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Date:: Fri Jan 15 14:03:45 2021 UTC
Message:: sandbox also on FreeBSD with capsicum
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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/stat.h>
19 
20 #include <assert.h>
21 #include <err.h>
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <limits.h>
25 #include <netdb.h>
26 #include <signal.h>
27 #include <stdarg.h>
28 #include <string.h>
29 
30 #include "gmid.h"
31 
32 struct vhost hosts[HOSTSLEN];
33 
34 int connected_clients;
35 int goterror;
36 
37 struct conf conf;
38 
39 struct etm {			/* file extension to mime */
40 	const char	*mime;
41 	const char	*ext;
42 } filetypes[] = {
43 	{"application/pdf",	"pdf"},
44 
45 	{"image/gif",		"gif"},
46 	{"image/jpeg",		"jpg"},
47 	{"image/jpeg",		"jpeg"},
48 	{"image/png",		"png"},
49 	{"image/svg+xml",	"svg"},
50 
51 	{"text/gemini",		"gemini"},
52 	{"text/gemini",		"gmi"},
53 	{"text/markdown",	"markdown"},
54 	{"text/markdown",	"md"},
55 	{"text/plain",		"txt"},
56 	{"text/xml",		"xml"},
57 
58 	{NULL, NULL}
59 };
60 
61 static inline void
62 safe_setenv(const char *name, const char *val)
63 {
64 	if (val == NULL)
65 		val = "";
66 	setenv(name, val, 1);
67 }
68 
69 __attribute__ ((format (printf, 1, 2)))
70 __attribute__ ((__noreturn__))
71 static inline void
72 fatal(const char *fmt, ...)
73 {
74 	va_list ap;
75 
76 	va_start(ap, fmt);
77 
78 	if (conf.foreground) {
79 		vfprintf(stderr, fmt, ap);
80 		fprintf(stderr, "\n");
81 	} else
82 		vsyslog(LOG_DAEMON | LOG_CRIT, fmt, ap);
83 
84 	va_end(ap);
85 	exit(1);
86 }
87 
88 void
89 logs(int priority, struct client *c,
90     const char *fmt, ...)
91 {
92 	char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
93 	char *fmted, *s;
94 	size_t len;
95 	int ec;
96 	va_list ap;
97 
98 	va_start(ap, fmt);
99 
100 	if (c == NULL) {
101 		strncpy(hbuf, "<internal>", sizeof(hbuf));
102 		sbuf[0] = '\0';
103 	} else {
104 		len = sizeof(c->addr);
105 		ec = getnameinfo((struct sockaddr*)&c->addr, len,
106 			hbuf, sizeof(hbuf),
107 			sbuf, sizeof(sbuf),
108 			NI_NUMERICHOST | NI_NUMERICSERV);
109 		if (ec != 0)
110 			fatal("getnameinfo: %s", gai_strerror(ec));
111 	}
112 
113 	if (vasprintf(&fmted, fmt, ap) == -1)
114 		fatal("vasprintf: %s", strerror(errno));
115 
116 	if (conf.foreground)
117 		fprintf(stderr, "%s:%s %s\n", hbuf, sbuf, fmted);
118 	else {
119 		if (asprintf(&s, "%s:%s %s", hbuf, sbuf, fmted) == -1)
120 			fatal("asprintf: %s", strerror(errno));
121 		syslog(priority | LOG_DAEMON, "%s", s);
122 		free(s);
123 	}
124 
125 	free(fmted);
126 
127 	va_end(ap);
128 }
129 
130 void
131 sig_handler(int sig)
132 {
133 	(void)sig;
134 }
135 
136 int
137 starts_with(const char *str, const char *prefix)
138 {
139 	size_t i;
140 
141 	for (i = 0; prefix[i] != '\0'; ++i)
142 		if (str[i] != prefix[i])
143 			return 0;
144 	return 1;
145 }
146 
147 int
148 start_reply(struct pollfd *pfd, struct client *client, int code, const char *reason)
149 {
150 	char buf[1030] = {0}; 	/* status + ' ' + max reply len + \r\n\0 */
151 	int len;
152 	int ret;
153 
154 	client->code = code;
155 	client->meta = reason;
156 	client->state = S_INITIALIZING;
157 
158 	len = snprintf(buf, sizeof(buf), "%d %s\r\n", code, reason);
159 	assert(len < (int)sizeof(buf));
160 	ret = tls_write(client->ctx, buf, len);
161 	if (ret == TLS_WANT_POLLIN) {
162 		pfd->events = POLLIN;
163 		return 0;
164 	}
165 
166 	if (ret == TLS_WANT_POLLOUT) {
167 		pfd->events = POLLOUT;
168 		return 0;
169 	}
170 
171 	return 1;
172 }
173 
174 ssize_t
175 filesize(int fd)
176 {
177 	ssize_t len;
178 
179 	if ((len = lseek(fd, 0, SEEK_END)) == -1)
180 		return -1;
181 	if (lseek(fd, 0, SEEK_SET) == -1)
182 		return -1;
183 	return len;
184 }
185 
186 const char *
187 path_ext(const char *path)
188 {
189 	const char *end;
190 
191 	end = path + strlen(path)-1; /* the last byte before the NUL */
192 	for (; end != path; --end) {
193 		if (*end == '.')
