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Date:: Wed Nov 18 08:32:07 2020 UTC
Message:: handle //example.com urls
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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 enum {
81 	FILE_EXISTS,
82 	FILE_EXECUTABLE,
83 	FILE_DIRECTORY,
84 	FILE_MISSING,
85 };
86 
87 struct etm {			/* file extension to mime */
88 	const char	*mime;
89 	const char	*ext;
90 } filetypes[] = {
91 	{"application/pdf",	"pdf"},
92 
93 	{"image/gif",		"gif"},
94 	{"image/jpeg",		"jpg"},
95 	{"image/jpeg",		"jpeg"},
96 	{"image/png",		"png"},
97 	{"image/svg+xml",	"svg"},
98 
99 	{"text/gemini",		"gemini"},
100 	{"text/gemini",		"gmi"},
101 	{"text/markdown",	"markdown"},
102 	{"text/markdown",	"md"},
103 	{"text/plain",		"txt"},
104 	{"text/xml",		"xml"},
105 
106 	{NULL, NULL}
107 };
108 
109 #define LOG(c, fmt, ...)						\
110 	do {								\
111 		char buf[INET_ADDRSTRLEN];				\
112 		if (inet_ntop((c)->af, &(c)->addr, buf, sizeof(buf)) == NULL) \
113 			err(1, "inet_ntop");				\
114 		dprintf(logfd, "[%s] " fmt "\n", buf, __VA_ARGS__);	\
115 	} while (0)
116 
117 const char *dir, *cgi;
118 int dirfd, logfd;
119 int port;
120 int connected_clients;
121 
122 void		 siginfo_handler(int);
123 int		 starts_with(const char*, const char*);
124 
125 char		*url_after_proto(char*);
126 char		*url_start_of_request(char*);
127 int		 url_trim(struct client*, char*);
128 char		*adjust_path(char*);
129 ssize_t		 filesize(int);
130 
131 int		 start_reply(struct pollfd*, struct client*, int, const char*);
132 const char	*path_ext(const char*);
133 const char	*mime(const char*);
134 int		 check_path(const char*, int*);
135 int		 check_for_cgi(char *, char*, struct pollfd*, struct client*);
136 int		 open_file(char*, char*, struct pollfd*, struct client*);
137 int		 start_cgi(const char*, const char*, const char*, struct pollfd*, struct client*);
138 void		 cgi_setpoll_on_child(struct pollfd*, struct client*);
139 void		 cgi_setpoll_on_client(struct pollfd*, struct client*);
140 void		 handle_cgi(struct pollfd*, struct client*);
141 void		 send_file(char*, char*, struct pollfd*, struct client*);
142 void		 send_dir(char*, struct pollfd*, struct client*);
143 void		 handle(struct pollfd*, struct client*);
144 
145 void		 mark_nonblock(int);
146 int		 make_soket(int);
147 void		 do_accept(int, struct tls*, struct pollfd*, struct client*);
148 void		 goodbye(struct pollfd*, struct client*);
149 void		 loop(struct tls*, int);
150 
151 void		 usage(const char*);
152 
153 void
154 siginfo_handler(int sig)
155 {
156 	(void)sig;
157 }
158 
159 int
160 starts_with(const char *str, const char *prefix)
161 {
162 	size_t i;
163 
164 	for (i = 0; prefix[i] != '\0'; ++i)
165 		if (str[i] != prefix[i])
166 			return 0;
167 	return 1;
168 }
169 
170 char *
171 url_after_proto(char *url)
172 {
173 	char *s;
174 	const char *proto = "gemini";
175 	const char *marker = "//";
176 
177 	/* a relative URL */
178 	if ((s = strstr(url, marker)) == NULL)
179 		return url;
180 
181 	/*
182 	 * if a protocol is not specified, gemini should be implied:
183 	 * this handles the case of //example.com
184 	 */
185 	if (s == url)
186 		return s + strlen(marker);
187 
188 	if (s - strlen(proto) != url)
189 		return NULL;
190 
191 	if (!starts_with(url, proto))
192 		return NULL;
193 
194 	return s + strlen(marker);
195 }
196 
197 char *
198 url_start_of_request(char *url)
199 {
200 	char *s, *t;
201 
202 	if ((s = url_after_proto(url)) == NULL)
203 		return NULL;
