/*
* daemon/unbound.c - main program for unbound DNS resolver daemon.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/

/**
* \file
*
* Main program to start the DNS resolver daemon.
*/

#include "config.h"
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#include <sys/time.h>
#include "util/log.h"
#include "daemon/daemon.h"
#include "daemon/remote.h"
#include "util/config_file.h"
#include "util/storage/slabhash.h"
#include "services/listen_dnsport.h"
#include "services/cache/rrset.h"
#include "services/cache/infra.h"
#include "util/fptr_wlist.h"
#include "util/data/msgreply.h"
#include "util/module.h"
#include "util/net_help.h"
#include "util/ub_event.h"
#include <signal.h>
#include <fcntl.h>
#include <openssl/crypto.h>
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
#ifdef HAVE_GRP_H
#include <grp.h>
#endif
#include <openssl/ssl.h>

#ifndef S_SPLINT_S
/* splint chokes on this system header file */
#ifdef HAVE_SYS_RESOURCE_H
#include <sys/resource.h>
#endif
#endif /* S_SPLINT_S */
#ifdef HAVE_LOGIN_CAP_H
#include <login_cap.h>
#endif

#ifdef UB_ON_WINDOWS
#  include "winrc/win_svc.h"
#endif

#ifdef HAVE_NSS
/* nss3 */
#  include "nss.h"
#endif

#ifdef HAVE_TARGETCONDITIONALS_H
#include <TargetConditionals.h>
#endif

#if (defined(TARGET_OS_TV) && TARGET_OS_TV) || (defined(TARGET_OS_WATCH) && TARGET_OS_WATCH)
#undef HAVE_FORK
#endif

/** print build options. */
static void
print_build_options(void)
{
       const char** m;
       const char *evnm="event", *evsys="", *evmethod="";
       time_t t;
       struct timeval now;
       struct ub_event_base* base;
       printf("Version %s\n\n", PACKAGE_VERSION);
       printf("Configure line: %s\n", CONFCMDLINE);
       base = ub_default_event_base(0,&t,&now);
       ub_get_event_sys(base, &evnm, &evsys, &evmethod);
       printf("Linked libs: %s %s (it uses %s), %s\n",
               evnm, evsys, evmethod,
#ifdef HAVE_SSL
#  ifdef SSLEAY_VERSION
               SSLeay_version(SSLEAY_VERSION)
#  else
               OpenSSL_version(OPENSSL_VERSION)
#  endif
#elif defined(HAVE_NSS)
               NSS_GetVersion()
#elif defined(HAVE_NETTLE)
               "nettle"
#endif
               );
       printf("Linked modules:");
       for(m = module_list_avail(); *m; m++)
               printf(" %s", *m);
       printf("\n");
#ifdef USE_DNSCRYPT
       printf("DNSCrypt feature available\n");
#endif
#ifdef USE_TCP_FASTOPEN
       printf("TCP Fastopen feature available\n");
#endif
       ub_event_base_free(base);
       printf("\nBSD licensed, see LICENSE in source package for details.\n");
       printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
}

/** print usage. */
static void
usage(void)
{
       printf("usage:  unbound [options]\n");
       printf("        start unbound daemon DNS resolver.\n");
       printf("-h      this help.\n");
       printf("-c file config file to read instead of %s\n", CONFIGFILE);
       printf("        file format is described in unbound.conf(5).\n");
       printf("-d      do not fork into the background.\n");
       printf("-p      do not create a pidfile.\n");
       printf("-v      verbose (more times to increase verbosity).\n");
       printf("-V      show version number and build options.\n");
#ifdef UB_ON_WINDOWS
       printf("-w opt  windows option: \n");
       printf("        install, remove - manage the services entry\n");
       printf("        service - used to start from services control panel\n");
#endif
       printf("\nVersion %s\n", PACKAGE_VERSION);
       printf("BSD licensed, see LICENSE in source package for details.\n");
       printf("Report bugs to %s\n", PACKAGE_BUGREPORT);
}

