/* Copyright (c) 1996 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.
 */

/*
 * Portions copyright (c) 1999, 2000
 * Intel Corporation.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *
 *    This product includes software developed by Intel Corporation and
 *    its contributors.
 *
 * 4. Neither the name of Intel Corporation or its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY INTEL CORPORATION AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL INTEL CORPORATION OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#if defined (LIBC_SCCS) && !defined (lint)
static char  rcsid[] = "$Id: inet_pton.c,v 1.1.1.1 2003/11/19 01:51:30 kyu3 Exp $";
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <string.h>
#include <errno.h>

/*
 * 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,
  u_char      *dst
  );

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

/* 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  *src,
  void        *dst
  )
{
  switch (af) {
    case AF_INET:
      return (inet_pton4 (src, dst));
    case AF_INET6:
      return (inet_pton6 (src, dst));
    default:
      errno = EAFNOSUPPORT;
      return (-1);
  }

  /* NOTREACHED */
}

/* int
 * inet_pton4(src, dst)
 *      like inet_aton() but without all the hexadecimal 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  *src,
  u_char      *dst
  )
{
  static const char  digits[] = "0123456789";
  int                saw_digit, octets, ch;
  u_char             tmp[NS_INADDRSZ], *tp;

  saw_digit   = 0;
  octets      = 0;
  *(tp = tmp) = 0;
  while ((ch = *src++) != '\0') {
    const char  *pch;

    if ((pch = strchr (digits, ch)) != NULL) {
      u_int  new = *tp * 10 + (u_int)(pch - digits);

      if (new > 255) {
        return (0);
      }

      *tp = (u_char)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);
}

/* 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  *src,
  u_char      *dst
  )
{
  static const char  xdigits_l[] = "0123456789abcdef",
                     xdigits_u[] = "0123456789ABCDEF";
  u_char      tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
  const char  *xdigits, *curtok;
  int         ch, saw_xdigit;
  u_int       val;

  memset ((tp = 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 = *src++) != '\0') {
    const char  *pch;

    if ((pch = strchr ((xdigits = xdigits_l), ch)) == NULL) {
      pch = strchr ((xdigits = xdigits_u), 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;
      }

      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 = (int)(tp - colonp);
    int        i;

    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);
}
