[NET]: Add IFB (Intermediate Functional Block) network device.

A new device to do intermidiate functional block in a system shared
manner.  To use the new functionality, you need to turn on
qos/classifier actions.

The new functionality can be grouped as:

1) qdiscs/policies that are per device as opposed to system wide.  ifb
allows for a device which can be redirected to thus providing an
impression of sharing.

2) Allows for queueing incoming traffic for shaping instead of
dropping.

Packets are redirected to this device using tc/action mirred redirect
construct. If they are sent to it by plain routing instead then they
will merely be dropped and the stats would indicate that.

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/Kconfig

@@ -27,6 +27,19 @@ config NETDEVICES
 # that for each of the symbols.
 if NETDEVICES
 
+config IFB
+	tristate "Intermediate Functional Block support"
+	depends on NET_CLS_ACT
+	---help---
+	  This is an intermidiate driver that allows sharing of
+	  resources.
+	  To compile this driver as a module, choose M here: the module
+	  will be called ifb.  If you want to use more than one ifb
+	  device at a time, you need to compile this driver as a module.
+	  Instead of 'ifb', the devices will then be called 'ifb0',
+	  'ifb1' etc.
+	  Look at the iproute2 documentation directory for usage etc
+
 config DUMMY
 	tristate "Dummy net driver support"
 	---help---