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/socket.h>
19 #include <sys/stat.h>
20 
21 #include <assert.h>
22 #include <err.h>
23 #include <errno.h>
24 #include <fcntl.h>
25 #include <limits.h>
26 #include <signal.h>
27 #include <string.h>
28 
29 #include "gmid.h"
30 
31 const char *dir, *cgi;
32 int dirfd;
33 int port;
34 int foreground;
35 int connected_clients;
36 
37 struct etm {			/* file extension to mime */
38 	const char	*mime;
39 	const char	*ext;
40 } filetypes[] = {
41 	{"application/pdf",	"pdf"},
42 
43 	{"image/gif",		"gif"},
44 	{"image/jpeg",		"jpg"},
45 	{"image/jpeg",		"jpeg"},
46 	{"image/png",		"png"},
47 	{"image/svg+xml",	"svg"},
48 
49 	{"text/gemini",		"gemini"},
50 	{"text/gemini",		"gmi"},
51 	{"text/markdown",	"markdown"},
52 	{"text/markdown",	"md"},
53 	{"text/plain",		"txt"},
54 	{"text/xml",		"xml"},
55 
56 	{NULL, NULL}
57 };
58 
59 void
60 sig_handler(int sig)
61 {
62 	(void)sig;
63 }
64 
65 int
66 starts_with(const char *str, const char *prefix)
67 {
68 	size_t i;
69 
70 	for (i = 0; prefix[i] != '\0'; ++i)
71 		if (str[i] != prefix[i])
72 			return 0;
73 	return 1;
74 }
75 
76 int
77 start_reply(struct pollfd *pfd, struct client *client, int code, const char *reason)
78 {
79 	char buf[1030] = {0}; 	/* status + ' ' + max reply len + \r\n\0 */
80 	int len;
81 	int ret;
82 
83 	client->code = code;
84 	client->meta = reason;
85 	client->state = S_INITIALIZING;
86 
87 	len = snprintf(buf, sizeof(buf), "%d %s\r\n", code, reason);
88 	assert(len < (int)sizeof(buf));
89 	ret = tls_write(client->ctx, buf, len);
90 	if (ret == TLS_WANT_POLLIN) {
91 		pfd->events = POLLIN;
92 		return 0;
93 	}
94 
95 	if (ret == TLS_WANT_POLLOUT) {
96 		pfd->events = POLLOUT;
97 		return 0;
98 	}
99 
100 	return 1;
101 }
102 
103 ssize_t
104 filesize(int fd)
105 {
106 	ssize_t len;
107 
108 	if ((len = lseek(fd, 0, SEEK_END)) == -1)
109 		return -1;
110 	if (lseek(fd, 0, SEEK_SET) == -1)
111 		return -1;
112 	return len;
113 }
114 
115 const char *
116 path_ext(const char *path)
117 {
118 	const char *end;
119 
120 	end = path + strlen(path)-1; /* the last byte before the NUL */
121 	for (; end != path; --end) {
122 		if (*end == '.')
123 			return end+1;
124 		if (*end == '/')
125 			break;
126 	}
127 
128 	return NULL;
129 }
130 
131 const char *
132 mime(const char *path)
133 {
134 	const char *ext, *def = "application/octet-stream";
135 	struct etm *t;
136 
137 	if ((ext = path_ext(path)) == NULL)
138 		return def;
139 
140 	for (t = filetypes; t->mime != NULL; ++t)
141 		if (!strcmp(ext, t->ext))
142 			return t->mime;
143 
144 	return def;
145 }
146 
147 int
148 check_path(struct client *c, const char *path, int *fd)
149 {
150 	struct stat sb;
151 
152 	assert(path != NULL);
153 	if ((*fd = openat(dirfd, *path ? path : ".",
154 		    O_RDONLY | O_NOFOLLOW | O_CLOEXEC)) == -1) {
155 		return FILE_MISSING;
156 	}
157 
158 	if (fstat(*fd, &sb) == -1) {
159 		LOGN(c, "failed stat for %s: %s", path, strerror(errno));
160 		return FILE_MISSING;
161 	}
162 
163 	if (S_ISDIR(sb.st_mode))
164 		return FILE_DIRECTORY;
165 
166 	if (sb.st_mode & S_IXUSR)
167 		return FILE_EXECUTABLE;
168 
169 	return FILE_EXISTS;
170 }
171 
172 /*
173  * the inverse of this algorithm, i.e. starting from the start of the
174  * path + strlen(cgi), and checking if each component, should be
175  * faster.  But it's tedious to write.  This does the opposite: starts
176  * from the end and strip one component at a time, until either an
177  * executable is found or we emptied the path.
