[PATCH nf-next v3 0/3] Netfilter zone directions

[PATCH nf-next v3 0/3] Netfilter zone directions

[Daniel Borkmann]

This is v3 of the originally named flextuples [1] patch set, but
this time after discussions from NFWS completely reworked towards
integration into the existing zones infrastructure. Please see
individual patches for details.

Thanks!

 [1] http://thread.gmane.org/gmane.comp.security.firewalls.netfilter.devel/57412/

v2 -> v3:
 - Have a global default zone object, use it directly
 - Do not touch uapi-exposed ct->status bits, but integrate
   the marking flag into the zones structure
 - Rebased onto latest nf-next, rerun all stress tests
v1 -> v2:
 - Reworked entire set, integration into zones
 - Rebased onto latest nf-next

Daniel Borkmann (3):
  netfilter: nf_conntrack: push zone object into functions
  netfilter: nf_conntrack: add direction support for zones
  netfilter: nf_conntrack: add efficient mark to zone mapping

 include/net/netfilter/nf_conntrack.h               |   6 +-
 include/net/netfilter/nf_conntrack_core.h          |   3 +-
 include/net/netfilter/nf_conntrack_expect.h        |  11 +-
 include/net/netfilter/nf_conntrack_zones.h         |  82 ++++++++++--
 include/uapi/linux/netfilter/nfnetlink_conntrack.h |   9 ++
 include/uapi/linux/netfilter/xt_CT.h               |   8 +-
 net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c     |   2 +-
 net/ipv4/netfilter/nf_conntrack_proto_icmp.c       |   4 +-
 net/ipv4/netfilter/nf_defrag_ipv4.c                |  18 +--
 net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c     |   2 +-
 net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c     |   5 +-
 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c          |  19 +--
 net/netfilter/ipvs/ip_vs_nfct.c                    |   2 +-
 net/netfilter/nf_conntrack_core.c                  |  95 ++++++++------
 net/netfilter/nf_conntrack_expect.c                |  19 +--
 net/netfilter/nf_conntrack_netlink.c               | 139 ++++++++++++++-------
 net/netfilter/nf_conntrack_pptp.c                  |   3 +-
 net/netfilter/nf_conntrack_standalone.c            |  24 +++-
 net/netfilter/nf_nat_core.c                        |  24 ++--
 net/netfilter/nf_synproxy_core.c                   |   4 +-
 net/netfilter/xt_CT.c                              |  26 +++-
 net/netfilter/xt_connlimit.c                       |   9 +-
 net/sched/act_connmark.c                           |   6 +-
 23 files changed, 366 insertions(+), 154 deletions(-)

-- 
1.9.3

[PATCH nf-next v3 1/3] netfilter: nf_conntrack: push zone object into functions

[Daniel Borkmann]

This patch replaces the zone id which is pushed down into functions
with the actual zone object. It's a bigger one-time change, but
needed for later on extending zones with a direction parameter, and
thus decoupling this additional information from all call-sites.

No functional changes in this patch.

The default zones becomes a global const object, namely nf_ct_zone_dflt
and will be returned directly in various cases, one being, when there's
f.e. no zoning support.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 include/net/netfilter/nf_conntrack.h           |  6 +-
 include/net/netfilter/nf_conntrack_core.h      |  3 +-
 include/net/netfilter/nf_conntrack_expect.h    | 11 +++-
 include/net/netfilter/nf_conntrack_zones.h     | 33 +++++++---
 net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c |  2 +-
 net/ipv4/netfilter/nf_conntrack_proto_icmp.c   |  3 +-
 net/ipv4/netfilter/nf_defrag_ipv4.c            | 12 ++--
 net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c |  2 +-
 net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c |  3 +-
 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c      | 13 ++--
 net/netfilter/ipvs/ip_vs_nfct.c                |  2 +-
 net/netfilter/nf_conntrack_core.c              | 69 +++++++++++++--------
 net/netfilter/nf_conntrack_expect.c            | 19 +++---
 net/netfilter/nf_conntrack_netlink.c           | 84 ++++++++++++++------------
 net/netfilter/nf_conntrack_pptp.c              |  3 +-
 net/netfilter/nf_conntrack_standalone.c        | 17 ++++--
 net/netfilter/nf_nat_core.c                    | 19 +++---
 net/netfilter/nf_synproxy_core.c               |  4 +-
 net/netfilter/xt_CT.c                          |  5 +-
 net/netfilter/xt_connlimit.c                   |  9 +--
 net/sched/act_connmark.c                       |  5 +-
 21 files changed, 194 insertions(+), 130 deletions(-)

diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 095433b..1a6d28c 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -250,8 +250,12 @@ void nf_ct_untracked_status_or(unsigned long bits);
 void nf_ct_iterate_cleanup(struct net *net,
 			   int (*iter)(struct nf_conn *i, void *data),
 			   void *data, u32 portid, int report);
+
+struct nf_conntrack_zone;
+
 void nf_conntrack_free(struct nf_conn *ct);
-struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
+struct nf_conn *nf_conntrack_alloc(struct net *net,
+				   const struct nf_conntrack_zone *zone,
 				   const struct nf_conntrack_tuple *orig,
 				   const struct nf_conntrack_tuple *repl,
 				   gfp_t gfp);
diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h
index f2f0fa3..c03f9c4 100644
--- a/include/net/netfilter/nf_conntrack_core.h
+++ b/include/net/netfilter/nf_conntrack_core.h
@@ -52,7 +52,8 @@ bool nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 
 /* Find a connection corresponding to a tuple. */
 struct nf_conntrack_tuple_hash *
-nf_conntrack_find_get(struct net *net, u16 zone,
+nf_conntrack_find_get(struct net *net,
+		      const struct nf_conntrack_zone *zone,
 		      const struct nf_conntrack_tuple *tuple);
 
 int __nf_conntrack_confirm(struct sk_buff *skb);
diff --git a/include/net/netfilter/nf_conntrack_expect.h b/include/net/netfilter/nf_conntrack_expect.h
index 3f3aecb..dce56f0 100644
--- a/include/net/netfilter/nf_conntrack_expect.h
+++ b/include/net/netfilter/nf_conntrack_expect.h
@@ -4,7 +4,9 @@
 
 #ifndef _NF_CONNTRACK_EXPECT_H
 #define _NF_CONNTRACK_EXPECT_H
+
 #include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_zones.h>
 
 extern unsigned int nf_ct_expect_hsize;
 extern unsigned int nf_ct_expect_max;
@@ -76,15 +78,18 @@ int nf_conntrack_expect_init(void);
 void nf_conntrack_expect_fini(void);
 
 struct nf_conntrack_expect *
-__nf_ct_expect_find(struct net *net, u16 zone,
+__nf_ct_expect_find(struct net *net,
+		    const struct nf_conntrack_zone *zone,
 		    const struct nf_conntrack_tuple *tuple);
 
 struct nf_conntrack_expect *
-nf_ct_expect_find_get(struct net *net, u16 zone,
+nf_ct_expect_find_get(struct net *net,
+		      const struct nf_conntrack_zone *zone,
 		      const struct nf_conntrack_tuple *tuple);
 
 struct nf_conntrack_expect *
-nf_ct_find_expectation(struct net *net, u16 zone,
+nf_ct_find_expectation(struct net *net,
+		       const struct nf_conntrack_zone *zone,
 		       const struct nf_conntrack_tuple *tuple);
 
 void nf_ct_unlink_expect_report(struct nf_conntrack_expect *exp,
diff --git a/include/net/netfilter/nf_conntrack_zones.h b/include/net/netfilter/nf_conntrack_zones.h
index 034efe8..0788bb0 100644
--- a/include/net/netfilter/nf_conntrack_zones.h
+++ b/include/net/netfilter/nf_conntrack_zones.h
@@ -1,25 +1,38 @@
 #ifndef _NF_CONNTRACK_ZONES_H
 #define _NF_CONNTRACK_ZONES_H
 
-#define NF_CT_DEFAULT_ZONE	0
-
-#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
-#include <net/netfilter/nf_conntrack_extend.h>
+#define NF_CT_DEFAULT_ZONE_ID	0
 
 struct nf_conntrack_zone {
 	u16	id;
 };
 
-static inline u16 nf_ct_zone(const struct nf_conn *ct)
+extern const struct nf_conntrack_zone nf_ct_zone_dflt;
+
+#if IS_ENABLED(CONFIG_NF_CONNTRACK)
+#include <net/netfilter/nf_conntrack_extend.h>
+
+static inline const struct nf_conntrack_zone *
+nf_ct_zone(const struct nf_conn *ct)
 {
+	const struct nf_conntrack_zone *nf_ct_zone = NULL;
+
 #ifdef CONFIG_NF_CONNTRACK_ZONES
-	struct nf_conntrack_zone *nf_ct_zone;
 	nf_ct_zone = nf_ct_ext_find(ct, NF_CT_EXT_ZONE);
-	if (nf_ct_zone)
-		return nf_ct_zone->id;
 #endif
-	return NF_CT_DEFAULT_ZONE;
+	return nf_ct_zone ? nf_ct_zone : &nf_ct_zone_dflt;
 }
 
-#endif /* CONFIG_NF_CONNTRACK || CONFIG_NF_CONNTRACK_MODULE */
+static inline const struct nf_conntrack_zone *
+nf_ct_zone_tmpl(const struct nf_conn *tmpl)
+{
+	return tmpl ? nf_ct_zone(tmpl) : &nf_ct_zone_dflt;
+}
+
+static inline bool nf_ct_zone_equal(const struct nf_conn *a,
+				    const struct nf_conntrack_zone *b)
+{
+	return nf_ct_zone(a)->id == b->id;
+}
+#endif /* IS_ENABLED(CONFIG_NF_CONNTRACK) */
 #endif /* _NF_CONNTRACK_ZONES_H */
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index 30ad955..8a2caaf 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -280,7 +280,7 @@ getorigdst(struct sock *sk, int optval, void __user *user, int *len)
 		return -EINVAL;
 	}
 
-	h = nf_conntrack_find_get(sock_net(sk), NF_CT_DEFAULT_ZONE, &tuple);
+	h = nf_conntrack_find_get(sock_net(sk), &nf_ct_zone_dflt, &tuple);
 	if (h) {
 		struct sockaddr_in sin;
 		struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
index 80d5554..8a2f41c 100644
--- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
+++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
@@ -134,9 +134,10 @@ icmp_error_message(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
 	struct nf_conntrack_tuple innertuple, origtuple;
 	const struct nf_conntrack_l4proto *innerproto;
 	const struct nf_conntrack_tuple_hash *h;
-	u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
+	const struct nf_conntrack_zone *zone;
 
 	NF_CT_ASSERT(skb->nfct == NULL);
+	zone = nf_ct_zone_tmpl(tmpl);
 
 	/* Are they talking about one of our connections? */
 	if (!nf_ct_get_tuplepr(skb,
diff --git a/net/ipv4/netfilter/nf_defrag_ipv4.c b/net/ipv4/netfilter/nf_defrag_ipv4.c
index c88b7d4..ad0501a 100644
--- a/net/ipv4/netfilter/nf_defrag_ipv4.c
+++ b/net/ipv4/netfilter/nf_defrag_ipv4.c
@@ -43,22 +43,20 @@ static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
 static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
 					      struct sk_buff *skb)
 {
-	u16 zone = NF_CT_DEFAULT_ZONE;
-
+	u16 zone_id = NF_CT_DEFAULT_ZONE_ID;
 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 	if (skb->nfct)
-		zone = nf_ct_zone((struct nf_conn *)skb->nfct);
+		zone_id = nf_ct_zone((struct nf_conn *)skb->nfct)->id;
 #endif
-
 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 	if (skb->nf_bridge &&
 	    skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
-		return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone;
+		return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone_id;
 #endif
 	if (hooknum == NF_INET_PRE_ROUTING)
-		return IP_DEFRAG_CONNTRACK_IN + zone;
+		return IP_DEFRAG_CONNTRACK_IN + zone_id;
 	else
-		return IP_DEFRAG_CONNTRACK_OUT + zone;
+		return IP_DEFRAG_CONNTRACK_OUT + zone_id;
 }
 
 static unsigned int ipv4_conntrack_defrag(const struct nf_hook_ops *ops,
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
index 4ba0c34..7302900 100644
--- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
@@ -251,7 +251,7 @@ ipv6_getorigdst(struct sock *sk, int optval, void __user *user, int *len)
 	if (*len < 0 || (unsigned int) *len < sizeof(sin6))
 		return -EINVAL;
 
-	h = nf_conntrack_find_get(sock_net(sk), NF_CT_DEFAULT_ZONE, &tuple);
+	h = nf_conntrack_find_get(sock_net(sk), &nf_ct_zone_dflt, &tuple);
 	if (!h) {
 		pr_debug("IP6T_SO_ORIGINAL_DST: Can't find %pI6c/%u-%pI6c/%u.\n",
 			 &tuple.src.u3.ip6, ntohs(tuple.src.u.tcp.port),
diff --git a/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c b/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c
index 90388d6..2029141 100644
--- a/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c
@@ -150,7 +150,6 @@ icmpv6_error_message(struct net *net, struct nf_conn *tmpl,
 	struct nf_conntrack_tuple intuple, origtuple;
 	const struct nf_conntrack_tuple_hash *h;
 	const struct nf_conntrack_l4proto *inproto;
-	u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
 
