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Date:: Fri Nov 6 17:05:44 2020 UTC
Message:: [cgi] execute cgi scripts only inside a specific directory change the meaning of the -x flag: now it takes a string and executes CGI scripts only if they are inside a directory with the given name, relatively to the document root.
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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 <arpa/inet.h>
22 #include <netinet/in.h>
23 
24 #include <assert.h>
25 #include <err.h>
26 #include <errno.h>
27 #include <fcntl.h>
28 #include <poll.h>
29 #include <signal.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <tls.h>
34 #include <unistd.h>
35 
36 #ifndef __OpenBSD__
37 # define pledge(a, b) 0
38 # define unveil(a, b) 0
39 #endif /* __OpenBSD__ */
40 
41 #ifndef INFTIM
42 # define INFTIM -1
43 #endif /* INFTIM */
44 
45 #define GEMINI_URL_LEN (1024+3)	/* URL max len + \r\n + \0 */
46 
47 /* large enough to hold a copy of a gemini URL and still have extra room */
48 #define PATHBUF		2048
49 
50 #define SUCCESS		20
51 #define TEMP_FAILURE	40
52 #define NOT_FOUND	51
53 #define BAD_REQUEST	59
54 
55 #ifndef MAX_USERS
56 #define MAX_USERS	64
57 #endif
58 
59 enum {
60 	S_OPEN,
61 	S_INITIALIZING,
62 	S_SENDING,
63 	S_CLOSING,
64 };
65 
66 struct client {
67 	struct tls	*ctx;
68 	int		 state;
69 	int		 code;
70 	const char	*meta;
71 	int		 fd, waiting_on_child;
72 	pid_t		 child;
73 	char		 sbuf[1024];	  /* static buffer */
74 	void		*buf, *i;	  /* mmap buffer */
75 	ssize_t		 len, off;	  /* mmap/static buffer  */
76 	int		 af;
77 	struct in_addr	 addr;
78 };
79 
80 struct etm {			/* file extension to mime */
81 	const char	*mime;
82 	const char	*ext;
83 } filetypes[] = {
84 	{"application/pdf",	"pdf"},
85 
86 	{"image/gif",		"gif"},
87 	{"image/jpeg",		"jpg"},
88 	{"image/jpeg",		"jpeg"},
89 	{"image/png",		"png"},
90 	{"image/svg+xml",	"svg"},
91 
92 	{"text/gemini",		"gemini"},
93 	{"text/gemini",		"gmi"},
94 	{"text/markdown",	"markdown"},
95 	{"text/markdown",	"md"},
96 	{"text/plain",		"txt"},
97 	{"text/xml",		"xml"},
98 
99 	{NULL, NULL}
100 };
101 
102 #define LOG(c, fmt, ...)						\
103 	do {								\
104 		char buf[INET_ADDRSTRLEN];				\
105 		if (inet_ntop((c)->af, &(c)->addr, buf, sizeof(buf)) == NULL) \
106 			err(1, "inet_ntop");				\
107 		dprintf(logfd, "[%s] " fmt "\n", buf, __VA_ARGS__);	\
108 	} while (0)
109 
110 const char *dir, *cgi;
111 int dirfd, logfd;
112 int connected_clients;
113 
114 void		 siginfo_handler(int);
115 int		 starts_with(const char*, const char*);
116 
117 char		*url_after_proto(char*);
118 char		*url_start_of_request(char*);
119 int		 url_trim(struct client*, char*);
120 char		*adjust_path(char*);
121 int		 path_isdir(char*);
122 ssize_t		 filesize(int);
123 
124 int		 start_reply(struct pollfd*, struct client*, int, const char*);
125 const char	*path_ext(const char*);
126 const char	*mime(const char*);
127 int		 open_file(char*, char*, struct pollfd*, struct client*);
128 void		 start_cgi(const char*, const char*, struct pollfd*, struct client*);
129 void		 cgi_setpoll_on_child(struct pollfd*, struct client*);
130 void		 cgi_setpoll_on_client(struct pollfd*, struct client*);
131 void		 handle_cgi(struct pollfd*, struct client*);
132 void		 send_file(char*, char*, struct pollfd*, struct client*);
133 void		 send_dir(char*, struct pollfd*, struct client*);
134 void		 handle(struct pollfd*, struct client*);
