net/netns: thread logf into control functions

So that darwin can log there without panicking during tests.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>

net/netns/netns.go

@@ -21,6 +21,7 @@ import (
 	"inet.af/netaddr"
 	"tailscale.com/net/netknob"
 	"tailscale.com/syncs"
+	"tailscale.com/types/logger"
 )
 
 var disabled syncs.AtomicBool
@@ -34,19 +35,19 @@ func SetEnabled(on bool) {
 // Listener returns a new net.Listener with its Control hook func
 // initialized as necessary to run in logical network namespace that
 // doesn't route back into Tailscale.
-func Listener() *net.ListenConfig {
+func Listener(logf logger.Logf) *net.ListenConfig {
 	if disabled.Get() {
 		return new(net.ListenConfig)
 	}
-	return &net.ListenConfig{Control: control}
+	return &net.ListenConfig{Control: control(logf)}
 }
 
 // NewDialer returns a new Dialer using a net.Dialer with its Control
 // hook func initialized as necessary to run in a logical network
 // namespace that doesn't route back into Tailscale. It also handles
 // using a SOCKS if configured in the environment with ALL_PROXY.
-func NewDialer() Dialer {
-	return FromDialer(&net.Dialer{
+func NewDialer(logf logger.Logf) Dialer {
+	return FromDialer(logf, &net.Dialer{
 		KeepAlive: netknob.PlatformTCPKeepAlive(),
 	})
 }
@@ -55,11 +56,11 @@ func NewDialer() Dialer {
 // network namespace that doesn't route back into Tailscale. It also
 // handles using a SOCKS if configured in the environment with
 // ALL_PROXY.
-func FromDialer(d *net.Dialer) Dialer {
+func FromDialer(logf logger.Logf, d *net.Dialer) Dialer {
 	if disabled.Get() {
 		return d
 	}
-	d.Control = control
+	d.Control = control(logf)
 	if wrapDialer != nil {
 		return wrapDialer(d)
 	}

net/netns/netns_android.go

@@ -11,6 +11,8 @@ import (
 	"fmt"
 	"sync"
 	"syscall"
+
+	"tailscale.com/types/logger"
 )
 
 var (
@@ -44,11 +46,15 @@ func SetAndroidProtectFunc(f func(fd int) error) {
 	androidProtectFunc = f
 }
 
-// control marks c as necessary to dial in a separate network namespace.
+func control(logger.Logf) func(network, address string, c syscall.RawConn) error {
+	return controlC
+}
+
+// controlC marks c as necessary to dial in a separate network namespace.
 //
 // It's intentionally the same signature as net.Dialer.Control
 // and net.ListenConfig.Control.
-func control(network, address string, c syscall.RawConn) error {
+func controlC(network, address string, c syscall.RawConn) error {
 	var sockErr error
 	err := c.Control(func(fd uintptr) {
 		androidProtectFuncMu.Lock()

net/netns/netns_darwin_tailscaled.go

@@ -9,26 +9,32 @@ package netns
 
 import (
 	"fmt"
-	"log"
 	"strings"
 	"syscall"
 
 	"golang.org/x/sys/unix"
 	"tailscale.com/net/interfaces"
+	"tailscale.com/types/logger"
 )
 
-// control marks c as necessary to dial in a separate network namespace.
+func control(logf logger.Logf) func(network, address string, c syscall.RawConn) error {
+	return func(network, address string, c syscall.RawConn) error {
+		return controlLogf(logf, network, address, c)
+	}
+}
+
+// controlLogf marks c as necessary to dial in a separate network namespace.
 //
 // It's intentionally the same signature as net.Dialer.Control
 // and net.ListenConfig.Control.
-func control(network, address string, c syscall.RawConn) error {
+func controlLogf(logf logger.Logf, network, address string, c syscall.RawConn) error {
 	if strings.HasPrefix(address, "127.") || address == "::1" {
 		// Don't bind to an interface for localhost connections.
 		return nil
 	}
 	idx, err := interfaces.DefaultRouteInterfaceIndex()
 	if err != nil {
-		log.Printf("netns: DefaultRouteInterfaceIndex: %v", err)
+		logf("[unexpected] netns: DefaultRouteInterfaceIndex: %v", err)
 		return nil
 	}
 	v6 := strings.Contains(address, "]:") || strings.HasSuffix(network, "6") // hacky test for v6
@@ -47,7 +53,7 @@ func control(network, address string, c syscall.RawConn) error {
 		return fmt.Errorf("RawConn.Control on %T: %w", c, err)
 	}
 	if sockErr != nil {
-		log.Printf("netns: control(%q, %q), v6=%v, index=%v: %v", network, address, v6, idx, sockErr)
+		logf("[unexpected] netns: control(%q, %q), v6=%v, index=%v: %v", network, address, v6, idx, sockErr)
 	}
 	return sockErr
 }

net/netns/netns_default.go

@@ -7,9 +7,17 @@
 
 package netns
 
-import "syscall"
+import (
+	"syscall"
 
-// control does nothing to c.
-func control(network, address string, c syscall.RawConn) error {
+	"tailscale.com/types/logger"
+)
+
+func control(logger.Logf) func(network, address string, c syscall.RawConn) error {
+	return controlC
+}
+
+// controlC does nothing to c.
+func controlC(network, address string, c syscall.RawConn) error {
 	return nil
 }

net/netns/netns_linux.go

@@ -17,6 +17,7 @@ import (
 
 	"golang.org/x/sys/unix"
 	"tailscale.com/net/interfaces"
+	"tailscale.com/types/logger"
 )
 
 // tailscaleBypassMark is the mark indicating that packets originating
@@ -82,11 +83,15 @@ func ignoreErrors() bool {
 	return false
 }
 
-// control marks c as necessary to dial in a separate network namespace.
+func control(logger.Logf) func(network, address string, c syscall.RawConn) error {
+	return controlC
+}
+
+// controlC marks c as necessary to dial in a separate network namespace.
 //
 // It's intentionally the same signature as net.Dialer.Control
 // and net.ListenConfig.Control.
-func control(network, address string, c syscall.RawConn) error {
+func controlC(network, address string, c syscall.RawConn) error {
 	if isLocalhost(address) {
 		// Don't bind to an interface for localhost connections.
 		return nil

net/netns/netns_test.go

@@ -25,7 +25,7 @@ func TestDial(t *testing.T) {
 	if !*extNetwork {
 		t.Skip("skipping test without --use-external-network")
 	}
-	d := NewDialer()
+	d := NewDialer(t.Logf)
 	c, err := d.Dial("tcp", "google.com:80")
 	if err != nil {
 		t.Fatal(err)

net/netns/netns_windows.go

@@ -12,6 +12,7 @@ import (
 	"golang.org/x/sys/windows"
 	"golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
 	"tailscale.com/net/interfaces"
+	"tailscale.com/types/logger"
 	"tailscale.com/util/endian"
 )
 
@@ -26,9 +27,13 @@ func interfaceIndex(iface *winipcfg.IPAdapterAddresses) uint32 {
 	return iface.IfIndex
 }
 
-// control binds c to the Windows interface that holds a default
+func control(logger.Logf) func(network, address string, c syscall.RawConn) error {
+	return controlC
+}
+
+// controlC binds c to the Windows interface that holds a default
 // route, and is not the Tailscale WinTun interface.
-func control(network, address string, c syscall.RawConn) error {
+func controlC(network, address string, c syscall.RawConn) error {
 	if strings.HasPrefix(address, "127.") {
 		// Don't bind to an interface for localhost connections,
 		// otherwise we get: