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 "gmid.h"
18 
19 #include <sys/stat.h>
20 
21 #include <assert.h>
22 #include <ctype.h>
23 #include <errno.h>
24 #include <event.h>
25 #include <fcntl.h>
26 #include <fnmatch.h>
27 #include <limits.h>
28 #include <string.h>
29 
30 #define MIN(a, b)	((a) < (b) ? (a) : (b))
31 
32 int shutting_down;
33 
34 static struct tls	*ctx;
35 
36 static struct event e4, e6, imsgev, siginfo, sigusr2;
37 static int has_ipv6, has_siginfo;
38 
39 int connected_clients;
40 
41 static inline int matches(const char*, const char*);
42 
43 static int	 check_path(struct client*, const char*, int*);
44 static void	 open_file(struct client*);
45 static void	 check_for_cgi(struct client*);
46 static void	 handle_handshake(int, short, void*);
47 static const char *strip_path(const char*, int);
48 static void	 fmt_sbuf(const char*, struct client*, const char*);
49 static int	 apply_block_return(struct client*);
50 static int	 apply_reverse_proxy(struct client *);
51 static int	 apply_fastcgi(struct client*);
52 static int	 apply_require_ca(struct client*);
53 static size_t	 host_nth(struct vhost*);
54 static void	 start_cgi(const char*, const char*, struct client*);
55 static void	 open_dir(struct client*);
56 static void	 redirect_canonical_dir(struct client*);
57 
58 static void	 client_tls_readcb(int, short, void *);
59 static void	 client_tls_writecb(int, short, void *);
60 
61 static void	 client_read(struct bufferevent *, void *);
62 void		 client_write(struct bufferevent *, void *);
63 static void	 client_error(struct bufferevent *, short, void *);
64 
65 static void	 client_close_ev(int, short, void *);
66 
67 static void	 cgi_read(struct bufferevent *, void *);
68 static void	 cgi_write(struct bufferevent *, void *);
69 static void	 cgi_error(struct bufferevent *, short, void *);
70 
71 static void	 do_accept(int, short, void*);
72 static struct client *client_by_id(int);
73 
74 static void	 handle_imsg_cgi_res(struct imsgbuf*, struct imsg*, size_t);
75 static void	 handle_imsg_fcgi_fd(struct imsgbuf*, struct imsg*, size_t);
76 static void	 handle_imsg_conn_fd(struct imsgbuf*, struct imsg*, size_t);
77 static void	 handle_imsg_quit(struct imsgbuf*, struct imsg*, size_t);
78 static void	 handle_dispatch_imsg(int, short, void *);
79 static void	 handle_siginfo(int, short, void*);
80 
81 static imsg_handlerfn *handlers[] = {
82 	[IMSG_QUIT] = handle_imsg_quit,
83 	[IMSG_CGI_RES] = handle_imsg_cgi_res,
84 	[IMSG_FCGI_FD] = handle_imsg_fcgi_fd,
85 	[IMSG_CONN_FD] = handle_imsg_conn_fd,
86 };
87 
88 static uint32_t server_client_id;
89 
90 struct client_tree_id clients;
91 
92 static inline int
93 matches(const char *pattern, const char *path)
94 {
95 	if (*path == '/')
96 		path++;
97 	return !fnmatch(pattern, path, 0);
98 }
99 
100 const char *
101 vhost_lang(struct vhost *v, const char *path)
102 {
103 	struct location *loc;
104 
105 	if (v == NULL || path == NULL)
106 		return NULL;
107 
108 	loc = TAILQ_FIRST(&v->locations);
109 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
110 		if (loc->lang != NULL) {
111 			if (matches(loc->match, path))
112 				return loc->lang;
113 		}
114 	}
115 
116 	return TAILQ_FIRST(&v->locations)->lang;
117 }
118 
119 const char *
120 vhost_default_mime(struct vhost *v, const char *path)
121 {
122 	struct location *loc;
123 	const char *default_mime = "application/octet-stream";
124 
125 	if (v == NULL || path == NULL)
126 		return default_mime;
127 
128 	loc = TAILQ_FIRST(&v->locations);
129 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
130 		if (loc->default_mime != NULL) {
131 			if (matches(loc->match, path))
132 				return loc->default_mime;
133 		}
134 	}
135 
136 	loc = TAILQ_FIRST(&v->locations);
137 	if (loc->default_mime != NULL)
138 		return loc->default_mime;
139 	return default_mime;
140 }
141 
142 const char *
143 vhost_index(struct vhost *v, const char *path)
144 {
145 	struct location *loc;
146 	const char *index = "index.gmi";
147 
148 	if (v == NULL || path == NULL)
149 		return index;
150 
151 	loc = TAILQ_FIRST(&v->locations);
152 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
153 		if (loc->index != NULL) {
154 			if (matches(loc->match, path))
155 				return loc->index;
156 		}
157 	}
158 
159 	loc = TAILQ_FIRST(&v->locations);
160 	if (loc->index != NULL)
161 		return loc->index;
162 	return index;
163 }
164 
165 int
166 vhost_auto_index(struct vhost *v, const char *path)
167 {
168 	struct location *loc;
169 
170 	if (v == NULL || path == NULL)
171 		return 0;
172 
173 	loc = TAILQ_FIRST(&v->locations);
174 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
175 		if (loc->auto_index != 0) {
176 			if (matches(loc->match, path))
177 				return loc->auto_index == 1;
178 		}
179 	}
180 
181 	loc = TAILQ_FIRST(&v->locations);
182 	return loc->auto_index == 1;
183 }
184 
185 int
186 vhost_block_return(struct vhost *v, const char *path, int *code, const char **fmt)
187 {
188 	struct location *loc;
189 
190 	if (v == NULL || path == NULL)
191 		return 0;
192 
193 	loc = TAILQ_FIRST(&v->locations);
194 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
195 		if (loc->block_code != 0) {
196 			if (matches(loc->match, path)) {
197 				*code = loc->block_code;
198 				*fmt = loc->block_fmt;
199 				return 1;
200 			}
201 		}
202 	}
203 
204 	loc = TAILQ_FIRST(&v->locations);
205 	*code = loc->block_code;
