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Date:: Sun Jul 25 10:01:20 2021 UTC
Message:: support finger:// urls!
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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 static struct proto protos[] = {
57 	{ "about",	load_about_url },
58 	{ "finger",	load_finger_url },
59 	{ "gemini",	load_gemini_url },
60 	{ NULL, NULL },
61 };
62 
63 
64 #define CANNOT_FETCH		0
65 #define TOO_MUCH_REDIRECTS	1
66 #define MALFORMED_RESPONSE	2
67 #define UNKNOWN_TYPE_OR_CSET	3
68 #define UNKNOWN_PROTOCOL	4
69 
70 /* XXX: keep in sync with telescope.c:/^normalize_code/ */
71 const char *err_pages[70] = {
72 	[CANNOT_FETCH]		= "# Couldn't load the page\n",
73 	[TOO_MUCH_REDIRECTS]	= "# Too much redirects\n",
74 	[MALFORMED_RESPONSE]	= "# Got a malformed response\n",
75 	[UNKNOWN_TYPE_OR_CSET]	= "# Unsupported type or charset\n",
76 	[UNKNOWN_PROTOCOL]	= "# Unknown protocol\n",
77 
78 	[10] = "# Input required\n",
79 	[11] = "# Input required\n",
80 	[40] = "# Temporary failure\n",
81 	[41] = "# Server unavailable\n",
82 	[42] = "# CGI error\n",
83 	[43] = "# Proxy error\n",
84 	[44] = "# Slow down\n",
85 	[50] = "# Permanent failure\n",
86 	[51] = "# Not found\n",
87 	[52] = "# Gone\n",
88 	[53] = "# Proxy request refused\n",
89 	[59] = "# Bad request\n",
90 	[60] = "# Client certificate required\n",
91 	[61] = "# Certificate not authorised\n",
92 	[62] = "# Certificate not valid\n"
93 };
94 
95 static void		 die(void) __attribute__((__noreturn__));
96 static struct tab	*tab_by_id(uint32_t);
97 static void		 handle_imsg_err(struct imsg*, size_t);
98 static void		 handle_imsg_check_cert(struct imsg*, size_t);
99 static void		 handle_check_cert_user_choice(int, struct tab *);
100 static void		 handle_maybe_save_new_cert(int, struct tab *);
101 static void		 handle_imsg_got_code(struct imsg*, size_t);
102 static void		 handle_imsg_got_meta(struct imsg*, size_t);
103 static void		 handle_maybe_save_page(int, struct tab *);
104 static void		 handle_save_page_path(const char *, struct tab *);
105 static void		 handle_imsg_file_opened(struct imsg*, size_t);
106 static void		 handle_imsg_buf(struct imsg*, size_t);
107 static void		 handle_imsg_eof(struct imsg*, size_t);
108 static void		 handle_imsg_bookmark_ok(struct imsg*, size_t);
109 static void		 handle_imsg_save_cert_ok(struct imsg*, size_t);
110 static void		 handle_imsg_update_cert_ok(struct imsg *, size_t);
111 static void		 handle_dispatch_imsg(int, short, void*);
112 static void		 load_page_from_str(struct tab*, const char*);
113 static int		 do_load_url(struct tab*, const char *, const char *);
114 static void		 parse_session_line(char *, const char **, uint32_t *);
115 static void		 load_last_session(void);
116 static pid_t		 start_child(enum telescope_process, const char *, int);
117 static int		 ui_send_net(int, uint32_t, const void *, uint16_t);
118 static int		 ui_send_fs(int, uint32_t, const void *, uint16_t);
119 
120 static imsg_handlerfn *handlers[] = {
121 	[IMSG_ERR] = handle_imsg_err,
122 	[IMSG_CHECK_CERT] = handle_imsg_check_cert,
123 	[IMSG_GOT_CODE] = handle_imsg_got_code,
124 	[IMSG_GOT_META] = handle_imsg_got_meta,
125 	[IMSG_BUF] = handle_imsg_buf,
126 	[IMSG_EOF] = handle_imsg_eof,
127 	[IMSG_BOOKMARK_OK] = handle_imsg_bookmark_ok,
