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 */ 22 #ifndef _LINUX_ETHERDEVICE_H 23 #define _LINUX_ETHERDEVICE_H 24 25 #include <linux/if_ether.h> 26 #include <linux/netdevice.h> 27 #include <linux/random.h> 28 #include <asm/unaligned.h> 29 30 #ifdef __KERNEL__ 31 extern __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev); 32 extern const struct header_ops eth_header_ops; 33 34 extern int eth_header(struct sk_buff *skb, struct net_device *dev, 35 unsigned short type, 36 const void *daddr, const void *saddr, unsigned len); 37 extern int eth_rebuild_header(struct sk_buff *skb); 38 extern int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr); 39 extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type); 40 extern void eth_header_cache_update(struct hh_cache *hh, 41 const struct net_device *dev, 42 const unsigned char *haddr); 43 extern int eth_mac_addr(struct net_device *dev, void *p); 44 extern int eth_change_mtu(struct net_device *dev, int new_mtu); 45 extern int eth_validate_addr(struct net_device *dev); 46 47 48 49 extern struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs, 50 unsigned int rxqs); 51 #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1) 52 #define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count) 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 */ 60 static inline bool 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 */ 72 static inline bool 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 */ 83 static inline bool 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 */ 94 static inline bool 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_unicast_ether_addr - Determine if the Ethernet address is unicast 101 * @addr: Pointer to a six-byte array containing the Ethernet address 102 * 103 * Return true if the address is a unicast address. 104 */ 105 static inline bool is_unicast_ether_addr(const u8 *addr) 106 { 107 return !is_multicast_ether_addr(addr); 108 } 109 110 /** 111 * is_valid_ether_addr - Determine if the given Ethernet address is valid 112 * @addr: Pointer to a six-byte array containing the Ethernet address 113 * 114 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not 115 * a multicast address, and is not FF:FF:FF:FF:FF:FF. 116 * 117 * Return true if the address is valid. 118 */ 119 static inline bool is_valid_ether_addr(const u8 *addr) 120 { 121 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to 122 * explicitly check for it here. */ 123 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr); 124 } 125 126 /** 127 * eth_random_addr - Generate software assigned random Ethernet address 128 * @addr: Pointer to a six-byte array containing the Ethernet address 129 * 130 * Generate a random Ethernet address (MAC) that is not multicast 131 * and has the local assigned bit set. 132 */ 133 static inline void eth_random_addr(u8 *addr) 134 { 135 get_random_bytes(addr, ETH_ALEN); 136 addr[0] &= 0xfe; /* clear multicast bit */ 137 addr[0] |= 0x02; /* set local assignment bit (IEEE802) */ 138 } 139 140 #define random_ether_addr(addr) eth_random_addr(addr) 141 142 /** 143 * eth_broadcast_addr - Assign broadcast address 144 * @addr: Pointer to a six-byte array containing the Ethernet address 145 * 146 * Assign the broadcast address to the given address array. 147 */ 148 static inline void eth_broadcast_addr(u8 *addr) 149 { 150 memset(addr, 0xff, ETH_ALEN); 151 } 152 153 /** 154 * eth_zero_addr - Assign zero address 155 * @addr: Pointer to a six-byte array containing the Ethernet address 156 * 157 * Assign the zero address to the given address array. 158 */ 159 static inline void eth_zero_addr(u8 *addr) 160 { 161 memset(addr, 0x00, ETH_ALEN); 162 } 163 164 /** 165 * eth_hw_addr_random - Generate software assigned random Ethernet and 166 * set device flag 167 * @dev: pointer to net_device structure 168 * 169 * Generate a random Ethernet address (MAC) to be used by a net device 170 * and set addr_assign_type so the state can be read by sysfs and be 171 * used by userspace. 172 */ 173 static inline void eth_hw_addr_random(struct net_device *dev) 174 { 175 dev->addr_assign_type |= NET_ADDR_RANDOM; 176 eth_random_addr(dev->dev_addr); 177 } 178 179 /** 180 * compare_ether_addr - Compare two Ethernet addresses 181 * @addr1: Pointer to a six-byte array containing the Ethernet address 182 * @addr2: Pointer other six-byte array containing the Ethernet address 183 * 184 * Compare two Ethernet addresses, returns 0 if equal, non-zero otherwise. 