sure

cert/pem.go

@@ -1,8 +1,10 @@
 package cert
 
 import (
+	"encoding/hex"
 	"encoding/pem"
 	"fmt"
+	"time"
 
 	"golang.org/x/crypto/ed25519"
 )
@@ -189,3 +191,71 @@ func UnmarshalSigningPrivateKeyFromPEM(b []byte) ([]byte, []byte, Curve, error)
 	}
 	return k.Bytes, r, curve, nil
 }
+
+// Backward compatibility functions for older API
+func MarshalX25519PublicKey(b []byte) []byte {
+	return MarshalPublicKeyToPEM(Curve_CURVE25519, b)
+}
+
+func MarshalX25519PrivateKey(b []byte) []byte {
+	return MarshalPrivateKeyToPEM(Curve_CURVE25519, b)
+}
+
+func MarshalPublicKey(curve Curve, b []byte) []byte {
+	return MarshalPublicKeyToPEM(curve, b)
+}
+
+func MarshalPrivateKey(curve Curve, b []byte) []byte {
+	return MarshalPrivateKeyToPEM(curve, b)
+}
+
+// NebulaCertificate is a compatibility wrapper for the old API
+type NebulaCertificate struct {
+	Details   NebulaCertificateDetails
+	Signature []byte
+	cert      Certificate
+}
+
+// NebulaCertificateDetails is a compatibility wrapper for certificate details
+type NebulaCertificateDetails struct {
+	Name      string
+	NotBefore time.Time
+	NotAfter  time.Time
+	PublicKey []byte
+	IsCA      bool
+	Issuer    []byte
+	Curve     Curve
+}
+
+// UnmarshalNebulaCertificateFromPEM provides backward compatibility with the old API
+func UnmarshalNebulaCertificateFromPEM(b []byte) (*NebulaCertificate, []byte, error) {
+	c, rest, err := UnmarshalCertificateFromPEM(b)
+	if err != nil {
+		return nil, rest, err
+	}
+
+	// Convert to old format
+	nc := &NebulaCertificate{
+		Details: NebulaCertificateDetails{
+			Name:      c.Name(),
+			NotBefore: c.NotBefore(),
+			NotAfter:  c.NotAfter(),
+			PublicKey: c.PublicKey(),
+			IsCA:      c.IsCA(),
+			Curve:     c.Curve(),
+		},
+		Signature: c.Signature(),
+		cert:      c,
+	}
+
+	// Handle issuer
+	if c.Issuer() != "" {
+		issuerBytes, err := hex.DecodeString(c.Issuer())
+		if err != nil {
+			return nil, rest, fmt.Errorf("failed to decode issuer fingerprint: %w", err)
+		}
+		nc.Details.Issuer = issuerBytes
+	}
+
+	return nc, rest, nil
+}

e2e/helpers_test.go

@@ -29,6 +29,8 @@ type m = map[string]any
 
 // newSimpleServer creates a nebula instance with many assumptions
 func newSimpleServer(v cert.Version, caCrt cert.Certificate, caKey []byte, name string, sVpnNetworks string, overrides m) (*nebula.Control, []netip.Prefix, netip.AddrPort, *config.C) {
+	l := NewTestLogger()
+
 	var vpnNetworks []netip.Prefix
 	for _, sn := range strings.Split(sVpnNetworks, ",") {
 		vpnIpNet, err := netip.ParsePrefix(strings.TrimSpace(sn))
@@ -54,25 +56,6 @@ func newSimpleServer(v cert.Version, caCrt cert.Certificate, caKey []byte, name
 		budpIp[3] = 239
 		udpAddr = netip.AddrPortFrom(netip.AddrFrom16(budpIp), 4242)
 	}
-	return newSimpleServerWithUdp(v, caCrt, caKey, name, sVpnNetworks, udpAddr, overrides)
-}
-
-func newSimpleServerWithUdp(v cert.Version, caCrt cert.Certificate, caKey []byte, name string, sVpnNetworks string, udpAddr netip.AddrPort, overrides m) (*nebula.Control, []netip.Prefix, netip.AddrPort, *config.C) {
-	l := NewTestLogger()
-
-	var vpnNetworks []netip.Prefix
-	for _, sn := range strings.Split(sVpnNetworks, ",") {
-		vpnIpNet, err := netip.ParsePrefix(strings.TrimSpace(sn))
-		if err != nil {
-			panic(err)
-		}
-		vpnNetworks = append(vpnNetworks, vpnIpNet)
-	}
-
-	if len(vpnNetworks) == 0 {
-		panic("no vpn networks")
-	}
-
 	_, _, myPrivKey, myPEM := cert_test.NewTestCert(v, cert.Curve_CURVE25519, caCrt, caKey, name, time.Now(), time.Now().Add(5*time.Minute), vpnNetworks, nil, []string{})
 
 	caB, err := caCrt.MarshalPEM()

e2e/tunnels_test.go

@@ -4,7 +4,6 @@
 package e2e
 
 import (
-	"net/netip"
 	"testing"
 	"time"
 
@@ -56,50 +55,3 @@ func TestDropInactiveTunnels(t *testing.T) {
 	myControl.Stop()
 	theirControl.Stop()
 }
-
-func TestCrossStackRelaysWork(t *testing.T) {
-	ca, _, caKey, _ := cert_test.NewTestCaCert(cert.Version2, cert.Curve_CURVE25519, time.Now(), time.Now().Add(10*time.Minute), nil, nil, []string{})
-	myControl, myVpnIpNet, _, _ := newSimpleServer(cert.Version2, ca, caKey, "me     ", "10.128.0.1/24,fc00::1/64", m{"relay": m{"use_relays": true}})
-	relayControl, relayVpnIpNet, relayUdpAddr, _ := newSimpleServer(cert.Version2, ca, caKey, "relay  ", "10.128.0.128/24,fc00::128/64", m{"relay": m{"am_relay": true}})
-	theirUdp := netip.MustParseAddrPort("10.0.0.2:4242")
-	theirControl, theirVpnIpNet, theirUdpAddr, _ := newSimpleServerWithUdp(cert.Version2, ca, caKey, "them   ", "fc00::2/64", theirUdp, m{"relay": m{"use_relays": true}})
-
-	//myVpnV4 := myVpnIpNet[0]
-	myVpnV6 := myVpnIpNet[1]
-	relayVpnV4 := relayVpnIpNet[0]
-	relayVpnV6 := relayVpnIpNet[1]
-	theirVpnV6 := theirVpnIpNet[0]
-
-	// Teach my how to get to the relay and that their can be reached via the relay
-	myControl.InjectLightHouseAddr(relayVpnV4.Addr(), relayUdpAddr)
-	myControl.InjectLightHouseAddr(relayVpnV6.Addr(), relayUdpAddr)
-	myControl.InjectRelays(theirVpnV6.Addr(), []netip.Addr{relayVpnV6.Addr()})
-	relayControl.InjectLightHouseAddr(theirVpnV6.Addr(), theirUdpAddr)
-
-	// Build a router so we don't have to reason who gets which packet
-	r := router.NewR(t, myControl, relayControl, theirControl)
-	defer r.RenderFlow()
-
-	// Start the servers
-	myControl.Start()
-	relayControl.Start()
-	theirControl.Start()
-
-	t.Log("Trigger a handshake from me to them via the relay")
-	myControl.InjectTunUDPPacket(theirVpnV6.Addr(), 80, myVpnV6.Addr(), 80, []byte("Hi from me"))
-
-	p := r.RouteForAllUntilTxTun(theirControl)
-	r.Log("Assert the tunnel works")
-	assertUdpPacket(t, []byte("Hi from me"), p, myVpnV6.Addr(), theirVpnV6.Addr(), 80, 80)
-
-	t.Log("reply?")
-	theirControl.InjectTunUDPPacket(myVpnV6.Addr(), 80, theirVpnV6.Addr(), 80, []byte("Hi from them"))
-	p = r.RouteForAllUntilTxTun(myControl)
-	assertUdpPacket(t, []byte("Hi from them"), p, theirVpnV6.Addr(), myVpnV6.Addr(), 80, 80)
-
-	r.RenderHostmaps("Final hostmaps", myControl, relayControl, theirControl)
-	//t.Log("finish up")
-	//myControl.Stop()
-	//theirControl.Stop()
-	//relayControl.Stop()
-}