135 
136 void		 mark_nonblock(int);
137 int		 make_soket(int);
138 void		 do_accept(int, struct tls*, struct pollfd*, struct client*);
139 void		 goodbye(struct pollfd*, struct client*);
140 void		 loop(struct tls*, int);
141 
142 void		 usage(const char*);
143 
144 void
145 siginfo_handler(int sig)
146 {
147 	(void)sig;
148 }
149 
150 int
151 starts_with(const char *str, const char *prefix)
152 {
153 	size_t i;
154 
155 	for (i = 0; prefix[i] != '\0'; ++i)
156 		if (str[i] != prefix[i])
157 			return 0;
158 	return 1;
159 }
160 
161 char *
162 url_after_proto(char *url)
163 {
164 	char *s;
165 	const char *proto = "gemini";
166 	const char *marker = "://";
167 
168 	/* a relative URL */
169 	if ((s = strstr(url, marker)) == NULL)
170 		return url;
171 
172 	if (s - strlen(proto) != url)
173 		return NULL;
174 
175 	if (!starts_with(url, proto))
176 		return NULL;
177 
178 	/* a valid gemini:// URL */
179 	return s + strlen(marker);
180 }
181 
182 char *
183 url_start_of_request(char *url)
184 {
185 	char *s, *t;
186 
187 	if ((s = url_after_proto(url)) == NULL)
188 		return NULL;
189 
190 	if ((t = strstr(s, "/")) == NULL)
191 		return s + strlen(s);
192 	return t;
193 }
194 
195 int
196 url_trim(struct client *c, char *url)
197 {
198 	const char *e = "\r\n";
199 	char *s;
200 
201 	if ((s = strstr(url, e)) == NULL)
202 		return 0;
203 	s[0] = '\0';
204 	s[1] = '\0';
205 
206 	if (s[2] != '\0') {
207 		LOG(c, "%s", "request longer than 1024 bytes\n");
208 		return 0;
209 	}
210 
211 	return 1;
212 }
213 
214 char *
215 adjust_path(char *path)
216 {
217 	char *s, *query;
218 	size_t len;
219 
220 	if ((query = strchr(path, '?')) != NULL) {
221 		*query = '\0';
222 		query++;
223 	}
224 
225 	/* /.. -> / */
226 	len = strlen(path);
227 	if (len >= 3) {
228 		if (!strcmp(&path[len-3], "/..")) {
229 			path[len-2] = '\0';
230 		}
231 	}
232 
233 	/* if the path is only `..` trim out and exit */
234 	if (!strcmp(path, "..")) {
235 		path[0] = '\0';
236 		return query;
237 	}
238 
239 	/* remove every ../ in the path */
240 	while (1) {
241 		if ((s = strstr(path, "../")) == NULL)
242 			return query;
243 		memmove(s, s+3, strlen(s)+1);	/* copy also the \0 */
244 	}
245 }
246 
247 int
248 path_isdir(char *path)
249 {
250 	if (*path == '\0')
251 		return 1;
252 	return path[strlen(path)-1] == '/';
253 }
254 
255 int
256 start_reply(struct pollfd *pfd, struct client *client, int code, const char *reason)
257 {
258 	char buf[1030] = {0}; 	/* status + ' ' + max reply len + \r\n\0 */
259 	int len;
260 	int ret;
261 
262 	client->code = code;
263 	client->meta = reason;
264 	client->state = S_INITIALIZING;
265 
266 	len = snprintf(buf, sizeof(buf), "%d %s\r\n", code, reason);
267 	assert(len < (int)sizeof(buf));
268 	ret = tls_write(client->ctx, buf, len);
269 	if (ret == TLS_WANT_POLLIN) {
270 		pfd->events = POLLIN;
271 		return 0;
272 	}
273 
274 	if (ret == TLS_WANT_POLLOUT) {
275 		pfd->events = POLLOUT;
276 		return 0;
277 	}
278 
279 	return 1;
280 }
281 
282 ssize_t
283 filesize(int fd)
284 {
285 	ssize_t len;
286 
287 	if ((len = lseek(fd, 0, SEEK_END)) == -1)
288 		return -1;
289 	if (lseek(fd, 0, SEEK_SET) == -1)
290 		return -1;
291 	return len;
292 }
293 
294 const char *
295 path_ext(const char *path)
296 {
297 	const char *end;
298 
299 	end = path + strlen(path)-1; /* the last byte before the NUL */
300 	for (; end != path; --end) {
301 		if (*end == '.')
