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 #include <sys/socket.h>
18 
19 #include <errno.h>
20 #include <getopt.h>
21 #include <limits.h>
22 #include <signal.h>
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <unistd.h>
27 
28 #include "defaults.h"
29 #include "minibuffer.h"
30 #include "parser.h"
31 #include "telescope.h"
32 #include "ui.h"
33 
34 static struct option longopts[] = {
35 	{"colors",	no_argument,	NULL,	'c'},
36 	{"help",	no_argument,	NULL,	'h'},
37 	{"version",	no_argument,	NULL,	'v'},
38 	{NULL,		0,		NULL,	0},
39 };
40 
41 static const char *opts = "Cc:hnT:v";
42 
43 static struct imsgev	*iev_fs, *iev_net;
44 
45 struct tabshead		 tabshead = TAILQ_HEAD_INITIALIZER(tabshead);
46 struct proxylist	 proxies = TAILQ_HEAD_INITIALIZER(proxies);
47 
48 enum telescope_process {
49 	PROC_UI,
50 	PROC_FS,
51 	PROC_NET,
52 };
53 
54 /* the first is also the fallback one */
55 static struct proto protos[] = {
56 	{ "gemini",	load_gemini_url },
57 	{ "about",	load_about_url },
58 	{ NULL, NULL },
59 };
60 
61 
62 #define CANNOT_FETCH		0
63 #define TOO_MUCH_REDIRECTS	1
64 #define MALFORMED_RESPONSE	2
65 #define UNKNOWN_TYPE_OR_CSET	3
66 #define UNKNOWN_PROTOCOL	4
67 
68 /* XXX: keep in sync with telescope.c:/^normalize_code/ */
69 const char *err_pages[70] = {
70 	[CANNOT_FETCH]		= "# Couldn't load the page\n",
71 	[TOO_MUCH_REDIRECTS]	= "# Too much redirects\n",
72 	[MALFORMED_RESPONSE]	= "# Got a malformed response\n",
73 	[UNKNOWN_TYPE_OR_CSET]	= "# Unsupported type or charset\n",
74 	[UNKNOWN_PROTOCOL]	= "# Unknown protocol\n",
75 
76 	[10] = "# Input required\n",
77 	[11] = "# Input required\n",
78 	[40] = "# Temporary failure\n",
79 	[41] = "# Server unavailable\n",
80 	[42] = "# CGI error\n",
81 	[43] = "# Proxy error\n",
82 	[44] = "# Slow down\n",
83 	[50] = "# Permanent failure\n",
84 	[51] = "# Not found\n",
85 	[52] = "# Gone\n",
86 	[53] = "# Proxy request refused\n",
87 	[59] = "# Bad request\n",
88 	[60] = "# Client certificate required\n",
89 	[61] = "# Certificate not authorised\n",
90 	[62] = "# Certificate not valid\n"
91 };
92 
93 static void		 die(void) __attribute__((__noreturn__));
94 static struct tab	*tab_by_id(uint32_t);
95 static void		 handle_imsg_err(struct imsg*, size_t);
96 static void		 handle_imsg_check_cert(struct imsg*, size_t);
97 static void		 handle_check_cert_user_choice(int, struct tab *);
98 static void		 handle_maybe_save_new_cert(int, struct tab *);
99 static void		 handle_imsg_got_code(struct imsg*, size_t);
100 static void		 handle_imsg_got_meta(struct imsg*, size_t);
101 static void		 handle_maybe_save_page(int, struct tab *);
102 static void		 handle_save_page_path(const char *, struct tab *);
103 static void		 handle_imsg_file_opened(struct imsg*, size_t);
104 static void		 handle_imsg_buf(struct imsg*, size_t);
105 static void		 handle_imsg_eof(struct imsg*, size_t);
106 static void		 handle_imsg_bookmark_ok(struct imsg*, size_t);
107 static void		 handle_imsg_save_cert_ok(struct imsg*, size_t);
108 static void		 handle_imsg_update_cert_ok(struct imsg *, size_t);
109 static void		 handle_dispatch_imsg(int, short, void*);
110 static void		 load_page_from_str(struct tab*, const char*);
111 static int		 do_load_url(struct tab*, const char *, const char *);
112 static void		 parse_session_line(char *, const char **, uint32_t *);
113 static void		 load_last_session(void);
114 static pid_t		 start_child(enum telescope_process, const char *, int);
115 static int		 ui_send_net(int, uint32_t, const void *, uint16_t);
116 static int		 ui_send_fs(int, uint32_t, const void *, uint16_t);
117 
118 static imsg_handlerfn *handlers[] = {