194 			return end+1;
195 		if (*end == '/')
196 			break;
197 	}
198 
199 	return NULL;
200 }
201 
202 const char *
203 mime(const char *path)
204 {
205 	const char *ext, *def = "application/octet-stream";
206 	struct etm *t;
207 
208 	if ((ext = path_ext(path)) == NULL)
209 		return def;
210 
211 	for (t = filetypes; t->mime != NULL; ++t)
212 		if (!strcmp(ext, t->ext))
213 			return t->mime;
214 
215 	return def;
216 }
217 
218 int
219 check_path(struct client *c, const char *path, int *fd)
220 {
221 	struct stat sb;
222 
223 	assert(path != NULL);
224 	if ((*fd = openat(c->host->dirfd, *path ? path : ".",
225 		    O_RDONLY | O_NOFOLLOW | O_CLOEXEC)) == -1) {
226 		return FILE_MISSING;
227 	}
228 
229 	if (fstat(*fd, &sb) == -1) {
230 		LOGN(c, "failed stat for %s: %s", path, strerror(errno));
231 		return FILE_MISSING;
232 	}
233 
234 	if (S_ISDIR(sb.st_mode))
235 		return FILE_DIRECTORY;
236 
237 	if (sb.st_mode & S_IXUSR)
238 		return FILE_EXECUTABLE;
239 
240 	return FILE_EXISTS;
241 }
242 
243 /*
244  * the inverse of this algorithm, i.e. starting from the start of the
245  * path + strlen(cgi), and checking if each component, should be
246  * faster.  But it's tedious to write.  This does the opposite: starts
247  * from the end and strip one component at a time, until either an
248  * executable is found or we emptied the path.
249  */
250 int
251 check_for_cgi(char *path, char *query, struct pollfd *fds, struct client *c)
252 {
253 	char *end;
254 	end = strchr(path, '\0');
255 
256 	/* NB: assume CGI is enabled and path matches cgi */
257 
258 	while (end > path) {
259 		/* go up one level.  UNIX paths are simple and POSIX
260 		 * dirname, with its ambiguities on if the given path
261 		 * is changed or not, gives me headaches. */
262 		while (*end != '/')
263 			end--;
264 		*end = '\0';
265 
266 		switch (check_path(c, path, &c->fd)) {
267 		case FILE_EXECUTABLE:
268 			return start_cgi(path, end+1, query, fds,c);
269 		case FILE_MISSING:
270 			break;
271 		default:
272 			goto err;
273 		}
274 
275 		*end = '/';
276 		end--;
277 	}
278 
279 err:
280 	if (!start_reply(fds, c, NOT_FOUND, "not found"))
281 		return 0;
282 	goodbye(fds, c);
283 	return 0;
284 }
285 
286 
287 int
288 open_file(char *fpath, char *query, struct pollfd *fds, struct client *c)
289 {
290 	switch (check_path(c, fpath, &c->fd)) {
291 	case FILE_EXECUTABLE:
292 		if (c->host->cgi != NULL && starts_with(fpath, c->host->cgi))
293 			return start_cgi(fpath, "", query, fds, c);
294 
295 		/* fallthrough */
296 
297 	case FILE_EXISTS:
298 		if ((c->len = filesize(c->fd)) == -1) {
299 			LOGE(c, "failed to get file size for %s", fpath);
300 			goodbye(fds, c);
301 			return 0;
302 		}
303 
304 		if ((c->buf = mmap(NULL, c->len, PROT_READ, MAP_PRIVATE,
305 			    c->fd, 0)) == MAP_FAILED) {
306 			warn("mmap: %s", fpath);
307 			goodbye(fds, c);
308 			return 0;
309 		}
310 		c->i = c->buf;
311 		return start_reply(fds, c, SUCCESS, mime(fpath));
312 
313 	case FILE_DIRECTORY:
314 		LOGD(c, "%s is a directory, trying %s/index.gmi", fpath, fpath);
315 		close(c->fd);
316 		c->fd = -1;
317 		send_dir(fpath, fds, c);
318 		return 0;
319 
320 	case FILE_MISSING:
321 		if (c->host->cgi != NULL && starts_with(fpath, c->host->cgi))
322 			return check_for_cgi(fpath, query, fds, c);
323 
324 		if (!start_reply(fds, c, NOT_FOUND, "not found"))
325 			return 0;
326 		goodbye(fds, c);
327 		return 0;
328 
329 	default:
330 		/* unreachable */
331 		abort();
332 	}
333 }
334 
335 int
336 start_cgi(const char *spath, const char *relpath, const char *query,
337     struct pollfd *fds, struct client *c)
338 {
339 	pid_t pid;
340 	int p[2]; 		/* read end, write end */
341 
342 	if (pipe(p) == -1)
343 		goto err;
344 
345 	switch (pid = fork()) {
346 	case -1:
347 		goto err;
348 
349 	case 0: { 		/* child */
350 		char *ex, *requri, *portno;
351 		char addr[NI_MAXHOST];
352 		char *argv[] = { NULL, NULL, NULL };
353 		int ec;
354 
355 		close(p[0]);
356 		if (dup2(p[1], 1) == -1)
357 			goto childerr;
358 
359 		if (inet_ntop(c->af, &c->addr, addr, sizeof(addr)) == NULL)
360 			goto childerr;
361 
362 		ec = getnameinfo((struct sockaddr*)&c->addr, sizeof(c->addr),
363 		    addr, sizeof(addr),
364 		    NULL, 0,
365 		    NI_NUMERICHOST | NI_NUMERICSERV);
366 		if (ec != 0)
367 			goto childerr;
368 
369 		if (asprintf(&portno, "%d", conf.port) == -1)
370 			goto childerr;
371 
372 		if (asprintf(&ex, "%s/%s", c->host->dir, spath) == -1)
373 			goto childerr;
374 
375 		if (asprintf(&requri, "%s%s%s", spath,
376 		    *relpath == '\0' ? "" : "/",
377 		    relpath) == -1)
378 			goto childerr;
379 
380 		argv[0] = argv[1] = ex;
381 
382 		/* fix the env */
383 		safe_setenv("GATEWAY_INTERFACE", "CGI/1.1");
384 		safe_setenv("SERVER_SOFTWARE", "gmid");
385 		safe_setenv("SERVER_PORT", portno);
386 		/* setenv("SERVER_NAME", "", 1); */
387 		safe_setenv("SCRIPT_NAME", spath);
388 		safe_setenv("SCRIPT_EXECUTABLE", ex);
389 		safe_setenv("REQUEST_URI", requri);
390 		safe_setenv("REQUEST_RELATIVE", relpath);
391 		safe_setenv("QUERY_STRING", query);
392 		safe_setenv("REMOTE_HOST", addr);
393 		safe_setenv("REMOTE_ADDR", addr);
394 		safe_setenv("DOCUMENT_ROOT", c->host->dir);
395 
396 		if (tls_peer_cert_provided(c->ctx)) {
397 			safe_setenv("AUTH_TYPE", "Certificate");
398 			safe_setenv("REMOTE_USER", tls_peer_cert_subject(c->ctx));
399 			safe_setenv("TLS_CLIENT_ISSUER", tls_peer_cert_issuer(c->ctx));
400 			safe_setenv("TLS_CLIENT_HASH", tls_peer_cert_hash(c->ctx));
401 		}
402 
403 		execvp(ex, argv);
404 		goto childerr;
405 	}
406 
407 	default:		/* parent */
408 		close(p[1]);
409 		close(c->fd);
410 		c->fd = p[0];
411 		c->child = pid;
