Update

vendor/tailscale.com/wgengine/netlog_hooks.go

@@ -0,0 +1,86 @@
+// Copyright (c) Tailscale Inc & contributors
+// SPDX-License-Identifier: BSD-3-Clause
+
+package wgengine
+
+import (
+	"net/netip"
+
+	"tailscale.com/feature"
+	"tailscale.com/health"
+	"tailscale.com/net/netmon"
+	"tailscale.com/net/tstun"
+	"tailscale.com/tailcfg"
+	"tailscale.com/types/logger"
+	"tailscale.com/types/logid"
+	"tailscale.com/util/eventbus"
+	"tailscale.com/wgengine/magicsock"
+	"tailscale.com/wgengine/router"
+)
+
+// NetLogSource provides the network flow logging feature what it needs
+// from the rest of the system (in practice, ipnlocal.LocalBackend):
+// on-demand node lookups and the current audit logging identity.
+type NetLogSource interface {
+	// SelfNode returns the current self node and its owning user profile.
+	// The views are invalid if there is no current node.
+	SelfNode() (tailcfg.NodeView, tailcfg.UserProfileView)
+
+	// NodeByAddr returns the node assigned the given address along with
+	// its owning user profile.
+	// ok is false if no node is known to own addr.
+	NodeByAddr(addr netip.Addr) (node tailcfg.NodeView, user tailcfg.UserProfileView, ok bool)
+
+	// NetLogIDs returns the audit logging IDs from the current netmap,
+	// along with whether exit node flows should be logged.
+	// ok is false if network flow logging should not run.
+	NetLogIDs() (nodeID, domainID logid.PrivateID, logExitFlows bool, ok bool)
+}
+
+// NetLogger is the engine's handle on the network flow logger
+// lifecycle, implemented by the feature/netlog package.
+//
+// Reconfig and ReconfigDone are only called from [Engine.Reconfig],
+// serialized by the engine's internal lock. Shutdown may be called
+// concurrently with them from [Engine.Close].
+type NetLogger interface {
+	// Reconfig is called near the top of every [Engine.Reconfig],
+	// before its ErrNoChanges early return (so identity-only changes
+	// still take effect) and before the router is configured (so a
+	// starting logger captures initial packets). It reports whether
+	// network logging state changed, which suppresses the engine's
+	// ErrNoChanges early return.
+	Reconfig(routerCfg *router.Config, routerChanged bool) (changed bool)
+
+	// ReconfigDone is called at the end of [Engine.Reconfig], after
+	// the router is configured, so that a logger stopping as a result
+	// of the preceding Reconfig call captures final packets. It may
+	// block to flush pending messages.
+	ReconfigDone()
+
+	// Shutdown stops the logger. It may block to flush pending
+	// messages, bounded by an internal upload timeout.
+	Shutdown()
+}
+
+// NetLoggerDeps are the engine-owned dependencies passed to
+// [HookNewNetLogger] to construct a [NetLogger].
+type NetLoggerDeps struct {
+	Logf   logger.Logf
+	Tun    *tstun.Wrapper
+	Sock   *magicsock.Conn
+	NetMon *netmon.Monitor
+	Health *health.Tracker
+	Bus    *eventbus.Bus
+
+	// Source returns the [NetLogSource] installed via
+	// [Engine.SetNetLogSource], or nil if none has been installed yet.
+	// It is a func because the source is installed after the engine
+	// (and thus the NetLogger) is constructed.
+	Source func() NetLogSource
+}
+
+// HookNewNetLogger is set by the feature/netlog package to construct
+// each engine's [NetLogger]. If unset, network flow logging is not
+// linked into the binary and the engine skips all NetLogger calls.
+var HookNewNetLogger feature.Hook[func(NetLoggerDeps) NetLogger]