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 int server_fd; 47 int server_exit; 48 struct event server_ev_accept; 49 50 struct cmd_find_state marked_pane; 51 52 int server_create_socket(void); 53 int server_loop(void); 54 int server_should_exit(void); 55 void server_send_exit(void); 56 void server_accept(int, short, void *); 57 void server_signal(int); 58 void server_child_signal(void); 59 void server_child_exited(pid_t, int); 60 void server_child_stopped(pid_t, int); 61 62 /* Set marked pane. */ 63 void 64 server_set_marked(struct session *s, struct winlink *wl, struct window_pane *wp) 65 { 66 cmd_find_clear_state(&marked_pane, NULL, 0); 67 marked_pane.s = s; 68 marked_pane.wl = wl; 69 marked_pane.w = wl->window; 70 marked_pane.wp = wp; 71 } 72 73 /* Clear marked pane. */ 74 void 75 server_clear_marked(void) 76 { 77 cmd_find_clear_state(&marked_pane, NULL, 0); 78 } 79 80 /* Is this the marked pane? */ 81 int 82 server_is_marked(struct session *s, struct winlink *wl, struct window_pane *wp) 83 { 84 if (s == NULL || wl == NULL || wp == NULL) 85 return (0); 86 if (marked_pane.s != s || marked_pane.wl != wl) 87 return (0); 88 if (marked_pane.wp != wp) 89 return (0); 90 return (server_check_marked()); 91 } 92 93 /* Check if the marked pane is still valid. */ 94 int 95 server_check_marked(void) 96 { 97 return (cmd_find_valid_state(&marked_pane)); 98 } 99 100 /* Create server socket. */ 101 int 102 server_create_socket(void) 103 { 104 struct sockaddr_un sa; 105 size_t size; 106 mode_t mask; 107 int fd; 108 109 memset(&sa, 0, sizeof sa); 110 sa.sun_family = AF_UNIX; 111 size = strlcpy(sa.sun_path, socket_path, sizeof sa.sun_path); 112 if (size >= sizeof sa.sun_path) { 113 errno = ENAMETOOLONG; 114 return (-1); 115 } 116 unlink(sa.sun_path); 117 118 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) 119 return (-1); 120 121 mask = umask(S_IXUSR|S_IXGRP|S_IRWXO); 122 if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) == -1) 123 return (-1); 124 umask(mask); 125 126 if (listen(fd, 128) == -1) 127 return (-1); 128 setblocking(fd, 0); 129 130 return (fd); 131 } 132 133 /* Fork new server. */ 134 int 135 server_start(struct event_base *base, int lockfd, char *lockfile) 136 { 137 int pair[2]; 138 139 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0) 140 fatal("socketpair failed"); 141 142 server_proc = proc_start("server", base, 1, server_signal); 143 if (server_proc == NULL) { 144 close(pair[1]); 145 return (pair[0]); 146 } 147 close(pair[0]); 148 149 if (log_get_level() > 3) 150 tty_create_log(); 151 152 #ifdef __OpenBSD__ 153 if (pledge("stdio rpath wpath cpath fattr unix getpw recvfd proc exec " 154 "tty ps", NULL) != 0) 155 fatal("pledge failed"); 156 #endif 157 158 RB_INIT(&windows); 159 RB_INIT(&all_window_panes); 160 TAILQ_INIT(&clients); 161 RB_INIT(&sessions); 162 TAILQ_INIT(&session_groups); 163 mode_key_init_trees(); 164 key_bindings_init(); 165 166 gettimeofday(&start_time, NULL); 167 168 server_fd = server_create_socket(); 169 if (server_fd == -1) 170 fatal("couldn't create socket"); 171 server_update_socket(); 172 server_client_create(pair[1]); 173 174 if (lockfd >= 0) { 175 unlink(lockfile); 176 free(lockfile); 177 close(lockfd); 178 } 179 180 start_cfg(); 181 182 status_prompt_load_history(); 183 184 server_add_accept(0); 185 186 proc_loop(server_proc, server_loop); 187 status_prompt_save_history(); 188 exit(0); 189 } 190 191 /* Server loop callback. */ 192 int 193 server_loop(void) 194 { 195 struct client *c; 196 197 server_client_loop(); 198 199 if (!options_get_number(global_options, "exit-unattached")) { 200 if (!RB_EMPTY(&sessions)) 201 return (0); 202 } 203 204 TAILQ_FOREACH(c, &clients, entry) { 205 if (c->session != NULL) 206 return (0); 207 } 208 209 /* 210 * No attached clients therefore want to exit - flush any waiting 211 * clients but don't actually exit until they've gone. 212 */ 213 cmd_wait_for_flush(); 214 if (!TAILQ_EMPTY(&clients)) 215 return (0); 216 217 return (1); 218 } 219 220 /* Exit the server by killing all clients and windows. */ 221 void 222 server_send_exit(void) 223 { 224 struct client *c, *c1; 225 struct session *s, *s1; 226 227 cmd_wait_for_flush(); 228 229 TAILQ_FOREACH_SAFE(c, &clients, entry, c1) { 230 if (c->flags & CLIENT_SUSPENDED) 231 server_client_lost(c); 232 else 233 proc_send(c->peer, MSG_SHUTDOWN, -1, NULL, 0); 234 c->session = NULL; 235 } 236 237 RB_FOREACH_SAFE(s, sessions, &sessions, s1) 238 session_destroy(s); 239 } 240 241 /* Update socket execute permissions based on whether sessions are attached. */ 242 void 243 server_update_socket(void) 244 { 245 struct session *s; 246 static int last = -1; 247 int n, mode; 248 struct stat sb; 249 250 n = 0; 251 RB_FOREACH(s, sessions, &sessions) { 252 if (!(s->flags & SESSION_UNATTACHED)) { 253 n++; 254 break; 255 } 256 } 257 258 if (n != last) { 259 last = n; 260 261 if (stat(socket_path, &sb) != 0) 262 return; 263 mode = sb.st_mode; 264 if (n != 0) { 265 if (mode & S_IRUSR) 266 mode |= S_IXUSR; 267 if (mode & S_IRGRP) 268 mode |= S_IXGRP; 269 if (mode & S_IROTH) 270 mode |= S_IXOTH; 271 } else 272 mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH); 273 chmod(socket_path, mode); 274 } 275 } 276 277 /* Callback for server socket. */ 278 void 279 server_accept(int fd, short events, __unused void *data) 280 { 281 struct sockaddr_storage sa; 282 socklen_t slen = sizeof sa; 283 int newfd; 284 285 server_add_accept(0); 286 if (!(events & EV_READ)) 287 return; 288 289 newfd = accept(fd, (struct sockaddr *) &sa, &slen); 290 if (newfd == -1) { 291 if (errno == EAGAIN || errno == EINTR || errno == ECONNABORTED) 292 return; 293 if (errno == ENFILE || errno == EMFILE) { 294 /* Delete and don't try again for 1 second. */ 295 server_add_accept(1); 296 return; 297 } 298 fatal("accept failed"); 299 } 300 if (server_exit) { 301 close(newfd); 302 return; 303 } 304 server_client_create(newfd); 305 } 306 307 /* 308 * Add accept event. If timeout is nonzero, add as a timeout instead of a read 309 * event - used to backoff when running out of file descriptors. 310 */ 311 void 312 server_add_accept(int timeout) 313 { 314 struct timeval tv = { timeout, 0 }; 315 316 if (event_initialized(&server_ev_accept)) 317 event_del(&server_ev_accept); 318 319 if (timeout == 0) { 320 event_set(&server_ev_accept, server_fd, EV_READ, server_accept, 321 NULL); 322 event_add(&server_ev_accept, NULL); 323 } else { 324 event_set(&server_ev_accept, server_fd, EV_TIMEOUT, 325 server_accept, NULL); 326 event_add(&server_ev_accept, &tv); 327 } 328 } 329 330 /* Signal handler. */ 331 void 332 server_signal(int sig) 333 { 334 int fd; 335 336 switch (sig) { 337 case SIGTERM: 338 server_exit = 1; 339 server_send_exit(); 340 break; 341 case SIGCHLD: 342 server_child_signal(); 343 break; 344 case SIGUSR1: 345 event_del(&server_ev_accept); 346 fd = server_create_socket(); 347 if (fd != -1) { 348 close(server_fd); 349 server_fd = fd; 350 server_update_socket(); 351 } 352 server_add_accept(0); 353 break; 354 } 355 } 356 357 /* Handle SIGCHLD. */ 358 void 359 server_child_signal(void) 360 { 361 int status; 362 pid_t pid; 363 364 for (;;) { 365 switch (pid = waitpid(WAIT_ANY, &status, WNOHANG|WUNTRACED)) { 366 case -1: 367 if (errno == ECHILD) 368 return; 369 fatal("waitpid failed"); 370 case 0: 371 return; 372 } 373 if (WIFSTOPPED(status)) 374 server_child_stopped(pid, status); 375 else if (WIFEXITED(status) || WIFSIGNALED(status)) 376 server_child_exited(pid, status); 377 } 378 } 379 380 /* Handle exited children. */ 381 void 382 server_child_exited(pid_t pid, int status) 383 { 384 struct window *w, *w1; 385 struct window_pane *wp; 386 struct job *job; 387 388 RB_FOREACH_SAFE(w, windows, &windows, w1) { 389 TAILQ_FOREACH(wp, &w->panes, entry) { 390 if (wp->pid == pid) { 391 wp->status = status; 392 server_destroy_pane(wp, 1); 393 break; 394 } 395 } 396 } 397 398 LIST_FOREACH(job, &all_jobs, lentry) { 399 if (pid == job->pid) { 400 job_died(job, status); /* might free job */ 401 break; 402 } 403 } 404 } 405 406 /* Handle stopped children. */ 407 void 408 server_child_stopped(pid_t pid, int status) 409 { 410 struct window *w; 411 struct window_pane *wp; 412 413 if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU) 414 return; 415 416 RB_FOREACH(w, windows, &windows) { 417 TAILQ_FOREACH(wp, &w->panes, entry) { 418 if (wp->pid == pid) { 419 if (killpg(pid, SIGCONT) != 0) 420 kill(pid, SIGCONT); 421 } 422 } 423 } 424 } 425