/*
* 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, <bir7@leland.Stanford.Edu>
* 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.
*
* 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 <asm/segment.h>
#include <asm/system.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/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <linux/config.h>
#include <net/arp.h>
#include <net/sock.h>
#include <asm/checksum.h>
void eth_setup(char *str, int *ints)
{
struct device *d = dev_base;
if (!str || !*str)
return;
while (d)
{
if (!strcmp(str,d->name))
{
if (ints[0] > 0)
d->irq=ints[1];
if (ints[0] > 1)
d->base_addr=ints[2];
if (ints[0] > 2)
d->mem_start=ints[3];
if (ints[0] > 3)
d->mem_end=ints[4];
break;
}
d=d->next;
}
}
/*
* 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 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)
memcpy(eth->h_source,saddr,dev->addr_len);
else
memcpy(eth->h_source,dev->dev_addr,dev->addr_len);
/*
* Anyway, the loopback-device should never use this function...
*/
if (dev->flags & IFF_LOOPBACK)
{
memset(eth->h_dest, 0, dev->addr_len);
return(dev->hard_header_len);
}
if(daddr)
{
memcpy(eth->h_dest,daddr,dev->addr_len);
return dev->hard_header_len;
}
return -dev->hard_header_len;
}
/*
* 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.
*/
int eth_rebuild_header(void *buff, struct device *dev, unsigned long dst,
struct sk_buff *skb)
{
struct ethhdr *eth = (struct ethhdr *)buff;
/*
* Only ARP/IP is currently supported
*/
if(eth->h_proto != htons(ETH_P_IP))
{
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);
return 0;
}
/*
* Try to get ARP to resolve the header.
*/
#ifdef CONFIG_INET
return arp_find(eth->h_dest, dst, dev, dev->pa_addr, skb)? 1 : 0;
#else
return 0;
#endif
}
/*
* 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.
*/
unsigned short eth_type_trans(struct sk_buff *skb, struct device *dev)
{
struct ethhdr *eth;
unsigned char *rawp;
skb->mac.raw=skb->data;
skb_pull(skb,dev->hard_header_len);
eth= skb->mac.ethernet;
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.
*/
else if(dev->flags&(IFF_PROMISC|IFF_ALLMULTI))
{
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);
}
/*
* Upper level calls this function to bind hardware header cache entry.
* If the call is successful, then corresponding Address Resolution Protocol
* (maybe, not ARP) takes responsibility for updating cache content.
*/
void eth_header_cache_bind(struct hh_cache ** hhp, struct device *dev,
unsigned short htype, __u32 daddr)
{
struct hh_cache *hh;
if (htype != ETH_P_IP)
{
printk(KERN_DEBUG "eth_header_cache_bind: %04x cache is not implemented\n", htype);
return;
}
if (arp_bind_cache(hhp, dev, htype, daddr))
return;
if ((hh=*hhp) != NULL)
{
memcpy(hh->hh_data+6, dev->dev_addr, ETH_ALEN);
hh->hh_data[12] = htype>>8;
hh->hh_data[13] = htype&0xFF;
}
}
/*
* Called by Address Resolution module to notify changes in address.
*/
void eth_header_cache_update(struct hh_cache *hh, struct device *dev, unsigned char * haddr)
{
if (hh->hh_type != ETH_P_IP)
{
printk(KERN_DEBUG "eth_header_cache_update: %04x cache is not implemented\n", hh->hh_type);
return;
}
memcpy(hh->hh_data, haddr, ETH_ALEN);
hh->hh_uptodate = 1;
}
/*
* Copy from an ethernet device memory space to an sk_buff while checksumming if IP
*/
void eth_copy_and_sum(struct sk_buff *dest, unsigned char *src, int length, int base)
{
#ifdef CONFIG_IP_ROUTER
memcpy(dest->data,src,length);
#else
struct ethhdr *eth;
struct iphdr *iph;
int ip_length;
IS_SKB(dest);
eth=(struct ethhdr *)src;
if(eth->h_proto!=htons(ETH_P_IP))
{
memcpy(dest->data,src,length);
return;
}
/*
* We have to watch for padded packets. The csum doesn't include the
* padding, and there is no point in copying the padding anyway.
* We have to use the smaller of length and ip_length because it
* can happen that ip_length > length.
*/
memcpy(dest->data,src,sizeof(struct iphdr)+ETH_HLEN); /* ethernet is always >= 34 */
length -= sizeof(struct iphdr) + ETH_HLEN;
iph=(struct iphdr*)(src+ETH_HLEN);
ip_length = ntohs(iph->tot_len) - sizeof(struct iphdr);
/* Also watch out for bogons - min IP size is 8 (rfc-1042) */
if ((ip_length <= length) && (ip_length > 7))
length=ip_length;
dest->csum=csum_partial_copy(src+sizeof(struct iphdr)+ETH_HLEN,dest->data+sizeof(struct iphdr)+ETH_HLEN,length,base);
dest->ip_summed=1;
#endif
}
