[NETFILTER]: Move ipv4 specific code from net/core/netfilter.c to net/ipv4/netfilter.c

Netfilter cleanup
- Move ipv4 code from net/core/netfilter.c to net/ipv4/netfilter.c
- Move ipv6 netfilter code from net/ipv6/ip6_output.c to net/ipv6/netfilter.c

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
new file mode 100644
index 0000000..5656d09
--- /dev/null
+++ b/net/ipv6/netfilter.c
@@ -0,0 +1,43 @@
+#include <linux/config.h>
+#include <linux/init.h>
+
+#ifdef CONFIG_NETFILTER
+
+#include <linux/kernel.h>
+#include <linux/ipv6.h>
+#include <net/dst.h>
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+
+int ip6_route_me_harder(struct sk_buff *skb)
+{
+	struct ipv6hdr *iph = skb->nh.ipv6h;
+	struct dst_entry *dst;
+	struct flowi fl = {
+		.oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
+		.nl_u =
+		{ .ip6_u =
+		  { .daddr = iph->daddr,
+		    .saddr = iph->saddr, } },
+		.proto = iph->nexthdr,
+	};
+
+	dst = ip6_route_output(skb->sk, &fl);
+
+	if (dst->error) {
+		IP6_INC_STATS(IPSTATS_MIB_OUTNOROUTES);
+		LIMIT_NETDEBUG(
+			printk(KERN_DEBUG "ip6_route_me_harder: No more route.\n"));
+		dst_release(dst);
+		return -EINVAL;
+	}
+
+	/* Drop old route. */
+	dst_release(skb->dst);
+
+	skb->dst = dst;
+	return 0;
+}
+EXPORT_SYMBOL(ip6_route_me_harder);
+
+#endif /* CONFIG_NETFILTER */