[ebpfless] Implement connection duration and fix IsOpen

[pimlu]

What does this PR do?

This PR adds bookkeeping for connection duration and IsOpen to the ebpfless TCP processor.

Motivation

Want the whole test suite to pass, goal is to have the test suite in a good state for KMT

Describe how you validated your changes

To run the test this fixes:

DD_REMOTE_CONFIGURATION_ENABLED=false TEST_EBPFLESS_OVERRIDE=true sudo -E go test -tags=linux,linux_bpf,npm,process,test ./pkg/network/tracer -v --run TestTracerSuite/eBPFless -run TestTracerSuite/eBPFless/TestConnectionDuration

To run the TCP processor unit test suite:

go test -tags=linux,linux_bpf,npm,process,test ./pkg/network/tracer/connection/ebpfless

To run just the unit test added by this PR:

go test -tags=linux,linux_bpf,npm,process,test ./pkg/network/tracer/connection/ebpfless -run TestOpenCloseConn

Possible Drawbacks / Trade-offs

We have multiple sources of timestamps in the ebpfless tracer:

• time.Now() (used by Duration)
• ddebpf.NowNanoseconds() (used by conn.LastUpdateEpoch and RTT)
• time.Time parameter from VisitPackets (currently unused, but available)
  In a future PR, we might want to switch to a single source of truth for this.

Additional Notes

[agent-platform-auto-pr]

Test changes on VM

Use this command from test-infra-definitions to manually test this PR changes on a VM:

inv aws.create-vm --pipeline-id=50348933 --os-family=ubuntu

Note: This applies to commit 1cc5caa

[pimlu]

/merge

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2024-12-05 16:10:56 UTC ℹ️ MergeQueue: waiting for PR to be ready

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Note: if you pushed new commits since the last approval, you may need additional approval.
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2024-12-05 20:10:51 UTC ⚠️ MergeQueue: This merge request was unqueued

This merge request was unqueued

[pimlu]

/merge

[dd-devflow]

Devflow running: /merge

View all feedbacks in Devflow UI.

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2024-12-05 20:46:19 UTC ℹ️ MergeQueue: pull request added to the queue

The median merge time in main is 23m.