119 	[IMSG_ERR] = handle_imsg_err,
120 	[IMSG_CHECK_CERT] = handle_imsg_check_cert,
121 	[IMSG_GOT_CODE] = handle_imsg_got_code,
122 	[IMSG_GOT_META] = handle_imsg_got_meta,
123 	[IMSG_BUF] = handle_imsg_buf,
124 	[IMSG_EOF] = handle_imsg_eof,
125 	[IMSG_BOOKMARK_OK] = handle_imsg_bookmark_ok,
126 	[IMSG_SAVE_CERT_OK] = handle_imsg_save_cert_ok,
127 	[IMSG_UPDATE_CERT_OK] = handle_imsg_update_cert_ok,
128 	[IMSG_FILE_OPENED] = handle_imsg_file_opened,
129 };
130 
131 static struct ohash	certs;
132 
133 static void __attribute__((__noreturn__))
134 die(void)
135 {
136 	abort(); 		/* TODO */
137 }
138 
139 static struct tab *
140 tab_by_id(uint32_t id)
141 {
142 	struct tab *t;
143 
144 	TAILQ_FOREACH(t, &tabshead, tabs) {
145 		if (t->id == id)
146 			return t;
147 	}
148 
149 	return NULL;
150 }
151 
152 static void
153 handle_imsg_err(struct imsg *imsg, size_t datalen)
154 {
155 	struct tab	*tab;
156 	char		*page;
157 
158 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
159 		return;
160 
161 	page = imsg->data;
162 	page[datalen-1] = '\0';
163 
164 	if (asprintf(&page, "# Error loading %s\n\n> %s\n",
165 	    tab->hist_cur->h, page) == -1)
166 		die();
167 	load_page_from_str(tab, page);
168 	free(page);
169 }
170 
171 static void
172 handle_imsg_check_cert(struct imsg *imsg, size_t datalen)
173 {
174 	const char		*hash, *host, *port;
175 	int			 tofu_res;
176 	struct tofu_entry	*e;
177 	struct tab		*tab;
178 
179 	hash = imsg->data;
180 	if (hash[datalen-1] != '\0')
181 		abort();
182 
183 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
184 		return;
185 
186 	if (tab->proxy != NULL) {
187 		host = tab->proxy->host;
188 		port = tab->proxy->port;
189 	} else {
190 		host = tab->uri.host;
191 		port = tab->uri.port;
192 	}
193 
194 	if ((e = tofu_lookup(&certs, host, port)) == NULL) {
195 		/* TODO: an update in libressl/libretls changed
196 		 * significantly.  Find a better approach at storing
197 		 * the certs! */
198 		if (datalen > sizeof(e->hash))
199 			abort();
200 
201 		tofu_res = 1;	/* trust on first use */
202 		if ((e = calloc(1, sizeof(*e))) == NULL)
203 			abort();
204 		strlcpy(e->domain, host, sizeof(e->domain));
205 		if (*port != '\0' && strcmp(port, "1965")) {
206 			strlcat(e->domain, ":", sizeof(e->domain));
207 			strlcat(e->domain, port, sizeof(e->domain));
208 		}
209 		strlcpy(e->hash, hash, sizeof(e->hash));
210 		tofu_add(&certs, e);
211 		ui_send_fs(IMSG_SAVE_CERT, tab->id, e, sizeof(*e));
212 	} else
213 		tofu_res = !strcmp(hash, e->hash);
214 
215 	if (tofu_res) {
216 		if (e->verified == -1)
217 			tab->trust = TS_TEMP_TRUSTED;
218 		else if (e->verified == 1)
219 			tab->trust = TS_VERIFIED;
220 		else
221 			tab->trust = TS_TRUSTED;
222 
223 		ui_send_net(IMSG_CERT_STATUS, imsg->hdr.peerid,
224 		    &tofu_res, sizeof(tofu_res));
225 	} else {
226 		tab->trust = TS_UNTRUSTED;
227 		load_page_from_str(tab, "# Certificate mismatch\n");
228 		if ((tab->cert = strdup(hash)) == NULL)
229 			die();
230 		ui_yornp("Certificate mismatch.  Proceed?",
231 		    handle_check_cert_user_choice, tab);
232 	}
233 }
234 
235 static void
236 handle_check_cert_user_choice(int accept, struct tab *tab)
237 {
238 	ui_send_net(IMSG_CERT_STATUS, tab->id, &accept,
239 	    sizeof(accept));
240 
241 	if (accept) {
242 		/*
243 		 * trust the certificate for this session only.  If
244 		 * the page results in a redirect while we're asking
245 		 * the user to save, we'll end up with an invalid
246 		 * tabid (one request == one tab id) and crash.  It
247 		 * also makes sense to save it for the current session
248 		 * if the user accepted it.
