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 /*
18  * Handles config and runtime files
19  */
20 
21 #include "compat.h"
22 
23 #include <sys/stat.h>
24 #include <sys/types.h>
25 
26 #include <dirent.h>
27 #include <errno.h>
28 #include <fcntl.h>
29 #include <limits.h>
30 #include <libgen.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.h>
34 #include <unistd.h>
35 
36 #include "fs.h"
37 #include "pages.h"
38 #include "telescope.h"
39 #include "session.h"
40 #include "utils.h"
41 
42 static void		 die(void) __attribute__((__noreturn__));
43 static void		 send_file(uint32_t, FILE *);
44 static void		 handle_get(struct imsg*, size_t);
45 static int		 select_non_dot(const struct dirent *);
46 static int		 select_non_dotdot(const struct dirent *);
47 static void		 handle_get_file(struct imsg*, size_t);
48 static void		 handle_misc(struct imsg *, size_t);
49 static void		 handle_bookmark_page(struct imsg*, size_t);
50 static void		 handle_save_cert(struct imsg*, size_t);
51 static void		 handle_update_cert(struct imsg*, size_t);
52 static void		 handle_file_open(struct imsg*, size_t);
53 static void		 handle_session_start(struct imsg*, size_t);
54 static void		 handle_session_tab(struct imsg*, size_t);
55 static void		 handle_session_tab_hist(struct imsg*, size_t);
56 static void		 handle_session_end(struct imsg*, size_t);
57 static void		 handle_dispatch_imsg(int, short, void*);
58 static int		 fs_send_ui(int, uint32_t, int, const void *, uint16_t);
59 static size_t		 join_path(char*, const char*, const char*, size_t);
60 static void		 getenv_default(char*, const char*, const char*, size_t);
61 static void		 mkdirs(const char*, mode_t);
62 static void		 init_paths(void);
63 static void		 load_last_session(void);
64 static int		 last_time_crashed(void);
65 static void		 load_certs(void);
66 
67 static struct imsgev		*iev_ui;
68 static FILE			*session;
69 
70 /*
71  * Where to store user data.  These are all equal to ~/.telescope if
72  * it exists.
73  */
74 char		config_path_base[PATH_MAX];
75 char		data_path_base[PATH_MAX];
76 char		cache_path_base[PATH_MAX];
77 
78 char		ctlsock_path[PATH_MAX];
79 char		config_path[PATH_MAX];
80 char		lockfile_path[PATH_MAX];
81 char		bookmark_file[PATH_MAX];
82 char		known_hosts_file[PATH_MAX], known_hosts_tmp[PATH_MAX];
83 char		crashed_file[PATH_MAX];
84 char		session_file[PATH_MAX];
85 
86 static imsg_handlerfn *handlers[] = {
87 	[IMSG_GET] = handle_get,
88 	[IMSG_GET_FILE] = handle_get_file,
89 	[IMSG_QUIT] = handle_misc,
90 	[IMSG_INIT] = handle_misc,
91 	[IMSG_BOOKMARK_PAGE] = handle_bookmark_page,
92 	[IMSG_SAVE_CERT] = handle_save_cert,
93 	[IMSG_UPDATE_CERT] = handle_update_cert,
94 	[IMSG_FILE_OPEN] = handle_file_open,
95 	[IMSG_SESSION_START] = handle_session_start,
96 	[IMSG_SESSION_TAB] = handle_session_tab,
