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