[src/trunk]: src/usr.sbin/ldpd speed up a little bit the string<->prefixlen t...

[kefren <kefren%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6e38829040e2
branches:  trunk
changeset: 787889:6e38829040e2
user:      kefren <kefren%NetBSD.org@localhost>
date:      Thu Jul 11 09:11:35 2013 +0000

description:
speed up a little bit the string<->prefixlen transforms

diffstat:

 usr.sbin/ldpd/mpls_routes.c |  37 ++++++++++++-------------------------
 1 files changed, 12 insertions(+), 25 deletions(-)

diffs (61 lines):

diff -r 719870495668 -r 6e38829040e2 usr.sbin/ldpd/mpls_routes.c
--- a/usr.sbin/ldpd/mpls_routes.c       Thu Jul 11 08:51:09 2013 +0000
+++ b/usr.sbin/ldpd/mpls_routes.c       Thu Jul 11 09:11:35 2013 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: mpls_routes.c,v 1.10 2013/01/26 17:29:55 kefren Exp $ */
+/* $NetBSD: mpls_routes.c,v 1.11 2013/07/11 09:11:35 kefren Exp $ */
 
 /*-
  * Copyright (c) 2010 The NetBSD Foundation, Inc.
@@ -229,16 +229,13 @@
 uint8_t 
 from_mask_to_cidr(char *mask)
 {
-       /* LoL (although I don't think about something faster right now) */
-       char            mtest[20];
-       uint8_t        i;
+       struct in_addr addr;
+       uint8_t plen = 0;
 
-       for (i = 1; i < 32; i++) {
-               from_cidr_to_mask(i, mtest);
-               if (!strcmp(mask, mtest))
-                       break;
-       }
-       return i;
+       if (inet_aton(mask, &addr) != 0)
+               for (; addr.s_addr; plen++)
+                       addr.s_addr &= addr.s_addr - 1;
+       return plen;
 }
 
 uint8_t
@@ -258,23 +255,13 @@
 void
 from_cidr_to_mask(uint8_t prefixlen, char *mask)
 {
-       uint32_t       a = 0, p = prefixlen;
-       if (prefixlen > 32) {
-               strlcpy(mask, "255.255.255.255", 16);
-               return;
-       }
-       for (; p > 0; p--) {
-               a = a >> (p - 1);
-               a += 1;
-               a = a << (p - 1);
-       }
-       /* is this OK ? */
-#if _BYTE_ORDER == _LITTLE_ENDIAN
-       a = a << (32 - prefixlen);
-#endif
+       uint32_t a = 0;
+       uint8_t plen = prefixlen < 32 ? prefixlen : 32;
 
+       if (plen != 0)
+               a = (0xffffffff >> (32 - plen)) << (32 - plen);
        snprintf(mask, 16, "%d.%d.%d.%d", a >> 24, (a << 8) >> 24,
-           (a << 16) >> 24, (a << 24) >> 24);
+           (a << 16) >> 24, (a << 24) >> 24);  
 }
 
 char *