204 
205 	if ((t = strstr(s, "/")) == NULL)
206 		return s + strlen(s);
207 	return t;
208 }
209 
210 int
211 url_trim(struct client *c, char *url)
212 {
213 	const char *e = "\r\n";
214 	char *s;
215 
216 	if ((s = strstr(url, e)) == NULL)
217 		return 0;
218 	s[0] = '\0';
219 	s[1] = '\0';
220 
221 	if (s[2] != '\0') {
222 		LOG(c, "%s", "request longer than 1024 bytes\n");
223 		return 0;
224 	}
225 
226 	return 1;
227 }
228 
229 char *
230 adjust_path(char *path)
231 {
232 	char *s, *query;
233 	size_t len;
234 
235 	if ((query = strchr(path, '?')) != NULL) {
236 		*query = '\0';
237 		query++;
238 	}
239 
240 	/* /.. -> / */
241 	len = strlen(path);
242 	if (len >= 3) {
243 		if (!strcmp(&path[len-3], "/..")) {
244 			path[len-2] = '\0';
245 		}
246 	}
247 
248 	/* if the path is only `..` trim out and exit */
249 	if (!strcmp(path, "..")) {
250 		path[0] = '\0';
251 		return query;
252 	}
253 
254 	/* remove every ../ in the path */
255 	while (1) {
256 		if ((s = strstr(path, "../")) == NULL)
257 			return query;
258 		memmove(s, s+3, strlen(s)+1);	/* copy also the \0 */
259 	}
260 }
261 
262 int
263 start_reply(struct pollfd *pfd, struct client *client, int code, const char *reason)
264 {
265 	char buf[1030] = {0}; 	/* status + ' ' + max reply len + \r\n\0 */
266 	int len;
267 	int ret;
268 
269 	client->code = code;
270 	client->meta = reason;
271 	client->state = S_INITIALIZING;
272 
273 	len = snprintf(buf, sizeof(buf), "%d %s\r\n", code, reason);
274 	assert(len < (int)sizeof(buf));
275 	ret = tls_write(client->ctx, buf, len);
276 	if (ret == TLS_WANT_POLLIN) {
277 		pfd->events = POLLIN;
278 		return 0;
279 	}
280 
281 	if (ret == TLS_WANT_POLLOUT) {
282 		pfd->events = POLLOUT;
283 		return 0;
284 	}
285 
286 	return 1;
287 }
288 
289 ssize_t
290 filesize(int fd)
291 {
292 	ssize_t len;
293 
294 	if ((len = lseek(fd, 0, SEEK_END)) == -1)
295 		return -1;
296 	if (lseek(fd, 0, SEEK_SET) == -1)
297 		return -1;
298 	return len;
299 }
300 
301 const char *
302 path_ext(const char *path)
303 {
304 	const char *end;
305 
306 	end = path + strlen(path)-1; /* the last byte before the NUL */
307 	for (; end != path; --end) {
308 		if (*end == '.')
309 			return end+1;
310 		if (*end == '/')
311 			break;
312 	}
313 
314 	return NULL;
315 }
316 
317 const char *
318 mime(const char *path)
319 {
320 	const char *ext, *def = "application/octet-stream";
321 	struct etm *t;
322 
323 	if ((ext = path_ext(path)) == NULL)
324 		return def;
325 
326 	for (t = filetypes; t->mime != NULL; ++t)
327 		if (!strcmp(ext, t->ext))
328 			return t->mime;
329 
330 	return def;
331 }
332 
333 int
334 check_path(const char *path, int *fd)
335 {
336 	struct stat sb;
337 
338 	assert(path != NULL);
339 	if ((*fd = openat(dirfd, path,
340 		    O_RDONLY | O_NOFOLLOW | O_CLOEXEC)) == -1) {
341 		return FILE_MISSING;
342 	}
343 
344 	if (fstat(*fd, &sb) == -1) {
345 		dprintf(logfd, "failed stat for %s\n", path);
346 		return FILE_MISSING;
347 	}
348 
349 	if (S_ISDIR(sb.st_mode))
350 		return FILE_DIRECTORY;
351 
352 	if (sb.st_mode & S_IXUSR)
353 		return FILE_EXECUTABLE;
354 
355 	return FILE_EXISTS;
356 }
357 
358 /*
359  * the inverse of this algorithm, i.e. starting from the start of the
360  * path + strlen(cgi), and checking if each component, should be
361  * faster.  But it's tedious to write.  This does the opposite: starts
362  * from the end and strip one component at a time, until either an
363  * executable is found or we emptied the path.
