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