tailscale/net/packet/packet_test.go
Will Norris 3ec5be3f51 all: remove AUTHORS file and references to it
This file was never truly necessary and has never actually been used in
the history of Tailscale's open source releases.

A Brief History of AUTHORS files
---

The AUTHORS file was a pattern developed at Google, originally for
Chromium, then adopted by Go and a bunch of other projects. The problem
was that Chromium originally had a copyright line only recognizing
Google as the copyright holder. Because Google (and most open source
projects) do not require copyright assignemnt for contributions, each
contributor maintains their copyright. Some large corporate contributors
then tried to add their own name to the copyright line in the LICENSE
file or in file headers. This quickly becomes unwieldy, and puts a
tremendous burden on anyone building on top of Chromium, since the
license requires that they keep all copyright lines intact.

The compromise was to create an AUTHORS file that would list all of the
copyright holders. The LICENSE file and source file headers would then
include that list by reference, listing the copyright holder as "The
Chromium Authors".

This also become cumbersome to simply keep the file up to date with a
high rate of new contributors. Plus it's not always obvious who the
copyright holder is. Sometimes it is the individual making the
contribution, but many times it may be their employer. There is no way
for the proejct maintainer to know.

Eventually, Google changed their policy to no longer recommend trying to
keep the AUTHORS file up to date proactively, and instead to only add to
it when requested: https://opensource.google/docs/releasing/authors.
They are also clear that:

> Adding contributors to the AUTHORS file is entirely within the
> project's discretion and has no implications for copyright ownership.

It was primarily added to appease a small number of large contributors
that insisted that they be recognized as copyright holders (which was
entirely their right to do). But it's not truly necessary, and not even
the most accurate way of identifying contributors and/or copyright
holders.

In practice, we've never added anyone to our AUTHORS file. It only lists
Tailscale, so it's not really serving any purpose. It also causes
confusion because Tailscalars put the "Tailscale Inc & AUTHORS" header
in other open source repos which don't actually have an AUTHORS file, so
it's ambiguous what that means.

Instead, we just acknowledge that the contributors to Tailscale (whoever
they are) are copyright holders for their individual contributions. We
also have the benefit of using the DCO (developercertificate.org) which
provides some additional certification of their right to make the
contribution.

The source file changes were purely mechanical with:

    git ls-files | xargs sed -i -e 's/\(Tailscale Inc &\) AUTHORS/\1 contributors/g'

Updates #cleanup

Change-Id: Ia101a4a3005adb9118051b3416f5a64a4a45987d
Signed-off-by: Will Norris <will@tailscale.com>
2026-01-23 15:49:45 -08:00

755 lines
22 KiB
Go

// Copyright (c) Tailscale Inc & contributors
// SPDX-License-Identifier: BSD-3-Clause
package packet
import (
"bytes"
"encoding/hex"
"net/netip"
"reflect"
"strings"
"testing"
"unicode"
"tailscale.com/tstest"
"tailscale.com/types/ipproto"
"tailscale.com/util/must"
)
const (
Unknown = ipproto.Unknown
TCP = ipproto.TCP
UDP = ipproto.UDP
SCTP = ipproto.SCTP
IGMP = ipproto.IGMP
ICMPv4 = ipproto.ICMPv4
ICMPv6 = ipproto.ICMPv6
TSMP = ipproto.TSMP
Fragment = ipproto.Fragment
)
func mustIPPort(s string) netip.AddrPort {
ipp, err := netip.ParseAddrPort(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,
}
// 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,
}
// First TCP fragment of a packet with leading 24 bytes of 'a's
var tcp4MediumFragmentBuffer = []byte{
// IP header up to checksum
0x45, 0x20, 0x00, 0x4c, 0x2c, 0x62, 0x20, 0x00, 0x22, 0x06, 0x3a, 0x0f,
// source IP
0x01, 0x02, 0x03, 0x04,
// destination IP
0x05, 0x06, 0x07, 0x08,
// TCP header
0x00, 0x50, 0xf3, 0x8c, 0x58, 0xad, 0x60, 0x94, 0x25, 0xe4, 0x23, 0xa8, 0x80,
0x10, 0x01, 0xfd, 0xc6, 0x6e, 0x00, 0x00, 0x01, 0x01, 0x08, 0x0a, 0xff, 0x60,
0xfb, 0xfe, 0xba, 0x31, 0x78, 0x6a,
// data
0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61,
0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61,
}
var tcp4MediumFragmentDecode = Parsed{
b: tcp4MediumFragmentBuffer,
subofs: 20,
dataofs: 52,
length: len(tcp4MediumFragmentBuffer),
IPVersion: 4,
IPProto: TCP,
Src: mustIPPort("1.2.3.4:80"),
Dst: mustIPPort("5.6.7.8:62348"),
TCPFlags: 0x10,
}
var tcp4ShortFragmentBuffer = []byte{
// IP header up to checksum
0x45, 0x20, 0x00, 0x1e, 0x2c, 0x62, 0x20, 0x00, 0x22, 0x06, 0x3c, 0x4f,
// source IP
0x01, 0x02, 0x03, 0x04,
// destination IP
0x05, 0x06, 0x07, 0x08,
// partial TCP header
0x00, 0x50, 0xf3, 0x8c, 0x58, 0xad, 0x60, 0x94, 0x00, 0x00,
}
var tcp4ShortFragmentDecode = Parsed{
b: tcp4ShortFragmentBuffer,
subofs: 20,
dataofs: 0,
length: len(tcp4ShortFragmentBuffer),
// short fragments are rejected (marked unknown) to avoid header attacks as described in RFC 1858
IPProto: ipproto.Unknown,
IPVersion: 4,
Src: mustIPPort("1.2.3.4:0"),
Dst: mustIPPort("5.6.7.8:0"),
}
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"),
}
// IPv4 SCTP
var sctpBuffer = []byte{
// IPv4 header:
0x45, 0x00,
0x00, 0x20, // 20 + 12 bytes total
0x00, 0x00, // ID
0x00, 0x00, // Fragment
0x40, // TTL
byte(SCTP),
// Checksum, unchecked:
1, 2,
// source IP:
0x64, 0x5e, 0x0c, 0x0e,
// dest IP:
0x64, 0x4a, 0x46, 0x03,
// Src Port, Dest Port:
0x00, 0x7b, 0x01, 0xc8,
// Verification tag:
1, 2, 3, 4,
// Checksum: (unchecked)
5, 6, 7, 8,
}
var sctpDecode = Parsed{
b: sctpBuffer,
subofs: 20,
length: 20 + 12,
IPVersion: 4,
IPProto: SCTP,
Src: mustIPPort("100.94.12.14:123"),
Dst: mustIPPort("100.74.70.3:456"),
}
var ipv4ShortFirstFragmentBuffer = []byte{
// IP header (20 bytes)
0x45, 0x00, 0x00, 0x4f, // Total length 79 bytes
0x00, 0x01, 0x20, 0x00, // ID, Flags (MoreFragments set, offset 0)
0x40, 0x06, 0x00, 0x00, // TTL, Protocol (TCP), Checksum
0x01, 0x02, 0x03, 0x04, // Source IP
0x05, 0x06, 0x07, 0x08, // Destination IP
// TCP header (20 bytes), but packet is truncated to 59 bytes of TCP data
// (total 79 bytes, 20 for IP)
0x00, 0x7b, 0x02, 0x37, 0x00, 0x00, 0x12, 0x34, 0x00, 0x00, 0x00, 0x00,
0x50, 0x12, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00,
// Payload (39 bytes)
