root/include/linux/etherdevice.h

INCLUDED FROM

DEFINITIONS

1. is_link_local_ether_addr
2. is_zero_ether_addr
3. is_multicast_ether_addr
4. is_multicast_ether_addr_64bits
5. is_local_ether_addr
6. is_broadcast_ether_addr
7. is_unicast_ether_addr
8. is_valid_ether_addr
9. eth_proto_is_802_3
10. eth_random_addr
11. eth_broadcast_addr
12. eth_zero_addr
13. eth_hw_addr_random
14. ether_addr_copy
15. eth_hw_addr_inherit
16. ether_addr_equal
17. ether_addr_equal_64bits
18. ether_addr_equal_unaligned
19. ether_addr_equal_masked
20. ether_addr_to_u64
21. u64_to_ether_addr
22. eth_addr_dec
23. eth_addr_inc
24. is_etherdev_addr
25. compare_ether_header
26. eth_skb_pad

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * INET         An implementation of the TCP/IP protocol suite for the LINUX
   4  *              operating system.  NET  is implemented using the  BSD Socket
   5  *              interface as the means of communication with the user level.
   6  *
   7  *              Definitions for the Ethernet handlers.
   8  *
   9  * Version:     @(#)eth.h       1.0.4   05/13/93
  10  *
  11  * Authors:     Ross Biro
  12  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  13  *
  14  *              Relocated to include/linux where it belongs by Alan Cox 
  15  *                                                      <gw4pts@gw4pts.ampr.org>
  16  */
  17 #ifndef _LINUX_ETHERDEVICE_H
  18 #define _LINUX_ETHERDEVICE_H
  19 
  20 #include <linux/if_ether.h>
  21 #include <linux/netdevice.h>
  22 #include <linux/random.h>
  23 #include <asm/unaligned.h>
  24 #include <asm/bitsperlong.h>
  25 
  26 #ifdef __KERNEL__
  27 struct device;
  28 int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr);
  29 unsigned char *arch_get_platform_mac_address(void);
  30 int nvmem_get_mac_address(struct device *dev, void *addrbuf);
  31 u32 eth_get_headlen(const struct net_device *dev, void *data, unsigned int len);
  32 __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  33 extern const struct header_ops eth_header_ops;
  34 
  35 int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
  36                const void *daddr, const void *saddr, unsigned len);
  37 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
  38 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
  39                      __be16 type);
  40 void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev,
  41                              const unsigned char *haddr);
  42 __be16 eth_header_parse_protocol(const struct sk_buff *skb);
  43 int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
  44 void eth_commit_mac_addr_change(struct net_device *dev, void *p);
  45 int eth_mac_addr(struct net_device *dev, void *p);
  46 int eth_change_mtu(struct net_device *dev, int new_mtu);
  47 int eth_validate_addr(struct net_device *dev);
  48 
  49 struct 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 
  54 struct net_device *devm_alloc_etherdev_mqs(struct device *dev, int sizeof_priv,
  55                                            unsigned int txqs,
  56                                            unsigned int rxqs);
  57 #define devm_alloc_etherdev(dev, sizeof_priv) devm_alloc_etherdev_mqs(dev, sizeof_priv, 1, 1)
  58 
  59 struct sk_buff *eth_gro_receive(struct list_head *head, struct sk_buff *skb);
  60 int eth_gro_complete(struct sk_buff *skb, int nhoff);
  61 
  62 /* Reserved Ethernet Addresses per IEEE 802.1Q */
  63 static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) =
  64 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
  65 #define eth_stp_addr eth_reserved_addr_base
  66 
  67 /**
  68  * is_link_local_ether_addr - Determine if given Ethernet address is link-local
  69  * @addr: Pointer to a six-byte array containing the Ethernet address
  70  *
  71  * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per
  72  * IEEE 802.1Q 8.6.3 Frame filtering.
  73  *
  74  * Please note: addr must be aligned to u16.