178  */
179 int
180 check_for_cgi(char *path, char *query, struct pollfd *fds, struct client *c)
181 {
182 	char *end;
183 	end = strchr(path, '\0');
184 
185 	/* NB: assume CGI is enabled and path matches cgi */
186 
187 	while (end > path) {
188 		/* go up one level.  UNIX paths are simple and POSIX
189 		 * dirname, with its ambiguities on if the given path
190 		 * is changed or not, gives me headaches. */
191 		while (*end != '/')
192 			end--;
193 		*end = '\0';
194 
195 		switch (check_path(c, path, &c->fd)) {
196 		case FILE_EXECUTABLE:
197 			return start_cgi(path, end+1, query, fds,c);
198 		case FILE_MISSING:
199 			break;
200 		default:
201 			goto err;
202 		}
203 
204 		*end = '/';
205 		end--;
206 	}
207 
208 err:
209 	if (!start_reply(fds, c, NOT_FOUND, "not found"))
210 		return 0;
211 	goodbye(fds, c);
212 	return 0;
213 }
214 
215 
216 int
217 open_file(char *fpath, char *query, struct pollfd *fds, struct client *c)
218 {
219 	switch (check_path(c, fpath, &c->fd)) {
220 	case FILE_EXECUTABLE:
221 		if (cgi != NULL && starts_with(fpath, cgi))
222 			return start_cgi(fpath, "", query, fds, c);
223 
224 		/* fallthrough */
225 
226 	case FILE_EXISTS:
227 		if ((c->len = filesize(c->fd)) == -1) {
228 			LOGE(c, "failed to get file size for %s", fpath);
229 			goodbye(fds, c);
230 			return 0;
231 		}
232 
233 		if ((c->buf = mmap(NULL, c->len, PROT_READ, MAP_PRIVATE,
234 			    c->fd, 0)) == MAP_FAILED) {
235 			warn("mmap: %s", fpath);
236 			goodbye(fds, c);
237 			return 0;
238 		}
239 		c->i = c->buf;
240 		return start_reply(fds, c, SUCCESS, mime(fpath));
241 
242 	case FILE_DIRECTORY:
243 		LOGD(c, "%s is a directory, trying %s/index.gmi", fpath, fpath);
244 		close(c->fd);
245 		c->fd = -1;
246 		send_dir(fpath, fds, c);
247 		return 0;
248 
249 	case FILE_MISSING:
250 		if (cgi != NULL && starts_with(fpath, cgi))
251 			return check_for_cgi(fpath, query, fds, c);
252 
253 		if (!start_reply(fds, c, NOT_FOUND, "not found"))
254 			return 0;
255 		goodbye(fds, c);
256 		return 0;
257 
258 	default:
259 		/* unreachable */
260 		abort();
261 	}
262 }
263 
264 int
265 start_cgi(const char *spath, const char *relpath, const char *query,
266     struct pollfd *fds, struct client *c)
267 {
268 	pid_t pid;
269 	int p[2]; 		/* read end, write end */
270 
271 	if (pipe(p) == -1)
272 		goto err;
273 
274 	switch (pid = fork()) {
275 	case -1:
276 		goto err;
277 
278 	case 0: { 		/* child */
279 		char *ex, *requri, *portno;
280 		char addr[INET_ADDRSTRLEN];
281 		char *argv[] = { NULL, NULL, NULL };
282 
283 		close(p[0]);
284 		if (dup2(p[1], 1) == -1)
285 			goto childerr;
286 
287 		if (inet_ntop(c->af, &c->addr, addr, sizeof(addr)) == NULL)
288 			goto childerr;
289 
290 		if (asprintf(&portno, "%d", port) == -1)
291 			goto childerr;
