/* Copyright (C) 1996-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

/*

 * Copyright (c) 1996,1999 by Internet Software Consortium.

 *

 * Permission to use, copy, modify, and distribute this software for any

 * purpose with or without fee is hereby granted, provided that the above

 * copyright notice and this permission notice appear in all copies.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS

 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE

 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL

 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR

 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS

 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS

 * SOFTWARE.

 */

#include <arpa/inet.h>

#include <arpa/nameser.h>

#include <ctype.h>

#include <errno.h>

#include <netinet/in.h>

#include <resolv/resolv-internal.h>

#include <string.h>

#include <sys/socket.h>

#include <sys/types.h>

static int inet_pton4 (const char *src, const char *src_end, u_char *dst);

static int inet_pton6 (const char *src, const char *src_end, u_char *dst);

int

__inet_pton_length (int af, const char *src, size_t srclen, void *dst)

{

  switch (af)

    {

    case AF_INET:

      return inet_pton4 (src, src + srclen, dst);

    case AF_INET6:

      return inet_pton6 (src, src + srclen, dst);

    default:

      __set_errno (EAFNOSUPPORT);

      return -1;

    }

}

libc_hidden_def (__inet_pton_length)

/* Like __inet_pton_length, but use strlen (SRC) as the length of

   SRC.  */

int

__inet_pton (int af, const char *src, void *dst)

{

  return __inet_pton_length (af, src, strlen (src), dst);

}

libc_hidden_def (__inet_pton)

weak_alias (__inet_pton, inet_pton)

libc_hidden_weak (inet_pton)

/* Like inet_aton but without all the hexadecimal, octal and shorthand

   (and trailing garbage is not ignored).  Return 1 if SRC is a valid

   dotted quad, else 0.  This function does not touch DST unless it's

   returning 1.

   Author: Paul Vixie, 1996.  */

static int

inet_pton4 (const char *src, const char *end, unsigned char *dst)

{

  int saw_digit, octets, ch;

  unsigned char tmp[NS_INADDRSZ], *tp;

  saw_digit = 0;

  octets = 0;

  *(tp = tmp) = 0;

  while (src < end)

    {

      ch = *src++;

      if (ch >= '0' && ch <= '9')

        {

          unsigned int new = *tp * 10 + (ch - '0');

          if (saw_digit && *tp == 0)

            return 0;

          if (new > 255)

            return 0;

          *tp = new;

          if (! saw_digit)

            {

              if (++octets > 4)

                return 0;

              saw_digit = 1;

            }

        }

      else if (ch == '.' && saw_digit)

        {

          if (octets == 4)

            return 0;

          *++tp = 0;

          saw_digit = 0;

        }

      else

        return 0;

    }

  if (octets < 4)

    return 0;

  memcpy (dst, tmp, NS_INADDRSZ);

  return 1;

}

/* Return the value of CH as a hexademical digit, or -1 if it is a

   different type of character.  */

static int

hex_digit_value (char ch)

{

  if ('0' <= ch && ch <= '9')

    return ch - '0';

  if ('a' <= ch && ch <= 'f')

    return ch - 'a' + 10;

  if ('A' <= ch && ch <= 'F')

    return ch - 'A' + 10;

  return -1;

}

/* Convert presentation-level IPv6 address to network order binary

   form.  Return 1 if SRC is a valid [RFC1884 2.2] address, else 0.

   This function does not touch DST unless it's returning 1.

   Author: Paul Vixie, 1996.  Inspired by Mark Andrews.  */

static int

inet_pton6 (const char *src, const char *src_endp, unsigned char *dst)

{

  unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;

  const char *curtok;

  int ch;

  size_t xdigits_seen;	/* Number of hex digits since colon.  */

  unsigned int val;

  tp = memset (tmp, '\0', NS_IN6ADDRSZ);

  endp = tp + NS_IN6ADDRSZ;

  colonp = NULL;

  /* Leading :: requires some special handling.  */

  if (src == src_endp)

    return 0;

  if (*src == ':')

    {

      ++src;

      if (src == src_endp || *src != ':')

        return 0;

    }

  curtok = src;

  xdigits_seen = 0;

  val = 0;

  while (src < src_endp)

    {

      ch = *src++;

      int digit = hex_digit_value (ch);

      if (digit >= 0)

	{

	  if (xdigits_seen == 4)

	    return 0;

	  val <<= 4;

	  val |= digit;

	  if (val > 0xffff)

	    return 0;

	  ++xdigits_seen;

	  continue;

	}

      if (ch == ':')

	{

	  curtok = src;

	  if (xdigits_seen == 0)

	    {

	      if (colonp)

		return 0;

	      colonp = tp;

	      continue;

	    }

	  else if (src == src_endp)

            return 0;

	  if (tp + NS_INT16SZ > endp)

	    return 0;

	  *tp++ = (unsigned char) (val >> 8) & 0xff;

	  *tp++ = (unsigned char) val & 0xff;

	  xdigits_seen = 0;

	  val = 0;

	  continue;

	}

      if (ch == '.' && ((tp + NS_INADDRSZ) <= endp)

          && inet_pton4 (curtok, src_endp, tp) > 0)

	{

	  tp += NS_INADDRSZ;

	  xdigits_seen = 0;

	  break;  /* '\0' was seen by inet_pton4.  */

	}

      return 0;

    }

  if (xdigits_seen > 0)

    {

      if (tp + NS_INT16SZ > endp)

	return 0;

      *tp++ = (unsigned char) (val >> 8) & 0xff;

      *tp++ = (unsigned char) val & 0xff;

    }

  if (colonp != NULL)

    {

      /* Replace :: with zeros.  */

      if (tp == endp)

        /* :: would expand to a zero-width field.  */

        return 0;

      size_t n = tp - colonp;

      memmove (endp - n, colonp, n);

      memset (colonp, 0, endp - n - colonp);

      tp = endp;

    }

  if (tp != endp)

    return 0;

  memcpy (dst, tmp, NS_IN6ADDRSZ);

  return 1;

}