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 #include <sys/wait.h>
21 
22 #include <errno.h>
23 #include <getopt.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 "fs.h"
32 #include "mcache.h"
33 #include "minibuffer.h"
34 #include "parser.h"
35 #include "session.h"
36 #include "telescope.h"
37 #include "ui.h"
38 #include "utils.h"
39 
40 static struct option longopts[] = {
41 	{"colors",      no_argument,    NULL,   'C'},
42 	{"colours",	no_argument,    NULL,   'C'},
43 	{"help",	no_argument,	NULL,	'h'},
44 	{"safe",	no_argument,	NULL,	'S'},
45 	{"version",	no_argument,	NULL,	'v'},
46 	{NULL,		0,		NULL,	0},
47 };
48 
49 static const char *opts = "Cc:hnST:v";
50 
51 static int	has_url;
52 static char	url[GEMINI_URL_LEN];
53 
54 /*
55  * Used to know when we're finished loading.
56  */
57 int			 operating;
58 
59 /*
60  * "Safe" (or "sandobox") mode.  If enabled, Telescope shouldn't write
61  * anything to the filesystem or execute external programs.
62  */
63 int			safe_mode;
64 
65 static struct imsgev	*iev_fs, *iev_net;
66 
67 struct tabshead		 tabshead = TAILQ_HEAD_INITIALIZER(tabshead);
68 struct tabshead		 ktabshead = TAILQ_HEAD_INITIALIZER(ktabshead);
69 struct proxylist	 proxies = TAILQ_HEAD_INITIALIZER(proxies);
70 
71 enum telescope_process {
72 	PROC_UI,
73 	PROC_FS,
74 	PROC_NET,
75 };
76 
77 #define CANNOT_FETCH		0
78 #define TOO_MUCH_REDIRECTS	1
79 #define MALFORMED_RESPONSE	2
80 #define UNKNOWN_TYPE_OR_CSET	3
81 #define UNKNOWN_PROTOCOL	4
82 
83 /* XXX: keep in sync with normalize_code */
84 const char *err_pages[70] = {
85 	[CANNOT_FETCH]		= "# Couldn't load the page\n",
86 	[TOO_MUCH_REDIRECTS]	= "# Too much redirects\n",
87 	[MALFORMED_RESPONSE]	= "# Got a malformed response\n",
88 	[UNKNOWN_TYPE_OR_CSET]	= "# Unsupported type or charset\n",
89 	[UNKNOWN_PROTOCOL]	= "# Unknown protocol\n",
90 
91 	[10] = "# Input required\n",
92 	[11] = "# Input required\n",
93 	[40] = "# Temporary failure\n",
94 	[41] = "# Server unavailable\n",
95 	[42] = "# CGI error\n",
96 	[43] = "# Proxy error\n",
97 	[44] = "# Slow down\n",
98 	[50] = "# Permanent failure\n",
99 	[51] = "# Not found\n",
100 	[52] = "# Gone\n",
101 	[53] = "# Proxy request refused\n",
102 	[59] = "# Bad request\n",
103 	[60] = "# Client certificate required\n",
104 	[61] = "# Certificate not authorised\n",
105 	[62] = "# Certificate not valid\n"
106 };
107 
108 static void		 die(void) __attribute__((__noreturn__));
109 static struct tab	*tab_by_id(uint32_t);
110 static void		 handle_imsg_err(struct imsg *, size_t);
111 static void		 handle_imsg_check_cert(struct imsg *, size_t);
112 static void		 handle_check_cert_user_choice(int, struct tab *);
113 static void		 handle_maybe_save_new_cert(int, struct tab *);
114 static void		 handle_imsg_got_code(struct imsg *, size_t);
115 static void		 handle_imsg_got_meta(struct imsg *, size_t);
116 static void		 handle_maybe_save_page(int, struct tab *);
117 static void		 handle_save_page_path(const char *, struct tab *);
118 static void		 handle_imsg_file_opened(struct imsg *, size_t);
119 static void		 handle_imsg_buf(struct imsg *, size_t);
120 static void		 handle_imsg_eof(struct imsg *, size_t);
121 static void		 handle_imsg_tofu(struct imsg *, size_t);
122 static void		 handle_imsg_bookmark_ok(struct imsg *, size_t);
123 static void		 handle_imsg_save_cert_ok(struct imsg *, size_t);
124 static void		 handle_imsg_update_cert_ok(struct imsg *, size_t);
125 static void		 handle_imsg_session(struct imsg *, size_t);
126 static void		 handle_dispatch_imsg(int, short, void *);
127 static int		 load_about_url(struct tab *, const char *);
128 static int		 load_file_url(struct tab *, const char *);
129 static int		 load_finger_url(struct tab *, const char *);
130 static int		 load_gemini_url(struct tab *, const char *);
131 static int		 load_gopher_url(struct tab *, const char *);
132 static int		 load_via_proxy(struct tab *, const char *,
133 			     struct proxy *);
134 static int		 make_request(struct tab *, struct get_req *, int,
135 			     const char *);
136 static int		 make_fs_request(struct tab *, int, const char *);
137 static int		 do_load_url(struct tab *, const char *, const char *, int);
138 static pid_t		 start_child(enum telescope_process, const char *, int);
