unbound/daemon/unbound.c

   1 /*
   2  * daemon/unbound.c - main program for unbound DNS resolver daemon.
   3  *
   4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
   5  *
   6  * This software is open source.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * Redistributions of source code must retain the above copyright notice,
  13  * this list of conditions and the following disclaimer.
  14  *
  15  * Redistributions in binary form must reproduce the above copyright notice,
  16  * this list of conditions and the following disclaimer in the documentation
  17  * and/or other materials provided with the distribution.
  18  *
  19  * Neither the name of the NLNET LABS nor the names of its contributors may
  20  * be used to endorse or promote products derived from this software without
  21  * specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  *
  35  */
  36
  37 /**
  38  * \file
  39  *
  40  * Main program to start the DNS resolver daemon.
  41  */
  42
  43 #include "config.h"
  44 #ifdef HAVE_GETOPT_H
  45 #include <getopt.h>
  46 #endif
  47 #include <sys/time.h>
  48 #include "util/log.h"
  49 #include "daemon/daemon.h"
  50 #include "daemon/remote.h"
  51 #include "util/config_file.h"
  52 #include "util/storage/slabhash.h"
  53 #include "services/listen_dnsport.h"
  54 #include "services/cache/rrset.h"
  55 #include "services/cache/infra.h"
  56 #include "util/fptr_wlist.h"
  57 #include "util/data/msgreply.h"
  58 #include "util/module.h"
  59 #include "util/net_help.h"
  60 #include <signal.h>
  61 #include <fcntl.h>
  62 #include <openssl/crypto.h>
  63 #ifdef HAVE_PWD_H
  64 #include <pwd.h>
  65 #endif
  66 #ifdef HAVE_GRP_H
  67 #include <grp.h>
  68 #endif
  69
  70 #ifndef S_SPLINT_S
  71 /* splint chokes on this system header file */
  72 #ifdef HAVE_SYS_RESOURCE_H
  73 #include <sys/resource.h>
  74 #endif
  75 #endif /* S_SPLINT_S */
  76 #ifdef HAVE_LOGIN_CAP_H
  77 #include <login_cap.h>
  78 #endif
  79
  80 #ifdef USE_MINI_EVENT
  81 #  ifdef USE_WINSOCK
  82 #    include "util/winsock_event.h"
  83 #  else
  84 #    include "util/mini_event.h"
  85 #  endif
  86 #else
  87 #  ifdef HAVE_EVENT_H
  88 #    include <event.h>
  89 #  else
  90 #    include "event2/event.h"
  91 #    include "event2/event_struct.h"
  92 #    include "event2/event_compat.h"
  93 #  endif
  94 #endif
  95
  96 #ifdef UB_ON_WINDOWS
  97 #  include "winrc/win_svc.h"
  98 #endif
  99
 100 #ifdef HAVE_NSS
 101 /* nss3 */
 102 #  include "nss.h"
 103 #endif
 104
 105 #ifdef HAVE_SBRK
 106 /** global debug value to keep track of heap memory allocation */
 107 void* unbound_start_brk = 0;
 108 #endif
 109
 110 #if !defined(HAVE_EVENT_BASE_GET_METHOD) && (defined(HAVE_EV_LOOP) || defined(HAVE_EV_DEFAULT_LOOP))
 111 static const char* ev_backend2str(int b)
 112 {
 113         switch(b) {
 114         case EVBACKEND_SELECT:  return "select";
 115         case EVBACKEND_POLL:    return "poll";
 116         case EVBACKEND_EPOLL:   return "epoll";
 117         case EVBACKEND_KQUEUE:  return "kqueue";
 118         case EVBACKEND_DEVPOLL: return "devpoll";
 119         case EVBACKEND_PORT:    return "evport";
 120         }
 121         return "unknown";
 122 }
 123 #endif
 124
