1/* $OpenBSD: session.c,v 1.96 2023/09/02 08:38:37 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 <vis.h>
27#include <time.h>
28
29#include "tmux.h"
30
31struct sessions		sessions;
32u_int			next_session_id;
33struct session_groups	session_groups = RB_INITIALIZER(&session_groups);
34
35static void	session_free(int, short, void *);
36
37static void	session_lock_timer(int, short, void *);
38
39static struct winlink *session_next_alert(struct winlink *);
40static struct winlink *session_previous_alert(struct winlink *);
41
42static void	session_group_remove(struct session *);
43static void	session_group_synchronize1(struct session *, struct session *);
44
45int
46session_cmp(struct session *s1, struct session *s2)
47{
48	return (strcmp(s1->name, s2->name));
49}
50RB_GENERATE(sessions, session, entry, session_cmp);
51
52static int
53session_group_cmp(struct session_group *s1, struct session_group *s2)
54{
55	return (strcmp(s1->name, s2->name));
56}
57RB_GENERATE_STATIC(session_groups, session_group, entry, session_group_cmp);
58
59/*
60 * Find if session is still alive. This is true if it is still on the global
61 * sessions list.
62 */
63int
64session_alive(struct session *s)
65{
66	struct session *s_loop;
67
68	RB_FOREACH(s_loop, sessions, &sessions) {
69		if (s_loop == s)
70			return (1);
71	}
72	return (0);
73}
74
75/* Find session by name. */
76struct session *
77session_find(const char *name)
78{
79	struct session	s;
80
81	s.name = (char *) name;
82	return (RB_FIND(sessions, &sessions, &s));
83}
84
85/* Find session by id parsed from a string. */
86struct session *
87session_find_by_id_str(const char *s)
88{
89	const char	*errstr;
90	u_int		 id;
91
92	if (*s != '$')
93		return (NULL);
94
95	id = strtonum(s + 1, 0, UINT_MAX, &errstr);
96	if (errstr != NULL)
97		return (NULL);
98	return (session_find_by_id(id));
99}
100
101/* Find session by id. */
102struct session *
103session_find_by_id(u_int id)
104{
105	struct session	*s;
106
107	RB_FOREACH(s, sessions, &sessions) {
108		if (s->id == id)
109			return (s);
110	}
111	return (NULL);
112}
113
114/* Create a new session. */
115struct session *
116session_create(const char *prefix, const char *name, const char *cwd,
117    struct environ *env, struct options *oo, struct termios *tio)
118{
119	struct session	*s;
120
121	s = xcalloc(1, sizeof *s);
122	s->references = 1;
123	s->flags = 0;
124
125	s->cwd = xstrdup(cwd);
126
127	TAILQ_INIT(&s->lastw);
128	RB_INIT(&s->windows);
129
130	s->environ = env;
131	s->options = oo;
132
133	status_update_cache(s);
134
135	s->tio = NULL;
136	if (tio != NULL) {
137		s->tio = xmalloc(sizeof *s->tio);
138		memcpy(s->tio, tio, sizeof *s->tio);
139	}
140
141	if (name != NULL) {
142		s->name = xstrdup(name);
143		s->id = next_session_id++;
144	} else {
145		do {
146			s->id = next_session_id++;
147			free(s->name);
148			if (prefix != NULL)
149				xasprintf(&s->name, "%s-%u", prefix, s->id);
150			else
151				xasprintf(&s->name, "%u", s->id);
152		} while (RB_FIND(sessions, &sessions, s) != NULL);
153	}
154	RB_INSERT(sessions, &sessions, s);
155
156	log_debug("new session %s $%u", s->name, s->id);
157
158	if (gettimeofday(&s->creation_time, NULL) != 0)
159		fatal("gettimeofday failed");
160	session_update_activity(s, &s->creation_time);
161
162	return (s);
163}
164
165/* Add a reference to a session. */
166void
167session_add_ref(struct session *s, const char *from)
168{
169	s->references++;
170	log_debug("%s: %s %s, now %d", __func__, s->name, from, s->references);
171}
172
173/* Remove a reference from a session. */
174void
175session_remove_ref(struct session *s, const char *from)
176{
177	s->references--;
