op public repos

Blob

Date:: Fri Jan 15 15:21:51 2021 UTC
Message:: style
Actions:: History | Blame | Raw File
1 /*
2  * Copyright (c) 2020 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 <sys/mman.h>
18 #include <sys/stat.h>
19 
20 #include <assert.h>
21 #include <err.h>
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <limits.h>
25 #include <netdb.h>
26 #include <signal.h>
27 #include <stdarg.h>
28 #include <string.h>
29 
30 #include "gmid.h"
31 
32 struct vhost hosts[HOSTSLEN];
33 
34 int connected_clients;
35 int goterror;
36 
37 struct conf conf;
38 
39 struct etm {			/* file extension to mime */
40 	const char	*mime;
41 	const char	*ext;
42 } filetypes[] = {
43 	{"application/pdf",	"pdf"},
44 
45 	{"image/gif",		"gif"},
46 	{"image/jpeg",		"jpg"},
47 	{"image/jpeg",		"jpeg"},
48 	{"image/png",		"png"},
49 	{"image/svg+xml",	"svg"},
50 
51 	{"text/gemini",		"gemini"},
52 	{"text/gemini",		"gmi"},
53 	{"text/markdown",	"markdown"},
54 	{"text/markdown",	"md"},
55 	{"text/plain",		"txt"},
56 	{"text/xml",		"xml"},
57 
58 	{NULL, NULL}
59 };
60 
61 static inline void
62 safe_setenv(const char *name, const char *val)
63 {
64 	if (val == NULL)
65 		val = "";
66 	setenv(name, val, 1);
67 }
68 
69 __attribute__ ((format (printf, 1, 2)))
70 __attribute__ ((__noreturn__))
71 static inline void
72 fatal(const char *fmt, ...)
73 {
74 	va_list ap;
75 
76 	va_start(ap, fmt);
77 
78 	if (conf.foreground) {
79 		vfprintf(stderr, fmt, ap);
80 		fprintf(stderr, "\n");
81 	} else
82 		vsyslog(LOG_DAEMON | LOG_CRIT, fmt, ap);
83 
84 	va_end(ap);
85 	exit(1);
86 }
87 
88 void
89 logs(int priority, struct client *c,
90     const char *fmt, ...)
91 {
92 	char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
93 	char *fmted, *s;
94 	size_t len;
95 	int ec;
96 	va_list ap;
97 
98 	va_start(ap, fmt);
99 
100 	if (c == NULL) {
101 		strncpy(hbuf, "<internal>", sizeof(hbuf));
102 		sbuf[0] = '\0';
103 	} else {
104 		len = sizeof(c->addr);
105 		ec = getnameinfo((struct sockaddr*)&c->addr, len,
106 		    hbuf, sizeof(hbuf),
107 		    sbuf, sizeof(sbuf),
108 		    NI_NUMERICHOST | NI_NUMERICSERV);
109 		if (ec != 0)
110 			fatal("getnameinfo: %s", gai_strerror(ec));
111 	}
112 
113 	if (vasprintf(&fmted, fmt, ap) == -1)
114 		fatal("vasprintf: %s", strerror(errno));
115 
116 	if (conf.foreground)
117 		fprintf(stderr, "%s:%s %s\n", hbuf, sbuf, fmted);
118 	else {
119 		if (asprintf(&s, "%s:%s %s", hbuf, sbuf, fmted) == -1)
120 			fatal("asprintf: %s", strerror(errno));
121 		syslog(priority | LOG_DAEMON, "%s", s);
122 		free(s);
123 	}
124 
125 	free(fmted);
126 
127 	va_end(ap);
128 }
129 
130 void
131 sig_handler(int sig)
132 {
133 	(void)sig;
134 }
135 
136 int
137 starts_with(const char *str, const char *prefix)
138 {
139 	size_t i;
140 
141 	for (i = 0; prefix[i] != '\0'; ++i)
142 		if (str[i] != prefix[i])
143 			return 0;
144 	return 1;
145 }
146 
147 int
148 start_reply(struct pollfd *pfd, struct client *client, int code, const char *reason)
149 {
150 	char buf[1030]; 	/* status + ' ' + max reply len + \r\n\0 */
151 	int len;
152 
153 	client->code = code;
154 	client->meta = reason;
155 	client->state = S_INITIALIZING;
156 
157 	len = snprintf(buf, sizeof(buf), "%d %s\r\n", code, reason);
158 	assert(len < (int)sizeof(buf));
159 
160 	switch (tls_write(client->ctx, buf, len)) {
161 	case TLS_WANT_POLLIN:
162 		pfd->events = POLLIN;
163 		return 0;
164 	case TLS_WANT_POLLOUT:
165 		pfd->events = POLLOUT;
166 		return 0;
167 	default:
168 		return 1;
169 	}
170 }
171 
172 ssize_t
173 filesize(int fd)
174 {
175 	ssize_t len;
176 
177 	if ((len = lseek(fd, 0, SEEK_END)) == -1)
178 		return -1;
179 	if (lseek(fd, 0, SEEK_SET) == -1)
180 		return -1;
181 	return len;
182 }
183 
184 const char *
185 path_ext(const char *path)
186 {
187 	const char *end;
188 
189 	end = path + strlen(path)-1;
190 	for (; end != path; --end) {
191 		if (*end == '.')