128 	[IMSG_SAVE_CERT_OK] = handle_imsg_save_cert_ok,
129 	[IMSG_UPDATE_CERT_OK] = handle_imsg_update_cert_ok,
130 	[IMSG_FILE_OPENED] = handle_imsg_file_opened,
131 };
132 
133 static struct ohash	certs;
134 
135 static void __attribute__((__noreturn__))
136 die(void)
137 {
138 	abort(); 		/* TODO */
139 }
140 
141 static struct tab *
142 tab_by_id(uint32_t id)
143 {
144 	struct tab *t;
145 
146 	TAILQ_FOREACH(t, &tabshead, tabs) {
147 		if (t->id == id)
148 			return t;
149 	}
150 
151 	return NULL;
152 }
153 
154 static void
155 handle_imsg_err(struct imsg *imsg, size_t datalen)
156 {
157 	struct tab	*tab;
158 	char		*page;
159 
160 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
161 		return;
162 
163 	page = imsg->data;
164 	page[datalen-1] = '\0';
165 
166 	if (asprintf(&page, "# Error loading %s\n\n> %s\n",
167 	    tab->hist_cur->h, page) == -1)
168 		die();
169 	load_page_from_str(tab, page);
170 	free(page);
171 }
172 
173 static void
174 handle_imsg_check_cert(struct imsg *imsg, size_t datalen)
175 {
176 	const char		*hash, *host, *port;
177 	int			 tofu_res;
178 	struct tofu_entry	*e;
179 	struct tab		*tab;
180 
181 	hash = imsg->data;
182 	if (hash[datalen-1] != '\0')
183 		abort();
184 
185 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
186 		return;
187 
188 	if (tab->proxy != NULL) {
189 		host = tab->proxy->host;
190 		port = tab->proxy->port;
191 	} else {
192 		host = tab->uri.host;
193 		port = tab->uri.port;
194 	}
195 
196 	if ((e = tofu_lookup(&certs, host, port)) == NULL) {
197 		/* TODO: an update in libressl/libretls changed
198 		 * significantly.  Find a better approach at storing
199 		 * the certs! */
200 		if (datalen > sizeof(e->hash))
201 			abort();
202 
203 		tofu_res = 1;	/* trust on first use */
204 		if ((e = calloc(1, sizeof(*e))) == NULL)
205 			abort();
206 		strlcpy(e->domain, host, sizeof(e->domain));
207 		if (*port != '\0' && strcmp(port, "1965")) {
208 			strlcat(e->domain, ":", sizeof(e->domain));
209 			strlcat(e->domain, port, sizeof(e->domain));
210 		}
211 		strlcpy(e->hash, hash, sizeof(e->hash));
212 		tofu_add(&certs, e);
213 		ui_send_fs(IMSG_SAVE_CERT, tab->id, e, sizeof(*e));
214 	} else
215 		tofu_res = !strcmp(hash, e->hash);
216 
217 	if (tofu_res) {
218 		if (e->verified == -1)
219 			tab->trust = TS_TEMP_TRUSTED;
220 		else if (e->verified == 1)
221 			tab->trust = TS_VERIFIED;
222 		else
223 			tab->trust = TS_TRUSTED;
224 
225 		ui_send_net(IMSG_CERT_STATUS, imsg->hdr.peerid,
226 		    &tofu_res, sizeof(tofu_res));
227 	} else {
228 		tab->trust = TS_UNTRUSTED;
229 		load_page_from_str(tab, "# Certificate mismatch\n");
230 		if ((tab->cert = strdup(hash)) == NULL)
231 			die();
232 		ui_yornp("Certificate mismatch.  Proceed?",
233 		    handle_check_cert_user_choice, tab);
234 	}
235 }
236 
237 static void
238 handle_check_cert_user_choice(int accept, struct tab *tab)
239 {
240 	ui_send_net(IMSG_CERT_STATUS, tab->id, &accept,
241 	    sizeof(accept));
242 
243 	if (accept) {
244 		/*
245 		 * trust the certificate for this session only.  If
246 		 * the page results in a redirect while we're asking
247 		 * the user to save, we'll end up with an invalid
248 		 * tabid (one request == one tab id) and crash.  It
249 		 * also makes sense to save it for the current session
250 		 * if the user accepted it.
