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  *      WARNING: This move may well be temporary. This file will get merged with others RSN.
  22  *
  23  */
  24 #ifndef _LINUX_ETHERDEVICE_H
  25 #define _LINUX_ETHERDEVICE_H
  26
  27 #include <linux/if_ether.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/random.h>
  30 #include <asm/unaligned.h>
  31
  32 #ifdef __KERNEL__
  33 extern __be16           eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  34 extern const struct header_ops eth_header_ops;
  35
  36 extern int eth_header(struct sk_buff *skb, struct net_device *dev,
  37                       unsigned short type,
  38                       const void *daddr, const void *saddr, unsigned len);
  39 extern int eth_rebuild_header(struct sk_buff *skb);
  40 extern int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
  41 extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh);
  42 extern void eth_header_cache_update(struct hh_cache *hh,
  43                                     const struct net_device *dev,
  44                                     const unsigned char *haddr);
  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 /**
  57  * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
  58  * @addr: Pointer to a six-byte array containing the Ethernet address
  59  *
  60  * Return true if the address is all zeroes.
  61  */
  62 static inline int is_zero_ether_addr(const u8 *addr)
  63 {
  64         return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
  65 }
  66
  67 /**
  68  * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
  69  * @addr: Pointer to a six-byte array containing the Ethernet address
  70  *
  71  * Return true if the address is a multicast address.
  72  * By definition the broadcast address is also a multicast address.
  73  */
  74 static inline int is_multicast_ether_addr(const u8 *addr)
  75 {
  76         return 0x01 & addr[0];
  77 }
  78
  79 /**
  80  * is_local_ether_addr - Determine if the Ethernet address is locally-assigned one (IEEE 802).
  81  * @addr: Pointer to a six-byte array containing the Ethernet address
  82  *
  83  * Return true if the address is a local address.
  84  */
  85 static inline int is_local_ether_addr(const u8 *addr)
  86 {
  87         return 0x02 & addr[0];
  88 }
  89
  90 /**
  91  * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
  92  * @addr: Pointer to a six-byte array containing the Ethernet address
  93  *
  94  * Return true if the address is the broadcast address.
  95  */
  96 static inline int is_broadcast_ether_addr(const u8 *addr)
  97 {
  98         return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
  99 }
 100
 101 /**
 102  * is_unicast_ether_addr - Determine if the Ethernet address is unicast
 103  * @addr: Pointer to a six-byte array containing the Ethernet address
 104  *
 105  * Return true if the address is a unicast address.
 106  */
 107 static inline int is_unicast_ether_addr(const u8 *addr)
 108 {
 109         return !is_multicast_ether_addr(addr);
 110 }
 111
 112 /**
 113  * is_valid_ether_addr - Determine if the given Ethernet address is valid
 114  * @addr: Pointer to a six-byte array containing the Ethernet address
 115  *
 116  * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
 117  * a multicast address, and is not FF:FF:FF:FF:FF:FF.
 118  *
 119  * Return true if the address is valid.
 120  */
 121 static inline int is_valid_ether_addr(const u8 *addr)
 122 {
 123         /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
 124          * explicitly check for it here. */
 125         return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
 126 }
 127
 128 /**
 129  * random_ether_addr - Generate software assigned random Ethernet address
 130  * @addr: Pointer to a six-byte array containing the Ethernet address
 131  *
 132  * Generate a random Ethernet address (MAC) that is not multicast
 133  * and has the local assigned bit set.
 134  */
 135 static inline void random_ether_addr(u8 *addr)
 136 {
 137         get_random_bytes (addr, ETH_ALEN);
 138         addr [0] &= 0xfe;       /* clear multicast bit */
 139         addr [0] |= 0x02;       /* set local assignment bit (IEEE802) */
 140 }
 141
 142 /**
 143  * dev_hw_addr_random - Create random MAC and set device flag
 144  * @dev: pointer to net_device structure
 145  * @hwaddr: Pointer to a six-byte array containing the Ethernet address
 146  *
 147  * Generate random MAC to be used by a device and set addr_assign_type
 148  * so the state can be read by sysfs and be used by udev.