192 			return end+1;
193 		if (*end == '/')
194 			break;
195 	}
196 
197 	return NULL;
198 }
199 
200 const char *
201 mime(const char *path)
202 {
203 	const char *ext, *def = "application/octet-stream";
204 	struct etm *t;
205 
206 	if ((ext = path_ext(path)) == NULL)
207 		return def;
208 
209 	for (t = filetypes; t->mime != NULL; ++t)
210 		if (!strcmp(ext, t->ext))
211 			return t->mime;
212 
213 	return def;
214 }
215 
216 int
217 check_path(struct client *c, const char *path, int *fd)
218 {
219 	struct stat sb;
220 
221 	assert(path != NULL);
222 	if ((*fd = openat(c->host->dirfd, *path ? path : ".",
223 	    O_RDONLY | O_NOFOLLOW | O_CLOEXEC)) == -1) {
224 		return FILE_MISSING;
225 	}
226 
227 	if (fstat(*fd, &sb) == -1) {
228 		LOGN(c, "failed stat for %s: %s", path, strerror(errno));
229 		return FILE_MISSING;
230 	}
231 
232 	if (S_ISDIR(sb.st_mode))
233 		return FILE_DIRECTORY;
234 
235 	if (sb.st_mode & S_IXUSR)
236 		return FILE_EXECUTABLE;
237 
238 	return FILE_EXISTS;
239 }
240 
241 /*
242  * the inverse of this algorithm, i.e. starting from the start of the
243  * path + strlen(cgi), and checking if each component, should be
244  * faster.  But it's tedious to write.  This does the opposite: starts
245  * from the end and strip one component at a time, until either an
246  * executable is found or we emptied the path.
247  */
248 int
249 check_for_cgi(char *path, char *query, struct pollfd *fds, struct client *c)
250 {
251 	char *end;
252 	end = strchr(path, '\0');
253 
254 	/* NB: assume CGI is enabled and path matches cgi */
255 
256 	while (end > path) {
257 		/* go up one level.  UNIX paths are simple and POSIX
258 		 * dirname, with its ambiguities on if the given path
259 		 * is changed or not, gives me headaches. */
260 		while (*end != '/')
261 			end--;
262 		*end = '\0';
263 
264 		switch (check_path(c, path, &c->fd)) {
265 		case FILE_EXECUTABLE:
266 			return start_cgi(path, end+1, query, fds,c);
267 		case FILE_MISSING:
268 			break;
269 		default:
270 			goto err;
271 		}
272 
273 		*end = '/';
274 		end--;
275 	}
276 
277 err:
278 	if (!start_reply(fds, c, NOT_FOUND, "not found"))
279 		return 0;
280 	goodbye(fds, c);
281 	return 0;
282 }
283 
284 int
285 open_file(char *fpath, char *query, struct pollfd *fds, struct client *c)
286 {
287 	switch (check_path(c, fpath, &c->fd)) {
288 	case FILE_EXECUTABLE:
289 		if (c->host->cgi != NULL && starts_with(fpath, c->host->cgi))
290 			return start_cgi(fpath, "", query, fds, c);
291 
292 		/* fallthrough */
293 
294 	case FILE_EXISTS:
295 		if ((c->len = filesize(c->fd)) == -1) {
296 			LOGE(c, "failed to get file size for %s", fpath);
297 			goodbye(fds, c);
298 			return 0;
299 		}
300 
301 		if ((c->buf = mmap(NULL, c->len, PROT_READ, MAP_PRIVATE,
302 			    c->fd, 0)) == MAP_FAILED) {
303 			warn("mmap: %s", fpath);
