op public repos

Blob

Date:: Fri Nov 11 23:46:06 2022 UTC
Message:: guard against a missing SERVER_NAME technically should always be sent; in practice don't crash if it's not set.
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2022 Omar Polo <op@omarpolo.com>
3  * Copyright (c) 2006 - 2015 Reyk Floeter <reyk@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #include <sys/types.h>
19 #include <sys/queue.h>
20 #include <sys/tree.h>
21 #include <sys/socket.h>
22 #include <sys/uio.h>
23 
24 #include <netinet/in.h>
25 #include <arpa/inet.h>
26 #include <netdb.h>
27 
28 #include <asr.h>
29 #include <ctype.h>
30 #include <errno.h>
31 #include <event.h>
32 #include <fnmatch.h>
33 #include <limits.h>
34 #include <stdlib.h>
35 #include <stdint.h>
36 #include <stdio.h>
37 #include <string.h>
38 #include <imsg.h>
39 #include <tls.h>
40 #include <unistd.h>
41 
42 #include "config.h"
43 #include "log.h"
44 #include "proc.h"
45 #include "tmpl.h"
46 
47 #include "galileo.h"
48 
49 #define MINIMUM(a, b)	((a) < (b) ? (a) : (b))
50 
51 #if HAVE_LIBEVENT2
52 # define G_TOUT(t)	((t).tv_sec)
53 #else
54 # define G_TOUT(t)	(t)
55 #endif
56 
57 /* provided by OpenBSD' base libevent but not in any header? */
58 extern void	 bufferevent_read_pressure_cb(struct evbuffer *, size_t,
59 		    size_t, void *);
60 
61 void	proxy_init(struct privsep *, struct privsep_proc *, void *);
62 int	proxy_launch(struct galileo *);
63 void	proxy_inflight_dec(const char *);
64 int	proxy_dispatch_parent(int, struct privsep_proc *, struct imsg *);
65 int	proxy_resurl(struct client *, const char *, char *, size_t);
66 void	proxy_translate_gemtext(struct client *);
67 void	proxy_resolved(struct asr_result *, void *);
68 void	proxy_connect(int, short, void *);
69 int	proxy_start_reply(struct client *, int, const char *);
70 void	proxy_read(struct bufferevent *, void *);
71 void	proxy_write(struct bufferevent *, void *);
72 void	proxy_error(struct bufferevent *, short, void *);
73 int	proxy_bufferevent_add(struct event *, int);
74 void	proxy_tls_writecb(int, short, void *);
75 void	proxy_tls_readcb(int, short, void *);
76 
77 static struct privsep_proc procs[] = {
78 	{ "parent",	PROC_PARENT, proxy_dispatch_parent },
79 };
80 
81 volatile int proxy_clients;
82 volatile int proxy_inflight;
83 uint32_t proxy_fcg_id;
84 
85 void
86 proxy(struct privsep *ps, struct privsep_proc *p)
87 {
88 	proc_run(ps, p, procs, nitems(procs), proxy_init, NULL);
89 }
90 
91 void
92 proxy_init(struct privsep *ps, struct privsep_proc *p, void *arg)
93 {
94 	if (config_init(ps->ps_env) == -1)
95 		fatal("failed to initialize configuration");
96 
97 	/* We use a custom shutdown callback */
98 	/* p->p_shutdown = proxy_shutdown */
99 
100 	if (pledge("stdio recvfd unix inet dns", NULL) == -1)
101 		fatal("pledge");
102 }
103 
104 int
105 proxy_launch(struct galileo *env)
106 {
107 	event_add(&env->sc_evsock, NULL);
108 	return (0);
109 }
110 
111 void
112 proxy_purge(struct proxy *pr)
113 {
114 	free(pr);
115 }
116 
117 void
118 proxy_inflight_dec(const char *why)
119 {
120 	proxy_inflight--;
121 	log_debug("%s: inflight decremented, now %d, %s",
122 	    __func__, proxy_inflight, why);
123 }
124 
125 int
126 proxy_dispatch_parent(int fd, struct privsep_proc *p, struct imsg *imsg)
127 {
128 	struct privsep	*ps = p->p_ps;
