protocol: add v2 wire protocol with binary framing and capability negotiation (#5294)

pkg/proto/wire/wire_test.go

@@ -0,0 +1,120 @@
+// Copyright 2026 The frp Authors
+//
+// 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 wire
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+	"net"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestFrameRoundTrip(t *testing.T) {
+	var buf bytes.Buffer
+	conn := NewConn(&buf)
+
+	in := DefaultClientHello(BootstrapInfo{
+		Transport: "tcp",
+		TLS:       true,
+		TCPMux:    true,
+	})
+	require.NoError(t, conn.WriteJSONFrame(FrameTypeClientHello, in))
+
+	var out ClientHello
+	require.NoError(t, conn.ReadJSONFrame(FrameTypeClientHello, &out))
+	require.Equal(t, in, out)
+}
+
+func TestReadFrameRejectsUnsupportedFlags(t *testing.T) {
+	var buf bytes.Buffer
+	header := make([]byte, 8)
+	binary.BigEndian.PutUint16(header[0:2], FrameTypeMessage)
+	binary.BigEndian.PutUint16(header[2:4], 1)
+	binary.BigEndian.PutUint32(header[4:8], 0)
+	buf.Write(header)
+
+	_, err := NewConn(&buf).ReadFrame()
+	require.ErrorContains(t, err, "unsupported frame flags")
+}
+
+func TestReadFrameRejectsOversizedPayload(t *testing.T) {
+	var buf bytes.Buffer
+	header := make([]byte, 8)
+	binary.BigEndian.PutUint16(header[0:2], FrameTypeMessage)
+	binary.BigEndian.PutUint32(header[4:8], DefaultMaxFramePayloadSize+1)
+	buf.Write(header)
+
+	_, err := NewConn(&buf).ReadFrame()
+	require.ErrorContains(t, err, "exceeds limit")
+}
+
+func TestCheckMagicV2ConsumesMagic(t *testing.T) {
+	client, server := net.Pipe()
+	defer server.Close()
+
+	want := []byte("payload")
+	go func() {
+		defer client.Close()
+		_, _ = client.Write(append([]byte(MagicV2), want...))
+	}()
+
+	out, isV2, err := CheckMagic(server)
+	require.NoError(t, err)
+	require.True(t, isV2)
+
+	got := make([]byte, len(want))
+	_, err = io.ReadFull(out, got)
+	require.NoError(t, err)
+	require.Equal(t, want, got)
+}
+
+func TestWriteMagicIfV2(t *testing.T) {
+	var buf bytes.Buffer
+	require.NoError(t, WriteMagicIfV2(&buf, ProtocolV1))
+	require.Empty(t, buf.Bytes())
+
+	require.NoError(t, WriteMagicIfV2(&buf, ProtocolV2))
+	require.Equal(t, []byte(MagicV2), buf.Bytes())
+}
+
+func TestCheckMagicV1PreservesReadBytes(t *testing.T) {
+	client, server := net.Pipe()
+	defer server.Close()
+
+	want := []byte("legacy payload")
+	go func() {
+		defer client.Close()
+		_, _ = client.Write(want)
+	}()
+
+	out, isV2, err := CheckMagic(server)
+	require.NoError(t, err)
+	require.False(t, isV2)
+
+	got, err := io.ReadAll(out)
+	require.NoError(t, err)
+	require.Equal(t, want, got)
+}
+
+func TestValidateClientHello(t *testing.T) {
+	require.NoError(t, ValidateClientHello(DefaultClientHello(BootstrapInfo{})))
+
+	hello := DefaultClientHello(BootstrapInfo{})
+	hello.Capabilities.Message.Codecs = []string{"unknown"}
+	require.ErrorContains(t, ValidateClientHello(hello), "unsupported message codec")
+}