net: mptcp: convert netlink from small_ops to ops

in the current MPTCP control plane, all operations use a netlink
attribute of the same type "MPTCP_PM_ATTR". However, add/del/get/flush
operations only parse the first element in the message _ the one that
describes MPTCP endpoints (that was named MPTCP_PM_ATTR_ADDR and
mostly used in ADD_ADDR operations _ probably the similarity of "attr",
"addr" and "add" might cause some confusion to human readers).
Convert MPTCP from 'small_ops' to 'ops', thus allowing different attributes
for each single operation, hopefully makes all this clearer to human
readers.

- use a separate attribute set for add/del/get/flush address operation,
  binary compatible with the existing one, to store the endpoint address.
  MPTCP_PM_ENDPOINT_ADDR is added to the uAPI (with the same value as
  MPTCP_PM_ATTR_ADDR) for these operations.
- convert mptcp_pm_ops[] and add policy files accordingly.

this prepares MPTCP control plane to be described as YAML spec.

Link: https://github.com/multipath-tcp/mptcp_net-next/issues/340
Acked-by: Paolo Abeni <[email protected]>
Signed-off-by: Davide Caratti <[email protected]>
Signed-off-by: Mat Martineau <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index ee9c49f949a2..0e62937ab17c 100644
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -66,6 +66,14 @@ enum {
 #define MPTCP_PM_ATTR_MAX (__MPTCP_PM_ATTR_MAX - 1)
 
 enum {
+	MPTCP_PM_ENDPOINT_ADDR = 1,
+
+	__MPTCP_PM_ENDPOINT_MAX
+};
+
+#define MPTCP_PM_ENDPOINT_MAX (__MPTCP_PM_ENDPOINT_MAX - 1)
+
+enum {
 	MPTCP_PM_ADDR_ATTR_UNSPEC,
 
 	MPTCP_PM_ADDR_ATTR_FAMILY,			/* u16 */