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