302 			return end+1;
303 		if (*end == '/')
304 			break;
305 	}
306 
307 	return NULL;
308 }
309 
310 const char *
311 mime(const char *path)
312 {
313 	const char *ext, *def = "application/octet-stream";
314 	struct etm *t;
315 
316 	if ((ext = path_ext(path)) == NULL)
317 		return def;
318 
319 	for (t = filetypes; t->mime != NULL; ++t)
320 		if (!strcmp(ext, t->ext))
321 			return t->mime;
322 
323 	return def;
324 }
325 
326 int
327 open_file(char *path, char *query, struct pollfd *fds, struct client *c)
328 {
329 	char fpath[PATHBUF];
330 	struct stat sb;
331 
332 	assert(path != NULL);
333 
334 	bzero(fpath, sizeof(fpath));
335 
336 	if (*path != '.')
337 		fpath[0] = '.';
338 	strlcat(fpath, path, PATHBUF);
339 
340 	if ((c->fd = openat(dirfd, fpath,
341 		    O_RDONLY | O_NOFOLLOW | O_CLOEXEC)) == -1) {
342 		LOG(c, "open failed: %s", fpath);
343 		if (!start_reply(fds, c, NOT_FOUND, "not found"))
344 			return 0;
345 		goodbye(fds, c);
346 		return 0;
347 	}
348 
349 	if (fstat(c->fd, &sb) == -1) {
350 		LOG(c, "fstat failed for %s", fpath);
351 		if (!start_reply(fds, c, TEMP_FAILURE, "internal server error"))
352 			return 0;
353 		goodbye(fds, c);
354 		return 0;
355 	}
356 
357 	if (S_ISDIR(sb.st_mode)) {
358 		LOG(c, "%s is a directory, trying %s/index.gmi", fpath, fpath);
359 		close(c->fd);
360 		c->fd = -1;
361 		send_dir(fpath, fds, c);
362 		return 0;
363 	}
364 
365 	/* +2 to skip the ./ */
366 	if ((sb.st_mode & S_IXUSR) && cgi != NULL && starts_with(fpath+2, cgi)) {
367 		start_cgi(fpath, query, fds, c);
368 		return 0;
369 	}
370 
371 	if ((c->len = filesize(c->fd)) == -1) {
372 		LOG(c, "failed to get file size for %s", fpath);
373 		goodbye(fds, c);
374 		return 0;
375 	}
376 
377 	if ((c->buf = mmap(NULL, c->len, PROT_READ, MAP_PRIVATE,
378 		    c->fd, 0)) == MAP_FAILED) {
379 		warn("mmap: %s", fpath);
380 		goodbye(fds, c);
381 		return 0;
382 	}
383 	c->i = c->buf;
384 
385 	return start_reply(fds, c, SUCCESS, mime(fpath));
386 }
387 
388 void
389 start_cgi(const char *path, const char *query,
390     struct pollfd *fds, struct client *c)
391 {
392 	pid_t pid;
393 	int p[2];
394 
395 	if (pipe(p) == -1)
396 		goto err;
397 
398 	switch (pid = fork()) {
399 	case -1:
400 		goto err;
401 
402 	case 0: {		/* child */
403                 char *expath;
404 		char addr[INET_ADDRSTRLEN];
405 		char *argv[] = { NULL, NULL, NULL };
406 
407 		/* skip the initial ./ */
408 		path += 2;
409 
410 		close(p[0]);	/* close the read end */
411 		if (dup2(p[1], 1) == -1)
412 			goto childerr;
413 
414 		if (inet_ntop(c->af, &c->addr, addr, sizeof(addr)) == NULL)
415                         goto childerr;
416 
417 		/* skip the ./ at the start of path*/
418 		if (asprintf(&expath, "%s%s", dir, path) == -1)
419 			goto childerr;
420 		argv[0] = argv[1] = expath;
421 
422 		/* fix the env */
423 		setenv("SERVER_SOFTWARE", "gmid", 1);
424 		/* setenv("SERVER_NAME", "", 1); */
425 		/* setenv("GATEWAY_INTERFACE", "CGI/version", 1); */
426 		setenv("SERVER_PROTOCOL", "gemini", 1);
427 		setenv("SERVER_PORT", "1965", 1);
428 		setenv("PATH_INFO", path, 1);
429 		setenv("PATH_TRANSLATED", expath, 1);
430 		if (query != NULL)
