/*
   * 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.
   *
   */
  #ifndef _LINUX_ETHERDEVICE_H
  #define _LINUX_ETHERDEVICE_H
  
  #include <linux/if_ether.h>
  #include <linux/netdevice.h>
  #include <linux/random.h>
  #include <asm/unaligned.h>
  #include <asm/bitsperlong.h>
  
  #ifdef __KERNEL__
  __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev);
  extern const struct header_ops eth_header_ops;
  
  int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
  	       const void *daddr, const void *saddr, unsigned len);
  int eth_rebuild_header(struct sk_buff *skb);
  int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr);
  int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh,
  		     __be16 type);
  void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev,
  			     const unsigned char *haddr);
  int eth_prepare_mac_addr_change(struct net_device *dev, void *p);
  void eth_commit_mac_addr_change(struct net_device *dev, void *p);
  int eth_mac_addr(struct net_device *dev, void *p);
  int eth_change_mtu(struct net_device *dev, int new_mtu);
  int eth_validate_addr(struct net_device *dev);
  
  struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
  					    unsigned int rxqs);
  #define alloc_etherdev(sizeof_priv) alloc_etherdev_mq(sizeof_priv, 1)
  #define alloc_etherdev_mq(sizeof_priv, count) alloc_etherdev_mqs(sizeof_priv, count, count)
  
  /* Reserved Ethernet Addresses per IEEE 802.1Q */
  static const u8 eth_reserved_addr_base[ETH_ALEN] __aligned(2) =
  { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
  
  /**
   * is_link_local_ether_addr - Determine if given Ethernet address is link-local
   * @addr: Pointer to a six-byte array containing the Ethernet address
   *
   * Return true if address is link local reserved addr (01:80:c2:00:00:0X) per
   * IEEE 802.1Q 8.6.3 Frame filtering.
   *
   * Please note: addr must be aligned to u16.
   */
  static inline bool is_link_local_ether_addr(const u8 *addr)
  {
  	__be16 *a = (__be16 *)addr;
  	static const __be16 *b = (const __be16 *)eth_reserved_addr_base;
  	static const __be16 m = cpu_to_be16(0xfff0);
  
  #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
  	return (((*(const u32 *)addr) ^ (*(const u32 *)b)) |
  		((a[2] ^ b[2]) & m)) == 0;
  #else
  	return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | ((a[2] ^ b[2]) & m)) == 0;
  #endif
  }
  
  /**
   * 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.
   *
   * Please note: addr must be aligned to u16.
   */
  static inline bool is_zero_ether_addr(const u8 *addr)
  {
  #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
  	return ((*(const u32 *)addr) | (*(const u16 *)(addr + 4))) == 0;
  #else
  	return (*(const u16 *)(addr + 0) |
  		*(const u16 *)(addr + 2) |
  		*(const u16 *)(addr + 4)) == 0;
  #endif
  }
  
  /**
   * 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 bool 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 bool 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.
   *
   * Please note: addr must be aligned to u16.
   */
  static inline bool is_broadcast_ether_addr(const u8 *addr)
  {
  	return (*(const u16 *)(addr + 0) &
  		*(const u16 *)(addr + 2) &
  		*(const u16 *)(addr + 4)) == 0xffff;
  }
  
  /**
   * is_unicast_ether_addr - Determine if the Ethernet address is unicast
   * @addr: Pointer to a six-byte array containing the Ethernet address
   *
   * Return true if the address is a unicast address.
   */
  static inline bool is_unicast_ether_addr(const u8 *addr)
  {
  	return !is_multicast_ether_addr(addr);
  }
  
  /**
   * 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.
   *
   * Please note: addr must be aligned to u16.
   */
  static inline bool 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);
  }
  
  /**
   * eth_random_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 eth_random_addr(u8 *addr)
  {
  	get_random_bytes(addr, ETH_ALEN);
  	addr[0] &= 0xfe;	/* clear multicast bit */
  	addr[0] |= 0x02;	/* set local assignment bit (IEEE802) */
  }
  
  #define random_ether_addr(addr) eth_random_addr(addr)
  
  /**
   * eth_broadcast_addr - Assign broadcast address
   * @addr: Pointer to a six-byte array containing the Ethernet address
   *
   * Assign the broadcast address to the given address array.
   */
  static inline void eth_broadcast_addr(u8 *addr)
  {
  	memset(addr, 0xff, ETH_ALEN);
  }
  
  /**
   * eth_zero_addr - Assign zero address
   * @addr: Pointer to a six-byte array containing the Ethernet address
   *
   * Assign the zero address to the given address array.
   */
  static inline void eth_zero_addr(u8 *addr)
  {
  	memset(addr, 0x00, ETH_ALEN);
  }
  
  /**
   * eth_hw_addr_random - Generate software assigned random Ethernet and
   * set device flag
   * @dev: pointer to net_device structure
   *
   * Generate a random Ethernet address (MAC) to be used by a net device
   * and set addr_assign_type so the state can be read by sysfs and be
   * used by userspace.
   */
  static inline void eth_hw_addr_random(struct net_device *dev)
  {
  	dev->addr_assign_type = NET_ADDR_RANDOM;
  	eth_random_addr(dev->dev_addr);
  }
  