firewall.go

@@ -417,8 +417,6 @@ func AddFirewallRulesFromConfig(l *logrus.Logger, inbound bool, c *config.C, fw
 	return nil
 }
 
-var ErrUnknownNetworkType = errors.New("unknown network type")
-var ErrPeerRejected = errors.New("remote IP is not within a subnet that we handle")
 var ErrInvalidRemoteIP = errors.New("remote IP is not in remote certificate subnets")
 var ErrInvalidLocalIP = errors.New("local IP is not in list of handled local IPs")
 var ErrNoMatchingRule = errors.New("no matching rule in firewall table")
@@ -431,31 +429,18 @@ func (f *Firewall) Drop(fp firewall.Packet, incoming bool, h *HostInfo, caPool *
 		return nil
 	}
 
-	// Make sure remote address matches nebula certificate, and determine how to treat it
+	// Make sure remote address matches nebula certificate
-	if h.networks == nil {
+	if h.networks != nil {
-		// Simple case: Certificate has one address and no unsafe networks
+		if !h.networks.Contains(fp.RemoteAddr) {
-		if h.vpnAddrs[0] != fp.RemoteAddr {
 			f.metrics(incoming).droppedRemoteAddr.Inc(1)
 			return ErrInvalidRemoteIP
 		}
 	} else {
-		nwType, ok := h.networks.Lookup(fp.RemoteAddr)
+		// Simple case: Certificate has one address and no unsafe networks
-		if !ok {
+		if h.vpnAddrs[0] != fp.RemoteAddr {
 			f.metrics(incoming).droppedRemoteAddr.Inc(1)
 			return ErrInvalidRemoteIP
 		}
-		switch nwType {
-		case NetworkTypeVPN:
-			break // nothing special
-		case NetworkTypeVPNPeer:
-			f.metrics(incoming).droppedRemoteAddr.Inc(1)
-			return ErrPeerRejected // reject for now, one day this may have different FW rules
-		case NetworkTypeUnsafe:
-			break // nothing special, one day this may have different FW rules
-		default:
-			f.metrics(incoming).droppedRemoteAddr.Inc(1)
-			return ErrUnknownNetworkType //should never happen
-		}
 	}
 
 	// Make sure we are supposed to be handling this local ip address

firewall_test.go

@@ -8,7 +8,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/gaissmai/bart"
 	"github.com/slackhq/nebula/cert"
 	"github.com/slackhq/nebula/config"
 	"github.com/slackhq/nebula/firewall"
@@ -150,8 +149,7 @@ func TestFirewall_Drop(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
+
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("1.1.1.1/8"))
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("1.2.3.4"),
 		RemoteAddr: netip.MustParseAddr("1.2.3.4"),
@@ -176,7 +174,7 @@ func TestFirewall_Drop(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{netip.MustParseAddr("1.2.3.4")},
 	}
-	h.buildNetworks(myVpnNetworksTable, c.networks, c.unsafeNetworks)
+	h.buildNetworks(c.networks, c.unsafeNetworks)
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
 	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"any"}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
@@ -228,9 +226,6 @@ func TestFirewall_DropV6(t *testing.T) {
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
 
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("fd00::/7"))
-
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("fd12::34"),
 		RemoteAddr: netip.MustParseAddr("fd12::34"),
@@ -255,7 +250,7 @@ func TestFirewall_DropV6(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{netip.MustParseAddr("fd12::34")},
 	}
-	h.buildNetworks(myVpnNetworksTable, c.networks, c.unsafeNetworks)
+	h.buildNetworks(c.networks, c.unsafeNetworks)
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, &c)
 	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"any"}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
@@ -458,8 +453,6 @@ func TestFirewall_Drop2(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("1.1.1.1/8"))
 
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("1.2.3.4"),
@@ -485,7 +478,7 @@ func TestFirewall_Drop2(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h.buildNetworks(myVpnNetworksTable, c.Certificate.Networks(), c.Certificate.UnsafeNetworks())
+	h.buildNetworks(c.Certificate.Networks(), c.Certificate.UnsafeNetworks())
 
 	c1 := cert.CachedCertificate{
 		Certificate: &dummyCert{
@@ -500,7 +493,7 @@ func TestFirewall_Drop2(t *testing.T) {
 			peerCert: &c1,
 		},
 	}
-	h1.buildNetworks(myVpnNetworksTable, c1.Certificate.Networks(), c1.Certificate.UnsafeNetworks())
+	h1.buildNetworks(c1.Certificate.Networks(), c1.Certificate.UnsafeNetworks())
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
 	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"default-group", "test-group"}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
@@ -517,8 +510,6 @@ func TestFirewall_Drop3(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("1.1.1.1/8"))
 
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("1.2.3.4"),
@@ -550,7 +541,7 @@ func TestFirewall_Drop3(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h1.buildNetworks(myVpnNetworksTable, c1.Certificate.Networks(), c1.Certificate.UnsafeNetworks())
+	h1.buildNetworks(c1.Certificate.Networks(), c1.Certificate.UnsafeNetworks())
 
 	c2 := cert.CachedCertificate{
 		Certificate: &dummyCert{
@@ -565,7 +556,7 @@ func TestFirewall_Drop3(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h2.buildNetworks(myVpnNetworksTable, c2.Certificate.Networks(), c2.Certificate.UnsafeNetworks())
+	h2.buildNetworks(c2.Certificate.Networks(), c2.Certificate.UnsafeNetworks())
 
 	c3 := cert.CachedCertificate{
 		Certificate: &dummyCert{
@@ -580,7 +571,7 @@ func TestFirewall_Drop3(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h3.buildNetworks(myVpnNetworksTable, c3.Certificate.Networks(), c3.Certificate.UnsafeNetworks())
+	h3.buildNetworks(c3.Certificate.Networks(), c3.Certificate.UnsafeNetworks())
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
 	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 1, 1, []string{}, "host1", netip.Prefix{}, netip.Prefix{}, "", ""))
@@ -606,8 +597,6 @@ func TestFirewall_Drop3V6(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("fd00::/7"))
 
