op public repos

Blob

Date:: Sat May 15 10:07:21 2021 UTC
Message:: const-ify strip_path
Actions:: History | Blame | Raw File
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 <errno.h>
23 #include <event.h>
24 #include <fcntl.h>
25 #include <fnmatch.h>
26 #include <limits.h>
27 #include <string.h>
28 
29 struct client	 clients[MAX_USERS];
30 
31 static struct tls	*ctx;
32 
33 static struct event e4, e6, imsgev, siginfo, sigusr2;
34 static int has_ipv6, has_siginfo;
35 
36 int connected_clients;
37 
38 static inline int matches(const char*, const char*);
39 
40 static inline void yield_read(int, struct client*, statefn);
41 static inline void yield_write(int, struct client*, statefn);
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_require_ca(struct client*);
51 static void	 handle_open_conn(int, short, void*);
52 static void	 handle_start_reply(int, short, void*);
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 static void	 enter_handle_dirlist(int, short, void*);
58 static void	 handle_dirlist(int, short, void*);
59 static int 	 read_next_dir_entry(struct client*);
60 static void	 send_directory_listing(int, short, void*);
61 static void	 handle_cgi_reply(int, short, void*);
62 static void	 handle_copy(int, short, void*);
63 static void	 do_accept(int, short, void*);
64 static void	 handle_imsg_cgi_res(struct imsgbuf*, struct imsg*, size_t);
65 static void	 handle_imsg_fcgi_fd(struct imsgbuf*, struct imsg*, size_t);
66 static void	 handle_imsg_quit(struct imsgbuf*, struct imsg*, size_t);
67 static void	 handle_siginfo(int, short, void*);
68 
69 static imsg_handlerfn *handlers[] = {
70 	[IMSG_QUIT] = handle_imsg_quit,
71 	[IMSG_CGI_RES] = handle_imsg_cgi_res,
72 	[IMSG_FCGI_FD] = handle_imsg_fcgi_fd,
73 };
74 
75 static inline int
76 matches(const char *pattern, const char *path)
77 {
78 	if (*path == '/')
79 		path++;
80 	return !fnmatch(pattern, path, 0);
81 }
82 
83 static inline void
84 yield_read(int fd, struct client *c, statefn fn)
85 {
86 	event_once(fd, EV_READ, fn, c, NULL);
87 }
88 
89 static inline void
90 yield_write(int fd, struct client *c, statefn fn)
91 {
92 	event_once(fd, EV_WRITE, fn, c, NULL);
93 }
94 
95 const char *
96 vhost_lang(struct vhost *v, const char *path)
97 {
98 	struct location *loc;
99 
100 	if (v == NULL || path == NULL)
101 		return NULL;
102 
103 	loc = TAILQ_FIRST(&v->locations);
104 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
105 		if (loc->lang != NULL) {
106 			if (matches(loc->match, path))
107 				return loc->lang;
108 		}
109 	}
110 
111 	return TAILQ_FIRST(&v->locations)->lang;
112 }
113 
114 const char *
115 vhost_default_mime(struct vhost *v, const char *path)
116 {
117 	struct location *loc;
118 	const char *default_mime = "application/octet-stream";
119 
120 	if (v == NULL || path == NULL)
121 		return default_mime;
122 
123 	loc = TAILQ_FIRST(&v->locations);
124 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
125 		if (loc->default_mime != NULL) {
126 			if (matches(loc->match, path))
127 				return loc->default_mime;
128 		}
129 	}
130 
131 	loc = TAILQ_FIRST(&v->locations);
132 	if (loc->default_mime != NULL)
133 		return loc->default_mime;
134 	return default_mime;
135 }
136 
137 const char *
138 vhost_index(struct vhost *v, const char *path)
139 {
140 	struct location *loc;
141 	const char *index = "index.gmi";
142 
143 	if (v == NULL || path == NULL)
144 		return index;
145 
146 	loc = TAILQ_FIRST(&v->locations);
147 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
148 		if (loc->index != NULL) {
149 			if (matches(loc->match, path))
150 				return loc->index;
151 		}
152 	}
153 
154 	loc = TAILQ_FIRST(&v->locations);
155 	if (loc->index != NULL)
156 		return loc->index;
157 	return index;
158 }
159 
160 int
161 vhost_auto_index(struct vhost *v, const char *path)
162 {
163 	struct location *loc;
164 
165 	if (v == NULL || path == NULL)
166 		return 0;
167 
168 	loc = TAILQ_FIRST(&v->locations);
169 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
170 		if (loc->auto_index != 0) {
171 			if (matches(loc->match, path))
172 				return loc->auto_index == 1;
173 		}
174 	}
175 
176 	loc = TAILQ_FIRST(&v->locations);
177 	return loc->auto_index == 1;
178 }
179 
180 int
181 vhost_block_return(struct vhost *v, const char *path, int *code, const char **fmt)
182 {
183 	struct location *loc;
184 
185 	if (v == NULL || path == NULL)
186 		return 0;
187 
188 	loc = TAILQ_FIRST(&v->locations);
189 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
190 		if (loc->block_code != 0) {
191 			if (matches(loc->match, path)) {
192 				*code = loc->block_code;