#ifndef unbound_testbound
int replay_var_compare(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
{
       log_assert(0);
       return 0;
}
#endif

/** check file descriptor count */
static void
checkrlimits(struct config_file* cfg)
{
#ifndef S_SPLINT_S
#ifdef HAVE_GETRLIMIT
       /* list has number of ports to listen to, ifs number addresses */
       int list = ((cfg->do_udp?1:0) + (cfg->do_tcp?1 +
                       (int)cfg->incoming_num_tcp:0));
       size_t listen_ifs = (size_t)(cfg->num_ifs==0?
               ((cfg->do_ip4 && !cfg->if_automatic?1:0) +
                (cfg->do_ip6?1:0)):cfg->num_ifs);
       size_t listen_num = list*listen_ifs;
       size_t outudpnum = (size_t)cfg->outgoing_num_ports;
       size_t outtcpnum = cfg->outgoing_num_tcp;
       size_t misc = 4; /* logfile, pidfile, stdout... */
       size_t perthread_noudp = listen_num + outtcpnum +
               2/*cmdpipe*/ + 2/*libevent*/ + misc;
       size_t perthread = perthread_noudp + outudpnum;

#if !defined(HAVE_PTHREAD) && !defined(HAVE_SOLARIS_THREADS)
       int numthread = 1; /* it forks */
#else
       int numthread = (cfg->num_threads?cfg->num_threads:1);
#endif
       size_t total = numthread * perthread + misc;
       size_t avail;
       struct rlimit rlim;
       size_t memsize_expect = cfg->msg_cache_size + cfg->rrset_cache_size
               + (cfg->do_tcp?cfg->stream_wait_size:0)
               + (cfg->ip_ratelimit?cfg->ip_ratelimit_size:0)
               + (cfg->ratelimit?cfg->ratelimit_size:0)
               + (cfg->dnscrypt?cfg->dnscrypt_shared_secret_cache_size + cfg->dnscrypt_nonce_cache_size:0)
               + cfg->infra_cache_numhosts * (sizeof(struct infra_key)+sizeof(struct infra_data));
       if(strstr(cfg->module_conf, "validator") && (cfg->trust_anchor_file_list || cfg->trust_anchor_list || cfg->auto_trust_anchor_file_list || cfg->trusted_keys_file_list)) {
               memsize_expect += cfg->key_cache_size + cfg->neg_cache_size;
       }
#ifdef HAVE_NGHTTP2_NGHTTP2_H
       if(cfg_has_https(cfg)) {
               memsize_expect += cfg->http_query_buffer_size + cfg->http_response_buffer_size;
       }
#endif

#ifdef RLIMIT_AS
       if(getrlimit(RLIMIT_AS, &rlim) == 0) {
               if(rlim.rlim_cur != (rlim_t)RLIM_INFINITY &&
                       rlim.rlim_cur < (rlim_t)memsize_expect) {
                       log_warn("the ulimit(max memory size) is smaller than the expected memory usage (added size of caches). %u < %u bytes", (unsigned)rlim.rlim_cur, (unsigned)memsize_expect);
               }
       }
#endif
       if(getrlimit(RLIMIT_DATA, &rlim) == 0) {
               if(rlim.rlim_cur != (rlim_t)RLIM_INFINITY &&
                       rlim.rlim_cur < (rlim_t)memsize_expect) {
                       log_warn("the ulimit(data seg size) is smaller than the expected memory usage (added size of caches). %u < %u bytes", (unsigned)rlim.rlim_cur, (unsigned)memsize_expect);
               }
       }