412 		mark_nonblock(c->fd);
413 		c->state = S_SENDING;
414 		handle_cgi(fds, c);
415 		return 0;
416 	}
417 
418 err:
419 	if (!start_reply(fds, c, TEMP_FAILURE, "internal server error"))
420 		return 0;
421 	goodbye(fds, c);
422 	return 0;
423 
424 childerr:
425 	dprintf(p[1], "%d internal server error\r\n", TEMP_FAILURE);
426 	close(p[1]);
427 	_exit(1);
428 }
429 
430 void
431 cgi_poll_on_child(struct pollfd *fds, struct client *c)
432 {
433 	int fd;
434 
435 	if (c->waiting_on_child)
436 		return;
437 	c->waiting_on_child = 1;
438 
439 	fds->events = POLLIN;
440 
441 	fd = fds->fd;
442 	fds->fd = c->fd;
443 	c->fd = fd;
444 }
445 
446 void
447 cgi_poll_on_client(struct pollfd *fds, struct client *c)
448 {
449 	int fd;
450 
451 	if (!c->waiting_on_child)
452 		return;
453 	c->waiting_on_child = 0;
454 
455 	fd = fds->fd;
456 	fds->fd = c->fd;
457 	c->fd = fd;
458 }
459 
460 void
461 handle_cgi(struct pollfd *fds, struct client *c)
462 {
463 	ssize_t r;
464 
465 	/* ensure c->fd is the child and fds->fd the client */
466 	cgi_poll_on_client(fds, c);
467 
468 	while (1) {
469 		if (c->len == 0) {
470 			if ((r = read(c->fd, c->sbuf, sizeof(c->sbuf))) == 0)
471 				goto end;
472 			if (r == -1) {
473 				if (errno == EAGAIN || errno == EWOULDBLOCK) {
474 					cgi_poll_on_child(fds, c);
475 					return;
476 				}
477                                 goto end;
478 			}
479 			c->len = r;
480 			c->off = 0;
481 		}
482 
483 		while (c->len > 0) {
484 			switch (r = tls_write(c->ctx, c->sbuf + c->off, c->len)) {
485 			case -1:
486 				goto end;
487 
488 			case TLS_WANT_POLLOUT:
489 				fds->events = POLLOUT;
490 				return;
491 
492 			case TLS_WANT_POLLIN:
493 				fds->events = POLLIN;
494 				return;
495 
496 			default:
497                                 c->off += r;
498 				c->len -= r;
499 				break;
500 			}
501 		}
502 	}
503 
504 end:
505 	goodbye(fds, c);
506 }
507 
508 void
509 send_file(char *path, char *query, struct pollfd *fds, struct client *c)
510 {
511 	ssize_t ret, len;
512 
513 	if (c->fd == -1) {
514 		if (!open_file(path, query, fds, c))
515 			return;
516 		c->state = S_SENDING;
517 	}
518 
519 	len = (c->buf + c->len) - c->i;
520 
521 	while (len > 0) {
522 		switch (ret = tls_write(c->ctx, c->i, len)) {
523 		case -1:
524 			LOGE(c, "tls_write: %s", tls_error(c->ctx));
525 			goodbye(fds, c);
526 			return;
527 
528 		case TLS_WANT_POLLIN:
529 			fds->events = POLLIN;
530 			return;
531 
532 		case TLS_WANT_POLLOUT:
533 			fds->events = POLLOUT;
534 			return;
535 
536 		default:
537 			c->i += ret;
538 			len -= ret;
539 			break;
540 		}
541 	}
542 
543 	goodbye(fds, c);
544 }
545 
546 void
547 send_dir(char *path, struct pollfd *fds, struct client *client)
548 {
549 	char fpath[PATHBUF];
550 	size_t len;
551 
552 	bzero(fpath, PATHBUF);
553 
554 	if (path[0] != '.')