97 	[IMSG_SESSION_TAB_HIST] = handle_session_tab_hist,
98 	[IMSG_SESSION_END] = handle_session_end,
99 };
100 
101 static void __attribute__((__noreturn__))
102 die(void)
103 {
104 	abort(); 		/* TODO */
105 }
106 
107 static void
108 send_file(uint32_t peerid, FILE *f)
109 {
110 	ssize_t	 r;
111 	char	 buf[BUFSIZ];
112 
113 	for (;;) {
114 		r = fread(buf, 1, sizeof(buf), f);
115 		if (r != 0)
116 			fs_send_ui(IMSG_BUF, peerid, -1, buf, r);
117 		if (r != sizeof(buf))
118 			break;
119 	}
120 	fs_send_ui(IMSG_EOF, peerid, -1, NULL, 0);
121 	fclose(f);
122 }
123 
124 static void
125 handle_get(struct imsg *imsg, size_t datalen)
126 {
127 	const char	*bpath = "bookmarks.gmi";
128 	char		 path[PATH_MAX];
129 	FILE		*f;
130 	const char	*data, *p;
131 	size_t		 i;
132 	struct page {
133 		const char	*name;
134 		const char	*path;
135 		const uint8_t	*data;
136 		size_t		 len;
137 	} pages[] = {
138 		{"about",	NULL,	about_about,	about_about_len},
139 		{"blank",	NULL,	about_blank,	about_blank_len},
140 		{"bookmarks",	bpath,	bookmarks,	bookmarks_len},
141 		{"crash",	NULL,	about_crash,	about_crash_len},
142 		{"help",	NULL,	about_help,	about_help_len},
143 		{"license",	NULL,	about_license,	about_license_len},
144 		{"new",		NULL,	about_new,	about_new_len},
145 	}, *page = NULL;
146 
147 	data = imsg->data;
148 	if (data[datalen-1] != '\0') /* make sure it's NUL-terminated */
149 		die();
150 	if ((data = strchr(data, ':')) == NULL)
151 		goto notfound;
152 	data++;
153 
154 	for (i = 0; i < sizeof(pages)/sizeof(pages[0]); ++i)
155 		if (!strcmp(data, pages[i].name)) {
156 			page = &pages[i];
157 			break;
158 		}
159 
160 	if (page == NULL)
161 		goto notfound;
162 
163 	strlcpy(path, data_path_base, sizeof(path));
164 	strlcat(path, "/", sizeof(path));
165 	if (page->path != NULL)
166 		strlcat(path, page->path, sizeof(path));
167 	else {
168 		strlcat(path, "pages/about_", sizeof(path));
169 		strlcat(path, page->name, sizeof(path));
170 		strlcat(path, ".gmi", sizeof(path));
171 	}
172 
173 	if ((f = fopen(path, "r")) == NULL) {
174 		fs_send_ui(IMSG_BUF, imsg->hdr.peerid, -1,
175 		    page->data, page->len);
176 		fs_send_ui(IMSG_EOF, imsg->hdr.peerid, -1,
177 		    NULL, 0);
178 		return;
179 	}
180 
181 	send_file(imsg->hdr.peerid, f);
182 	return;
183 
184 notfound:
185 	p = "# not found!\n";
186 	fs_send_ui(IMSG_BUF, imsg->hdr.peerid, -1, p, strlen(p));
187 	fs_send_ui(IMSG_EOF, imsg->hdr.peerid, -1, NULL, 0);
188 }
189 
190 static inline void
191 send_hdr(uint32_t peerid, int code, const char *meta)
192 {
193 	fs_send_ui(IMSG_GOT_CODE, peerid, -1, &code, sizeof(code));
194 	fs_send_ui(IMSG_GOT_META, peerid, -1, meta, strlen(meta)+1);
195 }
196 
197 static inline void
198 send_errno(uint32_t peerid, int code, const char *str, int no)
