Add linux build constraint on iptables files

Signed-off-by: galal-hussein <hussein.galal.ahmed.11@gmail.com>
Co-Authored-By: Hussein Galal  <hussein.galal@suse.com>

Author: galal-hussein

network/hostport/fake_iptables.go

@@ -1,3 +1,6 @@
+//go:build linux
+// +build linux
+
 /*
 Copyright 2021 Mirantis
 

network/hostport/hostport.go

@@ -1,3 +1,6 @@
+//go:build linux
+// +build linux
+
 /*
 Copyright 2021 Mirantis
 

network/hostport/hostport_manager.go

@@ -1,3 +1,6 @@
+//go:build linux
+// +build linux
+
 /*
 Copyright 2021 Mirantis
 

network/hostport/hostport_windows.go

@@ -0,0 +1,32 @@
+//go:build windows
+// +build windows
+
+/*
+Copyright 2021 Mirantis
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package hostport
+
+import (
+	"github.com/Mirantis/cri-dockerd/config"
+)
+
+// PortMapping represents a network port in a container
+type PortMapping struct {
+	HostPort      int32
+	ContainerPort int32
+	Protocol      config.Protocol
+	HostIP        string
+}