[NETFILTER]: nf_nat: use extension infrastructure

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 73 insertions, 36 deletions

diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index f1e0fee9aa9c..b2083d386f33 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -278,22 +278,5 @@ nf_conntrack_register_cache(u_int32_t features, const char *name, size_t size);
 extern void
 nf_conntrack_unregister_cache(u_int32_t features);
 
-/* valid combinations:
- * basic: nf_conn, nf_conn .. nf_conn_help
- * nat: nf_conn .. nf_conn_nat, nf_conn .. nf_conn_nat .. nf_conn help
- */
-#ifdef CONFIG_NF_NAT_NEEDED
-#include <net/netfilter/nf_nat.h>
-static inline struct nf_conn_nat *nfct_nat(const struct nf_conn *ct)
-{
-        unsigned int offset = sizeof(struct nf_conn);
-
-        if (!(ct->features & NF_CT_F_NAT))
-                return NULL;
-
-        offset = ALIGN(offset, __alignof__(struct nf_conn_nat));
-        return (struct nf_conn_nat *) ((void *)ct + offset);
-}
-#endif /* CONFIG_NF_NAT_NEEDED */
 #endif /* __KERNEL__ */
 #endif /* _NF_CONNTRACK_H */
diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h
index 05357dc5d2d2..73b5711faf32 100644
--- a/include/net/netfilter/nf_conntrack_extend.h
+++ b/include/net/netfilter/nf_conntrack_extend.h
@@ -6,10 +6,12 @@
 enum nf_ct_ext_id
 {
         NF_CT_EXT_HELPER,
+        NF_CT_EXT_NAT,
         NF_CT_EXT_NUM,
 };
 
 #define NF_CT_EXT_HELPER_TYPE struct nf_conn_help
+#define NF_CT_EXT_NAT_TYPE struct nf_conn_nat
 
 /* Extensions: optional stuff which isn't permanently in struct. */
 struct nf_ct_ext {
diff --git a/include/net/netfilter/nf_nat.h b/include/net/netfilter/nf_nat.h
index 575dc8ac48dc..0425e28c6a78 100644
--- a/include/net/netfilter/nf_nat.h
+++ b/include/net/netfilter/nf_nat.h
@@ -52,6 +52,7 @@ struct nf_nat_multi_range_compat
 #ifdef __KERNEL__
 #include <linux/list.h>
 #include <linux/netfilter/nf_conntrack_pptp.h>
+#include <net/netfilter/nf_conntrack_extend.h>
 
 struct nf_conn;
 
@@ -89,6 +90,11 @@ extern unsigned int nf_nat_setup_info(struct nf_conn *ct,
 extern int nf_nat_used_tuple(const struct nf_conntrack_tuple *tuple,
                              const struct nf_conn *ignored_conntrack);
 
+static inline struct nf_conn_nat *nfct_nat(const struct nf_conn *ct)
+{
+        return nf_ct_ext_find(ct, NF_CT_EXT_NAT);
+}
+
 extern int nf_nat_module_is_loaded;
 
 #else  /* !__KERNEL__: iptables wants this to compile. */
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index 6dc72a815f77..96f641d07a40 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -108,9 +108,6 @@ EXPORT_SYMBOL_GPL(nf_nat_module_is_loaded);
 
 static u_int32_t ipv4_get_features(const struct nf_conntrack_tuple *tuple)
 {
-        if (nf_nat_module_is_loaded)
-                return NF_CT_F_NAT;
-
         return NF_CT_F_BASIC;
 }
 
diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c
index ac7e8abbbdeb..4ce82d7014ff 100644
--- a/net/ipv4/netfilter/nf_nat_core.c
+++ b/net/ipv4/netfilter/nf_nat_core.c
@@ -297,11 +297,21 @@ nf_nat_setup_info(struct nf_conn *ct,
                   unsigned int hooknum)
 {
         struct nf_conntrack_tuple curr_tuple, new_tuple;
-        struct nf_conn_nat *nat = nfct_nat(ct);
-        struct nf_nat_info *info = &nat->info;
+        struct nf_conn_nat *nat;
+        struct nf_nat_info *info;
         int have_to_hash = !(ct->status & IPS_NAT_DONE_MASK);
         enum nf_nat_manip_type maniptype = HOOK2MANIP(hooknum);
 
+        /* nat helper or nfctnetlink also setup binding */
+        nat = nfct_nat(ct);
+        if (!nat) {
+                nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
+                if (nat == NULL) {
+                        DEBUGP("failed to add NAT extension\n");
+                        return NF_ACCEPT;
+                }
+        }
+
         NF_CT_ASSERT(hooknum == NF_IP_PRE_ROUTING ||
                      hooknum == NF_IP_POST_ROUTING ||
                      hooknum == NF_IP_LOCAL_IN ||
@@ -338,6 +348,8 @@ nf_nat_setup_info(struct nf_conn *ct,
 
                 srchash = hash_by_src(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
                 write_lock_bh(&nf_nat_lock);
+                /* nf_conntrack_alter_reply might re-allocate exntension aera */
+                info = &nfct_nat(ct)->info;
                 info->ct = ct;
                 list_add(&info->bysource, &bysource[srchash]);
                 write_unlock_bh(&nf_nat_lock);
@@ -592,17 +604,52 @@ nf_nat_port_nfattr_to_range(struct nfattr *tb[], struct nf_nat_range *range)
 EXPORT_SYMBOL_GPL(nf_nat_port_range_to_nfattr);
 #endif
 