193 				*fmt = loc->block_fmt;
194 				return 1;
195 			}
196 		}
197 	}
198 
199 	loc = TAILQ_FIRST(&v->locations);
200 	*code = loc->block_code;
201 	*fmt = loc->block_fmt;
202 	return loc->block_code != 0;
203 }
204 
205 int
206 vhost_fastcgi(struct vhost *v, const char *path)
207 {
208 	struct location *loc;
209 
210 	if (v == NULL || path == NULL)
211 		return -1;
212 
213 	loc = TAILQ_FIRST(&v->locations);
214 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
215 		if (loc->fcgi != -1)
216 			if (matches(loc->match, path))
217 				return loc->fcgi;
218 	}
219 
220 	loc = TAILQ_FIRST(&v->locations);
221 	return loc->fcgi;
222 }
223 
224 int
225 vhost_dirfd(struct vhost *v, const char *path)
226 {
227 	struct location *loc;
228 
229 	if (v == NULL || path == NULL)
230 		return -1;
231 
232 	loc = TAILQ_FIRST(&v->locations);
233 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
234 		if (loc->dirfd != -1)
235 			if (matches(loc->match, path))
236 				return loc->dirfd;
237 	}
238 
239 	loc = TAILQ_FIRST(&v->locations);
240 	return loc->dirfd;
241 }
242 
243 int
244 vhost_strip(struct vhost *v, const char *path)
245 {
246 	struct location *loc;
247 
248 	if (v == NULL || path == NULL)
249 		return 0;
250 
251 	loc = TAILQ_FIRST(&v->locations);
252 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
253 		if (loc->strip != 0) {
254 			if (matches(loc->match, path))
255 				return loc->strip;
256 		}
257 	}
258 
259 	loc = TAILQ_FIRST(&v->locations);
260 	return loc->strip;
261 }
262 
263 X509_STORE *
264 vhost_require_ca(struct vhost *v, const char *path)
265 {
266 	struct location *loc;
267 
268 	if (v == NULL || path == NULL)
269 		return NULL;
270 
271 	loc = TAILQ_FIRST(&v->locations);
272 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
273 		if (loc->reqca != NULL) {
274 			if (matches(loc->match, path))
275 				return loc->reqca;
276 		}
277 	}
278 
279 	loc = TAILQ_FIRST(&v->locations);
280 	return loc->reqca;
281 }
282 
283 int
284 vhost_disable_log(struct vhost *v, const char *path)
285 {
286 	struct location *loc;
287 
288 	if (v == NULL || path == NULL)
289 		return 0;
290 
291 	loc = TAILQ_FIRST(&v->locations);
292 	while ((loc = TAILQ_NEXT(loc, locations)) != NULL) {
293 		if (loc->disable_log && matches(loc->match, path))
294 				return 1;
295 	}
296 
297 	loc = TAILQ_FIRST(&v->locations);
298 	return loc->disable_log;
299 }
300 
301 static int
302 check_path(struct client *c, const char *path, int *fd)
303 {
304 	struct stat sb;
305 	const char *p;
306 	int flags, dirfd, strip;
307 
308 	assert(path != NULL);
309 
310 	/*
311 	 * in send_dir we add an initial / (to be redirect-friendly),
312 	 * but here we want to skip it
313 	 */
314 	if (*path == '/')
315 		path++;
316 
317 	strip = vhost_strip(c->host, path);
318 	p = strip_path(path, strip);
319 
320 	if (*p == '/')
321 		p = p+1;
322 	if (*p == '\0')
323 		p = ".";
324 
325 	dirfd = vhost_dirfd(c->host, path);
326 	log_debug(c, "check_path: strip=%d path=%s original=%s",
327 	    strip, p, path);
328 	flags = O_RDONLY | O_NOFOLLOW;
329 	if (*fd == -1 && (*fd = openat(dirfd, p, flags)) == -1)
330 		return FILE_MISSING;
331 
332 	if (fstat(*fd, &sb) == -1) {
333 		log_notice(c, "failed stat for %s: %s", path, strerror(errno));
334 		return FILE_MISSING;
335 	}
336 
337 	if (S_ISDIR(sb.st_mode))
338 		return FILE_DIRECTORY;
339 
340 	if (sb.st_mode & S_IXUSR)
341 		return FILE_EXECUTABLE;
342 
343 	return FILE_EXISTS;
344 }
345 
346 static void
347 open_file(struct client *c)
348 {
349 	switch (check_path(c, c->iri.path, &c->pfd)) {
350 	case FILE_EXECUTABLE:
351 		if (c->host->cgi != NULL && matches(c->host->cgi, c->iri.path)) {
352 			start_cgi(c->iri.path, "", c);
353 			return;
354 		}
355 
356 		/* fallthrough */
357 
358 	case FILE_EXISTS:
359 		c->next = handle_copy;
360 		start_reply(c, SUCCESS, mime(c->host, c->iri.path));
361 		return;
362 
363 	case FILE_DIRECTORY:
364 		open_dir(c);
365 		return;
366 
367 	case FILE_MISSING:
368 		if (c->host->cgi != NULL && matches(c->host->cgi, c->iri.path)) {
369 			check_for_cgi(c);
370 			return;
371 		}
372 		start_reply(c, NOT_FOUND, "not found");
373 		return;
374 
375 	default:
376 		/* unreachable */
377 		abort();
378 	}
379 }
380 
381 /*
382  * the inverse of this algorithm, i.e. starting from the start of the
383  * path + strlen(cgi), and checking if each component, should be
384  * faster.  But it's tedious to write.  This does the opposite: starts
385  * from the end and strip one component at a time, until either an
386  * executable is found or we emptied the path.
387  */
388 static void
389 check_for_cgi(struct client *c)
390 {
391 	char path[PATH_MAX];
392 	char *end;
393 
394 	strlcpy(path, c->iri.path, sizeof(path));
395 	end = strchr(path, '\0');
396 
397 	while (end > path) {
398 		/*
399 		 * go up one level.  UNIX paths are simple and POSIX
400 		 * dirname, with its ambiguities on if the given
401 		 * pointer is changed or not, gives me headaches.
402 		 */
403 		while (*end != '/')
404 			end--;
405 		*end = '\0';
406 
407 		switch (check_path(c, path, &c->pfd)) {
408 		case FILE_EXECUTABLE:
409 			start_cgi(path, end+1, c);
410 			return;
411 		case FILE_MISSING:
412 			break;
413 		default:
414 			goto err;
415 		}
416 
417 		*end = '/';
418 		end--;
419 	}
420 
421 err:
422 	start_reply(c, NOT_FOUND, "not found");
423 	return;
424 }
425 
426 void
427 mark_nonblock(int fd)
428 {
429 	int flags;
430 
431 	if ((flags = fcntl(fd, F_GETFL)) == -1)
432 		fatal("fcntl(F_GETFL): %s", strerror(errno));
433 	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
434 		fatal("fcntl(F_SETFL): %s", strerror(errno));
435 }
436 
437 static void
438 handle_handshake(int fd, short ev, void *d)
439 {
440 	struct client *c = d;
441 	struct vhost *h;
442 	struct alist *a;
443 	const char *servname;
444 	const char *parse_err = "unknown error";
445 
446 	switch (tls_handshake(c->ctx)) {
447 	case 0:  /* success */
448 	case -1: /* already handshaked */
449 		break;
450 	case TLS_WANT_POLLIN:
451 		yield_read(fd, c, &handle_handshake);
452 		return;
453 	case TLS_WANT_POLLOUT:
454 		yield_write(fd, c, &handle_handshake);
455 		return;
456 	default:
457 		/* unreachable */
458 		abort();
459 	}
460 
461 	servname = tls_conn_servername(c->ctx);
462 	if (!puny_decode(servname, c->domain, sizeof(c->domain), &parse_err)) {
463 		log_info(c, "puny_decode: %s", parse_err);
464 		goto err;
465 	}
466 
467 	TAILQ_FOREACH(h, &hosts, vhosts) {
468 		if (matches(h->domain, c->domain))
469 			goto found;
470 		TAILQ_FOREACH(a, &h->aliases, aliases) {
471 			if (matches(a->alias, c->domain))
472 				goto found;
473 		}
474 	}
475 
476 found:
477 	log_debug(c, "handshake: SNI: \"%s\"; decoded: \"%s\"; matched: \"%s\"",
478 	    servname != NULL ? servname : "(null)",
479 	    c->domain,
480 	    h != NULL ? h->domain : "(null)");
481 
482 	if (h != NULL) {
483 		c->host = h;
484 		handle_open_conn(fd, ev, c);
485 		return;
486 	}
487 
488 err:
489 	if (servname != NULL)
490 		strncpy(c->req, servname, sizeof(c->req));
491 	else
492 		strncpy(c->req, "null", sizeof(c->req));
493 
494 	start_reply(c, BAD_REQUEST, "Wrong/malformed host or missing SNI");
495 }
496 
497 static const char *
498 strip_path(const char *path, int strip)
499 {
500 	char *t;
501 
502 	while (strip > 0) {
503 		if ((t = strchr(path, '/')) == NULL) {
504 			path = strchr(path, '\0');
505 			break;
506 		}
507 		path = t;
508 		strip--;
509 	}
510 
511 	return path;
512 }
513 
514 static void
515 fmt_sbuf(const char *fmt, struct client *c, const char *path)
516 {
517 	size_t i;
518         char buf[32];
519 
520 	memset(buf, 0, sizeof(buf));
521 	for (i = 0; *fmt; ++fmt) {
522 		if (i == sizeof(buf)-1 || *fmt == '%') {
523 			strlcat(c->sbuf, buf, sizeof(c->sbuf));
524 			memset(buf, 0, sizeof(buf));
525 			i = 0;
526 		}
527 
528 		if (*fmt != '%') {
529 			buf[i++] = *fmt;
530 			continue;
531 		}
532 
533 		switch (*++fmt) {
534 		case '%':
535 			strlcat(c->sbuf, "%", sizeof(c->sbuf));
536 			break;
537 		case 'p':
538 			if (*path != '/')
539 				strlcat(c->sbuf, "/", sizeof(c->sbuf));
540 			strlcat(c->sbuf, path, sizeof(c->sbuf));
541 			break;
542 		case 'q':
543 			strlcat(c->sbuf, c->iri.query, sizeof(c->sbuf));
544 			break;
545 		case 'P':
546 			snprintf(buf, sizeof(buf), "%d", conf.port);