292 
293 		if (asprintf(&ex, "%s/%s", dir, spath) == -1)
294 			goto childerr;
295 
296 		if (asprintf(&requri, "%s%s%s", spath,
297 		    *relpath == '\0' ? "" : "/",
298 		    relpath) == -1)
299 			goto childerr;
300 
301 		argv[0] = argv[1] = ex;
302 
303 		/* fix the env */
304 		SAFE_SETENV("GATEWAY_INTERFACE", "CGI/1.1");
305 		SAFE_SETENV("SERVER_SOFTWARE", "gmid");
306 		SAFE_SETENV("SERVER_PORT", portno);
307 		/* setenv("SERVER_NAME", "", 1); */
308 		SAFE_SETENV("SCRIPT_NAME", spath);
309 		SAFE_SETENV("SCRIPT_EXECUTABLE", ex);
310 		SAFE_SETENV("REQUEST_URI", requri);
311 		SAFE_SETENV("REQUEST_RELATIVE", relpath);
312 		SAFE_SETENV("QUERY_STRING", query);
313 		SAFE_SETENV("REMOTE_HOST", addr);
314 		SAFE_SETENV("REMOTE_ADDR", addr);
315 		SAFE_SETENV("DOCUMENT_ROOT", dir);
316 
317 		if (tls_peer_cert_provided(c->ctx)) {
318 			SAFE_SETENV("AUTH_TYPE", "Certificate");
319 			SAFE_SETENV("REMOTE_USER", tls_peer_cert_subject(c->ctx));
320 			SAFE_SETENV("TLS_CLIENT_ISSUER", tls_peer_cert_issuer(c->ctx));
321 			SAFE_SETENV("TLS_CLIENT_HASH", tls_peer_cert_hash(c->ctx));
322 		}
323 
324 		execvp(ex, argv);
325 		goto childerr;
326 	}
327 
328 	default:		/* parent */
329 		close(p[1]);
330 		close(c->fd);
331 		c->fd = p[0];
332 		c->child = pid;
333 		mark_nonblock(c->fd);
334 		c->state = S_SENDING;
335 		handle_cgi(fds, c);
336 		return 0;
337 	}
338 
339 err:
340 	if (!start_reply(fds, c, TEMP_FAILURE, "internal server error"))
341 		return 0;
342 	goodbye(fds, c);
343 	return 0;
344 
345 childerr:
346 	dprintf(p[1], "%d internal server error\r\n", TEMP_FAILURE);
347 	close(p[1]);
348 	_exit(1);
349 }
350 
351 void
352 cgi_poll_on_child(struct pollfd *fds, struct client *c)
353 {
354 	int fd;
355 
356 	if (c->waiting_on_child)
357 		return;
358 	c->waiting_on_child = 1;
359 
360 	fds->events = POLLIN;
361 
362 	fd = fds->fd;
363 	fds->fd = c->fd;
364 	c->fd = fd;
365 }
366 
367 void
368 cgi_poll_on_client(struct pollfd *fds, struct client *c)
369 {
370 	int fd;
371 
372 	if (!c->waiting_on_child)
373 		return;
374 	c->waiting_on_child = 0;
375 
376 	fd = fds->fd;
377 	fds->fd = c->fd;
378 	c->fd = fd;
379 }
380 
381 void
382 handle_cgi(struct pollfd *fds, struct client *c)
383 {
384 	ssize_t r;
385 
386 	/* ensure c->fd is the child and fds->fd the client */
387 	cgi_poll_on_client(fds, c);
388 
389 	while (1) {
390 		if (c->len == 0) {
391 			if ((r = read(c->fd, c->sbuf, sizeof(c->sbuf))) == 0)
392 				goto end;
393 			if (r == -1) {
394 				if (errno == EAGAIN || errno == EWOULDBLOCK) {
395 					cgi_poll_on_child(fds, c);
396 					return;
397 				}
398                                 goto end;
399 			}
400 			c->len = r;
401 			c->off = 0;
402 		}
403 
404 		while (c->len > 0) {
405 			switch (r = tls_write(c->ctx, c->sbuf + c->off, c->len)) {
