text: /*
   * CDDL HEADER START
   *
   * The contents of this file are subject to the terms of the
   * Common Development and Distribution License (the "License").
   * You may not use this file except in compliance with the License.
   *
   * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   * or http://www.opensolaris.org/os/licensing.
   * See the License for the specific language governing permissions
   * and limitations under the License.
   *
   * When distributing Covered Code, include this CDDL HEADER in each
   * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
   * If applicable, add the following below this CDDL HEADER, with the
   * fields enclosed by brackets "[]" replaced with your own identifying
   * information: Portions Copyright [yyyy] [name of copyright owner]
   *
   * CDDL HEADER END
   */
  
  /*
   * Copyright 2015 Gary Mills
   * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
   * Use is subject to license terms.
   */
  
  /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
  /*	  All Rights Reserved  	*/
  
  /*
   * University Copyright- Copyright (c) 1982, 1986, 1988
   * The Regents of the University of California
   * All Rights Reserved
   *
   * University Acknowledgment- Portions of this document are derived from
   * software developed by the University of California, Berkeley, and its
   * contributors.
   */
  
  #include <sys/types.h>
  #include <sys/sockio.h>
  #include <sys/socket.h>
  #include <netinet/in.h>
  #include <stdio.h>
  #include <string.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <stropts.h>
  #include <arpa/nameser.h>
  #include <resolv.h>
  
  #include <netinet/in.h>
  #include <net/if.h>
  #include <netinet/if_ether.h>
  #include <arpa/inet.h>
  
  /*
   * Undocumented external function in libnsl
   */
  extern int
  getdomainname(char *, int);
  
  #define	MAXIFS	256
  
  /*
   * Resolver state default settings
   */
  
  struct state _res = {
  	RES_TIMEOUT,		/* retransmition time interval */
  	4,				/* number of times to retransmit */
  	RES_DEFAULT,		/* options flags */
  	1,				/* number of name servers */
  };
  
  /*
   * Set up default settings.  If the configuration file exist, the values
   * there will have precedence.  Otherwise, the server address is set to
   * INADDR_LOOPBACK and the default domain name comes from the gethostname().
   * BUT if the NIS/RPC domain name is set, that is used if all else fails.
   *
   * The configuration file should only be used if you want to redefine your
   * domain or run without a server on your machine.
   *
   * Note the user can always override then domain name with the environment
   * variable LOCALDOMAIN which has absolute priority.
   *
   *
   * Return 0 if completes successfully, -1 on error
   */
  int
  res_init(void)
  {
  	register FILE *fp;
  	register char *cp, **pp;
  	register int n;
  	char buf[BUFSIZ];
  	int nserv = 0;    /* number of nameserver records read from file */
  	int haveenv = 0;
  	int havesearch = 0;
  
  	_res.nsaddr.sin_addr.s_addr =  htonl(INADDR_LOOPBACK); /* INADDR_ANY */
  	_res.nsaddr.sin_family = AF_INET;
  	_res.nsaddr.sin_port = htons(NAMESERVER_PORT);
  	_res.nscount = 1;
  
  #ifdef SIOCGIFNUM
  	{	int numifs, s, n, int_up;
  		struct ifconf ifc;
  		register struct ifreq *ifrp;
  		struct ifreq ifr;
  		unsigned bufsize;
  		unsigned int flags;
  		char *buf;
  
  		if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
  			perror("socket");
  			return (-1);
  		}
  		if (ioctl(s, SIOCGIFNUM, (char *)&numifs) < 0) {
  			numifs = MAXIFS;
  		}
  		bufsize = numifs * sizeof (struct ifreq);
  		buf = (char *)malloc(bufsize);
  		if (buf == NULL) {
  			perror("out of memory");
  			(void) close(s);
  			return (-1);
  		}
  		ifc.ifc_len = bufsize;
  		ifc.ifc_buf = buf;
  		if (ioctl(s, SIOCGIFCONF, (char *)&ifc) < 0) {
  			perror("ifconfig: SIOCGIFCONF");
  			(void) close(s);
  			free(buf);
  			return (-1);
  		}
  
  		int_up = 0;
  		ifrp = ifc.ifc_req;
  		for (n = ifc.ifc_len / sizeof (struct ifreq); n > 0;
  								n--, ifrp++) {
  			(void) memset((void *) &ifr, 0, sizeof (ifr));
  			strncpy(ifr.ifr_name, ifrp->ifr_name,
  							sizeof (ifr.ifr_name));
  			if (ioctl(s, SIOCGIFFLAGS, (char *)&ifr) < 0) {
  				perror("SIOCGIFFLAGS");
  				(void) close(s);
  				free(buf);
  				return (-1);
  			}
  			flags = ifr.ifr_flags;
  			/* we are looking for a non-loopback interface */
  			if ((flags & IFF_UP) && ((flags & IFF_LOOPBACK) == 0))
  				int_up = 1;
  		}
  		(void) close(s);
  		free(buf);
  		if (int_up == 0) /* all the non-LOOPBACK interfaces are DOWN */
  			return (-1);
  	}
  #endif /* SIOCGIFNUM */
  
