net: neighbor: add fdb extended attribute

Add an attribute to NDA which will contain all future fdb-specific
attributes in order to avoid polluting the NDA namespace with e.g.
bridge or vxlan specific attributes. The attribute is called
NDA_FDB_EXT_ATTRS and the structure would look like:
 [NDA_FDB_EXT_ATTRS] = {
    [NFEA_xxx]
 }

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h
index eefcda8..540ff48 100644 (file)
--- a/include/uapi/linux/neighbour.h
+++ b/include/uapi/linux/neighbour.h
@@ -30,6 +30,7 @@ enum {
        NDA_SRC_VNI,
        NDA_PROTOCOL,  /* Originator of entry */
        NDA_NH_ID,
+       NDA_FDB_EXT_ATTRS,
        __NDA_MAX
 };
 
@@ -172,4 +173,15 @@ enum {
 };
 #define NDTA_MAX (__NDTA_MAX - 1)
 
+/* embedded into NDA_FDB_EXT_ATTRS:
+ * [NDA_FDB_EXT_ATTRS] = {
+ *     ...
+ * }
+ */
+enum {
+       NFEA_UNSPEC,
+       __NFEA_MAX
+};
+#define NFEA_MAX (__NFEA_MAX - 1)
+
 #endif

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index ef6b5a8..8e39e28 100644 (file)
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1783,6 +1783,7 @@ const struct nla_policy nda_policy[NDA_MAX+1] = {
        [NDA_MASTER]            = { .type = NLA_U32 },
        [NDA_PROTOCOL]          = { .type = NLA_U8 },
        [NDA_NH_ID]             = { .type = NLA_U32 },
+       [NDA_FDB_EXT_ATTRS]     = { .type = NLA_NESTED },
 };
 
 static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh,