xref: /openbsd-src/usr.bin/tmux/session.c (revision 0b7734b3d77bb9b21afec6f4621cae6c805dbd45)
1 /* $OpenBSD: session.c,v 1.62 2016/01/19 15:59:12 nicm Exp $ */
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/time.h>
21 
22 #include <paths.h>
23 #include <string.h>
24 #include <stdlib.h>
25 #include <unistd.h>
26 #include <time.h>
27 
28 #include "tmux.h"
29 
30 struct sessions	sessions;
31 u_int		next_session_id;
32 struct session_groups session_groups;
33 
34 void	session_free(int, short, void *);
35 
36 void	session_lock_timer(int, short, void *);
37 
38 struct winlink *session_next_alert(struct winlink *);
39 struct winlink *session_previous_alert(struct winlink *);
40 
41 RB_GENERATE(sessions, session, entry, session_cmp);
42 
43 int
44 session_cmp(struct session *s1, struct session *s2)
45 {
46 	return (strcmp(s1->name, s2->name));
47 }
48 
49 /*
50  * Find if session is still alive. This is true if it is still on the global
51  * sessions list.
52  */
53 int
54 session_alive(struct session *s)
55 {
56 	struct session *s_loop;
57 
58 	RB_FOREACH(s_loop, sessions, &sessions) {
59 		if (s_loop == s)
60 			return (1);
61 	}
62 	return (0);
63 }
64 
65 /* Find session by name. */
66 struct session *
67 session_find(const char *name)
68 {
69 	struct session	s;
70 
71 	s.name = (char *) name;
72 	return (RB_FIND(sessions, &sessions, &s));
73 }
74 
75 /* Find session by id parsed from a string. */
76 struct session *
77 session_find_by_id_str(const char *s)
78 {
79 	const char	*errstr;
80 	u_int		 id;
81 
82 	if (*s != '$')
83 		return (NULL);
84 
85 	id = strtonum(s + 1, 0, UINT_MAX, &errstr);
86 	if (errstr != NULL)
87 		return (NULL);
88 	return (session_find_by_id(id));
89 }
90 
91 /* Find session by id. */
92 struct session *
93 session_find_by_id(u_int id)
94 {
95 	struct session	*s;
96 
97 	RB_FOREACH(s, sessions, &sessions) {
98 		if (s->id == id)
99 			return (s);
100 	}
101 	return (NULL);
102 }
103 
104 /* Create a new session. */
105 struct session *
106 session_create(const char *name, int argc, char **argv, const char *path,
107     const char *cwd, struct environ *env, struct termios *tio, int idx,
108     u_int sx, u_int sy, char **cause)
109 {
110 	struct session	*s;
111 	struct winlink	*wl;
112 
113 	s = xcalloc(1, sizeof *s);
114 	s->references = 1;
115 	s->flags = 0;
116 
117 	s->cwd = xstrdup(cwd);
118 
119 	s->curw = NULL;
120 	TAILQ_INIT(&s->lastw);
121 	RB_INIT(&s->windows);
122 
123 	s->environ = environ_create();
124 	if (env != NULL)
125 		environ_copy(env, s->environ);
126 
127 	s->options = options_create(global_s_options);
128 	s->hooks = hooks_create(global_hooks);
129 
130 	s->tio = NULL;
131 	if (tio != NULL) {
132 		s->tio = xmalloc(sizeof *s->tio);
133 		memcpy(s->tio, tio, sizeof *s->tio);
134 	}
135 
136 	s->sx = sx;
137 	s->sy = sy;
138 
139 	if (name != NULL) {
140 		s->name = xstrdup(name);
141 		s->id = next_session_id++;
142 	} else {
143 		s->name = NULL;
144 		do {
145 			s->id = next_session_id++;
146 			free(s->name);
147 			xasprintf(&s->name, "%u", s->id);
148 		} while (RB_FIND(sessions, &sessions, s) != NULL);
149 	}
150 	RB_INSERT(sessions, &sessions, s);
151 
152 	log_debug("new session %s $%u", s->name, s->id);
153 
154 	if (gettimeofday(&s->creation_time, NULL) != 0)
155 		fatal("gettimeofday failed");
156 	session_update_activity(s, &s->creation_time);
157 
158 	if (argc >= 0) {
159 		wl = session_new(s, NULL, argc, argv, path, cwd, idx, cause);
160 		if (wl == NULL) {
161 			session_destroy(s);
162 			return (NULL);
163 		}
164 		session_select(s, RB_ROOT(&s->windows)->idx);
165 	}
166 
167 	log_debug("session %s created", s->name);
168 	notify_session_created(s);
169 
170 	return (s);
171 }
172 
173 /* Remove a reference from a session. */
174 void
175 session_unref(struct session *s)
176 {
177 	log_debug("session %s has %d references", s->name, s->references);
178 
179 	s->references--;
180 	if (s->references == 0)
181 		event_once(-1, EV_TIMEOUT, session_free, s, NULL);
182 }
183 
184 /* Free session. */
185 void
186 session_free(__unused int fd, __unused short events, void *arg)
187 {
188 	struct session	*s = arg;
189 
190 	log_debug("session %s freed (%d references)", s->name, s->references);
191 
192 	if (s->references == 0) {
193 		environ_free(s->environ);
194 
195 		options_free(s->options);
196 		hooks_free(s->hooks);
197 
198 		free(s->name);
199 		free(s);
200 	}
201 }
202 
203 /* Destroy a session. */
204 void
205 session_destroy(struct session *s)
206 {
207 	struct winlink	*wl;
208 
209 	log_debug("session %s destroyed", s->name);
210 
211 	RB_REMOVE(sessions, &sessions, s);
212 	notify_session_closed(s);
213 
214 	free(s->tio);
215 
216 	if (event_initialized(&s->lock_timer))
217 		event_del(&s->lock_timer);
218 
219 	session_group_remove(s);
220 
221 	while (!TAILQ_EMPTY(&s->lastw))
222 		winlink_stack_remove(&s->lastw, TAILQ_FIRST(&s->lastw));
223 	while (!RB_EMPTY(&s->windows)) {
224 		wl = RB_ROOT(&s->windows);
225 		notify_window_unlinked(s, wl->window);
226 		winlink_remove(&s->windows, wl);
227 	}
228 
229 	free((void *)s->cwd);
230 
231 	session_unref(s);
232 }
233 
234 /* Check a session name is valid: not empty and no colons or periods. */
235 int
236 session_check_name(const char *name)
237 {
238 	return (*name != '\0' && name[strcspn(name, ":.")] == '\0');
239 }
240 
241 /* Lock session if it has timed out. */
242 void
243 session_lock_timer(__unused int fd, __unused short events, void *arg)
244 {
245 	struct session	*s = arg;
246 
247 	if (s->flags & SESSION_UNATTACHED)
248 		return;
249 
250 	log_debug("session %s locked, activity time %lld", s->name,
251 	    (long long)s->activity_time.tv_sec);
252 
253 	server_lock_session(s);
254 	recalculate_sizes();
255 }
256 
257 /* Update activity time. */
258 void
259 session_update_activity(struct session *s, struct timeval *from)
260 {
261 	struct timeval	*last = &s->last_activity_time;
262 	struct timeval	 tv;
263 
264 	memcpy(last, &s->activity_time, sizeof *last);
265 	if (from == NULL)
266 		gettimeofday(&s->activity_time, NULL);
267 	else
268 		memcpy(&s->activity_time, from, sizeof s->activity_time);
269 
270 	log_debug("session %s activity %lld.%06d (last %lld.%06d)", s->name,
271 	    (long long)s->activity_time.tv_sec, (int)s->activity_time.tv_usec,
272 	    (long long)last->tv_sec, (int)last->tv_usec);
273 
274 	if (evtimer_initialized(&s->lock_timer))
275 		evtimer_del(&s->lock_timer);
276 	else
277 		evtimer_set(&s->lock_timer, session_lock_timer, s);
278 
279 	if (~s->flags & SESSION_UNATTACHED) {
280 		timerclear(&tv);
281 		tv.tv_sec = options_get_number(s->options, "lock-after-time");
282 		if (tv.tv_sec != 0)
283 			evtimer_add(&s->lock_timer, &tv);
284 	}
285 }
286 
287 /* Find the next usable session. */
288 struct session *
289 session_next_session(struct session *s)
