With net.netfilter.nf_conntrack_acct = 1, conntrack adds the following
fields in the output: packets=3 bytes=164
And with SELinux (e.g. Fedora), conntrack adds: secctx=...
The parsing with fmt.Sscanf introduced in #2095 was unfortunately
rejecting lines with those fields. This patch fixes that by adding more
complicated parsing in decodeFlowKeyValues() with FieldsFunc and SplitN.
Fixes#2117
Regression from #2095
- Unexport consts, types, vars, etc.
- Rename Conntracker (interface) to FlowWalker, to match its definition.
- Rename conntracker (type) to conntrackWalker, to match the interface.
- Move conntrack_test.go to conntrack_internal_test.go and package endpoint