Drop user features if an outdated user space instance that does not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 <tg...@suug.ch>
---
include/uapi/linux/openvswitch.h | 10 +++++++++-
net/openvswitch/datapath.c | 21 +++++++++++++++++++++
2 files changed, 30 insertions(+), 1 deletion(-)
diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index 07ef2c3..970553c 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h
@@ -40,7 +40,15 @@ struct ovs_header {
#define OVS_DATAPATH_FAMILY "ovs_datapath"
#define OVS_DATAPATH_MCGROUP "ovs_datapath"
-#define OVS_DATAPATH_VERSION 0x1
+
+/* V2:
+ * - API users are expected to provide OVS_DP_ATTR_USER_FEATURES
+ * when creating the datapath.
+ */
+#define OVS_DATAPATH_VERSION 2
+
+/* First OVS datapath version to support features */
+#define OVS_DP_VER_FEATURES 2
enum ovs_datapath_cmd {
OVS_DP_CMD_UNSPEC,
diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 95d4424..8eaa39a 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1175,6 +1175,18 @@ static struct datapath *lookup_datapath(struct net *net,
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])
@@ -1247,6 +1259,15 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct
genl_info *info)
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+ /* An outdated user space instance that does not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;
}
--
1.8.3.1
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