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 #include "got_reference.h"
55 #include "got_repository.h"
56 #include "got_privsep.h"
57 
58 #include "gotwebd.h"
59 #include "tmpl.h"
60 
61 #define SOCKS_BACKLOG 5
62 #define MAXIMUM(a, b)	(((a) > (b)) ? (a) : (b))
63 
64 volatile int client_cnt;
65 
66 static struct timeval	timeout = { TIMEOUT_DEFAULT, 0 };
67 
68 static void	 sockets_sighdlr(int, short, void *);
69 static void	 sockets_shutdown(void);
70 static void	 sockets_launch(void);
71 static void	 sockets_purge(struct gotwebd *);
72 static void	 sockets_accept_paused(int, short, void *);
73 static void	 sockets_rlimit(int);
74 
75 static void	 sockets_dispatch_main(int, short, void *);
76 static int	 sockets_unix_socket_listen(struct gotwebd *, struct socket *);
77 static int	 sockets_create_socket(struct address *);
78 static int	 sockets_accept_reserve(int, struct sockaddr *, socklen_t *,
79 		    int, volatile int *);
80 
81 static struct socket *sockets_conf_new_socket_unix(struct gotwebd *,
82 		    struct server *, int);
83 static struct socket *sockets_conf_new_socket_fcgi(struct gotwebd *,
84 		    struct server *, int, struct address *);
85 
86 int cgi_inflight = 0;
87 
88 void
89 sockets(struct gotwebd *env, int fd)
90 {
91 	struct event	 sighup, sigint, sigusr1, sigchld, sigterm;
92 
93 	event_init();
94 
95 	sockets_rlimit(-1);
96 
97 	if (config_init(env) == -1)
98 		fatal("failed to initialize configuration");
99 
100 	if ((env->iev_parent = malloc(sizeof(*env->iev_parent))) == NULL)
101 		fatal("malloc");
102 	imsg_init(&env->iev_parent->ibuf, fd);
103 	env->iev_parent->handler = sockets_dispatch_main;
104 	env->iev_parent->data = env->iev_parent;
105 	event_set(&env->iev_parent->ev, fd, EV_READ, sockets_dispatch_main,
106 	    env->iev_parent);
107 	event_add(&env->iev_parent->ev, NULL);
108 
109 	signal(SIGPIPE, SIG_IGN);
110 
111 	signal_set(&sighup, SIGHUP, sockets_sighdlr, env);
112 	signal_add(&sighup, NULL);
113 	signal_set(&sigint, SIGINT, sockets_sighdlr, env);
114 	signal_add(&sigint, NULL);
115 	signal_set(&sigusr1, SIGUSR1, sockets_sighdlr, env);
116 	signal_add(&sigusr1, NULL);
117 	signal_set(&sigchld, SIGCHLD, sockets_sighdlr, env);
118 	signal_add(&sigchld, NULL);
119 	signal_set(&sigterm, SIGTERM, sockets_sighdlr, env);
120 	signal_add(&sigterm, NULL);
121 
122 #ifndef PROFILE
123 	if (pledge("stdio rpath inet recvfd proc exec sendfd unveil",
124 	    NULL) == -1)
125 		fatal("pledge");
126 #endif
127 
128 	event_dispatch();
129 	sockets_shutdown();
130 }
131 
132 void
133 sockets_parse_sockets(struct gotwebd *env)
134 {
135 	struct server *srv;
136 	struct address *a;
137 	struct socket *new_sock = NULL;
138 	int sock_id = 1;
139 
140 	TAILQ_FOREACH(srv, &env->servers, entry) {
141 		if (srv->unix_socket) {
142 			new_sock = sockets_conf_new_socket_unix(env, srv,
143 			    sock_id);
144 			if (new_sock) {
145 				sock_id++;
146 				TAILQ_INSERT_TAIL(&env->sockets, new_sock,
147 				    entry);
148 			}
149 		}
150 
151 		if (srv->fcgi_socket) {
152 			if (TAILQ_EMPTY(&srv->al)) {
153 				fatalx("%s: server %s has no IP addresses to "
154 				    "listen for FCGI connections", __func__,
155 				    srv->name);
156 			}
157 			TAILQ_FOREACH(a, &srv->al, entry) {
158 				if (a->ss.ss_family != AF_INET &&
159 				    a->ss.ss_family != AF_INET6)
160 					continue;
161 				new_sock = sockets_conf_new_socket_fcgi(env,
162 				    srv, sock_id, a);
163 				if (new_sock) {
