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Date:: Fri Nov 6 17:02:41 2020 UTC
Message:: [cgi] set QUERY_STRING only if there is a query string
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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;
111 int dirfd, logfd;
112 int cgi;
113 int connected_clients;
114 
115 void		 siginfo_handler(int);
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 char *
151 url_after_proto(char *url)
152 {
153 	char *s;
154 	const char *proto = "gemini";
155 	const char *marker = "://";
156 	size_t i;
157 
158 	/* a relative URL */
159 	if ((s = strstr(url, marker)) == NULL)
160 		return url;
161 
162 	if (s - strlen(proto) != url)
163 		return NULL;
164 
165 	for (i = 0; proto[i] != '\0'; ++i)
166 		if (url[i] != proto[i])
167 			return NULL;
168 
169 	/* a valid gemini:// URL */
170 	return s + strlen(marker);
171 }
172 
173 char *
174 url_start_of_request(char *url)
175 {
176 	char *s, *t;
177 
178 	if ((s = url_after_proto(url)) == NULL)
179 		return NULL;
180 
181 	if ((t = strstr(s, "/")) == NULL)
182 		return s + strlen(s);
183 	return t;
184 }
185 
186 int
187 url_trim(struct client *c, char *url)
188 {
189 	const char *e = "\r\n";
190 	char *s;
191 
192 	if ((s = strstr(url, e)) == NULL)
193 		return 0;
194 	s[0] = '\0';
195 	s[1] = '\0';
196 
197 	if (s[2] != '\0') {
198 		LOG(c, "%s", "request longer than 1024 bytes\n");
199 		return 0;
200 	}
201 
202 	return 1;
203 }
204 
205 char *
206 adjust_path(char *path)
207 {
208 	char *s, *query;
209 	size_t len;
210 
211 	if ((query = strchr(path, '?')) != NULL) {
212 		*query = '\0';
213 		query++;
214 	}
215 
216 	/* /.. -> / */
217 	len = strlen(path);
218 	if (len >= 3) {
219 		if (!strcmp(&path[len-3], "/..")) {
220 			path[len-2] = '\0';
221 		}
222 	}
223 
224 	/* if the path is only `..` trim out and exit */
225 	if (!strcmp(path, "..")) {
226 		path[0] = '\0';
227 		return query;
228 	}
229 
230 	/* remove every ../ in the path */
231 	while (1) {
232 		if ((s = strstr(path, "../")) == NULL)
233 			return query;
234 		memmove(s, s+3, strlen(s)+1);	/* copy also the \0 */
235 	}
236 }
237 
238 int
239 path_isdir(char *path)
240 {
241 	if (*path == '\0')
242 		return 1;
243 	return path[strlen(path)-1] == '/';
244 }
245 
246 int
247 start_reply(struct pollfd *pfd, struct client *client, int code, const char *reason)
248 {
249 	char buf[1030] = {0}; 	/* status + ' ' + max reply len + \r\n\0 */
250 	int len;
251 	int ret;
252 
253 	client->code = code;
254 	client->meta = reason;
255 	client->state = S_INITIALIZING;
256 
257 	len = snprintf(buf, sizeof(buf), "%d %s\r\n", code, reason);
258 	assert(len < (int)sizeof(buf));
259 	ret = tls_write(client->ctx, buf, len);
260 	if (ret == TLS_WANT_POLLIN) {
261 		pfd->events = POLLIN;
262 		return 0;
263 	}
264 
265 	if (ret == TLS_WANT_POLLOUT) {
266 		pfd->events = POLLOUT;
267 		return 0;
268 	}
269 
270 	return 1;
271 }
272 
273 ssize_t
274 filesize(int fd)
275 {
276 	ssize_t len;
277 
278 	if ((len = lseek(fd, 0, SEEK_END)) == -1)
279 		return -1;
280 	if (lseek(fd, 0, SEEK_SET) == -1)
281 		return -1;
282 	return len;
283 }
284 
285 const char *
286 path_ext(const char *path)
287 {
288 	const char *end;
289 
290 	end = path + strlen(path)-1; /* the last byte before the NUL */
291 	for (; end != path; --end) {
292 		if (*end == '.')
293 			return end+1;
294 		if (*end == '/')
295 			break;
296 	}
297 
298 	return NULL;
299 }
300 
301 const char *
302 mime(const char *path)
303 {
304 	const char *ext, *def = "application/octet-stream";
305 	struct etm *t;
306 
307 	if ((ext = path_ext(path)) == NULL)
308 		return def;
309 
310 	for (t = filetypes; t->mime != NULL; ++t)
311 		if (!strcmp(ext, t->ext))
312 			return t->mime;
313 
314 	return def;
315 }
316 
317 int
318 open_file(char *path, char *query, struct pollfd *fds, struct client *c)
319 {
320 	char fpath[PATHBUF];
321 	struct stat sb;
322 
323 	assert(path != NULL);
324 
325 	bzero(fpath, sizeof(fpath));
326 
327 	if (*path != '.')
328 		fpath[0] = '.';
329 	strlcat(fpath, path, PATHBUF);
330 
331 	if ((c->fd = openat(dirfd, fpath,
332 		    O_RDONLY | O_NOFOLLOW | O_CLOEXEC)) == -1) {
333 		LOG(c, "open failed: %s", fpath);
334 		if (!start_reply(fds, c, NOT_FOUND, "not found"))
335 			return 0;
336 		goodbye(fds, c);
337 		return 0;
338 	}
339 
340 	if (fstat(c->fd, &sb) == -1) {
341 		LOG(c, "fstat failed for %s", fpath);
342 		if (!start_reply(fds, c, TEMP_FAILURE, "internal server error"))
343 			return 0;
344 		goodbye(fds, c);
345 		return 0;
346 	}
347 
348 	if (S_ISDIR(sb.st_mode)) {
349 		LOG(c, "%s is a directory, trying %s/index.gmi", fpath, fpath);
350 		close(c->fd);
351 		c->fd = -1;
352 		send_dir(fpath, fds, c);
353 		return 0;
354 	}
355 
356 	if (cgi && (sb.st_mode & S_IXUSR)) {
357 		start_cgi(fpath, query, fds, c);
358 		return 0;
359 	}
360 
361 	if ((c->len = filesize(c->fd)) == -1) {
362 		LOG(c, "failed to get file size for %s", fpath);
363 		goodbye(fds, c);
364 		return 0;
365 	}
366 
367 	if ((c->buf = mmap(NULL, c->len, PROT_READ, MAP_PRIVATE,
368 		    c->fd, 0)) == MAP_FAILED) {
369 		warn("mmap: %s", fpath);
370 		goodbye(fds, c);
371 		return 0;
372 	}
373 	c->i = c->buf;
374 
375 	return start_reply(fds, c, SUCCESS, mime(fpath));
376 }
377 
378 void
379 start_cgi(const char *path, const char *query,
380     struct pollfd *fds, struct client *c)
381 {
382 	pid_t pid;
383 	int p[2];
384 
385 	if (pipe(p) == -1)
386 		goto err;
387 
388 	switch (pid = fork()) {
389 	case -1:
390 		goto err;
391 
392 	case 0: {		/* child */
393                 char *expath;
394 		char addr[INET_ADDRSTRLEN];
395 		char *argv[] = { NULL, NULL, NULL };
396 
397 		/* skip the initial ./ */
398 		path += 2;
399 
400 		close(p[0]);	/* close the read end */
401 		if (dup2(p[1], 1) == -1)
402 			goto childerr;
403 
404 		if (inet_ntop(c->af, &c->addr, addr, sizeof(addr)) == NULL)
405                         goto childerr;
406 
407 		/* skip the ./ at the start of path*/
408 		if (asprintf(&expath, "%s%s", dir, path) == -1)
409 			goto childerr;
410 		argv[0] = argv[1] = expath;
411 
412 		/* fix the env */
413 		setenv("SERVER_SOFTWARE", "gmid", 1);
414 		/* setenv("SERVER_NAME", "", 1); */
415 		/* setenv("GATEWAY_INTERFACE", "CGI/version", 1); */
416 		setenv("SERVER_PROTOCOL", "gemini", 1);
417 		setenv("SERVER_PORT", "1965", 1);
418 		setenv("PATH_INFO", path, 1);
419 		setenv("PATH_TRANSLATED", expath, 1);
420 		if (query != NULL)
421 			setenv("QUERY_STRING", query, 1);
