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>

control/controlclient/direct.go

@@ -160,7 +160,7 @@ func NewDirect(opts Options) (*Direct, error) {
 			UseLastGood:      true,
 			LookupIPFallback: dnsfallback.Lookup,
 		}
-		dialer := netns.NewDialer()
+		dialer := netns.NewDialer(opts.Logf)
 		tr := http.DefaultTransport.(*http.Transport).Clone()
 		tr.Proxy = tshttpproxy.ProxyFromEnvironment
 		tshttpproxy.SetTransportGetProxyConnectHeader(tr)

derp/derphttp/derphttp_client.go

@@ -429,7 +429,7 @@ func (c *Client) dialURL(ctx context.Context) (net.Conn, error) {
 		return c.dialer(ctx, "tcp", net.JoinHostPort(host, urlPort(c.url)))
 	}
 	hostOrIP := host
-	dialer := netns.NewDialer()
+	dialer := netns.NewDialer(c.logf)
 
 	if c.DNSCache != nil {
 		ip, _, _, err := c.DNSCache.LookupIP(ctx, host)
@@ -519,7 +519,7 @@ func (c *Client) DialRegionTLS(ctx context.Context, reg *tailcfg.DERPRegion) (tl
 }
 
 func (c *Client) dialContext(ctx context.Context, proto, addr string) (net.Conn, error) {
-	return netns.NewDialer().DialContext(ctx, proto, addr)
+	return netns.NewDialer(c.logf).DialContext(ctx, proto, addr)
 }
 
 // shouldDialProto reports whether an explicitly provided IPv4 or IPv6

logpolicy/logpolicy.go

@@ -587,7 +587,7 @@ func newLogtailTransport(host string) *http.Transport {
 
 	// Log whenever we dial:
 	tr.DialContext = func(ctx context.Context, netw, addr string) (net.Conn, error) {
-		nd := netns.FromDialer(&net.Dialer{
+		nd := netns.FromDialer(log.Printf, &net.Dialer{
 			Timeout:   30 * time.Second,
 			KeepAlive: netknob.PlatformTCPKeepAlive(),
 		})

net/dns/resolver/forwarder.go

@@ -342,7 +342,7 @@ func (f *forwarder) getKnownDoHClient(ip netaddr.IP) (urlBase string, c *http.Cl
 	if f.dohClient == nil {
 		f.dohClient = map[string]*http.Client{}
 	}
-	nsDialer := netns.NewDialer()
+	nsDialer := netns.NewDialer(f.logf)
 	c = &http.Client{
 		Transport: &http.Transport{
 			IdleConnTimeout: dohTransportTimeout,

net/dnsfallback/dnsfallback.go

@@ -90,7 +90,7 @@ func Lookup(ctx context.Context, host string) ([]netaddr.IP, error) {
 // serverName and serverIP of are, say, "derpN.tailscale.com".
 // queryName is the name being sought (e.g. "controlplane.tailscale.com"), passed as hint.
 func bootstrapDNSMap(ctx context.Context, serverName string, serverIP netaddr.IP, queryName string) (dnsMap, error) {
-	dialer := netns.NewDialer()
+	dialer := netns.NewDialer(log.Printf)
 	tr := http.DefaultTransport.(*http.Transport).Clone()
 	tr.Proxy = tshttpproxy.ProxyFromEnvironment
 	tr.DialContext = func(ctx context.Context, netw, addr string) (net.Conn, error) {

net/netcheck/netcheck.go

@@ -807,7 +807,7 @@ func (c *Client) GetReport(ctx context.Context, dm *tailcfg.DERPMap) (_ *Report,
 	}
 
 	// Create a UDP4 socket used for sending to our discovered IPv4 address.
-	rs.pc4Hair, err = netns.Listener().ListenPacket(ctx, "udp4", ":0")
+	rs.pc4Hair, err = netns.Listener(c.logf).ListenPacket(ctx, "udp4", ":0")
 	if err != nil {
 		c.logf("udp4: %v", err)
 		return nil, err
@@ -835,7 +835,7 @@ func (c *Client) GetReport(ctx context.Context, dm *tailcfg.DERPMap) (_ *Report,
 	if f := c.GetSTUNConn4; f != nil {
 		rs.pc4 = f()
 	} else {
-		u4, err := netns.Listener().ListenPacket(ctx, "udp4", c.udpBindAddr())
+		u4, err := netns.Listener(c.logf).ListenPacket(ctx, "udp4", c.udpBindAddr())
 		if err != nil {
 			c.logf("udp4: %v", err)
 			return nil, err
@@ -848,7 +848,7 @@ func (c *Client) GetReport(ctx context.Context, dm *tailcfg.DERPMap) (_ *Report,
 		if f := c.GetSTUNConn6; f != nil {
 			rs.pc6 = f()
 		} else {
-			u6, err := netns.Listener().ListenPacket(ctx, "udp6", c.udpBindAddr())
+			u6, err := netns.Listener(c.logf).ListenPacket(ctx, "udp6", c.udpBindAddr())
 			if err != nil {
 				c.logf("udp6: %v", err)
 			} else {

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 {
+func NewDialer(logf logger.Logf) Dialer {
-	return FromDialer(&net.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.
+	"tailscale.com/types/logger"
-func control(network, address string, c syscall.RawConn) error {
+)
+
+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:

net/portmapper/portmapper.go

@@ -251,7 +251,7 @@ func (c *Client) listenPacket(ctx context.Context, network, addr string) (net.Pa
 		var lc net.ListenConfig
 		return lc.ListenPacket(ctx, network, addr)
 	}
-	return netns.Listener().ListenPacket(ctx, network, addr)
+	return netns.Listener(c.logf).ListenPacket(ctx, network, addr)
 }
 
 func (c *Client) invalidateMappingsLocked(releaseOld bool) {

net/portmapper/upnp.go

@@ -219,7 +219,7 @@ func (c *Client) upnpHTTPClientLocked() *http.Client {
 	if c.uPnPHTTPClient == nil {
 		c.uPnPHTTPClient = &http.Client{
 			Transport: &http.Transport{
-				DialContext:     netns.NewDialer().DialContext,
+				DialContext:     netns.NewDialer(c.logf).DialContext,
 				IdleConnTimeout: 2 * time.Second, // LAN is cheap
 			},
 		}

wgengine/magicsock/magicsock.go

@@ -2719,7 +2719,7 @@ func (c *Conn) listenPacket(network string, port uint16) (net.PacketConn, error)
 	if c.testOnlyPacketListener != nil {
 		return c.testOnlyPacketListener.ListenPacket(ctx, network, addr)
 	}
-	return netns.Listener().ListenPacket(ctx, network, addr)
+	return netns.Listener(c.logf).ListenPacket(ctx, network, addr)
 }
 
 // bindSocket initializes rucPtr if necessary and binds a UDP socket to it.