       if(total > 1024 &&
               strncmp(ub_event_get_version(), "mini-event", 10) == 0) {
               log_warn("too many file descriptors requested. The builtin"
                       "mini-event cannot handle more than 1024. Config "
                       "for less fds or compile with libevent");
               if(numthread*perthread_noudp+15 > 1024)
                       fatal_exit("too much tcp. not enough fds.");
               cfg->outgoing_num_ports = (int)((1024
                       - numthread*perthread_noudp
                       - 10 /* safety margin */) /numthread);
               log_warn("continuing with less udp ports: %u",
                       cfg->outgoing_num_ports);
               total = 1024;
       }
       if(perthread > 64 &&
               strncmp(ub_event_get_version(), "winsock-event", 13) == 0) {
               log_err("too many file descriptors requested. The winsock"
                       " event handler cannot handle more than 64 per "
                       " thread. Config for less fds");
               if(perthread_noudp+2 > 64)
                       fatal_exit("too much tcp. not enough fds.");
               cfg->outgoing_num_ports = (int)((64
                       - perthread_noudp
                       - 2/* safety margin */));
               log_warn("continuing with less udp ports: %u",
                       cfg->outgoing_num_ports);
               total = numthread*(perthread_noudp+
                       (size_t)cfg->outgoing_num_ports)+misc;
       }
       if(getrlimit(RLIMIT_NOFILE, &rlim) < 0) {
               log_warn("getrlimit: %s", strerror(errno));
               return;
       }
       if(rlim.rlim_cur == (rlim_t)RLIM_INFINITY)
               return;
       if((size_t)rlim.rlim_cur < total) {
               avail = (size_t)rlim.rlim_cur;
               rlim.rlim_cur = (rlim_t)(total + 10);
               rlim.rlim_max = (rlim_t)(total + 10);
#ifdef HAVE_SETRLIMIT
               if(setrlimit(RLIMIT_NOFILE, &rlim) < 0) {
                       log_warn("setrlimit: %s", strerror(errno));
#endif
                       log_warn("cannot increase max open fds from %u to %u",
                               (unsigned)avail, (unsigned)total+10);
                       /* check that calculation below does not underflow,
                        * with 15 as margin */
                       if(numthread*perthread_noudp+15 > avail)
                               fatal_exit("too much tcp. not enough fds.");
                       cfg->outgoing_num_ports = (int)((avail
                               - numthread*perthread_noudp
                               - 10 /* safety margin */) /numthread);
                       log_warn("continuing with less udp ports: %u",
                               cfg->outgoing_num_ports);
                       log_warn("increase ulimit or decrease threads, "
                               "ports in config to remove this warning");
                       return;
#ifdef HAVE_SETRLIMIT
               }
#endif
               verbose(VERB_ALGO, "increased limit(open files) from %u to %u",
                       (unsigned)avail, (unsigned)total+10);
       }
#else
       (void)cfg;
#endif /* HAVE_GETRLIMIT */
#endif /* S_SPLINT_S */
}

/** set verbosity, check rlimits, cache settings */
static void
apply_settings(struct daemon* daemon, struct config_file* cfg,
       int cmdline_verbose, int debug_mode)
{
       /* apply if they have changed */
       verbosity = cmdline_verbose + cfg->verbosity;
       if (debug_mode > 1) {
               cfg->use_syslog = 0;
               free(cfg->logfile);
               cfg->logfile = NULL;
       }
       daemon_apply_cfg(daemon, cfg);
       checkrlimits(cfg);

       if (cfg->use_systemd && cfg->do_daemonize) {
               log_warn("use-systemd and do-daemonize should not be enabled at the same time");
       }

       log_ident_set_or_default(cfg->log_identity);
}

#ifdef HAVE_KILL
/** Read existing pid from pidfile.
* @param file: file name of pid file.
* @return: the pid from the file or -1 if none.
*/
static pid_t
readpid (const char* file)
{
       int fd;
       pid_t pid;
       char pidbuf[32];
       char* t;
       ssize_t l;

       if ((fd = open(file, O_RDONLY)) == -1) {
               if(errno != ENOENT)
                       log_err("Could not read pidfile %s: %s",
                               file, strerror(errno));
               return -1;
       }

       if (((l = read(fd, pidbuf, sizeof(pidbuf)))) == -1) {
               if(errno != ENOENT)
                       log_err("Could not read pidfile %s: %s",
                               file, strerror(errno));
               close(fd);
               return -1;
       }

       close(fd);