178	log_debug("%s: %s %s, now %d", __func__, s->name, from, s->references);
179
180	if (s->references == 0)
181		event_once(-1, EV_TIMEOUT, session_free, s, NULL);
182}
183
184/* Free session. */
185static void
186session_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		options_free(s->options);
195
196		free(s->name);
197		free(s);
198	}
199}
200
201/* Destroy a session. */
202void
203session_destroy(struct session *s, int notify, const char *from)
204{
205	struct winlink	*wl;
206
207	log_debug("session %s destroyed (%s)", s->name, from);
208
209	if (s->curw == NULL)
210		return;
211	s->curw = NULL;
212
213	RB_REMOVE(sessions, &sessions, s);
214	if (notify)
215		notify_session("session-closed", s);
216
217	free(s->tio);
218
219	if (event_initialized(&s->lock_timer))
220		event_del(&s->lock_timer);
221
222	session_group_remove(s);
223
224	while (!TAILQ_EMPTY(&s->lastw))
225		winlink_stack_remove(&s->lastw, TAILQ_FIRST(&s->lastw));
226	while (!RB_EMPTY(&s->windows)) {
227		wl = RB_ROOT(&s->windows);
228		notify_session_window("window-unlinked", s, wl->window);
229		winlink_remove(&s->windows, wl);
230	}
231
232	free((void *)s->cwd);
233
234	session_remove_ref(s, __func__);
235}
236
237/* Sanitize session name. */
238char *
239session_check_name(const char *name)
240{
241	char	*copy, *cp, *new_name;
242
243	if (*name == '\0')
244		return (NULL);
245	copy = xstrdup(name);
246	for (cp = copy; *cp != '\0'; cp++) {
247		if (*cp == ':' || *cp == '.')
248			*cp = '_';
249	}
250	utf8_stravis(&new_name, copy, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);
251	free(copy);
252	return (new_name);
253}
254
255/* Lock session if it has timed out. */
256static void
257session_lock_timer(__unused int fd, __unused short events, void *arg)
258{
259	struct session	*s = arg;
260
261	if (s->attached == 0)
262		return;
263
264	log_debug("session %s locked, activity time %lld", s->name,
265	    (long long)s->activity_time.tv_sec);
266
267	server_lock_session(s);
268	recalculate_sizes();
269}
270
271/* Update activity time. */
272void
273session_update_activity(struct session *s, struct timeval *from)
274{
275	struct timeval	*last = &s->last_activity_time;
276	struct timeval	 tv;
277
278	memcpy(last, &s->activity_time, sizeof *last);
279	if (from == NULL)
280		gettimeofday(&s->activity_time, NULL);
281	else
282		memcpy(&s->activity_time, from, sizeof s->activity_time);
283
284	log_debug("session $%u %s activity %lld.%06d (last %lld.%06d)", s->id,
285	    s->name, (long long)s->activity_time.tv_sec,
286	    (int)s->activity_time.tv_usec, (long long)last->tv_sec,
287	    (int)last->tv_usec);
288
289	if (evtimer_initialized(&s->lock_timer))
290		evtimer_del(&s->lock_timer);
291	else
292		evtimer_set(&s->lock_timer, session_lock_timer, s);
293
294	if (s->attached != 0) {
295		timerclear(&tv);
296		tv.tv_sec = options_get_number(s->options, "lock-after-time");
297		if (tv.tv_sec != 0)
298			evtimer_add(&s->lock_timer, &tv);
299	}
300}
301
302/* Find the next usable session. */
303struct session *
304session_next_session(struct session *s)
305{
306	struct session *s2;
307
308	if (RB_EMPTY(&sessions) || !session_alive(s))
309		return (NULL);
310
311	s2 = RB_NEXT(sessions, &sessions, s);
312	if (s2 == NULL)
313		s2 = RB_MIN(sessions, &sessions);
314	if (s2 == s)
315		return (NULL);
316	return (s2);
317}
318
319/* Find the previous usable session. */
320struct session *
321session_previous_session(struct session *s)
322{
323	struct session *s2;
324
325	if (RB_EMPTY(&sessions) || !session_alive(s))
326		return (NULL);
327
328	s2 = RB_PREV(sessions, &sessions, s);
329	if (s2 == NULL)
330		s2 = RB_MAX(sessions, &sessions);
331	if (s2 == s)
332		return (NULL);
333	return (s2);
334}
335