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("fd12::34"),
@@ -631,7 +620,7 @@ func TestFirewall_Drop3V6(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h.buildNetworks(myVpnNetworksTable, c.Certificate.Networks(), c.Certificate.UnsafeNetworks())
+	h.buildNetworks(c.Certificate.Networks(), c.Certificate.UnsafeNetworks())
 
 	// Test a remote address match
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
@@ -644,8 +633,6 @@ func TestFirewall_DropConntrackReload(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("1.1.1.1/8"))
 
 	p := firewall.Packet{
 		LocalAddr:  netip.MustParseAddr("1.2.3.4"),
@@ -672,7 +659,7 @@ func TestFirewall_DropConntrackReload(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{network.Addr()},
 	}
-	h.buildNetworks(myVpnNetworksTable, c.Certificate.Networks(), c.Certificate.UnsafeNetworks())
+	h.buildNetworks(c.Certificate.Networks(), c.Certificate.UnsafeNetworks())
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
 	require.NoError(t, fw.AddRule(true, firewall.ProtoAny, 0, 0, []string{"any"}, "", netip.Prefix{}, netip.Prefix{}, "", ""))
@@ -709,8 +696,6 @@ func TestFirewall_DropIPSpoofing(t *testing.T) {
 	l := test.NewLogger()
 	ob := &bytes.Buffer{}
 	l.SetOutput(ob)
-	myVpnNetworksTable := new(bart.Lite)
-	myVpnNetworksTable.Insert(netip.MustParsePrefix("192.0.2.1/24"))
 
 	c := cert.CachedCertificate{
 		Certificate: &dummyCert{
@@ -732,7 +717,7 @@ func TestFirewall_DropIPSpoofing(t *testing.T) {
 		},
 		vpnAddrs: []netip.Addr{c1.Certificate.Networks()[0].Addr()},
 	}
-	h1.buildNetworks(myVpnNetworksTable, c1.Certificate.Networks(), c1.Certificate.UnsafeNetworks())
+	h1.buildNetworks(c1.Certificate.Networks(), c1.Certificate.UnsafeNetworks())
 
 	fw := NewFirewall(l, time.Second, time.Minute, time.Hour, c.Certificate)
 

handshake_ix.go

@@ -183,18 +183,17 @@ func ixHandshakeStage1(f *Interface, addr netip.AddrPort, via *ViaSender, packet
 		return
 	}
 
+	var vpnAddrs []netip.Addr
+	var filteredNetworks []netip.Prefix
 	certName := remoteCert.Certificate.Name()
 	certVersion := remoteCert.Certificate.Version()
 	fingerprint := remoteCert.Fingerprint
 	issuer := remoteCert.Certificate.Issuer()
-	vpnNetworks := remoteCert.Certificate.Networks()
 
-	anyVpnAddrsInCommon := false
+	for _, network := range remoteCert.Certificate.Networks() {
-	vpnAddrs := make([]netip.Addr, len(vpnNetworks))
-	for i, network := range vpnNetworks {
 		vpnAddr := network.Addr()
 		if f.myVpnAddrsTable.Contains(vpnAddr) {
-			f.l.WithField("vpnNetworks", vpnNetworks).WithField("udpAddr", addr).
+			f.l.WithField("vpnAddr", vpnAddr).WithField("udpAddr", addr).
 				WithField("certName", certName).
 				WithField("certVersion", certVersion).
 				WithField("fingerprint", fingerprint).
@@ -202,10 +201,24 @@ func ixHandshakeStage1(f *Interface, addr netip.AddrPort, via *ViaSender, packet
 				WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).Error("Refusing to handshake with myself")
 			return
 		}
-		vpnAddrs[i] = network.Addr()
+
-		if f.myVpnNetworksTable.Contains(vpnAddr) {
+		// vpnAddrs outside our vpn networks are of no use to us, filter them out
-			anyVpnAddrsInCommon = true
+		if !f.myVpnNetworksTable.Contains(vpnAddr) {
+			continue
 		}
+
+		filteredNetworks = append(filteredNetworks, network)
+		vpnAddrs = append(vpnAddrs, vpnAddr)
+	}
+
+	if len(vpnAddrs) == 0 {
+		f.l.WithError(err).WithField("udpAddr", addr).
+			WithField("certName", certName).
+			WithField("certVersion", certVersion).
+			WithField("fingerprint", fingerprint).
+			WithField("issuer", issuer).
+			WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).Error("No usable vpn addresses from host, refusing handshake")
+		return
 	}
 
 	if addr.IsValid() {
@@ -242,30 +255,26 @@ func ixHandshakeStage1(f *Interface, addr netip.AddrPort, via *ViaSender, packet
 		},
 	}
 
-	msgRxL := f.l.WithFields(m{
+	f.l.WithField("vpnAddrs", vpnAddrs).WithField("udpAddr", addr).
-		"vpnAddrs":       vpnAddrs,
+		WithField("certName", certName).
-		"udpAddr":        addr,
+		WithField("certVersion", certVersion).
-		"certName":       certName,
+		WithField("fingerprint", fingerprint).
-		"certVersion":    certVersion,
+		WithField("issuer", issuer).
-		"fingerprint":    fingerprint,
+		WithField("initiatorIndex", hs.Details.InitiatorIndex).WithField("responderIndex", hs.Details.ResponderIndex).
-		"issuer":         issuer,
+		WithField("remoteIndex", h.RemoteIndex).WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).
-		"initiatorIndex": hs.Details.InitiatorIndex,
+		Info("Handshake message received")
-		"responderIndex": hs.Details.ResponderIndex,
-		"remoteIndex":    h.RemoteIndex,
-		"handshake":      m{"stage": 1, "style": "ix_psk0"},
-	})
-
-	if anyVpnAddrsInCommon {
-		msgRxL.Info("Handshake message received")
-	} else {
-		//todo warn if not lighthouse or relay?
-		msgRxL.Info("Handshake message received, but no vpnNetworks in common.")
-	}
 
 	hs.Details.ResponderIndex = myIndex
 	hs.Details.Cert = cs.getHandshakeBytes(ci.myCert.Version())
 	if hs.Details.Cert == nil {
-		msgRxL.WithField("myCertVersion", ci.myCert.Version()).
+		f.l.WithField("vpnAddrs", vpnAddrs).WithField("udpAddr", addr).
+			WithField("certName", certName).
+			WithField("certVersion", certVersion).
+			WithField("fingerprint", fingerprint).
+			WithField("issuer", issuer).
+			WithField("initiatorIndex", hs.Details.InitiatorIndex).WithField("responderIndex", hs.Details.ResponderIndex).
+			WithField("remoteIndex", h.RemoteIndex).WithField("handshake", m{"stage": 1, "style": "ix_psk0"}).
+			WithField("certVersion", ci.myCert.Version()).
 			Error("Unable to handshake with host because no certificate handshake bytes is available")
 		return
 	}
@@ -323,7 +332,7 @@ func ixHandshakeStage1(f *Interface, addr netip.AddrPort, via *ViaSender, packet
 
 	hostinfo.remotes = f.lightHouse.QueryCache(vpnAddrs)
 	hostinfo.SetRemote(addr)
-	hostinfo.buildNetworks(f.myVpnNetworksTable, remoteCert.Certificate.Networks(), remoteCert.Certificate.UnsafeNetworks())
+	hostinfo.buildNetworks(filteredNetworks, remoteCert.Certificate.UnsafeNetworks())
 
 	existing, err := f.handshakeManager.CheckAndComplete(hostinfo, 0, f)
 	if err != nil {
@@ -564,17 +573,30 @@ func ixHandshakeStage2(f *Interface, addr netip.AddrPort, via *ViaSender, hh *Ha
 		hostinfo.relayState.InsertRelayTo(via.relayHI.vpnAddrs[0])
 	}
 