 125 /** get the event system in use */
 126 static void get_event_sys(const char** n, const char** s, const char** m)
 127 {
 128 #ifdef USE_WINSOCK
 129         *n = "event";
 130         *s = "winsock";
 131         *m = "WSAWaitForMultipleEvents";
 132 #elif defined(USE_MINI_EVENT)
 133         *n = "mini-event";
 134         *s = "internal";
 135         *m = "select";
 136 #else
 137         struct event_base* b;
 138         *s = event_get_version();
 139 #  ifdef HAVE_EVENT_BASE_GET_METHOD
 140         *n = "libevent";
 141         b = event_base_new();
 142         *m = event_base_get_method(b);
 143 #  elif defined(HAVE_EV_LOOP) || defined(HAVE_EV_DEFAULT_LOOP)
 144         *n = "libev";
 145         b = (struct event_base*)ev_default_loop(EVFLAG_AUTO);
 146         *m = ev_backend2str(ev_backend((struct ev_loop*)b));
 147 #  else
 148         *n = "unknown";
 149         *m = "not obtainable";
 150         b = NULL;
 151 #  endif
 152 #  ifdef HAVE_EVENT_BASE_FREE
 153         event_base_free(b);
 154 #  endif
 155 #endif
 156 }
 157
 158 /** print usage. */
 159 static void usage()
 160 {
 161         const char** m;
 162         const char *evnm="event", *evsys="", *evmethod="";
 163         printf("usage:  unbound [options]\n");
 164         printf("        start unbound daemon DNS resolver.\n");
 165         printf("-h      this help\n");
 166         printf("-c file config file to read instead of %s\n", CONFIGFILE);
 167         printf("        file format is described in unbound.conf(5).\n");
 168         printf("-d      do not fork into the background.\n");
 169         printf("-v      verbose (more times to increase verbosity)\n");
 170 #ifdef UB_ON_WINDOWS
 171         printf("-w opt  windows option: \n");
 172         printf("        install, remove - manage the services entry\n");
 173         printf("        service - used to start from services control panel\n");
 174 #endif
 175         printf("Version %s\n", PACKAGE_VERSION);
 176         get_event_sys(&evnm, &evsys, &evmethod);
 177         printf("linked libs: %s %s (it uses %s), %s\n",
 178                 evnm, evsys, evmethod,
 179 #ifdef HAVE_SSL
 180                 SSLeay_version(SSLEAY_VERSION)
 181 #elif defined(HAVE_NSS)
 182                 NSS_GetVersion()
 183 #endif
 184                 );
 185         printf("linked modules:");
 186         for(m = module_list_avail(); *m; m++)
 187                 printf(" %s", *m);
 188         printf("\n");
 189         printf("BSD licensed, see LICENSE in source package for details.\n");
 190         printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
 191 }
 192
 193 #ifndef unbound_testbound
 194 int replay_var_compare(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
 195 {
 196         log_assert(0);
 197         return 0;
 198 }
 199 #endif
 200
 201 /** check file descriptor count */
 202 static void
 203 checkrlimits(struct config_file* cfg)
 204 {
 205 #ifndef S_SPLINT_S
 206 #ifdef HAVE_GETRLIMIT
 207         /* list has number of ports to listen to, ifs number addresses */
 208         int list = ((cfg->do_udp?1:0) + (cfg->do_tcp?1 +
 209                         (int)cfg->incoming_num_tcp:0));
 210         size_t listen_ifs = (size_t)(cfg->num_ifs==0?