  75  */
  76 static inline bool is_link_local_ether_addr(const u8 *addr)
  77 {
  78         __be16 *a = (__be16 *)addr;
  79         static const __be16 *b = (const __be16 *)eth_reserved_addr_base;
  80         static const __be16 m = cpu_to_be16(0xfff0);
  81 
  82 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
  83         return (((*(const u32 *)addr) ^ (*(const u32 *)b)) |
  84                 (__force int)((a[2] ^ b[2]) & m)) == 0;
  85 #else
  86         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
  87 #endif
  88 }
  89 
  90 /**
  91  * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
  92  * @addr: Pointer to a six-byte array containing the Ethernet address
  93  *
  94  * Return true if the address is all zeroes.
  95  *
  96  * Please note: addr must be aligned to u16.
  97  */
  98 static inline bool is_zero_ether_addr(const u8 *addr)
  99 {
 100 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 101         return ((*(const u32 *)addr) | (*(const u16 *)(addr + 4))) == 0;
 102 #else
 103         return (*(const u16 *)(addr + 0) |
 104                 *(const u16 *)(addr + 2) |
 105                 *(const u16 *)(addr + 4)) == 0;
 106 #endif
 107 }
 108 
 109 /**
 110  * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
 111  * @addr: Pointer to a six-byte array containing the Ethernet address
 112  *
 113  * Return true if the address is a multicast address.
 114  * By definition the broadcast address is also a multicast address.
 115  */
 116 static inline bool is_multicast_ether_addr(const u8 *addr)
 117 {
 118 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 119         u32 a = *(const u32 *)addr;
 120 #else
 121         u16 a = *(const u16 *)addr;
 122 #endif
 123 #ifdef __BIG_ENDIAN
 124         return 0x01 & (a >> ((sizeof(a) * 8) - 8));
 125 #else
 126         return 0x01 & a;
 127 #endif
 128 }
 129 
 130 static inline bool is_multicast_ether_addr_64bits(const u8 addr[6+2])
 131 {
 132 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 133 #ifdef __BIG_ENDIAN
 134         return 0x01 & ((*(const u64 *)addr) >> 56);
 135 #else
 136         return 0x01 & (*(const u64 *)addr);
 137 #endif
 138 #else
 139         return is_multicast_ether_addr(addr);
 140 #endif
 141 }
 142 
 143 /**
 144  * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
 145  * @addr: Pointer to a six-byte array containing the Ethernet address
 146  *
 147  * Return true if the address is a local address.
 148  */
 149 static inline bool is_local_ether_addr(const u8 *addr)
 150 {
 151         return 0x02 & addr[0];
 152 }
 153 
 154 /**
 155  * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
 156  * @addr: Pointer to a six-byte array containing the Ethernet address
 157  *
 158  * Return true if the address is the broadcast address.
 159  *
 160  * Please note: addr must be aligned to u16.
 161  */
 162 static inline bool is_broadcast_ether_addr(const u8 *addr)
 163 {
 164         return (*(const u16 *)(addr + 0) &
 165                 *(const u16 *)(addr + 2) &
 166                 *(const u16 *)(addr + 4)) == 0xffff;
 167 }
 168 
 169 /**
 170  * is_unicast_ether_addr - Determine if the Ethernet address is unicast
 171  * @addr: Pointer to a six-byte array containing the Ethernet address
 172  *
 173  * Return true if the address is a unicast address.
 174  */
 175 static inline bool is_unicast_ether_addr(const u8 *addr)
 176 {
 177         return !is_multicast_ether_addr(addr);
 178 }
 179 
 180 /**
 181  * is_valid_ether_addr - Determine if the given Ethernet address is valid
 182  * @addr: Pointer to a six-byte array containing the Ethernet address
 183  *
 184  * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
 185  * a multicast address, and is not FF:FF:FF:FF:FF:FF.
 186  *
 187  * Return true if the address is valid.
 188  *
 189  * Please note: addr must be aligned to u16.
 190  */
 191 static inline bool is_valid_ether_addr(const u8 *addr)
 192 {
 193         /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
 194          * explicitly check for it here. */
 195         return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
 196 }
 197 
 198 /**
 199  * eth_proto_is_802_3 - Determine if a given Ethertype/length is a protocol
 200  * @proto: Ethertype/length value to be tested
 201  *
 202  * Check that the value from the Ethertype/length field is a valid Ethertype.