555 		fpath[0] = '.';
556 
557 	/* this cannot fail since sizeof(fpath) > maxlen of path */
558 	strlcat(fpath, path, PATHBUF);
559 	len = strlen(fpath);
560 
561 	/* add a trailing / in case. */
562 	if (fpath[len-1] != '/') {
563 		fpath[len] = '/';
564 	}
565 
566 	strlcat(fpath, "index.gmi", sizeof(fpath));
567 
568 	send_file(fpath, NULL, fds, client);
569 }
570 
571 void
572 handle_handshake(struct pollfd *fds, struct client *c)
573 {
574 	struct vhost *h;
575 	const char *servname;
576 
577 	switch (tls_handshake(c->ctx)) {
578 	case 0:  /* success */
579 	case -1: /* already handshaked */
580 		break;
581 	case TLS_WANT_POLLIN:
582 		fds->events = POLLIN;
583 		return;
584 	case TLS_WANT_POLLOUT:
585 		fds->events = POLLOUT;
586 		return;
587 	default:
588 		/* unreachable */
589 		abort();
590 	}
591 
592 	servname = tls_conn_servername(c->ctx);
593 	if (servname == NULL)
594 		goto wronghost;
595 
596 	for (h = hosts; h->domain != NULL; ++h) {
597 		if (!strcmp(h->domain, servname) || !strcmp(h->domain, "*"))
598 			break;
599 	}
600 
601 	if (h->domain != NULL) {
602 		c->state = S_OPEN;
603 		c->host = h;
604 		handle_open_conn(fds, c);
605 		return;
606 	}
607 
608 wronghost:
609 	/* XXX: check the correct response */
610 	if (!start_reply(fds, c, BAD_REQUEST, "Wrong host or missing SNI"))
611 		return;
612 	goodbye(fds, c);
613 }
614 
615 void
616 handle_open_conn(struct pollfd *fds, struct client *c)
617 {
618 	char buf[GEMINI_URL_LEN];
619 	const char *parse_err = "invalid request";
620 	struct iri iri;
621 
622 	bzero(buf, sizeof(buf));
623 
624 	switch (tls_read(c->ctx, buf, sizeof(buf)-1)) {
625 	case -1:
626 		LOGE(c, "tls_read: %s", tls_error(c->ctx));
627 		goodbye(fds, c);
628 		return;
629 
630 	case TLS_WANT_POLLIN:
631 		fds->events = POLLIN;
632 		return;
633 
634 	case TLS_WANT_POLLOUT:
635 		fds->events = POLLOUT;
636 		return;
637 	}
638 
639 	if (!trim_req_iri(buf) || !parse_iri(buf, &iri, &parse_err)) {
640 		if (!start_reply(fds, c, BAD_REQUEST, parse_err))
641 			return;
642 		goodbye(fds, c);
643 		return;
644 	}
645 
646 	if (strcmp(iri.schema, "gemini")) {
647 		if (!start_reply(fds, c, PROXY_REFUSED, "won't proxy request"))
648 			return;
649 		goodbye(fds, c);
650 		return;
651 	}
652 
653 	LOGI(c, "GET %s%s%s",
654 		*iri.path ? iri.path : "/",
655 		*iri.query ? "?" : "",
656 		*iri.query ? iri.query : "");
657 
658 	send_file(iri.path, iri.query, fds, c);
659 }
660 
661 void
662 handle(struct pollfd *fds, struct client *client)
663 {
664 	switch (client->state) {
665 	case S_HANDSHAKE:
666 		handle_handshake(fds, client);
667 		break;
668 
669 	case S_OPEN:
670                 handle_open_conn(fds, client);
671 		break;
672 
673 	case S_INITIALIZING:
674 		if (!start_reply(fds, client, client->code, client->meta))
675 			return;
676 
677 		if (client->code != SUCCESS) {
678 			/* we don't need a body */
679 			goodbye(fds, client);
680 			return;
681 		}
682 
683 		client->state = S_SENDING;
684 
685 		/* fallthrough */
686 
687 	case S_SENDING:
688 		if (client->child != -1)
689 			handle_cgi(fds, client);
690 		else
691 			send_file(NULL, NULL, fds, client);
692 		break;
693 
694 	case S_CLOSING:
695 		goodbye(fds, client);
696 		break;
