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// Copyright 2018 Google, Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file in the root of the source
// tree.
package layers
import (
"encoding/hex"
"testing"
"github.com/gopacket/gopacket"
)
var (
fingerprint uint64 = 0x6c636d2073656c66
shortPacket = []byte{
0x4c, 0x43, 0x30, 0x32, 0x00, 0x00, 0x00, 0x00, 0x4c, 0x43, 0x4d, 0x5f,
0x53, 0x45, 0x4c, 0x46, 0x5f, 0x54, 0x45, 0x53, 0x54, 0x00, 0x6c, 0x63,
0x6d, 0x20, 0x73, 0x65, 0x6c, 0x66, 0x20, 0x74, 0x65, 0x73, 0x74,
}
fragmentedPacket = []byte{
0x4c, 0x43, 0x30, 0x33, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x0d,
0x00, 0x00, 0x00, 0x2d, 0x00, 0x00, 0x00, 0x02, 0x4c, 0x43, 0x4d, 0x5f,
0x53, 0x45, 0x4c, 0x46, 0x5f, 0x54, 0x45, 0x53, 0x54, 0x00, 0x6c, 0x63,
0x6d, 0x20, 0x73, 0x65, 0x6c, 0x66, 0x20, 0x74, 0x65, 0x73, 0x74,
}
invalidPacket = []byte{
0x4c, 0x43, 0x30, 0x34, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
}
expectedChannel = "LCM_SELF_TEST"
)
func TestLCMDecode(t *testing.T) {
testShortLCM(t)
testFragmentedLCM(t)
testInvalidLCM(t)
}
func testShortLCM(t *testing.T) {
lcm := &LCM{}
err := lcm.DecodeFromBytes(shortPacket, gopacket.NilDecodeFeedback)
if err != nil {
t.Fatal(err)
}
if lcm.Magic != LCMShortHeaderMagic {
t.Errorf("Expected LCM Magic %x, but decoded %x.\n",
LCMShortHeaderMagic, lcm.Magic)
}
if lcm.SequenceNumber != 0x00 {
t.Errorf("Expected an LCM Sequence Number of %x, but decoded %x.\n",
0x00, lcm.SequenceNumber)
}
if lcm.ChannelName != expectedChannel {
t.Errorf("Expected channel name %s but received %s\n",
expectedChannel, lcm.ChannelName)
}
if lcm.Fragmented {
t.Errorf("Misinterpreted non-fragmented packet as fragmented.")
}
for i, val := range lcm.LayerContents() {
if val != shortPacket[i] {
t.Errorf("\nLCM Payload: expected\n%sbut received\n%s",
hex.Dump(shortPacket[:22]), hex.Dump(lcm.Payload()))
}
}
for i, val := range lcm.Payload() {
if val != shortPacket[i+22] {
t.Errorf("\nLCM Payload: expected\n%sbut received\n%s",
hex.Dump(shortPacket[22:]), hex.Dump(lcm.Payload()))
}
}
}
func testFragmentedLCM(t *testing.T) {
lcm := LCM{}
err := lcm.DecodeFromBytes(fragmentedPacket, gopacket.NilDecodeFeedback)
if err != nil {
t.Fatal(err)
}
if lcm.Magic != LCMFragmentedHeaderMagic {
t.Errorf("Expected LCM Magic %x, but decoded %x.\n",
LCMFragmentedHeaderMagic, lcm.Magic)
}
if lcm.SequenceNumber != 0x01 {
t.Errorf("Expected an LCM Sequence Number of %x, but decoded %x.\n",
0x01, lcm.SequenceNumber)
}
if lcm.PayloadSize != 0x0d {
t.Errorf("Expected an LCM Payload Size of %x, but decoded %x.\n", 0x0d,
lcm.PayloadSize)
}
if lcm.FragmentOffset != 0x2d {
t.Errorf("Expected an LCM Fragment Offset of %x, but decoded %x.\n",
0x2d, lcm.FragmentOffset)
}
if lcm.FragmentNumber != 0x00 {
t.Errorf("Expected the first LCM fragment (%x), but decoded %x.\n",
0x00, lcm.FragmentNumber)
}
if lcm.TotalFragments != 0x02 {
t.Errorf("Expected two LCM fragments (%x), but decoded %x.\n", 0x02,
lcm.TotalFragments)
}
if lcm.ChannelName != expectedChannel {
t.Errorf("Expected LCM Channel Name %s but decoded %s\n",
expectedChannel, lcm.ChannelName)
}
if !lcm.Fragmented {
t.Errorf("Misinterpreted fragmented packet as non-fragmented.")
}
for i, val := range lcm.LayerContents() {
if val != fragmentedPacket[i] {
t.Errorf("\nLCM Payload: expected\n%sbut received\n%s",
hex.Dump(fragmentedPacket[:22]), hex.Dump(lcm.Payload()))
}
}
for i, val := range lcm.Payload() {
if val != fragmentedPacket[i+34] {
t.Errorf("\nLCM Payload: expected\n%sbut received\n%s",
hex.Dump(fragmentedPacket[34:]), hex.Dump(lcm.Payload()))
}
}
}
func testInvalidLCM(t *testing.T) {
lcm := LCM{}
err := lcm.DecodeFromBytes(invalidPacket, gopacket.NilDecodeFeedback)
if err == nil {
t.Fatal("Did not detect LCM decode error.")
}
}
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