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Date:: Fri Nov 11 19:06:04 2022 UTC
Message:: fix url handling
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 	l = strlen(clt->clt_server_name);
193 
194 	if (len == 0) {
195 		log_warn("%s: zero-sized buffer!", __func__);
196 		return (-1);
197 	}
198 
199 	/* look if it's an absolute URI */
200 	if (strncmp(url, "//", 2) == 0) {
201 		tmp = url + 2;
202 		if (strncmp(tmp, clt->clt_server_name, l) != 0)
203 			goto done;
204 
205 		tmp += l;
206 		if (!portok(&tmp, clt))
207 			goto done;
208 		url = tmp;
209 	} else if (strncmp(url, "gemini://", 9) == 0) {
210 		tmp = url + 9;
211 		if (strncmp(tmp, clt->clt_server_name, l) != 0)
212 			goto done;
213 
214 		tmp += l;
215 		if (!portok(&tmp, clt))
216 			goto done;
217 		url = tmp;
218 	} else {
219 		tmp = url;
220 		while (isalpha((unsigned char)*tmp) || *tmp == '+')
221 			tmp++;
222 		if (strncmp(tmp, "://", 3) == 0)
223 			goto done;
224 	}
225 
226 	/* maybe it's an absolute path? */
227 	if (*url == '\0' || *url == '/') {
228 		if (strlcpy(buf, clt->clt_script_name, len) >= len)
229 			return (-1);
230 		if (strlcat(buf, url + 1, len) >= len)
231 			return (-1);
232 		return (0);
233 	}
234 
235 	/* otherwise, leave it as it is */
236  done:
237 	if (strlcpy(buf, url, len) >= len)
238 		return (-1);
239 	return (0);
240 }
241 
242 static int
243 gemtext_translate_line(struct client *clt, char *line)
244 {
245 	char		 buf[1025];
246 	char		*url;
247 
248 	/* preformatted line / closing */
249 	if (clt->clt_translate & TR_PRE) {
250 		if (!strncmp(line, "```", 3)) {
251 			clt->clt_translate &= ~TR_PRE;
252 			return (tp_pre_close(clt->clt_tp));
253 		}
254 
255 		if (tp_htmlescape(clt->clt_tp, line) == -1)
256 			return (-1);
257 		return (clt_putc(clt, '\n'));
258 	}
259 
260 	/* bullet */
261 	if (!strncmp(line, "* ", 2)) {
262 		if (clt->clt_translate & TR_NAV) {
263 			if (clt_puts(clt, "</ul></nav>") == -1)
264 				return (-1);
265 			clt->clt_translate &= ~TR_NAV;
266 		}
267 
268 		if (!(clt->clt_translate & TR_LIST)) {
269 			if (clt_puts(clt, "<ul>") == -1)
270 				return (-1);
271 			clt->clt_translate |= TR_LIST;
272 		}
273 
274 		if (clt_puts(clt, "<li>") == -1 ||
275 		    tp_htmlescape(clt->clt_tp, line + 2) == -1 ||
276 		    clt_puts(clt, "</li>") == -1)
277 			return (-1);
278 		return (0);
279 	}
280 
281 	if (clt->clt_translate & TR_LIST) {
282 		if (clt_puts(clt, "</ul>") == -1)
283 			return (-1);
284 		clt->clt_translate &= ~TR_LIST;
285 	}
286 
287 	/* link */
288 	if (!strncmp(line, "=>", 2)) {
289 		char *label;
290 
291 		line += 2;
292 		line += strspn(line, " \t");
293 
294 		label = line + strcspn(line, " \t");
295 		if (*label == '\0')
296 			label = line;
297 		else
298 			*label++ = '\0';
299 
300 		if (proxy_resurl(clt, line, buf, sizeof(buf)) == 0)
301 			url = buf;
302 		else
303 			url = line; /* leave the URL as it is */
304 
305 		if (fnmatch("*.jpg", url, 0) == 0 ||
306 		    fnmatch("*.jpeg", url, 0) == 0 ||
307 		    fnmatch("*.gif", url, 0) == 0 ||
308 		    fnmatch("*.png", url, 0) == 0 ||
