@@ -3530,6 +3530,22 @@ static void vxlan_raw_setup(struct net_device *dev)
dev->netdev_ops = &vxlan_netdev_raw_ops;
}
+/* Validate Ubuntu FAN payload.
+ *
+ * This is required to bypass the strict length validation enforced for the
+ * attribute types >= IFLA_VXLAN_LOCALBYPASS in vxlan_policy.
+ *
+ * In this way we can continue to use the same allocated ID for
+ * IFLA_VXLAN_FAN_MAP, without breaking the existing user-space and also
+ * future kernel ABIs that may add new attribute types to vxlan_policy.
+ */
+static int fan_map_validate_entry(const struct nlattr *attr,
+ struct netlink_ext_ack *extack)
+{
+ /* Accept any payload for Ubuntu FAN */
+ return 0;
+}
+
static const struct nla_policy vxlan_policy[IFLA_VXLAN_MAX + 1] = {
[IFLA_VXLAN_UNSPEC] = { .strict_start_type = IFLA_VXLAN_LOCALBYPASS },
[IFLA_VXLAN_ID] = { .type = NLA_U32 },
@@ -3564,6 +3580,9 @@ static const struct nla_policy vxlan_policy[IFLA_VXLAN_MAX + 1] = {
[IFLA_VXLAN_VNIFILTER] = { .type = NLA_U8 },
[IFLA_VXLAN_LOCALBYPASS] = NLA_POLICY_MAX(NLA_U8, 1),
[IFLA_VXLAN_LABEL_POLICY] = NLA_POLICY_MAX(NLA_U32, VXLAN_LABEL_MAX),
+ [IFLA_VXLAN_FAN_MAP] = NLA_POLICY_VALIDATE_FN(NLA_BINARY,
+ fan_map_validate_entry,
+ sizeof(struct ifla_fan_map) * 256),
};
static int vxlan_validate(struct nlattr *tb[], struct nlattr *data[],
BugLink: https://bugs.launchpad.net/bugs/2064508 Make IFLA_VXLAN_FAN_MAP compatible with the strict length check validation enforced by vxlan_policy for attribute types >= IFLA_VXLAN_LOCALBYPASS. This allows to support new vxlan attribute types with kernels >= 6.8, without breaking the existent user-space tools relying on Ubuntu FAN. Signed-off-by: Andrea Righi <andrea.righi@canonical.com> --- drivers/net/vxlan/vxlan_core.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)