206 	*fmt = loc->block_fmt;
207 	return loc->block_code != 0;
208 }
209 
210 struct location *
211 vhost_reverse_proxy(struct vhost *v, const char *path)
212 {
213 	struct location *loc;
214 
215 	if (v == NULL || path == NULL)
216 		return NULL;
217 
218 	loc = TAILQ_FIRST(&v->locations);
219 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
220 		if (loc->proxy_host != NULL)
221 			if (matches(loc->match, path))
222 				return loc;
223 	}
224 
225 	loc = TAILQ_FIRST(&v->locations);
226 	if (loc->proxy_host != NULL)
227 		return loc;
228 	return NULL;
229 }
230 
231 int
232 vhost_fastcgi(struct vhost *v, const char *path)
233 {
234 	struct location *loc;
235 
236 	if (v == NULL || path == NULL)
237 		return -1;
238 
239 	loc = TAILQ_FIRST(&v->locations);
240 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
241 		if (loc->fcgi != -1)
242 			if (matches(loc->match, path))
243 				return loc->fcgi;
244 	}
245 
246 	loc = TAILQ_FIRST(&v->locations);
247 	return loc->fcgi;
248 }
249 
250 int
251 vhost_dirfd(struct vhost *v, const char *path, size_t *retloc)
252 {
253 	struct location *loc;
254 	size_t		 l = 0;
255 
256 	if (v == NULL || path == NULL)
257 		return -1;
258 
259 	loc = TAILQ_FIRST(&v->locations);
260 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
261 		l++;
262 		if (loc->dirfd != -1)
263 			if (matches(loc->match, path)) {
264 				*retloc = l;
265 				return loc->dirfd;
266 			}
267 	}
268 
269 	*retloc = 0;
270 	loc = TAILQ_FIRST(&v->locations);
271 	return loc->dirfd;
272 }
273 
274 int
275 vhost_strip(struct vhost *v, const char *path)
276 {
277 	struct location *loc;
278 
279 	if (v == NULL || path == NULL)
280 		return 0;
281 
282 	loc = TAILQ_FIRST(&v->locations);
283 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
284 		if (loc->strip != 0) {
285 			if (matches(loc->match, path))
286 				return loc->strip;
287 		}
288 	}
289 
290 	loc = TAILQ_FIRST(&v->locations);
291 	return loc->strip;
292 }
293 
294 X509_STORE *
295 vhost_require_ca(struct vhost *v, const char *path)
296 {
297 	struct location *loc;
298 
299 	if (v == NULL || path == NULL)
300 		return NULL;
301 
302 	loc = TAILQ_FIRST(&v->locations);
303 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
304 		if (loc->reqca != NULL) {
305 			if (matches(loc->match, path))
306 				return loc->reqca;
307 		}
308 	}
309 
310 	loc = TAILQ_FIRST(&v->locations);
311 	return loc->reqca;
312 }
313 
314 int
315 vhost_disable_log(struct vhost *v, const char *path)
316 {
317 	struct location *loc;
318 
319 	if (v == NULL || path == NULL)
320 		return 0;
321 
322 	loc = TAILQ_FIRST(&v->locations);
323 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
324 		if (loc->disable_log && matches(loc->match, path))
325 				return 1;
326 	}
327 
328 	loc = TAILQ_FIRST(&v->locations);
329 	return loc->disable_log;
330 }
331 
332 static int
333 check_path(struct client *c, const char *path, int *fd)
334 {
335 	struct stat sb;
336 	const char *p;
337 	int dirfd, strip;
338 
339 	assert(path != NULL);
340 
341 	/*
342 	 * in send_dir we add an initial / (to be redirect-friendly),
343 	 * but here we want to skip it
344 	 */
345 	if (*path == '/')
346 		path++;
347 
348 	strip = vhost_strip(c->host, path);
349 	p = strip_path(path, strip);
350 
351 	if (*p == '/')
352 		p = p+1;
353 	if (*p == '\0')
354 		p = ".";
355 
356 	dirfd = vhost_dirfd(c->host, path, &c->loc);
357 	log_debug(c, "check_path: strip=%d path=%s original=%s",
358 	    strip, p, path);
359 	if (*fd == -1 && (*fd = openat(dirfd, p, O_RDONLY)) == -1)
360 		return FILE_MISSING;
361 
362 	if (fstat(*fd, &sb) == -1) {
363 		log_notice(c, "failed stat for %s: %s", path, strerror(errno));
364 		return FILE_MISSING;
365 	}
366 
367 	if (S_ISDIR(sb.st_mode))
368 		return FILE_DIRECTORY;
369 
370 	if (sb.st_mode & S_IXUSR)
371 		return FILE_EXECUTABLE;
372 
373 	return FILE_EXISTS;
374 }
375 
376 static void
377 open_file(struct client *c)
378 {
379 	switch (check_path(c, c->iri.path, &c->pfd)) {
380 	case FILE_EXECUTABLE:
381 		if (c->host->cgi != NULL && matches(c->host->cgi, c->iri.path)) {
382 			start_cgi(c->iri.path, "", c);
383 			return;
384 		}
385 
386 		/* fallthrough */
387 
388 	case FILE_EXISTS:
389 		c->type = REQUEST_FILE;
390 		start_reply(c, SUCCESS, mime(c->host, c->iri.path));
391 		return;
392 
393 	case FILE_DIRECTORY:
394 		open_dir(c);
395 		return;
396 
397 	case FILE_MISSING:
398 		if (c->host->cgi != NULL && matches(c->host->cgi, c->iri.path)) {
399 			check_for_cgi(c);
400 			return;
401 		}
402 		start_reply(c, NOT_FOUND, "not found");
403 		return;
404 
405 	default:
406 		/* unreachable */
407 		abort();
408 	}
409 }
410 
411 /*
412  * the inverse of this algorithm, i.e. starting from the start of the
413  * path + strlen(cgi), and checking if each component, should be
414  * faster.  But it's tedious to write.  This does the opposite: starts
415  * from the end and strip one component at a time, until either an
416  * executable is found or we emptied the path.
417  */
418 static void
419 check_for_cgi(struct client *c)
420 {
421 	char path[PATH_MAX];
422 	char *end;
423 
424 	strlcpy(path, c->iri.path, sizeof(path));
425 	end = strchr(path, '\0');
426 
427 	while (end > path) {
428 		/*
429 		 * go up one level.  UNIX paths are simple and POSIX
430 		 * dirname, with its ambiguities on if the given
431 		 * pointer is changed or not, gives me headaches.
