include/linux/etherdevice.h

   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__
  32 struct device;
  33 int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr);
  34 unsigned char *arch_get_platform_get_mac_address(void);
  35 u32 eth_get_headlen(void *data, unsigned int max_len);
  36 __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  37 extern const struct header_ops eth_header_ops;
  38
  39 int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
  40                const void *daddr, const void *saddr, unsigned len);
  41 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
  42 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
  43                      __be16 type);
  44 void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev,
  45                              const unsigned char *haddr);
  46 int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
  47 void eth_commit_mac_addr_change(struct net_device *dev, void *p);
  48 int eth_mac_addr(struct net_device *dev, void *p);
  49 int eth_change_mtu(struct net_device *dev, int new_mtu);
  50 int eth_validate_addr(struct net_device *dev);
  51
  52 struct 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
  57 struct net_device *devm_alloc_etherdev_mqs(struct device *dev, int sizeof_priv,
  58                                            unsigned int txqs,
  59                                            unsigned int rxqs);
  60 #define devm_alloc_etherdev(dev, sizeof_priv) devm_alloc_etherdev_mqs(dev, sizeof_priv, 1, 1)
  61
  62 struct sk_buff **eth_gro_receive(struct sk_buff **head,
  63                                  struct sk_buff *skb);
  64 int eth_gro_complete(struct sk_buff *skb, int nhoff);
  65
  66 /* Reserved Ethernet Addresses per IEEE 802.1Q */
  67 static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) =
  68 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
  69
  70 /**
  71  * is_link_local_ether_addr - Determine if given Ethernet address is link-local
  72  * @addr: Pointer to a six-byte array containing the Ethernet address
  73  *
  74  * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per
  75  * IEEE 802.1Q 8.6.3 Frame filtering.
  76  *
  77  * Please note: addr must be aligned to u16.
  78  */
  79 static inline bool is_link_local_ether_addr(const u8 *addr)
  80 {
  81         __be16 *a = (__be16 *)addr;
  82         static const __be16 *b = (const __be16 *)eth_reserved_addr_base;
  83         static const __be16 m = cpu_to_be16(0xfff0);
  84
  85 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
  86         return (((*(const u32 *)addr) ^ (*(const u32 *)b)) |
  87                 (__force int)((a[2] ^ b[2]) & m)) == 0;
  88 #else
  89         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
  90 #endif
  91 }
  92
  93 /**
  94  * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
  95  * @addr: Pointer to a six-byte array containing the Ethernet address
  96  *
  97  * Return true if the address is all zeroes.
  98  *
  99  * Please note: addr must be aligned to u16.
 100  */
 101 static inline bool is_zero_ether_addr(const u8 *addr)
 102 {
 103 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 104         return ((*(const u32 *)addr) | (*(const u16 *)(addr + 4))) == 0;
 105 #else
 106         return (*(const u16 *)(addr + 0) |
 107                 *(const u16 *)(addr + 2) |
 108                 *(const u16 *)(addr + 4)) == 0;
 109 #endif
 110 }
 111
 112 /**
 113  * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
 114  * @addr: Pointer to a six-byte array containing the Ethernet address
 115  *
 116  * Return true if the address is a multicast address.
 117  * By definition the broadcast address is also a multicast address.
 118  */
 119 static inline bool is_multicast_ether_addr(const u8 *addr)
 120 {
 121 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 122         u32 a = *(const u32 *)addr;
 123 #else
 124         u16 a = *(const u16 *)addr;
 125 #endif
 126 #ifdef __BIG_ENDIAN
 127         return 0x01 & (a >> ((sizeof(a) * 8) - 8));
 128 #else
 129         return 0x01 & a;
 130 #endif
 131 }
 132
 133 static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
 134 {
 135 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 136 #ifdef __BIG_ENDIAN
 137         return 0x01 & ((*(const u64 *)addr) >> 56);
 138 #else
 139         return 0x01 & (*(const u64 *)addr);
 140 #endif
 141 #else
 142         return is_multicast_ether_addr(addr);
 143 #endif
 144 }
 145
 146 /**
 147  * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
 148  * @addr: Pointer to a six-byte array containing the Ethernet address
 149  *
 150  * Return true if the address is a local address.
 151  */
 152 static inline bool is_local_ether_addr(const u8 *addr)
 153 {
 154         return 0x02 & addr[0];
 155 }
 156
 157 /**
 158  * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
 159  * @addr: Pointer to a six-byte array containing the Ethernet address
 160  *
 161  * Return true if the address is the broadcast address.
