3 files changed, 51 insertions, 35 deletions

diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 8a2b0ae7dbd2..ab86036bbf0c 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -209,7 +209,7 @@ extern struct nf_conntrack_tuple_hash *
 __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 int nf_conntrack_hash_check_insert(struct nf_conn *ct);
 extern void nf_ct_delete_from_lists(struct nf_conn *ct);
 extern void nf_ct_insert_dying_list(struct nf_conn *ct);
 
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 76613f5a55c0..ed86a3be678e 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -404,19 +404,49 @@ static void __nf_conntrack_hash_insert(struct nf_conn *ct,
                            &net->ct.hash[repl_hash]);
 }
 
-void nf_conntrack_hash_insert(struct nf_conn *ct)
+int
+nf_conntrack_hash_check_insert(struct nf_conn *ct)
 {
         struct net *net = nf_ct_net(ct);
         unsigned int hash, repl_hash;
+        struct nf_conntrack_tuple_hash *h;
+        struct hlist_nulls_node *n;
         u16 zone;
 
         zone = nf_ct_zone(ct);
-        hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
-        repl_hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+        hash = hash_conntrack(net, zone,
+                              &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+        repl_hash = hash_conntrack(net, zone,
+                                   &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+
+        spin_lock_bh(&nf_conntrack_lock);
 
+        /* See if there's one in the list already, including reverse */
+        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)))
+                        goto out;
+        hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_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)))
+                        goto out;
+
+        add_timer(&ct->timeout);
+        nf_conntrack_get(&ct->ct_general);
         __nf_conntrack_hash_insert(ct, hash, repl_hash);
+        NF_CT_STAT_INC(net, insert);
+        spin_unlock_bh(&nf_conntrack_lock);
+
+        return 0;
+
+out:
+        NF_CT_STAT_INC(net, insert_failed);
+        spin_unlock_bh(&nf_conntrack_lock);
+        return -EEXIST;
 }
-EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
+EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
 
 /* Confirm a connection given skb; places it in hash table */
 int
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 9307b033c0c9..30c9d4ca0218 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1367,15 +1367,12 @@ ctnetlink_create_conntrack(struct net *net, u16 zone,
                                                     nf_ct_protonum(ct));
                 if (helper == NULL) {
                         rcu_read_unlock();
-                        spin_unlock_bh(&nf_conntrack_lock);
 #ifdef CONFIG_MODULES
                         if (request_module("nfct-helper-%s", helpname) < 0) {
-                                spin_lock_bh(&nf_conntrack_lock);
                                 err = -EOPNOTSUPP;
                                 goto err1;
                         }
 
-                        spin_lock_bh(&nf_conntrack_lock);
                         rcu_read_lock();
                         helper = __nf_conntrack_helper_find(helpname,
                                                             nf_ct_l3num(ct),
@@ -1468,8 +1465,10 @@ ctnetlink_create_conntrack(struct net *net, u16 zone,
         if (tstamp)
                 tstamp->start = ktime_to_ns(ktime_get_real());
 
-        add_timer(&ct->timeout);
-        nf_conntrack_hash_insert(ct);
+        err = nf_conntrack_hash_check_insert(ct);
+        if (err < 0)
+                goto err2;
+
         rcu_read_unlock();
 
         return ct;
@@ -1490,6 +1489,7 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
         struct nf_conntrack_tuple otuple, rtuple;
         struct nf_conntrack_tuple_hash *h = NULL;
         struct nfgenmsg *nfmsg = nlmsg_data(nlh);
+        struct nf_conn *ct;
         u_int8_t u3 = nfmsg->nfgen_family;
         u16 zone;
         int err;
@@ -1510,27 +1510,22 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
                         return err;
         }
 
-        spin_lock_bh(&nf_conntrack_lock);
         if (cda[CTA_TUPLE_ORIG])
-                h = __nf_conntrack_find(net, zone, &otuple);
+                h = nf_conntrack_find_get(net, zone, &otuple);
         else if (cda[CTA_TUPLE_REPLY])
-                h = __nf_conntrack_find(net, zone, &rtuple);
+                h = nf_conntrack_find_get(net, zone, &rtuple);
 
         if (h == NULL) {
                 err = -ENOENT;
                 if (nlh->nlmsg_flags & NLM_F_CREATE) {
-                        struct nf_conn *ct;
                         enum ip_conntrack_events events;
 
                         ct = ctnetlink_create_conntrack(net, zone, cda, &otuple,
                                                         &rtuple, u3);
-                        if (IS_ERR(ct)) {
-                                err = PTR_ERR(ct);
-                                goto out_unlock;
-                        }
+                        if (IS_ERR(ct))
+                                return PTR_ERR(ct);
+
                         err = 0;
-                        nf_conntrack_get(&ct->ct_general);
-                        spin_unlock_bh(&nf_conntrack_lock);
                         if (test_bit(IPS_EXPECTED_BIT, &ct->status))
                                 events = IPCT_RELATED;
                         else
@@ -1545,23 +1540,19 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
                                                       ct, NETLINK_CB(skb).pid,
                                                       nlmsg_report(nlh));
                         nf_ct_put(ct);
-                } else
-                        spin_unlock_bh(&nf_conntrack_lock);
+                }
 
                 return err;
         }
         /* implicit 'else' */
 
-        /* We manipulate the conntrack inside the global conntrack table lock,
-         * so there's no need to increase the refcount */
         err = -EEXIST;
+        ct = nf_ct_tuplehash_to_ctrack(h);
         if (!(nlh->nlmsg_flags & NLM_F_EXCL)) {
-                struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
-
+                spin_lock_bh(&nf_conntrack_lock);
                 err = ctnetlink_change_conntrack(ct, cda);
+                spin_unlock_bh(&nf_conntrack_lock);
                 if (err == 0) {
-                        nf_conntrack_get(&ct->ct_general);
-                        spin_unlock_bh(&nf_conntrack_lock);
                         nf_conntrack_eventmask_report((1 << IPCT_REPLY) |
                                                       (1 << IPCT_ASSURED) |
                                                       (1 << IPCT_HELPER) |
@@ -1570,15 +1561,10 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
                                                       (1 << IPCT_MARK),
                                                       ct, NETLINK_CB(skb).pid,
                                                       nlmsg_report(nlh));
-                        nf_ct_put(ct);
-                } else
-                        spin_unlock_bh(&nf_conntrack_lock);
-
-                return err;
+                }
         }
 
-out_unlock:
-        spin_unlock_bh(&nf_conntrack_lock);
+        nf_ct_put(ct);
         return err;
 }