697 
698 	default:
699 		/* unreachable */
700 		abort();
701 	}
702 }
703 
704 void
705 mark_nonblock(int fd)
706 {
707 	int flags;
708 
709 	if ((flags = fcntl(fd, F_GETFL)) == -1)
710 		fatal("fcntl(F_GETFL): %s", strerror(errno));
711 	if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
712 		fatal("fcntl(F_SETFL): %s", strerror(errno));
713 }
714 
715 int
716 make_socket(int port, int family)
717 {
718 	int sock, v;
719 	struct sockaddr_in addr4;
720 	struct sockaddr_in6 addr6;
721 	struct sockaddr *addr;
722 	socklen_t len;
723 
724         switch (family) {
725 	case AF_INET:
726 		bzero(&addr4, sizeof(addr4));
727 		addr4.sin_family = family;
728 		addr4.sin_port = htons(port);
729 		addr4.sin_addr.s_addr = INADDR_ANY;
730 		addr = (struct sockaddr*)&addr4;
731 		len = sizeof(addr4);
732 		break;
733 
734 	case AF_INET6:
735 		bzero(&addr6, sizeof(addr6));
736 		addr6.sin6_family = AF_INET6;
737 		addr6.sin6_port = htons(port);
738 		addr6.sin6_addr = in6addr_any;
739 		addr = (struct sockaddr*)&addr6;
740 		len = sizeof(addr6);
741 		break;
742 
743 	default:
744 		/* unreachable */
745 		abort();
746 	}
747 
748 	if ((sock = socket(family, SOCK_STREAM, 0)) == -1)
749 		fatal("socket: %s", strerror(errno));
750 
751 	v = 1;
752 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &v, sizeof(v)) == -1)
753 		fatal("setsockopt(SO_REUSEADDR): %s", strerror(errno));
754 
755 	v = 1;
756 	if (setsockopt(sock, SOL_SOCKET, SO_REUSEPORT, &v, sizeof(v)) == -1)
757 		fatal("setsockopt(SO_REUSEPORT): %s", strerror(errno));
758 
759 	mark_nonblock(sock);
760 
761 	if (bind(sock, addr, len) == -1)
762 		fatal("bind: %s", strerror(errno));
763 
764 	if (listen(sock, 16) == -1)
765 		fatal("listen: %s", strerror(errno));
766 
767 	return sock;
768 }
769 
770 void
771 do_accept(int sock, struct tls *ctx, struct pollfd *fds, struct client *clients)
772 {
773 	int i, fd;
774 	struct sockaddr_storage addr;
775 	socklen_t len;
776 
777 	len = sizeof(addr);
778 	if ((fd = accept(sock, (struct sockaddr*)&addr, &len)) == -1) {
779 		if (errno == EWOULDBLOCK)
780 			return;
781 		fatal("accept: %s", strerror(errno));
782 	}
783 
784 	mark_nonblock(fd);
785 
786 	for (i = 0; i < MAX_USERS; ++i) {
787 		if (fds[i].fd == -1) {
788 			bzero(&clients[i], sizeof(struct client));
789 			if (tls_accept_socket(ctx, &clients[i].ctx, fd) == -1)
790 				break; /* goodbye fd! */
791 
792 			fds[i].fd = fd;
793 			fds[i].events = POLLIN;
794 
795 			clients[i].state = S_HANDSHAKE;
796 			clients[i].fd = -1;
797 			clients[i].child = -1;
798 			clients[i].buf = MAP_FAILED;
799 			clients[i].af = AF_INET;
800 			clients[i].addr = addr;
801 
802 			connected_clients++;
803 			return;
804 		}
805 	}
806 
807 	close(fd);
808 }
809 
810 void
811 goodbye(struct pollfd *pfd, struct client *c)
812 {
813 	ssize_t ret;
814 
815 	c->state = S_CLOSING;
816 
817 	ret = tls_close(c->ctx);
818 	if (ret == TLS_WANT_POLLIN) {
819 		pfd->events = POLLIN;
820 		return;
821 	}
822 	if (ret == TLS_WANT_POLLOUT) {
823 		pfd->events = POLLOUT;
824 		return;
825 	}
826 
827 	connected_clients--;
828 
829 	tls_free(c->ctx);
830 	c->ctx = NULL;
831 
832 	if (c->buf != MAP_FAILED)
833 		munmap(c->buf, c->len);
834 
