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Date:: Sun Jul 25 10:30:36 2021 UTC
Message:: indent
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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 #include "compat.h"
18 
19 #include <sys/socket.h>
20 
21 #include <errno.h>
22 #include <getopt.h>
23 #include <limits.h>
24 #include <signal.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <string.h>
28 #include <unistd.h>
29 
30 #include "defaults.h"
31 #include "minibuffer.h"
32 #include "parser.h"
33 #include "telescope.h"
34 #include "ui.h"
35 
36 static struct option longopts[] = {
37 	{"colors",	no_argument,	NULL,	'c'},
38 	{"help",	no_argument,	NULL,	'h'},
39 	{"version",	no_argument,	NULL,	'v'},
40 	{NULL,		0,		NULL,	0},
41 };
42 
43 static const char *opts = "Cc:hnT:v";
44 
45 static struct imsgev	*iev_fs, *iev_net;
46 
47 struct tabshead		 tabshead = TAILQ_HEAD_INITIALIZER(tabshead);
48 struct proxylist	 proxies = TAILQ_HEAD_INITIALIZER(proxies);
49 
50 enum telescope_process {
51 	PROC_UI,
52 	PROC_FS,
53 	PROC_NET,
54 };
55 
56 #define CANNOT_FETCH		0
57 #define TOO_MUCH_REDIRECTS	1
58 #define MALFORMED_RESPONSE	2
59 #define UNKNOWN_TYPE_OR_CSET	3
60 #define UNKNOWN_PROTOCOL	4
61 
62 /* XXX: keep in sync with telescope.c:/^normalize_code/ */
63 const char *err_pages[70] = {
64 	[CANNOT_FETCH]		= "# Couldn't load the page\n",
65 	[TOO_MUCH_REDIRECTS]	= "# Too much redirects\n",
66 	[MALFORMED_RESPONSE]	= "# Got a malformed response\n",
67 	[UNKNOWN_TYPE_OR_CSET]	= "# Unsupported type or charset\n",
68 	[UNKNOWN_PROTOCOL]	= "# Unknown protocol\n",
69 
70 	[10] = "# Input required\n",
71 	[11] = "# Input required\n",
72 	[40] = "# Temporary failure\n",
73 	[41] = "# Server unavailable\n",
74 	[42] = "# CGI error\n",
75 	[43] = "# Proxy error\n",
76 	[44] = "# Slow down\n",
77 	[50] = "# Permanent failure\n",
78 	[51] = "# Not found\n",
79 	[52] = "# Gone\n",
80 	[53] = "# Proxy request refused\n",
81 	[59] = "# Bad request\n",
82 	[60] = "# Client certificate required\n",
83 	[61] = "# Certificate not authorised\n",
84 	[62] = "# Certificate not valid\n"
85 };
86 
87 static void		 die(void) __attribute__((__noreturn__));
88 static struct tab	*tab_by_id(uint32_t);
89 static void		 handle_imsg_err(struct imsg*, size_t);
90 static void		 handle_imsg_check_cert(struct imsg*, size_t);
91 static void		 handle_check_cert_user_choice(int, struct tab *);
92 static void		 handle_maybe_save_new_cert(int, struct tab *);
93 static void		 handle_imsg_got_code(struct imsg*, size_t);
94 static void		 handle_imsg_got_meta(struct imsg*, size_t);
95 static void		 handle_maybe_save_page(int, struct tab *);
96 static void		 handle_save_page_path(const char *, struct tab *);
97 static void		 handle_imsg_file_opened(struct imsg*, size_t);
98 static void		 handle_imsg_buf(struct imsg*, size_t);
99 static void		 handle_imsg_eof(struct imsg*, size_t);
100 static void		 handle_imsg_bookmark_ok(struct imsg*, size_t);
101 static void		 handle_imsg_save_cert_ok(struct imsg*, size_t);
102 static void		 handle_imsg_update_cert_ok(struct imsg *, size_t);
103 static void		 handle_dispatch_imsg(int, short, void*);
104 static void		 load_page_from_str(struct tab*, const char*);
105 static void		 load_about_url(struct tab*, const char*);
106 static void		 load_finger_url(struct tab *, const char *);
107 static void		 load_gemini_url(struct tab*, const char*);
108 static void		 load_via_proxy(struct tab *, const char *,
109 			     struct proxy *);
110 static void		 make_request(struct tab *, struct get_req *, int,
111 			     const char *);
112 static int		 do_load_url(struct tab*, const char *, const char *);
113 static void		 parse_session_line(char *, const char **, uint32_t *);
114 static void		 load_last_session(void);
115 static pid_t		 start_child(enum telescope_process, const char *, int);
116 static int		 ui_send_net(int, uint32_t, const void *, uint16_t);
117 static int		 ui_send_fs(int, uint32_t, const void *, uint16_t);
