1 /*
2  * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include "compat.h"
18 
19 #include <sys/time.h>
20 
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <limits.h>
24 #include <stdio.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <time.h>
28 #include <unistd.h>
29 
30 #include "defaults.h"
31 #include "ev.h"
32 #include "fs.h"
33 #include "hist.h"
34 #include "imsgev.h"
35 #include "minibuffer.h"
36 #include "session.h"
37 #include "tofu.h"
38 #include "ui.h"
39 
40 struct history	history;
41 
42 static unsigned int	 autosavetimer;
43 
44 void
45 switch_to_tab(struct tab *tab)
46 {
47 	current_tab = tab;
48 	tab->flags &= ~TAB_URGENT;
49 
50 	if (operating && tab->flags & TAB_LAZY)
51 		load_url_in_tab(tab, hist_cur(tab->hist), NULL,
52 		    LU_MODE_NOHIST);
53 }
54 
55 unsigned int
56 tab_new_id(void)
57 {
58 	static uint32_t tab_counter;
59 
60 	return tab_counter++;
61 }
62 
63 struct tab *
64 new_tab(const char *url, const char *base, struct tab *after)
65 {
66 	struct tab	*tab;
67 
68 	ui_schedule_redraw();
69 	autosave_hook();
70 
71 	if ((tab = calloc(1, sizeof(*tab))) == NULL) {
72 		ev_break();
73 		return NULL;
74 	}
75 
76 	if ((tab->hist = hist_new(HIST_LINEAR)) == NULL) {
77 		free(tab);
78 		ev_break();
79 		return NULL;
80 	}
81 
82 	TAILQ_INIT(&tab->buffer.head);
83 	TAILQ_INIT(&tab->buffer.page.head);
84 
85 	tab->id = tab_new_id();
86 
87 	if (after != NULL)
88 		TAILQ_INSERT_AFTER(&tabshead, after, tab, tabs);
89 	else
90 		TAILQ_INSERT_TAIL(&tabshead, tab, tabs);
91 
92 	if (!operating)
93 		tab->flags |= TAB_LAZY;
94 	load_url_in_tab(tab, url, base, 0);
95 	switch_to_tab(tab);
96 	return tab;
97 }
98 
99 /*
100  * Move a tab from the tablist to the killed tab list and erase its
101  * contents.  Append should always be 0 to prepend tabs so unkill_tab
102  * can work correctly; appending is only useful during startup when
103  * receiving the list of killed tabs to keep the correct order.
104  * NB: doesn't update the current_tab.
105  */
106 void
107 kill_tab(struct tab *tab, int append)
108 {
109 	int count;
110 
111 	stop_tab(tab);
112 	erase_buffer(&tab->buffer);
113 	TAILQ_REMOVE(&tabshead, tab, tabs);
114 	ui_schedule_redraw();
115 	autosave_hook();
116 
117 	ev_timer_cancel(tab->loading_timer);
118 
119 	if (append)
120 		TAILQ_INSERT_TAIL(&ktabshead, tab, tabs);
121 	else
122 		TAILQ_INSERT_HEAD(&ktabshead, tab, tabs);
123 
124 	/* gc closed tabs */
125 	count = 0;
126 	TAILQ_FOREACH(tab, &ktabshead, tabs)
127 		count++;
128 	while (count > max_killed_tabs) {
129 		count--;
130 		free_tab(TAILQ_LAST(&ktabshead, tabshead));
131 	}
132 }
133 
134 /*
135  * Resurrects the lastest killed tab and returns it.  The tab is already
136  * added to the tab list with the TAB_LAZY flag set.  NB: this doesn't
137  * update current_tab.
138  */
139 struct tab *
140 unkill_tab(void)
141 {
142 	struct tab *t;
143 
144 	if (TAILQ_EMPTY(&ktabshead))
145 		return NULL;
146 
147 	ui_schedule_redraw();
148 	autosave_hook();
149 
150 	t = TAILQ_FIRST(&ktabshead);
151 	TAILQ_REMOVE(&ktabshead, t, tabs);
152 	TAILQ_INSERT_TAIL(&tabshead, t, tabs);
153 	t->flags |= TAB_LAZY;
154 	return t;
155 }
156 
157 /*
158  * Free every resource linked to the tab, including the tab itself, and
159  * removes it from the *killed* tablist.