129 	struct galileo	*env = ps->ps_env;
130 
131 	switch (imsg->hdr.type) {
132 	case IMSG_CFG_SRV:
133 		if (config_getproxy(env, imsg) == -1)
134 			fatal("config_getproxy");
135 		break;
136 	case IMSG_CFG_SOCK:
137 		/* XXX: improve */
138 
139 		env->sc_sock_fd = config_getsock(env, imsg);
140 		if (env->sc_sock_fd == -1)
141 			fatal("config_getsock");
142 
143 		event_set(&env->sc_evsock, env->sc_sock_fd,
144 		    EV_READ | EV_PERSIST, fcgi_accept, env);
145 		evtimer_set(&env->sc_evpause, fcgi_accept, env);
146 		break;
147 	case IMSG_CFG_DONE:
148 		config_getcfg(env, imsg);
149 		proxy_launch(env);
150 		break;
151 	case IMSG_CTL_START:
152 		break;
153 	case IMSG_CTL_RESET:
154 		config_getreset(env, imsg);
155 		break;
156 	default:
157 		return (-1);
158 	}
159 
160 	return (0);
161 }
162 
163 static int
164 portok(const char **url, struct client *clt)
165 {
166 	const char		*u = *url;
167 	const char		*port = clt->clt_pc->proxy_port;
168 	size_t			 len;
169 
170 	len = strlen(port);
171 
172 	if (*u == '\0' || *u == '/' || *u == '?' || *u == '#')
173 		return (1);
174 	if (*u != ':')
175 		return (0);
176 	u++;
177 	if (strncmp(u, port, len) != 0)
178 		return (0);
179 	u += len;
180 	if (*u != '\0' && *u != '/' && *u != '?' && *u != '#')
181 		return (0);
182 	*url = u;
183 	return (1);
184 }
185 
186 int
187 proxy_resurl(struct client *clt, const char *url, char *buf, size_t len)
188 {
189 	const char		*tmp;
190 	size_t			 l;
191 
192 	if (clt->clt_server_name == NULL)
193 		return (-1);
194 
195 	l = strlen(clt->clt_server_name);
196 
197 	if (len == 0) {
198 		log_warn("%s: zero-sized buffer!", __func__);
199 		return (-1);
200 	}
201 
202 	/* look if it's an absolute URI */
203 	if (strncmp(url, "//", 2) == 0) {
204 		tmp = url + 2;
205 		if (strncmp(tmp, clt->clt_server_name, l) != 0)
206 			goto done;
207 
208 		tmp += l;
209 		if (!portok(&tmp, clt))
210 			goto done;
211 		url = tmp;
212 	} else if (strncmp(url, "gemini://", 9) == 0) {
213 		tmp = url + 9;
214 		if (strncmp(tmp, clt->clt_server_name, l) != 0)
215 			goto done;
216 
217 		tmp += l;
218 		if (!portok(&tmp, clt))
219 			goto done;
220 		url = tmp;
221 	} else {
222 		tmp = url;
223 		while (isalpha((unsigned char)*tmp) || *tmp == '+')
224 			tmp++;
225 		if (strncmp(tmp, "://", 3) == 0)
226 			goto done;
227 	}
228 
229 	/* maybe it's an absolute path? */
230 	if (*url == '\0' || *url == '/') {
231 		if (strlcpy(buf, clt->clt_script_name, len) >= len)
232 			return (-1);
233 		if (strlcat(buf, url + 1, len) >= len)
234 			return (-1);
235 		return (0);
236 	}
237 
238 	/* otherwise, leave it as it is */
239  done:
240 	if (strlcpy(buf, url, len) >= len)
241 		return (-1);
242 	return (0);
243 }
244 
245 static int
246 gemtext_translate_line(struct client *clt, char *line)
247 {
248 	char		 buf[1025];
249 	char		*url;
250 
251 	/* preformatted line / closing */
252 	if (clt->clt_translate & TR_PRE) {
253 		if (!strncmp(line, "```", 3)) {
254 			clt->clt_translate &= ~TR_PRE;
255 			return (tp_pre_close(clt->clt_tp));
256 		}
257 
258 		if (tp_htmlescape(clt->clt_tp, line) == -1)
259 			return (-1);
260 		return (clt_putc(clt, '\n'));
261 	}
262 
263 	/* bullet */
264 	if (!strncmp(line, "* ", 2)) {
265 		if (clt->clt_translate & TR_NAV) {
266 			if (clt_puts(clt, "</ul></nav>") == -1)
