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 siginfo_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 		/* +2 to skip the ./ */
222 		if (cgi != NULL && starts_with(fpath+2, cgi))
223 			return start_cgi(fpath, "", query, fds, c);
224 
225 		/* fallthrough */
226 
227 	case FILE_EXISTS:
228 		if ((c->len = filesize(c->fd)) == -1) {
229 			LOGE(c, "failed to get file size for %s", fpath);
230 			goodbye(fds, c);
231 			return 0;
232 		}
233 
234 		if ((c->buf = mmap(NULL, c->len, PROT_READ, MAP_PRIVATE,
235 			    c->fd, 0)) == MAP_FAILED) {
236 			warn("mmap: %s", fpath);
237 			goodbye(fds, c);
238 			return 0;
239 		}
240 		c->i = c->buf;
241 		return start_reply(fds, c, SUCCESS, mime(fpath));
242 
243 	case FILE_DIRECTORY:
244 		LOGD(c, "%s is a directory, trying %s/index.gmi", fpath, fpath);
245 		close(c->fd);
246 		c->fd = -1;
247 		send_dir(fpath, fds, c);
248 		return 0;
249 
250 	case FILE_MISSING:
251 		if (cgi != NULL && starts_with(fpath+2, cgi))
252 			return check_for_cgi(fpath, query, fds, c);
253 
254 		if (!start_reply(fds, c, NOT_FOUND, "not found"))
255 			return 0;
256 		goodbye(fds, c);
257 		return 0;
258 
259 	default:
260 		/* unreachable */
261 		abort();
262 	}
263 }
264 
265 int
266 start_cgi(const char *spath, const char *relpath, const char *query,
267     struct pollfd *fds, struct client *c)
268 {
269 	pid_t pid;
270 	int p[2]; 		/* read end, write end */
271 
272 	if (pipe(p) == -1)
273 		goto err;
274 
275 	switch (pid = fork()) {
276 	case -1:
277 		goto err;
278 
279 	case 0: { 		/* child */
280 		char *ex, *requri, *portno;
281 		char addr[INET_ADDRSTRLEN];
282 		char *argv[] = { NULL, NULL, NULL };
283 
284 		spath++;
285 
286 		close(p[0]);
287 		if (dup2(p[1], 1) == -1)
288 			goto childerr;
289 
290 		if (inet_ntop(c->af, &c->addr, addr, sizeof(addr)) == NULL)
291 			goto childerr;
292 
293 		if (asprintf(&portno, "%d", port) == -1)
294 			goto childerr;
295 
296 		if (asprintf(&ex, "%s%s", dir, spath+1) == -1)
297 			goto childerr;
298 
299 		if (asprintf(&requri, "%s%s%s", spath,
300 		    *relpath == '\0' ? "" : "/",
301 		    relpath) == -1)
302 			goto childerr;
303 
304 		argv[0] = argv[1] = ex;
305 
306 		/* fix the env */
307 		SAFE_SETENV("GATEWAY_INTERFACE", "CGI/1.1");
308 		SAFE_SETENV("SERVER_SOFTWARE", "gmid");
309 		SAFE_SETENV("SERVER_PORT", portno);
310 		/* setenv("SERVER_NAME", "", 1); */
311 		SAFE_SETENV("SCRIPT_NAME", spath);
312 		SAFE_SETENV("SCRIPT_EXECUTABLE", ex);
313 		SAFE_SETENV("REQUEST_URI", requri);
314 		SAFE_SETENV("REQUEST_RELATIVE", relpath);
315 		SAFE_SETENV("QUERY_STRING", query);
316 		SAFE_SETENV("REMOTE_HOST", addr);
317 		SAFE_SETENV("REMOTE_ADDR", addr);
318 		SAFE_SETENV("DOCUMENT_ROOT", dir);
319 
320 		if (tls_peer_cert_provided(c->ctx)) {
321 			SAFE_SETENV("AUTH_TYPE", "Certificate");
322 			SAFE_SETENV("REMOTE_USER", tls_peer_cert_subject(c->ctx));
323 			SAFE_SETENV("TLS_CLIENT_ISSUER", tls_peer_cert_issuer(c->ctx));
324 			SAFE_SETENV("TLS_CLIENT_HASH", tls_peer_cert_hash(c->ctx));