       /* Empty pidfile means no pidfile... */
       if (l == 0) {
               return -1;
       }

       pidbuf[sizeof(pidbuf)-1] = 0;
       pid = (pid_t)strtol(pidbuf, &t, 10);

       if (*t && *t != '\n') {
               return -1;
       }
       return pid;
}

/** write pid to file.
* @param pidfile: file name of pid file.
* @param pid: pid to write to file.
*/
static void
writepid (const char* pidfile, pid_t pid)
{
       int fd;
       char pidbuf[32];
       size_t count = 0;
       snprintf(pidbuf, sizeof(pidbuf), "%lu\n", (unsigned long)pid);

       if((fd = open(pidfile, O_WRONLY | O_CREAT | O_TRUNC
#ifdef O_NOFOLLOW
               | O_NOFOLLOW
#endif
               , 0644)) == -1) {
               log_err("cannot open pidfile %s: %s",
                       pidfile, strerror(errno));
               return;
       }
       while(count < strlen(pidbuf)) {
               ssize_t r = write(fd, pidbuf+count, strlen(pidbuf)-count);
               if(r == -1) {
                       if(errno == EAGAIN || errno == EINTR)
                               continue;
                       log_err("cannot write to pidfile %s: %s",
                               pidfile, strerror(errno));
                       close(fd);
                       return;
               } else if(r == 0) {
                       log_err("cannot write any bytes to pidfile %s: "
                               "write returns 0 bytes written", pidfile);
                       close(fd);
                       return;
               }
               count += r;
       }
       close(fd);
}

/**
* check old pid file.
* @param pidfile: the file name of the pid file.
* @param inchroot: if pidfile is inchroot and we can thus expect to
*      be able to delete it.
*/
static void
checkoldpid(char* pidfile, int inchroot)
{
       pid_t old;
       if((old = readpid(pidfile)) != -1) {
               /* see if it is still alive */
               if(kill(old, 0) == 0 || errno == EPERM)
                       log_warn("unbound is already running as pid %u.",
                               (unsigned)old);
               else    if(inchroot)
                       log_warn("did not exit gracefully last time (%u)",
                               (unsigned)old);
       }
}
#endif /* HAVE_KILL */

/** detach from command line */
static void
detach(void)
{
#if defined(HAVE_DAEMON) && !defined(DEPRECATED_DAEMON)
       /* use POSIX daemon(3) function */
       if(daemon(1, 0) != 0)
               fatal_exit("daemon failed: %s", strerror(errno));
#else /* no HAVE_DAEMON */
#ifdef HAVE_FORK
       int fd;
       /* Take off... */
       switch (fork()) {
               case 0:
                       break;
               case -1:
                       fatal_exit("fork failed: %s", strerror(errno));
               default:
                       /* exit interactive session */
                       exit(0);
       }
       /* detach */
#ifdef HAVE_SETSID
       if(setsid() == -1)
               fatal_exit("setsid() failed: %s", strerror(errno));
#endif
       if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
               (void)dup2(fd, STDIN_FILENO);
               (void)dup2(fd, STDOUT_FILENO);
               (void)dup2(fd, STDERR_FILENO);
               if (fd > 2)
                       (void)close(fd);
       }
#endif /* HAVE_FORK */
#endif /* HAVE_DAEMON */
}