309 		    fnmatch("*.svg", url, 0) == 0 ||
310 		    fnmatch("*.webp", url, 0) == 0) {
311 			if (clt->clt_translate & TR_NAV) {
312 				if (clt_puts(clt, "</ul></nav>") == -1)
313 					return (-1);
314 				clt->clt_translate &= ~TR_NAV;
315 			}
316 
317 			if (tp_figure(clt->clt_tp, url, label) == -1)
318 				return (-1);
319 
320 			return (0);
321 		}
322 
323 		if (!(clt->clt_translate & TR_NAV)) {
324 			if (clt_puts(clt, "<nav><ul>") == -1)
325 				return (-1);
326 			clt->clt_translate |= TR_NAV;
327 		}
328 
329 		if (clt_puts(clt, "<li><a href='") == -1)
330 			return (-1);
331 
332 		if (tp_urlescape(clt->clt_tp, url) == -1 ||
333 		    clt_puts(clt, "'>") == -1 ||
334 		    tp_htmlescape(clt->clt_tp, label) == -1 ||
335 		    clt_puts(clt, "</a></li>") == -1)
336 			return (-1);
337 
338 		return (0);
339 	}
340 
341 	if (clt->clt_translate & TR_NAV) {
342 		if (clt_puts(clt, "</ul></nav>") == -1)
343 			return (-1);
344 		clt->clt_translate &= ~TR_NAV;
345 	}
346 
347 	/* pre opening */
348 	if (!strncmp(line, "```", 3)) {
349 		line += 3;
350 		line += strspn(line, " \t");
351 
352 		clt->clt_translate |= TR_PRE;
353 		return (tp_pre_open(clt->clt_tp, line));
354 	}
355 
356 	/* citation block */
357 	if (*line == '>') {
358 		if (clt_puts(clt, "<blockquote>") == -1 ||
359 		    tp_htmlescape(clt->clt_tp, line + 1) == -1 ||
360 		    clt_puts(clt, "</blockquote>") == -1)
361 			return (-1);
362 		return (0);
363 	}
364 
365 	/* headings */
366 	if (!strncmp(line, "###", 3)) {
367 		if (clt_puts(clt, "<h3>") == -1 ||
368 		    tp_htmlescape(clt->clt_tp, line + 3) == -1 ||
369 		    clt_puts(clt, "</h3>") == -1)
370 			return (-1);
371 		return (0);
372 	}
373 	if (!strncmp(line, "##", 2)) {
374 		if (clt_puts(clt, "<h2>") == -1 ||
375 		    tp_htmlescape(clt->clt_tp, line + 2) == -1 ||
376 		    clt_puts(clt, "</h2>") == -1)
377 			return (-1);
378 		return (0);
379 	}
380 	if (!strncmp(line, "#", 1)) {
381 		if (clt_puts(clt, "<h1>") == -1 ||
382 		    tp_htmlescape(clt->clt_tp, line + 1) == -1 ||
383 		    clt_puts(clt, "</h1>") == -1)
384 			return (-1);
385 		return (0);
386 	}
387 
388 	/* Not following strictly the gemini specification... */
389 	if (*line == '\0')
390 		return (0);
391 
392 	/* paragraph */
393 	if (clt_puts(clt, "<p>") == -1 ||
394 	    tp_htmlescape(clt->clt_tp, line) == -1 ||
395 	    clt_puts(clt, "</p>") == -1)
396 		return (-1);
397 
398 	return (0);
399 }
400 
401 void
402 proxy_translate_gemtext(struct client *clt)
403 {
404 	struct bufferevent	*bev = clt->clt_bev;
405 	struct evbuffer		*src = EVBUFFER_INPUT(bev);
406 	char			*line;
407 	size_t			 len;
408 	int			 r;
409 
410 	for (;;) {
411 		line = evbuffer_readln(src, &len, EVBUFFER_EOL_CRLF);
412 		if (line == NULL)
413 			return;
414 
415 		r = gemtext_translate_line(clt, line);
416 		free(line);
417 		if (r == -1)
418 			return;
419 	}
420 }
421 
422 struct proxy_config *
423 proxy_match(struct galileo *env, const char *name)
424 {
425 	struct proxy		*pr;
426 
427 	if (name == NULL)
428 		return (NULL);
429 
430 	TAILQ_FOREACH(pr, &env->sc_proxies, pr_entry) {
