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_mq(int sizeof_priv, unsigned int queue_count);
  43 #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
  44
  45 /**
  46  * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
  47  * @addr: Pointer to a six-byte array containing the Ethernet address
  48  *
  49  * Return true if the address is all zeroes.
  50  */
  51 static inline int is_zero_ether_addr(const u8 *addr)
  52 {
  53         return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
  54 }
  55
  56 /**
  57  * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
  58  * @addr: Pointer to a six-byte array containing the Ethernet address
  59  *
  60  * Return true if the address is a multicast address.
  61  * By definition the broadcast address is also a multicast address.
  62  */
  63 static inline int is_multicast_ether_addr(const u8 *addr)
  64 {
  65         return (0x01 & addr[0]);
  66 }
  67
  68 /**
  69  * is_local_ether_addr - Determine if the Ethernet address is locally-assigned
  70  * one (IEEE 802).
  71  * @addr: Pointer to a six-byte array containing the Ethernet address
  72  *
  73  * Return true if the address is a local address.
  74  */
  75 static inline int is_local_ether_addr(const u8 *addr)
  76 {
  77         return (0x02 & addr[0]);
  78 }
  79
  80 /**
  81  * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
  82  * @addr: Pointer to a six-byte array containing the Ethernet address
  83  *
  84  * Return true if the address is the broadcast address.
  85  */
  86 static inline int is_broadcast_ether_addr(const u8 *addr)
  87 {
  88         return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
  89 }
  90
  91 /**
  92  * is_valid_ether_addr - Determine if the given Ethernet address is valid
  93  * @addr: Pointer to a six-byte array containing the Ethernet address
  94  *
  95  * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
  96  * a multicast address, and is not FF:FF:FF:FF:FF:FF.
  97  *
  98  * Return true if the address is valid.
  99  */
 100 static inline int is_valid_ether_addr(const u8 *addr)
 101 {
 102         /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
 103          * explicitly check for it here. */
 104         return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
 105 }
 106
 107 /**
 108  * random_ether_addr - Generate software assigned random Ethernet address
 109  * @addr: Pointer to a six-byte array containing the Ethernet address
 110  *
 111  * Generate a random Ethernet address (MAC) that is not multicast
 112  * and has the local assigned bit set.
 113  */
 114 static inline void random_ether_addr(u8 *addr)
 115 {
 116         get_random_bytes (addr, ETH_ALEN);
 117         addr [0] &= 0xfe;       /* clear multicast bit */
 118         addr [0] |= 0x02;       /* set local assignment bit (IEEE802) */
 119 }
 120
 121 /**
 122  * compare_ether_addr - Compare two Ethernet addresses
 123  * @addr1: Pointer to a six-byte array containing the Ethernet address
 124  * @addr2: Pointer other six-byte array containing the Ethernet address
 125  *
 126  * Compare two ethernet addresses, returns 0 if equal
 127  */
 128 static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
 129 {
 130         const u16 *a = (const u16 *) addr1;
 131         const u16 *b = (const u16 *) addr2;
 132
 133         BUILD_BUG_ON(ETH_ALEN != 6);
 134         return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
 135 }
 136 #endif  /* __KERNEL__ */
 137
 138 #endif  /* _LINUX_ETHERDEVICE_H */