249 		 */
250 		tofu_temp_trust(&certs, tab->uri.host, tab->uri.port, tab->cert);
251 
252 		ui_yornp("Save the new certificate?",
253 		    handle_maybe_save_new_cert, tab);
254 	} else {
255 		free(tab->cert);
256 		tab->cert = NULL;
257 	}
258 }
259 
260 static void
261 handle_maybe_save_new_cert(int accept, struct tab *tab)
262 {
263 	struct tofu_entry *e;
264 	const char *host, *port;
265 
266 	if (tab->proxy != NULL) {
267 		host = tab->proxy->host;
268 		port = tab->proxy->port;
269 	} else {
270 		host = tab->uri.host;
271 		port = tab->uri.port;
272 	}
273 
274 	if (!accept)
275 		goto end;
276 
277 	if ((e = calloc(1, sizeof(*e))) == NULL)
278 		die();
279 
280 	strlcpy(e->domain, host, sizeof(e->domain));
281 	if (*port != '\0' && strcmp(port, "1965")) {
282 		strlcat(e->domain, ":", sizeof(e->domain));
283 		strlcat(e->domain, port, sizeof(e->domain));
284 	}
285 	strlcpy(e->hash, tab->cert, sizeof(e->hash));
286 	ui_send_fs(IMSG_UPDATE_CERT, 0, e, sizeof(*e));
287 
288 	tofu_update(&certs, e);
289 
290 	tab->trust = TS_TRUSTED;
291 
292 end:
293 	free(tab->cert);
294 	tab->cert = NULL;
295 }
296 
297 static inline int
298 normalize_code(int n)
299 {
300 	if (n < 20) {
301 		if (n == 10 || n == 11)
302 			return n;
303 		return 10;
304 	} else if (n < 30) {
305 		return 20;
306 	} else if (n < 40) {
307 		if (n == 30 || n == 31)
308 			return n;
309 		return 30;
310 	} else if (n < 50) {
311 		if (n <= 44)
312 			return n;
313 		return 40;
314 	} else if (n < 60) {
315 		if (n <= 53 || n == 59)
316 			return n;
317 		return 50;
318 	} else if (n < 70) {
319 		if (n <= 62)
320 			return n;
321 		return 60;
322 	} else
323 		return MALFORMED_RESPONSE;
324 }
325 
326 static void
327 handle_imsg_got_code(struct imsg *imsg, size_t datalen)
328 {
329 	struct tab	*tab;
330 
331 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
332 		return;
333 
334 	if (sizeof(tab->code) != datalen)
335 		die();
336 
337 	memcpy(&tab->code, imsg->data, sizeof(tab->code));
338 	tab->code = normalize_code(tab->code);
339 	if (tab->code != 30 && tab->code != 31)
340 		tab->redirect_count = 0;
341 }
342 
343 static void
344 handle_imsg_got_meta(struct imsg *imsg, size_t datalen)
345 {
346 	struct tab	*tab;
347 
348 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
349 		return;
350 
351 	if (sizeof(tab->meta) <= datalen)
352 		die();
353 
354 	memcpy(tab->meta, imsg->data, datalen);
355 
356 	if (tab->code < 10) {	/* internal errors */
357 		load_page_from_str(tab, err_pages[tab->code]);
358 	} else if (tab->code < 20) {	/* 1x */
359 		load_page_from_str(tab, err_pages[tab->code]);
360 		ui_require_input(tab, tab->code == 11);
361 	} else if (tab->code == 20) {
362 		if (setup_parser_for(tab)) {
363 			ui_send_net(IMSG_PROCEED, tab->id, NULL, 0);
364 		} else {
365 			load_page_from_str(tab, err_pages[UNKNOWN_TYPE_OR_CSET]);
366 			ui_yornp("Can't display page, wanna save?",
367 			    handle_maybe_save_page, tab);
368 		}
369 	} else if (tab->code < 40) { /* 3x */
370 		tab->redirect_count++;
371 
372 		/* TODO: make customizable? */
373 		if (tab->redirect_count > 5) {
374 			load_page_from_str(tab,
375 			    err_pages[TOO_MUCH_REDIRECTS]);
376 		} else
377 			do_load_url(tab, tab->meta, NULL);
378 	} else { /* 4x, 5x & 6x */
379 		load_page_from_str(tab, err_pages[tab->code]);
380 	}
381 }
382 
383 static void
384 handle_maybe_save_page(int dosave, struct tab *tab)
385 {
386 	if (dosave)
387 		ui_read("Save to path", handle_save_page_path, tab);
388 	else
389 		stop_tab(tab);
390 }
391 
392 static void
