Internal change.

PiperOrigin-RevId: 258424489

2 files changed, 10 insertions, 11 deletions

diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go
index ab9e80747..a80ceafd0 100644
--- a/pkg/tcpip/transport/icmp/endpoint.go
+++ b/pkg/tcpip/transport/icmp/endpoint.go
@@ -291,7 +291,7 @@ func (e *endpoint) Write(p tcpip.Payload, opts tcpip.WriteOptions) (uintptr, <-c
 
 	switch e.netProto {
 	case header.IPv4ProtocolNumber:
-		err = e.send4(route, v)
+		err = send4(route, e.id.LocalPort, v)
 
 	case header.IPv6ProtocolNumber:
 		err = send6(route, e.id.LocalPort, v)
@@ -352,20 +352,20 @@ func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 	}
 }
 
-func (e *endpoint) send4(r *stack.Route, data buffer.View) *tcpip.Error {
-	if len(data) < header.ICMPv4EchoMinimumSize {
+func send4(r *stack.Route, ident uint16, data buffer.View) *tcpip.Error {
+	if len(data) < header.ICMPv4MinimumSize {
 		return tcpip.ErrInvalidEndpointState
 	}
 
 	// Set the ident to the user-specified port. Sequence number should
 	// already be set by the user.
-	binary.BigEndian.PutUint16(data[header.ICMPv4MinimumSize:], e.id.LocalPort)
+	binary.BigEndian.PutUint16(data[header.ICMPv4PayloadOffset:], ident)
 
-	hdr := buffer.NewPrependable(header.ICMPv4EchoMinimumSize + int(r.MaxHeaderLength()))
+	hdr := buffer.NewPrependable(header.ICMPv4MinimumSize + int(r.MaxHeaderLength()))
 
-	icmpv4 := header.ICMPv4(hdr.Prepend(header.ICMPv4EchoMinimumSize))
+	icmpv4 := header.ICMPv4(hdr.Prepend(header.ICMPv4MinimumSize))
 	copy(icmpv4, data)
-	data = data[header.ICMPv4EchoMinimumSize:]
+	data = data[header.ICMPv4MinimumSize:]
 
 	// Linux performs these basic checks.
 	if icmpv4.Type() != header.ICMPv4Echo || icmpv4.Code() != 0 {
diff --git a/pkg/tcpip/transport/icmp/protocol.go b/pkg/tcpip/transport/icmp/protocol.go
index c89538131..7fdba5d56 100644
--- a/pkg/tcpip/transport/icmp/protocol.go
+++ b/pkg/tcpip/transport/icmp/protocol.go
@@ -90,19 +90,18 @@ func (p *protocol) NewRawEndpoint(stack *stack.Stack, netProto tcpip.NetworkProt
 func (p *protocol) MinimumPacketSize() int {
 	switch p.number {
 	case ProtocolNumber4:
-		return header.ICMPv4EchoMinimumSize
+		return header.ICMPv4MinimumSize
 	case ProtocolNumber6:
 		return header.ICMPv6EchoMinimumSize
 	}
 	panic(fmt.Sprint("unknown protocol number: ", p.number))
 }
 
-// ParsePorts returns the source and destination ports stored in the given icmp
-// packet.
+// ParsePorts in case of ICMP sets src to 0, dst to ICMP ID, and err to nil.
 func (p *protocol) ParsePorts(v buffer.View) (src, dst uint16, err *tcpip.Error) {
 	switch p.number {
 	case ProtocolNumber4:
-		return 0, binary.BigEndian.Uint16(v[header.ICMPv4MinimumSize:]), nil
+		return 0, binary.BigEndian.Uint16(v[header.ICMPv4PayloadOffset:]), nil
 	case ProtocolNumber6:
 		return 0, binary.BigEndian.Uint16(v[header.ICMPv6MinimumSize:]), nil
 	}