/* setup a listening ssl context, fatal_exit() on any failure */
static void
setup_listen_sslctx(void** ctx, int is_dot, int is_doh, struct config_file* cfg)
{
#ifdef HAVE_SSL
       if(!(*ctx = listen_sslctx_create(
               cfg->ssl_service_key, cfg->ssl_service_pem, NULL,
               cfg->tls_ciphers, cfg->tls_ciphersuites,
               (cfg->tls_session_ticket_keys.first &&
               cfg->tls_session_ticket_keys.first->str[0] != 0),
               is_dot, is_doh))) {
               fatal_exit("could not set up listen SSL_CTX");
       }
#else /* HAVE_SSL */
       (void)ctx;(void)is_dot;(void)is_doh;(void)cfg;
#endif /* HAVE_SSL */
}

/* setups the needed ssl contexts, fatal_exit() on any failure */
static void
setup_sslctxs(struct daemon* daemon, struct config_file* cfg)
{
#ifdef HAVE_SSL
       if(!(daemon->rc = daemon_remote_create(cfg)))
               fatal_exit("could not set up remote-control");
       if(cfg->ssl_service_key && cfg->ssl_service_key[0]) {
               /* setup the session keys; the callback to use them will be
                * attached to each sslctx separately */
               if(cfg->tls_session_ticket_keys.first &&
                       cfg->tls_session_ticket_keys.first->str[0] != 0) {
                       if(!listen_sslctx_setup_ticket_keys(
                               cfg->tls_session_ticket_keys.first)) {
                               fatal_exit("could not set session ticket SSL_CTX");
                       }
               }
               (void)setup_listen_sslctx(&daemon->listen_dot_sslctx, 1, 0, cfg);
#ifdef HAVE_NGHTTP2_NGHTTP2_H
               if(cfg_has_https(cfg)) {
                       (void)setup_listen_sslctx(&daemon->listen_doh_sslctx, 0, 1, cfg);
               }
#endif
#ifdef HAVE_NGTCP2
               if(cfg_has_quic(cfg)) {
                       if(!(daemon->listen_quic_sslctx = quic_sslctx_create(
                               cfg->ssl_service_key, cfg->ssl_service_pem, NULL))) {
                               fatal_exit("could not set up quic SSL_CTX");
                       }
               }
#endif /* HAVE_NGTCP2 */
       }
       if(!(daemon->connect_dot_sslctx = connect_sslctx_create(NULL, NULL,
               cfg->tls_cert_bundle, cfg->tls_win_cert)))
               fatal_exit("could not set up connect SSL_CTX");
#else /* HAVE_SSL */
       (void)daemon;(void)cfg;
#endif /* HAVE_SSL */
}

/** daemonize, drop user privileges and chroot if needed */
static void
perform_setup(struct daemon* daemon, struct config_file* cfg, int debug_mode,
       const char** cfgfile, int need_pidfile)
{
#ifdef HAVE_KILL
       int pidinchroot;
#endif
#ifdef HAVE_GETPWNAM
       struct passwd *pwd = NULL;
#endif

       if(!daemon_privileged(daemon))
               fatal_exit("could not do privileged setup");
#ifdef HAVE_GETPWNAM
       if(cfg->username && cfg->username[0]) {
               if((pwd = getpwnam(cfg->username)) == NULL)
                       fatal_exit("user '%s' does not exist.", cfg->username);
               /* endpwent below, in case we need pwd for setusercontext */
       }
#endif
#ifdef UB_ON_WINDOWS
       w_config_adjust_directory(cfg);
#endif

       /* read ssl keys while superuser and outside chroot */
       (void)setup_sslctxs(daemon, cfg);

       /* init syslog (as root) if needed, before daemonize, otherwise
        * a fork error could not be printed since daemonize closed stderr.*/
       if(cfg->use_syslog) {
               log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
       }
       /* if using a logfile, we cannot open it because the logfile would
        * be created with the wrong permissions, we cannot chown it because
        * we cannot chown system logfiles, so we do not open at all.
        * So, using a logfile, the user does not see errors unless -d is
        * given to unbound on the commandline. */

#ifdef HAVE_KILL
       /* true if pidfile is inside chrootdir, or nochroot */
       pidinchroot = need_pidfile && (!(cfg->chrootdir && cfg->chrootdir[0]) ||
                               (cfg->chrootdir && cfg->chrootdir[0] &&
                               strncmp(cfg->pidfile, cfg->chrootdir,
                               strlen(cfg->chrootdir))==0));

