1 /* $OpenBSD$ */ 2 3 /* 4 * Copyright (c) 2019 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 21 #include <errno.h> 22 #include <signal.h> 23 #include <stdlib.h> 24 #include <string.h> 25 #include <unistd.h> 26 27 #include "tmux.h" 28 29 /* 30 * Set up the environment and create a new window and pane or a new pane. 31 * 32 * We need to set up the following items: 33 * 34 * - history limit, comes from the session; 35 * 36 * - base index, comes from the session; 37 * 38 * - current working directory, may be specified - if it isn't it comes from 39 * either the client or the session; 40 * 41 * - PATH variable, comes from the client if any, otherwise from the session 42 * environment; 43 * 44 * - shell, comes from default-shell; 45 * 46 * - termios, comes from the session; 47 * 48 * - remaining environment, comes from the session. 49 */ 50 51 static void 52 spawn_log(const char *from, struct spawn_context *sc) 53 { 54 struct session *s = sc->s; 55 struct winlink *wl = sc->wl; 56 struct window_pane *wp0 = sc->wp0; 57 const char *name = cmdq_get_name(sc->item); 58 char tmp[128]; 59 60 log_debug("%s: %s, flags=%#x", from, name, sc->flags); 61 62 if (wl != NULL && wp0 != NULL) 63 xsnprintf(tmp, sizeof tmp, "wl=%d wp0=%%%u", wl->idx, wp0->id); 64 else if (wl != NULL) 65 xsnprintf(tmp, sizeof tmp, "wl=%d wp0=none", wl->idx); 66 else if (wp0 != NULL) 67 xsnprintf(tmp, sizeof tmp, "wl=none wp0=%%%u", wp0->id); 68 else 69 xsnprintf(tmp, sizeof tmp, "wl=none wp0=none"); 70 log_debug("%s: s=$%u %s idx=%d", from, s->id, tmp, sc->idx); 71 log_debug("%s: name=%s", from, sc->name == NULL ? "none" : sc->name); 72 } 73 74 struct winlink * 75 spawn_window(struct spawn_context *sc, char **cause) 76 { 77 struct cmdq_item *item = sc->item; 78 struct client *c = cmdq_get_client(item); 79 struct session *s = sc->s; 80 struct window *w; 81 struct window_pane *wp; 82 struct winlink *wl; 83 int idx = sc->idx; 84 u_int sx, sy, xpixel, ypixel; 85 86 spawn_log(__func__, sc); 87 88 /* 89 * If the window already exists, we are respawning, so destroy all the 90 * panes except one. 91 */ 92 if (sc->flags & SPAWN_RESPAWN) { 93 w = sc->wl->window; 94 if (~sc->flags & SPAWN_KILL) { 95 TAILQ_FOREACH(wp, &w->panes, entry) { 96 if (wp->fd != -1) 97 break; 98 } 99 if (wp != NULL) { 100 xasprintf(cause, "window %s:%d still active", 101 s->name, sc->wl->idx); 102 return (NULL); 103 } 104 } 105 106 sc->wp0 = TAILQ_FIRST(&w->panes); 107 TAILQ_REMOVE(&w->panes, sc->wp0, entry); 108 109 layout_free(w); 110 window_destroy_panes(w); 111 112 TAILQ_INSERT_HEAD(&w->panes, sc->wp0, entry); 113 window_pane_resize(sc->wp0, w->sx, w->sy); 114 115 layout_init(w, sc->wp0); 116 window_set_active_pane(w, sc->wp0, 0); 117 } 118 119 /* 120 * Otherwise we have no window so we will need to create one. First 121 * check if the given index already exists and destroy it if so. 122 */ 123 if ((~sc->flags & SPAWN_RESPAWN) && idx != -1) { 124 wl = winlink_find_by_index(&s->windows, idx); 125 if (wl != NULL && (~sc->flags & SPAWN_KILL)) { 126 xasprintf(cause, "index %d in use", idx); 127 return (NULL); 128 } 129 if (wl != NULL) { 130 /* 131 * Can't use session_detach as it will destroy session 132 * if this makes it empty. 