Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking changes from David Miller:

 1) GRE now works over ipv6, from Dmitry Kozlov.

 2) Make SCTP more network namespace aware, from Eric Biederman.

 3) TEAM driver now works with non-ethernet devices, from Jiri Pirko.

 4) Make openvswitch network namespace aware, from Pravin B Shelar.

 5) IPV6 NAT implementation, from Patrick McHardy.

 6) Server side support for TCP Fast Open, from Jerry Chu and others.

 7) Packet BPF filter supports MOD and XOR, from Eric Dumazet and Daniel
    Borkmann.

 8) Increate the loopback default MTU to 64K, from Eric Dumazet.

 9) Use a per-task rather than per-socket page fragment allocator for
    outgoing networking traffic.  This benefits processes that have very
    many mostly idle sockets, which is quite common.

    From Eric Dumazet.

10) Use up to 32K for page fragment allocations, with fallbacks to
    smaller sizes when higher order page allocations fail.  Benefits are
    a) less segments for driver to process b) less calls to page
    allocator c) less waste of space.

    From Eric Dumazet.

11) Allow GRO to be used on GRE tunnels, from Eric Dumazet.

12) VXLAN device driver, one way to handle VLAN issues such as the
    limitation of 4096 VLAN IDs yet still have some level of isolation.
    From Stephen Hemminger.

13) As usual there is a large boatload of driver changes, with the scale
    perhaps tilted towards the wireless side this time around.

Fix up various fairly trivial conflicts, mostly caused by the user
namespace changes.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1012 commits)
  hyperv: Add buffer for extended info after the RNDIS response message.
  hyperv: Report actual status in receive completion packet
  hyperv: Remove extra allocated space for recv_pkt_list elements
  hyperv: Fix page buffer handling in rndis_filter_send_request()
  hyperv: Fix the missing return value in rndis_filter_set_packet_filter()
  hyperv: Fix the max_xfer_size in RNDIS initialization
  vxlan: put UDP socket in correct namespace
  vxlan: Depend on CONFIG_INET
  sfc: Fix the reported priorities of different filter types
  sfc: Remove EFX_FILTER_FLAG_RX_OVERRIDE_IP
  sfc: Fix loopback self-test with separate_tx_channels=1
  sfc: Fix MCDI structure field lookup
  sfc: Add parentheses around use of bitfield macro arguments
  sfc: Fix null function pointer in efx_sriov_channel_type
  vxlan: virtual extensible lan
  igmp: export symbol ip_mc_leave_group
  netlink: add attributes to fdb interface
  tg3: unconditionally select HWMON support when tg3 is enabled.
  Revert "net: ti cpsw ethernet: allow reading phy interface mode from DT"
  gre: fix sparse warning
  ...

