[linux.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, <[email protected]>
 *		Mark Evans, <[email protected]>
 *		Florian  La Roche, <[email protected]>
 *		Alan Cox, <[email protected]>
 * 
 * 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 <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 <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 (is_multicast_ether_addr(eth->h_dest)) {
		if (!compare_ether_addr(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(eth->h_dest, dev->dev_addr)))
			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 > ETH_DATA_LEN)
		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		= ETH_DATA_LEN;
	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, <[email protected]>
	12	* Mark Evans, <[email protected]>
	13	* Florian La Roche, <[email protected]>
	14	* Alan Cox, <[email protected]>
	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>
46f25dff	56	#include <linux/if_ether.h>
1da177e4 LT	57	#include <net/dst.h>
	58	#include <net/arp.h>
	59	#include <net/sock.h>
	60	#include <net/ipv6.h>
	61	#include <net/ip.h>
	62	#include <asm/uaccess.h>
	63	#include <asm/system.h>
	64	#include <asm/checksum.h>
	65
1da177e4 LT	66	__setup("ether=", netdev_boot_setup);
	67
	68	/*
	69	* Create the Ethernet MAC header for an arbitrary protocol layer
	70	*
	71	* saddr=NULL means use device source address
	72	* daddr=NULL means leave destination address (eg unresolved arp)
	73	*/
	74
	75	int eth_header(struct sk_buff skb, struct net_device dev, unsigned short type,
	76	void daddr, void saddr, unsigned len)
	77	{
	78	struct ethhdr eth = (struct ethhdr )skb_push(skb,ETH_HLEN);
	79
	80	/*
	81	* Set the protocol type. For a packet of type ETH_P_802_3 we put the length
	82	* in here instead. It is up to the 802.2 layer to carry protocol information.
	83	*/
	84
	85	if(type!=ETH_P_802_3)
	86	eth->h_proto = htons(type);
	87	else
	88	eth->h_proto = htons(len);
	89
	90	/*
	91	* Set the source hardware address.
	92	*/
	93
ff593c59 DV	94	if(!saddr)
	95	saddr = dev->dev_addr;
	96	memcpy(eth->h_source,saddr,dev->addr_len);
1da177e4 LT	97
	98	/*
	99	* Anyway, the loopback-device should never use this function...
	100	*/
	101
	102	if (dev->flags & (IFF_LOOPBACK\|IFF_NOARP))
	103	{
	104	memset(eth->h_dest, 0, dev->addr_len);
	105	return ETH_HLEN;
	106	}
	107
	108	if(daddr)
	109	{
	110	memcpy(eth->h_dest,daddr,dev->addr_len);
	111	return ETH_HLEN;
	112	}
	113
	114	return -ETH_HLEN;
	115	}
	116
	117
	118	/*
	119	* Rebuild the Ethernet MAC header. This is called after an ARP
	120	* (or in future other address resolution) has completed on this
	121	* sk_buff. We now let ARP fill in the other fields.
	122	*
	123	* This routine CANNOT use cached dst->neigh!
	124	* Really, it is used only when dst->neigh is wrong.
	125	*/
	126
	127	int eth_rebuild_header(struct sk_buff *skb)
	128	{
	129	struct ethhdr eth = (struct ethhdr )skb->data;
	130	struct net_device *dev = skb->dev;
	131
	132	switch (eth->h_proto)
	133	{
	134	#ifdef CONFIG_INET
	135	case __constant_htons(ETH_P_IP):
	136	return arp_find(eth->h_dest, skb);
	137	#endif
	138	default:
	139	printk(KERN_DEBUG
	140	"%s: unable to resolve type %X addresses.\n",
	141	dev->name, (int)eth->h_proto);
	142
	143	memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
	144	break;
	145	}
	146
	147	return 0;
	148	}
	149
	150
	151	/*
	152	* Determine the packet's protocol ID. The rule here is that we
	153	* assume 802.3 if the type field is short enough to be a length.
	154	* This is normal practice and works for any 'now in use' protocol.
	155	*/
	156
ab611487	157	__be16 eth_type_trans(struct sk_buff skb, struct net_device dev)
1da177e4 LT	158	{
	159	struct ethhdr *eth;
	160	unsigned char *rawp;
	161
ba645c16	162	skb->mac.raw = skb->data;
1da177e4 LT	163	skb_pull(skb,ETH_HLEN);
1da177e4 LT	164	eth = eth_hdr(skb);
1da177e4	165
dbbc0988	166	if (is_multicast_ether_addr(eth->h_dest)) {
360ac8e2	167	if (!compare_ether_addr(eth->h_dest, dev->broadcast))
ba645c16	168	skb->pkt_type = PACKET_BROADCAST;
1da177e4	169	else
ba645c16	170	skb->pkt_type = PACKET_MULTICAST;
1da177e4 LT	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
ba645c16	181	else if(1 /dev->flags&IFF_PROMISC/) {
360ac8e2	182	if (unlikely(compare_ether_addr(eth->h_dest, dev->dev_addr)))
ba645c16	183	skb->pkt_type = PACKET_OTHERHOST;
1da177e4 LT	184	}
	185
	186	if (ntohs(eth->h_proto) >= 1536)
	187	return eth->h_proto;
	188
	189	rawp = skb->data;
	190
	191	/*
	192	* This is a magic hack to spot IPX packets. Older Novell breaks
	193	* the protocol design and runs IPX over 802.3 without an 802.2 LLC
	194	* layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This
	195	* won't work for fault tolerant netware but does for the rest.
