Author: melifaro
Date: Tue Dec 17 22:16:27 2013
New Revision: 259528
URL: http://svnweb.freebsd.org/changeset/base/259528
Log:
Simplify contiguous mask checking.
Suggested by: glebius
MFC after: 2 weeks
Modified:
head/sys/net/radix.c
Modified: head/sys/net/radix.c
==============================================================================
--- head/sys/net/radix.c Tue Dec 17 21:41:23 2013 (r259527)
+++ head/sys/net/radix.c Tue Dec 17 22:16:27 2013 (r259528)
@@ -484,13 +484,13 @@ on1:
struct radix_node *
rn_addmask(void *n_arg, struct radix_node_head *maskhead, int search, int skip)
{
- caddr_t netmask = (caddr_t)n_arg;
- register struct radix_node *x;
- register caddr_t cp, cplim;
- register int b = 0, mlen, j;
+ unsigned char *netmask = n_arg;
+ unsigned char *cp, *cplim;
+ struct radix_node *x;
+ int b = 0, mlen, j;
int maskduplicated, isnormal;
struct radix_node *saved_x;
- char addmask_key[RADIX_MAX_KEY_LEN];
+ unsigned char addmask_key[RADIX_MAX_KEY_LEN];
if ((mlen = LEN(netmask)) > RADIX_MAX_KEY_LEN)
mlen = RADIX_MAX_KEY_LEN;
@@ -532,20 +532,18 @@ rn_addmask(void *n_arg, struct radix_nod
* Calculate index of mask, and check for normalcy.
* First find the first byte with a 0 bit, then if there are
* more bits left (remember we already trimmed the trailing 0's),
- * the pattern must be one of those in normal_chars[], or we have
+ * the bits should be contiguous, otherwise we have got
* a non-contiguous mask.
*/
+#define CONTIG(_c) (((~(_c) + 1) & (_c)) == (unsigned char)(~(_c)
+ 1))
cplim = netmask + mlen;
isnormal = 1;
for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
cp++;
if (cp != cplim) {
- static char normal_chars[] = {
- 0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};
-
for (j = 0x80; (j & *cp) != 0; j >>= 1)
b++;
- if (*cp != normal_chars[b] || cp != (cplim - 1))
+ if (!CONTIG(*cp) || cp != (cplim - 1))
isnormal = 0;
}
b += (cp - netmask) << 3;
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