133 */ 134 wl->flags &= ~WINLINK_ALERTFLAGS; 135 notify_session_window("window-unlinked", s, wl->window); 136 winlink_stack_remove(&s->lastw, wl); 137 winlink_remove(&s->windows, wl); 138 139 if (s->curw == wl) { 140 s->curw = NULL; 141 sc->flags &= ~SPAWN_DETACHED; 142 } 143 } 144 } 145 146 /* Then create a window if needed. */ 147 if (~sc->flags & SPAWN_RESPAWN) { 148 if (idx == -1) 149 idx = -1 - options_get_number(s->options, "base-index"); 150 if ((sc->wl = winlink_add(&s->windows, idx)) == NULL) { 151 xasprintf(cause, "couldn't add window %d", idx); 152 return (NULL); 153 } 154 default_window_size(sc->tc, s, NULL, &sx, &sy, &xpixel, &ypixel, 155 -1); 156 if ((w = window_create(sx, sy, xpixel, ypixel)) == NULL) { 157 winlink_remove(&s->windows, sc->wl); 158 xasprintf(cause, "couldn't create window %d", idx); 159 return (NULL); 160 } 161 if (s->curw == NULL) 162 s->curw = sc->wl; 163 sc->wl->session = s; 164 w->latest = sc->tc; 165 winlink_set_window(sc->wl, w); 166 } else 167 w = NULL; 168 sc->flags |= SPAWN_NONOTIFY; 169 170 /* Spawn the pane. */ 171 wp = spawn_pane(sc, cause); 172 if (wp == NULL) { 173 if (~sc->flags & SPAWN_RESPAWN) 174 winlink_remove(&s->windows, sc->wl); 175 return (NULL); 176 } 177 178 /* Set the name of the new window. */ 179 if (~sc->flags & SPAWN_RESPAWN) { 180 if (sc->name != NULL) { 181 w->name = format_single(item, sc->name, c, s, NULL, 182 NULL); 183 options_set_number(w->options, "automatic-rename", 0); 184 } else 185 w->name = default_window_name(w); 186 } 187 188 /* Switch to the new window if required. */ 189 if (~sc->flags & SPAWN_DETACHED) 190 session_select(s, sc->wl->idx); 191 192 /* Fire notification if new window. */ 193 if (~sc->flags & SPAWN_RESPAWN) 194 notify_session_window("window-linked", s, w); 195 196 session_group_synchronize_from(s); 197 return (sc->wl); 198 } 199 200 struct window_pane * 201 spawn_pane(struct spawn_context *sc, char **cause) 202 { 203 struct cmdq_item *item = sc->item; 204 struct cmd_find_state *target = cmdq_get_target(item); 205 struct client *c = cmdq_get_client(item); 206 struct session *s = sc->s; 207 struct window *w = sc->wl->window; 208 struct window_pane *new_wp; 209 struct environ *child; 210 struct environ_entry *ee; 211 char **argv, *cp, **argvp, *argv0, *cwd; 212 const char *cmd, *tmp; 213 int argc; 214 u_int idx; 215 struct termios now; 216 u_int hlimit; 217 struct winsize ws; 218 sigset_t set, oldset; 219 key_code key; 220 221 spawn_log(__func__, sc); 222 223 /* 224 * Work out the current working directory. If respawning, use 225 * the pane's stored one unless specified. 226 */ 227 if (sc->cwd != NULL) 228 cwd = format_single(item, sc->cwd, c, target->s, NULL, NULL); 229 else if (~sc->flags & SPAWN_RESPAWN) 230 cwd = xstrdup(server_client_get_cwd(c, target->s)); 231 else 232 cwd = NULL; 233 234 /* 235 * If we are respawning then get rid of the old process. Otherwise 236 * either create a new cell or assign to the one we are given. 237 */ 238 hlimit = options_get_number(s->options, "history-limit"); 239 if (sc->flags & SPAWN_RESPAWN) { 240 if (sc->wp0->fd != -1 && (~sc->flags & SPAWN_KILL)) { 241 window_pane_index(sc->wp0, &idx); 242 xasprintf(cause, "pane %s:%d.