251 		 */
252 		tofu_temp_trust(&certs, tab->uri.host, tab->uri.port, tab->cert);
253 
254 		ui_yornp("Save the new certificate?",
255 		    handle_maybe_save_new_cert, tab);
256 	} else {
257 		free(tab->cert);
258 		tab->cert = NULL;
259 	}
260 }
261 
262 static void
263 handle_maybe_save_new_cert(int accept, struct tab *tab)
264 {
265 	struct tofu_entry *e;
266 	const char *host, *port;
267 
268 	if (tab->proxy != NULL) {
269 		host = tab->proxy->host;
270 		port = tab->proxy->port;
271 	} else {
272 		host = tab->uri.host;
273 		port = tab->uri.port;
274 	}
275 
276 	if (!accept)
277 		goto end;
278 
279 	if ((e = calloc(1, sizeof(*e))) == NULL)
280 		die();
281 
282 	strlcpy(e->domain, host, sizeof(e->domain));
283 	if (*port != '\0' && strcmp(port, "1965")) {
284 		strlcat(e->domain, ":", sizeof(e->domain));
285 		strlcat(e->domain, port, sizeof(e->domain));
286 	}
287 	strlcpy(e->hash, tab->cert, sizeof(e->hash));
288 	ui_send_fs(IMSG_UPDATE_CERT, 0, e, sizeof(*e));
289 
290 	tofu_update(&certs, e);
291 
292 	tab->trust = TS_TRUSTED;
293 
294 end:
295 	free(tab->cert);
296 	tab->cert = NULL;
297 }
298 
299 static inline int
300 normalize_code(int n)
301 {
302 	if (n < 20) {
303 		if (n == 10 || n == 11)
304 			return n;
305 		return 10;
306 	} else if (n < 30) {
307 		return 20;
308 	} else if (n < 40) {
309 		if (n == 30 || n == 31)
310 			return n;
311 		return 30;
312 	} else if (n < 50) {
313 		if (n <= 44)
314 			return n;
315 		return 40;
316 	} else if (n < 60) {
317 		if (n <= 53 || n == 59)
318 			return n;
319 		return 50;
320 	} else if (n < 70) {
321 		if (n <= 62)
322 			return n;
323 		return 60;
324 	} else
325 		return MALFORMED_RESPONSE;
326 }
327 
328 static void
329 handle_imsg_got_code(struct imsg *imsg, size_t datalen)
330 {
331 	struct tab	*tab;
332 
333 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
334 		return;
335 
336 	if (sizeof(tab->code) != datalen)
337 		die();
338 
339 	memcpy(&tab->code, imsg->data, sizeof(tab->code));
340 	tab->code = normalize_code(tab->code);
341 	if (tab->code != 30 && tab->code != 31)
342 		tab->redirect_count = 0;
343 }
344 
345 static void
346 handle_imsg_got_meta(struct imsg *imsg, size_t datalen)
347 {
348 	struct tab	*tab;
349 
350 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
351 		return;
352 
353 	if (sizeof(tab->meta) <= datalen)
354 		die();
355 
356 	memcpy(tab->meta, imsg->data, datalen);
357 
358 	if (tab->code < 10) {	/* internal errors */
359 		load_page_from_str(tab, err_pages[tab->code]);
360 	} else if (tab->code < 20) {	/* 1x */
361 		load_page_from_str(tab, err_pages[tab->code]);
362 		ui_require_input(tab, tab->code == 11);
363 	} else if (tab->code == 20) {
364 		if (setup_parser_for(tab)) {
365 			ui_send_net(IMSG_PROCEED, tab->id, NULL, 0);
366 		} else {
367 			load_page_from_str(tab, err_pages[UNKNOWN_TYPE_OR_CSET]);
368 			ui_yornp("Can't display page, wanna save?",
369 			    handle_maybe_save_page, tab);
370 		}
371 	} else if (tab->code < 40) { /* 3x */
372 		tab->redirect_count++;
373 
374 		/* TODO: make customizable? */
375 		if (tab->redirect_count > 5) {
376 			load_page_from_str(tab,
377 			    err_pages[TOO_MUCH_REDIRECTS]);
378 		} else
379 			do_load_url(tab, tab->meta, NULL);
380 	} else { /* 4x, 5x & 6x */
381 		load_page_from_str(tab, err_pages[tab->code]);
382 	}
383 }
384 
385 static void
386 handle_maybe_save_page(int dosave, struct tab *tab)
387 {
388 	if (dosave)
389 		ui_read("Save to path", handle_save_page_path, tab);
390 	else
391 		stop_tab(tab);
392 }
393 
394 static void
395 handle_save_page_path(const char *path, struct tab *tab)
396 {
397 	if (path == NULL) {
398 		stop_tab(tab);
399 		return;
400 	}
401 
402 	tab->path = strdup(path);
403 
404 	ui_send_fs(IMSG_FILE_OPEN, tab->id, path, strlen(path)+1);
405 }
406 
407 static void
408 handle_imsg_file_opened(struct imsg *imsg, size_t datalen)
409 {
410 	struct tab	*tab;
411 	char		*page;
412 	const char	*e;
413 	int		 l;
414 
415 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL) {
416 		if (imsg->fd != -1)
417 			close(imsg->fd);
418 		return;
419 	}
420 
421 	if (imsg->fd == -1) {
422 		stop_tab(tab);
