// 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 deephash
import (
"archive/tar"
"bufio"
"bytes"
"crypto/sha256"
"fmt"
"math"
"reflect"
"runtime"
"testing"
"inet.af/netaddr"
"tailscale.com/tailcfg"
"tailscale.com/types/dnstype"
"tailscale.com/types/ipproto"
"tailscale.com/types/wgkey"
"tailscale.com/util/dnsname"
"tailscale.com/version"
"tailscale.com/wgengine/filter"
"tailscale.com/wgengine/router"
"tailscale.com/wgengine/wgcfg"
)
type appendBytes []byte
func (p appendBytes) AppendTo(b []byte) []byte {
return append(b, p...)
}
func TestHash(t *testing.T) {
type tuple [2]interface{}
type iface struct{ X interface{} }
type scalars struct {
I8 int8
I16 int16
I32 int32
I64 int64
I int
U8 uint8
U16 uint16
U32 uint32
U64 uint64
U uint
UP uintptr
F32 float32
F64 float64
C64 complex64
C128 complex128
}
type MyBool bool
type MyHeader tar.Header
tests := []struct {
in tuple
wantEq bool
}{
{in: tuple{false, true}, wantEq: false},
{in: tuple{true, true}, wantEq: true},
{in: tuple{false, false}, wantEq: true},
{
in: tuple{
scalars{-8, -16, -32, -64, -1234, 8, 16, 32, 64, 1234, 5678, 32.32, 64.64, 32 + 32i, 64 + 64i},
scalars{-8, -16, -32, -64, -1234, 8, 16, 32, 64, 1234, 5678, 32.32, 64.64, 32 + 32i, 64 + 64i},
},
wantEq: true,
},
{in: tuple{scalars{I8: math.MinInt8}, scalars{I8: math.MinInt8 / 2}}, wantEq: false},
{in: tuple{scalars{I16: math.MinInt16}, scalars{I16: math.MinInt16 / 2}}, wantEq: false},
{in: tuple{scalars{I32: math.MinInt32}, scalars{I32: math.MinInt32 / 2}}, wantEq: false},
{in: tuple{scalars{I64: math.MinInt64}, scalars{I64: math.MinInt64 / 2}}, wantEq: false},
{in: tuple{scalars{I: -1234}, scalars{I: -1234 / 2}}, wantEq: false},
{in: tuple{scalars{U8: math.MaxUint8}, scalars{U8: math.MaxUint8 / 2}}, wantEq: false},
{in: tuple{scalars{U16: math.MaxUint16}, scalars{U16: math.MaxUint16 / 2}}, wantEq: false},
{in: tuple{scalars{U32: math.MaxUint32}, scalars{U32: math.MaxUint32 / 2}}, wantEq: false},
{in: tuple{scalars{U64: math.MaxUint64}, scalars{U64: math.MaxUint64 / 2}}, wantEq: false},
{in: tuple{scalars{U: 1234}, scalars{U: 1234 / 2}}, wantEq: false},
{in: tuple{scalars{UP: 5678}, scalars{UP: 5678 / 2}}, wantEq: false},
{in: tuple{scalars{F32: 32.32}, scalars{F32: math.Nextafter32(32.32, 0)}}, wantEq: false},
{in: tuple{scalars{F64: 64.64}, scalars{F64: math.Nextafter(64.64, 0)}}, wantEq: false},
{in: tuple{scalars{F32: float32(math.NaN())}, scalars{F32: float32(math.NaN())}}, wantEq: true},
{in: tuple{scalars{F64: float64(math.NaN())}, scalars{F64: float64(math.NaN())}}, wantEq: true},
{in: tuple{scalars{C64: 32 + 32i}, scalars{C64: complex(math.Nextafter32(32, 0), 32)}}, wantEq: false},
{in: tuple{scalars{C128: 64 + 64i}, scalars{C128: complex(math.Nextafter(64, 0), 64)}}, wantEq: false},
{in: tuple{[]appendBytes{{}, {0, 0, 0, 0, 0, 0, 0, 1}}, []appendBytes{{}, {0, 0, 0, 0, 0, 0, 0, 1}}}, wantEq: true},
{in: tuple{[]appendBytes{{}, {0, 0, 0, 0, 0, 0, 0, 1}}, []appendBytes{{0, 0, 0, 0, 0, 0, 0, 1}, {}}}, wantEq: false},
{in: tuple{iface{MyBool(true)}, iface{MyBool(true)}}, wantEq: true},
{in: tuple{iface{true}, iface{MyBool(true)}}, wantEq: false},
{in: tuple{iface{MyHeader{}}, iface{MyHeader{}}}, wantEq: true},
{in: tuple{iface{MyHeader{}}, iface{tar.Header{}}}, wantEq: false},
{in: tuple{iface{&MyHeader{}}, iface{&MyHeader{}}}, wantEq: true},
{in: tuple{iface{&MyHeader{}}, iface{&tar.Header{}}}, wantEq: false},
{in: tuple{iface{[]map[string]MyBool{}}, iface{[]map[string]MyBool{}}}, wantEq: true},
{in: tuple{iface{[]map[string]bool{}}, iface{[]map[string]MyBool{}}}, wantEq: false},
{
in: func() tuple {
i1 := 1
i2 := 2
v1 := [3]*int{&i1, &i2, &i1}
v2 := [3]*int{&i1, &i2, &i2}
return tuple{v1, v2}
}(),
wantEq: false,
},
}
for _, tt := range tests {
gotEq := Hash(tt.in[0]) == Hash(tt.in[1])
if gotEq != tt.wantEq {
t.Errorf("(Hash(%v) == Hash(%v)) = %v, want %v", tt.in[0], tt.in[1], gotEq, tt.wantEq)
}
}
}
func TestDeepHash(t *testing.T) {
// v contains the types of values we care about for our current callers.
// Mostly we're just testing that we don't panic on handled types.
v := getVal()
hash1 := Hash(v)
t.Logf("hash: %v", hash1)
for i := 0; i < 20; i++ {
hash2 := Hash(getVal())
if hash1 != hash2 {
t.Error("second hash didn't match")
}
}
}
func getVal() []interface{} {
return []interface{}{
&wgcfg.Config{
Name: "foo",
Addresses: []netaddr.IPPrefix{netaddr.IPPrefixFrom(netaddr.IPFrom16([16]byte{3: 3}), 5)},
Peers: []wgcfg.Peer{
{
PublicKey: wgkey.Key{},
},
},
},
&router.Config{
Routes: []netaddr.IPPrefix{
netaddr.MustParseIPPrefix("1.2.3.0/24"),
netaddr.MustParseIPPrefix("1234::/64"),
},
},
map[dnsname.FQDN][]netaddr.IP{
dnsname.FQDN("a."): {netaddr.MustParseIP("1.2.3.4"), netaddr.MustParseIP("4.3.2.1")},
dnsname.FQDN("b."): {netaddr.MustParseIP("8.8.8.8"), netaddr.MustParseIP("9.9.9.9")},
dnsname.FQDN("c."): {netaddr.MustParseIP("6.6.6.6"), netaddr.MustParseIP("7.7.7.7")},
dnsname.FQDN("d."): {netaddr.MustParseIP("6.7.6.6"), netaddr.MustParseIP("7.7.7.8")},
dnsname.FQDN("e."): {netaddr.MustParseIP("6.8.6.6"), netaddr.MustParseIP("7.7.7.9")},
dnsname.FQDN("f."): {netaddr.MustParseIP("6.9.6.6"), netaddr.MustParseIP("7.7.7.0")},
},
map[dnsname.FQDN][]netaddr.IPPort{
dnsname.FQDN("a."): {netaddr.MustParseIPPort("1.2.3.4:11"), netaddr.MustParseIPPort("4.3.2.1:22")},
dnsname.FQDN("b."): {netaddr.MustParseIPPort("8.8.8.8:11"), netaddr.MustParseIPPort("9.9.9.9:22")},
dnsname.FQDN("c."): {netaddr.MustParseIPPort("8.8.8.8:12"), netaddr.MustParseIPPort("9.9.9.9:23")},
dnsname.FQDN("d."): {netaddr.MustParseIPPort("8.8.8.8:13"), netaddr.MustParseIPPort("9.9.9.9:24")},
dnsname.FQDN("e."): {netaddr.MustParseIPPort("8.8.8.8:14"), netaddr.MustParseIPPort("9.9.9.9:25")},
},
map[tailcfg.DiscoKey]bool{
{1: 1}: true,
{1: 2}: false,
{2: 3}: true,
{3: 4}: false,
},
&tailcfg.MapResponse{
DERPMap: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
1: &tailcfg.DERPRegion{
RegionID: 1,
RegionCode: "foo",
Nodes: []*tailcfg.DERPNode{
{
Name: "n1",
RegionID: 1,
HostName: "foo.com",
},
{
Name: "n2",
RegionID: 1,
HostName: "bar.com",
},
},
},
},
},
DNSConfig: &tailcfg.DNSConfig{
Resolvers: []dnstype.Resolver{
{Addr: "10.0.0.1"},
},
},
PacketFilter: []tailcfg.FilterRule{
{
SrcIPs: []string{"1.2.3.4"},
DstPorts: []tailcfg.NetPortRange{
{
IP: "1.2.3.4/32",
Ports: tailcfg.PortRange{First: 1, Last: 2},
},
},
},
},
Peers: []*tailcfg.Node{
{
ID: 1,
},
{
ID: 2,
},
},
UserProfiles: []tailcfg.UserProfile{
{ID: 1, LoginName: "foo@bar.com"},
{ID: 2, LoginName: "bar@foo.com"},
},
},
filter.Match{
IPProto: []ipproto.Proto{1, 2, 3},
},
}
}
var sink = Hash("foo")
func BenchmarkHash(b *testing.B) {
b.ReportAllocs()
v := getVal()
for i := 0; i < b.N; i++ {
sink = Hash(v)
}
}
