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 u32 eth_get_headlen(void *data, unsigned int max_len);
  33 __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  34 extern const struct header_ops eth_header_ops;
  35
  36 int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
  37                const void *daddr, const void *saddr, unsigned len);
  38 int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
  39 int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
  40                      __be16 type);
  41 void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev,
  42                              const unsigned char *haddr);
  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 sk_buff **eth_gro_receive(struct sk_buff **head,
  55                                  struct sk_buff *skb);
  56 int eth_gro_complete(struct sk_buff *skb, int nhoff);
  57
  58 /* Reserved Ethernet Addresses per IEEE 802.1Q */
  59 static 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  */
  71 static 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  */
  93 static 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  */
 111 static 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  */
 122 static 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  */
 135 static 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  */
 148 static 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  */
 164 static 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  */
 178 static 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  */
 193 static 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  */
 204 static 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  */
 218 static 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  */
 231 static 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  */
 254 static 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  */
 270 static 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
 299 static 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  */
 324 static 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  */
 344 static 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
 373 static 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  */
 405 static 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 */