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_mac_addr(struct net_device *dev, void *p);
  44 extern int eth_change_mtu(struct net_device *dev, int new_mtu);
  45 extern int eth_validate_addr(struct net_device *dev);
  46
  47
  48
  49 extern 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 static inline bool is_link_local_ether_addr(const u8 *addr)
  66 {
  67         __be16 *a = (__be16 *)addr;
  68         static const __be16 *b = (const __be16 *)eth_reserved_addr_base;
  69         static const __be16 m = cpu_to_be16(0xfff0);
  70
  71         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
  72 }
  73
  74 /**
  75  * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
  76  * @addr: Pointer to a six-byte array containing the Ethernet address
  77  *
  78  * Return true if the address is all zeroes.
  79  */
  80 static inline bool is_zero_ether_addr(const u8 *addr)
  81 {
  82         return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
  83 }
  84
  85 /**
  86  * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
  87  * @addr: Pointer to a six-byte array containing the Ethernet address
  88  *
  89  * Return true if the address is a multicast address.
  90  * By definition the broadcast address is also a multicast address.
  91  */
  92 static inline bool is_multicast_ether_addr(const u8 *addr)
  93 {
  94         return 0x01 & addr[0];
  95 }
  96
  97 /**
  98  * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
  99  * @addr: Pointer to a six-byte array containing the Ethernet address
 100  *
 101  * Return true if the address is a local address.
 102  */
 103 static inline bool is_local_ether_addr(const u8 *addr)
 104 {
 105         return 0x02 & addr[0];
 106 }
 107
 108 /**
 109  * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
 110  * @addr: Pointer to a six-byte array containing the Ethernet address
 111  *
 112  * Return true if the address is the broadcast address.
 113  */
 114 static inline bool is_broadcast_ether_addr(const u8 *addr)
 115 {
 116         return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
 117 }
 118
 119 /**
 120  * is_unicast_ether_addr - Determine if the Ethernet address is unicast
 121  * @addr: Pointer to a six-byte array containing the Ethernet address
 122  *
 123  * Return true if the address is a unicast address.
 124  */
 125 static inline bool is_unicast_ether_addr(const u8 *addr)
 126 {
 127         return !is_multicast_ether_addr(addr);
 128 }
 129
 130 /**
 131  * is_valid_ether_addr - Determine if the given Ethernet address is valid
 132  * @addr: Pointer to a six-byte array containing the Ethernet address
 133  *
 134  * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
 135  * a multicast address, and is not FF:FF:FF:FF:FF:FF.
 136  *
 137  * Return true if the address is valid.
 138  */
 139 static inline bool is_valid_ether_addr(const u8 *addr)
 140 {
 141         /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
 142          * explicitly check for it here. */
 143         return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
 144 }
 145
 146 /**
 147  * eth_random_addr - Generate software assigned random Ethernet address
 148  * @addr: Pointer to a six-byte array containing the Ethernet address
 149  *
 150  * Generate a random Ethernet address (MAC) that is not multicast
 151  * and has the local assigned bit set.
 152  */
 153 static inline void eth_random_addr(u8 *addr)
 154 {
 155         get_random_bytes(addr, ETH_ALEN);
 156         addr[0] &= 0xfe;        /* clear multicast bit */
 157         addr[0] |= 0x02;        /* set local assignment bit (IEEE802) */
 158 }
 159
 160 #define random_ether_addr(addr) eth_random_addr(addr)
 161
 162 /**
 163  * eth_broadcast_addr - Assign broadcast address
 164  * @addr: Pointer to a six-byte array containing the Ethernet address
 165  *
 166  * Assign the broadcast address to the given address array.
 167  */
 168 static inline void eth_broadcast_addr(u8 *addr)
 169 {
 170         memset(addr, 0xff, ETH_ALEN);
 171 }
 172
 173 /**
 174  * eth_zero_addr - Assign zero address
 175  * @addr: Pointer to a six-byte array containing the Ethernet address
 176  *
 177  * Assign the zero address to the given address array.
 178  */
 179 static inline void eth_zero_addr(u8 *addr)
 180 {
 181         memset(addr, 0x00, ETH_ALEN);
 182 }
 183
 184 /**
 185  * eth_hw_addr_random - Generate software assigned random Ethernet and
 186  * set device flag
 187  * @dev: pointer to net_device structure
 188  *
 189  * Generate a random Ethernet address (MAC) to be used by a net device
 190  * and set addr_assign_type so the state can be read by sysfs and be
 191  * used by userspace.
