2005-08-10 04:42:34 +02:00
|
|
|
/* IPv4 specific functions of netfilter core */
|
2005-08-10 04:39:00 +02:00
|
|
|
#include <linux/kernel.h>
|
|
|
|
#include <linux/netfilter.h>
|
2005-08-10 04:42:34 +02:00
|
|
|
#include <linux/netfilter_ipv4.h>
|
2006-01-07 08:04:54 +01:00
|
|
|
#include <linux/ip.h>
|
2007-10-14 09:39:55 +02:00
|
|
|
#include <linux/skbuff.h>
|
2005-08-10 04:39:00 +02:00
|
|
|
#include <net/route.h>
|
2006-01-07 08:04:54 +01:00
|
|
|
#include <net/xfrm.h>
|
|
|
|
#include <net/ip.h>
|
2005-08-10 04:39:00 +02:00
|
|
|
|
|
|
|
/* route_me_harder function, used by iptable_nat, iptable_mangle + ip_queue */
|
2007-10-15 09:53:15 +02:00
|
|
|
int ip_route_me_harder(struct sk_buff *skb, unsigned addr_type)
|
2005-08-10 04:39:00 +02:00
|
|
|
{
|
2007-10-15 09:53:15 +02:00
|
|
|
const struct iphdr *iph = ip_hdr(skb);
|
2005-08-10 04:39:00 +02:00
|
|
|
struct rtable *rt;
|
|
|
|
struct flowi fl = {};
|
|
|
|
struct dst_entry *odst;
|
|
|
|
unsigned int hh_len;
|
2007-01-04 21:15:34 +01:00
|
|
|
unsigned int type;
|
2005-08-10 04:39:00 +02:00
|
|
|
|
2007-01-04 21:15:34 +01:00
|
|
|
type = inet_addr_type(iph->saddr);
|
2006-10-03 01:11:13 +02:00
|
|
|
if (addr_type == RTN_UNSPEC)
|
2007-01-04 21:15:34 +01:00
|
|
|
addr_type = type;
|
2006-10-03 01:11:13 +02:00
|
|
|
|
2005-08-10 04:39:00 +02:00
|
|
|
/* some non-standard hacks like ipt_REJECT.c:send_reset() can cause
|
2007-11-20 03:53:30 +01:00
|
|
|
* packets with foreign saddr to appear on the NF_INET_LOCAL_OUT hook.
|
2005-08-10 04:39:00 +02:00
|
|
|
*/
|
2006-10-03 01:11:13 +02:00
|
|
|
if (addr_type == RTN_LOCAL) {
|
2005-08-10 04:39:00 +02:00
|
|
|
fl.nl_u.ip4_u.daddr = iph->daddr;
|
2007-01-04 21:15:34 +01:00
|
|
|
if (type == RTN_LOCAL)
|
|
|
|
fl.nl_u.ip4_u.saddr = iph->saddr;
|
2005-08-10 04:39:00 +02:00
|
|
|
fl.nl_u.ip4_u.tos = RT_TOS(iph->tos);
|
2007-10-15 09:53:15 +02:00
|
|
|
fl.oif = skb->sk ? skb->sk->sk_bound_dev_if : 0;
|
|
|
|
fl.mark = skb->mark;
|
2005-08-10 04:39:00 +02:00
|
|
|
if (ip_route_output_key(&rt, &fl) != 0)
|
|
|
|
return -1;
|
|
|
|
|
|
|
|
/* Drop old route. */
|
2007-10-15 09:53:15 +02:00
|
|
|
dst_release(skb->dst);
|
|
|
|
skb->dst = &rt->u.dst;
|
2005-08-10 04:39:00 +02:00
|
|
|
} else {
|
|
|
|
/* non-local src, find valid iif to satisfy
|
|
|
|
* rp-filter when calling ip_route_input. */
|
|
|
|
fl.nl_u.ip4_u.daddr = iph->saddr;
|
|
|
|
if (ip_route_output_key(&rt, &fl) != 0)
|
|
|
|
return -1;
|
|
|
|
|
2007-10-15 09:53:15 +02:00
|
|
|
odst = skb->dst;
|
|
|
|
if (ip_route_input(skb, iph->daddr, iph->saddr,
|
2005-08-10 04:39:00 +02:00
|
|
|
RT_TOS(iph->tos), rt->u.dst.dev) != 0) {
|
|
|
|
dst_release(&rt->u.dst);
|
|
|
|
return -1;