431 			setenv("QUERY_STRING", query, 1);
432 		setenv("REMOTE_ADDR", addr, 1);
433 
434 		execvp(expath, argv);
435 		goto childerr;
436 	}
437 
438 	default:		/* parent */
439 		close(p[1]);	/* close the write end */
440 		close(c->fd);
441 		c->fd = p[0];
442 		c->child = pid;
443 		mark_nonblock(c->fd);
444 		c->state = S_SENDING;
445 		handle_cgi(fds, c);
446 		return;
447 	}
448 
449 err:
450 	if (!start_reply(fds, c, TEMP_FAILURE, "internal server error"))
451 		return;
452 	goodbye(fds, c);
453 	return;
454 
455 childerr:
456 	dprintf(p[1], "%d internal server error\r\n", TEMP_FAILURE);
457 	close(p[1]);
458 
459 	/* don't call atexit stuff */
460         _exit(1);
461 }
462 
463 void
464 cgi_setpoll_on_child(struct pollfd *fds, struct client *c)
465 {
466 	int fd;
467 
468 	if (c->waiting_on_child)
469 		return;
470 	c->waiting_on_child = 1;
471 
472 	fds->events = POLLIN;
473 
474 	fd = fds->fd;
475 	fds->fd = c->fd;
476 	c->fd = fd;
477 }
478 
479 void
480 cgi_setpoll_on_client(struct pollfd *fds, struct client *c)
481 {
482 	int fd;
483 
484 	if (!c->waiting_on_child)
485 		return;
486 	c->waiting_on_child = 0;
487 
488 	fd = fds->fd;
489 	fds->fd = c->fd;
490 	c->fd = fd;
491 }
492 
493 void
494 handle_cgi(struct pollfd *fds, struct client *c)
495 {
496 	ssize_t r;
497 
498 	/* ensure c->fd is the child and fds->fd the client */
499 	cgi_setpoll_on_client(fds, c);
500 
501 	while (1) {
502 		if (c->len == 0) {
503 			if ((r = read(c->fd, c->sbuf, sizeof(c->sbuf))) == 0)
504 				goto end;
505 			if (r == -1) {
506 				if (errno == EAGAIN || errno == EWOULDBLOCK) {
507 					cgi_setpoll_on_child(fds, c);
508 					return;
509 				}
510                                 goto end;
511 			}
512 			c->len = r;
513 			c->off = 0;
514 		}
515 
516 		while (c->len > 0) {
517 			switch (r = tls_write(c->ctx, c->sbuf + c->off, c->len)) {
518 			case -1:
519 				goto end;
520 
521 			case TLS_WANT_POLLOUT:
522 				fds->events = POLLOUT;
523 				return;
524 
525 			case TLS_WANT_POLLIN:
526 				fds->events = POLLIN;
527 				return;
528 
529 			default:
530                                 c->off += r;
531 				c->len -= r;
532 				break;
533 			}
534 		}
535 	}
536 
537 end:
538 	goodbye(fds, c);
539 }
540 
541 void
542 send_file(char *path, char *query, struct pollfd *fds, struct client *c)
543 {
544 	ssize_t ret, len;
545 
546 	if (c->fd == -1) {
547 		if (!open_file(path, query, fds, c))
548 			return;
549 		c->state = S_SENDING;
550 	}
551 
552 	len = (c->buf + c->len) - c->i;
553 
554 	while (len > 0) {
555 		switch (ret = tls_write(c->ctx, c->i, len)) {
556 		case -1:
557 			LOG(c, "tls_write: %s", tls_error(c->ctx));
558 			goodbye(fds, c);
559 			return;
560 
561 		case TLS_WANT_POLLIN:
562 			fds->events = POLLIN;
563 			return;
564 
565 		case TLS_WANT_POLLOUT:
566 			fds->events = POLLOUT;
567 			return;
568 
569 		default:
570 			c->i += ret;
571 			len -= ret;
572 			break;
573 		}
574 	}
575 
576 	goodbye(fds, c);
577 }
578 
579 void
580 send_dir(char *path, struct pollfd *fds, struct client *client)
581 {
582 	char fpath[PATHBUF];
583 	size_t len;
584 
585 	bzero(fpath, PATHBUF);
586 
587 	if (path[0] != '.')