199 {
200 	char *s;
201 
202 	if (asprintf(&s, "%s: %s", str, strerror(no)) == -1)
203 		s = NULL;
204 
205 	send_hdr(peerid, code, s == NULL ? str : s);
206 	free(s);
207 }
208 
209 static inline const char *
210 file_type(const char *path)
211 {
212 	struct mapping {
213 		const char	*ext;
214 		const char	*mime;
215 	} ms[] = {
216 		{"diff",	"text/x-patch"},
217 		{"gemini",	"text/gemini"},
218 		{"gmi",		"text/gemini"},
219 		{"markdown",	"text/plain"},
220 		{"md",		"text/plain"},
221 		{"patch",	"text/x-patch"},
222 		{"txt",		"text/plain"},
223 		{NULL, NULL},
224 	}, *m;
225 	char *dot;
226 
227 	if ((dot = strrchr(path, '.')) == NULL)
228 		return NULL;
229 
230 	dot++;
231 
232 	for (m = ms; m->ext != NULL; ++m)
233 		if (!strcmp(m->ext, dot))
234 			return m->mime;
235 
236 	return NULL;
237 }
238 
239 static int
240 select_non_dot(const struct dirent *d)
241 {
242 	return strcmp(d->d_name, ".");
243 }
244 
245 static int
246 select_non_dotdot(const struct dirent *d)
247 {
248 	return strcmp(d->d_name, ".") && strcmp(d->d_name, "..");
249 }
250 
251 static inline void
252 send_dir(uint32_t peerid, const char *path)
253 {
254 	struct dirent	**names;
255 	struct evbuffer	 *ev;
256 	char		 *s;
257 	int		(*selector)(const struct dirent *) = select_non_dot;
258 	int		  i, len, no;
259 
260 	if (!has_suffix(path, "/")) {
261 		if (asprintf(&s, "%s/", path) == -1)
262 			die();
263 		send_hdr(peerid, 30, s);
264 		free(s);
265 		return;
266 	}
267 
268 	if (!strcmp(path, "/"))
269 		selector = select_non_dotdot;
270 
271 	if ((ev = evbuffer_new()) == NULL ||
272 	    (len = scandir(path, &names, selector, alphasort)) == -1) {
273 		no = errno;
274 		evbuffer_free(ev);
275 		send_errno(peerid, 40, "failure reading the directory", no);
276 		return;
277 	}
278 
279 	evbuffer_add_printf(ev, "# Index of %s\n\n", path);
280 	for (i = 0; i < len; ++i) {
281 		evbuffer_add_printf(ev, "=> %s", names[i]->d_name);
282 		if (names[i]->d_type == DT_DIR)
283 			evbuffer_add(ev, "/", 1);
284 		evbuffer_add(ev, "\n", 1);
285 	}
286 
287 	send_hdr(peerid, 20, "text/gemini");
288 	fs_send_ui(IMSG_BUF, peerid, -1,
289 	    EVBUFFER_DATA(ev), EVBUFFER_LENGTH(ev));
290 	fs_send_ui(IMSG_EOF, peerid, -1, NULL, 0);
291 
292 	evbuffer_free(ev);
293 	free(names);
294 }
295 
296 static void
297 handle_get_file(struct imsg *imsg, size_t datalen)
298 {
299 	struct stat	 sb;
300 	FILE		*f;
301 	char		*data;
302 	const char	*meta = NULL;
303 
304 	data = imsg->data;
305 	data[datalen-1] = '\0';
306 
307 	if ((f = fopen(data, "r")) == NULL) {
308 		send_errno(imsg->hdr.peerid, 51, "can't open", errno);
309 		return;
310 	}
311 
312 	if (fstat(fileno(f), &sb) == -1) {
313 		send_errno(imsg->hdr.peerid, 40, "fstat", errno);
314 		return;
315 	}
316 
317 	if (S_ISDIR(sb.st_mode)) {