432 		 */
433 		while (*end != '/' && end > path)
434 			end--;
435 
436 		if (end == path)
437 			break;
438 
439 		*end = '\0';
440 
441 		switch (check_path(c, path, &c->pfd)) {
442 		case FILE_EXECUTABLE:
443 			start_cgi(path, end+1, c);
444 			return;
445 		case FILE_MISSING:
446 			break;
447 		default:
448 			goto err;
449 		}
450 
451 		*end = '/';
452 		end--;
453 	}
454 
455 err:
456 	start_reply(c, NOT_FOUND, "not found");
457 	return;
458 }
459 
460 void
461 mark_nonblock(int fd)
462 {
463 	int flags;
464 
465 	if ((flags = fcntl(fd, F_GETFL)) == -1)
466 		fatal("fcntl(F_GETFL): %s", strerror(errno));
467 	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
468 		fatal("fcntl(F_SETFL): %s", strerror(errno));
469 }
470 
471 static void
472 handle_handshake(int fd, short ev, void *d)
473 {
474 	struct client *c = d;
475 	struct vhost *h;
476 	struct alist *a;
477 	const char *servname;
478 	const char *parse_err = "unknown error";
479 
480 	switch (tls_handshake(c->ctx)) {
481 	case 0:  /* success */
482 	case -1: /* already handshaked */
483 		break;
484 	case TLS_WANT_POLLIN:
485 		event_once(c->fd, EV_READ, handle_handshake, c, NULL);
486 		return;
487 	case TLS_WANT_POLLOUT:
488 		event_once(c->fd, EV_WRITE, handle_handshake, c, NULL);
489 		return;
490 	default:
491 		/* unreachable */
492 		abort();
493 	}
494 
495 	c->bev = bufferevent_new(fd, client_read, client_write,
496 	    client_error, c);
497 	if (c->bev == NULL)
498 		fatal("%s: failed to allocate client buffer: %s",
499 		    __func__, strerror(errno));
500 
501 	event_set(&c->bev->ev_read, c->fd, EV_READ,
502 	    client_tls_readcb, c->bev);
503 	event_set(&c->bev->ev_write, c->fd, EV_WRITE,
504 	    client_tls_writecb, c->bev);
505 
506 #if HAVE_LIBEVENT2
507 	evbuffer_unfreeze(c->bev->input, 0);
508 	evbuffer_unfreeze(c->bev->output, 1);
509 #endif
510 
511 	if ((servname = tls_conn_servername(c->ctx)) == NULL) {
512 		log_debug(c, "handshake: missing SNI");
513 		goto err;
514 	}
515 
516 	if (!puny_decode(servname, c->domain, sizeof(c->domain), &parse_err)) {
517 		log_info(c, "puny_decode: %s", parse_err);
518 		goto err;
519 	}
520 
521 	TAILQ_FOREACH(h, &hosts, vhosts) {
522 		if (matches(h->domain, c->domain))
523 			goto found;
524 		TAILQ_FOREACH(a, &h->aliases, aliases) {
525 			if (matches(a->alias, c->domain))
526 				goto found;
527 		}
528 	}
529 
530 found:
531 	log_debug(c, "handshake: SNI: \"%s\"; decoded: \"%s\"; matched: \"%s\"",
532 	    servname != NULL ? servname : "(null)",
533 	    c->domain,
534 	    h != NULL ? h->domain : "(null)");
535 
536 	if (h != NULL) {
537 		c->host = h;
538 		bufferevent_enable(c->bev, EV_READ);
539 		return;
540 	}
541 
542 err:
543 	start_reply(c, BAD_REQUEST, "Wrong/malformed host or missing SNI");
544 }
545 
546 static const char *
547 strip_path(const char *path, int strip)
548 {
549 	char *t;
550 
551 	while (strip > 0) {
552 		if ((t = strchr(path, '/')) == NULL) {
553 			path = strchr(path, '\0');
554 			break;
555 		}
556 		path = t;
557 		strip--;
558 	}
559 
560 	return path;
561 }
562 
563 static void
564 fmt_sbuf(const char *fmt, struct client *c, const char *path)
565 {
566 	size_t i;
567 	char buf[32];
568 
569 	memset(buf, 0, sizeof(buf));
570 	for (i = 0; *fmt; ++fmt) {
571 		if (i == sizeof(buf)-1 || *fmt == '%') {
572 			strlcat(c->sbuf, buf, sizeof(c->sbuf));
573 			memset(buf, 0, sizeof(buf));
574 			i = 0;
575 		}
576 
577 		if (*fmt != '%') {
578 			buf[i++] = *fmt;
579 			continue;
580 		}
581 
582 		switch (*++fmt) {
583 		case '%':
584 			strlcat(c->sbuf, "%", sizeof(c->sbuf));
585 			break;
586 		case 'p':
587 			if (*path != '/')
588 				strlcat(c->sbuf, "/", sizeof(c->sbuf));
589 			strlcat(c->sbuf, path, sizeof(c->sbuf));
590 			break;
591 		case 'q':
592 			strlcat(c->sbuf, c->iri.query, sizeof(c->sbuf));
593 			break;
594 		case 'P':
595 			snprintf(buf, sizeof(buf), "%d", conf.port);
596 			strlcat(c->sbuf, buf, sizeof(c->sbuf));
597 			memset(buf, 0, sizeof(buf));
598 			break;
599 		case 'N':
600 			strlcat(c->sbuf, c->domain, sizeof(c->sbuf));
601 			break;
602 		default:
603 			fatal("%s: unknown fmt specifier %c",
604 			    __func__, *fmt);
605 		}
606 	}
607 
608 	if (i != 0)
609 		strlcat(c->sbuf, buf, sizeof(c->sbuf));
610 }
611 
612 /* 1 if a matching `block return' (and apply it), 0 otherwise */
613 static int
614 apply_block_return(struct client *c)
615 {
616 	const char *fmt, *path;
617 	int code;
618 
619 	if (!vhost_block_return(c->host, c->iri.path, &code, &fmt))
620 		return 0;
621 
622 	path = strip_path(c->iri.path, vhost_strip(c->host, c->iri.path));
623 	fmt_sbuf(fmt, c, path);
624 
625 	start_reply(c, code, c->sbuf);
626 	return 1;
627 }
628 
629 /* 1 if matching a proxy relay-to (and apply it), 0 otherwise */
630 static int
631 apply_reverse_proxy(struct client *c)
632 {
633 	struct location *loc;
634 	struct connreq r;
635 
636 	if ((loc = vhost_reverse_proxy(c->host, c->iri.path)) == NULL)
637 		return 0;
638 
639 	log_debug(c, "opening proxy connection for %s:%s",
640 	    loc->proxy_host, loc->proxy_port);
641 
642 	strlcpy(r.host, loc->proxy_host, sizeof(r.host));
643 	strlcpy(r.port, loc->proxy_port, sizeof(r.port));
644 
645 	strlcpy(c->domain, loc->proxy_host, sizeof(c->domain));
646 