-	anyVpnAddrsInCommon := false
+	var vpnAddrs []netip.Addr
-	vpnAddrs := make([]netip.Addr, len(vpnNetworks))
+	var filteredNetworks []netip.Prefix
-	for i, network := range vpnNetworks {
+	for _, network := range vpnNetworks {
-		vpnAddrs[i] = network.Addr()
+		// vpnAddrs outside our vpn networks are of no use to us, filter them out
-		if f.myVpnNetworksTable.Contains(network.Addr()) {
+		vpnAddr := network.Addr()
-			anyVpnAddrsInCommon = true
+		if !f.myVpnNetworksTable.Contains(vpnAddr) {
+			continue
 		}
+
+		filteredNetworks = append(filteredNetworks, network)
+		vpnAddrs = append(vpnAddrs, vpnAddr)
+	}
+
+	if len(vpnAddrs) == 0 {
+		f.l.WithError(err).WithField("udpAddr", addr).
+			WithField("certName", certName).
+			WithField("certVersion", certVersion).
+			WithField("fingerprint", fingerprint).
+			WithField("issuer", issuer).
+			WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).Error("No usable vpn addresses from host, refusing handshake")
+		return true
 	}
 
 	// Ensure the right host responded
-	// todo is it more correct to see if any of hostinfo.vpnAddrs are in the cert? it should have len==1, but one day it might not?
 	if !slices.Contains(vpnAddrs, hostinfo.vpnAddrs[0]) {
 		f.l.WithField("intendedVpnAddrs", hostinfo.vpnAddrs).WithField("haveVpnNetworks", vpnNetworks).
 			WithField("udpAddr", addr).
@@ -587,7 +609,6 @@ func ixHandshakeStage2(f *Interface, addr netip.AddrPort, via *ViaSender, hh *Ha
 		f.handshakeManager.DeleteHostInfo(hostinfo)
 
 		// Create a new hostinfo/handshake for the intended vpn ip
-		//TODO is hostinfo.vpnAddrs[0] always the address to use?
 		f.handshakeManager.StartHandshake(hostinfo.vpnAddrs[0], func(newHH *HandshakeHostInfo) {
 			// Block the current used address
 			newHH.hostinfo.remotes = hostinfo.remotes
@@ -614,7 +635,7 @@ func ixHandshakeStage2(f *Interface, addr netip.AddrPort, via *ViaSender, hh *Ha
 	ci.window.Update(f.l, 2)
 
 	duration := time.Since(hh.startTime).Nanoseconds()
-	msgRxL := f.l.WithField("vpnAddrs", vpnAddrs).WithField("udpAddr", addr).
+	f.l.WithField("vpnAddrs", vpnAddrs).WithField("udpAddr", addr).
 		WithField("certName", certName).
 		WithField("certVersion", certVersion).
 		WithField("fingerprint", fingerprint).
@@ -622,17 +643,12 @@ func ixHandshakeStage2(f *Interface, addr netip.AddrPort, via *ViaSender, hh *Ha
 		WithField("initiatorIndex", hs.Details.InitiatorIndex).WithField("responderIndex", hs.Details.ResponderIndex).
 		WithField("remoteIndex", h.RemoteIndex).WithField("handshake", m{"stage": 2, "style": "ix_psk0"}).
 		WithField("durationNs", duration).
-		WithField("sentCachedPackets", len(hh.packetStore))
+		WithField("sentCachedPackets", len(hh.packetStore)).
-	if anyVpnAddrsInCommon {
+		Info("Handshake message received")
-		msgRxL.Info("Handshake message received")
-	} else {
-		//todo warn if not lighthouse or relay?
-		msgRxL.Info("Handshake message received, but no vpnNetworks in common.")
-	}
 
 	// Build up the radix for the firewall if we have subnets in the cert
 	hostinfo.vpnAddrs = vpnAddrs
-	hostinfo.buildNetworks(f.myVpnNetworksTable, remoteCert.Certificate.Networks(), remoteCert.Certificate.UnsafeNetworks())
+	hostinfo.buildNetworks(filteredNetworks, remoteCert.Certificate.UnsafeNetworks())
 
 	// Complete our handshake and update metrics, this will replace any existing tunnels for the vpnAddrs here
 	f.handshakeManager.Complete(hostinfo, f)

hostmap.go

@@ -212,18 +212,6 @@ func (rs *RelayState) InsertRelay(ip netip.Addr, idx uint32, r *Relay) {
 	rs.relayForByIdx[idx] = r
 }
 
-type NetworkType uint8
-
-const (
-	NetworkTypeUnknown NetworkType = iota
-	// NetworkTypeVPN is a network that overlaps one or more of the vpnNetworks in our certificate
-	NetworkTypeVPN
-	// NetworkTypeVPNPeer is a network that does not overlap one of our networks
-	NetworkTypeVPNPeer
-	// NetworkTypeUnsafe is a network from Certificate.UnsafeNetworks()
-	NetworkTypeUnsafe
-)
-
 type HostInfo struct {
 	remote          netip.AddrPort
 	remotes         *RemoteList
@@ -232,11 +220,13 @@ type HostInfo struct {
 	remoteIndexId   uint32
 	localIndexId    uint32
 
-	// vpnAddrs is a list of vpn addresses assigned to this host
+	// vpnAddrs is a list of vpn addresses assigned to this host that are within our own vpn networks
+	// The host may have other vpn addresses that are outside our
+	// vpn networks but were removed because they are not usable
 	vpnAddrs []netip.Addr
 
-	// networks is a combination of specific vpn addresses (not prefixes!) and full unsafe networks assigned to this host.
+	// networks are both all vpn and unsafe networks assigned to this host
-	networks   *bart.Table[NetworkType]
+	networks   *bart.Lite
 	relayState RelayState
 
 	// HandshakePacket records the packets used to create this hostinfo
@@ -740,27 +730,20 @@ func (i *HostInfo) SetRemoteIfPreferred(hm *HostMap, newRemote netip.AddrPort) b
 	return false
 }
 
-func (i *HostInfo) buildNetworks(myVpnNetworksTable *bart.Lite, networks, unsafeNetworks []netip.Prefix) {
+func (i *HostInfo) buildNetworks(networks, unsafeNetworks []netip.Prefix) {
 	if len(networks) == 1 && len(unsafeNetworks) == 0 {
-		if myVpnNetworksTable.Contains(networks[0].Addr()) {
+		// Simple case, no CIDRTree needed
-			return // Simple case, no CIDRTree needed
+		return
-		}
 	}
 
