clients); 212 RB_INIT(&sessions); 213 key_bindings_init(); 214 TAILQ_INIT(&message_log); 215 gettimeofday(&start_time, NULL); 216 217 #ifdef HAVE_SYSTEMD 218 server_fd = systemd_create_socket(flags, &cause); 219 #else 220 server_fd = server_create_socket(flags, &cause); 221 #endif 222 if (server_fd != -1) 223 server_update_socket(); 224 if (~flags & CLIENT_NOFORK) 225 c = server_client_create(fd); 226 else 227 options_set_number(global_options, "exit-empty", 0); 228 229 if (lockfd >= 0) { 230 unlink(lockfile); 231 free(lockfile); 232 close(lockfd); 233 } 234 235 if (cause != NULL) { 236 if (c != NULL) { 237 c->exit_message = cause; 238 c->flags |= CLIENT_EXIT; 239 } else { 240 fprintf(stderr, "%s\n", cause); 241 exit(1); 242 } 243 } 244 245 evtimer_set(&server_ev_tidy, server_tidy_event, NULL); 246 evtimer_add(&server_ev_tidy, &tv); 247 248 server_acl_init(); 249 250 server_add_accept(0); 251 proc_loop(server_proc, server_loop); 252 253 job_kill_all(); 254 status_prompt_save_history(); 255 256 exit(0); 257 } 258 259 /* Server loop callback. */ 260 static int 261 server_loop(void) 262 { 263 struct client *c; 264 u_int items; 265 266 current_time = time(NULL); 267 268 do { 269 items = cmdq_next(NULL); 270 TAILQ_FOREACH(c, &clients, entry) { 271 if (c->flags & CLIENT_IDENTIFIED) 272 items += cmdq_next(c); 273 } 274 } while (items != 0); 275 276 server_client_loop(); 277 278 if (!options_get_number(global_options, "exit-empty") && !server_exit) 279 return (0); 280 281 if (!options_get_number(global_options, "exit-unattached")) { 282 if (!RB_EMPTY(&sessions)) 283 return (0); 284 } 285 286 TAILQ_FOREACH(c, &clients, entry) { 287 if (c->session != NULL) 288 return (0); 289 } 290 291 /* 292 * No attached clients therefore want to exit - flush any waiting 293 * clients but don't actually exit until they've gone. 294 */ 295 cmd_wait_for_flush(); 296 if (!TAILQ_EMPTY(&clients)) 297 return (0); 298 299 if (job_still_running()) 300 return (0); 301 302 return (1); 303 } 304 305 /* Exit the server by killing all clients and windows. */ 306 static void 307 server_send_exit(void) 308 { 309 struct client *c, *c1; 310 struct session *s, *s1; 311 312 cmd_wait_for_flush(); 313 314 TAILQ_FOREACH_SAFE(c, &clients, entry, c1) { 315 if (c->flags & CLIENT_SUSPENDED) 316 server_client_lost(c); 317 else { 318 c->flags |= CLIENT_EXIT; 319 c->exit_type = CLIENT_EXIT_SHUTDOWN; 320 } 321 c->session = NULL; 322 } 323 324 RB_FOREACH_SAFE(s, sessions, &sessions, s1) 325 session_destroy(s, 1, __func__); 326 } 327 328 /* Update socket execute permissions based on whether sessions are attached. */ 329 void 330 server_update_socket(void) 331 { 332 struct session *s; 333 static int last = -1; 334 int n, mode; 335 struct stat sb; 336 337 n = 0; 338 RB_FOREACH(s, sessions, &sessions) { 339 if (s->attached != 0) { 340 n++; 341 break; 342 } 343 } 344 345 if (n != last) { 346 last = n; 347 348 if (stat(socket_path, &sb) != 0) 349 return; 350 mode = sb.st_mode & ACCESSPERMS; 351 if (n != 0) { 352 if (mode & S_IRUSR) 353 mode |= S_IXUSR; 354 if (mode & S_IRGRP) 355 mode |= S_IXGRP; 356 if (mode & S_IROTH) 357 mode |= S_IXOTH; 358 } else 359 mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH); 360 chmod(socket_path, mode); 361 } 362 } 363 364 /* Callback for server socket. */ 365 static void 366 server_accept(int fd, short events, __unused void *data) 367 { 368 struct sockaddr_storage sa; 369 socklen_t slen = sizeof sa; 370 int newfd; 371 struct client *c; 372 373 server_add_accept(0); 374 if (!