422 		setenv("REMOTE_ADDR", addr, 1);
423 
424 		execvp(expath, argv);
425 		goto childerr;
426 	}
427 
428 	default:		/* parent */
429 		close(p[1]);	/* close the write end */
430 		close(c->fd);
431 		c->fd = p[0];
432 		c->child = pid;
433 		mark_nonblock(c->fd);
434 		c->state = S_SENDING;
435 		handle_cgi(fds, c);
436 		return;
437 	}
438 
439 err:
440 	if (!start_reply(fds, c, TEMP_FAILURE, "internal server error"))
441 		return;
442 	goodbye(fds, c);
443 	return;
444 
445 childerr:
446 	dprintf(p[1], "%d internal server error\r\n", TEMP_FAILURE);
447 	close(p[1]);
448 
449 	/* don't call atexit stuff */
450         _exit(1);
451 }
452 
453 void
454 cgi_setpoll_on_child(struct pollfd *fds, struct client *c)
455 {
456 	int fd;
457 
458 	if (c->waiting_on_child)
459 		return;
460 	c->waiting_on_child = 1;
461 
462 	fds->events = POLLIN;
463 
464 	fd = fds->fd;
465 	fds->fd = c->fd;
466 	c->fd = fd;
467 }
468 
469 void
470 cgi_setpoll_on_client(struct pollfd *fds, struct client *c)
471 {
472 	int fd;
473 
474 	if (!c->waiting_on_child)
475 		return;
476 	c->waiting_on_child = 0;
477 
478 	fd = fds->fd;
479 	fds->fd = c->fd;
480 	c->fd = fd;
481 }
482 
483 void
484 handle_cgi(struct pollfd *fds, struct client *c)
485 {
486 	ssize_t r;
487 
488 	/* ensure c->fd is the child and fds->fd the client */
489 	cgi_setpoll_on_client(fds, c);
490 
491 	while (1) {
492 		if (c->len == 0) {
493 			if ((r = read(c->fd, c->sbuf, sizeof(c->sbuf))) == 0)
494 				goto end;
495 			if (r == -1) {
496 				if (errno == EAGAIN || errno == EWOULDBLOCK) {
497 					cgi_setpoll_on_child(fds, c);
498 					return;
499 				}
500                                 goto end;
501 			}
502 			c->len = r;
503 			c->off = 0;
504 		}
505 
506 		while (c->len > 0) {
507 			switch (r = tls_write(c->ctx, c->sbuf + c->off, c->len)) {
508 			case -1:
509 				goto end;
510 
511 			case TLS_WANT_POLLOUT:
512 				fds->events = POLLOUT;
513 				return;
514 
515 			case TLS_WANT_POLLIN:
516 				fds->events = POLLIN;
517 				return;
518 
519 			default:
520                                 c->off += r;
521 				c->len -= r;
522 				break;
523 			}
524 		}
525 	}
526 
527 end:
528 	goodbye(fds, c);
529 }
530 
531 void
532 send_file(char *path, char *query, struct pollfd *fds, struct client *c)
533 {
534 	ssize_t ret, len;
535 
536 	if (c->fd == -1) {
537 		if (!open_file(path, query, fds, c))
538 			return;
539 		c->state = S_SENDING;
540 	}
541 
542 	len = (c->buf + c->len) - c->i;
543 
544 	while (len > 0) {
545 		switch (ret = tls_write(c->ctx, c->i, len)) {
546 		case -1:
547 			LOG(c, "tls_write: %s", tls_error(c->ctx));
548 			goodbye(fds, c);
549 			return;
550 
551 		case TLS_WANT_POLLIN:
552 			fds->events = POLLIN;
553 			return;
554 
555 		case TLS_WANT_POLLOUT:
556 			fds->events = POLLOUT;
557 			return;
558 
559 		default:
560 			c->i += ret;
561 			len -= ret;
562 			break;
563 		}
564 	}
565 
566 	goodbye(fds, c);
567 }
568 
569 void
570 send_dir(char *path, struct pollfd *fds, struct client *client)
571 {
572 	char fpath[PATHBUF];
573 	size_t len;
574 
575 	bzero(fpath, PATHBUF);
576 
577 	if (path[0] != '.')