290 {
291 	struct session *s2;
292 
293 	if (RB_EMPTY(&sessions) || !session_alive(s))
294 		return (NULL);
295 
296 	s2 = RB_NEXT(sessions, &sessions, s);
297 	if (s2 == NULL)
298 		s2 = RB_MIN(sessions, &sessions);
299 	if (s2 == s)
300 		return (NULL);
301 	return (s2);
302 }
303 
304 /* Find the previous usable session. */
305 struct session *
306 session_previous_session(struct session *s)
307 {
308 	struct session *s2;
309 
310 	if (RB_EMPTY(&sessions) || !session_alive(s))
311 		return (NULL);
312 
313 	s2 = RB_PREV(sessions, &sessions, s);
314 	if (s2 == NULL)
315 		s2 = RB_MAX(sessions, &sessions);
316 	if (s2 == s)
317 		return (NULL);
318 	return (s2);
319 }
320 
321 /* Create a new window on a session. */
322 struct winlink *
323 session_new(struct session *s, const char *name, int argc, char **argv,
324     const char *path, const char *cwd, int idx, char **cause)
325 {
326 	struct window	*w;
327 	struct winlink	*wl;
328 	struct environ	*env;
329 	const char	*shell;
330 	u_int		 hlimit;
331 
332 	if ((wl = winlink_add(&s->windows, idx)) == NULL) {
333 		xasprintf(cause, "index in use: %d", idx);
334 		return (NULL);
335 	}
336 
337 	env = environ_create();
338 	environ_copy(global_environ, env);
339 	environ_copy(s->environ, env);
340 	server_fill_environ(s, env);
341 
342 	shell = options_get_string(s->options, "default-shell");
343 	if (*shell == '\0' || areshell(shell))
344 		shell = _PATH_BSHELL;
345 
346 	hlimit = options_get_number(s->options, "history-limit");
347 	w = window_create(name, argc, argv, path, shell, cwd, env, s->tio,
348 	    s->sx, s->sy, hlimit, cause);
349 	if (w == NULL) {
350 		winlink_remove(&s->windows, wl);
351 		environ_free(env);
352 		return (NULL);
353 	}
354 	winlink_set_window(wl, w);
355 	notify_window_linked(s, w);
356 	environ_free(env);
357 
358 	if (options_get_number(s->options, "set-remain-on-exit"))
359 		options_set_number(w->options, "remain-on-exit", 1);
360 
361 	session_group_synchronize_from(s);
362 	return (wl);
363 }
364 
365 /* Attach a window to a session. */
366 struct winlink *
367 session_attach(struct session *s, struct window *w, int idx, char **cause)
368 {
369 	struct winlink	*wl;
370 
371 	if ((wl = winlink_add(&s->windows, idx)) == NULL) {
372 		xasprintf(cause, "index in use: %d", idx);
373 		return (NULL);
374 	}
375 	winlink_set_window(wl, w);
376 	notify_window_linked(s, w);
377 
378 	session_group_synchronize_from(s);
379 	return (wl);
380 }
381 
382 /* Detach a window from a session. */
383 int
384 session_detach(struct session *s, struct winlink *wl)
385 {
386 	if (s->curw == wl &&
387 	    session_last(s) != 0 && session_previous(s, 0) != 0)
388 		session_next(s, 0);
389 
390 	wl->flags &= ~WINLINK_ALERTFLAGS;
391 	notify_window_unlinked(s, wl->window);
392 	winlink_stack_remove(&s->lastw, wl);
393 	winlink_remove(&s->windows, wl);
394 	session_group_synchronize_from(s);
395 	if (RB_EMPTY(&s->windows)) {
396 		session_destroy(s);
397 		return (1);
398 	}
399 	return (0);
400 }
401 
402 /* Return if session has window. */
403 int
404 session_has(struct session *s, struct window *w)
405 {
406 	struct winlink	*wl;
407 
408 	RB_FOREACH(wl, winlinks, &s->windows) {
409 		if (wl->window == w)
410 			return (1);
411 	}
412 	return (0);
413 }
414 
415 /*
416  * Return 1 if a window is linked outside this session (not including session
417  * groups). The window must be in this session!
