vlan: inherit from parent interface state

[rjarry]

When {,re}configuring a vlan interface, replicate the state of its parent port. Otherwise, if its parent port is already running, the vlan interface will never appear running unless we set the port down and then up manually.

Summary by CodeRabbit

• Bug Fixes
  • VLAN interfaces now synchronize their operational state with the parent interface during reconfiguration (in addition to MTU), ensuring consistent status after parent changes.
  • Resolves cases where VLANs could appear incorrectly up/down, improving reliability for monitoring and automation tools.
  • Enhances stability during network updates without requiring configuration changes or impacting other attributes (e.g., VRF, MAC, flags).

[coderabbitai]

📝 Walkthrough

Walkthrough

The change modifies iface_vlan_reconfig in modules/infra/control/vlan.c to also synchronize iface->state with its parent interface during VLAN reconfiguration. Previously, the function updated mtu from the parent; it now assigns iface->state = parent->state as well. No other attributes or control flow are altered. Existing handling for VRF, MAC, flags, and event dispatch after reconfiguration remains unchanged. No public or exported declarations are modified.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Pre-merge checks

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The title accurately summarizes the main change by indicating that VLAN interfaces now inherit the parent interface state, which aligns directly with the code modifications. It is concise and focuses on the key update without extraneous detail. The phrasing clearly conveys the purpose of the pull request to any reviewer scanning through history.

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[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (1)

modules/infra/control/vlan.c (1)

129-131: Reuse the already-fetched parent pointer.

next_parent is already validated above, so we can copy MTU and state from it directly instead of doing two extra iface_from_id() lookups. Keeps the hot path leaner.

Apply this diff:

-	iface->mtu = iface_from_id(cur->parent_id)->mtu;
-	iface->state = iface_from_id(cur->parent_id)->state;
+	iface->mtu = next_parent->mtu;
+	iface->state = next_parent->state;

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 5f998b4 and ddc98e3.

📒 Files selected for processing (1)

• modules/infra/control/vlan.c (1 hunks)

🧰 Additional context used

🧬 Code graph analysis (1)

modules/infra/control/vlan.c (3)

modules/infra/control/gr_iface.h (1)

• iface (16-22)

modules/infra/control/iface.c (1)

• iface_from_id (215-222)

modules/infra/control/worker_test.c (1)

• iface_from_id (40-42)

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