139 
140 static struct proto {
141 	const char	*schema;
142 	const char	*port;
143 	int		 (*loadfn)(struct tab *, const char *);
144 } protos[] = {
145 	{"about",	NULL,	load_about_url},
146 	{"file",	NULL,	load_file_url},
147 	{"finger",	"79",	load_finger_url},
148 	{"gemini",	"1965",	load_gemini_url},
149 	{"gopher",	"70",	load_gopher_url},
150 	{NULL, NULL, NULL},
151 };
152 
153 static imsg_handlerfn *handlers[] = {
154 	[IMSG_ERR] = handle_imsg_err,
155 	[IMSG_CHECK_CERT] = handle_imsg_check_cert,
156 	[IMSG_GOT_CODE] = handle_imsg_got_code,
157 	[IMSG_GOT_META] = handle_imsg_got_meta,
158 	[IMSG_BUF] = handle_imsg_buf,
159 	[IMSG_EOF] = handle_imsg_eof,
160 	[IMSG_TOFU] = handle_imsg_tofu,
161 	[IMSG_BOOKMARK_OK] = handle_imsg_bookmark_ok,
162 	[IMSG_SAVE_CERT_OK] = handle_imsg_save_cert_ok,
163 	[IMSG_UPDATE_CERT_OK] = handle_imsg_update_cert_ok,
164 	[IMSG_FILE_OPENED] = handle_imsg_file_opened,
165 	[IMSG_SESSION_TAB] = handle_imsg_session,
166 	[IMSG_SESSION_TAB_HIST] = handle_imsg_session,
167 	[IMSG_SESSION_END] = handle_imsg_session,
168 };
169 
170 static struct ohash	certs;
171 
172 static void __attribute__((__noreturn__))
173 die(void)
174 {
175 	abort(); 		/* TODO */
176 }
177 
178 static struct tab *
179 tab_by_id(uint32_t id)
180 {
181 	struct tab *t;
182 
183 	TAILQ_FOREACH(t, &tabshead, tabs) {
184 		if (t->id == id)
185 			return t;
186 	}
187 
188 	return NULL;
189 }
190 
191 static void
192 handle_imsg_err(struct imsg *imsg, size_t datalen)
193 {
194 	struct tab	*tab;
195 	char		*page;
196 
197 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
198 		return;
199 
200 	page = imsg->data;
201 	page[datalen-1] = '\0';
202 
203 	if (asprintf(&page, "# Error loading %s\n\n> %s\n",
204 	    tab->hist_cur->h, page) == -1)
205 		die();
206 	load_page_from_str(tab, page);
207 	free(page);
208 }
209 
210 static void
211 handle_imsg_check_cert(struct imsg *imsg, size_t datalen)
212 {
213 	const char		*hash, *host, *port;
214 	int			 tofu_res;
215 	struct tofu_entry	*e;
216 	struct tab		*tab;
217 
218 	hash = imsg->data;
219 	if (hash[datalen-1] != '\0')
220 		abort();
221 
222 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
223 		return;
224 
225 	if (tab->proxy != NULL) {
226 		host = tab->proxy->host;
227 		port = tab->proxy->port;
228 	} else {
229 		host = tab->uri.host;
230 		port = tab->uri.port;
231 	}
232 
233 	if ((e = tofu_lookup(&certs, host, port)) == NULL) {
234 		/* TODO: an update in libressl/libretls changed
235 		 * significantly.  Find a better approach at storing
236 		 * the certs! */
237 		if (datalen > sizeof(e->hash))
238 			abort();
239 
240 		tofu_res = 1;	/* trust on first use */
241 		if ((e = calloc(1, sizeof(*e))) == NULL)
242 			abort();
243 		strlcpy(e->domain, host, sizeof(e->domain));
244 		if (*port != '\0' && strcmp(port, "1965")) {
245 			strlcat(e->domain, ":", sizeof(e->domain));
246 			strlcat(e->domain, port, sizeof(e->domain));
247 		}
248 		strlcpy(e->hash, hash, sizeof(e->hash));
249 		tofu_add(&certs, e);
250 		ui_send_fs(IMSG_SAVE_CERT, tab->id, e, sizeof(*e));
251 	} else
252 		tofu_res = !strcmp(hash, e->hash);
253 
254 	if (tofu_res) {
255 		if (e->verified == -1)
256 			tab->trust = TS_TEMP_TRUSTED;
257 		else if (e->verified == 1)
258 			tab->trust = TS_VERIFIED;
259 		else
260 			tab->trust = TS_TRUSTED;
261 
262 		ui_send_net(IMSG_CERT_STATUS, imsg->hdr.peerid,
263 		    &tofu_res, sizeof(tofu_res));
264 	} else {
265 		tab->trust = TS_UNTRUSTED;
266 		load_page_from_str(tab, "# Certificate mismatch\n");
267 		if ((tab->cert = strdup(hash)) == NULL)
268 			die();
269 		ui_yornp("Certificate mismatch.  Proceed?",
270 		    handle_check_cert_user_choice, tab);
271 	}
272 }
273 
274 static void
275 handle_check_cert_user_choice(int accept, struct tab *tab)
276 {
277 	ui_send_net(IMSG_CERT_STATUS, tab->id, &accept,
278 	    sizeof(accept));
279 
280 	if (accept) {
281 		/*
282 		 * trust the certificate for this session only.  If
283 		 * the page results in a redirect while we're asking
284 		 * the user to save, we'll end up with an invalid
285 		 * tabid (one request == one tab id).  It also makes
286 		 * sense to save it for the current session if the
287 		 * user accepted it.
