Update

vendor/github.com/pires/go-proxyproto/version_cmd.go

@@ -0,0 +1,47 @@
+package proxyproto
+
+// ProtocolVersionAndCommand represents the command in proxy protocol v2.
+// Command doesn't exist in v1 but it should be set since other parts of
+// this library may rely on it for determining connection details.
+type ProtocolVersionAndCommand byte
+
+const (
+	// LOCAL represents the LOCAL command in v2 or UNKNOWN transport in v1,
+	// in which case no address information is expected.
+	LOCAL ProtocolVersionAndCommand = '\x20'
+	// PROXY represents the PROXY command in v2 or transport is not UNKNOWN in v1,
+	// in which case valid local/remote address and port information is expected.
+	PROXY ProtocolVersionAndCommand = '\x21'
+)
+
+var supportedCommand = map[ProtocolVersionAndCommand]bool{
+	LOCAL: true,
+	PROXY: true,
+}
+
+// IsLocal returns true if the command in v2 is LOCAL or the transport in v1 is UNKNOWN,
+// i.e. when no address information is expected, false otherwise.
+func (pvc ProtocolVersionAndCommand) IsLocal() bool {
+	return LOCAL == pvc
+}
+
+// IsProxy returns true if the command in v2 is PROXY or the transport in v1 is not UNKNOWN,
+// i.e. when valid local/remote address and port information is expected, false otherwise.
+func (pvc ProtocolVersionAndCommand) IsProxy() bool {
+	return PROXY == pvc
+}
+
+// IsUnspec returns true if the command is unspecified, false otherwise.
+func (pvc ProtocolVersionAndCommand) IsUnspec() bool {
+	return !(pvc.IsLocal() || pvc.IsProxy())
+}
+
+func (pvc ProtocolVersionAndCommand) toByte() byte {
+	if pvc.IsLocal() {
+		return byte(LOCAL)
+	} else if pvc.IsProxy() {
+		return byte(PROXY)
+	}
+
+	return byte(LOCAL)
+}