netfilter: factorize ifname_compare()

We use same not trivial helper function in four places. We can factorize it.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

2 files changed, 3 insertions, 34 deletions

diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index 64a7c6c..4b35dba 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -80,19 +80,7 @@ static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
 static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask)
 {
 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
-	const unsigned long *a = (const unsigned long *)_a;
-	const unsigned long *b = (const unsigned long *)_b;
-	const unsigned long *mask = (const unsigned long *)_mask;
-	unsigned long ret;
-
-	ret = (a[0] ^ b[0]) & mask[0];
-	if (IFNAMSIZ > sizeof(unsigned long))
-		ret |= (a[1] ^ b[1]) & mask[1];
-	if (IFNAMSIZ > 2 * sizeof(unsigned long))
-		ret |= (a[2] ^ b[2]) & mask[2];
-	if (IFNAMSIZ > 3 * sizeof(unsigned long))
-		ret |= (a[3] ^ b[3]) & mask[3];
-	BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
+	unsigned long ret = ifname_compare_aligned(_a, _b, _mask);
 #else
 	unsigned long ret = 0;
 	int i;
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index e5294ae..41c59e3 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -74,25 +74,6 @@ do {								\
 
    Hence the start of any table is given by get_table() below.  */
 
-static unsigned long ifname_compare(const char *_a, const char *_b,
-				    const unsigned char *_mask)
-{
-	const unsigned long *a = (const unsigned long *)_a;
-	const unsigned long *b = (const unsigned long *)_b;
-	const unsigned long *mask = (const unsigned long *)_mask;
-	unsigned long ret;
-
-	ret = (a[0] ^ b[0]) & mask[0];
-	if (IFNAMSIZ > sizeof(unsigned long))
-		ret |= (a[1] ^ b[1]) & mask[1];
-	if (IFNAMSIZ > 2 * sizeof(unsigned long))
-		ret |= (a[2] ^ b[2]) & mask[2];
-	if (IFNAMSIZ > 3 * sizeof(unsigned long))
-		ret |= (a[3] ^ b[3]) & mask[3];
-	BUILD_BUG_ON(IFNAMSIZ > 4 * sizeof(unsigned long));
-	return ret;
-}
-
 /* Returns whether matches rule or not. */
 /* Performance critical - called for every packet */
 static inline bool
@@ -121,7 +102,7 @@ ip_packet_match(const struct iphdr *ip,
 		return false;
 	}
 
-	ret = ifname_compare(indev, ipinfo->iniface, ipinfo->iniface_mask);
+	ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask);
 
 	if (FWINV(ret != 0, IPT_INV_VIA_IN)) {
 		dprintf("VIA in mismatch (%s vs %s).%s\n",
@@ -130,7 +111,7 @@ ip_packet_match(const struct iphdr *ip,
 		return false;
 	}
 
-	ret = ifname_compare(outdev, ipinfo->outiface, ipinfo->outiface_mask);
+	ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask);
 
 	if (FWINV(ret != 0, IPT_INV_VIA_OUT)) {
 		dprintf("VIA out mismatch (%s vs %s).%s\n",