118 
119 static struct proto {
120 	const char	*schema;
121 	const char	*port;
122 	void		 (*loadfn)(struct tab*, const char*);
123 } protos[] = {
124 	{"about",	NULL,	load_about_url},
125 	{"finger",	"79",	load_finger_url},
126 	{"gemini",	"1965",	load_gemini_url},
127 	{NULL, NULL, NULL},
128 };
129 
130 static imsg_handlerfn *handlers[] = {
131 	[IMSG_ERR] = handle_imsg_err,
132 	[IMSG_CHECK_CERT] = handle_imsg_check_cert,
133 	[IMSG_GOT_CODE] = handle_imsg_got_code,
134 	[IMSG_GOT_META] = handle_imsg_got_meta,
135 	[IMSG_BUF] = handle_imsg_buf,
136 	[IMSG_EOF] = handle_imsg_eof,
137 	[IMSG_BOOKMARK_OK] = handle_imsg_bookmark_ok,
138 	[IMSG_SAVE_CERT_OK] = handle_imsg_save_cert_ok,
139 	[IMSG_UPDATE_CERT_OK] = handle_imsg_update_cert_ok,
140 	[IMSG_FILE_OPENED] = handle_imsg_file_opened,
141 };
142 
143 static struct ohash	certs;
144 
145 static void __attribute__((__noreturn__))
146 die(void)
147 {
148 	abort(); 		/* TODO */
149 }
150 
151 static struct tab *
152 tab_by_id(uint32_t id)
153 {
154 	struct tab *t;
155 
156 	TAILQ_FOREACH(t, &tabshead, tabs) {
157 		if (t->id == id)
158 			return t;
159 	}
160 
161 	return NULL;
162 }
163 
164 static void
165 handle_imsg_err(struct imsg *imsg, size_t datalen)
166 {
167 	struct tab	*tab;
168 	char		*page;
169 
170 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
171 		return;
172 
173 	page = imsg->data;
174 	page[datalen-1] = '\0';
175 
176 	if (asprintf(&page, "# Error loading %s\n\n> %s\n",
177 	    tab->hist_cur->h, page) == -1)
178 		die();
179 	load_page_from_str(tab, page);
180 	free(page);
181 }
182 
183 static void
184 handle_imsg_check_cert(struct imsg *imsg, size_t datalen)
185 {
186 	const char		*hash, *host, *port;
187 	int			 tofu_res;
188 	struct tofu_entry	*e;
189 	struct tab		*tab;
190 
191 	hash = imsg->data;
192 	if (hash[datalen-1] != '\0')
193 		abort();
194 
195 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
196 		return;
197 
198 	if (tab->proxy != NULL) {
199 		host = tab->proxy->host;
200 		port = tab->proxy->port;
201 	} else {
202 		host = tab->uri.host;
203 		port = tab->uri.port;
204 	}
205 
206 	if ((e = tofu_lookup(&certs, host, port)) == NULL) {
207 		/* TODO: an update in libressl/libretls changed
208 		 * significantly.  Find a better approach at storing
209 		 * the certs! */
210 		if (datalen > sizeof(e->hash))
211 			abort();
212 
213 		tofu_res = 1;	/* trust on first use */
214 		if ((e = calloc(1, sizeof(*e))) == NULL)
215 			abort();
216 		strlcpy(e->domain, host, sizeof(e->domain));
217 		if (*port != '\0' && strcmp(port, "1965")) {
218 			strlcat(e->domain, ":", sizeof(e->domain));
219 			strlcat(e->domain, port, sizeof(e->domain));
220 		}
221 		strlcpy(e->hash, hash, sizeof(e->hash));
222 		tofu_add(&certs, e);
223 		ui_send_fs(IMSG_SAVE_CERT, tab->id, e, sizeof(*e));
224 	} else
225 		tofu_res = !strcmp(hash, e->hash);
226 
227 	if (tofu_res) {
228 		if (e->verified == -1)
229 			tab->trust = TS_TEMP_TRUSTED;
230 		else if (e->verified == 1)
231 			tab->trust = TS_VERIFIED;
232 		else
233 			tab->trust = TS_TRUSTED;
234 
235 		ui_send_net(IMSG_CERT_STATUS, imsg->hdr.peerid,
236 		    &tofu_res, sizeof(tofu_res));
237 	} else {
238 		tab->trust = TS_UNTRUSTED;
239 		load_page_from_str(tab, "# Certificate mismatch\n");
240 		if ((tab->cert = strdup(hash)) == NULL)
241 			die();
242 		ui_yornp("Certificate mismatch.  Proceed?",
243 		    handle_check_cert_user_choice, tab);
244 	}
245 }
246 
247 static void
248 handle_check_cert_user_choice(int accept, struct tab *tab)
249 {
250 	ui_send_net(IMSG_CERT_STATUS, tab->id, &accept,
251 	    sizeof(accept));
252 
253 	if (accept) {
254 		/*
255 		 * trust the certificate for this session only.  If
256 		 * the page results in a redirect while we're asking
257 		 * the user to save, we'll end up with an invalid
258 		 * tabid (one request == one tab id) and crash.  It
259 		 * also makes sense to save it for the current session
260 		 * if the user accepted it.
