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, <waltje@uWalt.NL.Mugnet.ORG> 12 * 13 * Relocated to include/linux where it belongs by Alan Cox 14 * <gw4pts@gw4pts.ampr.org> 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#include <asm/unaligned.h> 31 32#ifdef __KERNEL__ 33extern __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev); 34extern const struct header_ops eth_header_ops; 35 36extern int eth_header(struct sk_buff *skb, struct net_device *dev, 37 unsigned short type, 38 const void *daddr, const void *saddr, unsigned len); 39extern int eth_rebuild_header(struct sk_buff *skb); 40extern int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr); 41extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh); 42extern void eth_header_cache_update(struct hh_cache *hh, 43 const struct net_device *dev, 44 const unsigned char *haddr); 45extern int eth_mac_addr(struct net_device *dev, void *p); 46extern int eth_change_mtu(struct net_device *dev, int new_mtu); 47extern int eth_validate_addr(struct net_device *dev); 48 49 50 51extern struct net_device *alloc_etherdev_mq(int sizeof_priv, unsigned int queue_count); 52#define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1) 53 54/** 55 * is_zero_ether_addr - Determine if give Ethernet address is all zeros. 56 * @addr: Pointer to a six-byte array containing the Ethernet address 57 * 58 * Return true if the address is all zeroes. 59 */ 60static inline int is_zero_ether_addr(const u8 *addr) 61{ 62 return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]); 63} 64 65/** 66 * is_multicast_ether_addr - Determine if the Ethernet address is a multicast. 67 * @addr: Pointer to a six-byte array containing the Ethernet address 68 * 69 * Return true if the address is a multicast address. 70 * By definition the broadcast address is also a multicast address. 71 */ 72static inline int is_multicast_ether_addr(const u8 *addr) 73{ 74 return (0x01 & addr[0]); 75} 76 77/** 78 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802). 79 * @addr: Pointer to a six-byte array containing the Ethernet address 80 * 81 * Return true if the address is a local address. 82 */ 83static inline int is_local_ether_addr(const u8 *addr) 84{ 85 return (0x02 & addr[0]); 86} 87 88/** 89 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast 90 * @addr: Pointer to a six-byte array containing the Ethernet address 91 * 92 * Return true if the address is the broadcast address. 93 */ 94static inline int is_broadcast_ether_addr(const u8 *addr) 95{ 96 return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff; 97} 98 99/** 100 * is_valid_ether_addr - Determine if the given Ethernet address is valid 101 * @addr: Pointer to a six-byte array containing the Ethernet address 102 * 103 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not 104 * a multicast address, and is not FF:FF:FF:FF:FF:FF. 105 * 106 * Return true if the address is valid. 107 */ 108static inline int is_valid_ether_addr(const u8 *addr) 109{ 110 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to 111 * explicitly check for it here. */ 112 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr); 113} 114 115/** 116 * random_ether_addr - Generate software assigned random Ethernet address 117 * @addr: Pointer to a six-byte array containing the Ethernet address 118 * 119 * Generate a random Ethernet address (MAC) that is not multicast 120 * and has the local assigned bit set. 121 */ 122static inline void random_ether_addr(u8 *addr) 123{ 124 get_random_bytes (addr, ETH_ALEN); 125 addr [0] &= 0xfe; /* clear multicast bit */ 126 addr [0] |= 0x02; /* set local assignment bit (IEEE802) */ 127} 128 129/** 130 * dev_hw_addr_random - Create random MAC and set device flag 131 * @dev: pointer to net_device structure 132 * @hwaddr: Pointer to a six-byte array containing the Ethernet address 133 * 134 * Generate random MAC to be used by a device and set addr_assign_type 135 * so the state can be read by sysfs and be used by udev. 136 */ 137static inline void dev_hw_addr_random(struct net_device *dev, u8 *hwaddr) 138{ 139 dev->addr_assign_type |= NET_ADDR_RANDOM; 140 random_ether_addr(hwaddr); 141} 142 143/** 144 * compare_ether_addr - Compare two Ethernet addresses 145 * @addr1: Pointer to a six-byte array containing the Ethernet address 146 * @addr2: Pointer other six-byte array containing the Ethernet address 147 * 148 * Compare two ethernet addresses, returns 0 if equal 149 */ 150static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2) 151{ 152 const u16 *a = (const u16 *) addr1; 153 const u16 *b = (const u16 *) addr2; 154 155 BUILD_BUG_ON(ETH_ALEN != 6); 156 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0; 157} 158 159static inline unsigned long zap_last_2bytes(unsigned long value) 160{ 161#ifdef __BIG_ENDIAN 162 return value >> 16; 163#else 164 return value << 16; 165#endif 166} 167 168/** 169 * compare_ether_addr_64bits - Compare two Ethernet addresses 170 * @addr1: Pointer to an array of 8 bytes 171 * @addr2: Pointer to an other array of 8 bytes 172 * 173 * Compare two ethernet addresses, returns 0 if equal. 174 * Same result than "memcmp(addr1, addr2, ETH_ALEN)" but without conditional 175 * branches, and possibly long word memory accesses on CPU allowing cheap 176 * unaligned memory reads. 177 * arrays = { byte1, byte2, byte3, byte4, byte6, byte7, pad1, pad2} 178 * 179 * Please note that alignment of addr1 & addr2 is only guaranted to be 16 bits. 180 */ 181 182static inline unsigned compare_ether_addr_64bits(const u8 addr1[6+2], 183 const u8 addr2[6+2]) 184{ 185#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 186 unsigned long fold = ((*(unsigned long *)addr1) ^ 187 (*(unsigned long *)addr2)); 188 189 if (sizeof(fold) == 8) 190 return zap_last_2bytes(fold) != 0; 191 192 fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^ 193 (*(unsigned long *)(addr2 + 4))); 194 return fold != 0; 195#else 196 return compare_ether_addr(addr1, addr2); 197#endif 198} 199 200/** 201 * is_etherdev_addr - Tell if given Ethernet address belongs to the device. 202 * @dev: Pointer to a device structure 203 * @addr: Pointer to a six-byte array containing the Ethernet address 204 * 205 * Compare passed address with all addresses of the device. Return true if the 206 * address if one of the device addresses. 207 * 208 * Note that this function calls compare_ether_addr_64bits() so take care of 209 * the right padding. 210 */ 211static inline bool is_etherdev_addr(const struct net_device *dev, 212 const u8 addr[6 + 2]) 213{ 214 struct netdev_hw_addr *ha; 215 int res = 1; 216 217 rcu_read_lock(); 218 for_each_dev_addr(dev, ha) { 219 res = compare_ether_addr_64bits(addr, ha->addr); 220 if (!res) 221 break; 222 } 223 rcu_read_unlock(); 224 return !res; 225} 226#endif /* __KERNEL__ */ 227 228/** 229 * compare_ether_header - Compare two Ethernet headers 230 * @a: Pointer to Ethernet header 231 * @b: Pointer to Ethernet header 232 * 233 * Compare two ethernet headers, returns 0 if equal. 234 * This assumes that the network header (i.e., IP header) is 4-byte 235 * aligned OR the platform can handle unaligned access. This is the 236 * case for all packets coming into netif_receive_skb or similar 237 * entry points. 238 */ 239 240static inline int compare_ether_header(const void *a, const void *b) 241{ 242 u32 *a32 = (u32 *)((u8 *)a + 2); 243 u32 *b32 = (u32 *)((u8 *)b + 2); 244 245 return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) | 246 (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]); 247} 248 249#endif /* _LINUX_ETHERDEVICE_H */ 250