|
|
|
|
}
|
|
|
|
dst_release(&rt->u.dst);
|
|
|
|
dst_release(odst);
|
|
|
|
}
|
2007-02-09 15:24:47 +01:00
|
|
|
|
2007-10-15 09:53:15 +02:00
|
|
|
if (skb->dst->error)
|
2005-08-10 04:39:00 +02:00
|
|
|
return -1;
|
|
|
|
|
2006-01-07 08:04:54 +01:00
|
|
|
#ifdef CONFIG_XFRM
|
2007-10-15 09:53:15 +02:00
|
|
|
if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
|
|
|
|
xfrm_decode_session(skb, &fl, AF_INET) == 0)
|
|
|
|
if (xfrm_lookup(&skb->dst, &fl, skb->sk, 0))
|
2006-01-07 08:04:54 +01:00
|
|
|
return -1;
|
|
|
|
#endif
|
|
|
|
|
2005-08-10 04:39:00 +02:00
|
|
|
/* Change in oif may mean change in hh_len. */
|
2007-10-15 09:53:15 +02:00
|
|
|
hh_len = skb->dst->dev->hard_header_len;
|
|
|
|
if (skb_headroom(skb) < hh_len &&
|
|
|
|
pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
|
2007-10-14 09:39:55 +02:00
|
|
|
return -1;
|
2005-08-10 04:39:00 +02:00
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(ip_route_me_harder);
|
2005-08-10 04:42:34 +02:00
|
|
|
|
2006-02-15 10:34:23 +01:00
|
|
|
#ifdef CONFIG_XFRM
|
2007-10-15 09:53:15 +02:00
|
|
|
int ip_xfrm_me_harder(struct sk_buff *skb)
|
2006-02-15 10:34:23 +01:00
|
|
|
{
|
|
|
|
struct flowi fl;
|
|
|
|
unsigned int hh_len;
|
|
|
|
struct dst_entry *dst;
|
|
|
|
|
2007-10-15 09:53:15 +02:00
|
|
|
if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
|
2006-02-15 10:34:23 +01:00
|
|
|
return 0;
|
2007-10-15 09:53:15 +02:00
|
|
|
if (xfrm_decode_session(skb, &fl, AF_INET) < 0)
|
2006-02-15 10:34:23 +01:00
|
|
|
return -1;
|
|
|
|
|
2007-10-15 09:53:15 +02:00
|
|
|
dst = skb->dst;
|
2006-02-15 10:34:23 +01:00
|
|
|
if (dst->xfrm)
|
|
|
|
dst = ((struct xfrm_dst *)dst)->route;
|
|
|
|
dst_hold(dst);
|
|
|
|
|
2007-10-15 09:53:15 +02:00
|
|
|
if (xfrm_lookup(&dst, &fl, skb->sk, 0) < 0)
|
2006-02-15 10:34:23 +01:00
|
|
|
return -1;
|
|
|
|
|
2007-10-15 09:53:15 +02:00
|
|
|
dst_release(skb->dst);
|
|
|
|
skb->dst = dst;
|
2006-02-15 10:34:23 +01:00
|
|
|
|
|
|
|
/* Change in oif may mean change in hh_len. */
|
2007-10-15 09:53:15 +02:00
|
|
|
hh_len = skb->dst->dev->hard_header_len;
|
|
|
|
if (skb_headroom(skb) < hh_len &&
|
|
|
|
pskb_expand_head(skb, hh_len - skb_headroom(skb), 0, GFP_ATOMIC))
|
2007-10-14 09:39:55 +02:00
|
|
|
return -1;
|
2006-02-15 10:34:23 +01:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(ip_xfrm_me_harder);
|
|
|
|
#endif
|
|
|
|
|
2006-01-07 08:06:30 +01:00
|
|
|
void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *);
|
|
|
|
EXPORT_SYMBOL(ip_nat_decode_session);
|
|
|
|
|
2005-08-10 04:42:34 +02:00
|
|
|
/*
|
|
|
|
* Extra routing may needed on local out, as the QUEUE target never
|
|
|
|
* returns control to the table.