func TestHashMapAcyclic(t *testing.T) {
m := map[int]string{}
for i := 0; i < 100; i++ {
m[i] = fmt.Sprint(i)
}
got := map[string]bool{}
var buf bytes.Buffer
bw := bufio.NewWriter(&buf)
for i := 0; i < 20; i++ {
v := reflect.ValueOf(m)
buf.Reset()
bw.Reset(&buf)
h := &hasher{bw: bw}
h.hashMap(v)
if got[string(buf.Bytes())] {
continue
}
got[string(buf.Bytes())] = true
}
if len(got) != 1 {
t.Errorf("got %d results; want 1", len(got))
}
}
func TestPrintArray(t *testing.T) {
type T struct {
X [32]byte
}
x := T{X: [32]byte{1: 1, 31: 31}}
var got bytes.Buffer
bw := bufio.NewWriter(&got)
h := &hasher{bw: bw}
h.hashValue(reflect.ValueOf(x))
bw.Flush()
const want = "\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x1f"
if got := got.Bytes(); string(got) != want {
t.Errorf("wrong:\n got: %q\nwant: %q\n", got, want)
}
}
func BenchmarkHashMapAcyclic(b *testing.B) {
b.ReportAllocs()
m := map[int]string{}
for i := 0; i < 100; i++ {
m[i] = fmt.Sprint(i)
}
var buf bytes.Buffer
bw := bufio.NewWriter(&buf)
v := reflect.ValueOf(m)
h := &hasher{bw: bw}
for i := 0; i < b.N; i++ {
buf.Reset()
bw.Reset(&buf)
h.hashMap(v)
}
}
func BenchmarkTailcfgNode(b *testing.B) {
b.ReportAllocs()
node := new(tailcfg.Node)
for i := 0; i < b.N; i++ {
sink = Hash(node)
}
}
func TestExhaustive(t *testing.T) {
seen := make(map[Sum]bool)
for i := 0; i < 100000; i++ {
s := Hash(i)
if seen[s] {
t.Fatalf("hash collision %v", i)
}
seen[s] = true
}
}
// verify this doesn't loop forever, as it used to (Issue 2340)
func TestMapCyclicFallback(t *testing.T) {
type T struct {
M map[string]interface{}
}
v := &T{
M: map[string]interface{}{},
}
v.M["m"] = v.M
Hash(v)
}
func TestArrayAllocs(t *testing.T) {
if version.IsRace() {
t.Skip("skipping test under race detector")
}
// In theory, there should be no allocations. However, escape analysis on
// certain architectures fails to detect that certain cases do not escape.
// This discrepency currently affects sha256.digest.Sum.
// Measure the number of allocations in sha256 to ensure that Hash does
// not allocate on top of its usage of sha256.
// See https://golang.org/issue/48055.
var b []byte
h := sha256.New()
want := int(testing.AllocsPerRun(1000, func() {
b = h.Sum(b[:0])
}))
switch runtime.GOARCH {
case "amd64", "arm64":
want = 0 // ensure no allocations on popular architectures
}
type T struct {
X [32]byte
}
x := &T{X: [32]byte{1: 1, 2: 2, 3: 3, 4: 4}}
got := int(testing.AllocsPerRun(1000, func() {
sink = Hash(x)
}))
if got > want {
t.Errorf("allocs = %v; want %v", got, want)
}
}
func BenchmarkHashArray(b *testing.B) {
b.ReportAllocs()
type T struct {
X [32]byte
}
x := &T{X: [32]byte{1: 1, 2: 2, 3: 3, 4: 4}}
for i := 0; i < b.N; i++ {
sink = Hash(x)
}
}