336/* Attach a window to a session. */
337struct winlink *
338session_attach(struct session *s, struct window *w, int idx, char **cause)
339{
340	struct winlink	*wl;
341
342	if ((wl = winlink_add(&s->windows, idx)) == NULL) {
343		xasprintf(cause, "index in use: %d", idx);
344		return (NULL);
345	}
346	wl->session = s;
347	winlink_set_window(wl, w);
348	notify_session_window("window-linked", s, w);
349
350	session_group_synchronize_from(s);
351	return (wl);
352}
353
354/* Detach a window from a session. */
355int
356session_detach(struct session *s, struct winlink *wl)
357{
358	if (s->curw == wl &&
359	    session_last(s) != 0 &&
360	    session_previous(s, 0) != 0)
361		session_next(s, 0);
362
363	wl->flags &= ~WINLINK_ALERTFLAGS;
364	notify_session_window("window-unlinked", s, wl->window);
365	winlink_stack_remove(&s->lastw, wl);
366	winlink_remove(&s->windows, wl);
367
368	session_group_synchronize_from(s);
369
370	if (RB_EMPTY(&s->windows))
371		return (1);
372       	return (0);
373}
374
375/* Return if session has window. */
376int
377session_has(struct session *s, struct window *w)
378{
379	struct winlink	*wl;
380
381	TAILQ_FOREACH(wl, &w->winlinks, wentry) {
382		if (wl->session == s)
383			return (1);
384	}
385	return (0);
386}
387
388/*
389 * Return 1 if a window is linked outside this session (not including session
390 * groups). The window must be in this session!
391 */
392int
393session_is_linked(struct session *s, struct window *w)
394{
395	struct session_group	*sg;
396
397	if ((sg = session_group_contains(s)) != NULL)
398		return (w->references != session_group_count(sg));
399	return (w->references != 1);
400}
401
402static struct winlink *
403session_next_alert(struct winlink *wl)
404{
405	while (wl != NULL) {
406		if (wl->flags & WINLINK_ALERTFLAGS)
407			break;
408		wl = winlink_next(wl);
409	}
410	return (wl);
411}
412
413/* Move session to next window. */
414int
415session_next(struct session *s, int alert)
416{
417	struct winlink	*wl;
418
419	if (s->curw == NULL)
420		return (-1);
421
422	wl = winlink_next(s->curw);
423	if (alert)
424		wl = session_next_alert(wl);
425	if (wl == NULL) {
426		wl = RB_MIN(winlinks, &s->windows);
427		if (alert && ((wl = session_next_alert(wl)) == NULL))
428			return (-1);
429	}
430	return (session_set_current(s, wl));
431}
432
433static struct winlink *
434session_previous_alert(struct winlink *wl)
435{
436	while (wl != NULL) {
437		if (wl->flags & WINLINK_ALERTFLAGS)
438			break;
439		wl = winlink_previous(wl);
440	}
441	return (wl);
442}
443
444/* Move session to previous window. */
445int
446session_previous(struct session *s, int alert)
447{
448	struct winlink	*wl;
449
450	if (s->curw == NULL)
451		return (-1);
452
453	wl = winlink_previous(s->curw);
454	if (alert)
455		wl = session_previous_alert(wl);
456	if (wl == NULL) {
457		wl = RB_MAX(winlinks, &s->windows);
458		if (alert && (wl = session_previous_alert(wl)) == NULL)
459			return (-1);
460	}
461	return (session_set_current(s, wl));
462}
463
464/* Move session to specific window. */
465int
466session_select(struct session *s, int idx)
467{
468	struct winlink	*wl;
469
470	wl = winlink_find_by_index(&s->windows, idx);
471	return (session_set_current(s, wl));
472}
473
474/* Move session to last used window. */
475int
476session_last(struct session *s)
477{
478	struct winlink	*wl;
479
480	wl = TAILQ_FIRST(&s->lastw);
481	if (wl == NULL)
482		return (-1);
483	if (wl == s->curw)
484		return (1);
485
486	return (session_set_current(s, wl));
487}
488
489/* Set current winlink to wl .*/
490int
491session_set_current(struct session *s, struct winlink *wl)
492{
493	struct winlink	*old = s->curw;
494
495	if (wl == NULL)
496		return (-1);