835 	if (c->fd != -1)
836 		close(c->fd);
837 
838 	close(pfd->fd);
839 	pfd->fd = -1;
840 }
841 
842 void
843 loop(struct tls *ctx, int sock4, int sock6)
844 {
845 	int i;
846 	struct client clients[MAX_USERS];
847 	struct pollfd fds[MAX_USERS];
848 
849 	for (i = 0; i < MAX_USERS; ++i) {
850 		fds[i].fd = -1;
851 		fds[i].events = POLLIN;
852 		bzero(&clients[i], sizeof(struct client));
853 	}
854 
855 	fds[0].fd = sock4;
856 	fds[1].fd = sock6;
857 
858 	for (;;) {
859 		if (poll(fds, MAX_USERS, INFTIM) == -1) {
860 			if (errno == EINTR) {
861                                 warnx("connected clients: %d",
862 				    connected_clients);
863 				continue;
864 			}
865 			fatal("poll: %s", strerror(errno));
866 		}
867 
868 		for (i = 0; i < MAX_USERS; i++) {
869 			if (fds[i].revents == 0)
870 				continue;
871 
872 			if (fds[i].revents & (POLLERR|POLLNVAL))
873 				fatal("bad fd %d: %s", fds[i].fd,
874 				    strerror(errno));
875 
876 			if (fds[i].revents & POLLHUP) {
877 				/* fds[i] may be the fd of the stdin
878 				 * of a cgi script that has exited. */
879 				if (!clients[i].waiting_on_child) {
880 					goodbye(&fds[i], &clients[i]);
881 					continue;
882 				}
883 			}
884 
885 			if (fds[i].fd == sock4)
886 				do_accept(sock4, ctx, fds, clients);
887 			else if (fds[i].fd == sock6)
888 				do_accept(sock6, ctx, fds, clients);
889 			else
890 				handle(&fds[i], &clients[i]);
891 		}
892 	}
893 }
894 
895 char *
896 absolutify_path(const char *path)
897 {
898 	char *wd, *r;
899 
900 	if (*path == '/')
901 		return strdup(path);
902 
903 	wd = getwd(NULL);
904 	if (asprintf(&r, "%s/%s", wd, path) == -1)
905 		err(1, "asprintf");
906 	free(wd);
907 	return r;
908 }
909 
910 void
911 yyerror(const char *msg)
912 {
913 	goterror = 1;
914 	fprintf(stderr, "%d: %s\n", yylineno, msg);
915 }
916 
917 int
918 parse_portno(const char *p)
919 {
920 	char *ep;
921 	long lval;
922 
923 	errno = 0;
924 	lval = strtol(p, &ep, 10);
925 	if (p[0] == '\0' || *ep != '\0')
926 		errx(1, "not a number: %s", p);
927 	if (lval < 0 || lval > UINT16_MAX)
928 		errx(1, "port number out of range for domain %s: %ld", p, lval);
929 	return lval;
930 }
931 
932 void
933 parse_conf(const char *path)
934 {
935 	if ((yyin = fopen(path, "r")) == NULL)
936 		err(1, "cannot open config %s", path);
937 	yyparse();
938 	fclose(yyin);
939 
940 	if (goterror)
941 		exit(1);
942 }
943 
944 void
945 load_vhosts(struct tls_config *tlsconf)
946 {
947 	struct vhost *h;
948 
949 	/* we need to set something, then we can add how many key we want */
950 	if (tls_config_set_keypair_file(tlsconf, hosts->cert, hosts->key))
951 		errx(1, "tls_config_set_keypair_file failed");
952 
953 	for (h = hosts; h->domain != NULL; ++h) {
954 		if (tls_config_add_keypair_file(tlsconf, h->cert, h->key) == -1)
955 			errx(1, "failed to load the keypair (%s, %s)",
956 			    h->cert, h->key);
957 
958 		if ((h->dirfd = open(h->dir, O_RDONLY | O_DIRECTORY)) == -1)
959 			err(1, "open %s for domain %s", h->dir, h->domain);
960 	}
961 }
962 
963 void
964 usage(const char *me)
965 {
966 	fprintf(stderr,
967 	    "USAGE: %s [-n] [-c config] | [-6fh] [-C cert] [-d root] [-K key] "
968 	    "[-p port] [-x cgi-bin]\n",
969 	    me);
970 }
