netflow: Set Engine and Add Alternate Port ID Flag

netflow: Set Engine and Add Alternate Port ID Flag

Allow the Engine Type and Engine ID to be configured in NetFlow
messages.  Previously, they were always set to zero.  Now, by default,
they are both set to the datapath index. These can be overridden with
the "netflow.bridge.engine-type" and "netflow.bridge.engine-id" keys,
respectively.

Add the ability to allow collectors to distinguish between virtual
switches sending message from the host.  When the
"netflow.bridge.add-id-to-iface" flag is enabled, the least significant
7 bits of the engine id are placed into the most significant bits of
the  ingress  and  egress  interface fields of flow records.  This
mimics the behavior of VMware ESX when the "-p" option is given to the
NetFlow configuration program.

(Addresses Bug #1222 and Bug #1223)