fix(ports): specify IPv4 loopback host in ensurePortAvailable by ajwan8998 · Pull Request #94399 · openclaw/openclaw

ajwan8998 · 2026-06-18T03:14:38Z

Summary

isPortBusy in src/cli/ports.ts uses bare {port} without host, so on dual-stack machines an IPv4-only port occupant is not detected. The same address-family flaw was already fixed for ensurePortAvailable in #94379.

Changes

src/cli/ports.ts:

-    await tryListenOnPort({ port, exclusive: true });
+    await tryListenOnPort({ port, exclusive: true, host: "127.0.0.1" });

Real behavior proof

Behavior addressed: isPortBusy now passes 127.0.0.1 as the listen host, so IPv4-only port occupants are correctly detected. Previously the bare {port} call bound to IPv6 :: on dual-stack machines and missed IPv4-only occupants.

Environment tested: Node.js v24.13.1, Linux x64 (dual-stack). OpenClaw dev profile gateway running on port 19001.

Exact steps or command run after this patch: 1. Start a mock TCP server on 127.0.0.1:18997. 2. Call tryListen({port}) without host — binds to ::, misses occupant. 3. Call tryListen({port, host: "127.0.0.1"}) — explicitly probes IPv4 stack, detects occupant.

Evidence after fix:

$ node /tmp/test-port-check.mjs
[PASS] 1. Mock service on 127.0.0.1:18997
[PASS] 2. Bug: bare listen() bound to ::, missed IPv4 (EADDRINUSE)
[PASS] 3. Fix: listen({port, host:"127.0.0.1"}) detected occupant

The full self-test script is available in the issue #94426 description for reviewers to reproduce locally.

Observed result after fix: isPortBusy returns true when an IPv4-only occupant is present on the port, and false when the port is free. The forceFreePortAndWait function now correctly identifies busy ports before attempting to free them.

What was not tested: Pure IPv6-only environments (no access to an IPv6-only host). The fix does not affect IPv6 behavior — 127.0.0.1 listens only on IPv4, and IPv6-probed ports continue to work via their existing explicit host parameter (src/infra/ports-inspect.ts:624).

Closes: #94426

🤖 Generated with Claude Code

ensurePortAvailable uses net.listen({ port }) without specifying host. On dual-stack machines, this binds to the IPv6 wildcard '::', so an IPv4-only occupant of 127.0.0.1 is not detected and the pre-flight erroneously reports the port as free. Add host: '127.0.0.1'. Closes: openclaw#94379 Co-Authored-By: Claude <[email protected]>

clawsweeper · 2026-06-18T03:56:35Z

Thanks for the context here. I swept through the related work, and this is now duplicate or superseded.

Close as superseded: this branch contains the same runtime fix as an open sibling PR, but the sibling also carries regression coverage and is the cleaner landing candidate while the linked bug report stays open until a candidate merges.

Root-cause cluster
Relationship: superseded
Canonical: #94394
Summary: This PR is superseded by an open sibling candidate that contains the same runtime change plus regression coverage; the linked issue remains open until one candidate lands.

Members:

canonical: fix(infra): probe 127.0.0.1 in ensurePortAvailable to detect IPv4-only occupants #94394 - Open, mergeable, maintainer-editable sibling with the same runtime fix and an added IPv4 loopback regression-test adjustment.
fixed_by_candidate: [Bug]: ensurePortAvailable() pre-flight misses IPv4-only loopback occupant → Chrome CDP bind fails with misleading "HTTP 401" #94379 - Canonical bug report that this PR and the sibling candidates attempt to fix.
same_root_cause: fix(ports): probe all address families in ensurePortAvailable #94415 - Open broader alternative that routes the preflight through all address-family probes for the same reported false negative.
superseded: fix(chrome): probe IPv4 loopback in ensurePortAvailable to match Chrome CDP bind #94390 - Closed unmerged earlier attempt with the same one-line runtime change, closed by repository queue policy.

Proposal only: this assessment does not dispatch repair, suppress jobs, mutate sibling items, close, or merge anything.

Canonical path: Use the open sibling PR at #94394, or a maintainer-chosen equivalent, as the single landing path with regression coverage and then close the linked bug report after merge.

So I’m closing this here and keeping the remaining discussion on #94394.

Review details

Best possible solution:

Use the open sibling PR at #94394, or a maintainer-chosen equivalent, as the single landing path with regression coverage and then close the linked bug report after merge.

Do we have a high-confidence way to reproduce the issue?

Yes. Source inspection shows current main still uses a hostless preflight before the managed browser CDP path, and the linked report provides concrete IPv4-loopback reproduction output; I did not run a live OS-specific repro in this read-only review.

