gotwebd/sockets.c

   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 "got_compat.h"
  21
  22 #include <sys/param.h>
  23 #include <sys/ioctl.h>
  24 #include <sys/queue.h>
  25 #include <sys/wait.h>
  26 #include <sys/uio.h>
  27 #include <sys/resource.h>
  28 #include <sys/socket.h>
  29 #include <sys/stat.h>
  30 #include <sys/time.h>
  31 #include <sys/types.h>
  32 #include <sys/mman.h>
  33 #include <sys/un.h>
  34
  35 #include <net/if.h>
  36 #include <netinet/in.h>
  37
  38 #include <errno.h>
  39 #include <event.h>
  40 #include <fcntl.h>
  41 #include <ifaddrs.h>
  42 #include <limits.h>
  43 #include <netdb.h>
  44 #include <poll.h>
  45 #include <pwd.h>
  46 #include <stddef.h>
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <unistd.h>
  51
  52 #include "got_error.h"
  53 #include "got_opentemp.h"
  54 #include "got_reference.h"
  55 #include "got_repository.h"
  56
  57 #include "proc.h"
  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
  65 volatile int client_cnt;
  66
  67 static struct timeval   timeout = { TIMEOUT_DEFAULT, 0 };
  68
  69 static void      sockets_sighdlr(int, short, void *);
  70 static void      sockets_run(struct privsep *, struct privsep_proc *, void *);
  71 static void      sockets_launch(void);
  72 static void      sockets_purge(struct gotwebd *);
  73 static void      sockets_accept_paused(int, short, void *);
  74 static void      sockets_rlimit(int);
  75
  76 static int       sockets_dispatch_gotwebd(int, struct privsep_proc *,
  77                     struct imsg *);
  78 static int       sockets_unix_socket_listen(struct privsep *, struct socket *);
  79 static int       sockets_create_socket(struct address *, in_port_t);
  80 static int       sockets_accept_reserve(int, struct sockaddr *, socklen_t *,
  81                     int, volatile int *);
  82
  83 static struct socket *sockets_conf_new_socket_unix(struct gotwebd *,
  84                     struct server *, int);
  85 static struct socket *sockets_conf_new_socket_fcgi(struct gotwebd *,
  86                     struct server *, int, struct address *);
  87
  88 int cgi_inflight = 0;
  89
  90 static struct privsep_proc procs[] = {
  91         { "gotwebd",    PROC_GOTWEBD,   sockets_dispatch_gotwebd  },
  92 };
  93
  94 void
  95 sockets(struct privsep *ps, struct privsep_proc *p)
  96 {
  97         proc_run(ps, p, procs, nitems(procs), sockets_run, NULL);
  98 }
  99
 100 static void
 101 sockets_run(struct privsep *ps, struct privsep_proc *p, void *arg)
 102 {
 103         if (config_init(ps->ps_env) == -1)
 104                 fatal("failed to initialize configuration");
 105
 106         p->p_shutdown = sockets_shutdown;
 107
 108         sockets_rlimit(-1);
 109
 110         signal_del(&ps->ps_evsigchld);
 111         signal_set(&ps->ps_evsigchld, SIGCHLD, sockets_sighdlr, ps);
 112         signal_add(&ps->ps_evsigchld, NULL);
 113
 114 #ifndef PROFILE
 115         if (pledge("stdio rpath wpath cpath inet recvfd proc exec sendfd",
 116             NULL) == -1)
 117                 fatal("pledge");
 118 #endif
 119 }
 120
 121 void
 122 sockets_parse_sockets(struct gotwebd *env)
 123 {
 124         struct server *srv;
 125         struct address *a;
 126         struct socket *new_sock = NULL;
 127         int sock_id = 1;
 128
 129         TAILQ_FOREACH(srv, &env->servers, entry) {
 130                 if (srv->unix_socket) {
 131                         new_sock = sockets_conf_new_socket_unix(env, srv,
 132                             sock_id);
 133                         if (new_sock) {
 134                                 sock_id++;
 135                                 TAILQ_INSERT_TAIL(&env->sockets, new_sock,
 136                                     entry);
 137                         }
 138                 }
 139
 140                 if (srv->fcgi_socket) {