588 		fpath[0] = '.';
589 
590 	/* this cannot fail since sizeof(fpath) > maxlen of path */
591 	strlcat(fpath, path, PATHBUF);
592 	len = strlen(fpath);
593 
594 	/* add a trailing / in case. */
595 	if (fpath[len-1] != '/') {
596 		fpath[len] = '/';
597 	}
598 
599 	strlcat(fpath, "index.gmi", sizeof(fpath));
600 
601 	send_file(fpath, NULL, fds, client);
602 }
603 
604 void
605 handle(struct pollfd *fds, struct client *client)
606 {
607 	char buf[GEMINI_URL_LEN];
608 	char *path;
609 	char *query;
610 
611 	switch (client->state) {
612 	case S_OPEN:
613 		bzero(buf, GEMINI_URL_LEN);
614 		switch (tls_read(client->ctx, buf, sizeof(buf)-1)) {
615 		case -1:
616 			LOG(client, "tls_read: %s", tls_error(client->ctx));
617 			goodbye(fds, client);
618 			return;
619 
620 		case TLS_WANT_POLLIN:
621 			fds->events = POLLIN;
622 			return;
623 
624 		case TLS_WANT_POLLOUT:
625 			fds->events = POLLOUT;
626 			return;
627 		}
628 
629 		if (!url_trim(client, buf)) {
630 			if (!start_reply(fds, client, BAD_REQUEST, "bad request"))
631 				return;
632 			goodbye(fds, client);
633 			return;
634 		}
635 
636 		if ((path = url_start_of_request(buf)) == NULL) {
637 			if (!start_reply(fds, client, BAD_REQUEST, "bad request"))
638 				return;
639 			goodbye(fds, client);
640 			return;
641 		}
642 
643 		query = adjust_path(path);
644 		LOG(client, "get %s%s%s", path,
645 		    query ? "?" : "",
646 		    query ? query : "");
647 
648 		if (path_isdir(path))
649 			send_dir(path, fds, client);
650 		else
651 			send_file(path, query, fds, client);
652 		break;
653 
654 	case S_INITIALIZING:
655 		if (!start_reply(fds, client, client->code, client->meta))
656 			return;
657 
658 		if (client->code != SUCCESS) {
659 			/* we don't need a body */
660 			goodbye(fds, client);
661 			return;
662 		}
663 
664 		client->state = S_SENDING;
665 
666 		/* fallthrough */
667 
668 	case S_SENDING:
669 		if (client->child != -1)
670 			handle_cgi(fds, client);
671 		else
672 			send_file(NULL, NULL, fds, client);
673 		break;
674 
675 	case S_CLOSING:
676 		goodbye(fds, client);
677 		break;
678 
679 	default:
680 		/* unreachable */
681 		abort();
682 	}
683 }
684 
685 void
686 mark_nonblock(int fd)
687 {
688 	int flags;
689 
690 	if ((flags = fcntl(fd, F_GETFL)) == -1)
691 		err(1, "fcntl(F_GETFL)");
692 	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
693 		err(1, "fcntl(F_SETFL)");
694 }
695 
696 int
697 make_socket(int port, int family)
698 {
699 	int sock, v;
700 	struct sockaddr_in addr4;
701 	struct sockaddr_in6 addr6;
702 	struct sockaddr *addr;
703 	socklen_t len;
704 
705         switch (family) {
706 	case AF_INET:
707 		bzero(&addr4, sizeof(addr4));
708 		addr4.sin_family = family;
709 		addr4.sin_port = htons(port);
710 		addr4.sin_addr.s_addr = INADDR_ANY;
711 		addr = (struct sockaddr*)&addr4;
712 		len = sizeof(addr4);
713 		break;
714 
715 	case AF_INET6:
716 		bzero(&addr6, sizeof(addr6));
717 		addr6.sin6_family = AF_INET6;
718 		addr6.sin6_port = htons(port);