  
  	/*
  	 * for the benefit of hidden NIS domains, we use the same procedure
  	 * as sendmail: convert leading + to dot, then drop to first dot
  	 */
  	(void) getdomainname(buf, BUFSIZ);
  	if (buf[0] == '+')
  		buf[0] = '.';
  #ifdef SYSV
  	cp = strchr(buf, (int)'.');
  #else
  	cp = index(buf, '.');
  #endif
  	if (cp == NULL)
  		strcpy(_res.defdname, buf);
  	else
  		strcpy(_res.defdname, cp+1);
  
  	/* Allow user to override the local domain definition */
  	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
  	(void) strncpy(_res.defdname, cp, sizeof (_res.defdname));
  	haveenv++;
  	}
  
  	if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
  	/* read the config file */
  	while (fgets(buf, sizeof (buf), fp) != NULL) {
  	    /* read default domain name */
  	    if (!strncmp(buf, "domain", sizeof ("domain") - 1)) {
  		if (haveenv)	/* skip if have from environ */
  			    continue;
  		cp = buf + sizeof ("domain") - 1;
  		while (*cp == ' ' || *cp == '\t')
  		    cp++;
  		if ((*cp == '\0') || (*cp == '\n'))
  		    continue;
  		(void) strncpy(_res.defdname, cp, sizeof (_res.defdname) - 1);
  #ifdef SYSV
  		if ((cp = strchr(_res.defdname, (int)'\n')) != NULL)
  #else
  		if ((cp = index(_res.defdname, '\n')) != NULL)
  #endif
  		    *cp = '\0';
  		havesearch = 0;
  		continue;
  	    }
  	    /* set search list */
  	    if (!strncmp(buf, "search", sizeof ("search") - 1)) {
  		if (haveenv)	/* skip if have from environ */
  		    continue;
  		cp = buf + sizeof ("search") - 1;
  		while (*cp == ' ' || *cp == '\t')
  		    cp++;
  		if ((*cp == '\0') || (*cp == '\n'))
  		    continue;
  		(void) strncpy(_res.defdname, cp, sizeof (_res.defdname) - 1);
  #ifdef SYSV
  		if ((cp = strchr(_res.defdname, (int)'\n')) != NULL)
  #else
  		if ((cp = index(_res.defdname, '\n')) != NULL)
  #endif
  		    *cp = '\0';
  		/*
  		 * Set search list to be blank-separated strings
  		 * on rest of line.
  		 */
  		cp = _res.defdname;
  		pp = _res.dnsrch;
  		*pp++ = cp;
  		for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
  		    if (*cp == ' ' || *cp == '\t') {
  			*cp = 0;
  			n = 1;
  		    } else if (n) {
  			*pp++ = cp;
  			n = 0;
  		    }
  		}
  		/* null terminate last domain if there are excess */
  		while (*cp != '\0' && *cp != ' ' && *cp != '\t')
  		    cp++;
  		*cp = '\0';
  		*pp++ = 0;
  		havesearch = 1;
  		continue;
  	    }
  	    /* read nameservers to query */
  	    if (!strncmp(buf, "nameserver", sizeof ("nameserver") - 1) &&
  		(nserv < MAXNS)) {
  		cp = buf + sizeof ("nameserver") - 1;
  		while (*cp == ' ' || *cp == '\t')
  		    cp++;
  		if ((*cp == '\0') || (*cp == '\n'))
  		    continue;
  		if ((_res.nsaddr_list[nserv].sin_addr.s_addr =
  				inet_addr(cp)) == (unsigned) -1) {
  		    _res.nsaddr_list[n].sin_addr.s_addr = INADDR_ANY;
  		    continue;
  		}
  		_res.nsaddr_list[nserv].sin_family = AF_INET;
  		_res.nsaddr_list[nserv].sin_port = htons(NAMESERVER_PORT);
  		nserv++;
  		continue;
  	    }
  	}
  	if (nserv > 1)
  	    _res.nscount = nserv;
  	(void) fclose(fp);
  	}
  	if (_res.defdname[0] == 0) {
  	if (gethostname(buf, sizeof (_res.defdname)) == 0 &&
  #ifdef SYSV
  	    (cp = strchr(buf, (int)'.')))
  #else
  	    (cp = index(buf, '.')))
  #endif
  		(void) strcpy(_res.defdname, cp + 1);
  	}
  
  	/* find components of local domain that might be searched */
  	if (havesearch == 0) {
  	pp = _res.dnsrch;
  	*pp++ = _res.defdname;
  	for (cp = _res.defdname, n = 0; *cp; cp++)
  	    if (*cp == '.')
  		n++;
  	cp = _res.defdname;
  	for (; n >= LOCALDOMAINPARTS && pp < _res.dnsrch + MAXDFLSRCH; n--) {
  #ifdef SYSV
  	    cp = strchr(cp, (int)'.');
  #else
  	    cp = index(cp, '.');
  #endif
  	    *pp++ = ++cp;
  	}
  	*pp++ = 0;
  	}
  	_res.options |= RES_INIT;
  	return (0);
  }
  