647 	imsg_compose(&exibuf, IMSG_CONN_REQ, c->id, 0, -1, &r, sizeof(r));
648 	imsg_flush(&exibuf);
649 
650 	return 1;
651 }
652 
653 /* 1 if matching `fcgi' (and apply it), 0 otherwise */
654 static int
655 apply_fastcgi(struct client *c)
656 {
657 	int		 id;
658 	struct fcgi	*f;
659 
660 	if ((id = vhost_fastcgi(c->host, c->iri.path)) == -1)
661 		return 0;
662 
663 	f = &fcgi[id];
664 
665 	log_debug(c, "opening fastcgi connection for (%s,%s,%s)",
666 	    f->path, f->port, f->prog);
667 
668 	imsg_compose(&exibuf, IMSG_FCGI_REQ, c->id, 0, -1,
669 	    &id, sizeof(id));
670 	imsg_flush(&exibuf);
671 	return 1;
672 }
673 
674 /* 1 if matching `require client ca' fails (and apply it), 0 otherwise */
675 static int
676 apply_require_ca(struct client *c)
677 {
678 	X509_STORE	*store;
679 	const uint8_t	*cert;
680 	size_t		 len;
681 
682 	if ((store = vhost_require_ca(c->host, c->iri.path)) == NULL)
683 		return 0;
684 
685 	if (!tls_peer_cert_provided(c->ctx)) {
686 		start_reply(c, CLIENT_CERT_REQ, "client certificate required");
687 		return 1;
688 	}
689 
690 	cert = tls_peer_cert_chain_pem(c->ctx, &len);
691 	if (!validate_against_ca(store, cert, len)) {
692 		start_reply(c, CERT_NOT_AUTH, "certificate not authorised");
693 		return 1;
694 	}
695 
696 	return 0;
697 }
698 
699 static size_t
700 host_nth(struct vhost *h)
701 {
702 	struct vhost	*v;
703 	size_t		 i = 0;
704 
705 	TAILQ_FOREACH(v, &hosts, vhosts) {
706 		if (v == h)
707 			return i;
708 		i++;
709 	}
710 
711 	abort();
712 }
713 
714 static void
715 start_cgi(const char *spath, const char *relpath, struct client *c)
716 {
717 	char addr[NI_MAXHOST];
718 	const char *t;
719 	struct cgireq req;
720 	int e;
721 
722 	c->type = REQUEST_CGI;
723 
724 	e = getnameinfo((struct sockaddr*)&c->addr, sizeof(c->addr),
725 	    addr, sizeof(addr),
726 	    NULL, 0,
727 	    NI_NUMERICHOST);
728 	if (e != 0)
729 		fatal("getnameinfo failed");
730 
731 	memset(&req, 0, sizeof(req));
732 
733 	memcpy(req.buf, c->req, sizeof(req.buf));
734 
735 	req.iri_schema_off = c->iri.schema - c->req;
736 	req.iri_host_off = c->iri.host - c->req;
737 	req.iri_port_off = c->iri.port - c->req;
738 	req.iri_path_off = c->iri.path - c->req;
739 	req.iri_query_off = c->iri.query - c->req;
740 	req.iri_fragment_off = c->iri.fragment - c->req;
741 
742 	req.iri_portno = c->iri.port_no;
743 
744 	strlcpy(req.spath, spath, sizeof(req.spath));
745 	strlcpy(req.relpath, relpath, sizeof(req.relpath));
746 	strlcpy(req.addr, addr, sizeof(req.addr));
747 
748 	if ((t = tls_peer_cert_subject(c->ctx)) != NULL)
749 		strlcpy(req.subject, t, sizeof(req.subject));
750 	if ((t = tls_peer_cert_issuer(c->ctx)) != NULL)
751 		strlcpy(req.issuer, t, sizeof(req.issuer));
752 	if ((t = tls_peer_cert_hash(c->ctx)) != NULL)
753 		strlcpy(req.hash, t, sizeof(req.hash));
754 	if ((t = tls_conn_version(c->ctx)) != NULL)
755 		strlcpy(req.version, t, sizeof(req.version));
756 	if ((t = tls_conn_cipher(c->ctx)) != NULL)
757 		strlcpy(req.cipher, t, sizeof(req.cipher));
758 
759 	req.cipher_strength = tls_conn_cipher_strength(c->ctx);
760 	req.notbefore = tls_peer_cert_notbefore(c->ctx);
761 	req.notafter = tls_peer_cert_notafter(c->ctx);
762 
763 	req.host_off = host_nth(c->host);
764 	req.loc_off = c->loc;
765 
766 	imsg_compose(&exibuf, IMSG_CGI_REQ, c->id, 0, -1, &req, sizeof(req));
767 	imsg_flush(&exibuf);
768 
769 	close(c->pfd);
770 }
771 
772 static void
773 open_dir(struct client *c)
774 {
775 	size_t len;
776 	int dirfd, root;
777 	char *before_file;
778 
779 	root = !strcmp(c->iri.path, "/") || *c->iri.path == '\0';
780 
781 	len = strlen(c->iri.path);
782 	if (len > 0 && !ends_with(c->iri.path, "/")) {
783 		redirect_canonical_dir(c);
784 		return;
785 	}
786 
787 	strlcpy(c->sbuf, "/", sizeof(c->sbuf));
788 	strlcat(c->sbuf, c->iri.path, sizeof(c->sbuf));
789 	if (!ends_with(c->sbuf, "/"))
790 		strlcat(c->sbuf, "/", sizeof(c->sbuf));
791 	before_file = strchr(c->sbuf, '\0');
792 	len = strlcat(c->sbuf, vhost_index(c->host, c->iri.path),
793 	    sizeof(c->sbuf));
794 	if (len >= sizeof(c->sbuf)) {
795 		start_reply(c, TEMP_FAILURE, "internal server error");
796 		return;
797 	}
798 
799 	c->iri.path = c->sbuf;
800 
801 	/* close later unless we have to generate the dir listing */
802 	dirfd = c->pfd;
803 	c->pfd = -1;
804 
805 	switch (check_path(c, c->iri.path, &c->pfd)) {
806 	case FILE_EXECUTABLE:
807 		if (c->host->cgi != NULL && matches(c->host->cgi, c->iri.path)) {
808 			start_cgi(c->iri.path, "", c);
809 			break;
810 		}
811 
812 		/* fallthrough */
813 
814 	case FILE_EXISTS:
815 		c->type = REQUEST_FILE;
816 		start_reply(c, SUCCESS, mime(c->host, c->iri.path));
817 		break;
818 
819 	case FILE_DIRECTORY:
820 		start_reply(c, TEMP_REDIRECT, c->sbuf);
821 		break;
822 
823 	case FILE_MISSING:
824 		*before_file = '\0';
825 
826 		if (!vhost_auto_index(c->host, c->iri.path)) {
827 			start_reply(c, NOT_FOUND, "not found");
828 			break;
829 		}
830 
831 		c->type = REQUEST_DIR;
832 
833 		c->dirlen = scandir_fd(dirfd, &c->dir,
834 		    root ? select_non_dotdot : select_non_dot,
835 		    alphasort);
836 		if (c->dirlen == -1) {
837 			log_err(c, "scandir_fd(%d) (vhost:%s) %s: %s",
838 			    c->pfd, c->host->domain, c->iri.path, strerror(errno));
