netfilter: nf_conntrack: add support for "conntrack zones"

Normally, each connection needs a unique identity. Conntrack zones allow
to specify a numerical zone using the CT target, connections in different
zones can use the same identity.

Example:

iptables -t raw -A PREROUTING -i veth0 -j CT --zone 1
iptables -t raw -A OUTPUT -o veth1 -j CT --zone 1

Signed-off-by: Patrick McHardy <kaber@trash.net>

7 files changed, 42 insertions, 6 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
index fb63371c07a8..7bc47873e3fc 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -352,8 +352,11 @@ enum ip_defrag_users {
         IP_DEFRAG_LOCAL_DELIVER,
         IP_DEFRAG_CALL_RA_CHAIN,
         IP_DEFRAG_CONNTRACK_IN,
+        __IP_DEFRAG_CONNTRACK_IN_END    = IP_DEFRAG_CONNTRACK_IN + USHORT_MAX,
         IP_DEFRAG_CONNTRACK_OUT,
+        __IP_DEFRAG_CONNTRACK_OUT_END   = IP_DEFRAG_CONNTRACK_OUT + USHORT_MAX,
         IP_DEFRAG_CONNTRACK_BRIDGE_IN,
+        __IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHORT_MAX,
         IP_DEFRAG_VS_IN,
         IP_DEFRAG_VS_OUT,
         IP_DEFRAG_VS_FWD
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 299bbf5adfb6..639ec53ea081 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -355,8 +355,11 @@ struct inet_frag_queue;
 enum ip6_defrag_users {
         IP6_DEFRAG_LOCAL_DELIVER,
         IP6_DEFRAG_CONNTRACK_IN,
+        __IP6_DEFRAG_CONNTRACK_IN       = IP6_DEFRAG_CONNTRACK_IN + USHORT_MAX,
         IP6_DEFRAG_CONNTRACK_OUT,
+        __IP6_DEFRAG_CONNTRACK_OUT      = IP6_DEFRAG_CONNTRACK_OUT + USHORT_MAX,
         IP6_DEFRAG_CONNTRACK_BRIDGE_IN,
+        __IP6_DEFRAG_CONNTRACK_BRIDGE_IN = IP6_DEFRAG_CONNTRACK_BRIDGE_IN + USHORT_MAX,
 };
 
 struct ip6_create_arg {
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 5b7d8835523f..bde095f7e845 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -198,7 +198,8 @@ extern void *nf_ct_alloc_hashtable(unsigned int *sizep, int *vmalloced, int null
 extern void nf_ct_free_hashtable(void *hash, int vmalloced, unsigned int size);
 
 extern struct nf_conntrack_tuple_hash *
-__nf_conntrack_find(struct net *net, const struct nf_conntrack_tuple *tuple);
+__nf_conntrack_find(struct net *net, u16 zone,
+                    const struct nf_conntrack_tuple *tuple);
 
 extern void nf_conntrack_hash_insert(struct nf_conn *ct);
 extern void nf_ct_delete_from_lists(struct nf_conn *ct);
@@ -267,7 +268,7 @@ extern void
 nf_ct_iterate_cleanup(struct net *net, int (*iter)(struct nf_conn *i, void *data), void *data);
 extern void nf_conntrack_free(struct nf_conn *ct);
 extern struct nf_conn *
-nf_conntrack_alloc(struct net *net,
+nf_conntrack_alloc(struct net *net, u16 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 5a449b44ba33..dffde8e6920e 100644
--- a/include/net/netfilter/nf_conntrack_core.h
+++ b/include/net/netfilter/nf_conntrack_core.h
@@ -49,7 +49,8 @@ nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
 
 /* Find a connection corresponding to a tuple. */
 extern struct nf_conntrack_tuple_hash *
-nf_conntrack_find_get(struct net *net, const struct nf_conntrack_tuple *tuple);
+nf_conntrack_find_get(struct net *net, u16 zone,
+                      const struct nf_conntrack_tuple *tuple);
 
 extern 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 4b47ec19ef39..11e815084fcf 100644
--- a/include/net/netfilter/nf_conntrack_expect.h
+++ b/include/net/netfilter/nf_conntrack_expect.h
@@ -74,13 +74,16 @@ int nf_conntrack_expect_init(struct net *net);
 void nf_conntrack_expect_fini(struct net *net);
 
 struct nf_conntrack_expect *
-__nf_ct_expect_find(struct net *net, const struct nf_conntrack_tuple *tuple);
+__nf_ct_expect_find(struct net *net, u16 zone,
+                    const struct nf_conntrack_tuple *tuple);
 
 struct nf_conntrack_expect *
-nf_ct_expect_find_get(struct net *net, const struct nf_conntrack_tuple *tuple);
+nf_ct_expect_find_get(struct net *net, u16 zone,
+                      const struct nf_conntrack_tuple *tuple);
 
 struct nf_conntrack_expect *
-nf_ct_find_expectation(struct net *net, const struct nf_conntrack_tuple *tuple);
+nf_ct_find_expectation(struct net *net, u16 zone,
+                       const struct nf_conntrack_tuple *tuple);
 
 void nf_ct_unlink_expect(struct nf_conntrack_expect *exp);
 void nf_ct_remove_expectations(struct nf_conn *ct);
diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h
index e192dc17c583..2d2a1f9a61d8 100644
--- a/include/net/netfilter/nf_conntrack_extend.h
+++ b/include/net/netfilter/nf_conntrack_extend.h
@@ -8,6 +8,7 @@ enum nf_ct_ext_id {
         NF_CT_EXT_NAT,
         NF_CT_EXT_ACCT,
         NF_CT_EXT_ECACHE,
+        NF_CT_EXT_ZONE,
         NF_CT_EXT_NUM,
 };
 
@@ -15,6 +16,7 @@ enum nf_ct_ext_id {
 #define NF_CT_EXT_NAT_TYPE struct nf_conn_nat
 #define NF_CT_EXT_ACCT_TYPE struct nf_conn_counter
 #define NF_CT_EXT_ECACHE_TYPE struct nf_conntrack_ecache
+#define NF_CT_EXT_ZONE_TYPE struct nf_conntrack_zone
 
 /* Extensions: optional stuff which isn't permanently in struct. */
 struct nf_ct_ext {
diff --git a/include/net/netfilter/nf_conntrack_zones.h b/include/net/netfilter/nf_conntrack_zones.h
new file mode 100644
index 000000000000..0bbb2bd51e89
--- /dev/null
+++ b/include/net/netfilter/nf_conntrack_zones.h
@@ -0,0 +1,23 @@
+#ifndef _NF_CONNTRACK_ZONES_H
+#define _NF_CONNTRACK_ZONES_H
+
+#include <net/netfilter/nf_conntrack_extend.h>
+
+#define NF_CT_DEFAULT_ZONE      0
+
+struct nf_conntrack_zone {
+        u16     id;
+};
+
+static inline u16 nf_ct_zone(const struct nf_conn *ct)
+{
+#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;
+}
+
+#endif /* _NF_CONNTRACK_ZONES_H */