431 		if (!strcmp(name, pr->pr_conf.host))
432 			return (&pr->pr_conf);
433 	}
434 
435 	return (NULL);
436 }
437 
438 int
439 proxy_start_request(struct galileo *env, struct client *clt)
440 {
441 	struct addrinfo		 hints;
442 	struct asr_query	*query;
443 	int			 r;
444 	char			*url;
445 
446 	if (clt->clt_path_info == NULL) {
447 		log_warnx("PATH_INFO not defined!");
448 		if (proxy_start_reply(clt, 501, "text/html") == -1)
449 			return (-1);
450 		if (tp_error(clt->clt_tp, -1, "internal server error") == -1)
451 			return (-1);
452 		return (fcgi_end_request(clt, 1));
453 	}
454 
455 	if ((clt->clt_pc = proxy_match(env, clt->clt_server_name)) == NULL) {
456 		if (proxy_start_reply(clt, 501, "text/html") == -1)
457 			return (-1);
458 		if (tp_error(clt->clt_tp, -1, "unknown server") == -1)
459 			return (-1);
460 		return (fcgi_end_request(clt, 1));
461 	}
462 
463 	if (clt->clt_bodylen != 0 && clt->clt_body == NULL) {
464 		if (proxy_start_reply(clt, 400, "text/html") == -1)
465 			return (-1);
466 		if (tp_error(clt->clt_tp, -1, "bad request") == -1)
467 			return (-1);
468 		return (fcgi_end_request(clt, 1));
469 	}
470 
471 	if (clt->clt_body) {
472 		r = asprintf(&url, "%s%s?%s", clt->clt_script_name,
473 		    clt->clt_path_info + 1, clt->clt_body);
474 		if (r == -1)
475 			return (fcgi_end_request(clt, 1));
476 
477 		if (proxy_start_reply(clt, 302, url) == -1 ||
478 		    fcgi_end_request(clt, 1) == -1) {
479 			free(url);
480 			return (-1);
481 		}
482 		free(url);
483 		return (0);
484 	}
485 
486 	memset(&hints, 0, sizeof(hints));
487 	hints.ai_family = AF_UNSPEC;
488 	hints.ai_socktype = SOCK_STREAM;
489 
490 	query = getaddrinfo_async(clt->clt_pc->proxy_addr,
491 	    clt->clt_pc->proxy_port, &hints, NULL);
492 	if (query == NULL) {
493 		log_warn("getaddrinfo_async");
494 		return (fcgi_abort_request(clt));
495 	}
496 
497 	clt->clt_evasr = event_asr_run(query, proxy_resolved, clt);
498 	if (clt->clt_evasr == NULL) {
499 		log_warn("event_asr_run");
500 		asr_abort(query);
501 		return (fcgi_abort_request(clt));
502 	}
503 
504 	return (0);
505 }
506 
507 void
508 proxy_resolved(struct asr_result *res, void *d)
509 {
510 	struct client		*clt = d;
511 	struct proxy_config	*pc = clt->clt_pc;
512 
513 	clt->clt_evasr = NULL;
514 
515 	if (res->ar_gai_errno != 0) {
516 		log_warnx("failed to resolve %s:%s: %s",
517 		    pc->proxy_addr, pc->proxy_port,
518 		    gai_strerror(res->ar_gai_errno));
519 		if (proxy_start_reply(clt, 501, "text/html") == -1)
520 			return;
521 		if (tp_error(clt->clt_tp, -1, "Can't resolve host") == -1)
522 			return;
523 		fcgi_end_request(clt, 1);
524 		return;
525 	}
526 
527 	clt->clt_addrinfo = res->ar_addrinfo;
528 	clt->clt_p = clt->clt_addrinfo;
529 	proxy_connect(-1, 0, clt);
530 }
531 
532 void
533 proxy_connect(int fd, short ev, void *d)
534 {
535 	struct client		*clt = d;
536 	struct evbuffer		*out;
537 	struct addrinfo		*p;
538 	struct tls_config	*conf;
539 	struct timeval		 conntv = {5, 0};
540 	int			 err = 0;
541 	socklen_t		 len = sizeof(err);
542 
543 again:
544 	if (clt->clt_p == NULL)
545 		goto err;
546 
547 	if (clt->clt_fd != -1) {
548 		if (getsockopt(clt->clt_fd, SOL_SOCKET, SO_ERROR, &err, &len)
549 		    == -1)
550 			goto err;
551 		if (err != 0) {
552 			errno = err;
553 			goto err;
554 		}
555 		goto done;
556 	}
557 
558 	p = clt->clt_p;
559 	clt->clt_fd = socket(p->ai_family, p->ai_socktype | SOCK_NONBLOCK,
560 	    p->ai_protocol);
561 	if (clt->clt_fd == -1) {
562 		clt->clt_p = clt->clt_p->ai_next;
563 		goto again;
564 	}
565 
566 	if (connect(clt->clt_fd, p->ai_addr, p->ai_addrlen) == 0)
567 		goto done;
568 
569 	clt->clt_evconn_live = 1;
570 	event_set(&clt->clt_evconn, clt->clt_fd, EV_WRITE, proxy_connect, clt);
571 	event_add(&clt->clt_evconn, &conntv);
572 	return;
573 
574 done:
575 	clt->clt_evconn_live = 0;
576 	freeaddrinfo(clt->clt_addrinfo);
577 	clt->clt_addrinfo = clt->clt_p = NULL;
578 
579 	clt->clt_bev = bufferevent_new(clt->clt_fd, proxy_read, proxy_write,
580 	    proxy_error, clt);
581 	if (clt->clt_bev == NULL) {
582 		log_warn("bufferevent_new");
583 		goto err;
584 	}
585 
586 	if (!clt->clt_pc->no_tls) {
587 		/* initialize TLS for Gemini */
588 		if ((conf = tls_config_new()) == NULL) {
589 			log_warn("tls_config_new failed");
590 			goto err;
591 		}
592 
593 		tls_config_insecure_noverifycert(conf);
594 
595 		if ((clt->clt_ctx = tls_client()) == NULL) {
596 			log_warnx("tls_client failed");
597 			tls_config_free(conf);
598 			goto err;
599 		}
600 
601 		if (tls_configure(clt->clt_ctx, conf) == -1) {
602 			log_warnx("tls_configure failed");
603 			tls_config_free(conf);
604 			goto err;
605 		}
606 
607 		tls_config_free(conf);
608 
609 		if (tls_connect_socket(clt->clt_ctx, clt->clt_fd,
610 			clt->clt_pc->proxy_name) == -1) {
611 			log_warnx("tls_connect_socket failed");
612 			goto err;
613 		}
614 
615 		event_set(&clt->clt_bev->ev_read, clt->clt_fd, EV_READ,
616 		    proxy_tls_readcb, clt->clt_bev);
617 		event_set(&clt->clt_bev->ev_write, clt->clt_fd, EV_WRITE,
618 		    proxy_tls_writecb, clt->clt_bev);
619 
620 #if HAVE_LIBEVENT2
621 		evbuffer_unfreeze(clt->clt_bev->input, 0);
622 		evbuffer_unfreeze(clt->clt_bev->output, 1);
623 #endif
624 	}
625 
626 	/* bufferevent_settimeout(); */
627 	bufferevent_enable(clt->clt_bev, EV_READ|EV_WRITE);
628 
629 	/* TODO: compute the URL */
630 	out = EVBUFFER_OUTPUT(clt->clt_bev);
631 	if (evbuffer_add_printf(out, "gemini://%s/%s",
632 	    clt->clt_pc->proxy_name, clt->clt_path_info) == -1) {
633 		log_warn("bufferevent_printf failed");
634 		goto err;
635 	}
636 
637 	if (clt->clt_query &&
638 	    evbuffer_add_printf(out, "?%s", clt->clt_query) == -1) {
639 		log_warn("bufferevent_printf failed");
640 		goto err;
641 	}
642 
643 	if (evbuffer_add(out, "\r\n", 2) == -1) {
644 		log_warn("bufferevent_add failed");
645 		goto err;
646 	}
647 
648 	return;
649 
650 err:
651 	log_warn("failed to connect to %s:%s",
652 	    clt->clt_pc->proxy_addr, clt->clt_pc->proxy_port);
653 	if (proxy_start_reply(clt, 501, "text/html") == -1)
654 		return;
655 	if (tp_error(clt->clt_tp, -1, "Can't connect") == -1)
656 		return;
657 	fcgi_end_request(clt, 1);
658 }
659 
660 static inline int