406 			case -1:
407 				goto end;
408 
409 			case TLS_WANT_POLLOUT:
410 				fds->events = POLLOUT;
411 				return;
412 
413 			case TLS_WANT_POLLIN:
414 				fds->events = POLLIN;
415 				return;
416 
417 			default:
418                                 c->off += r;
419 				c->len -= r;
420 				break;
421 			}
422 		}
423 	}
424 
425 end:
426 	goodbye(fds, c);
427 }
428 
429 void
430 send_file(char *path, char *query, struct pollfd *fds, struct client *c)
431 {
432 	ssize_t ret, len;
433 
434 	if (c->fd == -1) {
435 		if (!open_file(path, query, fds, c))
436 			return;
437 		c->state = S_SENDING;
438 	}
439 
440 	len = (c->buf + c->len) - c->i;
441 
442 	while (len > 0) {
443 		switch (ret = tls_write(c->ctx, c->i, len)) {
444 		case -1:
445 			LOGE(c, "tls_write: %s", tls_error(c->ctx));
446 			goodbye(fds, c);
447 			return;
448 
449 		case TLS_WANT_POLLIN:
450 			fds->events = POLLIN;
451 			return;
452 
453 		case TLS_WANT_POLLOUT:
454 			fds->events = POLLOUT;
455 			return;
456 
457 		default:
458 			c->i += ret;
459 			len -= ret;
460 			break;
461 		}
462 	}
463 
464 	goodbye(fds, c);
465 }
466 
467 void
468 send_dir(char *path, struct pollfd *fds, struct client *client)
469 {
470 	char fpath[PATHBUF];
471 	size_t len;
472 
473 	bzero(fpath, PATHBUF);
474 
475 	if (path[0] != '.')
476 		fpath[0] = '.';
477 
478 	/* this cannot fail since sizeof(fpath) > maxlen of path */
479 	strlcat(fpath, path, PATHBUF);
480 	len = strlen(fpath);
481 
482 	/* add a trailing / in case. */
483 	if (fpath[len-1] != '/') {
484 		fpath[len] = '/';
485 	}
486 
487 	strlcat(fpath, "index.gmi", sizeof(fpath));
488 
489 	send_file(fpath, NULL, fds, client);
490 }
491 
492 void
493 handle(struct pollfd *fds, struct client *client)
494 {
495 	char buf[GEMINI_URL_LEN];
496 	const char *parse_err;
497 	struct uri uri;
498 
499 	switch (client->state) {
500 	case S_OPEN:
501 		bzero(buf, GEMINI_URL_LEN);
502 		switch (tls_read(client->ctx, buf, sizeof(buf)-1)) {
503 		case -1:
504 			LOGE(client, "tls_read: %s", tls_error(client->ctx));
505 			goodbye(fds, client);
506 			return;
507 
508 		case TLS_WANT_POLLIN:
509 			fds->events = POLLIN;
510 			return;
511 
512 		case TLS_WANT_POLLOUT:
513 			fds->events = POLLOUT;
514 			return;
515 		}
516 
517 		parse_err = "invalid request";
518 		if (!trim_req_uri(buf) || !parse_uri(buf, &uri, &parse_err)) {
519 			if (!start_reply(fds, client, BAD_REQUEST, parse_err))
520 				return;
521 			goodbye(fds, client);
522 			return;
523 		}
524 
525 		LOGI(client, "GET %s%s%s",
526 		    *uri.path ? uri.path : "/",
527 		    *uri.query ? "?" : "",
528 		    *uri.query ? uri.query : "");
529 
530 		send_file(uri.path, uri.query, fds, client);
531 		break;
532 
533 	case S_INITIALIZING:
