/* Copyright 1998, 2011 by the Massachusetts Institute of Technology.

 *

 * Permission to use, copy, modify, and distribute this

 * software and its documentation for any purpose and without

 * fee is hereby granted, provided that the above copyright

 * notice appear in all copies and that both that copyright

 * notice and this permission notice appear in supporting

 * documentation, and that the name of M.I.T. not be used in

 * advertising or publicity pertaining to distribution of the

 * software without specific, written prior permission.

 * M.I.T. makes no representations about the suitability of

 * this software for any purpose.  It is provided "as is"

 * without express or implied warranty.

 */

#include "ares_setup.h"

#ifdef HAVE_NETINET_IN_H

#  include <netinet/in.h>

#endif

#ifdef HAVE_NETDB_H

#  include <netdb.h>

#endif

#ifdef HAVE_ARPA_INET_H

#  include <arpa/inet.h>

#endif

#include "ares.h"

#include "ares_inet_net_pton.h"

#include "ares_nowarn.h"

#include "ares_private.h"

int ares__get_hostent(FILE *fp, int family, struct hostent **host)

{

  char *line = NULL, *p, *q, **alias;

  char *txtaddr, *txthost, *txtalias;

  int status;

  size_t addrlen, linesize, naliases;

  struct ares_addr addr;

  struct hostent *hostent = NULL;

  *host = NULL; /* Assume failure */

  /* Validate family */

  switch (family) {

    case AF_INET:

    case AF_INET6:

    case AF_UNSPEC:

      break;

    default:

      return ARES_EBADFAMILY;

  }

  while ((status = ares__read_line(fp, &line, &linesize)) == ARES_SUCCESS)

    {

      /* Trim line comment. */

      p = line;

      while (*p && (*p != '#'))

        p++;

      *p = '\0';

      /* Trim trailing whitespace. */

      q = p - 1;

      while ((q >= line) && ISSPACE(*q))

        q--;

      *++q = '\0';

      /* Skip leading whitespace. */

      p = line;

      while (*p && ISSPACE(*p))

        p++;

      if (!*p)

        /* Ignore line if empty. */

        continue;

      /* Pointer to start of IPv4 or IPv6 address part. */

      txtaddr = p;

      /* Advance past address part. */

      while (*p && !ISSPACE(*p))

        p++;

      if (!*p)

        /* Ignore line if reached end of line. */

        continue;

      /* Null terminate address part. */

      *p = '\0';

      /* Advance to host name */

      p++;

      while (*p && ISSPACE(*p))

        p++;

      if (!*p)

        /* Ignore line if reached end of line. */

        continue;  /* LCOV_EXCL_LINE: trailing whitespace already stripped */

      /* Pointer to start of host name. */

      txthost = p;

      /* Advance past host name. */

      while (*p && !ISSPACE(*p))

        p++;

      /* Pointer to start of first alias. */

      txtalias = NULL;

      if (*p)

        {

          q = p + 1;

          while (*q && ISSPACE(*q))

            q++;

          if (*q)

            txtalias = q;

        }

      /* Null terminate host name. */

      *p = '\0';

      /* find out number of aliases. */

      naliases = 0;

      if (txtalias)

        {

          p = txtalias;

          while (*p)

            {

              while (*p && !ISSPACE(*p))

                p++;

              while (*p && ISSPACE(*p))

                p++;

              naliases++;

            }

        }

      /* Convert address string to network address for the requested family. */

      addrlen = 0;

      addr.family = AF_UNSPEC;

      addr.addrV4.s_addr = INADDR_NONE;

      if ((family == AF_INET) || (family == AF_UNSPEC))

        {

          addr.addrV4.s_addr = inet_addr(txtaddr);

          if (addr.addrV4.s_addr != INADDR_NONE)

            {

              /* Actual network address family and length. */

              addr.family = AF_INET;

              addrlen = sizeof(addr.addrV4);

            }

        }

      if ((family == AF_INET6) || ((family == AF_UNSPEC) && (!addrlen)))

        {

          if (ares_inet_pton(AF_INET6, txtaddr, &addr.addrV6) > 0)

            {

              /* Actual network address family and length. */

              addr.family = AF_INET6;

              addrlen = sizeof(addr.addrV6);

            }

        }

      if (!addrlen)

        /* Ignore line if invalid address string for the requested family. */

        continue;

      /*

      ** Actual address family possible values are AF_INET and AF_INET6 only.

      */

      /* Allocate memory for the hostent structure. */

      hostent = ares_malloc(sizeof(struct hostent));

      if (!hostent)

        break;

      /* Initialize fields for out of memory condition. */

      hostent->h_aliases = NULL;

      hostent->h_addr_list = NULL;

      /* Copy official host name. */

      hostent->h_name = ares_strdup(txthost);

      if (!hostent->h_name)

        break;

      /* Copy network address. */

      hostent->h_addr_list = ares_malloc(2 * sizeof(char *));

      if (!hostent->h_addr_list)

        break;

      hostent->h_addr_list[1] = NULL;

      hostent->h_addr_list[0] = ares_malloc(addrlen);

      if (!hostent->h_addr_list[0])

        break;

      if (addr.family == AF_INET)

        memcpy(hostent->h_addr_list[0], &addr.addrV4, sizeof(addr.addrV4));

      else

        memcpy(hostent->h_addr_list[0], &addr.addrV6, sizeof(addr.addrV6));

      /* Copy aliases. */

      hostent->h_aliases = ares_malloc((naliases + 1) * sizeof(char *));

      if (!hostent->h_aliases)

        break;

      alias = hostent->h_aliases;

      while (naliases)

        *(alias + naliases--) = NULL;

      *alias = NULL;

      while (txtalias)

        {

          p = txtalias;

          while (*p && !ISSPACE(*p))

            p++;

          q = p;

          while (*q && ISSPACE(*q))

            q++;

          *p = '\0';

          if ((*alias = ares_strdup(txtalias)) == NULL)

            break;

          alias++;

          txtalias = *q ? q : NULL;

        }

      if (txtalias)

        /* Alias memory allocation failure. */

        break;

      /* Copy actual network address family and length. */

      hostent->h_addrtype = aresx_sitoss(addr.family);

      hostent->h_length = aresx_uztoss(addrlen);

      /* Free line buffer. */

      ares_free(line);

      /* Return hostent successfully */

      *host = hostent;

      return ARES_SUCCESS;

    }

  /* If allocated, free line buffer. */

  if (line)

    ares_free(line);

  if (status == ARES_SUCCESS)

    {

      /* Memory allocation failure; clean up. */

      if (hostent)

        {

          if (hostent->h_name)

            ares_free((char *) hostent->h_name);

          if (hostent->h_aliases)

            {

              for (alias = hostent->h_aliases; *alias; alias++)

                ares_free(*alias);

              ares_free(hostent->h_aliases);

            }

          if (hostent->h_addr_list)

            {

              if (hostent->h_addr_list[0])

                ares_free(hostent->h_addr_list[0]);

              ares_free(hostent->h_addr_list);

            }

          ares_free(hostent);

        }

      return ARES_ENOMEM;

    }

  return status;

}