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
  30 #ifdef __KERNEL__
  31 extern __be16           eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  32 extern const struct header_ops eth_header_ops;
  33
  34 extern int eth_header(struct sk_buff *skb, struct net_device *dev,
  35                       unsigned short type,
  36                       const void *daddr, const void *saddr, unsigned len);
  37 extern int eth_rebuild_header(struct sk_buff *skb);
  38 extern int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
  39 extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type);
  40 extern void eth_header_cache_update(struct hh_cache *hh,
  41                                     const struct net_device *dev,
  42                                     const unsigned char *haddr);
  43 extern int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
  44 extern void eth_commit_mac_addr_change(struct net_device *dev, void *p);
  45 extern int eth_mac_addr(struct net_device *dev, void *p);
  46 extern int eth_change_mtu(struct net_device *dev, int new_mtu);
  47 extern int eth_validate_addr(struct net_device *dev);
  48
  49
  50
  51 extern struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
  52                                             unsigned int rxqs);
  53 #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
  54 #define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count)
  55
  56 /* Reserved Ethernet Addresses per IEEE 802.1Q */
  57 static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) =
  58 { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
  59
  60 /**
  61  * is_link_local_ether_addr - Determine if given Ethernet address is link-local
  62  * @addr: Pointer to a six-byte array containing the Ethernet address
  63  *
  64  * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per
  65  * IEEE 802.1Q 8.6.3 Frame filtering.
  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         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
  74 }
  75
  76 /**
  77  * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
  78  * @addr: Pointer to a six-byte array containing the Ethernet address
  79  *
  80  * Return true if the address is all zeroes.
  81  */
  82 static inline bool is_zero_ether_addr(const u8 *addr)
  83 {
  84         return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
  85 }
  86
  87 /**
  88  * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
  89  * @addr: Pointer to a six-byte array containing the Ethernet address
  90  *
  91  * Return true if the address is a multicast address.
  92  * By definition the broadcast address is also a multicast address.
  93  */
  94 static inline bool is_multicast_ether_addr(const u8 *addr)
  95 {
  96         return 0x01 & addr[0];
  97 }
  98
  99 /**
 100  * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
 101  * @addr: Pointer to a six-byte array containing the Ethernet address
 102  *
 103  * Return true if the address is a local address.
 104  */
 105 static inline bool is_local_ether_addr(const u8 *addr)
 106 {
 107         return 0x02 & addr[0];
 108 }
 109
 110 /**
 111  * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
 112  * @addr: Pointer to a six-byte array containing the Ethernet address
 113  *
 114  * Return true if the address is the broadcast address.
 115  */
 116 static inline bool is_broadcast_ether_addr(const u8 *addr)
 117 {
 118         return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
 119 }
 120
 121 /**
 122  * is_unicast_ether_addr - Determine if the Ethernet address is unicast
 123  * @addr: Pointer to a six-byte array containing the Ethernet address
 124  *
 125  * Return true if the address is a unicast address.
 126  */
 127 static inline bool is_unicast_ether_addr(const u8 *addr)
 128 {
 129         return !is_multicast_ether_addr(addr);
 130 }
 131
 132 /**
 133  * is_valid_ether_addr - Determine if the given Ethernet address is valid
 134  * @addr: Pointer to a six-byte array containing the Ethernet address
 135  *
 136  * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
 137  * a multicast address, and is not FF:FF:FF:FF:FF:FF.
 138  *
 139  * Return true if the address is valid.
 140  */
 141 static inline bool is_valid_ether_addr(const u8 *addr)
 142 {
 143         /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
 144          * explicitly check for it here. */
 145         return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
 146 }
 147
 148 /**
 149  * eth_random_addr - Generate software assigned random Ethernet address
 150  * @addr: Pointer to a six-byte array containing the Ethernet address
 151  *
 152  * Generate a random Ethernet address (MAC) that is not multicast
 153  * and has the local assigned bit set.
 154  */
 155 static inline void eth_random_addr(u8 *addr)
 156 {
 157         get_random_bytes(addr, ETH_ALEN);
 158         addr[0] &= 0xfe;        /* clear multicast bit */
 159         addr[0] |= 0x02;        /* set local assignment bit (IEEE802) */
 160 }
 161
 162 #define random_ether_addr(addr) eth_random_addr(addr)
 163
 164 /**
 165  * eth_broadcast_addr - Assign broadcast address
 166  * @addr: Pointer to a six-byte array containing the Ethernet address
 167  *
 168  * Assign the broadcast address to the given address array.
 169  */
 170 static inline void eth_broadcast_addr(u8 *addr)
 171 {
 172         memset(addr, 0xff, ETH_ALEN);
 173 }
 174
 175 /**
 176  * eth_zero_addr - Assign zero address
 177  * @addr: Pointer to a six-byte array containing the Ethernet address
 178  *
 179  * Assign the zero address to the given address array.
 180  */
 181 static inline void eth_zero_addr(u8 *addr)
 182 {
 183         memset(addr, 0x00, ETH_ALEN);
 184 }
 185
 186 /**
 187  * eth_hw_addr_random - Generate software assigned random Ethernet and
 188  * set device flag
 189  * @dev: pointer to net_device structure
 190  *
 191  * Generate a random Ethernet address (MAC) to be used by a net device
 192  * and set addr_assign_type so the state can be read by sysfs and be
 193  * used by userspace.