325 		}
326 
327 		execvp(ex, argv);
328 		goto childerr;
329 	}
330 
331 	default:		/* parent */
332 		close(p[1]);
333 		close(c->fd);
334 		c->fd = p[0];
335 		c->child = pid;
336 		mark_nonblock(c->fd);
337 		c->state = S_SENDING;
338 		handle_cgi(fds, c);
339 		return 0;
340 	}
341 
342 err:
343 	if (!start_reply(fds, c, TEMP_FAILURE, "internal server error"))
344 		return 0;
345 	goodbye(fds, c);
346 	return 0;
347 
348 childerr:
349 	dprintf(p[1], "%d internal server error\r\n", TEMP_FAILURE);
350 	close(p[1]);
351 	_exit(1);
352 }
353 
354 void
355 cgi_setpoll_on_child(struct pollfd *fds, struct client *c)
356 {
357 	int fd;
358 
359 	if (c->waiting_on_child)
360 		return;
361 	c->waiting_on_child = 1;
362 
363 	fds->events = POLLIN;
364 
365 	fd = fds->fd;
366 	fds->fd = c->fd;
367 	c->fd = fd;
368 }
369 
370 void
371 cgi_setpoll_on_client(struct pollfd *fds, struct client *c)
372 {
373 	int fd;
374 
375 	if (!c->waiting_on_child)
376 		return;
377 	c->waiting_on_child = 0;
378 
379 	fd = fds->fd;
380 	fds->fd = c->fd;
381 	c->fd = fd;
382 }
383 
384 void
385 handle_cgi(struct pollfd *fds, struct client *c)
386 {
387 	ssize_t r;
388 
389 	/* ensure c->fd is the child and fds->fd the client */
390 	cgi_setpoll_on_client(fds, c);
391 
392 	while (1) {
393 		if (c->len == 0) {
394 			if ((r = read(c->fd, c->sbuf, sizeof(c->sbuf))) == 0)
395 				goto end;
396 			if (r == -1) {
397 				if (errno == EAGAIN || errno == EWOULDBLOCK) {
398 					cgi_setpoll_on_child(fds, c);
399 					return;
400 				}
401                                 goto end;
402 			}
403 			c->len = r;
404 			c->off = 0;
405 		}
406 
407 		while (c->len > 0) {
408 			switch (r = tls_write(c->ctx, c->sbuf + c->off, c->len)) {
409 			case -1:
410 				goto end;
411 
412 			case TLS_WANT_POLLOUT:
413 				fds->events = POLLOUT;
414 				return;
415 
416 			case TLS_WANT_POLLIN:
417 				fds->events = POLLIN;
418 				return;
419 
420 			default:
421                                 c->off += r;
422 				c->len -= r;
423 				break;
424 			}
425 		}
426 	}
427 
428 end:
429 	goodbye(fds, c);
430 }
431 
432 void
433 send_file(char *path, char *query, struct pollfd *fds, struct client *c)
434 {
435 	ssize_t ret, len;
436 
437 	if (c->fd == -1) {
438 		if (!open_file(path, query, fds, c))
439 			return;
440 		c->state = S_SENDING;
441 	}
442 
443 	len = (c->buf + c->len) - c->i;
444 
445 	while (len > 0) {
446 		switch (ret = tls_write(c->ctx, c->i, len)) {
447 		case -1:
448 			LOGE(c, "tls_write: %s", tls_error(c->ctx));
449 			goodbye(fds, c);
450 			return;
451 
452 		case TLS_WANT_POLLIN:
453 			fds->events = POLLIN;
454 			return;
455 
456 		case TLS_WANT_POLLOUT:
457 			fds->events = POLLOUT;
458 			return;
459 
460 		default:
461 			c->i += ret;
462 			len -= ret;
463 			break;
464 		}
465 	}
466 
467 	goodbye(fds, c);
468 }
469 
470 void
471 send_dir(char *path, struct pollfd *fds, struct client *client)
472 {
473 	char fpath[PATHBUF];
474 	size_t len;
475 
476 	bzero(fpath, PATHBUF);
477 
478 	if (path[0] != '.')
