wip

dataplane/forwarding/protocol/mpls/BUILD

@@ -0,0 +1,13 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "mpls",
+    srcs = ["mpls.go"],
+    importpath = "github.com/openconfig/lemming/dataplane/forwarding/protocol/mpls",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//dataplane/forwarding/protocol",
+        "//dataplane/forwarding/util/frame",
+        "//proto/forwarding",
+    ],
+)

dataplane/forwarding/protocol/mpls/mpls.go

@@ -0,0 +1,54 @@
+// 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.
+
+package mpls
+
+import (
+	"github.com/openconfig/lemming/dataplane/forwarding/protocol"
+	"github.com/openconfig/lemming/dataplane/forwarding/util/frame"
+	fwdpb "github.com/openconfig/lemming/proto/forwarding"
+)
+
+type mpls struct {
+	protocol.Handler
+	desc *protocol.Desc
+}
+
+func parseMPLS(f *frame.Frame, desc *protocol.Desc) (protocol.Handler, fwdpb.PacketHeaderId, error) {
+	h := &mpls{
+		desc: desc,
+	}
+
+	for {
+		label, err := f.Peek(0, 3)
+		if err != nil {
+			return nil, 0, err
+		}
+		tc := label.BitField(20, 3)
+		bot := label.BitField(23, 1)
+		if bot.Value() == 1 {
+			break
+		}
+	}
+
+	return h, fwdpb.PacketHeaderId_PACKET_HEADER_ID_OPAQUE, nil
+}
+
+func add(id fwdpb.PacketHeaderId, _ *protocol.Desc) (protocol.Handler, error) {
+	return nil, nil
+}
+
+func init() {
+	protocol.Register(fwdpb.PacketHeaderId_PACKET_HEADER_ID_MPLS, parseMPLS, add)
+}