1 files changed, 856 insertions, 0 deletions

diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
new file mode 100644
index 0000000..5f2f910
--- /dev/null
+++ b/net/netfilter/nf_nat_core.c
@@ -0,0 +1,856 @@
+/*
+ * (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2011 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/timer.h>
+#include <linux/skbuff.h>
+#include <linux/gfp.h>
+#include <net/xfrm.h>
+#include <linux/jhash.h>
+#include <linux/rtnetlink.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_l3proto.h>
+#include <net/netfilter/nf_nat_l4proto.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_helper.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <net/netfilter/nf_conntrack_l3proto.h>
+#include <net/netfilter/nf_conntrack_zones.h>
+#include <linux/netfilter/nf_nat.h>
+
+static DEFINE_SPINLOCK(nf_nat_lock);
+
+static DEFINE_MUTEX(nf_nat_proto_mutex);
+static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO]
+						__read_mostly;
+static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO]
+						__read_mostly;
+
+
+inline const struct nf_nat_l3proto *
+__nf_nat_l3proto_find(u8 family)
+{
+	return rcu_dereference(nf_nat_l3protos[family]);
+}
+
+inline const struct nf_nat_l4proto *
+__nf_nat_l4proto_find(u8 family, u8 protonum)
+{
+	return rcu_dereference(nf_nat_l4protos[family][protonum]);
+}
+EXPORT_SYMBOL_GPL(__nf_nat_l4proto_find);
+
+#ifdef CONFIG_XFRM
+static void __nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl)
+{
+	const struct nf_nat_l3proto *l3proto;
+	const struct nf_conn *ct;
+	enum ip_conntrack_info ctinfo;
+	enum ip_conntrack_dir dir;
+	unsigned  long statusbit;
+	u8 family;
+
+	ct = nf_ct_get(skb, &ctinfo);
+	if (ct == NULL)
+		return;
+
+	family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
+	rcu_read_lock();
+	l3proto = __nf_nat_l3proto_find(family);
+	if (l3proto == NULL)
+		goto out;
+
+	dir = CTINFO2DIR(ctinfo);
+	if (dir == IP_CT_DIR_ORIGINAL)
+		statusbit = IPS_DST_NAT;
+	else
+		statusbit = IPS_SRC_NAT;
+
+	l3proto->decode_session(skb, ct, dir, statusbit, fl);
+out:
+	rcu_read_unlock();
+}
+
+int nf_xfrm_me_harder(struct sk_buff *skb, unsigned int family)
+{
+	struct flowi fl;
+	unsigned int hh_len;
+	struct dst_entry *dst;
+
+	if (xfrm_decode_session(skb, &fl, family) < 0)
+		return -1;
+
+	dst = skb_dst(skb);
+	if (dst->xfrm)
+		dst = ((struct xfrm_dst *)dst)->route;
+	dst_hold(dst);
+
+	dst = xfrm_lookup(dev_net(dst->dev), dst, &fl, skb->sk, 0);
+	if (IS_ERR(dst))
+		return -1;
+
+	skb_dst_drop(skb);
+	skb_dst_set(skb, dst);
+
+	/* 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_len - skb_headroom(skb), 0, GFP_ATOMIC))
+		return -1;
+	return 0;
+}
+EXPORT_SYMBOL(nf_xfrm_me_harder);
+#endif /* CONFIG_XFRM */
+
+/* We keep an extra hash for each conntrack, for fast searching. */
+static inline unsigned int
+hash_by_src(const struct net *net, u16 zone,
+	    const struct nf_conntrack_tuple *tuple)
+{
+	unsigned int hash;
+
+	/* Original src, to ensure we map it consistently if poss. */
+	hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32),
+		      tuple->dst.protonum ^ zone ^ nf_conntrack_hash_rnd);
+	return ((u64)hash * net->ct.nat_htable_size) >> 32;
+}
+
+/* Is this tuple already taken? (not by us) */
+int
+nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
+		  const struct nf_conn *ignored_conntrack)
+{
+	/* Conntrack tracking doesn't keep track of outgoing tuples; only
