tailscale/util/deephash/deephash_test.go
Joe Tsai 539c5e44c5
util/deephash: always keep values addressable (#5328)
The logic of deephash is both simpler and easier to reason about
if values are always addressable.

In Go, the composite kinds are slices, arrays, maps, structs,
interfaces, pointers, channels, and functions,
where we define "composite" as a Go value that encapsulates
some other Go value (e.g., a map is a collection of key-value entries).

In the cases of pointers and slices, the sub-values are always addressable.

In the cases of arrays and structs, the sub-values are always addressable
if and only if the parent value is addressable.

In the case of maps and interfaces, the sub-values are never addressable.
To make them addressable, we need to copy them onto the heap.

For the purposes of deephash, we do not care about channels and functions.

For all non-composite kinds (e.g., strings and ints), they are only addressable
if obtained from one of the composite kinds that produce addressable values
(i.e., pointers, slices, addressable arrays, and addressable structs).
A non-addressible, non-composite kind can be made addressable by
allocating it on the heap, obtaining a pointer to it, and dereferencing it.

Thus, if we can ensure that values are addressable at the entry points,
and shallow copy sub-values whenever we encounter an interface or map,
then we can ensure that all values are always addressable and
assume such property throughout all the logic.

Performance:

	name                 old time/op    new time/op    delta
	Hash-24                21.5µs ± 1%    19.7µs ± 1%  -8.29%  (p=0.000 n=9+9)
	HashPacketFilter-24    2.61µs ± 1%    2.62µs ± 0%  +0.29%  (p=0.037 n=10+9)
	HashMapAcyclic-24      30.8µs ± 1%    30.9µs ± 1%    ~     (p=0.400 n=9+10)
	TailcfgNode-24         1.84µs ± 1%    1.84µs ± 2%    ~     (p=0.928 n=10+10)
	HashArray-24            324ns ± 2%     332ns ± 2%  +2.45%  (p=0.000 n=10+10)

