linux/include/linux/etherdevice.h
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   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__
  32struct device;
  33int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr);
  34unsigned char *arch_get_platform_get_mac_address(void);
  35u32 eth_get_headlen(void *data, unsigned int max_len);
  36__be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  37extern const struct header_ops eth_header_ops;
  38
  39int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
  40               const void *daddr, const void *saddr, unsigned len);
  41int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
  42int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
  43                     __be16 type);
  44void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev,
  45                             const unsigned char *haddr);
  46int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
  47void eth_commit_mac_addr_change(struct net_device *dev, void *p);
  48int eth_mac_addr(struct net_device *dev, void *p);
  49int eth_change_mtu(struct net_device *dev, int new_mtu);
  50int eth_validate_addr(struct net_device *dev);
  51
  52struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
  53                                            unsigned int rxqs);
  54#define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
  55#define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count)
  56
  57struct sk_buff **eth_gro_receive(struct sk_buff **head,
  58                                 struct sk_buff *skb);
  59int eth_gro_complete(struct sk_buff *skb, int nhoff);
  60
  61/* Reserved Ethernet Addresses per IEEE 802.1Q */
  62static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) =
  63{ 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
  64
  65/**
  66 * is_link_local_ether_addr - Determine if given Ethernet address is link-local
  67 * @addr: Pointer to a six-byte array containing the Ethernet address
  68 *
  69 * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per
  70 * IEEE 802.1Q 8.6.3 Frame filtering.
  71 *
  72 * Please note: addr must be aligned to u16.
  73 */
  74static inline bool is_link_local_ether_addr(const u8 *addr)
  75{
  76        __be16 *a = (__be16 *)addr;
  77        static const __be16 *b = (const __be16 *)eth_reserved_addr_base;
  78        static const __be16 m = cpu_to_be16(0xfff0);
  79
  80#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
  81        return (((*(const u32 *)addr) ^ (*(const u32 *)b)) |
  82                (__force int)((a[2] ^ b[2]) & m)) == 0;
  83#else
  84        return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
  85#endif
  86}
  87
  88/**
  89 * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
  90 * @addr: Pointer to a six-byte array containing the Ethernet address
  91 *
  92 * Return true if the address is all zeroes.
  93 *
  94 * Please note: addr must be aligned to u16.
  95 */
  96static inline bool is_zero_ether_addr(const u8 *addr)
  97{
  98#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
  99        return ((*(const u32 *)addr) | (*(const u16 *)(addr + 4))) == 0;
 100#else
 101        return (*(const u16 *)(addr + 0) |
 102                *(const u16 *)(addr + 2) |
 103                *(const u16 *)(addr + 4)) == 0;
 104#endif
 105}
 106
 107/**
 108 * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
 109 * @addr: Pointer to a six-byte array containing the Ethernet address
 110 *
 111 * Return true if the address is a multicast address.
 112 * By definition the broadcast address is also a multicast address.
 113 */
 114static inline bool is_multicast_ether_addr(const u8 *addr)
 115{
 116#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 117        u32 a = *(const u32 *)addr;
 118#else
 119        u16 a = *(const u16 *)addr;
 120#endif
 121#ifdef __BIG_ENDIAN
 122        return 0x01 & (a >> ((sizeof(a) * 8) - 8));
 123#else
 124        return 0x01 & a;
 125#endif
 126}
 127
 128static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
 129{
 130#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 131#ifdef __BIG_ENDIAN
 132        return 0x01 & ((*(const u64 *)addr) >> 56);
 133#else
 134        return 0x01 & (*(const u64 *)addr);
 135#endif
 136#else
 137        return is_multicast_ether_addr(addr);
 138#endif
 139}
 140
 141/**
 142 * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
 143 * @addr: Pointer to a six-byte array containing the Ethernet address
 144 *
 145 * Return true if the address is a local address.
 146 */
 147static inline bool is_local_ether_addr(const u8 *addr)
 148{
 149        return 0x02 & addr[0];
 150}
 151
 152/**
 153 * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
 154 * @addr: Pointer to a six-byte array containing the Ethernet address
 155 *
 156 * Return true if the address is the broadcast address.
 157 *
 158 * Please note: addr must be aligned to u16.
 159 */
 160static inline bool is_broadcast_ether_addr(const u8 *addr)
 161{
 162        return (*(const u16 *)(addr + 0) &
 163                *(const u16 *)(addr + 2) &
 164                *(const u16 *)(addr + 4)) == 0xffff;
 165}
 166
 167/**
 168 * is_unicast_ether_addr - Determine if the Ethernet address is unicast
 169 * @addr: Pointer to a six-byte array containing the Ethernet address
 170 *
 171 * Return true if the address is a unicast address.
