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_mqs(int sizeof_priv, unsigned int txqs, 52 unsigned int rxqs); 53#define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1) 54#define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count) 55 56/** 57 * is_zero_ether_addr - Determine if give Ethernet address is all zeros. 58 * @addr: Pointer to a six-byte array containing the Ethernet address 59 * 60 * Return true if the address is all zeroes. 61 */ 62static inline int is_zero_ether_addr(const u8 *addr) 63{ 64 return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]); 65} 66 67/** 68 * is_multicast_ether_addr - Determine if the Ethernet address is a multicast. 69 * @addr: Pointer to a six-byte array containing the Ethernet address 70 * 71 * Return true if the address is a multicast address. 72 * By definition the broadcast address is also a multicast address. 73 */ 74static inline int is_multicast_ether_addr(const u8 *addr) 75{ 76 return 0x01 & addr[0]; 77} 78 79/** 80 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802). 81 * @addr: Pointer to a six-byte array containing the Ethernet address 82 * 83 * Return true if the address is a local address. 84 */ 85static inline int is_local_ether_addr(const u8 *addr) 86{ 87 return 0x02 & addr[0]; 88} 89 90/** 91 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast 92 * @addr: Pointer to a six-byte array containing the Ethernet address 93 * 94 * Return true if the address is the broadcast address. 95 */ 96static inline int is_broadcast_ether_addr(const u8 *addr) 97{ 98 return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff; 99} 100 101/** 102 * is_unicast_ether_addr - Determine if the Ethernet address is unicast 103 * @addr: Pointer to a six-byte array containing the Ethernet address 104 * 105 * Return true if the address is a unicast address. 106 */ 107static inline int is_unicast_ether_addr(const u8 *addr) 108{ 109 return !is_multicast_ether_addr(addr); 110} 111 112/** 113 * is_valid_ether_addr - Determine if the given Ethernet address is valid 114 * @addr: Pointer to a six-byte array containing the Ethernet address 115 * 116 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not 117 * a multicast address, and is not FF:FF:FF:FF:FF:FF. 118 * 119 * Return true if the address is valid. 120 */ 121static inline int is_valid_ether_addr(const u8 *addr) 122{ 123 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to 124 * explicitly check for it here. */ 125 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr); 126} 127 128/** 129 * random_ether_addr - Generate software assigned random Ethernet address 130 * @addr: Pointer to a six-byte array containing the Ethernet address 131 * 132 * Generate a random Ethernet address (MAC) that is not multicast 133 * and has the local assigned bit set. 134 */ 135static inline void random_ether_addr(u8 *addr) 136{ 137 get_random_bytes (addr, ETH_ALEN); 138 addr [0] &= 0xfe; /* clear multicast bit */ 139 addr [0] |= 0x02; /* set local assignment bit (IEEE802) */ 140} 141 142/** 143 * dev_hw_addr_random - Create random MAC and set device flag 144 * @dev: pointer to net_device structure 145 * @hwaddr: Pointer to a six-byte array containing the Ethernet address 146 * 147 * Generate random MAC to be used by a device and set addr_assign_type 148 * so the state can be read by sysfs and be used by udev. 149 */ 150static inline void dev_hw_addr_random(struct net_device *dev, u8 *hwaddr) 151{ 152 dev->addr_assign_type |= NET_ADDR_RANDOM; 153 random_ether_addr(hwaddr); 154} 155 156/** 157 * compare_ether_addr - Compare two Ethernet addresses 158 * @addr1: Pointer to a six-byte array containing the Ethernet address 159 * @addr2: Pointer other six-byte array containing the Ethernet address 160 * 161 * Compare two ethernet addresses, returns 0 if equal 162 */ 163static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2) 164{ 165 const u16 *a = (const u16 *) addr1; 166 const u16 *b = (const u16 *) addr2; 167 168 BUILD_BUG_ON(ETH_ALEN != 6); 169 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0; 170} 171 172static inline unsigned long zap_last_2bytes(unsigned long value) 173{ 174#ifdef __BIG_ENDIAN 175 return value >> 16; 176#else 177 return value << 16; 178#endif 179} 180 181/** 182 * compare_ether_addr_64bits - Compare two Ethernet addresses 183 * @addr1: Pointer to an array of 8 bytes 184 * @addr2: Pointer to an other array of 8 bytes 185 * 186 * Compare two ethernet addresses, returns 0 if equal. 187 * Same result than "memcmp(addr1, addr2, ETH_ALEN)" but without conditional 188 * branches, and possibly long word memory accesses on CPU allowing cheap 189 * unaligned memory reads. 190 * arrays = { byte1, byte2, byte3, byte4, byte6, byte7, pad1, pad2} 191 * 192 * Please note that alignment of addr1 & addr2 is only guaranted to be 16 bits. 193 */ 194 195static inline unsigned compare_ether_addr_64bits(const u8 addr1[6+2], 196 const u8 addr2[6+2]) 197{ 198#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 199 unsigned long fold = ((*(unsigned long *)addr1) ^ 200 (*(unsigned long *)addr2)); 201 202 if (sizeof(fold) == 8) 203 return zap_last_2bytes(fold) != 0; 204 205 fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^ 206 (*(unsigned long *)(addr2 + 4))); 207 return fold != 0; 208#else 209 return compare_ether_addr(addr1, addr2); 210#endif 211} 212 213/** 214 * is_etherdev_addr - Tell if given Ethernet address belongs to the device. 215 * @dev: Pointer to a device structure 216 * @addr: Pointer to a six-byte array containing the Ethernet address 217 * 218 * Compare passed address with all addresses of the device. Return true if the 219 * address if one of the device addresses. 220 * 221 * Note that this function calls compare_ether_addr_64bits() so take care of 222 * the right padding. 223 */ 224static inline bool is_etherdev_addr(const struct net_device *dev, 225 const u8 addr[6 + 2]) 226{ 227 struct netdev_hw_addr *ha; 228 int res = 1; 229 230 rcu_read_lock(); 231 for_each_dev_addr(dev, ha) { 232 res = compare_ether_addr_64bits(addr, ha->addr); 233 if (!res) 234 break; 235 } 236 rcu_read_unlock(); 237 return !res; 238} 239#endif /* __KERNEL__ */ 240 241/** 242 * compare_ether_header - Compare two Ethernet headers 243 * @a: Pointer to Ethernet header 244 * @b: Pointer to Ethernet header 245 * 246 * Compare two ethernet headers, returns 0 if equal. 247 * This assumes that the network header (i.e., IP header) is 4-byte 248 * aligned OR the platform can handle unaligned access. This is the 249 * case for all packets coming into netif_receive_skb or similar 250 * entry points. 251 */ 252 253static inline unsigned long compare_ether_header(const void *a, const void *b) 254{ 255#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 256 unsigned long fold; 257 258 /* 259 * We want to compare 14 bytes: 260 * [a0 ... a13] ^ [b0 ... b13] 261 * Use two long XOR, ORed together, with an overlap of two bytes. 262 * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] | 263 * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13] 264 * This means the [a6 a7] ^ [b6 b7] part is done two times. 265 */ 266 fold = *(unsigned long *)a ^ *(unsigned long *)b; 267 fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6); 268 return fold; 269#else 270 u32 *a32 = (u32 *)((u8 *)a + 2); 271 u32 *b32 = (u32 *)((u8 *)b + 2); 272 273 return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) | 274 (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]); 275#endif 276} 277 278#endif /* _LINUX_ETHERDEVICE_H */ 279