304 			goodbye(fds, c);
305 			return 0;
306 		}
307 		c->i = c->buf;
308 		return start_reply(fds, c, SUCCESS, mime(fpath));
309 
310 	case FILE_DIRECTORY:
311 		LOGD(c, "%s is a directory, trying %s/index.gmi", fpath, fpath);
312 		close(c->fd);
313 		c->fd = -1;
314 		send_dir(fpath, fds, c);
315 		return 0;
316 
317 	case FILE_MISSING:
318 		if (c->host->cgi != NULL && starts_with(fpath, c->host->cgi))
319 			return check_for_cgi(fpath, query, fds, c);
320 
321 		if (!start_reply(fds, c, NOT_FOUND, "not found"))
322 			return 0;
323 		goodbye(fds, c);
324 		return 0;
325 
326 	default:
327 		/* unreachable */
328 		abort();
329 	}
330 }
331 
332 int
333 start_cgi(const char *spath, const char *relpath, const char *query,
334     struct pollfd *fds, struct client *c)
335 {
336 	pid_t pid;
337 	int p[2];		/* read end, write end */
338 
339 	if (pipe(p) == -1)
340 		goto err;
341 
342 	switch (pid = fork()) {
343 	case -1:
344 		goto err;
345 
346 	case 0: {		/* child */
347 		char *ex, *requri, *portno;
348 		char addr[NI_MAXHOST];
349 		char *argv[] = { NULL, NULL, NULL };
350 		int ec;
351 
352 		close(p[0]);
353 		if (dup2(p[1], 1) == -1)
354 			goto childerr;
355 
356 		if (inet_ntop(c->af, &c->addr, addr, sizeof(addr)) == NULL)
357 			goto childerr;
358 
359 		ec = getnameinfo((struct sockaddr*)&c->addr, sizeof(c->addr),
360 		    addr, sizeof(addr),
361 		    NULL, 0,
362 		    NI_NUMERICHOST | NI_NUMERICSERV);
363 		if (ec != 0)
364 			goto childerr;
365 
366 		if (asprintf(&portno, "%d", conf.port) == -1)
367 			goto childerr;
368 
369 		if (asprintf(&ex, "%s/%s", c->host->dir, spath) == -1)
370 			goto childerr;
371 
372 		if (asprintf(&requri, "%s%s%s", spath,
373 		    *relpath == '\0' ? "" : "/", relpath) == -1)
374 			goto childerr;
375 
376 		argv[0] = argv[1] = ex;
377 
378 		/* fix the env */
379 		safe_setenv("GATEWAY_INTERFACE", "CGI/1.1");
380 		safe_setenv("SERVER_SOFTWARE", "gmid");
381 		safe_setenv("SERVER_PORT", portno);
382 		/* setenv("SERVER_NAME", "", 1); */
383 		safe_setenv("SCRIPT_NAME", spath);
384 		safe_setenv("SCRIPT_EXECUTABLE", ex);
385 		safe_setenv("REQUEST_URI", requri);
386 		safe_setenv("REQUEST_RELATIVE", relpath);
387 		safe_setenv("QUERY_STRING", query);
388 		safe_setenv("REMOTE_HOST", addr);
389 		safe_setenv("REMOTE_ADDR", addr);
390 		safe_setenv("DOCUMENT_ROOT", c->host->dir);
391 
392 		if (tls_peer_cert_provided(c->ctx)) {
393 			safe_setenv("AUTH_TYPE", "Certificate");
394 			safe_setenv("REMOTE_USER", tls_peer_cert_subject(c->ctx));
395 			safe_setenv("TLS_CLIENT_ISSUER", tls_peer_cert_issuer(c->ctx));
396 			safe_setenv("TLS_CLIENT_HASH", tls_peer_cert_hash(c->ctx));
397 		}
398 
399 		execvp(ex, argv);
400 		goto childerr;
401 	}
402 
403 	default:		/* parent */
404 		close(p[1]);
405 		close(c->fd);
406 		c->fd = p[0];
407 		c->child = pid;