534 		if (!start_reply(fds, client, client->code, client->meta))
535 			return;
536 
537 		if (client->code != SUCCESS) {
538 			/* we don't need a body */
539 			goodbye(fds, client);
540 			return;
541 		}
542 
543 		client->state = S_SENDING;
544 
545 		/* fallthrough */
546 
547 	case S_SENDING:
548 		if (client->child != -1)
549 			handle_cgi(fds, client);
550 		else
551 			send_file(NULL, NULL, fds, client);
552 		break;
553 
554 	case S_CLOSING:
555 		goodbye(fds, client);
556 		break;
557 
558 	default:
559 		/* unreachable */
560 		abort();
561 	}
562 }
563 
564 void
565 mark_nonblock(int fd)
566 {
567 	int flags;
568 
569 	if ((flags = fcntl(fd, F_GETFL)) == -1)
570 		FATAL("fcntl(F_GETFL): %s", strerror(errno));
571 	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
572 		FATAL("fcntl(F_SETFL): %s", strerror(errno));
573 }
574 
575 int
576 make_socket(int port, int family)
577 {
578 	int sock, v;
579 	struct sockaddr_in addr4;
580 	struct sockaddr_in6 addr6;
581 	struct sockaddr *addr;
582 	socklen_t len;
583 
584         switch (family) {
585 	case AF_INET:
586 		bzero(&addr4, sizeof(addr4));
587 		addr4.sin_family = family;
588 		addr4.sin_port = htons(port);
589 		addr4.sin_addr.s_addr = INADDR_ANY;
590 		addr = (struct sockaddr*)&addr4;
591 		len = sizeof(addr4);
592 		break;
593 
594 	case AF_INET6:
595 		bzero(&addr6, sizeof(addr6));
596 		addr6.sin6_family = AF_INET6;
597 		addr6.sin6_port = htons(port);
598 		addr6.sin6_addr = in6addr_any;
599 		addr = (struct sockaddr*)&addr6;
600 		len = sizeof(addr6);
601 		break;
602 
603 	default:
604 		/* unreachable */
605 		abort();
606 	}
607 
608 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
609 		FATAL("socket: %s", strerror(errno));
610 
611 	v = 1;
612 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
613 		FATAL("setsockopt(SO_REUSEADDR): %s", strerror(errno));
614 
615 	v = 1;
616 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
617 		FATAL("setsockopt(SO_REUSEPORT): %s", strerror(errno));
618 
619 	mark_nonblock(sock);
620 
621 	if (bind(sock, addr, len) == -1)
622 		FATAL("bind: %s", strerror(errno));
623 
624 	if (listen(sock, 16) == -1)
625 		FATAL("listen: %s", strerror(errno));
626 
627 	return sock;
628 }
629 
630 void
631 do_accept(int sock, struct tls *ctx, struct pollfd *fds, struct client *clients)
632 {
633 	int i, fd;
634 	struct sockaddr_in addr;
635 	socklen_t len;
636 
637 	len = sizeof(addr);
638 	if ((fd = accept(sock, (struct sockaddr*)&addr, &len)) == -1) {
639 		if (errno == EWOULDBLOCK)
640 			return;
641 		FATAL("accept: %s", strerror(errno));
642 	}
643 
644 	mark_nonblock(fd);
645 
646 	for (i = 0; i < MAX_USERS; ++i) {
647 		if (fds[i].fd == -1) {
648 			bzero(&clients[i], sizeof(struct client));
649 			if (tls_accept_socket(ctx, &clients[i].ctx, fd) == -1)