+	 * incoming ones.  NAT means they don't have a fixed mapping,
+	 * so we invert the tuple and look for the incoming reply.
+	 *
+	 * We could keep a separate hash if this proves too slow.
+	 */
+	struct nf_conntrack_tuple reply;
+
+	nf_ct_invert_tuplepr(&reply, tuple);
+	return nf_conntrack_tuple_taken(&reply, ignored_conntrack);
+}
+EXPORT_SYMBOL(nf_nat_used_tuple);
+
+/* If we source map this tuple so reply looks like reply_tuple, will
+ * that meet the constraints of range.
+ */
+static int in_range(const struct nf_nat_l3proto *l3proto,
+		    const struct nf_nat_l4proto *l4proto,
+		    const struct nf_conntrack_tuple *tuple,
+		    const struct nf_nat_range *range)
+{
+	/* If we are supposed to map IPs, then we must be in the
+	 * range specified, otherwise let this drag us onto a new src IP.
+	 */
+	if (range->flags & NF_NAT_RANGE_MAP_IPS &&
+	    !l3proto->in_range(tuple, range))
+		return 0;
+
+	if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) ||
+	    l4proto->in_range(tuple, NF_NAT_MANIP_SRC,
+			      &range->min_proto, &range->max_proto))
+		return 1;
+
+	return 0;
+}
+
+static inline int
+same_src(const struct nf_conn *ct,
+	 const struct nf_conntrack_tuple *tuple)
+{
+	const struct nf_conntrack_tuple *t;
+
+	t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
+	return (t->dst.protonum == tuple->dst.protonum &&
+		nf_inet_addr_cmp(&t->src.u3, &tuple->src.u3) &&
+		t->src.u.all == tuple->src.u.all);
+}
+
+/* Only called for SRC manip */
+static int
+find_appropriate_src(struct net *net, u16 zone,
+		     const struct nf_nat_l3proto *l3proto,
+		     const struct nf_nat_l4proto *l4proto,
+		     const struct nf_conntrack_tuple *tuple,
+		     struct nf_conntrack_tuple *result,
+		     const struct nf_nat_range *range)
+{
+	unsigned int h = hash_by_src(net, zone, tuple);
+	const struct nf_conn_nat *nat;
+	const struct nf_conn *ct;
+	const struct hlist_node *n;
+
+	hlist_for_each_entry_rcu(nat, n, &net->ct.nat_bysource[h], bysource) {
+		ct = nat->ct;
+		if (same_src(ct, tuple) && nf_ct_zone(ct) == zone) {
+			/* Copy source part from reply tuple. */
+			nf_ct_invert_tuplepr(result,
+				       &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+			result->dst = tuple->dst;
+
+			if (in_range(l3proto, l4proto, result, range))
+				return 1;
+		}
+	}
+	return 0;
+}
+
+/* For [FUTURE] fragmentation handling, we want the least-used
+ * src-ip/dst-ip/proto triple.  Fairness doesn't come into it.  Thus
+ * if the range specifies 1.2.3.4 ports 10000-10005 and 1.2.3.5 ports
+ * 1-65535, we don't do pro-rata allocation based on ports; we choose
+ * the ip with the lowest src-ip/dst-ip/proto usage.
+ */
+static void
+find_best_ips_proto(u16 zone, struct nf_conntrack_tuple *tuple,
+		    const struct nf_nat_range *range,
+		    const struct nf_conn *ct,
+		    enum nf_nat_manip_type maniptype)
+{
+	union nf_inet_addr *var_ipp;
+	unsigned int i, max;
+	/* Host order */
+	u32 minip, maxip, j, dist;
+	bool full_range;
+
+	/* No IP mapping?  Do nothing. */
+	if (!(range->flags & NF_NAT_RANGE_MAP_IPS))
+		return;
+
+	if (maniptype == NF_NAT_MANIP_SRC)
+		var_ipp = &tuple->src.u3;
+	else
+		var_ipp = &tuple->dst.u3;
+
+	/* Fast path: only one choice. */
+	if (nf_inet_addr_cmp(&range->min_addr, &range->max_addr)) {
+		*var_ipp = range->min_addr;
+		return;
+	}
+
+	if (nf_ct_l3num(ct) == NFPROTO_IPV4)
+		max = sizeof(var_ipp->ip) / sizeof(u32) - 1;
+	else
+		max = sizeof(var_ipp->ip6) / sizeof(u32) - 1;
+
