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/*
* $Id$
*
* Glenn Chisholm <glenn@ircache.net>
*
* Change log:
* 2002-04-16 francis a. vidal <francisv@dagupan.com>
* Module license tag
*
* 2002-04-13 Henrik Nordstrom <hno@squid-cache.org>
* Updated to Linux-2.4
* - there no longer is a len argument to ip_wccp_recv
* - deal with fragmented skb packets
* - incremental checksumming to allow detection of corrupted
* packets
*
* 1999-09-30 Glenn Chisholm <glenn@ircache.net>
* Original release
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/in.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/inetdevice.h>
#include <net/checksum.h>
#include <net/ip.h>
#define WCCP_PROTOCOL_TYPE 0x883E
#define WCCP_GRE_LEN sizeof(u32)
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,9)
/* New License scheme */
#ifdef MODULE_LICENSE
MODULE_AUTHOR("Glenn Chisholm");
MODULE_DESCRIPTION("WCCP module");
MODULE_LICENSE("GPL");
#endif
#endif
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
int ip_wccp_rcv(struct sk_buff *skb)
#else
int ip_wccp_rcv(struct sk_buff *skb, unsigned short len)
#endif
{
u32 *gre_hdr;
u8 *h;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
if (!pskb_may_pull(skb, 16))
goto drop;
#endif
gre_hdr = (u32 *)skb->h.raw;
h = skb->data;
if(*gre_hdr != htonl(WCCP_PROTOCOL_TYPE))
goto drop;
skb->mac.raw = skb->nh.raw;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
skb->nh.raw = pskb_pull(skb, WCCP_GRE_LEN);
#else /* old kernels */
skb->nh.raw = skb_pull(skb, skb->h.raw + WCCP_GRE_LEN - skb->data);
if (skb->len <= 0)
goto drop;
#endif
memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options));
skb->protocol = __constant_htons(ETH_P_IP);
skb->pkt_type = PACKET_HOST;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,0)
if (skb->ip_summed == CHECKSUM_HW)
skb->csum = csum_sub(skb->csum,
csum_partial(skb->mac.raw, skb->nh.raw-skb->mac.raw, 0));
#else
skb->ip_summed = 0;
#endif
dst_release(skb->dst);
skb->dst = NULL;
return ip_rcv(skb, skb->dev, NULL);
drop:
kfree_skb(skb);
return(0);
}
static struct inet_protocol ipgre_protocol = {
ip_wccp_rcv,
NULL,
0,
IPPROTO_GRE,
0,
NULL,
"GRE"
};
int init_module(void)
{
printk(KERN_INFO "WCCP IPv4/GRE driver\n");
inet_add_protocol(&ipgre_protocol);
return 0;
}
void cleanup_module(void)
{
if ( inet_del_protocol(&ipgre_protocol) < 0 )
printk(KERN_INFO "ipgre close: can't remove protocol\n");
else
printk(KERN_INFO "WCCP IPv4/GRE driver unloaded\n");
}
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