+static void nf_nat_move_storage(struct nf_conn *conntrack, void *old)
+{
+        struct nf_conn_nat *new_nat = nf_ct_ext_find(conntrack, NF_CT_EXT_NAT);
+        struct nf_conn_nat *old_nat = (struct nf_conn_nat *)old;
+        struct nf_conn *ct = old_nat->info.ct;
+        unsigned int srchash;
+
+        if (!(ct->status & IPS_NAT_DONE_MASK))
+                return;
+
+        srchash = hash_by_src(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+
+        write_lock_bh(&nf_nat_lock);
+        list_replace(&old_nat->info.bysource, &new_nat->info.bysource);
+        new_nat->info.ct = ct;
+        write_unlock_bh(&nf_nat_lock);
+}
+
+struct nf_ct_ext_type nat_extend = {
+        .len    = sizeof(struct nf_conn_nat),
+        .align  = __alignof__(struct nf_conn_nat),
+        .move   = nf_nat_move_storage,
+        .id     = NF_CT_EXT_NAT,
+        .flags  = NF_CT_EXT_F_PREALLOC,
+};
+
 static int __init nf_nat_init(void)
 {
         size_t i;
+        int ret;
+
+        ret = nf_ct_extend_register(&nat_extend);
+        if (ret < 0) {
+                printk(KERN_ERR "nf_nat_core: Unable to register extension\n");
+                return ret;
+        }
 
         /* Leave them the same for the moment. */
         nf_nat_htable_size = nf_conntrack_htable_size;
 
         /* One vmalloc for both hash tables */
         bysource = vmalloc(sizeof(struct list_head) * nf_nat_htable_size);
-        if (!bysource)
-                return -ENOMEM;
+        if (!bysource) {
+                ret = -ENOMEM;
+                goto cleanup_extend;
+        }
 
         /* Sew in builtin protocols. */
         write_lock_bh(&nf_nat_lock);
@@ -626,6 +673,10 @@ static int __init nf_nat_init(void)
 
         l3proto = nf_ct_l3proto_find_get((u_int16_t)AF_INET);
         return 0;
+
+ cleanup_extend:
+        nf_ct_extend_unregister(&nat_extend);
+        return ret;
 }
 
 /* Clear NAT section of all conntracks, in case we're loaded again. */
@@ -647,6 +698,7 @@ static void __exit nf_nat_cleanup(void)
         synchronize_rcu();
         vfree(bysource);
         nf_ct_l3proto_put(l3proto);
+        nf_ct_extend_unregister(&nat_extend);
 }
 
 MODULE_LICENSE("GPL");
diff --git a/net/ipv4/netfilter/nf_nat_standalone.c b/net/ipv4/netfilter/nf_nat_standalone.c
index 0b2f0c33f7cd..51a2708f7bf0 100644
--- a/net/ipv4/netfilter/nf_nat_standalone.c
+++ b/net/ipv4/netfilter/nf_nat_standalone.c
@@ -19,6 +19,7 @@
 
 #include <net/netfilter/nf_conntrack.h>
 #include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_extend.h>
 #include <net/netfilter/nf_nat.h>
 #include <net/netfilter/nf_nat_rule.h>
 #include <net/netfilter/nf_nat_protocol.h>
@@ -113,8 +114,13 @@ nf_nat_fn(unsigned int hooknum,
                 return NF_ACCEPT;
 
         nat = nfct_nat(ct);
-        if (!nat)
-                return NF_ACCEPT;
+        if (!nat) {
+                nat = nf_ct_ext_add(ct, NF_CT_EXT_NAT, GFP_ATOMIC);
+                if (nat == NULL) {
+                        DEBUGP("failed to add NAT extension\n");
+                        return NF_ACCEPT;
+                }
+        }
 
         switch (ctinfo) {
         case IP_CT_RELATED:
@@ -326,18 +332,10 @@ static struct nf_hook_ops nf_nat_ops[] = {
 
 static int __init nf_nat_standalone_init(void)
 {
-        int size, ret = 0;
+        int ret = 0;
 
         need_conntrack();
 
-        size = ALIGN(sizeof(struct nf_conn), __alignof__(struct nf_conn_nat)) +
-               sizeof(struct nf_conn_nat);
-        ret = nf_conntrack_register_cache(NF_CT_F_NAT, "nf_nat:base", size);
-        if (ret < 0) {
-                printk(KERN_ERR "nf_nat_init: Unable to create slab cache\n");
-                return ret;
-        }
-
 #ifdef CONFIG_XFRM
         BUG_ON(ip_nat_decode_session != NULL);
         ip_nat_decode_session = nat_decode_session;
@@ -362,7 +360,6 @@ static int __init nf_nat_standalone_init(void)
         ip_nat_decode_session = NULL;
         synchronize_net();
 #endif
-        nf_conntrack_unregister_cache(NF_CT_F_NAT);
         return ret;
 }