fix: filter virtual interface MACs in Linux miner fingerprint collection (#4820)

[lequangsang01]

Closes #4820

RTC wallet: RTCfe13452d122263caf633ab1876bd9631133b68b1

Changes

• Filter out virtual interface MACs (Docker, veth, Tailscale, virbr, tun, tap, etc.) from Linux miner fingerprint collection
• Applied to both ip -o link and ifconfig -a fallback paths
• Prevents false mac_churn detection during /epoch/enroll enrollment
• Virtual MACs from Docker bridges, VPN tunnels, and container interfaces are now excluded

Testing

• Code compiles without syntax errors
• Filter logic correctly identifies virtual interface prefixes

[jujujuda]

LGTM. Filters virtual interface MACs from fingerprint. Covers ip -o link and ifconfig -a. Ready to merge.

[FakerHideInBush]

Two concerns before merging:

1. _VIRT_PREFIXES is defined twice inside _get_mac_addresses — once for the ip link code path and once for the ifconfig fallback

Both definitions are identical:

_VIRT_PREFIXES = ("docker", "br-", "veth", "tailscale", "ts-", "virbr", "vnet", "tun", "tap", "wg", "bond", "dummy", "lo")

This violates DRY and creates a maintenance hazard: adding a new virtual prefix in the future requires updating two places. A future reviewer might update one definition and miss the other, resulting in inconsistent filtering between the two code paths.

The tuple should be extracted to a module-level constant (e.g. _VIRTUAL_IFACE_PREFIXES) defined once at the top of the file, referenced in both code paths. Being a module-level constant also means it's computed once rather than allocated on every call to _get_mac_addresses().

2. The _VIRT_PREFIXES variable name uses a leading underscore suggesting it is a module-private name, but it is currently defined as a local variable inside the method — the scope and the naming convention do not match

Module-private convention (_NAME) implies the variable lives at module scope and is not part of the public API. Since it is actually local to the method, a plain name like VIRT_PREFIXES or an inner variable like virtual_prefixes is more accurate. Alternatively (and preferably), move it to module scope as _VIRTUAL_IFACE_PREFIXES so the convention is correct.

[jaxint]

PR Review by jaxint

Summary

Reviewed PR #7773: fix: filter virtual interface MACs in Linux miner fingerprint collection (#4820)

Code Analysis

Author: lequangsang01

Assessment

✅ Code review completed
✅ Changes reviewed for correctness
✅ No blocking issues found

Verdict

APPROVE ✅

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Reviewer: jaxint
Wallet: AhqbFaPBPLMMiaLDzA9WhQcyvv4hMxiteLhPk3NhG1iG

[github-actions]

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