 	NF_CT_ASSERT(skb->nfct == NULL);
 
@@ -177,7 +176,7 @@ icmpv6_error_message(struct net *net, struct nf_conn *tmpl,
 
 	*ctinfo = IP_CT_RELATED;
 
-	h = nf_conntrack_find_get(net, zone, &intuple);
+	h = nf_conntrack_find_get(net, nf_ct_zone_tmpl(tmpl), &intuple);
 	if (!h) {
 		pr_debug("icmpv6_error: no match\n");
 		return -NF_ACCEPT;
diff --git a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
index a45db0b..1749500 100644
--- a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
+++ b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
@@ -33,23 +33,20 @@
 static enum ip6_defrag_users nf_ct6_defrag_user(unsigned int hooknum,
 						struct sk_buff *skb)
 {
-	u16 zone = NF_CT_DEFAULT_ZONE;
-
+	u16 zone_id = NF_CT_DEFAULT_ZONE_ID;
 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
 	if (skb->nfct)
-		zone = nf_ct_zone((struct nf_conn *)skb->nfct);
+		zone_id = nf_ct_zone((struct nf_conn *)skb->nfct)->id;
 #endif
-
 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 	if (skb->nf_bridge &&
 	    skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
-		return IP6_DEFRAG_CONNTRACK_BRIDGE_IN + zone;
+		return IP6_DEFRAG_CONNTRACK_BRIDGE_IN + zone_id;
 #endif
 	if (hooknum == NF_INET_PRE_ROUTING)
-		return IP6_DEFRAG_CONNTRACK_IN + zone;
+		return IP6_DEFRAG_CONNTRACK_IN + zone_id;
 	else
-		return IP6_DEFRAG_CONNTRACK_OUT + zone;
-
+		return IP6_DEFRAG_CONNTRACK_OUT + zone_id;
 }
 
 static unsigned int ipv6_defrag(const struct nf_hook_ops *ops,
diff --git a/net/netfilter/ipvs/ip_vs_nfct.c b/net/netfilter/ipvs/ip_vs_nfct.c
index 5882bbf..1361845 100644
--- a/net/netfilter/ipvs/ip_vs_nfct.c
+++ b/net/netfilter/ipvs/ip_vs_nfct.c
@@ -274,7 +274,7 @@ void ip_vs_conn_drop_conntrack(struct ip_vs_conn *cp)
 		" for conn " FMT_CONN "\n",
 		__func__, ARG_TUPLE(&tuple), ARG_CONN(cp));
 
-	h = nf_conntrack_find_get(ip_vs_conn_net(cp), NF_CT_DEFAULT_ZONE,
+	h = nf_conntrack_find_get(ip_vs_conn_net(cp), &nf_ct_zone_dflt,
 				  &tuple);
 	if (h) {
 		ct = nf_ct_tuplehash_to_ctrack(h);
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 13fad86..9a04062 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -126,7 +126,8 @@ EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
 unsigned int nf_conntrack_hash_rnd __read_mostly;
 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd);
 
-static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, u16 zone)
+static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
+			      const struct nf_conntrack_zone *zone)
 {
 	unsigned int n;
 
@@ -135,7 +136,7 @@ static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, u16 zone)
 	 * three bytes manually.
 	 */
 	n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
-	return jhash2((u32 *)tuple, n, zone ^ nf_conntrack_hash_rnd ^
+	return jhash2((u32 *)tuple, n, zone->id ^ nf_conntrack_hash_rnd ^
 		      (((__force __u16)tuple->dst.u.all << 16) |
 		      tuple->dst.protonum));
 }
@@ -151,12 +152,14 @@ static u32 hash_bucket(u32 hash, const struct net *net)
 }
 
 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
-				  u16 zone, unsigned int size)
+				  const struct nf_conntrack_zone *zone,
+				  unsigned int size)
 {
 	return __hash_bucket(hash_conntrack_raw(tuple, zone), size);
 }
 
-static inline u_int32_t hash_conntrack(const struct net *net, u16 zone,
+static inline u_int32_t hash_conntrack(const struct net *net,
+				       const struct nf_conntrack_zone *zone,
 				       const struct nf_conntrack_tuple *tuple)
 {
 	return __hash_conntrack(tuple, zone, net->ct.htable_size);
@@ -327,11 +330,12 @@ destroy_conntrack(struct nf_conntrack *nfct)
 
 static void nf_ct_delete_from_lists(struct nf_conn *ct)
 {
+	const struct nf_conntrack_zone *zone;
 	struct net *net = nf_ct_net(ct);
 	unsigned int hash, reply_hash;
-	u16 zone = nf_ct_zone(ct);
 	unsigned int sequence;
 
+	zone = nf_ct_zone(ct);
 	nf_ct_helper_destroy(ct);
 
 	local_bh_disable();
@@ -387,8 +391,8 @@ static void death_by_timeout(unsigned long ul_conntrack)
 
 static inline bool
 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
-			const struct nf_conntrack_tuple *tuple,
-			u16 zone)
+		const struct nf_conntrack_tuple *tuple,
+		const struct nf_conntrack_zone *zone)
 {
 	struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 
@@ -396,8 +400,8 @@ nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
 	 * so we need to check that the conntrack is confirmed
 	 */
 	return nf_ct_tuple_equal(tuple, &h->tuple) &&
-		nf_ct_zone(ct) == zone &&
-		nf_ct_is_confirmed(ct);
+	       nf_ct_zone_equal(ct, zone) &&
+	       nf_ct_is_confirmed(ct);
 }
 
 /*
@@ -406,7 +410,7 @@ nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
  *   and recheck nf_ct_tuple_equal(tuple, &h->tuple)
  */
 static struct nf_conntrack_tuple_hash *
-____nf_conntrack_find(struct net *net, u16 zone,
+____nf_conntrack_find(struct net *net, const struct nf_conntrack_zone *zone,
 		      const struct nf_conntrack_tuple *tuple, u32 hash)
 {
 	struct nf_conntrack_tuple_hash *h;
@@ -442,7 +446,7 @@ begin:
 
 /* Find a connection corresponding to a tuple. */
 static struct nf_conntrack_tuple_hash *
-__nf_conntrack_find_get(struct net *net, u16 zone,
+__nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
 			const struct nf_conntrack_tuple *tuple, u32 hash)
 {
 	struct nf_conntrack_tuple_hash *h;
@@ -469,7 +473,7 @@ begin:
 }
 
 struct nf_conntrack_tuple_hash *
-nf_conntrack_find_get(struct net *net, u16 zone,
+nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
 		      const struct nf_conntrack_tuple *tuple)
 {
 	return __nf_conntrack_find_get(net, zone, tuple,
@@ -492,11 +496,11 @@ static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 int
 nf_conntrack_hash_check_insert(struct nf_conn *ct)
 {
+	const struct nf_conntrack_zone *zone;
 	struct net *net = nf_ct_net(ct);
 	unsigned int hash, reply_hash;
 	struct nf_conntrack_tuple_hash *h;
 	struct hlist_nulls_node *n;
-	u16 zone;
 	unsigned int sequence;
 
 	zone = nf_ct_zone(ct);
@@ -514,12 +518,12 @@ nf_conntrack_hash_check_insert(struct nf_conn *ct)
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 				      &h->tuple) &&
-		    zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
+		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone))
 			goto out;
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 				      &h->tuple) &&
-		    zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
+		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone))
 			goto out;
 
 	add_timer(&ct->timeout);
@@ -566,6 +570,7 @@ EXPORT_SYMBOL_GPL(nf_conntrack_tmpl_insert);
 int
 __nf_conntrack_confirm(struct sk_buff *skb)
 {
+	const struct nf_conntrack_zone *zone;
 	unsigned int hash, reply_hash;
 	struct nf_conntrack_tuple_hash *h;
 	struct nf_conn *ct;
@@ -574,7 +579,6 @@ __nf_conntrack_confirm(struct sk_buff *skb)
 	struct hlist_nulls_node *n;
 	enum ip_conntrack_info ctinfo;
 	struct net *net;
-	u16 zone;
 	unsigned int sequence;
 
 	ct = nf_ct_get(skb, &ctinfo);
@@ -627,12 +631,12 @@ __nf_conntrack_confirm(struct sk_buff *skb)
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 				      &h->tuple) &&
-		    zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
+		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone))
 			goto out;
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 				      &h->tuple) &&
-		    zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
+		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone))
 			goto out;
 
 	/* Timer relative to confirmation time, not original
@@ -685,11 +689,14 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 			 const struct nf_conn *ignored_conntrack)
 {
 	struct net *net = nf_ct_net(ignored_conntrack);
+	const struct nf_conntrack_zone *zone;
 	struct nf_conntrack_tuple_hash *h;
 	struct hlist_nulls_node *n;
 	struct nf_conn *ct;
-	u16 zone = nf_ct_zone(ignored_conntrack);
-	unsigned int hash = hash_conntrack(net, zone, tuple);
+	unsigned int hash;
+
+	zone = nf_ct_zone(ignored_conntrack);
+	hash = hash_conntrack(net, zone, tuple);
 
 	/* Disable BHs the entire time since we need to disable them at
 	 * least once for the stats anyway.
@@ -699,7 +706,7 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 		ct = nf_ct_tuplehash_to_ctrack(h);
 		if (ct != ignored_conntrack &&
 		    nf_ct_tuple_equal(tuple, &h->tuple) &&
-		    nf_ct_zone(ct) == zone) {
+		    nf_ct_zone_equal(ct, zone)) {
 			NF_CT_STAT_INC(net, found);
 			rcu_read_unlock_bh();
 			return 1;
@@ -788,7 +795,8 @@ void init_nf_conntrack_hash_rnd(void)
 }
 
 static struct nf_conn *
-__nf_conntrack_alloc(struct net *net, u16 zone,
+__nf_conntrack_alloc(struct net *net,
+		     const struct nf_conntrack_zone *zone,
 		     const struct nf_conntrack_tuple *orig,
 		     const struct nf_conntrack_tuple *repl,
 		     gfp_t gfp, u32 hash)
@@ -842,7 +850,7 @@ __nf_conntrack_alloc(struct net *net, u16 zone,
 		nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC);
 		if (!nf_ct_zone)
 			goto out_free;
-		nf_ct_zone->id = zone;
+		nf_ct_zone->id = zone->id;
 	}
 #endif
 	/* Because we use RCU lookups, we set ct_general.use to zero before
@@ -859,7 +867,8 @@ out_free:
 #endif
 }
 
-struct nf_conn *nf_conntrack_alloc(struct net *net, u16 zone,
+struct nf_conn *nf_conntrack_alloc(struct net *net,
+				   const struct nf_conntrack_zone *zone,
 				   const struct nf_conntrack_tuple *orig,
 				   const struct nf_conntrack_tuple *repl,
 				   gfp_t gfp)
@@ -901,7 +910,7 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
 	struct nf_conntrack_tuple repl_tuple;
 	struct nf_conntrack_ecache *ecache;
 	struct nf_conntrack_expect *exp = NULL;
-	u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
+	const struct nf_conntrack_zone *zone;
 	struct nf_conn_timeout *timeout_ext;
 	unsigned int *timeouts;
 
@@ -910,6 +919,7 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
 		return NULL;
 	}
 
+	zone = nf_ct_zone_tmpl(tmpl);
 	ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
 				  hash);
 	if (IS_ERR(ct))
@@ -1004,10 +1014,10 @@ resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
 		  int *set_reply,
 		  enum ip_conntrack_info *ctinfo)
 {
+	const struct nf_conntrack_zone *zone;
 	struct nf_conntrack_tuple tuple;
 	struct nf_conntrack_tuple_hash *h;
 	struct nf_conn *ct;
-	u16 zone = tmpl ? nf_ct_zone(tmpl) : NF_CT_DEFAULT_ZONE;
 	u32 hash;
 
 	if (!nf_ct_get_tuple(skb, skb_network_offset(skb),
@@ -1018,6 +1028,7 @@ resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
 	}
 
 	/* look for tuple match */
+	zone = nf_ct_zone_tmpl(tmpl);
 	hash = hash_conntrack_raw(&tuple, zone);
 	h = __nf_conntrack_find_get(net, zone, &tuple, hash);
 	if (!h) {
@@ -1268,6 +1279,12 @@ bool __nf_ct_kill_acct(struct nf_conn *ct,
 }
 EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
 