 172 */
 173static inline bool is_unicast_ether_addr(const u8 *addr)
 174{
 175        return !is_multicast_ether_addr(addr);
 176}
 177
 178/**
 179 * is_valid_ether_addr - Determine if the given Ethernet address is valid
 180 * @addr: Pointer to a six-byte array containing the Ethernet address
 181 *
 182 * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
 183 * a multicast address, and is not FF:FF:FF:FF:FF:FF.
 184 *
 185 * Return true if the address is valid.
 186 *
 187 * Please note: addr must be aligned to u16.
 188 */
 189static inline bool is_valid_ether_addr(const u8 *addr)
 190{
 191        /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
 192         * explicitly check for it here. */
 193        return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
 194}
 195
 196/**
 197 * eth_proto_is_802_3 - Determine if a given Ethertype/length is a protocol
 198 * @proto: Ethertype/length value to be tested
 199 *
 200 * Check that the value from the Ethertype/length field is a valid Ethertype.
 201 *
 202 * Return true if the valid is an 802.3 supported Ethertype.
 203 */
 204static inline bool eth_proto_is_802_3(__be16 proto)
 205{
 206#ifndef __BIG_ENDIAN
 207        /* if CPU is little endian mask off bits representing LSB */
 208        proto &= htons(0xFF00);
 209#endif
 210        /* cast both to u16 and compare since LSB can be ignored */
 211        return (__force u16)proto >= (__force u16)htons(ETH_P_802_3_MIN);
 212}
 213
 214/**
 215 * eth_random_addr - Generate software assigned random Ethernet address
 216 * @addr: Pointer to a six-byte array containing the Ethernet address
 217 *
 218 * Generate a random Ethernet address (MAC) that is not multicast
 219 * and has the local assigned bit set.
 220 */
 221static inline void eth_random_addr(u8 *addr)
 222{
 223        get_random_bytes(addr, ETH_ALEN);
 224        addr[0] &= 0xfe;        /* clear multicast bit */
 225        addr[0] |= 0x02;        /* set local assignment bit (IEEE802) */
 226}
 227
 228#define random_ether_addr(addr) eth_random_addr(addr)
 229
 230/**
 231 * eth_broadcast_addr - Assign broadcast address
 232 * @addr: Pointer to a six-byte array containing the Ethernet address
 233 *
 234 * Assign the broadcast address to the given address array.
 235 */
 236static inline void eth_broadcast_addr(u8 *addr)
 237{
 238        memset(addr, 0xff, ETH_ALEN);
 239}
 240
 241/**
 242 * eth_zero_addr - Assign zero address
 243 * @addr: Pointer to a six-byte array containing the Ethernet address
 244 *
 245 * Assign the zero address to the given address array.
 246 */
 247static inline void eth_zero_addr(u8 *addr)
 248{
 249        memset(addr, 0x00, ETH_ALEN);
 250}
 251
 252/**
 253 * eth_hw_addr_random - Generate software assigned random Ethernet and
 254 * set device flag
 255 * @dev: pointer to net_device structure
 256 *
 257 * Generate a random Ethernet address (MAC) to be used by a net device
 258 * and set addr_assign_type so the state can be read by sysfs and be
 259 * used by userspace.
 260 */
 261static inline void eth_hw_addr_random(struct net_device *dev)
 262{
 263        dev->addr_assign_type = NET_ADDR_RANDOM;
 264        eth_random_addr(dev->dev_addr);
 265}
 266
 267/**
 268 * ether_addr_copy - Copy an Ethernet address
 269 * @dst: Pointer to a six-byte array Ethernet address destination
 270 * @src: Pointer to a six-byte array Ethernet address source
 271 *
 272 * Please note: dst & src must both be aligned to u16.
 273 */
 274static inline void ether_addr_copy(u8 *dst, const u8 *src)
 275{
 276#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 277        *(u32 *)dst = *(const u32 *)src;
 278        *(u16 *)(dst + 4) = *(const u16 *)(src + 4);
 279#else
 280        u16 *a = (u16 *)dst;
 281        const u16 *b = (const u16 *)src;
 282
 283        a[0] = b[0];
 284        a[1] = b[1];
 285        a[2] = b[2];
 286#endif
 287}
 288
 289/**
 290 * eth_hw_addr_inherit - Copy dev_addr from another net_device
 291 * @dst: pointer to net_device to copy dev_addr to
 292 * @src: pointer to net_device to copy dev_addr from
 293 *
 294 * Copy the Ethernet address from one net_device to another along with
 295 * the address attributes (addr_assign_type).
 296 */
 297static inline void eth_hw_addr_inherit(struct net_device *dst,
 298                                       struct net_device *src)
 299{
 300        dst->addr_assign_type = src->addr_assign_type;
 301        ether_addr_copy(dst->dev_addr, src->dev_addr);
 302}
 303
 304/**
 305 * ether_addr_equal - Compare two Ethernet addresses
 306 * @addr1: Pointer to a six-byte array containing the Ethernet address
 307 * @addr2: Pointer other six-byte array containing the Ethernet address
 308 *
 309 * Compare two Ethernet addresses, returns true if equal
 310 *
 311 * Please note: addr1 & addr2 must both be aligned to u16.
