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/*
* netfilter module for userspace packet logging daemons
*
* (C) 2000 by Harald Welte <laforge@sunbeam.franken.de>
*
* Released under the terms of the GPL
*
* $Id: ipt_ULOG.c,v 1.1 2000/07/31 09:08:10 laforge Exp laforge $
*/
#include <linux/module.h>
#include <linux/version.h>
#include <linux/config.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <linux/kernel.h>
#include <linux/netlink.h>
#include <linux/netdevice.h>
#include <linux/mm.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_ULOG.h>
#define NETLINK_NFLOG 25
#define ULOG_NL_EVENT 111
#if 1
#define DEBUGP printk
#else
#define DEBUGP(format, args ...)
#endif
struct sock *nflognl;
static void nflog_rcv(struct sock *sk, int len)
{
printk("nflog_rcv: did receive netlink message ?!?\n");
}
static unsigned int ipt_ulog_target(struct sk_buff **pskb,
unsigned int hooknum,
const struct net_device *in,
const struct net_device *out,
const void *targinfo, void *userinfo)
{
ulog_packet_msg_t *pm;
size_t size;
struct sk_buff *nlskb;
unsigned char *old_tail;
struct nlmsghdr *nlh;
struct ipt_ulog_info *loginfo = (struct ipt_ulog_info *) targinfo;
/* calculate the size of the skb needed */
size = NLMSG_SPACE(sizeof(*pm) + (*pskb)->len);
nlskb = alloc_skb(size, GFP_ATOMIC);
if (!nlskb)
goto nlmsg_failure;
old_tail = nlskb->tail;
nlh = NLMSG_PUT(nlskb, 0, 0, ULOG_NL_EVENT, size - sizeof(*nlh));
pm = NLMSG_DATA(nlh);
/* copy hook, prefix, timestamp, payload, etc. */
pm->data_len = (*pskb)->len;
pm->timestamp_sec = (*pskb)->stamp.tv_sec;
pm->timestamp_usec = (*pskb)->stamp.tv_usec;
pm->mark = (*pskb)->nfmark;
pm->hook = hooknum;
if (loginfo->prefix)
strcpy(pm->prefix, loginfo->prefix);
if (in && !out) {
if ((*pskb)->dev && (*pskb)->dev->hard_header_len > 0
&& (*pskb)->dev->hard_header_len <= ULOG_MAC_LEN) {
memcpy(pm->mac, (*pskb)->mac.raw,
(*pskb)->dev->hard_header_len);
pm->mac_len = (*pskb)->dev->hard_header_len;
}
}
/*
if (in) strcpy(pm->indev_name, in->name);
else pm->indev_name[0] = '\0';
*/
if ((*pskb)->len)
memcpy(pm->payload, (*pskb)->data, (*pskb)->len);
nlh->nlmsg_len = nlskb->tail - old_tail;
NETLINK_CB(nlskb).dst_groups = loginfo->nl_group;
DEBUGP
("ipt_ULOG: going to throw out a packet to netlink groupmask %u\n",
loginfo->nl_group);
netlink_broadcast(nflognl, nlskb, 0, loginfo->nl_group,
GFP_ATOMIC);
return IPT_CONTINUE;
nlmsg_failure:
if (nlskb)
kfree(nlskb);
printk("ipt_ULOG: Error building netlink message\n");
return IPT_CONTINUE;
}
static int ipt_ulog_checkentry(const char *tablename,
const struct ipt_entry *e,
void *targinfo,
unsigned int targinfosize,
unsigned int hookmask)
{
return 1;
}
static struct ipt_target ipt_ulog_reg =
{ {NULL, NULL}, "ULOG", ipt_ulog_target, ipt_ulog_checkentry, NULL,
THIS_MODULE
};
static int __init init(void)
{
DEBUGP("ipt_ULOG: init module\n");
nflognl = netlink_kernel_create(NETLINK_NFLOG, nflog_rcv);
if (ipt_register_target(&ipt_ulog_reg))
return -EINVAL;
return 0;
}
static void __exit fini(void)
{
DEBUGP("ipt_ULOG: cleanup_module\n");
ipt_unregister_target(&ipt_ulog_reg);
}
module_init(init);
module_exit(fini);
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