Merge release-20200921.0-52-ga376a0baf (automated)

5 files changed, 26 insertions, 28 deletions

diff --git a/pkg/tcpip/network/arp/arp.go b/pkg/tcpip/network/arp/arp.go
index 81e286e80..cb9225bd7 100644
--- a/pkg/tcpip/network/arp/arp.go
+++ b/pkg/tcpip/network/arp/arp.go
@@ -238,12 +238,6 @@ func (*protocol) Parse(pkt *stack.PacketBuffer) (proto tcpip.TransportProtocolNu
 	return 0, false, parse.ARP(pkt)
 }
 
-// ReturnError implements stack.TransportProtocol.ReturnError.
-func (*protocol) ReturnError(*stack.Route, tcpip.ICMPReason, *stack.PacketBuffer) *tcpip.Error {
-	// In ARP, there is no such response so do nothing.
-	return nil
-}
-
 // NewProtocol returns an ARP network protocol.
 func NewProtocol() stack.NetworkProtocol {
 	return &protocol{}
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go
index 5fe73315f..3e5cf2ad9 100644
--- a/pkg/tcpip/network/ipv4/icmp.go
+++ b/pkg/tcpip/network/ipv4/icmp.go
@@ -200,16 +200,6 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer) {
 
 // ======= ICMP Error packet generation =========
 
-// ReturnError implements stack.TransportProtocol.ReturnError.
-func (p *protocol) ReturnError(r *stack.Route, reason tcpip.ICMPReason, pkt *stack.PacketBuffer) *tcpip.Error {
-	switch reason.(type) {
-	case *tcpip.ICMPReasonPortUnreachable:
-		return returnError(r, &icmpReasonPortUnreachable{}, pkt)
-	default:
-		return tcpip.ErrNotSupported
-	}
-}
-
 // icmpReason is a marker interface for IPv4 specific ICMP errors.
 type icmpReason interface {
 	isICMPReason()
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index 135444222..e589d923d 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -21,6 +21,7 @@
 package ipv4
 
 import (
+	"fmt"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/tcpip"
@@ -463,7 +464,19 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
 		return
 	}
 	r.Stats().IP.PacketsDelivered.Increment()
-	e.dispatcher.DeliverTransportPacket(r, p, pkt)
+
+	switch res := e.dispatcher.DeliverTransportPacket(r, p, pkt); res {
+	case stack.TransportPacketHandled:
+	case stack.TransportPacketDestinationPortUnreachable:
+		// As per RFC: 1122 Section 3.2.2.1 A host SHOULD generate Destination
+		//   Unreachable messages with code:
+		//     3 (Port Unreachable), when the designated transport protocol
+		//     (e.g., UDP) is unable to demultiplex the datagram but has no
+		//     protocol mechanism to inform the sender.
+		_ = returnError(r, &icmpReasonPortUnreachable{}, pkt)
+	default:
+		panic(fmt.Sprintf("unrecognized result from DeliverTransportPacket = %d", res))
+	}
 }
 
 // Close cleans up resources associated with the endpoint.
diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go
index 072c8ccd7..dd3295b31 100644
--- a/pkg/tcpip/network/ipv6/icmp.go
+++ b/pkg/tcpip/network/ipv6/icmp.go
@@ -671,16 +671,6 @@ func (*protocol) ResolveStaticAddress(addr tcpip.Address) (tcpip.LinkAddress, bo
 
 // ======= ICMP Error packet generation =========
 
-// ReturnError implements stack.TransportProtocol.ReturnError.
-func (p *protocol) ReturnError(r *stack.Route, reason tcpip.ICMPReason, pkt *stack.PacketBuffer) *tcpip.Error {
-	switch reason.(type) {
-	case *tcpip.ICMPReasonPortUnreachable:
-		return returnError(r, &icmpReasonPortUnreachable{}, pkt)
-	default:
-		return tcpip.ErrNotSupported
-	}
-}
-
 // icmpReason is a marker interface for IPv6 specific ICMP errors.
 type icmpReason interface {
 	isICMPReason()
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index 5b1cca180..3d070ddea 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -482,7 +482,18 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) {
 				r.Stats().IP.PacketsDelivered.Increment()
 				// TODO(b/152019344): Send an ICMPv6 Parameter Problem, Code 1 error
 				// in response to unrecognized next header values.
-				e.dispatcher.DeliverTransportPacket(r, p, pkt)
+				switch res := e.dispatcher.DeliverTransportPacket(r, p, pkt); res {
+				case stack.TransportPacketHandled:
+				case stack.TransportPacketDestinationPortUnreachable:
+					// As per RFC 4443 section 3.1:
+					//   A destination node SHOULD originate a Destination Unreachable
+					//   message with Code 4 in response to a packet for which the
+					//   transport protocol (e.g., UDP) has no listener, if that transport
+					//   protocol has no alternative means to inform the sender.
+					_ = returnError(r, &icmpReasonPortUnreachable{}, pkt)
+				default:
+					panic(fmt.Sprintf("unrecognized result from DeliverTransportPacket = %d", res))
+				}
 			}
 
 		default: