1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. NET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Definitions for the Ethernet handlers. 7 * 8 * Version: @(#)eth.h 1.0.4 05/13/93 9 * 10 * Authors: Ross Biro 11 * Fred N. van Kempen, <[email protected]> 12 * 13 * Relocated to include/linux where it belongs by Alan Cox 14 * <[email protected]> 15 * 16 * This program is free software; you can redistribute it and/or 17 * modify it under the terms of the GNU General Public License 18 * as published by the Free Software Foundation; either version 19 * 2 of the License, or (at your option) any later version. 20 * 21 * WARNING: This move may well be temporary. This file will get merged with others RSN. 22 * 23 */ 24 #ifndef _LINUX_ETHERDEVICE_H 25 #define _LINUX_ETHERDEVICE_H 26 27 #include <linux/if_ether.h> 28 #include <linux/netdevice.h> 29 #include <linux/random.h> 30 31 #ifdef __KERNEL__ 32 extern int eth_header(struct sk_buff *skb, struct net_device *dev, 33 unsigned short type, void *daddr, 34 void *saddr, unsigned len); 35 extern int eth_rebuild_header(struct sk_buff *skb); 36 extern __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev); 37 extern void eth_header_cache_update(struct hh_cache *hh, struct net_device *dev, 38 unsigned char * haddr); 39 extern int eth_header_cache(struct neighbour *neigh, 40 struct hh_cache *hh); 41 42 extern struct net_device *alloc_etherdev(int sizeof_priv); 43 static inline void eth_copy_and_sum (struct sk_buff *dest, 44 const unsigned char *src, 45 int len, int base) 46 { 47 memcpy (dest->data, src, len); 48 } 49 50 /** 51 * is_zero_ether_addr - Determine if give Ethernet address is all zeros. 52 * @addr: Pointer to a six-byte array containing the Ethernet address 53 * 54 * Return true if the address is all zeroes. 55 */ 56 static inline int is_zero_ether_addr(const u8 *addr) 57 { 58 return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]); 59 } 60 61 /** 62 * is_multicast_ether_addr - Determine if the Ethernet address is a multicast. 63 * @addr: Pointer to a six-byte array containing the Ethernet address 64 * 65 * Return true if the address is a multicast address. 66 * By definition the broadcast address is also a multicast address. 67 */ 68 static inline int is_multicast_ether_addr(const u8 *addr) 69 { 70 return (0x01 & addr[0]); 71 } 72 73 /** 74 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned 75 * one (IEEE 802). 76 * @addr: Pointer to a six-byte array containing the Ethernet address 77 * 78 * Return true if the address is a local address. 79 */ 80 static inline int is_local_ether_addr(const u8 *addr) 81 { 82 return (0x02 & addr[0]); 83 } 84 85 /** 86 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast 87 * @addr: Pointer to a six-byte array containing the Ethernet address 88 * 89 * Return true if the address is the broadcast address. 90 */ 91 static inline int is_broadcast_ether_addr(const u8 *addr) 92 { 93 return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff; 94 } 95 96 /** 97 * is_valid_ether_addr - Determine if the given Ethernet address is valid 98 * @addr: Pointer to a six-byte array containing the Ethernet address 99 * 100 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not 101 * a multicast address, and is not FF:FF:FF:FF:FF:FF. 102 * 103 * Return true if the address is valid. 104 */ 105 static inline int is_valid_ether_addr(const u8 *addr) 106 { 107 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to 108 * explicitly check for it here. */ 109 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr); 110 } 111 112 /** 113 * random_ether_addr - Generate software assigned random Ethernet address 114 * @addr: Pointer to a six-byte array containing the Ethernet address 115 * 116 * Generate a random Ethernet address (MAC) that is not multicast 117 * and has the local assigned bit set. 118 */ 119 static inline void random_ether_addr(u8 *addr) 120 { 121 get_random_bytes (addr, ETH_ALEN); 122 addr [0] &= 0xfe; /* clear multicast bit */ 123 addr [0] |= 0x02; /* set local assignment bit (IEEE802) */ 124 } 125 126 /** 127 * compare_ether_addr - Compare two Ethernet addresses 128 * @addr1: Pointer to a six-byte array containing the Ethernet address 129 * @addr2: Pointer other six-byte array containing the Ethernet address 130 * 131 * Compare two ethernet addresses, returns 0 if equal 132 */ 133 static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2) 134 { 135 const u16 *a = (const u16 *) addr1; 136 const u16 *b = (const u16 *) addr2; 137 138 BUILD_BUG_ON(ETH_ALEN != 6); 139 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0; 140 } 141 #endif /* __KERNEL__ */ 142 143 #endif /* _LINUX_ETHERDEVICE_H */ 144