423 
424 		e = imsg->data;
425 		if (e[datalen-1] != '\0')
426 			die();
427 		l = asprintf(&page, "# Can't open file\n\n> %s: %s\n",
428 		    tab->path, e);
429 		if (l == -1)
430 			die();
431 		load_page_from_str(tab, page);
432 		free(page);
433 	} else {
434 		tab->fd = imsg->fd;
435 		ui_send_net(IMSG_PROCEED, tab->id, NULL, 0);
436 	}
437 }
438 
439 static void
440 handle_imsg_buf(struct imsg *imsg, size_t datalen)
441 {
442 	struct tab	*tab;
443 	int		 l;
444 	char		*page, buf[FMT_SCALED_STRSIZE] = {0};
445 
446 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
447 		return;
448 
449 	tab->bytes += datalen;
450 	if (tab->fd == -1) {
451 		if (!tab->buffer.page.parse(&tab->buffer.page,
452 		    imsg->data, datalen))
453 			die();
454 	} else {
455 		write(tab->fd, imsg->data, datalen);
456 		fmt_scaled(tab->bytes, buf);
457 		l = asprintf(&page, "Saving to \"%s\"... (%s)\n",
458 		    tab->path,
459 		    buf);
460 		if (l == -1)
461 			die();
462 		load_page_from_str(tab, page);
463 		free(page);
464 	}
465 
466 	ui_on_tab_refresh(tab);
467 }
468 
469 static void
470 handle_imsg_eof(struct imsg *imsg, size_t datalen)
471 {
472 	struct tab	*tab;
473 	int		 l;
474 	char		*page, buf[FMT_SCALED_STRSIZE] = {0};
475 
476 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
477 		return;
478 
479 	if (tab->fd == -1) {
480 		if (!tab->buffer.page.free(&tab->buffer.page))
481 			die();
482 	} else {
483 		fmt_scaled(tab->bytes, buf);
484 		l = asprintf(&page, "Saved to \"%s\" (%s)\n",
485 		    tab->path,
486 		    buf);
487 		if (l == -1)
488 			die();
489 		load_page_from_str(tab, page);
490 		free(page);
491 
492 		close(tab->fd);
493 		tab->fd = -1;
494 		free(tab->path);
495 		tab->path = NULL;
496 	}
497 
498 	ui_on_tab_refresh(tab);
499 	ui_on_tab_loaded(tab);
500 }
501 
502 static void
503 handle_imsg_bookmark_ok(struct imsg *imsg, size_t datalen)
504 {
505 	int res;
506 
507 	if (datalen != sizeof(res))
508 		die();
509 
510 	memcpy(&res, imsg->data, sizeof(res));
511 	if (res == 0)
512 		message("Added to bookmarks!");
513 	else
514 		message("Failed to add to bookmarks: %s",
515 		    strerror(res));
516 }
517 
518 static void
519 handle_imsg_save_cert_ok(struct imsg *imsg, size_t datalen)
520 {
521 	int res;
522 
523 	if (datalen != sizeof(res))
524 		die();
525 	memcpy(&res, imsg->data, datalen);
526 	if (res != 0)
527 		message("Failed to save the cert for: %s",
528 		    strerror(res));
529 }
530 
531 static void
532 handle_imsg_update_cert_ok(struct imsg *imsg, size_t datalen)
533 {
534 	int res;
535 
536 	if (datalen != sizeof(res))
537 		die();
538 	memcpy(&res, imsg->data, datalen);
539 	if (!res)
540 		message("Failed to update the certificate");
541 }
542 
543 static void
544 handle_dispatch_imsg(int fd, short ev, void *d)
545 {
546 	struct imsgev	*iev = d;
547 
548 	if (dispatch_imsg(iev, ev, handlers, sizeof(handlers)) == -1)
549 		err(1, "connection closed");
550 }
551 
552 static void
553 load_page_from_str(struct tab *tab, const char *page)
554 {
555 	erase_buffer(&tab->buffer);
556 	gemtext_initparser(&tab->buffer.page);
557 	if (!tab->buffer.page.parse(&tab->buffer.page, page, strlen(page)))
558 		die();
559 	if (!tab->buffer.page.free(&tab->buffer.page))
560 		die();
561 	ui_on_tab_refresh(tab);
562 	ui_on_tab_loaded(tab);
563 }
564 
565 void
566 load_about_url(struct tab *tab, const char *url)
567 {
568 	tab->trust = TS_VERIFIED;
569 
570 	gemtext_initparser(&tab->buffer.page);
571 
572 	ui_send_fs(IMSG_GET, tab->id,
573 	    tab->hist_cur->h, strlen(tab->hist_cur->h)+1);
574 }
575 
576 void
577 load_finger_url(struct tab *tab, const char *url)
578 {
579 	struct get_req	 req;
580 	size_t		 len;
581 	char		*at;
582 
583 	stop_tab(tab);
584 	tab->id = tab_new_id();
585 
586 	memset(&req, 0, sizeof(req));
587 	if (*tab->uri.port != '\0')
588 		strlcpy(req.port, tab->uri.port, sizeof(req.port));
589 	else
590 		strlcpy(req.port, "79", sizeof(req.port));
591 
592 	/*
593 	 * Sometimes the finger url have the user as path component
594 	 * (e.g. finger://thelambdalab.xyz/plugd), sometimes as
595 	 * userinfo (e.g. finger://cobradile@finger.farm).
