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tailscale/net/packet/packet_test.go

487 lines
12 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"
"reflect"
"testing"
"inet.af/netaddr"
)
func mustIPPort(s string) netaddr.IPPort {
ipp, err := netaddr.ParseIPPort(s)
if err != nil {
panic(err)
}
return ipp
}
var icmp4RequestBuffer = []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 icmp4RequestDecode = Parsed{
b: icmp4RequestBuffer,
subofs: 20,
dataofs: 24,
length: len(icmp4RequestBuffer),
IPVersion: 4,
IPProto: ICMPv4,
Src: mustIPPort("1.2.3.4:0"),
Dst: mustIPPort("5.6.7.8:0"),
}
var icmp4ReplyBuffer = []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 icmp4ReplyDecode = Parsed{
b: icmp4ReplyBuffer,
subofs: 20,
dataofs: 24,
length: len(icmp4ReplyBuffer),
IPVersion: 4,
IPProto: ICMPv4,
Src: mustIPPort("1.2.3.4:0"),
Dst: mustIPPort("5.6.7.8:0"),
}
// ICMPv6 Router Solicitation
var icmp6PacketBuffer = []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 icmp6PacketDecode = Parsed{
b: icmp6PacketBuffer,
subofs: 40,
dataofs: 44,
length: len(icmp6PacketBuffer),
IPVersion: 6,
IPProto: ICMPv6,
Src: mustIPPort("[fe80::fb57:1dea:9c39:8fb7]:0"),
Dst: mustIPPort("[ff02::2]:0"),
}
// 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 = Parsed{
b: unknownPacketBuffer,
IPVersion: 0,
IPProto: Unknown,
}
var tcp4PacketBuffer = []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 tcp4PacketDecode = Parsed{
b: tcp4PacketBuffer,
subofs: 20,
dataofs: 40,
length: len(tcp4PacketBuffer),
IPVersion: 4,
IPProto: TCP,
Src: mustIPPort("1.2.3.4:123"),
Dst: mustIPPort("5.6.7.8:567"),
TCPFlags: TCPSynAck,
}
var tcp6RequestBuffer = []byte{
// IPv6 header up to hop limit
0x60, 0x06, 0xef, 0xcc, 0x00, 0x28, 0x06, 0x40,
// Src addr
0x20, 0x01, 0x05, 0x59, 0xbc, 0x13, 0x54, 0x00, 0x17, 0x49, 0x46, 0x28, 0x39, 0x34, 0x0e, 0x1b,
// Dst addr
0x26, 0x07, 0xf8, 0xb0, 0x40, 0x0a, 0x08, 0x09, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0x0e,
// TCP SYN segment, no payload
0xa4, 0x60, 0x00, 0x50, 0xf3, 0x82, 0xa1, 0x25, 0x00, 0x00, 0x00, 0x00, 0xa0, 0x02, 0xfd, 0x20,
0xb1, 0xc6, 0x00, 0x00, 0x02, 0x04, 0x05, 0xa0, 0x04, 0x02, 0x08, 0x0a, 0xca, 0x76, 0xa6, 0x8e,
0x00, 0x00, 0x00, 0x00, 0x01, 0x03, 0x03, 0x07,
}
var tcp6RequestDecode = Parsed{
b: tcp6RequestBuffer,
subofs: 40,
dataofs: len(tcp6RequestBuffer),
length: len(tcp6RequestBuffer),
IPVersion: 6,
IPProto: TCP,
Src: mustIPPort("[2001:559:bc13:5400:1749:4628:3934:e1b]:42080"),
Dst: mustIPPort("[2607:f8b0:400a:809::200e]:80"),
TCPFlags: TCPSyn,
}
var udp4RequestBuffer = []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 udp4RequestDecode = Parsed{
b: udp4RequestBuffer,
subofs: 20,
dataofs: 28,
length: len(udp4RequestBuffer),
IPVersion: 4,
IPProto: UDP,
Src: mustIPPort("1.2.3.4:123"),
Dst: mustIPPort("5.6.7.8:567"),
}
var invalid4RequestBuffer = []byte{
// IP header up to checksum. IHL field points beyond end of packet.
