[mirror_ubuntu-artful-kernel.git] / net / ethernet / eth.c

/*
 * 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/sched.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/config.h>
#include <linux/init.h>
#include <net/dst.h>
#include <net/arp.h>
#include <net/sock.h>
#include <net/ipv6.h>
#include <net/ip.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/checksum.h>

__setup("ether=", netdev_boot_setup);

/*
 *	 Create the Ethernet MAC header for an arbitrary protocol layer 
 *
 *	saddr=NULL	means use device source address
 *	daddr=NULL	means leave destination address (eg unresolved arp)
 */

int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
	   void *daddr, void *saddr, unsigned len)
{
	struct ethhdr *eth = (struct ethhdr *)skb_push(skb,ETH_HLEN);

	/* 
	 *	Set the protocol type. For a packet of type ETH_P_802_3 we put the length
	 *	in here instead. It is up to the 802.2 layer to carry protocol information.
	 */
	
	if(type!=ETH_P_802_3) 
		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,dev->addr_len);

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

	if (dev->flags & (IFF_LOOPBACK|IFF_NOARP)) 
	{
		memset(eth->h_dest, 0, dev->addr_len);
		return ETH_HLEN;
	}
	
	if(daddr)
	{
		memcpy(eth->h_dest,daddr,dev->addr_len);
		return ETH_HLEN;
	}
	
	return -ETH_HLEN;
}


/*
 *	Rebuild the Ethernet MAC header. This is called after an ARP
 *	(or in future other address resolution) has completed on this
 *	sk_buff. We now let 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 __constant_htons(ETH_P_IP):
 		return arp_find(eth->h_dest, skb);
#endif	
	default:
		printk(KERN_DEBUG
		       "%s: unable to resolve type %X addresses.\n", 
		       dev->name, (int)eth->h_proto);
		
		memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
		break;
	}

	return 0;
}


/*
 *	Determine the packet's protocol ID. 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;
	unsigned char *rawp;
	
	skb->mac.raw=skb->data;
	skb_pull(skb,ETH_HLEN);
	eth = eth_hdr(skb);
	
	if(*eth->h_dest&1)
	{
		if(memcmp(eth->h_dest,dev->broadcast, ETH_ALEN)==0)
			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(memcmp(eth->h_dest,dev->dev_addr, ETH_ALEN))
			skb->pkt_type=PACKET_OTHERHOST;
	}
	
	if (ntohs(eth->h_proto) >= 1536)
		return eth->h_proto;
		
	rawp = skb->data;
	
	/*
	 *	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 (*(unsigned short *)rawp == 0xFFFF)
		return htons(ETH_P_802_3);
		
	/*
	 *	Real 802.2 LLC
	 */
	return htons(ETH_P_802_2);
}

static int eth_header_parse(struct sk_buff *skb, unsigned char *haddr)
{
	struct ethhdr *eth = eth_hdr(skb);
	memcpy(haddr, eth->h_source, ETH_ALEN);
	return ETH_ALEN;
}

int eth_header_cache(struct neighbour *neigh, struct hh_cache *hh)
{
	unsigned short type = hh->hh_type;
	struct ethhdr *eth;
	struct net_device *dev = neigh->dev;

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

	if (type == __constant_htons(ETH_P_802_3))
		return -1;

	eth->h_proto = type;
	memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
	memcpy(eth->h_dest, neigh->ha, dev->addr_len);
	hh->hh_len = ETH_HLEN;
	return 0;
}

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

void eth_header_cache_update(struct hh_cache *hh, struct net_device *dev, unsigned char * haddr)
{
	memcpy(((u8*)hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
	       haddr, dev->addr_len);
}

EXPORT_SYMBOL(eth_type_trans);

static int eth_mac_addr(struct net_device *dev, void *p)
{
	struct sockaddr *addr=p;
	if (netif_running(dev))
		return -EBUSY;
	memcpy(dev->dev_addr, addr->sa_data,dev->addr_len);
	return 0;
}

static int eth_change_mtu(struct net_device *dev, int new_mtu)
{
	if ((new_mtu < 68) || (new_mtu > 1500))
		return -EINVAL;
	dev->mtu = new_mtu;
	return 0;
}