 141                         if (TAILQ_EMPTY(&srv->al)) {
 142                                 fatalx("%s: server %s has no IP addresses to "
 143                                     "listen for FCGI connections", __func__,
 144                                     srv->name);
 145                         }
 146                         TAILQ_FOREACH(a, &srv->al, entry) {
 147                                 if (a->ss.ss_family != AF_INET &&
 148                                     a->ss.ss_family != AF_INET6)
 149                                         continue;
 150                                 new_sock = sockets_conf_new_socket_fcgi(env,
 151                                     srv, sock_id, a);
 152                                 if (new_sock) {
 153                                         sock_id++;
 154                                         TAILQ_INSERT_TAIL(&env->sockets,
 155                                             new_sock, entry);
 156                                 }
 157                         }
 158                 }
 159         }
 160 }
 161
 162 static struct socket *
 163 sockets_conf_new_socket_unix(struct gotwebd *env, struct server *srv, int id)
 164 {
 165         struct socket *sock;
 166         int n;
 167
 168         if ((sock = calloc(1, sizeof(*sock))) == NULL)
 169                 fatalx("%s: calloc", __func__);
 170
 171         sock->conf.id = id;
 172         sock->fd = -1;
 173         sock->conf.af_type = AF_UNIX;
 174
 175         if (strlcpy(sock->conf.unix_socket_name,
 176             srv->unix_socket_name,
 177             sizeof(sock->conf.unix_socket_name)) >=
 178             sizeof(sock->conf.unix_socket_name)) {
 179                 free(sock);
 180                 fatalx("%s: strlcpy", __func__);
 181         }
 182
 183         n = snprintf(sock->conf.name, GOTWEBD_MAXTEXT, "%s_parent",
 184             srv->name);
 185         if (n < 0 || (size_t)n >= GOTWEBD_MAXTEXT) {
 186                 free(sock);
 187                 fatalx("%s: snprintf", __func__);
 188         }
 189
 190         if (strlcpy(sock->conf.srv_name, srv->name,
 191             sizeof(sock->conf.srv_name)) >= sizeof(sock->conf.srv_name)) {
 192                 free(sock);
 193                 fatalx("%s: strlcpy", __func__);
 194         }
 195
 196         return sock;
 197 }
 198
 199 static struct socket *
 200 sockets_conf_new_socket_fcgi(struct gotwebd *env, struct server *srv, int id,
 201     struct address *a)
 202 {
 203         struct socket *sock;
 204         struct address *acp;
 205         int n;
 206
 207         if ((sock = calloc(1, sizeof(*sock))) == NULL)
 208                 fatalx("%s: calloc", __func__);
 209
 210         sock->conf.id = id;
 211         sock->fd = -1;
 212         sock->conf.af_type = a->ss.ss_family;
 213
 214         sock->conf.fcgi_socket_port = a->port;
 215
 216         n = snprintf(sock->conf.name, GOTWEBD_MAXTEXT, "%s_parent",
 217             srv->name);
 218         if (n < 0 || (size_t)n >= GOTWEBD_MAXTEXT) {
 219                 free(sock);
 220                 fatalx("%s: snprintf", __func__);
 221         }
 222
 223         if (strlcpy(sock->conf.srv_name, srv->name,
 224             sizeof(sock->conf.srv_name)) >= sizeof(sock->conf.srv_name)) {
 225                 free(sock);
 226                 fatalx("%s: strlcpy", __func__);
 227         }
 228
 229         acp = &sock->conf.addr;
 230
 231         memcpy(&acp->ss, &a->ss, sizeof(acp->ss));
 232         acp->ipproto = a->ipproto;
 233         acp->prefixlen = a->prefixlen;
 234         acp->port = a->port;
 235         if (strlen(a->ifname) != 0) {
 236                 if (strlcpy(acp->ifname, a->ifname,
 237                     sizeof(acp->ifname)) >= sizeof(acp->ifname)) {
 238                         fatalx("%s: interface name truncated",
