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 52 * zeros. 53 */ 54 static inline int is_zero_ether_addr(const u8 *addr) 55 { 56 return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]); 57 } 58 59 /** 60 * is_multicast_ether_addr - Determine if the given Ethernet address is a 61 * multicast address. 62 * 63 * @addr: Pointer to a six-byte array containing the Ethernet address 64 * 65 * Return true if the address is a multicast address. 66 */ 67 static inline int is_multicast_ether_addr(const u8 *addr) 68 { 69 return ((addr[0] != 0xff) && (0x01 & addr[0])); 70 } 71 72 static inline int is_broadcast_ether_addr(const u8 *addr) 73 { 74 return ((addr[0] == 0xff) && (addr[1] == 0xff) && (addr[2] == 0xff) && 75 (addr[3] == 0xff) && (addr[4] == 0xff) && (addr[5] == 0xff)); 76 } 77 78 /** 79 * is_valid_ether_addr - Determine if the given Ethernet address is valid 80 * @addr: Pointer to a six-byte array containing the Ethernet address 81 * 82 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not 83 * a multicast address, and is not FF:FF:FF:FF:FF:FF. 84 * 85 * Return true if the address is valid. 86 */ 87 static inline int is_valid_ether_addr(const u8 *addr) 88 { 89 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to 90 * explicitly check for it here. */ 91 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr); 92 } 93 94 /** 95 * random_ether_addr - Generate software assigned random Ethernet address 96 * @addr: Pointer to a six-byte array containing the Ethernet address 97 * 98 * Generate a random Ethernet address (MAC) that is not multicast 99 * and has the local assigned bit set. 100 */ 101 static inline void random_ether_addr(u8 *addr) 102 { 103 get_random_bytes (addr, ETH_ALEN); 104 addr [0] &= 0xfe; /* clear multicast bit */ 105 addr [0] |= 0x02; /* set local assignment bit (IEEE802) */ 106 } 107 108 /** 109 * compare_ether_addr - Compare two Ethernet addresses 110 * @addr1: Pointer to a six-byte array containing the Ethernet address 111 * @addr2 Pointer other six-byte array containing the Ethernet address 112 * 113 * Compare two ethernet addresses, returns 0 if equal 114 */ 115 static inline unsigned compare_ether_addr(const u8 *_a, const u8 *_b) 116 { 117 const u16 *a = (const u16 *) _a; 118 const u16 *b = (const u16 *) _b; 119 120 BUILD_BUG_ON(ETH_ALEN != 6); 121 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0; 122 } 123 #endif /* __KERNEL__ */ 124 125 #endif /* _LINUX_ETHERDEVICE_H */ 126