0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61,
0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61,
0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61,
}
var ipv4ShortFirstFragmentDecode = Parsed{
b: ipv4ShortFirstFragmentBuffer,
subofs: 20,
dataofs: 40,
length: len(ipv4ShortFirstFragmentBuffer),
IPVersion: 4,
IPProto: ipproto.TCP,
Src: mustIPPort("1.2.3.4:123"),
Dst: mustIPPort("5.6.7.8:567"),
TCPFlags: 0x12, // SYN + ACK
}
var ipv4SmallOffsetFragmentBuffer = []byte{
// IP header (20 bytes)
0x45, 0x00, 0x00, 0x28, // Total length 40 bytes
0x00, 0x01, 0x20, 0x08, // ID, Flags (MoreFragments set, offset 8 bytes (0x08 / 8 = 1))
0x40, 0x06, 0x00, 0x00, // TTL, Protocol (TCP), Checksum
0x01, 0x02, 0x03, 0x04, // Source IP
0x05, 0x06, 0x07, 0x08, // Destination IP
// Payload (20 bytes) - this would be part of the TCP header in a real scenario
0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61, 0x61,
0x61, 0x61, 0x61, 0x61,
}
var ipv4SmallOffsetFragmentDecode = Parsed{
b: ipv4SmallOffsetFragmentBuffer,
subofs: 20, // subofs will still be set based on IHL
dataofs: 0, // It's unknown, so dataofs should be 0
length: len(ipv4SmallOffsetFragmentBuffer),
IPVersion: 4,
IPProto: ipproto.Unknown, // Expected to be Unknown
Src: mustIPPort("1.2.3.4:0"),
Dst: mustIPPort("5.6.7.8:0"),
}
// First fragment packet missing exactly one byte of the TCP header
var ipv4OneByteShortTCPHeaderBuffer = []byte{
// IP header (20 bytes)
0x45, 0x00, 0x00, 0x27, // Total length 51 bytes (20 IP + 19 TCP)
0x00, 0x01, 0x20, 0x00, // ID, Flags (MoreFragments set, offset 0)
0x40, 0x06, 0x00, 0x00, // TTL, Protocol (TCP), Checksum
0x01, 0x02, 0x03, 0x04, // Source IP
0x05, 0x06, 0x07, 0x08, // Destination IP
// TCP header - only 19 bytes (one byte short of the required 20)
0x00, 0x7b, 0x02, 0x37, // Source port, Destination port
0x00, 0x00, 0x12, 0x34, // Sequence number
0x00, 0x00, 0x00, 0x00, // Acknowledgment number
0x50, 0x12, 0x01, 0x00, // Data offset, flags, window size
0x00, 0x00, 0x00, // Checksum (missing the last byte of urgent pointer)
}
// IPv4 packet with maximum header length (60 bytes = 15 words) and a TCP header that's
// one byte short of being complete
var ipv4MaxHeaderShortTCPBuffer = []byte{
// IP header with max options (60 bytes)
0x4F, 0x00, 0x00, 0x4F, // Version (4) + IHL (15), ToS, Total length 79 bytes (60 IP + 19 TCP)
0x00, 0x01, 0x20, 0x00, // ID, Flags (MoreFragments set, offset 0)
0x40, 0x06, 0x00, 0x00, // TTL, Protocol (TCP), Checksum
0x01, 0x02, 0x03, 0x04, // Source IP
0x05, 0x06, 0x07, 0x08, // Destination IP
// IPv4 options (40 bytes)
0x01, 0x01, 0x01, 0x01, // 4 NOP options (padding)
0x01, 0x01, 0x01, 0x01, // 4 NOP options (padding)
0x01, 0x01, 0x01, 0x01, // 4 NOP options (padding)
0x01, 0x01, 0x01, 0x01, // 4 NOP options (padding)
0x01, 0x01, 0x01, 0x01, // 4 NOP options (padding)
0x01, 0x01, 0x01, 0x01, // 4 NOP options (padding)
0x01, 0x01, 0x01, 0x01, // 4 NOP options (padding)
0x01, 0x01, 0x01, 0x01, // 4 NOP options (padding)
0x01, 0x01, 0x01, 0x01, // 4 NOP options (padding)
0x01, 0x01, 0x01, 0x01, // 4 NOP options (padding)
// TCP header - only 19 bytes (one byte short of the required 20)
0x00, 0x7b, 0x02, 0x37, // Source port, Destination port
0x00, 0x00, 0x12, 0x34, // Sequence number
0x00, 0x00, 0x00, 0x00, // Acknowledgment number
0x50, 0x12, 0x01, 0x00, // Data offset, flags, window size
