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Date:: Mon Aug 29 17:48:00 2022 UTC
Message:: allow multiple "listen on" statements per server in gotwebd.conf ok tracey
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1 /*
2  * Copyright (c) 2016, 2019, 2020-2021 Tracey Emery <tracey@traceyemery.net>
3  * Copyright (c) 2015 Mike Larkin <mlarkin@openbsd.org>
4  * Copyright (c) 2013 David Gwynne <dlg@openbsd.org>
5  * Copyright (c) 2013 Florian Obser <florian@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/param.h>
21 #include <sys/ioctl.h>
22 #include <sys/queue.h>
23 #include <sys/wait.h>
24 #include <sys/uio.h>
25 #include <sys/resource.h>
26 #include <sys/socket.h>
27 #include <sys/stat.h>
28 #include <sys/time.h>
29 #include <sys/types.h>
30 #include <sys/mman.h>
31 #include <sys/un.h>
32 
33 #include <net/if.h>
34 #include <netinet/in.h>
35 
36 #include <errno.h>
37 #include <event.h>
38 #include <fcntl.h>
39 #include <ifaddrs.h>
40 #include <imsg.h>
41 #include <limits.h>
42 #include <netdb.h>
43 #include <poll.h>
44 #include <pwd.h>
45 #include <stddef.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 #include <util.h>
51 
52 #include "got_error.h"
53 #include "got_opentemp.h"
54 
55 #include "proc.h"
56 #include "gotwebd.h"
57 
58 #define SOCKS_BACKLOG 5
59 #define MAXIMUM(a, b)	(((a) > (b)) ? (a) : (b))
60 
61 
62 volatile int client_cnt;
63 
64 static struct timeval	timeout = { TIMEOUT_DEFAULT, 0 };
65 
66 static void	 sockets_sighdlr(int, short, void *);
67 static void	 sockets_run(struct privsep *, struct privsep_proc *, void *);
68 static void	 sockets_launch(void);
69 static void	 sockets_purge(struct gotwebd *);
70 static void	 sockets_accept_paused(int, short, void *);
71 static void	 sockets_rlimit(int);
72 
73 static int	 sockets_dispatch_gotwebd(int, struct privsep_proc *,
74 		    struct imsg *);
75 static int	 sockets_unix_socket_listen(struct privsep *, struct socket *);
76 static int	 sockets_create_socket(struct address *, in_port_t);
77 static int	 sockets_accept_reserve(int, struct sockaddr *, socklen_t *,
78 		    int, volatile int *);
79 
80 static struct socket *sockets_conf_new_socket_unix(struct gotwebd *,
81 		    struct server *, int);
82 static struct socket *sockets_conf_new_socket_fcgi(struct gotwebd *,
83 		    struct server *, int, struct address *);
84 
85 int cgi_inflight = 0;
86 
87 static struct privsep_proc procs[] = {
88 	{ "gotwebd",	PROC_GOTWEBD,	sockets_dispatch_gotwebd  },
89 };
90 
91 void
92 sockets(struct privsep *ps, struct privsep_proc *p)
93 {
94 	proc_run(ps, p, procs, nitems(procs), sockets_run, NULL);
95 }
96 
97 static void
98 sockets_run(struct privsep *ps, struct privsep_proc *p, void *arg)
99 {
100 	if (config_init(ps->ps_env) == -1)
101 		fatal("failed to initialize configuration");
102 
103 	p->p_shutdown = sockets_shutdown;
104 
105 	sockets_rlimit(-1);
106 
107 	signal_del(&ps->ps_evsigchld);
108 	signal_set(&ps->ps_evsigchld, SIGCHLD, sockets_sighdlr, ps);
109 	signal_add(&ps->ps_evsigchld, NULL);
110 
111 #ifndef PROFILE
112 	if (pledge("stdio rpath wpath cpath inet recvfd proc exec sendfd",
113 	    NULL) == -1)
114 		fatal("pledge");
115 #endif
116 }
117 
118 void
119 sockets_parse_sockets(struct gotwebd *env)
120 {
121 	struct server *srv;
122 	struct address *a;
123 	struct socket *new_sock = NULL;
124 	int sock_id = 1;
125 
126 	TAILQ_FOREACH(srv, &env->servers, entry) {
127 		if (srv->unix_socket) {
