glibc/inet/inet_addr.c
1995-02-18 01:27:10 +00:00

153 lines
4.2 KiB
C

/*
* Copyright (c) 1983, 1990, 1993
* The 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 8.1 (Berkeley) 6/17/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ctype.h>
/*
* Ascii internet address interpretation routine.
* The value returned is in network order.
*/
u_long
inet_addr(cp)
register const char *cp;
{
struct in_addr val;
if (inet_aton(cp, &val))
return (val.s_addr);
return (INADDR_NONE);
}
/*
* 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(cp, addr)
register const char *cp;
struct in_addr *addr;
{
register u_long val;
register int base, n;
register char c;
u_int parts[4];
register u_int *pp = parts;
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);
}