+	/* Hashing source and destination IPs gives a fairly even
+	 * spread in practice (if there are a small number of IPs
+	 * involved, there usually aren't that many connections
+	 * anyway).  The consistency means that servers see the same
+	 * client coming from the same IP (some Internet Banking sites
+	 * like this), even across reboots.
+	 */
+	j = jhash2((u32 *)&tuple->src.u3, sizeof(tuple->src.u3) / sizeof(u32),
+		   range->flags & NF_NAT_RANGE_PERSISTENT ?
+			0 : (__force u32)tuple->dst.u3.all[max] ^ zone);
+
+	full_range = false;
+	for (i = 0; i <= max; i++) {
+		/* If first bytes of the address are at the maximum, use the
+		 * distance. Otherwise use the full range.
+		 */
+		if (!full_range) {
+			minip = ntohl((__force __be32)range->min_addr.all[i]);
+			maxip = ntohl((__force __be32)range->max_addr.all[i]);
+			dist  = maxip - minip + 1;
+		} else {
+			minip = 0;
+			dist  = ~0;
+		}
+
+		var_ipp->all[i] = (__force __u32)
+			htonl(minip + (((u64)j * dist) >> 32));
+		if (var_ipp->all[i] != range->max_addr.all[i])
+			full_range = true;
+
+		if (!(range->flags & NF_NAT_RANGE_PERSISTENT))
+			j ^= (__force u32)tuple->dst.u3.all[i];
+	}
+}
+
+/* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING,
+ * we change the source to map into the range. For NF_INET_PRE_ROUTING
+ * and NF_INET_LOCAL_OUT, we change the destination to map into the
+ * range. It might not be possible to get a unique tuple, but we try.
+ * At worst (or if we race), we will end up with a final duplicate in
+ * __ip_conntrack_confirm and drop the packet. */
+static void
+get_unique_tuple(struct nf_conntrack_tuple *tuple,
+		 const struct nf_conntrack_tuple *orig_tuple,
+		 const struct nf_nat_range *range,
+		 struct nf_conn *ct,
+		 enum nf_nat_manip_type maniptype)
+{
+	const struct nf_nat_l3proto *l3proto;
+	const struct nf_nat_l4proto *l4proto;
+	struct net *net = nf_ct_net(ct);
+	u16 zone = nf_ct_zone(ct);
+
+	rcu_read_lock();
+	l3proto = __nf_nat_l3proto_find(orig_tuple->src.l3num);
+	l4proto = __nf_nat_l4proto_find(orig_tuple->src.l3num,
+					orig_tuple->dst.protonum);
+
+	/* 1) If this srcip/proto/src-proto-part is currently mapped,
+	 * and that same mapping gives a unique tuple within the given
+	 * range, use that.
+	 *
+	 * This is only required for source (ie. NAT/masq) mappings.
+	 * So far, we don't do local source mappings, so multiple
+	 * manips not an issue.
+	 */
+	if (maniptype == NF_NAT_MANIP_SRC &&
+	    !(range->flags & NF_NAT_RANGE_PROTO_RANDOM)) {
+		/* try the original tuple first */
+		if (in_range(l3proto, l4proto, orig_tuple, range)) {
+			if (!nf_nat_used_tuple(orig_tuple, ct)) {
+				*tuple = *orig_tuple;
+				goto out;
+			}
+		} else if (find_appropriate_src(net, zone, l3proto, l4proto,
+						orig_tuple, tuple, range)) {
+			pr_debug("get_unique_tuple: Found current src map\n");
+			if (!nf_nat_used_tuple(tuple, ct))
+				goto out;
+		}
+	}
+
+	/* 2) Select the least-used IP/proto combination in the given range */
+	*tuple = *orig_tuple;
+	find_best_ips_proto(zone, tuple, range, ct, maniptype);
+
+	/* 3) The per-protocol part of the manip is made to map into
+	 * the range to make a unique tuple.
+	 */
+
+	/* Only bother mapping if it's not already in range and unique */
+	if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM)) {
+		if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
+			if (l4proto->in_range(tuple, maniptype,
+					      &range->min_proto,
+					      &range->max_proto) &&