971 
972 int
973 main(int argc, char **argv)
974 {
975 	struct tls *ctx = NULL;
976 	struct tls_config *tlsconf;
977 	int sock4, sock6, ch;
978 	const char *config_path = NULL;
979 	size_t i;
980 	int conftest = 0;
981 
982 	bzero(hosts, sizeof(hosts));
983 	for (i = 0; i < HOSTSLEN; ++i)
984 		hosts[i].dirfd = -1;
985 
986 	conf.foreground = 1;
987 	conf.port = 1965;
988 	conf.ipv6 = 0;
989 
990 	connected_clients = 0;
991 
992 	while ((ch = getopt(argc, argv, "6C:c:d:fhK:np:x:")) != -1) {
993 		switch (ch) {
994 		case '6':
995 			conf.ipv6 = 1;
996 			break;
997 
998 		case 'C':
999 			hosts[0].cert = optarg;
1000 			break;
1001 
1002 		case 'c':
1003 			config_path = optarg;
1004 			break;
1005 
1006 		case 'd':
1007 			free((char*)hosts[0].dir);
1008 			if ((hosts[0].dir = absolutify_path(optarg)) == NULL)
1009 				err(1, "absolutify_path");
1010 			break;
1011 
1012 		case 'f':
1013 			conf.foreground = 1;
1014 			break;
1015 
1016 		case 'h':
1017 			usage(*argv);
1018 			return 0;
1019 
1020 		case 'K':
1021 			hosts[0].key = optarg;
1022 			break;
1023 
1024 		case 'n':
1025 			conftest = 1;
1026 			break;
1027 
1028 		case 'p':
1029 			conf.port = parse_portno(optarg);
1030 
1031 		case 'x':
1032 			/* drop the starting / (if any) */
1033 			if (*optarg == '/')
1034 				optarg++;
1035 			hosts[0].cgi = optarg;
1036 			break;
1037 
1038 		default:
1039 			usage(*argv);
1040 			return 1;
1041 		}
1042 	}
1043 
1044 	if (config_path != NULL) {
1045 		if (hosts[0].cert != NULL || hosts[0].key != NULL ||
1046 		    hosts[0].dir != NULL)
1047 			errx(1, "can't specify options in conf mode");
1048 		parse_conf(config_path);
1049 	} else {
1050 		if (hosts[0].cert == NULL || hosts[0].key == NULL ||
1051 		    hosts[0].dir == NULL)
1052 			errx(1, "missing cert, key or root directory to serve");
1053 		hosts[0].domain = "*";
1054 	}
1055 
1056 	if (conftest)
1057                 errx(0, "config OK");
1058 
1059 	signal(SIGPIPE, SIG_IGN);
1060 	signal(SIGCHLD, SIG_IGN);
1061 
1062 #ifdef SIGINFO
1063 	signal(SIGINFO, sig_handler);
1064 #endif
1065 	signal(SIGUSR2, sig_handler);
1066 
1067 	if (!conf.foreground)
1068 		signal(SIGHUP, SIG_IGN);
1069 
1070 	if ((tlsconf = tls_config_new()) == NULL)
1071 		err(1, "tls_config_new");
1072 
1073 	/* optionally accept client certs, but don't try to verify them */
1074 	tls_config_verify_client_optional(tlsconf);
1075 	tls_config_insecure_noverifycert(tlsconf);
1076 
1077 	if (tls_config_set_protocols(tlsconf,
1078 	    TLS_PROTOCOL_TLSv1_2 | TLS_PROTOCOL_TLSv1_3) == -1)
1079 		err(1, "tls_config_set_protocols");
1080 
1081 	load_vhosts(tlsconf);
1082 
1083 	if ((ctx = tls_server()) == NULL)
1084 		err(1, "tls_server");
1085 
1086 	if (tls_configure(ctx, tlsconf) == -1)
1087 		errx(1, "tls_configure: %s", tls_error(ctx));
1088 
1089 	sock4 = make_socket(conf.port, AF_INET);
1090 	if (conf.ipv6)
1091 		sock6 = make_socket(conf.port, AF_INET6);
1092 	else
1093 		sock6 = -1;
1094 
1095 
1096 	if (!conf.foreground && daemon(0, 1) == -1)
1097 		exit(1);
1098 
1099 	sandbox();
1100 
1101 	loop(ctx, sock4, sock6);
1102 
1103 	close(sock4);
1104 	close(sock6);
1105 	tls_free(ctx);
1106 	tls_config_free(tlsconf);
1107 
1108 	return 0;
1109 }