       /* check old pid file before forking */
       if(cfg->pidfile && cfg->pidfile[0] && need_pidfile) {
               /* calculate position of pidfile */
               if(cfg->pidfile[0] == '/')
                       daemon->pidfile = strdup(cfg->pidfile);
               else    daemon->pidfile = fname_after_chroot(cfg->pidfile,
                               cfg, 1);
               if(!daemon->pidfile)
                       fatal_exit("pidfile alloc: out of memory");
               /* Check old pid if there is no username configured.
                * With a username, the assumption is that the privilege
                * drop makes a pidfile not removed when the server stopped
                * last time. The server does not chown the pidfile for it,
                * because that creates privilege escape problems, with the
                * pidfile writable by unprivileged users, but used by
                * privileged users. */
               if(!(cfg->username && cfg->username[0]))
                       checkoldpid(daemon->pidfile, pidinchroot);
       }
#endif

       /* daemonize because pid is needed by the writepid func */
       if(!debug_mode && cfg->do_daemonize) {
               detach();
       }

       /* write new pidfile (while still root, so can be outside chroot) */
#ifdef HAVE_KILL
       if(cfg->pidfile && cfg->pidfile[0] && need_pidfile) {
               writepid(daemon->pidfile, getpid());
       }
#else
       (void)daemon;
       (void)need_pidfile;
#endif /* HAVE_KILL */

       /* Set user context */
#ifdef HAVE_GETPWNAM
       if(cfg->username && cfg->username[0] && cfg_uid != (uid_t)-1) {
#ifdef HAVE_SETUSERCONTEXT
               /* setusercontext does initgroups, setuid, setgid, and
                * also resource limits from login config, but we
                * still call setresuid, setresgid to be sure to set all uid*/
               if(setusercontext(NULL, pwd, cfg_uid, (unsigned)
                       LOGIN_SETALL & ~LOGIN_SETUSER & ~LOGIN_SETGROUP) != 0)
                       log_warn("unable to setusercontext %s: %s",
                               cfg->username, strerror(errno));
#else
               (void)pwd;
#endif /* HAVE_SETUSERCONTEXT */
       }
#endif /* HAVE_GETPWNAM */

       /* box into the chroot */
#ifdef HAVE_CHROOT
       if(cfg->chrootdir && cfg->chrootdir[0]) {
               if(chdir(cfg->chrootdir)) {
                       fatal_exit("unable to chdir to chroot %s: %s",
                               cfg->chrootdir, strerror(errno));
               }
               verbose(VERB_QUERY, "chdir to %s", cfg->chrootdir);
               if(chroot(cfg->chrootdir))
                       fatal_exit("unable to chroot to %s: %s",
                               cfg->chrootdir, strerror(errno));
               if(chdir("/"))
                       fatal_exit("unable to chdir to / in chroot %s: %s",
                               cfg->chrootdir, strerror(errno));
               verbose(VERB_QUERY, "chroot to %s", cfg->chrootdir);
               if(strncmp(*cfgfile, cfg->chrootdir,
                       strlen(cfg->chrootdir)) == 0)
                       (*cfgfile) += strlen(cfg->chrootdir);