0x4a, 0x00, 0x00, 0x14, 0xde, 0xad, 0x00, 0x00, 0x40, 0x11, 0x8c, 0x01,
// source ip
0x01, 0x02, 0x03, 0x04,
// destination ip
0x05, 0x06, 0x07, 0x08,
}
// Regression check for the IHL field pointing beyond the end of the
// packet.
var invalid4RequestDecode = Parsed{
b: invalid4RequestBuffer,
subofs: 40,
length: len(invalid4RequestBuffer),
IPVersion: 4,
IPProto: Unknown,
Src: mustIPPort("1.2.3.4:0"),
Dst: mustIPPort("5.6.7.8:0"),
}
var udp6RequestBuffer = []byte{
// IPv6 header up to hop limit
0x60, 0x0e, 0xc9, 0x67, 0x00, 0x29, 0x11, 0x40,
// Src addr
0x20, 0x01, 0x05, 0x59, 0xbc, 0x13, 0x54, 0x00, 0x17, 0x49, 0x46, 0x28, 0x39, 0x34, 0x0e, 0x1b,
// Dst addr
0x26, 0x07, 0xf8, 0xb0, 0x40, 0x0a, 0x08, 0x09, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0x0e,
// UDP header
0xd4, 0x04, 0x01, 0xbb, 0x00, 0x29, 0x96, 0x84,
// Payload
0x5c, 0x06, 0xae, 0x85, 0x02, 0xf5, 0xdb, 0x90, 0xe0, 0xe0, 0x93, 0xed, 0x9a, 0xd9, 0x92, 0x69, 0xbe, 0x36, 0x8a, 0x7d, 0xd7, 0xce, 0xd0, 0x8a, 0xf2, 0x51, 0x95, 0xff, 0xb6, 0x92, 0x70, 0x10, 0xd7,
}
var udp6RequestDecode = Parsed{
b: udp6RequestBuffer,
subofs: 40,
dataofs: 48,
length: len(udp6RequestBuffer),
IPVersion: 6,
IPProto: UDP,
Src: mustIPPort("[2001:559:bc13:5400:1749:4628:3934:e1b]:54276"),
Dst: mustIPPort("[2607:f8b0:400a:809::200e]:443"),
}
var udp4ReplyBuffer = []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 udp4ReplyDecode = Parsed{
b: udp4ReplyBuffer,
subofs: 20,
dataofs: 28,
length: len(udp4ReplyBuffer),
IPProto: UDP,
Src: mustIPPort("1.2.3.4:567"),
Dst: mustIPPort("5.6.7.8:123"),
}
var igmpPacketBuffer = []byte{
// IP header up to checksum
0x46, 0xc0, 0x00, 0x20, 0x00, 0x00, 0x40, 0x00, 0x01, 0x02, 0x41, 0x22,
// source IP
0xc0, 0xa8, 0x01, 0x52,
// destination IP
0xe0, 0x00, 0x00, 0xfb,
// IGMP Membership Report
0x94, 0x04, 0x00, 0x00, 0x16, 0x00, 0x09, 0x04, 0xe0, 0x00, 0x00, 0xfb,
//0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
}
var igmpPacketDecode = Parsed{
b: igmpPacketBuffer,
subofs: 24,
length: len(igmpPacketBuffer),
IPVersion: 4,
IPProto: IGMP,
Src: mustIPPort("192.168.1.82:0"),
Dst: mustIPPort("224.0.0.251:0"),
}
var ipv4TSMPBuffer = []byte{
// IPv4 header:
0x45, 0x00,
0x00, 0x1b, // 20 + 7 bytes total
0x00, 0x00, // ID
0x00, 0x00, // Fragment
0x40, // TTL
byte(TSMP),
0x5f, 0xc3, // header checksum (wrong here)
// source IP:
0x64, 0x5e, 0x0c, 0x0e,
// dest IP:
0x64, 0x4a, 0x46, 0x03,
byte(TSMPTypeRejectedConn),
byte(TCP),
byte(RejectedDueToACLs),
0x00, 123, // src port
0x00, 80, // dst port
}
var ipv4TSMPDecode = Parsed{
b: ipv4TSMPBuffer,
subofs: 20,
dataofs: 20,
length: 27,
IPVersion: 4,
IPProto: TSMP,
Src: mustIPPort("100.94.12.14:0"),
Dst: mustIPPort("100.74.70.3:0"),
}
func TestParsedString(t *testing.T) {
tests := []struct {
name string
qdecode Parsed
want string
}{
{"tcp4", tcp4PacketDecode, "TCP{1.2.3.4:123 > 5.6.7.8:567}"},
{"tcp6", tcp6RequestDecode, "TCP{[2001:559:bc13:5400:1749:4628:3934:e1b]:42080 > [2607:f8b0:400a:809::200e]:80}"},
{"udp4", udp4RequestDecode, "UDP{1.2.3.4:123 > 5.6.7.8:567}"},
{"udp6", udp6RequestDecode, "UDP{[2001:559:bc13:5400:1749:4628:3934:e1b]:54276 > [2607:f8b0:400a:809::200e]:443}"},
{"icmp4", icmp4RequestDecode, "ICMPv4{1.2.3.4:0 > 5.6.7.8:0}"},
{"icmp6", icmp6PacketDecode, "ICMPv6{[fe80::fb57:1dea:9c39:8fb7]:0 > [ff02::2]:0}"},
{"igmp", igmpPacketDecode, "IGMP{192.168.1.82:0 > 224.0.0.251:0}"},
{"unknown", unknownPacketDecode, "Unknown{???}"},
{"ipv4_tsmp", ipv4TSMPDecode, "TSMP{100.94.12.14:0 > 100.74.70.3:0}"},
}
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 Parsed
}{
{"icmp4", icmp4RequestBuffer, icmp4RequestDecode},
{"icmp6", icmp6PacketBuffer, icmp6PacketDecode},
{"tcp4", tcp4PacketBuffer, tcp4PacketDecode},
{"tcp6", tcp6RequestBuffer, tcp6RequestDecode},
{"udp4", udp4RequestBuffer, udp4RequestDecode},
{"udp6", udp6RequestBuffer, udp6RequestDecode},
{"igmp", igmpPacketBuffer, igmpPacketDecode},
{"unknown", unknownPacketBuffer, unknownPacketDecode},
{"invalid4", invalid4RequestBuffer, invalid4RequestDecode},
{"ipv4_tsmp", ipv4TSMPBuffer, ipv4TSMPDecode},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
var got Parsed
got.Decode(tt.buf)
if !reflect.DeepEqual(got, tt.want) {
t.Errorf("mismatch\n got: %s %#v\nwant: %s %#v", got.String(), got, tt.want.String(), tt.want)
}
})
}
allocs := testing.AllocsPerRun(1000, func() {
var got Parsed
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
}{
{"tcp4", tcp4PacketBuffer},
{"tcp6", tcp6RequestBuffer},
{"udp4", udp4RequestBuffer},
{"udp6", udp6RequestBuffer},
{"icmp4", icmp4RequestBuffer},
{"icmp6", icmp6PacketBuffer},
{"igmp", igmpPacketBuffer},
{"unknown", unknownPacketBuffer},
}
for _, bench := range benches {
b.Run(bench.name, func(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
var p Parsed
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 := icmp4RequestDecode.ICMP4Header()
udpHeader := udp4RequestDecode.UDP4Header()
tests := []struct {
name string
header Header
want []byte
}{
{"icmp", &icmpHeader, icmp4RequestBuffer},
{"udp", &udpHeader, udp4RequestBuffer},
}
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 := icmp4RequestDecode.ICMP4Header()
udpHeader := udp4RequestDecode.UDP4Header()
type HeaderToResponser interface {
Header
// ToResponse transforms the header into one for a response packet.
// For instance, this swaps the source and destination IPs.
ToResponse()
}
tests := []struct {
name string
header HeaderToResponser
want []byte
}{
{"icmp", &icmpHeader, icmp4ReplyBuffer},
{"udp", &udpHeader, udp4ReplyBuffer},
}
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)
}
})
}
}