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
2022-08-09 22:00:02 -07:00

877 lines
26 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 deephash
import (
"archive/tar"
"bufio"
"bytes"
"crypto/sha256"
"fmt"
"io"
"math"
"math/rand"
"net/netip"
"reflect"
"runtime"
"testing"
"testing/quick"
"time"
"unsafe"
"go4.org/mem"
"tailscale.com/tailcfg"
"tailscale.com/types/dnstype"
"tailscale.com/types/ipproto"
"tailscale.com/types/key"
"tailscale.com/types/structs"
"tailscale.com/util/deephash/testtype"
"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]any
type iface struct{ X any }
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
var zeroFloat64 float64
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: tuple{zeroFloat64, -zeroFloat64}, wantEq: false}, // Issue 4883 (false alarm)
{in: tuple{[]any(nil), 0.0}, wantEq: false}, // Issue 4883
{in: tuple{[]any(nil), uint8(0)}, wantEq: false}, // Issue 4883
{in: tuple{nil, nil}, wantEq: true}, // Issue 4883
{
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(%T %v) == Hash(%T %v)) = %v, want %v", tt.in[0], tt.in[0], tt.in[1], 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")
}
}
}
// Tests that we actually hash map elements. Whoops.
func TestIssue4868(t *testing.T) {
m1 := map[int]string{1: "foo"}
m2 := map[int]string{1: "bar"}
if Hash(m1) == Hash(m2) {
t.Error("bogus")
}
}
func TestIssue4871(t *testing.T) {
m1 := map[string]string{"": "", "x": "foo"}
m2 := map[string]string{}
if h1, h2 := Hash(m1), Hash(m2); h1 == h2 {
t.Errorf("bogus: h1=%x, h2=%x", h1, h2)
}
}
func TestNilVsEmptymap(t *testing.T) {
m1 := map[string]string(nil)
m2 := map[string]string{}
if h1, h2 := Hash(m1), Hash(m2); h1 == h2 {
t.Errorf("bogus: h1=%x, h2=%x", h1, h2)
}
}
func TestMapFraming(t *testing.T) {
m1 := map[string]string{"foo": "", "fo": "o"}
m2 := map[string]string{}
if h1, h2 := Hash(m1), Hash(m2); h1 == h2 {
t.Errorf("bogus: h1=%x, h2=%x", h1, h2)
}
}
func TestQuick(t *testing.T) {
initSeed()
err := quick.Check(func(v, w map[string]string) bool {
return (Hash(v) == Hash(w)) == reflect.DeepEqual(v, w)
}, &quick.Config{MaxCount: 1000, Rand: rand.New(rand.NewSource(int64(seed)))})
if err != nil {
t.Fatalf("seed=%v, err=%v", seed, err)
}
}
func getVal() any {
return &struct {
WGConfig *wgcfg.Config
RouterConfig *router.Config
MapFQDNAddrs map[dnsname.FQDN][]netip.Addr
MapFQDNAddrPorts map[dnsname.FQDN][]netip.AddrPort
MapDiscoPublics map[key.DiscoPublic]bool
MapResponse *tailcfg.MapResponse
FilterMatch filter.Match
}{
&wgcfg.Config{
Name: "foo",
Addresses: []netip.Prefix{netip.PrefixFrom(netip.AddrFrom16([16]byte{3: 3}).Unmap(), 5)},
Peers: []wgcfg.Peer{
{
PublicKey: key.NodePublic{},
},
},
},
&router.Config{
Routes: []netip.Prefix{
netip.MustParsePrefix("1.2.3.0/24"),
netip.MustParsePrefix("1234::/64"),
},
},
map[dnsname.FQDN][]netip.Addr{
dnsname.FQDN("a."): {netip.MustParseAddr("1.2.3.4"), netip.MustParseAddr("4.3.2.1")},
dnsname.FQDN("b."): {netip.MustParseAddr("8.8.8.8"), netip.MustParseAddr("9.9.9.9")},
dnsname.FQDN("c."): {netip.MustParseAddr("6.6.6.6"), netip.MustParseAddr("7.7.7.7")},
dnsname.FQDN("d."): {netip.MustParseAddr("6.7.6.6"), netip.MustParseAddr("7.7.7.8")},
dnsname.FQDN("e."): {netip.MustParseAddr("6.8.6.6"), netip.MustParseAddr("7.7.7.9")},
dnsname.FQDN("f."): {netip.MustParseAddr("6.9.6.6"), netip.MustParseAddr("7.7.7.0")},
},
map[dnsname.FQDN][]netip.AddrPort{
dnsname.FQDN("a."): {netip.MustParseAddrPort("1.2.3.4:11"), netip.MustParseAddrPort("4.3.2.1:22")},
dnsname.FQDN("b."): {netip.MustParseAddrPort("8.8.8.8:11"), netip.MustParseAddrPort("9.9.9.9:22")},
dnsname.FQDN("c."): {netip.MustParseAddrPort("8.8.8.8:12"), netip.MustParseAddrPort("9.9.9.9:23")},
dnsname.FQDN("d."): {netip.MustParseAddrPort("8.8.8.8:13"), netip.MustParseAddrPort("9.9.9.9:24")},
