4 files changed, 33 insertions, 22 deletions
diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go
index 750aa4022..95efada3a 100644
--- a/pkg/tcpip/network/ipv6/icmp.go
+++ b/pkg/tcpip/network/ipv6/icmp.go
@@ -688,25 +688,38 @@ func (*protocol) LinkAddressProtocol() tcpip.NetworkProtocolNumber {
 
 // LinkAddressRequest implements stack.LinkAddressResolver.
 func (p *protocol) LinkAddressRequest(targetAddr, localAddr tcpip.Address, remoteLinkAddr tcpip.LinkAddress, nic stack.NetworkInterface) *tcpip.Error {
+	nicID := nic.ID()
+
+	p.mu.Lock()
+	netEP, ok := p.mu.eps[nicID]
+	p.mu.Unlock()
+	if !ok {
+		return tcpip.ErrNotConnected
+	}
+
 	remoteAddr := targetAddr
 	if len(remoteLinkAddr) == 0 {
 		remoteAddr = header.SolicitedNodeAddr(targetAddr)
 		remoteLinkAddr = header.EthernetAddressFromMulticastIPv6Address(remoteAddr)
 	}
 
-	r, err := p.stack.FindRoute(nic.ID(), localAddr, remoteAddr, ProtocolNumber, false /* multicastLoop */)
-	if err != nil {
-		return err
+	if len(localAddr) == 0 {
+		addressEndpoint := netEP.AcquireOutgoingPrimaryAddress(remoteAddr, false /* allowExpired */)
+		if addressEndpoint == nil {
+			return tcpip.ErrNetworkUnreachable
+		}
+
+		localAddr = addressEndpoint.AddressWithPrefix().Address
+	} else if p.stack.CheckLocalAddress(nicID, ProtocolNumber, localAddr) == 0 {
+		return tcpip.ErrBadLocalAddress
 	}
-	defer r.Release()
-	r.ResolveWith(remoteLinkAddr)
 
 	optsSerializer := header.NDPOptionsSerializer{
 		header.NDPSourceLinkLayerAddressOption(nic.LinkAddress()),
 	}
 	neighborSolicitSize := header.ICMPv6NeighborSolicitMinimumSize + optsSerializer.Length()
 	pkt := stack.NewPacketBuffer(stack.PacketBufferOptions{
-		ReserveHeaderBytes: int(r.MaxHeaderLength()) + neighborSolicitSize,
+		ReserveHeaderBytes: int(nic.MaxHeaderLength()) + header.IPv6FixedHeaderSize + neighborSolicitSize,
 	})
 	pkt.TransportProtocolNumber = header.ICMPv6ProtocolNumber
 	packet := header.ICMPv6(pkt.TransportHeader().Push(neighborSolicitSize))
@@ -714,20 +727,18 @@ func (p *protocol) LinkAddressRequest(targetAddr, localAddr tcpip.Address, remot
 	ns := header.NDPNeighborSolicit(packet.MessageBody())
 	ns.SetTargetAddress(targetAddr)
 	ns.Options().Serialize(optsSerializer)
-	packet.SetChecksum(header.ICMPv6Checksum(packet, r.LocalAddress, r.RemoteAddress, buffer.VectorisedView{}))
+	packet.SetChecksum(header.ICMPv6Checksum(packet, localAddr, remoteAddr, buffer.VectorisedView{}))
 
-	p.mu.Lock()
-	netEP, ok := p.mu.eps[nic.ID()]
-	p.mu.Unlock()
-	if !ok {
-		return tcpip.ErrNotConnected
+	if err := addIPHeader(localAddr, remoteAddr, pkt, stack.NetworkHeaderParams{
+		Protocol: header.ICMPv6ProtocolNumber,
+		TTL:      header.NDPHopLimit,
+	}, header.IPv6ExtHdrSerializer{}); err != nil {
+		panic(fmt.Sprintf("failed to add IP header: %s", err))
 	}
+
 	stat := netEP.stats.icmp.packetsSent
 
-	if err := r.WritePacket(nil /* gso */, stack.NetworkHeaderParams{
-		Protocol: header.ICMPv6ProtocolNumber,
-		TTL:      header.NDPHopLimit,
-	}, pkt); err != nil {
+	if err := nic.WritePacketToRemote(remoteLinkAddr, nil /* gso */, ProtocolNumber, pkt); err != nil {
 		stat.dropped.Increment()
 		return err
 	}
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index 40176594e..d658f9bcb 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -555,7 +555,7 @@ func (e *endpoint) MaxHeaderLength() uint16 {
 	return e.nic.MaxHeaderLength() + header.IPv6MinimumSize
 }
 