164 					sock_id++;
165 					TAILQ_INSERT_TAIL(&env->sockets,
166 					    new_sock, entry);
167 				}
168 			}
169 		}
170 	}
171 }
172 
173 static struct socket *
174 sockets_conf_new_socket_unix(struct gotwebd *env, struct server *srv, int id)
175 {
176 	struct socket *sock;
177 	int n;
178 
179 	if ((sock = calloc(1, sizeof(*sock))) == NULL)
180 		fatalx("%s: calloc", __func__);
181 
182 	sock->conf.id = id;
183 	sock->fd = -1;
184 	sock->conf.af_type = AF_UNIX;
185 
186 	if (strlcpy(sock->conf.unix_socket_name,
187 	    srv->unix_socket_name,
188 	    sizeof(sock->conf.unix_socket_name)) >=
189 	    sizeof(sock->conf.unix_socket_name)) {
190 		free(sock);
191 		fatalx("%s: strlcpy", __func__);
192 	}
193 
194 	n = snprintf(sock->conf.name, GOTWEBD_MAXTEXT, "%s_parent",
195 	    srv->name);
196 	if (n < 0 || (size_t)n >= GOTWEBD_MAXTEXT) {
197 		free(sock);
198 		fatalx("%s: snprintf", __func__);
199 	}
200 
201 	if (strlcpy(sock->conf.srv_name, srv->name,
202 	    sizeof(sock->conf.srv_name)) >= sizeof(sock->conf.srv_name)) {
203 		free(sock);
204 		fatalx("%s: strlcpy", __func__);
205 	}
206 
207 	return sock;
208 }
209 
210 static struct socket *
211 sockets_conf_new_socket_fcgi(struct gotwebd *env, struct server *srv, int id,
212     struct address *a)
213 {
214 	struct socket *sock;
215 	struct address *acp;
216 	int n;
217 
218 	if ((sock = calloc(1, sizeof(*sock))) == NULL)
219 		fatalx("%s: calloc", __func__);
220 
221 	sock->conf.id = id;
222 	sock->fd = -1;
223 	sock->conf.af_type = a->ss.ss_family;
224 
225 	sock->conf.fcgi_socket_port = a->port;
226 
227 	n = snprintf(sock->conf.name, GOTWEBD_MAXTEXT, "%s_parent",
228 	    srv->name);
229 	if (n < 0 || (size_t)n >= GOTWEBD_MAXTEXT) {
230 		free(sock);
231 		fatalx("%s: snprintf", __func__);
232 	}
233 
234 	if (strlcpy(sock->conf.srv_name, srv->name,
235 	    sizeof(sock->conf.srv_name)) >= sizeof(sock->conf.srv_name)) {
236 		free(sock);
237 		fatalx("%s: strlcpy", __func__);
238 	}
239 
240 	acp = &sock->conf.addr;
241 
242 	memcpy(&acp->ss, &a->ss, sizeof(acp->ss));
243 	acp->slen = a->slen;
244 	acp->ai_family = a->ai_family;
245 	acp->ai_socktype = a->ai_socktype;
246 	acp->ai_protocol = a->ai_protocol;
247 	acp->port = a->port;
248 	if (*a->ifname != '\0') {
249 		if (strlcpy(acp->ifname, a->ifname,
250 		    sizeof(acp->ifname)) >= sizeof(acp->ifname)) {
251 			fatalx("%s: interface name truncated",
252 			    __func__);
253 		}
254 	}
255 
256 	return (sock);
257 }
258 
259 static void
260 sockets_launch(void)
261 {
262 	struct socket *sock;
263 	struct server *srv;
264 	const struct got_error *error;
265 
266 	TAILQ_FOREACH(sock, &gotwebd_env->sockets, entry) {
267 		log_debug("%s: configuring socket %d (%d)", __func__,
268 		    sock->conf.id, sock->fd);
269 
270 		event_set(&sock->ev, sock->fd, EV_READ | EV_PERSIST,
271 		    sockets_socket_accept, sock);
272 
273 		if (event_add(&sock->ev, NULL))
274 			fatalx("event add sock");
275 
276 		evtimer_set(&sock->pause, sockets_accept_paused, sock);
277 
278 		log_debug("%s: running socket listener %d", __func__,
279 		    sock->conf.id);
280 	}
281 
282 	TAILQ_FOREACH(srv, &gotwebd_env->servers, entry) {
283 		if (unveil(srv->repos_path, "r") == -1)
284 			fatal("unveil %s", srv->repos_path);
285 	}
286 
287 	error = got_privsep_unveil_exec_helpers();
288 	if (error)
289 		fatal("%s", error->msg);
290 
291 	if (unveil(NULL, NULL) == -1)
292 		fatal("unveil");
293 }
294 
