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 #include <asm/bitsperlong.h> 30 31 #ifdef __KERNEL__ 32 u32 eth_get_headlen(void *data, unsigned int max_len); 33 __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev); 34 extern const struct header_ops eth_header_ops; 35 36 int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, 37 const void *daddr, const void *saddr, unsigned len); 38 int eth_rebuild_header(struct sk_buff *skb); 39 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr); 40 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, 41 __be16 type); 42 void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev, 43 const unsigned char *haddr); 44 int eth_prepare_mac_addr_change(struct net_device *dev, void *p); 45 void eth_commit_mac_addr_change(struct net_device *dev, void *p); 46 int eth_mac_addr(struct net_device *dev, void *p); 47 int eth_change_mtu(struct net_device *dev, int new_mtu); 48 int eth_validate_addr(struct net_device *dev); 49 50 struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs, 51 unsigned int rxqs); 52 #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1) 53 #define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count) 54 55 struct sk_buff **eth_gro_receive(struct sk_buff **head, 56 struct sk_buff *skb); 57 int eth_gro_complete(struct sk_buff *skb, int nhoff); 58 59 /* Reserved Ethernet Addresses per IEEE 802.1Q */ 60 static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) = 61 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 }; 62 63 /** 64 * is_link_local_ether_addr - Determine if given Ethernet address is link-local 65 * @addr: Pointer to a six-byte array containing the Ethernet address 66 * 67 * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per 68 * IEEE 802.1Q 8.6.3 Frame filtering. 69 * 70 * Please note: addr must be aligned to u16. 71 */ 72 static inline bool is_link_local_ether_addr(const u8 *addr) 73 { 74 __be16 *a = (__be16 *)addr; 75 static const __be16 *b = (const __be16 *)eth_reserved_addr_base; 76 static const __be16 m = cpu_to_be16(0xfff0); 77 78 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) 79 return (((*(const u32 *)addr) ^ (*(const u32 *)b)) | 80 ((a[2] ^ b[2]) & m)) == 0; 81 #else 82 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0; 83 #endif 84 } 85 86 /** 87 * is_zero_ether_addr - Determine if give Ethernet address is all zeros. 88 * @addr: Pointer to a six-byte array containing the Ethernet address 89 * 90 * Return true if the address is all zeroes. 91 * 92 * Please note: addr must be aligned to u16. 93 */ 94 static inline bool is_zero_ether_addr(const u8 *addr) 95 { 96 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) 97 return ((*(const u32 *)addr) | (*(const u16 *)(addr + 4))) == 0; 98 #else 99 return (*(const u16 *)(addr + 0) | 100 *(const u16 *)(addr + 2) | 101 *(const u16 *)(addr + 4)) == 0; 102 #endif 103 } 104 105 /** 106 * is_multicast_ether_addr - Determine if the Ethernet address is a multicast. 107 * @addr: Pointer to a six-byte array containing the Ethernet address 108 * 109 * Return true if the address is a multicast address. 110 * By definition the broadcast address is also a multicast address. 111 */ 112 static inline bool is_multicast_ether_addr(const u8 *addr) 113 { 114 return 0x01 & addr[0]; 115 } 116 117 /** 118 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802). 119 * @addr: Pointer to a six-byte array containing the Ethernet address 120 * 121 * Return true if the address is a local address. 122 */ 123 static inline bool is_local_ether_addr(const u8 *addr) 124 { 125 return 0x02 & addr[0]; 126 } 127 128 /** 129 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast 130 * @addr: Pointer to a six-byte array containing the Ethernet address 131 * 132 * Return true if the address is the broadcast address. 133 * 134 * Please note: addr must be aligned to u16. 135 */ 136 static inline bool is_broadcast_ether_addr(const u8 *addr) 137 { 138 return (*(const u16 *)(addr + 0) & 139 *(const u16 *)(addr + 2) & 140 *(const u16 *)(addr + 4)) == 0xffff; 141 } 142 143 /** 144 * is_unicast_ether_addr - Determine if the Ethernet address is unicast 145 * @addr: Pointer to a six-byte array containing the Ethernet address 146 * 147 * Return true if the address is a unicast address. 