288 		 */
289 		tofu_temp_trust(&certs, tab->uri.host, tab->uri.port,
290 		    tab->cert);
291 
292 		if (!safe_mode)
293 			ui_yornp("Save the new certificate?",
294 			    handle_maybe_save_new_cert, tab);
295 		else
296 			message("Certificate temporarly trusted");
297 	} else {
298 		free(tab->cert);
299 		tab->cert = NULL;
300 	}
301 }
302 
303 static void
304 handle_maybe_save_new_cert(int accept, struct tab *tab)
305 {
306 	struct tofu_entry *e;
307 	const char *host, *port;
308 
309 	if (tab->proxy != NULL) {
310 		host = tab->proxy->host;
311 		port = tab->proxy->port;
312 	} else {
313 		host = tab->uri.host;
314 		port = tab->uri.port;
315 	}
316 
317 	if (!accept)
318 		goto end;
319 
320 	if ((e = calloc(1, sizeof(*e))) == NULL)
321 		die();
322 
323 	strlcpy(e->domain, host, sizeof(e->domain));
324 	if (*port != '\0' && strcmp(port, "1965")) {
325 		strlcat(e->domain, ":", sizeof(e->domain));
326 		strlcat(e->domain, port, sizeof(e->domain));
327 	}
328 	strlcpy(e->hash, tab->cert, sizeof(e->hash));
329 	ui_send_fs(IMSG_UPDATE_CERT, 0, e, sizeof(*e));
330 
331 	tofu_update(&certs, e);
332 
333 	tab->trust = TS_TRUSTED;
334 
335 end:
336 	free(tab->cert);
337 	tab->cert = NULL;
338 }
339 
340 static inline int
341 normalize_code(int n)
342 {
343 	if (n < 20) {
344 		if (n == 10 || n == 11)
345 			return n;
346 		return 10;
347 	} else if (n < 30) {
348 		return 20;
349 	} else if (n < 40) {
350 		if (n == 30 || n == 31)
351 			return n;
352 		return 30;
353 	} else if (n < 50) {
354 		if (n <= 44)
355 			return n;
356 		return 40;
357 	} else if (n < 60) {
358 		if (n <= 53 || n == 59)
359 			return n;
360 		return 50;
361 	} else if (n < 70) {
362 		if (n <= 62)
363 			return n;
364 		return 60;
365 	} else
366 		return MALFORMED_RESPONSE;
367 }
368 
369 static void
370 handle_imsg_got_code(struct imsg *imsg, size_t datalen)
371 {
372 	struct tab	*tab;
373 
374 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
375 		return;
376 
377 	if (sizeof(tab->code) != datalen)
378 		die();
379 
380 	memcpy(&tab->code, imsg->data, sizeof(tab->code));
381 	tab->code = normalize_code(tab->code);
382 	if (tab->code != 30 && tab->code != 31)
383 		tab->redirect_count = 0;
384 }
385 
386 static void
387 handle_imsg_got_meta(struct imsg *imsg, size_t datalen)
388 {
389 	struct tab	*tab;
390 	char		 buf[128];
391 
392 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL)
393 		return;
394 
395 	if (sizeof(tab->meta) <= datalen)
396 		die();
397 
398 	memcpy(tab->meta, imsg->data, datalen);
399 
400 	if (tab->code < 10) {	/* internal errors */
401 		load_page_from_str(tab, err_pages[tab->code]);
402 	} else if (tab->code < 20) {	/* 1x */
403 		load_page_from_str(tab, err_pages[tab->code]);
404 		ui_require_input(tab, tab->code == 11, PROTO_GEMINI);
405 	} else if (tab->code == 20) {
406 		if (setup_parser_for(tab)) {
407 			ui_send_net(IMSG_PROCEED, tab->id, NULL, 0);
408 		} else if (safe_mode) {
409 			load_page_from_str(tab,
410 			    err_pages[UNKNOWN_TYPE_OR_CSET]);
411 		} else {
412 			struct hist *h;
413 
414 			if ((h = hist_pop(&tab->hist)) != NULL)
415 				tab->hist_cur = h;
416 			snprintf(buf, sizeof(buf),
417 			    "Can't display \"%s\", save it?", tab->meta);
418 			ui_yornp(buf, handle_maybe_save_page, tab);
419 		}
420 	} else if (tab->code < 40) { /* 3x */
421 		tab->redirect_count++;
422 
423 		/* TODO: make customizable? */
424 		if (tab->redirect_count > 5) {
425 			load_page_from_str(tab,
426 			    err_pages[TOO_MUCH_REDIRECTS]);
427 		} else
428 			do_load_url(tab, tab->meta, NULL, LU_MODE_NOCACHE);
429 	} else { /* 4x, 5x & 6x */
430 		load_page_from_str(tab, err_pages[tab->code]);
431 	}
432 }
433 
434 static void
435 handle_maybe_save_page(int dosave, struct tab *tab)
436 {
437 	const char	*f;
438 	char		 input[PATH_MAX];
439 
440 	/* XXX: this print a message that is confusing  */
441 	ui_on_tab_loaded(tab);
442 
443 	if (!dosave) {
444 		stop_tab(tab);
445 		return;
446 	}
447 
448 	if ((f = strrchr(tab->uri.path, '/')) == NULL)
449 		f = "";
450 	else
451 		f++;
452 
453 	strlcpy(input, download_path, sizeof(input));
454 	strlcat(input, f, sizeof(input));
455 
456 	ui_read("Save to path", handle_save_page_path, tab, input);
457 }
458 
459 static void
460 handle_save_page_path(const char *path, struct tab *tab)
461 {
462 	if (path == NULL) {
463 		stop_tab(tab);
464 		return;
465 	}
466 
467 	ui_show_downloads_pane();
468 
469 	enqueue_download(tab->id, path);
470 	ui_send_fs(IMSG_FILE_OPEN, tab->id, path, strlen(path)+1);
471 
472 	/*
473 	 * Change this tab id, the old one is associated with the
474 	 * download now.