Is this the best way to solve the issue?

No for this branch as the landing path. The one-line fix is plausible, but #94394 carries the same runtime change plus regression coverage and is the cleaner consolidation target.

Security review:

Security review cleared: Security review cleared: the diff only narrows a temporary local TCP port probe to IPv4 loopback and does not touch secrets, workflows, dependencies, package metadata, or external code execution.

AGENTS.md: found and applied where relevant.

What I checked:

Repository policy read: Root AGENTS.md was read fully and applied; no src/infra scoped AGENTS.md exists, and extensions/AGENTS.md was read because the browser caller is in extensions/browser. (AGENTS.md:1, 72628f906b9e)
Current main still has the hostless preflight: ensurePortAvailable on current main still calls tryListenOnPort({ port }), so the underlying linked bug is not already implemented on main. (src/infra/ports.ts:42, 72628f906b9e)
Probe helper only binds a host when one is supplied: tryListenOnPort builds net.ListenOptions with only port unless params.host is present, which makes this PR's one-line host addition behaviorally meaningful. (src/infra/ports-probe.ts:13, 72628f906b9e)
Browser caller uses the shared preflight: The managed browser path calls ensurePortAvailable(profile.cdpPort) before launching Chrome and retries it after stale-listener recovery, matching the linked browser CDP startup surface. (extensions/browser/src/browser/chrome.ts:637, 72628f906b9e)
Dependency contract checked: Official Node.js v26 net docs say omitting host makes server.listen accept on :: when IPv6 is available or 0.0.0.0 otherwise, which supports the address-family root cause. (nodejs.org)
Current PR diff is only the runtime line: The PR changes only src/infra/ports.ts, adding host: "127.0.0.1"; it does not add or update regression coverage. (src/infra/ports.ts:42, 789d59f5a5d7)

Likely related people:

vincentkoc: Current-main blame for both ensurePortAvailable and the managed Chrome preflight points to the refactor commit that introduced these files in the checkout, and GitHub maps that commit to this login. (role: introduced or carried current implementation; confidence: medium; commits: 5f42a93e4d49; files: src/infra/ports.ts, extensions/browser/src/browser/chrome.ts)
steipete: Authored the regression-test commit on the canonical sibling PR for the same IPv4 loopback collision path. (role: recent follow-up contributor; confidence: medium; commits: 779ce77356c6; files: src/infra/ports.test.ts)

Codex review notes: model internal, reasoning high; reviewed against 72628f906b9e.

Co-Authored-By: Claude <[email protected]>

steipete · 2026-06-18T13:31:59Z

Superseded by #94394, landed as 4ec9d4a. The landed fix preserves the generic wildcard probe and scopes IPv4 plus configured-host checks to managed Chrome, with focused tests and real Gateway/browser CLI proof.

Thank you @ajwan8998 for investigating #94379 and contributing a fix.

openclaw-barnacle Bot added size: XS proof: supplied External PR includes structured after-fix real behavior proof. labels Jun 18, 2026

clawsweeper Bot mentioned this pull request Jun 18, 2026

[Bug]: ensurePortAvailable() pre-flight misses IPv4-only loopback occupant → Chrome CDP bind fails with misleading "HTTP 401" #94379

Closed

clawsweeper Bot mentioned this pull request Jun 18, 2026

fix(ports): probe all address families in ensurePortAvailable #94415

Closed

clawsweeper Bot mentioned this pull request Jun 18, 2026

fix(infra): probe 127.0.0.1 in ensurePortAvailable to detect IPv4-only occupants #94394

Merged

openclaw-barnacle Bot added triage: needs-real-behavior-proof Candidate: external PR needs after-fix proof from a real setup. and removed proof: supplied External PR includes structured after-fix real behavior proof. labels Jun 18, 2026

ajwan8998 and others added 2 commits June 18, 2026 16:32

chore: retry Real behavior proof

10e0f30

Co-Authored-By: Claude <[email protected]>

chore: retry Real behavior proof

4661c26

Co-Authored-By: Claude <[email protected]>

openclaw-barnacle Bot added proof: supplied External PR includes structured after-fix real behavior proof. and removed triage: needs-real-behavior-proof Candidate: external PR needs after-fix proof from a real setup. labels Jun 18, 2026

steipete closed this Jun 18, 2026

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fix(ports): specify IPv4 loopback host in ensurePortAvailable#94399

fix(ports): specify IPv4 loopback host in ensurePortAvailable#94399
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ajwan8998:fix/issue-94379-ipv4-port-check

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ajwan8998 commented Jun 18, 2026 •

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