393 handle_save_page_path(const char *path, struct tab *tab)
394 {
395 	if (path == NULL) {
396 		stop_tab(tab);
397 		return;
398 	}
399 
400 	tab->path = strdup(path);
401 
402 	ui_send_fs(IMSG_FILE_OPEN, tab->id, path, strlen(path)+1);
403 }
404 
405 static void
406 handle_imsg_file_opened(struct imsg *imsg, size_t datalen)
407 {
408 	struct tab	*tab;
409 	char		*page;
410 	const char	*e;
411 	int		 l;
412 
413 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL) {
414 		if (imsg->fd != -1)
415 			close(imsg->fd);
416 		return;
417 	}
418 
419 	if (imsg->fd == -1) {
420 		stop_tab(tab);
421 
422 		e = imsg->data;
423 		if (e[datalen-1] != '\0')
424 			die();
425 		l = asprintf(&page, "# Can't open file\n\n> %s: %s\n",
426 		    tab->path, e);
427 		if (l == -1)
428 			die();
429 		load_page_from_str(tab, page);
430 		free(page);
431 	} else {
432 		tab->fd = imsg->fd;
433 		ui_send_net(IMSG_PROCEED, tab->id, NULL, 0);
434 	}
435 }
436 
437 static void
438 handle_imsg_buf(struct imsg *imsg, size_t datalen)
439 {
440 	struct tab	*tab;
441 	int		 l;
442 	char		*page, buf[FMT_SCALED_STRSIZE] = {0};
443 
444 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
445 		return;
446 
447 	tab->bytes += datalen;
448 	if (tab->fd == -1) {
449 		if (!tab->buffer.page.parse(&tab->buffer.page,
450 		    imsg->data, datalen))
451 			die();
452 	} else {
453 		write(tab->fd, imsg->data, datalen);
454 		fmt_scaled(tab->bytes, buf);
455 		l = asprintf(&page, "Saving to \"%s\"... (%s)\n",
456 		    tab->path,
457 		    buf);
458 		if (l == -1)
459 			die();
460 		load_page_from_str(tab, page);
461 		free(page);
462 	}
463 
464 	ui_on_tab_refresh(tab);
465 }
466 
467 static void
468 handle_imsg_eof(struct imsg *imsg, size_t datalen)
469 {
470 	struct tab	*tab;
471 	int		 l;
472 	char		*page, buf[FMT_SCALED_STRSIZE] = {0};
473 
474 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
475 		return;
476 
477 	if (tab->fd == -1) {
478 		if (!tab->buffer.page.free(&tab->buffer.page))
479 			die();
480 	} else {
481 		fmt_scaled(tab->bytes, buf);
482 		l = asprintf(&page, "Saved to \"%s\" (%s)\n",
483 		    tab->path,
484 		    buf);
485 		if (l == -1)
486 			die();
487 		load_page_from_str(tab, page);
488 		free(page);
489 
490 		close(tab->fd);
491 		tab->fd = -1;
492 		free(tab->path);
493 		tab->path = NULL;
494 	}
495 
496 	ui_on_tab_refresh(tab);
497 	ui_on_tab_loaded(tab);
498 }
499 
500 static void
501 handle_imsg_bookmark_ok(struct imsg *imsg, size_t datalen)
502 {
503 	int res;
504 
505 	if (datalen != sizeof(res))
506 		die();
507 
508 	memcpy(&res, imsg->data, sizeof(res));
509 	if (res == 0)
510 		message("Added to bookmarks!");
511 	else
512 		message("Failed to add to bookmarks: %s",
513 		    strerror(res));
514 }
515 
516 static void
517 handle_imsg_save_cert_ok(struct imsg *imsg, size_t datalen)
518 {
519 	int res;
520 
521 	if (datalen != sizeof(res))
522 		die();
523 	memcpy(&res, imsg->data, datalen);
524 	if (res != 0)
525 		message("Failed to save the cert for: %s",
526 		    strerror(res));
527 }
528 
529 static void
530 handle_imsg_update_cert_ok(struct imsg *imsg, size_t datalen)
531 {
532 	int res;
533 
534 	if (datalen != sizeof(res))
535 		die();
536 	memcpy(&res, imsg->data, datalen);
537 	if (!res)
538 		message("Failed to update the certificate");
539 }
540 
541 static void
542 handle_dispatch_imsg(int fd, short ev, void *d)
543 {
544 	struct imsgev	*iev = d;
545 
546 	if (dispatch_imsg(iev, ev, handlers, sizeof(handlers)) == -1)
547 		err(1, "connection closed");
548 }
549 
550 static void
551 load_page_from_str(struct tab *tab, const char *page)
