5 files changed, 36 insertions, 28 deletions
diff --git a/pkg/tcpip/stack/linkaddrcache_test.go b/pkg/tcpip/stack/linkaddrcache_test.go
index 6883045b5..03b2f2d6f 100644
--- a/pkg/tcpip/stack/linkaddrcache_test.go
+++ b/pkg/tcpip/stack/linkaddrcache_test.go
@@ -83,7 +83,7 @@ func getBlocking(c *linkAddrCache, addr tcpip.FullAddress, linkRes LinkAddressRe
 		got, ch, err := c.get(addr, linkRes, "", nil, nil)
 		if err == tcpip.ErrWouldBlock {
 			if attemptedResolution {
-				return got, tcpip.ErrNoLinkAddress
+				return got, tcpip.ErrTimeout
 			}
 			attemptedResolution = true
 			<-ch
@@ -253,8 +253,8 @@ func TestCacheResolutionFailed(t *testing.T) {
 	before := atomic.LoadUint32(&requestCount)
 
 	e.addr.Addr += "2"
-	if _, err := getBlocking(c, e.addr, linkRes); err != tcpip.ErrNoLinkAddress {
-		t.Errorf("c.get(%q), got error: %v, want: error ErrNoLinkAddress", string(e.addr.Addr), err)
+	if a, err := getBlocking(c, e.addr, linkRes); err != tcpip.ErrTimeout {
+		t.Errorf("got getBlocking(_, %#v, _) = (%s, %s), want = (_, %s)", e.addr, a, err, tcpip.ErrTimeout)
 	}
 
 	if got, want := int(atomic.LoadUint32(&requestCount)-before), c.resolutionAttempts; got != want {
@@ -269,8 +269,8 @@ func TestCacheResolutionTimeout(t *testing.T) {
 	linkRes := &testLinkAddressResolver{cache: c, delay: resolverDelay}
 
 	e := testAddrs[0]
-	if _, err := getBlocking(c, e.addr, linkRes); err != tcpip.ErrNoLinkAddress {
-		t.Errorf("c.get(%q), got error: %v, want: error ErrNoLinkAddress", string(e.addr.Addr), err)
+	if a, err := getBlocking(c, e.addr, linkRes); err != tcpip.ErrTimeout {
+		t.Errorf("got getBlocking(_, %#v, _) = (%s, %s), want = (_, %s)", e.addr, a, err, tcpip.ErrTimeout)
 	}
 }
 
diff --git a/pkg/tcpip/stack/packet_buffer.go b/pkg/tcpip/stack/packet_buffer.go
index 664cc6fa0..5f216ca21 100644
--- a/pkg/tcpip/stack/packet_buffer.go
+++ b/pkg/tcpip/stack/packet_buffer.go
@@ -268,17 +268,6 @@ func (pk *PacketBuffer) Clone() *PacketBuffer {
 	}
 }
 
-// SourceLinkAddress returns the source link address of the packet.
-func (pk *PacketBuffer) SourceLinkAddress() tcpip.LinkAddress {
-	link := pk.LinkHeader().View()
-
-	if link.IsEmpty() {
-		return ""
-	}
-
-	return header.Ethernet(link).SourceAddress()
-}
-
 // Network returns the network header as a header.Network.
 //
 // Network should only be called when NetworkHeader has been set.
diff --git a/pkg/tcpip/stack/pending_packets.go b/pkg/tcpip/stack/pending_packets.go
index 4a3adcf33..bded8814e 100644
--- a/pkg/tcpip/stack/pending_packets.go
+++ b/pkg/tcpip/stack/pending_packets.go
@@ -101,10 +101,12 @@ func (f *packetsPendingLinkResolution) enqueue(ch <-chan struct{}, r *Route, pro
 		}
 
