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 <event.h> 28 #include <fcntl.h> 29 #include <signal.h> 30 #include <stdio.h> 31 #include <stdlib.h> 32 #include <string.h> 33 #include <termios.h> 34 #include <time.h> 35 #include <unistd.h> 36 37 #include "tmux.h" 38 39 /* 40 * Main server functions. 41 */ 42 43 struct clients clients; 44 45 struct tmuxproc *server_proc; 46 static int server_fd; 47 static int server_exit; 48 static struct event server_ev_accept; 49 50 struct cmd_find_state marked_pane; 51 52 static int server_loop(void); 53 static void server_send_exit(void); 54 static void server_accept(int, short, void *); 55 static void server_signal(int); 56 static void server_child_signal(void); 57 static void server_child_exited(pid_t, int); 58 static void server_child_stopped(pid_t, int); 59 60 /* Set marked pane. */ 61 void 62 server_set_marked(struct session *s, struct winlink *wl, struct window_pane *wp) 63 { 64 cmd_find_clear_state(&marked_pane, 0); 65 marked_pane.s = s; 66 marked_pane.wl = wl; 67 marked_pane.w = wl->window; 68 marked_pane.wp = wp; 69 } 70 71 /* Clear marked pane. */ 72 void 73 server_clear_marked(void) 74 { 75 cmd_find_clear_state(&marked_pane, 0); 76 } 77 78 /* Is this the marked pane? */ 79 int 80 server_is_marked(struct session *s, struct winlink *wl, struct window_pane *wp) 81 { 82 if (s == NULL || wl == NULL || wp == NULL) 83 return (0); 84 if (marked_pane.s != s || marked_pane.wl != wl) 85 return (0); 86 if (marked_pane.wp != wp) 87 return (0); 88 return (server_check_marked()); 89 } 90 91 /* Check if the marked pane is still valid. */ 92 int 93 server_check_marked(void) 94 { 95 return (cmd_find_valid_state(&marked_pane)); 96 } 97 98 /* Create server socket. */ 99 static int 100 server_create_socket(char **cause) 101 { 102 struct sockaddr_un sa; 103 size_t size; 104 mode_t mask; 105 int fd, saved_errno; 106 107 memset(&sa, 0, sizeof sa); 108 sa.sun_family = AF_UNIX; 109 size = strlcpy(sa.sun_path, socket_path, sizeof sa.sun_path); 110 if (size >= sizeof sa.sun_path) { 111 errno = ENAMETOOLONG; 112 goto fail; 113 } 114 unlink(sa.sun_path); 115 116 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) 117 goto fail; 118 119 mask = umask(S_IXUSR|S_IXGRP|S_IRWXO); 120 if (bind(fd, (struct sockaddr *)&sa, sizeof sa) == -1) { 121 saved_errno = errno; 122 close(fd); 123 errno = saved_errno; 124 goto fail; 125 } 126 umask(mask); 127 128 if (listen(fd, 128) == -1) { 129 saved_errno = errno; 130 close(fd); 131 errno = saved_errno; 132 goto fail; 133 } 134 setblocking(fd, 0); 135 136 return (fd); 137 138 fail: 139 if (cause != NULL) { 140 xasprintf(cause, "error creating %s (%s)", socket_path, 141 strerror(errno)); 142 } 143 return (-1); 144 } 145 146 /* Server error callback. */ 147 static enum cmd_retval 148 server_start_error(struct cmdq_item *item, void *data) 149 { 150 char *error = data; 151 152 cmdq_error(item, "%s", error); 153 free(error); 154 155 return (CMD_RETURN_NORMAL); 156 } 157 158 /* Fork new server. */ 159 int 160 server_start(struct tmuxproc *client, struct event_base *base, int lockfd, 161 char *lockfile) 162 { 163 int pair[2]; 164 struct job *job; 165 sigset_t set, oldset; 166 struct client *c; 167 char *cause = NULL; 168 169 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0) 170 fatal("socketpair failed"); 171 172 sigfillset(&set); 173 sigprocmask(SIG_BLOCK, &set, &oldset); 174 switch (fork()) { 175 case -1: 176 fatal("fork failed"); 177 case 0: 178 break; 179 default: 180 sigprocmask(SIG_SETMASK, &oldset, NULL); 181 close(pair[1]); 182 return (pair[0]); 183 } 184 close(pair[0]); 