261 		 */
262 		tofu_temp_trust(&certs, tab->uri.host, tab->uri.port, tab->cert);
263 
264 		ui_yornp("Save the new certificate?",
265 		    handle_maybe_save_new_cert, tab);
266 	} else {
267 		free(tab->cert);
268 		tab->cert = NULL;
269 	}
270 }
271 
272 static void
273 handle_maybe_save_new_cert(int accept, struct tab *tab)
274 {
275 	struct tofu_entry *e;
276 	const char *host, *port;
277 
278 	if (tab->proxy != NULL) {
279 		host = tab->proxy->host;
280 		port = tab->proxy->port;
281 	} else {
282 		host = tab->uri.host;
283 		port = tab->uri.port;
284 	}
285 
286 	if (!accept)
287 		goto end;
288 
289 	if ((e = calloc(1, sizeof(*e))) == NULL)
290 		die();
291 
292 	strlcpy(e->domain, host, sizeof(e->domain));
293 	if (*port != '\0' && strcmp(port, "1965")) {
294 		strlcat(e->domain, ":", sizeof(e->domain));
295 		strlcat(e->domain, port, sizeof(e->domain));
296 	}
297 	strlcpy(e->hash, tab->cert, sizeof(e->hash));
298 	ui_send_fs(IMSG_UPDATE_CERT, 0, e, sizeof(*e));
299 
300 	tofu_update(&certs, e);
301 
302 	tab->trust = TS_TRUSTED;
303 
304 end:
305 	free(tab->cert);
306 	tab->cert = NULL;
307 }
308 
309 static inline int
310 normalize_code(int n)
311 {
312 	if (n < 20) {
313 		if (n == 10 || n == 11)
314 			return n;
315 		return 10;
316 	} else if (n < 30) {
317 		return 20;
318 	} else if (n < 40) {
319 		if (n == 30 || n == 31)
320 			return n;
321 		return 30;
322 	} else if (n < 50) {
323 		if (n <= 44)
324 			return n;
325 		return 40;
326 	} else if (n < 60) {
327 		if (n <= 53 || n == 59)
328 			return n;
329 		return 50;
330 	} else if (n < 70) {
331 		if (n <= 62)
332 			return n;
333 		return 60;
334 	} else
335 		return MALFORMED_RESPONSE;
336 }
337 
338 static void
339 handle_imsg_got_code(struct imsg *imsg, size_t datalen)
340 {
341 	struct tab	*tab;
342 
343 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
344 		return;
345 
346 	if (sizeof(tab->code) != datalen)
347 		die();
348 
349 	memcpy(&tab->code, imsg->data, sizeof(tab->code));
350 	tab->code = normalize_code(tab->code);
351 	if (tab->code != 30 && tab->code != 31)
352 		tab->redirect_count = 0;
353 }
354 
355 static void
356 handle_imsg_got_meta(struct imsg *imsg, size_t datalen)
357 {
358 	struct tab	*tab;
359 
360 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
361 		return;
362 
363 	if (sizeof(tab->meta) <= datalen)
364 		die();
365 
366 	memcpy(tab->meta, imsg->data, datalen);
367 
368 	if (tab->code < 10) {	/* internal errors */
369 		load_page_from_str(tab, err_pages[tab->code]);
370 	} else if (tab->code < 20) {	/* 1x */
371 		load_page_from_str(tab, err_pages[tab->code]);
372 		ui_require_input(tab, tab->code == 11);
373 	} else if (tab->code == 20) {
374 		if (setup_parser_for(tab)) {
375 			ui_send_net(IMSG_PROCEED, tab->id, NULL, 0);
376 		} else {
377 			load_page_from_str(tab, err_pages[UNKNOWN_TYPE_OR_CSET]);
378 			ui_yornp("Can't display page, wanna save?",
379 			    handle_maybe_save_page, tab);
380 		}
381 	} else if (tab->code < 40) { /* 3x */
382 		tab->redirect_count++;
383 
384 		/* TODO: make customizable? */
385 		if (tab->redirect_count > 5) {
386 			load_page_from_str(tab,
387 			    err_pages[TOO_MUCH_REDIRECTS]);
388 		} else
389 			do_load_url(tab, tab->meta, NULL);
390 	} else { /* 4x, 5x & 6x */
391 		load_page_from_str(tab, err_pages[tab->code]);
392 	}
393 }
394 
395 static void
396 handle_maybe_save_page(int dosave, struct tab *tab)
397 {
398 	if (dosave)
399 		ui_read("Save to path", handle_save_page_path, tab);
400 	else
401 		stop_tab(tab);
402 }
403 
404 static void
405 handle_save_page_path(const char *path, struct tab *tab)
406 {
407 	if (path == NULL) {
408 		stop_tab(tab);
409 		return;
410 	}
411 
412 	tab->path = strdup(path);
413 
414 	ui_send_fs(IMSG_FILE_OPEN, tab->id, path, strlen(path)+1);
415 }
416 
417 static void
418 handle_imsg_file_opened(struct imsg *imsg, size_t datalen)
419 {
420 	struct tab	*tab;
421 	char		*page;
422 	const char	*e;
423 	int		 l;
424 
425 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL) {
426 		if (imsg->fd != -1)
427 			close(imsg->fd);