318 		fclose(f);
319 		send_dir(imsg->hdr.peerid, data);
320 		return;
321 	}
322 
323 	if ((meta = file_type(data)) == NULL) {
324 		fclose(f);
325 		send_hdr(imsg->hdr.peerid, 51,
326 		    "don't know how to visualize this file");
327 		return;
328 	}
329 
330 	send_hdr(imsg->hdr.peerid, 20, meta);
331 	send_file(imsg->hdr.peerid, f);
332 }
333 
334 static void
335 handle_misc(struct imsg *imsg, size_t datalen)
336 {
337 	switch (imsg->hdr.type) {
338 	case IMSG_INIT:
339 		load_certs();
340 		load_last_session();
341 		break;
342 
343 	case IMSG_QUIT:
344 		if (!safe_mode)
345 			unlink(crashed_file);
346 		event_loopbreak();
347 		break;
348 
349 	default:
350 		die();
351 	}
352 }
353 
354 static void
355 handle_bookmark_page(struct imsg *imsg, size_t datalen)
356 {
357 	char	*data;
358 	int	 res;
359 	FILE	*f;
360 
361 	data = imsg->data;
362 	if (data[datalen-1] != '\0')
363 		die();
364 
365 	if ((f = fopen(bookmark_file, "a")) == NULL) {
366 		res = errno;
367 		goto end;
368 	}
369 	fprintf(f, "=> %s\n", data);
370 	fclose(f);
371 
372 	res = 0;
373 end:
374 	fs_send_ui(IMSG_BOOKMARK_OK, 0, -1, &res, sizeof(res));
375 }
376 
377 static void
378 handle_save_cert(struct imsg *imsg, size_t datalen)
379 {
380 	struct tofu_entry	 e;
381 	FILE			*f;
382 	int			 res;
383 
384 	/* TODO: traverse the file to avoid duplications? */
385 
386 	if (datalen != sizeof(e))
387 		die();
388 	memcpy(&e, imsg->data, datalen);
389 
390 	if ((f = fopen(known_hosts_file, "a")) == NULL) {
391 		res = errno;
392 		goto end;
393 	}
394 	fprintf(f, "%s %s %d\n", e.domain, e.hash, e.verified);
395 	fclose(f);
396 
397 	res = 0;
398 end:
399 	fs_send_ui(IMSG_SAVE_CERT_OK, imsg->hdr.peerid, -1,
400 	    &res, sizeof(res));
401 }
402 
403 static void
404 handle_update_cert(struct imsg *imsg, size_t datalen)
405 {
406 	FILE	*tmp, *f;
407 	struct	 tofu_entry entry;
408 	char	 sfn[PATH_MAX], *line = NULL, *t;
409 	size_t	 l, linesize = 0;
410 	ssize_t	 linelen;
411 	int	 fd, e, res = 0;
412 
413 	if (datalen != sizeof(entry))
414 		die();
415 	memcpy(&entry, imsg->data, datalen);
416 
417 	strlcpy(sfn, known_hosts_tmp, sizeof(sfn));
418 	if ((fd = mkstemp(sfn)) == -1 ||
419 	    (tmp = fdopen(fd, "w")) == NULL) {
420 		if (fd != -1) {
421 			unlink(sfn);
422 			close(fd);
423 		}
424 		res = 0;
425 		goto end;
426 	}
427 
428 	if ((f = fopen(known_hosts_file, "r")) == NULL) {
429 		unlink(sfn);
430 		fclose(tmp);
431                 res = 0;
432 		goto end;
433 	}
434 
435 	l = strlen(entry.domain);
436 	while ((linelen = getline(&line, &linesize, f)) != -1) {
437 		if ((t = strstr(line, entry.domain)) != NULL &&
438 		    (line[l] == ' ' || line[l] == '\t'))
439 			continue;
440 		/* line has a trailing \n */
441 		fprintf(tmp, "%s", line);
442 	}
443 	fprintf(tmp, "%s %s %d\n", entry.domain, entry.hash, entry.verified);
444 
445 	free(line);
446 	e = ferror(tmp);
447 
448 	fclose(tmp);
449 	fclose(f);
450 
451 	if (e) {
452 		unlink(sfn);
453 		res = 0;
454 		goto end;
455 	}
456 
457 	res = rename(sfn, known_hosts_file) != -1;
458 
459 end:
460 	fs_send_ui(IMSG_UPDATE_CERT_OK, imsg->hdr.peerid, -1,
461 	    &res, sizeof(res));
462 }
463 
464 static void
465 handle_file_open(struct imsg *imsg, size_t datalen)
466 {
467 	char	*path, *e;
468 	int	 fd;
469 
470 	path = imsg->data;
471 	if (path[datalen-1] != '\0')
472 		die();
473 
474 	if ((fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, 0644)) == -1) {
475 		e = strerror(errno);
476 		fs_send_ui(IMSG_FILE_OPENED, imsg->hdr.peerid, -1,
477 		    e, strlen(e)+1);
478 	} else
479 		fs_send_ui(IMSG_FILE_OPENED, imsg->hdr.peerid, fd,
480 		    NULL, 0);
481 }
482 
483 static void
484 handle_session_start(struct imsg *imsg, size_t datalen)
485 {
486 	if (datalen != 0)
487 		die();
488 
489 	if ((session = fopen(session_file, "w")) == NULL)
490 		die();
491 }
492 
493 static void
494 handle_session_tab(struct imsg *imsg, size_t datalen)
495 {
496 	struct session_tab	tab;
497 
498 	if (session == NULL)
499 		die();
500 
501 	if (datalen != sizeof(tab))
502 		die();
503 
504 	memcpy(&tab, imsg->data, sizeof(tab));
505 	if (tab.uri[sizeof(tab.uri)-1] != '\0' ||
506 	    tab.title[sizeof(tab.title)-1] != '\0')
507 		die();
508 
509 	fprintf(session, "%s ", tab.uri);
510 
511 	if (tab.flags & TAB_CURRENT)
512 		fprintf(session, "current,");
513 	if (tab.flags & TAB_KILLED)
514 		fprintf(session, "killed,");
515 
516 	fprintf(session, "top=%zu,cur=%zu %s\n", tab.top_line,
517 	    tab.current_line, tab.title);
518 }
519 
520 static void
521 handle_session_tab_hist(struct imsg *imsg, size_t datalen)
522 {
523 	struct session_tab_hist th;
524 
525 	if (session == NULL)
526 		die();
527 
528 	if (datalen != sizeof(th))
529 		die();
530 
531 	memcpy(&th, imsg->data, sizeof(th));
532 	if (th.uri[sizeof(th.uri)-1] != '\0')
533 		die();
534 
535 	fprintf(session, "%s %s\n", th.future ? ">" : "<", th.uri);
536 }
537 
538 static void
539 handle_session_end(struct imsg *imsg, size_t datalen)
540 {
541 	if (session == NULL)
542 		die();
543 	fclose(session);
544 	session = NULL;
545 }
546 
547 static void
548 handle_dispatch_imsg(int fd, short ev, void *d)
549 {
550 	struct imsgev	*iev = d;
551 	int		 e;
552 
553 	if (dispatch_imsg(iev, ev, handlers, sizeof(handlers)) == -1) {
554 		/*
555 		 * This should leave a ~/.cache/telescope/crashed file to
556 		 * trigger about:crash on next run.  Unfortunately, if
557 		 * the main process dies the fs sticks around and
558 		 * doesn't notice that the fd was closed.  Why EV_READ
559 		 * is not triggered when a fd is closed on the other end?
560 		 */
561 		e = errno;
562 		if ((fd = open(crashed_file, O_CREAT|O_TRUNC|O_WRONLY, 0600))
563 		    == -1)
564 			err(1, "open");
565 		close(fd);
566 		errx(1, "connection closed: %s", strerror(e));
567 	}
568 }
569 
570 static int
571 fs_send_ui(int type, uint32_t peerid, int fd, const void *data,
572     uint16_t datalen)
573 {
574 	return imsg_compose_event(iev_ui, type, peerid, 0, fd,
575 	    data, datalen);
576 }
577 
578 static size_t
579 join_path(char *buf, const char *lhs, const char *rhs, size_t buflen)
580 {
581 	strlcpy(buf, lhs, buflen);
582 	return strlcat(buf, rhs, buflen);
583 }
584 
585 static void
586 getenv_default(char *buf, const char *name, const char *def, size_t buflen)
587 {
588 	size_t ret;
589 	char *home, *env;
590 
591 	if ((home = getenv("HOME")) == NULL)
592 		errx(1, "HOME is not defined");
593 
594 	if ((env = getenv(name)) != NULL)
595 		ret = strlcpy(buf, env, buflen);
596 	else
597 		ret = join_path(buf, home, def, buflen);
598 
599 	if (ret >= buflen)
600 		errx(1, "buffer too small for %s", name);
601 }
602 
603 static void
604 mkdirs(const char *path, mode_t mode)
605 {
606 	char copy[PATH_MAX+1], orig[PATH_MAX+1], *parent;
607 
608 	strlcpy(copy, path, sizeof(copy));
609 	strlcpy(orig, path, sizeof(orig));
610 	parent = dirname(copy);
611 	if (!strcmp(parent, "/"))
612 		return;
613 	mkdirs(parent, mode);
614 
615 	if (mkdir(orig, mode) != 0) {
616 		if (errno == EEXIST)
617 			return;
618 		err(1, "can't mkdir %s", orig);
619 	}
620 }
621 
622 static void
623 init_paths(void)
624 {
625 	char		 xdg_config_base[PATH_MAX];
626 	char		 xdg_data_base[PATH_MAX];
627 	char		 xdg_cache_base[PATH_MAX];
628 	char		 old_path[PATH_MAX];
629 	char		*home;
630 	struct stat	 info;
631 
632 	/* old path */
633 	if ((home = getenv("HOME")) == NULL)
634 		errx(1, "HOME is not defined");
635 	join_path(old_path, home, "/.telescope", sizeof(old_path));
636 
637 	/* if ~/.telescope exists, use that instead of xdg dirs */
638 	if (stat(old_path, &info) == 0 && S_ISDIR(info.st_mode)) {
639 		join_path(config_path_base, home, "/.telescope",
640 		    sizeof(config_path_base));
641 		join_path(data_path_base, home, "/.telescope",
642 		    sizeof(data_path_base));
643 		join_path(cache_path_base, home, "/.telescope",
644 		    sizeof(cache_path_base));
645 		return;
646 	}
647 
648 	/* xdg paths */
649 	getenv_default(xdg_config_base, "XDG_CONFIG_HOME", "/.config",
650 	    sizeof(xdg_config_base));
651 	getenv_default(xdg_data_base, "XDG_DATA_HOME", "/.local/share",
652 	    sizeof(xdg_data_base));
653 	getenv_default(xdg_cache_base, "XDG_CACHE_HOME", "/.cache",
654 	    sizeof(xdg_cache_base));
655 
656 	join_path(config_path_base, xdg_config_base, "/telescope",
657 	    sizeof(config_path_base));
658 	join_path(data_path_base, xdg_data_base, "/telescope",
659 	    sizeof(data_path_base));
660 	join_path(cache_path_base, xdg_cache_base, "/telescope",
661 	    sizeof(cache_path_base));
662 
663 	mkdirs(xdg_config_base, S_IRWXU);
664 	mkdirs(xdg_data_base, S_IRWXU);
665 	mkdirs(xdg_cache_base, S_IRWXU);
666 
667 	mkdirs(config_path_base, S_IRWXU);
668 	mkdirs(data_path_base, S_IRWXU);
669 	mkdirs(cache_path_base, S_IRWXU);
670 }
671 
672 int
673 fs_init(void)
674 {
675 	init_paths();
676 
677 	join_path(ctlsock_path, cache_path_base, "/ctl",
678 	    sizeof(ctlsock_path));
679 	join_path(config_path, config_path_base, "/config",
680 	    sizeof(config_path));
681 	join_path(lockfile_path, cache_path_base, "/lock",
682 	    sizeof(lockfile_path));
683 	join_path(bookmark_file, data_path_base, "/bookmarks.gmi",
684 	    sizeof(bookmark_file));
685 	join_path(known_hosts_file, data_path_base, "/known_hosts",