661 parse_mime(struct client *clt, char *mime, char *lang, size_t len)
662 {
663 	char			*t, *semi;
664 
665 	if (strncmp(mime, "text/gemini", 11) != 0)
666 		return (0);
667 
668 	clt->clt_translate = TR_ENABLED;
669 
670 	if ((mime = strchr(mime, ';')) == NULL)
671 		return (0);
672 
673 	*mime++ = '\0';
674 	while ((t = strsep(&mime, ";")) != NULL) {
675 		if (!strncmp(t, "charset=", 8)) {
676 			t += 8;
677 			if (!strncasecmp(t, "utf8", 4) ||
678 			    !strncasecmp(t, "utf-8", 5) ||
679 			    !strncasecmp(t, "ascii", 5)) {
680 				log_debug("unknown charset %s", t);
681 				return (-1);
682 			}
683 			continue;
684 		}
685 
686 		if (!strncmp(t, "lang=", 5)) {
687 			t += 5;
688 			if ((semi = strchr(t, ';')) != NULL)
689 				*semi = '\0';
690 
691 			if (strlcpy(lang, t, len) >= len) {
692 				log_debug("lang too long: %s", t);
693 				*lang = '\0';
694 			}
695 
696 			if (semi)
697 				*semi = ';';
698 			continue;
699 		}
700 	}
701 
702 	return (0);
703 }
704 
705 int
706 proxy_start_reply(struct client *clt, int status, const char *ctype)
707 {
708 	const char	*csp;
709 
710 	csp = "Content-Security-Policy: default-src 'self'; "
711 	    "script-src 'none'; object-src 'none';\r\n";
712 
713 	if (status != 200 &&
714 	    clt_printf(clt, "Status: %d\r\n", status) == -1)
715 		return (-1);
716 
717 	if (clt_puts(clt, csp) == -1)
718 		return (-1);
719 
720 	if (status == 302) {
721 		/* use "ctype" as redirect target */
722 		if (clt_printf(clt, "Location: %s\r\n", ctype) == -1)
723 			return (-1);
724 		if (clt_puts(clt, "\r\n") == -1)
725 			return (-1);
726 		return (0);
727 	}
728 
729 	if (ctype != NULL) {
730 		if (!strcmp(ctype, "text/html"))
731 			ctype = "text/html;charset=utf-8";
732 		if (clt_printf(clt, "Content-Type: %s\r\n", ctype)
733 		    == -1)
734 			return (-1);
735 	}
736 
737 	if (clt_puts(clt, "\r\n") == -1)
738 		return (-1);
739 
740 	return (0);
741 }
742 
743 void
744 proxy_read(struct bufferevent *bev, void *d)
745 {
746 	struct client		*clt = d;
747 	struct evbuffer		*src = EVBUFFER_INPUT(bev);
748 	const char		*ctype;
749 	char			 buf[1025];
750 	char			 lang[16];
751 	char			*hdr, *mime;
752 	size_t			 len;
753 	int			 code;
754 
755 	if (clt->clt_headersdone) {
756 		if (clt->clt_translate)
757 			proxy_translate_gemtext(clt);
758 		else
759 			clt_write_bufferevent(clt, bev);
760 		return;
761 	}
762 
763 	hdr = evbuffer_readln(src, &len, EVBUFFER_EOL_CRLF_STRICT);
764 	if (hdr == NULL) {
765 		if (EVBUFFER_LENGTH(src) >= 1026)
766 			proxy_error(bev, EV_READ, clt);
767 		return;
768 	}
769 
770 	if (len < 4 ||
771 	    !isdigit((unsigned char)hdr[0]) ||
772 	    !isdigit((unsigned char)hdr[1]) ||
773 	    hdr[2] != ' ') {
774 		log_warnx("invalid ");
775 		proxy_error(bev, EV_READ, clt);
776 		goto err;
777 	}
778 
779 	code = (hdr[0] - '0') * 10 + (hdr[1] - '0');
780 
781 	switch (hdr[0]) {
782 	case '1':
783 		if (proxy_start_reply(clt, 200, "text/html") == -1)
784 			goto err;
785 		if (tp_inputpage(clt->clt_tp, &hdr[3]) == -1)
786 			goto err;
787 		fcgi_end_request(clt, 0);
788 		goto err;
789 	case '2':