+			    (range->min_proto.all == range->max_proto.all ||
+			     !nf_nat_used_tuple(tuple, ct)))
+				goto out;
+		} else if (!nf_nat_used_tuple(tuple, ct)) {
+			goto out;
+		}
+	}
+
+	/* Last change: get protocol to try to obtain unique tuple. */
+	l4proto->unique_tuple(l3proto, tuple, range, maniptype, ct);
+out:
+	rcu_read_unlock();
+}
+
+unsigned int
+nf_nat_setup_info(struct nf_conn *ct,
+		  const struct nf_nat_range *range,
+		  enum nf_nat_manip_type maniptype)
+{
+	struct net *net = nf_ct_net(ct);
+	struct nf_conntrack_tuple curr_tuple, new_tuple;
+	struct nf_conn_nat *nat;
+
+	/* nat helper or nfctnetlink also setup binding */
+	nat = nfct_nat(ct);
+	if (!nat) {
+		nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
+		if (nat == NULL) {
+			pr_debug("failed to add NAT extension\n");
+			return NF_ACCEPT;
+		}
+	}
+
+	NF_CT_ASSERT(maniptype == NF_NAT_MANIP_SRC ||
+		     maniptype == NF_NAT_MANIP_DST);
+	BUG_ON(nf_nat_initialized(ct, maniptype));
+
+	/* What we've got will look like inverse of reply. Normally
+	 * this is what is in the conntrack, except for prior
+	 * manipulations (future optimization: if num_manips == 0,
+	 * orig_tp = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
+	 */
+	nf_ct_invert_tuplepr(&curr_tuple,
+			     &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+
+	get_unique_tuple(&new_tuple, &curr_tuple, range, ct, maniptype);
+
+	if (!nf_ct_tuple_equal(&new_tuple, &curr_tuple)) {
+		struct nf_conntrack_tuple reply;
+
+		/* Alter conntrack table so will recognize replies. */
+		nf_ct_invert_tuplepr(&reply, &new_tuple);
+		nf_conntrack_alter_reply(ct, &reply);
+
+		/* Non-atomic: we own this at the moment. */
+		if (maniptype == NF_NAT_MANIP_SRC)
+			ct->status |= IPS_SRC_NAT;
+		else
+			ct->status |= IPS_DST_NAT;
+	}
+
+	if (maniptype == NF_NAT_MANIP_SRC) {
+		unsigned int srchash;
+
+		srchash = hash_by_src(net, nf_ct_zone(ct),
+				      &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+		spin_lock_bh(&nf_nat_lock);
+		/* nf_conntrack_alter_reply might re-allocate extension aera */
+		nat = nfct_nat(ct);
+		nat->ct = ct;
+		hlist_add_head_rcu(&nat->bysource,
+				   &net->ct.nat_bysource[srchash]);
+		spin_unlock_bh(&nf_nat_lock);
+	}
+
+	/* It's done. */
+	if (maniptype == NF_NAT_MANIP_DST)
+		ct->status |= IPS_DST_NAT_DONE;
+	else
+		ct->status |= IPS_SRC_NAT_DONE;
+
+	return NF_ACCEPT;
+}
+EXPORT_SYMBOL(nf_nat_setup_info);
+
+/* Do packet manipulations according to nf_nat_setup_info. */
+unsigned int nf_nat_packet(struct nf_conn *ct,
+			   enum ip_conntrack_info ctinfo,
+			   unsigned int hooknum,
+			   struct sk_buff *skb)
+{
+	const struct nf_nat_l3proto *l3proto;
+	const struct nf_nat_l4proto *l4proto;
+	enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
+	unsigned long statusbit;
+	enum nf_nat_manip_type mtype = HOOK2MANIP(hooknum);
+
+	if (mtype == NF_NAT_MANIP_SRC)
+		statusbit = IPS_SRC_NAT;
+	else
+		statusbit = IPS_DST_NAT;
+
+	/* Invert if this is reply dir. */
+	if (dir == IP_CT_DIR_REPLY)
+		statusbit ^= IPS_NAT_MASK;
+
+	/* Non-atomic: these bits don't change. */
+	if (ct->status & statusbit) {
+		struct nf_conntrack_tuple target;
+
+		/* We are aiming to look like inverse of other direction. */
+		nf_ct_invert_tuplepr(&target, &ct->tuplehash[!dir].tuple);
+
+		l3proto = __nf_nat_l3proto_find(target.src.l3num);
+		l4proto = __nf_nat_l4proto_find(target.src.l3num,
+						target.dst.protonum);
