Function TestDecodeBadPackets

packet/decoder_test.go:166–216

TestDecodeBadPackets makes sure decoders don't decode invalid packets

(t *testing.T)

// TestDecodeBadPackets makes sure decoders don't decode invalid packets
func TestDecodeBadPackets(t *testing.T) {
	var (
		srcIPv4 = net.ParseIP("172.16.0.1")
		dstIPv4 = net.ParseIP("10.0.0.1")
	)

	ipLayer := layers.IPv4{
		Version:  10,
		SrcIP:    srcIPv4,
		DstIP:    dstIPv4,
		Protocol: layers.IPProtocolICMPv4,
		TTL:      DefaultTTL,
	}
	icmpLayer := layers.ICMPv4{
		TypeCode: layers.CreateICMPv4TypeCode(uint8(ipv4.ICMPTypeEcho), 0),
		Id:       100,
		Seq:      52819,
	}
	wrongIPVersion, err := createPacket(&ipLayer, &icmpLayer, nil, nil)
	require.NoError(t, err)

	tests := []struct {
		testCase string
		packet   []byte
	}{
		{
			testCase: "unknown IP version",
			packet:   wrongIPVersion,
		},
		{
			testCase: "invalid packet",
			packet:   []byte("not a packet"),
		},
		{
			testCase: "zero length packet",
			packet:   []byte{},
		},
	}

	ipDecoder := NewIPDecoder()
	icmpDecoder := NewICMPDecoder()
	for _, test := range tests {
		ipPacket, err := ipDecoder.Decode(RawPacket{Data: test.packet})
		require.Error(t, err)
		require.Nil(t, ipPacket)

		icmpPacket, err := icmpDecoder.Decode(RawPacket{Data: test.packet})
		require.Error(t, err)
		require.Nil(t, icmpPacket)
	}
}

func createPacket(ipLayer, secondLayer, thirdLayer gopacket.SerializableLayer, body []byte) ([]byte, error) {
	payload := gopacket.Payload(body)