295 static void
296 sockets_purge(struct gotwebd *env)
297 {
298 	struct socket *sock, *tsock;
299 
300 	/* shutdown and remove sockets */
301 	TAILQ_FOREACH_SAFE(sock, &env->sockets, entry, tsock) {
302 		if (event_initialized(&sock->ev))
303 			event_del(&sock->ev);
304 		if (evtimer_initialized(&sock->evt))
305 			evtimer_del(&sock->evt);
306 		if (evtimer_initialized(&sock->pause))
307 			evtimer_del(&sock->pause);
308 		if (sock->fd != -1)
309 			close(sock->fd);
310 		TAILQ_REMOVE(&env->sockets, sock, entry);
311 	}
312 }
313 
314 static void
315 sockets_dispatch_main(int fd, short event, void *arg)
316 {
317 	struct imsgev		*iev = arg;
318 	struct imsgbuf		*ibuf;
319 	struct imsg		 imsg;
320 	struct gotwebd		*env = gotwebd_env;
321 	ssize_t			 n;
322 	int			 shut = 0;
323 
324 	ibuf = &iev->ibuf;
325 
326 	if (event & EV_READ) {
327 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
328 			fatal("imsg_read error");
329 		if (n == 0)	/* Connection closed */
330 			shut = 1;
331 	}
332 	if (event & EV_WRITE) {
333 		if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
334 			fatal("msgbuf_write");
335 		if (n == 0)	/* Connection closed */
336 			shut = 1;
337 	}
338 
339 	for (;;) {
340 		if ((n = imsg_get(ibuf, &imsg)) == -1)
341 			fatal("imsg_get");
342 		if (n == 0)	/* No more messages. */
343 			break;
344 
345 		switch (imsg.hdr.type) {
346 		case IMSG_CFG_SRV:
347 			config_getserver(env, &imsg);
348 			break;
349 		case IMSG_CFG_SOCK:
350 			config_getsock(env, &imsg);
351 			break;
352 		case IMSG_CFG_FD:
353 			config_getfd(env, &imsg);
354 			break;
355 		case IMSG_CFG_DONE:
356 			config_getcfg(env, &imsg);
357 			break;
358 		case IMSG_CTL_START:
359 			sockets_launch();
360 			break;
361 		default:
362 			fatalx("%s: unknown imsg type %d", __func__,
363 			    imsg.hdr.type);
364 		}
365 
366 		imsg_free(&imsg);
367 	}
368 
369 	if (!shut)
370 		imsg_event_add(iev);
371 	else {
372 		/* This pipe is dead.  Remove its event handler */
373 		event_del(&iev->ev);
374 		event_loopexit(NULL);
375 	}
376 }
377 
378 static void
379 sockets_sighdlr(int sig, short event, void *arg)
380 {
381 	switch (sig) {
382 	case SIGHUP:
383 		log_info("%s: ignoring SIGHUP", __func__);
384 		break;
385 	case SIGPIPE:
386 		log_info("%s: ignoring SIGPIPE", __func__);
387 		break;
388 	case SIGUSR1:
389 		log_info("%s: ignoring SIGUSR1", __func__);
390 		break;
391 	case SIGCHLD:
392 		break;
393 	case SIGINT:
394 	case SIGTERM:
395 		sockets_shutdown();
396 		break;
397 	default:
398 		log_info("SIGNAL: %d", sig);
399 		fatalx("unexpected signal");
400 	}
401 }
402 
403 static void
404 sockets_shutdown(void)
405 {
406 	struct server *srv, *tsrv;
407 	struct socket *sock, *tsock;
408 
409 	sockets_purge(gotwebd_env);
410 
411 	/* clean sockets */
412 	TAILQ_FOREACH_SAFE(sock, &gotwebd_env->sockets, entry, tsock) {
413 		TAILQ_REMOVE(&gotwebd_env->sockets, sock, entry);
414 		close(sock->fd);
415 		free(sock);
416 	}
417 
418 	/* clean servers */
419 	TAILQ_FOREACH_SAFE(srv, &gotwebd_env->servers, entry, tsrv)
420 		free(srv);
421 
422 	free(gotwebd_env);
423 
424 	exit(0);
425 }
426 
427 int
428 sockets_privinit(struct gotwebd *env, struct socket *sock)
429 {
430 	if (sock->conf.af_type == AF_UNIX) {
431 		log_debug("%s: initializing unix socket %s", __func__,
432 		    sock->conf.unix_socket_name);
433 		sock->fd = sockets_unix_socket_listen(env, sock);
434 		if (sock->fd == -1) {