 194  */
 195 static inline void eth_hw_addr_random(struct net_device *dev)
 196 {
 197         dev->addr_assign_type = NET_ADDR_RANDOM;
 198         eth_random_addr(dev->dev_addr);
 199 }
 200
 201 /**
 202  * eth_hw_addr_inherit - Copy dev_addr from another net_device
 203  * @dst: pointer to net_device to copy dev_addr to
 204  * @src: pointer to net_device to copy dev_addr from
 205  *
 206  * Copy the Ethernet address from one net_device to another along with
 207  * the address attributes (addr_assign_type).
 208  */
 209 static inline void eth_hw_addr_inherit(struct net_device *dst,
 210                                        struct net_device *src)
 211 {
 212         dst->addr_assign_type = src->addr_assign_type;
 213         memcpy(dst->dev_addr, src->dev_addr, ETH_ALEN);
 214 }
 215
 216 /**
 217  * compare_ether_addr - Compare two Ethernet addresses
 218  * @addr1: Pointer to a six-byte array containing the Ethernet address
 219  * @addr2: Pointer other six-byte array containing the Ethernet address
 220  *
 221  * Compare two Ethernet addresses, returns 0 if equal, non-zero otherwise.
 222  * Unlike memcmp(), it doesn't return a value suitable for sorting.
 223  */
 224 static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
 225 {
 226         const u16 *a = (const u16 *) addr1;
 227         const u16 *b = (const u16 *) addr2;
 228
 229         BUILD_BUG_ON(ETH_ALEN != 6);
 230         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
 231 }
 232
 233 /**
 234  * ether_addr_equal - Compare two Ethernet addresses
 235  * @addr1: Pointer to a six-byte array containing the Ethernet address
 236  * @addr2: Pointer other six-byte array containing the Ethernet address
 237  *
 238  * Compare two Ethernet addresses, returns true if equal
 239  */
 240 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
 241 {
 242         return !compare_ether_addr(addr1, addr2);
 243 }
 244
 245 static inline unsigned long zap_last_2bytes(unsigned long value)
 246 {
 247 #ifdef __BIG_ENDIAN
 248         return value >> 16;
 249 #else
 250         return value << 16;
 251 #endif
 252 }
 253
 254 /**
 255  * ether_addr_equal_64bits - Compare two Ethernet addresses
 256  * @addr1: Pointer to an array of 8 bytes
 257  * @addr2: Pointer to an other array of 8 bytes
 258  *
 259  * Compare two Ethernet addresses, returns true if equal, false otherwise.
 260  *
 261  * The function doesn't need any conditional branches and possibly uses
 262  * word memory accesses on CPU allowing cheap unaligned memory reads.
 263  * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
 264  *
 265  * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
 266  */
 267
 268 static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
 269                                            const u8 addr2[6+2])
 270 {
 271 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
 272         unsigned long fold = ((*(unsigned long *)addr1) ^
 273                               (*(unsigned long *)addr2));
 274
 275         if (sizeof(fold) == 8)
 276                 return zap_last_2bytes(fold) == 0;
 277
 278         fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
 279                                 (*(unsigned long *)(addr2 + 4)));
 280         return fold == 0;
 281 #else
 282         return ether_addr_equal(addr1, addr2);
 283 #endif
 284 }
 285
 286 /**
 287  * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
 288  * @dev: Pointer to a device structure
 289  * @addr: Pointer to a six-byte array containing the Ethernet address
 290  *
 291  * Compare passed address with all addresses of the device. Return true if the
 292  * address if one of the device addresses.
 293  *
 294  * Note that this function calls ether_addr_equal_64bits() so take care of
 295  * the right padding.
 296  */
 297 static inline bool is_etherdev_addr(const struct net_device *dev,
 298                                     const u8 addr[6 + 2])
 299 {
 300         struct netdev_hw_addr *ha;
 301         bool res = false;
 302
 303         rcu_read_lock();
 304         for_each_dev_addr(dev, ha) {
 305                 res = ether_addr_equal_64bits(addr, ha->addr);
 306                 if (res)
 307                         break;
 308         }
 309         rcu_read_unlock();
 310         return res;
 311 }
 312 #endif  /* __KERNEL__ */
 313
 314 /**
 315  * compare_ether_header - Compare two Ethernet headers
 316  * @a: Pointer to Ethernet header
 317  * @b: Pointer to Ethernet header
 318  *
 319  * Compare two Ethernet headers, returns 0 if equal.
 320  * This assumes that the network header (i.e., IP header) is 4-byte
 321  * aligned OR the platform can handle unaligned access.  This is the
 322  * case for all packets coming into netif_receive_skb or similar
 323  * entry points.
 324  */
 325
 326 static inline unsigned long compare_ether_header(const void *a, const void *b)
 327 {
 328 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 329         unsigned long fold;
 330
 331         /*
 332          * We want to compare 14 bytes:
 333          *  [a0 ... a13] ^ [b0 ... b13]
 334          * Use two long XOR, ORed together, with an overlap of two bytes.
 335          *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
 336          *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
 337          * This means the [a6 a7] ^ [b6 b7] part is done two times.
 338         */
 339         fold = *(unsigned long *)a ^ *(unsigned long *)b;
 340         fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
 341         return fold;
 342 #else
 343         u32 *a32 = (u32 *)((u8 *)a + 2);
 344         u32 *b32 = (u32 *)((u8 *)b + 2);
 345
 346         return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
 347                (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
 348 #endif
 349 }
 350
 351 #endif  /* _LINUX_ETHERDEVICE_H */