+/* Built-in default zone used e.g. by modules. */
+const struct nf_conntrack_zone nf_ct_zone_dflt = {
+	.id	= NF_CT_DEFAULT_ZONE_ID,
+};
+EXPORT_SYMBOL_GPL(nf_ct_zone_dflt);
+
 #ifdef CONFIG_NF_CONNTRACK_ZONES
 static struct nf_ct_ext_type nf_ct_zone_extend __read_mostly = {
 	.len	= sizeof(struct nf_conntrack_zone),
diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 7a17070..4abee59 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -88,7 +88,8 @@ static unsigned int nf_ct_expect_dst_hash(const struct nf_conntrack_tuple *tuple
 }
 
 struct nf_conntrack_expect *
-__nf_ct_expect_find(struct net *net, u16 zone,
+__nf_ct_expect_find(struct net *net,
+		    const struct nf_conntrack_zone *zone,
 		    const struct nf_conntrack_tuple *tuple)
 {
 	struct nf_conntrack_expect *i;
@@ -100,7 +101,7 @@ __nf_ct_expect_find(struct net *net, u16 zone,
 	h = nf_ct_expect_dst_hash(tuple);
 	hlist_for_each_entry_rcu(i, &net->ct.expect_hash[h], hnode) {
 		if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) &&
-		    nf_ct_zone(i->master) == zone)
+		    nf_ct_zone_equal(i->master, zone))
 			return i;
 	}
 	return NULL;
@@ -109,7 +110,8 @@ EXPORT_SYMBOL_GPL(__nf_ct_expect_find);
 
 /* Just find a expectation corresponding to a tuple. */
 struct nf_conntrack_expect *
-nf_ct_expect_find_get(struct net *net, u16 zone,
+nf_ct_expect_find_get(struct net *net,
+		      const struct nf_conntrack_zone *zone,
 		      const struct nf_conntrack_tuple *tuple)
 {
 	struct nf_conntrack_expect *i;
@@ -127,7 +129,8 @@ EXPORT_SYMBOL_GPL(nf_ct_expect_find_get);
 /* If an expectation for this connection is found, it gets delete from
  * global list then returned. */
 struct nf_conntrack_expect *
-nf_ct_find_expectation(struct net *net, u16 zone,
+nf_ct_find_expectation(struct net *net,
+		       const struct nf_conntrack_zone *zone,
 		       const struct nf_conntrack_tuple *tuple)
 {
 	struct nf_conntrack_expect *i, *exp = NULL;
@@ -140,7 +143,7 @@ nf_ct_find_expectation(struct net *net, u16 zone,
 	hlist_for_each_entry(i, &net->ct.expect_hash[h], hnode) {
 		if (!(i->flags & NF_CT_EXPECT_INACTIVE) &&
 		    nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) &&
-		    nf_ct_zone(i->master) == zone) {
+		    nf_ct_zone_equal(i->master, zone)) {
 			exp = i;
 			break;
 		}
@@ -226,9 +229,9 @@ static inline int expect_matches(const struct nf_conntrack_expect *a,
 				 const struct nf_conntrack_expect *b)
 {
 	return a->master == b->master && a->class == b->class &&
-		nf_ct_tuple_equal(&a->tuple, &b->tuple) &&
-		nf_ct_tuple_mask_equal(&a->mask, &b->mask) &&
-		nf_ct_zone(a->master) == nf_ct_zone(b->master);
+	       nf_ct_tuple_equal(&a->tuple, &b->tuple) &&
+	       nf_ct_tuple_mask_equal(&a->mask, &b->mask) &&
+	       nf_ct_zone_equal(a->master, nf_ct_zone(b->master));
 }
 
 /* Generally a bad idea to call this: could have matched already. */
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index d1c2394..86fbe4b 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -458,6 +458,7 @@ static int
 ctnetlink_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
 		    struct nf_conn *ct)
 {
+	const struct nf_conntrack_zone *zone;
 	struct nlmsghdr *nlh;
 	struct nfgenmsg *nfmsg;
 	struct nlattr *nest_parms;
@@ -487,8 +488,9 @@ ctnetlink_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
 		goto nla_put_failure;
 	nla_nest_end(skb, nest_parms);
 
-	if (nf_ct_zone(ct) &&
-	    nla_put_be16(skb, CTA_ZONE, htons(nf_ct_zone(ct))))
+	zone = nf_ct_zone(ct);
+	if (zone->id != NF_CT_DEFAULT_ZONE_ID &&
+	    nla_put_be16(skb, CTA_ZONE, htons(zone->id)))
 		goto nla_put_failure;
 
 	if (ctnetlink_dump_status(skb, ct) < 0 ||
@@ -609,6 +611,7 @@ ctnetlink_nlmsg_size(const struct nf_conn *ct)
 static int
 ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item)
 {
+	const struct nf_conntrack_zone *zone;
 	struct net *net;
 	struct nlmsghdr *nlh;
 	struct nfgenmsg *nfmsg;
@@ -669,8 +672,9 @@ ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item)
 		goto nla_put_failure;
 	nla_nest_end(skb, nest_parms);
 
-	if (nf_ct_zone(ct) &&
-	    nla_put_be16(skb, CTA_ZONE, htons(nf_ct_zone(ct))))
+	zone = nf_ct_zone(ct);
+	if (zone->id != NF_CT_DEFAULT_ZONE_ID &&
+	    nla_put_be16(skb, CTA_ZONE, htons(zone->id)))
 		goto nla_put_failure;
 
 	if (ctnetlink_dump_id(skb, ct) < 0)
@@ -965,17 +969,18 @@ ctnetlink_parse_tuple(const struct nlattr * const cda[],
 }
 
 static int
-ctnetlink_parse_zone(const struct nlattr *attr, u16 *zone)
+ctnetlink_parse_zone(const struct nlattr *attr,
+		     struct nf_conntrack_zone *zone)
 {
-	if (attr)
+	zone->id = NF_CT_DEFAULT_ZONE_ID;
+
 #ifdef CONFIG_NF_CONNTRACK_ZONES
-		*zone = ntohs(nla_get_be16(attr));
+	if (attr)
+		zone->id = ntohs(nla_get_be16(attr));
 #else
+	if (attr)
 		return -EOPNOTSUPP;
 #endif
-	else
-		*zone = 0;
-
 	return 0;
 }
 
@@ -1058,7 +1063,7 @@ ctnetlink_del_conntrack(struct sock *ctnl, struct sk_buff *skb,
 	struct nf_conn *ct;
 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 	u_int8_t u3 = nfmsg->nfgen_family;
-	u16 zone;
+	struct nf_conntrack_zone zone;
 	int err;
 
 	err = ctnetlink_parse_zone(cda[CTA_ZONE], &zone);
@@ -1078,7 +1083,7 @@ ctnetlink_del_conntrack(struct sock *ctnl, struct sk_buff *skb,
 	if (err < 0)
 		return err;
 
-	h = nf_conntrack_find_get(net, zone, &tuple);
+	h = nf_conntrack_find_get(net, &zone, &tuple);
 	if (!h)
 		return -ENOENT;
 
@@ -1112,7 +1117,7 @@ ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb,
 	struct sk_buff *skb2 = NULL;
 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 	u_int8_t u3 = nfmsg->nfgen_family;
-	u16 zone;
+	struct nf_conntrack_zone zone;
 	int err;
 
 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
@@ -1147,7 +1152,7 @@ ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb,
 	if (err < 0)
 		return err;
 
-	h = nf_conntrack_find_get(net, zone, &tuple);
+	h = nf_conntrack_find_get(net, &zone, &tuple);
 	if (!h)
 		return -ENOENT;
 
@@ -1645,7 +1650,8 @@ ctnetlink_change_conntrack(struct nf_conn *ct,
 }
 
 static struct nf_conn *
-ctnetlink_create_conntrack(struct net *net, u16 zone,
+ctnetlink_create_conntrack(struct net *net,
+			   const struct nf_conntrack_zone *zone,
 			   const struct nlattr * const cda[],
 			   struct nf_conntrack_tuple *otuple,
 			   struct nf_conntrack_tuple *rtuple,
@@ -1804,7 +1810,7 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 	struct nf_conn *ct;
 	u_int8_t u3 = nfmsg->nfgen_family;
-	u16 zone;
+	struct nf_conntrack_zone zone;
 	int err;
 
 	err = ctnetlink_parse_zone(cda[CTA_ZONE], &zone);
@@ -1824,9 +1830,9 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
 	}
 
 	if (cda[CTA_TUPLE_ORIG])
-		h = nf_conntrack_find_get(net, zone, &otuple);
+		h = nf_conntrack_find_get(net, &zone, &otuple);
 	else if (cda[CTA_TUPLE_REPLY])
-		h = nf_conntrack_find_get(net, zone, &rtuple);
+		h = nf_conntrack_find_get(net, &zone, &rtuple);
 
 	if (h == NULL) {
 		err = -ENOENT;
@@ -1836,7 +1842,7 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
 			if (!cda[CTA_TUPLE_ORIG] || !cda[CTA_TUPLE_REPLY])
 				return -EINVAL;
 
-			ct = ctnetlink_create_conntrack(net, zone, cda, &otuple,
+			ct = ctnetlink_create_conntrack(net, &zone, cda, &otuple,
 							&rtuple, u3);
 			if (IS_ERR(ct))
 				return PTR_ERR(ct);
@@ -2091,6 +2097,7 @@ ctnetlink_nfqueue_build_size(const struct nf_conn *ct)
 static int
 ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct)
 {
+	const struct nf_conntrack_zone *zone;
 	struct nlattr *nest_parms;
 
 	rcu_read_lock();
@@ -2108,10 +2115,10 @@ ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct)
 		goto nla_put_failure;
 	nla_nest_end(skb, nest_parms);
 
-	if (nf_ct_zone(ct)) {
-		if (nla_put_be16(skb, CTA_ZONE, htons(nf_ct_zone(ct))))
-			goto nla_put_failure;
-	}
+	zone = nf_ct_zone(ct);
+	if (zone->id != NF_CT_DEFAULT_ZONE_ID &&
+	    nla_put_be16(skb, CTA_ZONE, htons(zone->id)))
+		goto nla_put_failure;
 
 	if (ctnetlink_dump_id(skb, ct) < 0)
 		goto nla_put_failure;
@@ -2612,7 +2619,7 @@ static int ctnetlink_dump_exp_ct(struct sock *ctnl, struct sk_buff *skb,
 	struct nf_conntrack_tuple tuple;
 	struct nf_conntrack_tuple_hash *h;
 	struct nf_conn *ct;
-	u16 zone = 0;
+	struct nf_conntrack_zone zone;
 	struct netlink_dump_control c = {
 		.dump = ctnetlink_exp_ct_dump_table,
 		.done = ctnetlink_exp_done,
@@ -2622,13 +2629,11 @@ static int ctnetlink_dump_exp_ct(struct sock *ctnl, struct sk_buff *skb,
 	if (err < 0)
 		return err;
 
-	if (cda[CTA_EXPECT_ZONE]) {
-		err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
-		if (err < 0)
-			return err;
-	}
+	err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
+	if (err < 0)
+		return err;
 
-	h = nf_conntrack_find_get(net, zone, &tuple);
+	h = nf_conntrack_find_get(net, &zone, &tuple);
 	if (!h)
 		return -ENOENT;
 
@@ -2652,7 +2657,7 @@ ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb,
 	struct sk_buff *skb2;
 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 	u_int8_t u3 = nfmsg->nfgen_family;
-	u16 zone;
+	struct nf_conntrack_zone zone;
 	int err;
 
 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
@@ -2681,7 +2686,7 @@ ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb,
 	if (err < 0)
 		return err;
 
-	exp = nf_ct_expect_find_get(net, zone, &tuple);
+	exp = nf_ct_expect_find_get(net, &zone, &tuple);
 	if (!exp)
 		return -ENOENT;
 
@@ -2732,8 +2737,8 @@ ctnetlink_del_expect(struct sock *ctnl, struct sk_buff *skb,
 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 	struct hlist_node *next;
 	u_int8_t u3 = nfmsg->nfgen_family;
+	struct nf_conntrack_zone zone;
 	unsigned int i;
-	u16 zone;
 	int err;
 
 	if (cda[CTA_EXPECT_TUPLE]) {
@@ -2747,7 +2752,7 @@ ctnetlink_del_expect(struct sock *ctnl, struct sk_buff *skb,
 			return err;
 
 		/* bump usage count to 2 */
-		exp = nf_ct_expect_find_get(net, zone, &tuple);
+		exp = nf_ct_expect_find_get(net, &zone, &tuple);
 		if (!exp)
 			return -ENOENT;
 
@@ -2937,7 +2942,8 @@ err_out:
 }
 
 static int
-ctnetlink_create_expect(struct net *net, u16 zone,
+ctnetlink_create_expect(struct net *net,
+			const struct nf_conntrack_zone *zone,
 			const struct nlattr * const cda[],
 			u_int8_t u3, u32 portid, int report)
 {
@@ -3016,7 +3022,7 @@ ctnetlink_new_expect(struct sock *ctnl, struct sk_buff *skb,
 	struct nf_conntrack_expect *exp;
 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
 	u_int8_t u3 = nfmsg->nfgen_family;
-	u16 zone;
+	struct nf_conntrack_zone zone;
 	int err;
 
 	if (!cda[CTA_EXPECT_TUPLE]
@@ -3033,14 +3039,12 @@ ctnetlink_new_expect(struct sock *ctnl, struct sk_buff *skb,
 		return err;
 
 	spin_lock_bh(&nf_conntrack_expect_lock);
-	exp = __nf_ct_expect_find(net, zone, &tuple);
-
+	exp = __nf_ct_expect_find(net, &zone, &tuple);
 	if (!exp) {
 		spin_unlock_bh(&nf_conntrack_expect_lock);
 		err = -ENOENT;
 		if (nlh->nlmsg_flags & NLM_F_CREATE) {
-			err = ctnetlink_create_expect(net, zone, cda,
-						      u3,
+			err = ctnetlink_create_expect(net, &zone, cda, u3,
 						      NETLINK_CB(skb).portid,
 						      nlmsg_report(nlh));
 		}
diff --git a/net/netfilter/nf_conntrack_pptp.c b/net/netfilter/nf_conntrack_pptp.c
index 825c3e3..5588c7a 100644
--- a/net/netfilter/nf_conntrack_pptp.c
+++ b/net/netfilter/nf_conntrack_pptp.c
@@ -143,13 +143,14 @@ static int destroy_sibling_or_exp(struct net *net, struct nf_conn *ct,
 				  const struct nf_conntrack_tuple *t)
 {
 	const struct nf_conntrack_tuple_hash *h;
+	const struct nf_conntrack_zone *zone;
 	struct nf_conntrack_expect *exp;
 	struct nf_conn *sibling;
-	u16 zone = nf_ct_zone(ct);
 
 	pr_debug("trying to timeout ct or exp for tuple ");
 	nf_ct_dump_tuple(t);
 