435 			log_warnx("%s: create unix socket failed", __func__);
436 			return -1;
437 		}
438 	}
439 
440 	if (sock->conf.af_type == AF_INET || sock->conf.af_type == AF_INET6) {
441 		log_debug("%s: initializing %s FCGI socket on port %d for %s",
442 		    __func__, sock->conf.af_type == AF_INET ? "inet" : "inet6",
443 		    sock->conf.fcgi_socket_port, sock->conf.name);
444 		sock->fd = sockets_create_socket(&sock->conf.addr);
445 		if (sock->fd == -1) {
446 			log_warnx("%s: create FCGI socket failed", __func__);
447 			return -1;
448 		}
449 	}
450 
451 	return 0;
452 }
453 
454 static int
455 sockets_unix_socket_listen(struct gotwebd *env, struct socket *sock)
456 {
457 	struct sockaddr_un sun;
458 	struct socket *tsock;
459 	int u_fd = -1;
460 	mode_t old_umask, mode;
461 
462 	TAILQ_FOREACH(tsock, &env->sockets, entry) {
463 		if (strcmp(tsock->conf.unix_socket_name,
464 		    sock->conf.unix_socket_name) == 0 &&
465 		    tsock->fd != -1)
466 			return (tsock->fd);
467 	}
468 
469 	u_fd = socket(AF_UNIX, SOCK_STREAM | SOCK_NONBLOCK| SOCK_CLOEXEC, 0);
470 	if (u_fd == -1) {
471 		log_warn("%s: socket", __func__);
472 		return -1;
473 	}
474 
475 	sun.sun_family = AF_UNIX;
476 	if (strlcpy(sun.sun_path, sock->conf.unix_socket_name,
477 	    sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
478 		log_warn("%s: %s name too long", __func__,
479 		    sock->conf.unix_socket_name);
480 		close(u_fd);
481 		return -1;
482 	}
483 
484 	if (unlink(sock->conf.unix_socket_name) == -1) {
485 		if (errno != ENOENT) {
486 			log_warn("%s: unlink %s", __func__,
487 			    sock->conf.unix_socket_name);
488 			close(u_fd);
489 			return -1;
490 		}
491 	}
492 
493 	old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
494 	mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
495 
496 	if (bind(u_fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
497 		log_warn("%s: bind: %s", __func__, sock->conf.unix_socket_name);
498 		close(u_fd);
499 		(void)umask(old_umask);
500 		return -1;
501 	}
502 
503 	(void)umask(old_umask);
504 
505 	if (chmod(sock->conf.unix_socket_name, mode) == -1) {
506 		log_warn("%s: chmod", __func__);
507 		close(u_fd);
508 		(void)unlink(sock->conf.unix_socket_name);
509 		return -1;
510 	}
511 
512 	if (chown(sock->conf.unix_socket_name, env->pw->pw_uid,
513 	    env->pw->pw_gid) == -1) {
514 		log_warn("%s: chown", __func__);
515 		close(u_fd);
516 		(void)unlink(sock->conf.unix_socket_name);
517 		return -1;
518 	}
519 
520 	if (listen(u_fd, SOCKS_BACKLOG) == -1) {
521 		log_warn("%s: listen", __func__);
522 		return -1;
523 	}
524 
525 	return u_fd;
526 }
527 
528 static int
529 sockets_create_socket(struct address *a)
530 {
531 	int fd = -1, o_val = 1, flags;
532 
533 	fd = socket(a->ai_family, a->ai_socktype, a->ai_protocol);
534 	if (fd == -1)
535 		return -1;
536 
537 	log_debug("%s: opened socket (%d) for %s", __func__,
538 	    fd, a->ifname);
539 
540 	if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &o_val,
541 	    sizeof(int)) == -1) {
542 		log_warn("%s: setsockopt error", __func__);
543 		close(fd);
544 		return -1;
545 	}
546 
547 	/* non-blocking */
548 	flags = fcntl(fd, F_GETFL);
549 	flags |= O_NONBLOCK;
550 	if (fcntl(fd, F_SETFL, flags) == -1) {
551 		log_info("%s: could not enable non-blocking I/O", __func__);
552 		close(fd);
553 		return -1;
554 	}
555 
556 	if (bind(fd, (struct sockaddr *)&a->ss, a->slen) == -1) {
557 		close(fd);
558 		log_info("%s: can't bind to port %d", __func__, a->port);