475 	 */
476 	tab->id = tab_new_id();
477 }
478 
479 static void
480 handle_imsg_file_opened(struct imsg *imsg, size_t datalen)
481 {
482 	struct download	*d;
483 	const char	*e;
484 
485 	/*
486 	 * There are no reason we shouldn't be able to find the
487 	 * required download.
488 	 */
489 	if ((d = download_by_id(imsg->hdr.peerid)) == NULL)
490 		die();
491 
492 	if (imsg->fd == -1) {
493 		e = imsg->data;
494 		if (e[datalen-1] != '\0')
495 			die();
496 		message("Can't open file %s: %s", d->path, e);
497 	} else {
498 		d->fd = imsg->fd;
499 		ui_send_net(IMSG_PROCEED, d->id, NULL, 0);
500 	}
501 }
502 
503 static void
504 handle_imsg_session(struct imsg *imsg, size_t datalen)
505 {
506 	static struct tab	*curr;
507 	static struct tab	*tab;
508 	struct session_tab	 st;
509 	struct session_tab_hist	 sth;
510 	struct hist		*h;
511 	int			 first_time;
512 
513 	/*
514 	 * The fs process tried to send tabs after it has announced
515 	 * that he's done.  Something fishy is going on, better die.
516 	 */
517 	if (operating)
518 		die();
519 
520 	switch (imsg->hdr.type) {
521 	case IMSG_SESSION_TAB:
522 		if (datalen != sizeof(st))
523 			die();
524 
525 		memcpy(&st, imsg->data, sizeof(st));
526 		if ((tab = new_tab(st.uri, NULL, NULL)) == NULL)
527 			die();
528 		strlcpy(tab->buffer.page.title, st.title,
529 		    sizeof(tab->buffer.page.title));
530 		if (st.flags & TAB_CURRENT)
531 			curr = tab;
532 		if (st.flags & TAB_KILLED)
533 			kill_tab(tab, 1);
534 		break;
535 
536 	case IMSG_SESSION_TAB_HIST:
537 		if (tab == NULL || datalen != sizeof(sth))
538 			die();
539 
540 		memcpy(&sth, imsg->data, sizeof(sth));
541 		if (sth.uri[sizeof(sth.uri)-1] != '\0')
542 			die();
543 
544 		if ((h = calloc(1, sizeof(*h))) == NULL)
545 			die();
546 		strlcpy(h->h, sth.uri, sizeof(h->h));
547 
548 		if (sth.future)
549 			hist_push(&tab->hist, h);
550 		else
551 			hist_add_before(&tab->hist, tab->hist_cur, h);
552 		break;
553 
554 	case IMSG_SESSION_END:
555 		if (datalen != sizeof(first_time))
556 			die();
557 		memcpy(&first_time, imsg->data, sizeof(first_time));
558 		if (first_time) {
559 			new_tab("about:new", NULL, NULL);
560 			curr = new_tab("about:help", NULL, NULL);
561 		}
562 
563 		operating = 1;
564 		if (curr != NULL)
565 			switch_to_tab(curr);
566 		if (has_url || TAILQ_EMPTY(&tabshead))
567 			new_tab(url, NULL, NULL);
568 		ui_main_loop();
569 		break;
570 
571 	default:
572 		die();
573 	}
574 }
575 
576 static void
577 handle_imsg_buf(struct imsg *imsg, size_t datalen)
578 {
579 	struct tab	*tab = NULL;
580 	struct download	*d = NULL;
581 
582 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL &&
583 	    (d = download_by_id(imsg->hdr.peerid)) == NULL)
584 		return;
585 
586 	if (tab != NULL) {
587 		if (!parser_parse(tab, imsg->data, datalen))
588 			die();
589 		ui_on_tab_refresh(tab);
590 	} else {
591 		d->bytes += datalen;
592 		write(d->fd, imsg->data, datalen);
593 		ui_on_download_refresh();
594 	}
595 }
596 
597 static void
598 handle_imsg_eof(struct imsg *imsg, size_t datalen)
599 {
600 	struct tab	*tab = NULL;
601 	struct download	*d = NULL;
602 
603 	if ((tab = tab_by_id(imsg->hdr.peerid)) == NULL &&
604 	    (d = download_by_id(imsg->hdr.peerid)) == NULL)
605 		return;
606 
607 	if (tab != NULL) {
608 		if (!parser_free(tab))
609 			die();
610 		if (has_prefix(tab->hist_cur->h, "gemini://") ||
611 		    has_prefix(tab->hist_cur->h, "gopher://"))
612 			mcache_tab(tab);
613 		ui_on_tab_refresh(tab);
614 		ui_on_tab_loaded(tab);
615 	} else {
616 		close(d->fd);
617 		d->fd = -1;
618 		ui_on_download_refresh();
619 	}
620 }
621 
622 static void
623 handle_imsg_tofu(struct imsg *imsg, size_t datalen)
624 {
625 	struct tofu_entry *e;
626 
627 	if (operating)
628 		die();
629 
630 	if ((e = calloc(1, sizeof(*e))) == NULL)
631 		die();
632 
633 	if (datalen != sizeof(*e))
634 		die();
635 	memcpy(e, imsg->data, sizeof(*e));
636 	if (e->domain[sizeof(e->domain)-1] != '\0' ||
637 	    e->hash[sizeof(e->hash)-1] != '\0')
638 		die();
639 	tofu_add(&certs, e);
640 }
641 
642 static void
643 handle_imsg_bookmark_ok(struct imsg *imsg, size_t datalen)
644 {
645 	int res;
646 
647 	if (datalen != sizeof(res))
648 		die();
649 
650 	memcpy(&res, imsg->data, sizeof(res));
651 	if (res == 0)
652 		message("Added to bookmarks!");
653 	else
654 		message("Failed to add to bookmarks: %s",
655 		    strerror(res));
656 }
657 
658 static void
659 handle_imsg_save_cert_ok(struct imsg *imsg, size_t datalen)
660 {
661 	int res;
662 
663 	if (datalen != sizeof(res))
664 		die();
665 	memcpy(&res, imsg->data, datalen);
666 	if (res != 0)
667 		message("Failed to save the cert for: %s",