596 	 */
597 	if ((at = strchr(tab->uri.host, '@')) != NULL) {
598 		len = at - tab->uri.host;
599 		memcpy(req.req, tab->uri.host, len);
600 
601 		if (len >= sizeof(req.req))
602 			die();
603 		req.req[len] = '\0';
604 
605 		strlcpy(req.host, at+1, sizeof(req.host));
606 	} else {
607 		strlcpy(req.host, tab->uri.host, sizeof(req.host));
608 
609 		/* +1 to skip the initial `/' */
610 		strlcpy(req.req, tab->uri.path+1, sizeof(req.req));
611 	}
612 
613 	strlcat(req.req, "\r\n", sizeof(req.req));
614 
615 	req.proto = PROTO_FINGER;
616 
617 	ui_send_net(IMSG_GET_RAW, tab->id, &req, sizeof(req));
618 
619 	textplain_initparser(&tab->buffer.page);
620 }
621 
622 void
623 load_gemini_url(struct tab *tab, const char *url)
624 {
625 	struct get_req	 req;
626 
627 	stop_tab(tab);
628 	tab->id = tab_new_id();
629 
630 	memset(&req, 0, sizeof(req));
631 	strlcpy(req.host, tab->uri.host, sizeof(req.host));
632 	strlcpy(req.port, tab->uri.port, sizeof(req.host));
633 
634 	strlcpy(req.req, tab->hist_cur->h, sizeof(req.req));
635 	strlcat(req.req, "\r\n", sizeof(req.req));
636 
637 	req.proto = PROTO_GEMINI;
638 
639 	ui_send_net(IMSG_GET_RAW, tab->id,
640 	    &req, sizeof(req));
641 }
642 
643 void
644 load_via_proxy(struct tab *tab, const char *url, struct proxy *p)
645 {
646 	struct get_req req;
647 
648 	stop_tab(tab);
649 	tab->id = tab_new_id();
650 	tab->proxy = p;
651 
652 	memset(&req, 0, sizeof(req));
653 	strlcpy(req.host, p->host, sizeof(req.host));
654 	strlcpy(req.port, p->port, sizeof(req.host));
655 
656 	strlcpy(req.req, tab->hist_cur->h, sizeof(req.req));
657 	strlcat(req.req, "\r\n", sizeof(req.req));
658 
659 	req.proto = p->proto;
660 
661 	ui_send_net(IMSG_GET_RAW, tab->id,
662 	    &req, sizeof(req));
663 }
664 
665 /*
666  * Effectively load the given url in the given tab.  Return 1 when
667  * loading the page asynchronously, and thus when an erase_buffer can
668  * be done right after this function return, or 0 when loading the
669  * page synchronously.  In this last case, erase_buffer *MUST* be
670  * called by the handling function (such as load_page_from_str).
671  */
672 static int
673 do_load_url(struct tab *tab, const char *url, const char *base)
674 {
675 	struct phos_uri	 uri;
676 	struct proto	*p;
677 	struct proxy	*proxy;
678 	char		*t;
679 
680 	tab->proxy = NULL;
681 
682 	if (tab->fd != -1) {
683 		close(tab->fd);
684 		tab->fd = -1;
685 		free(tab->path);
686 		tab->path = NULL;
687 	}
688 
689 	tab->trust = TS_UNKNOWN;
690 
691 	if (base == NULL)
692 		memcpy(&uri, &tab->uri, sizeof(tab->uri));
693 	else
694 		phos_parse_absolute_uri(base, &uri);
695 
696 	if (!phos_resolve_uri_from_str(&uri, url, &tab->uri)) {
697                 if (asprintf(&t, "#error loading %s\n>%s\n",
698 		    url, "Can't parse the URI") == -1)
699 			die();
700 		strlcpy(tab->hist_cur->h, url, sizeof(tab->hist_cur->h));
701 		load_page_from_str(tab, t);
702 		free(t);
703 		return 0;
704 	}
705 
706 	phos_serialize_uri(&tab->uri, tab->hist_cur->h,
707 	    sizeof(tab->hist_cur->h));
708 
709 	for (p = protos; p->schema != NULL; ++p) {
710 		if (!strcmp(tab->uri.scheme, p->schema)) {
711 			p->loadfn(tab, url);
712                         return 1;
713 		}
714 	}
715 
716 	TAILQ_FOREACH(proxy, &proxies, proxies) {
717 		if (!strcmp(tab->uri.scheme, proxy->match_proto)) {
718 			load_via_proxy(tab, url, proxy);
719 			return 1;
720 		}
721 	}
722 
723 	load_page_from_str(tab, err_pages[UNKNOWN_PROTOCOL]);
724 	return 0;
725 }
726 
727 /*
728  * Load url in tab.  If tab is marked as lazy, only prepare the url
729  * but don't load it.  If tab is lazy and a url was already prepared,
730  * do load it!
