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 30#ifdef __KERNEL__ 31extern __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev); 32extern const struct header_ops eth_header_ops; 33 34extern int eth_header(struct sk_buff *skb, struct net_device *dev, 35 unsigned short type, 36 const void *daddr, const void *saddr, unsigned len); 37extern int eth_rebuild_header(struct sk_buff *skb); 38extern int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr); 39extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type); 40extern void eth_header_cache_update(struct hh_cache *hh, 41 const struct net_device *dev, 42 const unsigned char *haddr); 43extern int eth_prepare_mac_addr_change(struct net_device *dev, void *p); 44extern void eth_commit_mac_addr_change(struct net_device *dev, void *p); 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/* Reserved Ethernet Addresses per IEEE 802.1Q */ 57static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) = 58{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 }; 59 60/** 61 * is_link_local_ether_addr - Determine if given Ethernet address is link-local 62 * @addr: Pointer to a six-byte array containing the Ethernet address 63 * 64 * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per 65 * IEEE 802.1Q 8.6.3 Frame filtering. 66 */ 67static inline bool is_link_local_ether_addr(const u8 *addr) 68{ 69 __be16 *a = (__be16 *)addr; 70 static const __be16 *b = (const __be16 *)eth_reserved_addr_base; 71 static const __be16 m = cpu_to_be16(0xfff0); 72 73 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0; 74} 75 76/** 77 * is_zero_ether_addr - Determine if give Ethernet address is all zeros. 78 * @addr: Pointer to a six-byte array containing the Ethernet address 79 * 80 * Return true if the address is all zeroes. 81 */ 82static inline bool is_zero_ether_addr(const u8 *addr) 83{ 84 return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]); 85} 86 87/** 88 * is_multicast_ether_addr - Determine if the Ethernet address is a multicast. 89 * @addr: Pointer to a six-byte array containing the Ethernet address 90 * 91 * Return true if the address is a multicast address. 92 * By definition the broadcast address is also a multicast address. 93 */ 94static inline bool is_multicast_ether_addr(const u8 *addr) 95{ 96 return 0x01 & addr[0]; 97} 98 99/** 100 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802). 101 * @addr: Pointer to a six-byte array containing the Ethernet address 102 * 103 * Return true if the address is a local address. 104 */ 105static inline bool is_local_ether_addr(const u8 *addr) 106{ 107 return 0x02 & addr[0]; 108} 109 110/** 111 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast 112 * @addr: Pointer to a six-byte array containing the Ethernet address 113 * 114 * Return true if the address is the broadcast address. 115 */ 116static inline bool is_broadcast_ether_addr(const u8 *addr) 117{ 118 return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff; 119} 120 121/** 122 * is_unicast_ether_addr - Determine if the Ethernet address is unicast 123 * @addr: Pointer to a six-byte array containing the Ethernet address 124 * 125 * Return true if the address is a unicast address. 126 */ 127static inline bool is_unicast_ether_addr(const u8 *addr) 128{ 129 return !is_multicast_ether_addr(addr); 130} 131 132/** 133 * is_valid_ether_addr - Determine if the given Ethernet address is valid 134 * @addr: Pointer to a six-byte array containing the Ethernet address 135 * 136 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not 137 * a multicast address, and is not FF:FF:FF:FF:FF:FF. 138 * 139 * Return true if the address is valid. 140 */ 141static inline bool is_valid_ether_addr(const u8 *addr) 142{ 143 /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to 144 * explicitly check for it here. */ 145 return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr); 146} 147 148/** 149 * eth_random_addr - Generate software assigned random Ethernet address 150 * @addr: Pointer to a six-byte array containing the Ethernet address 151 * 152 * Generate a random Ethernet address (MAC) that is not multicast 153 * and has the local assigned bit set. 154 */ 155static inline void eth_random_addr(u8 *addr) 156{ 157 get_random_bytes(addr, ETH_ALEN); 158 addr[0] &= 0xfe; /* clear multicast bit */ 159 addr[0] |= 0x02; /* set local assignment bit (IEEE802) */ 160} 161 162#define random_ether_addr(addr) eth_random_addr(addr) 163 164/** 165 * eth_broadcast_addr - Assign broadcast address 166 * @addr: Pointer to a six-byte array containing the Ethernet address 167 * 168 * Assign the broadcast address to the given address array. 169 */ 170static inline void eth_broadcast_addr(u8 *addr) 171{ 172 memset(addr, 0xff, ETH_ALEN); 173} 174 175/** 176 * eth_zero_addr - Assign zero address 177 * @addr: Pointer to a six-byte array containing the Ethernet address 178 * 179 * Assign the zero address to the given address array. 