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tailscale/wgengine/packet/packet_test.go

350 lines
8.0 KiB
Go

// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"bytes"
"net"
"reflect"
"testing"
)
func TestIPString(t *testing.T) {
const str = "1.2.3.4"
ip := NewIP(net.ParseIP(str))
var got string
allocs := testing.AllocsPerRun(1000, func() {
got = ip.String()
})
if got != str {
t.Errorf("got %q; want %q", got, str)
}
if allocs != 1 {
t.Errorf("allocs = %v; want 1", allocs)
}
}
var icmpRequestBuffer = []byte{
// IP header up to checksum
0x45, 0x00, 0x00, 0x27, 0xde, 0xad, 0x00, 0x00, 0x40, 0x01, 0x8c, 0x15,
// source ip
0x01, 0x02, 0x03, 0x04,
// destination ip
0x05, 0x06, 0x07, 0x08,
// ICMP header
0x08, 0x00, 0x7d, 0x22,
// "request_payload"
0x72, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x5f, 0x70, 0x61, 0x79, 0x6c, 0x6f, 0x61, 0x64,
}
var icmpRequestDecode = ParsedPacket{
b: icmpRequestBuffer,
subofs: 20,
dataofs: 24,
length: len(icmpRequestBuffer),
IPVersion: 4,
IPProto: ICMP,
SrcIP: NewIP(net.ParseIP("1.2.3.4")),
DstIP: NewIP(net.ParseIP("5.6.7.8")),
SrcPort: 0,
DstPort: 0,
}
var icmpReplyBuffer = []byte{
0x45, 0x00, 0x00, 0x25, 0x21, 0x52, 0x00, 0x00, 0x40, 0x01, 0x49, 0x73,
// source ip
0x05, 0x06, 0x07, 0x08,
// destination ip
0x01, 0x02, 0x03, 0x04,
// ICMP header
0x00, 0x00, 0xe6, 0x9e,
// "reply_payload"
0x72, 0x65, 0x70, 0x6c, 0x79, 0x5f, 0x70, 0x61, 0x79, 0x6c, 0x6f, 0x61, 0x64,
}
var icmpReplyDecode = ParsedPacket{
b: icmpReplyBuffer,
subofs: 20,
dataofs: 24,
length: len(icmpReplyBuffer),
IPVersion: 4,
IPProto: ICMP,
SrcIP: NewIP(net.ParseIP("1.2.3.4")),
DstIP: NewIP(net.ParseIP("5.6.7.8")),
SrcPort: 0,
DstPort: 0,
}
// IPv6 Router Solicitation
var ipv6PacketBuffer = []byte{
0x60, 0x00, 0x00, 0x00, 0x00, 0x08, 0x3a, 0xff,
0xfe, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0xfb, 0x57, 0x1d, 0xea, 0x9c, 0x39, 0x8f, 0xb7,
0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02,
0x85, 0x00, 0x38, 0x04, 0x00, 0x00, 0x00, 0x00,
}
var ipv6PacketDecode = ParsedPacket{
b: ipv6PacketBuffer,
IPVersion: 6,
IPProto: ICMPv6,
}
// This is a malformed IPv4 packet.
// Namely, the string "tcp_payload" follows the first byte of the IPv4 header.
var unknownPacketBuffer = []byte{
0x45, 0x74, 0x63, 0x70, 0x5f, 0x70, 0x61, 0x79, 0x6c, 0x6f, 0x61, 0x64,
}
var unknownPacketDecode = ParsedPacket{
b: unknownPacketBuffer,
IPVersion: 0,
IPProto: Unknown,
}
var tcpPacketBuffer = []byte{
// IP header up to checksum
0x45, 0x00, 0x00, 0x37, 0xde, 0xad, 0x00, 0x00, 0x40, 0x06, 0x49, 0x5f,
// source ip
0x01, 0x02, 0x03, 0x04,
// destination ip
0x05, 0x06, 0x07, 0x08,
// TCP header with SYN, ACK set
0x00, 0x7b, 0x02, 0x37, 0x00, 0x00, 0x12, 0x34, 0x00, 0x00, 0x00, 0x00,
0x50, 0x12, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
// "request_payload"
0x72, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x5f, 0x70, 0x61, 0x79, 0x6c, 0x6f, 0x61, 0x64,
}
var tcpPacketDecode = ParsedPacket{
b: tcpPacketBuffer,
subofs: 20,
dataofs: 40,
length: len(tcpPacketBuffer),
IPVersion: 4,
IPProto: TCP,
SrcIP: NewIP(net.ParseIP("1.2.3.4")),
DstIP: NewIP(net.ParseIP("5.6.7.8")),
SrcPort: 123,
DstPort: 567,
TCPFlags: TCPSynAck,
}
var udpRequestBuffer = []byte{
// IP header up to checksum
0x45, 0x00, 0x00, 0x2b, 0xde, 0xad, 0x00, 0x00, 0x40, 0x11, 0x8c, 0x01,
// source ip
0x01, 0x02, 0x03, 0x04,
// destination ip
0x05, 0x06, 0x07, 0x08,
// UDP header
0x00, 0x7b, 0x02, 0x37, 0x00, 0x17, 0x72, 0x1d,
// "request_payload"
0x72, 0x65, 0x71, 0x75, 0x65, 0x73, 0x74, 0x5f, 0x70, 0x61, 0x79, 0x6c, 0x6f, 0x61, 0x64,
}
var udpRequestDecode = ParsedPacket{
b: udpRequestBuffer,
subofs: 20,
dataofs: 28,
length: len(udpRequestBuffer),
IPVersion: 4,
IPProto: UDP,
SrcIP: NewIP(net.ParseIP("1.2.3.4")),
DstIP: NewIP(net.ParseIP("5.6.7.8")),
SrcPort: 123,
DstPort: 567,
}
var udpReplyBuffer = []byte{
// IP header up to checksum
0x45, 0x00, 0x00, 0x29, 0x21, 0x52, 0x00, 0x00, 0x40, 0x11, 0x49, 0x5f,
// source ip
0x05, 0x06, 0x07, 0x08,
// destination ip
0x01, 0x02, 0x03, 0x04,
// UDP header
0x02, 0x37, 0x00, 0x7b, 0x00, 0x15, 0xd3, 0x9d,
// "reply_payload"
0x72, 0x65, 0x70, 0x6c, 0x79, 0x5f, 0x70, 0x61, 0x79, 0x6c, 0x6f, 0x61, 0x64,
}
var udpReplyDecode = ParsedPacket{
b: udpReplyBuffer,
subofs: 20,
dataofs: 28,
length: len(udpReplyBuffer),
IPProto: UDP,
SrcIP: NewIP(net.ParseIP("1.2.3.4")),
DstIP: NewIP(net.ParseIP("5.6.7.8")),
SrcPort: 567,
DstPort: 123,
}
func TestParsedPacket(t *testing.T) {
tests := []struct {
name string
qdecode ParsedPacket
want string
}{
{"tcp", tcpPacketDecode, "TCP{1.2.3.4:123 > 5.6.7.8:567}"},
{"icmp", icmpRequestDecode, "ICMP{1.2.3.4:0 > 5.6.7.8:0}"},
{"unknown", unknownPacketDecode, "Unknown{???}"},
{"ipv6", ipv6PacketDecode, "IPv6{Proto=58}"},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got := tt.qdecode.String()
if got != tt.want {
t.Errorf("got %q; want %q", got, tt.want)
}
})
}
var sink string
allocs := testing.AllocsPerRun(1000, func() {
sink = tests[0].qdecode.String()
})
_ = sink
if allocs != 1 {
t.Errorf("allocs = %v; want 1", allocs)
}
}
func TestDecode(t *testing.T) {
tests := []struct {
name string
buf []byte
want ParsedPacket
}{
{"icmp", icmpRequestBuffer, icmpRequestDecode},
{"ipv6", ipv6PacketBuffer, ipv6PacketDecode},
{"unknown", unknownPacketBuffer, unknownPacketDecode},
{"tcp", tcpPacketBuffer, tcpPacketDecode},
{"udp", udpRequestBuffer, udpRequestDecode},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
var got ParsedPacket
got.Decode(tt.buf)
if !reflect.DeepEqual(got, tt.want) {
t.Errorf("mismatch\n got: %#v\nwant: %#v", got, tt.want)
}
})
}
allocs := testing.AllocsPerRun(1000, func() {
var got ParsedPacket
got.Decode(tests[0].buf)
})
if allocs != 0 {
t.Errorf("allocs = %v; want 0", allocs)
}
}
func BenchmarkDecode(b *testing.B) {
benches := []struct {
name string
buf []byte
}{
{"icmp", icmpRequestBuffer},
{"unknown", unknownPacketBuffer},
{"tcp", tcpPacketBuffer},
}
for _, bench := range benches {
b.Run(bench.name, func(b *testing.B) {
for i := 0; i < b.N; i++ {
var p ParsedPacket
p.Decode(bench.buf)
}
})
}
}
func TestMarshalRequest(t *testing.T) {
// Too small to hold our packets, but only barely.
var small [20]byte
var large [64]byte
icmpHeader := icmpRequestDecode.ICMPHeader()
udpHeader := udpRequestDecode.UDPHeader()
tests := []struct {
name string
header Header
want []byte
}{
{"icmp", &icmpHeader, icmpRequestBuffer},
{"udp", &udpHeader, udpRequestBuffer},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
err := tt.header.Marshal(small[:])
if err != errSmallBuffer {
t.Errorf("got err: nil; want: %s", errSmallBuffer)
}
dataOffset := tt.header.Len()
dataLength := copy(large[dataOffset:], []byte("request_payload"))
end := dataOffset + dataLength
err = tt.header.Marshal(large[:end])
if err != nil {
t.Errorf("got err: %s; want nil", err)
}
if !bytes.Equal(large[:end], tt.want) {
t.Errorf("got %x; want %x", large[:end], tt.want)
}
})
}
}
func TestMarshalResponse(t *testing.T) {
var buf [64]byte
icmpHeader := icmpRequestDecode.ICMPHeader()
udpHeader := udpRequestDecode.UDPHeader()
tests := []struct {
name string
header Header
want []byte
}{
{"icmp", &icmpHeader, icmpReplyBuffer},
{"udp", &udpHeader, udpReplyBuffer},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
tt.header.ToResponse()
dataOffset := tt.header.Len()
dataLength := copy(buf[dataOffset:], []byte("reply_payload"))
end := dataOffset + dataLength
err := tt.header.Marshal(buf[:end])
if err != nil {
t.Errorf("got err: %s; want nil", err)
}
if !bytes.Equal(buf[:end], tt.want) {
t.Errorf("got %x; want %x", buf[:end], tt.want)
}
})
}
}