/*
 * Fill in the fields of the device structure with ethernet-generic values.
 */
void ether_setup(struct net_device *dev)
{
	dev->change_mtu		= eth_change_mtu;
	dev->hard_header	= eth_header;
	dev->rebuild_header 	= eth_rebuild_header;
	dev->set_mac_address 	= eth_mac_addr;
	dev->hard_header_cache	= eth_header_cache;
	dev->header_cache_update= eth_header_cache_update;
	dev->hard_header_parse	= eth_header_parse;

	dev->type		= ARPHRD_ETHER;
	dev->hard_header_len 	= ETH_HLEN;
	dev->mtu		= 1500; /* eth_mtu */
	dev->addr_len		= ETH_ALEN;
	dev->tx_queue_len	= 1000;	/* Ethernet wants good queues */	
	dev->flags		= IFF_BROADCAST|IFF_MULTICAST;
	
	memset(dev->broadcast,0xFF, ETH_ALEN);

}
EXPORT_SYMBOL(ether_setup);

/**
 * alloc_etherdev - Allocates and sets up an ethernet device
 * @sizeof_priv: Size of additional driver-private structure to be allocated
 *	for this ethernet device
 *
 * 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(int sizeof_priv)
{
	return alloc_netdev(sizeof_priv, "eth%d", ether_setup);
}
EXPORT_SYMBOL(alloc_etherdev);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* INET An implementation of the TCP/IP protocol suite for the LINUX
	3	* operating system. INET is implemented using the BSD Socket
	4	* interface as the means of communication with the user level.
	5	*
	6	* Ethernet-type device handling.
	7	*
	8	* Version: @(#)eth.c 1.0.7 05/25/93
	9	*
02c30a84	10	* Authors: Ross Biro
1da177e4 LT	11	* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
	12	* Mark Evans, <evansmp@uhura.aston.ac.uk>
	13	* Florian La Roche, <rzsfl@rz.uni-sb.de>
	14	* Alan Cox, <gw4pts@gw4pts.ampr.org>
	15	*
	16	* Fixes:
	17	* Mr Linux : Arp problems
	18	* Alan Cox : Generic queue tidyup (very tiny here)
	19	* Alan Cox : eth_header ntohs should be htons
	20	* Alan Cox : eth_rebuild_header missing an htons and
	21	* minor other things.
	22	* Tegge : Arp bug fixes.
	23	* Florian : Removed many unnecessary functions, code cleanup
	24	* and changes for new arp and skbuff.
	25	* Alan Cox : Redid header building to reflect new format.
	26	* Alan Cox : ARP only when compiled with CONFIG_INET
	27	* Greg Page : 802.2 and SNAP stuff.
	28	* Alan Cox : MAC layer pointers/new format.
	29	* Paul Gortmaker : eth_copy_and_sum shouldn't csum padding.
	30	* Alan Cox : Protect against forwarding explosions with
	31	* older network drivers and IFF_ALLMULTI.
	32	* Christer Weinigel : Better rebuild header message.
	33	* Andrew Morton : 26Feb01: kill ether_setup() - use netdev_boot_setup().
	34	*
	35	* This program is free software; you can redistribute it and/or
	36	* modify it under the terms of the GNU General Public License
	37	* as published by the Free Software Foundation; either version
	38	* 2 of the License, or (at your option) any later version.
	39	*/
	40	#include <linux/module.h>
	41	#include <linux/types.h>
	42	#include <linux/kernel.h>
	43	#include <linux/sched.h>
	44	#include <linux/string.h>
	45	#include <linux/mm.h>
	46	#include <linux/socket.h>
	47	#include <linux/in.h>
	48	#include <linux/inet.h>
	49	#include <linux/ip.h>
	50	#include <linux/netdevice.h>
	51	#include <linux/etherdevice.h>
	52	#include <linux/skbuff.h>
	53	#include <linux/errno.h>
	54	#include <linux/config.h>
	55	#include <linux/init.h>
	56	#include <net/dst.h>
	57	#include <net/arp.h>
	58	#include <net/sock.h>
	59	#include <net/ipv6.h>
	60	#include <net/ip.h>
