lib: fix endianness bug in prefix.c

While defining two "maskbytes" arrays for the respective endiannesses,
the code was unconditionally using one that only worked on little endian
systems.

Use preprocessor macros to avoid the somewhat expensive
htonl/ntohl macros.

From: Renato Westphal <renatowestphal@gmail.com>
Signed-off-by: David Lamparter <equinox@diac24.net>
This commit is contained in:
Renato Westphal 2012-03-23 16:27:40 -03:00 committed by David Lamparter
parent aee567450e
commit fe67e66888

View File

@ -31,7 +31,7 @@
/* Maskbit. */
static const u_char maskbit[] = {0x00, 0x80, 0xc0, 0xe0, 0xf0,
0xf8, 0xfc, 0xfe, 0xff};
static const u_int32_t maskbytes_host[] =
static const u_int32_t maskbytes_big_endian[] =
{
0x00000000, /* /0 0.0.0.0 */
0x80000000, /* /1 128.0.0.0 */
@ -67,7 +67,8 @@ static const u_int32_t maskbytes_host[] =
0xfffffffe, /* /31 255.255.255.254 */
0xffffffff /* /32 255.255.255.255 */
};
static const u_int32_t maskbytes_network[] =
static const u_int32_t maskbytes_little_endian[] =
{
0x00000000, /* /0 0.0.0.0 */
0x00000080, /* /1 128.0.0.0 */
@ -103,6 +104,7 @@ static const u_int32_t maskbytes_network[] =
0xfeffffff, /* /31 255.255.255.254 */
0xffffffff /* /32 255.255.255.255 */
};
static const struct in6_addr maskbytes6[] =
{
/* /0 */ { { { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 } } },
@ -2599,7 +2601,11 @@ void
masklen2ip (const int masklen, struct in_addr *netmask)
{
assert (masklen >= 0 && masklen <= IPV4_MAX_BITLEN);
netmask->s_addr = maskbytes_network[masklen];
#if (BYTE_ORDER == LITTLE_ENDIAN)
netmask->s_addr = maskbytes_little_endian[masklen];
#elif (BYTE_ORDER == BIG_ENDIAN)
netmask->s_addr = maskbytes_big_endian[masklen];
#endif
}
/* Convert IP address's netmask into integer. We assume netmask is
@ -2621,7 +2627,11 @@ void
apply_mask_ipv4 (struct prefix_ipv4 *p)
{
assert (p->prefixlen >= 0 && p->prefixlen <= IPV4_MAX_BITLEN);
p->prefix.s_addr &= maskbytes_network[p->prefixlen];
#if (BYTE_ORDER == LITTLE_ENDIAN)
p->prefix.s_addr &= maskbytes_little_endian[p->prefixlen];
#elif (BYTE_ORDER == BIG_ENDIAN)
p->prefix.s_addr &= maskbytes_big_endian[p->prefixlen];
#endif
}
/* If prefix is 0.0.0.0/0 then return 1 else return 0. */