(events & EV_READ)) 375 return; 376 377 newfd = accept(fd, (struct sockaddr *) &sa, &slen); 378 if (newfd == -1) { 379 if (errno == EAGAIN || errno == EINTR || errno == ECONNABORTED) 380 return; 381 if (errno == ENFILE || errno == EMFILE) { 382 /* Delete and don't try again for 1 second. */ 383 server_add_accept(1); 384 return; 385 } 386 fatal("accept failed"); 387 } 388 389 if (server_exit) { 390 close(newfd); 391 return; 392 } 393 c = server_client_create(newfd); 394 if (!server_acl_join(c)) { 395 c->exit_message = xstrdup("access not allowed"); 396 c->flags |= CLIENT_EXIT; 397 } 398 } 399 400 /* 401 * Add accept event. If timeout is nonzero, add as a timeout instead of a read 402 * event - used to backoff when running out of file descriptors. 403 */ 404 void 405 server_add_accept(int timeout) 406 { 407 struct timeval tv = { timeout, 0 }; 408 409 if (server_fd == -1) 410 return; 411 412 if (event_initialized(&server_ev_accept)) 413 event_del(&server_ev_accept); 414 415 if (timeout == 0) { 416 event_set(&server_ev_accept, server_fd, EV_READ, server_accept, 417 NULL); 418 event_add(&server_ev_accept, NULL); 419 } else { 420 event_set(&server_ev_accept, server_fd, EV_TIMEOUT, 421 server_accept, NULL); 422 event_add(&server_ev_accept, &tv); 423 } 424 } 425 426 /* Signal handler. */ 427 static void 428 server_signal(int sig) 429 { 430 int fd; 431 432 log_debug("%s: %s", __func__, strsignal(sig)); 433 switch (sig) { 434 case SIGINT: 435 case SIGTERM: 436 server_exit = 1; 437 server_send_exit(); 438 break; 439 case SIGCHLD: 440 server_child_signal(); 441 break; 442 case SIGUSR1: 443 event_del(&server_ev_accept); 444 fd = server_create_socket(server_client_flags, NULL); 445 if (fd != -1) { 446 close(server_fd); 447 server_fd = fd; 448 server_update_socket(); 449 } 450 server_add_accept(0); 451 break; 452 case SIGUSR2: 453 proc_toggle_log(server_proc); 454 break; 455 } 456 } 457 458 /* Handle SIGCHLD. */ 459 static void 460 server_child_signal(void) 461 { 462 int status; 463 pid_t pid; 464 465 for (;;) { 466 switch (pid = waitpid(WAIT_ANY, &status, WNOHANG|WUNTRACED)) { 467 case -1: 468 if (errno == ECHILD) 469 return; 470 fatal("waitpid failed"); 471 case 0: 472 return; 473 } 474 if (WIFSTOPPED(status)) 475 server_child_stopped(pid, status); 476 else if (WIFEXITED(status) || WIFSIGNALED(status)) 477 server_child_exited(pid, status); 478 } 479 } 480 481 /* Handle exited children. */ 482 static void 483 server_child_exited(pid_t pid, int status) 484 { 485 struct window *w, *w1; 486 struct window_pane *wp; 487 488 RB_FOREACH_SAFE(w, windows, &windows, w1) { 489 TAILQ_FOREACH(wp, &w->panes, entry) { 490 if (wp->pid == pid) { 491 wp->status = status; 492 wp->flags |= PANE_STATUSREADY; 493 494 log_debug("%%%u exited", wp->id); 495 wp->flags |= PANE_EXITED; 496 497 if (window_pane_destroy_ready(wp)) 498 server_destroy_pane(wp, 1); 499 break; 500 } 501 } 502 } 503 job_check_died(pid, status); 504 } 505 506 /* Handle stopped children. */ 507 static void 508 server_child_stopped(pid_t pid, int status) 509 { 510 struct window *w; 511 struct window_pane *wp; 512 513 if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU) 514 return; 515 516 RB_FOREACH(w, windows, &windows) { 517 TAILQ_FOREACH(wp, &w->panes, entry) { 518 if (wp->pid == pid) { 519 if (killpg(pid, SIGCONT) != 0) 520 kill(pid, SIGCONT); 521 } 522 } 523 } 524 job_check_died(pid, status); 525 } 526 527 /* Add to message log. */ 528 void 529 server_add_message(const char *fmt, ...) 530 { 531 struct message_entry *msg, *msg1; 532 char *s; 533 va_list ap; 534 u_int limit; 535 536 va_start(ap, fmt); 537 xvasprintf(&s, fmt, ap); 538 va_end(ap); 539 540 log_debug("message: %s", s); 541 542 msg = xcalloc(1, sizeof *msg); 543 gettimeofday(&msg->msg_time, NULL); 544 msg->msg_num = message_next++; 545 msg->msg = s; 546 TAILQ_INSERT_TAIL(&message_log, msg, entry); 547 548 limit = options_get_number(global_options, "message-limit"); 549 TAILQ_FOREACH_SAFE(msg, &message_log, entry, msg1) { 550 if (msg->msg_num + limit >= message_next) 551 break; 552 free(msg->msg); 553 TAILQ_REMOVE(&message_log, msg, entry); 554 free(msg); 555 } 556 } 557