185 if (daemon(1, 0) != 0) 186 fatal("daemon failed"); 187 proc_clear_signals(client, 0); 188 if (event_reinit(base) != 0) 189 fatalx("event_reinit failed"); 190 server_proc = proc_start("server"); 191 proc_set_signals(server_proc, server_signal); 192 sigprocmask(SIG_SETMASK, &oldset, NULL); 193 194 if (log_get_level() > 1) 195 tty_create_log(); 196 if (pledge("stdio rpath wpath cpath fattr unix getpw recvfd proc exec " 197 "tty ps", NULL) != 0) 198 fatal("pledge failed"); 199 200 RB_INIT(&windows); 201 RB_INIT(&all_window_panes); 202 TAILQ_INIT(&clients); 203 RB_INIT(&sessions); 204 key_bindings_init(); 205 206 gettimeofday(&start_time, NULL); 207 208 server_fd = server_create_socket(&cause); 209 if (server_fd != -1) 210 server_update_socket(); 211 c = server_client_create(pair[1]); 212 213 if (lockfd >= 0) { 214 unlink(lockfile); 215 free(lockfile); 216 close(lockfd); 217 } 218 219 if (cause != NULL) { 220 cmdq_append(c, cmdq_get_callback(server_start_error, cause)); 221 c->flags |= CLIENT_EXIT; 222 } 223 224 start_cfg(); 225 226 server_add_accept(0); 227 228 proc_loop(server_proc, server_loop); 229 230 LIST_FOREACH(job, &all_jobs, entry) { 231 if (job->pid != -1) 232 kill(job->pid, SIGTERM); 233 } 234 235 status_prompt_save_history(); 236 exit(0); 237 } 238 239 /* Server loop callback. */ 240 static int 241 server_loop(void) 242 { 243 struct client *c; 244 u_int items; 245 struct job *job; 246 247 do { 248 items = cmdq_next(NULL); 249 TAILQ_FOREACH(c, &clients, entry) { 250 if (c->flags & CLIENT_IDENTIFIED) 251 items += cmdq_next(c); 252 } 253 } while (items != 0); 254 255 server_client_loop(); 256 257 if (!options_get_number(global_options, "exit-empty") && !server_exit) 258 return (0); 259 260 if (!options_get_number(global_options, "exit-unattached")) { 261 if (!RB_EMPTY(&sessions)) 262 return (0); 263 } 264 265 TAILQ_FOREACH(c, &clients, entry) { 266 if (c->session != NULL) 267 return (0); 268 } 269 270 /* 271 * No attached clients therefore want to exit - flush any waiting 272 * clients but don't actually exit until they've gone. 273 */ 274 cmd_wait_for_flush(); 275 if (!TAILQ_EMPTY(&clients)) 276 return (0); 277 278 LIST_FOREACH(job, &all_jobs, entry) { 279 if ((~job->flags & JOB_NOWAIT) && job->state == JOB_RUNNING) 280 return (0); 281 } 282 283 return (1); 284 } 285 286 /* Exit the server by killing all clients and windows. */ 287 static void 288 server_send_exit(void) 289 { 290 struct client *c, *c1; 291 struct session *s, *s1; 292 293 cmd_wait_for_flush(); 294 295 TAILQ_FOREACH_SAFE(c, &clients, entry, c1) { 296 if (c->flags & CLIENT_SUSPENDED) 297 server_client_lost(c); 298 else { 299 if (c->flags & CLIENT_ATTACHED) 300 notify_client("client-detached", c); 301 proc_send(c->peer, MSG_SHUTDOWN, -1, NULL, 0); 302 } 303 c->session = NULL; 304 } 305 306 RB_FOREACH_SAFE(s, sessions, &sessions, s1) 307 session_destroy(s, __func__); 308 } 309 310 /* Update socket execute permissions based on whether sessions are attached. */ 311 void 312 server_update_socket(void) 313 { 314 struct session *s; 315 static int last = -1; 316 int n, mode; 317 struct stat sb; 318 319 n = 0; 320 RB_FOREACH(s, sessions, &sessions) { 321 if (!(s->flags & SESSION_UNATTACHED)) { 322 n++; 323 break; 324 } 325 } 326 327 if (n != last) { 328 last = n; 329 330 if (stat(socket_path, &sb) != 0) 331 return; 332 mode = sb.st_mode & ACCESSPERMS; 333 if (n != 0) { 334 if (mode & S_IRUSR) 335 mode |= S_IXUSR; 336 if (mode & S_IRGRP) 337 mode |= S_IXGRP; 338 if (mode & S_IROTH) 339 mode |= S_IXOTH; 340 } else 341 mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH); 342 chmod(socket_path, mode); 343 } 344 } 345 346 /* Callback for server socket. */ 347 static void 348 server_accept(int fd, short events, __unused void *data) 349 { 350 struct sockaddr_storage sa; 351 socklen_t slen = sizeof sa; 352 int newfd; 353 354 server_add_accept(0); 355 if (!