/*
   * INET		An implementation of the TCP/IP protocol suite for the LINUX
   *		operating system.  INET is implemented using the  BSD Socket
   *		interface as the means of communication with the user level.
   *
   *		Ethernet-type device handling.
   *
   * Version:	@(#)eth.c	1.0.7	05/25/93
   *

   * Authors:	Ross Biro

   *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   *		Mark Evans, <evansmp@uhura.aston.ac.uk>
   *		Florian  La Roche, <rzsfl@rz.uni-sb.de>
   *		Alan Cox, <gw4pts@gw4pts.ampr.org>

   *

   * Fixes:
   *		Mr Linux	: Arp problems
   *		Alan Cox	: Generic queue tidyup (very tiny here)
   *		Alan Cox	: eth_header ntohs should be htons
   *		Alan Cox	: eth_rebuild_header missing an htons and
   *				  minor other things.

   *		Tegge		: Arp bug fixes.

   *		Florian		: Removed many unnecessary functions, code cleanup
   *				  and changes for new arp and skbuff.
   *		Alan Cox	: Redid header building to reflect new format.
   *		Alan Cox	: ARP only when compiled with CONFIG_INET
   *		Greg Page	: 802.2 and SNAP stuff.
   *		Alan Cox	: MAC layer pointers/new format.
   *		Paul Gortmaker	: eth_copy_and_sum shouldn't csum padding.
   *		Alan Cox	: Protect against forwarding explosions with
   *				  older network drivers and IFF_ALLMULTI.
   *	Christer Weinigel	: Better rebuild header message.
   *             Andrew Morton    : 26Feb01: kill ether_setup() - use netdev_boot_setup().
   *
   *		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.
   */
  #include <linux/module.h>
  #include <linux/types.h>
  #include <linux/kernel.h>

  #include <linux/string.h>
  #include <linux/mm.h>
  #include <linux/socket.h>
  #include <linux/in.h>
  #include <linux/inet.h>
  #include <linux/ip.h>
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/skbuff.h>
  #include <linux/errno.h>

  #include <linux/init.h>

  #include <linux/if_ether.h>

  #include <net/dst.h>
  #include <net/arp.h>
  #include <net/sock.h>
  #include <net/ipv6.h>
  #include <net/ip.h>

  #include <net/dsa.h>

  #include <asm/uaccess.h>
  #include <asm/system.h>

  __setup("ether=", netdev_boot_setup);

  /**
   * eth_header - create the Ethernet header
   * @skb:	buffer to alter
   * @dev:	source device
   * @type:	Ethernet type field
   * @daddr: destination address (NULL leave destination address)
   * @saddr: source address (NULL use device source address)
   * @len:   packet length (<= skb->len)

   *

   *

   * Set the protocol type. For a packet of type ETH_P_802_3/2 we put the length
   * in here instead.

   */

  int eth_header(struct sk_buff *skb, struct net_device *dev,
  	       unsigned short type,
  	       const void *daddr, const void *saddr, unsigned len)

  {

  	struct ethhdr *eth = (struct ethhdr *)skb_push(skb, ETH_HLEN);

  	if (type != ETH_P_802_3 && type != ETH_P_802_2)

  		eth->h_proto = htons(type);
  	else
  		eth->h_proto = htons(len);
  
  	/*

  	 *      Set the source hardware address.

  	 */

  
  	if (!saddr)

  		saddr = dev->dev_addr;

  	memcpy(eth->h_source, saddr, ETH_ALEN);

  	if (daddr) {

  		memcpy(eth->h_dest, daddr, ETH_ALEN);

  		return ETH_HLEN;
  	}

  	/*

  	 *      Anyway, the loopback-device should never use this function...

  	 */

  	if (dev->flags & (IFF_LOOPBACK | IFF_NOARP)) {

  		memset(eth->h_dest, 0, ETH_ALEN);

  		return ETH_HLEN;
  	}

  	return -ETH_HLEN;
  }

  EXPORT_SYMBOL(eth_header);

  /**
   * eth_rebuild_header- rebuild the Ethernet MAC header.
   * @skb: socket buffer to update
   *
   * This is called after an ARP or IPV6 ndisc it's resolution on this
   * sk_buff. We now let protocol (ARP) fill in the other fields.

   *

   * This routine CANNOT use cached dst->neigh!
   * Really, it is used only when dst->neigh is wrong.