686 	    sizeof(known_hosts_file));
687 	join_path(known_hosts_tmp, cache_path_base,
688 	    "/known_hosts.tmp.XXXXXXXXXX", sizeof(known_hosts_tmp));
689 	join_path(session_file, cache_path_base, "/session",
690 	    sizeof(session_file));
691 	join_path(crashed_file, cache_path_base, "/crashed",
692 	    sizeof(crashed_file));
693 
694 	return 1;
695 }
696 
697 /*
698  * Parse a line of the session file.  The format is:
699  *
700  *	URL [flags,...] [title]\n
701  */
702 static void
703 parse_session_line(char *line)
704 {
705 	struct session_tab tab;
706 	char *s, *t, *ap;
707 
708 	memset(&tab, 0, sizeof(tab));
709 
710 	if ((s = strchr(line, ' ')) == NULL)
711 		return;
712 
713 	*s++ = '\0';
714 
715 	if (strlcpy(tab.uri, line, sizeof(tab.uri)) >= sizeof(tab.uri))
716 		return;
717 
718 	if ((t = strchr(s, ' ')) != NULL) {
719 		*t++ = '\0';
720 
721 		/* don't worry about cached title truncation */
722 		strlcpy(tab.title, t, sizeof(tab.title));
723 	}
724 
725 	while ((ap = strsep(&s, ",")) != NULL) {
726 		if (!strcmp(ap, "current"))
727 			tab.flags |= TAB_CURRENT;
728 		else if (!strcmp(ap, "killed"))
729 			tab.flags |= TAB_KILLED;
730 		else if (has_prefix(ap, "top="))
731 			tab.top_line = strtonum(ap+4, 0, UINT32_MAX, NULL);
732 		else if (has_prefix(ap, "cur="))
733 			tab.current_line = strtonum(ap+4, 0, UINT32_MAX, NULL);
734 	}
735 
736 	if (tab.top_line > tab.current_line) {
737 		tab.top_line = 0;
738 		tab.current_line = 0;
739 	}
740 
741 	fs_send_ui(IMSG_SESSION_TAB, 0, -1, &tab, sizeof(tab));
742 }
743 
744 static inline void
745 sendhist(const char *uri, int future)
746 {
747 	struct session_tab_hist sth;
748 
749 	memset(&sth, 0, sizeof(sth));
750 	sth.future = future;
751 
752 	if (strlcpy(sth.uri, uri, sizeof(sth.uri)) >= sizeof(sth.uri))
753 		return;
754 
755 	fs_send_ui(IMSG_SESSION_TAB_HIST, 0, -1, &sth, sizeof(sth));
756 }
757 
758 static void
759 load_last_session(void)
760 {
761 	FILE		*session;
762 	size_t		 linesize = 0;
763 	ssize_t		 linelen;
764 	int		 first_time = 0;
765 	int		 future;
766 	char		*nl, *s, *line = NULL;
767 
768 	if ((session = fopen(session_file, "r")) == NULL) {
769 		/* first time? */
770 		first_time = 1;
771 		goto end;
772 	}
773 
774 	while ((linelen = getline(&line, &linesize, session)) != -1) {
775 		if ((nl = strchr(line, '\n')) != NULL)
776 			*nl = '\0';
777 
778 		if (*line == '<' || *line == '>') {
779 			future = *line == '>';
780 			s = line+1;
781 			if (*s != ' ')
782 				continue;
783 			sendhist(++s, future);
784 		} else {
785 			parse_session_line(line);
786 		}
787 	}
788 
789 	fclose(session);
790 	free(line);
791 
792 	if (last_time_crashed()) {
793 		struct session_tab tab;
794 		memset(&tab, 0, sizeof(tab));
795 		tab.flags = TAB_CURRENT;
796 		strlcpy(tab.uri, "about:crash", sizeof(tab.uri));
797 		fs_send_ui(IMSG_SESSION_TAB, 0, -1, &tab, sizeof(tab));
798 	}
799 
800 end:
801 	fs_send_ui(IMSG_SESSION_END, 0, -1, &first_time, sizeof(first_time));
802 }
803 
804 int
805 fs_main(void)
806 {
807 	setproctitle("fs");
808 
809 	fs_init();
810 
811 	event_init();
812 
813 	/* Setup pipe and event handler to the main process */
814 	if ((iev_ui = malloc(sizeof(*iev_ui))) == NULL)
815 		die();
816 	imsg_init(&iev_ui->ibuf, 3);
817 	iev_ui->handler = handle_dispatch_imsg;
818 	iev_ui->events = EV_READ;
819 	event_set(&iev_ui->ev, iev_ui->ibuf.fd, iev_ui->events,
820 	    iev_ui->handler, iev_ui);
821 	event_add(&iev_ui->ev, NULL);
822 
823 	sandbox_fs_process();
824 
825 	event_dispatch();
826 	return 0;
827 }
828 
829 /*
830  * Check if the last time telescope crashed.  The check is done by
831  * looking at `crashed_file': if it exists then last time we crashed.