428 		return;
429 	}
430 
431 	if (imsg->fd == -1) {
432 		stop_tab(tab);
433 
434 		e = imsg->data;
435 		if (e[datalen-1] != '\0')
436 			die();
437 		l = asprintf(&page, "# Can't open file\n\n> %s: %s\n",
438 		    tab->path, e);
439 		if (l == -1)
440 			die();
441 		load_page_from_str(tab, page);
442 		free(page);
443 	} else {
444 		tab->fd = imsg->fd;
445 		ui_send_net(IMSG_PROCEED, tab->id, NULL, 0);
446 	}
447 }
448 
449 static void
450 handle_imsg_buf(struct imsg *imsg, size_t datalen)
451 {
452 	struct tab	*tab;
453 	int		 l;
454 	char		*page, buf[FMT_SCALED_STRSIZE] = {0};
455 
456 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
457 		return;
458 
459 	tab->bytes += datalen;
460 	if (tab->fd == -1) {
461 		if (!tab->buffer.page.parse(&tab->buffer.page,
462 		    imsg->data, datalen))
463 			die();
464 	} else {
465 		write(tab->fd, imsg->data, datalen);
466 		fmt_scaled(tab->bytes, buf);
467 		l = asprintf(&page, "Saving to \"%s\"... (%s)\n",
468 		    tab->path,
469 		    buf);
470 		if (l == -1)
471 			die();
472 		load_page_from_str(tab, page);
473 		free(page);
474 	}
475 
476 	ui_on_tab_refresh(tab);
477 }
478 
479 static void
480 handle_imsg_eof(struct imsg *imsg, size_t datalen)
481 {
482 	struct tab	*tab;
483 	int		 l;
484 	char		*page, buf[FMT_SCALED_STRSIZE] = {0};
485 
486 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
487 		return;
488 
489 	if (tab->fd == -1) {
490 		if (!tab->buffer.page.free(&tab->buffer.page))
491 			die();
492 	} else {
493 		fmt_scaled(tab->bytes, buf);
494 		l = asprintf(&page, "Saved to \"%s\" (%s)\n",
495 		    tab->path,
496 		    buf);
497 		if (l == -1)
498 			die();
499 		load_page_from_str(tab, page);
500 		free(page);
501 
502 		close(tab->fd);
503 		tab->fd = -1;
504 		free(tab->path);
505 		tab->path = NULL;
506 	}
507 
508 	ui_on_tab_refresh(tab);
509 	ui_on_tab_loaded(tab);
510 }
511 
512 static void
513 handle_imsg_bookmark_ok(struct imsg *imsg, size_t datalen)
514 {
515 	int res;
516 
517 	if (datalen != sizeof(res))
518 		die();
519 
520 	memcpy(&res, imsg->data, sizeof(res));
521 	if (res == 0)
522 		message("Added to bookmarks!");
523 	else
524 		message("Failed to add to bookmarks: %s",
525 		    strerror(res));
526 }
527 
528 static void
529 handle_imsg_save_cert_ok(struct imsg *imsg, size_t datalen)
530 {
531 	int res;
532 
533 	if (datalen != sizeof(res))
534 		die();
535 	memcpy(&res, imsg->data, datalen);
536 	if (res != 0)
537 		message("Failed to save the cert for: %s",
538 		    strerror(res));
539 }
540 
541 static void
542 handle_imsg_update_cert_ok(struct imsg *imsg, size_t datalen)
543 {
544 	int res;
545 
546 	if (datalen != sizeof(res))
547 		die();
548 	memcpy(&res, imsg->data, datalen);
549 	if (!res)
550 		message("Failed to update the certificate");
551 }
552 
553 static void
554 handle_dispatch_imsg(int fd, short ev, void *d)
555 {
556 	struct imsgev	*iev = d;
557 
558 	if (dispatch_imsg(iev, ev, handlers, sizeof(handlers)) == -1)
559 		err(1, "connection closed");
560 }
561 
562 static void
563 load_page_from_str(struct tab *tab, const char *page)
564 {
565 	erase_buffer(&tab->buffer);
566 	gemtext_initparser(&tab->buffer.page);
567 	if (!tab->buffer.page.parse(&tab->buffer.page, page, strlen(page)))
568 		die();
569 	if (!tab->buffer.page.free(&tab->buffer.page))
570 		die();
571 	ui_on_tab_refresh(tab);
572 	ui_on_tab_loaded(tab);
573 }
574 
575 static void
576 load_about_url(struct tab *tab, const char *url)
577 {
578 	tab->trust = TS_VERIFIED;
579 
580 	gemtext_initparser(&tab->buffer.page);
581 
582 	ui_send_fs(IMSG_GET, tab->id,
583 	    tab->hist_cur->h, strlen(tab->hist_cur->h)+1);
584 }
585 
586 static void
587 load_finger_url(struct tab *tab, const char *url)
588 {
589 	struct get_req	 req;
590 	size_t		 len;
591 	char		*at;
592 
593 	memset(&req, 0, sizeof(req));
594 	strlcpy(req.port, tab->uri.port, sizeof(req.port));
595 
596 	/*
597 	 * Sometimes the finger url have the user as path component
598 	 * (e.g. finger://thelambdalab.xyz/plugd), sometimes as
599 	 * userinfo (e.g. finger://cobradile@finger.farm).
