Merge release-20200622.1-240-g8dbf428a1 (automated)

4 files changed, 16 insertions, 8 deletions

diff --git a/pkg/tcpip/network/arp/arp.go b/pkg/tcpip/network/arp/arp.go
index b0f57040c..31a242482 100644
--- a/pkg/tcpip/network/arp/arp.go
+++ b/pkg/tcpip/network/arp/arp.go
@@ -160,9 +160,12 @@ func (*protocol) LinkAddressProtocol() tcpip.NetworkProtocolNumber {
 }
 
 // LinkAddressRequest implements stack.LinkAddressResolver.LinkAddressRequest.
-func (*protocol) LinkAddressRequest(addr, localAddr tcpip.Address, linkEP stack.LinkEndpoint) *tcpip.Error {
+func (*protocol) LinkAddressRequest(addr, localAddr tcpip.Address, remoteLinkAddr tcpip.LinkAddress, linkEP stack.LinkEndpoint) *tcpip.Error {
 	r := &stack.Route{
-		RemoteLinkAddress: header.EthernetBroadcastAddress,
+		RemoteLinkAddress: remoteLinkAddr,
+	}
+	if len(r.RemoteLinkAddress) == 0 {
+		r.RemoteLinkAddress = header.EthernetBroadcastAddress
 	}
 
 	hdr := buffer.NewPrependable(int(linkEP.MaxHeaderLength()) + header.ARPSize)
diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go
index ff1cb53dd..24600d877 100644
--- a/pkg/tcpip/network/ipv6/icmp.go
+++ b/pkg/tcpip/network/ipv6/icmp.go
@@ -504,7 +504,7 @@ func (*protocol) LinkAddressProtocol() tcpip.NetworkProtocolNumber {
 }
 
 // LinkAddressRequest implements stack.LinkAddressResolver.
-func (*protocol) LinkAddressRequest(addr, localAddr tcpip.Address, linkEP stack.LinkEndpoint) *tcpip.Error {
+func (*protocol) LinkAddressRequest(addr, localAddr tcpip.Address, remoteLinkAddr tcpip.LinkAddress, linkEP stack.LinkEndpoint) *tcpip.Error {
 	snaddr := header.SolicitedNodeAddr(addr)
 
 	// TODO(b/148672031): Use stack.FindRoute instead of manually creating the
@@ -513,8 +513,12 @@ func (*protocol) LinkAddressRequest(addr, localAddr tcpip.Address, linkEP stack.
 	r := &stack.Route{
 		LocalAddress:      localAddr,
 		RemoteAddress:     snaddr,
-		RemoteLinkAddress: header.EthernetAddressFromMulticastIPv6Address(snaddr),
+		RemoteLinkAddress: remoteLinkAddr,
 	}
+	if len(r.RemoteLinkAddress) == 0 {
+		r.RemoteLinkAddress = header.EthernetAddressFromMulticastIPv6Address(snaddr)
+	}
+
 	hdr := buffer.NewPrependable(int(linkEP.MaxHeaderLength()) + header.IPv6MinimumSize + header.ICMPv6NeighborAdvertSize)
 	pkt := header.ICMPv6(hdr.Prepend(header.ICMPv6NeighborAdvertSize))
 	pkt.SetType(header.ICMPv6NeighborSolicit)
diff --git a/pkg/tcpip/stack/linkaddrcache.go b/pkg/tcpip/stack/linkaddrcache.go
index 403557fd7..6f73a0ce4 100644
--- a/pkg/tcpip/stack/linkaddrcache.go
+++ b/pkg/tcpip/stack/linkaddrcache.go
@@ -244,7 +244,7 @@ func (c *linkAddrCache) startAddressResolution(k tcpip.FullAddress, linkRes Link
 	for i := 0; ; i++ {
 		// Send link request, then wait for the timeout limit and check
 		// whether the request succeeded.
-		linkRes.LinkAddressRequest(k.Addr, localAddr, linkEP)
+		linkRes.LinkAddressRequest(k.Addr, localAddr, "" /* linkAddr */, linkEP)
 
 		select {
 		case now := <-time.After(c.resolutionTimeout):
diff --git a/pkg/tcpip/stack/registration.go b/pkg/tcpip/stack/registration.go
index 9e1b2d25f..8604c4259 100644
--- a/pkg/tcpip/stack/registration.go
+++ b/pkg/tcpip/stack/registration.go
@@ -478,12 +478,13 @@ type InjectableLinkEndpoint interface {
 // A LinkAddressResolver is an extension to a NetworkProtocol that
 // can resolve link addresses.
 type LinkAddressResolver interface {
-	// LinkAddressRequest sends a request for the LinkAddress of addr.
-	// The request is sent on linkEP with localAddr as the source.
+	// LinkAddressRequest sends a request for the LinkAddress of addr. Broadcasts
+	// the request on the local network if remoteLinkAddr is the zero value. The
+	// request is sent on linkEP with localAddr as the source.
 	//
 	// A valid response will cause the discovery protocol's network
 	// endpoint to call AddLinkAddress.
-	LinkAddressRequest(addr, localAddr tcpip.Address, linkEP LinkEndpoint) *tcpip.Error
+	LinkAddressRequest(addr, localAddr tcpip.Address, remoteLinkAddr tcpip.LinkAddress, linkEP LinkEndpoint) *tcpip.Error
 
 	// ResolveStaticAddress attempts to resolve address without sending
 	// requests. It either resolves the name immediately or returns the