839 			start_reply(c, TEMP_FAILURE, "internal server error");
840 			return;
841 		}
842 		c->diroff = 0;
843 		c->off = 0;
844 
845 		start_reply(c, SUCCESS, "text/gemini");
846 		evbuffer_add_printf(EVBUFFER_OUTPUT(c->bev),
847 		    "# Index of %s\n\n", c->iri.path);
848 		return;
849 
850 	default:
851 		/* unreachable */
852 		abort();
853 	}
854 
855 	close(dirfd);
856 }
857 
858 static void
859 redirect_canonical_dir(struct client *c)
860 {
861 	size_t len;
862 
863 	strlcpy(c->sbuf, "/", sizeof(c->sbuf));
864 	strlcat(c->sbuf, c->iri.path, sizeof(c->sbuf));
865 	len = strlcat(c->sbuf, "/", sizeof(c->sbuf));
866 
867 	if (len >= sizeof(c->sbuf)) {
868 		start_reply(c, TEMP_FAILURE, "internal server error");
869 		return;
870 	}
871 
872 	start_reply(c, TEMP_REDIRECT, c->sbuf);
873 }
874 
875 static void
876 client_tls_readcb(int fd, short event, void *d)
877 {
878 	struct bufferevent	*bufev = d;
879 	struct client		*client = bufev->cbarg;
880 	ssize_t			 ret;
881 	size_t			 len;
882 	int			 what = EVBUFFER_READ;
883 	int			 howmuch = IBUF_READ_SIZE;
884 	char			 buf[IBUF_READ_SIZE];
885 
886 	if (event == EV_TIMEOUT) {
887 		what |= EVBUFFER_TIMEOUT;
888 		goto err;
889 	}
890 
891 	if (bufev->wm_read.high != 0)
892 		howmuch = MIN(sizeof(buf), bufev->wm_read.high);
893 
894 	switch (ret = tls_read(client->ctx, buf, howmuch)) {
895 	case TLS_WANT_POLLIN:
896 	case TLS_WANT_POLLOUT:
897 		goto retry;
898 	case -1:
899 		what |= EVBUFFER_ERROR;
900 		goto err;
901 	}
902 	len = ret;
903 
904 	if (len == 0) {
905 		what |= EVBUFFER_EOF;
906 		goto err;
907 	}
908 
909 	if (evbuffer_add(bufev->input, buf, len) == -1) {
910 		what |= EVBUFFER_ERROR;
911 		goto err;
912 	}
913 
914 	event_add(&bufev->ev_read, NULL);
915 	if (bufev->wm_read.low != 0 && len < bufev->wm_read.low)
916 		return;
917 	if (bufev->wm_read.high != 0 && len > bufev->wm_read.high) {
918 		/*
919 		 * here we could implement a read pressure policy.
920 		 */
921 	}
922 
923 	if (bufev->readcb != NULL)
924 		(*bufev->readcb)(bufev, bufev->cbarg);
925 
926 	return;
927 
928 retry:
929 	event_add(&bufev->ev_read, NULL);
930 	return;
931 
932 err:
933 	(*bufev->errorcb)(bufev, what, bufev->cbarg);
934 }
935 
936 static void
937 client_tls_writecb(int fd, short event, void *d)
938 {
939 	struct bufferevent	*bufev = d;
940 	struct client		*client = bufev->cbarg;
941 	ssize_t			 ret;
942 	size_t			 len;
943 	short			 what = EVBUFFER_WRITE;
944 
945 	if (event == EV_TIMEOUT) {
946 		what |= EVBUFFER_TIMEOUT;
947 		goto err;
948 	}
949 
950 	if (EVBUFFER_LENGTH(bufev->output) != 0) {
951 		ret = tls_write(client->ctx,
952 		    EVBUFFER_DATA(bufev->output),
953 		    EVBUFFER_LENGTH(bufev->output));
954 		switch (ret) {
955 		case TLS_WANT_POLLIN:
956 		case TLS_WANT_POLLOUT:
957 			goto retry;
958 		case -1:
959 			what |= EVBUFFER_ERROR;
960 			goto err;
961 		}
962 		len = ret;
963 		evbuffer_drain(bufev->output, len);
964 	}
965 
966 	if (EVBUFFER_LENGTH(bufev->output) != 0)
967 		event_add(&bufev->ev_write, NULL);
968 
969 	if (bufev->writecb != NULL &&
970 	    EVBUFFER_LENGTH(bufev->output) <= bufev->wm_write.low)
971 		(*bufev->writecb)(bufev, bufev->cbarg);
972 	return;
973 
974 retry:
975 	event_add(&bufev->ev_write, NULL);
976 	return;
977 err:
978 	log_err(client, "tls error: %s", tls_error(client->ctx));
979 	(*bufev->errorcb)(bufev, what, bufev->cbarg);
980 }
981 
982 static void
983 client_read(struct bufferevent *bev, void *d)
984 {
985 	struct client	*c = d;
986 	struct evbuffer	*src = EVBUFFER_INPUT(bev);
987 	const char	*parse_err = "invalid request";
988 	char		 decoded[DOMAIN_NAME_LEN];
989 	size_t		 len;
990 
991 	bufferevent_disable(bev, EVBUFFER_READ);
992 
993 	/* max url len + \r\n */
994 	if (EVBUFFER_LENGTH(src) > 1024 + 2) {
995 		log_err(c, "too much data received");
996 		start_reply(c, BAD_REQUEST, "bad request");
997 		return;
998 	}
999 
1000 	c->req = evbuffer_readln(src, &len, EVBUFFER_EOL_CRLF_STRICT);
1001 	if (c->req == NULL) {
1002 		/* not enough data yet. */
1003 		bufferevent_enable(bev, EVBUFFER_READ);
1004 		return;
1005 	}
1006 
1007 	if (!parse_iri(c->req, &c->iri, &parse_err) ||
1008 	    !puny_decode(c->iri.host, decoded, sizeof(decoded), &parse_err)) {
1009 		log_err(c, "IRI parse error: %s", parse_err);
1010 		start_reply(c, BAD_REQUEST, "bad request");
1011 		return;
1012 	}
1013 
1014 	if (apply_reverse_proxy(c))
1015 		return;
1016 
1017 	/* ignore the port number */
1018 	if (strcmp(c->iri.schema, "gemini") ||
1019 	    strcmp(decoded, c->domain)) {
1020 		start_reply(c, PROXY_REFUSED, "won't proxy request");
1021 		return;
1022 	}
1023 
1024 	if (apply_require_ca(c) ||
1025 	    apply_block_return(c)||
1026 	    apply_fastcgi(c))
1027 		return;
1028 
1029 	if (c->host->entrypoint != NULL) {
1030 		c->loc = 0;
1031 		start_cgi(c->host->entrypoint, c->iri.path, c);
1032 		return;
1033 	}
1034 
1035 	open_file(c);
1036 }
1037 
1038 void
1039 client_write(struct bufferevent *bev, void *d)
1040 {
1041 	struct client	*c = d;
1042 	struct evbuffer	*out = EVBUFFER_OUTPUT(bev);
1043 	char		 buf[BUFSIZ];
1044 	ssize_t		 r;
1045 
1046 	switch (c->type) {
1047 	case REQUEST_UNDECIDED:
1048 		/*
1049 		 * Ignore spurious calls when we still don't have idea
1050 		 * what to do with the request.
