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