 203  *
 204  * Return true if the valid is an 802.3 supported Ethertype.
 205  */
 206 static inline bool eth_proto_is_802_3(__be16 proto)
 207 {
 208 #ifndef __BIG_ENDIAN
 209         /* if CPU is little endian mask off bits representing LSB */
 210         proto &= htons(0xFF00);
 211 #endif
 212         /* cast both to u16 and compare since LSB can be ignored */
 213         return (__force u16)proto >= (__force u16)htons(ETH_P_802_3_MIN);
 214 }
 215 
 216 /**
 217  * eth_random_addr - Generate software assigned random Ethernet address
 218  * @addr: Pointer to a six-byte array containing the Ethernet address
 219  *
 220  * Generate a random Ethernet address (MAC) that is not multicast
 221  * and has the local assigned bit set.
 222  */
 223 static inline void eth_random_addr(u8 *addr)
 224 {
 225         get_random_bytes(addr, ETH_ALEN);
 226         addr[0] &= 0xfe;        /* clear multicast bit */
 227         addr[0] |= 0x02;        /* set local assignment bit (IEEE802) */
 228 }
 229 
 230 #define random_ether_addr(addr) eth_random_addr(addr)
 231 
 232 /**
 233  * eth_broadcast_addr - Assign broadcast address
 234  * @addr: Pointer to a six-byte array containing the Ethernet address
 235  *
 236  * Assign the broadcast address to the given address array.
 237  */
 238 static inline void eth_broadcast_addr(u8 *addr)
 239 {
 240         memset(addr, 0xff, ETH_ALEN);
 241 }
 242 
 243 /**
 244  * eth_zero_addr - Assign zero address
 245  * @addr: Pointer to a six-byte array containing the Ethernet address
 246  *
 247  * Assign the zero address to the given address array.
 248  */
 249 static inline void eth_zero_addr(u8 *addr)
 250 {
 251         memset(addr, 0x00, ETH_ALEN);
 252 }
 253 
 254 /**
 255  * eth_hw_addr_random - Generate software assigned random Ethernet and
 256  * set device flag
 257  * @dev: pointer to net_device structure
 258  *
 259  * Generate a random Ethernet address (MAC) to be used by a net device
 260  * and set addr_assign_type so the state can be read by sysfs and be
 261  * used by userspace.
 262  */
 263 static inline void eth_hw_addr_random(struct net_device *dev)
 264 {
 265         dev->addr_assign_type = NET_ADDR_RANDOM;
 266         eth_random_addr(dev->dev_addr);
 267 }
 268 
 269 /**
 270  * ether_addr_copy - Copy an Ethernet address
 271  * @dst: Pointer to a six-byte array Ethernet address destination
 272  * @src: Pointer to a six-byte array Ethernet address source
 273  *
 274  * Please note: dst & src must both be aligned to u16.
 275  */
 276 static inline void ether_addr_copy(u8 *dst, const u8 *src)
 277 {
 278 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 279         *(u32 *)dst = *(const u32 *)src;
 280         *(u16 *)(dst + 4) = *(const u16 *)(src + 4);
 281 #else
 282         u16 *a = (u16 *)dst;
 283         const u16 *b = (const u16 *)src;
 284 
 285         a[0] = b[0];
 286         a[1] = b[1];
 287         a[2] = b[2];
 288 #endif
 289 }
 290 
 291 /**
 292  * eth_hw_addr_inherit - Copy dev_addr from another net_device
 293  * @dst: pointer to net_device to copy dev_addr to
 294  * @src: pointer to net_device to copy dev_addr from
 295  *
 296  * Copy the Ethernet address from one net_device to another along with
 297  * the address attributes (addr_assign_type).
 298  */
 299 static inline void eth_hw_addr_inherit(struct net_device *dst,
 300                                        struct net_device *src)
 301 {
 302         dst->addr_assign_type = src->addr_assign_type;
 303         ether_addr_copy(dst->dev_addr, src->dev_addr);
 304 }
 305 
 306 /**
 307  * ether_addr_equal - Compare two Ethernet addresses
 308  * @addr1: Pointer to a six-byte array containing the Ethernet address
 309  * @addr2: Pointer other six-byte array containing the Ethernet address
 310  *
 311  * Compare two Ethernet addresses, returns true if equal
 312  *
 313  * Please note: addr1 & addr2 must both be aligned to u16.
 314  */
 315 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
 316 {
 317 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 318         u32 fold = ((*(const u32 *)addr1) ^ (*(const u32 *)addr2)) |
 319                    ((*(const u16 *)(addr1 + 4)) ^ (*(const u16 *)(addr2 + 4)));
 320 
 321         return fold == 0;
 322 #else
 323         const u16 *a = (const u16 *)addr1;
 324         const u16 *b = (const u16 *)addr2;
 325 
 326         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) == 0;
 327 #endif
 328 }
 329 
 330 /**
 331  * ether_addr_equal_64bits - Compare two Ethernet addresses
 332  * @addr1: Pointer to an array of 8 bytes
 333  * @addr2: Pointer to an other array of 8 bytes
 334  *
 335  * Compare two Ethernet addresses, returns true if equal, false otherwise.
 336  *
 337  * The function doesn't need any conditional branches and possibly uses
 338  * word memory accesses on CPU allowing cheap unaligned memory reads.
 339  * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
 340  *
 341  * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
 342  */
 343 
 344 static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
 345                                            const u8 addr2[6+2])
 346 {
 347 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 348         u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
 349 
 350 #ifdef __BIG_ENDIAN
 351         return (fold >> 16) == 0;
 352 #else
 353         return (fold << 16) == 0;
 354 #endif
 355 #else
 356         return ether_addr_equal(addr1, addr2);
 357 #endif
 358 }
 359 
 360 /**
 361  * ether_addr_equal_unaligned - Compare two not u16 aligned Ethernet addresses
 362  * @addr1: Pointer to a six-byte array containing the Ethernet address
 363  * @addr2: Pointer other six-byte array containing the Ethernet address
 364  *
 365  * Compare two Ethernet addresses, returns true if equal
 366  *
 367  * Please note: Use only when any Ethernet address may not be u16 aligned.
 368  */
 369 static inline bool ether_addr_equal_unaligned(const u8 *addr1, const u8 *addr2)
 370 {
 371 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 372         return ether_addr_equal(addr1, addr2);
 373 #else
 374         return memcmp(addr1, addr2, ETH_ALEN) == 0;
 375 #endif
 376 }
 377 
 378 /**
 379  * ether_addr_equal_masked - Compare two Ethernet addresses with a mask
 380  * @addr1: Pointer to a six-byte array containing the 1st Ethernet address
 381  * @addr2: Pointer to a six-byte array containing the 2nd Ethernet address
 382  * @mask: Pointer to a six-byte array containing the Ethernet address bitmask
 383  *
 384  * Compare two Ethernet addresses with a mask, returns true if for every bit
 385  * set in the bitmask the equivalent bits in the ethernet addresses are equal.
 386  * Using a mask with all bits set is a slower ether_addr_equal.
 387  */
 388 static inline bool ether_addr_equal_masked(const u8 *addr1, const u8 *addr2,
 389                                            const u8 *mask)
 390 {
 391         int i;
 392 
 393         for (i = 0; i < ETH_ALEN; i++) {
 394                 if ((addr1[i] ^ addr2[i]) & mask[i])
 395                         return false;
 396         }
 397 
 398         return true;
 399 }
 400 
 401 /**
 402  * ether_addr_to_u64 - Convert an Ethernet address into a u64 value.
 403  * @addr: Pointer to a six-byte array containing the Ethernet address
 404  *
 405  * Return a u64 value of the address
 406  */
 407 static inline u64 ether_addr_to_u64(const u8 *addr)
 408 {
 409         u64 u = 0;
 410         int i;
 411 
 412         for (i = 0; i < ETH_ALEN; i++)
 413                 u = u << 8 | addr[i];
 414 
 415         return u;
 416 }
 417 
 418 /**
 419  * u64_to_ether_addr - Convert a u64 to an Ethernet address.