364  */
365 int
366 check_for_cgi(char *path, char *query, struct pollfd *fds, struct client *c)
367 {
368 	char *end;
369 	end = strchr(path, '\0');
370 
371 	/* NB: assume CGI is enabled and path matches cgi */
372 
373 	while (end > path) {
374 		/* go up one level.  UNIX paths are simple and POSIX
375 		 * dirname, with its ambiguities on if the given path
376 		 * is changed or not, gives me headaches. */
377 		while (*end != '/')
378 			end--;
379 		*end = '\0';
380 
381 		switch (check_path(path, &c->fd)) {
382 		case FILE_EXECUTABLE:
383 			return start_cgi(path, end+1, query, fds,c);
384 		case FILE_MISSING:
385 			break;
386 		default:
387 			goto err;
388 		}
389 
390 		*end = '/';
391 		end--;
392 	}
393 
394 err:
395 	if (!start_reply(fds, c, NOT_FOUND, "not found"))
396 		return 0;
397 	goodbye(fds, c);
398 	return 0;
399 }
400 
401 
402 int
403 open_file(char *path, char *query, struct pollfd *fds, struct client *c)
404 {
405 	char fpath[PATHBUF];
406 
407 	bzero(fpath, sizeof(fpath));
408 
409 	if (*path != '.')
410 		fpath[0] = '.';
411 	strlcat(fpath, path, PATHBUF);
412 
413 	switch (check_path(fpath, &c->fd)) {
414 	case FILE_EXECUTABLE:
415 		/* +2 to skip the ./ */
416 		if (cgi != NULL && starts_with(fpath+2, cgi))
417 			return start_cgi(fpath, "", query, fds, c);
418 
419 		/* fallthrough */
420 
421 	case FILE_EXISTS:
422 		if ((c->len = filesize(c->fd)) == -1) {
423 			LOG(c, "failed to get file size for %s", fpath);
424 			goodbye(fds, c);
425 			return 0;
426 		}
427 
428 		if ((c->buf = mmap(NULL, c->len, PROT_READ, MAP_PRIVATE,
429 			    c->fd, 0)) == MAP_FAILED) {
430 			warn("mmap: %s", fpath);
431 			goodbye(fds, c);
432 			return 0;
433 		}
434 		c->i = c->buf;
435 		return start_reply(fds, c, SUCCESS, mime(fpath));
436 
437 	case FILE_DIRECTORY:
438 		LOG(c, "%s is a directory, trying %s/index.gmi", fpath, fpath);
439 		close(c->fd);
440 		c->fd = -1;
441 		send_dir(fpath, fds, c);
442 		return 0;
443 
444 	case FILE_MISSING:
445 		if (cgi != NULL && starts_with(fpath+2, cgi))
446 			return check_for_cgi(fpath, query, fds, c);
447 
448 		if (!start_reply(fds, c, NOT_FOUND, "not found"))
449 			return 0;
450 		goodbye(fds, c);
451 		return 0;
452 
453 	default:
454 		/* unreachable */
455 		abort();
456 	}
457 }
458 
459 int
460 start_cgi(const char *spath, const char *relpath, const char *query,
461     struct pollfd *fds, struct client *c)
462 {
463 	pid_t pid;
464 	int p[2]; 		/* read end, write end */
465 
466 	if (pipe(p) == -1)
467 		goto err;
468 
469 	switch (pid = fork()) {
470 	case -1:
471 		goto err;
472 
473 	case 0: { 		/* child */
474 		char *ex, *requri, *portno;
475 		char addr[INET_ADDRSTRLEN];
476 		char *argv[] = { NULL, NULL, NULL };
477 
478 		spath++;
479 
480 		close(p[0]);
481 		if (dup2(p[1], 1) == -1)
482 			goto childerr;
483 
484 		if (inet_ntop(c->af, &c->addr, addr, sizeof(addr)) == NULL)
485 			goto childerr;
486 
487 		if (asprintf(&portno, "%d", port) == -1)
488 			goto childerr;
489 
490 		if (asprintf(&ex, "%s%s", dir, spath+1) == -1)
491 			goto childerr;
492 
493 		if (asprintf(&requri, "%s%s%s", spath,
494 		    *relpath == '\0' ? "" : "/",
495 		    relpath) == -1)
496 			goto childerr;
497 
498 		argv[0] = argv[1] = ex;
499 
500 		/* fix the env */
501 		setenv("SERVER_SOFTWARE", "gmid", 1);
502 		setenv("SERVER_PORT", portno, 1);