 149  */
 150 static inline void dev_hw_addr_random(struct net_device *dev, u8 *hwaddr)
 151 {
 152         dev->addr_assign_type |= NET_ADDR_RANDOM;
 153         random_ether_addr(hwaddr);
 154 }
 155
 156 /**
 157  * compare_ether_addr - Compare two Ethernet addresses
 158  * @addr1: Pointer to a six-byte array containing the Ethernet address
 159  * @addr2: Pointer other six-byte array containing the Ethernet address
 160  *
 161  * Compare two ethernet addresses, returns 0 if equal
 162  */
 163 static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
 164 {
 165         const u16 *a = (const u16 *) addr1;
 166         const u16 *b = (const u16 *) addr2;
 167
 168         BUILD_BUG_ON(ETH_ALEN != 6);
 169         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
 170 }
 171
 172 static inline unsigned long zap_last_2bytes(unsigned long value)
 173 {
 174 #ifdef __BIG_ENDIAN
 175         return value >> 16;
 176 #else
 177         return value << 16;
 178 #endif
 179 }
 180
 181 /**
 182  * compare_ether_addr_64bits - Compare two Ethernet addresses
 183  * @addr1: Pointer to an array of 8 bytes
 184  * @addr2: Pointer to an other array of 8 bytes
 185  *
 186  * Compare two ethernet addresses, returns 0 if equal.
 187  * Same result than "memcmp(addr1, addr2, ETH_ALEN)" but without conditional
 188  * branches, and possibly long word memory accesses on CPU allowing cheap
 189  * unaligned memory reads.
 190  * arrays = { byte1, byte2, byte3, byte4, byte6, byte7, pad1, pad2}
 191  *
 192  * Please note that alignment of addr1 & addr2 is only guaranted to be 16 bits.
 193  */
 194
 195 static inline unsigned compare_ether_addr_64bits(const u8 addr1[6+2],
 196                                                  const u8 addr2[6+2])
 197 {
 198 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
 199         unsigned long fold = ((*(unsigned long *)addr1) ^
 200                               (*(unsigned long *)addr2));
 201
 202         if (sizeof(fold) == 8)
 203                 return zap_last_2bytes(fold) != 0;
 204
 205         fold |= zap_last_2bytes((*(unsigned long *)(addr1 + 4)) ^
 206                                 (*(unsigned long *)(addr2 + 4)));
 207         return fold != 0;
 208 #else
 209         return compare_ether_addr(addr1, addr2);
 210 #endif
 211 }
 212
 213 /**
 214  * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
 215  * @dev: Pointer to a device structure
 216  * @addr: Pointer to a six-byte array containing the Ethernet address
 217  *
 218  * Compare passed address with all addresses of the device. Return true if the
 219  * address if one of the device addresses.
 220  *
 221  * Note that this function calls compare_ether_addr_64bits() so take care of
 222  * the right padding.
 223  */
 224 static inline bool is_etherdev_addr(const struct net_device *dev,
 225                                     const u8 addr[6 + 2])
 226 {
 227         struct netdev_hw_addr *ha;
 228         int res = 1;
 229
 230         rcu_read_lock();
 231         for_each_dev_addr(dev, ha) {
 232                 res = compare_ether_addr_64bits(addr, ha->addr);
 233                 if (!res)
 234                         break;
 235         }
 236         rcu_read_unlock();
 237         return !res;
 238 }
 239 #endif  /* __KERNEL__ */
 240
 241 /**
 242  * compare_ether_header - Compare two Ethernet headers
 243  * @a: Pointer to Ethernet header
 244  * @b: Pointer to Ethernet header
 245  *
 246  * Compare two ethernet headers, returns 0 if equal.
 247  * This assumes that the network header (i.e., IP header) is 4-byte
 248  * aligned OR the platform can handle unaligned access.  This is the
 249  * case for all packets coming into netif_receive_skb or similar
 250  * entry points.
 251  */
 252
 253 static inline unsigned long compare_ether_header(const void *a, const void *b)
 254 {
 255 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
 256         unsigned long fold;
 257
 258         /*
 259          * We want to compare 14 bytes:
 260          *  [a0 ... a13] ^ [b0 ... b13]
 261          * Use two long XOR, ORed together, with an overlap of two bytes.
 262          *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
 263          *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
 264          * This means the [a6 a7] ^ [b6 b7] part is done two times.
 265         */
 266         fold = *(unsigned long *)a ^ *(unsigned long *)b;
 267         fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
 268         return fold;
 269 #else
 270         u32 *a32 = (u32 *)((u8 *)a + 2);
 271         u32 *b32 = (u32 *)((u8 *)b + 2);
 272
 273         return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
 274                (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
 275 #endif
 276 }
 277
 278 #endif  /* _LINUX_ETHERDEVICE_H */