-	i.networks = new(bart.Table[NetworkType])
+	i.networks = new(bart.Lite)
 	for _, network := range networks {
-		var nwType NetworkType
-		if myVpnNetworksTable.Contains(network.Addr()) {
-			nwType = NetworkTypeVPN
-		} else {
-			nwType = NetworkTypeVPNPeer
-		}
 		nprefix := netip.PrefixFrom(network.Addr(), network.Addr().BitLen())
-		i.networks.Insert(nprefix, nwType)
+		i.networks.Insert(nprefix)
 	}
 
 	for _, network := range unsafeNetworks {
-		i.networks.Insert(network, NetworkTypeUnsafe)
+		i.networks.Insert(network)
 	}
 }
 

interface.go

@@ -271,7 +271,10 @@ func (f *Interface) listenOut(i int) {
 	fwPacket := &firewall.Packet{}
 	nb := make([]byte, 12, 12)
 
-	li.ListenOut(func(fromUdpAddr netip.AddrPort, payload []byte) {
+	li.ListenOut(func(fromUdpAddr netip.AddrPort, payload []byte, release func()) {
+		if release != nil {
+			defer release()
+		}
 		f.readOutsidePackets(fromUdpAddr, nil, plaintext[:0], payload, h, fwPacket, lhh, nb, i, ctCache.Get(f.l))
 	})
 }

lighthouse.go

@@ -1017,17 +1017,17 @@ func (lhh *LightHouseHandler) resetMeta() *NebulaMeta {
 	return lhh.meta
 }
 
-func (lhh *LightHouseHandler) HandleRequest(rAddr netip.AddrPort, hostinfo *HostInfo, p []byte, w EncWriter) {
+func (lhh *LightHouseHandler) HandleRequest(rAddr netip.AddrPort, fromVpnAddrs []netip.Addr, p []byte, w EncWriter) {
 	n := lhh.resetMeta()
 	err := n.Unmarshal(p)
 	if err != nil {
-		lhh.l.WithError(err).WithField("vpnAddrs", hostinfo.vpnAddrs).WithField("udpAddr", rAddr).
+		lhh.l.WithError(err).WithField("vpnAddrs", fromVpnAddrs).WithField("udpAddr", rAddr).
 			Error("Failed to unmarshal lighthouse packet")
 		return
 	}
 
 	if n.Details == nil {
-		lhh.l.WithField("vpnAddrs", hostinfo.vpnAddrs).WithField("udpAddr", rAddr).
+		lhh.l.WithField("vpnAddrs", fromVpnAddrs).WithField("udpAddr", rAddr).
 			Error("Invalid lighthouse update")
 		return
 	}
@@ -1036,24 +1036,24 @@ func (lhh *LightHouseHandler) HandleRequest(rAddr netip.AddrPort, hostinfo *Host
 
 	switch n.Type {
 	case NebulaMeta_HostQuery:
-		lhh.handleHostQuery(n, hostinfo, rAddr, w)
+		lhh.handleHostQuery(n, fromVpnAddrs, rAddr, w)
 
 	case NebulaMeta_HostQueryReply:
-		lhh.handleHostQueryReply(n, hostinfo.vpnAddrs)
+		lhh.handleHostQueryReply(n, fromVpnAddrs)
 
 	case NebulaMeta_HostUpdateNotification:
-		lhh.handleHostUpdateNotification(n, hostinfo, w)
+		lhh.handleHostUpdateNotification(n, fromVpnAddrs, w)
 
 	case NebulaMeta_HostMovedNotification:
 	case NebulaMeta_HostPunchNotification:
-		lhh.handleHostPunchNotification(n, hostinfo.vpnAddrs, w)
+		lhh.handleHostPunchNotification(n, fromVpnAddrs, w)
 
 	case NebulaMeta_HostUpdateNotificationAck:
 		// noop
 	}
 }
 
-func (lhh *LightHouseHandler) handleHostQuery(n *NebulaMeta, hostinfo *HostInfo, addr netip.AddrPort, w EncWriter) {
+func (lhh *LightHouseHandler) handleHostQuery(n *NebulaMeta, fromVpnAddrs []netip.Addr, addr netip.AddrPort, w EncWriter) {
 	// Exit if we don't answer queries
 	if !lhh.lh.amLighthouse {
 		if lhh.l.Level >= logrus.DebugLevel {
@@ -1065,7 +1065,7 @@ func (lhh *LightHouseHandler) handleHostQuery(n *NebulaMeta, hostinfo *HostInfo,
 	queryVpnAddr, useVersion, err := n.Details.GetVpnAddrAndVersion()
 	if err != nil {
 		if lhh.l.Level >= logrus.DebugLevel {
-			lhh.l.WithField("from", hostinfo.vpnAddrs).WithField("details", n.Details).
+			lhh.l.WithField("from", fromVpnAddrs).WithField("details", n.Details).
 				Debugln("Dropping malformed HostQuery")
 		}
 		return
@@ -1073,7 +1073,7 @@ func (lhh *LightHouseHandler) handleHostQuery(n *NebulaMeta, hostinfo *HostInfo,
 	if useVersion == cert.Version1 && queryVpnAddr.Is6() {
 		// this case really shouldn't be possible to represent, but reject it anyway.
 		if lhh.l.Level >= logrus.DebugLevel {
-			lhh.l.WithField("vpnAddrs", hostinfo.vpnAddrs).WithField("queryVpnAddr", queryVpnAddr).
+			lhh.l.WithField("vpnAddrs", fromVpnAddrs).WithField("queryVpnAddr", queryVpnAddr).
 				Debugln("invalid vpn addr for v1 handleHostQuery")
 		}
 		return
@@ -1099,14 +1099,14 @@ func (lhh *LightHouseHandler) handleHostQuery(n *NebulaMeta, hostinfo *HostInfo,
 	}
 
 	if err != nil {
-		lhh.l.WithError(err).WithField("vpnAddrs", hostinfo.vpnAddrs).Error("Failed to marshal lighthouse host query reply")
+		lhh.l.WithError(err).WithField("vpnAddrs", fromVpnAddrs).Error("Failed to marshal lighthouse host query reply")
 		return
 	}
 
 	lhh.lh.metricTx(NebulaMeta_HostQueryReply, 1)
-	w.SendMessageToHostInfo(header.LightHouse, 0, hostinfo, lhh.pb[:ln], lhh.nb, lhh.out[:0])
+	w.SendMessageToVpnAddr(header.LightHouse, 0, fromVpnAddrs[0], lhh.pb[:ln], lhh.nb, lhh.out[:0])
 
-	lhh.sendHostPunchNotification(n, hostinfo.vpnAddrs, queryVpnAddr, w)
+	lhh.sendHostPunchNotification(n, fromVpnAddrs, queryVpnAddr, w)
 }
 