668 		    strerror(res));
669 }
670 
671 static void
672 handle_imsg_update_cert_ok(struct imsg *imsg, size_t datalen)
673 {
674 	int res;
675 
676 	if (datalen != sizeof(res))
677 		die();
678 	memcpy(&res, imsg->data, datalen);
679 	if (!res)
680 		message("Failed to update the certificate");
681 }
682 
683 static void
684 handle_dispatch_imsg(int fd, short ev, void *d)
685 {
686 	struct imsgev	*iev = d;
687 
688 	if (dispatch_imsg(iev, ev, handlers, sizeof(handlers)) == -1)
689 		err(1, "connection closed");
690 }
691 
692 static int
693 load_about_url(struct tab *tab, const char *url)
694 {
695 	tab->trust = TS_UNKNOWN;
696 	parser_init(tab, gemtext_initparser);
697 	return make_fs_request(tab, IMSG_GET, url);
698 }
699 
700 static int
701 load_file_url(struct tab *tab, const char *url)
702 {
703 	tab->trust = TS_UNKNOWN;
704 	return make_fs_request(tab, IMSG_GET_FILE, tab->uri.path);
705 }
706 
707 static int
708 load_finger_url(struct tab *tab, const char *url)
709 {
710 	struct get_req	 req;
711 	size_t		 len;
712 	char		*at;
713 
714 	memset(&req, 0, sizeof(req));
715 	strlcpy(req.port, tab->uri.port, sizeof(req.port));
716 
717 	/*
718 	 * Sometimes the finger url have the user as path component
719 	 * (e.g. finger://thelambdalab.xyz/plugd), sometimes as
720 	 * userinfo (e.g. finger://cobradile@finger.farm).
721 	 */
722 	if ((at = strchr(tab->uri.host, '@')) != NULL) {
723 		len = at - tab->uri.host;
724 		memcpy(req.req, tab->uri.host, len);
725 
726 		if (len >= sizeof(req.req))
727 			die();
728 		req.req[len] = '\0';
729 
730 		strlcpy(req.host, at+1, sizeof(req.host));
731 	} else {
732 		strlcpy(req.host, tab->uri.host, sizeof(req.host));
733 
734 		/* +1 to skip the initial `/' */
735 		strlcpy(req.req, tab->uri.path+1, sizeof(req.req));
736 	}
737 	strlcat(req.req, "\r\n", sizeof(req.req));
738 
739 	parser_init(tab, textplain_initparser);
740 	return make_request(tab, &req, PROTO_FINGER, NULL);
741 }
742 
743 static int
744 load_gemini_url(struct tab *tab, const char *url)
745 {
746 	struct get_req	 req;
747 
748 	memset(&req, 0, sizeof(req));
749 	strlcpy(req.host, tab->uri.host, sizeof(req.host));
750 	strlcpy(req.port, tab->uri.port, sizeof(req.port));
751 
752 	return make_request(tab, &req, PROTO_GEMINI, tab->hist_cur->h);
753 }
754 
755 static inline const char *
756 gopher_skip_selector(const char *path, int *ret_type)
757 {
758 	*ret_type = 0;
759 
760 	if (!strcmp(path, "/") || *path == '\0') {
761 		*ret_type = '1';
762 		return path;
763 	}
764 
765 	if (*path != '/')
766 		return path;
767 	path++;
768 
769 	switch (*ret_type = *path) {
770 	case '0':
771 	case '1':
772 	case '7':
773 		break;
774 
775 	default:
776 		*ret_type = 0;
777 		path -= 1;
778 		return path;
779 	}
780 
781 	return ++path;
782 }
783 
784 static int
785 load_gopher_url(struct tab *tab, const char *url)
786 {
787 	struct get_req	 req;
788 	int		 type;
789 	const char	*path;
790 
791 	memset(&req, 0, sizeof(req));
792 	strlcpy(req.host, tab->uri.host, sizeof(req.host));
793 	strlcpy(req.port, tab->uri.port, sizeof(req.port));
794 
795 	path = gopher_skip_selector(tab->uri.path, &type);
796 	switch (type) {
797 	case '0':
798 		parser_init(tab, textplain_initparser);
799 		break;
800 	case '1':
801 		parser_init(tab, gophermap_initparser);
802 		break;
803 	case '7':
804 		ui_require_input(tab, 0, PROTO_GOPHER);
805 		return load_page_from_str(tab, err_pages[10]);
806 	default:
807 		return load_page_from_str(tab, "Unknown gopher selector");
808 	}
809 
810 	strlcpy(req.req, path, sizeof(req.req));
811 	if (*tab->uri.query != '\0') {
812 		strlcat(req.req, "?", sizeof(req.req));
813 		strlcat(req.req, tab->uri.query, sizeof(req.req));
814 	}
815 	strlcat(req.req, "\r\n", sizeof(req.req));
816 
817 	return make_request(tab, &req, PROTO_GOPHER, NULL);
818 }
819 
820 static int
821 load_via_proxy(struct tab *tab, const char *url, struct proxy *p)
822 {
823 	struct get_req req;
824 
825 	memset(&req, 0, sizeof(req));
826 	strlcpy(req.host, p->host, sizeof(req.host));
827 	strlcpy(req.port, p->port, sizeof(req.port));
828 
829 	tab->proxy = p;
830 
831 	return make_request(tab, &req, p->proto, tab->hist_cur->h);
832 }
833 
834 static int
835 make_request(struct tab *tab, struct get_req *req, int proto, const char *r)
836 {
837 	stop_tab(tab);
838 	tab->id = tab_new_id();
839 	req->proto = proto;
840 
841 	if (r != NULL) {
842 		strlcpy(req->req, r, sizeof(req->req));
843 		strlcat(req->req, "\r\n", sizeof(req->req));
844 	}
845 
846 	start_loading_anim(tab);
847 	ui_send_net(IMSG_GET_RAW, tab->id, req, sizeof(*req));
848 
849 	/*
850 	 * So the various load_*_url can `return make_request` and
851 	 * do_load_url is happy.