160  */
161 void
162 free_tab(struct tab *tab)
163 {
164 	TAILQ_REMOVE(&ktabshead, tab, tabs);
165 	hist_free(tab->hist);
166 	free(tab);
167 }
168 
169 void
170 stop_tab(struct tab *tab)
171 {
172 	ui_send_net(IMSG_STOP, tab->id, -1, NULL, 0);
173 }
174 
175 static inline void
176 savetab(FILE *fp, struct tab *tab, int killed)
177 {
178 	size_t		 i, size, cur;
179 	size_t		 top_line, current_line;
180 
181 	get_scroll_position(tab, &top_line, &current_line);
182 
183 	fprintf(fp, "%s ", hist_cur(tab->hist));
184 	if (tab == current_tab)
185 		fprintf(fp, "current,");
186 	if (killed)
187 		fprintf(fp, "killed,");
188 
189 	fprintf(fp, "top=%zu,cur=%zu %s\n", top_line, current_line,
190 	    tab->buffer.page.title);
191 
192 	cur = hist_off(tab->hist);
193 	size = hist_size(tab->hist);
194 	for (i = 0; i < size; ++i) {
195 		if (i == cur)
196 			continue;
197 		fprintf(fp, "%s %s\n", i > cur ? ">" : "<",
198 		    hist_nth(tab->hist, i));
199 	}
200 }
201 
202 static void
203 save_tabs(void)
204 {
205 	FILE		*fp;
206 	struct tab	*tab;
207 	int		 fd, err;
208 	char		 sfn[PATH_MAX];
209 
210 	strlcpy(sfn, session_file_tmp, sizeof(sfn));
211 	if ((fd = mkstemp(sfn)) == -1 ||
212 	    (fp = fdopen(fd, "w")) == NULL) {
213 		if (fd != -1) {
214 			unlink(sfn);
215 			close(fd);
216 		}
217 		return;
218 	}
219 
220 	TAILQ_FOREACH(tab, &tabshead, tabs)
221 		savetab(fp, tab, 0);
222 	TAILQ_FOREACH(tab, &ktabshead, tabs)
223 		savetab(fp, tab, 1);
224 
225 	err = fflush(fp) == EOF;
226 	fclose(fp);
227 
228 	if (err || rename(sfn, session_file) == -1)
229 		unlink(sfn);
230 }
231 
232 static void
233 save_all_history(void)
234 {
235 	FILE	*fp;
236 	size_t	 i;
237 	int	 fd, err;
238 	char	 sfn[PATH_MAX];
239 
240 	strlcpy(sfn, history_file_tmp, sizeof(sfn));
241 	if ((fd = mkstemp(sfn)) == -1 ||
242 	    (fp = fdopen(fd, "w")) == NULL) {
243 		if (fd != -1) {
244 			unlink(sfn);
245 			close(fd);
246 		}
247 		return;
248 	}
249 
250 	for (i = 0; i < history.len; ++i) {
251 		history.items[i].dirty = 0;
252 		fprintf(fp, "%lld %s\n", (long long)history.items[i].ts,
253 		    history.items[i].uri);
254 	}
255 
256 	err = fflush(fp) == EOF;
257 	fclose(fp);
258 
259 	if (err || rename(sfn, history_file) == -1) {
260 		unlink(sfn);
261 		return;
262 	}
263 
264 	history.dirty = 0;
265 	history.extra = 0;
266 }
267 
268 static void
269 save_dirty_history(void)
270 {
271 	FILE	*fp;
272 	size_t	 i;
273 
274 	if ((fp = fopen(history_file, "a")) == NULL)
275 		return;
276 
277 	for (i = 0; i < history.len && history.dirty > 0; ++i) {
278 		if (!history.items[i].dirty)
279 			continue;
280 		history.dirty--;
281 		history.items[i].dirty = 0;
282 		fprintf(fp, "%lld %s\n", (long long)history.items[i].ts,
283 		    history.items[i].uri);
284 	}
285 	history.dirty = 0;
286 
287 	fclose(fp);
288 }
289 
290 void
291 save_session(void)
292 {
293 	if (safe_mode)
294 		return;
295 
296 	save_tabs();
297 
