ipvlan: Initial check-in of the IPVLAN driver.

This driver is very similar to the macvlan driver except that it
uses L3 on the frame to determine the logical interface while
functioning as packet dispatcher. It inherits L2 of the master
device hence the packets on wire will have the same L2 for all
the packets originating from all virtual devices off of the same
master device.

This driver was developed keeping the namespace use-case in
mind. Hence most of the examples given here take that as the
base setup where main-device belongs to the default-ns and
virtual devices are assigned to the additional namespaces.

The device operates in two different modes and the difference
in these two modes in primarily in the TX side.

(a) L2 mode : In this mode, the device behaves as a L2 device.
TX processing upto L2 happens on the stack of the virtual device
associated with (namespace). Packets are switched after that
into the main device (default-ns) and queued for xmit.

RX processing is simple and all multicast, broadcast (if
applicable), and unicast belonging to the address(es) are
delivered to the virtual devices.

(b) L3 mode : In this mode, the device behaves like a L3 device.
TX processing upto L3 happens on the stack of the virtual device
associated with (namespace). Packets are switched to the
main-device (default-ns) for the L2 processing. Hence the routing
table of the default-ns will be used in this mode.

RX processins is somewhat similar to the L2 mode except that in
this mode only Unicast packets are delivered to the virtual device
while main-dev will handle all other packets.

The devices can be added using the "ip" command from the iproute2
package -

	ip link add link <master> <virtual> type ipvlan mode [ l2 | l3 ]

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Laurent Chavey <chavey@google.com>
Cc: Tim Hockin <thockin@google.com>
Cc: Brandon Philips <brandon.philips@coreos.com>
Cc: Pavel Emelianov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index f9009be3f30..b6d64f54657 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -145,6 +145,24 @@ config MACVTAP
 	  To compile this driver as a module, choose M here: the module
 	  will be called macvtap.
 
+
+config IPVLAN
+    tristate "IP-VLAN support"
+    ---help---
+      This allows one to create virtual devices off of a main interface
+      and packets will be delivered based on the dest L3 (IPv6/IPv4 addr)
+      on packets. All interfaces (including the main interface) share L2
+      making it transparent to the connected L2 switch.
+
+      Ipvlan devices can be added using the "ip" command from the
+      iproute2 package starting with the iproute2-X.Y.ZZ release:
+
+      "ip link add link <main-dev> [ NAME ] type ipvlan"
+
+      To compile this driver as a module, choose M here: the module
+      will be called ipvlan.
+
+
 config VXLAN
        tristate "Virtual eXtensible Local Area Network (VXLAN)"
        depends on INET