852 	 */
853 	return 1;
854 }
855 
856 static int
857 make_fs_request(struct tab *tab, int type, const char *r)
858 {
859 	stop_tab(tab);
860 	tab->id = tab_new_id();
861 
862 	ui_send_fs(type, tab->id, r, strlen(r)+1);
863 
864 	/*
865 	 * So load_{about,file}_url can `return make_fs_request` and
866 	 * do_load_url is happy.
867 	 */
868 	return 1;
869 }
870 
871 void
872 gopher_send_search_req(struct tab *tab, const char *text)
873 {
874 	struct get_req	req;
875 
876 	memset(&req, 0, sizeof(req));
877 	strlcpy(req.host, tab->uri.host, sizeof(req.host));
878 	strlcpy(req.port, tab->uri.port, sizeof(req.port));
879 
880 	/* +2 to skip /7 */
881 	strlcpy(req.req, tab->uri.path+2, sizeof(req.req));
882 	if (*tab->uri.query != '\0') {
883 		strlcat(req.req, "?", sizeof(req.req));
884 		strlcat(req.req, tab->uri.query, sizeof(req.req));
885 	}
886 
887 	strlcat(req.req, "\t", sizeof(req.req));
888 	strlcat(req.req, text, sizeof(req.req));
889 	strlcat(req.req, "\r\n", sizeof(req.req));
890 
891 	erase_buffer(&tab->buffer);
892 	parser_init(tab, gophermap_initparser);
893 
894 	make_request(tab, &req, PROTO_GOPHER, NULL);
895 }
896 
897 /*
898  * Effectively load the given url in the given tab.  Return 1 when
899  * loading the page asynchronously, and thus when an erase_buffer can
900  * be done right after this function return, or 0 when loading the
901  * page synchronously.
902  */
903 static int
904 do_load_url(struct tab *tab, const char *url, const char *base, int mode)
905 {
906 	struct phos_uri	 uri;
907 	struct proto	*p;
908 	struct proxy	*proxy;
909 	int		 nocache = mode & LU_MODE_NOCACHE;
910 	char		*t;
911 
912 	tab->proxy = NULL;
913 	tab->trust = TS_UNKNOWN;
914 
915 	if (base == NULL)
916 		memcpy(&uri, &tab->uri, sizeof(tab->uri));
917 	else
918 		phos_parse_absolute_uri(base, &uri);
919 
920 	if (!phos_resolve_uri_from_str(&uri, url, &tab->uri)) {
921 		if (asprintf(&t, "#error loading %s\n>%s\n",
922 		    url, "Can't parse the URI") == -1)
923 			die();
924 		strlcpy(tab->hist_cur->h, url, sizeof(tab->hist_cur->h));
925 		load_page_from_str(tab, t);
926 		free(t);
927 		return 0;
928 	}
929 
930 	phos_serialize_uri(&tab->uri, tab->hist_cur->h,
931 	    sizeof(tab->hist_cur->h));
932 
933 	if (!nocache && mcache_lookup(tab->hist_cur->h, tab)) {
934 		ui_on_tab_refresh(tab);
935 		ui_on_tab_loaded(tab);
936 		return 0;
937 	}
938 
939 	for (p = protos; p->schema != NULL; ++p) {
940 		if (!strcmp(tab->uri.scheme, p->schema)) {
941 			/* patch the port */
942 			if (*tab->uri.port == '\0' && p->port != NULL)
943 				strlcpy(tab->uri.port, p->port,
944 				    sizeof(tab->uri.port));
945 
946 			return p->loadfn(tab, url);
947 		}
948 	}
949 
950 	TAILQ_FOREACH(proxy, &proxies, proxies) {
951 		if (!strcmp(tab->uri.scheme, proxy->match_proto))
952 			return load_via_proxy(tab, url, proxy);
953 	}
954 
955 	return load_page_from_str(tab, err_pages[UNKNOWN_PROTOCOL]);
956 }
957 
958 /*
959  * Load url in tab and handle history.  If a tab is marked as lazy, only
960  * prepare the url but don't load it.
