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