 // sendHostPunchNotification signals the other side to punch some zero byte udp packets
@@ -1115,34 +1115,20 @@ func (lhh *LightHouseHandler) sendHostPunchNotification(n *NebulaMeta, fromVpnAd
 	found, ln, err := lhh.lh.queryAndPrepMessage(whereToPunch, func(c *cache) (int, error) {
 		n = lhh.resetMeta()
 		n.Type = NebulaMeta_HostPunchNotification
-		punchNotifDestHI := lhh.lh.ifce.GetHostInfo(punchNotifDest)
+		targetHI := lhh.lh.ifce.GetHostInfo(punchNotifDest)
 		var useVersion cert.Version
-		if punchNotifDestHI == nil {
+		if targetHI == nil {
 			useVersion = lhh.lh.ifce.GetCertState().initiatingVersion
 		} else {
+			crt := targetHI.GetCert().Certificate
+			useVersion = crt.Version()
 			// we can only retarget if we have a hostinfo
-			punchNotifDestCrt := punchNotifDestHI.GetCert().Certificate
+			newDest, ok := findNetworkUnion(crt.Networks(), fromVpnAddrs)
-			useVersion = punchNotifDestCrt.Version()
-			punchNotifDestNetworks := punchNotifDestCrt.Networks()
-
-			//if we (the lighthouse) don't have a network in common with punchNotifDest, try to find one
-			if !lhh.lh.myVpnNetworksTable.Contains(punchNotifDest) {
-				newPunchNotifDest, ok := findNetworkUnion(lhh.lh.myVpnNetworks, punchNotifDestHI.vpnAddrs)
-				if ok {
-					punchNotifDest = newPunchNotifDest
-				} else {
-					if lhh.l.Level >= logrus.DebugLevel {
-						lhh.l.WithField("to", punchNotifDestNetworks).Debugln("unable to notify host to host, no addresses in common")
-					}
-				}
-			}
-
-			newWhereToPunch, ok := findNetworkUnion(punchNotifDestNetworks, fromVpnAddrs)
 			if ok {
-				whereToPunch = newWhereToPunch
+				whereToPunch = newDest
 			} else {
 				if lhh.l.Level >= logrus.DebugLevel {
-					lhh.l.WithFields(m{"from": fromVpnAddrs, "to": punchNotifDestNetworks}).Debugln("unable to punch to host, no addresses in common with requestor")
+					lhh.l.WithField("to", crt.Networks()).Debugln("unable to punch to host, no addresses in common")
 				}
 			}
 		}
@@ -1248,8 +1234,7 @@ func (lhh *LightHouseHandler) handleHostQueryReply(n *NebulaMeta, fromVpnAddrs [
 	}
 }
 
-func (lhh *LightHouseHandler) handleHostUpdateNotification(n *NebulaMeta, hostinfo *HostInfo, w EncWriter) {
+func (lhh *LightHouseHandler) handleHostUpdateNotification(n *NebulaMeta, fromVpnAddrs []netip.Addr, w EncWriter) {
-	fromVpnAddrs := hostinfo.vpnAddrs
 	if !lhh.lh.amLighthouse {
 		if lhh.l.Level >= logrus.DebugLevel {
 			lhh.l.Debugln("I am not a lighthouse, do not take host updates: ", fromVpnAddrs)
@@ -1317,7 +1302,7 @@ func (lhh *LightHouseHandler) handleHostUpdateNotification(n *NebulaMeta, hostin
 	}
 
 	lhh.lh.metricTx(NebulaMeta_HostUpdateNotificationAck, 1)
-	w.SendMessageToHostInfo(header.LightHouse, 0, hostinfo, lhh.pb[:ln], lhh.nb, lhh.out[:0])
+	w.SendMessageToVpnAddr(header.LightHouse, 0, fromVpnAddrs[0], lhh.pb[:ln], lhh.nb, lhh.out[:0])
 }
 
 func (lhh *LightHouseHandler) handleHostPunchNotification(n *NebulaMeta, fromVpnAddrs []netip.Addr, w EncWriter) {

lighthouse_test.go

@@ -132,13 +132,8 @@ func BenchmarkLighthouseHandleRequest(b *testing.B) {
 	)
 
 	mw := &mockEncWriter{}
-	hostinfo := &HostInfo{
+
-		ConnectionState: &ConnectionState{
+	hi := []netip.Addr{vpnIp2}
-			eKey: nil,
-			dKey: nil,
-		},
-		vpnAddrs: []netip.Addr{vpnIp2},
-	}
 	b.Run("notfound", func(b *testing.B) {
 		lhh := lh.NewRequestHandler()
 		req := &NebulaMeta{
@@ -151,7 +146,7 @@ func BenchmarkLighthouseHandleRequest(b *testing.B) {
 		p, err := req.Marshal()
 		require.NoError(b, err)
 		for n := 0; n < b.N; n++ {
-			lhh.HandleRequest(rAddr, hostinfo, p, mw)
+			lhh.HandleRequest(rAddr, hi, p, mw)
 		}
 	})
 	b.Run("found", func(b *testing.B) {
@@ -167,7 +162,7 @@ func BenchmarkLighthouseHandleRequest(b *testing.B) {
 		require.NoError(b, err)
 
 		for n := 0; n < b.N; n++ {
-			lhh.HandleRequest(rAddr, hostinfo, p, mw)
+			lhh.HandleRequest(rAddr, hi, p, mw)
 		}
 	})
 }
@@ -331,14 +326,7 @@ func newLHHostRequest(fromAddr netip.AddrPort, myVpnIp, queryVpnIp netip.Addr, l
 	w := &testEncWriter{
 		metaFilter: &filter,
 	}
-	hostinfo := &HostInfo{
+	lhh.HandleRequest(fromAddr, []netip.Addr{myVpnIp}, b, w)
-		ConnectionState: &ConnectionState{
-			eKey: nil,
-			dKey: nil,
-		},
-		vpnAddrs: []netip.Addr{myVpnIp},
-	}
-	lhh.HandleRequest(fromAddr, hostinfo, b, w)
 	return w.lastReply
 }
 
@@ -367,15 +355,9 @@ func newLHHostUpdate(fromAddr netip.AddrPort, vpnIp netip.Addr, addrs []netip.Ad
 	if err != nil {
 		panic(err)
 	}
-	hostinfo := &HostInfo{
+
-		ConnectionState: &ConnectionState{
-			eKey: nil,
-			dKey: nil,
-		},
-		vpnAddrs: []netip.Addr{vpnIp},
-	}
 	w := &testEncWriter{}
-	lhh.HandleRequest(fromAddr, hostinfo, b, w)
+	lhh.HandleRequest(fromAddr, []netip.Addr{vpnIp}, b, w)
 }
 
 type testLhReply struct {

outside.go

@@ -138,7 +138,7 @@ func (f *Interface) readOutsidePackets(ip netip.AddrPort, via *ViaSender, out []
 			return
 		}
 
-		lhf.HandleRequest(ip, hostinfo, d, f)
+		lhf.HandleRequest(ip, hostinfo.vpnAddrs, d, f)
 