418  */
419 int
420 session_is_linked(struct session *s, struct window *w)
421 {
422 	struct session_group	*sg;
423 
424 	if ((sg = session_group_find(s)) != NULL)
425 		return (w->references != session_group_count(sg));
426 	return (w->references != 1);
427 }
428 
429 struct winlink *
430 session_next_alert(struct winlink *wl)
431 {
432 	while (wl != NULL) {
433 		if (wl->flags & WINLINK_ALERTFLAGS)
434 			break;
435 		wl = winlink_next(wl);
436 	}
437 	return (wl);
438 }
439 
440 /* Move session to next window. */
441 int
442 session_next(struct session *s, int alert)
443 {
444 	struct winlink	*wl;
445 
446 	if (s->curw == NULL)
447 		return (-1);
448 
449 	wl = winlink_next(s->curw);
450 	if (alert)
451 		wl = session_next_alert(wl);
452 	if (wl == NULL) {
453 		wl = RB_MIN(winlinks, &s->windows);
454 		if (alert && ((wl = session_next_alert(wl)) == NULL))
455 			return (-1);
456 	}
457 	return (session_set_current(s, wl));
458 }
459 
460 struct winlink *
461 session_previous_alert(struct winlink *wl)
462 {
463 	while (wl != NULL) {
464 		if (wl->flags & WINLINK_ALERTFLAGS)
465 			break;
466 		wl = winlink_previous(wl);
467 	}
468 	return (wl);
469 }
470 
471 /* Move session to previous window. */
472 int
473 session_previous(struct session *s, int alert)
474 {
475 	struct winlink	*wl;
476 
477 	if (s->curw == NULL)
478 		return (-1);
479 
480 	wl = winlink_previous(s->curw);
481 	if (alert)
482 		wl = session_previous_alert(wl);
483 	if (wl == NULL) {
484 		wl = RB_MAX(winlinks, &s->windows);
485 		if (alert && (wl = session_previous_alert(wl)) == NULL)
486 			return (-1);
487 	}
488 	return (session_set_current(s, wl));
489 }
490 
491 /* Move session to specific window. */
492 int
493 session_select(struct session *s, int idx)
494 {
495 	struct winlink	*wl;
496 
497 	wl = winlink_find_by_index(&s->windows, idx);
498 	return (session_set_current(s, wl));
499 }
500 
501 /* Move session to last used window. */
502 int
503 session_last(struct session *s)
504 {
505 	struct winlink	*wl;
506 
507 	wl = TAILQ_FIRST(&s->lastw);
508 	if (wl == NULL)
509 		return (-1);
510 	if (wl == s->curw)
511 		return (1);
512 
513 	return (session_set_current(s, wl));
514 }
515 
516 /* Set current winlink to wl .*/
517 int
518 session_set_current(struct session *s, struct winlink *wl)
519 {
520 	if (wl == NULL)
521 		return (-1);
522 	if (wl == s->curw)
523 		return (1);
524 
525 	winlink_stack_remove(&s->lastw, wl);
526 	winlink_stack_push(&s->lastw, s->curw);
527 	s->curw = wl;
528 	winlink_clear_flags(wl);
529 	window_update_activity(wl->window);
530 	return (0);
531 }
532 
533 /* Find the session group containing a session. */
534 struct session_group *
535 session_group_find(struct session *target)
536 {
537 	struct session_group	*sg;
538 	struct session		*s;
539 
540 	TAILQ_FOREACH(sg, &session_groups, entry) {
541 		TAILQ_FOREACH(s, &sg->sessions, gentry) {
542 			if (s == target)
543 				return (sg);
544 		}
545 	}
546 	return (NULL);
547 }
548 
549 /* Find session group index. */
550 u_int
551 session_group_index(struct session_group *sg)
552 {
553 	struct session_group   *sg2;
554 	u_int			i;
555 
556 	i = 0;
557 	TAILQ_FOREACH(sg2, &session_groups, entry) {
558 		if (sg == sg2)
559 			return (i);
560 		i++;
561 	}
562 
563 	fatalx("session group not found");
564 }
565 
566 /*
567  * Add a session to the session group containing target, creating it if
568  * necessary.