298 	if (history.extra > HISTORY_CAP/2)
299 		save_all_history();
300 	else if (history.dirty)
301 		save_dirty_history();
302 }
303 
304 void
305 history_push(struct histitem *hi)
306 {
307 	size_t		 i, oldest = 0;
308 	char		*uri;
309 
310 	for (i = 0; i < history.len; ++i) {
311 		if (history.items[i].ts < history.items[oldest].ts)
312 			oldest = i;
313 
314 		/* remove duplicates */
315 		if (!strcmp(history.items[i].uri, hi->uri))
316 			return;
317 	}
318 
319 	if ((uri = strdup(hi->uri)) == NULL)
320 		abort();
321 
322 	/* don't grow too much; replace the oldest */
323 	if (history.len == HISTORY_CAP) {
324 		history.items[oldest].ts = hi->ts;
325 		free(history.items[oldest].uri);
326 		history.items[oldest].uri = uri;
327 
328 		/* Growed past the max value, signal to regen the file. */
329 		history.extra++;
330 		return;
331 	}
332 
333 	history.items[history.len].ts = hi->ts;
334 	history.items[history.len].uri = uri;
335 	history.len++;
336 }
337 
338 static int
339 history_cmp(const void *a, const void *b)
340 {
341 	const struct history_item *i = a, *j = b;
342 	return strcmp(i->uri, j->uri);
343 }
344 
345 void
346 history_sort(void)
347 {
348 	qsort(history.items, history.len, sizeof(history.items[0]),
349 	    history_cmp);
350 }
351 
352 void
353 history_add(const char *uri)
354 {
355 	size_t	 i, j, insert = 0, oldest = 0;
356 	char	*u;
357 	int	 c;
358 
359 	for (i = 0; i < history.len; ++i) {
360 		if (history.items[i].ts < history.items[oldest].ts)
361 			oldest = i;
362 
363 		if (insert != 0 && insert < i)
364 			continue;
365 
366 		c = strcmp(uri, history.items[i].uri);
367 		if (c == 0) {
368 			history.items[i].ts = time(NULL);
369 			history.items[i].dirty = 1;
370 			history.dirty++;
371 			autosave_hook();
372 			return;
373 		}
374 
375 		if (c > 0)
376 			insert = i;
377 	}
378 
379 	if ((u = strdup(uri)) == NULL)
380 		return;
381 
382 	/* if history is full, replace the oldest one */
383 	if (history.len == HISTORY_CAP) {
384 		free(history.items[oldest].uri);
385 		history.items[oldest].uri = u;
386 		history.items[oldest].ts = time(NULL);
387 		history.items[oldest].dirty = 1;
388 		history.dirty++;
389 		history_sort();
390 		autosave_hook();
391 		return;
392 	}
393 
394 	/* otherwise just insert in the right spot */
395 
396 	for (j = history.len; j > insert; --j)
397 		memcpy(&history.items[j], &history.items[j-1],
398 		    sizeof(history.items[j]));
399 
400 	history.items[insert].ts = time(NULL);
401 	history.items[insert].uri = u;
402 	history.items[insert].dirty = 1;
403 	history.dirty++;
404 	history.len++;
405 	autosave_hook();
406 }
407 
408 void
409 autosave_init(void)
410 {
411 	return;
412 }
413 
414 void
415 autosave_timer(int fd, int event, void *data)
416 {
417 	save_session();
418 }
419 
420 /*
421  * Function to be called in "interesting" places where we may want to
422  * schedule an autosave (like on new tab or before loading an url.)
