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
  31 #ifdef __KERNEL__
  32 extern int              eth_header(struct sk_buff *skb, struct net_device *dev,
  33                                    unsigned short type, void *daddr,
  34                                    void *saddr, unsigned len);
  35 extern int              eth_rebuild_header(struct sk_buff *skb);
  36 extern __be16           eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  37 extern void             eth_header_cache_update(struct hh_cache *hh, struct net_device *dev,
  38                                                 unsigned char * haddr);
  39 extern int              eth_header_cache(struct neighbour *neigh,
  40                                          struct hh_cache *hh);
  41
  42 extern struct net_device *alloc_etherdev(int sizeof_priv);
  43 static inline void eth_copy_and_sum (struct sk_buff *dest,
  44                                      const unsigned char *src,
  45                                      int len, int base)
  46 {
  47         memcpy (dest->data, src, len);
  48 }
  49
  50 /**
  51  * is_zero_ether_addr - Determine if give Ethernet address is all
  52  * zeros.
  53  */
  54 static inline int is_zero_ether_addr(const u8 *addr)
  55 {
  56         return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
  57 }
  58
  59 /**
  60  * is_multicast_ether_addr - Determine if the given Ethernet address is a
  61  * multicast address.
  62  *
  63  * @addr: Pointer to a six-byte array containing the Ethernet address
  64  *
  65  * Return true if the address is a multicast address.
  66  */
  67 static inline int is_multicast_ether_addr(const u8 *addr)
  68 {
  69         return ((addr[0] != 0xff) && (0x01 & addr[0]));
  70 }
  71
  72 static inline int is_broadcast_ether_addr(const u8 *addr)
  73 {
  74         return ((addr[0] == 0xff) && (addr[1] == 0xff) && (addr[2] == 0xff) &&
  75                 (addr[3] == 0xff) && (addr[4] == 0xff) && (addr[5] == 0xff));
  76 }
  77
  78 /**
  79  * is_valid_ether_addr - Determine if the given Ethernet address is valid
  80  * @addr: Pointer to a six-byte array containing the Ethernet address
  81  *
  82  * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
  83  * a multicast address, and is not FF:FF:FF:FF:FF:FF.
  84  *
  85  * Return true if the address is valid.
  86  */
  87 static inline int is_valid_ether_addr(const u8 *addr)
  88 {
  89         /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
  90          * explicitly check for it here. */
  91         return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
  92 }
  93
  94 /**
  95  * random_ether_addr - Generate software assigned random Ethernet address
  96  * @addr: Pointer to a six-byte array containing the Ethernet address
  97  *
  98  * Generate a random Ethernet address (MAC) that is not multicast
  99  * and has the local assigned bit set.
 100  */
 101 static inline void random_ether_addr(u8 *addr)
 102 {
 103         get_random_bytes (addr, ETH_ALEN);
 104         addr [0] &= 0xfe;       /* clear multicast bit */
 105         addr [0] |= 0x02;       /* set local assignment bit (IEEE802) */
 106 }
 107
 108 /**
 109  * compare_ether_addr - Compare two Ethernet addresses
 110  * @addr1: Pointer to a six-byte array containing the Ethernet address
 111  * @addr2 Pointer other six-byte array containing the Ethernet address
 112  *
 113  * Compare two ethernet addresses, returns 0 if equal
 114  */
 115 static inline unsigned compare_ether_addr(const u8 *_a, const u8 *_b)
 116 {
 117         const u16 *a = (const u16 *) _a;
 118         const u16 *b = (const u16 *) _b;
 119
 120         BUILD_BUG_ON(ETH_ALEN != 6);
 121         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
 122 }
 123 #endif  /* __KERNEL__ */
 124
 125 #endif  /* _LINUX_ETHERDEVICE_H */