text: /*
   * 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
  
  #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_SBRK
  /** global debug value to keep track of heap memory allocation */
  void* unbound_start_brk = 0;
  #endif
  
  /** print usage. */
  static void usage()
  {
  	const char** m;
  	const char *evnm="event", *evsys="", *evmethod="";
  	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("-v	verbose (more times to increase verbosity)\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("Version %s\n", PACKAGE_VERSION);
  	ub_get_event_sys(NULL, &evnm, &evsys, &evmethod);
  	printf("linked libs: %s %s (it uses %s), %s\n", 
  		evnm, evsys, evmethod,
  #ifdef HAVE_SSL
  		SSLeay_version(SSLEAY_VERSION)
  #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");
  	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;
  
  	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;
  		cfg->logfile = NULL;
  	}
  	daemon_apply_cfg(daemon, cfg);
  	checkrlimits(cfg);
  }
  
  #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)
  {
  	FILE* f;
  
  	if ((f = fopen(pidfile, "w")) ==  NULL ) {
  		log_err("cannot open pidfile %s: %s", 
  			pidfile, strerror(errno));
  		return;
  	}
  	if(fprintf(f, "%lu\n", (unsigned long)pid) < 0) {
  		log_err("cannot write to pidfile %s: %s", 
  			pidfile, strerror(errno));
  	}
  	fclose(f);
  }
  
  /**
   * 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 */
  }
  
  /** daemonize, drop user priviliges and chroot if needed */
  static void
  perform_setup(struct daemon* daemon, struct config_file* cfg, int debug_mode,
  	const char** cfgfile)
  {
  #ifdef HAVE_KILL
  	int pidinchroot;
  #endif
  #ifdef HAVE_GETPWNAM
  	struct passwd *pwd = NULL;
  
  	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
  
  	/* 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. */
  
  	/* read ssl keys while superuser and outside chroot */
  #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]) {
  		if(!(daemon->listen_sslctx = listen_sslctx_create(
  			cfg->ssl_service_key, cfg->ssl_service_pem, NULL)))
  			fatal_exit("could not set up listen SSL_CTX");
  	}
  	if(!(daemon->connect_sslctx = connect_sslctx_create(NULL, NULL, NULL)))
  		fatal_exit("could not set up connect SSL_CTX");
  #endif
  
  #ifdef HAVE_KILL
  	/* true if pidfile is inside chrootdir, or nochroot */
  	pidinchroot = !(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]) {
  		/* 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");
  		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]) {
  		writepid(daemon->pidfile, getpid());
  		if(cfg->username && cfg->username[0] && cfg_uid != (uid_t)-1 &&
  			pidinchroot) {
  #  ifdef HAVE_CHOWN
  			if(chown(daemon->pidfile, cfg_uid, cfg_gid) == -1) {
  				verbose(VERB_QUERY, "cannot chown %u.%u %s: %s",
  					(unsigned)cfg_uid, (unsigned)cfg_gid,
  					daemon->pidfile, strerror(errno));
  			}
  #  endif /* HAVE_CHOWN */
  		}
  	}
  #else
  	(void)daemon;
  #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));
  #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 */
  		endpwent();
  
  #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);
  }
  
  /**
   * 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.
   */
  static void 
  run_daemon(const char* cfgfile, int cmdline_verbose, int debug_mode)
  {
  	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",
  					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); 
  			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, 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;
  	int cmdline_verbose = 0;
  	int debug_mode = 0;
  #ifdef UB_ON_WINDOWS
  	int cmdline_cfg = 0;
  #endif
  
  #ifdef HAVE_SBRK
  	/* take debug snapshot of heap */
  	unbound_start_brk = sbrk(0);
  #endif
  
  	log_init(NULL, 0, NULL);
  	log_ident_set(strrchr(argv[0],'/')?strrchr(argv[0],'/')+1:argv[0]);
  	/* parse the options */
  	while( (c=getopt(argc, argv, "c:dhvw:")) != -1) {
  		switch(c) {
  		case 'c':
  			cfgfile = optarg;
  #ifdef UB_ON_WINDOWS
  			cmdline_cfg = 1;
  #endif
  			break;
  		case 'v':
  			cmdline_verbose++;
  			verbosity++;
  			break;
  		case 'd':
  			debug_mode++;
  			break;
  		case 'w':
  			winopt = optarg;
  			break;
  		case '?':
  		case 'h':
  		default:
  			usage();
  			return 1;
  		}
  	}
  	argc -= optind;
  	argv += optind;
  
  	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);
  	log_init(NULL, 0, NULL); /* close logfile */
  	return 0;
  }
  