479 		fpath[0] = '.';
480 
481 	/* this cannot fail since sizeof(fpath) > maxlen of path */
482 	strlcat(fpath, path, PATHBUF);
483 	len = strlen(fpath);
484 
485 	/* add a trailing / in case. */
486 	if (fpath[len-1] != '/') {
487 		fpath[len] = '/';
488 	}
489 
490 	strlcat(fpath, "index.gmi", sizeof(fpath));
491 
492 	send_file(fpath, NULL, fds, client);
493 }
494 
495 void
496 handle(struct pollfd *fds, struct client *client)
497 {
498 	char buf[GEMINI_URL_LEN];
499 	const char *parse_err;
500 	struct uri uri;
501 
502 	switch (client->state) {
503 	case S_OPEN:
504 		bzero(buf, GEMINI_URL_LEN);
505 		switch (tls_read(client->ctx, buf, sizeof(buf)-1)) {
506 		case -1:
507 			LOGE(client, "tls_read: %s", tls_error(client->ctx));
508 			goodbye(fds, client);
509 			return;
510 
511 		case TLS_WANT_POLLIN:
512 			fds->events = POLLIN;
513 			return;
514 
515 		case TLS_WANT_POLLOUT:
516 			fds->events = POLLOUT;
517 			return;
518 		}
519 
520 		if (!trim_req_uri(buf) || !parse_uri(buf, &uri, &parse_err)) {
521 			if (!start_reply(fds, client, BAD_REQUEST, parse_err))
522 				return;
523 			goodbye(fds, client);
524 			return;
525 		}
526 
527 		LOGI(client, "GET %s%s%s",
528 		    *uri.path ? uri.path : "/",
529 		    *uri.query ? "?" : "",
530 		    *uri.query ? uri.query : "");
531 
532 		send_file(uri.path, uri.query, fds, client);
533 		break;
534 
535 	case S_INITIALIZING:
536 		if (!start_reply(fds, client, client->code, client->meta))
537 			return;
538 
539 		if (client->code != SUCCESS) {
540 			/* we don't need a body */
541 			goodbye(fds, client);
542 			return;
543 		}
544 
545 		client->state = S_SENDING;
546 
547 		/* fallthrough */
548 
549 	case S_SENDING:
550 		if (client->child != -1)
551 			handle_cgi(fds, client);
552 		else
553 			send_file(NULL, NULL, fds, client);
554 		break;
555 
556 	case S_CLOSING:
557 		goodbye(fds, client);
558 		break;
559 
560 	default:
561 		/* unreachable */
562 		abort();
563 	}
564 }
565 
566 void
567 mark_nonblock(int fd)
568 {
569 	int flags;
570 
571 	if ((flags = fcntl(fd, F_GETFL)) == -1)
572 		FATAL("fcntl(F_GETFL): %s", strerror(errno));
573 	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
574 		FATAL("fcntl(F_SETFL): %s", strerror(errno));
575 }
576 
577 int
578 make_socket(int port, int family)
579 {
580 	int sock, v;
581 	struct sockaddr_in addr4;
582 	struct sockaddr_in6 addr6;
583 	struct sockaddr *addr;
584 	socklen_t len;
585 
586         switch (family) {
587 	case AF_INET:
588 		bzero(&addr4, sizeof(addr4));
589 		addr4.sin_family = family;
590 		addr4.sin_port = htons(port);
591 		addr4.sin_addr.s_addr = INADDR_ANY;
592 		addr = (struct sockaddr*)&addr4;
593 		len = sizeof(addr4);
594 		break;
595 
596 	case AF_INET6:
597 		bzero(&addr6, sizeof(addr6));
598 		addr6.sin6_family = AF_INET6;
599 		addr6.sin6_port = htons(port);
600 		addr6.sin6_addr = in6addr_any;
601 		addr = (struct sockaddr*)&addr6;
602 		len = sizeof(addr6);
603 		break;
604 
605 	default:
606 		/* unreachable */
607 		abort();
608 	}
609 
610 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
611 		FATAL("socket: %s", strerror(errno));
612 
613 	v = 1;
614 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
615 		FATAL("setsockopt(SO_REUSEADDR): %s", strerror(errno));
616 
617 	v = 1;