1051 		 */
1052 		break;
1053 
1054 	case REQUEST_FILE:
1055 		if ((r = read(c->pfd, buf, sizeof(buf))) == -1) {
1056 			log_warn(c, "read: %s", strerror(errno));
1057 			client_error(bev, EVBUFFER_ERROR, c);
1058 			return;
1059 		} else if (r == 0) {
1060 			client_close(c);
1061 			return;
1062 		} else if (r != sizeof(buf))
1063 			c->type = REQUEST_DONE;
1064 		bufferevent_write(bev, buf, r);
1065 		break;
1066 
1067 	case REQUEST_DIR:
1068 		/* TODO: handle big big directories better */
1069 		for (c->diroff = 0; c->diroff < c->dirlen; ++c->diroff) {
1070 			evbuffer_add_printf(out, "=> %s\n",
1071 			    c->dir[c->diroff]->d_name);
1072 			free(c->dir[c->diroff]);
1073 		}
1074 		free(c->dir);
1075 		c->dir = NULL;
1076 
1077 		c->type = REQUEST_DONE;
1078 
1079 		event_add(&c->bev->ev_write, NULL);
1080 		break;
1081 
1082 	case REQUEST_CGI:
1083 	case REQUEST_FCGI:
1084 	case REQUEST_PROXY:
1085 		/*
1086 		 *  Here we depend on on the cgi script or fastcgi
1087 		 *  connection to provide data.
1088 		 */
1089 		break;
1090 
1091 	case REQUEST_DONE:
1092 		if (EVBUFFER_LENGTH(out) == 0)
1093 			client_close(c);
1094 		break;
1095 	}
1096 }
1097 
1098 static void
1099 client_error(struct bufferevent *bev, short error, void *d)
1100 {
1101 	struct client	*c = d;
1102 
1103 	c->type = REQUEST_DONE;
1104 
1105 	if (error & EVBUFFER_TIMEOUT) {
1106 		log_warn(c, "timeout reached, "
1107 		    "forcefully closing the connection");
1108 		if (c->code == 0)
1109 			start_reply(c, BAD_REQUEST, "timeout");
1110 		else
1111 			client_close(c);
1112 		return;
1113 	}
1114 
1115 	if (error & EVBUFFER_EOF) {
1116 		client_close(c);
1117 		return;
1118 	}
1119 
1120 	log_err(c, "unknown bufferevent error: %s", strerror(errno));
1121 	client_close(c);
1122 }
1123 
1124 void
1125 start_reply(struct client *c, int code, const char *meta)
1126 {
1127 	struct evbuffer	*evb = EVBUFFER_OUTPUT(c->bev);
1128 	const char	*lang;
1129 	int		 r, rr;
1130 
1131 	bufferevent_enable(c->bev, EVBUFFER_WRITE);
1132 
1133 	c->code = code;
1134 	c->meta = meta;
1135 
1136 	r = evbuffer_add_printf(evb, "%d %s", code, meta);
1137 	if (r == -1)
1138 		goto err;
1139 
1140 	/* 2 digit status + space + 1024 max reply */
1141 	if (r > 1027)
1142 		goto overflow;
1143 
1144 	if (c->type != REQUEST_CGI &&
1145 	    c->type != REQUEST_FCGI &&
1146 	    c->type != REQUEST_PROXY &&
1147 	    !strcmp(meta, "text/gemini") &&
1148 	    (lang = vhost_lang(c->host, c->iri.path)) != NULL) {
1149 		rr = evbuffer_add_printf(evb, ";lang=%s", lang);
1150 		if (rr == -1)
1151 			goto err;
1152 		if (r + rr > 1027)
1153 			goto overflow;
1154 	}
1155 
1156 	bufferevent_write(c->bev, "\r\n", 2);
1157 
1158 	if (!vhost_disable_log(c->host, c->iri.path))
1159 		log_request(c, EVBUFFER_DATA(evb), EVBUFFER_LENGTH(evb));
1160 
1161 	if (code != 20 && IS_INTERNAL_REQUEST(c->type))
1162 		c->type = REQUEST_DONE;
1163 
1164 	return;
1165 
1166 err:
1167 	log_err(c, "evbuffer_add_printf error: no memory");
1168 	evbuffer_drain(evb, EVBUFFER_LENGTH(evb));
1169 	client_close(c);
1170 	return;
1171 
1172 overflow:
1173 	log_warn(c, "reply header overflow");
1174 	evbuffer_drain(evb, EVBUFFER_LENGTH(evb));
1175 	start_reply(c, TEMP_FAILURE, "internal error");
1176 }
1177 
1178 static void
1179 client_close_ev(int fd, short event, void *d)
1180 {
1181 	struct client	*c = d;
1182 
1183 	switch (tls_close(c->ctx)) {
1184 	case TLS_WANT_POLLIN:
1185 		event_once(c->fd, EV_READ, client_close_ev, c, NULL);
1186 		break;
1187 	case TLS_WANT_POLLOUT:
1188 		event_once(c->fd, EV_WRITE, client_close_ev, c, NULL);
1189 		break;
1190 	}
1191 
1192 	connected_clients--;
1193 
1194 	free(c->req);
1195 
1196 	tls_free(c->ctx);
1197 	c->ctx = NULL;
1198 
1199 	free(c->header);
1200 
1201 	if (c->pfd != -1)
1202 		close(c->pfd);
1203 
1204 	if (c->dir != NULL)
1205 		free(c->dir);
1206 
1207 	close(c->fd);
1208 	c->fd = -1;
1209 }
1210 
1211 static void
1212 client_proxy_close(int fd, short event, void *d)
1213 {
1214 	struct tls *ctx = d;
1215 
1216 	if (ctx == NULL) {
1217 		close(fd);
1218 		return;
1219 	}
1220 
1221 	switch (tls_close(ctx)) {
1222 	case TLS_WANT_POLLIN:
1223 		event_once(fd, EV_READ, client_proxy_close, d, NULL);
1224 		break;
1225 	case TLS_WANT_POLLOUT:
1226 		event_once(fd, EV_WRITE, client_proxy_close, d, NULL);
1227 		break;
1228 	}
1229 
1230 	tls_free(ctx);
1231 	close(fd);
1232 }
1233 
1234 void
1235 client_close(struct client *c)
1236 {
1237 	/*
1238 	 * We may end up calling client_close in various situations
1239 	 * and for the most unexpected reasons.  Therefore, we need to
1240 	 * ensure that everything is properly released once we reach
1241 	 * this point.
