GetHostFlows gets host flows by netlink, and try to get by procfs if it fails.

GetHostFlowsByNetlink gets host flows by Linux netlink API.

GetHostFlowsByProcfs gets host flows from procfs.

FlowActive are 'active open'.

FlowPassive are 'passive open'.

FlowUnknown are unknown flow.

AddrPort are <addr>:<port>.

GetHostFlowsOption represens an option for func GetHostFlows().

HostFlow represents a `host flow`.

Process represents a OS process.

FlowDirection are bitmask that represents both Active or Passive.

HostFlows represents a group of host flow by unique key.