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 __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev); 32 extern const struct header_ops eth_header_ops; 33 34 int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, 35 const void *daddr, const void *saddr, unsigned len); 36 int eth_rebuild_header(struct sk_buff *skb); 37 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr); 38 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, 39 __be16 type); 40 void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev, 41 const unsigned char *haddr); 42 int eth_prepare_mac_addr_change(struct net_device *dev, void *p); 43 void eth_commit_mac_addr_change(struct net_device *dev, void *p); 44 int eth_mac_addr(struct net_device *dev, void *p); 45 int eth_change_mtu(struct net_device *dev, int new_mtu); 46 int eth_validate_addr(struct net_device *dev); 47 48 struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs, 49 unsigned int rxqs); 50 #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1) 51 #define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count) 52 53 /* Reserved Ethernet Addresses per IEEE 802.1Q */ 54 static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) = 55 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 }; 56 57 /** 58 * is_link_local_ether_addr - Determine if given Ethernet address is link-local 59 * @addr: Pointer to a six-byte array containing the Ethernet address 60 * 61 * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per 62 * IEEE 802.1Q 8.6.3 Frame filtering. 63 */ 64 static inline bool is_link_local_ether_addr(const u8 *addr) 65 { 66 __be16 *a = (__be16 *)addr; 67 static const __be16 *b = (const __be16 *)eth_reserved_addr_base; 68 static const __be16 m = cpu_to_be16(0xfff0); 69 70 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0; 71 } 72 73 /** 74 * is_zero_ether_addr - Determine if give Ethernet address is all zeros. 75 * @addr: Pointer to a six-byte array containing the Ethernet address 76 * 77 * Return true if the address is all zeroes. 78 */ 79 static inline bool is_zero_ether_addr(const u8 *addr) 80 { 81 return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]); 82 } 83 84 /** 85 * is_multicast_ether_addr - Determine if the Ethernet address is a multicast. 86 * @addr: Pointer to a six-byte array containing the Ethernet address 87 * 88 * Return true if the address is a multicast address. 89 * By definition the broadcast address is also a multicast address. 90 */ 91 static inline bool is_multicast_ether_addr(const u8 *addr) 92 { 93 return 0x01 & addr[0]; 94 } 95 96 /** 97 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802). 98 * @addr: Pointer to a six-byte array containing the Ethernet address 99 * 100 * Return true if the address is a local address. 101 */ 102 static inline bool is_local_ether_addr(const u8 *addr) 103 { 104 return 0x02 & addr[0]; 105 } 106 107 /** 108 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast 109 * @addr: Pointer to a six-byte array containing the Ethernet address 110 * 111 * Return true if the address is the broadcast address. 112 */ 113 static inline bool is_broadcast_ether_addr(const u8 *addr) 114 { 115 return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff; 116 } 117 118 /** 119 * is_unicast_ether_addr - Determine if the Ethernet address is unicast 120 * @addr: Pointer to a six-byte array containing the Ethernet address 121 * 122 * Return true if the address is a unicast address. 123 */ 124 static inline bool is_unicast_ether_addr(const u8 *addr) 125 { 126 return !is_multicast_ether_addr(addr); 127 } 128 129 /** 130 * is_valid_ether_addr - Determine if the given Ethernet address is valid 131 * @addr: Pointer to a six-byte array containing the Ethernet address 132 * 133 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not 134 * a multicast address, and is not FF:FF:FF:FF:FF:FF. 135 * 136 * Return true if the address is valid. 137 */ 138 static inline bool is_valid_ether_addr(const u8 *addr) 139 { 140 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to 141 * explicitly check for it here. */ 142 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr); 143 } 144 145 /** 146 * eth_random_addr - Generate software assigned random Ethernet address 147 * @addr: Pointer to a six-byte array containing the Ethernet address 148 * 149 * Generate a random Ethernet address (MAC) that is not multicast 150 * and has the local assigned bit set. 151 */ 152 static inline void eth_random_addr(u8 *addr) 153 { 154 get_random_bytes(addr, ETH_ALEN); 155 addr[0] &= 0xfe; /* clear multicast bit */ 156 addr[0] |= 0x02; /* set local assignment bit (IEEE802) */ 157 } 158 159 #define random_ether_addr(addr) eth_random_addr(addr) 160 161 /** 162 * eth_broadcast_addr - Assign broadcast address 163 * @addr: Pointer to a six-byte array containing the Ethernet address 164 * 165 * Assign the broadcast address to the given address array. 166 */ 167 static inline void eth_broadcast_addr(u8 *addr) 168 { 169 memset(addr, 0xff, ETH_ALEN); 170 } 171 172 /** 173 * eth_zero_addr - Assign zero address 174 * @addr: Pointer to a six-byte array containing the Ethernet address 175 * 176 * Assign the zero address to the given address array. 