 211                 ((cfg->do_ip4 && !cfg->if_automatic?1:0) +
 212                  (cfg->do_ip6?1:0)):cfg->num_ifs);
 213         size_t listen_num = list*listen_ifs;
 214         size_t outudpnum = (size_t)cfg->outgoing_num_ports;
 215         size_t outtcpnum = cfg->outgoing_num_tcp;
 216         size_t misc = 4; /* logfile, pidfile, stdout... */
 217         size_t perthread_noudp = listen_num + outtcpnum +
 218                 2/*cmdpipe*/ + 2/*libevent*/ + misc;
 219         size_t perthread = perthread_noudp + outudpnum;
 220
 221 #if !defined(HAVE_PTHREAD) && !defined(HAVE_SOLARIS_THREADS)
 222         int numthread = 1; /* it forks */
 223 #else
 224         int numthread = (cfg->num_threads?cfg->num_threads:1);
 225 #endif
 226         size_t total = numthread * perthread + misc;
 227         size_t avail;
 228         struct rlimit rlim;
 229
 230         if(total > 1024 &&
 231                 strncmp(event_get_version(), "mini-event", 10) == 0) {
 232                 log_warn("too many file descriptors requested. The builtin"
 233                         "mini-event cannot handle more than 1024. Config "
 234                         "for less fds or compile with libevent");
 235                 if(numthread*perthread_noudp+15 > 1024)
 236                         fatal_exit("too much tcp. not enough fds.");
 237                 cfg->outgoing_num_ports = (int)((1024
 238                         - numthread*perthread_noudp
 239                         - 10 /* safety margin */) /numthread);
 240                 log_warn("continuing with less udp ports: %u",
 241                         cfg->outgoing_num_ports);
 242                 total = 1024;
 243         }
 244         if(perthread > 64 &&
 245                 strncmp(event_get_version(), "winsock-event", 13) == 0) {
 246                 log_err("too many file descriptors requested. The winsock"
 247                         " event handler cannot handle more than 64 per "
 248                         " thread. Config for less fds");
 249                 if(perthread_noudp+2 > 64)
 250                         fatal_exit("too much tcp. not enough fds.");
 251                 cfg->outgoing_num_ports = (int)((64
 252                         - perthread_noudp
 253                         - 2/* safety margin */));
 254                 log_warn("continuing with less udp ports: %u",
 255                         cfg->outgoing_num_ports);
 256                 total = numthread*(perthread_noudp+
 257                         (size_t)cfg->outgoing_num_ports)+misc;
 258         }
 259         if(getrlimit(RLIMIT_NOFILE, &rlim) < 0) {
 260                 log_warn("getrlimit: %s", strerror(errno));
 261                 return;
 262         }
 263         if(rlim.rlim_cur == (rlim_t)RLIM_INFINITY)
 264                 return;
 265         if((size_t)rlim.rlim_cur < total) {
 266                 avail = (size_t)rlim.rlim_cur;
 267                 rlim.rlim_cur = (rlim_t)(total + 10);
 268                 rlim.rlim_max = (rlim_t)(total + 10);
 269 #ifdef HAVE_SETRLIMIT
 270                 if(setrlimit(RLIMIT_NOFILE, &rlim) < 0) {
 271                         log_warn("setrlimit: %s", strerror(errno));
 272 #endif
 273                         log_warn("cannot increase max open fds from %u to %u",
 274                                 (unsigned)avail, (unsigned)total+10);
 275                         /* check that calculation below does not underflow,
 276                          * with 15 as margin */
 277                         if(numthread*perthread_noudp+15 > avail)
 278                                 fatal_exit("too much tcp. not enough fds.");
 279                         cfg->outgoing_num_ports = (int)((avail
 280                                 - numthread*perthread_noudp
 281                                 - 10 /* safety margin */) /numthread);
 282                         log_warn("continuing with less udp ports: %u",
 283                                 cfg->outgoing_num_ports);
 284                         log_warn("increase ulimit or decrease threads, "
 285                                 "ports in config to remove this warning");
 286                         return;
 287 #ifdef HAVE_SETRLIMIT
 288                 }
 289 #endif
 290                 verbose(VERB_ALGO, "increased limit(open files) from %u to %u",
 291                         (unsigned)avail, (unsigned)total+10);
 292         }
 293 #else
 294         (void)cfg;
 295 #endif /* HAVE_GETRLIMIT */
 296 #endif /* S_SPLINT_S */
 297 }
 298
 299 /** set verbosity, check rlimits, cache settings */
 300 static void
 301 apply_settings(struct daemon* daemon, struct config_file* cfg,
 302         int cmdline_verbose, int debug_mode)
 303 {
 304         /* apply if they have changed */
 305         verbosity = cmdline_verbose + cfg->verbosity;
 306         if (debug_mode > 1) {
 307                 cfg->use_syslog = 0;
 308                 cfg->logfile = NULL;
 309         }
 310         daemon_apply_cfg(daemon, cfg);
 311         checkrlimits(cfg);
 312 }
 313
 314 #ifdef HAVE_KILL
 315 /** Read existing pid from pidfile.