 162  *
 163  * Please note: addr must be aligned to u16.
 164  */
 165 static inline bool is_broadcast_ether_addr(const u8 *addr)
 166 {
 167         return (*(const u16 *)(addr + 0) &
 168                 *(const u16 *)(addr + 2) &
 169                 *(const u16 *)(addr + 4)) == 0xffff;
 170 }
 171
 172 /**
 173  * is_unicast_ether_addr - Determine if the Ethernet address is unicast
 174  * @addr: Pointer to a six-byte array containing the Ethernet address
 175  *
 176  * Return true if the address is a unicast address.
 177  */
 178 static inline bool is_unicast_ether_addr(const u8 *addr)
 179 {
 180         return !is_multicast_ether_addr(addr);
 181 }
 182
 183 /**
 184  * is_valid_ether_addr - Determine if the given Ethernet address is valid
 185  * @addr: Pointer to a six-byte array containing the Ethernet address
 186  *
 187  * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
 188  * a multicast address, and is not FF:FF:FF:FF:FF:FF.
 189  *
 190  * Return true if the address is valid.
 191  *
 192  * Please note: addr must be aligned to u16.
 193  */
 194 static inline bool is_valid_ether_addr(const u8 *addr)
 195 {
 196         /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
 197          * explicitly check for it here. */
 198         return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
 199 }
 200
 201 /**
 202  * eth_proto_is_802_3 - Determine if a given Ethertype/length is a protocol
 203  * @proto: Ethertype/length value to be tested
 204  *
 205  * Check that the value from the Ethertype/length field is a valid Ethertype.
 206  *
 207  * Return true if the valid is an 802.3 supported Ethertype.
 208  */
 209 static inline bool eth_proto_is_802_3(__be16 proto)
 210 {
 211 #ifndef __BIG_ENDIAN
 212         /* if CPU is little endian mask off bits representing LSB */
 213         proto &= htons(0xFF00);
 214 #endif
 215         /* cast both to u16 and compare since LSB can be ignored */
 216         return (__force u16)proto >= (__force u16)htons(ETH_P_802_3_MIN);
 217 }
 218
 219 /**
 220  * eth_random_addr - Generate software assigned random Ethernet address
 221  * @addr: Pointer to a six-byte array containing the Ethernet address
 222  *
 223  * Generate a random Ethernet address (MAC) that is not multicast
 224  * and has the local assigned bit set.
 225  */
 226 static inline void eth_random_addr(u8 *addr)
 227 {
 228         get_random_bytes(addr, ETH_ALEN);
 229         addr[0] &= 0xfe;        /* clear multicast bit */
 230         addr[0] |= 0x02;        /* set local assignment bit (IEEE802) */
 231 }
 232
 233 #define random_ether_addr(addr) eth_random_addr(addr)
 234
 235 /**
 236  * eth_broadcast_addr - Assign broadcast address
 237  * @addr: Pointer to a six-byte array containing the Ethernet address
 238  *
 239  * Assign the broadcast address to the given address array.
 240  */
 241 static inline void eth_broadcast_addr(u8 *addr)
 242 {
 243         memset(addr, 0xff, ETH_ALEN);
 244 }
 245
 246 /**
 247  * eth_zero_addr - Assign zero address
 248  * @addr: Pointer to a six-byte array containing the Ethernet address
 249  *
 250  * Assign the zero address to the given address array.
 251  */
 252 static inline void eth_zero_addr(u8 *addr)
 253 {
 254         memset(addr, 0x00, ETH_ALEN);
 255 }
 256
 257 /**
 258  * eth_hw_addr_random - Generate software assigned random Ethernet and
 259  * set device flag
 260  * @dev: pointer to net_device structure
 261  *
 262  * Generate a random Ethernet address (MAC) to be used by a net device
 263  * and set addr_assign_type so the state can be read by sysfs and be
 264  * used by userspace.
 265  */
 266 static inline void eth_hw_addr_random(struct net_device *dev)
 267 {
 268         dev->addr_assign_type = NET_ADDR_RANDOM;
 269         eth_random_addr(dev->dev_addr);
 270 }
 271
 272 /**
 273  * ether_addr_copy - Copy an Ethernet address
 274  * @dst: Pointer to a six-byte array Ethernet address destination
 275  * @src: Pointer to a six-byte array Ethernet address source
 276  *
 277  * Please note: dst & src must both be aligned to u16.