|
|
|
|
*/
|
|
|
|
|
|
|
|
struct ip_rt_info {
|
2006-09-28 23:21:07 +02:00
|
|
|
__be32 daddr;
|
|
|
|
__be32 saddr;
|
2005-08-10 04:42:34 +02:00
|
|
|
u_int8_t tos;
|
|
|
|
};
|
|
|
|
|
2006-04-06 23:18:09 +02:00
|
|
|
static void nf_ip_saveroute(const struct sk_buff *skb, struct nf_info *info)
|
2005-08-10 04:42:34 +02:00
|
|
|
{
|
|
|
|
struct ip_rt_info *rt_info = nf_info_reroute(info);
|
|
|
|
|
2007-11-20 03:53:30 +01:00
|
|
|
if (info->hook == NF_INET_LOCAL_OUT) {
|
2007-04-21 07:47:35 +02:00
|
|
|
const struct iphdr *iph = ip_hdr(skb);
|
2005-08-10 04:42:34 +02:00
|
|
|
|
|
|
|
rt_info->tos = iph->tos;
|
|
|
|
rt_info->daddr = iph->daddr;
|
|
|
|
rt_info->saddr = iph->saddr;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2007-10-15 09:53:15 +02:00
|
|
|
static int nf_ip_reroute(struct sk_buff *skb, const struct nf_info *info)
|
2005-08-10 04:42:34 +02:00
|
|
|
{
|
|
|
|
const struct ip_rt_info *rt_info = nf_info_reroute(info);
|
|
|
|
|
2007-11-20 03:53:30 +01:00
|
|
|
if (info->hook == NF_INET_LOCAL_OUT) {
|
2007-10-15 09:53:15 +02:00
|
|
|
const struct iphdr *iph = ip_hdr(skb);
|
2005-08-10 04:42:34 +02:00
|
|
|
|
|
|
|
if (!(iph->tos == rt_info->tos
|
|
|
|
&& iph->daddr == rt_info->daddr
|
|
|
|
&& iph->saddr == rt_info->saddr))
|
2007-10-15 09:53:15 +02:00
|
|
|
return ip_route_me_harder(skb, RTN_UNSPEC);
|
2005-08-10 04:42:34 +02:00
|
|
|
}
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2006-11-15 06:40:42 +01:00
|
|
|
__sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
|
2006-04-06 23:18:43 +02:00
|
|
|
unsigned int dataoff, u_int8_t protocol)
|
|
|
|
{
|
2007-04-21 07:47:35 +02:00
|
|
|
const struct iphdr *iph = ip_hdr(skb);
|
2006-11-15 06:40:42 +01:00
|
|
|
__sum16 csum = 0;
|
2006-04-06 23:18:43 +02:00
|
|
|
|
|
|
|
switch (skb->ip_summed) {
|
2006-08-30 01:44:56 +02:00
|
|
|
case CHECKSUM_COMPLETE:
|
2007-11-20 03:53:30 +01:00
|
|
|
if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
|
2006-04-06 23:18:43 +02:00
|
|
|
break;
|
2006-11-15 06:24:49 +01:00
|
|
|
if ((protocol == 0 && !csum_fold(skb->csum)) ||
|
2006-04-06 23:18:43 +02:00
|
|
|
!csum_tcpudp_magic(iph->saddr, iph->daddr,
|
2007-02-09 15:24:47 +01:00
|
|
|
skb->len - dataoff, protocol,
|
2006-04-06 23:18:43 +02:00
|
|
|
skb->csum)) {
|
|
|
|
skb->ip_summed = CHECKSUM_UNNECESSARY;
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
/* fall through */
|
|
|
|
case CHECKSUM_NONE:
|
|
|
|
if (protocol == 0)
|
|
|
|
skb->csum = 0;
|
|
|
|
else
|
|
|
|
skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
|
|
|
|
skb->len - dataoff,
|
|
|
|
protocol, 0);
|
|
|
|
csum = __skb_checksum_complete(skb);
|
|
|
|
}
|
|
|
|
return csum;
|
|
|
|
}
|
|
|
|
|
|
|
|
EXPORT_SYMBOL(nf_ip_checksum);
|
|
|
|
|
2007-12-05 10:22:05 +01:00
|
|
|
static int nf_ip_route(struct dst_entry **dst, struct flowi *fl)
|
|
|
|
{
|
|
|
|
return ip_route_output_key((struct rtable **)dst, fl);
|
|
|
|
}
|
|
|
|
|
2006-04-06 23:18:09 +02:00
|
|
|
static struct nf_afinfo nf_ip_afinfo = {
|
|
|
|
.family = AF_INET,
|
2006-04-06 23:18:43 +02:00
|
|
|
.checksum = nf_ip_checksum,
|
2007-12-05 10:22:05 +01:00
|
|
|
.route = nf_ip_route,
|
2006-04-06 23:18:09 +02:00
|
|
|
.saveroute = nf_ip_saveroute,
|
|
|
|
.reroute = nf_ip_reroute,
|
|
|
|
.route_key_size = sizeof(struct ip_rt_info),
|
2005-08-10 04:42:34 +02:00
|
|
|
};
|
|
|
|
|
2006-03-29 02:37:06 +02:00
|
|
|
static int ipv4_netfilter_init(void)
|
2005-08-10 04:42:34 +02:00
|
|
|
{
|
2006-04-06 23:18:09 +02:00
|
|
|
return nf_register_afinfo(&nf_ip_afinfo);
|
2005-08-10 04:42:34 +02:00
|
|
|
}
|
|
|
|
|
2006-03-29 02:37:06 +02:00
|
|
|
static void ipv4_netfilter_fini(void)
|
2005-08-10 04:42:34 +02:00
|
|
|
{
|
2006-04-06 23:18:09 +02:00
|
|
|
nf_unregister_afinfo(&nf_ip_afinfo);
|
2005-08-10 04:42:34 +02:00
|
|
|
}
|
|
|
|
|
2006-03-29 02:37:06 +02:00
|
|
|
module_init(ipv4_netfilter_init);
|
|
|
|
module_exit(ipv4_netfilter_fini);
|