185 * Unlike memcmp(), it doesn't return a value suitable for sorting. 186 */ 187 static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2) 188 { 189 const u16 *a = (const u16 *) addr1; 190 const u16 *b = (const u16 *) addr2; 191 192 BUILD_BUG_ON(ETH_ALEN != 6); 193 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0; 194 } 195 196 /** 197 * ether_addr_equal - Compare two Ethernet addresses 198 * @addr1: Pointer to a six-byte array containing the Ethernet address 199 * @addr2: Pointer other six-byte array containing the Ethernet address 200 * 201 * Compare two Ethernet addresses, returns true if equal 202 */ 203 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2) 204 { 205 return !compare_ether_addr(addr1, addr2); 206 } 207 208 static inline unsigned long zap_last_2bytes(unsigned long value) 209 { 210 #ifdef __BIG_ENDIAN 211 return value >> 16; 212 #else 213 return value << 16; 214 #endif 215 } 216 217 /** 218 * ether_addr_equal_64bits - Compare two Ethernet addresses 219 * @addr1: Pointer to an array of 8 bytes 220 * @addr2: Pointer to an other array of 8 bytes 221 * 222 * Compare two Ethernet addresses, returns true if equal, false otherwise. 223 * 224 * The function doesn't need any conditional branches and possibly uses 225 * word memory accesses on CPU allowing cheap unaligned memory reads. 226 * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 } 227 * 228 * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits. 229 */ 230 231 static inline bool ether_addr_equal_64bits(const u8 addr1[6+2], 232 const u8 addr2[6+2]) 233 { 234 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 235 unsigned long fold = ((*(unsigned long *)addr1) ^ 236 (*(unsigned long *)addr2)); 237 238 if (sizeof(fold) == 8) 239 return zap_last_2bytes(fold) == 0; 240 241 fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^ 242 (*(unsigned long *)(addr2 + 4))); 243 return fold == 0; 244 #else 245 return ether_addr_equal(addr1, addr2); 246 #endif 247 } 248 249 /** 250 * is_etherdev_addr - Tell if given Ethernet address belongs to the device. 251 * @dev: Pointer to a device structure 252 * @addr: Pointer to a six-byte array containing the Ethernet address 253 * 254 * Compare passed address with all addresses of the device. Return true if the 255 * address if one of the device addresses. 256 * 257 * Note that this function calls ether_addr_equal_64bits() so take care of 258 * the right padding. 259 */ 260 static inline bool is_etherdev_addr(const struct net_device *dev, 261 const u8 addr[6 + 2]) 262 { 263 struct netdev_hw_addr *ha; 264 bool res = false; 265 266 rcu_read_lock(); 267 for_each_dev_addr(dev, ha) { 268 res = ether_addr_equal_64bits(addr, ha->addr); 269 if (res) 270 break; 271 } 272 rcu_read_unlock(); 273 return res; 274 } 275 #endif /* __KERNEL__ */ 276 277 /** 278 * compare_ether_header - Compare two Ethernet headers 279 * @a: Pointer to Ethernet header 280 * @b: Pointer to Ethernet header 281 * 282 * Compare two Ethernet headers, returns 0 if equal. 283 * This assumes that the network header (i.e., IP header) is 4-byte 284 * aligned OR the platform can handle unaligned access. This is the 285 * case for all packets coming into netif_receive_skb or similar 286 * entry points. 287 */ 288 289 static inline unsigned long compare_ether_header(const void *a, const void *b) 290 { 291 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 292 unsigned long fold; 293 294 /* 295 * We want to compare 14 bytes: 296 * [a0 ... a13] ^ [b0 ... b13] 297 * Use two long XOR, ORed together, with an overlap of two bytes. 298 * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] | 299 * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13] 300 * This means the [a6 a7] ^ [b6 b7] part is done two times. 301 */ 302 fold = *(unsigned long *)a ^ *(unsigned long *)b; 303 fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6); 304 return fold; 305 #else 306 u32 *a32 = (u32 *)((u8 *)a + 2); 307 u32 *b32 = (u32 *)((u8 *)b + 2); 308 309 return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) | 310 (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]); 311 #endif 312 } 313 314 #endif /* _LINUX_ETHERDEVICE_H */ 315