569  */
570 void
571 session_group_add(struct session *target, struct session *s)
572 {
573 	struct session_group	*sg;
574 
575 	if ((sg = session_group_find(target)) == NULL) {
576 		sg = xmalloc(sizeof *sg);
577 		TAILQ_INSERT_TAIL(&session_groups, sg, entry);
578 		TAILQ_INIT(&sg->sessions);
579 		TAILQ_INSERT_TAIL(&sg->sessions, target, gentry);
580 	}
581 	TAILQ_INSERT_TAIL(&sg->sessions, s, gentry);
582 }
583 
584 /* Remove a session from its group and destroy the group if empty. */
585 void
586 session_group_remove(struct session *s)
587 {
588 	struct session_group	*sg;
589 
590 	if ((sg = session_group_find(s)) == NULL)
591 		return;
592 	TAILQ_REMOVE(&sg->sessions, s, gentry);
593 	if (TAILQ_NEXT(TAILQ_FIRST(&sg->sessions), gentry) == NULL)
594 		TAILQ_REMOVE(&sg->sessions, TAILQ_FIRST(&sg->sessions), gentry);
595 	if (TAILQ_EMPTY(&sg->sessions)) {
596 		TAILQ_REMOVE(&session_groups, sg, entry);
597 		free(sg);
598 	}
599 }
600 
601 /* Count number of sessions in session group. */
602 u_int
603 session_group_count(struct session_group *sg)
604 {
605 	struct session	*s;
606 	u_int		 n;
607 
608 	n = 0;
609 	TAILQ_FOREACH(s, &sg->sessions, gentry)
610 	    n++;
611 	return (n);
612 }
613 
614 /* Synchronize a session to its session group. */
615 void
616 session_group_synchronize_to(struct session *s)
617 {
618 	struct session_group	*sg;
619 	struct session		*target;
620 
621 	if ((sg = session_group_find(s)) == NULL)
622 		return;
623 
624 	target = NULL;
625 	TAILQ_FOREACH(target, &sg->sessions, gentry) {
626 		if (target != s)
627 			break;
628 	}
629 	session_group_synchronize1(target, s);
630 }
631 
632 /* Synchronize a session group to a session. */
633 void
634 session_group_synchronize_from(struct session *target)
635 {
636 	struct session_group	*sg;
637 	struct session		*s;
638 
639 	if ((sg = session_group_find(target)) == NULL)
640 		return;
641 
642 	TAILQ_FOREACH(s, &sg->sessions, gentry) {
643 		if (s != target)
644 			session_group_synchronize1(target, s);
645 	}
646 }
647 
648 /*
649  * Synchronize a session with a target session. This means destroying all
650  * winlinks then recreating them, then updating the current window, last window
651  * stack and alerts.
