ipv4: update icmp parameters

Updates golang/go#24440.

Change-Id: Icd7dbb9b6748ba8dd165eec1c0021650b7f4d97d
Reviewed-on: https://go-review.googlesource.com/63997
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

ipv4/gen.go

@@ -80,7 +80,7 @@ var registries = []struct {
 func geniana() error {
 	var bb bytes.Buffer
 	fmt.Fprintf(&bb, "// go generate gen.go\n")
-	fmt.Fprintf(&bb, "// GENERATED BY THE COMMAND ABOVE; DO NOT EDIT\n\n")
+	fmt.Fprintf(&bb, "// Code generated by the command above; DO NOT EDIT.\n\n")
 	fmt.Fprintf(&bb, "package ipv4\n\n")
 	for _, r := range registries {
 		resp, err := http.Get(r.url)

ipv4/iana.go

 // go generate gen.go
-// GENERATED BY THE COMMAND ABOVE; DO NOT EDIT
+// Code generated by the command above; DO NOT EDIT.
 
 package ipv4
 
-// Internet Control Message Protocol (ICMP) Parameters, Updated: 2013-04-19
+// Internet Control Message Protocol (ICMP) Parameters, Updated: 2018-02-26
 const (
 	ICMPTypeEchoReply              ICMPType = 0  // Echo Reply
 	ICMPTypeDestinationUnreachable ICMPType = 3  // Destination Unreachable
@@ -16,9 +16,11 @@ const (
 	ICMPTypeTimestamp              ICMPType = 13 // Timestamp
 	ICMPTypeTimestampReply         ICMPType = 14 // Timestamp Reply
 	ICMPTypePhoturis               ICMPType = 40 // Photuris
+	ICMPTypeExtendedEchoRequest    ICMPType = 42 // Extended Echo Request
+	ICMPTypeExtendedEchoReply      ICMPType = 43 // Extended Echo Reply
 )
 
-// Internet Control Message Protocol (ICMP) Parameters, Updated: 2013-04-19
+// Internet Control Message Protocol (ICMP) Parameters, Updated: 2018-02-26
 var icmpTypes = map[ICMPType]string{
 	0:  "echo reply",
 	3:  "destination unreachable",
@@ -31,4 +33,6 @@ var icmpTypes = map[ICMPType]string{
 	13: "timestamp",
 	14: "timestamp reply",
 	40: "photuris",
+	42: "extended echo request",
+	43: "extended echo reply",
 }