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Date:: Mon Jan 3 12:12:51 2022 UTC
Message:: mark parse_khost_line as inline
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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 
40 static void		 die(void) __attribute__((__noreturn__));
41 static void		 send_file(uint32_t, FILE *);
42 static void		 handle_get(struct imsg*, size_t);
43 static int		 select_non_dot(const struct dirent *);
44 static int		 select_non_dotdot(const struct dirent *);
45 static void		 handle_get_file(struct imsg*, size_t);
46 static void		 handle_misc(struct imsg *, size_t);
47 static void		 handle_bookmark_page(struct imsg*, size_t);
48 static void		 handle_save_cert(struct imsg*, size_t);
49 static void		 handle_update_cert(struct imsg*, size_t);
50 static void		 handle_file_open(struct imsg*, size_t);
51 static void		 handle_session_start(struct imsg*, size_t);
52 static void		 handle_session_tab(struct imsg*, size_t);
53 static void		 handle_session_tab_hist(struct imsg*, size_t);
54 static void		 handle_session_end(struct imsg*, size_t);
55 static void		 handle_dispatch_imsg(int, short, void*);
56 static int		 fs_send_ui(int, uint32_t, int, const void *, uint16_t);
57 static size_t		 join_path(char*, const char*, const char*, size_t);
58 static void		 getenv_default(char*, const char*, const char*, size_t);
59 static void		 mkdirs(const char*, mode_t);
60 static void		 xdg_init(void);
61 static void		 load_last_session(void);
62 static void		 load_certs(void);
63 
64 static struct imsgev		*iev_ui;
65 static FILE			*session;
66 
67 /*
68  * Note: these are empty if ~/.telescope exists, use *_path_base
69  * below.
70  */
71 static char	xdg_config_base[PATH_MAX];
72 static char	xdg_data_base[PATH_MAX];
73 static char	xdg_cache_base[PATH_MAX];
74 
75 /*
76  * Where to store user data.  These are all equal to ~/.telescope if
77  * it exists.
78  */
79 char		config_path_base[PATH_MAX];
80 char		data_path_base[PATH_MAX];
81 char		cache_path_base[PATH_MAX];
82 
83 char		config_path[PATH_MAX];
84 char		lockfile_path[PATH_MAX];
85 char		bookmark_file[PATH_MAX];
86 char		known_hosts_file[PATH_MAX], known_hosts_tmp[PATH_MAX];
87 char		crashed_file[PATH_MAX];
88 char		session_file[PATH_MAX];
89 
90 static imsg_handlerfn *handlers[] = {
91 	[IMSG_GET] = handle_get,
92 	[IMSG_GET_FILE] = handle_get_file,
93 	[IMSG_QUIT] = handle_misc,
94 	[IMSG_INIT] = handle_misc,
95 	[IMSG_BOOKMARK_PAGE] = handle_bookmark_page,
96 	[IMSG_SAVE_CERT] = handle_save_cert,
97 	[IMSG_UPDATE_CERT] = handle_update_cert,
98 	[IMSG_FILE_OPEN] = handle_file_open,
99 	[IMSG_SESSION_START] = handle_session_start,
100 	[IMSG_SESSION_TAB] = handle_session_tab,
101 	[IMSG_SESSION_TAB_HIST] = handle_session_tab_hist,
102 	[IMSG_SESSION_END] = handle_session_end,
103 };
104 
105 static void __attribute__((__noreturn__))
106 die(void)
107 {
108 	abort(); 		/* TODO */
109 }
110 
111 static void
112 send_file(uint32_t peerid, FILE *f)
113 {
114 	ssize_t	 r;
115 	char	 buf[BUFSIZ];
116 
117 	for (;;) {
118 		r = fread(buf, 1, sizeof(buf), f);
119 		if (r != 0)
120 			fs_send_ui(IMSG_BUF, peerid, -1, buf, r);
121 		if (r != sizeof(buf))
122 			break;
123 	}
124 	fs_send_ui(IMSG_EOF, peerid, -1, NULL, 0);
125 	fclose(f);
126 }
127 
128 static void
129 handle_get(struct imsg *imsg, size_t datalen)
130 {
131 	const char	*bpath = "bookmarks.gmi";
132 	char		 path[PATH_MAX];
133 	FILE		*f;
134 	const char	*data, *p;
135 	size_t		 i;
136 	struct page {
137 		const char	*name;
138 		const char	*path;
139 		const uint8_t	*data;
140 		size_t		 len;
141 	} pages[] = {
142 		{"about",	NULL,	about_about,	about_about_len},
143 		{"blank",	NULL,	about_blank,	about_blank_len},
144 		{"bookmarks",	bpath,	bookmarks,	bookmarks_len},
145 		{"crash",	NULL,	about_crash,	about_crash_len},
146 		{"help",	NULL,	about_help,	about_help_len},
147 		{"license",	NULL,	about_license,	about_license_len},
148 		{"new",		NULL,	about_new,	about_new_len},
149 	}, *page = NULL;
150 
151 	data = imsg->data;
152 	if (data[datalen-1] != '\0') /* make sure it's NUL-terminated */
153 		die();
154 	if ((data = strchr(data, ':')) == NULL)
155 		goto notfound;
156 	data++;
157 
158 	for (i = 0; i < sizeof(pages)/sizeof(pages[0]); ++i)
159 		if (!strcmp(data, pages[i].name)) {
160 			page = &pages[i];
161 			break;
162 		}
163 
164 	if (page == NULL)
165 		goto notfound;
166 
167 	strlcpy(path, data_path_base, sizeof(path));
168 	strlcat(path, "/", sizeof(path));
169 	if (page->path != NULL)
170 		strlcat(path, page->path, sizeof(path));
171 	else {
172 		strlcat(path, "pages/about_", sizeof(path));
173 		strlcat(path, page->name, sizeof(path));
174 		strlcat(path, ".gmi", sizeof(path));
175 	}
176 
177 	if ((f = fopen(path, "r")) == NULL) {
178 		fs_send_ui(IMSG_BUF, imsg->hdr.peerid, -1,
179 		    page->data, page->len);
180 		fs_send_ui(IMSG_EOF, imsg->hdr.peerid, -1,
181 		    NULL, 0);
182 		return;
183 	}
184 
185 	send_file(imsg->hdr.peerid, f);
186 	return;
187 
188 notfound:
189 	p = "# not found!\n";
190 	fs_send_ui(IMSG_BUF, imsg->hdr.peerid, -1, p, strlen(p));
191 	fs_send_ui(IMSG_EOF, imsg->hdr.peerid, -1, NULL, 0);
192 }
193 
194 static inline void
195 send_hdr(uint32_t peerid, int code, const char *meta)
196 {
197 	fs_send_ui(IMSG_GOT_CODE, peerid, -1, &code, sizeof(code));
198 	fs_send_ui(IMSG_GOT_META, peerid, -1, meta, strlen(meta)+1);
199 }
200 
201 static inline void
202 send_errno(uint32_t peerid, int code, const char *str, int no)
203 {
204 	char *s;
205 
206 	if (asprintf(&s, "%s: %s", str, strerror(no)) == -1)
207 		s = NULL;
208 
209 	send_hdr(peerid, code, s == NULL ? str : s);
210 	free(s);
211 }
212 
213 static inline const char *
214 file_type(const char *path)
215 {
216 	struct mapping {
217 		const char	*ext;
218 		const char	*mime;
219 	} ms[] = {
220 		{"diff",	"text/x-patch"},
221 		{"gemini",	"text/gemini"},
222 		{"gmi",		"text/gemini"},
223 		{"markdown",	"text/plain"},
224 		{"md",		"text/plain"},
225 		{"patch",	"text/x-patch"},
226 		{"txt",		"text/plain"},
227 		{NULL, NULL},
228 	}, *m;
229 	char *dot;
230 
231 	if ((dot = strrchr(path, '.')) == NULL)
232 		return NULL;
233 
234 	dot++;
235 
236 	for (m = ms; m->ext != NULL; ++m)
237 		if (!strcmp(m->ext, dot))
238 			return m->mime;
239 
240 	return NULL;
241 }
242 
243 static int
244 select_non_dot(const struct dirent *d)
245 {
246 	return strcmp(d->d_name, ".");
247 }
248 
249 static int
250 select_non_dotdot(const struct dirent *d)
251 {
252 	return strcmp(d->d_name, ".") && strcmp(d->d_name, "..");
253 }
254 
255 static inline void
256 send_dir(uint32_t peerid, const char *path)
257 {
258 	struct dirent	**names;
259 	struct evbuffer	 *ev;
260 	char		 *s;
261 	int		(*selector)(const struct dirent *) = select_non_dot;
262 	int		  i, len, no;
263 
264 	if (!has_suffix(path, "/")) {
265 		if (asprintf(&s, "%s/", path) == -1)
266 			die();
267 		send_hdr(peerid, 30, s);
268 		free(s);
269 		return;
270 	}
271 
272 	if (!strcmp(path, "/"))
273 		selector = select_non_dotdot;
274 
275 	if ((ev = evbuffer_new()) == NULL ||
276 	    (len = scandir(path, &names, selector, alphasort)) == -1) {
277 		no = errno;
278 		evbuffer_free(ev);
279 		send_errno(peerid, 40, "failure reading the directory", no);
280 		return;
281 	}
282 
283 	evbuffer_add_printf(ev, "# Index of %s\n\n", path);
284 	for (i = 0; i < len; ++i) {
285 		evbuffer_add_printf(ev, "=> %s", names[i]->d_name);
286 		if (names[i]->d_type == DT_DIR)
287 			evbuffer_add(ev, "/", 1);
288 		evbuffer_add(ev, "\n", 1);
289 	}
290 
291 	send_hdr(peerid, 20, "text/gemini");
292 	fs_send_ui(IMSG_BUF, peerid, -1,
293 	    EVBUFFER_DATA(ev), EVBUFFER_LENGTH(ev));
294 	fs_send_ui(IMSG_EOF, peerid, -1, NULL, 0);
295 
296 	evbuffer_free(ev);
297 	free(names);
298 }
299 
300 static void
301 handle_get_file(struct imsg *imsg, size_t datalen)
302 {
303 	struct stat	 sb;
304 	FILE		*f;
305 	char		*data;
306 	const char	*meta = NULL;
307 
308 	data = imsg->data;
309 	data[datalen-1] = '\0';
310 
311 	if ((f = fopen(data, "r")) == NULL) {
312 		send_errno(imsg->hdr.peerid, 51, "can't open", errno);
313 		return;
314 	}
315 
316 	if (fstat(fileno(f), &sb) == -1) {
317 		send_errno(imsg->hdr.peerid, 40, "fstat", errno);
318 		return;
319 	}
320 
321 	if (S_ISDIR(sb.st_mode)) {
322 		fclose(f);
323 		send_dir(imsg->hdr.peerid, data);
324 		return;
325 	}
326 
327 	if ((meta = file_type(data)) == NULL) {
328 		fclose(f);
329 		send_hdr(imsg->hdr.peerid, 51,
330 		    "don't know how to visualize this file");
331 		return;
332 	}
333 
334 	send_hdr(imsg->hdr.peerid, 20, meta);
335 	send_file(imsg->hdr.peerid, f);
336 }
337 
338 static void
339 handle_misc(struct imsg *imsg, size_t datalen)
340 {
341 	switch (imsg->hdr.type) {
342 	case IMSG_INIT:
343 		load_certs();
344 		load_last_session();
345 		break;
346 
347 	case IMSG_QUIT:
348 		if (!safe_mode)
349 			unlink(crashed_file);
350 		event_loopbreak();
351 		break;
352 
353 	default:
354 		die();
355 	}
356 }
357 
358 static void
359 handle_bookmark_page(struct imsg *imsg, size_t datalen)
360 {
361 	char	*data;
362 	int	 res;
363 	FILE	*f;
364 
365 	data = imsg->data;
366 	if (data[datalen-1] != '\0')
367 		die();
368 
369 	if ((f = fopen(bookmark_file, "a")) == NULL) {
370 		res = errno;
371 		goto end;
372 	}
373 	fprintf(f, "=> %s\n", data);
374 	fclose(f);
375 
376 	res = 0;
377 end:
378 	fs_send_ui(IMSG_BOOKMARK_OK, 0, -1, &res, sizeof(res));
379 }
380 
381 static void
382 handle_save_cert(struct imsg *imsg, size_t datalen)
383 {
384 	struct tofu_entry	 e;
385 	FILE			*f;
386 	int			 res;
387 
388 	/* TODO: traverse the file to avoid duplications? */
389 
390 	if (datalen != sizeof(e))
391 		die();
392 	memcpy(&e, imsg->data, datalen);
393 
394 	if ((f = fopen(known_hosts_file, "a")) == NULL) {
395 		res = errno;
396 		goto end;
397 	}
398 	fprintf(f, "%s %s %d\n", e.domain, e.hash, e.verified);
399 	fclose(f);
400 
401 	res = 0;
402 end:
403 	fs_send_ui(IMSG_SAVE_CERT_OK, imsg->hdr.peerid, -1,
404 	    &res, sizeof(res));
405 }
406 
407 static void
408 handle_update_cert(struct imsg *imsg, size_t datalen)
409 {
410 	FILE	*tmp, *f;
411 	struct	 tofu_entry entry;
412 	char	 sfn[PATH_MAX], *line = NULL, *t;
413 	size_t	 l, linesize = 0;
414 	ssize_t	 linelen;
415 	int	 fd, e, res = 0;
416 
417 	if (datalen != sizeof(entry))
418 		die();
419 	memcpy(&entry, imsg->data, datalen);
420 
421 	strlcpy(sfn, known_hosts_tmp, sizeof(sfn));
422 	if ((fd = mkstemp(sfn)) == -1 ||
423 	    (tmp = fdopen(fd, "w")) == NULL) {
424 		if (fd != -1) {
425 			unlink(sfn);
426 			close(fd);
427 		}
428 		res = 0;
429 		goto end;
430 	}
431 
432 	if ((f = fopen(known_hosts_file, "r")) == NULL) {
433 		unlink(sfn);
434 		fclose(tmp);
435                 res = 0;
436 		goto end;
437 	}
438 
439 	l = strlen(entry.domain);
440 	while ((linelen = getline(&line, &linesize, f)) != -1) {
441 		if ((t = strstr(line, entry.domain)) != NULL &&
442 		    (line[l] == ' ' || line[l] == '\t'))
443 			continue;
444 		/* line has a trailing \n */
445 		fprintf(tmp, "%s", line);
446 	}
447 	fprintf(tmp, "%s %s %d\n", entry.domain, entry.hash, entry.verified);
448 
449 	free(line);
450 	e = ferror(tmp);
451 
452 	fclose(tmp);
453 	fclose(f);
454 
455 	if (e) {
456 		unlink(sfn);
457 		res = 0;
458 		goto end;
459 	}
460 
461 	res = rename(sfn, known_hosts_file) != -1;
462 
463 end:
464 	fs_send_ui(IMSG_UPDATE_CERT_OK, imsg->hdr.peerid, -1,
465 	    &res, sizeof(res));
466 }
467 
468 static void
469 handle_file_open(struct imsg *imsg, size_t datalen)
470 {
471 	char	*path, *e;
472 	int	 fd;
473 
474 	path = imsg->data;
475 	if (path[datalen-1] != '\0')
476 		die();
477 
478 	if ((fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, 0644)) == -1) {
479 		e = strerror(errno);
480 		fs_send_ui(IMSG_FILE_OPENED, imsg->hdr.peerid, -1,
481 		    e, strlen(e)+1);
482 	} else
483 		fs_send_ui(IMSG_FILE_OPENED, imsg->hdr.peerid, fd,
484 		    NULL, 0);
485 }
486 
487 static void
488 handle_session_start(struct imsg *imsg, size_t datalen)
489 {
490 	if (datalen != 0)
491 		die();
492 
493 	if ((session = fopen(session_file, "w")) == NULL)
494 		die();
495 }
496 
497 static void
498 handle_session_tab(struct imsg *imsg, size_t datalen)
499 {
500 	struct session_tab	tab;
501 
502 	if (session == NULL)
503 		die();
504 
505 	if (datalen != sizeof(tab))
506 		die();
507 
508 	memcpy(&tab, imsg->data, sizeof(tab));
509 	if (tab.uri[sizeof(tab.uri)-1] != '\0' ||
510 	    tab.title[sizeof(tab.title)-1] != '\0')
511 		die();
512 
513 	fprintf(session, "%s", tab.uri);
514 
515 	if (tab.flags & TAB_CURRENT)
516 		fprintf(session, " current ");
517 	else
518 		fprintf(session, " - ");
519 
520 	fprintf(session, "%s\n", tab.title);
521 }
522 
523 static void
524 handle_session_tab_hist(struct imsg *imsg, size_t datalen)
525 {
526 	struct session_tab_hist th;
527 
528 	if (session == NULL)
529 		die();
530 
531 	if (datalen != sizeof(th))
532 		die();
533 
534 	memcpy(&th, imsg->data, sizeof(th));
535 	if (th.uri[sizeof(th.uri)-1] != '\0')
536 		die();
537 
538 	fprintf(session, "%s %s\n", th.future ? ">" : "<", th.uri);
539 }
540 
541 static void
542 handle_session_end(struct imsg *imsg, size_t datalen)
543 {
544 	if (session == NULL)
545 		die();
546 	fclose(session);
547 	session = NULL;
548 }
549 
550 static void
551 handle_dispatch_imsg(int fd, short ev, void *d)
552 {
553 	struct imsgev	*iev = d;
554 	int		 e;
555 
556 	if (dispatch_imsg(iev, ev, handlers, sizeof(handlers)) == -1) {
557 		/*
558 		 * This should leave a ~/.cache/telescope/crashed file to
559 		 * trigger about:crash on next run.  Unfortunately, if
560 		 * the main process dies the fs sticks around and
561 		 * doesn't notice that the fd was closed.  Why EV_READ
562 		 * is not triggered when a fd is closed on the other end?
563 		 */
564 		e = errno;
565 		if ((fd = open(crashed_file, O_CREAT|O_TRUNC|O_WRONLY, 0600))
566 		    == -1)
567 			err(1, "open");
568 		close(fd);
569 		errx(1, "connection closed: %s", strerror(e));
570 	}
571 }
572 
573 static int
574 fs_send_ui(int type, uint32_t peerid, int fd, const void *data,
575     uint16_t datalen)
576 {
577 	return imsg_compose_event(iev_ui, type, peerid, 0, fd,
578 	    data, datalen);
579 }
580 
581 static size_t
582 join_path(char *buf, const char *lhs, const char *rhs, size_t buflen)
583 {
584 	strlcpy(buf, lhs, buflen);
585 	return strlcat(buf, rhs, buflen);
586 }
587 
588 static void
589 getenv_default(char *buf, const char *name, const char *def, size_t buflen)
590 {
591 	size_t ret;
592 	char *home, *env;
593 
594 	if ((home = getenv("HOME")) == NULL)
595 		errx(1, "HOME is not defined");
596 
597 	if ((env = getenv(name)) != NULL)
598 		ret = strlcpy(buf, env, buflen);
599 	else
600 		ret = join_path(buf, home, def, buflen);
601 
602 	if (ret >= buflen)
603 		errx(1, "buffer too small for %s", name);
604 }
605 
606 static void
607 mkdirs(const char *path, mode_t mode)
608 {
609 	char copy[PATH_MAX+1], orig[PATH_MAX+1], *parent;
610 
611 	strlcpy(copy, path, sizeof(copy));
612 	strlcpy(orig, path, sizeof(orig));
613 	parent = dirname(copy);
614 	if (!strcmp(parent, "/"))
615 		return;
616 	mkdirs(parent, mode);
617 
618 	if (mkdir(orig, mode) != 0) {
619 		if (errno == EEXIST)
620 			return;
621 		err(1, "can't mkdir %s", orig);
622 	}
623 }
624 
625 static void
626 xdg_init(void)
627 {
628 	char *home, old_path[PATH_MAX];
629 	struct stat info;
630 
631 	/* old path */
632 	if ((home = getenv("HOME")) == NULL)
633 		errx(1, "HOME is not defined");
634 	join_path(old_path, home, "/.telescope", sizeof(old_path));
635 
636 	/* if ~/.telescope exists, use that instead of xdg dirs */
637 	if (stat(old_path, &info) == 0 && S_ISDIR(info.st_mode)) {
638 		join_path(config_path_base, home, "/.telescope",
639 		    sizeof(config_path_base));
640 		join_path(data_path_base, home, "/.telescope",
641 		    sizeof(data_path_base));
642 		join_path(cache_path_base, home, "/.telescope",
643 		    sizeof(cache_path_base));
644 		return;
645 	}
646 
647 	/* xdg paths */
648 	getenv_default(xdg_config_base, "XDG_CONFIG_HOME", "/.config",
649 	    sizeof(xdg_config_base));
650 	getenv_default(xdg_data_base, "XDG_DATA_HOME", "/.local/share",
651 	    sizeof(xdg_data_base));
652 	getenv_default(xdg_cache_base, "XDG_CACHE_HOME", "/.cache",
653 	    sizeof(xdg_cache_base));
654 
655 	join_path(config_path_base, xdg_config_base, "/telescope",
656 	    sizeof(config_path_base));
657 	join_path(data_path_base, xdg_data_base, "/telescope",
658 	    sizeof(data_path_base));
659 	join_path(cache_path_base, xdg_cache_base, "/telescope",
660 	    sizeof(cache_path_base));
661 
662 	mkdirs(xdg_config_base, S_IRWXU);
663 	mkdirs(xdg_data_base, S_IRWXU);
664 	mkdirs(xdg_cache_base, S_IRWXU);
665 
666 	mkdirs(config_path_base, S_IRWXU);
667 	mkdirs(data_path_base, S_IRWXU);
668 	mkdirs(cache_path_base, S_IRWXU);
669 }
670 
671 int
672 fs_init(void)
673 {
674 	xdg_init();
675 
676 	join_path(config_path, config_path_base, "/config",
677 	    sizeof(config_path));
678 	join_path(lockfile_path, cache_path_base, "/lock",
679 	    sizeof(lockfile_path));
680 	join_path(bookmark_file, data_path_base, "/bookmarks.gmi",
681 	    sizeof(bookmark_file));
682 	join_path(known_hosts_file, data_path_base, "/known_hosts",
683 	    sizeof(known_hosts_file));
684 	join_path(known_hosts_tmp, cache_path_base,
685 	    "/known_hosts.tmp.XXXXXXXXXX", sizeof(known_hosts_tmp));
686 	join_path(session_file, cache_path_base, "/session",
687 	    sizeof(session_file));
688 	join_path(crashed_file, cache_path_base, "/crashed",
689 	    sizeof(crashed_file));
690 
691 	return 1;
692 }
693 
694 /*
695  * Parse a line of the session file.  The format is:
696  *
697  *	URL [flags,...] [title]\n
698  */
699 static void
700 parse_session_line(char *line, const char **title, uint32_t *flags)
701 {
702 	char *s, *t, *ap;
703 
704 	*title = "";
705 	*flags = 0;
706 	if ((s = strchr(line, ' ')) == NULL)
707 		return;
708 
709 	*s++ = '\0';
710 
711 	if ((t = strchr(s, ' ')) != NULL) {
712 		*t++ = '\0';
713 		*title = t;
714 	}
715 
716 	while ((ap = strsep(&s, ",")) != NULL) {
717 		if (!strcmp(ap, "current"))
718 			*flags |= TAB_CURRENT;
719 	}
720 }
721 
722 static inline void
723 sendtab(uint32_t flags, const char *uri, const char *title)
724 {
725 	struct session_tab tab;
726 
727 	memset(&tab, 0, sizeof(tab));
728 	tab.flags = flags;
729 
730 	if (strlcpy(tab.uri, uri, sizeof(tab.uri)) >= sizeof(tab.uri))
731 		return;
732 
733 	/* don't worry about cached title truncation */
734 	if (title != NULL)
735 		strlcpy(tab.title, title, sizeof(tab.title));
736 
737 	fs_send_ui(IMSG_SESSION_TAB, 0, -1, &tab, sizeof(tab));
738 }
739 
740 static inline void
741 sendhist(const char *uri, int future)
742 {
743 	struct session_tab_hist sth;
744 
745 	memset(&sth, 0, sizeof(sth));
746 	sth.future = future;
747 
748 	if (strlcpy(sth.uri, uri, sizeof(sth.uri)) >= sizeof(sth.uri))
749 		return;
750 
751 	fs_send_ui(IMSG_SESSION_TAB_HIST, 0, -1, &sth, sizeof(sth));
752 }
753 
754 static void
755 load_last_session(void)
756 {
757 	FILE		*session;
758 	uint32_t	 flags;
759 	size_t		 linesize = 0;
760 	ssize_t		 linelen;
761 	int		 first_time = 0;
762 	int		 future;
763 	const char	*title;
764 	char		*nl, *s, *line = NULL;
765 
766 	if ((session = fopen(session_file, "r")) == NULL) {
767 		/* first time? */
768 		first_time = 1;
769 		goto end;
770 	}
771 
772 	while ((linelen = getline(&line, &linesize, session)) != -1) {
773 		if ((nl = strchr(line, '\n')) != NULL)
774 			*nl = '\0';
775 
776 		if (*line == '<' || *line == '>') {
777 			future = *line == '>';
778 			s = line+1;
779 			if (*s != ' ')
780 				continue;
781 			sendhist(++s, future);
782 		} else {
783 			parse_session_line(line, &title, &flags);
784 			sendtab(flags, line, title);
785 		}
786 	}
787 
788 	fclose(session);
789 	free(line);
790 
791 	if (last_time_crashed())
792 		sendtab(TAB_CURRENT, "about:crash", NULL);
793 
794 end:
795 	fs_send_ui(IMSG_SESSION_END, 0, -1, &first_time, sizeof(first_time));
796 }
797 
798 int
799 fs_main(void)
800 {
801 	setproctitle("fs");
802 
803 	fs_init();
804 
805 	event_init();
806 
807 	/* Setup pipe and event handler to the main process */
808 	if ((iev_ui = malloc(sizeof(*iev_ui))) == NULL)
809 		die();
810 	imsg_init(&iev_ui->ibuf, 3);
811 	iev_ui->handler = handle_dispatch_imsg;
812 	iev_ui->events = EV_READ;
813 	event_set(&iev_ui->ev, iev_ui->ibuf.fd, iev_ui->events,
814 	    iev_ui->handler, iev_ui);
815 	event_add(&iev_ui->ev, NULL);
816 
817 	sandbox_fs_process();
818 
819 	event_dispatch();
820 	return 0;
821 }
822 
823 
824 
825 /*
826  * Check if the last time telescope crashed.  The check is done by
827  * looking at `crashed_file': if it exists then last time we crashed.
828  * Then, while here, touch the file too.  During IMSG_QUIT we'll
829  * remove it.
830  */
831 int
832 last_time_crashed(void)
833 {
834 	int fd, crashed = 1;
835 
836 	if (safe_mode)
837 		return 0;
838 
839 	if (unlink(crashed_file) == -1 && errno == ENOENT)
840 		crashed = 0;
841 
842 	if ((fd = open(crashed_file, O_CREAT|O_WRONLY, 0600)) == -1)
843 		return crashed;
844 	close(fd);
845 
846 	return crashed;
847 }
848 
849 int
850 lock_session(void)
851 {
852 	struct flock	lock;
853 	int		fd;
854 
855 	if ((fd = open(lockfile_path, O_WRONLY|O_CREAT, 0600)) == -1)
856 		return -1;
857 
858 	lock.l_start = 0;
859 	lock.l_len = 0;
860 	lock.l_type = F_WRLCK;
861 	lock.l_whence = SEEK_SET;
862 
863 	if (fcntl(fd, F_SETLK, &lock) == -1) {
864 		close(fd);
865 		return -1;
866 	}
867 
868 	return fd;
869 }
870 
871 static inline int
872 parse_khost_line(char *line, char *tmp[3])
873 {
874 	char **ap;
875 
876 	for (ap = tmp; ap < &tmp[3] &&
877 	    (*ap = strsep(&line, " \t\n")) != NULL;) {
878 		if (**ap != '\0')
879 			ap++;
880 	}
881 
882 	return ap == &tmp[3] && *line == '\0';
883 }
884 
885 static void
886 load_certs(void)
887 {
888 	char		*tmp[3], *line = NULL;
889 	const char	*errstr;
890 	size_t		 lineno = 0, linesize = 0;
891 	ssize_t		 linelen;
892 	FILE		*f;
893 	struct tofu_entry e;
894 
895 	if ((f = fopen(known_hosts_file, "r")) == NULL)
896 		return;
897 
898 	while ((linelen = getline(&line, &linesize, f)) != -1) {
899 		lineno++;
900 
901 		memset(&e, 0, sizeof(e));
902 		if (parse_khost_line(line, tmp)) {
903 			strlcpy(e.domain, tmp[0], sizeof(e.domain));
904 			strlcpy(e.hash, tmp[1], sizeof(e.hash));
905 
906 			e.verified = strtonum(tmp[2], 0, 1, &errstr);
907 			if (errstr != NULL)
908 				errx(1, "%s:%zu verification for %s is %s: %s",
909 				    known_hosts_file, lineno,
910 				    e.domain, errstr, tmp[2]);
911 
912 			fs_send_ui(IMSG_TOFU, 0, -1, &e, sizeof(e));
913 		} else {
914 			warnx("%s:%zu invalid entry",
915 			    known_hosts_file, lineno);
916 		}
917 	}
918 
919 	free(line);
920 	fclose(f);
921 	return;
922 }
923