148 */ 149 static inline bool is_unicast_ether_addr(const u8 *addr) 150 { 151 return !is_multicast_ether_addr(addr); 152 } 153 154 /** 155 * is_valid_ether_addr - Determine if the given Ethernet address is valid 156 * @addr: Pointer to a six-byte array containing the Ethernet address 157 * 158 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not 159 * a multicast address, and is not FF:FF:FF:FF:FF:FF. 160 * 161 * Return true if the address is valid. 162 * 163 * Please note: addr must be aligned to u16. 164 */ 165 static inline bool is_valid_ether_addr(const u8 *addr) 166 { 167 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to 168 * explicitly check for it here. */ 169 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr); 170 } 171 172 /** 173 * eth_random_addr - Generate software assigned random Ethernet address 174 * @addr: Pointer to a six-byte array containing the Ethernet address 175 * 176 * Generate a random Ethernet address (MAC) that is not multicast 177 * and has the local assigned bit set. 178 */ 179 static inline void eth_random_addr(u8 *addr) 180 { 181 get_random_bytes(addr, ETH_ALEN); 182 addr[0] &= 0xfe; /* clear multicast bit */ 183 addr[0] |= 0x02; /* set local assignment bit (IEEE802) */ 184 } 185 186 #define random_ether_addr(addr) eth_random_addr(addr) 187 188 /** 189 * eth_broadcast_addr - Assign broadcast address 190 * @addr: Pointer to a six-byte array containing the Ethernet address 191 * 192 * Assign the broadcast address to the given address array. 193 */ 194 static inline void eth_broadcast_addr(u8 *addr) 195 { 196 memset(addr, 0xff, ETH_ALEN); 197 } 198 199 /** 200 * eth_zero_addr - Assign zero address 201 * @addr: Pointer to a six-byte array containing the Ethernet address 202 * 203 * Assign the zero address to the given address array. 204 */ 205 static inline void eth_zero_addr(u8 *addr) 206 { 207 memset(addr, 0x00, ETH_ALEN); 208 } 209 210 /** 211 * eth_hw_addr_random - Generate software assigned random Ethernet and 212 * set device flag 213 * @dev: pointer to net_device structure 214 * 215 * Generate a random Ethernet address (MAC) to be used by a net device 216 * and set addr_assign_type so the state can be read by sysfs and be 217 * used by userspace. 218 */ 219 static inline void eth_hw_addr_random(struct net_device *dev) 220 { 221 dev->addr_assign_type = NET_ADDR_RANDOM; 222 eth_random_addr(dev->dev_addr); 223 } 224 225 /** 226 * ether_addr_copy - Copy an Ethernet address 227 * @dst: Pointer to a six-byte array Ethernet address destination 228 * @src: Pointer to a six-byte array Ethernet address source 229 * 230 * Please note: dst & src must both be aligned to u16. 231 */ 232 static inline void ether_addr_copy(u8 *dst, const u8 *src) 233 { 234 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) 235 *(u32 *)dst = *(const u32 *)src; 236 *(u16 *)(dst + 4) = *(const u16 *)(src + 4); 237 #else 238 u16 *a = (u16 *)dst; 239 const u16 *b = (const u16 *)src; 240 241 a[0] = b[0]; 242 a[1] = b[1]; 243 a[2] = b[2]; 244 #endif 245 } 246 247 /** 248 * eth_hw_addr_inherit - Copy dev_addr from another net_device 249 * @dst: pointer to net_device to copy dev_addr to 250 * @src: pointer to net_device to copy dev_addr from 251 * 252 * Copy the Ethernet address from one net_device to another along with 253 * the address attributes (addr_assign_type). 254 */ 255 static inline void eth_hw_addr_inherit(struct net_device *dst, 256 struct net_device *src) 257 { 258 dst->addr_assign_type = src->addr_assign_type; 259 ether_addr_copy(dst->dev_addr, src->dev_addr); 260 } 261 262 /** 263 * ether_addr_equal - Compare two Ethernet addresses 264 * @addr1: Pointer to a six-byte array containing the Ethernet address 265 * @addr2: Pointer other six-byte array containing the Ethernet address 266 * 267 * Compare two Ethernet addresses, returns true if equal 268 * 269 * Please note: addr1 & addr2 must both be aligned to u16. 270 */ 271 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2) 272 { 273 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) 274 u32 fold = ((*(const u32 *)addr1) ^ (*(const u32 *)addr2)) | 275 ((*(const u16 *)(addr1 + 4)) ^ (*(const u16 *)(addr2 + 4))); 276 277 return fold == 0; 278 #else 279 const u16 *a = (const u16 *)addr1; 280 const u16 *b = (const u16 *)addr2; 281 282 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) == 0; 283 #endif 284 } 285 286 /** 287 * ether_addr_equal_64bits - Compare two Ethernet addresses 288 * @addr1: Pointer to an array of 8 bytes 289 * @addr2: Pointer to an other array of 8 bytes 290 * 291 * Compare two Ethernet addresses, returns true if equal, false otherwise. 292 * 293 * The function doesn't need any conditional branches and possibly uses 294 * word memory accesses on CPU allowing cheap unaligned memory reads. 295 * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 } 296 * 297 * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits. 298 */ 299 300 static inline bool ether_addr_equal_64bits(const u8 addr1[6+2], 301 const u8 addr2[6+2]) 302 { 303 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 304 u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2); 305 306 #ifdef __BIG_ENDIAN 307 return (fold >> 16) == 0; 308 #else 309 return (fold << 16) == 0; 310 #endif 311 #else 312 return ether_addr_equal(addr1, addr2); 313 #endif 314 } 315 316 /** 317 * ether_addr_equal_unaligned - Compare two not u16 aligned Ethernet addresses 318 * @addr1: Pointer to a six-byte array containing the Ethernet address 319 * @addr2: Pointer other six-byte array containing the Ethernet address 320 * 321 * Compare two Ethernet addresses, returns true if equal 322 * 323 * Please note: Use only when any Ethernet address may not be u16 aligned. 324 */ 325 static inline bool ether_addr_equal_unaligned(const u8 *addr1, const u8 *addr2) 326 { 327 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) 328 return ether_addr_equal(addr1, addr2); 329 #else 330 return memcmp(addr1, addr2, ETH_ALEN) == 0; 331 #endif 332 } 333 334 /** 335 * is_etherdev_addr - Tell if given Ethernet address belongs to the device. 336 * @dev: Pointer to a device structure 337 * @addr: Pointer to a six-byte array containing the Ethernet address 338 * 339 * Compare passed address with all addresses of the device. Return true if the 340 * address if one of the device addresses. 341 * 342 * Note that this function calls ether_addr_equal_64bits() so take care of 343 * the right padding. 344 */ 345 static inline bool is_etherdev_addr(const struct net_device *dev, 346 const u8 addr[6 + 2]) 347 { 348 struct netdev_hw_addr *ha; 349 bool res = false; 350 351 rcu_read_lock(); 352 for_each_dev_addr(dev, ha) { 353 res = ether_addr_equal_64bits(addr, ha->addr); 354 if (res) 355 break; 356 } 357 rcu_read_unlock(); 358 return res; 359 } 360 #endif /* __KERNEL__ */ 361 362 /** 363 * compare_ether_header - Compare two Ethernet headers 364 * @a: Pointer to Ethernet header 365 * @b: Pointer to Ethernet header 366 * 367 * Compare two Ethernet headers, returns 0 if equal. 368 * This assumes that the network header (i.e., IP header) is 4-byte 369 * aligned OR the platform can handle unaligned access. This is the 370 * case for all packets coming into netif_receive_skb or similar 371 * entry points. 372 */ 373 374 static inline unsigned long compare_ether_header(const void *a, const void *b) 375 { 376 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 377 unsigned long fold; 378 379 /* 380 * We want to compare 14 bytes: 381 * [a0 ... a13] ^ [b0 ... b13] 382 * Use two long XOR, ORed together, with an overlap of two bytes. 383 * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] | 384 * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13] 385 * This means the [a6 a7] ^ [b6 b7] part is done two times. 386 */ 387 fold = *(unsigned long *)a ^ *(unsigned long *)b; 388 fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6); 389 return fold; 390 #else 391 u32 *a32 = (u32 *)((u8 *)a + 2); 392 u32 *b32 = (u32 *)((u8 *)b + 2); 393 394 return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) | 395 (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]); 396 #endif 397 } 398 399 /** 400 * eth_skb_pad - Pad buffer to mininum number of octets for Ethernet frame 401 * @skb: Buffer to pad 402 * 403 * An Ethernet frame should have a minimum size of 60 bytes. This function 404 * takes short frames and pads them with zeros up to the 60 byte limit. 405 */ 406 static inline int eth_skb_pad(struct sk_buff *skb) 407 { 408 return skb_put_padto(skb, ETH_ZLEN); 409 } 410 411 #endif /* _LINUX_ETHERDEVICE_H */ 412