719 		addr6.sin6_addr = in6addr_any;
720 		addr = (struct sockaddr*)&addr6;
721 		len = sizeof(addr6);
722 		break;
723 
724 	default:
725 		/* unreachable */
726 		abort();
727 	}
728 
729 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
730 		err(1, "socket");
731 
732 	v = 1;
733 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
734 		err(1, "setsockopt(SO_REUSEADDR)");
735 
736 	v = 1;
737 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
738 		err(1, "setsockopt(SO_REUSEPORT)");
739 
740 	mark_nonblock(sock);
741 
742 	if (bind(sock, addr, len) == -1)
743 		err(1, "bind");
744 
745 	if (listen(sock, 16) == -1)
746 		err(1, "listen");
747 
748 	return sock;
749 }
750 
751 void
752 do_accept(int sock, struct tls *ctx, struct pollfd *fds, struct client *clients)
753 {
754 	int i, fd;
755 	struct sockaddr_in addr;
756 	socklen_t len;
757 
758 	len = sizeof(addr);
759 	if ((fd = accept(sock, (struct sockaddr*)&addr, &len)) == -1) {
760 		if (errno == EWOULDBLOCK)
761 			return;
762 		err(1, "accept");
763 	}
764 
765 	mark_nonblock(fd);
766 
767 	for (i = 0; i < MAX_USERS; ++i) {
768 		if (fds[i].fd == -1) {
769 			bzero(&clients[i], sizeof(struct client));
770 			if (tls_accept_socket(ctx, &clients[i].ctx, fd) == -1)
771 				break; /* goodbye fd! */
772 
773 			fds[i].fd = fd;
774 			fds[i].events = POLLIN;
775 
776 			clients[i].state = S_OPEN;
777 			clients[i].fd = -1;
778 			clients[i].child = -1;
779 			clients[i].buf = MAP_FAILED;
780 			clients[i].af = AF_INET;
781 			clients[i].addr = addr.sin_addr;
782 
783 			connected_clients++;
784 			return;
785 		}
786 	}
787 
788 	close(fd);
789 }
790 
791 void
792 goodbye(struct pollfd *pfd, struct client *c)
793 {
794 	ssize_t ret;
795 
796 	c->state = S_CLOSING;
797 
798 	ret = tls_close(c->ctx);
799 	if (ret == TLS_WANT_POLLIN) {
800 		pfd->events = POLLIN;
801 		return;
802 	}
803 	if (ret == TLS_WANT_POLLOUT) {
804 		pfd->events = POLLOUT;
805 		return;
806 	}
807 
808 	connected_clients--;
809 
810 	tls_free(c->ctx);
811 	c->ctx = NULL;
812 
813 	if (c->buf != MAP_FAILED)
814 		munmap(c->buf, c->len);
815 
816 	if (c->fd != -1)
817 		close(c->fd);
818 
819 	close(pfd->fd);
820 	pfd->fd = -1;
821 }
822 
823 void
824 loop(struct tls *ctx, int sock)
825 {
826 	int i, todo;
827 	struct client clients[MAX_USERS];
828 	struct pollfd fds[MAX_USERS];
829 
830 	for (i = 0; i < MAX_USERS; ++i) {
831 		fds[i].fd = -1;
832 		fds[i].events = POLLIN;
833 		bzero(&clients[i], sizeof(struct client));
834 	}
835 
836 	fds[0].fd = sock;
837 
838 	for (;;) {
839 		if ((todo = poll(fds, MAX_USERS, INFTIM)) == -1) {
840 			if (errno == EINTR) {
841                                 warnx("connected clients: %d", connected_clients);
842 				continue;
843 			}
844 			err(1, "poll");
845 		}
846 
847 		for (i = 0; i < MAX_USERS; i++) {
848 			assert(i < MAX_USERS);
849 
850 			if (fds[i].revents == 0)
851 				continue;
852 
853 			if (fds[i].revents & (POLLERR|POLLNVAL))
854 				err(1, "bad fd %d", fds[i].fd);