177 */ 178 static inline void eth_zero_addr(u8 *addr) 179 { 180 memset(addr, 0x00, ETH_ALEN); 181 } 182 183 /** 184 * eth_hw_addr_random - Generate software assigned random Ethernet and 185 * set device flag 186 * @dev: pointer to net_device structure 187 * 188 * Generate a random Ethernet address (MAC) to be used by a net device 189 * and set addr_assign_type so the state can be read by sysfs and be 190 * used by userspace. 191 */ 192 static inline void eth_hw_addr_random(struct net_device *dev) 193 { 194 dev->addr_assign_type = NET_ADDR_RANDOM; 195 eth_random_addr(dev->dev_addr); 196 } 197 198 /** 199 * eth_hw_addr_inherit - Copy dev_addr from another net_device 200 * @dst: pointer to net_device to copy dev_addr to 201 * @src: pointer to net_device to copy dev_addr from 202 * 203 * Copy the Ethernet address from one net_device to another along with 204 * the address attributes (addr_assign_type). 205 */ 206 static inline void eth_hw_addr_inherit(struct net_device *dst, 207 struct net_device *src) 208 { 209 dst->addr_assign_type = src->addr_assign_type; 210 memcpy(dst->dev_addr, src->dev_addr, ETH_ALEN); 211 } 212 213 /** 214 * compare_ether_addr - Compare two Ethernet addresses 215 * @addr1: Pointer to a six-byte array containing the Ethernet address 216 * @addr2: Pointer other six-byte array containing the Ethernet address 217 * 218 * Compare two Ethernet addresses, returns 0 if equal, non-zero otherwise. 219 * Unlike memcmp(), it doesn't return a value suitable for sorting. 220 */ 221 static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2) 222 { 223 const u16 *a = (const u16 *) addr1; 224 const u16 *b = (const u16 *) addr2; 225 226 BUILD_BUG_ON(ETH_ALEN != 6); 227 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0; 228 } 229 230 /** 231 * ether_addr_equal - Compare two Ethernet addresses 232 * @addr1: Pointer to a six-byte array containing the Ethernet address 233 * @addr2: Pointer other six-byte array containing the Ethernet address 234 * 235 * Compare two Ethernet addresses, returns true if equal 236 */ 237 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2) 238 { 239 return !compare_ether_addr(addr1, addr2); 240 } 241 242 static inline unsigned long zap_last_2bytes(unsigned long value) 243 { 244 #ifdef __BIG_ENDIAN 245 return value >> 16; 246 #else 247 return value << 16; 248 #endif 249 } 250 251 /** 252 * ether_addr_equal_64bits - Compare two Ethernet addresses 253 * @addr1: Pointer to an array of 8 bytes 254 * @addr2: Pointer to an other array of 8 bytes 255 * 256 * Compare two Ethernet addresses, returns true if equal, false otherwise. 257 * 258 * The function doesn't need any conditional branches and possibly uses 259 * word memory accesses on CPU allowing cheap unaligned memory reads. 260 * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 } 261 * 262 * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits. 263 */ 264 265 static inline bool ether_addr_equal_64bits(const u8 addr1[6+2], 266 const u8 addr2[6+2]) 267 { 268 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 269 unsigned long fold = ((*(unsigned long *)addr1) ^ 270 (*(unsigned long *)addr2)); 271 272 if (sizeof(fold) == 8) 273 return zap_last_2bytes(fold) == 0; 274 275 fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^ 276 (*(unsigned long *)(addr2 + 4))); 277 return fold == 0; 278 #else 279 return ether_addr_equal(addr1, addr2); 280 #endif 281 } 282 283 /** 284 * is_etherdev_addr - Tell if given Ethernet address belongs to the device. 285 * @dev: Pointer to a device structure 286 * @addr: Pointer to a six-byte array containing the Ethernet address 287 * 288 * Compare passed address with all addresses of the device. Return true if the 289 * address if one of the device addresses. 290 * 291 * Note that this function calls ether_addr_equal_64bits() so take care of 292 * the right padding. 293 */ 294 static inline bool is_etherdev_addr(const struct net_device *dev, 295 const u8 addr[6 + 2]) 296 { 297 struct netdev_hw_addr *ha; 298 bool res = false; 299 300 rcu_read_lock(); 301 for_each_dev_addr(dev, ha) { 302 res = ether_addr_equal_64bits(addr, ha->addr); 303 if (res) 304 break; 305 } 306 rcu_read_unlock(); 307 return res; 308 } 309 #endif /* __KERNEL__ */ 310 311 /** 312 * compare_ether_header - Compare two Ethernet headers 313 * @a: Pointer to Ethernet header 314 * @b: Pointer to Ethernet header 315 * 316 * Compare two Ethernet headers, returns 0 if equal. 317 * This assumes that the network header (i.e., IP header) is 4-byte 318 * aligned OR the platform can handle unaligned access. This is the 319 * case for all packets coming into netif_receive_skb or similar 320 * entry points. 321 */ 322 323 static inline unsigned long compare_ether_header(const void *a, const void *b) 324 { 325 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 326 unsigned long fold; 327 328 /* 329 * We want to compare 14 bytes: 330 * [a0 ... a13] ^ [b0 ... b13] 331 * Use two long XOR, ORed together, with an overlap of two bytes. 332 * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] | 333 * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13] 334 * This means the [a6 a7] ^ [b6 b7] part is done two times. 335 */ 336 fold = *(unsigned long *)a ^ *(unsigned long *)b; 337 fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6); 338 return fold; 339 #else 340 u32 *a32 = (u32 *)((u8 *)a + 2); 341 u32 *b32 = (u32 *)((u8 *)b + 2); 342 343 return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) | 344 (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]); 345 #endif 346 } 347 348 #endif /* _LINUX_ETHERDEVICE_H */ 349