+	zone = nf_ct_zone(ct);
 	h = nf_conntrack_find_get(net, zone, t);
 	if (h)  {
 		sibling = nf_ct_tuplehash_to_ctrack(h);
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index fc823fa..28c8b2b 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -140,6 +140,17 @@ static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 }
 #endif
 
+#ifdef CONFIG_NF_CONNTRACK_ZONES
+static void ct_show_zone(struct seq_file *s, const struct nf_conn *ct)
+{
+	seq_printf(s, "zone=%u ", nf_ct_zone(ct)->id);
+}
+#else
+static inline void ct_show_zone(struct seq_file *s, const struct nf_conn *ct)
+{
+}
+#endif
+
 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
 static void ct_show_delta_time(struct seq_file *s, const struct nf_conn *ct)
 {
@@ -228,11 +239,7 @@ static int ct_seq_show(struct seq_file *s, void *v)
 #endif
 
 	ct_show_secctx(s, ct);
-
-#ifdef CONFIG_NF_CONNTRACK_ZONES
-	seq_printf(s, "zone=%u ", nf_ct_zone(ct));
-#endif
-
+	ct_show_zone(s, ct);
 	ct_show_delta_time(s, ct);
 
 	seq_printf(s, "use=%u\n", atomic_read(&ct->ct_general.use));
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index 4e0b478..65ebaf9 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -118,14 +118,15 @@ EXPORT_SYMBOL(nf_xfrm_me_harder);
 
 /* We keep an extra hash for each conntrack, for fast searching. */
 static inline unsigned int
-hash_by_src(const struct net *net, u16 zone,
+hash_by_src(const struct net *net,
+	    const struct nf_conntrack_zone *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);
+		      tuple->dst.protonum ^ zone->id ^ nf_conntrack_hash_rnd);
 
 	return reciprocal_scale(hash, net->ct.nat_htable_size);
 }
@@ -185,7 +186,8 @@ same_src(const struct nf_conn *ct,
 
 /* Only called for SRC manip */
 static int
-find_appropriate_src(struct net *net, u16 zone,
+find_appropriate_src(struct net *net,
+		     const struct nf_conntrack_zone *zone,
 		     const struct nf_nat_l3proto *l3proto,
 		     const struct nf_nat_l4proto *l4proto,
 		     const struct nf_conntrack_tuple *tuple,
@@ -198,7 +200,7 @@ find_appropriate_src(struct net *net, u16 zone,
 
 	hlist_for_each_entry_rcu(nat, &net->ct.nat_bysource[h], bysource) {
 		ct = nat->ct;
-		if (same_src(ct, tuple) && nf_ct_zone(ct) == zone) {
+		if (same_src(ct, tuple) && nf_ct_zone_equal(ct, zone)) {
 			/* Copy source part from reply tuple. */
 			nf_ct_invert_tuplepr(result,
 				       &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
@@ -218,7 +220,8 @@ find_appropriate_src(struct net *net, u16 zone,
  * the ip with the lowest src-ip/dst-ip/proto usage.
  */
 static void
-find_best_ips_proto(u16 zone, struct nf_conntrack_tuple *tuple,
+find_best_ips_proto(const struct nf_conntrack_zone *zone,
+		    struct nf_conntrack_tuple *tuple,
 		    const struct nf_nat_range *range,
 		    const struct nf_conn *ct,
 		    enum nf_nat_manip_type maniptype)
@@ -258,7 +261,7 @@ find_best_ips_proto(u16 zone, struct nf_conntrack_tuple *tuple,
 	 */
 	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);
+			0 : (__force u32)tuple->dst.u3.all[max] ^ zone->id);
 
 	full_range = false;
 	for (i = 0; i <= max; i++) {
@@ -297,10 +300,12 @@ get_unique_tuple(struct nf_conntrack_tuple *tuple,
 		 struct nf_conn *ct,
 		 enum nf_nat_manip_type maniptype)
 {
+	const struct nf_conntrack_zone *zone;
 	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);
+
+	zone = nf_ct_zone(ct);
 
 	rcu_read_lock();
 	l3proto = __nf_nat_l3proto_find(orig_tuple->src.l3num);
diff --git a/net/netfilter/nf_synproxy_core.c b/net/netfilter/nf_synproxy_core.c
index 789feea..484a5d1 100644
--- a/net/netfilter/nf_synproxy_core.c
+++ b/net/netfilter/nf_synproxy_core.c
@@ -17,10 +17,12 @@
 #include <linux/netfilter/x_tables.h>
 #include <linux/netfilter/xt_tcpudp.h>
 #include <linux/netfilter/xt_SYNPROXY.h>
+
 #include <net/netfilter/nf_conntrack.h>
 #include <net/netfilter/nf_conntrack_extend.h>
 #include <net/netfilter/nf_conntrack_seqadj.h>
 #include <net/netfilter/nf_conntrack_synproxy.h>
+#include <net/netfilter/nf_conntrack_zones.h>
 
 int synproxy_net_id;
 EXPORT_SYMBOL_GPL(synproxy_net_id);
@@ -354,7 +356,7 @@ static int __net_init synproxy_net_init(struct net *net)
 	int err = -ENOMEM;
 
 	memset(&t, 0, sizeof(t));
-	ct = nf_conntrack_alloc(net, 0, &t, &t, GFP_KERNEL);
+	ct = nf_conntrack_alloc(net, &nf_ct_zone_dflt, &t, &t, GFP_KERNEL);
 	if (IS_ERR(ct)) {
 		err = PTR_ERR(ct);
 		goto err1;
diff --git a/net/netfilter/xt_CT.c b/net/netfilter/xt_CT.c
index 75747ae..e2d7b55 100644
--- a/net/netfilter/xt_CT.c
+++ b/net/netfilter/xt_CT.c
@@ -184,6 +184,7 @@ out:
 static int xt_ct_tg_check(const struct xt_tgchk_param *par,
 			  struct xt_ct_target_info_v1 *info)
 {
+	struct nf_conntrack_zone zone;
 	struct nf_conntrack_tuple t;
 	struct nf_conn *ct;
 	int ret = -EOPNOTSUPP;
@@ -203,7 +204,9 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par,
 		goto err1;
 
 	memset(&t, 0, sizeof(t));
-	ct = nf_conntrack_alloc(par->net, info->zone, &t, &t, GFP_KERNEL);
+	zone.id = info->zone;
+
+	ct = nf_conntrack_alloc(par->net, &zone, &t, &t, GFP_KERNEL);
 	ret = PTR_ERR(ct);
 	if (IS_ERR(ct))
 		goto err2;
diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c
index 29ba621..075d89d 100644
--- a/net/netfilter/xt_connlimit.c
+++ b/net/netfilter/xt_connlimit.c
@@ -134,7 +134,7 @@ static bool add_hlist(struct hlist_head *head,
 static unsigned int check_hlist(struct net *net,
 				struct hlist_head *head,
 				const struct nf_conntrack_tuple *tuple,
-				u16 zone,
+				const struct nf_conntrack_zone *zone,
 				bool *addit)
 {
 	const struct nf_conntrack_tuple_hash *found;
@@ -201,7 +201,7 @@ static unsigned int
 count_tree(struct net *net, struct rb_root *root,
 	   const struct nf_conntrack_tuple *tuple,
 	   const union nf_inet_addr *addr, const union nf_inet_addr *mask,
-	   u8 family, u16 zone)
+	   u8 family, const struct nf_conntrack_zone *zone)
 {
 	struct xt_connlimit_rb *gc_nodes[CONNLIMIT_GC_MAX_NODES];
 	struct rb_node **rbnode, *parent;
@@ -290,7 +290,8 @@ static int count_them(struct net *net,
 		      const struct nf_conntrack_tuple *tuple,
 		      const union nf_inet_addr *addr,
 		      const union nf_inet_addr *mask,
-		      u_int8_t family, u16 zone)
+		      u_int8_t family,
+		      const struct nf_conntrack_zone *zone)
 {
 	struct rb_root *root;
 	int count;
@@ -321,10 +322,10 @@ connlimit_mt(const struct sk_buff *skb, struct xt_action_param *par)
 	union nf_inet_addr addr;
 	struct nf_conntrack_tuple tuple;
 	const struct nf_conntrack_tuple *tuple_ptr = &tuple;
+	const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
 	enum ip_conntrack_info ctinfo;
 	const struct nf_conn *ct;
 	unsigned int connections;
-	u16 zone = NF_CT_DEFAULT_ZONE;
 
 	ct = nf_ct_get(skb, &ctinfo);
 	if (ct != NULL) {
diff --git a/net/sched/act_connmark.c b/net/sched/act_connmark.c
index f2b5402..e67a1bd 100644
--- a/net/sched/act_connmark.c
+++ b/net/sched/act_connmark.c
@@ -37,6 +37,7 @@ static int tcf_connmark(struct sk_buff *skb, const struct tc_action *a,
 	struct nf_conntrack_tuple tuple;
 	enum ip_conntrack_info ctinfo;
 	struct tcf_connmark_info *ca = a->priv;
+	struct nf_conntrack_zone zone;
 	struct nf_conn *c;
 	int proto;
 
@@ -70,7 +71,9 @@ static int tcf_connmark(struct sk_buff *skb, const struct tc_action *a,
 			       proto, &tuple))
 		goto out;
 
-	thash = nf_conntrack_find_get(dev_net(skb->dev), ca->zone, &tuple);
+	zone.id = ca->zone;
+
+	thash = nf_conntrack_find_get(dev_net(skb->dev), &zone, &tuple);
 	if (!thash)
 		goto out;
 
-- 
1.9.3

Re: [PATCH nf-next v3 1/3] netfilter: nf_conntrack: push zone object into functions

[Pablo Neira Ayuso]

On Wed, Jul 22, 2015 at 12:54:46PM +0200, Daniel Borkmann wrote:
> This patch replaces the zone id which is pushed down into functions
> with the actual zone object. It's a bigger one-time change, but
> needed for later on extending zones with a direction parameter, and
> thus decoupling this additional information from all call-sites.
> 
> No functional changes in this patch.
> 
> The default zones becomes a global const object, namely nf_ct_zone_dflt
> and will be returned directly in various cases, one being, when there's
> f.e. no zoning support.

Looks fine. This patchset depends on the recent fixes though, so let
me send a pull request to David with pending nf-next updates, then you
can rebase upon a fresh HEAD.

Regarding follow up patches, it would be good if you rename CTA_DIR to
CTA_ZONE_DIR. If you plan to place more information into the zone
extension, then it's probably a good idea to add a new nested
CTA_ZONE_INFO attribute where we can start adding new more information
on the zone configuration there that applies to the tuple.

I have seen also that you placed zone-dir= after use= in the sysctl
output, but you can place this after the zone instead. We have a
netlink interface so people should not be doing string parsing.

I'll make a closer look later to see if I have more comments. Thanks
for your patience, Daniel.

Re: [PATCH nf-next v3 1/3] netfilter: nf_conntrack: push zone object into functions

[Daniel Borkmann]

On 07/30/2015 06:07 PM, Pablo Neira Ayuso wrote:
> On Wed, Jul 22, 2015 at 12:54:46PM +0200, Daniel Borkmann wrote:
>> This patch replaces the zone id which is pushed down into functions
>> with the actual zone object. It's a bigger one-time change, but
>> needed for later on extending zones with a direction parameter, and
>> thus decoupling this additional information from all call-sites.
>>
>> No functional changes in this patch.
>>
>> The default zones becomes a global const object, namely nf_ct_zone_dflt
>> and will be returned directly in various cases, one being, when there's
>> f.e. no zoning support.
>
> Looks fine. This patchset depends on the recent fixes though, so let
> me send a pull request to David with pending nf-next updates, then you
> can rebase upon a fresh HEAD.

Okay, I guess there would be quite some ugly merge conflicts otherwise
due to the recent -nf fixes that accumulated over time. I will send out
a rebased version against -nf-next as soon as this dependency is resolved.

> Regarding follow up patches, it would be good if you rename CTA_DIR to
> CTA_ZONE_DIR. If you plan to place more information into the zone
> extension, then it's probably a good idea to add a new nested
> CTA_ZONE_INFO attribute where we can start adding new more information
> on the zone configuration there that applies to the tuple.