547 			strlcat(c->sbuf, buf, sizeof(c->sbuf));
548 			memset(buf, 0, sizeof(buf));
549 			break;
550 		case 'N':
551 			strlcat(c->sbuf, c->domain, sizeof(c->sbuf));
552 			break;
553 		default:
554 			fatal("%s: unknown fmt specifier %c",
555 			    __func__, *fmt);
556 		}
557 	}
558 
559 	if (i != 0)
560 		strlcat(c->sbuf, buf, sizeof(c->sbuf));
561 }
562 
563 /* 1 if a matching `block return' (and apply it), 0 otherwise */
564 static int
565 apply_block_return(struct client *c)
566 {
567 	const char *fmt, *path;
568 	int code;
569 
570 	if (!vhost_block_return(c->host, c->iri.path, &code, &fmt))
571 		return 0;
572 
573 	path = strip_path(c->iri.path, vhost_strip(c->host, c->iri.path));
574 	fmt_sbuf(fmt, c, path);
575 
576 	start_reply(c, code, c->sbuf);
577 	return 1;
578 }
579 
580 /* 1 if matching `fcgi' (and apply it), 0 otherwise */
581 static int
582 apply_fastcgi(struct client *c)
583 {
584 	int		 id;
585 	struct fcgi	*f;
586 
587 	if ((id = vhost_fastcgi(c->host, c->iri.path)) == -1)
588 		return 0;
589 
590 	switch ((f = &fcgi[id])->s) {
591 	case FCGI_OFF:
592 		f->s = FCGI_INFLIGHT;
593 		log_info(c, "opening fastcgi connection for (%s,%s,%s)",
594 		    f->path, f->port, f->prog);
595 		imsg_compose(&exibuf, IMSG_FCGI_REQ, 0, 0, -1,
596 		    &id, sizeof(id));
597 		imsg_flush(&exibuf);
598                 /* fallthrough */
599 	case FCGI_INFLIGHT:
600                 c->fcgi = id;
601 		break;
602 	case FCGI_READY:
603                 c->fcgi = id;
604 		send_fcgi_req(f, c);
605 		break;
606 	}
607 
608 	return 1;
609 }
610 
611 /* 1 if matching `require client ca' fails (and apply it), 0 otherwise */
612 static int
613 apply_require_ca(struct client *c)
614 {
615 	X509_STORE	*store;
616 	const uint8_t	*cert;
617 	size_t		 len;
618 
619 	if ((store = vhost_require_ca(c->host, c->iri.path)) == NULL)
620 		return 0;
621 
622 	if (!tls_peer_cert_provided(c->ctx)) {
623 		start_reply(c, CLIENT_CERT_REQ, "client certificate required");
624 		return 1;
625 	}
626 
627 	cert = tls_peer_cert_chain_pem(c->ctx, &len);
628 	if (!validate_against_ca(store, cert, len)) {
629 		start_reply(c, CERT_NOT_AUTH, "certificate not authorised");
630 		return 1;
631 	}
632 
633 	return 0;
634 }
635 
636 static void
637 handle_open_conn(int fd, short ev, void *d)
638 {
639 	struct client *c = d;
640 	const char *parse_err = "invalid request";
641 	char decoded[DOMAIN_NAME_LEN];
642 
643 	bzero(c->req, sizeof(c->req));
644 	bzero(&c->iri, sizeof(c->iri));
645 
646 	switch (tls_read(c->ctx, c->req, sizeof(c->req)-1)) {
647 	case -1:
648 		log_err(c, "tls_read: %s", tls_error(c->ctx));
649 		close_conn(fd, ev, c);
650 		return;
651 
652 	case TLS_WANT_POLLIN:
653 		yield_read(fd, c, &handle_open_conn);
654 		return;
655 
656 	case TLS_WANT_POLLOUT:
657 		yield_write(fd, c, &handle_open_conn);
658 		return;
659 	}
660 
661 	if (!trim_req_iri(c->req, &parse_err)
662 	    || !parse_iri(c->req, &c->iri, &parse_err)
663 	    || !puny_decode(c->iri.host, decoded, sizeof(decoded), &parse_err)) {
664 		log_info(c, "iri parse error: %s", parse_err);
665 		start_reply(c, BAD_REQUEST, "invalid request");
666 		return;
667 	}
668 
669 	if (c->iri.port_no != conf.port
670 	    || strcmp(c->iri.schema, "gemini")
671 	    || strcmp(decoded, c->domain)) {
672 		start_reply(c, PROXY_REFUSED, "won't proxy request");
673 		return;
674 	}
675 
676 	if (apply_require_ca(c))
677 		return;
678 
679 	if (apply_block_return(c))
680 		return;
681 
682 	if (apply_fastcgi(c))
683 		return;
684 
685 	if (c->host->entrypoint != NULL) {
686 		start_cgi(c->host->entrypoint, c->iri.path, c);
687 		return;
688 	}
689 
690 	open_file(c);
691 }
692 
693 void
694 start_reply(struct client *c, int code, const char *meta)
