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