790 		/* handled below */
791 		break;
792 	case '3':
793 		if (proxy_resurl(clt, &hdr[3], buf, sizeof(buf)) == 0) {
794 			if (proxy_start_reply(clt, 302, buf) == -1)
795 				goto err;
796 			fcgi_end_request(clt, 0);
797 			goto err;
798 		}
799 		/* fallthrough */
800 	default:
801 		if (proxy_start_reply(clt, 501, "text/html") == -1)
802 			goto err;
803 		if (tp_error(clt->clt_tp, code, &hdr[3]) == -1)
804 			goto err;
805 		fcgi_end_request(clt, 1);
806 		goto err;
807 	}
808 
809 	mime = hdr + 2 + strspn(hdr + 2, " \t");
810 	if (parse_mime(clt, mime, lang, sizeof(lang)) == -1) {
811 		if (proxy_start_reply(clt, 501, "text/html") == -1)
812 			goto err;
813 		if (tp_error(clt->clt_tp, -1, "Bad response") == -1)
814 			goto err;
815 		fcgi_end_request(clt, 1);
816 		goto err;
817 	}
818 
819 	if (clt->clt_translate)
820 		ctype = "text/html;charset=utf-8";
821 	else
822 		ctype = mime;
823 
824 	if (clt_printf(clt, "Content-Type: %s\r\n\r\n", ctype) == -1)
825 		goto err;
826 
827 	clt->clt_headersdone = 1;
828 
829 	if (clt->clt_translate &&
830 	    tp_head(clt->clt_tp, lang, NULL) == -1)
831 		goto err;
832 
833 	/*
834 	 * Trigger the read again so we proceed with the response
835 	 * body, if any.
836 	 */
837 	free(hdr);
838 	proxy_read(bev, d);
839 	return;
840 
841 err:
842 	free(hdr);
843 }
844 
845 void
846 proxy_write(struct bufferevent *bev, void *d)
847 {
848 	return;
849 }
850 
851 void
852 proxy_error(struct bufferevent *bev, short err, void *d)
853 {
854 	struct client		*clt = d;
855 	int			 status = !(err & EVBUFFER_EOF);
856 
857 	log_debug("proxy error, shutting down the connection (err: %x)",
858 	    err);
859 
860 	if (!clt->clt_headersdone) {
861 		if (proxy_start_reply(clt, 501, "text/html") == -1)
862 			return;
863 		if (tp_error(clt->clt_tp, -1, "Proxy error") == -1)
864 			return;
865 	} else if (status == 0) {
866 		if (clt->clt_translate & TR_PRE) {
867 			if (tp_pre_close(clt->clt_tp))
868 				return;
869 			clt->clt_translate &= ~TR_PRE;
870 		}
871 
872 		if (clt->clt_translate & TR_LIST) {
873 			if (clt_puts(clt, "</ul>") == -1)
874 				return;
875 			clt->clt_translate &= ~TR_LIST;
876 		}
877 
878 		if (clt->clt_translate & TR_NAV) {
879 			if (clt_puts(clt, "</ul></nav>") == -1)
880 				return;
881 			clt->clt_translate &= ~TR_NAV;
882 		}
883 
884 		if (clt->clt_translate &&
885 		    tp_foot(clt->clt_tp) == -1)
886 			return;
887 	}
888 
889 	fcgi_end_request(clt, status);
890 }
891 
892 void
893 proxy_tls_readcb(int fd, short event, void *arg)
894 {
895 	struct bufferevent	*bufev = arg;
896 	struct client		*clt = bufev->cbarg;
897 	char			 rbuf[IBUF_READ_SIZE];
898 	int			 what = EVBUFFER_READ;
899 	int			 howmuch = IBUF_READ_SIZE;
900 	ssize_t			 ret;
901 	size_t			 len;
902 
903 	if (event == EV_TIMEOUT) {
904 		what |= EVBUFFER_TIMEOUT;
905 		goto err;
906 	}
907 
908 	if (bufev->wm_read.high != 0)
909 		howmuch = MINIMUM(sizeof(rbuf), bufev->wm_read.high);
910 
911 	ret = tls_read(clt->clt_ctx, rbuf, howmuch);
912 	if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) {
913 		goto retry;
914 	} else if (ret == -1) {
