Riccardo Manfrin 2f268c8141 [client] fix stale routing peer on overlapping-prefix network removal (#6799)
## Describe your changes

The AllowedIPs reference counter
([refcounter/types.go#L9](https://github.com/netbirdio/netbird/blob/e1a24376a/client/internal/routemanager/refcounter/types.go#L9))
was keyed only by prefix and stored a single active peer set by
the first registrar, never swapped. When two networks advertised the
same prefix via different routing peers, removing the one whose peer was
installed in WireGuard left the prefix pointing at the removed peer
instead of the
surviving one — traffic kept flowing to the old peer until a manual
`netbird down/up`.

Made the AllowedIPs counter peer-aware: it tracks a per-peer reference
count per prefix plus the installed peer, and swaps WireGuard to a
surviving peer when the active one releases its last reference (removes
the prefix when
none remain). `Decrement` now takes the peer key so the exact
incremented peer is released; the static handler records its selected
routing peer like the dynamic and DNS handlers already did. The generic
`Counter` (routes,
  exclusion, ipset) is unchanged.

  ## Issue ticket number and link

No public issue — reported internally (routes not updating without
`netbird down/up` when two networks share a subnet). Root cause is the
prefix-only key at

[refcounter/types.go#L9](https://github.com/netbirdio/netbird/blob/e1a24376a/client/internal/routemanager/refcounter/types.go#L9).

  ## Stack

  <!-- branch-stack -->

  ### Checklist
  - [x] Is it a bug fix
  - [ ] Is a typo/documentation fix
  - [ ] Is a feature enhancement
  - [ ] It is a refactor
  - [x] Created tests that fail without the change (if possible)

> By submitting this pull request, you confirm that you have read and
agree to the terms of the [Contributor License
Agreement](https://github.com/netbirdio/netbird/blob/main/CONTRIBUTOR_LICENSE_AGREEMENT.md).

  ## Documentation
  Select exactly one:

  - [ ] I added/updated documentation for this change
  - [x] Documentation is **not needed** for this change (explain why)

Internal client-side routing fix. No public API, CLI, or config change —
only the WireGuard AllowedIPs hand-off when overlapping-prefix networks
are removed.

  ### Docs PR URL (required if "docs added" is checked)
  Paste the PR link from https://github.com/netbirdio/docs here:

  N/A

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<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Bug Fixes**
* Improved routing behavior when multiple peers share the same Allowed
IP by making Allowed IP reference tracking peer-aware.
* Allowed IPs now correctly decrement using the active peer key and
transfer to another surviving active peer when the current peer is
removed.
* Prevented stale routing and incorrect reference cleanup during route
and DNS-driven teardown.

* **Tests**
* Added/extended coverage for peer handoffs, repeated references,
non-active peer removal, flushing behavior, and self-healing after swap
add/remove failures.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
2026-07-28 14:10:58 +09:00
2025-04-09 20:18:52 +01:00
2024-10-30 17:18:27 +01:00
2022-12-02 13:54:22 +01:00

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