552 {
553 	erase_buffer(&tab->buffer);
554 	gemtext_initparser(&tab->buffer.page);
555 	if (!tab->buffer.page.parse(&tab->buffer.page, page, strlen(page)))
556 		die();
557 	if (!tab->buffer.page.free(&tab->buffer.page))
558 		die();
559 	ui_on_tab_refresh(tab);
560 	ui_on_tab_loaded(tab);
561 }
562 
563 void
564 load_about_url(struct tab *tab, const char *url)
565 {
566 	tab->trust = TS_VERIFIED;
567 
568 	gemtext_initparser(&tab->buffer.page);
569 
570 	ui_send_fs(IMSG_GET, tab->id,
571 	    tab->hist_cur->h, strlen(tab->hist_cur->h)+1);
572 }
573 
574 void
575 load_gemini_url(struct tab *tab, const char *url)
576 {
577 	struct get_req	 req;
578 
579 	stop_tab(tab);
580 	tab->id = tab_new_id();
581 
582 	memset(&req, 0, sizeof(req));
583 	strlcpy(req.host, tab->uri.host, sizeof(req.host));
584 	strlcpy(req.port, tab->uri.port, sizeof(req.host));
585 
586 	strlcpy(req.req, tab->hist_cur->h, sizeof(req.req));
587 	strlcat(req.req, "\r\n", sizeof(req.req));
588 
589 	req.proto = PROTO_GEMINI;
590 
591 	ui_send_net(IMSG_GET_RAW, tab->id,
592 	    &req, sizeof(req));
593 }
594 
595 void
596 load_via_proxy(struct tab *tab, const char *url, struct proxy *p)
597 {
598 	struct get_req req;
599 
600 	stop_tab(tab);
601 	tab->id = tab_new_id();
602 	tab->proxy = p;
603 
604 	memset(&req, 0, sizeof(req));
605 	strlcpy(req.host, p->host, sizeof(req.host));
606 	strlcpy(req.port, p->port, sizeof(req.host));
607 
608 	strlcpy(req.req, tab->hist_cur->h, sizeof(req.req));
609 	strlcat(req.req, "\r\n", sizeof(req.req));
610 
611 	req.proto = p->proto;
612 
613 	ui_send_net(IMSG_GET_RAW, tab->id,
614 	    &req, sizeof(req));
615 }
616 
617 /*
618  * Effectively load the given url in the given tab.  Return 1 when
619  * loading the page asynchronously, and thus when an erase_buffer can
620  * be done right after this function return, or 0 when loading the
621  * page synchronously.  In this last case, erase_buffer *MUST* be
622  * called by the handling function (such as load_page_from_str).
623  */
624 static int
625 do_load_url(struct tab *tab, const char *url, const char *base)
626 {
627 	struct phos_uri	 uri;
628 	struct proto	*p;
629 	struct proxy	*proxy;
630 	char		*t;
631 
632 	tab->proxy = NULL;
633 
634 	if (tab->fd != -1) {
635 		close(tab->fd);
636 		tab->fd = -1;
637 		free(tab->path);
638 		tab->path = NULL;
639 	}
640 
641 	tab->trust = TS_UNKNOWN;
642 
643 	if (base == NULL)
644 		memcpy(&uri, &tab->uri, sizeof(tab->uri));
645 	else
646 		phos_parse_absolute_uri(base, &uri);
647 
648 	if (!phos_resolve_uri_from_str(&uri, url, &tab->uri)) {
649                 if (asprintf(&t, "#error loading %s\n>%s\n",
650 		    url, "Can't parse the URI") == -1)
651 			die();
652 		strlcpy(tab->hist_cur->h, url, sizeof(tab->hist_cur->h));
653 		load_page_from_str(tab, t);
654 		free(t);
655 		return 0;
656 	}
657 
658 	phos_serialize_uri(&tab->uri, tab->hist_cur->h,
659 	    sizeof(tab->hist_cur->h));
660 
661 	for (p = protos; p->schema != NULL; ++p) {
662 		if (!strcmp(tab->uri.scheme, p->schema)) {
663 			p->loadfn(tab, url);
664                         return 1;
665 		}
666 	}
667 
668 	TAILQ_FOREACH(proxy, &proxies, proxies) {
669 		if (!strcmp(tab->uri.scheme, proxy->match_proto)) {
670 			load_via_proxy(tab, url, proxy);
671 			return 1;
672 		}
673 	}
674 
675 	load_page_from_str(tab, err_pages[UNKNOWN_PROTOCOL]);
676 	return 0;
677 }
678 
679 /*
680  * Load url in tab.  If tab is marked as lazy, only prepare the url
681  * but don't load it.  If tab is lazy and a url was already prepared,
682  * do load it!
