/*-
 * Copyright (c) 1985, 1989 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted provided
 * that: (1) source distributions retain this entire copyright notice and
 * comment, and (2) distributions including binaries display the following
 * acknowledgement:  ``This product includes software developed by the
 * University of California, Berkeley and its contributors'' in the
 * documentation or other materials provided with the distribution and in
 * all advertising materials mentioning features or use of this software.
 * Neither the name of the University 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)res_init.c	6.14.1 (Berkeley) 6/27/90";

static char *rcs_version = "$Id: res_init.c,v 1.1.1.1 1997/09/29 15:35:27 db Exp $";

#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include "config.h"	/* To get #define SOL20		Vesa */
#include "sys.h"
#include "nameser.h"
#include "resolv.h"

/*
 * 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_ANY and the default domain name comes from the gethostname().
 *
 * The configuration file should only be used if you want to redefine your
 * domain or run without a server on your machine.
 *
 * Return 0 if completes successfully, -1 on error
 */
res_init()
{
  register FILE *fp;
  register char *cp, *dp, **pp;
  register int n;
  char buf[BUFSIZ];
  extern u_long inet_addr();
  extern char *getenv();
  int nserv = 0;    /* number of nameserver records read from file */
  int norder = 0;
  int haveenv = 0;
  int havesearch = 0;

  _res.nsaddr.sin_addr.s_addr = INADDR_ANY;
  _res.nsaddr.sin_family = AF_INET;
  _res.nsaddr.sin_port = htons(NAMESERVER_PORT);
  _res.nscount = 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);
	      if ((cp = index(_res.defdname, '\n')) != NULL)
		*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);
	      if ((cp = index(_res.defdname, '\n')) != NULL)
		*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[nserv].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;
	    }
	  /* read service order */
	  if (!strncmp(buf, "order", sizeof("order") - 1))
	    {
	      cp = buf + sizeof("order") - 1;
	      while (*cp == ' ' || *cp == '\t')
		cp++;
	      if ((*cp == '\0') || (*cp == '\n'))
		continue;
	      norder = 0;
	      do {
		if ((dp = index(cp, ',')) != NULL)
		  *dp = '\0';
		if (norder >= MAXSERVICES)
		  continue;
		if (!strncmp(cp, "bind", sizeof("bind") - 1))
		  _res.order[norder++] = RES_SERVICE_BIND;
		else if (!strncmp(cp, "local", sizeof("local") - 1))
		  _res.order[norder++] = RES_SERVICE_LOCAL;
		cp = dp + 1;
	      } while (dp != NULL);
	      _res.order[norder] = RES_SERVICE_NONE;
	      continue;
	    }
	}
      if (nserv > 1) 
	_res.nscount = nserv;
      (void) fclose(fp);
    }
  if (_res.defdname[0] == 0)
    {
      if (gethostname(buf, sizeof(_res.defdname)) == 0 &&
	  (cp = index(buf, '.')))
	(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--)
	{
	  cp = index(cp, '.');
	  *pp++ = ++cp;
	}
      *pp++ = 0;
    }
  /* default search order to bind only */
  if (norder == 0)
    {
      _res.order[0] = RES_SERVICE_BIND;
      _res.order[1] = RES_SERVICE_NONE;
    }
  _res.options |= RES_INIT;
  return (0);
}