600 	 */
601 	if ((at = strchr(tab->uri.host, '@')) != NULL) {
602 		len = at - tab->uri.host;
603 		memcpy(req.req, tab->uri.host, len);
604 
605 		if (len >= sizeof(req.req))
606 			die();
607 		req.req[len] = '\0';
608 
609 		strlcpy(req.host, at+1, sizeof(req.host));
610 	} else {
611 		strlcpy(req.host, tab->uri.host, sizeof(req.host));
612 
613 		/* +1 to skip the initial `/' */
614 		strlcpy(req.req, tab->uri.path+1, sizeof(req.req));
615 	}
616 	strlcat(req.req, "\r\n", sizeof(req.req));
617 
618 	textplain_initparser(&tab->buffer.page);
619 	make_request(tab, &req, PROTO_FINGER, NULL);
620 }
621 
622 static void
623 load_gemini_url(struct tab *tab, const char *url)
624 {
625 	struct get_req	 req;
626 
627 	memset(&req, 0, sizeof(req));
628 	strlcpy(req.host, tab->uri.host, sizeof(req.host));
629 	strlcpy(req.port, tab->uri.port, sizeof(req.host));
630 
631 	make_request(tab, &req, PROTO_GEMINI, tab->hist_cur->h);
632 }
633 
634 static void
635 load_via_proxy(struct tab *tab, const char *url, struct proxy *p)
636 {
637 	struct get_req req;
638 
639 	memset(&req, 0, sizeof(req));
640 	strlcpy(req.host, p->host, sizeof(req.host));
641 	strlcpy(req.port, p->port, sizeof(req.host));
642 
643 	tab->proxy = p;
644 
645 	make_request(tab, &req, p->proto, tab->hist_cur->h);
646 }
647 
648 static void
649 make_request(struct tab *tab, struct get_req *req, int proto, const char *r)
650 {
651 	stop_tab(tab);
652 	tab->id = tab_new_id();
653 	req->proto = proto;
654 
655 	if (r != NULL) {
656 		strlcpy(req->req, r, sizeof(req->req));
657 		strlcat(req->req, "\r\n", sizeof(req->req));
658 	}
659 
660 	ui_send_net(IMSG_GET_RAW, tab->id, req, sizeof(*req));
661 }
662 
663 /*
664  * Effectively load the given url in the given tab.  Return 1 when
665  * loading the page asynchronously, and thus when an erase_buffer can
666  * be done right after this function return, or 0 when loading the
667  * page synchronously.  In this last case, erase_buffer *MUST* be
668  * called by the handling function (such as load_page_from_str).