695 {
696 	c->code = code;
697 	c->meta = meta;
698 	handle_start_reply(c->fd, 0, c);
699 }
700 
701 static void
702 handle_start_reply(int fd, short ev, void *d)
703 {
704 	struct client *c = d;
705 	char buf[1030];		/* status + ' ' + max reply len + \r\n\0 */
706 	const char *lang;
707 	size_t len;
708 
709 	lang = vhost_lang(c->host, c->iri.path);
710 
711 	snprintf(buf, sizeof(buf), "%d ", c->code);
712 	strlcat(buf, c->meta, sizeof(buf));
713 	if (!strcmp(c->meta, "text/gemini") && lang != NULL) {
714 		strlcat(buf, "; lang=", sizeof(buf));
715 		strlcat(buf, lang, sizeof(buf));
716 	}
717 
718 	len = strlcat(buf, "\r\n", sizeof(buf));
719 	assert(len < sizeof(buf));
720 
721 	switch (tls_write(c->ctx, buf, len)) {
722 	case -1:
723 		close_conn(fd, ev, c);
724 		return;
725 	case TLS_WANT_POLLIN:
726 		yield_read(fd, c, &handle_start_reply);
727 		return;
728 	case TLS_WANT_POLLOUT:
729 		yield_write(fd, c, &handle_start_reply);
730 		return;
731 	}
732 
733 	if (!vhost_disable_log(c->host, c->iri.path))
734 		log_request(c, buf, sizeof(buf));
735 
736 	if (c->code != SUCCESS)
737 		close_conn(fd, ev, c);
738 	else
739 		c->next(fd, ev, c);
740 }
741 
742 static size_t
743 host_nth(struct vhost *h)
744 {
745 	struct vhost	*v;
746 	size_t		 i = 0;
747 
748 	TAILQ_FOREACH(v, &hosts, vhosts) {
749 		if (v == h)
750 			return i;
751 		i++;
752 	}
753 
754 	abort();
755 }
756 
757 static void
758 start_cgi(const char *spath, const char *relpath, struct client *c)
759 {
760 	char addr[NI_MAXHOST];
761 	const char *t;
762 	struct cgireq req;
763 	int e;
764 
765 	e = getnameinfo((struct sockaddr*)&c->addr, sizeof(c->addr),
766 	    addr, sizeof(addr),
767 	    NULL, 0,
768 	    NI_NUMERICHOST);
769 	if (e != 0)
770 		fatal("getnameinfo failed");
771 
772 	memset(&req, 0, sizeof(req));
773 
774 	memcpy(req.buf, c->req, sizeof(req.buf));
775 
776 	req.iri_schema_off = c->iri.schema - c->req;
777 	req.iri_host_off = c->iri.host - c->req;
778 	req.iri_port_off = c->iri.port - c->req;
779 	req.iri_path_off = c->iri.path - c->req;
780 	req.iri_query_off = c->iri.query - c->req;
781 	req.iri_fragment_off = c->iri.fragment - c->req;
782 
783 	req.iri_portno = c->iri.port_no;
784 
785 	strlcpy(req.spath, spath, sizeof(req.spath));
786 	strlcpy(req.relpath, relpath, sizeof(req.relpath));
787 	strlcpy(req.addr, addr, sizeof(req.addr));
788 
789 	if ((t = tls_peer_cert_subject(c->ctx)) != NULL)
790 		strlcpy(req.subject, t, sizeof(req.subject));
791 	if ((t = tls_peer_cert_issuer(c->ctx)) != NULL)
792 		strlcpy(req.issuer, t, sizeof(req.issuer));
793 	if ((t = tls_peer_cert_hash(c->ctx)) != NULL)
794 		strlcpy(req.hash, t, sizeof(req.hash));
795 	if ((t = tls_conn_version(c->ctx)) != NULL)
796 		strlcpy(req.version, t, sizeof(req.version));
797 	if ((t = tls_conn_cipher(c->ctx)) != NULL)
798 		strlcpy(req.cipher, t, sizeof(req.cipher));
799 
800 	req.cipher_strength = tls_conn_cipher_strength(c->ctx);
801 	req.notbefore = tls_peer_cert_notbefore(c->ctx);
802 	req.notafter = tls_peer_cert_notafter(c->ctx);
803 
804 	req.host_off = host_nth(c->host);
805 
806 	imsg_compose(&exibuf, IMSG_CGI_REQ, c->id, 0, -1, &req, sizeof(req));
807 	imsg_flush(&exibuf);
808 
809 	close(c->pfd);
810 }
811 
812 static void
813 open_dir(struct client *c)
814 {
815 	size_t len;
816 	int dirfd, root;
817 	char *before_file;
818 
819 	root = !strcmp(c->iri.path, "/") || *c->iri.path == '\0';
820 
821 	len = strlen(c->iri.path);
822 	if (len > 0 && !ends_with(c->iri.path, "/")) {
823 		redirect_canonical_dir(c);
824 		return;
825 	}
826 
827 	strlcpy(c->sbuf, "/", sizeof(c->sbuf));
828 	strlcat(c->sbuf, c->iri.path, sizeof(c->sbuf));
829 	if (!ends_with(c->sbuf, "/"))
830 		strlcat(c->sbuf, "/", sizeof(c->sbuf));