267 				return (-1);
268 			clt->clt_translate &= ~TR_NAV;
269 		}
270 
271 		if (!(clt->clt_translate & TR_LIST)) {
272 			if (clt_puts(clt, "<ul>") == -1)
273 				return (-1);
274 			clt->clt_translate |= TR_LIST;
275 		}
276 
277 		if (clt_puts(clt, "<li>") == -1 ||
278 		    tp_htmlescape(clt->clt_tp, line + 2) == -1 ||
279 		    clt_puts(clt, "</li>") == -1)
280 			return (-1);
281 		return (0);
282 	}
283 
284 	if (clt->clt_translate & TR_LIST) {
285 		if (clt_puts(clt, "</ul>") == -1)
286 			return (-1);
287 		clt->clt_translate &= ~TR_LIST;
288 	}
289 
290 	/* link */
291 	if (!strncmp(line, "=>", 2)) {
292 		char *label;
293 
294 		line += 2;
295 		line += strspn(line, " \t");
296 
297 		label = line + strcspn(line, " \t");
298 		if (*label == '\0')
299 			label = line;
300 		else {
301 			*label++ = '\0';
302 			label += strspn(label, " \t");
303 			if (*label == '\0')
304 				label = line;
305 		}
306 
307 		if (proxy_resurl(clt, line, buf, sizeof(buf)) == 0)
308 			url = buf;
309 		else
310 			url = line; /* leave the URL as it is */
311 
312 		if (fnmatch("*.jpg", url, 0) == 0 ||
313 		    fnmatch("*.jpeg", url, 0) == 0 ||
314 		    fnmatch("*.gif", url, 0) == 0 ||
315 		    fnmatch("*.png", url, 0) == 0 ||
316 		    fnmatch("*.svg", url, 0) == 0 ||
317 		    fnmatch("*.webp", url, 0) == 0) {
318 			if (clt->clt_translate & TR_NAV) {
319 				if (clt_puts(clt, "</ul></nav>") == -1)
320 					return (-1);
321 				clt->clt_translate &= ~TR_NAV;
322 			}
323 
324 			if (tp_figure(clt->clt_tp, url, label) == -1)
325 				return (-1);
326 
327 			return (0);
328 		}
329 
330 		if (!(clt->clt_translate & TR_NAV)) {
331 			if (clt_puts(clt, "<nav><ul>") == -1)
332 				return (-1);
333 			clt->clt_translate |= TR_NAV;
334 		}
335 
336 		if (clt_puts(clt, "<li><a href='") == -1)
337 			return (-1);
338 
339 		if (tp_urlescape(clt->clt_tp, url) == -1 ||
340 		    clt_puts(clt, "'>") == -1 ||
341 		    tp_htmlescape(clt->clt_tp, label) == -1 ||
342 		    clt_puts(clt, "</a></li>") == -1)
343 			return (-1);
344 
345 		return (0);
346 	}
347 
348 	if (clt->clt_translate & TR_NAV) {
349 		if (clt_puts(clt, "</ul></nav>") == -1)
350 			return (-1);
351 		clt->clt_translate &= ~TR_NAV;
352 	}
353 
354 	/* pre opening */
355 	if (!strncmp(line, "```", 3)) {
356 		line += 3;
357 		line += strspn(line, " \t");
358 
359 		clt->clt_translate |= TR_PRE;
360 		return (tp_pre_open(clt->clt_tp, line));
361 	}
362 
363 	/* citation block */
364 	if (*line == '>') {
365 		if (clt_puts(clt, "<blockquote>") == -1 ||
366 		    tp_htmlescape(clt->clt_tp, line + 1) == -1 ||
367 		    clt_puts(clt, "</blockquote>") == -1)
368 			return (-1);
369 		return (0);
370 	}
371 
372 	/* headings */
373 	if (!strncmp(line, "###", 3)) {
374 		if (clt_puts(clt, "<h3>") == -1 ||
375 		    tp_htmlescape(clt->clt_tp, line + 3) == -1 ||
376 		    clt_puts(clt, "</h3>") == -1)
377 			return (-1);
378 		return (0);
379 	}
380 	if (!strncmp(line, "##", 2)) {
381 		if (clt_puts(clt, "<h2>") == -1 ||
382 		    tp_htmlescape(clt->clt_tp, line + 2) == -1 ||
383 		    clt_puts(clt, "</h2>") == -1)
384 			return (-1);
385 		return (0);
386 	}
387 	if (!strncmp(line, "#", 1)) {
388 		if (clt_puts(clt, "<h1>") == -1 ||
389 		    tp_htmlescape(clt->clt_tp, line + 1) == -1 ||
390 		    clt_puts(clt, "</h1>") == -1)
391 			return (-1);
392 		return (0);
393 	}
394 
395 	/* Not following strictly the gemini specification... */
396 	if (*line == '\0')
397 		return (0);
398 
399 	/* paragraph */
400 	if (clt_puts(clt, "<p>") == -1 ||
401 	    tp_htmlescape(clt->clt_tp, line) == -1 ||
402 	    clt_puts(clt, "</p>") == -1)
403 		return (-1);
404 
405 	return (0);
406 }
407 
408 void
409 proxy_translate_gemtext(struct client *clt)
410 {
411 	struct bufferevent	*bev = clt->clt_bev;
412 	struct evbuffer		*src = EVBUFFER_INPUT(bev);
413 	char			*line;
414 	size_t			 len;
415 	int			 r;
416 
417 	for (;;) {
418 		line = evbuffer_readln(src, &len, EVBUFFER_EOL_CRLF);
419 		if (line == NULL)
420 			return;
421 
422 		r = gemtext_translate_line(clt, line);
423 		free(line);
424 		if (r == -1)
425 			return;
426 	}
427 }
428 
429 struct proxy_config *
430 proxy_match(struct galileo *env, const char *name)
431 {
432 	struct proxy		*pr;
433 
434 	if (name == NULL)
435 		return (NULL);
436 
437 	TAILQ_FOREACH(pr, &env->sc_proxies, pr_entry) {
438 		if (!strcmp(name, pr->pr_conf.host))
439 			return (&pr->pr_conf);
440 	}
441 
442 	return (NULL);
443 }
444 
445 int
446 proxy_start_request(struct galileo *env, struct client *clt)
447 {
448 	struct addrinfo		 hints;
449 	struct asr_query	*query;
450 	int			 r;
451 	char			*url;
452 
453 	if (clt->clt_path_info == NULL) {
454 		log_warnx("PATH_INFO not defined!");
455 		if (proxy_start_reply(clt, 501, "text/html") == -1)
456 			return (-1);
457 		if (tp_error(clt->clt_tp, -1, "internal server error") == -1)
458 			return (-1);
459 		return (fcgi_end_request(clt, 1));
460 	}
461 
462 	if ((clt->clt_pc = proxy_match(env, clt->clt_server_name)) == NULL) {
463 		if (proxy_start_reply(clt, 501, "text/html") == -1)
464 			return (-1);
465 		if (tp_error(clt->clt_tp, -1, "unknown server") == -1)
466 			return (-1);
467 		return (fcgi_end_request(clt, 1));
468 	}
469 
470 	if (clt->clt_bodylen != 0 && clt->clt_body == NULL) {
471 		if (proxy_start_reply(clt, 400, "text/html") == -1)
472 			return (-1);
473 		if (tp_error(clt->clt_tp, -1, "bad request") == -1)
474 			return (-1);
475 		return (fcgi_end_request(clt, 1));
476 	}
477 
478 	if (clt->clt_body) {
479 		r = asprintf(&url, "%s%s?%s", clt->clt_script_name,
480 		    clt->clt_path_info + 1, clt->clt_body);
481 		if (r == -1)
482 			return (fcgi_end_request(clt, 1));
483 
484 		if (proxy_start_reply(clt, 302, url) == -1 ||
485 		    fcgi_end_request(clt, 1) == -1) {
486 			free(url);
487 			return (-1);
488 		}
489 		free(url);
490 		return (0);
491 	}
492 
493 	memset(&hints, 0, sizeof(hints));
494 	hints.ai_family = AF_UNSPEC;
495 	hints.ai_socktype = SOCK_STREAM;
496 
497 	query = getaddrinfo_async(clt->clt_pc->proxy_addr,
498 	    clt->clt_pc->proxy_port, &hints, NULL);
499 	if (query == NULL) {
500 		log_warn("getaddrinfo_async");
501 		return (fcgi_abort_request(clt));
502 	}
503 
504 	clt->clt_evasr = event_asr_run(query, proxy_resolved, clt);
505 	if (clt->clt_evasr == NULL) {
506 		log_warn("event_asr_run");
507 		asr_abort(query);
508 		return (fcgi_abort_request(clt));
509 	}
510 
511 	return (0);
512 }
513 
514 void
515 proxy_resolved(struct asr_result *res, void *d)
516 {
517 	struct client		*clt = d;
518 	struct proxy_config	*pc = clt->clt_pc;
519 
520 	clt->clt_evasr = NULL;
521 
522 	if (res->ar_gai_errno != 0) {
523 		log_warnx("failed to resolve %s:%s: %s",
524 		    pc->proxy_addr, pc->proxy_port,
525 		    gai_strerror(res->ar_gai_errno));
526 		if (proxy_start_reply(clt, 501, "text/html") == -1)
527 			return;
528 		if (tp_error(clt->clt_tp, -1, "Can't resolve host") == -1)
529 			return;
530 		fcgi_end_request(clt, 1);
531 		return;
532 	}
533 
534 	clt->clt_addrinfo = res->ar_addrinfo;
535 	clt->clt_p = clt->clt_addrinfo;
536 	proxy_connect(-1, 0, clt);
537 }
538 
539 void
540 proxy_connect(int fd, short ev, void *d)
541 {
542 	struct client		*clt = d;
543 	struct evbuffer		*out;
544 	struct addrinfo		*p;
545 	struct tls_config	*conf;
546 	struct timeval		 conntv = {5, 0};
547 	int			 err = 0;
548 	socklen_t		 len = sizeof(err);
549 
550 again:
551 	if (clt->clt_p == NULL)
552 		goto err;
553 
554 	if (clt->clt_fd != -1) {
555 		if (getsockopt(clt->clt_fd, SOL_SOCKET, SO_ERROR, &err, &len)
556 		    == -1)
557 			goto err;
558 		if (err != 0) {
559 			errno = err;
560 			goto err;
561 		}
562 		goto done;
563 	}
564 
565 	p = clt->clt_p;
566 	clt->clt_fd = socket(p->ai_family, p->ai_socktype | SOCK_NONBLOCK,
567 	    p->ai_protocol);
568 	if (clt->clt_fd == -1) {
569 		clt->clt_p = clt->clt_p->ai_next;
570 		goto again;
571 	}
572 
573 	if (connect(clt->clt_fd, p->ai_addr, p->ai_addrlen) == 0)
574 		goto done;
575 
576 	clt->clt_evconn_live = 1;
577 	event_set(&clt->clt_evconn, clt->clt_fd, EV_WRITE, proxy_connect, clt);
578 	event_add(&clt->clt_evconn, &conntv);
579 	return;
580 
581 done:
582 	clt->clt_evconn_live = 0;
583 	freeaddrinfo(clt->clt_addrinfo);
584 	clt->clt_addrinfo = clt->clt_p = NULL;
585 
586 	clt->clt_bev = bufferevent_new(clt->clt_fd, proxy_read, proxy_write,
587 	    proxy_error, clt);
588 	if (clt->clt_bev == NULL) {
589 		log_warn("bufferevent_new");
590 		goto err;
591 	}
592 
593 	if (!clt->clt_pc->no_tls) {
594 		/* initialize TLS for Gemini */
595 		if ((conf = tls_config_new()) == NULL) {
596 			log_warn("tls_config_new failed");
597 			goto err;
598 		}
599 
600 		tls_config_insecure_noverifycert(conf);
601 
602 		if ((clt->clt_ctx = tls_client()) == NULL) {
603 			log_warnx("tls_client failed");
604 			tls_config_free(conf);
605 			goto err;
606 		}
607 
608 		if (tls_configure(clt->clt_ctx, conf) == -1) {
609 			log_warnx("tls_configure failed");
610 			tls_config_free(conf);
611 			goto err;
612 		}
613 
614 		tls_config_free(conf);
615 
616 		if (tls_connect_socket(clt->clt_ctx, clt->clt_fd,
617 			clt->clt_pc->proxy_name) == -1) {
618 			log_warnx("tls_connect_socket failed");
619 			goto err;
620 		}
621 
622 		event_set(&clt->clt_bev->ev_read, clt->clt_fd, EV_READ,
623 		    proxy_tls_readcb, clt->clt_bev);
624 		event_set(&clt->clt_bev->ev_write, clt->clt_fd, EV_WRITE,
625 		    proxy_tls_writecb, clt->clt_bev);
626 
627 #if HAVE_LIBEVENT2
628 		evbuffer_unfreeze(clt->clt_bev->input, 0);
629 		evbuffer_unfreeze(clt->clt_bev->output, 1);
630 #endif
631 	}
632 
633 	/* bufferevent_settimeout(); */
634 	bufferevent_enable(clt->clt_bev, EV_READ|EV_WRITE);
635 
636 	/* TODO: compute the URL */
637 	out = EVBUFFER_OUTPUT(clt->clt_bev);
638 	if (evbuffer_add_printf(out, "gemini://%s/%s",
639 	    clt->clt_pc->proxy_name, clt->clt_path_info) == -1) {
640 		log_warn("bufferevent_printf failed");
641 		goto err;
642 	}
643 