128 			new_sock = sockets_conf_new_socket_unix(env, srv,
129 			    sock_id);
130 			if (new_sock) {
131 				sock_id++;
132 				TAILQ_INSERT_TAIL(&env->sockets, new_sock,
133 				    entry);
134 			}
135 		}
136 
137 		if (srv->fcgi_socket) {
138 			if (TAILQ_EMPTY(&srv->al)) {
139 				fatalx("%s: server %s has no IP addresses to "
140 				    "listen for FCGI connections", __func__,
141 				    srv->name);
142 			}
143 			TAILQ_FOREACH(a, &srv->al, entry) {
144 				if (a->ss.ss_family != AF_INET &&
145 				    a->ss.ss_family != AF_INET6)
146 					continue;
147 				new_sock = sockets_conf_new_socket_fcgi(env,
148 				    srv, sock_id, a);
149 				if (new_sock) {
150 					sock_id++;
151 					TAILQ_INSERT_TAIL(&env->sockets,
152 					    new_sock, entry);
153 				}
154 			}
155 		}
156 	}
157 }
158 
159 static struct socket *
160 sockets_conf_new_socket_unix(struct gotwebd *env, struct server *srv, int id)
161 {
162 	struct socket *sock;
163 	int n;
164 
165 	if ((sock = calloc(1, sizeof(*sock))) == NULL)
166 		fatalx("%s: calloc", __func__);
167 
168 	sock->conf.id = id;
169 	sock->fd = -1;
170 	sock->conf.af_type = AF_UNIX;
171 
172 	if (strlcpy(sock->conf.unix_socket_name,
173 	    srv->unix_socket_name,
174 	    sizeof(sock->conf.unix_socket_name)) >=
175 	    sizeof(sock->conf.unix_socket_name)) {
176 		free(sock);
177 		fatalx("%s: strlcpy", __func__);
178 	}
179 
180 	n = snprintf(sock->conf.name, GOTWEBD_MAXTEXT, "%s_parent",
181 	    srv->name);
182 	if (n < 0 || (size_t)n >= GOTWEBD_MAXTEXT) {
183 		free(sock);
184 		fatalx("%s: snprintf", __func__);
185 	}
186 
187 	if (strlcpy(sock->conf.srv_name, srv->name,
188 	    sizeof(sock->conf.srv_name)) >= sizeof(sock->conf.srv_name)) {
189 		free(sock);
190 		fatalx("%s: strlcpy", __func__);
191 	}
192 
193 	return sock;
194 }
195 
196 static struct socket *
197 sockets_conf_new_socket_fcgi(struct gotwebd *env, struct server *srv, int id,
198     struct address *a)
199 {
200 	struct socket *sock;
201 	struct address *acp;
202 	int n;
203 
204 	if ((sock = calloc(1, sizeof(*sock))) == NULL)
205 		fatalx("%s: calloc", __func__);
206 
207 	sock->conf.id = id;
208 	sock->fd = -1;
209 	sock->conf.af_type = a->ss.ss_family;
210 
211 	sock->conf.fcgi_socket_port = a->port;
212 
213 	n = snprintf(sock->conf.name, GOTWEBD_MAXTEXT, "%s_parent",
214 	    srv->name);
215 	if (n < 0 || (size_t)n >= GOTWEBD_MAXTEXT) {
216 		free(sock);
217 		fatalx("%s: snprintf", __func__);
218 	}
219 
220 	if (strlcpy(sock->conf.srv_name, srv->name,
221 	    sizeof(sock->conf.srv_name)) >= sizeof(sock->conf.srv_name)) {
222 		free(sock);
223 		fatalx("%s: strlcpy", __func__);
224 	}
225 
226 	acp = &sock->conf.addr;
227 
228 	memcpy(&acp->ss, &a->ss, sizeof(acp->ss));
229 	acp->ipproto = a->ipproto;
230 	acp->prefixlen = a->prefixlen;
231 	acp->port = a->port;
232 	if (strlen(a->ifname) != 0) {
233 		if (strlcpy(acp->ifname, a->ifname,
234 		    sizeof(acp->ifname)) >= sizeof(acp->ifname)) {
235 			fatalx("%s: interface name truncated",
236 			    __func__);
237 		}
238 	}
239 
240 	return (sock);
241 }
242 
243 static void
244 sockets_launch(void)
245 {
246 	struct socket *sock;
247 
248 	TAILQ_FOREACH(sock, &gotwebd_env->sockets, entry) {
249 		log_debug("%s: configuring socket %d (%d)", __func__,
250 		    sock->conf.id, sock->fd);
251 
252 		event_set(&sock->ev, sock->fd, EV_READ | EV_PERSIST,
253 		    sockets_socket_accept, sock);
254 
255 		if (event_add(&sock->ev, NULL))
256 			fatalx("event add sock");