683  */
684 void
685 load_url(struct tab *tab, const char *url, const char *base)
686 {
687 	int lazy;
688 
689 	lazy = tab->flags & TAB_LAZY;
690 
691 	if (lazy && tab->hist_cur != NULL) {
692 		lazy = 0;
693 		tab->flags &= ~TAB_LAZY;
694 	}
695 
696 	if (!lazy || tab->hist_cur == NULL) {
697 		if (tab->hist_cur != NULL)
698 			hist_clear_forward(&tab->hist,
699 			    TAILQ_NEXT(tab->hist_cur, entries));
700 
701 		if ((tab->hist_cur = calloc(1, sizeof(*tab->hist_cur))) == NULL) {
702 			event_loopbreak();
703 			return;
704 		}
705 
706 		strlcpy(tab->buffer.page.title, url,
707 		    sizeof(tab->buffer.page.title));
708 		hist_push(&tab->hist, tab->hist_cur);
709 
710 		if (lazy)
711 			strlcpy(tab->hist_cur->h, url,
712 			    sizeof(tab->hist_cur->h));
713 	}
714 
715 	if (!lazy && do_load_url(tab, url, base))
716 		erase_buffer(&tab->buffer);
717 }
718 
719 int
720 load_previous_page(struct tab *tab)
721 {
722 	struct hist	*h;
723 
724 	if ((h = TAILQ_PREV(tab->hist_cur, mhisthead, entries)) == NULL)
725 		return 0;
726 	tab->hist_cur = h;
727 	do_load_url(tab, h->h, NULL);
728 	return 1;
729 }
730 
731 int
732 load_next_page(struct tab *tab)
733 {
734 	struct hist	*h;
735 
736 	if ((h = TAILQ_NEXT(tab->hist_cur, entries)) == NULL)
737 		return 0;
738 	tab->hist_cur = h;
739 	do_load_url(tab, h->h, NULL);
740 	return 1;
741 }
742 
743 /*
744  * Free every resource linked to the tab, including the tab itself.
745  * Removes the tab from the tablist, but doesn't update the
746  * current_tab though.
747  */
748 void
749 free_tab(struct tab *tab)
750 {
751 	stop_tab(tab);
752 
753 	if (evtimer_pending(&tab->loadingev, NULL))
754 		evtimer_del(&tab->loadingev);
755 
756 	TAILQ_REMOVE(&tabshead, tab, tabs);
757 	free(tab);
758 }
759 
760 void
761 stop_tab(struct tab *tab)
762 {
763 	ui_send_net(IMSG_STOP, tab->id, NULL, 0);
764 
765 	if (tab->fd != -1) {
766 		close(tab->fd);
767 		tab->fd = -1;
768 		free(tab->path);
769 		tab->path = NULL;
770 		load_page_from_str(tab, "Stopped.\n");
771 	}
772 }
773 
774 void
775 add_to_bookmarks(const char *str)
776 {
777 	ui_send_fs(IMSG_BOOKMARK_PAGE, 0,
778 	    str, strlen(str)+1);
779 }
780 
781 void
782 save_session(void)
783 {
784 	struct tab	*tab;
785 	char		*t;
786 	int		 flags;
787 
788 	ui_send_fs(IMSG_SESSION_START, 0, NULL, 0);
789 
790 	TAILQ_FOREACH(tab, &tabshead, tabs) {
791 		flags = tab->flags;
792 		if (tab == current_tab)
793 			flags |= TAB_CURRENT;
794 
795 		t = tab->hist_cur->h;
796 		ui_send_fs(IMSG_SESSION_TAB, flags, t, strlen(t)+1);
797 
798 		t = tab->buffer.page.title;
799 		ui_send_fs(IMSG_SESSION_TAB_TITLE, 0, t, strlen(t)+1);
800 	}
801 
802 	ui_send_fs(IMSG_SESSION_END, 0, NULL, 0);
803 }
804 
805 /*
806  * Parse a line of the session file.  The format is:
807  *
808  *	URL [flags,...] [title]\n
809  */
810 static void
811 parse_session_line(char *line, const char **title, uint32_t *flags)
812 {
813 	char *s, *t, *ap;
814 
815 	*title = "";
816 	*flags = 0;
817 	if ((s = strchr(line, ' ')) == NULL)
818 		return;
819 
820 	*s++ = '\0';
821 
822         if ((t = strchr(s, ' ')) != NULL) {
823 		*t++ = '\0';
824 		*title = t;
825 	}
826 
827 	while ((ap = strsep(&s, ",")) != NULL) {
828 		if (*ap == '\0')
