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/random.h>
  29
  30 #ifdef __KERNEL__
  31 extern int              eth_header(struct sk_buff *skb, struct net_device *dev,
  32                                    unsigned short type, void *daddr,
  33                                    void *saddr, unsigned len);
  34 extern int              eth_rebuild_header(struct sk_buff *skb);
  35 extern unsigned short   eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  36 extern void             eth_header_cache_update(struct hh_cache *hh, struct net_device *dev,
  37                                                 unsigned char * haddr);
  38 extern int              eth_header_cache(struct neighbour *neigh,
  39                                          struct hh_cache *hh);
  40
  41 extern struct net_device *alloc_etherdev(int sizeof_priv);
  42 static inline void eth_copy_and_sum (struct sk_buff *dest,
  43                                      const unsigned char *src,
  44                                      int len, int base)
  45 {
  46         memcpy (dest->data, src, len);
  47 }
  48
  49 /**
  50  * is_zero_ether_addr - Determine if give Ethernet address is all
  51  * zeros.
  52  */
  53 static inline int is_zero_ether_addr(const u8 *addr)
  54 {
  55         return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
  56 }
  57
  58 /**
  59  * is_multicast_ether_addr - Determine if the given Ethernet address is a
  60  * multicast address.
  61  *
  62  * @addr: Pointer to a six-byte array containing the Ethernet address
  63  *
  64  * Return true if the address is a multicast address.
  65  */
  66 static inline int is_multicast_ether_addr(const u8 *addr)
  67 {
  68         return addr[0] & 0x01;
  69 }
  70
  71 /**
  72  * is_valid_ether_addr - Determine if the given Ethernet address is valid
  73  * @addr: Pointer to a six-byte array containing the Ethernet address
  74  *
  75  * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
  76  * a multicast address, and is not FF:FF:FF:FF:FF:FF.
  77  *
  78  * Return true if the address is valid.
  79  */
  80 static inline int is_valid_ether_addr(const u8 *addr)
  81 {
  82         /* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
  83          * explicitly check for it here. */
  84         return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
  85 }
  86
  87 /**
  88  * random_ether_addr - Generate software assigned random Ethernet address
  89  * @addr: Pointer to a six-byte array containing the Ethernet address
  90  *
  91  * Generate a random Ethernet address (MAC) that is not multicast
  92  * and has the local assigned bit set.
  93  */
  94 static inline void random_ether_addr(u8 *addr)
  95 {
  96         get_random_bytes (addr, ETH_ALEN);
  97         addr [0] &= 0xfe;       /* clear multicast bit */
  98         addr [0] |= 0x02;       /* set local assignment bit (IEEE802) */
  99 }
 100 #endif  /* __KERNEL__ */
 101
 102 #endif  /* _LINUX_ETHERDEVICE_H */