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| author | Stephen Hemminger <shemminger@linux-foundation.org> | 2007-03-13 00:25:32 +0100 |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-26 07:25:11 +0200 |
| commit | fd74e6ccd522e2f26163eb5ac1abebcab2bd017c (patch) | |
| tree | 12908a8736012d0c7203724c90139615dc221143 | |
| parent | [SK_BUFF]: Introduce ip_hdr(), remove skb->nh.iph (diff) | |
| download | linux-fd74e6ccd522e2f26163eb5ac1abebcab2bd017c.tar.xz linux-fd74e6ccd522e2f26163eb5ac1abebcab2bd017c.zip | |
[BRIDGE]: faster compare for link local addresses
Use logic operations rather than memcmp() to compare destination
address with link local multicast addresses.
Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/bridge/br_input.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 35b94f9a1ac5..a260679afad8 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -112,7 +112,11 @@ static int br_handle_local_finish(struct sk_buff *skb) */ static inline int is_link_local(const unsigned char *dest) { - return memcmp(dest, br_group_address, 5) == 0 && (dest[5] & 0xf0) == 0; + const u16 *a = (const u16 *) dest; + static const u16 *const b = (const u16 *const ) br_group_address; + static const u16 m = __constant_cpu_to_be16(0xfff0); + + return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0; } /* |