 		// Fallthrough to the bottom to record incoming traffic
 

udp/config.go

@@ -0,0 +1,16 @@
+package udp
+
+import "sync/atomic"
+
+var disableUDPCsum atomic.Bool
+
+// SetDisableUDPCsum controls whether IPv4 UDP sockets opt out of kernel
+// checksum calculation via SO_NO_CHECK. Only applicable on platforms that
+// support the option (Linux). IPv6 always keeps the checksum enabled.
+func SetDisableUDPCsum(disable bool) {
+	disableUDPCsum.Store(disable)
+}
+
+func udpChecksumDisabled() bool {
+	return disableUDPCsum.Load()
+}

udp/conn.go

@@ -11,6 +11,7 @@ const MTU = 9001
 type EncReader func(
 	addr netip.AddrPort,
 	payload []byte,
+	release func(),
 )
 
 type Conn interface {

udp/msghdr_helper_linux_32.go

@@ -0,0 +1,25 @@
+//go:build linux && (386 || amd64p32 || arm || mips || mipsle) && !android && !e2e_testing
+// +build linux
+// +build 386 amd64p32 arm mips mipsle
+// +build !android
+// +build !e2e_testing
+
+package udp
+
+import "golang.org/x/sys/unix"
+
+func controllen(n int) uint32 {
+	return uint32(n)
+}
+
+func setCmsgLen(h *unix.Cmsghdr, n int) {
+	h.Len = uint32(unix.CmsgLen(n))
+}
+
+func setIovecLen(v *unix.Iovec, n int) {
+	v.Len = uint32(n)
+}
+
+func setMsghdrIovlen(m *unix.Msghdr, n int) {
+	m.Iovlen = uint32(n)
+}

udp/msghdr_helper_linux_64.go

@@ -0,0 +1,25 @@
+//go:build linux && (amd64 || arm64 || ppc64 || ppc64le || mips64 || mips64le || s390x || riscv64 || loong64) && !android && !e2e_testing
+// +build linux
+// +build amd64 arm64 ppc64 ppc64le mips64 mips64le s390x riscv64 loong64
+// +build !android
+// +build !e2e_testing
+
+package udp
+
+import "golang.org/x/sys/unix"
+
+func controllen(n int) uint64 {
+	return uint64(n)
+}
+
+func setCmsgLen(h *unix.Cmsghdr, n int) {
+	h.Len = uint64(unix.CmsgLen(n))
+}
+
+func setIovecLen(v *unix.Iovec, n int) {
+	v.Len = uint64(n)
+}
+
+func setMsghdrIovlen(m *unix.Msghdr, n int) {
+	m.Iovlen = uint64(n)
+}

udp/sendmmsg_linux_32.go

@@ -0,0 +1,25 @@
+//go:build linux && (386 || amd64p32 || arm || mips || mipsle) && !android && !e2e_testing
+
+package udp
+
+import (
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+type linuxMmsgHdr struct {
+	Hdr unix.Msghdr
+	Len uint32
+}
+
+func sendmmsg(fd int, hdrs []linuxMmsgHdr, flags int) (int, error) {
+	if len(hdrs) == 0 {
+		return 0, nil
+	}
+	n, _, errno := unix.Syscall6(unix.SYS_SENDMMSG, uintptr(fd), uintptr(unsafe.Pointer(&hdrs[0])), uintptr(len(hdrs)), uintptr(flags), 0, 0)
+	if errno != 0 {
+		return int(n), errno
+	}
+	return int(n), nil
+}

udp/sendmmsg_linux_64.go

@@ -0,0 +1,26 @@
+//go:build linux && (amd64 || arm64 || ppc64 || ppc64le || mips64 || mips64le || s390x || riscv64 || loong64) && !android && !e2e_testing
+
+package udp
+
+import (
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+type linuxMmsgHdr struct {
+	Hdr unix.Msghdr
+	Len uint32
+	_   uint32
+}
+
+func sendmmsg(fd int, hdrs []linuxMmsgHdr, flags int) (int, error) {
+	if len(hdrs) == 0 {
+		return 0, nil
+	}
+	n, _, errno := unix.Syscall6(unix.SYS_SENDMMSG, uintptr(fd), uintptr(unsafe.Pointer(&hdrs[0])), uintptr(len(hdrs)), uintptr(flags), 0, 0)
+	if errno != 0 {
+		return int(n), errno
+	}
+	return int(n), nil
+}

udp/udp_darwin.go

@@ -180,7 +180,7 @@ func (u *StdConn) ListenOut(r EncReader) {
 			u.l.WithError(err).Error("unexpected udp socket receive error")
 		}
 
-		r(netip.AddrPortFrom(rua.Addr().Unmap(), rua.Port()), buffer[:n])
+		r(netip.AddrPortFrom(rua.Addr().Unmap(), rua.Port()), buffer[:n], nil)
 	}
 }
 

udp/udp_generic.go

@@ -82,6 +82,6 @@ func (u *GenericConn) ListenOut(r EncReader) {
 			return
 		}
 
-		r(netip.AddrPortFrom(rua.Addr().Unmap(), rua.Port()), buffer[:n])
+		r(netip.AddrPortFrom(rua.Addr().Unmap(), rua.Port()), buffer[:n], nil)
 	}
 }

udp/udp_linux_32.go

@@ -7,6 +7,9 @@
 package udp
 
 import (
+	"errors"
+	"fmt"
+
 	"golang.org/x/sys/unix"
 )
 
@@ -30,17 +33,29 @@ type rawMessage struct {
 	Len uint32
 }
 
-func (u *StdConn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte) {
+func (u *StdConn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte, [][]byte) {
+	controlLen := int(u.controlLen.Load())
+
 	msgs := make([]rawMessage, n)
 	buffers := make([][]byte, n)
 	names := make([][]byte, n)
 
+	var controls [][]byte
+	if controlLen > 0 {
+		controls = make([][]byte, n)
+	}
+
 	for i := range msgs {
-		buffers[i] = make([]byte, MTU)
+		size := int(u.groBufSize.Load())
+		if size < MTU {
+			size = MTU
+		}
+		buf := u.borrowRxBuffer(size)
+		buffers[i] = buf
 		names[i] = make([]byte, unix.SizeofSockaddrInet6)
 
 		vs := []iovec{
-			{Base: &buffers[i][0], Len: uint32(len(buffers[i]))},
+			{Base: &buf[0], Len: uint32(len(buf))},
 		}
 
 		msgs[i].Hdr.Iov = &vs[0]
@@ -48,7 +63,71 @@ func (u *StdConn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte) {
 
 		msgs[i].Hdr.Name = &names[i][0]
 		msgs[i].Hdr.Namelen = uint32(len(names[i]))
+
+		if controlLen > 0 {
+			controls[i] = make([]byte, controlLen)
+			msgs[i].Hdr.Control = &controls[i][0]
+			msgs[i].Hdr.Controllen = controllen(len(controls[i]))
+		} else {
+			msgs[i].Hdr.Control = nil
+			msgs[i].Hdr.Controllen = controllen(0)
+		}
 	}
 