 239                             __func__);
 240                 }
 241         }
 242
 243         return (sock);
 244 }
 245
 246 static void
 247 sockets_launch(void)
 248 {
 249         struct socket *sock;
 250
 251         TAILQ_FOREACH(sock, &gotwebd_env->sockets, entry) {
 252                 log_debug("%s: configuring socket %d (%d)", __func__,
 253                     sock->conf.id, sock->fd);
 254
 255                 event_set(&sock->ev, sock->fd, EV_READ | EV_PERSIST,
 256                     sockets_socket_accept, sock);
 257
 258                 if (event_add(&sock->ev, NULL))
 259                         fatalx("event add sock");
 260
 261                 evtimer_set(&sock->pause, sockets_accept_paused, sock);
 262
 263                 log_debug("%s: running socket listener %d", __func__,
 264                     sock->conf.id);
 265         }
 266 }
 267
 268 static void
 269 sockets_purge(struct gotwebd *env)
 270 {
 271         struct socket *sock, *tsock;
 272
 273         /* shutdown and remove sockets */
 274         TAILQ_FOREACH_SAFE(sock, &env->sockets, entry, tsock) {
 275                 if (event_initialized(&sock->ev))
 276                         event_del(&sock->ev);
 277                 if (evtimer_initialized(&sock->evt))
 278                         evtimer_del(&sock->evt);
 279                 if (evtimer_initialized(&sock->pause))
 280                         evtimer_del(&sock->pause);
 281                 if (sock->fd != -1)
 282                         close(sock->fd);
 283                 TAILQ_REMOVE(&env->sockets, sock, entry);
 284         }
 285 }
 286
 287 static int
 288 sockets_dispatch_gotwebd(int fd, struct privsep_proc *p, struct imsg *imsg)
 289 {
 290         struct privsep *ps = p->p_ps;
 291         int res = 0, cmd = 0, verbose;
 292
 293         switch (imsg->hdr.type) {
 294         case IMSG_CFG_SRV:
 295                 config_getserver(gotwebd_env, imsg);
 296                 break;
 297         case IMSG_CFG_SOCK:
 298                 config_getsock(gotwebd_env, imsg);
 299                 break;
 300         case IMSG_CFG_FD:
 301                 config_getfd(gotwebd_env, imsg);
 302                 break;
 303         case IMSG_CFG_DONE:
 304                 config_getcfg(gotwebd_env, imsg);
 305                 break;
 306         case IMSG_CTL_START:
 307                 sockets_launch();
 308                 break;
 309         case IMSG_CTL_VERBOSE:
 310                 IMSG_SIZE_CHECK(imsg, &verbose);
 311                 memcpy(&verbose, imsg->data, sizeof(verbose));
 312                 log_setverbose(verbose);
 313                 break;
 314         default:
 315                 return -1;
 316         }
 317
 318         switch (cmd) {
 319         case 0:
 320                 break;
 321         default:
 322                 if (proc_compose_imsg(ps, PROC_GOTWEBD, -1, cmd,
 323                     imsg->hdr.peerid, -1, &res, sizeof(res)) == -1)
 324                         return -1;
 325                 break;
 326         }
 327
 328         return 0;
 329 }
 330
 331 static void
 332 sockets_sighdlr(int sig, short event, void *arg)
 333 {
 334         switch (sig) {
 335         case SIGHUP:
 336                 log_info("%s: ignoring SIGHUP", __func__);
 337                 break;
 338         case SIGPIPE:
 339                 log_info("%s: ignoring SIGPIPE", __func__);
 340                 break;
 341         case SIGUSR1:
 342                 log_info("%s: ignoring SIGUSR1", __func__);
 343                 break;
 344         case SIGCHLD:
 345                 break;
 346         default:
 347                 log_info("SIGNAL: %d", sig);
 348                 fatalx("unexpected signal");
 349         }
 350 }
 351
 352 void
 353 sockets_shutdown(void)
 354 {
 355         struct server *srv, *tsrv;
 356         struct socket *sock, *tsock;
 357         int i;
 358
 359         sockets_purge(gotwebd_env);
 360
 361         /* clean sockets */
 362         TAILQ_FOREACH_SAFE(sock, &gotwebd_env->sockets, entry, tsock) {
 363                 TAILQ_REMOVE(&gotwebd_env->sockets, sock, entry);
 364                 close(sock->fd);
 365                 free(sock);
 366         }
 367
 368         /* clean servers */
 369         TAILQ_FOREACH_SAFE(srv, &gotwebd_env->servers, entry, tsrv) {
 370                 for (i = 0; i < srv->ncached_repos; i++)
 371                         got_repo_close(srv->cached_repos[i].repo);
 372                 free(srv);
 373         }
 374
 375         free(gotwebd_env);
 376 }
 377
 378 int
 379 sockets_privinit(struct gotwebd *env, struct socket *sock)
 380 {
 381         struct privsep *ps = env->gotwebd_ps;
 382
 383         if (sock->conf.af_type == AF_UNIX) {
 384                 log_debug("%s: initializing unix socket %s", __func__,
 385                     sock->conf.unix_socket_name);
 386                 sock->fd = sockets_unix_socket_listen(ps, sock);
 387                 if (sock->fd == -1) {
 388                         log_warnx("%s: create unix socket failed", __func__);
 389                         return -1;
 390                 }
 391         }
 392
 393         if (sock->conf.af_type == AF_INET || sock->conf.af_type == AF_INET6) {
 394                 log_debug("%s: initializing %s FCGI socket on port %d for %s",
 395                     __func__, sock->conf.af_type == AF_INET ? "inet" : "inet6",
 396                     sock->conf.fcgi_socket_port, sock->conf.name);
 397                 sock->fd = sockets_create_socket(&sock->conf.addr,
 398                     sock->conf.fcgi_socket_port);
 399                 if (sock->fd == -1) {
 400                         log_warnx("%s: create FCGI socket failed", __func__);
 401                         return -1;
 402                 }
 403         }
 404
 405         return 0;
 406 }
 407
 408 static int
 409 sockets_unix_socket_listen(struct privsep *ps, struct socket *sock)
 410 {
 411         struct gotwebd *env = ps->ps_env;
 412         struct sockaddr_un sun;
 413         struct socket *tsock;
 414         int u_fd = -1;
 415         mode_t old_umask, mode;
 416
 417         TAILQ_FOREACH(tsock, &env->sockets, entry) {
 418                 if (strcmp(tsock->conf.unix_socket_name,
 419                     sock->conf.unix_socket_name) == 0 &&
 420                     tsock->fd != -1)
 421                         return (tsock->fd);
 422         }
 423
 424         /* TA: FIXME:  this needs upstreaming. */
 425         int socket_flags = SOCK_STREAM | SOCK_NONBLOCK;
 426 #ifdef SOCK_CLOEXEC
 427         socket_flags |= SOCK_CLOEXEC;
 428 #endif
 429         u_fd = socket(AF_UNIX, socket_flags, 0);
 430         if (u_fd == -1) {
 431                 log_warn("%s: socket", __func__);
 432                 return -1;
 433         }
 434
 435         sun.sun_family = AF_UNIX;
 436         if (strlcpy(sun.sun_path, sock->conf.unix_socket_name,
 437             sizeof(sun.sun_path)) >= sizeof(sun.sun_path)) {
 438                 log_warn("%s: %s name too long", __func__,
 439                     sock->conf.unix_socket_name);
 440                 close(u_fd);
 441                 return -1;
 442         }
 443
 444         if (unlink(sock->conf.unix_socket_name) == -1) {
 445                 if (errno != ENOENT) {
 446                         log_warn("%s: unlink %s", __func__,
 447                             sock->conf.unix_socket_name);
 448                         close(u_fd);
 449                         return -1;
 450                 }
 451         }
 452
 453         old_umask = umask(S_IXUSR|S_IXGRP|S_IWOTH|S_IROTH|S_IXOTH);
 454         mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP;