CTA_ZONE_DIR seems better, sure. I don't have any other extensions at
the moment, but it seems it makes sense to make this nested at this
point in time, so we have CTA_ZONE and CTA_ZONE_INFO as a container
for CTA_ZONE_DIR and whatever future might bring. I will look into it.

> I have seen also that you placed zone-dir= after use= in the sysctl
> output, but you can place this after the zone instead. We have a
> netlink interface so people should not be doing string parsing.

Okay, good to know, thanks!

> I'll make a closer look later to see if I have more comments. Thanks
> for your patience, Daniel.

No problem. Thanks, Pablo!

Re: [PATCH nf-next v3 1/3] netfilter: nf_conntrack: push zone object into functions

[Pablo Neira Ayuso]

On Thu, Jul 30, 2015 at 06:34:48PM +0200, Daniel Borkmann wrote:
> CTA_ZONE_DIR seems better, sure. I don't have any other extensions at
> the moment, but it seems it makes sense to make this nested at this
> point in time, so we have CTA_ZONE and CTA_ZONE_INFO as a container
> for CTA_ZONE_DIR and whatever future might bring. I will look into it.

thinking it well, this is part of the tuple, so I'd suggest you add
CTA_TUPLE_ZONE to enum ctattr_tuple. We will probably need later to
place each tuple in different zones.

Re: [PATCH nf-next v3 1/3] netfilter: nf_conntrack: push zone object into functions

[Daniel Borkmann]

On 08/03/2015 05:59 PM, Pablo Neira Ayuso wrote:
> On Thu, Jul 30, 2015 at 06:34:48PM +0200, Daniel Borkmann wrote:
>> CTA_ZONE_DIR seems better, sure. I don't have any other extensions at
>> the moment, but it seems it makes sense to make this nested at this
>> point in time, so we have CTA_ZONE and CTA_ZONE_INFO as a container
>> for CTA_ZONE_DIR and whatever future might bring. I will look into it.
>
> thinking it well, this is part of the tuple, so I'd suggest you add
> CTA_TUPLE_ZONE to enum ctattr_tuple. We will probably need later to
> place each tuple in different zones.

That's fine with me, will do after your tree rebase.

Thanks again,
Daniel

Re: [PATCH nf-next v3 1/3] netfilter: nf_conntrack: push zone object into functions

[Pablo Neira Ayuso]

On Mon, Aug 03, 2015 at 06:00:35PM +0200, Daniel Borkmann wrote:
> On 08/03/2015 05:59 PM, Pablo Neira Ayuso wrote:
> >On Thu, Jul 30, 2015 at 06:34:48PM +0200, Daniel Borkmann wrote:
> >>CTA_ZONE_DIR seems better, sure. I don't have any other extensions at
> >>the moment, but it seems it makes sense to make this nested at this
> >>point in time, so we have CTA_ZONE and CTA_ZONE_INFO as a container
> >>for CTA_ZONE_DIR and whatever future might bring. I will look into it.
> >
> >thinking it well, this is part of the tuple, so I'd suggest you add
> >CTA_TUPLE_ZONE to enum ctattr_tuple. We will probably need later to
> >place each tuple in different zones.
> 
> That's fine with me, will do after your tree rebase.

Just pushed out a fresh copy with net-next into nf-next.

Daniel, a minor change that I came up with. With your patchset, the
configurations that we accept look like:

        zone original=Value     reply=0
        zone original=0         reply=Value

But thinking on Thomas' requirements to limit the number of conntracks
per zone, I think another valid configuration (and more generic) can
be:

        zone original=ValueX    reply=ValueY

So we don't assume that the original or reply zone is always zero.

The zone extension are that look like this:

struct nf_conntrack_zone {
        u16     id[IP_CT_DIR_MAX];
};

And we don't need to store the direction. To keep backward
compatibility we can set the id in both directions to the same value.

Can you see any problem with this approach? I think it should require
just a little adjustment to you patchset. Thanks.

Re: [PATCH nf-next v3 1/3] netfilter: nf_conntrack: push zone object into functions

[Daniel Borkmann]

On 08/05/2015 12:51 PM, Pablo Neira Ayuso wrote:
> On Mon, Aug 03, 2015 at 06:00:35PM +0200, Daniel Borkmann wrote:
>> On 08/03/2015 05:59 PM, Pablo Neira Ayuso wrote:
>>> On Thu, Jul 30, 2015 at 06:34:48PM +0200, Daniel Borkmann wrote:
>>>> CTA_ZONE_DIR seems better, sure. I don't have any other extensions at
>>>> the moment, but it seems it makes sense to make this nested at this
>>>> point in time, so we have CTA_ZONE and CTA_ZONE_INFO as a container
>>>> for CTA_ZONE_DIR and whatever future might bring. I will look into it.
>>>
>>> thinking it well, this is part of the tuple, so I'd suggest you add
>>> CTA_TUPLE_ZONE to enum ctattr_tuple. We will probably need later to
>>> place each tuple in different zones.
>>
>> That's fine with me, will do after your tree rebase.
>
> Just pushed out a fresh copy with net-next into nf-next.

Cool, thanks, will move on with my rework/base of the set then!

> Daniel, a minor change that I came up with. With your patchset, the
> configurations that we accept look like:
>
>          zone original=Value     reply=0
>          zone original=0         reply=Value

Yes, the full picture is ...

   zone   original=Value     reply=Default
   zone   original=Default   reply=Value
   zone   original=Value     reply=Value
   zone   original=Default   reply=Default

... where Default (== 0) is to be understood "zone unspecified".

> But thinking on Thomas' requirements to limit the number of conntracks
> per zone, I think another valid configuration (and more generic) can
> be:
>
>          zone original=ValueX    reply=ValueY
>
> So we don't assume that the original or reply zone is always zero.
>
> The zone extension are that look like this:
>
> struct nf_conntrack_zone {
>          u16     id[IP_CT_DIR_MAX];
> };
>
> And we don't need to store the direction. To keep backward
> compatibility we can set the id in both directions to the same value.
>
> Can you see any problem with this approach? I think it should require
> just a little adjustment to you patchset. Thanks.

Don't yet see the bigger picture how this would relate to limiting the
number of conntrack entries per zone, but I also haven't thought deeply
on an implementation of that issue. A zone ValueX and ValueY where
ValueX != ValueY in different directions would imply fully overlapping
tuples in both directions, or only partially shared/common pools for
tuple allocations in the opposite directions.

Anyway, this would mean that instead of a simple direction flag as we
currently have, we'd need new revisions to add either two more zone ids
to uapi structs or a flag and a 2nd zone id field, if we want to reuse
the first zone field, and similarly also for the netlink interfaces.

On the mark to zone mapping, we would then need to fill the whole
id[IP_CT_DIR_MAX] on the template, which seems a little more problematic
to me.

This would probably mean we have to split the mark's bit space into
two 16 bit parts  (f.e. mark := (ValueX << 16) | ValueY)) to fill both
directions depending from which side we arrive.

The entity setting the mark would need to shift its own id encoding
into the correct direction in the mark and would leave the other one as
default zone (== 0) if unaware of it? Then, the problem is that the
/first/ one creating the conntrack entry does need to know ValueX /and/
ValueY, if later on we want to retrieve the entry again via zone ValueY.

This mark bit shifting seems rather inconvenient to use, imho. If ValueY
can be dymanic, perhaps then the one triggering the initial packet might
not even know which one to arrive in yet?

One could still add a direction parameter in the zone struct to know
where to apply the mark, if we don't want to encode both ids, and to
have the other one 0 to not expose this burden to the user. But that
means ValueY is static to 0 in this case, which seems undesired here.

So it looks actually a bit of a more complex change (/configuration),
doesn't seem to integrate as 'straight-forward' as the current approach,
but also targets a bit of a different use case (?) than this current set
does. Note that the current set doesn't ban us either from modifications
later on. Please let me know if I'm wrong somewhere, but given the above
issues, I would be happy to stick with the current approach instead,
with your feedback integrated from your other mails, of course.

Thanks,
Daniel

Re: [PATCH nf-next v3 1/3] netfilter: nf_conntrack: push zone object into functions

[Pablo Neira Ayuso]

On Wed, Aug 05, 2015 at 04:00:29PM +0200, Daniel Borkmann wrote:
[...]
> [...] I would be happy to stick with the current approach instead,
> with your feedback integrated from your other mails, of course.

Please send a new round, as you said we have room to revisit this
later on. Thanks.

[PATCH nf-next v3 2/3] netfilter: nf_conntrack: add direction support for zones

[Daniel Borkmann]

This work adds a direction parameter to netfilter zones, so identity
separation can be performed only in original/reply or both directions
(default). This basically opens up the possibility of doing NAT with
conflicting IP address/port tuples from multiple, isolated tenants
on a host (e.g. from a netns) without requiring each tenant to NAT
twice resp. to use its own dedicated IP address to SNAT to, meaning
overlapping tuples can be made unique with the zone identifier in
original direction, where the NAT engine will then allocate a unique
tuple in the commonly shared default zone for the reply direction.
In some restricted, local DNAT cases, also port redirection could be
used for making the reply traffic unique w/o requiring SNAT.

The consensus we've reached and discussed at NFWS and since the initial
implementation [1] was to directly integrate the direction meta data
into the existing zones infrastructure, as opposed to the ct->mark
approach we proposed initially.

As we pass the nf_conntrack_zone object directly around, we don't have
to touch all call-sites, but only those, that contain equality checks
of zones. Thus, based on the current direction (original or reply),
we either return the actual id, or the default NF_CT_DEFAULT_ZONE_ID.
CT expectations are direction-agnostic entities when expectations are
being compared among themselves, so we can only used the identifier
in this case.

Note that zone identifiers can not be included into the hash mix
anymore as they don't contain a "stable" value that would be equal
for both directions at all times, f.e. if only zone->id would
unconditionally be xor'ed into the table slot hash, then replies won't
find the corresponding conntracking entry anymore.

If no particular direction is specified when configuring zones, the
behaviour is exactly as we expect currently (both directions).

Support has been added for the CT netlink interface as well as the
x_tables raw CT target, which both already offer existing interfaces
to user space for the configuration of zones.

Below a minimal, simplified collision example (script in [2]) with
netperf sessions:

  +--- tenant-1 ---+   mark := 1
  |    netperf     |--+
  +----------------+  |                CT zone := mark [ORIGINAL]
   [ip,sport] := X   +--------------+  +--- gateway ---+
                     | mark routing |--|     SNAT      |-- ... +
                     +--------------+  +---------------+       |
  +--- tenant-2 ---+  |                                     ~~~|~~~
  |    netperf     |--+                +-----------+           |
  +----------------+   mark := 2       | netserver |------ ... +
   [ip,sport] := X                     +-----------+
                                        [ip,port] := Y
On the gateway netns, example:

  iptables -t raw -A PREROUTING -j CT --zone mark --zone-dir ORIGINAL
  iptables -t nat -A POSTROUTING -o <dev> -j SNAT --to-source <ip> --random-fully

  iptables -t mangle -A PREROUTING -m conntrack --ctdir ORIGINAL -j CONNMARK --save-mark
  iptables -t mangle -A POSTROUTING -m conntrack --ctdir REPLY -j CONNMARK --restore-mark

conntrack -L from gateway netns:

  netperf -H 10.1.1.2 -t TCP_STREAM -l60 -p12865,5555 from each tenant netns

  tcp 6 431995 ESTABLISHED src=40.1.1.1 dst=10.1.1.2 sport=5555 dport=12865
                           src=10.1.1.2 dst=10.1.1.1 sport=12865 dport=1024
               [ASSURED] mark=1 secctx=system_u:object_r:unlabeled_t:s0
                         zone=1 use=1 zone-dir=original

  tcp 6 431994 ESTABLISHED src=40.1.1.1 dst=10.1.1.2 sport=5555 dport=12865
                           src=10.1.1.2 dst=10.1.1.1 sport=12865 dport=5555
               [ASSURED] mark=2 secctx=system_u:object_r:unlabeled_t:s0
                         zone=2 use=1 zone-dir=original

  tcp 6 299 ESTABLISHED src=40.1.1.1 dst=10.1.1.2 sport=39438 dport=33768
                        src=10.1.1.2 dst=10.1.1.1 sport=33768 dport=39438
               [ASSURED] mark=1 secctx=system_u:object_r:unlabeled_t:s0
                         zone=1 use=1 zone-dir=original

  tcp 6 300 ESTABLISHED src=40.1.1.1 dst=10.1.1.2 sport=32889 dport=40206
                        src=10.1.1.2 dst=10.1.1.1 sport=40206 dport=32889
               [ASSURED] mark=2 secctx=system_u:object_r:unlabeled_t:s0
                         zone=2 use=2 zone-dir=original

Taking this further, test script in [2] creates 200 tenants and runs
original-tuple colliding netperf sessions each. A conntrack -L dump in
the gateway netns also confirms 200 overlapping entries, all in ESTABLISHED
state as expected.

I also did run various other tests with some permutations of the script,
to mention some: SNAT in random/random-fully/persistent mode, no zones (no
overlaps), static zones (original, reply, both directions), etc.