1242 	 */
1243 
1244 	SPLAY_REMOVE(client_tree_id, &clients, c);
1245 
1246 	if (c->cgibev != NULL) {
1247 		bufferevent_disable(c->cgibev, EVBUFFER_READ|EVBUFFER_WRITE);
1248 		bufferevent_free(c->cgibev);
1249 		c->cgibev = NULL;
1250 		close(c->pfd);
1251 		c->pfd = -1;
1252 	}
1253 
1254 	bufferevent_disable(c->bev, EVBUFFER_READ|EVBUFFER_WRITE);
1255 	bufferevent_free(c->bev);
1256 	c->bev = NULL;
1257 
1258 	if (c->proxybev != NULL) {
1259 		if (event_pending(&c->proxyev, EV_READ|EV_WRITE, NULL))
1260 			event_del(&c->proxyev);
1261 
1262 		if (c->pfd != -1) {
1263 			client_proxy_close(c->pfd, 0, c->proxyctx);
1264 			c->pfd = -1;
1265 		}
1266 
1267 		bufferevent_free(c->proxybev);
1268 	}
1269 
1270 	client_close_ev(c->fd, 0, c);
1271 }
1272 
1273 static void
1274 cgi_read(struct bufferevent *bev, void *d)
1275 {
1276 	struct client	*client = d;
1277 	struct evbuffer	*src = EVBUFFER_INPUT(bev);
1278 	char		*header;
1279 	size_t		 len;
1280 	int		 code;
1281 
1282 	/* intercept the header */
1283 	if (client->code == 0) {
1284 		header = evbuffer_readln(src, &len, EVBUFFER_EOL_CRLF_STRICT);
1285 		if (header == NULL) {
1286 			/* max reply + \r\n */
1287 			if (EVBUFFER_LENGTH(src) > 1026) {
1288 				log_warn(client, "CGI script is trying to "
1289 				    "send a header too long.");
1290 				cgi_error(bev, EVBUFFER_READ, client);
1291 			}
1292 
1293 			/* wait a bit */
1294 			return;
1295 		}
1296 
1297 		if (len < 3 || len > 1029 ||
1298 		    !isdigit(header[0]) ||
1299 		    !isdigit(header[1]) ||
1300 		    !isspace(header[2])) {
1301 			free(header);
1302 			log_warn(client, "CGI script is trying to send a "
1303 			    "malformed header");
1304 			cgi_error(bev, EVBUFFER_READ, client);
1305 			return;
1306 		}
1307 
1308 		client->header = header;
1309 		code = (header[0] - '0') * 10 + (header[1] - '0');
1310 
1311 		if (code < 10 || code >= 70) {
1312 			log_warn(client, "CGI script is trying to send an "
1313 			    "invalid reply code (%d)", code);
1314 			cgi_error(bev, EVBUFFER_READ, client);
1315 			return;
1316 		}
1317 
1318 		start_reply(client, code, header + 3);
1319 
1320 		if (client->code < 20 || client->code > 29) {
1321 			cgi_error(client->cgibev, EVBUFFER_EOF, client);
1322 			return;
1323 		}
1324 	}
1325 
1326 	bufferevent_write_buffer(client->bev, src);
1327 }
1328 
1329 static void
1330 cgi_write(struct bufferevent *bev, void *d)
1331 {
1332 	/*
1333 	 * Never called.  We don't send data to a CGI script.
