Two related fixes for the embedded netbird client and the per-account
inbound listeners that ride on its gVisor netstack.
client/internal/engine.go — replace hasIPv6Changed with reconcileIPv6:
- First v6 assignment (current had no v6, conf carries one) is applied
in place via WGIface.UpdateAddr instead of returning ErrResetConnection.
Pre-fix, every embedded client whose account had IPv6 enabled would
reset on its first NetworkMap sync — boot config has no v6, the sync
introduces one, the engine tore itself down to "apply" it. That
teardown destroys the gVisor netstack and orphans every listener
bound on it, which is what made the proxy's per-account :80/:443
silently stop accepting traffic.
- v6 removed clears in place.
- v6 swapped to a different non-empty value still resets (gVisor
netstack can't safely swap its address at runtime).
- Mutates e.config.WgAddr to match the applied state so subsequent
PeerConfig comparisons are stable.
proxy/internal/tcp/accept.go (new) + proxy/inbound.go +
proxy/internal/tcp/router.go — harden the two Accept() loops on
netstack-backed listeners:
- IsClosedListenerErr recognises net.ErrClosed AND gVisor's
"endpoint is in invalid state" — the latter survives gonet's
*net.OpError wrapping in a way errors.Is(.., net.ErrClosed) does
not. Without this the loop spins CPU-hot after the underlying
netstack is destroyed (peer rekey, embedded-client reset, account
churn), emitting one log line per iteration.
- AcceptBackoff implements the exponential backoff that
net/http.Server.Serve uses on transient Accept errors: 5ms doubling
up to 1s. Defence-in-depth so an unknown sticky error cannot burn
a CPU core even if IsClosedListenerErr misses its signature.
proxy/internal/roundtrip/netbird.go — emit a single structured INFO
line summarising every embed.Options flag (account_id, service_id,
public_key, management_url, wg_port, block_inbound, block_lan_access,
disable_ipv6, no_userspace, presence of credentials) when each
per-account embedded client is created. Secrets reduced to a "present"
boolean — never logged verbatim. Diagnostic-only; no behavior change,
but it makes the "why is this embedded peer misbehaving" loop a single
log read instead of a code dive.
Tests (real listeners, scripted errors, no mocks of production code):
- engine_reconcileipv6_test.go: 8 cases for every transition (first
assignment, no change, removed, prefix-length changed, value
changed, invalid bytes, UpdateAddr error) plus a updateConfig
integration check that the fix actually fires on a v6-added
PeerConfig.
- accept_test.go: IsClosedListenerErr matrix + AcceptBackoff
progression / cap / reset / cancel-during-wait / cancel-before-call.
- router_test.go, inbound_test.go: scriptedAcceptListener +
TestRouter_Serve_ExitsOnGVisorInvalidEndpoint and
TestFeedRouterFromListener_ExitsOnGVisorInvalidEndpoint —
regression guards that fail in 2 s if the loop ever spins.
Adds a new "private" service mode for the reverse proxy: services reachable exclusively over the embedded WireGuard tunnel, gated by per-peer group membership instead of operator auth schemes.
Wire contract
- ProxyMapping.private (field 13): the proxy MUST call ValidateTunnelPeer and fail closed; operator schemes are bypassed.
- ProxyCapabilities.private (4) + supports_private_service (5): capability gate. Management never streams private mappings to proxies that don't claim the capability; the broadcast path applies the same filter via filterMappingsForProxy.
- ValidateTunnelPeer RPC: resolves an inbound tunnel IP to a peer, checks the peer's groups against service.AccessGroups, and mints a session JWT on success. checkPeerGroupAccess fails closed when a private service has empty AccessGroups.
- ValidateSession/ValidateTunnelPeer responses now carry peer_group_ids + peer_group_names so the proxy can authorise policy-aware middlewares without an extra management round-trip.
- ProxyInboundListener + SendStatusUpdate.inbound_listener: per-account inbound listener state surfaced to dashboards.
- PathTargetOptions.direct_upstream (11): bypass the embedded NetBird client and dial the target via the proxy host's network stack for upstreams reachable without WireGuard.
Data model
- Service.Private (bool) + Service.AccessGroups ([]string, JSON- serialised). Validate() rejects bearer auth on private services. Copy() deep-copies AccessGroups. pgx getServices loads the columns.
- DomainConfig.Private threaded into the proxy auth middleware. Request handler routes private services through forwardWithTunnelPeer and returns 403 on validation failure.
- Account-level SynthesizePrivateServiceZones (synthetic DNS) and injectPrivateServicePolicies (synthetic ACL) gate on len(svc.AccessGroups) > 0.
Proxy
- /netbird proxy --private (embedded mode) flag; Config.Private in proxy/lifecycle.go.
- Per-account inbound listener (proxy/inbound.go) binding HTTP/HTTPS on the embedded NetBird client's WireGuard tunnel netstack.
- proxy/internal/auth/tunnel_cache: ValidateTunnelPeer response cache with single-flight de-duplication and per-account eviction.
- Local peerstore short-circuit: when the inbound IP isn't in the account roster, deny fast without an RPC.
- proxy/server.go reports SupportsPrivateService=true and redacts the full ProxyMapping JSON from info logs (auth_token + header-auth hashed values now only at debug level).
Identity forwarding
- ValidateSessionJWT returns user_id, email, method, groups, group_names. sessionkey.Claims carries Email + Groups + GroupNames so the proxy can stamp identity onto upstream requests without an extra management round-trip on every cookie-bearing request.
- CapturedData carries userEmail / userGroups / userGroupNames; the proxy stamps X-NetBird-User and X-NetBird-Groups on r.Out from the authenticated identity (strips client-supplied values first to prevent spoofing).
- AccessLog.UserGroups: access-log enrichment captures the user's group memberships at write time so the dashboard can render group context without reverse-resolving stale memberships.
OpenAPI/dashboard surface
- ReverseProxyService gains private + access_groups; ReverseProxyCluster gains private + supports_private. ReverseProxyTarget target_type enum gains "cluster". ServiceTargetOptions gains direct_upstream. ProxyAccessLog gains user_groups.