+		if (!l3proto->manip_pkt(skb, 0, l4proto, &target, mtype))
+			return NF_DROP;
+	}
+	return NF_ACCEPT;
+}
+EXPORT_SYMBOL_GPL(nf_nat_packet);
+
+struct nf_nat_proto_clean {
+	u8	l3proto;
+	u8	l4proto;
+	bool	hash;
+};
+
+/* Clear NAT section of all conntracks, in case we're loaded again. */
+static int nf_nat_proto_clean(struct nf_conn *i, void *data)
+{
+	const struct nf_nat_proto_clean *clean = data;
+	struct nf_conn_nat *nat = nfct_nat(i);
+
+	if (!nat)
+		return 0;
+	if (!(i->status & IPS_SRC_NAT_DONE))
+		return 0;
+	if ((clean->l3proto && nf_ct_l3num(i) != clean->l3proto) ||
+	    (clean->l4proto && nf_ct_protonum(i) != clean->l4proto))
+		return 0;
+
+	if (clean->hash) {
+		spin_lock_bh(&nf_nat_lock);
+		hlist_del_rcu(&nat->bysource);
+		spin_unlock_bh(&nf_nat_lock);
+	} else {
+		memset(nat, 0, sizeof(*nat));
+		i->status &= ~(IPS_NAT_MASK | IPS_NAT_DONE_MASK |
+			       IPS_SEQ_ADJUST);
+	}
+	return 0;
+}
+
+static void nf_nat_l4proto_clean(u8 l3proto, u8 l4proto)
+{
+	struct nf_nat_proto_clean clean = {
+		.l3proto = l3proto,
+		.l4proto = l4proto,
+	};
+	struct net *net;
+
+	rtnl_lock();
+	/* Step 1 - remove from bysource hash */
+	clean.hash = true;
+	for_each_net(net)
+		nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean);
+	synchronize_rcu();
+
+	/* Step 2 - clean NAT section */
+	clean.hash = false;
+	for_each_net(net)
+		nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean);
+	rtnl_unlock();
+}
+
+static void nf_nat_l3proto_clean(u8 l3proto)
+{
+	struct nf_nat_proto_clean clean = {
+		.l3proto = l3proto,
+	};
+	struct net *net;
+
+	rtnl_lock();
+	/* Step 1 - remove from bysource hash */
+	clean.hash = true;
+	for_each_net(net)
+		nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean);
+	synchronize_rcu();
+
+	/* Step 2 - clean NAT section */
+	clean.hash = false;
+	for_each_net(net)
+		nf_ct_iterate_cleanup(net, nf_nat_proto_clean, &clean);
+	rtnl_unlock();
+}
+
+/* Protocol registration. */
+int nf_nat_l4proto_register(u8 l3proto, const struct nf_nat_l4proto *l4proto)
+{
+	const struct nf_nat_l4proto **l4protos;
+	unsigned int i;
+	int ret = 0;
+
+	mutex_lock(&nf_nat_proto_mutex);
+	if (nf_nat_l4protos[l3proto] == NULL) {
+		l4protos = kmalloc(IPPROTO_MAX * sizeof(struct nf_nat_l4proto *),
+				   GFP_KERNEL);
+		if (l4protos == NULL) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		for (i = 0; i < IPPROTO_MAX; i++)
+			RCU_INIT_POINTER(l4protos[i], &nf_nat_l4proto_unknown);
+
+		/* Before making proto_array visible to lockless readers,
+		 * we must make sure its content is committed to memory.
+		 */
+		smp_wmb();
+
+		nf_nat_l4protos[l3proto] = l4protos;
+	}
+
+	if (rcu_dereference_protected(
+			nf_nat_l4protos[l3proto][l4proto->l4proto],
+			lockdep_is_held(&nf_nat_proto_mutex)
+			) != &nf_nat_l4proto_unknown) {
+		ret = -EBUSY;
+		goto out;
+	}
+	RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto], l4proto);
+ out:
+	mutex_unlock(&nf_nat_proto_mutex);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(nf_nat_l4proto_register);
+
+/* No one stores the protocol anywhere; simply delete it. */
+void nf_nat_l4proto_unregister(u8 l3proto, const struct nf_nat_l4proto *l4proto)
+{
+	mutex_lock(&nf_nat_proto_mutex);
+	RCU_INIT_POINTER(nf_nat_l4protos[l3proto][l4proto->l4proto],
+			 &nf_nat_l4proto_unknown);
+	mutex_unlock(&nf_nat_proto_mutex);
+	synchronize_rcu();
+
+	nf_nat_l4proto_clean(l3proto, l4proto->l4proto);
+}
+EXPORT_SYMBOL_GPL(nf_nat_l4proto_unregister);
