/*

  chronyd/chronyc - Programs for keeping computer clocks accurate.

 **********************************************************************

 * Copyright (C) Richard P. Curnow  1997-2003

 * Copyright (C) Miroslav Lichvar  2009-2011

 * 

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of version 2 of the GNU General Public License as

 * published by the Free Software Foundation.

 * 

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

 * 

 **********************************************************************

  =======================================================================

  Functions to do name to IP address conversion

  */

#include "config.h"

#include "sysincl.h"

#include <netdb.h>

#include <resolv.h>

#include "nameserv.h"

#include "util.h"

/* ================================================== */

static int address_family = IPADDR_UNSPEC;

void

DNS_SetAddressFamily(int family)

{

  address_family = family;

}

DNS_Status 

DNS_Name2IPAddress(const char *name, IPAddr *ip_addrs, int max_addrs)

{

#ifdef HAVE_GETADDRINFO

  struct addrinfo hints, *res, *ai;

  int i, result;

  max_addrs = MIN(max_addrs, DNS_MAX_ADDRESSES);

  memset(&hints, 0, sizeof (hints));

  switch (address_family) {

    case IPADDR_INET4:

      hints.ai_family = AF_INET;

      break;

#ifdef FEAT_IPV6

    case IPADDR_INET6:

      hints.ai_family = AF_INET6;

      break;

#endif

    default:

      hints.ai_family = AF_UNSPEC;

  }

  hints.ai_socktype = SOCK_STREAM;

  result = getaddrinfo(name, NULL, &hints, &res;;

  if (result) {

#ifdef FORCE_DNSRETRY

    return DNS_TryAgain;

#else

    return result == EAI_AGAIN ? DNS_TryAgain : DNS_Failure;

#endif

  }

  for (ai = res, i = 0; i < max_addrs && ai != NULL; ai = ai->ai_next) {

    switch (ai->ai_family) {

      case AF_INET:

        if (address_family != IPADDR_UNSPEC && address_family != IPADDR_INET4)

          continue;

        ip_addrs[i].family = IPADDR_INET4;

        ip_addrs[i].addr.in4 = ntohl(((struct sockaddr_in *)ai->ai_addr)->sin_addr.s_addr);

        i++;

        break;

#ifdef FEAT_IPV6

      case AF_INET6:

        if (address_family != IPADDR_UNSPEC && address_family != IPADDR_INET6)

          continue;

        ip_addrs[i].family = IPADDR_INET6;

        memcpy(&ip_addrs[i].addr.in6, &((struct sockaddr_in6 *)ai->ai_addr)->sin6_addr.s6_addr,

               sizeof (ip_addrs->addr.in6));

        i++;

        break;

#endif

    }

  }

  for (; i < max_addrs; i++)

        ip_addrs[i].family = IPADDR_UNSPEC;

  freeaddrinfo(res);

  return !max_addrs || ip_addrs[0].family != IPADDR_UNSPEC ? DNS_Success : DNS_Failure;

#else

  struct hostent *host;

  int i;

  if (address_family != IPADDR_UNSPEC && address_family != IPADDR_INET4)

    return DNS_Failure;

  max_addrs = MIN(max_addrs, DNS_MAX_ADDRESSES);

  host = gethostbyname(name);

  if (host == NULL) {

    if (h_errno == TRY_AGAIN)

      return DNS_TryAgain;

  } else {

    if (host->h_addrtype != AF_INET || !host->h_addr_list[0])

      return DNS_Failure;

    for (i = 0; host->h_addr_list[i] && i < max_addrs; i++) {

      ip_addrs[i].family = IPADDR_INET4;

      ip_addrs[i].addr.in4 = ntohl(*(uint32_t *)host->h_addr_list[i]);

    }

    for (; i < max_addrs; i++)

      ip_addrs[i].family = IPADDR_UNSPEC;

    return DNS_Success;

  }

#ifdef FORCE_DNSRETRY

  return DNS_TryAgain;

#else

  return DNS_Failure;

#endif

#endif

}

/* ================================================== */

int

DNS_IPAddress2Name(IPAddr *ip_addr, char *name, int len)

{

  char *result = NULL;

#ifdef FEAT_IPV6

  struct sockaddr_in6 in6;

  socklen_t slen;

  char hbuf[NI_MAXHOST];

  slen = UTI_IPAndPortToSockaddr(ip_addr, 0, (struct sockaddr *)&in6;;

  if (!getnameinfo((struct sockaddr *)&in6, slen, hbuf, sizeof (hbuf), NULL, 0, 0))

    result = hbuf;

#else

  struct hostent *host;

  uint32_t addr;

  switch (ip_addr->family) {

    case IPADDR_INET4:

      addr = htonl(ip_addr->addr.in4);

      host = gethostbyaddr((const char *) &addr, sizeof (ip_addr), AF_INET);

      break;

#ifdef FEAT_IPV6

    case IPADDR_INET6:

      host = gethostbyaddr((const void *) ip_addr->addr.in6, sizeof (ip_addr->addr.in6), AF_INET6);

      break;

#endif

    default:

      host = NULL;

  }

  if (host)

    result = host->h_name;

#endif

  if (result == NULL)

    result = UTI_IPToString(ip_addr);

  if (snprintf(name, len, "%s", result) >= len)

    return 0;

  return 1;

}

/* ================================================== */

void

DNS_Reload(void)

{

  res_init();

}

/* ================================================== */