669  */
670 static int
671 do_load_url(struct tab *tab, const char *url, const char *base)
672 {
673 	struct phos_uri	 uri;
674 	struct proto	*p;
675 	struct proxy	*proxy;
676 	char		*t;
677 
678 	tab->proxy = NULL;
679 
680 	if (tab->fd != -1) {
681 		close(tab->fd);
682 		tab->fd = -1;
683 		free(tab->path);
684 		tab->path = NULL;
685 	}
686 
687 	tab->trust = TS_UNKNOWN;
688 
689 	if (base == NULL)
690 		memcpy(&uri, &tab->uri, sizeof(tab->uri));
691 	else
692 		phos_parse_absolute_uri(base, &uri);
693 
694 	if (!phos_resolve_uri_from_str(&uri, url, &tab->uri)) {
695 		if (asprintf(&t, "#error loading %s\n>%s\n",
696 		    url, "Can't parse the URI") == -1)
697 			die();
698 		strlcpy(tab->hist_cur->h, url, sizeof(tab->hist_cur->h));
699 		load_page_from_str(tab, t);
700 		free(t);
701 		return 0;
702 	}
703 
704 	phos_serialize_uri(&tab->uri, tab->hist_cur->h,
705 	    sizeof(tab->hist_cur->h));
706 
707 	for (p = protos; p->schema != NULL; ++p) {
708 		if (!strcmp(tab->uri.scheme, p->schema)) {
709 			/* patch the port */
710 			if (*tab->uri.port == '\0' && p->port != NULL)
711 				strlcpy(tab->uri.port, p->port,
712 				    sizeof(tab->uri.port));
713 
714 			p->loadfn(tab, url);
715                         return 1;
716 		}
717 	}
718 
719 	TAILQ_FOREACH(proxy, &proxies, proxies) {
720 		if (!strcmp(tab->uri.scheme, proxy->match_proto)) {
721 			load_via_proxy(tab, url, proxy);
722 			return 1;
723 		}
724 	}
725 
726 	load_page_from_str(tab, err_pages[UNKNOWN_PROTOCOL]);
727 	return 0;
728 }
729 
730 /*
731  * Load url in tab.  If tab is marked as lazy, only prepare the url
732  * but don't load it.  If tab is lazy and a url was already prepared,
733  * do load it!
734  */
735 void
736 load_url(struct tab *tab, const char *url, const char *base)
737 {
738 	int lazy;
739 
740 	lazy = tab->flags & TAB_LAZY;
741 
742 	if (lazy && tab->hist_cur != NULL) {
743 		lazy = 0;
744 		tab->flags &= ~TAB_LAZY;
745 	}
746 
747 	if (!lazy || tab->hist_cur == NULL) {
748 		if (tab->hist_cur != NULL)
749 			hist_clear_forward(&tab->hist,
750 			    TAILQ_NEXT(tab->hist_cur, entries));
751 
752 		if ((tab->hist_cur = calloc(1, sizeof(*tab->hist_cur))) == NULL) {
753 			event_loopbreak();
754 			return;
755 		}
756 
757 		strlcpy(tab->buffer.page.title, url,
758 		    sizeof(tab->buffer.page.title));
759 		hist_push(&tab->hist, tab->hist_cur);
760 
761 		if (lazy)
762 			strlcpy(tab->hist_cur->h, url,
763 			    sizeof(tab->hist_cur->h));
764 	}
765 
766 	if (!lazy && do_load_url(tab, url, base))
767 		erase_buffer(&tab->buffer);
768 }
769 
770 int
771 load_previous_page(struct tab *tab)
772 {
773 	struct hist	*h;
774 
775 	if ((h = TAILQ_PREV(tab->hist_cur, mhisthead, entries)) == NULL)
776 		return 0;
777 	tab->hist_cur = h;
778 	do_load_url(tab, h->h, NULL);
779 	return 1;
780 }
781 
782 int
783 load_next_page(struct tab *tab)
784 {
785 	struct hist	*h;
786 
787 	if ((h = TAILQ_NEXT(tab->hist_cur, entries)) == NULL)
788 		return 0;
789 	tab->hist_cur = h;
790 	do_load_url(tab, h->h, NULL);
791 	return 1;
792 }
793 
794 /*
795  * Free every resource linked to the tab, including the tab itself.
796  * Removes the tab from the tablist, but doesn't update the
797  * current_tab though.
798  */
799 void
800 free_tab(struct tab *tab)
801 {
802 	stop_tab(tab);
803 
804 	if (evtimer_pending(&tab->loadingev, NULL))
805 		evtimer_del(&tab->loadingev);
806 
807 	TAILQ_REMOVE(&tabshead, tab, tabs);
808 	free(tab);
809 }
810 
811 void
812 stop_tab(struct tab *tab)
813 {
814 	ui_send_net(IMSG_STOP, tab->id, NULL, 0);
815 
816 	if (tab->fd != -1) {
817 		close(tab->fd);
818 		tab->fd = -1;
819 		free(tab->path);
820 		tab->path = NULL;
821 		load_page_from_str(tab, "Stopped.\n");
822 	}
823 }
824 
825 void
826 add_to_bookmarks(const char *str)
827 {
828 	ui_send_fs(IMSG_BOOKMARK_PAGE, 0,