644 	if (clt->clt_query &&
645 	    evbuffer_add_printf(out, "?%s", clt->clt_query) == -1) {
646 		log_warn("bufferevent_printf failed");
647 		goto err;
648 	}
649 
650 	if (evbuffer_add(out, "\r\n", 2) == -1) {
651 		log_warn("bufferevent_add failed");
652 		goto err;
653 	}
654 
655 	return;
656 
657 err:
658 	log_warn("failed to connect to %s:%s",
659 	    clt->clt_pc->proxy_addr, clt->clt_pc->proxy_port);
660 	if (proxy_start_reply(clt, 501, "text/html") == -1)
661 		return;
662 	if (tp_error(clt->clt_tp, -1, "Can't connect") == -1)
663 		return;
664 	fcgi_end_request(clt, 1);
665 }
666 
667 static inline int
668 parse_mime(struct client *clt, char *mime, char *lang, size_t len)
669 {
670 	char			*t, *semi;
671 
672 	if (strncmp(mime, "text/gemini", 11) != 0)
673 		return (0);
674 
675 	clt->clt_translate = TR_ENABLED;
676 
677 	if ((mime = strchr(mime, ';')) == NULL)
678 		return (0);
679 
680 	*mime++ = '\0';
681 	while ((t = strsep(&mime, ";")) != NULL) {
682 		if (!strncmp(t, "charset=", 8)) {
683 			t += 8;
684 			if (!strncasecmp(t, "utf8", 4) ||
685 			    !strncasecmp(t, "utf-8", 5) ||
686 			    !strncasecmp(t, "ascii", 5)) {
687 				log_debug("unknown charset %s", t);
688 				return (-1);
689 			}
690 			continue;
691 		}
692 
693 		if (!strncmp(t, "lang=", 5)) {
694 			t += 5;
695 			if ((semi = strchr(t, ';')) != NULL)
696 				*semi = '\0';
697 
698 			if (strlcpy(lang, t, len) >= len) {
699 				log_debug("lang too long: %s", t);
700 				*lang = '\0';
701 			}
702 
703 			if (semi)
704 				*semi = ';';
705 			continue;
706 		}
707 	}
708 
709 	return (0);
710 }
711 
712 int
713 proxy_start_reply(struct client *clt, int status, const char *ctype)
714 {
715 	const char	*csp;
716 
717 	csp = "Content-Security-Policy: default-src 'self'; "
718 	    "script-src 'none'; object-src 'none';\r\n";
719 
720 	if (status != 200 &&
721 	    clt_printf(clt, "Status: %d\r\n", status) == -1)
722 		return (-1);
723 
724 	if (clt_puts(clt, csp) == -1)
725 		return (-1);
726 
727 	if (status == 302) {
728 		/* use "ctype" as redirect target */
729 		if (clt_printf(clt, "Location: %s\r\n", ctype) == -1)
730 			return (-1);
731 		if (clt_puts(clt, "\r\n") == -1)
732 			return (-1);
733 		return (0);
734 	}
735 
736 	if (ctype != NULL) {
737 		if (!strcmp(ctype, "text/html"))
738 			ctype = "text/html;charset=utf-8";
739 		if (clt_printf(clt, "Content-Type: %s\r\n", ctype)
740 		    == -1)
741 			return (-1);
742 	}
743 
744 	if (clt_puts(clt, "\r\n") == -1)
745 		return (-1);
746 
747 	return (0);
748 }
749 
750 void
751 proxy_read(struct bufferevent *bev, void *d)
752 {
753 	struct client		*clt = d;
754 	struct evbuffer		*src = EVBUFFER_INPUT(bev);
755 	const char		*ctype;
756 	char			 buf[1025];
757 	char			 lang[16];
758 	char			*hdr, *mime;
759 	size_t			 len;
760 	int			 code;
761 
762 	if (clt->clt_headersdone) {
763 		if (clt->clt_translate)
764 			proxy_translate_gemtext(clt);
765 		else
766 			clt_write_bufferevent(clt, bev);
767 		return;
768 	}
769 
770 	hdr = evbuffer_readln(src, &len, EVBUFFER_EOL_CRLF_STRICT);
771 	if (hdr == NULL) {
772 		if (EVBUFFER_LENGTH(src) >= 1026)
773 			proxy_error(bev, EV_READ, clt);
774 		return;
775 	}
776 
777 	if (len < 4 ||
778 	    !isdigit((unsigned char)hdr[0]) ||
779 	    !isdigit((unsigned char)hdr[1]) ||
780 	    hdr[2] != ' ') {