-func (e *endpoint) addIPHeader(srcAddr, dstAddr tcpip.Address, pkt *stack.PacketBuffer, params stack.NetworkHeaderParams, extensionHeaders header.IPv6ExtHdrSerializer) *tcpip.Error {
+func addIPHeader(srcAddr, dstAddr tcpip.Address, pkt *stack.PacketBuffer, params stack.NetworkHeaderParams, extensionHeaders header.IPv6ExtHdrSerializer) *tcpip.Error {
 	extHdrsLen := extensionHeaders.Length()
 	length := pkt.Size() + extensionHeaders.Length()
 	if length > math.MaxUint16 {
@@ -625,7 +625,7 @@ func (e *endpoint) handleFragments(r *stack.Route, gso *stack.GSO, networkMTU ui
 
 // WritePacket writes a packet to the given destination address and protocol.
 func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.NetworkHeaderParams, pkt *stack.PacketBuffer) *tcpip.Error {
-	if err := e.addIPHeader(r.LocalAddress, r.RemoteAddress, pkt, params, nil /* extensionHeaders */); err != nil {
+	if err := addIPHeader(r.LocalAddress, r.RemoteAddress, pkt, params, nil /* extensionHeaders */); err != nil {
 		return err
 	}
 
@@ -718,7 +718,7 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe
 	stats := e.stats.ip
 	linkMTU := e.nic.MTU()
 	for pb := pkts.Front(); pb != nil; pb = pb.Next() {
-		if err := e.addIPHeader(r.LocalAddress, r.RemoteAddress, pb, params, nil /* extensionHeaders */); err != nil {
+		if err := addIPHeader(r.LocalAddress, r.RemoteAddress, pb, params, nil /* extensionHeaders */); err != nil {
 			return 0, err
 		}
 
diff --git a/pkg/tcpip/network/ipv6/mld.go b/pkg/tcpip/network/ipv6/mld.go
index 78d86e523..c376016e9 100644
--- a/pkg/tcpip/network/ipv6/mld.go
+++ b/pkg/tcpip/network/ipv6/mld.go
@@ -249,7 +249,7 @@ func (mld *mldState) writePacket(destAddress, groupAddress tcpip.Address, mldTyp
 		Data:               buffer.View(icmp).ToVectorisedView(),
 	})
 
-	if err := mld.ep.addIPHeader(localAddress, destAddress, pkt, stack.NetworkHeaderParams{
+	if err := addIPHeader(localAddress, destAddress, pkt, stack.NetworkHeaderParams{
 		Protocol: header.ICMPv6ProtocolNumber,
 		TTL:      header.MLDHopLimit,
 	}, extensionHeaders); err != nil {
diff --git a/pkg/tcpip/network/ipv6/ndp.go b/pkg/tcpip/network/ipv6/ndp.go
index 41112a0c4..ca4ff621d 100644
--- a/pkg/tcpip/network/ipv6/ndp.go
+++ b/pkg/tcpip/network/ipv6/ndp.go
@@ -732,7 +732,7 @@ func (ndp *ndpState) sendDADPacket(addr tcpip.Address, addressEndpoint stack.Add
 	})
 
 	sent := ndp.ep.stats.icmp.packetsSent
-	if err := ndp.ep.addIPHeader(header.IPv6Any, snmc, pkt, stack.NetworkHeaderParams{
+	if err := addIPHeader(header.IPv6Any, snmc, pkt, stack.NetworkHeaderParams{
 		Protocol: header.ICMPv6ProtocolNumber,
 		TTL:      header.NDPHopLimit,
 	}, nil /* extensionHeaders */); err != nil {
@@ -1857,7 +1857,7 @@ func (ndp *ndpState) startSolicitingRouters() {
 		})
 
 		sent := ndp.ep.stats.icmp.packetsSent
-		if err := ndp.ep.addIPHeader(localAddr, header.IPv6AllRoutersMulticastAddress, pkt, stack.NetworkHeaderParams{
+		if err := addIPHeader(localAddr, header.IPv6AllRoutersMulticastAddress, pkt, stack.NetworkHeaderParams{
 			Protocol: header.ICMPv6ProtocolNumber,
 			TTL:      header.NDPHopLimit,
 		}, nil /* extensionHeaders */); err != nil {