 316  * @param file: file name of pid file.
 317  * @return: the pid from the file or -1 if none.
 318  */
 319 static pid_t
 320 readpid (const char* file)
 321 {
 322         int fd;
 323         pid_t pid;
 324         char pidbuf[32];
 325         char* t;
 326         ssize_t l;
 327
 328         if ((fd = open(file, O_RDONLY)) == -1) {
 329                 if(errno != ENOENT)
 330                         log_err("Could not read pidfile %s: %s",
 331                                 file, strerror(errno));
 332                 return -1;
 333         }
 334
 335         if (((l = read(fd, pidbuf, sizeof(pidbuf)))) == -1) {
 336                 if(errno != ENOENT)
 337                         log_err("Could not read pidfile %s: %s",
 338                                 file, strerror(errno));
 339                 close(fd);
 340                 return -1;
 341         }
 342
 343         close(fd);
 344
 345         /* Empty pidfile means no pidfile... */
 346         if (l == 0) {
 347                 return -1;
 348         }
 349
 350         pidbuf[sizeof(pidbuf)-1] = 0;
 351         pid = (pid_t)strtol(pidbuf, &t, 10);
 352
 353         if (*t && *t != '\n') {
 354                 return -1;
 355         }
 356         return pid;
 357 }
 358
 359 /** write pid to file.
 360  * @param pidfile: file name of pid file.
 361  * @param pid: pid to write to file.
 362  */
 363 static void
 364 writepid (const char* pidfile, pid_t pid)
 365 {
 366         FILE* f;
 367
 368         if ((f = fopen(pidfile, "w")) ==  NULL ) {
 369                 log_err("cannot open pidfile %s: %s",
 370                         pidfile, strerror(errno));
 371                 return;
 372         }
 373         if(fprintf(f, "%lu\n", (unsigned long)pid) < 0) {
 374                 log_err("cannot write to pidfile %s: %s",
 375                         pidfile, strerror(errno));
 376         }
 377         fclose(f);
 378 }
 379
 380 /**
 381  * check old pid file.
 382  * @param pidfile: the file name of the pid file.
 383  * @param inchroot: if pidfile is inchroot and we can thus expect to
 384  *      be able to delete it.