781 		log_warnx("invalid ");
782 		proxy_error(bev, EV_READ, clt);
783 		goto err;
784 	}
785 
786 	code = (hdr[0] - '0') * 10 + (hdr[1] - '0');
787 
788 	switch (hdr[0]) {
789 	case '1':
790 		if (proxy_start_reply(clt, 200, "text/html") == -1)
791 			goto err;
792 		if (tp_inputpage(clt->clt_tp, &hdr[3]) == -1)
793 			goto err;
794 		fcgi_end_request(clt, 0);
795 		goto err;
796 	case '2':
797 		/* handled below */
798 		break;
799 	case '3':
800 		if (proxy_resurl(clt, &hdr[3], buf, sizeof(buf)) == 0) {
801 			if (proxy_start_reply(clt, 302, buf) == -1)
802 				goto err;
803 			fcgi_end_request(clt, 0);
804 			goto err;
805 		}
806 		/* fallthrough */
807 	default:
808 		if (proxy_start_reply(clt, 501, "text/html") == -1)
809 			goto err;
810 		if (tp_error(clt->clt_tp, code, &hdr[3]) == -1)
811 			goto err;
812 		fcgi_end_request(clt, 1);
813 		goto err;
814 	}
815 
816 	mime = hdr + 2 + strspn(hdr + 2, " \t");
817 	if (parse_mime(clt, mime, lang, sizeof(lang)) == -1) {
818 		if (proxy_start_reply(clt, 501, "text/html") == -1)
819 			goto err;
820 		if (tp_error(clt->clt_tp, -1, "Bad response") == -1)
821 			goto err;
822 		fcgi_end_request(clt, 1);
823 		goto err;
824 	}
825 
826 	if (clt->clt_translate)
827 		ctype = "text/html;charset=utf-8";
828 	else
829 		ctype = mime;
830 
831 	if (clt_printf(clt, "Content-Type: %s\r\n\r\n", ctype) == -1)
832 		goto err;
833 
834 	clt->clt_headersdone = 1;
835 
836 	if (clt->clt_translate &&
837 	    tp_head(clt->clt_tp, lang, NULL) == -1)
838 		goto err;
839 
840 	/*
841 	 * Trigger the read again so we proceed with the response
842 	 * body, if any.
843 	 */
844 	free(hdr);
845 	proxy_read(bev, d);
846 	return;
847 
848 err:
849 	free(hdr);
850 }
851 
852 void
853 proxy_write(struct bufferevent *bev, void *d)
854 {
855 	return;
856 }
857 
858 void
859 proxy_error(struct bufferevent *bev, short err, void *d)
860 {
861 	struct client		*clt = d;
862 	int			 status = !(err & EVBUFFER_EOF);
863 
864 	log_debug("proxy error, shutting down the connection (err: %x)",
865 	    err);
866 
867 	if (!clt->clt_headersdone) {
868 		if (proxy_start_reply(clt, 501, "text/html") == -1)
869 			return;
870 		if (tp_error(clt->clt_tp, -1, "Proxy error") == -1)
871 			return;
872 	} else if (status == 0) {
873 		if (clt->clt_translate & TR_PRE) {
874 			if (tp_pre_close(clt->clt_tp))
875 				return;
876 			clt->clt_translate &= ~TR_PRE;
877 		}
878 
879 		if (clt->clt_translate & TR_LIST) {
880 			if (clt_puts(clt, "</ul>") == -1)
881 				return;
882 			clt->clt_translate &= ~TR_LIST;
883 		}
884 
885 		if (clt->clt_translate & TR_NAV) {
886 			if (clt_puts(clt, "</ul></nav>") == -1)
887 				return;
888 			clt->clt_translate &= ~TR_NAV;
889 		}
890 
891 		if (clt->clt_translate &&
892 		    tp_foot(clt->clt_tp) == -1)
893 			return;
894 	}
895 
896 	fcgi_end_request(clt, status);
897 }
898 
899 void
900 proxy_tls_readcb(int fd, short event, void *arg)
901 {
902 	struct bufferevent	*bufev = arg;
903 	struct client		*clt = bufev->cbarg;
904 	char			 rbuf[IBUF_READ_SIZE];
905 	int			 what = EVBUFFER_READ;
906 	int			 howmuch = IBUF_READ_SIZE;
907 	ssize_t			 ret;
908 	size_t			 len;
909 
910 	if (event == EV_TIMEOUT) {
911 		what |= EVBUFFER_TIMEOUT;
912 		goto err;
913 	}
914 
915 	if (bufev->wm_read.high != 0)
916 		howmuch = MINIMUM(sizeof(rbuf), bufev->wm_read.high);