831 	before_file = strchr(c->sbuf, '\0');
832 	len = strlcat(c->sbuf, vhost_index(c->host, c->iri.path),
833 	    sizeof(c->sbuf));
834 	if (len >= sizeof(c->sbuf)) {
835 		start_reply(c, TEMP_FAILURE, "internal server error");
836 		return;
837 	}
838 
839 	c->iri.path = c->sbuf;
840 
841 	/* close later unless we have to generate the dir listing */
842 	dirfd = c->pfd;
843 	c->pfd = -1;
844 
845 	switch (check_path(c, c->iri.path, &c->pfd)) {
846 	case FILE_EXECUTABLE:
847 		if (c->host->cgi != NULL && matches(c->host->cgi, c->iri.path)) {
848 			start_cgi(c->iri.path, "", c);
849 			break;
850 		}
851 
852 		/* fallthrough */
853 
854 	case FILE_EXISTS:
855 		c->next = handle_copy;
856 		start_reply(c, SUCCESS, mime(c->host, c->iri.path));
857 		break;
858 
859 	case FILE_DIRECTORY:
860 		start_reply(c, TEMP_REDIRECT, c->sbuf);
861 		break;
862 
863 	case FILE_MISSING:
864 		*before_file = '\0';
865 
866 		if (!vhost_auto_index(c->host, c->iri.path)) {
867 			start_reply(c, NOT_FOUND, "not found");
868 			break;
869 		}
870 
871 		c->next = enter_handle_dirlist;
872 
873 		c->dirlen = scandir_fd(dirfd, &c->dir,
874 		    root ? select_non_dotdot : select_non_dot,
875 		    alphasort);
876 		if (c->dirlen == -1) {
877 			log_err(c, "scandir_fd(%d) (vhost:%s) %s: %s",
878 			    c->pfd, c->host->domain, c->iri.path, strerror(errno));
879 			start_reply(c, TEMP_FAILURE, "internal server error");
880 			return;
881 		}
882 		c->diroff = 0;
883 		c->off = 0;
884 
885                 start_reply(c, SUCCESS, "text/gemini");
886 		return;
887 
888 	default:
889 		/* unreachable */
890 		abort();
891 	}
892 
893 	close(dirfd);
894 }
895 
896 static void
897 redirect_canonical_dir(struct client *c)
898 {
899 	size_t len;
900 
901 	strlcpy(c->sbuf, "/", sizeof(c->sbuf));
902 	strlcat(c->sbuf, c->iri.path, sizeof(c->sbuf));
903 	len = strlcat(c->sbuf, "/", sizeof(c->sbuf));
904 
905 	if (len >= sizeof(c->sbuf)) {
906 		start_reply(c, TEMP_FAILURE, "internal server error");
907 		return;
908 	}
909 
910 	start_reply(c, TEMP_REDIRECT, c->sbuf);
911 }
912 
913 static void
914 enter_handle_dirlist(int fd, short ev, void *d)
915 {
916 	struct client *c = d;
917 	char b[PATH_MAX];
918 	size_t l;
919 
920 	strlcpy(b, c->iri.path, sizeof(b));
921 	l = snprintf(c->sbuf, sizeof(c->sbuf),
922 	    "# Index of %s\n\n", b);
923 	if (l >= sizeof(c->sbuf)) {
924 		/* this is impossible, given that we have enough space
925 		 * in c->sbuf to hold the ancilliary string plus the
926 		 * full path; but it wouldn't read nice without some
927 		 * error checking, and I'd like to avoid a strlen. */
928 		close_conn(fd, ev, c);
929 		return;
930 	}
931 
932 	c->len = l;
933 	handle_dirlist(fd, ev, c);
934 }
935 
936 static void
937 handle_dirlist(int fd, short ev, void *d)
938 {
939 	struct client *c = d;
940 	ssize_t r;
941 
942 	while (c->len > 0) {
943 		switch (r = tls_write(c->ctx, c->sbuf + c->off, c->len)) {
944 		case -1:
945 			close_conn(fd, ev, c);
946 			return;
947 		case TLS_WANT_POLLOUT:
948 			yield_read(fd, c, &handle_dirlist);
949 			return;
950 		case TLS_WANT_POLLIN:
951 			yield_write(fd, c, &handle_dirlist);
952 			return;
953 		default:
954 			c->off += r;
955 			c->len -= r;
956 		}
957 	}
958 
959 	send_directory_listing(fd, ev, c);
960 }
961 
962 static int
963 read_next_dir_entry(struct client *c)
964 {
965 	if (c->diroff == c->dirlen)
966 		return 0;
967 
968 	/* XXX: url escape */
969 	snprintf(c->sbuf, sizeof(c->sbuf), "=> %s\n",
970 	    c->dir[c->diroff]->d_name);
971 
972 	free(c->dir[c->diroff]);
973 	c->diroff++;
974 
975 	c->len = strlen(c->sbuf);
976 	c->off = 0;
977 	return 1;
978 }
979 
980 static void
981 send_directory_listing(int fd, short ev, void *d)
982 {