423  */
424 void
425 autosave_hook(void)
426 {
427 	struct timeval tv;
428 
429 	if (autosave <= 0)
430 		return;
431 
432 	if (!ev_timer_pending(autosavetimer)) {
433 		tv.tv_sec = autosave;
434 		tv.tv_usec = 0;
435 
436 		autosavetimer = ev_timer(&tv, autosave_timer, NULL);
437 	}
438 }
439 
440 static inline int
441 parse_khost_line(char *line, char *tmp[3])
442 {
443 	char **ap;
444 
445 	for (ap = tmp; ap < &tmp[3] &&
446 	    (*ap = strsep(&line, " \t\n")) != NULL;) {
447 		if (**ap != '\0')
448 			ap++;
449 	}
450 
451 	return ap == &tmp[3] && *line == '\0';
452 }
453 
454 static void
455 load_certs(struct ohash *certs)
456 {
457 	char		*tmp[3], *line = NULL;
458 	const char	*errstr;
459 	size_t		 lineno = 0, linesize = 0;
460 	ssize_t		 linelen;
461 	FILE		*f;
462 	struct tofu_entry *e;
463 
464 	if ((f = fopen(known_hosts_file, "r")) == NULL)
465 		return;
466 
467 	if ((e = calloc(1, sizeof(*e))) == NULL) {
468 		fclose(f);
469 		return;
470 	}
471 
472 	while ((linelen = getline(&line, &linesize, f)) != -1) {
473 		lineno++;
474 
475 		if (parse_khost_line(line, tmp)) {
476 			strlcpy(e->domain, tmp[0], sizeof(e->domain));
477 			strlcpy(e->hash, tmp[1], sizeof(e->hash));
478 
479 			e->verified = strtonum(tmp[2], 0, 1, &errstr);
480 			if (errstr != NULL)
481 				errx(1, "%s:%zu verification for %s is %s: %s",
482 				    known_hosts_file, lineno,
483 				    e->domain, errstr, tmp[2]);
484 
485 			tofu_add(certs, e);
486 		} else
487 			warnx("%s:%zu invalid entry",
488 			    known_hosts_file, lineno);
489 	}
490 
491 	free(line);
492 	fclose(f);
493 	return;
494 }
495 
496 
497 static void
498 load_hist(void)
499 {
500 	FILE		*hist;
501 	size_t		 linesize = 0;
502 	ssize_t		 linelen;
503 	char		*nl, *spc, *line = NULL;
504 	const char	*errstr;
505 	struct histitem	 hi;
506 
507 	if ((hist = fopen(history_file, "r")) == NULL)
508 		return;
509 
510 	while ((linelen = getline(&line, &linesize, hist)) != -1) {
511 		if ((nl = strchr(line, '\n')) != NULL)
512 			*nl = '\0';
513 		if ((spc = strchr(line, ' ')) == NULL)
514 			continue;
515 		*spc = '\0';
516 		spc++;
517 
518 		memset(&hi, 0, sizeof(hi));
519 		hi.ts = strtonum(line, INT64_MIN, INT64_MAX, &errstr);
520 		if (errstr != NULL)
521 			continue;
522 		if (strlcpy(hi.uri, spc, sizeof(hi.uri)) >= sizeof(hi.uri))
523 			continue;
524 
525 		history_push(&hi);
526 	}
527 
528 	fclose(hist);
529 	free(line);
530 
531 	history_sort();
532 }
533 
534 /*
535  * Check if the last time telescope crashed.  The check is done by
536  * looking at `crashed_file': if it exists then last time we crashed.
537  * Then, while here, touch the file too, it's removed during the
538  * teardown.
