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 br_reserved_address[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
  56
  57 /**
  58  * is_link_local -  Determine if given Eth addr is a link local mcast address.
  59  * @addr: Pointer to a six-byte array containing the Ethernet address
  60  *
  61  * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per
  62  * IEEE 802.1Q 8.6.3 Frame filtering.
  63  */
  64 static inline int is_link_local(const unsigned char *dest)
  65 {
  66         __be16 *a = (__be16 *)dest;
  67         static const __be16 *b = (const __be16 *)br_reserved_address;
  68         static const __be16 m = cpu_to_be16(0xfff0);
  69
  70         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
  71 }
  72
  73 /**
  74  * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
  75  * @addr: Pointer to a six-byte array containing the Ethernet address
  76  *
  77  * Return true if the address is all zeroes.
  78  */
  79 static inline bool is_zero_ether_addr(const u8 *addr)
  80 {
  81         return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
  82 }
  83
  84 /**
  85  * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
  86  * @addr: Pointer to a six-byte array containing the Ethernet address
  87  *
  88  * Return true if the address is a multicast address.
  89  * By definition the broadcast address is also a multicast address.
  90  */
  91 static inline bool is_multicast_ether_addr(const u8 *addr)
  92 {
  93         return 0x01 & addr[0];
  94 }
  95
  96 /**
  97  * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
  98  * @addr: Pointer to a six-byte array containing the Ethernet address
  99  *
 100  * Return true if the address is a local address.
 101  */
 102 static inline bool is_local_ether_addr(const u8 *addr)
 103 {
 104         return 0x02 & addr[0];
 105 }
 106
 107 /**
 108  * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
 109  * @addr: Pointer to a six-byte array containing the Ethernet address
 110  *
 111  * Return true if the address is the broadcast address.
 112  */
 113 static inline bool is_broadcast_ether_addr(const u8 *addr)
 114 {
 115         return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
 116 }
 117
 118 /**
 119  * is_unicast_ether_addr - Determine if the Ethernet address is unicast
 120  * @addr: Pointer to a six-byte array containing the Ethernet address
 121  *
 122  * Return true if the address is a unicast address.
 123  */
 124 static inline bool is_unicast_ether_addr(const u8 *addr)
 125 {
 126         return !is_multicast_ether_addr(addr);
 127 }
 128
 129 /**
 130  * is_valid_ether_addr - Determine if the given Ethernet address is valid
 131  * @addr: Pointer to a six-byte array containing the Ethernet address
 132  *
 133  * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
 134  * a multicast address, and is not FF:FF:FF:FF:FF:FF.
 135  *
 136  * Return true if the address is valid.
 137  */
 138 static inline bool is_valid_ether_addr(const u8 *addr)
 139 {
 140         /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
 141          * explicitly check for it here. */
 142         return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
 143 }
 144
 145 /**
 146  * eth_random_addr - Generate software assigned random Ethernet address
 147  * @addr: Pointer to a six-byte array containing the Ethernet address
 148  *
 149  * Generate a random Ethernet address (MAC) that is not multicast
 150  * and has the local assigned bit set.
 151  */
 152 static inline void eth_random_addr(u8 *addr)
 153 {
 154         get_random_bytes(addr, ETH_ALEN);
 155         addr[0] &= 0xfe;        /* clear multicast bit */
 156         addr[0] |= 0x02;        /* set local assignment bit (IEEE802) */
 157 }
 158
 159 #define random_ether_addr(addr) eth_random_addr(addr)
 160
 161 /**
 162  * eth_broadcast_addr - Assign broadcast address
 163  * @addr: Pointer to a six-byte array containing the Ethernet address
 164  *
 165  * Assign the broadcast address to the given address array.
 166  */
 167 static inline void eth_broadcast_addr(u8 *addr)
 168 {
 169         memset(addr, 0xff, ETH_ALEN);
 170 }
 171
 172 /**
 173  * eth_zero_addr - Assign zero address
 174  * @addr: Pointer to a six-byte array containing the Ethernet address
 175  *
 176  * Assign the zero address to the given address array.
 177  */
 178 static inline void eth_zero_addr(u8 *addr)
 179 {
 180         memset(addr, 0x00, ETH_ALEN);
 181 }
 182
 183 /**
 184  * eth_hw_addr_random - Generate software assigned random Ethernet and
 185  * set device flag
 186  * @dev: pointer to net_device structure
 187  *
 188  * Generate a random Ethernet address (MAC) to be used by a net device
 189  * and set addr_assign_type so the state can be read by sysfs and be
 190  * used by userspace.
