ethtool: add tunnel info interface

Add an interface to report offloaded UDP ports via ethtool netlink.

Now that core takes care of tracking which UDP tunnel ports the NICs
are aware of we can quite easily export this information out to
user space.

The responsibility of writing the netlink dumps is split between
ethtool code and udp_tunnel_nic.c - since udp_tunnel module may
not always be loaded, yet we should always report the capabilities
of the NIC.

$ ethtool --show-tunnels eth0
Tunnel information for eth0:
  UDP port table 0:
    Size: 4
    Types: vxlan
    No entries
  UDP port table 1:
    Size: 4
    Types: geneve, vxlan-gpe
    Entries (1):
        port 1230, vxlan-gpe

v4:
 - back to v2, build fix is now directly in udp_tunnel.h
v3:
 - don't compile ETHTOOL_MSG_TUNNEL_INFO_GET in if CONFIG_INET
   not set.
v2:
 - fix string set count,
 - reorder enums in the uAPI,
 - fix type of ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES to bitset
   in docs and comments.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 33 insertions, 0 deletions

diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index 459a0d11cfde..7d75f1e32152 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -1230,6 +1230,39 @@ used to report the amplitude of the reflection for a given pair.
  | | | ``ETHTOOL_A_CABLE_AMPLITUDE_mV``        | s16    | Reflection amplitude |
  +-+-+-----------------------------------------+--------+----------------------+
 
+TUNNEL_INFO
+===========
+
+Gets information about the tunnel state NIC is aware of.
+
+Request contents:
+
+  =====================================  ======  ==========================
+  ``ETHTOOL_A_TUNNEL_INFO_HEADER``       nested  request header
+  =====================================  ======  ==========================
+
+Kernel response contents:
+
+ +---------------------------------------------+--------+---------------------+
+ | ``ETHTOOL_A_TUNNEL_INFO_HEADER``            | nested | reply header        |
+ +---------------------------------------------+--------+---------------------+
+ | ``ETHTOOL_A_TUNNEL_INFO_UDP_PORTS``         | nested | all UDP port tables |
+ +-+-------------------------------------------+--------+---------------------+
+ | | ``ETHTOOL_A_TUNNEL_UDP_TABLE``            | nested | one UDP port table  |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_TUNNEL_UDP_TABLE_SIZE``     | u32    | max size of the     |
+ | | |                                         |        | table               |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_TUNNEL_UDP_TABLE_TYPES``    | bitset | tunnel types which  |
+ | | |                                         |        | table can hold      |
+ +-+-+-----------------------------------------+--------+---------------------+
+ | | | ``ETHTOOL_A_TUNNEL_UDP_TABLE_ENTRY``    | nested | offloaded UDP port  |
+ +-+-+-+---------------------------------------+--------+---------------------+
+ | | | | ``ETHTOOL_A_TUNNEL_UDP_ENTRY_PORT``   | be16   | UDP port            |
+ +-+-+-+---------------------------------------+--------+---------------------+
+ | | | | ``ETHTOOL_A_TUNNEL_UDP_ENTRY_TYPE``   | u32    | tunnel type         |
+ +-+-+-+---------------------------------------+--------+---------------------+
+
 Request translation
 ===================