1 files changed, 31 insertions, 34 deletions

diff --git a/net/ipv4/protocol.c b/net/ipv4/protocol.c
index 542f22fc98b..46d6a1c923a 100644
--- a/net/ipv4/protocol.c
+++ b/net/ipv4/protocol.c
@@ -28,54 +28,51 @@
 #include <linux/spinlock.h>
 #include <net/protocol.h>
 
-const struct net_protocol *inet_protos[MAX_INET_PROTOS] ____cacheline_aligned_in_smp;
-static DEFINE_SPINLOCK(inet_proto_lock);
-
-/*
- *	Add a protocol handler to the hash tables
- */
+const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS] __read_mostly;
+const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS] __read_mostly;
 
 int inet_add_protocol(const struct net_protocol *prot, unsigned char protocol)
 {
-	int hash, ret;
-
-	hash = protocol & (MAX_INET_PROTOS - 1);
-
-	spin_lock_bh(&inet_proto_lock);
-	if (inet_protos[hash]) {
-		ret = -1;
-	} else {
-		inet_protos[hash] = prot;
-		ret = 0;
+	if (!prot->netns_ok) {
+		pr_err("Protocol %u is not namespace aware, cannot register.\n",
+			protocol);
+		return -EINVAL;
 	}
-	spin_unlock_bh(&inet_proto_lock);
 
-	return ret;
+	return !cmpxchg((const struct net_protocol **)&inet_protos[protocol],
+			NULL, prot) ? 0 : -1;
 }
+EXPORT_SYMBOL(inet_add_protocol);
 
-/*
- *	Remove a protocol from the hash tables.
- */
+int inet_add_offload(const struct net_offload *prot, unsigned char protocol)
+{
+	return !cmpxchg((const struct net_offload **)&inet_offloads[protocol],
+			NULL, prot) ? 0 : -1;
+}
+EXPORT_SYMBOL(inet_add_offload);
 
 int inet_del_protocol(const struct net_protocol *prot, unsigned char protocol)
 {
-	int hash, ret;
+	int ret;
 
-	hash = protocol & (MAX_INET_PROTOS - 1);
-
-	spin_lock_bh(&inet_proto_lock);
-	if (inet_protos[hash] == prot) {
-		inet_protos[hash] = NULL;
-		ret = 0;
-	} else {
-		ret = -1;
-	}
-	spin_unlock_bh(&inet_proto_lock);
+	ret = (cmpxchg((const struct net_protocol **)&inet_protos[protocol],
+		       prot, NULL) == prot) ? 0 : -1;
 
 	synchronize_net();
 
 	return ret;
 }
-
-EXPORT_SYMBOL(inet_add_protocol);
 EXPORT_SYMBOL(inet_del_protocol);
+
+int inet_del_offload(const struct net_offload *prot, unsigned char protocol)
+{
+	int ret;
+
+	ret = (cmpxchg((const struct net_offload **)&inet_offloads[protocol],
+		       prot, NULL) == prot) ? 0 : -1;
+
+	synchronize_net();
+
+	return ret;
+}
+EXPORT_SYMBOL(inet_del_offload);