 191  */
 192 static inline void eth_hw_addr_random(struct net_device *dev)
 193 {
 194         dev->addr_assign_type |= NET_ADDR_RANDOM;
 195         eth_random_addr(dev->dev_addr);
 196 }
 197
 198 /**
 199  * compare_ether_addr - Compare two Ethernet addresses
 200  * @addr1: Pointer to a six-byte array containing the Ethernet address
 201  * @addr2: Pointer other six-byte array containing the Ethernet address
 202  *
 203  * Compare two Ethernet addresses, returns 0 if equal, non-zero otherwise.
 204  * Unlike memcmp(), it doesn't return a value suitable for sorting.
 205  */
 206 static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
 207 {
 208         const u16 *a = (const u16 *) addr1;
 209         const u16 *b = (const u16 *) addr2;
 210
 211         BUILD_BUG_ON(ETH_ALEN != 6);
 212         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
 213 }
 214
 215 /**
 216  * ether_addr_equal - Compare two Ethernet addresses
 217  * @addr1: Pointer to a six-byte array containing the Ethernet address
 218  * @addr2: Pointer other six-byte array containing the Ethernet address
 219  *
 220  * Compare two Ethernet addresses, returns true if equal
 221  */
 222 static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
 223 {
 224         return !compare_ether_addr(addr1, addr2);
 225 }
 226
 227 static inline unsigned long zap_last_2bytes(unsigned long value)
 228 {
 229 #ifdef __BIG_ENDIAN
 230         return value >> 16;
 231 #else
 232         return value << 16;
 233 #endif
 234 }
 235
 236 /**
 237  * ether_addr_equal_64bits - Compare two Ethernet addresses
 238  * @addr1: Pointer to an array of 8 bytes
 239  * @addr2: Pointer to an other array of 8 bytes
 240  *
 241  * Compare two Ethernet addresses, returns true if equal, false otherwise.
 242  *
 243  * The function doesn't need any conditional branches and possibly uses
 244  * word memory accesses on CPU allowing cheap unaligned memory reads.
 245  * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
 246  *
 247  * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
 248  */
 249
 250 static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
 251                                            const u8 addr2[6+2])
 252 {
 253 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
 254         unsigned long fold = ((*(unsigned long *)addr1) ^
 255                               (*(unsigned long *)addr2));
 256
 257         if (sizeof(fold) == 8)
 258                 return zap_last_2bytes(fold) == 0;
 259
 260         fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
 261                                 (*(unsigned long *)(addr2 + 4)));
 262         return fold == 0;
 263 #else
 264         return ether_addr_equal(addr1, addr2);
 265 #endif
 266 }
 267
 268 /**
 269  * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
 270  * @dev: Pointer to a device structure
 271  * @addr: Pointer to a six-byte array containing the Ethernet address
 272  *
 273  * Compare passed address with all addresses of the device. Return true if the
 274  * address if one of the device addresses.
 275  *
 276  * Note that this function calls ether_addr_equal_64bits() so take care of
 277  * the right padding.
 278  */
 279 static inline bool is_etherdev_addr(const struct net_device *dev,
 280                                     const u8 addr[6 + 2])
 281 {
 282         struct netdev_hw_addr *ha;
 283         bool res = false;
 284
 285         rcu_read_lock();
 286         for_each_dev_addr(dev, ha) {
 287                 res = ether_addr_equal_64bits(addr, ha->addr);
 288                 if (res)
 289                         break;
 290         }
 291         rcu_read_unlock();
 292         return res;
 293 }
 294 #endif  /* __KERNEL__ */
 295
 296 /**
 297  * compare_ether_header - Compare two Ethernet headers
 298  * @a: Pointer to Ethernet header
 299  * @b: Pointer to Ethernet header
 300  *
 301  * Compare two Ethernet headers, returns 0 if equal.
 302  * This assumes that the network header (i.e., IP header) is 4-byte
 303  * aligned OR the platform can handle unaligned access.  This is the
 304  * case for all packets coming into netif_receive_skb or similar
 305  * entry points.
 306  */
 307
 308 static inline unsigned long compare_ether_header(const void *a, const void *b)
 309 {
 310 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 311         unsigned long fold;
 312
 313         /*
 314          * We want to compare 14 bytes:
 315          *  [a0 ... a13] ^ [b0 ... b13]
 316          * Use two long XOR, ORed together, with an overlap of two bytes.
 317          *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
 318          *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
 319          * This means the [a6 a7] ^ [b6 b7] part is done two times.
 320         */
 321         fold = *(unsigned long *)a ^ *(unsigned long *)b;
 322         fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
 323         return fold;
 324 #else
 325         u32 *a32 = (u32 *)((u8 *)a + 2);
 326         u32 *b32 = (u32 *)((u8 *)b + 2);
 327
 328         return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
 329                (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
 330 #endif
 331 }
 332
 333 #endif  /* _LINUX_ETHERDEVICE_H */