652  */
653 void
654 session_group_synchronize1(struct session *target, struct session *s)
655 {
656 	struct winlinks		 old_windows, *ww;
657 	struct winlink_stack	 old_lastw;
658 	struct winlink		*wl, *wl2;
659 
660 	/* Don't do anything if the session is empty (it'll be destroyed). */
661 	ww = &target->windows;
662 	if (RB_EMPTY(ww))
663 		return;
664 
665 	/* If the current window has vanished, move to the next now. */
666 	if (s->curw != NULL &&
667 	    winlink_find_by_index(ww, s->curw->idx) == NULL &&
668 	    session_last(s) != 0 && session_previous(s, 0) != 0)
669 		session_next(s, 0);
670 
671 	/* Save the old pointer and reset it. */
672 	memcpy(&old_windows, &s->windows, sizeof old_windows);
673 	RB_INIT(&s->windows);
674 
675 	/* Link all the windows from the target. */
676 	RB_FOREACH(wl, winlinks, ww) {
677 		wl2 = winlink_add(&s->windows, wl->idx);
678 		winlink_set_window(wl2, wl->window);
679 		notify_window_linked(s, wl2->window);
680 		wl2->flags |= wl->flags & WINLINK_ALERTFLAGS;
681 	}
682 
683 	/* Fix up the current window. */
684 	if (s->curw != NULL)
685 		s->curw = winlink_find_by_index(&s->windows, s->curw->idx);
686 	else
687 		s->curw = winlink_find_by_index(&s->windows, target->curw->idx);
688 
689 	/* Fix up the last window stack. */
690 	memcpy(&old_lastw, &s->lastw, sizeof old_lastw);
691 	TAILQ_INIT(&s->lastw);
692 	TAILQ_FOREACH(wl, &old_lastw, sentry) {
693 		wl2 = winlink_find_by_index(&s->windows, wl->idx);
694 		if (wl2 != NULL)
695 			TAILQ_INSERT_TAIL(&s->lastw, wl2, sentry);
696 	}
697 
698 	/* Then free the old winlinks list. */
699 	while (!RB_EMPTY(&old_windows)) {
700 		wl = RB_ROOT(&old_windows);
701 		wl2 = winlink_find_by_window_id(&s->windows, wl->window->id);
702 		if (wl2 == NULL)
703 			notify_window_unlinked(s, wl->window);
704 		winlink_remove(&old_windows, wl);
705 	}
706 }
707 
708 /* Renumber the windows across winlinks attached to a specific session. */
709 void
710 session_renumber_windows(struct session *s)
711 {
712 	struct winlink		*wl, *wl1, *wl_new;
713 	struct winlinks		 old_wins;
714 	struct winlink_stack	 old_lastw;
715 	int			 new_idx, new_curw_idx;
716 
717 	/* Save and replace old window list. */
718 	memcpy(&old_wins, &s->windows, sizeof old_wins);
719 	RB_INIT(&s->windows);
720 
721 	/* Start renumbering from the base-index if it's set. */
722 	new_idx = options_get_number(s->options, "base-index");
723 	new_curw_idx = 0;
724 
725 	/* Go through the winlinks and assign new indexes. */
726 	RB_FOREACH(wl, winlinks, &old_wins) {
727 		wl_new = winlink_add(&s->windows, new_idx);
728 		winlink_set_window(wl_new, wl->window);
729 		wl_new->flags |= wl->flags & WINLINK_ALERTFLAGS;
730 
731 		if (wl == s->curw)
732 			new_curw_idx = wl_new->idx;
733 
734 		new_idx++;
735 	}
736 
737 	/* Fix the stack of last windows now. */
738 	memcpy(&old_lastw, &s->lastw, sizeof old_lastw);
739 	TAILQ_INIT(&s->lastw);
740 	TAILQ_FOREACH(wl, &old_lastw, sentry) {
741 		wl_new = winlink_find_by_window(&s->windows, wl->window);
742 		if (wl_new != NULL)
743 			TAILQ_INSERT_TAIL(&s->lastw, wl_new, sentry);
744 	}
745 
746 	/* Set the current window. */
747 	s->curw = winlink_find_by_index(&s->windows, new_curw_idx);
748 
749 	/* Free the old winlinks (reducing window references too). */
750 	RB_FOREACH_SAFE(wl, winlinks, &old_wins, wl1)
751 		winlink_remove(&old_wins, wl);
752 }
753