917 
918 	ret = tls_read(clt->clt_ctx, rbuf, howmuch);
919 	if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) {
920 		goto retry;
921 	} else if (ret == -1) {
922 		what |= EVBUFFER_ERROR;
923 		goto err;
924 	}
925 	len = ret;
926 
927 	if (len == 0) {
928 		what |= EVBUFFER_EOF;
929 		goto err;
930 	}
931 
932 	if (evbuffer_add(bufev->input, rbuf, len) == -1) {
933 		what |= EVBUFFER_ERROR;
934 		goto err;
935 	}
936 
937 	proxy_bufferevent_add(&bufev->ev_read, G_TOUT(bufev->timeout_read));
938 
939 	len = EVBUFFER_LENGTH(bufev->input);
940 	if (bufev->wm_read.low != 0 && len < bufev->wm_read.low)
941 		return;
942 	if (bufev->wm_read.high != 0 && len > bufev->wm_read.high) {
943 		struct evbuffer *buf = bufev->input;
944 		event_del(&bufev->ev_read);
945 		evbuffer_setcb(buf, bufferevent_read_pressure_cb, bufev);
946 		return;
947 	}
948 
949 	if (bufev->readcb != NULL)
950 		(*bufev->readcb)(bufev, bufev->cbarg);
951 	return;
952 
953 retry:
954 	proxy_bufferevent_add(&bufev->ev_read, G_TOUT(bufev->timeout_read));
955 	return;
956 
957 err:
958 	(*bufev->errorcb)(bufev, what, bufev->cbarg);
959 }
960 
961 int
962 proxy_bufferevent_add(struct event *ev, int timeout)
963 {
964 	struct timeval tv, *ptv = NULL;
965 
966 	if (timeout) {
967 		timerclear(&tv);
968 		tv.tv_sec = timeout;
969 		ptv = &tv;
970 	}
971 
972 	return (event_add(ev, ptv));
973 }
974 
975 void
976 proxy_tls_writecb(int fd, short event, void *arg)
977 {
978 	struct bufferevent	*bufev = arg;
979 	struct client		*clt = bufev->cbarg;
980 	ssize_t			 ret;
981 	short			 what = EVBUFFER_WRITE;
982 	size_t			 len;
983 
984 	if (event == EV_TIMEOUT) {
985 		what |= EVBUFFER_TIMEOUT;
986 		goto err;
987 	}
988 
989 	if (EVBUFFER_LENGTH(bufev->output)) {
990 		ret = tls_write(clt->clt_ctx,
991 		    EVBUFFER_DATA(bufev->output),
992 		    EVBUFFER_LENGTH(bufev->output));
993 		if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) {
994 			goto retry;
995 		} else if (ret == -1) {
996 			what |= EVBUFFER_ERROR;
997 			goto err;
998 		}
999 		len = ret;
1000 		evbuffer_drain(bufev->output, len);
1001 	}
1002 
1003 	if (EVBUFFER_LENGTH(bufev->output) != 0)
1004 		proxy_bufferevent_add(&bufev->ev_write,
1005 		    G_TOUT(bufev->timeout_write));
1006 
1007 	if (bufev->writecb != NULL &&
1008 	    EVBUFFER_LENGTH(bufev->output) <= bufev->wm_write.low)
1009 		(*bufev->writecb)(bufev, bufev->cbarg);
1010 	return;
1011 
1012 retry:
1013 	proxy_bufferevent_add(&bufev->ev_write, G_TOUT(bufev->timeout_write));
1014 	return;
1015 
1016 err:
1017 	(*bufev->errorcb)(bufev, what, bufev->cbarg);
1018 }
1019 
1020 void
1021 proxy_client_free(struct client *clt)
1022 {
1023 	if (clt->clt_evasr)
1024 		event_asr_abort(clt->clt_evasr);
1025 
1026 	if (clt->clt_addrinfo)
1027 		freeaddrinfo(clt->clt_addrinfo);
1028 
1029 	if (clt->clt_evconn_live)
1030 		event_del(&clt->clt_evconn);
1031 
1032 	if (clt->clt_fd != -1)
1033 		close(clt->clt_fd);
1034 
1035 	if (clt->clt_ctx)
1036 		tls_free(clt->clt_ctx);
1037 
1038 	if (clt->clt_bev)
1039 		bufferevent_free(clt->clt_bev);
1040 
1041 	template_free(clt->clt_tp);
1042 
1043 	free(clt->clt_body);
1044 	free(clt->clt_server_name);
1045 	free(clt->clt_script_name);
1046 	free(clt->clt_path_info);
1047 	free(clt->clt_query);
1048 	free(clt);
1049 }