   */

  int eth_rebuild_header(struct sk_buff *skb)
  {
  	struct ethhdr *eth = (struct ethhdr *)skb->data;
  	struct net_device *dev = skb->dev;

  	switch (eth->h_proto) {

  #ifdef CONFIG_INET

  	case htons(ETH_P_IP):

  		return arp_find(eth->h_dest, skb);
  #endif

  	default:
  		printk(KERN_DEBUG

  		       "%s: unable to resolve type %X addresses.
  ",

  		       dev->name, ntohs(eth->h_proto));

  		memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);

  		break;
  	}
  
  	return 0;
  }

  EXPORT_SYMBOL(eth_rebuild_header);

  /**
   * eth_type_trans - determine the packet's protocol ID.
   * @skb: received socket data
   * @dev: receiving network device
   *
   * The rule here is that we
   * assume 802.3 if the type field is short enough to be a length.
   * This is normal practice and works for any 'now in use' protocol.

   */

  __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev)

  {
  	struct ethhdr *eth;

  	skb->dev = dev;

  	skb_reset_mac_header(skb);

  	skb_pull_inline(skb, ETH_HLEN);

  	eth = eth_hdr(skb);

  	if (unlikely(is_multicast_ether_addr(eth->h_dest))) {
  		if (!compare_ether_addr_64bits(eth->h_dest, dev->broadcast))

  			skb->pkt_type = PACKET_BROADCAST;

  		else

  			skb->pkt_type = PACKET_MULTICAST;

  	}

  	/*

  	 *      This ALLMULTI check should be redundant by 1.4
  	 *      so don't forget to remove it.

  	 *

  	 *      Seems, you forgot to remove it. All silly devices
  	 *      seems to set IFF_PROMISC.

  	 */

  
  	else if (1 /*dev->flags&IFF_PROMISC */ ) {

  		if (unlikely(compare_ether_addr_64bits(eth->h_dest, dev->dev_addr)))

  			skb->pkt_type = PACKET_OTHERHOST;

  	}

  	/*
  	 * Some variants of DSA tagging don't have an ethertype field
  	 * at all, so we check here whether one of those tagging
  	 * variants has been configured on the receiving interface,
  	 * and if so, set skb->protocol without looking at the packet.
  	 */
  	if (netdev_uses_dsa_tags(dev))
  		return htons(ETH_P_DSA);

  	if (netdev_uses_trailer_tags(dev))
  		return htons(ETH_P_TRAILER);

  	if (ntohs(eth->h_proto) >= 1536)
  		return eth->h_proto;

  	/*

  	 *      This is a magic hack to spot IPX packets. Older Novell breaks
  	 *      the protocol design and runs IPX over 802.3 without an 802.2 LLC
  	 *      layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
  	 *      won't work for fault tolerant netware but does for the rest.

  	 */

  	if (skb->len >= 2 && *(unsigned short *)(skb->data) == 0xFFFF)

  		return htons(ETH_P_802_3);

  	/*

  	 *      Real 802.2 LLC

  	 */
  	return htons(ETH_P_802_2);
  }

  EXPORT_SYMBOL(eth_type_trans);

  /**
   * eth_header_parse - extract hardware address from packet
   * @skb: packet to extract header from
   * @haddr: destination buffer
   */

  int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr)

  {

  	const struct ethhdr *eth = eth_hdr(skb);

  	memcpy(haddr, eth->h_source, ETH_ALEN);
  	return ETH_ALEN;
  }

  EXPORT_SYMBOL(eth_header_parse);

  /**
   * eth_header_cache - fill cache entry from neighbour
   * @neigh: source neighbour
   * @hh: destination cache entry

   * @type: Ethernet type field

   * Create an Ethernet header template from the neighbour.
   */

  int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type)

  {

  	struct ethhdr *eth;

  	const struct net_device *dev = neigh->dev;

  	eth = (struct ethhdr *)
  	    (((u8 *) hh->hh_data) + (HH_DATA_OFF(sizeof(*eth))));

  	if (type == htons(ETH_P_802_3))

  		return -1;
  
  	eth->h_proto = type;

  	memcpy(eth->h_source, dev->dev_addr, ETH_ALEN);
  	memcpy(eth->h_dest, neigh->ha, ETH_ALEN);

  	hh->hh_len = ETH_HLEN;
  	return 0;
  }

  EXPORT_SYMBOL(eth_header_cache);

  /**
   * eth_header_cache_update - update cache entry
   * @hh: destination cache entry
   * @dev: network device
   * @haddr: new hardware address
   *

   * Called by Address Resolution module to notify changes in address.
   */

  void eth_header_cache_update(struct hh_cache *hh,
  			     const struct net_device *dev,
  			     const unsigned char *haddr)