               /* adjust stored pidfile for chroot */
               if(daemon->pidfile && daemon->pidfile[0] &&
                       strncmp(daemon->pidfile, cfg->chrootdir,
                       strlen(cfg->chrootdir))==0) {
                       char* old = daemon->pidfile;
                       daemon->pidfile = strdup(old+strlen(cfg->chrootdir));
                       free(old);
                       if(!daemon->pidfile)
                               log_err("out of memory in pidfile adjust");
               }
               daemon->chroot = strdup(cfg->chrootdir);
               if(!daemon->chroot)
                       log_err("out of memory in daemon chroot dir storage");
       }
#else
       (void)cfgfile;
#endif
       /* change to working directory inside chroot */
       if(cfg->directory && cfg->directory[0]) {
               char* dir = cfg->directory;
               if(cfg->chrootdir && cfg->chrootdir[0] &&
                       strncmp(dir, cfg->chrootdir,
                       strlen(cfg->chrootdir)) == 0)
                       dir += strlen(cfg->chrootdir);
               if(dir[0]) {
                       if(chdir(dir)) {
                               fatal_exit("Could not chdir to %s: %s",
                                       dir, strerror(errno));
                       }
                       verbose(VERB_QUERY, "chdir to %s", dir);
               }
       }

       /* drop permissions after chroot, getpwnam, pidfile, syslog done*/
#ifdef HAVE_GETPWNAM
       if(cfg->username && cfg->username[0] && cfg_uid != (uid_t)-1) {
#  ifdef HAVE_INITGROUPS
               if(initgroups(cfg->username, cfg_gid) != 0)
                       log_warn("unable to initgroups %s: %s",
                               cfg->username, strerror(errno));
#  endif /* HAVE_INITGROUPS */
#  ifdef HAVE_ENDPWENT
               endpwent();
#  endif

#ifdef HAVE_SETRESGID
               if(setresgid(cfg_gid,cfg_gid,cfg_gid) != 0)
#elif defined(HAVE_SETREGID) && !defined(DARWIN_BROKEN_SETREUID)
               if(setregid(cfg_gid,cfg_gid) != 0)
#else /* use setgid */
               if(setgid(cfg_gid) != 0)
#endif /* HAVE_SETRESGID */
                       fatal_exit("unable to set group id of %s: %s",
                               cfg->username, strerror(errno));
#ifdef HAVE_SETRESUID
               if(setresuid(cfg_uid,cfg_uid,cfg_uid) != 0)
#elif defined(HAVE_SETREUID) && !defined(DARWIN_BROKEN_SETREUID)
               if(setreuid(cfg_uid,cfg_uid) != 0)
#else /* use setuid */
               if(setuid(cfg_uid) != 0)
#endif /* HAVE_SETRESUID */
                       fatal_exit("unable to set user id of %s: %s",
                               cfg->username, strerror(errno));
               verbose(VERB_QUERY, "drop user privileges, run as %s",
                       cfg->username);
       }
#endif /* HAVE_GETPWNAM */
       /* file logging inited after chroot,chdir,setuid is done so that
        * it would succeed on SIGHUP as well */
       if(!cfg->use_syslog)
               log_init(cfg->logfile, cfg->use_syslog, cfg->chrootdir);
       daemon->cfgfile = strdup(*cfgfile);
       if(!daemon->cfgfile)
               fatal_exit("out of memory in daemon cfgfile strdup");
}

/**
* Run the daemon.
* @param cfgfile: the config file name.
* @param cmdline_verbose: verbosity resulting from commandline -v.
*    These increase verbosity as specified in the config file.
* @param debug_mode: if set, do not daemonize.
* @param need_pidfile: if false, no pidfile is checked or created.
*/
static void
run_daemon(const char* cfgfile, int cmdline_verbose, int debug_mode, int need_pidfile)
{
       struct config_file* cfg = NULL;
       struct daemon* daemon = NULL;
       int done_setup = 0;

       if(!(daemon = daemon_init()))
               fatal_exit("alloc failure");
       while(!daemon->need_to_exit) {
               if(done_setup)
                       verbose(VERB_OPS, "Restart of %s.", PACKAGE_STRING);
               else    verbose(VERB_OPS, "Start of %s.", PACKAGE_STRING);