180 */ 181static inline void eth_zero_addr(u8 *addr) 182{ 183 memset(addr, 0x00, ETH_ALEN); 184} 185 186/** 187 * eth_hw_addr_random - Generate software assigned random Ethernet and 188 * set device flag 189 * @dev: pointer to net_device structure 190 * 191 * Generate a random Ethernet address (MAC) to be used by a net device 192 * and set addr_assign_type so the state can be read by sysfs and be 193 * used by userspace. 194 */ 195static inline void eth_hw_addr_random(struct net_device *dev) 196{ 197 dev->addr_assign_type = NET_ADDR_RANDOM; 198 eth_random_addr(dev->dev_addr); 199} 200 201/** 202 * compare_ether_addr - Compare two Ethernet addresses 203 * @addr1: Pointer to a six-byte array containing the Ethernet address 204 * @addr2: Pointer other six-byte array containing the Ethernet address 205 * 206 * Compare two Ethernet addresses, returns 0 if equal, non-zero otherwise. 207 * Unlike memcmp(), it doesn't return a value suitable for sorting. 208 */ 209static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2) 210{ 211 const u16 *a = (const u16 *) addr1; 212 const u16 *b = (const u16 *) addr2; 213 214 BUILD_BUG_ON(ETH_ALEN != 6); 215 return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0; 216} 217 218/** 219 * ether_addr_equal - Compare two Ethernet addresses 220 * @addr1: Pointer to a six-byte array containing the Ethernet address 221 * @addr2: Pointer other six-byte array containing the Ethernet address 222 * 223 * Compare two Ethernet addresses, returns true if equal 224 */ 225static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2) 226{ 227 return !compare_ether_addr(addr1, addr2); 228} 229 230static inline unsigned long zap_last_2bytes(unsigned long value) 231{ 232#ifdef __BIG_ENDIAN 233 return value >> 16; 234#else 235 return value << 16; 236#endif 237} 238 239/** 240 * ether_addr_equal_64bits - Compare two Ethernet addresses 241 * @addr1: Pointer to an array of 8 bytes 242 * @addr2: Pointer to an other array of 8 bytes 243 * 244 * Compare two Ethernet addresses, returns true if equal, false otherwise. 245 * 246 * The function doesn't need any conditional branches and possibly uses 247 * word memory accesses on CPU allowing cheap unaligned memory reads. 248 * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 } 249 * 250 * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits. 251 */ 252 253static inline bool ether_addr_equal_64bits(const u8 addr1[6+2], 254 const u8 addr2[6+2]) 255{ 256#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 257 unsigned long fold = ((*(unsigned long *)addr1) ^ 258 (*(unsigned long *)addr2)); 259 260 if (sizeof(fold) == 8) 261 return zap_last_2bytes(fold) == 0; 262 263 fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^ 264 (*(unsigned long *)(addr2 + 4))); 265 return fold == 0; 266#else 267 return ether_addr_equal(addr1, addr2); 268#endif 269} 270 271/** 272 * is_etherdev_addr - Tell if given Ethernet address belongs to the device. 273 * @dev: Pointer to a device structure 274 * @addr: Pointer to a six-byte array containing the Ethernet address 275 * 276 * Compare passed address with all addresses of the device. Return true if the 277 * address if one of the device addresses. 278 * 279 * Note that this function calls ether_addr_equal_64bits() so take care of 280 * the right padding. 281 */ 282static inline bool is_etherdev_addr(const struct net_device *dev, 283 const u8 addr[6 + 2]) 284{ 285 struct netdev_hw_addr *ha; 286 bool res = false; 287 288 rcu_read_lock(); 289 for_each_dev_addr(dev, ha) { 290 res = ether_addr_equal_64bits(addr, ha->addr); 291 if (res) 292 break; 293 } 294 rcu_read_unlock(); 295 return res; 296} 297#endif /* __KERNEL__ */ 298 299/** 300 * compare_ether_header - Compare two Ethernet headers 301 * @a: Pointer to Ethernet header 302 * @b: Pointer to Ethernet header 303 * 304 * Compare two Ethernet headers, returns 0 if equal. 305 * This assumes that the network header (i.e., IP header) is 4-byte 306 * aligned OR the platform can handle unaligned access. This is the 307 * case for all packets coming into netif_receive_skb or similar 308 * entry points. 309 */ 310 311static inline unsigned long compare_ether_header(const void *a, const void *b) 312{ 313#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64 314 unsigned long fold; 315 316 /* 317 * We want to compare 14 bytes: 318 * [a0 ... a13] ^ [b0 ... b13] 319 * Use two long XOR, ORed together, with an overlap of two bytes. 320 * [a0 a1 a2 a3 a4 a5 a6 a7 ] ^ [b0 b1 b2 b3 b4 b5 b6 b7 ] | 321 * [a6 a7 a8 a9 a10 a11 a12 a13] ^ [b6 b7 b8 b9 b10 b11 b12 b13] 322 * This means the [a6 a7] ^ [b6 b7] part is done two times. 323 */ 324 fold = *(unsigned long *)a ^ *(unsigned long *)b; 325 fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6); 326 return fold; 327#else 328 u32 *a32 = (u32 *)((u8 *)a + 2); 329 u32 *b32 = (u32 *)((u8 *)b + 2); 330 331 return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) | 332 (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]); 333#endif 334} 335 336#endif /* _LINUX_ETHERDEVICE_H */ 337