539  */
540 static int
541 last_time_crashed(void)
542 {
543 	int fd, crashed = 1;
544 
545 	if (safe_mode)
546 		return 0;
547 
548 	if (unlink(crashed_file) == -1 && errno == ENOENT)
549 		crashed = 0;
550 
551 	if ((fd = open(crashed_file, O_CREAT|O_WRONLY, 0600)) == -1)
552 		return crashed;
553 	close(fd);
554 
555 	return crashed;
556 }
557 
558 /*
559  * Parse and restore a tab from the session file.  The format is:
560  *
561  *	URL [flags,...] [title]\n
562  */
563 static inline struct tab *
564 parse_tab_line(char *line, struct tab **ct)
565 {
566 	struct tab *tab;
567 	char *s, *t, *ap;
568 	const char *uri, *title = "";
569 	int current = 0, killed = 0;
570 	size_t tline = 0, cline = 0;
571 
572 	uri = line;
573 	if ((s = strchr(line, ' ')) == NULL)
574 		return NULL;
575 	*s++ = '\0';
576 
577 	if ((t = strchr(s, ' ')) != NULL) {
578 		*t++ = '\0';
579 		title = t;
580 	}
581 
582 	while ((ap = strsep(&s, ",")) != NULL) {
583 		if (!strcmp(ap, "current"))
584 			current = 1;
585 		else if (!strcmp(ap, "killed"))
586 			killed = 1;
587 		else if (!strncmp(ap, "top=", 4))
588 			tline = strtonum(ap+4, 0, UINT32_MAX, NULL);
589 		else if (!strncmp(ap, "cur=", 4))
590 			cline = strtonum(ap + 4, 0, UINT32_MAX, NULL);
591 	}
592 
593 	if (tline > cline) {
594 		tline = 0;
595 		cline = 0;
596 	}
597 
598 	if ((tab = new_tab(uri, NULL, NULL)) == NULL)
599 		err(1, "new_tab");
600 	hist_set_offs(tab->hist, tline, cline);
601 	strlcpy(tab->buffer.page.title, title, sizeof(tab->buffer.page.title));
602 
603 	if (current)
604 		*ct = tab;
605 	else if (killed)
606 		kill_tab(tab, 1);
607 
608 	return tab;
609 }
610 
611 static void
612 load_tabs(void)
613 {
614 	struct tab	*tab = NULL, *ct = NULL;
615 	FILE		*session;
616 	size_t		 lineno = 0, linesize = 0;
617 	ssize_t		 linelen;
618 	char		*uri, *line = NULL;
619 
620 	if ((session = fopen(session_file, "r")) == NULL) {
621 		new_tab("about:new", NULL, NULL);
622 		new_tab("about:help", NULL, NULL);
623 		return;
624 	}
625 
626 	while ((linelen = getline(&line, &linesize, session)) != -1) {
627 		lineno++;
628 
629 		if (linelen > 0 && line[linelen-1] == '\n')
630 			line[linelen-1] = '\0';
631 
632 		if (*line == '<' || *line == '>') {
633 			uri = line + 1;
634 			if (*uri != ' ' || tab == NULL) {
635 				fprintf(stderr, "%s:%zu invalid line\n",
636 				    session_file, lineno);
637 				continue;
638 			}
639 			uri++;
640 
641 			if (*line == '>') /* future hist */
642 				hist_append(tab->hist, uri);
643 			else
644 				hist_prepend(tab->hist, uri);
645 		} else
646 			tab = parse_tab_line(line, &ct);
647 	}
648 
649 	fclose(session);
650 	free(line);
651 
652 	if (ct == NULL || TAILQ_EMPTY(&tabshead))
653 		ct = new_tab("about:new", NULL, NULL);
654 
655 	switch_to_tab(ct);
656 
657 	if (last_time_crashed())
658 		new_tab("about:crash", NULL, NULL);
659 }
660 
661 int
662 load_session(struct ohash *certs)
663 {
664 	load_certs(certs);
665 	load_hist();
666 	load_tabs();
667 	return 0;
668 }
669 
670 int
671 lock_session(void)
672 {
673 	struct flock	lock;
674 	int		fd;
675 
676 	if ((fd = open(lockfile_path, O_WRONLY|O_CREAT, 0600)) == -1)
677 		return -1;
678 
679 	lock.l_start = 0;
680 	lock.l_len = 0;
681 	lock.l_type = F_WRLCK;
682 	lock.l_whence = SEEK_SET;
683 
684 	if (fcntl(fd, F_SETLK, &lock) == -1) {
685 		close(fd);
686 		return -1;
687 	}
688 
689 	return fd;
690 }