all: remove some Debug fields, NetworkMap.Debug, Reconfig Debug arg

Updates #8923

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

wgengine/bench/wg.go

@@ -114,7 +114,7 @@ func setupWGTest(b *testing.B, logf logger.Logf, traf *TrafficGen, a1, a2 netip.
 			AllowedIPs: []netip.Prefix{a1},
 		}
 		c2.Peers = []wgcfg.Peer{p}
-		e2.Reconfig(&c2, &router.Config{}, new(dns.Config), nil)
+		e2.Reconfig(&c2, &router.Config{}, new(dns.Config))
 		e1waitDoneOnce.Do(wait.Done)
 	})
 
@@ -151,7 +151,7 @@ func setupWGTest(b *testing.B, logf logger.Logf, traf *TrafficGen, a1, a2 netip.
 			AllowedIPs: []netip.Prefix{a2},
 		}
 		c1.Peers = []wgcfg.Peer{p}
-		e1.Reconfig(&c1, &router.Config{}, new(dns.Config), nil)
+		e1.Reconfig(&c1, &router.Config{}, new(dns.Config))
 		e2waitDoneOnce.Do(wait.Done)
 	})
 

wgengine/magicsock/magicsock.go

@@ -13,7 +13,6 @@ import (
 	"io"
 	"net"
 	"net/netip"
-	"reflect"
 	"runtime"
 	"slices"
 	"strconv"
@@ -1756,17 +1755,12 @@ func (c *Conn) SetNetworkMap(nm *netmap.NetworkMap) {
 	}
 
 	priorNetmap := c.netMap
-	var priorDebug *tailcfg.Debug
-	if priorNetmap != nil {
-		priorDebug = priorNetmap.Debug
-	}
-	debugChanged := !reflect.DeepEqual(priorDebug, nm.Debug)
 	metricNumPeers.Set(int64(len(nm.Peers)))
 
 	// Update c.netMap regardless, before the following early return.
 	c.netMap = nm
 
-	if priorNetmap != nil && nodesEqual(priorNetmap.Peers, nm.Peers) && !debugChanged {
+	if priorNetmap != nil && nodesEqual(priorNetmap.Peers, nm.Peers) {
 		// The rest of this function is all adjusting state for peers that have
 		// changed. But if the set of peers is equal and the debug flags (for
 		// silent disco) haven't changed, no need to do anything else.

wgengine/userspace.go

@@ -766,7 +766,9 @@ func hasOverlap(aips, rips []netip.Prefix) bool {
 	return false
 }
 
-func (e *userspaceEngine) Reconfig(cfg *wgcfg.Config, routerCfg *router.Config, dnsCfg *dns.Config, debug *tailcfg.Debug) error {
+var randomizeClientPort = controlclient.RandomizeClientPort
+
+func (e *userspaceEngine) Reconfig(cfg *wgcfg.Config, routerCfg *router.Config, dnsCfg *dns.Config) error {
 	if routerCfg == nil {
 		panic("routerCfg must not be nil")
 	}
@@ -792,8 +794,7 @@ func (e *userspaceEngine) Reconfig(cfg *wgcfg.Config, routerCfg *router.Config,
 	e.mu.Unlock()
 
 	listenPort := e.confListenPort
-	if controlclient.RandomizeClientPort() || // new way (capver 70)
-		debug != nil && debug.RandomizeClientPort { // old way which server might still send (as of 2023-08-16)
+	if randomizeClientPort() {
 		listenPort = 0
 	}
 

wgengine/userspace_test.go

@@ -121,7 +121,7 @@ func TestUserspaceEngineReconfig(t *testing.T) {
 		}
 
 		e.SetNetworkMap(nm)
-		err = e.Reconfig(cfg, routerCfg, &dns.Config{}, nil)
+		err = e.Reconfig(cfg, routerCfg, &dns.Config{})
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -143,6 +143,8 @@ func TestUserspaceEngineReconfig(t *testing.T) {
 }
 
 func TestUserspaceEnginePortReconfig(t *testing.T) {
+	tstest.Replace(t, &randomizeClientPort, func() bool { return false })
+
 	flakytest.Mark(t, "https://github.com/tailscale/tailscale/issues/2855")
 	const defaultPort = 49983
 	// Keep making a wgengine until we find an unused port
@@ -181,13 +183,15 @@ func TestUserspaceEnginePortReconfig(t *testing.T) {
 		},
 	}
 	routerCfg := &router.Config{}
-	if err := ue.Reconfig(cfg, routerCfg, &dns.Config{}, nil); err != nil {
+	if err := ue.Reconfig(cfg, routerCfg, &dns.Config{}); err != nil {
 		t.Fatal(err)
 	}
 	if got := ue.magicConn.LocalPort(); got != startingPort {
 		t.Errorf("no debug setting changed local port to %d from %d", got, startingPort)
 	}
-	if err := ue.Reconfig(cfg, routerCfg, &dns.Config{}, &tailcfg.Debug{RandomizeClientPort: true}); err != nil {
+
+	randomizeClientPort = func() bool { return true }
+	if err := ue.Reconfig(cfg, routerCfg, &dns.Config{}); err != nil {
 		t.Fatal(err)
 	}
 	if got := ue.magicConn.LocalPort(); got == startingPort {
@@ -195,7 +199,8 @@ func TestUserspaceEnginePortReconfig(t *testing.T) {
 	}
 
 	lastPort := ue.magicConn.LocalPort()
-	if err := ue.Reconfig(cfg, routerCfg, &dns.Config{}, nil); err != nil {
+	randomizeClientPort = func() bool { return false }
+	if err := ue.Reconfig(cfg, routerCfg, &dns.Config{}); err != nil {
 		t.Fatal(err)
 	}
 	if startingPort == defaultPort {

wgengine/watchdog.go

@@ -119,8 +119,8 @@ func (e *watchdogEngine) watchdog(name string, fn func()) {
 	})
 }
 
-func (e *watchdogEngine) Reconfig(cfg *wgcfg.Config, routerCfg *router.Config, dnsCfg *dns.Config, debug *tailcfg.Debug) error {
-	return e.watchdogErr("Reconfig", func() error { return e.wrap.Reconfig(cfg, routerCfg, dnsCfg, debug) })
+func (e *watchdogEngine) Reconfig(cfg *wgcfg.Config, routerCfg *router.Config, dnsCfg *dns.Config) error {
+	return e.watchdogErr("Reconfig", func() error { return e.wrap.Reconfig(cfg, routerCfg, dnsCfg) })
 }
 func (e *watchdogEngine) GetFilter() *filter.Filter {
 	return e.wrap.GetFilter()

wgengine/wgengine.go

@@ -72,10 +72,8 @@ type Engine interface {
 	// This is called whenever tailcontrol (the control plane)
 	// sends an updated network map.
 	//
-	// The *tailcfg.Debug parameter can be nil.
-	//
 	// The returned error is ErrNoChanges if no changes were made.
-	Reconfig(*wgcfg.Config, *router.Config, *dns.Config, *tailcfg.Debug) error
+	Reconfig(*wgcfg.Config, *router.Config, *dns.Config) error
 
 	// PeerForIP returns the node to which the provided IP routes,
 	// if any. If none is found, (nil, false) is returned.