 385  */
 386 static void
 387 checkoldpid(char* pidfile, int inchroot)
 388 {
 389         pid_t old;
 390         if((old = readpid(pidfile)) != -1) {
 391                 /* see if it is still alive */
 392                 if(kill(old, 0) == 0 || errno == EPERM)
 393                         log_warn("unbound is already running as pid %u.",
 394                                 (unsigned)old);
 395                 else    if(inchroot)
 396                         log_warn("did not exit gracefully last time (%u)",
 397                                 (unsigned)old);
 398         }
 399 }
 400 #endif /* HAVE_KILL */
 401
 402 /** detach from command line */
 403 static void
 404 detach(void)
 405 {
 406 #if defined(HAVE_DAEMON) && !defined(DEPRECATED_DAEMON)
 407         /* use POSIX daemon(3) function */
 408         if(daemon(1, 0) != 0)
 409                 fatal_exit("daemon failed: %s", strerror(errno));
 410 #else /* no HAVE_DAEMON */
 411 #ifdef HAVE_FORK
 412         int fd;
 413         /* Take off... */
 414         switch (fork()) {
 415                 case 0:
 416                         break;
 417                 case -1:
 418                         fatal_exit("fork failed: %s", strerror(errno));
 419                 default:
 420                         /* exit interactive session */
 421                         exit(0);
 422         }
 423         /* detach */
 424 #ifdef HAVE_SETSID
 425         if(setsid() == -1)
 426                 fatal_exit("setsid() failed: %s", strerror(errno));
 427 #endif
 428         if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
 429                 (void)dup2(fd, STDIN_FILENO);
 430                 (void)dup2(fd, STDOUT_FILENO);
 431                 (void)dup2(fd, STDERR_FILENO);
 432                 if (fd > 2)
 433                         (void)close(fd);
 434         }
 435 #endif /* HAVE_FORK */
 436 #endif /* HAVE_DAEMON */
 437 }
 438
 439 /** daemonize, drop user priviliges and chroot if needed */
 440 static void
 441 perform_setup(struct daemon* daemon, struct config_file* cfg, int debug_mode,
 442         const char** cfgfile)
 443 {
 444 #ifdef HAVE_GETPWNAM
 445         struct passwd *pwd = NULL;
 446         uid_t uid;
 447         gid_t gid;
 448         /* initialize, but not to 0 (root) */
 449         memset(&uid, 112, sizeof(uid));
 450         memset(&gid, 112, sizeof(gid));
 451         log_assert(cfg);
 452
 453         if(cfg->username && cfg->username[0]) {
 454                 if((pwd = getpwnam(cfg->username)) == NULL)
 455                         fatal_exit("user '%s' does not exist.", cfg->username);
 456                 uid = pwd->pw_uid;
 457                 gid = pwd->pw_gid;
 458                 /* endpwent below, in case we need pwd for setusercontext */
 459         }
 460 #endif
 461
 462         /* init syslog (as root) if needed, before daemonize, otherwise
 463          * a fork error could not be printed since daemonize closed stderr.*/
 464         if(cfg->use_syslog) {
 465                 log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
 466         }
 467         /* if using a logfile, we cannot open it because the logfile would
 468          * be created with the wrong permissions, we cannot chown it because
 469          * we cannot chown system logfiles, so we do not open at all.
 470          * So, using a logfile, the user does not see errors unless -d is
 471          * given to unbound on the commandline. */
 472
 473         /* read ssl keys while superuser and outside chroot */
 474 #ifdef HAVE_SSL
 475         if(!(daemon->rc = daemon_remote_create(cfg)))
 476                 fatal_exit("could not set up remote-control");
 477         if(cfg->ssl_service_key && cfg->ssl_service_key[0]) {
 478                 if(!(daemon->listen_sslctx = listen_sslctx_create(
 479                         cfg->ssl_service_key, cfg->ssl_service_pem, NULL)))
 480                         fatal_exit("could not set up listen SSL_CTX");