497	if (wl == s->curw)
498		return (1);
499
500	winlink_stack_remove(&s->lastw, wl);
501	winlink_stack_push(&s->lastw, s->curw);
502	s->curw = wl;
503	if (options_get_number(global_options, "focus-events")) {
504		if (old != NULL)
505			window_update_focus(old->window);
506		window_update_focus(wl->window);
507	}
508	winlink_clear_flags(wl);
509	window_update_activity(wl->window);
510	tty_update_window_offset(wl->window);
511	notify_session("session-window-changed", s);
512	return (0);
513}
514
515/* Find the session group containing a session. */
516struct session_group *
517session_group_contains(struct session *target)
518{
519	struct session_group	*sg;
520	struct session		*s;
521
522	RB_FOREACH(sg, session_groups, &session_groups) {
523		TAILQ_FOREACH(s, &sg->sessions, gentry) {
524			if (s == target)
525				return (sg);
526		}
527	}
528	return (NULL);
529}
530
531/* Find session group by name. */
532struct session_group *
533session_group_find(const char *name)
534{
535	struct session_group	sg;
536
537	sg.name = name;
538	return (RB_FIND(session_groups, &session_groups, &sg));
539}
540
541/* Create a new session group. */
542struct session_group *
543session_group_new(const char *name)
544{
545	struct session_group	*sg;
546
547	if ((sg = session_group_find(name)) != NULL)
548		return (sg);
549
550	sg = xcalloc(1, sizeof *sg);
551	sg->name = xstrdup(name);
552	TAILQ_INIT(&sg->sessions);
553
554	RB_INSERT(session_groups, &session_groups, sg);
555	return (sg);
556}
557
558/* Add a session to a session group. */
559void
560session_group_add(struct session_group *sg, struct session *s)
561{
562	if (session_group_contains(s) == NULL)
563		TAILQ_INSERT_TAIL(&sg->sessions, s, gentry);
564}
565
566/* Remove a session from its group and destroy the group if empty. */
567static void
568session_group_remove(struct session *s)
569{
570	struct session_group	*sg;
571
572	if ((sg = session_group_contains(s)) == NULL)
573		return;
574	TAILQ_REMOVE(&sg->sessions, s, gentry);
575	if (TAILQ_EMPTY(&sg->sessions)) {
576		RB_REMOVE(session_groups, &session_groups, sg);
577		free((void *)sg->name);
578		free(sg);
579	}
580}
581
582/* Count number of sessions in session group. */
583u_int
584session_group_count(struct session_group *sg)
585{
586	struct session	*s;
587	u_int		 n;
588
589	n = 0;
590	TAILQ_FOREACH(s, &sg->sessions, gentry)
591		n++;
592	return (n);
593}
594
595/* Count number of clients attached to sessions in session group. */
596u_int
597session_group_attached_count(struct session_group *sg)
598{
599	struct session	*s;
600	u_int		 n;
601
602	n = 0;
603	TAILQ_FOREACH(s, &sg->sessions, gentry)
604		n += s->attached;
605	return (n);
606}
607
608/* Synchronize a session to its session group. */
609void
610session_group_synchronize_to(struct session *s)
611{
612	struct session_group	*sg;
613	struct session		*target;
614
615	if ((sg = session_group_contains(s)) == NULL)
616		return;
617
618	target = NULL;
619	TAILQ_FOREACH(target, &sg->sessions, gentry) {
620		if (target != s)
621			break;
622	}
623	if (target != NULL)
624		session_group_synchronize1(target, s);
625}
626
627/* Synchronize a session group to a session. */
628void
629session_group_synchronize_from(struct session *target)
630{
631	struct session_group	*sg;
632	struct session		*s;
633
634	if ((sg = session_group_contains(target)) == NULL)
635		return;
636
637	TAILQ_FOREACH(s, &sg->sessions, gentry) {
638		if (s != target)
639			session_group_synchronize1(target, s);
640	}
641}
642
643/*
644 * Synchronize a session with a target session. This means destroying all
645 * winlinks then recreating them, then updating the current window, last window
646 * stack and alerts.