257 
258 		evtimer_set(&sock->pause, sockets_accept_paused, sock);
259 
260 		log_debug("%s: running socket listener %d", __func__,
261 		    sock->conf.id);
262 	}
263 }
264 
265 static void
266 sockets_purge(struct gotwebd *env)
267 {
268 	struct socket *sock, *tsock;
269 
270 	/* shutdown and remove sockets */
271 	TAILQ_FOREACH_SAFE(sock, &env->sockets, entry, tsock) {
272 		if (event_initialized(&sock->ev))
273 			event_del(&sock->ev);
274 		if (evtimer_initialized(&sock->evt))
275 			evtimer_del(&sock->evt);
276 		if (evtimer_initialized(&sock->pause))
277 			evtimer_del(&sock->pause);
278 		if (sock->fd != -1)
279 			close(sock->fd);
280 		TAILQ_REMOVE(&env->sockets, sock, entry);
281 	}
282 }
283 
284 static int
285 sockets_dispatch_gotwebd(int fd, struct privsep_proc *p, struct imsg *imsg)
286 {
287 	struct privsep *ps = p->p_ps;
288 	int res = 0, cmd = 0, verbose;
289 
290 	switch (imsg->hdr.type) {
291 	case IMSG_CFG_SRV:
292 		config_getserver(gotwebd_env, imsg);
293 		break;
294 	case IMSG_CFG_SOCK:
295 		config_getsock(gotwebd_env, imsg);
296 		break;
297 	case IMSG_CFG_FD:
298 		config_getfd(gotwebd_env, imsg);
299 		break;
300 	case IMSG_CFG_DONE:
301 		config_getcfg(gotwebd_env, imsg);
302 		break;
303 	case IMSG_CTL_START:
304 		sockets_launch();
305 		break;
306 	case IMSG_CTL_VERBOSE:
307 		IMSG_SIZE_CHECK(imsg, &verbose);
308 		memcpy(&verbose, imsg->data, sizeof(verbose));
309 		log_setverbose(verbose);
310 		break;
311 	default:
312 		return -1;
313 	}
314 
315 	switch (cmd) {
316 	case 0:
317 		break;
318 	default:
319 		if (proc_compose_imsg(ps, PROC_GOTWEBD, -1, cmd,
320 		    imsg->hdr.peerid, -1, &res, sizeof(res)) == -1)
321 			return -1;
322 		break;
323 	}
324 
325 	return 0;
326 }
327 
328 static void
329 sockets_sighdlr(int sig, short event, void *arg)
330 {
331 	switch (sig) {
332 	case SIGHUP:
333 		log_info("%s: ignoring SIGHUP", __func__);
334 		break;
335 	case SIGPIPE:
336 		log_info("%s: ignoring SIGPIPE", __func__);
337 		break;
338 	case SIGUSR1:
339 		log_info("%s: ignoring SIGUSR1", __func__);
340 		break;
341 	case SIGCHLD:
342 		break;
343 	default:
344 		log_info("SIGNAL: %d", sig);
345 		fatalx("unexpected signal");
346 	}
347 }
348 
349 void
350 sockets_shutdown(void)
351 {
352 	struct server *srv, *tsrv;
353 	struct socket *sock, *tsock;
354 
355 	sockets_purge(gotwebd_env);
356 
357 	/* clean sockets */
358 	TAILQ_FOREACH_SAFE(sock, &gotwebd_env->sockets, entry, tsock) {
359 		TAILQ_REMOVE(&gotwebd_env->sockets, sock, entry);
360 		close(sock->fd);
361 		free(sock);
362 	}
363 
364 	/* clean servers */
365 	TAILQ_FOREACH_SAFE(srv, &gotwebd_env->servers, entry, tsrv)
366 		free(srv);
367 
368 	free(gotwebd_env);
369 }
370 
371 int
372 sockets_privinit(struct gotwebd *env, struct socket *sock)
373 {
374 	struct privsep *ps = env->gotwebd_ps;
375 
376 	if (sock->conf.af_type == AF_UNIX) {
377 		log_debug("%s: initializing unix socket %s", __func__,
378 		    sock->conf.unix_socket_name);
379 		sock->fd = sockets_unix_socket_listen(ps, sock);
380 		if (sock->fd == -1) {
381 			log_warnx("%s: create unix socket failed", __func__);
382 			return -1;
383 		}
384 	}
385 
386 	if (sock->conf.af_type == AF_INET || sock->conf.af_type == AF_INET6) {
387 		log_debug("%s: initializing %s FCGI socket on port %d for %s",
388 		    __func__, sock->conf.af_type == AF_INET ? "inet" : "inet6",
389 		    sock->conf.fcgi_socket_port, sock->conf.name);