 481         }
 482         if(!(daemon->connect_sslctx = connect_sslctx_create(NULL, NULL, NULL)))
 483                 fatal_exit("could not set up connect SSL_CTX");
 484 #endif
 485
 486 #ifdef HAVE_KILL
 487         /* check old pid file before forking */
 488         if(cfg->pidfile && cfg->pidfile[0]) {
 489                 /* calculate position of pidfile */
 490                 if(cfg->pidfile[0] == '/')
 491                         daemon->pidfile = strdup(cfg->pidfile);
 492                 else    daemon->pidfile = fname_after_chroot(cfg->pidfile,
 493                                 cfg, 1);
 494                 if(!daemon->pidfile)
 495                         fatal_exit("pidfile alloc: out of memory");
 496                 checkoldpid(daemon->pidfile,
 497                         /* true if pidfile is inside chrootdir, or nochroot */
 498                         !(cfg->chrootdir && cfg->chrootdir[0]) ||
 499                         (cfg->chrootdir && cfg->chrootdir[0] &&
 500                         strncmp(daemon->pidfile, cfg->chrootdir,
 501                                 strlen(cfg->chrootdir))==0));
 502         }
 503 #endif
 504
 505         /* daemonize because pid is needed by the writepid func */
 506         if(!debug_mode && cfg->do_daemonize) {
 507                 detach();
 508         }
 509
 510         /* write new pidfile (while still root, so can be outside chroot) */
 511 #ifdef HAVE_KILL
 512         if(cfg->pidfile && cfg->pidfile[0]) {
 513                 writepid(daemon->pidfile, getpid());
 514                 if(!(cfg->chrootdir && cfg->chrootdir[0]) ||
 515                         (cfg->chrootdir && cfg->chrootdir[0] &&
 516                         strncmp(daemon->pidfile, cfg->chrootdir,
 517                         strlen(cfg->chrootdir))==0)) {
 518                         /* delete of pidfile could potentially work,
 519                          * chown to get permissions */
 520                         if(cfg->username && cfg->username[0]) {
 521                           if(chown(daemon->pidfile, uid, gid) == -1) {
 522                                 log_err("cannot chown %u.%u %s: %s",
 523                                         (unsigned)uid, (unsigned)gid,
 524                                         daemon->pidfile, strerror(errno));
 525                           }
 526                         }
 527                 }
 528         }
 529 #else
 530         (void)daemon;
 531 #endif
 532
 533         /* Set user context */
 534 #ifdef HAVE_GETPWNAM
 535         if(cfg->username && cfg->username[0]) {
 536 #ifdef HAVE_SETUSERCONTEXT
 537                 /* setusercontext does initgroups, setuid, setgid, and
 538                  * also resource limits from login config, but we
 539                  * still call setresuid, setresgid to be sure to set all uid*/
 540                 if(setusercontext(NULL, pwd, uid, (unsigned)
 541                         LOGIN_SETALL & ~LOGIN_SETUSER & ~LOGIN_SETGROUP) != 0)
 542                         log_warn("unable to setusercontext %s: %s",
 543                                 cfg->username, strerror(errno));
 544 #endif /* HAVE_SETUSERCONTEXT */
 545         }
 546 #endif /* HAVE_GETPWNAM */
 547
 548         /* box into the chroot */
 549 #ifdef HAVE_CHROOT
 550         if(cfg->chrootdir && cfg->chrootdir[0]) {
 551                 if(chdir(cfg->chrootdir)) {
 552                         fatal_exit("unable to chdir to chroot %s: %s",
 553                                 cfg->chrootdir, strerror(errno));
 554                 }
 555                 verbose(VERB_QUERY, "chdir to %s", cfg->chrootdir);
 556                 if(chroot(cfg->chrootdir))
 557                         fatal_exit("unable to chroot to %s: %s",
 558                                 cfg->chrootdir, strerror(errno));
 559                 if(chdir("/"))
 560                         fatal_exit("unable to chdir to / in chroot %s: %s",