647 */
648static void
649session_group_synchronize1(struct session *target, struct session *s)
650{
651	struct winlinks		 old_windows, *ww;
652	struct winlink_stack	 old_lastw;
653	struct winlink		*wl, *wl2;
654
655	/* Don't do anything if the session is empty (it'll be destroyed). */
656	ww = &target->windows;
657	if (RB_EMPTY(ww))
658		return;
659
660	/* If the current window has vanished, move to the next now. */
661	if (s->curw != NULL &&
662	    winlink_find_by_index(ww, s->curw->idx) == NULL &&
663	    session_last(s) != 0 && session_previous(s, 0) != 0)
664		session_next(s, 0);
665
666	/* Save the old pointer and reset it. */
667	memcpy(&old_windows, &s->windows, sizeof old_windows);
668	RB_INIT(&s->windows);
669
670	/* Link all the windows from the target. */
671	RB_FOREACH(wl, winlinks, ww) {
672		wl2 = winlink_add(&s->windows, wl->idx);
673		wl2->session = s;
674		winlink_set_window(wl2, wl->window);
675		notify_session_window("window-linked", s, wl2->window);
676		wl2->flags |= wl->flags & WINLINK_ALERTFLAGS;
677	}
678
679	/* Fix up the current window. */
680	if (s->curw != NULL)
681		s->curw = winlink_find_by_index(&s->windows, s->curw->idx);
682	else
683		s->curw = winlink_find_by_index(&s->windows, target->curw->idx);
684
685	/* Fix up the last window stack. */
686	memcpy(&old_lastw, &s->lastw, sizeof old_lastw);
687	TAILQ_INIT(&s->lastw);
688	TAILQ_FOREACH(wl, &old_lastw, sentry) {
689		wl2 = winlink_find_by_index(&s->windows, wl->idx);
690		if (wl2 != NULL) {
691			TAILQ_INSERT_TAIL(&s->lastw, wl2, sentry);
692			wl2->flags |= WINLINK_VISITED;
693		}
694	}
695
696	/* Then free the old winlinks list. */
697	while (!RB_EMPTY(&old_windows)) {
698		wl = RB_ROOT(&old_windows);
699		wl2 = winlink_find_by_window_id(&s->windows, wl->window->id);
700		if (wl2 == NULL)
701			notify_session_window("window-unlinked", s, wl->window);
702		winlink_remove(&old_windows, wl);
703	}
704}
705
706/* Renumber the windows across winlinks attached to a specific session. */
707void
708session_renumber_windows(struct session *s)
709{
710	struct winlink		*wl, *wl1, *wl_new;
711	struct winlinks		 old_wins;
712	struct winlink_stack	 old_lastw;
713	int			 new_idx, new_curw_idx, marked_idx = -1;
714
715	/* Save and replace old window list. */
716	memcpy(&old_wins, &s->windows, sizeof old_wins);
717	RB_INIT(&s->windows);
718
719	/* Start renumbering from the base-index if it's set. */
720	new_idx = options_get_number(s->options, "base-index");
721	new_curw_idx = 0;
722
723	/* Go through the winlinks and assign new indexes. */
724	RB_FOREACH(wl, winlinks, &old_wins) {
725		wl_new = winlink_add(&s->windows, new_idx);
726		wl_new->session = s;
727		winlink_set_window(wl_new, wl->window);
728		wl_new->flags |= wl->flags & WINLINK_ALERTFLAGS;
729
730		if (wl == marked_pane.wl)
731			marked_idx = wl_new->idx;
732		if (wl == s->curw)
733			new_curw_idx = wl_new->idx;
734
735		new_idx++;
736	}
737
738	/* Fix the stack of last windows now. */
739	memcpy(&old_lastw, &s->lastw, sizeof old_lastw);
740	TAILQ_INIT(&s->lastw);
741	TAILQ_FOREACH(wl, &old_lastw, sentry) {
742		wl->flags &= ~WINLINK_VISITED;
743		wl_new = winlink_find_by_window(&s->windows, wl->window);
744		if (wl_new != NULL) {
745			TAILQ_INSERT_TAIL(&s->lastw, wl_new, sentry);
746			wl_new->flags |= WINLINK_VISITED;
747		}
748	}
749
750	/* Set the current window. */
751	if (marked_idx != -1) {
752		marked_pane.wl = winlink_find_by_index(&s->windows, marked_idx);
753		if (marked_pane.wl == NULL)
754			server_clear_marked();
755	}
756	s->curw = winlink_find_by_index(&s->windows, new_curw_idx);
757
758	/* Free the old winlinks (reducing window references too). */
759	RB_FOREACH_SAFE(wl, winlinks, &old_wins, wl1)
760		winlink_remove(&old_wins, wl);
761}
762