503 		/* setenv("SERVER_NAME", "", 1); */
504 		setenv("SCRIPT_NAME", spath, 1);
505 		setenv("SCRIPT_EXECUTABLE", ex, 1);
506 		setenv("REQUEST_URI", requri, 1);
507 		setenv("REQUEST_RELATIVE", relpath, 1);
508 		if (query != NULL)
509 			setenv("QUERY_STRING", query, 1);
510 		setenv("REMOTE_HOST", addr, 1);
511 		setenv("DOCUMENT_ROOT", dir, 1);
512 
513 		execvp(ex, argv);
514 		goto childerr;
515 	}
516 
517 	default:		/* parent */
518 		close(p[1]);
519 		close(c->fd);
520 		c->fd = p[0];
521 		c->child = pid;
522 		mark_nonblock(c->fd);
523 		c->state = S_SENDING;
524 		handle_cgi(fds, c);
525 		return 0;
526 	}
527 
528 err:
529 	if (!start_reply(fds, c, TEMP_FAILURE, "internal server error"))
530 		return 0;
531 	goodbye(fds, c);
532 	return 0;
533 
534 childerr:
535 	dprintf(p[1], "%d internal server error\r\n", TEMP_FAILURE);
536 	close(p[1]);
537 	_exit(1);
538 }
539 
540 void
541 cgi_setpoll_on_child(struct pollfd *fds, struct client *c)
542 {
543 	int fd;
544 
545 	if (c->waiting_on_child)
546 		return;
547 	c->waiting_on_child = 1;
548 
549 	fds->events = POLLIN;
550 
551 	fd = fds->fd;
552 	fds->fd = c->fd;
553 	c->fd = fd;
554 }
555 
556 void
557 cgi_setpoll_on_client(struct pollfd *fds, struct client *c)
558 {
559 	int fd;
560 
561 	if (!c->waiting_on_child)
562 		return;
563 	c->waiting_on_child = 0;
564 
565 	fd = fds->fd;
566 	fds->fd = c->fd;
567 	c->fd = fd;
568 }
569 
570 void
571 handle_cgi(struct pollfd *fds, struct client *c)
572 {
573 	ssize_t r;
574 
575 	/* ensure c->fd is the child and fds->fd the client */
576 	cgi_setpoll_on_client(fds, c);
577 
578 	while (1) {
579 		if (c->len == 0) {
580 			if ((r = read(c->fd, c->sbuf, sizeof(c->sbuf))) == 0)
581 				goto end;
582 			if (r == -1) {
583 				if (errno == EAGAIN || errno == EWOULDBLOCK) {
584 					cgi_setpoll_on_child(fds, c);
585 					return;
586 				}
587                                 goto end;
588 			}
589 			c->len = r;
590 			c->off = 0;
591 		}
592 
593 		while (c->len > 0) {
594 			switch (r = tls_write(c->ctx, c->sbuf + c->off, c->len)) {
595 			case -1:
596 				goto end;
597 
598 			case TLS_WANT_POLLOUT:
599 				fds->events = POLLOUT;
600 				return;
601 
602 			case TLS_WANT_POLLIN:
603 				fds->events = POLLIN;
604 				return;
605 
606 			default:
607                                 c->off += r;
608 				c->len -= r;
609 				break;
610 			}
611 		}
612 	}
613 
614 end:
615 	goodbye(fds, c);
616 }
617 
618 void
619 send_file(char *path, char *query, struct pollfd *fds, struct client *c)
620 {
621 	ssize_t ret, len;
622 
623 	if (c->fd == -1) {
624 		if (!open_file(path, query, fds, c))
625 			return;
626 		c->state = S_SENDING;
627 	}
628 
629 	len = (c->buf + c->len) - c->i;
630 
631 	while (len > 0) {
632 		switch (ret = tls_write(c->ctx, c->i, len)) {
633 		case -1:
634 			LOG(c, "tls_write: %s", tls_error(c->ctx));
635 			goodbye(fds, c);
636 			return;
637 
638 		case TLS_WANT_POLLIN:
639 			fds->events = POLLIN;
640 			return;
641 
642 		case TLS_WANT_POLLOUT:
643 			fds->events = POLLOUT;
644 			return;
645 
646 		default:
647 			c->i += ret;
648 			len -= ret;
649 			break;
650 		}
651 	}
652 
653 	goodbye(fds, c);
654 }
655 
656 void
657 send_dir(char *path, struct pollfd *fds, struct client *client)
658 {
659 	char fpath[PATHBUF];
660 	size_t len;
661 
662 	bzero(fpath, PATHBUF);
663 
664 	if (path[0] != '.')