390 		sock->fd = sockets_create_socket(&sock->conf.addr,
391 		    sock->conf.fcgi_socket_port);
392 		if (sock->fd == -1) {
393 			log_warnx("%s: create FCGI socket failed", __func__);
394 			return -1;
395 		}
396 	}
397 
398 	return 0;
399 }
400 
401 static int
402 sockets_unix_socket_listen(struct privsep *ps, struct socket *sock)
403 {
404 	struct gotwebd *env = ps->ps_env;
405 	struct sockaddr_un sun;
406 	struct socket *tsock;
407 	int u_fd = -1;
408 	mode_t old_umask, mode;
409 
410 	TAILQ_FOREACH(tsock, &env->sockets, entry) {
411 		if (strcmp(tsock->conf.unix_socket_name,
412 		    sock->conf.unix_socket_name) == 0 &&
413 		    tsock->fd != -1)
414 			return (tsock->fd);
415 	}
416 
417 	u_fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
418 	if (u_fd == -1) {
419 		log_warn("%s: socket", __func__);
420 		return -1;
421 	}
422 
423 	sun.sun_family = AF_UNIX;
424 	if (strlcpy(sun.sun_path, sock->conf.unix_socket_name,
425 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
426 		log_warn("%s: %s name too long", __func__,
427 		    sock->conf.unix_socket_name);
428 		close(u_fd);
429 		return -1;
430 	}
431 
432 	if (unlink(sock->conf.unix_socket_name) == -1) {
433 		if (errno != ENOENT) {
434 			log_warn("%s: unlink %s", __func__,
435 			    sock->conf.unix_socket_name);
436 			close(u_fd);
437 			return -1;
438 		}
439 	}
440 
441 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
442 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
443 
444 	if (bind(u_fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
445 		log_warn("%s: bind: %s", __func__, sock->conf.unix_socket_name);
446 		close(u_fd);
447 		(void)umask(old_umask);
448 		return -1;
449 	}
450 
451 	(void)umask(old_umask);
452 
453 	if (chmod(sock->conf.unix_socket_name, mode) == -1) {
454 		log_warn("%s: chmod", __func__);
455 		close(u_fd);
456 		(void)unlink(sock->conf.unix_socket_name);
457 		return -1;
458 	}
459 
460 	if (chown(sock->conf.unix_socket_name, ps->ps_pw->pw_uid,
461 	    ps->ps_pw->pw_gid) == -1) {
462 		log_warn("%s: chown", __func__);
463 		close(u_fd);
464 		(void)unlink(sock->conf.unix_socket_name);
465 		return -1;
466 	}
467 
468 	if (listen(u_fd, SOCKS_BACKLOG) == -1) {
469 		log_warn("%s: listen", __func__);
470 		return -1;
471 	}
472 
473 	return u_fd;
474 }
475 
476 static int
477 sockets_create_socket(struct address *a, in_port_t port)
478 {
479 	struct addrinfo hints;
480 	int fd = -1, o_val = 1, flags;
481 
482 	memset(&hints, 0, sizeof(hints));
483 	hints.ai_family = AF_UNSPEC;
484 	hints.ai_socktype = SOCK_STREAM;
485 	hints.ai_flags |= AI_PASSIVE;
486 
487 	switch (a->ss.ss_family) {
488 	case AF_INET:
489 		((struct sockaddr_in *)(&a->ss))->sin_port = htons(port);
490 		break;
491 	case AF_INET6:
492 		((struct sockaddr_in6 *)(&a->ss))->sin6_port = htons(port);
493 		break;
494 	default:
495 		log_warnx("%s: unknown address family", __func__);
496 		return -1;
497 	}
498 
499 	fd = socket(a->ss.ss_family, hints.ai_socktype, a->ipproto);
500 	if (fd == -1)
501 		return -1;
502 
503 	log_debug("%s: opened socket (%d) for %s", __func__,
504 	    fd, a->ifname);
505 
506 	if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &o_val,
507 	    sizeof(int)) == -1) {
508 		log_warn("%s: setsockopt error", __func__);
509 		close(fd);
510 		return -1;
511 	}
512 
513 	/* non-blocking */
514 	flags = fcntl(fd, F_GETFL);
515 	flags |= O_NONBLOCK;
516 	if (fcntl(fd, F_SETFL, flags) == -1) {
