l2tp: Add L2TP ethernet pseudowire support

This driver presents a regular net_device for each L2TP ethernet
pseudowire instance. These interfaces are named l2tpethN by default,
though userspace can specify an alternative name when the L2TP
session is created, if preferred. When the pseudowire is established,
regular Linux networking utilities may be used to configure the
interface, i.e. give it IP address info or add it to a bridge. Any
data passed over the interface is carried over an L2TP tunnel.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 24 insertions, 0 deletions

diff --git a/net/l2tp/Kconfig b/net/l2tp/Kconfig
index 0a11ccf2d95b..a292270c0abe 100644
--- a/net/l2tp/Kconfig
+++ b/net/l2tp/Kconfig
@@ -68,3 +68,27 @@ config L2TP_IP
 
           To compile this driver as a module, choose M here. The module
           will be called l2tp_ip.
+
+config L2TP_ETH
+        tristate "L2TP ethernet pseudowire support for L2TPv3"
+        depends on L2TP_V3
+        help
+          Support for carrying raw ethernet frames over L2TPv3.
+
+          From RFC 4719 <http://www.ietf.org/rfc/rfc4719.txt>.
+
+          The Layer 2 Tunneling Protocol, Version 3 (L2TPv3) can be
+          used as a control protocol and for data encapsulation to set
+          up Pseudowires for transporting layer 2 Packet Data Units
+          across an IP network [RFC3931].
+
+          This driver provides an ethernet virtual interface for each
+          L2TP ethernet pseudowire instance. Standard Linux tools may
+          be used to assign an IP address to the local virtual
+          interface, or add the interface to a bridge.
+
+          If you are using L2TPv3, you will almost certainly want to
+          enable this option.
+
+          To compile this driver as a module, choose M here. The module
+          will be called l2tp_eth.