650 				break; /* goodbye fd! */
651 
652 			fds[i].fd = fd;
653 			fds[i].events = POLLIN;
654 
655 			clients[i].state = S_OPEN;
656 			clients[i].fd = -1;
657 			clients[i].child = -1;
658 			clients[i].buf = MAP_FAILED;
659 			clients[i].af = AF_INET;
660 			clients[i].addr = addr.sin_addr;
661 
662 			connected_clients++;
663 			return;
664 		}
665 	}
666 
667 	close(fd);
668 }
669 
670 void
671 goodbye(struct pollfd *pfd, struct client *c)
672 {
673 	ssize_t ret;
674 
675 	c->state = S_CLOSING;
676 
677 	ret = tls_close(c->ctx);
678 	if (ret == TLS_WANT_POLLIN) {
679 		pfd->events = POLLIN;
680 		return;
681 	}
682 	if (ret == TLS_WANT_POLLOUT) {
683 		pfd->events = POLLOUT;
684 		return;
685 	}
686 
687 	connected_clients--;
688 
689 	tls_free(c->ctx);
690 	c->ctx = NULL;
691 
692 	if (c->buf != MAP_FAILED)
693 		munmap(c->buf, c->len);
694 
695 	if (c->fd != -1)
696 		close(c->fd);
697 
698 	close(pfd->fd);
699 	pfd->fd = -1;
700 }
701 
702 void
703 loop(struct tls *ctx, int sock)
704 {
705 	int i;
706 	struct client clients[MAX_USERS];
707 	struct pollfd fds[MAX_USERS];
708 
709 	for (i = 0; i < MAX_USERS; ++i) {
710 		fds[i].fd = -1;
711 		fds[i].events = POLLIN;
712 		bzero(&clients[i], sizeof(struct client));
713 	}
714 
715 	fds[0].fd = sock;
716 
717 	for (;;) {
718 		if (poll(fds, MAX_USERS, INFTIM) == -1) {
719 			if (errno == EINTR) {
720                                 warnx("connected clients: %d",
721 				    connected_clients);
722 				continue;
723 			}
724 			FATAL("poll: %s", strerror(errno));
725 		}
726 
727 		for (i = 0; i < MAX_USERS; i++) {
728 			if (fds[i].revents == 0)
729 				continue;
730 
731 			if (fds[i].revents & (POLLERR|POLLNVAL))
732 				FATAL("bad fd %d: %s", fds[i].fd,
733 				    strerror(errno));
734 
735 			if (fds[i].revents & POLLHUP) {
736 				/* fds[i] may be the fd of the stdin
737 				 * of a cgi script that has exited. */
738 				if (!clients[i].waiting_on_child) {
739 					goodbye(&fds[i], &clients[i]);
740 					continue;
741 				}
742 			}
743 
744 			if (i == 0) { /* new client */
745 				do_accept(sock, ctx, fds, clients);
746 				continue;
747 			}
748 
749 			handle(&fds[i], &clients[i]);
750 		}
751 	}
752 }
753 
754 char *
755 absolutify_path(const char *path)
756 {
757 	char *wd, *r;
758 
759 	if (*path == '/')
760 		return strdup(path);
761 
762 	wd = getwd(NULL);
763 	if (asprintf(&r, "%s/%s", wd, path) == -1)
764 		err(1, "asprintf");
765 	free(wd);
766 	return r;
767 }
768 
769 void
770 usage(const char *me)
771 {
772 	fprintf(stderr,
773 	    "USAGE: %s [-h] [-c cert.pem] [-d docs] [-k key.pem] "
774 	    "[-l logfile] [-p port] [-x cgi-bin]\n",
775 	    me);
776 }
777 
778 int
779 main(int argc, char **argv)
780 {
781 	const char *cert = "cert.pem", *key = "key.pem";
782 	struct tls *ctx = NULL;