1334 	 */
1335 	abort();
1336 }
1337 
1338 static void
1339 cgi_error(struct bufferevent *bev, short error, void *d)
1340 {
1341 	struct client	*client = d;
1342 
1343 	if (error & EVBUFFER_ERROR)
1344 		log_err(client, "%s: evbuffer error (%x): %s",
1345 		    __func__, error, strerror(errno));
1346 
1347 	bufferevent_disable(bev, EVBUFFER_READ|EVBUFFER_WRITE);
1348 	bufferevent_free(bev);
1349 	client->cgibev = NULL;
1350 
1351 	close(client->pfd);
1352 	client->pfd = -1;
1353 
1354 	client->type = REQUEST_DONE;
1355 	if (client->code != 0)
1356 		client_write(client->bev, client);
1357 	else
1358 		start_reply(client, CGI_ERROR, "CGI error");
1359 }
1360 
1361 static void
1362 do_accept(int sock, short et, void *d)
1363 {
1364 	struct client *c;
1365 	struct sockaddr_storage addr;
1366 	struct sockaddr *saddr;
1367 	socklen_t len;
1368 	int fd;
1369 
1370 	saddr = (struct sockaddr*)&addr;
1371 	len = sizeof(addr);
1372 	if ((fd = accept(sock, saddr, &len)) == -1) {
1373 		if (errno == EWOULDBLOCK || errno == EAGAIN ||
1374 		    errno == ECONNABORTED)
1375 			return;
1376 		fatal("accept: %s", strerror(errno));
1377 	}
1378 
1379 	mark_nonblock(fd);
1380 
1381 	c = xcalloc(1, sizeof(*c));
1382 	c->id = ++server_client_id;
1383 	c->fd = fd;
1384 	c->pfd = -1;
1385 	c->addr = addr;
1386 
1387 	if (tls_accept_socket(ctx, &c->ctx, fd) == -1) {
1388 		log_warn(c, "failed to accept socket: %s", tls_error(c->ctx));
1389 		close(c->fd);
1390 		free(c);
1391 		return;
1392 	}
1393 
1394 	SPLAY_INSERT(client_tree_id, &clients, c);
1395 	event_once(c->fd, EV_READ|EV_WRITE, handle_handshake, c, NULL);
1396 	connected_clients++;
1397 }
1398 
1399 static struct client *
1400 client_by_id(int id)
1401 {
1402 	struct client *c;
1403 
1404 	if ((c = try_client_by_id(id)) == NULL)
1405 		fatal("in client_by_id: invalid id %d", id);
1406 	return c;
1407 }
1408 
1409 struct client *
1410 try_client_by_id(int id)
1411 {
1412 	struct client find;
1413 
1414 	find.id = id;
1415 	return SPLAY_FIND(client_tree_id, &clients, &find);
1416 }
1417 
1418 static void
1419 handle_imsg_cgi_res(struct imsgbuf *ibuf, struct imsg *imsg, size_t len)
1420 {
1421 	struct client *c;
1422 
1423 	c = client_by_id(imsg->hdr.peerid);
1424 
1425 	if ((c->pfd = imsg->fd) == -1) {
1426 		start_reply(c, TEMP_FAILURE, "internal server error");
1427 		return;
1428 	}
1429 
1430 	c->type = REQUEST_CGI;
1431 
1432 	c->cgibev = bufferevent_new(c->pfd, cgi_read, cgi_write,
1433 	    cgi_error, c);
1434 
1435 	bufferevent_enable(c->cgibev, EV_READ);
1436 }
1437 
1438 static void
1439 handle_imsg_fcgi_fd(struct imsgbuf *ibuf, struct imsg *imsg, size_t len)
1440 {
1441 	struct client	*c;
1442 	int		 id;
1443 
1444 	id = imsg->hdr.peerid;
1445 
1446 	if ((c = try_client_by_id(id)) == NULL) {
1447 		if (imsg->fd != -1)
1448 			close(imsg->fd);
1449 		return;
1450 	}
1451 
1452 	if ((c->pfd = imsg->fd) == -1) {
1453 		start_reply(c, CGI_ERROR, "CGI error");
1454 		return;
1455 	}
1456 
1457 	mark_nonblock(c->pfd);
1458 
1459 	c->cgibev = bufferevent_new(c->pfd, fcgi_read, fcgi_write,
1460 	    fcgi_error, c);
1461 	if (c->cgibev == NULL) {
1462 		start_reply(c, TEMP_FAILURE, "internal server error");
1463 		return;
1464 	}
1465 
1466 	bufferevent_enable(c->cgibev, EV_READ|EV_WRITE);
1467 	fcgi_req(c);
1468 }
1469 
1470 static void
1471 handle_imsg_conn_fd(struct imsgbuf *ibuf, struct imsg *imsg, size_t len)
1472 {
1473 	struct client	*c;
1474 	int		 id;
1475 
1476 	id = imsg->hdr.peerid;
1477 	if ((c = try_client_by_id(id)) == NULL) {
1478 		if (imsg->fd != -1)
1479 			close(imsg->fd);
1480 		return;
1481 	}
1482 
1483 	if ((c->pfd = imsg->fd) == -1) {
1484 		start_reply(c, PROXY_ERROR, "proxy error");
1485 		return;
1486 	}
1487 
1488 	mark_nonblock(c->pfd);
1489 
1490 	if (proxy_init(c) == -1)
1491 		start_reply(c, PROXY_ERROR, "proxy error");
1492 }
1493 
1494 static void
1495 handle_imsg_quit(struct imsgbuf *ibuf, struct imsg *imsg, size_t len)
1496 {
1497 	/*
1498 	 * don't call event_loopbreak since we want to finish to
1499 	 * handle the ongoing connections.
1500 	 */
1501 
1502 	shutting_down = 1;
1503 
1504 	event_del(&e4);
1505 	if (has_ipv6)
1506 		event_del(&e6);
1507 	if (has_siginfo)
1508 		signal_del(&siginfo);
1509 	event_del(&imsgev);
1510 	signal_del(&sigusr2);
1511 }
1512 
1513 static void
1514 handle_dispatch_imsg(int fd, short ev, void *d)
1515 {
1516 	struct imsgbuf *ibuf = d;
1517 	dispatch_imsg(ibuf, handlers, sizeof(handlers));
1518 }
1519 
1520 static void
1521 handle_siginfo(int fd, short ev, void *d)
1522 {
1523 	log_info(NULL, "%d connected clients", connected_clients);
1524 }
1525 
1526 void
1527 loop(struct tls *ctx_, int sock4, int sock6, struct imsgbuf *ibuf)
1528 {
1529 	ctx = ctx_;
1530 
1531 	SPLAY_INIT(&clients);
1532 
1533 	event_init();
1534 
1535 	event_set(&e4, sock4, EV_READ | EV_PERSIST, &do_accept, NULL);
1536 	event_add(&e4, NULL);
1537 
1538 	if (sock6 != -1) {
1539 		has_ipv6 = 1;
1540 		event_set(&e6, sock6, EV_READ | EV_PERSIST, &do_accept, NULL);
1541 		event_add(&e6, NULL);
1542 	}
1543 
1544 	event_set(&imsgev, ibuf->fd, EV_READ | EV_PERSIST, handle_dispatch_imsg, ibuf);
1545 	event_add(&imsgev, NULL);
1546 
1547 #ifdef SIGINFO
1548 	has_siginfo = 1;
1549 	signal_set(&siginfo, SIGINFO, &handle_siginfo, NULL);
1550 	signal_add(&siginfo, NULL);
1551 #endif
1552 	signal_set(&sigusr2, SIGUSR2, &handle_siginfo, NULL);
1553 	signal_add(&sigusr2, NULL);
1554 
1555 	sandbox_server_process();
1556 	event_dispatch();
1557 	_exit(0);
1558 }
1559 
1560 int
1561 client_tree_cmp(struct client *a, struct client *b)
1562 {
1563 	if (a->id == b->id)
1564 		return 0;
1565 	else if (a->id < b->id)
1566 		return -1;
1567 	else
1568 		return +1;
1569 }
1570 
1571 SPLAY_GENERATE(client_tree_id, client, entry, client_tree_cmp)