618 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
619 		FATAL("setsockopt(SO_REUSEPORT): %s", strerror(errno));
620 
621 	mark_nonblock(sock);
622 
623 	if (bind(sock, addr, len) == -1)
624 		FATAL("bind: %s", strerror(errno));
625 
626 	if (listen(sock, 16) == -1)
627 		FATAL("listen: %s", strerror(errno));
628 
629 	return sock;
630 }
631 
632 void
633 do_accept(int sock, struct tls *ctx, struct pollfd *fds, struct client *clients)
634 {
635 	int i, fd;
636 	struct sockaddr_in addr;
637 	socklen_t len;
638 
639 	len = sizeof(addr);
640 	if ((fd = accept(sock, (struct sockaddr*)&addr, &len)) == -1) {
641 		if (errno == EWOULDBLOCK)
642 			return;
643 		FATAL("accept: %s", strerror(errno));
644 	}
645 
646 	mark_nonblock(fd);
647 
648 	for (i = 0; i < MAX_USERS; ++i) {
649 		if (fds[i].fd == -1) {
650 			bzero(&clients[i], sizeof(struct client));
651 			if (tls_accept_socket(ctx, &clients[i].ctx, fd) == -1)
652 				break; /* goodbye fd! */
653 
654 			fds[i].fd = fd;
655 			fds[i].events = POLLIN;
656 
657 			clients[i].state = S_OPEN;
658 			clients[i].fd = -1;
659 			clients[i].child = -1;
660 			clients[i].buf = MAP_FAILED;
661 			clients[i].af = AF_INET;
662 			clients[i].addr = addr.sin_addr;
663 
664 			connected_clients++;
665 			return;
666 		}
667 	}
668 
669 	close(fd);
670 }
671 
672 void
673 goodbye(struct pollfd *pfd, struct client *c)
674 {
675 	ssize_t ret;
676 
677 	c->state = S_CLOSING;
678 
679 	ret = tls_close(c->ctx);
680 	if (ret == TLS_WANT_POLLIN) {
681 		pfd->events = POLLIN;
682 		return;
683 	}
684 	if (ret == TLS_WANT_POLLOUT) {
685 		pfd->events = POLLOUT;
686 		return;
687 	}
688 
689 	connected_clients--;
690 
691 	tls_free(c->ctx);
692 	c->ctx = NULL;
693 
694 	if (c->buf != MAP_FAILED)
695 		munmap(c->buf, c->len);
696 
697 	if (c->fd != -1)
698 		close(c->fd);
699 
700 	close(pfd->fd);
701 	pfd->fd = -1;
702 }
703 
704 void
705 loop(struct tls *ctx, int sock)
706 {
707 	int i, todo;
708 	struct client clients[MAX_USERS];
709 	struct pollfd fds[MAX_USERS];
710 
711 	for (i = 0; i < MAX_USERS; ++i) {
712 		fds[i].fd = -1;
713 		fds[i].events = POLLIN;
714 		bzero(&clients[i], sizeof(struct client));
715 	}
716 
717 	fds[0].fd = sock;
718 
719 	for (;;) {
720 		if ((todo = poll(fds, MAX_USERS, INFTIM)) == -1) {
721 			if (errno == EINTR) {
722                                 warnx("connected clients: %d",
723 				    connected_clients);
724 				continue;
725 			}
726 			FATAL("poll: %s", strerror(errno));
727 		}
728 
729 		for (i = 0; i < MAX_USERS; i++) {
730 			assert(i < MAX_USERS);
731 
732 			if (fds[i].revents == 0)
733 				continue;
734 
735 			if (fds[i].revents & (POLLERR|POLLNVAL))
736 				FATAL("bad fd %d: %s", fds[i].fd,
737 				    strerror(errno));
738 
739 			if (fds[i].revents & POLLHUP) {
740 				/* fds[i] may be the fd of the stdin
741 				 * of a cgi script that has exited. */
742 				if (!clients[i].waiting_on_child) {
743 					goodbye(&fds[i], &clients[i]);
744 					continue;
745 				}
746 			}
747 
748 			todo--;
749 
750 			if (i == 0) { /* new client */
751 				do_accept(sock, ctx, fds, clients);
752 				continue;
753 			}
754 
755 			handle(&fds[i], &clients[i]);
756 		}
757 	}
758 }
759 
760 char *
761 absolutify_path(const char *path)
762 {
763 	char *wd, *r;
764 