961  */
962 void
963 load_url(struct tab *tab, const char *url, const char *base, int mode)
964 {
965 	int lazy = tab->flags & TAB_LAZY;
966 	int nohist = mode & LU_MODE_NOHIST;
967 
968 	if (!nohist && (!lazy || tab->hist_cur == NULL)) {
969 		if (tab->hist_cur != NULL)
970 			hist_clear_forward(&tab->hist,
971 			    TAILQ_NEXT(tab->hist_cur, entries));
972 
973 		if ((tab->hist_cur = calloc(1, sizeof(*tab->hist_cur)))
974 		    == NULL) {
975 			event_loopbreak();
976 			return;
977 		}
978 
979 		strlcpy(tab->buffer.page.title, url,
980 		    sizeof(tab->buffer.page.title));
981 		hist_push(&tab->hist, tab->hist_cur);
982 
983 		if (lazy)
984 			strlcpy(tab->hist_cur->h, url,
985 			    sizeof(tab->hist_cur->h));
986 	}
987 
988 	if (!lazy)
989 		do_load_url(tab, url, base, mode);
990 }
991 
992 void
993 load_url_in_tab(struct tab *tab, const char *url, const char *base, int mode)
994 {
995 	if (operating) {
996 		autosave_hook();
997 		message("Loading %s...", url);
998 	}
999 
1000 	load_url(tab, url, base, mode);
1001 }
1002 
1003 int
1004 load_previous_page(struct tab *tab)
1005 {
1006 	struct hist	*h;
1007 
1008 	if ((h = TAILQ_PREV(tab->hist_cur, mhisthead, entries)) == NULL)
1009 		return 0;
1010 	tab->hist_cur = h;
1011 	do_load_url(tab, h->h, NULL, LU_MODE_NONE);
1012 	return 1;
1013 }
1014 
1015 int
1016 load_next_page(struct tab *tab)
1017 {
1018 	struct hist	*h;
1019 
1020 	if ((h = TAILQ_NEXT(tab->hist_cur, entries)) == NULL)
1021 		return 0;
1022 	tab->hist_cur = h;
1023 	do_load_url(tab, h->h, NULL, LU_MODE_NONE);
1024 	return 1;
1025 }
1026 
1027 void
1028 add_to_bookmarks(const char *str)
1029 {
1030 	ui_send_fs(IMSG_BOOKMARK_PAGE, 0,
1031 	    str, strlen(str)+1);
1032 }
1033 
1034 /*
1035  * Given a user-entered URL, apply some heuristics to use it:
1036  *
1037  * - if it's a proper url use it
1038  * - if it starts with a `./' or a `/' assume its a file:// url
1039  * - assume it's a gemini:// url
1040  *
1041  * `ret' (of which len is the size) will be filled with the resulting
1042  * url.
1043  */
1044 void
1045 humanify_url(const char *raw, char *ret, size_t len)
1046 {
1047 	struct phos_uri	uri;
1048 	char		buf[PATH_MAX];
1049 
1050 	if (phos_parse_absolute_uri(raw, &uri)) {
1051 		strlcpy(ret, raw, len);
1052 		return;
1053 	}
1054 
1055 	if (has_prefix(raw, "./")) {
1056 		strlcpy(ret, "file://", len);
1057 		getcwd(buf, sizeof(buf));
1058 		strlcat(ret, buf, len);
1059 		strlcat(ret, "/", len);
1060 		strlcat(ret, raw+2, len);
1061 		return;
1062 	}
1063 
1064 	if (*raw == '/') {
1065 		strlcpy(ret, "file://", len);
1066 		strlcat(ret, raw, len);
1067 		return;
1068 	}
1069 
1070 	strlcpy(ret, "gemini://", len);
1071 	strlcat(ret, raw, len);
1072 }
1073 
1074 static pid_t
1075 start_child(enum telescope_process p, const char *argv0, int fd)
1076 {
1077 	const char	*argv[5];
1078 	int		 argc = 0;
1079 	pid_t		 pid;
1080 
1081 	switch (pid = fork()) {
1082 	case -1:
1083 		die();
1084 	case 0:
1085 		break;
1086 	default:
1087 		close(fd);
1088 		return pid;
1089 	}
1090 
1091 	if (dup2(fd, 3) == -1)
1092 		err(1, "cannot setup imsg fd");
1093 
1094 	argv[argc++] = argv0;
1095 	switch (p) {
1096 	case PROC_UI:
1097 		errx(1, "Can't start ui process");
1098 	case PROC_FS:
1099 		argv[argc++] = "-Tf";
1100 		break;
1101 	case PROC_NET:
1102 		argv[argc++] = "-Tn";
1103 		break;
1104 	}
1105 
1106 	if (safe_mode)
1107 		argv[argc++] = "-S";
1108 
1109 	argv[argc++] = NULL;
1110 	execvp(argv0, (char *const *)argv);
1111 	err(1, "execvp(%s)", argv0);
1112 }
1113 
1114 int
1115 ui_send_net(int type, uint32_t peerid, const void *data,
1116     uint16_t datalen)
1117 {
1118 	return imsg_compose_event(iev_net, type, peerid, 0, -1, data,
1119 	    datalen);
1120 }
1121 
1122 int
1123 ui_send_fs(int type, uint32_t peerid, const void *data, uint16_t datalen)
1124 {
1125 	return imsg_compose_event(iev_fs, type, peerid, 0, -1, data,
1126 	    datalen);
1127 }
1128 
1129 static void __attribute__((noreturn))
1130 usage(int r)
1131 {
1132 	fprintf(stderr, "USAGE: %s [-ChnSv] [-c config] [url]\n",
1133 	    getprogname());
1134 	fprintf(stderr, "version: " PACKAGE " " VERSION "\n");
1135 	exit(r);
1136 }
1137 
1138 int
1139 main(int argc, char * const *argv)
1140 {
1141 	struct imsgev	 net_ibuf, fs_ibuf;