829 	    str, strlen(str)+1);
830 }
831 
832 void
833 save_session(void)
834 {
835 	struct tab	*tab;
836 	char		*t;
837 	int		 flags;
838 
839 	ui_send_fs(IMSG_SESSION_START, 0, NULL, 0);
840 
841 	TAILQ_FOREACH(tab, &tabshead, tabs) {
842 		flags = tab->flags;
843 		if (tab == current_tab)
844 			flags |= TAB_CURRENT;
845 
846 		t = tab->hist_cur->h;
847 		ui_send_fs(IMSG_SESSION_TAB, flags, t, strlen(t)+1);
848 
849 		t = tab->buffer.page.title;
850 		ui_send_fs(IMSG_SESSION_TAB_TITLE, 0, t, strlen(t)+1);
851 	}
852 
853 	ui_send_fs(IMSG_SESSION_END, 0, NULL, 0);
854 }
855 
856 /*
857  * Parse a line of the session file.  The format is:
858  *
859  *	URL [flags,...] [title]\n
860  */
861 static void
862 parse_session_line(char *line, const char **title, uint32_t *flags)
863 {
864 	char *s, *t, *ap;
865 
866 	*title = "";
867 	*flags = 0;
868 	if ((s = strchr(line, ' ')) == NULL)
869 		return;
870 
871 	*s++ = '\0';
872 
873         if ((t = strchr(s, ' ')) != NULL) {
874 		*t++ = '\0';
875 		*title = t;
876 	}
877 
878 	while ((ap = strsep(&s, ",")) != NULL) {
879 		if (*ap == '\0')
880 			;
881 		else if (!strcmp(ap, "current"))
882 			*flags |= TAB_CURRENT;
883 		else
884 			message("unknown tab flag: %s", ap);
885 	}
886 }
887 
888 static void
889 load_last_session(void)
890 {
891 	const char	*title;
892 	char		*nl, *line = NULL;
893 	uint32_t	 flags;
894 	size_t		 linesize = 0;
895 	ssize_t		 linelen;
896 	FILE		*session;
897 	struct tab	*tab, *curr = NULL;
898 
899 	if ((session = fopen(session_file, "r")) == NULL) {
900 		/* first time? */
901 		new_tab("about:new", NULL);
902 		switch_to_tab(new_tab("about:help", NULL));
903 		return;
904 	}
905 
906 	while ((linelen = getline(&line, &linesize, session)) != -1) {
907                 if ((nl = strchr(line, '\n')) != NULL)
908 			*nl = '\0';
909 		parse_session_line(line, &title, &flags);
910 		if ((tab = new_tab(line, NULL)) == NULL)
911 			err(1, "new_tab");
912                 strlcpy(tab->buffer.page.title, title,
913 		    sizeof(tab->buffer.page.title));
914 		if (flags & TAB_CURRENT)
915 			curr = tab;
916 	}
917 
918 	if (ferror(session))
919 		message("error reading %s: %s",
920 		    session_file, strerror(errno));
921 	fclose(session);
922 	free(line);
923 
924 	if (curr != NULL)
925 		switch_to_tab(curr);
926 
927 	if (last_time_crashed())
928 		switch_to_tab(new_tab("about:crash", NULL));
929 
930 	return;
931 }
932 
933 static pid_t
934 start_child(enum telescope_process p, const char *argv0, int fd)
935 {
936 	const char	*argv[4];
937 	int		 argc = 0;
938 	pid_t		 pid;
939 
940 	switch (pid = fork()) {
941 	case -1:
942 		die();
943 	case 0:
944 		break;
945 	default:
946 		close(fd);
947 		return pid;
948 	}
949 
950 	if (dup2(fd, 3) == -1)
951 		err(1, "cannot setup imsg fd");
952 
953 	argv[argc++] = argv0;
954 	switch (p) {
955 	case PROC_UI:
956 		errx(1, "Can't start ui process");
957 	case PROC_FS:
958 		argv[argc++] = "-Tf";
959 		break;
960 	case PROC_NET:
961 		argv[argc++] = "-Tn";
962 		break;
963 	}
964 
965 	argv[argc++] = NULL;
966 	execvp(argv0, (char *const *)argv);
967 	err(1, "execvp(%s)", argv0);
968 }
969 
970 static int
971 ui_send_net(int type, uint32_t peerid, const void *data,
972     uint16_t datalen)
973 {
974 	return imsg_compose_event(iev_net, type, peerid, 0, -1, data,
975 	    datalen);
976 }
977 
978 static int
979 ui_send_fs(int type, uint32_t peerid, const void *data, uint16_t datalen)
980 {
981 	return imsg_compose_event(iev_fs, type, peerid, 0, -1, data,
982 	    datalen);
983 }
984 
985 static void __attribute__((noreturn))
986 usage(int r)
987 {
988 	fprintf(stderr, "USAGE: %s [-hnv] [-c config] [url]\n",
989 	    getprogname());
990 	fprintf(stderr, "version: " PACKAGE " " VERSION "\n");
991 	exit(r);
992 }
993 
994 int