 278  */
 279 static inline void ether_addr_copy(u8 *dst, const u8 *src)
 280 {
 281 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 282         *(u32 *)dst = *(const u32 *)src;
 283         *(u16 *)(dst + 4) = *(const u16 *)(src + 4);
 284 #else
 285         u16 *a = (u16 *)dst;
 286         const u16 *b = (const u16 *)src;
 287
 288         a[0] = b[0];
 289         a[1] = b[1];
 290         a[2] = b[2];
 291 #endif
 292 }
 293
 294 /**
 295  * eth_hw_addr_inherit - Copy dev_addr from another net_device
 296  * @dst: pointer to net_device to copy dev_addr to
 297  * @src: pointer to net_device to copy dev_addr from
 298  *
 299  * Copy the Ethernet address from one net_device to another along with
 300  * the address attributes (addr_assign_type).
 301  */
 302 static inline void eth_hw_addr_inherit(struct net_device *dst,
 303                                        struct net_device *src)
 304 {
 305         dst->addr_assign_type = src->addr_assign_type;
 306         ether_addr_copy(dst->dev_addr, src->dev_addr);
 307 }
 308
 309 /**
 310  * ether_addr_equal - Compare two Ethernet addresses
 311  * @addr1: Pointer to a six-byte array containing the Ethernet address
 312  * @addr2: Pointer other six-byte array containing the Ethernet address
 313  *
 314  * Compare two Ethernet addresses, returns true if equal
 315  *
 316  * Please note: addr1 & addr2 must both be aligned to u16.
 317  */
 318 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
 319 {
 320 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 321         u32 fold = ((*(const u32 *)addr1) ^ (*(const u32 *)addr2)) |
 322                    ((*(const u16 *)(addr1 + 4)) ^ (*(const u16 *)(addr2 + 4)));
 323
 324         return fold == 0;
 325 #else
 326         const u16 *a = (const u16 *)addr1;
 327         const u16 *b = (const u16 *)addr2;
 328
 329         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) == 0;
 330 #endif
 331 }
 332
 333 /**
 334  * ether_addr_equal_64bits - Compare two Ethernet addresses
 335  * @addr1: Pointer to an array of 8 bytes
 336  * @addr2: Pointer to an other array of 8 bytes
 337  *
 338  * Compare two Ethernet addresses, returns true if equal, false otherwise.
 339  *
 340  * The function doesn't need any conditional branches and possibly uses
 341  * word memory accesses on CPU allowing cheap unaligned memory reads.
 342  * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
 343  *
 344  * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
 345  */
 346
 347 static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
 348                                            const u8 addr2[6+2])
 349 {
 350 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 351         u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
 352
 353 #ifdef __BIG_ENDIAN
 354         return (fold >> 16) == 0;
 355 #else
 356         return (fold << 16) == 0;
 357 #endif
 358 #else
 359         return ether_addr_equal(addr1, addr2);
 360 #endif
 361 }
 362
 363 /**
 364  * ether_addr_equal_unaligned - Compare two not u16 aligned Ethernet addresses
 365  * @addr1: Pointer to a six-byte array containing the Ethernet address
 366  * @addr2: Pointer other six-byte array containing the Ethernet address
 367  *
 368  * Compare two Ethernet addresses, returns true if equal
 369  *
 370  * Please note: Use only when any Ethernet address may not be u16 aligned.
 371  */
 372 static inline bool ether_addr_equal_unaligned(const u8 *addr1, const u8 *addr2)
 373 {
 374 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 375         return ether_addr_equal(addr1, addr2);
 376 #else
 377         return memcmp(addr1, addr2, ETH_ALEN) == 0;
 378 #endif
 379 }
 380
 381 /**
 382  * ether_addr_equal_masked - Compare two Ethernet addresses with a mask
 383  * @addr1: Pointer to a six-byte array containing the 1st Ethernet address
 384  * @addr2: Pointer to a six-byte array containing the 2nd Ethernet address
 385  * @mask: Pointer to a six-byte array containing the Ethernet address bitmask
 386  *
 387  * Compare two Ethernet addresses with a mask, returns true if for every bit
 388  * set in the bitmask the equivalent bits in the ethernet addresses are equal.
 389  * Using a mask with all bits set is a slower ether_addr_equal.
