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 = -1; 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 /* Fork new server. */ 147 int 148 server_start(struct tmuxproc *client, struct event_base *base, int lockfd, 149 char *lockfile) 150 { 151 int pair[2]; 152 sigset_t set, oldset; 153 struct client *c; 154 char *cause = NULL; 155 156 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0) 157 fatal("socketpair failed"); 158 159 sigfillset(&set); 160 sigprocmask(SIG_BLOCK, &set, &oldset); 161 switch (fork()) { 162 case -1: 163 fatal("fork failed"); 164 case 0: 165 break; 166 default: 167 sigprocmask(SIG_SETMASK, &oldset, NULL); 168 close(pair[1]); 169 return (pair[0]); 170 } 171 close(pair[0]); 172 if (daemon(1, 0) != 0) 173 fatal("daemon failed"); 174 proc_clear_signals(client, 0); 175 if (event_reinit(base) != 0) 176 fatalx("event_reinit failed"); 177 server_proc = proc_start("server"); 178 proc_set_signals(server_proc, server_signal); 179 sigprocmask(SIG_SETMASK, &oldset, NULL); 180 181 if (log_get_level() > 1) 182 tty_create_log(); 183 if (pledge("stdio rpath wpath cpath fattr unix getpw recvfd proc exec " 184 "tty ps", NULL) != 0) 185 fatal("pledge failed"); 186 187 RB_INIT(&windows); 188 RB_INIT(&all_window_panes); 189 TAILQ_INIT(&clients); 190 RB_INIT(&sessions); 191 key_bindings_init(); 192 193 gettimeofday(&start_time, NULL); 194 195 server_fd = server_create_socket(&cause); 196 if (server_fd != -1) 197 server_update_socket(); 198 c = server_client_create(pair[1]); 199 200 if (lockfd >= 0) { 201 unlink(lockfile); 202 free(lockfile); 203 close(lockfd); 204 } 205 206 if (cause != NULL) { 207 cmdq_append(c, cmdq_get_error(cause)); 208 free(cause); 209 c->flags |= CLIENT_EXIT; 210 } 211 212 server_add_accept(0); 213 proc_loop(server_proc, server_loop); 214 215 job_kill_all(); 216 status_prompt_save_history(); 217 218 exit(0); 219 } 220 221 /* Server loop callback. */ 222 static int 223 server_loop(void) 224 { 225 struct client *c; 226 u_int items; 227 228 do { 229 items = cmdq_next(NULL); 230 TAILQ_FOREACH(c, &clients, entry) { 231 if (c->flags & CLIENT_IDENTIFIED) 232 items += cmdq_next(c); 233 } 234 } while (items != 0); 235 236 server_client_loop(); 237 238 if (!options_get_number(global_options, "exit-empty") && !server_exit) 239 return (0); 240 241 if (!options_get_number(global_options, "exit-unattached")) { 242 if (!RB_EMPTY(&sessions)) 243 return (0); 244 } 245 246 TAILQ_FOREACH(c, &clients, entry) { 247 if (c->session != NULL) 248 return (0); 249 } 250 251 /* 252 * No attached clients therefore want to exit - flush any waiting 253 * clients but don't actually exit until they've gone. 254 */ 255 cmd_wait_for_flush(); 256 if (!TAILQ_EMPTY(&clients)) 257 return (0); 258 259 if (job_still_running()) 260 return (0); 261 262 return (1); 263 } 264 265 /* Exit the server by killing all clients and windows. */ 266 static void 267 server_send_exit(void) 268 { 269 struct client *c, *c1; 270 struct session *s, *s1; 271 272 cmd_wait_for_flush(); 273 274 TAILQ_FOREACH_SAFE(c, &clients, entry, c1) { 275 if (c->flags & CLIENT_SUSPENDED) 276 server_client_lost(c); 277 else { 278 if (c->flags & CLIENT_ATTACHED) 279 notify_client("client-detached", c); 280 proc_send(c->peer, MSG_SHUTDOWN, -1, NULL, 0); 281 } 282 c->session = NULL; 283 } 284 285 RB_FOREACH_SAFE(s, sessions, &sessions, s1) 286 session_destroy(s, 1, __func__); 287 } 288 289 /* Update socket execute permissions based on whether sessions are attached. */ 290 void 291 server_update_socket(void) 292 { 293 struct session *s; 294 static int last = -1; 295 int n, mode; 296 struct stat sb; 297 298 n = 0; 299 RB_FOREACH(s, sessions, &sessions) { 300 if (s->attached != 0) { 301 n++; 302 break; 303 } 304 } 305 306 if (n != last) { 307 last = n; 308 309 if (stat(socket_path, &sb) != 0) 310 return; 311 mode = sb.st_mode & ACCESSPERMS; 312 if (n != 0) { 313 if (mode & S_IRUSR) 314 mode |= S_IXUSR; 315 if (mode & S_IRGRP) 316 mode |= S_IXGRP; 317 if (mode & S_IROTH) 318 mode |= S_IXOTH; 319 } else 320 mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH); 321 chmod(socket_path, mode); 322 } 323 } 324 325 /* Callback for server socket. */ 326 static void 327 server_accept(int fd, short events, __unused void *data) 328 { 329 struct sockaddr_storage sa; 330 socklen_t slen = sizeof sa; 331 int newfd; 332 333 server_add_accept(0); 334 if (!(events & EV_READ)) 335 return; 336 337 newfd = accept(fd, (struct sockaddr *) &sa, &slen); 338 if (newfd == -1) { 339 if (errno == EAGAIN || errno == EINTR || errno == ECONNABORTED) 340 return; 341 if (errno == ENFILE || errno == EMFILE) { 342 /* Delete and don't try again for 1 second. */ 343 server_add_accept(1); 344 return; 345 } 346 fatal("accept failed"); 347 } 348 if (server_exit) { 349 close(newfd); 350 return; 351 } 352 server_client_create(newfd); 353 } 354 355 /* 356 * Add accept event. If timeout is nonzero, add as a timeout instead of a read 357 * event - used to backoff when running out of file descriptors. 358 */ 359 void 360 server_add_accept(int timeout) 361 { 362 struct timeval tv = { timeout, 0 }; 363 364 if (server_fd == -1) 365 return; 366 367 if (event_initialized(&server_ev_accept)) 368 event_del(&server_ev_accept); 369 370 if (timeout == 0) { 371 event_set(&server_ev_accept, server_fd, EV_READ, server_accept, 372 NULL); 373 event_add(&server_ev_accept, NULL); 374 } else { 375 event_set(&server_ev_accept, server_fd, EV_TIMEOUT, 376 server_accept, NULL); 377 event_add(&server_ev_accept, &tv); 378 } 379 } 380 381 /* Signal handler. */ 382 static void 383 server_signal(int sig) 384 { 385 int fd; 386 387 log_debug("%s: %s", __func__, strsignal(sig)); 388 switch (sig) { 389 case SIGTERM: 390 server_exit = 1; 391 server_send_exit(); 392 break; 393 case SIGCHLD: 394 server_child_signal(); 395 break; 396 case SIGUSR1: 397 event_del(&server_ev_accept); 398 fd = server_create_socket(NULL); 399 if (fd != -1) { 400 close(server_fd); 401 server_fd = fd; 402 server_update_socket(); 403 } 404 server_add_accept(0); 405 break; 406 case SIGUSR2: 407 proc_toggle_log(server_proc); 408 break; 409 } 410 } 411 412 /* Handle SIGCHLD. */ 413 static void 414 server_child_signal(void) 415 { 416 int status; 417 pid_t pid; 418 419 for (;;) { 420 switch (pid = waitpid(WAIT_ANY, &status, WNOHANG|WUNTRACED)) { 421 case -1: 422 if (errno == ECHILD) 423 return; 424 fatal("waitpid failed"); 425 case 0: 426 return; 427 } 428 if (WIFSTOPPED(status)) 429 server_child_stopped(pid, status); 430 else if (WIFEXITED(status) || WIFSIGNALED(status)) 431 server_child_exited(pid, status); 432 } 433 } 434 435 /* Handle exited children. */ 436 static void 437 server_child_exited(pid_t pid, int status) 438 { 439 struct window *w, *w1; 440 struct window_pane *wp; 441 442 RB_FOREACH_SAFE(w, windows, &windows, w1) { 443 TAILQ_FOREACH(wp, &w->panes, entry) { 444 if (wp->pid == pid) { 445 wp->status = status; 446 wp->flags |= PANE_STATUSREADY; 447 448 log_debug("%%%u exited", wp->id); 449 wp->flags |= PANE_EXITED; 450 451 if (window_pane_destroy_ready(wp)) 452 server_destroy_pane(wp, 1); 453 break; 454 } 455 } 456 } 457 job_check_died(pid, status); 458 } 459 460 /* Handle stopped children. */ 461 static void 462 server_child_stopped(pid_t pid, int status) 463 { 464 struct window *w; 465 struct window_pane *wp; 466 467 if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU) 468 return; 469 470 RB_FOREACH(w, windows, &windows) { 471 TAILQ_FOREACH(wp, &w->panes, entry) { 472 if (wp->pid == pid) { 473 if (killpg(pid, SIGCONT) != 0) 474 kill(pid, SIGCONT); 475 } 476 } 477 } 478 } 479