1142 	pid_t		 pid;
1143 	int		 pipe2net[2], pipe2fs[2];
1144 	int		 ch, configtest = 0, fail = 0;
1145 	int		 proc = -1;
1146 	int		 sessionfd = -1;
1147 	int		 status;
1148 	const char	*argv0;
1149 
1150 	argv0 = argv[0];
1151 
1152 	signal(SIGCHLD, SIG_IGN);
1153 	signal(SIGPIPE, SIG_IGN);
1154 
1155 	if (getenv("NO_COLOR") != NULL)
1156 		enable_colors = 0;
1157 
1158 	fs_init();
1159 
1160 	while ((ch = getopt_long(argc, argv, opts, longopts, NULL)) != -1) {
1161 		switch (ch) {
1162 		case 'C':
1163 			exit(ui_print_colors());
1164 		case 'c':
1165 			fail = 1;
1166 			strlcpy(config_path, optarg, sizeof(config_path));
1167 			break;
1168 		case 'n':
1169 			configtest = 1;
1170 			break;
1171 		case 'h':
1172 			usage(0);
1173 		case 'S':
1174 			safe_mode = 1;
1175 			break;
1176 		case 'T':
1177 			switch (*optarg) {
1178 			case 'f':
1179 				proc = PROC_FS;
1180 				break;
1181 			case 'n':
1182 				proc = PROC_NET;
1183 				break;
1184 			default:
1185 				errx(1, "invalid process spec %c",
1186 				    *optarg);
1187 			}
1188 			break;
1189 		case 'v':
1190 			printf("%s %s\n", PACKAGE_NAME, PACKAGE_VERSION);
1191 			exit(0);
1192 			break;
1193 		default:
1194 			usage(1);
1195 		}
1196 	}
1197 
1198 	argc -= optind;
1199 	argv += optind;
1200 
1201 	if (proc != -1) {
1202 		if (argc > 0)
1203 			usage(1);
1204 		else if (proc == PROC_FS)
1205 			return fs_main();
1206 		else if (proc == PROC_NET)
1207 			return net_main();
1208 		else
1209 			usage(1);
1210 	}
1211 
1212 	if (argc != 0) {
1213 		has_url = 1;
1214 		humanify_url(argv[0], url, sizeof(url));
1215 	}
1216 
1217 	/* setup keys before reading the config */
1218 	TAILQ_INIT(&global_map.m);
1219 	global_map.unhandled_input = global_key_unbound;
1220 	TAILQ_INIT(&minibuffer_map.m);
1221 
1222 	config_init();
1223 	parseconfig(config_path, fail);
1224 	if (configtest) {
1225 		puts("config OK");
1226 		exit(0);
1227 	}
1228 
1229 	if (download_path == NULL &&
1230 	    (download_path = strdup("/tmp/")) == NULL)
1231 		errx(1, "strdup");
1232 
1233 	if (!safe_mode && (sessionfd = lock_session()) == -1)
1234 		errx(1, "can't lock session, is another instance of "
1235 		    "telescope already running?");
1236 
1237 	/* Start children. */
1238 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe2fs) == -1)
1239 		err(1, "socketpair");
1240 	start_child(PROC_FS, argv0, pipe2fs[1]);
1241 	imsg_init(&fs_ibuf.ibuf, pipe2fs[0]);
1242 	iev_fs = &fs_ibuf;
1243 	iev_fs->handler = handle_dispatch_imsg;
1244 
1245 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe2net) == -1)
1246 		err(1, "socketpair");
1247 	start_child(PROC_NET, argv0, pipe2net[1]);
1248 	imsg_init(&net_ibuf.ibuf, pipe2net[0]);
1249 	iev_net = &net_ibuf;
1250 	iev_net->handler = handle_dispatch_imsg;
1251 
1252 	setproctitle("ui");
1253 
1254 	/* initialize tofu store */
1255 	tofu_init(&certs, 5, offsetof(struct tofu_entry, domain));
1256 
1257 	event_init();
1258 
1259 	/* initialize the in-memory cache store */
1260 	mcache_init();
1261 
1262 	/* Setup event handler for the autosave */
1263 	autosave_init();
1264 
1265 	/* Setup event handlers for pipes to fs/net */
1266 	iev_fs->events = EV_READ;
1267 	event_set(&iev_fs->ev, iev_fs->ibuf.fd, iev_fs->events,
1268 	    iev_fs->handler, iev_fs);
1269 	event_add(&iev_fs->ev, NULL);
1270 
1271 	iev_net->events = EV_READ;
1272 	event_set(&iev_net->ev, iev_net->ibuf.fd, iev_net->events,
1273 	    iev_net->handler, iev_net);
1274 	event_add(&iev_net->ev, NULL);
1275 
1276 	if (ui_init()) {
1277 		sandbox_ui_process();
1278 		ui_send_fs(IMSG_INIT, 0, NULL, 0);
1279 		event_dispatch();
1280 		ui_end();
1281 	}
1282 
1283 	ui_send_fs(IMSG_QUIT, 0, NULL, 0);
1284 	ui_send_net(IMSG_QUIT, 0, NULL, 0);
1285 	imsg_flush(&iev_fs->ibuf);
1286 	imsg_flush(&iev_net->ibuf);
1287 
1288 	/* wait for children to terminate */
1289 	do {
1290 		pid = wait(&status);
1291 		if (pid == -1) {
1292 			if (errno != EINTR && errno != ECHILD)
1293 				err(1, "wait");
1294 		} else if (WIFSIGNALED(status))
1295 			warnx("child terminated; signal %d", WTERMSIG(status));
1296 	} while (pid != -1 || (pid == -1 && errno == EINTR));
1297 
1298 	if (!safe_mode && close(sessionfd) == -1)
1299 		err(1, "close(sessionfd = %d)", sessionfd);
1300 
1301 	return 0;
1302 }