995 main(int argc, char * const *argv)
996 {
997 	struct imsgev	 net_ibuf, fs_ibuf;
998 	int		 pipe2net[2], pipe2fs[2];
999 	int		 ch, configtest = 0, fail = 0;
1000 	int		 has_url = 0;
1001 	int		 proc = -1;
1002 	int		 sessionfd;
1003 	char		 path[PATH_MAX];
1004 	const char	*url = NEW_TAB_URL;
1005 	const char	*argv0;
1006 
1007 	argv0 = argv[0];
1008 
1009 	signal(SIGCHLD, SIG_IGN);
1010 	signal(SIGPIPE, SIG_IGN);
1011 
1012 	if (getenv("NO_COLOR") != NULL)
1013 		enable_colors = 0;
1014 
1015 	strlcpy(path, getenv("HOME"), sizeof(path));
1016 	strlcat(path, "/.telescope/config", sizeof(path));
1017 
1018 	while ((ch = getopt_long(argc, argv, opts, longopts, NULL)) != -1) {
1019 		switch (ch) {
1020 		case 'C':
1021 			exit(ui_print_colors());
1022 		case 'c':
1023 			fail = 1;
1024 			strlcpy(path, optarg, sizeof(path));
1025 			break;
1026 		case 'n':
1027 			configtest = 1;
1028 			break;
1029 		case 'h':
1030 			usage(0);
1031 		case 'T':
1032 			switch (*optarg) {
1033 			case 'f':
1034 				proc = PROC_FS;
1035 				break;
1036 			case 'n':
1037 				proc = PROC_NET;
1038 				break;
1039 			default:
1040 				errx(1, "invalid process spec %c",
1041 				    *optarg);
1042 			}
1043 			break;
1044 		case 'v':
1045 			printf("%s %s\n", PACKAGE_NAME, PACKAGE_VERSION);
1046 			exit(0);
1047 			break;
1048 		default:
1049 			usage(1);
1050 		}
1051 	}
1052 
1053 	argc -= optind;
1054 	argv += optind;
1055 
1056 	if (proc != -1) {
1057 		if (argc > 0)
1058 			usage(1);
1059 		else if (proc == PROC_FS)
1060 			return fs_main();
1061 		else if (proc == PROC_NET)
1062 			return net_main();
1063 		else
1064 			usage(1);
1065 	}
1066 
1067 	if (argc != 0) {
1068 		has_url = 1;
1069 		url = argv[0];
1070 	}
1071 
1072 	/* setup keys before reading the config */
1073 	TAILQ_INIT(&global_map.m);
1074 	global_map.unhandled_input = global_key_unbound;
1075 	TAILQ_INIT(&minibuffer_map.m);
1076 
1077 	config_init();
1078 	parseconfig(path, fail);
1079 	if (configtest){
1080 		puts("config OK");
1081 		exit(0);
1082 	}
1083 
1084 	fs_init();
1085 	if ((sessionfd = lock_session()) == -1)
1086 		errx(1, "can't lock session, is another instance of "
1087 		    "telescope already running?");
1088 
1089 	/* Start children. */
1090 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe2fs) == -1)
1091 		err(1, "socketpair");
1092 	start_child(PROC_FS, argv0, pipe2fs[1]);
1093 	imsg_init(&fs_ibuf.ibuf, pipe2fs[0]);
1094 	iev_fs = &fs_ibuf;
1095 	iev_fs->handler = handle_dispatch_imsg;
1096 
1097 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe2net) == -1)
1098 		err(1, "socketpair");
1099 	start_child(PROC_NET, argv0, pipe2net[1]);
1100 	imsg_init(&net_ibuf.ibuf, pipe2net[0]);
1101 	iev_net = &net_ibuf;
1102 	iev_net->handler = handle_dispatch_imsg;
1103 
1104 	setproctitle("ui");
1105 
1106 	/* initialize tofu & load certificates */
1107 	tofu_init(&certs, 5, offsetof(struct tofu_entry, domain));
1108 	load_certs(&certs);
1109 
1110 	event_init();
1111 
1112 	/* Setup event handlers for pipes to fs/net */
1113 	iev_fs->events = EV_READ;
1114 	event_set(&iev_fs->ev, iev_fs->ibuf.fd, iev_fs->events,
1115 	    iev_fs->handler, iev_fs);
1116 	event_add(&iev_fs->ev, NULL);
1117 
1118 	iev_net->events = EV_READ;
1119 	event_set(&iev_net->ev, iev_net->ibuf.fd, iev_net->events,
1120 	    iev_net->handler, iev_net);
1121 	event_add(&iev_net->ev, NULL);
1122 
1123 	if (ui_init()) {
1124 		load_last_session();
1125 		if (has_url || TAILQ_EMPTY(&tabshead))
1126 			new_tab(url, NULL);
1127 
1128 		sandbox_ui_process();
1129 		ui_main_loop();
1130 		ui_end();
1131 	}
1132 
1133 	ui_send_fs(IMSG_QUIT, 0, NULL, 0);
1134 	ui_send_net(IMSG_QUIT, 0, NULL, 0);
1135 	imsg_flush(&iev_fs->ibuf);
1136 	imsg_flush(&iev_net->ibuf);
1137 
1138 	close(sessionfd);
1139 
1140 	return 0;
1141 }