915 		what |= EVBUFFER_ERROR;
916 		goto err;
917 	}
918 	len = ret;
919 
920 	if (len == 0) {
921 		what |= EVBUFFER_EOF;
922 		goto err;
923 	}
924 
925 	if (evbuffer_add(bufev->input, rbuf, len) == -1) {
926 		what |= EVBUFFER_ERROR;
927 		goto err;
928 	}
929 
930 	proxy_bufferevent_add(&bufev->ev_read, G_TOUT(bufev->timeout_read));
931 
932 	len = EVBUFFER_LENGTH(bufev->input);
933 	if (bufev->wm_read.low != 0 && len < bufev->wm_read.low)
934 		return;
935 	if (bufev->wm_read.high != 0 && len > bufev->wm_read.high) {
936 		struct evbuffer *buf = bufev->input;
937 		event_del(&bufev->ev_read);
938 		evbuffer_setcb(buf, bufferevent_read_pressure_cb, bufev);
939 		return;
940 	}
941 
942 	if (bufev->readcb != NULL)
943 		(*bufev->readcb)(bufev, bufev->cbarg);
944 	return;
945 
946 retry:
947 	proxy_bufferevent_add(&bufev->ev_read, G_TOUT(bufev->timeout_read));
948 	return;
949 
950 err:
951 	(*bufev->errorcb)(bufev, what, bufev->cbarg);
952 }
953 
954 int
955 proxy_bufferevent_add(struct event *ev, int timeout)
956 {
957 	struct timeval tv, *ptv = NULL;
958 
959 	if (timeout) {
960 		timerclear(&tv);
961 		tv.tv_sec = timeout;
962 		ptv = &tv;
963 	}
964 
965 	return (event_add(ev, ptv));
966 }
967 
968 void
969 proxy_tls_writecb(int fd, short event, void *arg)
970 {
971 	struct bufferevent	*bufev = arg;
972 	struct client		*clt = bufev->cbarg;
973 	ssize_t			 ret;
974 	short			 what = EVBUFFER_WRITE;
975 	size_t			 len;
976 
977 	if (event == EV_TIMEOUT) {
978 		what |= EVBUFFER_TIMEOUT;
979 		goto err;
980 	}
981 
982 	if (EVBUFFER_LENGTH(bufev->output)) {
983 		ret = tls_write(clt->clt_ctx,
984 		    EVBUFFER_DATA(bufev->output),
985 		    EVBUFFER_LENGTH(bufev->output));
986 		if (ret == TLS_WANT_POLLIN || ret == TLS_WANT_POLLOUT) {
987 			goto retry;
988 		} else if (ret == -1) {
989 			what |= EVBUFFER_ERROR;
990 			goto err;
991 		}
992 		len = ret;
993 		evbuffer_drain(bufev->output, len);
994 	}
995 
996 	if (EVBUFFER_LENGTH(bufev->output) != 0)
997 		proxy_bufferevent_add(&bufev->ev_write,
998 		    G_TOUT(bufev->timeout_write));
999 
1000 	if (bufev->writecb != NULL &&
1001 	    EVBUFFER_LENGTH(bufev->output) <= bufev->wm_write.low)
1002 		(*bufev->writecb)(bufev, bufev->cbarg);
1003 	return;
1004 
1005 retry:
1006 	proxy_bufferevent_add(&bufev->ev_write, G_TOUT(bufev->timeout_write));
1007 	return;
1008 
1009 err:
1010 	(*bufev->errorcb)(bufev, what, bufev->cbarg);
1011 }
1012 
1013 void
1014 proxy_client_free(struct client *clt)
1015 {
1016 	if (clt->clt_evasr)
1017 		event_asr_abort(clt->clt_evasr);
1018 
1019 	if (clt->clt_addrinfo)
1020 		freeaddrinfo(clt->clt_addrinfo);
1021 
1022 	if (clt->clt_evconn_live)
1023 		event_del(&clt->clt_evconn);
1024 
1025 	if (clt->clt_fd != -1)
1026 		close(clt->clt_fd);
1027 
1028 	if (clt->clt_ctx)
1029 		tls_free(clt->clt_ctx);
1030 
1031 	if (clt->clt_bev)
1032 		bufferevent_free(clt->clt_bev);
1033 
1034 	template_free(clt->clt_tp);
1035 
1036 	free(clt->clt_body);
1037 	free(clt->clt_server_name);
1038 	free(clt->clt_script_name);
1039 	free(clt->clt_path_info);
1040 	free(clt->clt_query);
1041 	free(clt);
1042 }