731  */
732 void
733 load_url(struct tab *tab, const char *url, const char *base)
734 {
735 	int lazy;
736 
737 	lazy = tab->flags & TAB_LAZY;
738 
739 	if (lazy && tab->hist_cur != NULL) {
740 		lazy = 0;
741 		tab->flags &= ~TAB_LAZY;
742 	}
743 
744 	if (!lazy || tab->hist_cur == NULL) {
745 		if (tab->hist_cur != NULL)
746 			hist_clear_forward(&tab->hist,
747 			    TAILQ_NEXT(tab->hist_cur, entries));
748 
749 		if ((tab->hist_cur = calloc(1, sizeof(*tab->hist_cur))) == NULL) {
750 			event_loopbreak();
751 			return;
752 		}
753 
754 		strlcpy(tab->buffer.page.title, url,
755 		    sizeof(tab->buffer.page.title));
756 		hist_push(&tab->hist, tab->hist_cur);
757 
758 		if (lazy)
759 			strlcpy(tab->hist_cur->h, url,
760 			    sizeof(tab->hist_cur->h));
761 	}
762 
763 	if (!lazy && do_load_url(tab, url, base))
764 		erase_buffer(&tab->buffer);
765 }
766 
767 int
768 load_previous_page(struct tab *tab)
769 {
770 	struct hist	*h;
771 
772 	if ((h = TAILQ_PREV(tab->hist_cur, mhisthead, entries)) == NULL)
773 		return 0;
774 	tab->hist_cur = h;
775 	do_load_url(tab, h->h, NULL);
776 	return 1;
777 }
778 
779 int
780 load_next_page(struct tab *tab)
781 {
782 	struct hist	*h;
783 
784 	if ((h = TAILQ_NEXT(tab->hist_cur, entries)) == NULL)
785 		return 0;
786 	tab->hist_cur = h;
787 	do_load_url(tab, h->h, NULL);
788 	return 1;
789 }
790 
791 /*
792  * Free every resource linked to the tab, including the tab itself.
793  * Removes the tab from the tablist, but doesn't update the
794  * current_tab though.
795  */
796 void
797 free_tab(struct tab *tab)
798 {
799 	stop_tab(tab);
800 
801 	if (evtimer_pending(&tab->loadingev, NULL))
802 		evtimer_del(&tab->loadingev);
803 
804 	TAILQ_REMOVE(&tabshead, tab, tabs);
805 	free(tab);
806 }
807 
808 void
809 stop_tab(struct tab *tab)
810 {
811 	ui_send_net(IMSG_STOP, tab->id, NULL, 0);
812 
813 	if (tab->fd != -1) {
814 		close(tab->fd);
815 		tab->fd = -1;
816 		free(tab->path);
817 		tab->path = NULL;
818 		load_page_from_str(tab, "Stopped.\n");
819 	}
820 }
821 
822 void
823 add_to_bookmarks(const char *str)
824 {
825 	ui_send_fs(IMSG_BOOKMARK_PAGE, 0,
826 	    str, strlen(str)+1);
827 }
828 
829 void
830 save_session(void)
831 {
832 	struct tab	*tab;
833 	char		*t;
834 	int		 flags;
835 
836 	ui_send_fs(IMSG_SESSION_START, 0, NULL, 0);
837 
838 	TAILQ_FOREACH(tab, &tabshead, tabs) {
839 		flags = tab->flags;
840 		if (tab == current_tab)
841 			flags |= TAB_CURRENT;
842 
843 		t = tab->hist_cur->h;
844 		ui_send_fs(IMSG_SESSION_TAB, flags, t, strlen(t)+1);
845 
846 		t = tab->buffer.page.title;
847 		ui_send_fs(IMSG_SESSION_TAB_TITLE, 0, t, strlen(t)+1);
848 	}
849 
850 	ui_send_fs(IMSG_SESSION_END, 0, NULL, 0);
851 }
852 
853 /*
854  * Parse a line of the session file.  The format is:
855  *
856  *	URL [flags,...] [title]\n
857  */
858 static void
859 parse_session_line(char *line, const char **title, uint32_t *flags)
860 {
861 	char *s, *t, *ap;
862 
863 	*title = "";
864 	*flags = 0;
865 	if ((s = strchr(line, ' ')) == NULL)
866 		return;
867 
868 	*s++ = '\0';
869 
870         if ((t = strchr(s, ' ')) != NULL) {
871 		*t++ = '\0';
872 		*title = t;
873 	}
874 
875 	while ((ap = strsep(&s, ",")) != NULL) {
876 		if (*ap == '\0')
877 			;
