/*
 * Copyright (c) 1983, 1990 Regents of the University of California.
 * 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 the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 THE REGENTS 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 sccsid[] = "@(#)inet_addr.c 5.10 (Berkeley) 2/24/91";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ctype.h>

/*
 * Ascii internet address interpretation routine.
 * The value returned is in network order.
 */
in_addr_t
inet_addr(const char *cp)
{
  struct in_addr val;

  if (inet_aton(cp, &val))
    return (val.s_addr);
  return (in_addr_t)-1;
}

/*
 * Check whether "cp" is a valid ascii representation
 * of an Internet address and convert to a binary address.
 * Returns 1 if the address is valid, 0 if not.
 * This replaces inet_addr, the return value from which
 * cannot distinguish between failure and a local broadcast address.
 */
int
inet_aton(const char *cp, struct in_addr *addr)
{
  u_long parts[4], val, base, n, *pp = parts;
  char c;

  for (;;) {
    /*
     * Collect number up to ``.''.
     * Values are specified as for C:
     * 0x=hex, 0=octal, other=decimal.
     */
    val = 0; base = 10;
    if (*cp == '0') {
      if (*++cp == 'x' || *cp == 'X')
        base = 16, cp++;
      else
        base = 8;
    }
    while ((c = *cp) != '\0') {
      if (isascii(c) && isdigit(c)) {
        val = (val * base) + (c - '0');
        cp++;
        continue;
      }
      if (base == 16 && isascii(c) && isxdigit(c)) {
        val = (val << 4) +
          (c + 10 - (islower(c) ? 'a' : 'A'));
        cp++;
        continue;
      }
      break;
    }
    if (*cp == '.') {
      /*
       * Internet format:
       *  a.b.c.d
       *  a.b.c  (with c treated as 16-bits)
       *  a.b  (with b treated as 24 bits)
       */
      if (pp >= parts + 3 || val > 0xff)
        return (0);
      *pp++ = val, cp++;
    } else
      break;
  }

  /*
   * Check for trailing characters.
   */
  if (*cp && (!isascii(*cp) || !isspace(*cp)))
    return (0);

  /*
   * Concoct the address according to
   * the number of parts specified.
   */
  n = pp - parts + 1;
  switch (n) {

  case 1:       /* a -- 32 bits */
    break;

  case 2:       /* a.b -- 8.24 bits */
    if (val > 0xffffff)
      return (0);
    val |= parts[0] << 24;
    break;

  case 3:       /* a.b.c -- 8.8.16 bits */
    if (val > 0xffff)
      return (0);
    val |= (parts[0] << 24) | (parts[1] << 16);
    break;

  case 4:       /* a.b.c.d -- 8.8.8.8 bits */
    if (val > 0xff)
      return (0);
    val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
    break;
  }
  if (addr)
    addr->s_addr = htonl(val);

  return 1;
}