               /* config stuff */
               if(!(cfg = config_create()))
                       fatal_exit("Could not alloc config defaults");
               if(!config_read(cfg, cfgfile, daemon->chroot)) {
                       if(errno != ENOENT)
                               fatal_exit("Could not read config file: %s."
                                       " Maybe try unbound -dd, it stays on "
                                       "the commandline to see more errors, "
                                       "or unbound-checkconf", cfgfile);
                       log_warn("Continuing with default config settings");
               }
               apply_settings(daemon, cfg, cmdline_verbose, debug_mode);
               if(!done_setup)
                       config_lookup_uid(cfg);

               /* prepare */
               if(!daemon_open_shared_ports(daemon))
                       fatal_exit("could not open ports");
               if(!done_setup) {
                       perform_setup(daemon, cfg, debug_mode, &cfgfile, need_pidfile);
                       done_setup = 1;
               } else {
                       /* reopen log after HUP to facilitate log rotation */
                       if(!cfg->use_syslog)
                               log_init(cfg->logfile, 0, cfg->chrootdir);
               }
               /* work */
               daemon_fork(daemon);

               /* clean up for restart */
               verbose(VERB_ALGO, "cleanup.");
               daemon_cleanup(daemon);
               config_delete(cfg);
       }
       verbose(VERB_ALGO, "Exit cleanup.");
       /* this unlink may not work if the pidfile is located outside
        * of the chroot/workdir or we no longer have permissions */
       if(daemon->pidfile) {
               int fd;
               /* truncate pidfile */
               fd = open(daemon->pidfile, O_WRONLY | O_TRUNC
#ifdef O_NOFOLLOW
                       | O_NOFOLLOW
#endif
                       , 0644);
               if(fd != -1)
                       close(fd);
               /* delete pidfile */
               unlink(daemon->pidfile);
       }
       daemon_delete(daemon);
}

/** getopt global, in case header files fail to declare it. */
extern int optind;
/** getopt global, in case header files fail to declare it. */
extern char* optarg;

/**
* main program. Set options given commandline arguments.
* @param argc: number of commandline arguments.
* @param argv: array of commandline arguments.
* @return: exit status of the program.
*/
int
main(int argc, char* argv[])
{
       int c;
       const char* cfgfile = CONFIGFILE;
       const char* winopt = NULL;
       const char* log_ident_default;
       int cmdline_verbose = 0;
       int debug_mode = 0;
       int need_pidfile = 1;

#ifdef UB_ON_WINDOWS
       int cmdline_cfg = 0;
#endif

       checklock_start();
       log_init(NULL, 0, NULL);
       log_ident_default = strrchr(argv[0],'/')?strrchr(argv[0],'/')+1:argv[0];
       log_ident_set_default(log_ident_default);
       log_ident_set(log_ident_default);
       /* parse the options */
       while( (c=getopt(argc, argv, "c:dhpvw:V")) != -1) {
               switch(c) {
               case 'c':
                       cfgfile = optarg;
#ifdef UB_ON_WINDOWS
                       cmdline_cfg = 1;
#endif
                       break;
               case 'v':
                       cmdline_verbose++;
                       verbosity++;
                       break;
               case 'p':
                       need_pidfile = 0;
                       break;
               case 'd':
                       debug_mode++;
                       break;
               case 'w':
                       winopt = optarg;
                       break;
               case 'V':
                       print_build_options();
                       return 0;
               case '?':
               case 'h':
               default:
                       usage();
                       return 1;
               }
       }
       argc -= optind;
       /* argv += optind; not using further arguments */

       if(winopt) {
#ifdef UB_ON_WINDOWS
               wsvc_command_option(winopt, cfgfile, cmdline_verbose,
                       cmdline_cfg);
#else
               fatal_exit("option not supported");
#endif
       }

       if(argc != 0) {
               usage();
               return 1;
       }

       run_daemon(cfgfile, cmdline_verbose, debug_mode, need_pidfile);
       log_init(NULL, 0, NULL); /* close logfile */
#ifndef unbound_testbound
       if(log_get_lock()) {
               lock_basic_destroy((lock_basic_type*)log_get_lock());
       }
#endif
       return 0;
}