665 		fpath[0] = '.';
666 
667 	/* this cannot fail since sizeof(fpath) > maxlen of path */
668 	strlcat(fpath, path, PATHBUF);
669 	len = strlen(fpath);
670 
671 	/* add a trailing / in case. */
672 	if (fpath[len-1] != '/') {
673 		fpath[len] = '/';
674 	}
675 
676 	strlcat(fpath, "index.gmi", sizeof(fpath));
677 
678 	send_file(fpath, NULL, fds, client);
679 }
680 
681 void
682 handle(struct pollfd *fds, struct client *client)
683 {
684 	char buf[GEMINI_URL_LEN];
685 	char *path;
686 	char *query;
687 
688 	switch (client->state) {
689 	case S_OPEN:
690 		bzero(buf, GEMINI_URL_LEN);
691 		switch (tls_read(client->ctx, buf, sizeof(buf)-1)) {
692 		case -1:
693 			LOG(client, "tls_read: %s", tls_error(client->ctx));
694 			goodbye(fds, client);
695 			return;
696 
697 		case TLS_WANT_POLLIN:
698 			fds->events = POLLIN;
699 			return;
700 
701 		case TLS_WANT_POLLOUT:
702 			fds->events = POLLOUT;
703 			return;
704 		}
705 
706 		if (!url_trim(client, buf)) {
707 			if (!start_reply(fds, client, BAD_REQUEST, "bad request"))
708 				return;
709 			goodbye(fds, client);
710 			return;
711 		}
712 
713 		if ((path = url_start_of_request(buf)) == NULL) {
714 			if (!start_reply(fds, client, BAD_REQUEST, "bad request"))
715 				return;
716 			goodbye(fds, client);
717 			return;
718 		}
719 
720 		query = adjust_path(path);
721 		LOG(client, "get %s%s%s", path,
722 		    query ? "?" : "",
723 		    query ? query : "");
724 
725 		send_file(path, query, fds, client);
726 		break;
727 
728 	case S_INITIALIZING:
729 		if (!start_reply(fds, client, client->code, client->meta))
730 			return;
731 
732 		if (client->code != SUCCESS) {
733 			/* we don't need a body */
734 			goodbye(fds, client);
735 			return;
736 		}
737 
738 		client->state = S_SENDING;
739 
740 		/* fallthrough */
741 
742 	case S_SENDING:
743 		if (client->child != -1)
744 			handle_cgi(fds, client);
745 		else
746 			send_file(NULL, NULL, fds, client);
747 		break;
748 
749 	case S_CLOSING:
750 		goodbye(fds, client);
751 		break;
752 
753 	default:
754 		/* unreachable */
755 		abort();
756 	}
757 }
758 
759 void
760 mark_nonblock(int fd)
761 {
762 	int flags;
763 
764 	if ((flags = fcntl(fd, F_GETFL)) == -1)
765 		err(1, "fcntl(F_GETFL)");
766 	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
767 		err(1, "fcntl(F_SETFL)");
768 }
769 
770 int
771 make_socket(int port, int family)
772 {
773 	int sock, v;
774 	struct sockaddr_in addr4;
775 	struct sockaddr_in6 addr6;
776 	struct sockaddr *addr;
777 	socklen_t len;
778 
779         switch (family) {
780 	case AF_INET:
781 		bzero(&addr4, sizeof(addr4));
782 		addr4.sin_family = family;
783 		addr4.sin_port = htons(port);
784 		addr4.sin_addr.s_addr = INADDR_ANY;
785 		addr = (struct sockaddr*)&addr4;
786 		len = sizeof(addr4);
787 		break;
788 
789 	case AF_INET6:
790 		bzero(&addr6, sizeof(addr6));
791 		addr6.sin6_family = AF_INET6;
792 		addr6.sin6_port = htons(port);
793 		addr6.sin6_addr = in6addr_any;
794 		addr = (struct sockaddr*)&addr6;
795 		len = sizeof(addr6);
796 		break;
797 
798 	default:
799 		/* unreachable */
800 		abort();
801 	}
802 
