From 79165121bc09c209451487d977df910c4ff6fc94 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Sun, 29 May 2005 20:24:30 -0700 Subject: [PATCH] [NET]: Add is_multicast_ether_addr() in include/linux/etherdevice.h This patch adds is_multicast_ether_addr() to go along with is_valid_ether_addr() and friends. It then changes is_valid_ether_addr() to use the new macro, and fixes up the comment on that function to move implementation details out of the API doco. Signed-off-by: Michael Ellerman Signed-off-by: David S. Miller --- include/linux/etherdevice.h | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h index 220748b7abea..a1478258d002 100644 --- a/include/linux/etherdevice.h +++ b/include/linux/etherdevice.h @@ -55,19 +55,33 @@ static inline int is_zero_ether_addr(const u8 *addr) return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]); } +/** + * is_multicast_ether_addr - Determine if the given Ethernet address is a + * multicast address. + * + * @addr: Pointer to a six-byte array containing the Ethernet address + * + * Return true if the address is a multicast address. + */ +static inline int is_multicast_ether_addr(const u8 *addr) +{ + return addr[0] & 0x01; +} + /** * is_valid_ether_addr - Determine if the given Ethernet address is valid * @addr: Pointer to a six-byte array containing the Ethernet address * * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not - * a multicast address, and is not FF:FF:FF:FF:FF:FF. The multicast - * and FF:FF:... tests are combined into the single test "!(addr[0]&1)". + * a multicast address, and is not FF:FF:FF:FF:FF:FF. * * Return true if the address is valid. */ static inline int is_valid_ether_addr(const u8 *addr) { - return !(addr[0]&1) && !is_zero_ether_addr(addr); + /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to + * explicitly check for it here. */ + return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr); } /** @@ -83,6 +97,6 @@ static inline void random_ether_addr(u8 *addr) addr [0] &= 0xfe; /* clear multicast bit */ addr [0] |= 0x02; /* set local assignment bit (IEEE802) */ } -#endif +#endif /* __KERNEL__ */ #endif /* _LINUX_ETHERDEVICE_H */ -- 2.30.2