0x00, 0x00, 0x00, // Checksum (missing the last byte of urgent pointer)
}
var ipv4MaxHeaderShortTCPDecode = Parsed{
b: ipv4MaxHeaderShortTCPBuffer,
subofs: 60, // 60 bytes for full IPv4 header with max options
dataofs: 0, // It's unknown, so dataofs should be 0
length: len(ipv4MaxHeaderShortTCPBuffer),
IPVersion: 4,
IPProto: ipproto.Unknown, // Expected to be Unknown
Src: mustIPPort("1.2.3.4:0"),
Dst: mustIPPort("5.6.7.8:0"),
}
var ipv4OneByteShortTCPHeaderDecode = Parsed{
b: ipv4OneByteShortTCPHeaderBuffer,
subofs: 20,
dataofs: 0, // It's unknown, so dataofs should be 0
length: len(ipv4OneByteShortTCPHeaderBuffer),
IPVersion: 4,
IPProto: ipproto.Unknown, // Expected to be Unknown
Src: mustIPPort("1.2.3.4:0"),
Dst: mustIPPort("5.6.7.8:0"),
}
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}"},
{"sctp", sctpDecode, "SCTP{100.94.12.14:123 > 100.74.70.3:456}"},
}
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)
}
})
}
err := tstest.MinAllocsPerRun(t, 1, func() {
sinkString = tests[0].qdecode.String()
})
if err != nil {
t.Error(err)
}
}
// mustHexDecode is like hex.DecodeString, but panics on error
// and ignores whitespace in s.
func mustHexDecode(s string) []byte {
return must.Get(hex.DecodeString(strings.Map(func(r rune) rune {
if unicode.IsSpace(r) {
return -1
}
return r
}, s)))
}
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},
{"ipv4_sctp", sctpBuffer, sctpDecode},
{"ipv4_frag", tcp4MediumFragmentBuffer, tcp4MediumFragmentDecode},
{"ipv4_fragtooshort", tcp4ShortFragmentBuffer, tcp4ShortFragmentDecode},
{"ipv4_short_first_fragment", ipv4ShortFirstFragmentBuffer, ipv4ShortFirstFragmentDecode},
{"ipv4_small_offset_fragment", ipv4SmallOffsetFragmentBuffer, ipv4SmallOffsetFragmentDecode},
{"ipv4_one_byte_short_tcp_header", ipv4OneByteShortTCPHeaderBuffer, ipv4OneByteShortTCPHeaderDecode},
{"ipv4_max_header_short_tcp", ipv4MaxHeaderShortTCPBuffer, ipv4MaxHeaderShortTCPDecode},
{"ip97", mustHexDecode("4500 0019 d186 4000 4061 751d 644a 4603 6449 e549 6865 6c6c 6f"), Parsed{
IPVersion: 4,
IPProto: 97,
Src: netip.MustParseAddrPort("100.74.70.3:0"),
Dst: netip.MustParseAddrPort("100.73.229.73:0"),
b: mustHexDecode("4500 0019 d186 4000 4061 751d 644a 4603 6449 e549 6865 6c6c 6f"),
length: 25,
subofs: 20,
}},
// This packet purports to use protocol 0xFF, which is verboten and
// used internally as a sentinel value for fragments. So test that
// we map packets using 0xFF to Unknown (0) instead.
{"bogus_proto_ff", mustHexDecode("4500 0019 d186 4000 40" + "FF" /* bogus FF */ + " 751d 644a 4603 6449 e549 6865 6c6c 6f"), Parsed{
IPVersion: 4,
IPProto: ipproto.Unknown, // 0, not bogus 0xFF
Src: netip.MustParseAddrPort("100.74.70.3:0"),
Dst: netip.MustParseAddrPort("100.73.229.73:0"),
b: mustHexDecode("4500 0019 d186 4000 40" + "FF" /* bogus FF */ + " 751d 644a 4603 6449 e549 6865 6c6c 6f"),
length: 25,
subofs: 20,
}},
}
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)
}
})
}
err := tstest.MinAllocsPerRun(t, 0, func() {
var got Parsed
got.Decode(tests[0].buf)
})
if err != nil {
t.Error(err)
}
}
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 range b.N {
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)
}
})
}
}
var sinkString string
func BenchmarkString(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()
var p Parsed
p.Decode(bench.buf)
b.ResetTimer()
for range b.N {
sinkString = p.String()
}
})
}
}