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