Add FORWARD node type and implementation

.gitignore

@@ -9,5 +9,8 @@ kne_cli/kne_cli
 kne_cli/kne
 controller/server/server
 x/webhook/webhook
-x/wire/client/client
-x/wire/server/server
+x/wire/file/client/client
+x/wire/file/server/server
+x/wire/intf/client/client
+x/wire/intf/server/server
+x/wire/forward/forward

examples/forward/topology.textproto

@@ -0,0 +1,109 @@
+name: "forward-basic"
+nodes: {
+  name: "r1"
+  vendor: OPENCONFIG
+  model: "LEMMING"
+}
+nodes: {
+  name: "r2"
+  vendor: OPENCONFIG
+  model: "LEMMING"
+}
+nodes: {
+  name: "fwd1"
+  vendor: FORWARD
+  config: {
+    image: "forward:latest"
+    vendor_data {
+      [type.googleapis.com/forward.ForwardConfig] {
+        wires: {
+          a: {
+            interface: {
+              name: "eth1"
+            }
+          }
+          z: {
+            local_node: {
+              name: "fwd2"
+              interface: "eth1"
+            }
+          }
+        }
+        wires: {
+          a: {
+            local_node: {
+              name: "fw2"
+              interface: "eth2"
+            }
+          }
+          z: {
+            interface: {
+              name: "eth2"
+            }
+          }
+        }
+      }
+    }
+  }
+}
+nodes: {
+  name: "fwd2"
+  vendor: FORWARD
+  config: {
+    image: "forward:latest"
+    vendor_data {
+      [type.googleapis.com/forward.ForwardConfig] {
+        wires: {
+          a: {
+            interface: {
+              name: "eth2"
+            }
+          }
+          z: {
+            local_node: {
+              name: "fwd1"
+              interface: "eth2"
+            }
+          }
+        }
+        wires: {
+          a: {
+            local_node: {
+              name: "fw1"
+              interface: "eth1"
+            }
+          }
+          z: {
+            interface: {
+              name: "eth1"
+            }
+          }
+        }
+      }
+    }
+  }
+}
+links: {
+  a_node: "r1"
+  a_int: "eth1"
+  z_node: "fwd1"
+  z_int: "eth1"
+}
+links: {
+  a_node: "fwd2"
+  a_int: "eth1"
+  z_node: "r2"
+  z_int: "eth1"
+}
+links: {
+  a_node: "r2"
+  a_int: "eth2"
+  z_node: "fwd2"
+  z_int: "eth2"
+}
+links: {
+  a_node: "fwd1"
+  a_int: "eth2"
+  z_node: "r1"
+  z_int: "eth2"
+}

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/golang/glog v1.2.0
 	github.com/golang/mock v1.6.0
 	github.com/google/go-cmp v0.6.0
+	github.com/google/gopacket v1.1.19
 	github.com/kr/pretty v0.3.1
 	github.com/networkop/meshnet-cni v0.3.1-0.20230525201116-d7c306c635cf
 	github.com/open-traffic-generator/keng-operator v0.3.28

go.sum

@@ -1028,6 +1028,8 @@ github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeN
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/google/gofuzz v1.2.0 h1:xRy4A+RhZaiKjJ1bPfwQ8sedCA+YS2YcCHW6ec7JMi0=
 github.com/google/gofuzz v1.2.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
+github.com/google/gopacket v1.1.19 h1:ves8RnFZPGiFnTS0uPQStjwru6uO6h+nlr9j6fL7kF8=
+github.com/google/gopacket v1.1.19/go.mod h1:iJ8V8n6KS+z2U1A8pUwu8bW5SyEMkXJB8Yo/Vo+TKTo=
 github.com/google/martian v2.1.0+incompatible/go.mod h1:9I4somxYTbIHy5NJKHRl3wXiIaQGbYVAs8BPL6v8lEs=
 github.com/google/martian/v3 v3.0.0/go.mod h1:y5Zk1BBys9G+gd6Jrk0W3cC1+ELVxBWuIGO+w/tUAp0=
 github.com/google/martian/v3 v3.1.0/go.mod h1:y5Zk1BBys9G+gd6Jrk0W3cC1+ELVxBWuIGO+w/tUAp0=

proto/forward.proto

@@ -0,0 +1,59 @@
+// Copyright 2024 Google LLC
+//
+// 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.
+syntax = "proto3";
+
+package forward;
+
+option go_package = "github.com/openconfig/kne/proto/forward";
+
+// Forward specific config data for KNE
+message ForwardConfig {
+  repeated Wire wires = 1;
+}
+
+// Wire is a connection between two endpoints intended to forward
+// data bidirectionally between them. One of the endpoints must be
+// of type Interface.
+message Wire {
+  // The a endpoint serves as the client endpoint in the bidirectional stream.
+  Endpoint a = 1;
+  // The z endpoint serves as the server endpoint in the bidirectional stream.
+  Endpoint z = 2;
+}
+
+message Endpoint {
+  oneof endpoint {
+    // Interface is a local interface (ex. eth0) on the node.
+    Interface interface = 1;
+    // LocalNode is a node in the same cluster.
+    LocalNode local_node = 2;
+    // RemoteNode is a node in a different cluster.
+    RemoteNode remote_node = 3;
+  }
+}
+
+message Interface {
+  string name = 1;
+  // TODO: Add MTU and other configurable fields.
+}
+
+message LocalNode {
+  string name = 1;
+  string interface = 2;
+}
+
+message RemoteNode {
+  string addr = 1;
+  string interface = 2;
+}