  /**
   * ether_addr_copy - Copy an Ethernet address
   * @dst: Pointer to a six-byte array Ethernet address destination
   * @src: Pointer to a six-byte array Ethernet address source
   *
   * Please note: dst & src must both be aligned to u16.
   */
  static inline void ether_addr_copy(u8 *dst, const u8 *src)
  {
  #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
  	*(u32 *)dst = *(const u32 *)src;
  	*(u16 *)(dst + 4) = *(const u16 *)(src + 4);
  #else
  	u16 *a = (u16 *)dst;
  	const u16 *b = (const u16 *)src;
  
  	a[0] = b[0];
  	a[1] = b[1];
  	a[2] = b[2];
  #endif
  }
  
  /**
   * eth_hw_addr_inherit - Copy dev_addr from another net_device
   * @dst: pointer to net_device to copy dev_addr to
   * @src: pointer to net_device to copy dev_addr from
   *
   * Copy the Ethernet address from one net_device to another along with
   * the address attributes (addr_assign_type).
   */
  static inline void eth_hw_addr_inherit(struct net_device *dst,
  				       struct net_device *src)
  {
  	dst->addr_assign_type = src->addr_assign_type;
  	ether_addr_copy(dst->dev_addr, src->dev_addr);
  }
  
  /**
   * ether_addr_equal - 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 true if equal
   *
   * Please note: addr1 & addr2 must both be aligned to u16.
   */
  static inline bool ether_addr_equal(const u8 *addr1, const u8 *addr2)
  {
  #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
  	u32 fold = ((*(const u32 *)addr1) ^ (*(const u32 *)addr2)) |
  		   ((*(const u16 *)(addr1 + 4)) ^ (*(const u16 *)(addr2 + 4)));
  
  	return fold == 0;
  #else
  	const u16 *a = (const u16 *)addr1;
  	const u16 *b = (const u16 *)addr2;
  
  	return ((a[0] ^ b[0]) | (a[1] ^ b[1]) | (a[2] ^ b[2])) == 0;
  #endif
  }
  
  /**
   * ether_addr_equal_64bits - Compare two Ethernet addresses
   * @addr1: Pointer to an array of 8 bytes
   * @addr2: Pointer to an other array of 8 bytes
   *
   * Compare two Ethernet addresses, returns true if equal, false otherwise.
   *
   * The function doesn't need any conditional branches and possibly uses
   * word memory accesses on CPU allowing cheap unaligned memory reads.
   * arrays = { byte1, byte2, byte3, byte4, byte5, byte6, pad1, pad2 }
   *
   * Please note that alignment of addr1 & addr2 are only guaranteed to be 16 bits.
   */
  
  static inline bool ether_addr_equal_64bits(const u8 addr1[6+2],
  					   const u8 addr2[6+2])
  {
  #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
  	u64 fold = (*(const u64 *)addr1) ^ (*(const u64 *)addr2);
  
  #ifdef __BIG_ENDIAN
  	return (fold >> 16) == 0;
  #else
  	return (fold << 16) == 0;
  #endif
  #else
  	return ether_addr_equal(addr1, addr2);
  #endif
  }
  
  /**
   * ether_addr_equal_unaligned - Compare two not u16 aligned 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 true if equal
   *
   * Please note: Use only when any Ethernet address may not be u16 aligned.
   */
  static inline bool ether_addr_equal_unaligned(const u8 *addr1, const u8 *addr2)
  {
  #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
  	return ether_addr_equal(addr1, addr2);
  #else
  	return memcmp(addr1, addr2, ETH_ALEN) == 0;
  #endif
  }
  
  /**
   * is_etherdev_addr - Tell if given Ethernet address belongs to the device.
   * @dev: Pointer to a device structure
   * @addr: Pointer to a six-byte array containing the Ethernet address
   *
   * Compare passed address with all addresses of the device. Return true if the
   * address if one of the device addresses.
   *
   * Note that this function calls ether_addr_equal_64bits() so take care of
   * the right padding.
   */
  static inline bool is_etherdev_addr(const struct net_device *dev,
  				    const u8 addr[6 + 2])
  {
  	struct netdev_hw_addr *ha;
  	bool res = false;
  
  	rcu_read_lock();
  	for_each_dev_addr(dev, ha) {
  		res = ether_addr_equal_64bits(addr, ha->addr);
  		if (res)
  			break;
  	}
  	rcu_read_unlock();
  	return res;
  }
  #endif	/* __KERNEL__ */
  
  /**
   * compare_ether_header - Compare two Ethernet headers
   * @a: Pointer to Ethernet header
   * @b: Pointer to Ethernet header
   *
   * Compare two Ethernet headers, returns 0 if equal.
   * This assumes that the network header (i.e., IP header) is 4-byte
   * aligned OR the platform can handle unaligned access.  This is the
   * case for all packets coming into netif_receive_skb or similar
   * entry points.
   */
  
  static inline unsigned long compare_ether_header(const void *a, const void *b)
  {
  #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && BITS_PER_LONG == 64
  	unsigned long fold;
  
  	/*
  	 * We want to compare 14 bytes:
  	 *  [a0 ... a13] ^ [b0 ... b13]
  	 * Use two long XOR, ORed together, with an overlap of two bytes.
  	 *  [a0  a1  a2  a3  a4  a5  a6  a7 ] ^ [b0  b1  b2  b3  b4  b5  b6  b7 ] |
  	 *  [a6  a7  a8  a9  a10 a11 a12 a13] ^ [b6  b7  b8  b9  b10 b11 b12 b13]
  	 * This means the [a6 a7] ^ [b6 b7] part is done two times.
  	*/
  	fold = *(unsigned long *)a ^ *(unsigned long *)b;
  	fold |= *(unsigned long *)(a + 6) ^ *(unsigned long *)(b + 6);
  	return fold;
  #else
  	u32 *a32 = (u32 *)((u8 *)a + 2);
  	u32 *b32 = (u32 *)((u8 *)b + 2);
  
  	return (*(u16 *)a ^ *(u16 *)b) | (a32[0] ^ b32[0]) |
  	       (a32[1] ^ b32[1]) | (a32[2] ^ b32[2]);
  #endif
  }
  
  #endif	/* _LINUX_ETHERDEVICE_H */