408 		mark_nonblock(c->fd);
409 		c->state = S_SENDING;
410 		handle_cgi(fds, c);
411 		return 0;
412 	}
413 
414 err:
415 	if (!start_reply(fds, c, TEMP_FAILURE, "internal server error"))
416 		return 0;
417 	goodbye(fds, c);
418 	return 0;
419 
420 childerr:
421 	dprintf(p[1], "%d internal server error\r\n", TEMP_FAILURE);
422 	close(p[1]);
423 	_exit(1);
424 }
425 
426 void
427 cgi_poll_on_child(struct pollfd *fds, struct client *c)
428 {
429 	int fd;
430 
431 	if (c->waiting_on_child)
432 		return;
433 	c->waiting_on_child = 1;
434 
435 	fds->events = POLLIN;
436 
437 	fd = fds->fd;
438 	fds->fd = c->fd;
439 	c->fd = fd;
440 }
441 
442 void
443 cgi_poll_on_client(struct pollfd *fds, struct client *c)
444 {
445 	int fd;
446 
447 	if (!c->waiting_on_child)
448 		return;
449 	c->waiting_on_child = 0;
450 
451 	fd = fds->fd;
452 	fds->fd = c->fd;
453 	c->fd = fd;
454 }
455 
456 void
457 handle_cgi(struct pollfd *fds, struct client *c)
458 {
459 	ssize_t r;
460 
461 	/* ensure c->fd is the child and fds->fd the client */
462 	cgi_poll_on_client(fds, c);
463 
464 	while (1) {
465 		if (c->len == 0) {
466 			if ((r = read(c->fd, c->sbuf, sizeof(c->sbuf))) == 0)
467 				goto end;
468 			if (r == -1) {
469 				if (errno == EAGAIN || errno == EWOULDBLOCK) {
470 					cgi_poll_on_child(fds, c);
471 					return;
472 				}
473                                 goto end;
474 			}
475 			c->len = r;
476 			c->off = 0;
477 		}
478 
479 		while (c->len > 0) {
480 			switch (r = tls_write(c->ctx, c->sbuf + c->off, c->len)) {
481 			case -1:
482 				goto end;
483 
484 			case TLS_WANT_POLLOUT:
485 				fds->events = POLLOUT;
486 				return;
487 
488 			case TLS_WANT_POLLIN:
489 				fds->events = POLLIN;
490 				return;
491 
492 			default:
493                                 c->off += r;
494 				c->len -= r;
495 				break;
496 			}
497 		}
498 	}
499 
500 end:
501 	goodbye(fds, c);
502 }
503 
504 void
505 send_file(char *path, char *query, struct pollfd *fds, struct client *c)
506 {
507 	ssize_t ret, len;
508 
509 	if (c->fd == -1) {
510 		if (!open_file(path, query, fds, c))
511 			return;
512 		c->state = S_SENDING;
513 	}
514 
515 	len = (c->buf + c->len) - c->i;
516 
517 	while (len > 0) {
518 		switch (ret = tls_write(c->ctx, c->i, len)) {
519 		case -1:
520 			LOGE(c, "tls_write: %s", tls_error(c->ctx));
521 			goodbye(fds, c);
522 			return;
523 
524 		case TLS_WANT_POLLIN:
525 			fds->events = POLLIN;
526 			return;
527 
528 		case TLS_WANT_POLLOUT:
529 			fds->events = POLLOUT;
530 			return;
531 
532 		default:
533 			c->i += ret;
534 			len -= ret;
535 			break;
536 		}
537 	}
538 
539 	goodbye(fds, c);
540 }
541 
542 void
543 send_dir(char *path, struct pollfd *fds, struct client *client)
544 {
545 	char fpath[PATHBUF];
546 	size_t len;
547 
548 	bzero(fpath, PATHBUF);
549 
550 	if (path[0] != '.')
551 		fpath[0] = '.';
552 
553 	/* this cannot fail since sizeof(fpath) > maxlen of path */
554 	strlcat(fpath, path, PATHBUF);
555 	len = strlen(fpath);
556 
557 	/* add a trailing / in case. */
558 	if (fpath[len-1] != '/') {
559 		fpath[len] = '/';
560 	}
561 
562 	strlcat(fpath, "index.gmi", sizeof(fpath));
563 
564 	send_file(fpath, NULL, fds, client);
565 }
566 
567 void
568 handle_handshake(struct pollfd *fds, struct client *c)
569 {
570 	struct vhost *h;
571 	const char *servname;
572 
573 	switch (tls_handshake(c->ctx)) {
574 	case 0:  /* success */
575 	case -1: /* already handshaked */
576 		break;
577 	case TLS_WANT_POLLIN:
578 		fds->events = POLLIN;
579 		return;
580 	case TLS_WANT_POLLOUT:
581 		fds->events = POLLOUT;
582 		return;
583 	default:
584 		/* unreachable */
585 		abort();
586 	}
587 
588 	servname = tls_conn_servername(c->ctx);
589 	if (servname == NULL)
590 		goto hostnotfound;
591 
592 	for (h = hosts; h->domain != NULL; ++h) {
593 		if (!strcmp(h->domain, servname) || !strcmp(h->domain, "*"))
594 			break;
595 	}
596 
597 	if (h->domain != NULL) {
598 		c->state = S_OPEN;
599 		c->host = h;
600 		handle_open_conn(fds, c);
601 		return;
602 	}
603 
604 hostnotfound:
605 	/* XXX: check the correct response */
606 	if (!start_reply(fds, c, BAD_REQUEST, "Wrong host or missing SNI"))
607 		return;
608 	goodbye(fds, c);
609 }
610 
611 void
612 handle_open_conn(struct pollfd *fds, struct client *c)
613 {
614 	char buf[GEMINI_URL_LEN];
615 	const char *parse_err = "invalid request";
616 	struct iri iri;
617 
618 	bzero(buf, sizeof(buf));
619 
620 	switch (tls_read(c->ctx, buf, sizeof(buf)-1)) {
621 	case -1:
622 		LOGE(c, "tls_read: %s", tls_error(c->ctx));
623 		goodbye(fds, c);
624 		return;
625 
626 	case TLS_WANT_POLLIN:
627 		fds->events = POLLIN;
628 		return;
629 
630 	case TLS_WANT_POLLOUT:
631 		fds->events = POLLOUT;
632 		return;
633 	}
634 
635 	if (!trim_req_iri(buf) || !parse_iri(buf, &iri, &parse_err)) {
636 		if (!start_reply(fds, c, BAD_REQUEST, parse_err))
637 			return;
638 		goodbye(fds, c);
639 		return;
640 	}
641 
642 	if (strcmp(iri.schema, "gemini")) {
643 		if (!start_reply(fds, c, PROXY_REFUSED, "won't proxy request"))
644 			return;
645 		goodbye(fds, c);
646 		return;
647 	}
648 
649 	LOGI(c, "GET %s%s%s",
650 	    *iri.path ? iri.path : "/",
651 	    *iri.query ? "?" : "",
652 	    *iri.query ? iri.query : "");
653 
654 	send_file(iri.path, iri.query, fds, c);
655 }
656 
657 void
658 handle(struct pollfd *fds, struct client *client)
659 {
660 	switch (client->state) {
661 	case S_HANDSHAKE:
662 		handle_handshake(fds, client);
663 		break;
664 
665 	case S_OPEN:
666                 handle_open_conn(fds, client);
667 		break;
668 
669 	case S_INITIALIZING:
670 		if (!start_reply(fds, client, client->code, client->meta))
671 			return;
672 
673 		if (client->code != SUCCESS) {
674 			/* we don't need a body */
675 			goodbye(fds, client);
676 			return;
677 		}
678 
679 		client->state = S_SENDING;
680 
681 		/* fallthrough */
682 
683 	case S_SENDING:
684 		if (client->child != -1)
685 			handle_cgi(fds, client);
686 		else
687 			send_file(NULL, NULL, fds, client);
688 		break;
689 
690 	case S_CLOSING:
691 		goodbye(fds, client);
692 		break;
693 
694 	default:
695 		/* unreachable */
696 		abort();
697 	}
698 }
699 
700 void
701 mark_nonblock(int fd)
702 {
703 	int flags;
704 
705 	if ((flags = fcntl(fd, F_GETFL)) == -1)
706 		fatal("fcntl(F_GETFL): %s", strerror(errno));
707 	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
708 		fatal("fcntl(F_SETFL): %s", strerror(errno));
709 }
710 
711 int
712 make_socket(int port, int family)
713 {
714 	int sock, v;
715 	struct sockaddr_in addr4;
716 	struct sockaddr_in6 addr6;
717 	struct sockaddr *addr;
718 	socklen_t len;
719 
720         switch (family) {
721 	case AF_INET:
722 		bzero(&addr4, sizeof(addr4));
723 		addr4.sin_family = family;
724 		addr4.sin_port = htons(port);
725 		addr4.sin_addr.s_addr = INADDR_ANY;
726 		addr = (struct sockaddr*)&addr4;
727 		len = sizeof(addr4);
728 		break;
729 
730 	case AF_INET6:
731 		bzero(&addr6, sizeof(addr6));
732 		addr6.sin6_family = AF_INET6;
733 		addr6.sin6_port = htons(port);
734 		addr6.sin6_addr = in6addr_any;
735 		addr = (struct sockaddr*)&addr6;
736 		len = sizeof(addr6);
737 		break;
738 
739 	default:
740 		/* unreachable */
741 		abort();
742 	}
743 
744 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
745 		fatal("socket: %s", strerror(errno));
746 
747 	v = 1;
748 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
749 		fatal("setsockopt(SO_REUSEADDR): %s", strerror(errno));
750 
751 	v = 1;
752 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
753 		fatal("setsockopt(SO_REUSEPORT): %s", strerror(errno));
754 
755 	mark_nonblock(sock);
756 
757 	if (bind(sock, addr, len) == -1)
758 		fatal("bind: %s", strerror(errno));
759 
760 	if (listen(sock, 16) == -1)
761 		fatal("listen: %s", strerror(errno));
762 
763 	return sock;
764 }
765 
766 void
767 do_accept(int sock, struct tls *ctx, struct pollfd *fds, struct client *clients)
768 {
769 	int i, fd;
770 	struct sockaddr_storage addr;
771 	socklen_t len;
772 
773 	len = sizeof(addr);
774 	if ((fd = accept(sock, (struct sockaddr*)&addr, &len)) == -1) {
775 		if (errno == EWOULDBLOCK)
776 			return;
777 		fatal("accept: %s", strerror(errno));
778 	}
779 
780 	mark_nonblock(fd);
781 
782 	for (i = 0; i < MAX_USERS; ++i) {
783 		if (fds[i].fd == -1) {
784 			bzero(&clients[i], sizeof(struct client));
785 			if (tls_accept_socket(ctx, &clients[i].ctx, fd) == -1)
786 				break; /* goodbye fd! */
787 
788 			fds[i].fd = fd;
789 			fds[i].events = POLLIN;
790 
791 			clients[i].state = S_HANDSHAKE;
792 			clients[i].fd = -1;
793 			clients[i].child = -1;
794 			clients[i].buf = MAP_FAILED;
795 			clients[i].af = AF_INET;
796 			clients[i].addr = addr;
797 
798 			connected_clients++;
799 			return;
800 		}
801 	}
802 
803 	close(fd);
804 }
805 
806 void
807 goodbye(struct pollfd *pfd, struct client *c)
808 {
809 	c->state = S_CLOSING;
810 
811 	switch (tls_close(c->ctx)) {
812 	case TLS_WANT_POLLIN:
813 		pfd->events = POLLIN;
814 		return;
815 	case TLS_WANT_POLLOUT:
816 		pfd->events = POLLOUT;
817 		return;
818 	}
819 
820 	connected_clients--;
821 
822 	tls_free(c->ctx);
823 	c->ctx = NULL;
824 
825 	if (c->buf != MAP_FAILED)
826 		munmap(c->buf, c->len);
827 
828 	if (c->fd != -1)
829 		close(c->fd);
830 
831 	close(pfd->fd);
832 	pfd->fd = -1;
833 }
834 
835 void
836 loop(struct tls *ctx, int sock4, int sock6)
837 {
838 	int i;
839 	struct client clients[MAX_USERS];
840 	struct pollfd fds[MAX_USERS];
841 
842 	for (i = 0; i < MAX_USERS; ++i) {
843 		fds[i].fd = -1;
844 		fds[i].events = POLLIN;
845 		bzero(&clients[i], sizeof(struct client));
846 	}
847 
848 	fds[0].fd = sock4;
849 	fds[1].fd = sock6;
850 
851 	for (;;) {
852 		if (poll(fds, MAX_USERS, INFTIM) == -1) {
853 			if (errno == EINTR) {
854                                 warnx("connected clients: %d",
855 				    connected_clients);
856 				continue;
857 			}
858 			fatal("poll: %s", strerror(errno));
859 		}
860 
861 		for (i = 0; i < MAX_USERS; i++) {
862 			if (fds[i].revents == 0)
863 				continue;
864 
865 			if (fds[i].revents & (POLLERR|POLLNVAL))
866 				fatal("bad fd %d: %s", fds[i].fd,
867 				    strerror(errno));
868 
869 			if (fds[i].revents & POLLHUP) {
870 				/* fds[i] may be the fd of the stdin
871 				 * of a cgi script that has exited. */
872 				if (!clients[i].waiting_on_child) {
873 					goodbye(&fds[i], &clients[i]);
874 					continue;
875 				}
876 			}
877 
878 			if (fds[i].fd == sock4)
879 				do_accept(sock4, ctx, fds, clients);
880 			else if (fds[i].fd == sock6)
881 				do_accept(sock6, ctx, fds, clients);
882 			else
883 				handle(&fds[i], &clients[i]);
884 		}
885 	}
886 }
887 
888 char *
889 absolutify_path(const char *path)
890 {
891 	char *wd, *r;
892 
893 	if (*path == '/')
894 		return strdup(path);
895 
896 	wd = getwd(NULL);
897 	if (asprintf(&r, "%s/%s", wd, path) == -1)
898 		err(1, "asprintf");
899 	free(wd);
900 	return r;
901 }
902 
903 void
904 yyerror(const char *msg)
905 {
906 	goterror = 1;
907 	fprintf(stderr, "%d: %s\n", yylineno, msg);
908 }
909 
910 int
911 parse_portno(const char *p)
912 {
913 	char *ep;
914 	long lval;
915 
916 	errno = 0;
917 	lval = strtol(p, &ep, 10);
918 	if (p[0] == '\0' || *ep != '\0')
919 		errx(1, "not a number: %s", p);
920 	if (lval < 0 || lval > UINT16_MAX)
921 		errx(1, "port number out of range for domain %s: %ld", p, lval);
922 	return lval;
923 }
924 
925 void
926 parse_conf(const char *path)
927 {
928 	if ((yyin = fopen(path, "r")) == NULL)
929 		err(1, "cannot open config %s", path);
930 	yyparse();
931 	fclose(yyin);
932 
933 	if (goterror)
934 		exit(1);
935 }
936 
937 void
938 load_vhosts(struct tls_config *tlsconf)
939 {
940 	struct vhost *h;
941 
942 	/* we need to set something, then we can add how many key we want */
943 	if (tls_config_set_keypair_file(tlsconf, hosts->cert, hosts->key))
944 		errx(1, "tls_config_set_keypair_file failed");
945 
946 	for (h = hosts; h->domain != NULL; ++h) {
947 		if (tls_config_add_keypair_file(tlsconf, h->cert, h->key) == -1)
948 			errx(1, "failed to load the keypair (%s, %s)",
949 			    h->cert, h->key);
950 
951 		if ((h->dirfd = open(h->dir, O_RDONLY | O_DIRECTORY)) == -1)
952 			err(1, "open %s for domain %s", h->dir, h->domain);
953 	}
954 }
955 
956 void
957 usage(const char *me)
958 {
959 	fprintf(stderr,
960 	    "USAGE: %s [-n] [-c config] | [-6fh] [-C cert] [-d root] [-K key] "
961 	    "[-p port] [-x cgi-bin]\n",
962 	    me);
963 }
964 
965 int
966 main(int argc, char **argv)
967 {
968 	struct tls *ctx = NULL;
969 	struct tls_config *tlsconf;
970 	int sock4, sock6, ch;
971 	const char *config_path = NULL;
972 	size_t i;
973 	int conftest = 0;
974 
975 	bzero(hosts, sizeof(hosts));
976 	for (i = 0; i < HOSTSLEN; ++i)
977 		hosts[i].dirfd = -1;
978 
979 	conf.foreground = 1;
980 	conf.port = 1965;
981 	conf.ipv6 = 0;
982 
983 	connected_clients = 0;
984 
985 	while ((ch = getopt(argc, argv, "6C:c:d:fhK:np:x:")) != -1) {
986 		switch (ch) {
987 		case '6':
988 			conf.ipv6 = 1;
989 			break;
990 
991 		case 'C':
992 			hosts[0].cert = optarg;
993 			break;
994 
995 		case 'c':
996 			config_path = optarg;
997 			break;
998 
999 		case 'd':
1000 			free((char*)hosts[0].dir);
1001 			if ((hosts[0].dir = absolutify_path(optarg)) == NULL)
1002 				err(1, "absolutify_path");
1003 			break;
1004 
1005 		case 'f':
1006 			conf.foreground = 1;
1007 			break;
1008 
1009 		case 'h':
1010 			usage(*argv);
1011 			return 0;
1012 
1013 		case 'K':
1014 			hosts[0].key = optarg;
1015 			break;
1016 
1017 		case 'n':
1018 			conftest = 1;
1019 			break;
1020 
1021 		case 'p':
1022 			conf.port = parse_portno(optarg);
1023 
1024 		case 'x':
1025 			/* drop the starting / (if any) */
1026 			if (*optarg == '/')
1027 				optarg++;
1028 			hosts[0].cgi = optarg;
1029 			break;
1030 
1031 		default:
1032 			usage(*argv);
1033 			return 1;
1034 		}
1035 	}
1036 
1037 	if (config_path != NULL) {
1038 		if (hosts[0].cert != NULL || hosts[0].key != NULL ||
1039 		    hosts[0].dir != NULL)
1040 			errx(1, "can't specify options in conf mode");
1041 		parse_conf(config_path);
1042 	} else {
1043 		if (hosts[0].cert == NULL || hosts[0].key == NULL ||
1044 		    hosts[0].dir == NULL)
1045 			errx(1, "missing cert, key or root directory to serve");
1046 		hosts[0].domain = "*";
1047 	}
1048 
1049 	if (conftest)
1050                 errx(0, "config OK");
1051 
1052 	signal(SIGPIPE, SIG_IGN);
1053 	signal(SIGCHLD, SIG_IGN);
1054 
1055 #ifdef SIGINFO
1056 	signal(SIGINFO, sig_handler);
1057 #endif
1058 	signal(SIGUSR2, sig_handler);
1059 
1060 	if (!conf.foreground)
1061 		signal(SIGHUP, SIG_IGN);
1062 
1063 	if ((tlsconf = tls_config_new()) == NULL)
1064 		err(1, "tls_config_new");
1065 
1066 	/* optionally accept client certs, but don't try to verify them */
1067 	tls_config_verify_client_optional(tlsconf);
1068 	tls_config_insecure_noverifycert(tlsconf);
1069 
1070 	if (tls_config_set_protocols(tlsconf,
1071 	    TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3) == -1)
1072 		err(1, "tls_config_set_protocols");
1073 
1074 	load_vhosts(tlsconf);
1075 
1076 	if ((ctx = tls_server()) == NULL)
1077 		err(1, "tls_server");
1078 
1079 	if (tls_configure(ctx, tlsconf) == -1)
1080 		errx(1, "tls_configure: %s", tls_error(ctx));
1081 
1082 	sock4 = make_socket(conf.port, AF_INET);
1083 	if (conf.ipv6)
1084 		sock6 = make_socket(conf.port, AF_INET6);
1085 	else
1086 		sock6 = -1;
1087 
1088 	if (!conf.foreground && daemon(0, 1) == -1)
1089 		exit(1);
1090 
1091 	sandbox();
1092 
1093 	loop(ctx, sock4, sock6);
1094 
1095 	close(sock4);
1096 	close(sock6);
1097 	tls_free(ctx);
1098 	tls_config_free(tlsconf);
1099 
1100 	return 0;
1101 }