578 		fpath[0] = '.';
579 
580 	/* this cannot fail since sizeof(fpath) > maxlen of path */
581 	strlcat(fpath, path, PATHBUF);
582 	len = strlen(fpath);
583 
584 	/* add a trailing / in case. */
585 	if (fpath[len-1] != '/') {
586 		fpath[len] = '/';
587 	}
588 
589 	strlcat(fpath, "index.gmi", sizeof(fpath));
590 
591 	send_file(fpath, NULL, fds, client);
592 }
593 
594 void
595 handle(struct pollfd *fds, struct client *client)
596 {
597 	char buf[GEMINI_URL_LEN];
598 	char *path;
599 	char *query;
600 
601 	switch (client->state) {
602 	case S_OPEN:
603 		bzero(buf, GEMINI_URL_LEN);
604 		switch (tls_read(client->ctx, buf, sizeof(buf)-1)) {
605 		case -1:
606 			LOG(client, "tls_read: %s", tls_error(client->ctx));
607 			goodbye(fds, client);
608 			return;
609 
610 		case TLS_WANT_POLLIN:
611 			fds->events = POLLIN;
612 			return;
613 
614 		case TLS_WANT_POLLOUT:
615 			fds->events = POLLOUT;
616 			return;
617 		}
618 
619 		if (!url_trim(client, buf)) {
620 			if (!start_reply(fds, client, BAD_REQUEST, "bad request"))
621 				return;
622 			goodbye(fds, client);
623 			return;
624 		}
625 
626 		if ((path = url_start_of_request(buf)) == NULL) {
627 			if (!start_reply(fds, client, BAD_REQUEST, "bad request"))
628 				return;
629 			goodbye(fds, client);
630 			return;
631 		}
632 
633 		query = adjust_path(path);
634 		LOG(client, "get %s%s%s", path,
635 		    query ? "?" : "",
636 		    query ? query : "");
637 
638 		if (path_isdir(path))
639 			send_dir(path, fds, client);
640 		else
641 			send_file(path, query, fds, client);
642 		break;
643 
644 	case S_INITIALIZING:
645 		if (!start_reply(fds, client, client->code, client->meta))
646 			return;
647 
648 		if (client->code != SUCCESS) {
649 			/* we don't need a body */
650 			goodbye(fds, client);
651 			return;
652 		}
653 
654 		client->state = S_SENDING;
655 
656 		/* fallthrough */
657 
658 	case S_SENDING:
659 		if (client->child != -1)
660 			handle_cgi(fds, client);
661 		else
662 			send_file(NULL, NULL, fds, client);
663 		break;
664 
665 	case S_CLOSING:
666 		goodbye(fds, client);
667 		break;
668 
669 	default:
670 		/* unreachable */
671 		abort();
672 	}
673 }
674 
675 void
676 mark_nonblock(int fd)
677 {
678 	int flags;
679 
680 	if ((flags = fcntl(fd, F_GETFL)) == -1)
681 		err(1, "fcntl(F_GETFL)");
682 	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
683 		err(1, "fcntl(F_SETFL)");
684 }
685 
686 int
687 make_socket(int port, int family)
688 {
689 	int sock, v;
690 	struct sockaddr_in addr4;
691 	struct sockaddr_in6 addr6;
692 	struct sockaddr *addr;
693 	socklen_t len;
694 
695         switch (family) {
696 	case AF_INET:
697 		bzero(&addr4, sizeof(addr4));
698 		addr4.sin_family = family;
699 		addr4.sin_port = htons(port);
700 		addr4.sin_addr.s_addr = INADDR_ANY;
701 		addr = (struct sockaddr*)&addr4;
702 		len = sizeof(addr4);
703 		break;
704 
705 	case AF_INET6:
706 		bzero(&addr6, sizeof(addr6));
