openvswitch: Drop user features if old user space attempted to create datapath
Drop user features if an outdated user space instance that does not
understand the concept of user_features attempted to create a new
datapath.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Jesse Gross <jesse@nicira.com>
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 6a9b0cb..497b2fd 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1148,6 +1148,18 @@
return dp ? dp : ERR_PTR(-ENODEV);
}
+static void ovs_dp_reset_user_features(struct sk_buff *skb, struct genl_info *info)
+{
+ struct datapath *dp;
+
+ dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
+ if (!dp)
+ return;
+
+ WARN(dp->user_features, "Dropping previously announced user features\n");
+ dp->user_features = 0;
+}
+
static void ovs_dp_change(struct datapath *dp, struct nlattr **a)
{
if (a[OVS_DP_ATTR_USER_FEATURES])
@@ -1220,6 +1232,15 @@
if (err == -EBUSY)
err = -EEXIST;
+ if (err == -EEXIST) {
+ /* An outdated user space instance that does not understand
+ * the concept of user_features has attempted to create a new
+ * datapath and is likely to reuse it. Drop all user features.
+ */
+ if (info->genlhdr->version < OVS_DP_VER_FEATURES)
+ ovs_dp_reset_user_features(skb, info);
+ }
+
goto err_destroy_ports_array;
}