1 files changed, 27 insertions, 5 deletions
diff --git a/pkg/tcpip/stack/route.go b/pkg/tcpip/stack/route.go
index 391ab4344..e72373964 100644
--- a/pkg/tcpip/stack/route.go
+++ b/pkg/tcpip/stack/route.go
@@ -59,6 +59,8 @@ func makeRoute(netProto tcpip.NetworkProtocolNumber, localAddr, remoteAddr tcpip
 		loop = PacketLoop
 	} else if multicastLoop && (header.IsV4MulticastAddress(remoteAddr) || header.IsV6MulticastAddress(remoteAddr)) {
 		loop |= PacketLoop
+	} else if remoteAddr == header.IPv4Broadcast {
+		loop |= PacketLoop
 	}
 
 	return Route{
@@ -148,12 +150,16 @@ func (r *Route) RemoveWaker(waker *sleep.Waker) {
 // IsResolutionRequired returns true if Resolve() must be called to resolve
 // the link address before the this route can be written to.
 func (r *Route) IsResolutionRequired() bool {
-	return r.ref.linkCache != nil && r.RemoteLinkAddress == ""
+	return r.ref.isValidForOutgoing() && r.ref.linkCache != nil && r.RemoteLinkAddress == ""
 }
 
 // WritePacket writes the packet through the given route.
-func (r *Route) WritePacket(gso *GSO, hdr buffer.Prependable, payload buffer.VectorisedView, protocol tcpip.TransportProtocolNumber, ttl uint8) *tcpip.Error {
-	err := r.ref.ep.WritePacket(r, gso, hdr, payload, protocol, ttl, r.loop)
+func (r *Route) WritePacket(gso *GSO, hdr buffer.Prependable, payload buffer.VectorisedView, params NetworkHeaderParams) *tcpip.Error {
+	if !r.ref.isValidForOutgoing() {
+		return tcpip.ErrInvalidEndpointState
+	}
+
+	err := r.ref.ep.WritePacket(r, gso, hdr, payload, params, r.loop)
 	if err != nil {
 		r.Stats().IP.OutgoingPacketErrors.Increment()
 	} else {
@@ -166,6 +172,10 @@ func (r *Route) WritePacket(gso *GSO, hdr buffer.Prependable, payload buffer.Vec
 // WriteHeaderIncludedPacket writes a packet already containing a network
 // header through the given route.
 func (r *Route) WriteHeaderIncludedPacket(payload buffer.VectorisedView) *tcpip.Error {
+	if !r.ref.isValidForOutgoing() {
+		return tcpip.ErrInvalidEndpointState
+	}
+
 	if err := r.ref.ep.WriteHeaderIncludedPacket(r, payload, r.loop); err != nil {
 		r.Stats().IP.OutgoingPacketErrors.Increment()
 		return err
@@ -200,12 +210,24 @@ func (r *Route) Clone() Route {
 	return *r
 }
 
-// MakeLoopedRoute duplicates the given route and tweaks it in case of multicast.
+// MakeLoopedRoute duplicates the given route with special handling for routes
+// used for sending multicast or broadcast packets. In those cases the
+// multicast/broadcast address is the remote address when sending out, but for
+// incoming (looped) packets it becomes the local address. Similarly, the local
+// interface address that was the local address going out becomes the remote
+// address coming in. This is different to unicast routes where local and
+// remote addresses remain the same as they identify location (local vs remote)
+// not direction (source vs destination).
 func (r *Route) MakeLoopedRoute() Route {
 	l := r.Clone()
-	if header.IsV4MulticastAddress(r.RemoteAddress) || header.IsV6MulticastAddress(r.RemoteAddress) {
+	if r.RemoteAddress == header.IPv4Broadcast || header.IsV4MulticastAddress(r.RemoteAddress) || header.IsV6MulticastAddress(r.RemoteAddress) {
 		l.RemoteAddress, l.LocalAddress = l.LocalAddress, l.RemoteAddress
 		l.RemoteLinkAddress = l.LocalLinkAddress
 	}
 	return l
 }
+
+// Stack returns the instance of the Stack that owns this route.
+func (r *Route) Stack() *Stack {
+	return r.ref.stack()
+}