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