Initial import

1 files changed, 219 insertions, 0 deletions

diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c
new file mode 100644
index 000000000..d958718b5
--- /dev/null
+++ b/net/ipv6/netfilter.c
@@ -0,0 +1,219 @@
+/*
+ * IPv6 specific functions of netfilter core
+ *
+ * Rusty Russell (C) 2000 -- This code is GPL.
+ * Patrick McHardy (C) 2006-2012
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/ipv6.h>
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv6.h>
+#include <linux/export.h>
+#include <net/addrconf.h>
+#include <net/dst.h>
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+#include <net/xfrm.h>
+#include <net/ip6_checksum.h>
+#include <net/netfilter/nf_queue.h>
+
+int ip6_route_me_harder(struct sk_buff *skb)
+{
+	struct net *net = dev_net(skb_dst(skb)->dev);
+	const struct ipv6hdr *iph = ipv6_hdr(skb);
+	unsigned int hh_len;
+	struct dst_entry *dst;
+	struct flowi6 fl6 = {
+		.flowi6_oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
+		.flowi6_mark = skb->mark,
+		.daddr = iph->daddr,
+		.saddr = iph->saddr,
+	};
+	int err;
+
+	dst = ip6_route_output(net, skb->sk, &fl6);
+	err = dst->error;
+	if (err) {
+		IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
+		net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
+		dst_release(dst);
+		return err;
+	}
+
+	/* Drop old route. */
+	skb_dst_drop(skb);
+
+	skb_dst_set(skb, dst);
+
+#ifdef CONFIG_XFRM
+	if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
+	    xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
+		skb_dst_set(skb, NULL);
+		dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), skb->sk, 0);
+		if (IS_ERR(dst))
+			return PTR_ERR(dst);
+		skb_dst_set(skb, dst);
+	}
+#endif
+
+	/* Change in oif may mean change in hh_len. */
+	hh_len = skb_dst(skb)->dev->hard_header_len;
+	if (skb_headroom(skb) < hh_len &&
+	    pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
+			     0, GFP_ATOMIC))
+		return -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL(ip6_route_me_harder);
+
+/*
+ * Extra routing may needed on local out, as the QUEUE target never
+ * returns control to the table.
+ */
+
+struct ip6_rt_info {
+	struct in6_addr daddr;
+	struct in6_addr saddr;
+	u_int32_t mark;
+};
+
+static void nf_ip6_saveroute(const struct sk_buff *skb,
+			     struct nf_queue_entry *entry)
+{
+	struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
+
+	if (entry->state.hook == NF_INET_LOCAL_OUT) {
+		const struct ipv6hdr *iph = ipv6_hdr(skb);
+
+		rt_info->daddr = iph->daddr;
+		rt_info->saddr = iph->saddr;
+		rt_info->mark = skb->mark;
+	}
+}
+
+static int nf_ip6_reroute(struct sk_buff *skb,
+			  const struct nf_queue_entry *entry)
+{
+	struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
+
+	if (entry->state.hook == NF_INET_LOCAL_OUT) {
+		const struct ipv6hdr *iph = ipv6_hdr(skb);
+		if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
+		    !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
+		    skb->mark != rt_info->mark)
+			return ip6_route_me_harder(skb);
+	}
+	return 0;
+}
+
+static int nf_ip6_route(struct net *net, struct dst_entry **dst,
+			struct flowi *fl, bool strict)
+{
+	static const struct ipv6_pinfo fake_pinfo;
+	static const struct inet_sock fake_sk = {
+		/* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
+		.sk.sk_bound_dev_if = 1,
+		.pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
+	};
+	const void *sk = strict ? &fake_sk : NULL;
+	struct dst_entry *result;
+	int err;
+
+	result = ip6_route_output(net, sk, &fl->u.ip6);
+	err = result->error;
+	if (err)
+		dst_release(result);
+	else
+		*dst = result;
+	return err;
+}
+
+__sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
+			     unsigned int dataoff, u_int8_t protocol)
+{
+	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
+	__sum16 csum = 0;
+
+	switch (skb->ip_summed) {
+	case CHECKSUM_COMPLETE:
+		if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
+			break;
+		if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+				     skb->len - dataoff, protocol,
+				     csum_sub(skb->csum,
+					      skb_checksum(skb, 0,
+							   dataoff, 0)))) {
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+			break;
+		}
+		/* fall through */
+	case CHECKSUM_NONE:
+		skb->csum = ~csum_unfold(
+				csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+					     skb->len - dataoff,
+					     protocol,
+					     csum_sub(0,
+						      skb_checksum(skb, 0,
+								   dataoff, 0))));
+		csum = __skb_checksum_complete(skb);
+	}
+	return csum;
+}
+EXPORT_SYMBOL(nf_ip6_checksum);
+
+static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook,
+				       unsigned int dataoff, unsigned int len,
+				       u_int8_t protocol)
+{
+	const struct ipv6hdr *ip6h = ipv6_hdr(skb);
+	__wsum hsum;
+	__sum16 csum = 0;
+
+	switch (skb->ip_summed) {
+	case CHECKSUM_COMPLETE:
+		if (len == skb->len - dataoff)
+			return nf_ip6_checksum(skb, hook, dataoff, protocol);
+		/* fall through */
+	case CHECKSUM_NONE:
+		hsum = skb_checksum(skb, 0, dataoff, 0);
+		skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
+							 &ip6h->daddr,
+							 skb->len - dataoff,
+							 protocol,
+							 csum_sub(0, hsum)));
+		skb->ip_summed = CHECKSUM_NONE;
+		return __skb_checksum_complete_head(skb, dataoff + len);
+	}
+	return csum;
+};
+
+static const struct nf_ipv6_ops ipv6ops = {
+	.chk_addr	= ipv6_chk_addr,
+};
+
+static const struct nf_afinfo nf_ip6_afinfo = {
+	.family			= AF_INET6,
+	.checksum		= nf_ip6_checksum,
+	.checksum_partial	= nf_ip6_checksum_partial,
+	.route			= nf_ip6_route,
+	.saveroute		= nf_ip6_saveroute,
+	.reroute		= nf_ip6_reroute,
+	.route_key_size		= sizeof(struct ip6_rt_info),
+};
+
+int __init ipv6_netfilter_init(void)
+{
+	RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
+	return nf_register_afinfo(&nf_ip6_afinfo);
+}
+
+/* This can be called from inet6_init() on errors, so it cannot
+ * be marked __exit. -DaveM
+ */
+void ipv6_netfilter_fini(void)
+{
+	RCU_INIT_POINTER(nf_ipv6_ops, NULL);
+	nf_unregister_afinfo(&nf_ip6_afinfo);
+}