Add setiptables4nattemplate chain element

go.mod

@@ -4,7 +4,7 @@ go 1.18
 
 require (
 	github.com/golang/protobuf v1.5.2
-	github.com/networkservicemesh/api v1.3.0-rc.1.0.20220405210054-fbcde048efa5
+	github.com/networkservicemesh/api v1.3.2-0.20220509143420-a1414febd727
 	github.com/networkservicemesh/sdk v0.5.1-0.20220507173809-41196bdf49db
 	github.com/pkg/errors v0.9.1
 	github.com/stretchr/testify v1.7.0

go.sum

@@ -70,8 +70,8 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/networkservicemesh/api v1.3.0-rc.1.0.20220405210054-fbcde048efa5 h1:5zQY4PhShozvj/GFJS0dX6ocamAB9oWwEOJviAhGUaw=
-github.com/networkservicemesh/api v1.3.0-rc.1.0.20220405210054-fbcde048efa5/go.mod h1:B6meq/SWjWR6bGXZdXPfbOeaBK+T1JayLdtEJQCsXKU=
+github.com/networkservicemesh/api v1.3.2-0.20220509143420-a1414febd727 h1:IonbJeVgkwPLOrvDjd+c5Q2QPxtAUrwdLfAUv+8qk4w=
+github.com/networkservicemesh/api v1.3.2-0.20220509143420-a1414febd727/go.mod h1:hOF2844BSstH1311oDMDgqqXS+kdc77htZNPRKl9mf8=
 github.com/networkservicemesh/sdk v0.5.1-0.20220507173809-41196bdf49db h1:Ux4NNmYfPm/ayaR1DD5AWMXGSkPm+PdGHbvu34TAAno=
 github.com/networkservicemesh/sdk v0.5.1-0.20220507173809-41196bdf49db/go.mod h1:G+NdPbtzcOWx1VljOj+L4kvZPQyYpiwCp84JYs+hGtc=
 github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
@@ -197,7 +197,6 @@ google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZi
 google.golang.org/grpc v1.23.0/go.mod h1:Y5yQAOtifL1yxbo5wqy6BxZv8vAUGQwXBOALyacEbxg=
 google.golang.org/grpc v1.25.1/go.mod h1:c3i+UQWmh7LiEpx4sFZnkU36qjEYZ0imhYfXVyQciAY=
 google.golang.org/grpc v1.27.0/go.mod h1:qbnxyOmOxrQa7FizSgH+ReBfzJrCY1pSN7KXBS8abTk=
-google.golang.org/grpc v1.32.0/go.mod h1:N36X2cJ7JwdamYAgDz+s+rVMFjt3numwzf/HckM8pak=
 google.golang.org/grpc v1.33.1/go.mod h1:fr5YgcSWrqhRRxogOsw7RzIpsmvOZ6IcH4kBYTpR3n0=
 google.golang.org/grpc v1.36.0/go.mod h1:qjiiYl8FncCW8feJPdyg3v6XW24KsRHe+dy9BAGRRjU=
 google.golang.org/grpc v1.40.0/go.mod h1:ogyxbiOoUXAkP+4+xa6PZSE9DZgIHtSpzjDTB9KAK34=

pkg/kernel/networkservice/setiptables4nattemplate/server.go

@@ -0,0 +1,55 @@
+// Copyright (c) 2022 Xored Software Inc and others.
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+// 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.
+
+//go:build linux
+// +build linux
+
+// Package setiptables4nattemplate provides chain element for setup iptables rules template properties
+package setiptables4nattemplate
+
+import (
+	"context"
+
+	"github.com/golang/protobuf/ptypes/empty"
+	"github.com/networkservicemesh/api/pkg/api/networkservice"
+	"github.com/networkservicemesh/api/pkg/api/networkservice/mechanisms/kernel"
+	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
+)
+
+type setIPTablesTemplateServer struct {
+	template string
+}
+
+// NewServer - returns a new networkservice.NetworkServiceServer that writes IP Tables rules template
+// to kernel mechanism
+func NewServer(template string) networkservice.NetworkServiceServer {
+	return &setIPTablesTemplateServer{
+		template: template,
+	}
+}
+
+func (s *setIPTablesTemplateServer) Request(ctx context.Context, request *networkservice.NetworkServiceRequest) (*networkservice.Connection, error) {
+	mechanism := kernel.ToMechanism(request.GetConnection().GetMechanism())
+	if mechanism != nil {
+		mechanism.SetIPTables4NatTemplate(s.template)
+	}
+
+	return next.Server(ctx).Request(ctx, request)
+}
+
+func (s *setIPTablesTemplateServer) Close(ctx context.Context, conn *networkservice.Connection) (*empty.Empty, error) {
+	return next.Server(ctx).Close(ctx, conn)
+}