text: /*
   * INET		An implementation of the TCP/IP protocol suite for the LINUX
   *		operating system.  NET  is implemented using the  BSD Socket
   *		interface as the means of communication with the user level.
   *
   *		Definitions for the Ethernet handlers.
   *
   * Version:	@(#)eth.h	1.0.4	05/13/93
   *
   * Authors:	Ross Biro
   *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   *
   *		Relocated to include/linux where it belongs by Alan Cox 
   *							<gw4pts@gw4pts.ampr.org>
   *
   *		This program is free software; you can redistribute it and/or
   *		modify it under the terms of the GNU General Public License
   *		as published by the Free Software Foundation; either version
   *		2 of the License, or (at your option) any later version.
   *
   *	WARNING: This move may well be temporary. This file will get merged with others RSN.
   *
   */
  #ifndef _LINUX_ETHERDEVICE_H
  #define _LINUX_ETHERDEVICE_H
  
  #include <linux/if_ether.h>
  #include <linux/netdevice.h>
  #include <linux/random.h>
  
  #ifdef __KERNEL__
  extern __be16		eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  extern const struct header_ops eth_header_ops;
  
  extern int eth_header(struct sk_buff *skb, struct net_device *dev,
  		      unsigned short type,
  		      const void *daddr, const void *saddr, unsigned len);
  extern int eth_rebuild_header(struct sk_buff *skb);
  extern int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
  extern int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh);
  extern void eth_header_cache_update(struct hh_cache *hh,
  				    const struct net_device *dev,
  				    const unsigned char *haddr);
  
  
  extern struct net_device *alloc_etherdev_mq(int sizeof_priv, unsigned int queue_count);
  #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
  
  /**
   * is_zero_ether_addr - Determine if give Ethernet address is all zeros.
   * @addr: Pointer to a six-byte array containing the Ethernet address
   *
   * Return true if the address is all zeroes.
   */
  static inline int is_zero_ether_addr(const u8 *addr)
  {
  	return !(addr[0] | addr[1] | addr[2] | addr[3] | addr[4] | addr[5]);
  }
  
  /**
   * is_multicast_ether_addr - Determine if the Ethernet address is a multicast.
   * @addr: Pointer to a six-byte array containing the Ethernet address
   *
   * Return true if the address is a multicast address.
   * By definition the broadcast address is also a multicast address.
   */
  static inline int is_multicast_ether_addr(const u8 *addr)
  {
  	return (0x01 & addr[0]);
  }
  
  /**
   * is_local_ether_addr - Determine if the Ethernet address is locally-assigned
   * one (IEEE 802).
   * @addr: Pointer to a six-byte array containing the Ethernet address
   *
   * Return true if the address is a local address.
   */
  static inline int is_local_ether_addr(const u8 *addr)
  {
  	return (0x02 & addr[0]);
  }
  
  /**
   * is_broadcast_ether_addr - Determine if the Ethernet address is broadcast
   * @addr: Pointer to a six-byte array containing the Ethernet address
   *
   * Return true if the address is the broadcast address.
   */
  static inline int is_broadcast_ether_addr(const u8 *addr)
  {
  	return (addr[0] & addr[1] & addr[2] & addr[3] & addr[4] & addr[5]) == 0xff;
  }
  
  /**
   * is_valid_ether_addr - Determine if the given Ethernet address is valid
   * @addr: Pointer to a six-byte array containing the Ethernet address
   *
   * Check that the Ethernet address (MAC) is not 00:00:00:00:00:00, is not
   * a multicast address, and is not FF:FF:FF:FF:FF:FF.
   *
   * Return true if the address is valid.
   */
  static inline int is_valid_ether_addr(const u8 *addr)
  {
  	/* FF:FF:FF:FF:FF:FF is a multicast address so we don't need to
  	 * explicitly check for it here. */
  	return !is_multicast_ether_addr(addr) && !is_zero_ether_addr(addr);
  }
  
  /**
   * random_ether_addr - Generate software assigned random Ethernet address
   * @addr: Pointer to a six-byte array containing the Ethernet address
   *
   * Generate a random Ethernet address (MAC) that is not multicast
   * and has the local assigned bit set.
   */
  static inline void random_ether_addr(u8 *addr)
  {
  	get_random_bytes (addr, ETH_ALEN);
  	addr [0] &= 0xfe;	/* clear multicast bit */
  	addr [0] |= 0x02;	/* set local assignment bit (IEEE802) */
  }
  
  /**
   * compare_ether_addr - Compare two Ethernet addresses
   * @addr1: Pointer to a six-byte array containing the Ethernet address
   * @addr2: Pointer other six-byte array containing the Ethernet address
   *
   * Compare two ethernet addresses, returns 0 if equal
   */
  static inline unsigned compare_ether_addr(const u8 *addr1, const u8 *addr2)
  {
  	const u16 *a = (const u16 *) addr1;
  	const u16 *b = (const u16 *) addr2;
  
  	BUILD_BUG_ON(ETH_ALEN != 6);
  	return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) != 0;
  }
  #endif	/* __KERNEL__ */
  
  #endif	/* _LINUX_ETHERDEVICE_H */
  