control/controlknobs: move more controlknobs code from controlclient

Updates #cleanup

Change-Id: I2b8b6ac97589270f307bfb20e33674894ce873b5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/tailscaled/depaware.txt

@@ -315,7 +315,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/types/netlogtype                               from tailscale.com/net/connstats+
         tailscale.com/types/netmap                                   from tailscale.com/control/controlclient+
         tailscale.com/types/nettype                                  from tailscale.com/wgengine/magicsock+
-        tailscale.com/types/opt                                      from tailscale.com/control/controlclient+
+        tailscale.com/types/opt                                      from tailscale.com/client/tailscale+
         tailscale.com/types/persist                                  from tailscale.com/control/controlclient+
         tailscale.com/types/preftype                                 from tailscale.com/ipn+
         tailscale.com/types/ptr                                      from tailscale.com/hostinfo+

control/controlclient/direct.go

@@ -49,7 +49,6 @@
 	"tailscale.com/types/key"
 	"tailscale.com/types/logger"
 	"tailscale.com/types/netmap"
-	"tailscale.com/types/opt"
 	"tailscale.com/types/persist"
 	"tailscale.com/types/ptr"
 	"tailscale.com/types/tkatype"
@@ -1304,49 +1303,6 @@ func initDevKnob() devKnobs {
 
 var clock tstime.Clock = tstime.StdClock{}
 
-func (ms *mapSession) setControlKnobsFromNodeAttrs(selfNodeAttrs []string) {
-	k := ms.controlKnobs
-	if k == nil {
-		return
-	}
-	var (
-		keepFullWG          bool
-		disableDRPO         bool
-		disableUPnP         bool
-		randomizeClientPort bool
-		disableDeltaUpdates bool
-		oneCGNAT            opt.Bool
-		forceBackgroundSTUN bool
-	)
-	for _, attr := range selfNodeAttrs {
-		switch attr {
-		case tailcfg.NodeAttrDebugDisableWGTrim:
-			keepFullWG = true
-		case tailcfg.NodeAttrDebugDisableDRPO:
-			disableDRPO = true
-		case tailcfg.NodeAttrDisableUPnP:
-			disableUPnP = true
-		case tailcfg.NodeAttrRandomizeClientPort:
-			randomizeClientPort = true
-		case tailcfg.NodeAttrOneCGNATEnable:
-			oneCGNAT.Set(true)
-		case tailcfg.NodeAttrOneCGNATDisable:
-			oneCGNAT.Set(false)
-		case tailcfg.NodeAttrDebugForceBackgroundSTUN:
-			forceBackgroundSTUN = true
-		case tailcfg.NodeAttrDisableDeltaUpdates:
-			disableDeltaUpdates = true
-		}
-	}
-	k.KeepFullWGConfig.Store(keepFullWG)
-	k.DisableDRPO.Store(disableDRPO)
-	k.DisableUPnP.Store(disableUPnP)
-	k.RandomizeClientPort.Store(randomizeClientPort)
-	k.OneCGNAT.Store(oneCGNAT)
-	k.ForceBackgroundSTUN.Store(forceBackgroundSTUN)
-	k.DisableDeltaUpdates.Store(disableDeltaUpdates)
-}
-
 // ipForwardingBroken reports whether the system's IP forwarding is disabled
 // and will definitely not work for the routes provided.
 //

control/controlclient/map.go

@@ -188,7 +188,7 @@ func (ms *mapSession) HandleNonKeepAliveMapResponse(ctx context.Context, resp *t
 		if DevKnob.StripCaps() {
 			resp.Node.Capabilities = nil
 		}
-		ms.setControlKnobsFromNodeAttrs(resp.Node.Capabilities)
+		ms.controlKnobs.UpdateFromNodeAttributes(resp.Node.Capabilities)
 	}
 
 	// Call Node.InitDisplayNames on any changed nodes.

control/controlknobs/controlknobs.go

@@ -9,6 +9,7 @@
 	"sync/atomic"
 
 	"tailscale.com/syncs"
+	"tailscale.com/tailcfg"
 	"tailscale.com/types/opt"
 )
 
@@ -45,6 +46,50 @@ type Knobs struct {
 	DisableDeltaUpdates atomic.Bool
 }
 
+// UpdateFromNodeAttributes updates k (if non-nil) based on the provided self
+// node attributes (Node.Capabilities).
+func (k *Knobs) UpdateFromNodeAttributes(selfNodeAttrs []string) {
+	if k == nil {
+		return
+	}
+	var (
+		keepFullWG          bool
+		disableDRPO         bool
+		disableUPnP         bool
+		randomizeClientPort bool
+		disableDeltaUpdates bool
+		oneCGNAT            opt.Bool
+		forceBackgroundSTUN bool
+	)
+	for _, attr := range selfNodeAttrs {
+		switch attr {
+		case tailcfg.NodeAttrDebugDisableWGTrim:
+			keepFullWG = true
+		case tailcfg.NodeAttrDebugDisableDRPO:
+			disableDRPO = true
+		case tailcfg.NodeAttrDisableUPnP:
+			disableUPnP = true
+		case tailcfg.NodeAttrRandomizeClientPort:
+			randomizeClientPort = true
+		case tailcfg.NodeAttrOneCGNATEnable:
+			oneCGNAT.Set(true)
+		case tailcfg.NodeAttrOneCGNATDisable:
+			oneCGNAT.Set(false)
+		case tailcfg.NodeAttrDebugForceBackgroundSTUN:
+			forceBackgroundSTUN = true
+		case tailcfg.NodeAttrDisableDeltaUpdates:
+			disableDeltaUpdates = true
+		}
+	}
+	k.KeepFullWGConfig.Store(keepFullWG)
+	k.DisableDRPO.Store(disableDRPO)
+	k.DisableUPnP.Store(disableUPnP)
+	k.RandomizeClientPort.Store(randomizeClientPort)
+	k.OneCGNAT.Store(oneCGNAT)
+	k.ForceBackgroundSTUN.Store(forceBackgroundSTUN)
+	k.DisableDeltaUpdates.Store(disableDeltaUpdates)
+}
+
 // AsDebugJSON returns k as something that can be marshalled with json.Marshal
 // for debug.
 func (k *Knobs) AsDebugJSON() map[string]any {