 561                                 cfg->chrootdir, strerror(errno));
 562                 verbose(VERB_QUERY, "chroot to %s", cfg->chrootdir);
 563                 if(strncmp(*cfgfile, cfg->chrootdir,
 564                         strlen(cfg->chrootdir)) == 0)
 565                         (*cfgfile) += strlen(cfg->chrootdir);
 566
 567                 /* adjust stored pidfile for chroot */
 568                 if(daemon->pidfile && daemon->pidfile[0] &&
 569                         strncmp(daemon->pidfile, cfg->chrootdir,
 570                         strlen(cfg->chrootdir))==0) {
 571                         char* old = daemon->pidfile;
 572                         daemon->pidfile = strdup(old+strlen(cfg->chrootdir));
 573                         free(old);
 574                         if(!daemon->pidfile)
 575                                 log_err("out of memory in pidfile adjust");
 576                 }
 577                 daemon->chroot = strdup(cfg->chrootdir);
 578                 if(!daemon->chroot)
 579                         log_err("out of memory in daemon chroot dir storage");
 580         }
 581 #else
 582         (void)cfgfile;
 583 #endif
 584         /* change to working directory inside chroot */
 585         if(cfg->directory && cfg->directory[0]) {
 586                 char* dir = cfg->directory;
 587                 if(cfg->chrootdir && cfg->chrootdir[0] &&
 588                         strncmp(dir, cfg->chrootdir,
 589                         strlen(cfg->chrootdir)) == 0)
 590                         dir += strlen(cfg->chrootdir);
 591                 if(dir[0]) {
 592                         if(chdir(dir)) {
 593                                 fatal_exit("Could not chdir to %s: %s",
 594                                         dir, strerror(errno));
 595                         }
 596                         verbose(VERB_QUERY, "chdir to %s", dir);
 597                 }
 598         }
 599
 600         /* drop permissions after chroot, getpwnam, pidfile, syslog done*/
 601 #ifdef HAVE_GETPWNAM
 602         if(cfg->username && cfg->username[0]) {
 603 #  ifdef HAVE_INITGROUPS
 604                 if(initgroups(cfg->username, gid) != 0)
 605                         log_warn("unable to initgroups %s: %s",
 606                                 cfg->username, strerror(errno));
 607 #  endif /* HAVE_INITGROUPS */
 608                 endpwent();
 609
 610 #ifdef HAVE_SETRESGID
 611                 if(setresgid(gid,gid,gid) != 0)
 612 #elif defined(HAVE_SETREGID) && !defined(DARWIN_BROKEN_SETREUID)
 613                 if(setregid(gid,gid) != 0)
 614 #else /* use setgid */
 615                 if(setgid(gid) != 0)
 616 #endif /* HAVE_SETRESGID */
 617                         fatal_exit("unable to set group id of %s: %s",
 618                                 cfg->username, strerror(errno));
 619 #ifdef HAVE_SETRESUID
 620                 if(setresuid(uid,uid,uid) != 0)
 621 #elif defined(HAVE_SETREUID) && !defined(DARWIN_BROKEN_SETREUID)
 622                 if(setreuid(uid,uid) != 0)
 623 #else /* use setuid */
 624                 if(setuid(uid) != 0)
 625 #endif /* HAVE_SETRESUID */
 626                         fatal_exit("unable to set user id of %s: %s",
 627                                 cfg->username, strerror(errno));
 628                 verbose(VERB_QUERY, "drop user privileges, run as %s",
 629                         cfg->username);
 630         }
 631 #endif /* HAVE_GETPWNAM */
 632         /* file logging inited after chroot,chdir,setuid is done so that
 633          * it would succeed on SIGHUP as well */
 634         if(!cfg->use_syslog)
 635                 log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
 636 }
 637
 638 /**
 639  * Run the daemon.
 640  * @param cfgfile: the config file name.
 641  * @param cmdline_verbose: verbosity resulting from commandline -v.
 642  *    These increase verbosity as specified in the config file.
 643  * @param debug_mode: if set, do not daemonize.
