/* inet_pton.c -- convert IPv4 and IPv6 addresses from text to binary form

   Copyright (C) 2006, 2008-2020 Free Software Foundation, Inc.

   This program 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.

   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 Lesser General Public License for more details.

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

   along with this program.  If not, see <https://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 <config.h>

/* Specification.  */

#include <arpa/inet.h>

#if HAVE_DECL_INET_PTON

# undef inet_pton

int

rpl_inet_pton (int af, const char *restrict src, void *restrict dst)

{

  return inet_pton (af, src, dst);

}

#else

# include <c-ctype.h>

# include <string.h>

# include <errno.h>

# define NS_INADDRSZ 4

# define NS_IN6ADDRSZ 16

# define NS_INT16SZ 2

/*

 * WARNING: Don't even consider trying to compile this on a system where

 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.

 */

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

# if HAVE_IPV6

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

# endif

/* int

 * inet_pton(af, src, dst)

 *      convert from presentation format (which usually means ASCII printable)

 *      to network format (which is usually some kind of binary format).

 * return:

 *      1 if the address was valid for the specified address family

 *      0 if the address wasn't valid ('dst' is untouched in this case)

 *      -1 if some other error occurred ('dst' is untouched in this case, too)

 * author:

 *      Paul Vixie, 1996.

 */

int

inet_pton (int af, const char *restrict src, void *restrict dst)

{

  switch (af)

    {

    case AF_INET:

      return (inet_pton4 (src, dst));

# if HAVE_IPV6

    case AF_INET6:

      return (inet_pton6 (src, dst));

# endif

    default:

      errno = EAFNOSUPPORT;

      return (-1);

    }

  /* NOTREACHED */

}

/* int

 * inet_pton4(src, dst)

 *      like inet_aton() but without all the hexadecimal, octal (with the

 *      exception of 0) and shorthand.

 * return:

 *      1 if 'src' is a valid dotted quad, else 0.

 * notice:

 *      does not touch 'dst' unless it's returning 1.

 * author:

 *      Paul Vixie, 1996.

 */

static int

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

{

  int saw_digit, octets, ch;

  unsigned char tmp[NS_INADDRSZ], *tp;

  saw_digit = 0;

  octets = 0;

  *(tp = tmp) = 0;

  while ((ch = *src++) != '\0')

    {

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

        {

          unsigned 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);

}

# if HAVE_IPV6

/* int

 * inet_pton6(src, dst)

 *      convert presentation level address to network order binary form.

 * return:

 *      1 if 'src' is a valid [RFC1884 2.2] address, else 0.

 * notice:

 *      (1) does not touch 'dst' unless it's returning 1.

 *      (2) :: in a full address is silently ignored.

 * credit:

 *      inspired by Mark Andrews.

 * author:

 *      Paul Vixie, 1996.

 */

static int

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

{

  static const char xdigits[] = "0123456789abcdef";

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

  const char *curtok;

  int ch, saw_xdigit;

  unsigned val;

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

  endp = tp + NS_IN6ADDRSZ;

  colonp = NULL;

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

  if (*src == ':')

    if (*++src != ':')

      return (0);

  curtok = src;

  saw_xdigit = 0;

  val = 0;

  while ((ch = c_tolower (*src++)) != '\0')

    {

      const char *pch;

      pch = strchr (xdigits, ch);

      if (pch != NULL)

        {

          val <<= 4;

          val |= (pch - xdigits);

          if (val > 0xffff)

            return (0);

          saw_xdigit = 1;

          continue;

        }

      if (ch == ':')

        {

          curtok = src;

          if (!saw_xdigit)

            {

              if (colonp)

                return (0);

              colonp = tp;

              continue;

            }

          else if (*src == '\0')

            {

              return (0);

            }

          if (tp + NS_INT16SZ > endp)

            return (0);

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

          *tp++ = (u_char) val & 0xff;

          saw_xdigit = 0;

          val = 0;

          continue;

        }

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

          inet_pton4 (curtok, tp) > 0)

        {

          tp += NS_INADDRSZ;

          saw_xdigit = 0;

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

        }

      return (0);

    }

  if (saw_xdigit)

    {

      if (tp + NS_INT16SZ > endp)

        return (0);

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

      *tp++ = (u_char) val & 0xff;

    }

  if (colonp != NULL)

    {

      /*

       * Since some memmove()'s erroneously fail to handle

       * overlapping regions, we'll do the shift by hand.

       */

      const int n = tp - colonp;

      int i;

      if (tp == endp)

        return (0);

      for (i = 1; i <= n; i++)

        {

          endp[-i] = colonp[n - i];

          colonp[n - i] = 0;

        }

      tp = endp;

    }

  if (tp != endp)

    return (0);

  memcpy (dst, tmp, NS_IN6ADDRSZ);

  return (1);

}

# endif

#endif