783 	struct tls_config *conf;
784 	int sock, ch;
785 	connected_clients = 0;
786 
787 	if ((dir = absolutify_path("docs")) == NULL)
788 		err(1, "absolutify_path");
789 
790 	cgi = NULL;
791 	port = 1965;
792 	foreground = 0;
793 
794 	while ((ch = getopt(argc, argv, "c:d:fhk:p:x:")) != -1) {
795 		switch (ch) {
796 		case 'c':
797 			cert = optarg;
798 			break;
799 
800 		case 'd':
801 			free((char*)dir);
802 			if ((dir = absolutify_path(optarg)) == NULL)
803 				err(1, "absolutify_path");
804 			break;
805 
806 		case 'f':
807 			foreground = 1;
808 			break;
809 
810 		case 'h':
811 			usage(*argv);
812 			return 0;
813 
814 		case 'k':
815 			key = optarg;
816 			break;
817 
818 		case 'p': {
819 			char *ep;
820 			long lval;
821 
822 			errno = 0;
823 			lval = strtol(optarg, &ep, 10);
824 			if (optarg[0] == '\0' || *ep != '\0')
825 				err(1, "not a number: %s", optarg);
826 			if (lval < 0 || lval > UINT16_MAX)
827 				err(1, "port number out of range: %s", optarg);
828 			port = lval;
829 			break;
830 		}
831 
832 		case 'x':
833 			cgi = optarg;
834 			break;
835 
836 		default:
837 			usage(*argv);
838 			return 1;
839 		}
840 	}
841 
842 	signal(SIGPIPE, SIG_IGN);
843 	signal(SIGCHLD, SIG_IGN);
844 
845 #ifdef SIGINFO
846 	signal(SIGINFO, sig_handler);
847 #endif
848 	signal(SIGUSR2, sig_handler);
849 
850 	if (!foreground)
851 		signal(SIGHUP, SIG_IGN);
852 
853 	if ((conf = tls_config_new()) == NULL)
854 		err(1, "tls_config_new");
855 
856 	/* optionally accept client certs, but don't try to verify them */
857 	tls_config_verify_client_optional(conf);
858 	tls_config_insecure_noverifycert(conf);
859 
860 	if (tls_config_set_protocols(conf,
861 	    TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3) == -1)
862 		err(1, "tls_config_set_protocols");
863 
864 	if (tls_config_set_cert_file(conf, cert) == -1)
865 		err(1, "tls_config_set_cert_file: %s", cert);
866 
867 	if (tls_config_set_key_file(conf, key) == -1)
868 		err(1, "tls_config_set_key_file: %s", key);
869 
870 	if ((ctx = tls_server()) == NULL)
871 		err(1, "tls_server");
872 
873 	if (tls_configure(ctx, conf) == -1)
874 		errx(1, "tls_configure: %s", tls_error(ctx));
875 
876 	sock = make_socket(port, AF_INET);
877 
878 	if ((dirfd = open(dir, O_RDONLY | O_DIRECTORY)) == -1)
879 		err(1, "open: %s", dir);
880 
881 	if (!foreground && daemon(0, 1) == -1)
882 		exit(1);
883 
884 	if (unveil(dir, "rx") == -1)
885 		err(1, "unveil");
886 
887 	if (pledge("stdio rpath inet proc exec", NULL) == -1)
888 		err(1, "pledge");
889 
890 	/* drop proc and exec if cgi isn't enabled */
891 	if (cgi == NULL && pledge("stdio rpath inet", NULL) == -1)
892 		err(1, "pledge");
893 
894 	loop(ctx, sock);
895 
896 	close(sock);
897 	tls_free(ctx);
898 	tls_config_free(conf);
899 }