 		for _, p := range packets {
-			if cancelled {
-				p.route.Stats().IP.OutgoingPacketErrors.Increment()
-			} else if p.route.IsResolutionRequired() {
+			if cancelled || p.route.IsResolutionRequired() {
 				p.route.Stats().IP.OutgoingPacketErrors.Increment()
+
+				if linkResolvableEP, ok := p.route.outgoingNIC.getNetworkEndpoint(p.route.NetProto).(LinkResolvableNetworkEndpoint); ok {
+					linkResolvableEP.HandleLinkResolutionFailure(pkt)
+				}
 			} else {
 				p.route.outgoingNIC.writePacket(p.route, nil /* gso */, p.proto, p.pkt)
 			}
diff --git a/pkg/tcpip/stack/registration.go b/pkg/tcpip/stack/registration.go
index 4795208b4..924790779 100644
--- a/pkg/tcpip/stack/registration.go
+++ b/pkg/tcpip/stack/registration.go
@@ -55,7 +55,19 @@ type ControlType int
 // The following are the allowed values for ControlType values.
 // TODO(http://gvisor.dev/issue/3210): Support time exceeded messages.
 const (
-	ControlNetworkUnreachable ControlType = iota
+	// ControlAddressUnreachable indicates that an IPv6 packet did not reach its
+	// destination as the destination address was unreachable.
+	//
+	// This maps to the ICMPv6 Destination Ureachable Code 3 error; see
+	// RFC 4443 section 3.1 for more details.
+	ControlAddressUnreachable ControlType = iota
+	ControlNetworkUnreachable
+	// ControlNoRoute indicates that an IPv4 packet did not reach its destination
+	// because the destination host was unreachable.
+	//
+	// This maps to the ICMPv4 Destination Ureachable Code 1 error; see
+	// RFC 791's Destination Unreachable Message section (page 4) for more
+	// details.
 	ControlNoRoute
 	ControlPacketTooBig
 	ControlPortUnreachable
@@ -503,6 +515,13 @@ type NetworkInterface interface {
 	WritePacketToRemote(tcpip.LinkAddress, *GSO, tcpip.NetworkProtocolNumber, *PacketBuffer) *tcpip.Error
 }
 
+// LinkResolvableNetworkEndpoint handles link resolution events.
+type LinkResolvableNetworkEndpoint interface {
+	// HandleLinkResolutionFailure is called when link resolution prevents the
+	// argument from having been sent.
+	HandleLinkResolutionFailure(*PacketBuffer)
+}
+
 // NetworkEndpoint is the interface that needs to be implemented by endpoints
 // of network layer protocols (e.g., ipv4, ipv6).
 type NetworkEndpoint interface {
diff --git a/pkg/tcpip/stack/transport_test.go b/pkg/tcpip/stack/transport_test.go
index 0ff32c6ea..a2ab7537c 100644
--- a/pkg/tcpip/stack/transport_test.go
+++ b/pkg/tcpip/stack/transport_test.go
@@ -90,14 +90,14 @@ func (*fakeTransportEndpoint) Read(io.Writer, int, tcpip.ReadOptions) (tcpip.Rea
 	return tcpip.ReadResult{}, nil
 }
 
-func (f *fakeTransportEndpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-chan struct{}, *tcpip.Error) {
+func (f *fakeTransportEndpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, *tcpip.Error) {
 	if len(f.route.RemoteAddress) == 0 {
-		return 0, nil, tcpip.ErrNoRoute
+		return 0, tcpip.ErrNoRoute
 	}
 
 	v, err := p.FullPayload()
 	if err != nil {
-		return 0, nil, err
+		return 0, err
 	}
 	pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
 		ReserveHeaderBytes: int(f.route.MaxHeaderLength()) + fakeTransHeaderLen,
@@ -105,10 +105,10 @@ func (f *fakeTransportEndpoint) Write(p tcpip.Payloader, opts tcpip.WriteOptions
 	})
 	_ = pkt.TransportHeader().Push(fakeTransHeaderLen)
 	if err := f.route.WritePacket(nil /* gso */, stack.NetworkHeaderParams{Protocol: fakeTransNumber, TTL: 123, TOS: stack.DefaultTOS}, pkt); err != nil {
-		return 0, nil, err
+		return 0, err
 	}
 
-	return int64(len(v)), nil, nil
+	return int64(len(v)), nil
 }
 
 // SetSockOpt sets a socket option. Currently not supported.
@@ -222,7 +222,6 @@ func (f *fakeTransportEndpoint) HandlePacket(id stack.TransportEndpointID, pkt *
 	if err != nil {
 		return
 	}
-	route.ResolveWith(pkt.SourceLinkAddress())
 
 	ep := &fakeTransportEndpoint{
 		TransportEndpointInfo: stack.TransportEndpointInfo{
@@ -522,8 +521,7 @@ func TestTransportSend(t *testing.T) {
 
 	// Create buffer that will hold the payload.
 	view := buffer.NewView(30)
-	_, _, err = ep.Write(tcpip.SlicePayload(view), tcpip.WriteOptions{})
-	if err != nil {
+	if _, err := ep.Write(tcpip.SlicePayload(view), tcpip.WriteOptions{}); err != nil {
 		t.Fatalf("write failed: %v", err)
 	}