(events & EV_READ)) 356 return; 357 358 newfd = accept(fd, (struct sockaddr *) &sa, &slen); 359 if (newfd == -1) { 360 if (errno == EAGAIN || errno == EINTR || errno == ECONNABORTED) 361 return; 362 if (errno == ENFILE || errno == EMFILE) { 363 /* Delete and don't try again for 1 second. */ 364 server_add_accept(1); 365 return; 366 } 367 fatal("accept failed"); 368 } 369 if (server_exit) { 370 close(newfd); 371 return; 372 } 373 server_client_create(newfd); 374 } 375 376 /* 377 * Add accept event. If timeout is nonzero, add as a timeout instead of a read 378 * event - used to backoff when running out of file descriptors. 379 */ 380 void 381 server_add_accept(int timeout) 382 { 383 struct timeval tv = { timeout, 0 }; 384 385 if (event_initialized(&server_ev_accept)) 386 event_del(&server_ev_accept); 387 388 if (timeout == 0) { 389 event_set(&server_ev_accept, server_fd, EV_READ, server_accept, 390 NULL); 391 event_add(&server_ev_accept, NULL); 392 } else { 393 event_set(&server_ev_accept, server_fd, EV_TIMEOUT, 394 server_accept, NULL); 395 event_add(&server_ev_accept, &tv); 396 } 397 } 398 399 /* Signal handler. */ 400 static void 401 server_signal(int sig) 402 { 403 int fd; 404 405 log_debug("%s: %s", __func__, strsignal(sig)); 406 switch (sig) { 407 case SIGTERM: 408 server_exit = 1; 409 server_send_exit(); 410 break; 411 case SIGCHLD: 412 server_child_signal(); 413 break; 414 case SIGUSR1: 415 event_del(&server_ev_accept); 416 fd = server_create_socket(NULL); 417 if (fd != -1) { 418 close(server_fd); 419 server_fd = fd; 420 server_update_socket(); 421 } 422 server_add_accept(0); 423 break; 424 case SIGUSR2: 425 proc_toggle_log(server_proc); 426 break; 427 } 428 } 429 430 /* Handle SIGCHLD. */ 431 static void 432 server_child_signal(void) 433 { 434 int status; 435 pid_t pid; 436 437 for (;;) { 438 switch (pid = waitpid(WAIT_ANY, &status, WNOHANG|WUNTRACED)) { 439 case -1: 440 if (errno == ECHILD) 441 return; 442 fatal("waitpid failed"); 443 case 0: 444 return; 445 } 446 if (WIFSTOPPED(status)) 447 server_child_stopped(pid, status); 448 else if (WIFEXITED(status) || WIFSIGNALED(status)) 449 server_child_exited(pid, status); 450 } 451 } 452 453 /* Handle exited children. */ 454 static void 455 server_child_exited(pid_t pid, int status) 456 { 457 struct window *w, *w1; 458 struct window_pane *wp; 459 struct job *job; 460 461 RB_FOREACH_SAFE(w, windows, &windows, w1) { 462 TAILQ_FOREACH(wp, &w->panes, entry) { 463 if (wp->pid == pid) { 464 wp->status = status; 465 wp->flags |= PANE_STATUSREADY; 466 467 log_debug("%%%u exited", wp->id); 468 wp->flags |= PANE_EXITED; 469 470 if (window_pane_destroy_ready(wp)) 471 server_destroy_pane(wp, 1); 472 break; 473 } 474 } 475 } 476 477 LIST_FOREACH(job, &all_jobs, entry) { 478 if (pid == job->pid) { 479 job_died(job, status); /* might free job */ 480 break; 481 } 482 } 483 } 484 485 /* Handle stopped children. */ 486 static void 487 server_child_stopped(pid_t pid, int status) 488 { 489 struct window *w; 490 struct window_pane *wp; 491 492 if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU) 493 return; 494 495 RB_FOREACH(w, windows, &windows) { 496 TAILQ_FOREACH(wp, &w->panes, entry) { 497 if (wp->pid == pid) { 498 if (killpg(pid, SIGCONT) != 0) 499 kill(pid, SIGCONT); 500 } 501 } 502 } 503 } 504