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Date:: Mon Jan 3 12:56:38 2022 UTC
Message:: s/xdg_init/init_paths/g
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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 
41 static void		 die(void) __attribute__((__noreturn__));
42 static void		 send_file(uint32_t, FILE *);
43 static void		 handle_get(struct imsg*, size_t);
44 static int		 select_non_dot(const struct dirent *);
45 static int		 select_non_dotdot(const struct dirent *);
46 static void		 handle_get_file(struct imsg*, size_t);
47 static void		 handle_misc(struct imsg *, size_t);
48 static void		 handle_bookmark_page(struct imsg*, size_t);
49 static void		 handle_save_cert(struct imsg*, size_t);
50 static void		 handle_update_cert(struct imsg*, size_t);
51 static void		 handle_file_open(struct imsg*, size_t);
52 static void		 handle_session_start(struct imsg*, size_t);
53 static void		 handle_session_tab(struct imsg*, size_t);
54 static void		 handle_session_tab_hist(struct imsg*, size_t);
55 static void		 handle_session_end(struct imsg*, size_t);
56 static void		 handle_dispatch_imsg(int, short, void*);
57 static int		 fs_send_ui(int, uint32_t, int, const void *, uint16_t);
58 static size_t		 join_path(char*, const char*, const char*, size_t);
59 static void		 getenv_default(char*, const char*, const char*, size_t);
60 static void		 mkdirs(const char*, mode_t);
61 static void		 init_paths(void);
62 static void		 load_last_session(void);
63 static void		 load_certs(void);
64 
65 static struct imsgev		*iev_ui;
66 static FILE			*session;
67 
68 /*
69  * Where to store user data.  These are all equal to ~/.telescope if
70  * it exists.
71  */
72 char		config_path_base[PATH_MAX];
73 char		data_path_base[PATH_MAX];
74 char		cache_path_base[PATH_MAX];
75 
76 char		config_path[PATH_MAX];
77 char		lockfile_path[PATH_MAX];
78 char		bookmark_file[PATH_MAX];
79 char		known_hosts_file[PATH_MAX], known_hosts_tmp[PATH_MAX];
80 char		crashed_file[PATH_MAX];
81 char		session_file[PATH_MAX];
82 
83 static imsg_handlerfn *handlers[] = {
84 	[IMSG_GET] = handle_get,
85 	[IMSG_GET_FILE] = handle_get_file,
86 	[IMSG_QUIT] = handle_misc,
87 	[IMSG_INIT] = handle_misc,
88 	[IMSG_BOOKMARK_PAGE] = handle_bookmark_page,
89 	[IMSG_SAVE_CERT] = handle_save_cert,
90 	[IMSG_UPDATE_CERT] = handle_update_cert,
91 	[IMSG_FILE_OPEN] = handle_file_open,
92 	[IMSG_SESSION_START] = handle_session_start,
93 	[IMSG_SESSION_TAB] = handle_session_tab,
94 	[IMSG_SESSION_TAB_HIST] = handle_session_tab_hist,
95 	[IMSG_SESSION_END] = handle_session_end,
96 };
97 
98 static void __attribute__((__noreturn__))
99 die(void)
100 {
101 	abort(); 		/* TODO */
102 }
103 
104 static void
105 send_file(uint32_t peerid, FILE *f)
106 {
107 	ssize_t	 r;
108 	char	 buf[BUFSIZ];
109 
110 	for (;;) {
111 		r = fread(buf, 1, sizeof(buf), f);
112 		if (r != 0)
113 			fs_send_ui(IMSG_BUF, peerid, -1, buf, r);
114 		if (r != sizeof(buf))
115 			break;
116 	}
117 	fs_send_ui(IMSG_EOF, peerid, -1, NULL, 0);
118 	fclose(f);
119 }
120 
121 static void
122 handle_get(struct imsg *imsg, size_t datalen)
123 {
124 	const char	*bpath = "bookmarks.gmi";
125 	char		 path[PATH_MAX];
126 	FILE		*f;
127 	const char	*data, *p;
128 	size_t		 i;
129 	struct page {
130 		const char	*name;
131 		const char	*path;
132 		const uint8_t	*data;
133 		size_t		 len;
134 	} pages[] = {
135 		{"about",	NULL,	about_about,	about_about_len},
136 		{"blank",	NULL,	about_blank,	about_blank_len},
137 		{"bookmarks",	bpath,	bookmarks,	bookmarks_len},
138 		{"crash",	NULL,	about_crash,	about_crash_len},
139 		{"help",	NULL,	about_help,	about_help_len},
140 		{"license",	NULL,	about_license,	about_license_len},
141 		{"new",		NULL,	about_new,	about_new_len},
142 	}, *page = NULL;
143 
144 	data = imsg->data;
145 	if (data[datalen-1] != '\0') /* make sure it's NUL-terminated */
146 		die();
147 	if ((data = strchr(data, ':')) == NULL)
148 		goto notfound;
149 	data++;
150 
151 	for (i = 0; i < sizeof(pages)/sizeof(pages[0]); ++i)
152 		if (!strcmp(data, pages[i].name)) {
153 			page = &pages[i];
154 			break;
155 		}
156 
157 	if (page == NULL)
158 		goto notfound;
159 
160 	strlcpy(path, data_path_base, sizeof(path));
161 	strlcat(path, "/", sizeof(path));
162 	if (page->path != NULL)
163 		strlcat(path, page->path, sizeof(path));
164 	else {
165 		strlcat(path, "pages/about_", sizeof(path));
166 		strlcat(path, page->name, sizeof(path));
167 		strlcat(path, ".gmi", sizeof(path));
168 	}
169 
170 	if ((f = fopen(path, "r")) == NULL) {
171 		fs_send_ui(IMSG_BUF, imsg->hdr.peerid, -1,
172 		    page->data, page->len);
173 		fs_send_ui(IMSG_EOF, imsg->hdr.peerid, -1,
174 		    NULL, 0);
175 		return;
176 	}
177 
178 	send_file(imsg->hdr.peerid, f);
179 	return;
180 
181 notfound:
182 	p = "# not found!\n";
183 	fs_send_ui(IMSG_BUF, imsg->hdr.peerid, -1, p, strlen(p));
184 	fs_send_ui(IMSG_EOF, imsg->hdr.peerid, -1, NULL, 0);
185 }
186 
187 static inline void
188 send_hdr(uint32_t peerid, int code, const char *meta)
189 {
190 	fs_send_ui(IMSG_GOT_CODE, peerid, -1, &code, sizeof(code));
191 	fs_send_ui(IMSG_GOT_META, peerid, -1, meta, strlen(meta)+1);
192 }
193 
194 static inline void
195 send_errno(uint32_t peerid, int code, const char *str, int no)
196 {
197 	char *s;
198 
199 	if (asprintf(&s, "%s: %s", str, strerror(no)) == -1)
200 		s = NULL;
201 
202 	send_hdr(peerid, code, s == NULL ? str : s);
203 	free(s);
204 }
205 
206 static inline const char *
207 file_type(const char *path)
208 {
209 	struct mapping {
210 		const char	*ext;
211 		const char	*mime;
212 	} ms[] = {
213 		{"diff",	"text/x-patch"},
214 		{"gemini",	"text/gemini"},
215 		{"gmi",		"text/gemini"},
216 		{"markdown",	"text/plain"},
217 		{"md",		"text/plain"},
218 		{"patch",	"text/x-patch"},
219 		{"txt",		"text/plain"},
220 		{NULL, NULL},
221 	}, *m;
222 	char *dot;
223 
224 	if ((dot = strrchr(path, '.')) == NULL)
225 		return NULL;
226 
227 	dot++;
228 
229 	for (m = ms; m->ext != NULL; ++m)
230 		if (!strcmp(m->ext, dot))
231 			return m->mime;
232 
233 	return NULL;
234 }
235 
236 static int
237 select_non_dot(const struct dirent *d)
238 {
239 	return strcmp(d->d_name, ".");
240 }
241 
242 static int
243 select_non_dotdot(const struct dirent *d)
244 {
245 	return strcmp(d->d_name, ".") && strcmp(d->d_name, "..");
246 }
247 
248 static inline void
249 send_dir(uint32_t peerid, const char *path)
250 {
251 	struct dirent	**names;
252 	struct evbuffer	 *ev;
253 	char		 *s;
254 	int		(*selector)(const struct dirent *) = select_non_dot;
255 	int		  i, len, no;
256 
257 	if (!has_suffix(path, "/")) {
258 		if (asprintf(&s, "%s/", path) == -1)
259 			die();
260 		send_hdr(peerid, 30, s);
261 		free(s);
262 		return;
263 	}
264 
265 	if (!strcmp(path, "/"))
266 		selector = select_non_dotdot;
267 
268 	if ((ev = evbuffer_new()) == NULL ||
269 	    (len = scandir(path, &names, selector, alphasort)) == -1) {
270 		no = errno;
271 		evbuffer_free(ev);
272 		send_errno(peerid, 40, "failure reading the directory", no);
273 		return;
274 	}
275 
276 	evbuffer_add_printf(ev, "# Index of %s\n\n", path);
277 	for (i = 0; i < len; ++i) {
278 		evbuffer_add_printf(ev, "=> %s", names[i]->d_name);
279 		if (names[i]->d_type == DT_DIR)
280 			evbuffer_add(ev, "/", 1);
281 		evbuffer_add(ev, "\n", 1);
282 	}
283 
284 	send_hdr(peerid, 20, "text/gemini");
285 	fs_send_ui(IMSG_BUF, peerid, -1,
286 	    EVBUFFER_DATA(ev), EVBUFFER_LENGTH(ev));
287 	fs_send_ui(IMSG_EOF, peerid, -1, NULL, 0);
288 
289 	evbuffer_free(ev);
290 	free(names);
291 }
292 
293 static void
294 handle_get_file(struct imsg *imsg, size_t datalen)
295 {
296 	struct stat	 sb;
297 	FILE		*f;
298 	char		*data;
299 	const char	*meta = NULL;
300 
301 	data = imsg->data;
302 	data[datalen-1] = '\0';
303 
304 	if ((f = fopen(data, "r")) == NULL) {
305 		send_errno(imsg->hdr.peerid, 51, "can't open", errno);
306 		return;
307 	}
308 
309 	if (fstat(fileno(f), &sb) == -1) {
310 		send_errno(imsg->hdr.peerid, 40, "fstat", errno);
311 		return;
312 	}
313 
314 	if (S_ISDIR(sb.st_mode)) {
315 		fclose(f);
316 		send_dir(imsg->hdr.peerid, data);
317 		return;
318 	}
319 
320 	if ((meta = file_type(data)) == NULL) {
321 		fclose(f);
322 		send_hdr(imsg->hdr.peerid, 51,
323 		    "don't know how to visualize this file");
324 		return;
325 	}
326 
327 	send_hdr(imsg->hdr.peerid, 20, meta);
328 	send_file(imsg->hdr.peerid, f);
329 }
330 
331 static void
332 handle_misc(struct imsg *imsg, size_t datalen)
333 {
334 	switch (imsg->hdr.type) {
335 	case IMSG_INIT:
336 		load_certs();
337 		load_last_session();
338 		break;
339 
340 	case IMSG_QUIT:
341 		if (!safe_mode)
342 			unlink(crashed_file);
343 		event_loopbreak();
344 		break;
345 
346 	default:
347 		die();
348 	}
349 }
350 
351 static void
352 handle_bookmark_page(struct imsg *imsg, size_t datalen)
353 {
354 	char	*data;
355 	int	 res;
356 	FILE	*f;
357 
358 	data = imsg->data;
359 	if (data[datalen-1] != '\0')
360 		die();
361 
362 	if ((f = fopen(bookmark_file, "a")) == NULL) {
363 		res = errno;
364 		goto end;
365 	}
366 	fprintf(f, "=> %s\n", data);
367 	fclose(f);
368 
369 	res = 0;
370 end:
371 	fs_send_ui(IMSG_BOOKMARK_OK, 0, -1, &res, sizeof(res));
372 }
373 
374 static void
375 handle_save_cert(struct imsg *imsg, size_t datalen)
376 {
377 	struct tofu_entry	 e;
378 	FILE			*f;
379 	int			 res;
380 
381 	/* TODO: traverse the file to avoid duplications? */
382 
383 	if (datalen != sizeof(e))
384 		die();
385 	memcpy(&e, imsg->data, datalen);
386 
387 	if ((f = fopen(known_hosts_file, "a")) == NULL) {
388 		res = errno;
389 		goto end;
390 	}
391 	fprintf(f, "%s %s %d\n", e.domain, e.hash, e.verified);
392 	fclose(f);
393 
394 	res = 0;
395 end:
396 	fs_send_ui(IMSG_SAVE_CERT_OK, imsg->hdr.peerid, -1,
397 	    &res, sizeof(res));
398 }
399 
400 static void
401 handle_update_cert(struct imsg *imsg, size_t datalen)
402 {
403 	FILE	*tmp, *f;
404 	struct	 tofu_entry entry;
405 	char	 sfn[PATH_MAX], *line = NULL, *t;
406 	size_t	 l, linesize = 0;
407 	ssize_t	 linelen;
408 	int	 fd, e, res = 0;
409 
410 	if (datalen != sizeof(entry))
411 		die();
412 	memcpy(&entry, imsg->data, datalen);
413 
414 	strlcpy(sfn, known_hosts_tmp, sizeof(sfn));
415 	if ((fd = mkstemp(sfn)) == -1 ||
416 	    (tmp = fdopen(fd, "w")) == NULL) {
417 		if (fd != -1) {
418 			unlink(sfn);
419 			close(fd);
420 		}
421 		res = 0;
422 		goto end;
423 	}
424 
425 	if ((f = fopen(known_hosts_file, "r")) == NULL) {
426 		unlink(sfn);
427 		fclose(tmp);
428                 res = 0;
429 		goto end;
430 	}
431 
432 	l = strlen(entry.domain);
433 	while ((linelen = getline(&line, &linesize, f)) != -1) {
434 		if ((t = strstr(line, entry.domain)) != NULL &&
435 		    (line[l] == ' ' || line[l] == '\t'))
436 			continue;
437 		/* line has a trailing \n */
438 		fprintf(tmp, "%s", line);
439 	}
440 	fprintf(tmp, "%s %s %d\n", entry.domain, entry.hash, entry.verified);
441 
442 	free(line);
443 	e = ferror(tmp);
444 
445 	fclose(tmp);
446 	fclose(f);
447 
448 	if (e) {
449 		unlink(sfn);
450 		res = 0;
451 		goto end;
452 	}
453 
454 	res = rename(sfn, known_hosts_file) != -1;
455 
456 end:
457 	fs_send_ui(IMSG_UPDATE_CERT_OK, imsg->hdr.peerid, -1,
458 	    &res, sizeof(res));
459 }
460 
461 static void
462 handle_file_open(struct imsg *imsg, size_t datalen)
463 {
464 	char	*path, *e;
465 	int	 fd;
466 
467 	path = imsg->data;
468 	if (path[datalen-1] != '\0')
469 		die();
470 
471 	if ((fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, 0644)) == -1) {
472 		e = strerror(errno);
473 		fs_send_ui(IMSG_FILE_OPENED, imsg->hdr.peerid, -1,
474 		    e, strlen(e)+1);
475 	} else
476 		fs_send_ui(IMSG_FILE_OPENED, imsg->hdr.peerid, fd,
477 		    NULL, 0);
478 }
479 
480 static void
481 handle_session_start(struct imsg *imsg, size_t datalen)
482 {
483 	if (datalen != 0)
484 		die();
485 
486 	if ((session = fopen(session_file, "w")) == NULL)
487 		die();
488 }
489 
490 static void
491 handle_session_tab(struct imsg *imsg, size_t datalen)
492 {
493 	struct session_tab	tab;
494 
495 	if (session == NULL)
496 		die();
497 
498 	if (datalen != sizeof(tab))
499 		die();
500 
501 	memcpy(&tab, imsg->data, sizeof(tab));
502 	if (tab.uri[sizeof(tab.uri)-1] != '\0' ||
503 	    tab.title[sizeof(tab.title)-1] != '\0')
504 		die();
505 
506 	fprintf(session, "%s", tab.uri);
507 
508 	if (tab.flags & TAB_CURRENT)
509 		fprintf(session, " current ");
510 	else
511 		fprintf(session, " - ");
512 
513 	fprintf(session, "%s\n", tab.title);
514 }
515 
516 static void
517 handle_session_tab_hist(struct imsg *imsg, size_t datalen)
518 {
519 	struct session_tab_hist th;
520 
521 	if (session == NULL)
522 		die();
523 
524 	if (datalen != sizeof(th))
525 		die();
526 
527 	memcpy(&th, imsg->data, sizeof(th));
528 	if (th.uri[sizeof(th.uri)-1] != '\0')
529 		die();
530 
531 	fprintf(session, "%s %s\n", th.future ? ">" : "<", th.uri);
532 }
533 
534 static void
535 handle_session_end(struct imsg *imsg, size_t datalen)
536 {
537 	if (session == NULL)
538 		die();
539 	fclose(session);
540 	session = NULL;
541 }
542 
543 static void
544 handle_dispatch_imsg(int fd, short ev, void *d)
545 {
546 	struct imsgev	*iev = d;
547 	int		 e;
548 
549 	if (dispatch_imsg(iev, ev, handlers, sizeof(handlers)) == -1) {
550 		/*
551 		 * This should leave a ~/.cache/telescope/crashed file to
552 		 * trigger about:crash on next run.  Unfortunately, if
553 		 * the main process dies the fs sticks around and
554 		 * doesn't notice that the fd was closed.  Why EV_READ
555 		 * is not triggered when a fd is closed on the other end?
556 		 */
557 		e = errno;
558 		if ((fd = open(crashed_file, O_CREAT|O_TRUNC|O_WRONLY, 0600))
559 		    == -1)
560 			err(1, "open");
561 		close(fd);
562 		errx(1, "connection closed: %s", strerror(e));
563 	}
564 }
565 
566 static int
567 fs_send_ui(int type, uint32_t peerid, int fd, const void *data,
568     uint16_t datalen)
569 {
570 	return imsg_compose_event(iev_ui, type, peerid, 0, fd,
571 	    data, datalen);
572 }
573 
574 static size_t
575 join_path(char *buf, const char *lhs, const char *rhs, size_t buflen)
576 {
577 	strlcpy(buf, lhs, buflen);
578 	return strlcat(buf, rhs, buflen);
579 }
580 
581 static void
582 getenv_default(char *buf, const char *name, const char *def, size_t buflen)
583 {
584 	size_t ret;
585 	char *home, *env;
586 
587 	if ((home = getenv("HOME")) == NULL)
588 		errx(1, "HOME is not defined");
589 
590 	if ((env = getenv(name)) != NULL)
591 		ret = strlcpy(buf, env, buflen);
592 	else
593 		ret = join_path(buf, home, def, buflen);
594 
595 	if (ret >= buflen)
596 		errx(1, "buffer too small for %s", name);
597 }
598 
599 static void
600 mkdirs(const char *path, mode_t mode)
601 {
602 	char copy[PATH_MAX+1], orig[PATH_MAX+1], *parent;
603 
604 	strlcpy(copy, path, sizeof(copy));
605 	strlcpy(orig, path, sizeof(orig));
606 	parent = dirname(copy);
607 	if (!strcmp(parent, "/"))
608 		return;
609 	mkdirs(parent, mode);
610 
611 	if (mkdir(orig, mode) != 0) {
612 		if (errno == EEXIST)
613 			return;
614 		err(1, "can't mkdir %s", orig);
615 	}
616 }
617 
618 static void
619 init_paths(void)
620 {
621 	char		 xdg_config_base[PATH_MAX];
622 	char		 xdg_data_base[PATH_MAX];
623 	char		 xdg_cache_base[PATH_MAX];
624 	char		 old_path[PATH_MAX];
625 	char		*home;
626 	struct stat	 info;
627 
628 	/* old path */
629 	if ((home = getenv("HOME")) == NULL)
630 		errx(1, "HOME is not defined");
631 	join_path(old_path, home, "/.telescope", sizeof(old_path));
632 
633 	/* if ~/.telescope exists, use that instead of xdg dirs */
634 	if (stat(old_path, &info) == 0 && S_ISDIR(info.st_mode)) {
635 		join_path(config_path_base, home, "/.telescope",
636 		    sizeof(config_path_base));
637 		join_path(data_path_base, home, "/.telescope",
638 		    sizeof(data_path_base));
639 		join_path(cache_path_base, home, "/.telescope",
640 		    sizeof(cache_path_base));
641 		return;
642 	}
643 
644 	/* xdg paths */
645 	getenv_default(xdg_config_base, "XDG_CONFIG_HOME", "/.config",
646 	    sizeof(xdg_config_base));
647 	getenv_default(xdg_data_base, "XDG_DATA_HOME", "/.local/share",
648 	    sizeof(xdg_data_base));
649 	getenv_default(xdg_cache_base, "XDG_CACHE_HOME", "/.cache",
650 	    sizeof(xdg_cache_base));
651 
652 	join_path(config_path_base, xdg_config_base, "/telescope",
653 	    sizeof(config_path_base));
654 	join_path(data_path_base, xdg_data_base, "/telescope",
655 	    sizeof(data_path_base));
656 	join_path(cache_path_base, xdg_cache_base, "/telescope",
657 	    sizeof(cache_path_base));
658 
659 	mkdirs(xdg_config_base, S_IRWXU);
660 	mkdirs(xdg_data_base, S_IRWXU);
661 	mkdirs(xdg_cache_base, S_IRWXU);
662 
663 	mkdirs(config_path_base, S_IRWXU);
664 	mkdirs(data_path_base, S_IRWXU);
665 	mkdirs(cache_path_base, S_IRWXU);
666 }
667 
668 int
669 fs_init(void)
670 {
671 	init_paths();
672 
673 	join_path(config_path, config_path_base, "/config",
674 	    sizeof(config_path));
675 	join_path(lockfile_path, cache_path_base, "/lock",
676 	    sizeof(lockfile_path));
677 	join_path(bookmark_file, data_path_base, "/bookmarks.gmi",
678 	    sizeof(bookmark_file));
679 	join_path(known_hosts_file, data_path_base, "/known_hosts",
680 	    sizeof(known_hosts_file));
681 	join_path(known_hosts_tmp, cache_path_base,
682 	    "/known_hosts.tmp.XXXXXXXXXX", sizeof(known_hosts_tmp));
683 	join_path(session_file, cache_path_base, "/session",
684 	    sizeof(session_file));
685 	join_path(crashed_file, cache_path_base, "/crashed",
686 	    sizeof(crashed_file));
687 
688 	return 1;
689 }
690 
691 /*
692  * Parse a line of the session file.  The format is:
693  *
694  *	URL [flags,...] [title]\n
695  */
696 static void
697 parse_session_line(char *line, const char **title, uint32_t *flags)
698 {
699 	char *s, *t, *ap;
700 
701 	*title = "";
702 	*flags = 0;
703 	if ((s = strchr(line, ' ')) == NULL)
704 		return;
705 
706 	*s++ = '\0';
707 
708 	if ((t = strchr(s, ' ')) != NULL) {
709 		*t++ = '\0';
710 		*title = t;
711 	}
712 
713 	while ((ap = strsep(&s, ",")) != NULL) {
714 		if (!strcmp(ap, "current"))
715 			*flags |= TAB_CURRENT;
716 	}
717 }
718 
719 static inline void
720 sendtab(uint32_t flags, const char *uri, const char *title)
721 {
722 	struct session_tab tab;
723 
724 	memset(&tab, 0, sizeof(tab));
725 	tab.flags = flags;
726 
727 	if (strlcpy(tab.uri, uri, sizeof(tab.uri)) >= sizeof(tab.uri))
728 		return;
729 
730 	/* don't worry about cached title truncation */
731 	if (title != NULL)
732 		strlcpy(tab.title, title, sizeof(tab.title));
733 
734 	fs_send_ui(IMSG_SESSION_TAB, 0, -1, &tab, sizeof(tab));
735 }
736 
737 static inline void
738 sendhist(const char *uri, int future)
739 {
740 	struct session_tab_hist sth;
741 
742 	memset(&sth, 0, sizeof(sth));
743 	sth.future = future;
744 
745 	if (strlcpy(sth.uri, uri, sizeof(sth.uri)) >= sizeof(sth.uri))
746 		return;
747 
748 	fs_send_ui(IMSG_SESSION_TAB_HIST, 0, -1, &sth, sizeof(sth));
749 }
750 
751 static void
752 load_last_session(void)
753 {
754 	FILE		*session;
755 	uint32_t	 flags;
756 	size_t		 linesize = 0;
757 	ssize_t		 linelen;
758 	int		 first_time = 0;
759 	int		 future;
760 	const char	*title;
761 	char		*nl, *s, *line = NULL;
762 
763 	if ((session = fopen(session_file, "r")) == NULL) {
764 		/* first time? */
765 		first_time = 1;
766 		goto end;
767 	}
768 
769 	while ((linelen = getline(&line, &linesize, session)) != -1) {
770 		if ((nl = strchr(line, '\n')) != NULL)
771 			*nl = '\0';
772 
773 		if (*line == '<' || *line == '>') {
774 			future = *line == '>';
775 			s = line+1;
776 			if (*s != ' ')
777 				continue;
778 			sendhist(++s, future);
779 		} else {
780 			parse_session_line(line, &title, &flags);
781 			sendtab(flags, line, title);
782 		}
783 	}
784 
785 	fclose(session);
786 	free(line);
787 
788 	if (last_time_crashed())
789 		sendtab(TAB_CURRENT, "about:crash", NULL);
790 
791 end:
792 	fs_send_ui(IMSG_SESSION_END, 0, -1, &first_time, sizeof(first_time));
793 }
794 
795 int
796 fs_main(void)
797 {
798 	setproctitle("fs");
799 
800 	fs_init();
801 
802 	event_init();
803 
804 	/* Setup pipe and event handler to the main process */
805 	if ((iev_ui = malloc(sizeof(*iev_ui))) == NULL)
806 		die();
807 	imsg_init(&iev_ui->ibuf, 3);
808 	iev_ui->handler = handle_dispatch_imsg;
809 	iev_ui->events = EV_READ;
810 	event_set(&iev_ui->ev, iev_ui->ibuf.fd, iev_ui->events,
811 	    iev_ui->handler, iev_ui);
812 	event_add(&iev_ui->ev, NULL);
813 
814 	sandbox_fs_process();
815 
816 	event_dispatch();
817 	return 0;
818 }
819 
820 
821 
822 /*
823  * Check if the last time telescope crashed.  The check is done by
824  * looking at `crashed_file': if it exists then last time we crashed.
825  * Then, while here, touch the file too.  During IMSG_QUIT we'll
826  * remove it.
827  */
828 int
829 last_time_crashed(void)
830 {
831 	int fd, crashed = 1;
832 
833 	if (safe_mode)
834 		return 0;
835 
836 	if (unlink(crashed_file) == -1 && errno == ENOENT)
837 		crashed = 0;
838 
839 	if ((fd = open(crashed_file, O_CREAT|O_WRONLY, 0600)) == -1)
840 		return crashed;
841 	close(fd);
842 
843 	return crashed;
844 }
845 
846 int
847 lock_session(void)
848 {
849 	struct flock	lock;
850 	int		fd;
851 
852 	if ((fd = open(lockfile_path, O_WRONLY|O_CREAT, 0600)) == -1)
853 		return -1;
854 
855 	lock.l_start = 0;
856 	lock.l_len = 0;
857 	lock.l_type = F_WRLCK;
858 	lock.l_whence = SEEK_SET;
859 
860 	if (fcntl(fd, F_SETLK, &lock) == -1) {
861 		close(fd);
862 		return -1;
863 	}
864 
865 	return fd;
866 }
867 
868 static inline int
869 parse_khost_line(char *line, char *tmp[3])
870 {
871 	char **ap;
872 
873 	for (ap = tmp; ap < &tmp[3] &&
874 	    (*ap = strsep(&line, " \t\n")) != NULL;) {
875 		if (**ap != '\0')
876 			ap++;
877 	}
878 
879 	return ap == &tmp[3] && *line == '\0';
880 }
881 
882 static void
883 load_certs(void)
884 {
885 	char		*tmp[3], *line = NULL;
886 	const char	*errstr;
887 	size_t		 lineno = 0, linesize = 0;
888 	ssize_t		 linelen;
889 	FILE		*f;
890 	struct tofu_entry e;
891 
892 	if ((f = fopen(known_hosts_file, "r")) == NULL)
893 		return;
894 
895 	while ((linelen = getline(&line, &linesize, f)) != -1) {
896 		lineno++;
897 
898 		memset(&e, 0, sizeof(e));
899 		if (parse_khost_line(line, tmp)) {
900 			strlcpy(e.domain, tmp[0], sizeof(e.domain));
901 			strlcpy(e.hash, tmp[1], sizeof(e.hash));
902 
903 			e.verified = strtonum(tmp[2], 0, 1, &errstr);
904 			if (errstr != NULL)
905 				errx(1, "%s:%zu verification for %s is %s: %s",
906 				    known_hosts_file, lineno,
907 				    e.domain, errstr, tmp[2]);
908 
909 			fs_send_ui(IMSG_TOFU, 0, -1, &e, sizeof(e));
910 		} else {
911 			warnx("%s:%zu invalid entry",
912 			    known_hosts_file, lineno);
913 		}
914 	}
915 
916 	free(line);
917 	fclose(f);
918 	return;
919 }
920