803 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
804 		err(1, "socket");
805 
806 	v = 1;
807 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
808 		err(1, "setsockopt(SO_REUSEADDR)");
809 
810 	v = 1;
811 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
812 		err(1, "setsockopt(SO_REUSEPORT)");
813 
814 	mark_nonblock(sock);
815 
816 	if (bind(sock, addr, len) == -1)
817 		err(1, "bind");
818 
819 	if (listen(sock, 16) == -1)
820 		err(1, "listen");
821 
822 	return sock;
823 }
824 
825 void
826 do_accept(int sock, struct tls *ctx, struct pollfd *fds, struct client *clients)
827 {
828 	int i, fd;
829 	struct sockaddr_in addr;
830 	socklen_t len;
831 
832 	len = sizeof(addr);
833 	if ((fd = accept(sock, (struct sockaddr*)&addr, &len)) == -1) {
834 		if (errno == EWOULDBLOCK)
835 			return;
836 		err(1, "accept");
837 	}
838 
839 	mark_nonblock(fd);
840 
841 	for (i = 0; i < MAX_USERS; ++i) {
842 		if (fds[i].fd == -1) {
843 			bzero(&clients[i], sizeof(struct client));
844 			if (tls_accept_socket(ctx, &clients[i].ctx, fd) == -1)
845 				break; /* goodbye fd! */
846 
847 			fds[i].fd = fd;
848 			fds[i].events = POLLIN;
849 
850 			clients[i].state = S_OPEN;
851 			clients[i].fd = -1;
852 			clients[i].child = -1;
853 			clients[i].buf = MAP_FAILED;
854 			clients[i].af = AF_INET;
855 			clients[i].addr = addr.sin_addr;
856 
857 			connected_clients++;
858 			return;
859 		}
860 	}
861 
862 	close(fd);
863 }
864 
865 void
866 goodbye(struct pollfd *pfd, struct client *c)
867 {
868 	ssize_t ret;
869 
870 	c->state = S_CLOSING;
871 
872 	ret = tls_close(c->ctx);
873 	if (ret == TLS_WANT_POLLIN) {
874 		pfd->events = POLLIN;
875 		return;
876 	}
877 	if (ret == TLS_WANT_POLLOUT) {
878 		pfd->events = POLLOUT;
879 		return;
880 	}
881 
882 	connected_clients--;
883 
884 	tls_free(c->ctx);
885 	c->ctx = NULL;
886 
887 	if (c->buf != MAP_FAILED)
888 		munmap(c->buf, c->len);
889 
890 	if (c->fd != -1)
891 		close(c->fd);
892 
893 	close(pfd->fd);
894 	pfd->fd = -1;
895 }
896 
897 void
898 loop(struct tls *ctx, int sock)
899 {
900 	int i, todo;
901 	struct client clients[MAX_USERS];
902 	struct pollfd fds[MAX_USERS];
903 
904 	for (i = 0; i < MAX_USERS; ++i) {
905 		fds[i].fd = -1;
906 		fds[i].events = POLLIN;
907 		bzero(&clients[i], sizeof(struct client));
908 	}
909 
910 	fds[0].fd = sock;
911 
912 	for (;;) {
913 		if ((todo = poll(fds, MAX_USERS, INFTIM)) == -1) {
914 			if (errno == EINTR) {
915                                 warnx("connected clients: %d", connected_clients);
916 				continue;
917 			}
918 			err(1, "poll");
919 		}
920 
921 		for (i = 0; i < MAX_USERS; i++) {
922 			assert(i < MAX_USERS);
923 
924 			if (fds[i].revents == 0)
925 				continue;
926 
927 			if (fds[i].revents & (POLLERR|POLLNVAL))
928 				err(1, "bad fd %d", fds[i].fd);
929 
930 			if (fds[i].revents & POLLHUP) {
931 				/* fds[i] may be the fd of the stdin
932 				 * of a cgi script that has exited. */
933 				if (!clients[i].waiting_on_child) {
934 					goodbye(&fds[i], &clients[i]);
935 					continue;
936 				}
937 			}
938 
939 			todo--;
940 
941 			if (i == 0) { /* new client */