983 	struct client *c = d;
984 	ssize_t r;
985 
986 	while (1) {
987 		if (c->len == 0) {
988 			if (!read_next_dir_entry(c))
989 				goto end;
990 		}
991 
992 		while (c->len > 0) {
993 			switch (r = tls_write(c->ctx, c->sbuf + c->off, c->len)) {
994 			case -1:
995 				goto end;
996 
997 			case TLS_WANT_POLLOUT:
998 				yield_read(fd, c, &send_directory_listing);
999 				return;
1000 
1001 			case TLS_WANT_POLLIN:
1002 				yield_write(fd, c, &send_directory_listing);
1003 				return;
1004 
1005 			default:
1006 				c->off += r;
1007 				c->len -= r;
1008 				break;
1009 			}
1010 		}
1011 	}
1012 
1013 end:
1014 	close_conn(fd, ev, d);
1015 }
1016 
1017 /* accumulate the meta line from the cgi script. */
1018 static void
1019 handle_cgi_reply(int fd, short ev, void *d)
1020 {
1021 	struct client *c = d;
1022 	void	*buf, *e;
1023 	size_t	 len;
1024 	ssize_t	 r;
1025 
1026 
1027 	buf = c->sbuf + c->len;
1028 	len = sizeof(c->sbuf) - c->len;
1029 
1030 	r = read(c->pfd, buf, len);
1031 	if (r == 0 || r == -1) {
1032 		start_reply(c, CGI_ERROR, "CGI error");
1033 		return;
1034 	}
1035 
1036 	c->len += r;
1037 
1038 	/* TODO: error if the CGI script don't reply correctly */
1039 	e = strchr(c->sbuf, '\n');
1040 	if (e != NULL || c->len == sizeof(c->sbuf)) {
1041 		log_request(c, c->sbuf, c->len);
1042 
1043 		c->off = 0;
1044 		handle_copy(fd, ev, c);
1045 		return;
1046 	}
1047 
1048 	yield_read(fd, c, &handle_cgi_reply);
1049 }
1050 
1051 static void
1052 handle_copy(int fd, short ev, void *d)
1053 {
1054 	struct client *c = d;
1055 	ssize_t r;
1056 
1057 	while (1) {
1058 		while (c->len > 0) {
1059 			switch (r = tls_write(c->ctx, c->sbuf + c->off, c->len)) {
1060 			case -1:
1061 				goto end;
1062 
1063 			case TLS_WANT_POLLOUT:
1064 				yield_write(c->fd, c, &handle_copy);
1065 				return;
1066 
1067 			case TLS_WANT_POLLIN:
1068 				yield_read(c->fd, c, &handle_copy);
1069 				return;
1070 
1071 			default:
1072                                 c->off += r;
1073 				c->len -= r;
1074 				break;
1075 			}
1076 		}
1077 
1078 		switch (r = read(c->pfd, c->sbuf, sizeof(c->sbuf))) {
1079 		case 0:
1080 			goto end;
1081 		case -1:
1082 			if (errno == EAGAIN || errno == EWOULDBLOCK) {
1083 				yield_read(c->pfd, c, &handle_copy);
1084 				return;
1085 			}
1086 			goto end;
1087 		default:
1088 			c->len = r;
1089 			c->off = 0;
1090 		}
1091 	}
1092 
1093 end:
1094 	close_conn(c->fd, ev, d);
1095 }
1096 
1097 void
1098 close_conn(int fd, short ev, void *d)
1099 {
1100 	struct client	*c = d;
1101 	struct mbuf	*mbuf;
1102 
1103 	switch (tls_close(c->ctx)) {
1104 	case TLS_WANT_POLLIN:
1105 		yield_read(fd, c, &close_conn);
1106 		return;
1107 	case TLS_WANT_POLLOUT:
1108 		yield_read(fd, c, &close_conn);
1109 		return;
1110 	}
1111 
1112 	connected_clients--;
1113 
1114 	while ((mbuf = TAILQ_FIRST(&c->mbufhead)) != NULL) {
1115 		TAILQ_REMOVE(&c->mbufhead, mbuf, mbufs);
1116 		free(mbuf);
1117 	}
1118 
1119 	tls_free(c->ctx);
1120 	c->ctx = NULL;
1121 
1122 	if (c->pfd != -1)
1123 		close(c->pfd);
1124 
1125 	if (c->dir != NULL)
1126 		free(c->dir);
1127 
1128 	close(c->fd);
1129 	c->fd = -1;
1130 }
1131 
1132 static void
1133 do_accept(int sock, short et, void *d)
1134 {
1135 	struct client *c;
1136 	struct sockaddr_storage addr;
1137 	struct sockaddr *saddr;
1138 	socklen_t len;
1139 	int i, fd;
1140 
1141 	(void)et;
1142 
1143 	saddr = (struct sockaddr*)&addr;
1144 	len = sizeof(addr);
1145 	if ((fd = accept(sock, saddr, &len)) == -1) {
1146 		if (errno == EWOULDBLOCK || errno == EAGAIN)
1147 			return;
1148 		fatal("accept: %s", strerror(errno));
1149 	}
1150 
1151 	mark_nonblock(fd);
1152 
1153 	for (i = 0; i < MAX_USERS; ++i) {
1154 		c = &clients[i];
1155 		if (c->fd == -1) {