 644  */
 645 static void
 646 run_daemon(const char* cfgfile, int cmdline_verbose, int debug_mode)
 647 {
 648         struct config_file* cfg = NULL;
 649         struct daemon* daemon = NULL;
 650         int done_setup = 0;
 651
 652         if(!(daemon = daemon_init()))
 653                 fatal_exit("alloc failure");
 654         while(!daemon->need_to_exit) {
 655                 if(done_setup)
 656                         verbose(VERB_OPS, "Restart of %s.", PACKAGE_STRING);
 657                 else    verbose(VERB_OPS, "Start of %s.", PACKAGE_STRING);
 658
 659                 /* config stuff */
 660                 if(!(cfg = config_create()))
 661                         fatal_exit("Could not alloc config defaults");
 662                 if(!config_read(cfg, cfgfile, daemon->chroot)) {
 663                         if(errno != ENOENT)
 664                                 fatal_exit("Could not read config file: %s",
 665                                         cfgfile);
 666                         log_warn("Continuing with default config settings");
 667                 }
 668                 apply_settings(daemon, cfg, cmdline_verbose, debug_mode);
 669
 670                 /* prepare */
 671                 if(!daemon_open_shared_ports(daemon))
 672                         fatal_exit("could not open ports");
 673                 if(!done_setup) {
 674                         perform_setup(daemon, cfg, debug_mode, &cfgfile);
 675                         done_setup = 1;
 676                 } else {
 677                         /* reopen log after HUP to facilitate log rotation */
 678                         if(!cfg->use_syslog)
 679                                 log_init(cfg->logfile, 0, cfg->chrootdir);
 680                 }
 681                 /* work */
 682                 daemon_fork(daemon);
 683
 684                 /* clean up for restart */
 685                 verbose(VERB_ALGO, "cleanup.");
 686                 daemon_cleanup(daemon);
 687                 config_delete(cfg);
 688         }
 689         verbose(VERB_ALGO, "Exit cleanup.");
 690         /* this unlink may not work if the pidfile is located outside
 691          * of the chroot/workdir or we no longer have permissions */
 692         if(daemon->pidfile) {
 693                 int fd;
 694                 /* truncate pidfile */
 695                 fd = open(daemon->pidfile, O_WRONLY | O_TRUNC, 0644);
 696                 if(fd != -1)
 697                         close(fd);
 698                 /* delete pidfile */
 699                 unlink(daemon->pidfile);
 700         }
 701         daemon_delete(daemon);
 702 }
 703
 704 /** getopt global, in case header files fail to declare it. */
 705 extern int optind;
 706 /** getopt global, in case header files fail to declare it. */
 707 extern char* optarg;
 708
 709 /**
 710  * main program. Set options given commandline arguments.
 711  * @param argc: number of commandline arguments.
 712  * @param argv: array of commandline arguments.
 713  * @return: exit status of the program.
 714  */
 715 int
 716 main(int argc, char* argv[])
 717 {
 718         int c;
 719         const char* cfgfile = CONFIGFILE;
 720         const char* winopt = NULL;
 721         int cmdline_verbose = 0;
 722         int debug_mode = 0;
 723 #ifdef UB_ON_WINDOWS
 724         int cmdline_cfg = 0;
 725 #endif
 726
 727 #ifdef HAVE_SBRK
 728         /* take debug snapshot of heap */
 729         unbound_start_brk = sbrk(0);
 730 #endif
 731
 732         log_init(NULL, 0, NULL);
 733         log_ident_set(strrchr(argv[0],'/')?strrchr(argv[0],'/')+1:argv[0]);
 734         /* parse the options */
 735         while( (c=getopt(argc, argv, "c:dhvw:")) != -1) {
 736                 switch(c) {
 737                 case 'c':
 738                         cfgfile = optarg;
 739 #ifdef UB_ON_WINDOWS
 740                         cmdline_cfg = 1;
 741 #endif
 742                         break;
 743                 case 'v':
 744                         cmdline_verbose ++;
 745                         verbosity++;
 746                         break;
 747                 case 'd':
 748                         debug_mode++;
 749                         break;
 750                 case 'w':
 751                         winopt = optarg;
 752                         break;
 753                 case '?':
 754                 case 'h':
 755                 default:
 756                         usage();
 757                         return 1;
 758                 }
 759         }
 760         argc -= optind;
 761         argv += optind;
 762
 763         if(winopt) {
 764 #ifdef UB_ON_WINDOWS
 765                 wsvc_command_option(winopt, cfgfile, cmdline_verbose,
 766                         cmdline_cfg);
 767 #else
 768                 fatal_exit("option not supported");
 769 #endif
 770         }
 771
 772         if(argc != 0) {
 773                 usage();
 774                 return 1;
 775         }
 776
 777         run_daemon(cfgfile, cmdline_verbose, debug_mode);
 778         log_init(NULL, 0, NULL); /* close logfile */
 779         return 0;
 780 }