942 				do_accept(sock, ctx, fds, clients);
943 				continue;
944 			}
945 
946 			handle(&fds[i], &clients[i]);
947 		}
948 	}
949 }
950 
951 void
952 usage(const char *me)
953 {
954 	fprintf(stderr,
955 	    "USAGE: %s [-h] [-c cert.pem] [-d docs] [-k key.pem] "
956 	    "[-l logfile] [-p port] [-x cgi-bin]\n",
957 	    me);
958 }
959 
960 int
961 main(int argc, char **argv)
962 {
963 	const char *cert = "cert.pem", *key = "key.pem";
964 	struct tls *ctx = NULL;
965 	struct tls_config *conf;
966 	int sock, ch;
967 
968 	signal(SIGPIPE, SIG_IGN);
969 	signal(SIGCHLD, SIG_IGN);
970 
971 #ifdef SIGINFO
972 	signal(SIGINFO, siginfo_handler);
973 #endif
974 	signal(SIGUSR2, siginfo_handler);
975 
976 	connected_clients = 0;
977 
978 	dir = "docs/";
979 	logfd = 2;		/* stderr */
980 	cgi = NULL;
981 	port = 1965;
982 
983 	while ((ch = getopt(argc, argv, "c:d:hk:l:p:x:")) != -1) {
984 		switch (ch) {
985 		case 'c':
986 			cert = optarg;
987 			break;
988 
989 		case 'd':
990 			dir = optarg;
991 			break;
992 
993 		case 'h':
994 			usage(*argv);
995 			return 0;
996 
997 		case 'k':
998 			key = optarg;
999 			break;
1000 
1001 		case 'l':
1002 			/* open log file or create it with 644 */
1003 			if ((logfd = open(optarg, O_WRONLY | O_CREAT | O_CLOEXEC,
1004 					S_IRUSR | S_IWUSR | S_IRGRP | S_IWOTH)) == -1)
1005 				err(1, "%s", optarg);
1006 			break;
1007 
1008 		case 'p': {
1009 			char *ep;
1010 			long lval;
1011 
1012 			errno = 0;
1013 			lval = strtol(optarg, &ep, 10);
1014 			if (optarg[0] == '\0' || *ep != '\0')
1015 				err(1, "not a number: %s", optarg);
1016 			if (lval < 0 || lval > UINT16_MAX)
1017 				err(1, "port number out of range: %s", optarg);
1018 			port = lval;
1019 			break;
1020 		}
1021 
1022 		case 'x':
1023 			cgi = optarg;
1024 			break;
1025 
1026 		default:
1027 			usage(*argv);
1028 			return 1;
1029 		}
1030 	}
1031 
1032 	if ((conf = tls_config_new()) == NULL)
1033 		err(1, "tls_config_new");
1034 
1035 	if (tls_config_set_protocols(conf,
1036 	    TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3) == -1)
1037 		err(1, "tls_config_set_protocols");
1038 
1039 	if (tls_config_set_cert_file(conf, cert) == -1)
1040 		err(1, "tls_config_set_cert_file: %s", cert);
1041 
1042 	if (tls_config_set_key_file(conf, key) == -1)
1043 		err(1, "tls_config_set_key_file: %s", key);
1044 
1045 	if ((ctx = tls_server()) == NULL)
1046 		err(1, "tls_server");
1047 
1048 	if (tls_configure(ctx, conf) == -1)
1049 		errx(1, "tls_configure: %s", tls_error(ctx));
1050 
1051 	sock = make_socket(port, AF_INET);
1052 
1053 	if ((dirfd = open(dir, O_RDONLY | O_DIRECTORY)) == -1)
1054 		err(1, "open: %s", dir);
1055 
1056 	if (cgi != NULL) {
1057 		if (unveil(dir, "rx") == -1)
1058 			err(1, "unveil");
1059 		if (pledge("stdio rpath inet proc exec", NULL) == -1)
1060 			err(1, "pledge");
1061 	} else {
1062 		if (unveil(dir, "r") == -1)
1063 			err(1, "unveil");
1064 		if (pledge("stdio rpath inet", NULL) == -1)
1065 			err(1, "pledge");
1066 	}
1067 
1068 	loop(ctx, sock);
1069 
1070 	close(sock);
1071 	tls_free(ctx);
1072 	tls_config_free(conf);
1073 }