 192  */
 193 static inline void eth_hw_addr_random(struct net_device *dev)
 194 {
 195         dev->addr_assign_type = NET_ADDR_RANDOM;
 196         eth_random_addr(dev->dev_addr);
 197 }
 198
 199 /**
 200  * compare_ether_addr - Compare two Ethernet addresses
 201  * @addr1: Pointer to a six-byte array containing the Ethernet address
 202  * @addr2: Pointer other six-byte array containing the Ethernet address
 203  *
 204  * Compare two Ethernet addresses, returns 0 if equal, non-zero otherwise.
 205  * Unlike memcmp(), it doesn't return a value suitable for sorting.
 206  */
 207 static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
 208 {
 209         const u16 *a = (const u16 *) addr1;
 210         const u16 *b = (const u16 *) addr2;
 211
 212         BUILD_BUG_ON(ETH_ALEN != 6);
 213         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
 214 }
 215
 216 /**
 217  * ether_addr_equal - 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 true if equal
 222  */
 223 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
 224 {
 225         return !compare_ether_addr(addr1, addr2);
 226 }
 227
 228 static inline unsigned long zap_last_2bytes(unsigned long value)
 229 {
 230 #ifdef __BIG_ENDIAN
 231         return value >> 16;
 232 #else
 233         return value << 16;
 234 #endif
 235 }
 236
 237 /**
 238  * ether_addr_equal_64bits - Compare two Ethernet addresses
 239  * @addr1: Pointer to an array of 8 bytes
 240  * @addr2: Pointer to an other array of 8 bytes
 241  *
 242  * Compare two Ethernet addresses, returns true if equal, false otherwise.
 243  *
 244  * The function doesn't need any conditional branches and possibly uses
 245  * word memory accesses on CPU allowing cheap unaligned memory reads.
 246  * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
 247  *
 248  * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
 249  */
 250
 251 static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
 252                                            const u8 addr2[6+2])
 253 {
 254 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
 255         unsigned long fold = ((*(unsigned long *)addr1) ^
 256                               (*(unsigned long *)addr2));
 257
 258         if (sizeof(fold) == 8)
 259                 return zap_last_2bytes(fold) == 0;
 260
 261         fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
 262                                 (*(unsigned long *)(addr2 + 4)));
 263         return fold == 0;
 264 #else
 265         return ether_addr_equal(addr1, addr2);
 266 #endif
 267 }
 268
 269 /**
 270  * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
 271  * @dev: Pointer to a device structure
 272  * @addr: Pointer to a six-byte array containing the Ethernet address
 273  *
 274  * Compare passed address with all addresses of the device. Return true if the
 275  * address if one of the device addresses.
 276  *
 277  * Note that this function calls ether_addr_equal_64bits() so take care of
 278  * the right padding.
 279  */
 280 static inline bool is_etherdev_addr(const struct net_device *dev,
 281                                     const u8 addr[6 + 2])
 282 {
 283         struct netdev_hw_addr *ha;
 284         bool res = false;
 285
 286         rcu_read_lock();
 287         for_each_dev_addr(dev, ha) {
 288                 res = ether_addr_equal_64bits(addr, ha->addr);
 289                 if (res)
 290                         break;
 291         }
 292         rcu_read_unlock();
 293         return res;
 294 }
 295 #endif  /* __KERNEL__ */
 296
 297 /**
 298  * compare_ether_header - Compare two Ethernet headers
 299  * @a: Pointer to Ethernet header
 300  * @b: Pointer to Ethernet header
 301  *
 302  * Compare two Ethernet headers, returns 0 if equal.
 303  * This assumes that the network header (i.e., IP header) is 4-byte
 304  * aligned OR the platform can handle unaligned access.  This is the
 305  * case for all packets coming into netif_receive_skb or similar
 306  * entry points.
 307  */
 308
 309 static inline unsigned long compare_ether_header(const void *a, const void *b)
 310 {
 311 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 312         unsigned long fold;
 313
 314         /*
 315          * We want to compare 14 bytes:
 316          *  [a0 ... a13] ^ [b0 ... b13]
 317          * Use two long XOR, ORed together, with an overlap of two bytes.
 318          *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
 319          *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
 320          * This means the [a6 a7] ^ [b6 b7] part is done two times.
 321         */
 322         fold = *(unsigned long *)a ^ *(unsigned long *)b;
 323         fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
 324         return fold;
 325 #else
 326         u32 *a32 = (u32 *)((u8 *)a + 2);
 327         u32 *b32 = (u32 *)((u8 *)b + 2);
 328
 329         return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
 330                (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
 331 #endif
 332 }
 333
 334 #endif  /* _LINUX_ETHERDEVICE_H */