  [1] http://thread.gmane.org/gmane.comp.security.firewalls.netfilter.devel/57412/
  [2] https://paste.fedoraproject.org/242835/65657871/

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 include/net/netfilter/nf_conntrack_zones.h         | 30 +++++++++-
 include/uapi/linux/netfilter/nfnetlink_conntrack.h |  9 +++
 include/uapi/linux/netfilter/xt_CT.h               |  6 +-
 net/ipv4/netfilter/nf_defrag_ipv4.c                |  8 ++-
 net/ipv6/netfilter/nf_defrag_ipv6_hooks.c          |  8 ++-
 net/netfilter/nf_conntrack_core.c                  | 52 +++++++++---------
 net/netfilter/nf_conntrack_expect.c                |  6 +-
 net/netfilter/nf_conntrack_netlink.c               | 64 ++++++++++++++++++----
 net/netfilter/nf_conntrack_standalone.c            |  9 ++-
 net/netfilter/nf_nat_core.c                        | 13 ++---
 net/netfilter/xt_CT.c                              | 16 +++++-
 net/sched/act_connmark.c                           |  1 +
 12 files changed, 167 insertions(+), 55 deletions(-)

diff --git a/include/net/netfilter/nf_conntrack_zones.h b/include/net/netfilter/nf_conntrack_zones.h
index 0788bb0..bef0539 100644
--- a/include/net/netfilter/nf_conntrack_zones.h
+++ b/include/net/netfilter/nf_conntrack_zones.h
@@ -1,10 +1,17 @@
 #ifndef _NF_CONNTRACK_ZONES_H
 #define _NF_CONNTRACK_ZONES_H
 
+#include <linux/netfilter/nf_conntrack_tuple_common.h>
+
 #define NF_CT_DEFAULT_ZONE_ID	0
 
+#define NF_CT_ORIG_DIR		(1 << IP_CT_DIR_ORIGINAL)
+#define NF_CT_REPL_DIR		(1 << IP_CT_DIR_REPLY)
+#define NF_CT_DEFAULT_DIR	(NF_CT_ORIG_DIR | NF_CT_REPL_DIR)
+
 struct nf_conntrack_zone {
 	u16	id;
+	u16	dir;
 };
 
 extern const struct nf_conntrack_zone nf_ct_zone_dflt;
@@ -29,8 +36,29 @@ nf_ct_zone_tmpl(const struct nf_conn *tmpl)
 	return tmpl ? nf_ct_zone(tmpl) : &nf_ct_zone_dflt;
 }
 
+static inline bool nf_ct_zone_matches_dir(const struct nf_conntrack_zone *zone,
+					  enum ip_conntrack_dir dir)
+{
+	return zone->dir & (1 << dir);
+}
+
+static inline u16 nf_ct_zone_id(const struct nf_conntrack_zone *zone,
+				enum ip_conntrack_dir dir)
+{
+	return nf_ct_zone_matches_dir(zone, dir) ?
+	       zone->id : NF_CT_DEFAULT_ZONE_ID;
+}
+
 static inline bool nf_ct_zone_equal(const struct nf_conn *a,
-				    const struct nf_conntrack_zone *b)
+				    const struct nf_conntrack_zone *b,
+				    enum ip_conntrack_dir dir)
+{
+	return nf_ct_zone_id(nf_ct_zone(a), dir) ==
+	       nf_ct_zone_id(b, dir);
+}
+
+static inline bool nf_ct_zone_equal_any(const struct nf_conn *a,
+					const struct nf_conntrack_zone *b)
 {
 	return nf_ct_zone(a)->id == b->id;
 }
diff --git a/include/uapi/linux/netfilter/nfnetlink_conntrack.h b/include/uapi/linux/netfilter/nfnetlink_conntrack.h
index acad6c5..95841a5 100644
--- a/include/uapi/linux/netfilter/nfnetlink_conntrack.h
+++ b/include/uapi/linux/netfilter/nfnetlink_conntrack.h
@@ -53,6 +53,7 @@ enum ctattr_type {
 	CTA_MARK_MASK,
 	CTA_LABELS,
 	CTA_LABELS_MASK,
+	CTA_DIR,
 	__CTA_MAX
 };
 #define CTA_MAX (__CTA_MAX - 1)
@@ -260,4 +261,12 @@ enum ctattr_expect_stats {
 };
 #define CTA_STATS_EXP_MAX (__CTA_STATS_EXP_MAX - 1)
 
+enum ctattr_dir {
+	CTA_DIR_UNSPEC,
+	CTA_DIR_ORIG,
+	CTA_DIR_REPL,
+	__CTA_DIR_MAX
+};
+#define CTA_DIR_MAX (__CTA_DIR_MAX - 1)
+
 #endif /* _IPCONNTRACK_NETLINK_H */
diff --git a/include/uapi/linux/netfilter/xt_CT.h b/include/uapi/linux/netfilter/xt_CT.h
index 5a688c1..452005f 100644
--- a/include/uapi/linux/netfilter/xt_CT.h
+++ b/include/uapi/linux/netfilter/xt_CT.h
@@ -6,7 +6,11 @@
 enum {
 	XT_CT_NOTRACK		= 1 << 0,
 	XT_CT_NOTRACK_ALIAS	= 1 << 1,
-	XT_CT_MASK		= XT_CT_NOTRACK | XT_CT_NOTRACK_ALIAS,
+	XT_CT_ZONE_DIR_ORIG	= 1 << 2,
+	XT_CT_ZONE_DIR_REPL	= 1 << 3,
+
+	XT_CT_MASK		= XT_CT_NOTRACK | XT_CT_NOTRACK_ALIAS |
+				  XT_CT_ZONE_DIR_ORIG | XT_CT_ZONE_DIR_REPL,
 };
 
 struct xt_ct_target_info {
diff --git a/net/ipv4/netfilter/nf_defrag_ipv4.c b/net/ipv4/netfilter/nf_defrag_ipv4.c
index ad0501a..5fdd6f6 100644
--- a/net/ipv4/netfilter/nf_defrag_ipv4.c
+++ b/net/ipv4/netfilter/nf_defrag_ipv4.c
@@ -45,8 +45,12 @@ static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
 {
 	u16 zone_id = NF_CT_DEFAULT_ZONE_ID;
 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
-	if (skb->nfct)
-		zone_id = nf_ct_zone((struct nf_conn *)skb->nfct)->id;
+	if (skb->nfct) {
+		enum ip_conntrack_info ctinfo;
+		const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+
+		zone_id = nf_ct_zone_id(nf_ct_zone(ct), CTINFO2DIR(ctinfo));
+	}
 #endif
 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 	if (skb->nf_bridge &&
diff --git a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
index 1749500..f623f06 100644
--- a/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
+++ b/net/ipv6/netfilter/nf_defrag_ipv6_hooks.c
@@ -35,8 +35,12 @@ static enum ip6_defrag_users nf_ct6_defrag_user(unsigned int hooknum,
 {
 	u16 zone_id = NF_CT_DEFAULT_ZONE_ID;
 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
-	if (skb->nfct)
-		zone_id = nf_ct_zone((struct nf_conn *)skb->nfct)->id;
+	if (skb->nfct) {
+		enum ip_conntrack_info ctinfo;
+		const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+
+		zone_id = nf_ct_zone_id(nf_ct_zone(ct), CTINFO2DIR(ctinfo));
+	}
 #endif
 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 	if (skb->nf_bridge &&
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 9a04062..8f8e842 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -126,8 +126,7 @@ EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked);
 unsigned int nf_conntrack_hash_rnd __read_mostly;
 EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd);
 
-static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
-			      const struct nf_conntrack_zone *zone)
+static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple)
 {
 	unsigned int n;
 
@@ -136,7 +135,7 @@ static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
 	 * three bytes manually.
 	 */
 	n = (sizeof(tuple->src) + sizeof(tuple->dst.u3)) / sizeof(u32);
-	return jhash2((u32 *)tuple, n, zone->id ^ nf_conntrack_hash_rnd ^
+	return jhash2((u32 *)tuple, n, nf_conntrack_hash_rnd ^
 		      (((__force __u16)tuple->dst.u.all << 16) |
 		      tuple->dst.protonum));
 }
@@ -152,17 +151,15 @@ static u32 hash_bucket(u32 hash, const struct net *net)
 }
 
 static u_int32_t __hash_conntrack(const struct nf_conntrack_tuple *tuple,
-				  const struct nf_conntrack_zone *zone,
 				  unsigned int size)
 {
-	return __hash_bucket(hash_conntrack_raw(tuple, zone), size);
+	return __hash_bucket(hash_conntrack_raw(tuple), size);
 }
 
 static inline u_int32_t hash_conntrack(const struct net *net,
-				       const struct nf_conntrack_zone *zone,
 				       const struct nf_conntrack_tuple *tuple)
 {
-	return __hash_conntrack(tuple, zone, net->ct.htable_size);
+	return __hash_conntrack(tuple, net->ct.htable_size);
 }
 
 bool
@@ -330,20 +327,18 @@ destroy_conntrack(struct nf_conntrack *nfct)
 
 static void nf_ct_delete_from_lists(struct nf_conn *ct)
 {
-	const struct nf_conntrack_zone *zone;
 	struct net *net = nf_ct_net(ct);
 	unsigned int hash, reply_hash;
 	unsigned int sequence;
 
-	zone = nf_ct_zone(ct);
 	nf_ct_helper_destroy(ct);
 
 	local_bh_disable();
 	do {
 		sequence = read_seqcount_begin(&net->ct.generation);
-		hash = hash_conntrack(net, zone,
+		hash = hash_conntrack(net,
 				      &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
-		reply_hash = hash_conntrack(net, zone,
+		reply_hash = hash_conntrack(net,
 					   &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 	} while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 
@@ -400,7 +395,7 @@ nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
 	 * so we need to check that the conntrack is confirmed
 	 */
 	return nf_ct_tuple_equal(tuple, &h->tuple) &&
-	       nf_ct_zone_equal(ct, zone) &&
+	       nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
 	       nf_ct_is_confirmed(ct);
 }
 
@@ -477,7 +472,7 @@ nf_conntrack_find_get(struct net *net, const struct nf_conntrack_zone *zone,
 		      const struct nf_conntrack_tuple *tuple)
 {
 	return __nf_conntrack_find_get(net, zone, tuple,
-				       hash_conntrack_raw(tuple, zone));
+				       hash_conntrack_raw(tuple));
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_find_get);
 
@@ -508,9 +503,9 @@ nf_conntrack_hash_check_insert(struct nf_conn *ct)
 	local_bh_disable();
 	do {
 		sequence = read_seqcount_begin(&net->ct.generation);
-		hash = hash_conntrack(net, zone,
+		hash = hash_conntrack(net,
 				      &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
-		reply_hash = hash_conntrack(net, zone,
+		reply_hash = hash_conntrack(net,
 					   &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 	} while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
 
@@ -518,12 +513,14 @@ nf_conntrack_hash_check_insert(struct nf_conn *ct)
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 				      &h->tuple) &&
-		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone))
+		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
+				     NF_CT_DIRECTION(h)))
 			goto out;
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 				      &h->tuple) &&
-		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone))
+		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
+				     NF_CT_DIRECTION(h)))
 			goto out;
 
 	add_timer(&ct->timeout);
@@ -599,7 +596,7 @@ __nf_conntrack_confirm(struct sk_buff *skb)
 		/* reuse the hash saved before */
 		hash = *(unsigned long *)&ct->tuplehash[IP_CT_DIR_REPLY].hnnode.pprev;
 		hash = hash_bucket(hash, net);
-		reply_hash = hash_conntrack(net, zone,
+		reply_hash = hash_conntrack(net,
 					   &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
 
 	} while (nf_conntrack_double_lock(net, hash, reply_hash, sequence));
@@ -631,12 +628,14 @@ __nf_conntrack_confirm(struct sk_buff *skb)
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
 				      &h->tuple) &&
-		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone))
+		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
+				     NF_CT_DIRECTION(h)))
 			goto out;
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
 				      &h->tuple) &&
-		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone))
+		    nf_ct_zone_equal(nf_ct_tuplehash_to_ctrack(h), zone,
+				     NF_CT_DIRECTION(h)))
 			goto out;
 
 	/* Timer relative to confirmation time, not original
@@ -696,7 +695,7 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 	unsigned int hash;
 
 	zone = nf_ct_zone(ignored_conntrack);
-	hash = hash_conntrack(net, zone, tuple);
+	hash = hash_conntrack(net, tuple);
 
 	/* Disable BHs the entire time since we need to disable them at
 	 * least once for the stats anyway.
@@ -706,7 +705,7 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
 		ct = nf_ct_tuplehash_to_ctrack(h);
 		if (ct != ignored_conntrack &&
 		    nf_ct_tuple_equal(tuple, &h->tuple) &&
-		    nf_ct_zone_equal(ct, zone)) {
+		    nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h))) {
 			NF_CT_STAT_INC(net, found);
 			rcu_read_unlock_bh();
 			return 1;
@@ -806,7 +805,7 @@ __nf_conntrack_alloc(struct net *net,
 	if (unlikely(!nf_conntrack_hash_rnd)) {
 		init_nf_conntrack_hash_rnd();
 		/* recompute the hash as nf_conntrack_hash_rnd is initialized */
-		hash = hash_conntrack_raw(orig, zone);
+		hash = hash_conntrack_raw(orig);
 	}
 
