fix(srv6): rewrite tenant localsid decap VRF after an agent restart#21
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The per-tenant VRF table id comes from an in-memory vrfAllocator that is not persisted or seeded from VPP. On an agent-only restart the End.DT6 localsid persists in VPP with its decap VRF baked into SwIfIndex from the previous process, but installTenantDataPath merely skipped the re-add and installed ::/0 in the freshly-allocated VRF. When the ids differ, traffic decapped into the old VRF (no egress route -> blackhole) or another tenant's VRF (cross-wire). findLocalsid now returns the persisted entry so its decap VRF can be compared; on mismatch the localsid is rewritten (del+add) to decap into this process's VRF. Steady state (matching VRF) stays a no-op, so there is no per-reconcile churn.
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What
The per-tenant VRF table id comes from an in-memory
vrfAllocatorthat is not persisted or seeded from VPP. On an agent-only restart the End.DT6 localsid persists in VPP with its decap VRF baked intoSwIfIndexfrom the previous process, butinstallTenantDataPathmerely skipped the re-add and installed::/0in the freshly-allocated VRF. When the ids differ, traffic decapped into the old VRF (no egress route → blackhole) or another tenant's VRF (cross-wire).Fix
findLocalsidreturns the persisted entry (the dump mapsxconnect_iface_or_vrf_table→SwIfIndex) so its decap VRF can be compared; on mismatch the localsid is rewritten (del+add) to decap into this process's VRF. Steady state (matching VRF) stays a no-op — no per-reconcile churn.Review finding
Medium #8, corroborated by dp-gateway (2/3). Builds on #20 (VRF alloc/free symmetry).
Test
GOOS=linux go build/vetgreen;go test ./calico-vpp-agent/srv6egress/...green. Data-path behavior can't be exercised on darwin (no VPP).