%u still active", 243 s->name, sc->wl->idx, idx); 244 free(cwd); 245 return (NULL); 246 } 247 if (sc->wp0->fd != -1) { 248 bufferevent_free(sc->wp0->event); 249 close(sc->wp0->fd); 250 } 251 window_pane_reset_mode_all(sc->wp0); 252 screen_reinit(&sc->wp0->base); 253 input_free(sc->wp0->ictx); 254 sc->wp0->ictx = NULL; 255 new_wp = sc->wp0; 256 new_wp->flags &= ~(PANE_STATUSREADY|PANE_STATUSDRAWN); 257 } else if (sc->lc == NULL) { 258 new_wp = window_add_pane(w, NULL, hlimit, sc->flags); 259 layout_init(w, new_wp); 260 } else { 261 new_wp = window_add_pane(w, sc->wp0, hlimit, sc->flags); 262 if (sc->flags & SPAWN_ZOOM) 263 layout_assign_pane(sc->lc, new_wp, 1); 264 else 265 layout_assign_pane(sc->lc, new_wp, 0); 266 } 267 268 /* 269 * Now we have a pane with nothing running in it ready for the new 270 * process. Work out the command and arguments and store the working 271 * directory. 272 */ 273 if (sc->argc == 0 && (~sc->flags & SPAWN_RESPAWN)) { 274 cmd = options_get_string(s->options, "default-command"); 275 if (cmd != NULL && *cmd != '\0') { 276 argc = 1; 277 argv = __UNCONST(&cmd); 278 } else { 279 argc = 0; 280 argv = NULL; 281 } 282 } else { 283 argc = sc->argc; 284 argv = sc->argv; 285 } 286 if (cwd != NULL) { 287 free(new_wp->cwd); 288 new_wp->cwd = cwd; 289 } 290 291 /* 292 * Replace the stored arguments if there are new ones. If not, the 293 * existing ones will be used (they will only exist for respawn). 294 */ 295 if (argc > 0) { 296 cmd_free_argv(new_wp->argc, new_wp->argv); 297 new_wp->argc = argc; 298 new_wp->argv = cmd_copy_argv(argc, argv); 299 } 300 301 /* Create an environment for this pane. */ 302 child = environ_for_session(s, 0); 303 if (sc->environ != NULL) 304 environ_copy(sc->environ, child); 305 environ_set(child, "TMUX_PANE", 0, "%%%u", new_wp->id); 306 307 /* 308 * Then the PATH environment variable. The session one is replaced from 309 * the client if there is one because otherwise running "tmux new 310 * myprogram" wouldn't work if myprogram isn't in the session's path. 311 */ 312 if (c != NULL && c->session == NULL) { /* only unattached clients */ 313 ee = environ_find(c->environ, "PATH"); 314 if (ee != NULL) 315 environ_set(child, "PATH", 0, "%s", ee->value); 316 } 317 if (environ_find(child, "PATH") == NULL) 318 environ_set(child, "PATH", 0, "%s", _PATH_DEFPATH); 319 320 /* Then the shell. If respawning, use the old one. */ 321 if (~sc->flags & SPAWN_RESPAWN) { 322 tmp = options_get_string(s->options, "default-shell"); 323 if (!checkshell(tmp)) 324 tmp = _PATH_BSHELL; 325 free(new_wp->shell); 326 new_wp->shell = xstrdup(tmp); 327 } 328 environ_set(child, "SHELL", 0, "%s", new_wp->shell); 329 330 /* Log the arguments we are going to use. */ 331 log_debug("%s: shell=%s", __func__, new_wp->shell); 332 if (new_wp->argc != 0) { 333 cp = cmd_stringify_argv(new_wp->argc, new_wp->argv); 334 log_debug("%s: cmd=%s", __func__, cp); 335 free(cp); 336 } 337 if (cwd != NULL) 338 log_debug("%s: cwd=%s", __func__, cwd); 339 cmd_log_argv(new_wp->argc, new_wp->argv, "%s", __func__); 340 environ_log(child, "%s: environment ", __func__); 341 342 /* Initialize the window size. */ 343 memset(&ws, 0, sizeof ws); 344 ws.ws_col = screen_size_x(&new_wp->base); 345 ws.ws_row = screen_size_y(&new_wp->base); 346 ws.ws_xpixel = w->xpixel * ws.ws_col; 347 ws.ws_ypixel = w->ypixel * ws.ws_row; 348 349 /* Block signals until fork has completed. */ 350 sigfillset(&set); 351 sigprocmask(SIG_BLOCK, &set, &oldset); 352 353 /* If the command is empty, don't fork a child process. */ 354 if (sc->flags & SPAWN_EMPTY) { 355 new_wp->flags |= PANE_EMPTY; 356 new_wp->base.mode &= ~MODE_CURSOR; 357 new_wp->base.mode |= MODE_CRLF; 358 goto complete; 359 } 360 361 /* Fork the new process. */ 362 new_wp->pid = fdforkpty(ptm_fd, &new_wp->fd, new_wp->tty, NULL, &ws); 363 if (new_wp->pid == -1) { 364 xasprintf(cause, "fork failed: %s", strerror(errno)); 365 new_wp->fd = -1; 366 if (~sc->flags & SPAWN_RESPAWN) { 367 server_client_remove_pane(new_wp); 368 layout_close_pane(new_wp); 369 window_remove_pane(w, new_wp); 370 } 371 sigprocmask(SIG_SETMASK, &oldset, NULL); 372 environ_free(child); 373 return (NULL); 374 } 375 376 /* In the parent process, everything is done now. */ 377 if (new_wp->pid != 0) 378 goto complete; 379 380 /* 381 * Child process. Change to the working directory or home if that 382 * fails. 383 */ 384 if (chdir(new_wp->cwd) != 0 && 385 ((tmp = find_home()) == NULL || chdir(tmp) != 0) && 386 chdir("/") != 0) 387 fatal("chdir failed"); 388 389 /* 390 * Update terminal escape characters from the session if available and 391 * force VERASE to tmux's backspace. 392 */ 393 if (tcgetattr(STDIN_FILENO, &now) != 0) 394 _exit(1); 395 if (s->tio != NULL) 396 memcpy(now.c_cc, s->tio->c_cc, sizeof now.c_cc); 397 key = options_get_number(global_options, "backspace"); 398 if (key >= 0x7f) 399 now.c_cc[VERASE] = '\177'; 400 else 401 now.c_cc[VERASE] = key; 402 #ifdef IUTF8 403 now.c_iflag |= IUTF8; 404 #endif 405 if (tcsetattr(STDIN_FILENO, TCSANOW, &now) != 0) 406 _exit(1); 407 408 /* Clean up file descriptors and signals and update the environment. */ 409 closefrom(STDERR_FILENO + 1); 410 proc_clear_signals(server_proc, 1); 411 sigprocmask(SIG_SETMASK, &oldset, NULL); 412 log_close(); 413 environ_push(child); 414 415 /* 416 * If given multiple arguments, use execvp(). Copy the arguments to 417 * ensure they end in a NULL. 418 */ 419 if (new_wp->argc != 0 && new_wp->argc != 1) { 420 argvp = cmd_copy_argv(new_wp->argc, new_wp->argv); 421 execvp(argvp[0], argvp); 422 _exit(1); 423 } 424 425 /* 426 * If one argument, pass it to $SHELL -c. Otherwise create a login 427 * shell. 428 */ 429 cp = strrchr(new_wp->shell, '/'); 430 if (new_wp->argc == 1) { 431 tmp = new_wp->argv[0]; 432 if (cp != NULL && cp[1] != '\0') 433 xasprintf(&argv0, "%s", cp + 1); 434 else 435 xasprintf(&argv0, "%s", new_wp->shell); 436 execl(new_wp->shell, argv0, "-c", tmp, (char *)NULL); 437 _exit(1); 438 } 439 if (cp != NULL && cp[1] != '\0') 440 xasprintf(&argv0, "-%s", cp + 1); 441 else 442 xasprintf(&argv0, "-%s", new_wp->shell); 443 execl(new_wp->shell, argv0, (char *)NULL); 444 _exit(1); 445 446 complete: 447 #ifdef HAVE_UTEMPTER 448 if (~new_wp->flags & PANE_EMPTY) { 449 xasprintf(&cp, "tmux(%lu).%%%u", (long)getpid(), new_wp->id); 450 utempter_add_record(new_wp->fd, cp); 451 kill(getpid(), SIGCHLD); 452 free(cp); 453 } 454 #endif 455 456 new_wp->flags &= ~PANE_EXITED; 457 458 sigprocmask(SIG_SETMASK, &oldset, NULL); 459 window_pane_set_event(new_wp); 460 461 environ_free(child); 462 463 if (sc->flags & SPAWN_RESPAWN) 464 return (new_wp); 465 if ((~sc->flags & SPAWN_DETACHED) || w->active == NULL) { 466 if (sc->flags & SPAWN_NONOTIFY) 467 window_set_active_pane(w, new_wp, 0); 468 else 469 window_set_active_pane(w, new_wp, 1); 470 } 471 if (~sc->flags & SPAWN_NONOTIFY) 472 notify_window("window-layout-changed", w); 473 return (new_wp); 474 } 475