765 	if (*path == '/')
766 		return strdup(path);
767 
768 	wd = getwd(NULL);
769 	if (asprintf(&r, "%s/%s", wd, path) == -1)
770 		err(1, "asprintf");
771 	free(wd);
772 	return r;
773 }
774 
775 void
776 usage(const char *me)
777 {
778 	fprintf(stderr,
779 	    "USAGE: %s [-h] [-c cert.pem] [-d docs] [-k key.pem] "
780 	    "[-l logfile] [-p port] [-x cgi-bin]\n",
781 	    me);
782 }
783 
784 int
785 main(int argc, char **argv)
786 {
787 	const char *cert = "cert.pem", *key = "key.pem";
788 	struct tls *ctx = NULL;
789 	struct tls_config *conf;
790 	int sock, ch;
791 
792 	signal(SIGPIPE, SIG_IGN);
793 	signal(SIGCHLD, SIG_IGN);
794 
795 #ifdef SIGINFO
796 	signal(SIGINFO, siginfo_handler);
797 #endif
798 	signal(SIGUSR2, siginfo_handler);
799 
800 	connected_clients = 0;
801 
802 	if ((dir = absolutify_path("docs")) == NULL)
803 		err(1, "absolutify_path");
804 
805 	cgi = NULL;
806 	port = 1965;
807 	foreground = 0;
808 
809 	while ((ch = getopt(argc, argv, "c:d:fhk:p:x:")) != -1) {
810 		switch (ch) {
811 		case 'c':
812 			cert = optarg;
813 			break;
814 
815 		case 'd':
816 			free((char*)dir);
817 			if ((dir = absolutify_path(optarg)) == NULL)
818 				err(1, "absolutify_path");
819 			break;
820 
821 		case 'f':
822 			foreground = 1;
823 			break;
824 
825 		case 'h':
826 			usage(*argv);
827 			return 0;
828 
829 		case 'k':
830 			key = optarg;
831 			break;
832 
833 		case 'p': {
834 			char *ep;
835 			long lval;
836 
837 			errno = 0;
838 			lval = strtol(optarg, &ep, 10);
839 			if (optarg[0] == '\0' || *ep != '\0')
840 				err(1, "not a number: %s", optarg);
841 			if (lval < 0 || lval > UINT16_MAX)
842 				err(1, "port number out of range: %s", optarg);
843 			port = lval;
844 			break;
845 		}
846 
847 		case 'x':
848 			cgi = optarg;
849 			break;
850 
851 		default:
852 			usage(*argv);
853 			return 1;
854 		}
855 	}
856 
857 	if ((conf = tls_config_new()) == NULL)
858 		err(1, "tls_config_new");
859 
860 	/* optionally accept client certs, but don't try to verify them */
861 	tls_config_verify_client_optional(conf);
862 	tls_config_insecure_noverifycert(conf);
863 
864 	if (tls_config_set_protocols(conf,
865 	    TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3) == -1)
866 		err(1, "tls_config_set_protocols");
867 
868 	if (tls_config_set_cert_file(conf, cert) == -1)
869 		err(1, "tls_config_set_cert_file: %s", cert);
870 
871 	if (tls_config_set_key_file(conf, key) == -1)
872 		err(1, "tls_config_set_key_file: %s", key);
873 
874 	if ((ctx = tls_server()) == NULL)
875 		err(1, "tls_server");
876 
877 	if (tls_configure(ctx, conf) == -1)
878 		errx(1, "tls_configure: %s", tls_error(ctx));
879 
880 	sock = make_socket(port, AF_INET);
881 
882 	if ((dirfd = open(dir, O_RDONLY | O_DIRECTORY)) == -1)
883 		err(1, "open: %s", dir);
884 
885 	if (!foreground && daemon(0, 1) == -1)
886 		exit(1);
887 
888 	if (cgi != NULL) {
889 		if (unveil(dir, "rx") == -1)
890 			err(1, "unveil");
891 		if (pledge("stdio rpath inet proc exec", NULL) == -1)
892 			err(1, "pledge");
893 	} else {
894 		if (unveil(dir, "r") == -1)
895 			err(1, "unveil");
896 		if (pledge("stdio rpath inet", NULL) == -1)
897 			err(1, "pledge");
898 	}
899 
900 	loop(ctx, sock);
901 
902 	close(sock);
903 	tls_free(ctx);
904 	tls_config_free(conf);
905 }