878 		else if (!strcmp(ap, "current"))
879 			*flags |= TAB_CURRENT;
880 		else
881 			message("unknown tab flag: %s", ap);
882 	}
883 }
884 
885 static void
886 load_last_session(void)
887 {
888 	const char	*title;
889 	char		*nl, *line = NULL;
890 	uint32_t	 flags;
891 	size_t		 linesize = 0;
892 	ssize_t		 linelen;
893 	FILE		*session;
894 	struct tab	*tab, *curr = NULL;
895 
896 	if ((session = fopen(session_file, "r")) == NULL) {
897 		/* first time? */
898 		new_tab("about:new", NULL);
899 		switch_to_tab(new_tab("about:help", NULL));
900 		return;
901 	}
902 
903 	while ((linelen = getline(&line, &linesize, session)) != -1) {
904                 if ((nl = strchr(line, '\n')) != NULL)
905 			*nl = '\0';
906 		parse_session_line(line, &title, &flags);
907 		if ((tab = new_tab(line, NULL)) == NULL)
908 			err(1, "new_tab");
909                 strlcpy(tab->buffer.page.title, title,
910 		    sizeof(tab->buffer.page.title));
911 		if (flags & TAB_CURRENT)
912 			curr = tab;
913 	}
914 
915 	if (ferror(session))
916 		message("error reading %s: %s",
917 		    session_file, strerror(errno));
918 	fclose(session);
919 	free(line);
920 
921 	if (curr != NULL)
922 		switch_to_tab(curr);
923 
924 	if (last_time_crashed())
925 		switch_to_tab(new_tab("about:crash", NULL));
926 
927 	return;
928 }
929 
930 static pid_t
931 start_child(enum telescope_process p, const char *argv0, int fd)
932 {
933 	const char	*argv[4];
934 	int		 argc = 0;
935 	pid_t		 pid;
936 
937 	switch (pid = fork()) {
938 	case -1:
939 		die();
940 	case 0:
941 		break;
942 	default:
943 		close(fd);
944 		return pid;
945 	}
946 
947 	if (dup2(fd, 3) == -1)
948 		err(1, "cannot setup imsg fd");
949 
950 	argv[argc++] = argv0;
951 	switch (p) {
952 	case PROC_UI:
953 		errx(1, "Can't start ui process");
954 	case PROC_FS:
955 		argv[argc++] = "-Tf";
956 		break;
957 	case PROC_NET:
958 		argv[argc++] = "-Tn";
959 		break;
960 	}
961 
962 	argv[argc++] = NULL;
963 	execvp(argv0, (char *const *)argv);
964 	err(1, "execvp(%s)", argv0);
965 }
966 
967 static int
968 ui_send_net(int type, uint32_t peerid, const void *data,
969     uint16_t datalen)
970 {
971 	return imsg_compose_event(iev_net, type, peerid, 0, -1, data,
972 	    datalen);
973 }
974 
975 static int
976 ui_send_fs(int type, uint32_t peerid, const void *data, uint16_t datalen)
977 {
978 	return imsg_compose_event(iev_fs, type, peerid, 0, -1, data,
979 	    datalen);
980 }
981 
982 static void __attribute__((noreturn))
983 usage(int r)
984 {
985 	fprintf(stderr, "USAGE: %s [-hnv] [-c config] [url]\n",
986 	    getprogname());
987 	fprintf(stderr, "version: " PACKAGE " " VERSION "\n");
988 	exit(r);
989 }
990 
991 int
992 main(int argc, char * const *argv)
993 {
994 	struct imsgev	 net_ibuf, fs_ibuf;
995 	int		 pipe2net[2], pipe2fs[2];
996 	int		 ch, configtest = 0, fail = 0;
997 	int		 has_url = 0;
998 	int		 proc = -1;
999 	int		 sessionfd;
1000 	char		 path[PATH_MAX];
1001 	const char	*url = NEW_TAB_URL;
1002 	const char	*argv0;
1003 
1004 	argv0 = argv[0];
1005 
1006 	signal(SIGCHLD, SIG_IGN);
1007 	signal(SIGPIPE, SIG_IGN);
1008 
1009 	if (getenv("NO_COLOR") != NULL)
1010 		enable_colors = 0;
1011 
1012 	strlcpy(path, getenv("HOME"), sizeof(path));