707 		addr6.sin6_family = AF_INET6;
708 		addr6.sin6_port = htons(port);
709 		addr6.sin6_addr = in6addr_any;
710 		addr = (struct sockaddr*)&addr6;
711 		len = sizeof(addr6);
712 		break;
713 
714 	default:
715 		/* unreachable */
716 		abort();
717 	}
718 
719 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
720 		err(1, "socket");
721 
722 	v = 1;
723 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
724 		err(1, "setsockopt(SO_REUSEADDR)");
725 
726 	v = 1;
727 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
728 		err(1, "setsockopt(SO_REUSEPORT)");
729 
730 	mark_nonblock(sock);
731 
732 	if (bind(sock, addr, len) == -1)
733 		err(1, "bind");
734 
735 	if (listen(sock, 16) == -1)
736 		err(1, "listen");
737 
738 	return sock;
739 }
740 
741 void
742 do_accept(int sock, struct tls *ctx, struct pollfd *fds, struct client *clients)
743 {
744 	int i, fd;
745 	struct sockaddr_in addr;
746 	socklen_t len;
747 
748 	len = sizeof(addr);
749 	if ((fd = accept(sock, (struct sockaddr*)&addr, &len)) == -1) {
750 		if (errno == EWOULDBLOCK)
751 			return;
752 		err(1, "accept");
753 	}
754 
755 	mark_nonblock(fd);
756 
757 	for (i = 0; i < MAX_USERS; ++i) {
758 		if (fds[i].fd == -1) {
759 			bzero(&clients[i], sizeof(struct client));
760 			if (tls_accept_socket(ctx, &clients[i].ctx, fd) == -1)
761 				break; /* goodbye fd! */
762 
763 			fds[i].fd = fd;
764 			fds[i].events = POLLIN;
765 
766 			clients[i].state = S_OPEN;
767 			clients[i].fd = -1;
768 			clients[i].child = -1;
769 			clients[i].buf = MAP_FAILED;
770 			clients[i].af = AF_INET;
771 			clients[i].addr = addr.sin_addr;
772 
773 			connected_clients++;
774 			return;
775 		}
776 	}
777 
778 	close(fd);
779 }
780 
781 void
782 goodbye(struct pollfd *pfd, struct client *c)
783 {
784 	ssize_t ret;
785 
786 	c->state = S_CLOSING;
787 
788 	ret = tls_close(c->ctx);
789 	if (ret == TLS_WANT_POLLIN) {
790 		pfd->events = POLLIN;
791 		return;
792 	}
793 	if (ret == TLS_WANT_POLLOUT) {
794 		pfd->events = POLLOUT;
795 		return;
796 	}
797 
798 	connected_clients--;
799 
800 	tls_free(c->ctx);
801 	c->ctx = NULL;
802 
803 	if (c->buf != MAP_FAILED)
804 		munmap(c->buf, c->len);
805 
806 	if (c->fd != -1)
807 		close(c->fd);
808 
809 	close(pfd->fd);
810 	pfd->fd = -1;
811 }
812 
813 void
814 loop(struct tls *ctx, int sock)
815 {
816 	int i, todo;
817 	struct client clients[MAX_USERS];
818 	struct pollfd fds[MAX_USERS];
819 
820 	for (i = 0; i < MAX_USERS; ++i) {
821 		fds[i].fd = -1;
822 		fds[i].events = POLLIN;
823 		bzero(&clients[i], sizeof(struct client));
824 	}
825 
826 	fds[0].fd = sock;
827 
828 	for (;;) {
829 		if ((todo = poll(fds, MAX_USERS, INFTIM)) == -1) {
830 			if (errno == EINTR) {
831                                 warnx("connected clients: %d", connected_clients);
832 				continue;
833 			}
834 			err(1, "poll");
835 		}
836 
837 		for (i = 0; i < MAX_USERS; i++) {
838 			assert(i < MAX_USERS);
839 