 455
 456         if (bind(u_fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
 457                 log_warn("%s: bind: %s", __func__, sock->conf.unix_socket_name);
 458                 close(u_fd);
 459                 (void)umask(old_umask);
 460                 return -1;
 461         }
 462
 463         (void)umask(old_umask);
 464
 465         if (chmod(sock->conf.unix_socket_name, mode) == -1) {
 466                 log_warn("%s: chmod", __func__);
 467                 close(u_fd);
 468                 (void)unlink(sock->conf.unix_socket_name);
 469                 return -1;
 470         }
 471
 472         if (chown(sock->conf.unix_socket_name, ps->ps_pw->pw_uid,
 473             ps->ps_pw->pw_gid) == -1) {
 474                 log_warn("%s: chown", __func__);
 475                 close(u_fd);
 476                 (void)unlink(sock->conf.unix_socket_name);
 477                 return -1;
 478         }
 479
 480         if (listen(u_fd, SOCKS_BACKLOG) == -1) {
 481                 log_warn("%s: listen", __func__);
 482                 return -1;
 483         }
 484
 485         return u_fd;
 486 }
 487
 488 static int
 489 sockets_create_socket(struct address *a, in_port_t port)
 490 {
 491         struct addrinfo hints;
 492         int fd = -1, o_val = 1, flags;
 493
 494         memset(&hints, 0, sizeof(hints));
 495         hints.ai_family = AF_UNSPEC;
 496         hints.ai_socktype = SOCK_STREAM;
 497         hints.ai_flags |= AI_PASSIVE;
 498
 499         switch (a->ss.ss_family) {
 500         case AF_INET:
 501                 ((struct sockaddr_in *)(&a->ss))->sin_port = htons(port);
 502                 break;
 503         case AF_INET6:
 504                 ((struct sockaddr_in6 *)(&a->ss))->sin6_port = htons(port);
 505                 break;
 506         default:
 507                 log_warnx("%s: unknown address family", __func__);
 508                 return -1;
 509         }
 510
 511         fd = socket(a->ss.ss_family, hints.ai_socktype, a->ipproto);
 512         if (fd == -1)
 513                 return -1;
 514
 515         log_debug("%s: opened socket (%d) for %s", __func__,
 516             fd, a->ifname);
 517
 518         if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &o_val,
 519             sizeof(int)) == -1) {
 520                 log_warn("%s: setsockopt error", __func__);
 521                 close(fd);
 522                 return -1;
 523         }
 524
 525         /* non-blocking */
 526         flags = fcntl(fd, F_GETFL);
 527         flags |= O_NONBLOCK;
 528         if (fcntl(fd, F_SETFL, flags) == -1) {
 529                 log_info("%s: could not enable non-blocking I/O", __func__);
 530                 close(fd);
 531                 return -1;
 532         }
 533
 534         if (bind(fd, (struct sockaddr *)&a->ss, SS_LEN(&a->ss)) == -1) {
 535                 close(fd);
 536                 log_info("%s: can't bind to port %d", __func__,
 537                     ntohs(port));
 538                 return -1;
 539         }
 540
 541         if (listen(fd, SOMAXCONN) == -1) {
 542                 log_warn("%s, unable to listen on socket", __func__);
 543                 close(fd);
 544                 return -1;
 545         }
 546
 547         return (fd);
 548 }
 549
 550 static int
 551 sockets_accept_reserve(int sockfd, struct sockaddr *addr, socklen_t *addrlen,
 552     int reserve, volatile int *counter)
 553 {
 554         int ret;
 555
 556         if (getdtablecount() + reserve +
 557             ((*counter + 1) * FD_NEEDED) >= getdtablesize()) {
 558                 log_debug("inflight fds exceeded");
 559                 errno = EMFILE;
 560                 return -1;
 561         }
 562 /* TA:  This needs fixing upstream. */
 563 #ifdef __APPLE__
 564         ret = accept(sockfd, addr, addrlen);
 565 #else
 566         ret = accept4(sockfd, addr, addrlen, SOCK_NONBLOCK | SOCK_CLOEXEC);
 567 #endif
 568
 569         if (ret > -1) {
 570                 (*counter)++;
 571                 log_debug("inflight incremented, now %d", *counter);
 572         }
 573
 574         return ret;
 575 }
 576
 577 static void
 578 sockets_accept_paused(int fd, short events, void *arg)
 579 {
 580         struct socket *sock = (struct socket *)arg;
 581
 582         event_add(&sock->ev, NULL);
 583 }
 584
 585 void
 586 sockets_socket_accept(int fd, short event, void *arg)
 587 {
 588         struct socket *sock = (struct socket *)arg;
 589         struct sockaddr_storage ss;
 590         struct timeval backoff;
 591         struct request *c = NULL;
 592         socklen_t len;
 593         int s;
 594
 595         backoff.tv_sec = 1;
 596         backoff.tv_usec = 0;
 597
 598         event_add(&sock->ev, NULL);
 599         if (event & EV_TIMEOUT)
 600                 return;
 601
 602         len = sizeof(ss);
 603
 604         s = sockets_accept_reserve(fd, (struct sockaddr *)&ss, &len,
 605             FD_RESERVE, &cgi_inflight);
 606
 607         if (s == -1) {
 608                 switch (errno) {
 609                 case EINTR:
 610                 case EWOULDBLOCK:
 611                 case ECONNABORTED:
 612                         return;
 613                 case EMFILE:
 614                 case ENFILE:
 615                         event_del(&sock->ev);
 616                         evtimer_add(&sock->pause, &backoff);
 617                         return;
 618                 default:
 619                         log_warn("%s: accept", __func__);
 620                 }
 621         }
 622
 623         if (client_cnt > GOTWEBD_MAXCLIENTS)
 624                 goto err;
 625
 626         c = calloc(1, sizeof(struct request));
 627         if (c == NULL) {
 628                 log_warn("%s", __func__);
 629                 close(s);
 630                 cgi_inflight--;
 631                 return;
 632         }
 633
 634         c->tp = template(c, fcgi_puts, fcgi_putc);
 635         if (c->tp == NULL) {
 636                 log_warn("%s", __func__);
 637                 close(s);
 638                 cgi_inflight--;
 639                 free(c);
 640                 return;
 641         }
 642
 643         c->fd = s;
 644         c->sock = sock;
 645         memcpy(c->priv_fd, sock->priv_fd, sizeof(c->priv_fd));
 646         c->buf_pos = 0;
 647         c->buf_len = 0;
 648         c->request_started = 0;
 649         c->sock->client_status = CLIENT_CONNECT;
 650
 651         event_set(&c->ev, s, EV_READ|EV_PERSIST, fcgi_request, c);
 652         event_add(&c->ev, NULL);
 653
 654         evtimer_set(&c->tmo, fcgi_timeout, c);
 655         evtimer_add(&c->tmo, &timeout);
 656
 657         client_cnt++;
 658
 659         return;
 660 err:
 661         cgi_inflight--;
 662         close(s);
 663         if (c != NULL)
 664                 free(c);
 665 }
 666
 667 static void
 668 sockets_rlimit(int maxfd)
 669 {
 670         struct rlimit rl;
 671
 672         if (getrlimit(RLIMIT_NOFILE, &rl) == -1)
 673                 fatal("%s: failed to get resource limit", __func__);
 674         log_debug("%s: max open files %llu", __func__,
 675             (unsigned long long)rl.rlim_max);
 676
 677         /*
 678          * Allow the maximum number of open file descriptors for this
 679          * login class (which should be the class "daemon" by default).
 680          */
 681         if (maxfd == -1)
 682                 rl.rlim_cur = rl.rlim_max;
 683         else
 684                 rl.rlim_cur = MAXIMUM(rl.rlim_max, (rlim_t)maxfd);
 685         if (setrlimit(RLIMIT_NOFILE, &rl) == -1)
 686                 fatal("%s: failed to set resource limit", __func__);
 687 }