517 		log_info("%s: could not enable non-blocking I/O", __func__);
518 		close(fd);
519 		return -1;
520 	}
521 
522 	if (bind(fd, (struct sockaddr *)&a->ss, a->ss.ss_len) == -1) {
523 		close(fd);
524 		log_info("%s: can't bind to port %d", __func__,
525 		    ntohs(port));
526 		return -1;
527 	}
528 
529 	if (listen(fd, SOMAXCONN) == -1) {
530 		log_warn("%s, unable to listen on socket", __func__);
531 		close(fd);
532 		return -1;
533 	}
534 
535 	return (fd);
536 }
537 
538 static int
539 sockets_accept_reserve(int sockfd, struct sockaddr *addr, socklen_t *addrlen,
540     int reserve, volatile int *counter)
541 {
542 	int ret;
543 
544 	if (getdtablecount() + reserve +
545 	    ((*counter + 1) * FD_NEEDED) >= getdtablesize()) {
546 		log_debug("inflight fds exceeded");
547 		errno = EMFILE;
548 		return -1;
549 	}
550 
551 	if ((ret = accept4(sockfd, addr, addrlen,
552 	    SOCK_NONBLOCK | SOCK_CLOEXEC)) > -1) {
553 		(*counter)++;
554 		log_debug("inflight incremented, now %d", *counter);
555 	}
556 
557 	return ret;
558 }
559 
560 static void
561 sockets_accept_paused(int fd, short events, void *arg)
562 {
563 	struct socket *sock = (struct socket *)arg;
564 
565 	event_add(&sock->ev, NULL);
566 }
567 
568 void
569 sockets_socket_accept(int fd, short event, void *arg)
570 {
571 	struct socket *sock = (struct socket *)arg;
572 	struct sockaddr_storage ss;
573 	struct timeval backoff;
574 	struct request *c = NULL;
575 	socklen_t len;
576 	int s;
577 
578 	backoff.tv_sec = 1;
579 	backoff.tv_usec = 0;
580 
581 	event_add(&sock->ev, NULL);
582 	if (event & EV_TIMEOUT)
583 		return;
584 
585 	len = sizeof(ss);
586 
587 	s = sockets_accept_reserve(fd, (struct sockaddr *)&ss, &len,
588 	    FD_RESERVE, &cgi_inflight);
589 
590 	if (s == -1) {
591 		switch (errno) {
592 		case EINTR:
593 		case EWOULDBLOCK:
594 		case ECONNABORTED:
595 			return;
596 		case EMFILE:
597 		case ENFILE:
598 			event_del(&sock->ev);
599 			evtimer_add(&sock->pause, &backoff);
600 			return;
601 		default:
602 			log_warn("%s: accept", __func__);
603 		}
604 	}
605 
606 	if (client_cnt > GOTWEBD_MAXCLIENTS)
607 		goto err;
608 
609 	c = calloc(1, sizeof(struct request));
610 	if (c == NULL) {
611 		log_warn("%s", __func__);
612 		close(s);
613 		cgi_inflight--;
614 		return;
615 	}
616 
617 	c->fd = s;
618 	c->sock = sock;
619 	memcpy(c->priv_fd, sock->priv_fd, sizeof(c->priv_fd));
620 	c->buf_pos = 0;
621 	c->buf_len = 0;
622 	c->request_started = 0;
623 	c->sock->client_status = CLIENT_CONNECT;
624 
625 	event_set(&c->ev, s, EV_READ, fcgi_request, c);
626 	event_add(&c->ev, NULL);
627 
628 	evtimer_set(&c->tmo, fcgi_timeout, c);
629 	evtimer_add(&c->tmo, &timeout);
630 
631 	client_cnt++;
632 
633 	return;
634 err:
635 	cgi_inflight--;
636 	close(s);
637 	if (c != NULL)
638 		free(c);
639 }
640 
641 static void
642 sockets_rlimit(int maxfd)
643 {
644 	struct rlimit rl;
645 
646 	if (getrlimit(RLIMIT_NOFILE, &rl) == -1)
647 		fatal("%s: failed to get resource limit", __func__);
648 	log_debug("%s: max open files %llu", __func__,
649 	    (unsigned long long)rl.rlim_max);
650 
651 	/*
652 	 * Allow the maximum number of open file descriptors for this
653 	 * login class (which should be the class "daemon" by default).
654 	 */
655 	if (maxfd == -1)
656 		rl.rlim_cur = rl.rlim_max;
657 	else
658 		rl.rlim_cur = MAXIMUM(rl.rlim_max, (rlim_t)maxfd);
659 	if (setrlimit(RLIMIT_NOFILE, &rl) == -1)
660 		fatal("%s: failed to set resource limit", __func__);
661 }