1013 	strlcat(path, "/.telescope/config", sizeof(path));
1014 
1015 	while ((ch = getopt_long(argc, argv, opts, longopts, NULL)) != -1) {
1016 		switch (ch) {
1017 		case 'C':
1018 			exit(ui_print_colors());
1019 		case 'c':
1020 			fail = 1;
1021 			strlcpy(path, optarg, sizeof(path));
1022 			break;
1023 		case 'n':
1024 			configtest = 1;
1025 			break;
1026 		case 'h':
1027 			usage(0);
1028 		case 'T':
1029 			switch (*optarg) {
1030 			case 'f':
1031 				proc = PROC_FS;
1032 				break;
1033 			case 'n':
1034 				proc = PROC_NET;
1035 				break;
1036 			default:
1037 				errx(1, "invalid process spec %c",
1038 				    *optarg);
1039 			}
1040 			break;
1041 		case 'v':
1042 			printf("%s %s\n", PACKAGE_NAME, PACKAGE_VERSION);
1043 			exit(0);
1044 			break;
1045 		default:
1046 			usage(1);
1047 		}
1048 	}
1049 
1050 	argc -= optind;
1051 	argv += optind;
1052 
1053 	if (proc != -1) {
1054 		if (argc > 0)
1055 			usage(1);
1056 		else if (proc == PROC_FS)
1057 			return fs_main();
1058 		else if (proc == PROC_NET)
1059 			return net_main();
1060 		else
1061 			usage(1);
1062 	}
1063 
1064 	if (argc != 0) {
1065 		has_url = 1;
1066 		url = argv[0];
1067 	}
1068 
1069 	/* setup keys before reading the config */
1070 	TAILQ_INIT(&global_map.m);
1071 	global_map.unhandled_input = global_key_unbound;
1072 	TAILQ_INIT(&minibuffer_map.m);
1073 
1074 	config_init();
1075 	parseconfig(path, fail);
1076 	if (configtest){
1077 		puts("config OK");
1078 		exit(0);
1079 	}
1080 
1081 	fs_init();
1082 	if ((sessionfd = lock_session()) == -1)
1083 		errx(1, "can't lock session, is another instance of "
1084 		    "telescope already running?");
1085 
1086 	/* Start children. */
1087 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe2fs) == -1)
1088 		err(1, "socketpair");
1089 	start_child(PROC_FS, argv0, pipe2fs[1]);
1090 	imsg_init(&fs_ibuf.ibuf, pipe2fs[0]);
1091 	iev_fs = &fs_ibuf;
1092 	iev_fs->handler = handle_dispatch_imsg;
1093 
1094 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe2net) == -1)
1095 		err(1, "socketpair");
1096 	start_child(PROC_NET, argv0, pipe2net[1]);
1097 	imsg_init(&net_ibuf.ibuf, pipe2net[0]);
1098 	iev_net = &net_ibuf;
1099 	iev_net->handler = handle_dispatch_imsg;
1100 
1101 	setproctitle("ui");
1102 
1103 	/* initialize tofu & load certificates */
1104 	tofu_init(&certs, 5, offsetof(struct tofu_entry, domain));
1105 	load_certs(&certs);
1106 
1107 	event_init();
1108 
1109 	/* Setup event handlers for pipes to fs/net */
1110 	iev_fs->events = EV_READ;
1111 	event_set(&iev_fs->ev, iev_fs->ibuf.fd, iev_fs->events,
1112 	    iev_fs->handler, iev_fs);
1113 	event_add(&iev_fs->ev, NULL);
1114 
1115 	iev_net->events = EV_READ;
1116 	event_set(&iev_net->ev, iev_net->ibuf.fd, iev_net->events,
1117 	    iev_net->handler, iev_net);
1118 	event_add(&iev_net->ev, NULL);
1119 
1120 	if (ui_init()) {
1121 		load_last_session();
1122 		if (has_url || TAILQ_EMPTY(&tabshead))
1123 			new_tab(url, NULL);
1124 
1125 		sandbox_ui_process();
1126 		ui_main_loop();
1127 		ui_end();
1128 	}
1129 
1130 	ui_send_fs(IMSG_QUIT, 0, NULL, 0);
1131 	ui_send_net(IMSG_QUIT, 0, NULL, 0);
1132 	imsg_flush(&iev_fs->ibuf);
1133 	imsg_flush(&iev_net->ibuf);
1134 
1135 	close(sessionfd);
1136 
1137 	return 0;
1138 }