559 		return -1;
560 	}
561 
562 	if (listen(fd, SOMAXCONN) == -1) {
563 		log_warn("%s, unable to listen on socket", __func__);
564 		close(fd);
565 		return -1;
566 	}
567 
568 	return (fd);
569 }
570 
571 static int
572 sockets_accept_reserve(int sockfd, struct sockaddr *addr, socklen_t *addrlen,
573     int reserve, volatile int *counter)
574 {
575 	int ret;
576 
577 	if (getdtablecount() + reserve +
578 	    ((*counter + 1) * FD_NEEDED) >= getdtablesize()) {
579 		log_debug("inflight fds exceeded");
580 		errno = EMFILE;
581 		return -1;
582 	}
583 
584 	if ((ret = accept4(sockfd, addr, addrlen,
585 	    SOCK_NONBLOCK | SOCK_CLOEXEC)) > -1) {
586 		(*counter)++;
587 		log_debug("inflight incremented, now %d", *counter);
588 	}
589 
590 	return ret;
591 }
592 
593 static void
594 sockets_accept_paused(int fd, short events, void *arg)
595 {
596 	struct socket *sock = (struct socket *)arg;
597 
598 	event_add(&sock->ev, NULL);
599 }
600 
601 void
602 sockets_socket_accept(int fd, short event, void *arg)
603 {
604 	struct socket *sock = (struct socket *)arg;
605 	struct sockaddr_storage ss;
606 	struct timeval backoff;
607 	struct request *c = NULL;
608 	socklen_t len;
609 	int s;
610 
611 	backoff.tv_sec = 1;
612 	backoff.tv_usec = 0;
613 
614 	event_add(&sock->ev, NULL);
615 	if (event & EV_TIMEOUT)
616 		return;
617 
618 	len = sizeof(ss);
619 
620 	s = sockets_accept_reserve(fd, (struct sockaddr *)&ss, &len,
621 	    FD_RESERVE, &cgi_inflight);
622 
623 	if (s == -1) {
624 		switch (errno) {
625 		case EINTR:
626 		case EWOULDBLOCK:
627 		case ECONNABORTED:
628 			return;
629 		case EMFILE:
630 		case ENFILE:
631 			event_del(&sock->ev);
632 			evtimer_add(&sock->pause, &backoff);
633 			return;
634 		default:
635 			log_warn("%s: accept", __func__);
636 		}
637 	}
638 
639 	if (client_cnt > GOTWEBD_MAXCLIENTS)
640 		goto err;
641 
642 	c = calloc(1, sizeof(struct request));
643 	if (c == NULL) {
644 		log_warn("%s", __func__);
645 		close(s);
646 		cgi_inflight--;
647 		return;
648 	}
649 
650 	c->tp = template(c, &fcgi_write, c->outbuf, sizeof(c->outbuf));
651 	if (c->tp == NULL) {
652 		log_warn("%s", __func__);
653 		close(s);
654 		cgi_inflight--;
655 		free(c);
656 		return;
657 	}
658 
659 	c->fd = s;
660 	c->sock = sock;
661 	memcpy(c->priv_fd, sock->priv_fd, sizeof(c->priv_fd));
662 	c->buf_pos = 0;
663 	c->buf_len = 0;
664 	c->request_started = 0;
665 	c->sock->client_status = CLIENT_CONNECT;
666 
667 	event_set(&c->ev, s, EV_READ|EV_PERSIST, fcgi_request, c);
668 	event_add(&c->ev, NULL);
669 
670 	evtimer_set(&c->tmo, fcgi_timeout, c);
671 	evtimer_add(&c->tmo, &timeout);
672 
673 	client_cnt++;
674 
675 	return;
676 err:
677 	cgi_inflight--;
678 	close(s);
679 	if (c != NULL)
680 		free(c);
681 }
682 
683 static void
684 sockets_rlimit(int maxfd)
685 {
686 	struct rlimit rl;
687 
688 	if (getrlimit(RLIMIT_NOFILE, &rl) == -1)
689 		fatal("%s: failed to get resource limit", __func__);
690 	log_debug("%s: max open files %llu", __func__,
691 	    (unsigned long long)rl.rlim_max);
692 
693 	/*
694 	 * Allow the maximum number of open file descriptors for this
695 	 * login class (which should be the class "daemon" by default).
696 	 */
697 	if (maxfd == -1)
698 		rl.rlim_cur = rl.rlim_max;
699 	else
700 		rl.rlim_cur = MAXIMUM(rl.rlim_max, (rlim_t)maxfd);
701 	if (setrlimit(RLIMIT_NOFILE, &rl) == -1)
702 		fatal("%s: failed to set resource limit", __func__);
703 }