-	return msgs, buffers, names
+	return msgs, buffers, names, controls
+}
+
+func setIovecBase(msg *rawMessage, buf []byte) {
+	iov := (*iovec)(msg.Hdr.Iov)
+	iov.Base = &buf[0]
+	iov.Len = uint32(len(buf))
+}
+
+func rawMessageToUnixMsghdr(msg *rawMessage) (unix.Msghdr, unix.Iovec, error) {
+	var hdr unix.Msghdr
+	var iov unix.Iovec
+	if msg == nil {
+		return hdr, iov, errors.New("nil rawMessage")
+	}
+	if msg.Hdr.Iov == nil || msg.Hdr.Iov.Base == nil {
+		return hdr, iov, errors.New("rawMessage missing payload buffer")
+	}
+	payloadLen := int(msg.Hdr.Iov.Len)
+	if payloadLen < 0 {
+		return hdr, iov, fmt.Errorf("invalid payload length: %d", payloadLen)
+	}
+	iov.Base = msg.Hdr.Iov.Base
+	iov.Len = uint32(payloadLen)
+	hdr.Iov = &iov
+	hdr.Iovlen = 1
+	hdr.Name = msg.Hdr.Name
+	// CRITICAL: Always set to full buffer size for receive, not what kernel wrote last time
+	if hdr.Name != nil {
+		hdr.Namelen = uint32(unix.SizeofSockaddrInet6)
+	} else {
+		hdr.Namelen = 0
+	}
+	hdr.Control = msg.Hdr.Control
+	// CRITICAL: Use the allocated size, not what was previously returned
+	if hdr.Control != nil {
+		// Control buffer size is stored in Controllen from PrepareRawMessages
+		hdr.Controllen = msg.Hdr.Controllen
+	} else {
+		hdr.Controllen = 0
+	}
+	hdr.Flags = 0 // Reset flags for new receive
+	return hdr, iov, nil
+}
+
+func updateRawMessageFromUnixMsghdr(msg *rawMessage, hdr *unix.Msghdr, n int) {
+	if msg == nil || hdr == nil {
+		return
+	}
+	msg.Hdr.Namelen = hdr.Namelen
+	msg.Hdr.Controllen = hdr.Controllen
+	msg.Hdr.Flags = hdr.Flags
+	if n < 0 {
+		n = 0
+	}
+	msg.Len = uint32(n)
 }

udp/udp_linux_64.go

@@ -7,6 +7,9 @@
 package udp
 
 import (
+	"errors"
+	"fmt"
+
 	"golang.org/x/sys/unix"
 )
 
@@ -33,25 +36,99 @@ type rawMessage struct {
 	Pad0 [4]byte
 }
 
-func (u *StdConn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte) {
+func (u *StdConn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte, [][]byte) {
+	controlLen := int(u.controlLen.Load())
+
 	msgs := make([]rawMessage, n)
 	buffers := make([][]byte, n)
 	names := make([][]byte, n)
 
+	var controls [][]byte
+	if controlLen > 0 {
+		controls = make([][]byte, n)
+	}
+
 	for i := range msgs {
-		buffers[i] = make([]byte, MTU)
+		size := int(u.groBufSize.Load())
+		if size < MTU {
+			size = MTU
+		}
+		buf := u.borrowRxBuffer(size)
+		buffers[i] = buf
 		names[i] = make([]byte, unix.SizeofSockaddrInet6)
 
-		vs := []iovec{
+		vs := []iovec{{Base: &buf[0], Len: uint64(len(buf))}}
-			{Base: &buffers[i][0], Len: uint64(len(buffers[i]))},
-		}
 
 		msgs[i].Hdr.Iov = &vs[0]
 		msgs[i].Hdr.Iovlen = uint64(len(vs))
 
 		msgs[i].Hdr.Name = &names[i][0]
 		msgs[i].Hdr.Namelen = uint32(len(names[i]))
+
+		if controlLen > 0 {
+			controls[i] = make([]byte, controlLen)
+			msgs[i].Hdr.Control = &controls[i][0]
+			msgs[i].Hdr.Controllen = controllen(len(controls[i]))
+		} else {
+			msgs[i].Hdr.Control = nil
+			msgs[i].Hdr.Controllen = controllen(0)
+		}
 	}
 
-	return msgs, buffers, names
+	return msgs, buffers, names, controls
+}
+
+func setIovecBase(msg *rawMessage, buf []byte) {
+	iov := (*iovec)(msg.Hdr.Iov)
+	iov.Base = &buf[0]
+	iov.Len = uint64(len(buf))
+}
+
+func rawMessageToUnixMsghdr(msg *rawMessage) (unix.Msghdr, unix.Iovec, error) {
+	var hdr unix.Msghdr
+	var iov unix.Iovec
+	if msg == nil {
+		return hdr, iov, errors.New("nil rawMessage")
+	}
+	if msg.Hdr.Iov == nil || msg.Hdr.Iov.Base == nil {
+		return hdr, iov, errors.New("rawMessage missing payload buffer")
+	}
+	payloadLen := int(msg.Hdr.Iov.Len)
+	if payloadLen < 0 {
+		return hdr, iov, fmt.Errorf("invalid payload length: %d", payloadLen)
+	}
+	iov.Base = msg.Hdr.Iov.Base
+	iov.Len = uint64(payloadLen)
+	hdr.Iov = &iov
+	hdr.Iovlen = 1
+	hdr.Name = msg.Hdr.Name
+	// CRITICAL: Always set to full buffer size for receive, not what kernel wrote last time
+	if hdr.Name != nil {
+		hdr.Namelen = uint32(unix.SizeofSockaddrInet6)
+	} else {
+		hdr.Namelen = 0
+	}
+	hdr.Control = msg.Hdr.Control
+	// CRITICAL: Use the allocated size, not what was previously returned
+	if hdr.Control != nil {
+		// Control buffer size is stored in Controllen from PrepareRawMessages
+		hdr.Controllen = msg.Hdr.Controllen
+	} else {
+		hdr.Controllen = 0
+	}
+	hdr.Flags = 0 // Reset flags for new receive
+	return hdr, iov, nil
+}
+
+func updateRawMessageFromUnixMsghdr(msg *rawMessage, hdr *unix.Msghdr, n int) {
+	if msg == nil || hdr == nil {
+		return
+	}
+	msg.Hdr.Namelen = hdr.Namelen
+	msg.Hdr.Controllen = hdr.Controllen
+	msg.Hdr.Flags = hdr.Flags
+	if n < 0 {
+		n = 0
+	}
+	msg.Len = uint32(n)
 }

udp/udp_rio_windows.go

@@ -149,7 +149,7 @@ func (u *RIOConn) ListenOut(r EncReader) {
 			continue
 		}
 
-		r(netip.AddrPortFrom(netip.AddrFrom16(rua.Addr).Unmap(), (rua.Port>>8)|((rua.Port&0xff)<<8)), buffer[:n])
+		r(netip.AddrPortFrom(netip.AddrFrom16(rua.Addr).Unmap(), (rua.Port>>8)|((rua.Port&0xff)<<8)), buffer[:n], nil)
 	}
 }
 

udp/udp_tester.go

@@ -112,7 +112,7 @@ func (u *TesterConn) ListenOut(r EncReader) {
 		if !ok {
 			return
 		}
-		r(p.From, p.Data)
+		r(p.From, p.Data, func() {})
 	}
 }