 420  * @u: u64 to convert to an Ethernet MAC address
 421  * @addr: Pointer to a six-byte array to contain the Ethernet address
 422  */
 423 static inline void u64_to_ether_addr(u64 u, u8 *addr)
 424 {
 425         int i;
 426 
 427         for (i = ETH_ALEN - 1; i >= 0; i--) {
 428                 addr[i] = u & 0xff;
 429                 u = u >> 8;
 430         }
 431 }
 432 
 433 /**
 434  * eth_addr_dec - Decrement the given MAC address
 435  *
 436  * @addr: Pointer to a six-byte array containing Ethernet address to decrement
 437  */
 438 static inline void eth_addr_dec(u8 *addr)
 439 {
 440         u64 u = ether_addr_to_u64(addr);
 441 
 442         u--;
 443         u64_to_ether_addr(u, addr);
 444 }
 445 
 446 /**
 447  * eth_addr_inc() - Increment the given MAC address.
 448  * @addr: Pointer to a six-byte array containing Ethernet address to increment.
 449  */
 450 static inline void eth_addr_inc(u8 *addr)
 451 {
 452         u64 u = ether_addr_to_u64(addr);
 453 
 454         u++;
 455         u64_to_ether_addr(u, addr);
 456 }
 457 
 458 /**
 459  * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
 460  * @dev: Pointer to a device structure
 461  * @addr: Pointer to a six-byte array containing the Ethernet address
 462  *
 463  * Compare passed address with all addresses of the device. Return true if the
 464  * address if one of the device addresses.
 465  *
 466  * Note that this function calls ether_addr_equal_64bits() so take care of
 467  * the right padding.
 468  */
 469 static inline bool is_etherdev_addr(const struct net_device *dev,
 470                                     const u8 addr[6 + 2])
 471 {
 472         struct netdev_hw_addr *ha;
 473         bool res = false;
 474 
 475         rcu_read_lock();
 476         for_each_dev_addr(dev, ha) {
 477                 res = ether_addr_equal_64bits(addr, ha->addr);
 478                 if (res)
 479                         break;
 480         }
 481         rcu_read_unlock();
 482         return res;
 483 }
 484 #endif  /* __KERNEL__ */
 485 
 486 /**
 487  * compare_ether_header - Compare two Ethernet headers
 488  * @a: Pointer to Ethernet header
 489  * @b: Pointer to Ethernet header
 490  *
 491  * Compare two Ethernet headers, returns 0 if equal.
 492  * This assumes that the network header (i.e., IP header) is 4-byte
 493  * aligned OR the platform can handle unaligned access.  This is the
 494  * case for all packets coming into netif_receive_skb or similar
 495  * entry points.
 496  */
 497 
 498 static inline unsigned long compare_ether_header(const void *a, const void *b)
 499 {
 500 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 501         unsigned long fold;
 502 
 503         /*
 504          * We want to compare 14 bytes:
 505          *  [a0 ... a13] ^ [b0 ... b13]
 506          * Use two long XOR, ORed together, with an overlap of two bytes.
 507          *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
 508          *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
 509          * This means the [a6 a7] ^ [b6 b7] part is done two times.
 510         */
 511         fold = *(unsigned long *)a ^ *(unsigned long *)b;
 512         fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
 513         return fold;
 514 #else
 515         u32 *a32 = (u32 *)((u8 *)a + 2);
 516         u32 *b32 = (u32 *)((u8 *)b + 2);
 517 
 518         return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
 519                (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
 520 #endif
 521 }
 522 
 523 /**
 524  * eth_skb_pad - Pad buffer to mininum number of octets for Ethernet frame
 525  * @skb: Buffer to pad
 526  *
 527  * An Ethernet frame should have a minimum size of 60 bytes.  This function
 528  * takes short frames and pads them with zeros up to the 60 byte limit.
 529  */
 530 static inline int eth_skb_pad(struct sk_buff *skb)
 531 {
 532         return skb_put_padto(skb, ETH_ZLEN);
 533 }
 534 
 535 #endif  /* _LINUX_ETHERDEVICE_H */