/* $Id: inet_pton.c,v 1.10 2012/10/22 15:15:58 karls Exp $ */

#ifdef HAVE_CONFIG_H
#include "autoconf.h"
#endif /* HAVE_CONFIG_H */

#include "osdep.h"

/*   $OpenBSD: inet_pton.c,v 1.2 1997/04/13 05:08:24 deraadt Exp $   */

/* 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char rcsid[] = "$From: inet_pton.c,v 8.7 1996/08/05 08:31:35 vixie Exp $";
#else
static char rcsid[] = "$OpenBSD: inet_pton.c,v 1.2 1997/04/13 05:08:24 deraadt Exp $";
#endif
#endif /* LIBC_SCCS and not lint */

#ifndef AF_INET6
#define     AF_INET6  24     /* IPv6 */
#endif /* !AF_INET6 */
#ifndef INADDRSZ
#define INADDRSZ        4               /* IPv4 T_A */
#endif /* !INADDRSZ */
#ifndef IN6ADDRSZ
#define IN6ADDRSZ 16      /* IPv6 T_AAAA */
#endif /* !IN6ADDRSZ */
#ifndef INT16SZ
#define INT16SZ     2     /* for systems without 16-bit ints */
#endif /* !INT16SZ */

/*
 * 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(af, src, dst)
   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(src, dst)
   const char *src;
   u_char *dst;
{
   static const char digits[] = "0123456789";
   int saw_digit, octets, ch;
   u_char tmp[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 + (pch - digits);

         if (new > 255)
            return (0);
         if (! saw_digit) {
            if (++octets > 4)
               return (0);
            saw_digit = 1;
         }
         *tp = new;
      } 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, 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(src, dst)
   const char *src;
   u_char *dst;
{
   static const char xdigits_l[] = "0123456789abcdef",
           xdigits_u[] = "0123456789ABCDEF";
   u_char tmp[IN6ADDRSZ], *tp, *endp, *colonp;
   const char *xdigits, *curtok;
   int ch, saw_xdigit;
   u_int val;

   memset((tp = tmp), '\0', IN6ADDRSZ);
   endp = tp + 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 + INT16SZ > endp)
            return (0);
         *tp++ = (u_char) (val >> 8) & 0xff;
         *tp++ = (u_char) val & 0xff;
         saw_xdigit = 0;
         val = 0;
         continue;
      }
      if (ch == '.' && ((tp + INADDRSZ) <= endp) &&
          inet_pton4(curtok, tp) > 0) {
         tp += INADDRSZ;
         saw_xdigit = 0;
         break;   /* '\0' was seen by inet_pton4(). */
      }
      return (0);
   }
   if (saw_xdigit) {
      if (tp + 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;

      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, IN6ADDRSZ);
   return (1);
}
