[PATCH] netfilter: conntrack: allow insertion clash of gre protocol

[Faicker Mo]

NVGRE tunnel is used in the VM-to-VM communications. The VM packets
are encapsulated in NVGRE and sent from the host. For NVGRE
there are two tuples(outer sip and outer dip) in the host conntrack item.
Insertion clashes are more likely to happen if the concurrent connections
are sent from the VM.

Signed-off-by: Faicker Mo <faicker.mo@xxxxxxxxx>
---
 net/netfilter/nf_conntrack_proto_gre.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c
index 728eeb0aea87..ad6f0ca40cd2 100644
--- a/net/netfilter/nf_conntrack_proto_gre.c
+++ b/net/netfilter/nf_conntrack_proto_gre.c
@@ -296,6 +296,7 @@ void nf_conntrack_gre_init_net(struct net *net)
 /* protocol helper struct */
 const struct nf_conntrack_l4proto nf_conntrack_l4proto_gre = {
 	.l4proto	 = IPPROTO_GRE,
+	.allow_clash	 = true,
 #ifdef CONFIG_NF_CONNTRACK_PROCFS
 	.print_conntrack = gre_print_conntrack,
 #endif
-- 
2.39.1