 390  */
 391 static inline bool ether_addr_equal_masked(const u8 *addr1, const u8 *addr2,
 392                                            const u8 *mask)
 393 {
 394         int i;
 395
 396         for (i = 0; i < ETH_ALEN; i++) {
 397                 if ((addr1[i] ^ addr2[i]) & mask[i])
 398                         return false;
 399         }
 400
 401         return true;
 402 }
 403
 404 /**
 405  * ether_addr_to_u64 - Convert an Ethernet address into a u64 value.
 406  * @addr: Pointer to a six-byte array containing the Ethernet address
 407  *
 408  * Return a u64 value of the address
 409  */
 410 static inline u64 ether_addr_to_u64(const u8 *addr)
 411 {
 412         u64 u = 0;
 413         int i;
 414
 415         for (i = 0; i < ETH_ALEN; i++)
 416                 u = u << 8 | addr[i];
 417
 418         return u;
 419 }
 420
 421 /**
 422  * u64_to_ether_addr - Convert a u64 to an Ethernet address.
 423  * @u: u64 to convert to an Ethernet MAC address
 424  * @addr: Pointer to a six-byte array to contain the Ethernet address
 425  */
 426 static inline void u64_to_ether_addr(u64 u, u8 *addr)
 427 {
 428         int i;
 429
 430         for (i = ETH_ALEN - 1; i >= 0; i--) {
 431                 addr[i] = u & 0xff;
 432                 u = u >> 8;
 433         }
 434 }
 435
 436 /**
 437  * eth_addr_dec - Decrement the given MAC address
 438  *
 439  * @addr: Pointer to a six-byte array containing Ethernet address to decrement
 440  */
 441 static inline void eth_addr_dec(u8 *addr)
 442 {
 443         u64 u = ether_addr_to_u64(addr);
 444
 445         u--;
 446         u64_to_ether_addr(u, addr);
 447 }
 448
 449 /**
 450  * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
 451  * @dev: Pointer to a device structure
 452  * @addr: Pointer to a six-byte array containing the Ethernet address
 453  *
 454  * Compare passed address with all addresses of the device. Return true if the
 455  * address if one of the device addresses.
 456  *
 457  * Note that this function calls ether_addr_equal_64bits() so take care of
 458  * the right padding.
 459  */
 460 static inline bool is_etherdev_addr(const struct net_device *dev,
 461                                     const u8 addr[6 + 2])
 462 {
 463         struct netdev_hw_addr *ha;
 464         bool res = false;
 465
 466         rcu_read_lock();
 467         for_each_dev_addr(dev, ha) {
 468                 res = ether_addr_equal_64bits(addr, ha->addr);
 469                 if (res)
 470                         break;
 471         }
 472         rcu_read_unlock();
 473         return res;
 474 }
 475 #endif  /* __KERNEL__ */
 476
 477 /**
 478  * compare_ether_header - Compare two Ethernet headers
 479  * @a: Pointer to Ethernet header
 480  * @b: Pointer to Ethernet header
 481  *
 482  * Compare two Ethernet headers, returns 0 if equal.
 483  * This assumes that the network header (i.e., IP header) is 4-byte
 484  * aligned OR the platform can handle unaligned access.  This is the
 485  * case for all packets coming into netif_receive_skb or similar
 486  * entry points.
 487  */
 488
 489 static inline unsigned long compare_ether_header(const void *a, const void *b)
 490 {
 491 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 492         unsigned long fold;
 493
 494         /*
 495          * We want to compare 14 bytes:
 496          *  [a0 ... a13] ^ [b0 ... b13]
 497          * Use two long XOR, ORed together, with an overlap of two bytes.
 498          *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
 499          *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
 500          * This means the [a6 a7] ^ [b6 b7] part is done two times.
 501         */
 502         fold = *(unsigned long *)a ^ *(unsigned long *)b;
 503         fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
 504         return fold;
 505 #else
 506         u32 *a32 = (u32 *)((u8 *)a + 2);
 507         u32 *b32 = (u32 *)((u8 *)b + 2);
 508
 509         return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
 510                (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
 511 #endif
 512 }
 513
 514 /**
 515  * eth_skb_pad - Pad buffer to mininum number of octets for Ethernet frame
 516  * @skb: Buffer to pad
 517  *
 518  * An Ethernet frame should have a minimum size of 60 bytes.  This function
 519  * takes short frames and pads them with zeros up to the 60 byte limit.
 520  */
 521 static inline int eth_skb_pad(struct sk_buff *skb)
 522 {
 523         return skb_put_padto(skb, ETH_ZLEN);
 524 }
 525
 526 #endif  /* _LINUX_ETHERDEVICE_H */