netdev - [PATCH net 1/2] vxlan: correctly handle ipv6.disable module parameter

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Date:   Thu, 27 Apr 2017 21:24:35 +0200
From:   Jiri Benc <jbenc@...hat.com>
To:     netdev@...r.kernel.org
Cc:     Marcelo Ricardo Leitner <mleitner@...hat.com>
Subject: [PATCH net 1/2] vxlan: correctly handle ipv6.disable module parameter

When IPv6 is compiled but disabled at runtime, __vxlan_sock_add returns
-EAFNOSUPPORT. For metadata based tunnels, this causes failure of the whole
operation of bringing up the tunnel.

Ignore failure of IPv6 socket creation for metadata based tunnels caused by
IPv6 not being available.

Fixes: b1be00a6c39f ("vxlan: support both IPv4 and IPv6 sockets in a single vxlan device")
Signed-off-by: Jiri Benc <jbenc@...hat.com>
---
 drivers/net/vxlan.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index bdb6ae16d4a8..118e508f1889 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2818,17 +2818,21 @@ static int __vxlan_sock_add(struct vxlan_dev *vxlan, bool ipv6)
 
 static int vxlan_sock_add(struct vxlan_dev *vxlan)
 {
-	bool ipv6 = vxlan->flags & VXLAN_F_IPV6;
 	bool metadata = vxlan->flags & VXLAN_F_COLLECT_METADATA;
+	bool ipv6 = vxlan->flags & VXLAN_F_IPV6 || metadata;
+	bool ipv4 = !ipv6 || metadata;
 	int ret = 0;
 
 	RCU_INIT_POINTER(vxlan->vn4_sock, NULL);
 #if IS_ENABLED(CONFIG_IPV6)
 	RCU_INIT_POINTER(vxlan->vn6_sock, NULL);
-	if (ipv6 || metadata)
+	if (ipv6) {
 		ret = __vxlan_sock_add(vxlan, true);
+		if (ret < 0 && ret != -EAFNOSUPPORT)
+			ipv4 = false;
+	}
 #endif
-	if (!ret && (!ipv6 || metadata))
+	if (ipv4)
 		ret = __vxlan_sock_add(vxlan, false);
 	if (ret < 0)
 		vxlan_sock_release(vxlan);
-- 
1.8.3.1