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