	61	#include <asm/uaccess.h>
	62	#include <asm/system.h>
	63	#include <asm/checksum.h>
	64
1da177e4 LT	65	__setup("ether=", netdev_boot_setup);
	66
	67	/*
	68	* Create the Ethernet MAC header for an arbitrary protocol layer
	69	*
	70	* saddr=NULL means use device source address
	71	* daddr=NULL means leave destination address (eg unresolved arp)
	72	*/
	73
	74	int eth_header(struct sk_buff skb, struct net_device dev, unsigned short type,
	75	void daddr, void saddr, unsigned len)
	76	{
	77	struct ethhdr eth = (struct ethhdr )skb_push(skb,ETH_HLEN);
	78
	79	/*
	80	* Set the protocol type. For a packet of type ETH_P_802_3 we put the length
	81	* in here instead. It is up to the 802.2 layer to carry protocol information.
	82	*/
	83
	84	if(type!=ETH_P_802_3)
	85	eth->h_proto = htons(type);
	86	else
	87	eth->h_proto = htons(len);
	88
	89	/*
	90	* Set the source hardware address.
	91	*/
	92
ff593c59 DV	93	if(!saddr)
	94	saddr = dev->dev_addr;
	95	memcpy(eth->h_source,saddr,dev->addr_len);
1da177e4 LT	96
	97	/*
	98	* Anyway, the loopback-device should never use this function...
	99	*/
	100
	101	if (dev->flags & (IFF_LOOPBACK\|IFF_NOARP))
	102	{
	103	memset(eth->h_dest, 0, dev->addr_len);
	104	return ETH_HLEN;
	105	}
	106
	107	if(daddr)
	108	{
	109	memcpy(eth->h_dest,daddr,dev->addr_len);
	110	return ETH_HLEN;
	111	}
	112
	113	return -ETH_HLEN;
	114	}
	115
	116
	117	/*
	118	* Rebuild the Ethernet MAC header. This is called after an ARP
	119	* (or in future other address resolution) has completed on this
	120	* sk_buff. We now let ARP fill in the other fields.
	121	*
	122	* This routine CANNOT use cached dst->neigh!
	123	* Really, it is used only when dst->neigh is wrong.
	124	*/
	125
	126	int eth_rebuild_header(struct sk_buff *skb)
	127	{
	128	struct ethhdr eth = (struct ethhdr )skb->data;
	129	struct net_device *dev = skb->dev;
	130
	131	switch (eth->h_proto)
	132	{
	133	#ifdef CONFIG_INET
	134	case __constant_htons(ETH_P_IP):
	135	return arp_find(eth->h_dest, skb);
	136	#endif
	137	default:
	138	printk(KERN_DEBUG
	139	"%s: unable to resolve type %X addresses.\n",
	140	dev->name, (int)eth->h_proto);
	141
	142	memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
	143	break;
	144	}
	145
	146	return 0;
	147	}
	148
	149
	150	/*
	151	* Determine the packet's protocol ID. The rule here is that we
	152	* assume 802.3 if the type field is short enough to be a length.
	153	* This is normal practice and works for any 'now in use' protocol.
	154	*/
	155
ab611487	156	__be16 eth_type_trans(struct sk_buff skb, struct net_device dev)
1da177e4 LT	157	{
	158	struct ethhdr *eth;
	159	unsigned char *rawp;
	160
	161	skb->mac.raw=skb->data;
	162	skb_pull(skb,ETH_HLEN);
	163	eth = eth_hdr(skb);
1da177e4 LT	164
	165	if(*eth->h_dest&1)
	166	{
	167	if(memcmp(eth->h_dest,dev->broadcast, ETH_ALEN)==0)
	168	skb->pkt_type=PACKET_BROADCAST;
	169	else
	170	skb->pkt_type=PACKET_MULTICAST;
	171	}
	172
	173	/*
	174	* This ALLMULTI check should be redundant by 1.4
	175	* so don't forget to remove it.
	176	*
	177	* Seems, you forgot to remove it. All silly devices
	178	* seems to set IFF_PROMISC.
	179	*/
	180
	181	else if(1 /dev->flags&IFF_PROMISC/)
	182	{
	183	if(memcmp(eth->h_dest,dev->dev_addr, ETH_ALEN))
	184	skb->pkt_type=PACKET_OTHERHOST;
	185	}
	186
	187	if (ntohs(eth->h_proto) >= 1536)
	188	return eth->h_proto;
	189
	190	rawp = skb->data;
	191
	192	/*