840 			if (fds[i].revents == 0)
841 				continue;
842 
843 			if (fds[i].revents & (POLLERR|POLLNVAL))
844 				err(1, "bad fd %d", fds[i].fd);
845 
846 			if (fds[i].revents & POLLHUP) {
847 				/* fds[i] may be the fd of the stdin
848 				 * of a cgi script that has exited. */
849 				if (!clients[i].waiting_on_child) {
850 					goodbye(&fds[i], &clients[i]);
851 					continue;
852 				}
853 			}
854 
855 			todo--;
856 
857 			if (i == 0) { /* new client */
858 				do_accept(sock, ctx, fds, clients);
859 				continue;
860 			}
861 
862 			handle(&fds[i], &clients[i]);
863 		}
864 	}
865 }
866 
867 void
868 usage(const char *me)
869 {
870 	fprintf(stderr,
871 	    "USAGE: %s [-h] [-c cert.pem] [-d docs] [-k key.pem]\n",
872 	    me);
873 }
874 
875 int
876 main(int argc, char **argv)
877 {
878 	const char *cert = "cert.pem", *key = "key.pem";
879 	struct tls *ctx = NULL;
880 	struct tls_config *conf;
881 	int sock, ch;
882 
883 	signal(SIGPIPE, SIG_IGN);
884 	signal(SIGCHLD, SIG_IGN);
885 
886 #ifdef SIGINFO
887 	signal(SIGINFO, siginfo_handler);
888 #endif
889 	signal(SIGUSR2, siginfo_handler);
890 
891 	connected_clients = 0;
892 
893 	dir = "docs/";
894 	logfd = 2;		/* stderr */
895 	cgi = 0;
896 
897 	while ((ch = getopt(argc, argv, "c:d:hk:l:x")) != -1) {
898 		switch (ch) {
899 		case 'c':
900 			cert = optarg;
901 			break;
902 
903 		case 'd':
904 			dir = optarg;
905 			break;
906 
907 		case 'h':
908 			usage(*argv);
909 			return 0;
910 
911 		case 'k':
912 			key = optarg;
913 			break;
914 
915 		case 'l':
916 			/* open log file or create it with 644 */
917 			if ((logfd = open(optarg, O_WRONLY | O_CREAT | O_CLOEXEC,
918 					S_IRUSR | S_IWUSR | S_IRGRP | S_IWOTH)) == -1)
919 				err(1, "%s", optarg);
920 			break;
921 
922 		case 'x':
923 			cgi = 1;
924 			break;
925 
926 		default:
927 			usage(*argv);
928 			return 1;
929 		}
930 	}
931 
932 	if ((conf = tls_config_new()) == NULL)
933 		err(1, "tls_config_new");
934 
935 	if (tls_config_set_protocols(conf,
936 	    TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3) == -1)
937 		err(1, "tls_config_set_protocols");
938 
939 	if (tls_config_set_cert_file(conf, cert) == -1)
940 		err(1, "tls_config_set_cert_file: %s", cert);
941 
942 	if (tls_config_set_key_file(conf, key) == -1)
943 		err(1, "tls_config_set_key_file: %s", key);
944 
945 	if ((ctx = tls_server()) == NULL)
946 		err(1, "tls_server");
947 
948 	if (tls_configure(ctx, conf) == -1)
949 		errx(1, "tls_configure: %s", tls_error(ctx));
950 
951 	sock = make_socket(1965, AF_INET);
952 
953 	if ((dirfd = open(dir, O_RDONLY | O_DIRECTORY)) == -1)
954 		err(1, "open: %s", dir);
955 
956 	if (unveil(dir, cgi ? "rx" : "r") == -1)
957 		err(1, "unveil");
958 
959 	if (pledge(cgi ? "stdio rpath inet proc exec" : "stdio rpath inet", NULL) == -1)
960 		err(1, "pledge");
961 
962 	loop(ctx, sock);
963 
964 	close(sock);
965 	tls_free(ctx);
966 	tls_config_free(conf);
967 }