1flowi structure:
2
3The secid member in the flow structure is used in LSMs (e.g. SELinux) to indicate
4the label of the flow. This label of the flow is currently used in selecting
5matching labeled xfrm(s).
6
7If this is an outbound flow, the label is derived from the socket, if any, or
8the incoming packet this flow is being generated as a response to (e.g. tcp
9resets, timewait ack, etc.). It is also conceivable that the label could be
10derived from other sources such as process context, device, etc., in special
11cases, as may be appropriate.
12
13If this is an inbound flow, the label is derived from the IPSec security
14associations, if any, used by the packet.
15