 312 */
 313static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
 314{
 315#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 316        u32 fold = ((*(const u32 *)addr1) ^ (*(const u32 *)addr2)) |
 317                   ((*(const u16 *)(addr1 + 4)) ^ (*(const u16 *)(addr2 + 4)));
 318
 319        return fold == 0;
 320#else
 321        const u16 *a = (const u16 *)addr1;
 322        const u16 *b = (const u16 *)addr2;
 323
 324        return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) == 0;
 325#endif
 326}
 327
 328/**
 329 * ether_addr_equal_64bits - Compare two Ethernet addresses
 330 * @addr1: Pointer to an array of 8 bytes
 331 * @addr2: Pointer to an other array of 8 bytes
 332 *
 333 * Compare two Ethernet addresses, returns true if equal, false otherwise.
 334 *
 335 * The function doesn't need any conditional branches and possibly uses
 336 * word memory accesses on CPU allowing cheap unaligned memory reads.
 337 * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
 338 *
 339 * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
 340 */
 341
 342static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
 343                                           const u8 addr2[6+2])
 344{
 345#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 346        u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
 347
 348#ifdef __BIG_ENDIAN
 349        return (fold >> 16) == 0;
 350#else
 351        return (fold << 16) == 0;
 352#endif
 353#else
 354        return ether_addr_equal(addr1, addr2);
 355#endif
 356}
 357
 358/**
 359 * ether_addr_equal_unaligned - Compare two not u16 aligned Ethernet addresses
 360 * @addr1: Pointer to a six-byte array containing the Ethernet address
 361 * @addr2: Pointer other six-byte array containing the Ethernet address
 362 *
 363 * Compare two Ethernet addresses, returns true if equal
 364 *
 365 * Please note: Use only when any Ethernet address may not be u16 aligned.
 366 */
 367static inline bool ether_addr_equal_unaligned(const u8 *addr1, const u8 *addr2)
 368{
 369#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 370        return ether_addr_equal(addr1, addr2);
 371#else
 372        return memcmp(addr1, addr2, ETH_ALEN) == 0;
 373#endif
 374}
 375
 376/**
 377 * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
 378 * @dev: Pointer to a device structure
 379 * @addr: Pointer to a six-byte array containing the Ethernet address
 380 *
 381 * Compare passed address with all addresses of the device. Return true if the
 382 * address if one of the device addresses.
 383 *
 384 * Note that this function calls ether_addr_equal_64bits() so take care of
 385 * the right padding.
 386 */
 387static inline bool is_etherdev_addr(const struct net_device *dev,
 388                                    const u8 addr[6 + 2])
 389{
 390        struct netdev_hw_addr *ha;
 391        bool res = false;
 392
 393        rcu_read_lock();
 394        for_each_dev_addr(dev, ha) {
 395                res = ether_addr_equal_64bits(addr, ha->addr);
 396                if (res)
 397                        break;
 398        }
 399        rcu_read_unlock();
 400        return res;
 401}
 402#endif  /* __KERNEL__ */
 403
 404/**
 405 * compare_ether_header - Compare two Ethernet headers
 406 * @a: Pointer to Ethernet header
 407 * @b: Pointer to Ethernet header
 408 *
 409 * Compare two Ethernet headers, returns 0 if equal.
 410 * This assumes that the network header (i.e., IP header) is 4-byte
 411 * aligned OR the platform can handle unaligned access.  This is the
 412 * case for all packets coming into netif_receive_skb or similar
 413 * entry points.
 414 */
 415
 416static inline unsigned long compare_ether_header(const void *a, const void *b)
 417{
 418#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 419        unsigned long fold;
 420
 421        /*
 422         * We want to compare 14 bytes:
 423         *  [a0 ... a13] ^ [b0 ... b13]
 424         * Use two long XOR, ORed together, with an overlap of two bytes.
 425         *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
 426         *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
 427         * This means the [a6 a7] ^ [b6 b7] part is done two times.
 428        */
 429        fold = *(unsigned long *)a ^ *(unsigned long *)b;
 430        fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
 431        return fold;
 432#else
 433        u32 *a32 = (u32 *)((u8 *)a + 2);
 434        u32 *b32 = (u32 *)((u8 *)b + 2);
 435
 436        return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
 437               (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
 438#endif
 439}
 440
 441/**
 442 * eth_skb_pad - Pad buffer to mininum number of octets for Ethernet frame
 443 * @skb: Buffer to pad
 444 *
 445 * An Ethernet frame should have a minimum size of 60 bytes.  This function
 446 * takes short frames and pads them with zeros up to the 60 byte limit.
 447 */
 448static inline int eth_skb_pad(struct sk_buff *skb)
 449{
 450        return skb_put_padto(skb, ETH_ZLEN);
 451}
 452
 453#endif  /* _LINUX_ETHERDEVICE_H */
 454
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