+
+int nf_nat_l3proto_register(const struct nf_nat_l3proto *l3proto)
+{
+	int err;
+
+	err = nf_ct_l3proto_try_module_get(l3proto->l3proto);
+	if (err < 0)
+		return err;
+
+	mutex_lock(&nf_nat_proto_mutex);
+	RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_TCP],
+			 &nf_nat_l4proto_tcp);
+	RCU_INIT_POINTER(nf_nat_l4protos[l3proto->l3proto][IPPROTO_UDP],
+			 &nf_nat_l4proto_udp);
+	mutex_unlock(&nf_nat_proto_mutex);
+
+	RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], l3proto);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nf_nat_l3proto_register);
+
+void nf_nat_l3proto_unregister(const struct nf_nat_l3proto *l3proto)
+{
+	mutex_lock(&nf_nat_proto_mutex);
+	RCU_INIT_POINTER(nf_nat_l3protos[l3proto->l3proto], NULL);
+	mutex_unlock(&nf_nat_proto_mutex);
+	synchronize_rcu();
+
+	nf_nat_l3proto_clean(l3proto->l3proto);
+	nf_ct_l3proto_module_put(l3proto->l3proto);
+}
+EXPORT_SYMBOL_GPL(nf_nat_l3proto_unregister);
+
+/* No one using conntrack by the time this called. */
+static void nf_nat_cleanup_conntrack(struct nf_conn *ct)
+{
+	struct nf_conn_nat *nat = nf_ct_ext_find(ct, NF_CT_EXT_NAT);
+
+	if (nat == NULL || nat->ct == NULL)
+		return;
+
+	NF_CT_ASSERT(nat->ct->status & IPS_SRC_NAT_DONE);
+
+	spin_lock_bh(&nf_nat_lock);
+	hlist_del_rcu(&nat->bysource);
+	spin_unlock_bh(&nf_nat_lock);
+}
+
+static void nf_nat_move_storage(void *new, void *old)
+{
+	struct nf_conn_nat *new_nat = new;
+	struct nf_conn_nat *old_nat = old;
+	struct nf_conn *ct = old_nat->ct;
+
+	if (!ct || !(ct->status & IPS_SRC_NAT_DONE))
+		return;
+
+	spin_lock_bh(&nf_nat_lock);
+	hlist_replace_rcu(&old_nat->bysource, &new_nat->bysource);
+	spin_unlock_bh(&nf_nat_lock);
+}
+
+static struct nf_ct_ext_type nat_extend __read_mostly = {
+	.len		= sizeof(struct nf_conn_nat),
+	.align		= __alignof__(struct nf_conn_nat),
+	.destroy	= nf_nat_cleanup_conntrack,
+	.move		= nf_nat_move_storage,
+	.id		= NF_CT_EXT_NAT,
+	.flags		= NF_CT_EXT_F_PREALLOC,
+};
+
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+
+static const struct nla_policy protonat_nla_policy[CTA_PROTONAT_MAX+1] = {
+	[CTA_PROTONAT_PORT_MIN]	= { .type = NLA_U16 },
+	[CTA_PROTONAT_PORT_MAX]	= { .type = NLA_U16 },
+};
+
+static int nfnetlink_parse_nat_proto(struct nlattr *attr,
+				     const struct nf_conn *ct,
+				     struct nf_nat_range *range)
+{
+	struct nlattr *tb[CTA_PROTONAT_MAX+1];
+	const struct nf_nat_l4proto *l4proto;
+	int err;
+
+	err = nla_parse_nested(tb, CTA_PROTONAT_MAX, attr, protonat_nla_policy);
+	if (err < 0)
+		return err;
+
+	l4proto = __nf_nat_l4proto_find(nf_ct_l3num(ct), nf_ct_protonum(ct));
+	if (l4proto->nlattr_to_range)
+		err = l4proto->nlattr_to_range(tb, range);
+
+	return err;
+}
+
+static const struct nla_policy nat_nla_policy[CTA_NAT_MAX+1] = {
+	[CTA_NAT_V4_MINIP]	= { .type = NLA_U32 },
+	[CTA_NAT_V4_MAXIP]	= { .type = NLA_U32 },
+	[CTA_NAT_V6_MINIP]	= { .len = sizeof(struct in6_addr) },
+	[CTA_NAT_V6_MAXIP]	= { .len = sizeof(struct in6_addr) },
+	[CTA_NAT_PROTO]		= { .type = NLA_NESTED },
+};
+
+static int
+nfnetlink_parse_nat(const struct nlattr *nat,
+		    const struct nf_conn *ct, struct nf_nat_range *range)
+{
+	const struct nf_nat_l3proto *l3proto;
+	struct nlattr *tb[CTA_NAT_MAX+1];
+	int err;
+
+	memset(range, 0, sizeof(*range));
+
+	err = nla_parse_nested(tb, CTA_NAT_MAX, nat, nat_nla_policy);
+	if (err < 0)
+		return err;
+
+	rcu_read_lock();
+	l3proto = __nf_nat_l3proto_find(nf_ct_l3num(ct));