  {

  	memcpy(((u8 *) hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),

  	       haddr, ETH_ALEN);

  }

  EXPORT_SYMBOL(eth_header_cache_update);

  /**
   * eth_mac_addr - set new Ethernet hardware address
   * @dev: network device
   * @p: socket address
   * Change hardware address of device.
   *
   * This doesn't change hardware matching, so needs to be overridden
   * for most real devices.
   */

  int eth_mac_addr(struct net_device *dev, void *p)

  {

  	struct sockaddr *addr = p;

  	if (netif_running(dev))
  		return -EBUSY;

  	if (!is_valid_ether_addr(addr->sa_data))
  		return -EADDRNOTAVAIL;

  	memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);

  	return 0;
  }

  EXPORT_SYMBOL(eth_mac_addr);

  /**
   * eth_change_mtu - set new MTU size
   * @dev: network device
   * @new_mtu: new Maximum Transfer Unit
   *
   * Allow changing MTU size. Needs to be overridden for devices
   * supporting jumbo frames.
   */

  int eth_change_mtu(struct net_device *dev, int new_mtu)

  {

  	if (new_mtu < 68 || new_mtu > ETH_DATA_LEN)

  		return -EINVAL;
  	dev->mtu = new_mtu;
  	return 0;
  }

  EXPORT_SYMBOL(eth_change_mtu);

  int eth_validate_addr(struct net_device *dev)

  {
  	if (!is_valid_ether_addr(dev->dev_addr))

  		return -EADDRNOTAVAIL;

  
  	return 0;
  }

  EXPORT_SYMBOL(eth_validate_addr);

  const struct header_ops eth_header_ops ____cacheline_aligned = {
  	.create		= eth_header,
  	.parse		= eth_header_parse,
  	.rebuild	= eth_rebuild_header,
  	.cache		= eth_header_cache,
  	.cache_update	= eth_header_cache_update,
  };

  /**
   * ether_setup - setup Ethernet network device
   * @dev: network device
   * Fill in the fields of the device structure with Ethernet-generic values.

   */
  void ether_setup(struct net_device *dev)
  {

  	dev->header_ops		= &eth_header_ops;

  	dev->type		= ARPHRD_ETHER;
  	dev->hard_header_len 	= ETH_HLEN;

  	dev->mtu		= ETH_DATA_LEN;

  	dev->addr_len		= ETH_ALEN;

  	dev->tx_queue_len	= 1000;	/* Ethernet wants good queues */

  	dev->flags		= IFF_BROADCAST|IFF_MULTICAST;

  	dev->priv_flags		|= IFF_TX_SKB_SHARING;

  	memset(dev->broadcast, 0xFF, ETH_ALEN);

  
  }
  EXPORT_SYMBOL(ether_setup);
  
  /**

   * alloc_etherdev_mqs - Allocates and sets up an Ethernet device

   * @sizeof_priv: Size of additional driver-private structure to be allocated

   *	for this Ethernet device

   * @txqs: The number of TX queues this device has.

   * @rxqs: The number of RX queues this device has.

   *

   * Fill in the fields of the device structure with Ethernet-generic

   * values. Basically does everything except registering the device.
   *
   * Constructs a new net device, complete with a private data area of

   * size (sizeof_priv).  A 32-byte (not bit) alignment is enforced for

   * this private data area.
   */

  struct net_device *alloc_etherdev_mqs(int sizeof_priv, unsigned int txqs,
  				      unsigned int rxqs)

  {

  	return alloc_netdev_mqs(sizeof_priv, "eth%d", ether_setup, txqs, rxqs);

  }

  EXPORT_SYMBOL(alloc_etherdev_mqs);

  static size_t _format_mac_addr(char *buf, int buflen,

  			       const unsigned char *addr, int len)

  {

  	int i;
  	char *cp = buf;
  
  	for (i = 0; i < len; i++) {
  		cp += scnprintf(cp, buflen - (cp - buf), "%02x", addr[i]);
  		if (i == len - 1)
  			break;

  		cp += scnprintf(cp, buflen - (cp - buf), ":");

  	}
  	return cp - buf;
  }
  
  ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len)
  {
  	size_t l;
  
  	l = _format_mac_addr(buf, PAGE_SIZE, addr, len);

  	l += scnprintf(buf + l, PAGE_SIZE - l, "
  ");

  	return (ssize_t)l;

  }
  EXPORT_SYMBOL(sysfs_format_mac);