829 			;
830 		else if (!strcmp(ap, "current"))
831 			*flags |= TAB_CURRENT;
832 		else
833 			message("unknown tab flag: %s", ap);
834 	}
835 }
836 
837 static void
838 load_last_session(void)
839 {
840 	const char	*title;
841 	char		*nl, *line = NULL;
842 	uint32_t	 flags;
843 	size_t		 linesize = 0;
844 	ssize_t		 linelen;
845 	FILE		*session;
846 	struct tab	*tab, *curr = NULL;
847 
848 	if ((session = fopen(session_file, "r")) == NULL) {
849 		/* first time? */
850 		new_tab("about:new", NULL);
851 		switch_to_tab(new_tab("about:help", NULL));
852 		return;
853 	}
854 
855 	while ((linelen = getline(&line, &linesize, session)) != -1) {
856                 if ((nl = strchr(line, '\n')) != NULL)
857 			*nl = '\0';
858 		parse_session_line(line, &title, &flags);
859 		if ((tab = new_tab(line, NULL)) == NULL)
860 			err(1, "new_tab");
861                 strlcpy(tab->buffer.page.title, title,
862 		    sizeof(tab->buffer.page.title));
863 		if (flags & TAB_CURRENT)
864 			curr = tab;
865 	}
866 
867 	if (ferror(session))
868 		message("error reading %s: %s",
869 		    session_file, strerror(errno));
870 	fclose(session);
871 	free(line);
872 
873 	if (curr != NULL)
874 		switch_to_tab(curr);
875 
876 	if (last_time_crashed())
877 		switch_to_tab(new_tab("about:crash", NULL));
878 
879 	return;
880 }
881 
882 static pid_t
883 start_child(enum telescope_process p, const char *argv0, int fd)
884 {
885 	const char	*argv[4];
886 	int		 argc = 0;
887 	pid_t		 pid;
888 
889 	switch (pid = fork()) {
890 	case -1:
891 		die();
892 	case 0:
893 		break;
894 	default:
895 		close(fd);
896 		return pid;
897 	}
898 
899 	if (dup2(fd, 3) == -1)
900 		err(1, "cannot setup imsg fd");
901 
902 	argv[argc++] = argv0;
903 	switch (p) {
904 	case PROC_UI:
905 		errx(1, "Can't start ui process");
906 	case PROC_FS:
907 		argv[argc++] = "-Tf";
908 		break;
909 	case PROC_NET:
910 		argv[argc++] = "-Tn";
911 		break;
912 	}
913 
914 	argv[argc++] = NULL;
915 	execvp(argv0, (char *const *)argv);
916 	err(1, "execvp(%s)", argv0);
917 }
918 
919 static int
920 ui_send_net(int type, uint32_t peerid, const void *data,
921     uint16_t datalen)
922 {
923 	return imsg_compose_event(iev_net, type, peerid, 0, -1, data,
924 	    datalen);
925 }
926 
927 static int
928 ui_send_fs(int type, uint32_t peerid, const void *data, uint16_t datalen)
929 {
930 	return imsg_compose_event(iev_fs, type, peerid, 0, -1, data,
931 	    datalen);
932 }
933 
934 static void __attribute__((noreturn))
935 usage(int r)
936 {
937 	fprintf(stderr, "USAGE: %s [-hnv] [-c config] [url]\n",
938 	    getprogname());
939 	fprintf(stderr, "version: " PACKAGE " " VERSION "\n");
940 	exit(r);
941 }
942 
943 int
944 main(int argc, char * const *argv)
945 {
946 	struct imsgev	 net_ibuf, fs_ibuf;
947 	int		 pipe2net[2], pipe2fs[2];
948 	int		 ch, configtest = 0, fail = 0;
949 	int		 has_url = 0;
950 	int		 proc = -1;
951 	int		 sessionfd;
952 	char		 path[PATH_MAX];
953 	const char	*url = NEW_TAB_URL;
954 	const char	*argv0;
955 
956 	argv0 = argv[0];
957 
958 	signal(SIGCHLD, SIG_IGN);
959 	signal(SIGPIPE, SIG_IGN);
960 
961 	if (getenv("NO_COLOR") != NULL)
962 		enable_colors = 0;
963 
964 	strlcpy(path, getenv("HOME"), sizeof(path));
