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