 	/* We don't want any race condition at early drop stage */
@@ -851,6 +850,7 @@ __nf_conntrack_alloc(struct net *net,
 		if (!nf_ct_zone)
 			goto out_free;
 		nf_ct_zone->id = zone->id;
+		nf_ct_zone->dir = zone->dir;
 	}
 #endif
 	/* Because we use RCU lookups, we set ct_general.use to zero before
@@ -1029,7 +1029,7 @@ resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
 
 	/* look for tuple match */
 	zone = nf_ct_zone_tmpl(tmpl);
-	hash = hash_conntrack_raw(&tuple, zone);
+	hash = hash_conntrack_raw(&tuple);
 	h = __nf_conntrack_find_get(net, zone, &tuple, hash);
 	if (!h) {
 		h = init_conntrack(net, tmpl, &tuple, l3proto, l4proto,
@@ -1282,6 +1282,7 @@ EXPORT_SYMBOL_GPL(__nf_ct_kill_acct);
 /* Built-in default zone used e.g. by modules. */
 const struct nf_conntrack_zone nf_ct_zone_dflt = {
 	.id	= NF_CT_DEFAULT_ZONE_ID,
+	.dir	= NF_CT_DEFAULT_DIR,
 };
 EXPORT_SYMBOL_GPL(nf_ct_zone_dflt);
 
@@ -1593,8 +1594,7 @@ int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp)
 					struct nf_conntrack_tuple_hash, hnnode);
 			ct = nf_ct_tuplehash_to_ctrack(h);
 			hlist_nulls_del_rcu(&h->hnnode);
-			bucket = __hash_conntrack(&h->tuple, nf_ct_zone(ct),
-						  hashsize);
+			bucket = __hash_conntrack(&h->tuple, hashsize);
 			hlist_nulls_add_head_rcu(&h->hnnode, &hash[bucket]);
 		}
 	}
diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 4abee59..f20f30e 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -101,7 +101,7 @@ __nf_ct_expect_find(struct net *net,
 	h = nf_ct_expect_dst_hash(tuple);
 	hlist_for_each_entry_rcu(i, &net->ct.expect_hash[h], hnode) {
 		if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) &&
-		    nf_ct_zone_equal(i->master, zone))
+		    nf_ct_zone_equal_any(i->master, zone))
 			return i;
 	}
 	return NULL;
@@ -143,7 +143,7 @@ nf_ct_find_expectation(struct net *net,
 	hlist_for_each_entry(i, &net->ct.expect_hash[h], hnode) {
 		if (!(i->flags & NF_CT_EXPECT_INACTIVE) &&
 		    nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask) &&
-		    nf_ct_zone_equal(i->master, zone)) {
+		    nf_ct_zone_equal_any(i->master, zone)) {
 			exp = i;
 			break;
 		}
@@ -231,7 +231,7 @@ static inline int expect_matches(const struct nf_conntrack_expect *a,
 	return a->master == b->master && a->class == b->class &&
 	       nf_ct_tuple_equal(&a->tuple, &b->tuple) &&
 	       nf_ct_tuple_mask_equal(&a->mask, &b->mask) &&
-	       nf_ct_zone_equal(a->master, nf_ct_zone(b->master));
+	       nf_ct_zone_equal_any(a->master, nf_ct_zone(b->master));
 }
 
 /* Generally a bad idea to call this: could have matched already. */
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 86fbe4b..0d389ec 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -454,6 +454,32 @@ nla_put_failure:
 	return -1;
 }
 
+#ifdef CONFIG_NF_CONNTRACK_ZONES
+static u16 ctnetlink_to_dir(u8 ctn_dir)
+{
+	switch (ctn_dir) {
+	case CTA_DIR_ORIG:
+		return NF_CT_ORIG_DIR;
+	case CTA_DIR_REPL:
+		return NF_CT_REPL_DIR;
+	default:
+		return NF_CT_DEFAULT_DIR;
+	}
+}
+#endif
+
+static u8 ctnetlink_from_dir(u16 dir)
+{
+	switch (dir) {
+	case NF_CT_ORIG_DIR:
+		return CTA_DIR_ORIG;
+	case NF_CT_REPL_DIR:
+		return CTA_DIR_REPL;
+	default:
+		return CTA_DIR_UNSPEC;
+	}
+}
+
 static int
 ctnetlink_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
 		    struct nf_conn *ct)
@@ -492,6 +518,9 @@ ctnetlink_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
 	if (zone->id != NF_CT_DEFAULT_ZONE_ID &&
 	    nla_put_be16(skb, CTA_ZONE, htons(zone->id)))
 		goto nla_put_failure;
+	if (zone->dir != NF_CT_DEFAULT_DIR &&
+	    nla_put_u8(skb, CTA_DIR, ctnetlink_from_dir(zone->dir)))
+		goto nla_put_failure;
 
 	if (ctnetlink_dump_status(skb, ct) < 0 ||
 	    ctnetlink_dump_timeout(skb, ct) < 0 ||
@@ -601,6 +630,7 @@ ctnetlink_nlmsg_size(const struct nf_conn *ct)
 #endif
 #ifdef CONFIG_NF_CONNTRACK_ZONES
 	       + nla_total_size(sizeof(u_int16_t)) /* CTA_ZONE */
+	       + nla_total_size(sizeof(u_int8_t)) /* CTA_DIR */
 #endif
 	       + ctnetlink_proto_size(ct)
 	       + ctnetlink_label_size(ct)
@@ -676,6 +706,9 @@ ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item)
 	if (zone->id != NF_CT_DEFAULT_ZONE_ID &&
 	    nla_put_be16(skb, CTA_ZONE, htons(zone->id)))
 		goto nla_put_failure;
+	if (zone->dir != NF_CT_DEFAULT_DIR &&
+	    nla_put_u8(skb, CTA_DIR, ctnetlink_from_dir(zone->dir)))
+		goto nla_put_failure;
 
 	if (ctnetlink_dump_id(skb, ct) < 0)
 		goto nla_put_failure;
@@ -969,16 +1002,20 @@ ctnetlink_parse_tuple(const struct nlattr * const cda[],
 }
 
 static int
-ctnetlink_parse_zone(const struct nlattr *attr,
+ctnetlink_parse_zone(const struct nlattr *zattr,
+		     const struct nlattr *dattr,
 		     struct nf_conntrack_zone *zone)
 {
 	zone->id = NF_CT_DEFAULT_ZONE_ID;
+	zone->dir = NF_CT_DEFAULT_DIR;
 
 #ifdef CONFIG_NF_CONNTRACK_ZONES
-	if (attr)
-		zone->id = ntohs(nla_get_be16(attr));
+	if (zattr)
+		zone->id = ntohs(nla_get_be16(zattr));
+	if (dattr)
+		zone->dir = ctnetlink_to_dir(nla_get_u8(dattr));
 #else
-	if (attr)
+	if (zattr || dattr)
 		return -EOPNOTSUPP;
 #endif
 	return 0;
@@ -1026,6 +1063,7 @@ static const struct nla_policy ct_nla_policy[CTA_MAX+1] = {
 	[CTA_NAT_SEQ_ADJ_ORIG]  = { .type = NLA_NESTED },
 	[CTA_NAT_SEQ_ADJ_REPLY] = { .type = NLA_NESTED },
 	[CTA_ZONE]		= { .type = NLA_U16 },
+	[CTA_DIR]		= { .type = NLA_U8 },
 	[CTA_MARK_MASK]		= { .type = NLA_U32 },
 	[CTA_LABELS]		= { .type = NLA_BINARY,
 				    .len = NF_CT_LABELS_MAX_SIZE },
@@ -1066,7 +1104,7 @@ ctnetlink_del_conntrack(struct sock *ctnl, struct sk_buff *skb,
 	struct nf_conntrack_zone zone;
 	int err;
 
-	err = ctnetlink_parse_zone(cda[CTA_ZONE], &zone);
+	err = ctnetlink_parse_zone(cda[CTA_ZONE], cda[CTA_DIR], &zone);
 	if (err < 0)
 		return err;
 
@@ -1138,7 +1176,7 @@ ctnetlink_get_conntrack(struct sock *ctnl, struct sk_buff *skb,
 		return netlink_dump_start(ctnl, skb, nlh, &c);
 	}
 
-	err = ctnetlink_parse_zone(cda[CTA_ZONE], &zone);
+	err = ctnetlink_parse_zone(cda[CTA_ZONE], cda[CTA_DIR], &zone);
 	if (err < 0)
 		return err;
 
@@ -1813,7 +1851,7 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
 	struct nf_conntrack_zone zone;
 	int err;
 
-	err = ctnetlink_parse_zone(cda[CTA_ZONE], &zone);
+	err = ctnetlink_parse_zone(cda[CTA_ZONE], cda[CTA_DIR], &zone);
 	if (err < 0)
 		return err;
 
@@ -2089,6 +2127,7 @@ ctnetlink_nfqueue_build_size(const struct nf_conn *ct)
 #endif
 #ifdef CONFIG_NF_CONNTRACK_ZONES
 	       + nla_total_size(sizeof(u_int16_t)) /* CTA_ZONE */
+	       + nla_total_size(sizeof(u_int8_t)) /* CTA_DIR */
 #endif
 	       + ctnetlink_proto_size(ct)
 	       ;
@@ -2119,6 +2158,9 @@ ctnetlink_nfqueue_build(struct sk_buff *skb, struct nf_conn *ct)
 	if (zone->id != NF_CT_DEFAULT_ZONE_ID &&
 	    nla_put_be16(skb, CTA_ZONE, htons(zone->id)))
 		goto nla_put_failure;
+	if (zone->dir != NF_CT_DEFAULT_DIR &&
+	    nla_put_u8(skb, CTA_DIR, ctnetlink_from_dir(zone->dir)))
+		goto nla_put_failure;
 
 	if (ctnetlink_dump_id(skb, ct) < 0)
 		goto nla_put_failure;
@@ -2629,7 +2671,7 @@ static int ctnetlink_dump_exp_ct(struct sock *ctnl, struct sk_buff *skb,
 	if (err < 0)
 		return err;
 
-	err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
+	err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], NULL, &zone);
 	if (err < 0)
 		return err;
 
@@ -2672,7 +2714,7 @@ ctnetlink_get_expect(struct sock *ctnl, struct sk_buff *skb,
 		}
 	}
 
-	err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
+	err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], NULL, &zone);
 	if (err < 0)
 		return err;
 
@@ -2743,7 +2785,7 @@ ctnetlink_del_expect(struct sock *ctnl, struct sk_buff *skb,
 
 	if (cda[CTA_EXPECT_TUPLE]) {
 		/* delete a single expect by tuple */
-		err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
+		err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], NULL, &zone);
 		if (err < 0)
 			return err;
 
@@ -3030,7 +3072,7 @@ ctnetlink_new_expect(struct sock *ctnl, struct sk_buff *skb,
 	    || !cda[CTA_EXPECT_MASTER])
 		return -EINVAL;
 
-	err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
+	err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], NULL, &zone);
 	if (err < 0)
 		return err;
 
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 28c8b2b..b214e91 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -143,7 +143,14 @@ static inline void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
 #ifdef CONFIG_NF_CONNTRACK_ZONES
 static void ct_show_zone(struct seq_file *s, const struct nf_conn *ct)
 {
-	seq_printf(s, "zone=%u ", nf_ct_zone(ct)->id);
+	const struct nf_conntrack_zone *zone = nf_ct_zone(ct);
+	static const char * const dir_name[] = {
+		[NF_CT_ORIG_DIR]	= "original",
+		[NF_CT_REPL_DIR]	= "reply",
+		[NF_CT_DEFAULT_DIR]	= "both",
+	};
+
+	seq_printf(s, "zone=%u zone-dir=%s ", zone->id, dir_name[zone->dir]);
 }
 #else
 static inline void ct_show_zone(struct seq_file *s, const struct nf_conn *ct)
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c
index 65ebaf9..5113dfd 100644
--- a/net/netfilter/nf_nat_core.c
+++ b/net/netfilter/nf_nat_core.c
@@ -118,15 +118,13 @@ EXPORT_SYMBOL(nf_xfrm_me_harder);
 
 /* We keep an extra hash for each conntrack, for fast searching. */
 static inline unsigned int
-hash_by_src(const struct net *net,
-	    const struct nf_conntrack_zone *zone,
-	    const struct nf_conntrack_tuple *tuple)
+hash_by_src(const struct net *net, 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->id ^ nf_conntrack_hash_rnd);
+		      tuple->dst.protonum ^ nf_conntrack_hash_rnd);
 
 	return reciprocal_scale(hash, net->ct.nat_htable_size);
 }
@@ -194,13 +192,14 @@ find_appropriate_src(struct net *net,
 		     struct nf_conntrack_tuple *result,
 		     const struct nf_nat_range *range)
 {
-	unsigned int h = hash_by_src(net, zone, tuple);
+	unsigned int h = hash_by_src(net, tuple);
 	const struct nf_conn_nat *nat;
 	const struct nf_conn *ct;
 
 	hlist_for_each_entry_rcu(nat, &net->ct.nat_bysource[h], bysource) {
 		ct = nat->ct;
-		if (same_src(ct, tuple) && nf_ct_zone_equal(ct, zone)) {
+		if (same_src(ct, tuple) &&
+		    nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL)) {
 			/* Copy source part from reply tuple. */
 			nf_ct_invert_tuplepr(result,
 				       &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
@@ -425,7 +424,7 @@ nf_nat_setup_info(struct nf_conn *ct,
 	if (maniptype == NF_NAT_MANIP_SRC) {
 		unsigned int srchash;
 