	193	* This is a magic hack to spot IPX packets. Older Novell breaks
	194	* the protocol design and runs IPX over 802.3 without an 802.2 LLC
	195	* layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
	196	* won't work for fault tolerant netware but does for the rest.
	197	*/
	198	if ((unsigned short )rawp == 0xFFFF)
	199	return htons(ETH_P_802_3);
	200
	201	/*
	202	* Real 802.2 LLC
	203	*/
	204	return htons(ETH_P_802_2);
	205	}
	206
	207	static int eth_header_parse(struct sk_buff skb, unsigned char haddr)
	208	{
	209	struct ethhdr *eth = eth_hdr(skb);
	210	memcpy(haddr, eth->h_source, ETH_ALEN);
	211	return ETH_ALEN;
	212	}
	213
	214	int eth_header_cache(struct neighbour neigh, struct hh_cache hh)
	215	{
	216	unsigned short type = hh->hh_type;
	217	struct ethhdr *eth;
	218	struct net_device *dev = neigh->dev;
	219
	220	eth = (struct ethhdr*)
	221	(((u8)hh->hh_data) + (HH_DATA_OFF(sizeof(eth))));
	222
	223	if (type == __constant_htons(ETH_P_802_3))
	224	return -1;
	225
	226	eth->h_proto = type;
	227	memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
228	memcpy(eth->h_dest, neigh->ha, dev->addr_len);
229	hh->hh_len = ETH_HLEN;
230	return 0;
231	}
232
233	/*
234	* Called by Address Resolution module to notify changes in address.
235	*/
236
237	void eth_header_cache_update(struct hh_cache hh, struct net_device dev, unsigned char * haddr)
238	{
239	memcpy(((u8*)hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
240	haddr, dev->addr_len);
241	}
242
243	EXPORT_SYMBOL(eth_type_trans);
244
245	static int eth_mac_addr(struct net_device dev, void p)
246	{
247	struct sockaddr *addr=p;
248	if (netif_running(dev))
249	return -EBUSY;
250	memcpy(dev->dev_addr, addr->sa_data,dev->addr_len);
251	return 0;
252	}
253
254	static int eth_change_mtu(struct net_device *dev, int new_mtu)
255	{
256	if ((new_mtu < 68) \|\| (new_mtu > 1500))
257	return -EINVAL;
258	dev->mtu = new_mtu;
259	return 0;
260	}
261
262	/*
263	* Fill in the fields of the device structure with ethernet-generic values.
264	*/
265	void ether_setup(struct net_device *dev)
266	{
267	dev->change_mtu = eth_change_mtu;
268	dev->hard_header = eth_header;
269	dev->rebuild_header = eth_rebuild_header;
270	dev->set_mac_address = eth_mac_addr;
271	dev->hard_header_cache = eth_header_cache;
272	dev->header_cache_update= eth_header_cache_update;
273	dev->hard_header_parse = eth_header_parse;
274
275	dev->type = ARPHRD_ETHER;
276	dev->hard_header_len = ETH_HLEN;
277	dev->mtu = 1500; /* eth_mtu */
278	dev->addr_len = ETH_ALEN;
279	dev->tx_queue_len = 1000; /* Ethernet wants good queues */
280	dev->flags = IFF_BROADCAST\|IFF_MULTICAST;
281
282	memset(dev->broadcast,0xFF, ETH_ALEN);
283
284	}
285	EXPORT_SYMBOL(ether_setup);
286
287	/**
288	* alloc_etherdev - Allocates and sets up an ethernet device
289	* @sizeof_priv: Size of additional driver-private structure to be allocated
290	* for this ethernet device
291	*
292	* Fill in the fields of the device structure with ethernet-generic
293	* values. Basically does everything except registering the device.
294	*
295	* Constructs a new net device, complete with a private data area of
296	* size @sizeof_priv. A 32-byte (not bit) alignment is enforced for
297	* this private data area.
298	*/
299
300	struct net_device *alloc_etherdev(int sizeof_priv)
301	{
302	return alloc_netdev(sizeof_priv, "eth%d", ether_setup);
303	}
304	EXPORT_SYMBOL(alloc_etherdev);