From: Renato Westphal <renatowestphal@gmail.com>
Date: Fri, 23 Mar 2012 19:27:40 +0000 (-0300)
Subject: lib: fix endianness bug in prefix.c
X-Git-Tag: frr-2.0-rc1~1872
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=fe67e668881b8b8d71b1570575c913cd287fafcf;p=mirror_frr.git

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>
---

diff --git a/lib/prefix.c b/lib/prefix.c
index 5e8cff04b..fa2d2eb3b 100644
--- a/lib/prefix.c
+++ b/lib/prefix.c
@@ -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. */