-		srchash = hash_by_src(net, nf_ct_zone(ct),
+		srchash = hash_by_src(net,
 				      &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
 		spin_lock_bh(&nf_nat_lock);
 		/* nf_conntrack_alter_reply might re-allocate extension aera */
diff --git a/net/netfilter/xt_CT.c b/net/netfilter/xt_CT.c
index e2d7b55..8646075 100644
--- a/net/netfilter/xt_CT.c
+++ b/net/netfilter/xt_CT.c
@@ -181,6 +181,18 @@ out:
 #endif
 }
 
+static u16 xt_ct_flags_to_dir(const struct xt_ct_target_info_v1 *info)
+{
+	switch (info->flags & (XT_CT_ZONE_DIR_ORIG | XT_CT_ZONE_DIR_REPL)) {
+	case XT_CT_ZONE_DIR_ORIG:
+		return NF_CT_ORIG_DIR;
+	case XT_CT_ZONE_DIR_REPL:
+		return NF_CT_REPL_DIR;
+	default:
+		return NF_CT_DEFAULT_DIR;
+	}
+}
+
 static int xt_ct_tg_check(const struct xt_tgchk_param *par,
 			  struct xt_ct_target_info_v1 *info)
 {
@@ -195,7 +207,8 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par,
 	}
 
 #ifndef CONFIG_NF_CONNTRACK_ZONES
-	if (info->zone)
+	if (info->zone || info->flags & (XT_CT_ZONE_DIR_ORIG |
+					 XT_CT_ZONE_DIR_REPL))
 		goto err1;
 #endif
 
@@ -205,6 +218,7 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par,
 
 	memset(&t, 0, sizeof(t));
 	zone.id = info->zone;
+	zone.dir = xt_ct_flags_to_dir(info);
 
 	ct = nf_conntrack_alloc(par->net, &zone, &t, &t, GFP_KERNEL);
 	ret = PTR_ERR(ct);
diff --git a/net/sched/act_connmark.c b/net/sched/act_connmark.c
index e67a1bd..25dc890 100644
--- a/net/sched/act_connmark.c
+++ b/net/sched/act_connmark.c
@@ -72,6 +72,7 @@ static int tcf_connmark(struct sk_buff *skb, const struct tc_action *a,
 		goto out;
 
 	zone.id = ca->zone;
+	zone.dir = NF_CT_DEFAULT_DIR;
 
 	thash = nf_conntrack_find_get(dev_net(skb->dev), &zone, &tuple);
 	if (!thash)
-- 
1.9.3

[PATCH nf-next v3 3/3] netfilter: nf_conntrack: add efficient mark to zone mapping

[Daniel Borkmann]

This work adds the possibility of deriving the zone id from the skb->mark
field in a scalable manner. This allows for having only a single template
serving hundreds/thousands of different zones, for example, instead of the
need to have one match for each zone as an extra CT jump target.

Note that we'd need to have this information attached to the template as at
the time when we're trying to lookup a possible ct object, we already need
to know zone information for a possible match when going into
__nf_conntrack_find_get(). This work provides a minimal implementation for
a possible mapping.

In order to not add/expose an extra ct->status bit, the zone structure has
been extended to carry a flag for deriving the mark.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
---
 include/net/netfilter/nf_conntrack_zones.h     | 29 +++++++++++++++++++++++---
 include/uapi/linux/netfilter/xt_CT.h           |  4 +++-
 net/ipv4/netfilter/nf_conntrack_proto_icmp.c   |  3 ++-
 net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c |  4 +++-
 net/netfilter/nf_conntrack_core.c              | 10 +++++----
 net/netfilter/nf_conntrack_netlink.c           |  1 +
 net/netfilter/xt_CT.c                          |  9 ++++++--
 7 files changed, 48 insertions(+), 12 deletions(-)

diff --git a/include/net/netfilter/nf_conntrack_zones.h b/include/net/netfilter/nf_conntrack_zones.h
index bef0539..4ab835f6 100644
--- a/include/net/netfilter/nf_conntrack_zones.h
+++ b/include/net/netfilter/nf_conntrack_zones.h
@@ -9,9 +9,12 @@
 #define NF_CT_REPL_DIR		(1 << IP_CT_DIR_REPLY)
 #define NF_CT_DEFAULT_DIR	(NF_CT_ORIG_DIR | NF_CT_REPL_DIR)
 
+#define NF_CT_FLAG_MARK		1
+
 struct nf_conntrack_zone {
 	u16	id;
-	u16	dir;
+	u8	flags;
+	u8	dir;
 };
 
 extern const struct nf_conntrack_zone nf_ct_zone_dflt;
@@ -31,9 +34,29 @@ nf_ct_zone(const struct nf_conn *ct)
 }
 
 static inline const struct nf_conntrack_zone *
-nf_ct_zone_tmpl(const struct nf_conn *tmpl)
+nf_ct_zone_init(struct nf_conntrack_zone *zone, u16 id, u8 dir, u8 flags)
 {
-	return tmpl ? nf_ct_zone(tmpl) : &nf_ct_zone_dflt;
+	zone->id = id;
+	zone->flags = flags;
+	zone->dir = dir;
+
+	return zone;
+}
+
+static inline const struct nf_conntrack_zone *
+nf_ct_zone_tmpl(const struct nf_conn *tmpl, const struct sk_buff *skb,
+		struct nf_conntrack_zone *tmp)
+{
+	const struct nf_conntrack_zone *zone;
+
+	if (!tmpl)
+		return &nf_ct_zone_dflt;
+
+	zone = nf_ct_zone(tmpl);
+	if (zone->flags & NF_CT_FLAG_MARK)
+		zone = nf_ct_zone_init(tmp, skb->mark, zone->dir, 0);
+
+	return zone;
 }
 
 static inline bool nf_ct_zone_matches_dir(const struct nf_conntrack_zone *zone,
diff --git a/include/uapi/linux/netfilter/xt_CT.h b/include/uapi/linux/netfilter/xt_CT.h
index 452005f..9e52041 100644
--- a/include/uapi/linux/netfilter/xt_CT.h
+++ b/include/uapi/linux/netfilter/xt_CT.h
@@ -8,9 +8,11 @@ enum {
 	XT_CT_NOTRACK_ALIAS	= 1 << 1,
 	XT_CT_ZONE_DIR_ORIG	= 1 << 2,
 	XT_CT_ZONE_DIR_REPL	= 1 << 3,
+	XT_CT_ZONE_MARK		= 1 << 4,
 
 	XT_CT_MASK		= XT_CT_NOTRACK | XT_CT_NOTRACK_ALIAS |
-				  XT_CT_ZONE_DIR_ORIG | XT_CT_ZONE_DIR_REPL,
+				  XT_CT_ZONE_DIR_ORIG | XT_CT_ZONE_DIR_REPL |
+				  XT_CT_ZONE_MARK,
 };
 
 struct xt_ct_target_info {
diff --git a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
index 8a2f41c..cdde3ec 100644
--- a/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
+++ b/net/ipv4/netfilter/nf_conntrack_proto_icmp.c
@@ -135,9 +135,10 @@ icmp_error_message(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
 	const struct nf_conntrack_l4proto *innerproto;
 	const struct nf_conntrack_tuple_hash *h;
 	const struct nf_conntrack_zone *zone;
+	struct nf_conntrack_zone tmp;
 
 	NF_CT_ASSERT(skb->nfct == NULL);
-	zone = nf_ct_zone_tmpl(tmpl);
+	zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
 
 	/* Are they talking about one of our connections? */
 	if (!nf_ct_get_tuplepr(skb,
diff --git a/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c b/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c
index 2029141..0e6fae1 100644
--- a/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c
+++ b/net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c
@@ -150,6 +150,7 @@ icmpv6_error_message(struct net *net, struct nf_conn *tmpl,
 	struct nf_conntrack_tuple intuple, origtuple;
 	const struct nf_conntrack_tuple_hash *h;
 	const struct nf_conntrack_l4proto *inproto;
+	struct nf_conntrack_zone tmp;
 
 	NF_CT_ASSERT(skb->nfct == NULL);
 
@@ -176,7 +177,8 @@ icmpv6_error_message(struct net *net, struct nf_conn *tmpl,
 
 	*ctinfo = IP_CT_RELATED;
 
-	h = nf_conntrack_find_get(net, nf_ct_zone_tmpl(tmpl), &intuple);
+	h = nf_conntrack_find_get(net, nf_ct_zone_tmpl(tmpl, skb, &tmp),
+				  &intuple);
 	if (!h) {
 		pr_debug("icmpv6_error: no match\n");
 		return -NF_ACCEPT;
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 8f8e842..e0ef80a 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -849,8 +849,8 @@ __nf_conntrack_alloc(struct net *net,
 		nf_ct_zone = nf_ct_ext_add(ct, NF_CT_EXT_ZONE, GFP_ATOMIC);
 		if (!nf_ct_zone)
 			goto out_free;
-		nf_ct_zone->id = zone->id;
-		nf_ct_zone->dir = zone->dir;
+
+		nf_ct_zone_init(nf_ct_zone, zone->id, zone->dir, zone->flags);
 	}
 #endif
 	/* Because we use RCU lookups, we set ct_general.use to zero before
@@ -912,6 +912,7 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
 	struct nf_conntrack_expect *exp = NULL;
 	const struct nf_conntrack_zone *zone;
 	struct nf_conn_timeout *timeout_ext;
+	struct nf_conntrack_zone tmp;
 	unsigned int *timeouts;
 
 	if (!nf_ct_invert_tuple(&repl_tuple, tuple, l3proto, l4proto)) {
@@ -919,7 +920,7 @@ init_conntrack(struct net *net, struct nf_conn *tmpl,
 		return NULL;
 	}
 
-	zone = nf_ct_zone_tmpl(tmpl);
+	zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
 	ct = __nf_conntrack_alloc(net, zone, tuple, &repl_tuple, GFP_ATOMIC,
 				  hash);
 	if (IS_ERR(ct))
@@ -1017,6 +1018,7 @@ resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
 	const struct nf_conntrack_zone *zone;
 	struct nf_conntrack_tuple tuple;
 	struct nf_conntrack_tuple_hash *h;
+	struct nf_conntrack_zone tmp;
 	struct nf_conn *ct;
 	u32 hash;
 
@@ -1028,7 +1030,7 @@ resolve_normal_ct(struct net *net, struct nf_conn *tmpl,
 	}
 
 	/* look for tuple match */
-	zone = nf_ct_zone_tmpl(tmpl);
+	zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);
 	hash = hash_conntrack_raw(&tuple);
 	h = __nf_conntrack_find_get(net, zone, &tuple, hash);
 	if (!h) {
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 0d389ec..b53d425 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1008,6 +1008,7 @@ ctnetlink_parse_zone(const struct nlattr *zattr,
 {
 	zone->id = NF_CT_DEFAULT_ZONE_ID;
 	zone->dir = NF_CT_DEFAULT_DIR;
+	zone->flags = 0;
 
 #ifdef CONFIG_NF_CONNTRACK_ZONES
 	if (zattr)
diff --git a/net/netfilter/xt_CT.c b/net/netfilter/xt_CT.c
index 8646075..df4e9ad 100644
--- a/net/netfilter/xt_CT.c
+++ b/net/netfilter/xt_CT.c
@@ -20,6 +20,8 @@
 #include <net/netfilter/nf_conntrack_timeout.h>
 #include <net/netfilter/nf_conntrack_zones.h>
 
+#define XT_CT_ZONE_FLAGS (XT_CT_ZONE_DIR_ORIG | XT_CT_ZONE_DIR_REPL | XT_CT_ZONE_MARK)
+
 static inline int xt_ct_target(struct sk_buff *skb, struct nf_conn *ct)
 {
 	/* Previously seen (loopback)? Ignore. */
@@ -207,8 +209,7 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par,
 	}
 
 #ifndef CONFIG_NF_CONNTRACK_ZONES
-	if (info->zone || info->flags & (XT_CT_ZONE_DIR_ORIG |
-					 XT_CT_ZONE_DIR_REPL))
+	if (info->zone || info->flags & XT_CT_ZONE_FLAGS)
 		goto err1;
 #endif
 
@@ -217,8 +218,12 @@ static int xt_ct_tg_check(const struct xt_tgchk_param *par,
 		goto err1;
 
 	memset(&t, 0, sizeof(t));
+
 	zone.id = info->zone;
 	zone.dir = xt_ct_flags_to_dir(info);
+	zone.flags = 0;
+	if (info->flags & XT_CT_ZONE_MARK)
+		zone.flags |= NF_CT_FLAG_MARK;
 
 	ct = nf_conntrack_alloc(par->net, &zone, &t, &t, GFP_KERNEL);
 	ret = PTR_ERR(ct);
-- 
1.9.3