965 	strlcat(path, "/.telescope/config", sizeof(path));
966 
967 	while ((ch = getopt_long(argc, argv, opts, longopts, NULL)) != -1) {
968 		switch (ch) {
969 		case 'C':
970 			exit(ui_print_colors());
971 		case 'c':
972 			fail = 1;
973 			strlcpy(path, optarg, sizeof(path));
974 			break;
975 		case 'n':
976 			configtest = 1;
977 			break;
978 		case 'h':
979 			usage(0);
980 		case 'T':
981 			switch (*optarg) {
982 			case 'f':
983 				proc = PROC_FS;
984 				break;
985 			case 'n':
986 				proc = PROC_NET;
987 				break;
988 			default:
989 				errx(1, "invalid process spec %c",
990 				    *optarg);
991 			}
992 			break;
993 		case 'v':
994 			printf("%s %s\n", PACKAGE_NAME, PACKAGE_VERSION);
995 			exit(0);
996 			break;
997 		default:
998 			usage(1);
999 		}
1000 	}
1001 
1002 	argc -= optind;
1003 	argv += optind;
1004 
1005 	if (proc != -1) {
1006 		if (argc > 0)
1007 			usage(1);
1008 		else if (proc == PROC_FS)
1009 			return fs_main();
1010 		else if (proc == PROC_NET)
1011 			return client_main();
1012 		else
1013 			usage(1);
1014 	}
1015 
1016 	if (argc != 0) {
1017 		has_url = 1;
1018 		url = argv[0];
1019 	}
1020 
1021 	/* setup keys before reading the config */
1022 	TAILQ_INIT(&global_map.m);
1023 	global_map.unhandled_input = global_key_unbound;
1024 	TAILQ_INIT(&minibuffer_map.m);
1025 
1026 	config_init();
1027 	parseconfig(path, fail);
1028 	if (configtest){
1029 		puts("config OK");
1030 		exit(0);
1031 	}
1032 
1033 	fs_init();
1034 	if ((sessionfd = lock_session()) == -1)
1035 		errx(1, "can't lock session, is another instance of "
1036 		    "telescope already running?");
1037 
1038 	/* Start children. */
1039 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe2fs) == -1)
1040 		err(1, "socketpair");
1041 	start_child(PROC_FS, argv0, pipe2fs[1]);
1042 	imsg_init(&fs_ibuf.ibuf, pipe2fs[0]);
1043 	iev_fs = &fs_ibuf;
1044 	iev_fs->handler = handle_dispatch_imsg;
1045 
1046 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe2net) == -1)
1047 		err(1, "socketpair");
1048 	start_child(PROC_NET, argv0, pipe2net[1]);
1049 	imsg_init(&net_ibuf.ibuf, pipe2net[0]);
1050 	iev_net = &net_ibuf;
1051 	iev_net->handler = handle_dispatch_imsg;
1052 
1053 	setproctitle("ui");
1054 
1055 	/* initialize tofu & load certificates */
1056 	tofu_init(&certs, 5, offsetof(struct tofu_entry, domain));
1057 	load_certs(&certs);
1058 
1059 	event_init();
1060 
1061 	/* Setup event handlers for pipes to fs/net */
1062 	iev_fs->events = EV_READ;
1063 	event_set(&iev_fs->ev, iev_fs->ibuf.fd, iev_fs->events,
1064 	    iev_fs->handler, iev_fs);
1065 	event_add(&iev_fs->ev, NULL);
1066 
1067 	iev_net->events = EV_READ;
1068 	event_set(&iev_net->ev, iev_net->ibuf.fd, iev_net->events,
1069 	    iev_net->handler, iev_net);
1070 	event_add(&iev_net->ev, NULL);
1071 
1072 	if (ui_init()) {
1073 		load_last_session();
1074 		if (has_url || TAILQ_EMPTY(&tabshead))
1075 			new_tab(url, NULL);
1076 
1077 		sandbox_ui_process();
1078 		ui_main_loop();
1079 		ui_end();
1080 	}
1081 
1082 	ui_send_fs(IMSG_QUIT, 0, NULL, 0);
1083 	ui_send_net(IMSG_QUIT, 0, NULL, 0);
1084 	imsg_flush(&iev_fs->ibuf);
1085 	imsg_flush(&iev_net->ibuf);
1086 
1087 	close(sessionfd);
1088 
1089 	return 0;
1090 }