+	if (l3proto == NULL) {
+		err = -EAGAIN;
+		goto out;
+	}
+	err = l3proto->nlattr_to_range(tb, range);
+	if (err < 0)
+		goto out;
+
+	if (!tb[CTA_NAT_PROTO])
+		goto out;
+
+	err = nfnetlink_parse_nat_proto(tb[CTA_NAT_PROTO], ct, range);
+out:
+	rcu_read_unlock();
+	return err;
+}
+
+static int
+nfnetlink_parse_nat_setup(struct nf_conn *ct,
+			  enum nf_nat_manip_type manip,
+			  const struct nlattr *attr)
+{
+	struct nf_nat_range range;
+	int err;
+
+	err = nfnetlink_parse_nat(attr, ct, &range);
+	if (err < 0)
+		return err;
+	if (nf_nat_initialized(ct, manip))
+		return -EEXIST;
+
+	return nf_nat_setup_info(ct, &range, manip);
+}
+#else
+static int
+nfnetlink_parse_nat_setup(struct nf_conn *ct,
+			  enum nf_nat_manip_type manip,
+			  const struct nlattr *attr)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+static int __net_init nf_nat_net_init(struct net *net)
+{
+	/* Leave them the same for the moment. */
+	net->ct.nat_htable_size = net->ct.htable_size;
+	net->ct.nat_bysource = nf_ct_alloc_hashtable(&net->ct.nat_htable_size, 0);
+	if (!net->ct.nat_bysource)
+		return -ENOMEM;
+	return 0;
+}
+
+static void __net_exit nf_nat_net_exit(struct net *net)
+{
+	struct nf_nat_proto_clean clean = {};
+
+	nf_ct_iterate_cleanup(net, &nf_nat_proto_clean, &clean);
+	synchronize_rcu();
+	nf_ct_free_hashtable(net->ct.nat_bysource, net->ct.nat_htable_size);
+}
+
+static struct pernet_operations nf_nat_net_ops = {
+	.init = nf_nat_net_init,
+	.exit = nf_nat_net_exit,
+};
+
+static struct nf_ct_helper_expectfn follow_master_nat = {
+	.name		= "nat-follow-master",
+	.expectfn	= nf_nat_follow_master,
+};
+
+static struct nfq_ct_nat_hook nfq_ct_nat = {
+	.seq_adjust	= nf_nat_tcp_seq_adjust,
+};
+
+static int __init nf_nat_init(void)
+{
+	int ret;
+
+	ret = nf_ct_extend_register(&nat_extend);
+	if (ret < 0) {
+		printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
+		return ret;
+	}
+
+	ret = register_pernet_subsys(&nf_nat_net_ops);
+	if (ret < 0)
+		goto cleanup_extend;
+
+	nf_ct_helper_expectfn_register(&follow_master_nat);
+
+	/* Initialize fake conntrack so that NAT will skip it */
+	nf_ct_untracked_status_or(IPS_NAT_DONE_MASK);
+
+	BUG_ON(nf_nat_seq_adjust_hook != NULL);
+	RCU_INIT_POINTER(nf_nat_seq_adjust_hook, nf_nat_seq_adjust);
+	BUG_ON(nfnetlink_parse_nat_setup_hook != NULL);
+	RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook,
+			   nfnetlink_parse_nat_setup);
+	BUG_ON(nf_ct_nat_offset != NULL);
+	RCU_INIT_POINTER(nf_ct_nat_offset, nf_nat_get_offset);
+	RCU_INIT_POINTER(nfq_ct_nat_hook, &nfq_ct_nat);
+#ifdef CONFIG_XFRM
+	BUG_ON(nf_nat_decode_session_hook != NULL);
+	RCU_INIT_POINTER(nf_nat_decode_session_hook, __nf_nat_decode_session);
+#endif
+	return 0;
+
+ cleanup_extend:
+	nf_ct_extend_unregister(&nat_extend);
+	return ret;
+}
+
+static void __exit nf_nat_cleanup(void)
+{
+	unsigned int i;
+
+	unregister_pernet_subsys(&nf_nat_net_ops);
+	nf_ct_extend_unregister(&nat_extend);
+	nf_ct_helper_expectfn_unregister(&follow_master_nat);
+	RCU_INIT_POINTER(nf_nat_seq_adjust_hook, NULL);
+	RCU_INIT_POINTER(nfnetlink_parse_nat_setup_hook, NULL);
+	RCU_INIT_POINTER(nf_ct_nat_offset, NULL);
+	RCU_INIT_POINTER(nfq_ct_nat_hook, NULL);
+#ifdef CONFIG_XFRM
+	RCU_INIT_POINTER(nf_nat_decode_session_hook, NULL);
+#endif
+	for (i = 0; i < NFPROTO_NUMPROTO; i++)
+		kfree(nf_nat_l4protos[i]);
+	synchronize_net();
+}
+
+MODULE_LICENSE("GPL");
+
+module_init(nf_nat_init);
+module_exit(nf_nat_cleanup);