1156 			memset(c, 0, sizeof(*c));
1157 			c->id = i;
1158 			if (tls_accept_socket(ctx, &c->ctx, fd) == -1)
1159 				break; /* goodbye fd! */
1160 
1161 			c->fd = fd;
1162 			c->pfd = -1;
1163 			c->dir = NULL;
1164 			c->addr = addr;
1165 			c->fcgi = -1;
1166 
1167 			yield_read(fd, c, &handle_handshake);
1168 			connected_clients++;
1169 			return;
1170 		}
1171 	}
1172 
1173 	close(fd);
1174 }
1175 
1176 static struct client *
1177 client_by_id(int id)
1178 {
1179 	if ((size_t)id > sizeof(clients)/sizeof(clients[0]))
1180 		fatal("in client_by_id: invalid id %d", id);
1181 	return &clients[id];
1182 }
1183 
1184 struct client *
1185 try_client_by_id(int id)
1186 {
1187 	if ((size_t)id > sizeof(clients)/sizeof(clients[0]))
1188                 return NULL;
1189 	return &clients[id];
1190 }
1191 
1192 static void
1193 handle_imsg_cgi_res(struct imsgbuf *ibuf, struct imsg *imsg, size_t len)
1194 {
1195 	struct client *c;
1196 
1197 	c = client_by_id(imsg->hdr.peerid);
1198 
1199 	if ((c->pfd = imsg->fd) == -1)
1200 		start_reply(c, TEMP_FAILURE, "internal server error");
1201 	else
1202 		yield_read(c->pfd, c, &handle_cgi_reply);
1203 }
1204 
1205 static void
1206 handle_imsg_fcgi_fd(struct imsgbuf *ibuf, struct imsg *imsg, size_t len)
1207 {
1208 	struct client	*c;
1209 	struct fcgi	*f;
1210 	int		 i, id;
1211 
1212 	id = imsg->hdr.peerid;
1213 	f = &fcgi[id];
1214 
1215 	if ((f->fd = imsg->fd) != -1) {
1216 		event_set(&f->e, imsg->fd, EV_READ | EV_PERSIST, &handle_fcgi,
1217 		    &fcgi[id]);
1218 		event_add(&f->e, NULL);
1219 	} else {
1220 		f->s = FCGI_OFF;
1221 	}
1222 
1223 	for (i = 0; i < MAX_USERS; ++i) {
1224 		c = &clients[i];
1225 		if (c->fd == -1)
1226 			continue;
1227 		if (c->fcgi != id)
1228 			continue;
1229 
1230 		if (f->fd == -1) {
1231 			c->fcgi = -1;
1232 			start_reply(c, TEMP_FAILURE, "internal server error");
1233 		} else
1234 			send_fcgi_req(f, c);
1235 	}
1236 }
1237 
1238 static void
1239 handle_imsg_quit(struct imsgbuf *ibuf, struct imsg *imsg, size_t len)
1240 {
1241 	(void)imsg;
1242 	(void)len;
1243 
1244 	/* don't call event_loopbreak since we want to finish to
1245 	 * handle the ongoing connections. */
1246 
1247 	event_del(&e4);
1248 	if (has_ipv6)
1249 		event_del(&e6);
1250 	if (has_siginfo)
1251 		signal_del(&siginfo);
1252 	event_del(&imsgev);
1253 	signal_del(&sigusr2);
1254 }
1255 
1256 static void
1257 handle_dispatch_imsg(int fd, short ev, void *d)
1258 {
1259 	struct imsgbuf *ibuf = d;
1260 	dispatch_imsg(ibuf, handlers, sizeof(handlers));
1261 }
1262 
1263 static void
1264 handle_siginfo(int fd, short ev, void *d)
1265 {
1266 	(void)fd;
1267 	(void)ev;
1268 	(void)d;
1269 
1270 	log_info(NULL, "%d connected clients", connected_clients);
1271 }
1272 
1273 void
1274 loop(struct tls *ctx_, int sock4, int sock6, struct imsgbuf *ibuf)
1275 {
1276 	size_t i;
1277 
1278 	ctx = ctx_;
1279 
1280 	event_init();
1281 
1282 	memset(&clients, 0, sizeof(clients));
1283 	for (i = 0; i < MAX_USERS; ++i)
1284 		clients[i].fd = -1;
1285 
1286 	event_set(&e4, sock4, EV_READ | EV_PERSIST, &do_accept, NULL);
1287 	event_add(&e4, NULL);
1288 
1289 	if (sock6 != -1) {
1290 		has_ipv6 = 1;
1291 		event_set(&e6, sock6, EV_READ | EV_PERSIST, &do_accept, NULL);
1292 		event_add(&e6, NULL);
1293 	}
1294 
1295 	event_set(&imsgev, ibuf->fd, EV_READ | EV_PERSIST, handle_dispatch_imsg, ibuf);
1296 	event_add(&imsgev, NULL);
1297 
1298 #ifdef SIGINFO
1299 	has_siginfo = 1;
1300 	signal_set(&siginfo, SIGINFO, &handle_siginfo, NULL);
1301 	signal_add(&siginfo, NULL);
1302 #endif
1303 	signal_set(&sigusr2, SIGUSR2, &handle_siginfo, NULL);
1304 	signal_add(&sigusr2, NULL);
1305 
1306 	sandbox_server_process();
1307 	event_dispatch();
1308 	_exit(0);
1309 }