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