832  * Then, while here, touch the file too.  During IMSG_QUIT we'll
833  * remove it.
834  */
835 static int
836 last_time_crashed(void)
837 {
838 	int fd, crashed = 1;
839 
840 	if (safe_mode)
841 		return 0;
842 
843 	if (unlink(crashed_file) == -1 && errno == ENOENT)
844 		crashed = 0;
845 
846 	if ((fd = open(crashed_file, O_CREAT|O_WRONLY, 0600)) == -1)
847 		return crashed;
848 	close(fd);
849 
850 	return crashed;
851 }
852 
853 int
854 lock_session(void)
855 {
856 	struct flock	lock;
857 	int		fd;
858 
859 	if ((fd = open(lockfile_path, O_WRONLY|O_CREAT, 0600)) == -1)
860 		return -1;
861 
862 	lock.l_start = 0;
863 	lock.l_len = 0;
864 	lock.l_type = F_WRLCK;
865 	lock.l_whence = SEEK_SET;
866 
867 	if (fcntl(fd, F_SETLK, &lock) == -1) {
868 		close(fd);
869 		return -1;
870 	}
871 
872 	return fd;
873 }
874 
875 static inline int
876 parse_khost_line(char *line, char *tmp[3])
877 {
878 	char **ap;
879 
880 	for (ap = tmp; ap < &tmp[3] &&
881 	    (*ap = strsep(&line, " \t\n")) != NULL;) {
882 		if (**ap != '\0')
883 			ap++;
884 	}
885 
886 	return ap == &tmp[3] && *line == '\0';
887 }
888 
889 static void
890 load_certs(void)
891 {
892 	char		*tmp[3], *line = NULL;
893 	const char	*errstr;
894 	size_t		 lineno = 0, linesize = 0;
895 	ssize_t		 linelen;
896 	FILE		*f;
897 	struct tofu_entry e;
898 
899 	if ((f = fopen(known_hosts_file, "r")) == NULL)
900 		return;
901 
902 	while ((linelen = getline(&line, &linesize, f)) != -1) {
903 		lineno++;
904 
905 		memset(&e, 0, sizeof(e));
906 		if (parse_khost_line(line, tmp)) {
907 			strlcpy(e.domain, tmp[0], sizeof(e.domain));
908 			strlcpy(e.hash, tmp[1], sizeof(e.hash));
909 
910 			e.verified = strtonum(tmp[2], 0, 1, &errstr);
911 			if (errstr != NULL)
912 				errx(1, "%s:%zu verification for %s is %s: %s",
913 				    known_hosts_file, lineno,
914 				    e.domain, errstr, tmp[2]);
915 
916 			fs_send_ui(IMSG_TOFU, 0, -1, &e, sizeof(e));
917 		} else {
918 			warnx("%s:%zu invalid entry",
919 			    known_hosts_file, lineno);
920 		}
921 	}
922 
923 	free(line);
924 	fclose(f);
925 	return;
926 }
927