855 
856 			if (fds[i].revents & POLLHUP) {
857 				/* fds[i] may be the fd of the stdin
858 				 * of a cgi script that has exited. */
859 				if (!clients[i].waiting_on_child) {
860 					goodbye(&fds[i], &clients[i]);
861 					continue;
862 				}
863 			}
864 
865 			todo--;
866 
867 			if (i == 0) { /* new client */
868 				do_accept(sock, ctx, fds, clients);
869 				continue;
870 			}
871 
872 			handle(&fds[i], &clients[i]);
873 		}
874 	}
875 }
876 
877 void
878 usage(const char *me)
879 {
880 	fprintf(stderr,
881 	    "USAGE: %s [-h] [-c cert.pem] [-d docs] [-k key.pem] "
882 	    "[-l logfile] [-x cgi-bin]\n",
883 	    me);
884 }
885 
886 int
887 main(int argc, char **argv)
888 {
889 	const char *cert = "cert.pem", *key = "key.pem";
890 	struct tls *ctx = NULL;
891 	struct tls_config *conf;
892 	int sock, ch;
893 
894 	signal(SIGPIPE, SIG_IGN);
895 	signal(SIGCHLD, SIG_IGN);
896 
897 #ifdef SIGINFO
898 	signal(SIGINFO, siginfo_handler);
899 #endif
900 	signal(SIGUSR2, siginfo_handler);
901 
902 	connected_clients = 0;
903 
904 	dir = "docs/";
905 	logfd = 2;		/* stderr */
906 	cgi = NULL;
907 
908 	while ((ch = getopt(argc, argv, "c:d:hk:l:x:")) != -1) {
909 		switch (ch) {
910 		case 'c':
911 			cert = optarg;
912 			break;
913 
914 		case 'd':
915 			dir = optarg;
916 			break;
917 
918 		case 'h':
919 			usage(*argv);
920 			return 0;
921 
922 		case 'k':
923 			key = optarg;
924 			break;
925 
926 		case 'l':
927 			/* open log file or create it with 644 */
928 			if ((logfd = open(optarg, O_WRONLY | O_CREAT | O_CLOEXEC,
929 					S_IRUSR | S_IWUSR | S_IRGRP | S_IWOTH)) == -1)
930 				err(1, "%s", optarg);
931 			break;
932 
933 		case 'x':
934 			cgi = optarg;
935 			break;
936 
937 		default:
938 			usage(*argv);
939 			return 1;
940 		}
941 	}
942 
943 	if ((conf = tls_config_new()) == NULL)
944 		err(1, "tls_config_new");
945 
946 	if (tls_config_set_protocols(conf,
947 	    TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3) == -1)
948 		err(1, "tls_config_set_protocols");
949 
950 	if (tls_config_set_cert_file(conf, cert) == -1)
951 		err(1, "tls_config_set_cert_file: %s", cert);
952 
953 	if (tls_config_set_key_file(conf, key) == -1)
954 		err(1, "tls_config_set_key_file: %s", key);
955 
956 	if ((ctx = tls_server()) == NULL)
957 		err(1, "tls_server");
958 
959 	if (tls_configure(ctx, conf) == -1)
960 		errx(1, "tls_configure: %s", tls_error(ctx));
961 
962 	sock = make_socket(1965, AF_INET);
963 
964 	if ((dirfd = open(dir, O_RDONLY | O_DIRECTORY)) == -1)
965 		err(1, "open: %s", dir);
966 
967 	if (cgi != NULL) {
968 		if (unveil(dir, "rx") == -1)
969 			err(1, "unveil");
970 		if (pledge("stdio rpath inet proc exec", NULL) == -1)
971 			err(1, "pledge");
972 	} else {
973 		if (unveil(dir, "r") == -1)
974 			err(1, "unveil");
975 		if (pledge("stdio rpath inet", NULL) == -1)
976 			err(1, "pledge");
977 	}
978 
979 	loop(ctx, sock);
980 
981 	close(sock);
982 	tls_free(ctx);
983 	tls_config_free(conf);
984 }