	196	*/
	197	if ((unsigned short )rawp == 0xFFFF)
	198	return htons(ETH_P_802_3);
	199
	200	/*
	201	* Real 802.2 LLC
	202	*/
	203	return htons(ETH_P_802_2);
	204	}
	205
	206	static int eth_header_parse(struct sk_buff skb, unsigned char haddr)
	207	{
	208	struct ethhdr *eth = eth_hdr(skb);
	209	memcpy(haddr, eth->h_source, ETH_ALEN);
	210	return ETH_ALEN;
	211	}
	212
	213	int eth_header_cache(struct neighbour neigh, struct hh_cache hh)
	214	{
	215	unsigned short type = hh->hh_type;
	216	struct ethhdr *eth;
	217	struct net_device *dev = neigh->dev;
	218
	219	eth = (struct ethhdr*)
	220	(((u8)hh->hh_data) + (HH_DATA_OFF(sizeof(eth))));
	221
	222	if (type == __constant_htons(ETH_P_802_3))
	223	return -1;
	224
	225	eth->h_proto = type;
	226	memcpy(eth->h_source, dev->dev_addr, dev->addr_len);
	227	memcpy(eth->h_dest, neigh->ha, dev->addr_len);
	228	hh->hh_len = ETH_HLEN;
	229	return 0;
	230	}
	231
	232	/*
	233	* Called by Address Resolution module to notify changes in address.
	234	*/
	235
	236	void eth_header_cache_update(struct hh_cache hh, struct net_device dev, unsigned char * haddr)
	237	{
	238	memcpy(((u8*)hh->hh_data) + HH_DATA_OFF(sizeof(struct ethhdr)),
	239	haddr, dev->addr_len);
	240	}
	241
	242	EXPORT_SYMBOL(eth_type_trans);
	243
	244	static int eth_mac_addr(struct net_device dev, void p)
	245	{
	246	struct sockaddr *addr=p;
	247	if (netif_running(dev))
248	return -EBUSY;
249	memcpy(dev->dev_addr, addr->sa_data,dev->addr_len);
250	return 0;
251	}
252
253	static int eth_change_mtu(struct net_device *dev, int new_mtu)
254	{
46f25dff	255	if (new_mtu < 68 \|\| new_mtu > ETH_DATA_LEN)
1da177e4 LT	256	return -EINVAL;
	257	dev->mtu = new_mtu;
	258	return 0;
	259	}
	260
	261	/*
	262	* Fill in the fields of the device structure with ethernet-generic values.
	263	*/
	264	void ether_setup(struct net_device *dev)
	265	{
	266	dev->change_mtu = eth_change_mtu;
	267	dev->hard_header = eth_header;
	268	dev->rebuild_header = eth_rebuild_header;
	269	dev->set_mac_address = eth_mac_addr;
	270	dev->hard_header_cache = eth_header_cache;
	271	dev->header_cache_update= eth_header_cache_update;
	272	dev->hard_header_parse = eth_header_parse;
	273
	274	dev->type = ARPHRD_ETHER;
	275	dev->hard_header_len = ETH_HLEN;
46f25dff	276	dev->mtu = ETH_DATA_LEN;
1da177e4 LT	277	dev->addr_len = ETH_ALEN;
	278	dev->tx_queue_len = 1000; /* Ethernet wants good queues */
	279	dev->flags = IFF_BROADCAST\|IFF_MULTICAST;
	280
	281	memset(dev->broadcast,0xFF, ETH_ALEN);
	282
	283	}
	284	EXPORT_SYMBOL(ether_setup);
	285
	286	/**
	287	* alloc_etherdev - Allocates and sets up an ethernet device
	288	* @sizeof_priv: Size of additional driver-private structure to be allocated
	289	* for this ethernet device
	290	*
	291	* Fill in the fields of the device structure with ethernet-generic
	292	* values. Basically does everything except registering the device.
	293	*
	294	* Constructs a new net device, complete with a private data area of
	295	* size @sizeof_priv. A 32-byte (not bit) alignment is enforced for
	296	* this private data area.
	297	*/
	298
	299	struct net_device *alloc_etherdev(int sizeof_priv)
	300	{
	301	return alloc_netdev(sizeof_priv, "eth%d", ether_setup);
	302	}
	303	EXPORT_SYMBOL(alloc_etherdev);