dnsname.FQDN("e."): {netip.MustParseAddrPort("8.8.8.8:14"), netip.MustParseAddrPort("9.9.9.9:25")},
},
map[key.DiscoPublic]bool{
key.DiscoPublicFromRaw32(mem.B([]byte{1: 1, 31: 0})): true,
key.DiscoPublicFromRaw32(mem.B([]byte{1: 2, 31: 0})): false,
key.DiscoPublicFromRaw32(mem.B([]byte{1: 3, 31: 0})): true,
key.DiscoPublicFromRaw32(mem.B([]byte{1: 4, 31: 0})): false,
},
&tailcfg.MapResponse{
DERPMap: &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
1: {
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},
},
}
}
func TestTypeIsRecursive(t *testing.T) {
type RecursiveStruct struct {
v *RecursiveStruct
}
type RecursiveChan chan *RecursiveChan
tests := []struct {
val any
want bool
}{
{val: 42, want: false},
{val: "string", want: false},
{val: 1 + 2i, want: false},
{val: struct{}{}, want: false},
{val: (*RecursiveStruct)(nil), want: true},
{val: RecursiveStruct{}, want: true},
{val: time.Unix(0, 0), want: false},
{val: structs.Incomparable{}, want: false}, // ignore its [0]func()
{val: tailcfg.NetPortRange{}, want: false}, // uses structs.Incomparable
{val: (*tailcfg.Node)(nil), want: false},
{val: map[string]bool{}, want: false},
{val: func() {}, want: false},
{val: make(chan int), want: false},
{val: unsafe.Pointer(nil), want: false},
{val: make(RecursiveChan), want: true},
{val: make(chan int), want: false},
}
for _, tt := range tests {
got := typeIsRecursive(reflect.TypeOf(tt.val))
if got != tt.want {
t.Errorf("for type %T: got %v, want %v", tt.val, got, tt.want)
}
}
}
type IntThenByte struct {
i int
b byte
}
type TwoInts struct{ a, b int }
type IntIntByteInt struct {
i1, i2 int32
b byte // padding after
i3 int32
}
func TestCanMemHash(t *testing.T) {
tests := []struct {
val any
want bool
}{
{true, true},
{uint(1), true},
{uint8(1), true},
{uint16(1), true},
{uint32(1), true},
{uint64(1), true},
{uintptr(1), true},
{int(1), true},
{int8(1), true},
{int16(1), true},
{int32(1), true},
{int64(1), true},
{float32(1), true},
{float64(1), true},
{complex64(1), true},
{complex128(1), true},
{[32]byte{}, true},
{func() {}, false},
{make(chan int), false},
{struct{ io.Writer }{nil}, false},
{unsafe.Pointer(nil), false},
{new(int), false},
{TwoInts{}, true},
{[4]TwoInts{}, true},
{IntThenByte{}, false},
{[4]IntThenByte{}, false},
{tailcfg.PortRange{}, true},
{int16(0), true},
{struct {
_ int
_ int
}{}, true},
{struct {
_ int
_ uint8
_ int
}{}, false}, // gap
{
struct {
_ structs.Incomparable // if not last, zero-width
x int
}{},
true,
},
{
struct {
x int
_ structs.Incomparable // zero-width last: has space, can't memhash
}{},
false,
}}
for _, tt := range tests {
got := canMemHash(reflect.TypeOf(tt.val))
if got != tt.want {
t.Errorf("for type %T: got %v, want %v", tt.val, got, tt.want)
}
}
}
func TestGetTypeHasher(t *testing.T) {
switch runtime.GOARCH {
case "amd64", "arm64", "arm", "386", "riscv64":
default:
// Test outputs below are specifically for little-endian machines.
// Just skip everything else for now. Feel free to add more above if
// you have the hardware to test and it's little-endian.
t.Skipf("skipping on %v", runtime.GOARCH)
}
type typedString string
var (
someInt = int('A')
someComplex128 = complex128(1 + 2i)
someIP = netip.MustParseAddr("1.2.3.4")
)
tests := []struct {
name string
val any
want bool // set true automatically if out != ""
out string
out32 string // overwrites out if 32-bit
}{
{
name: "int",
val: int(1),
out: "\x01\x00\x00\x00\x00\x00\x00\x00",
},
{
name: "int_negative",
val: int(-1),
out: "\xff\xff\xff\xff\xff\xff\xff\xff",
},
{
name: "int8",
val: int8(1),
out: "\x01",
},
{
name: "float64",
val: float64(1.0),
out: "\x00\x00\x00\x00\x00\x00\xf0?",
},
{
name: "float32",
val: float32(1.0),
out: "\x00\x00\x80?",
},
{
name: "string",
val: "foo",
out: "\x03\x00\x00\x00\x00\x00\x00\x00foo",
},
{
name: "typedString",
val: typedString("foo"),
out: "\x03\x00\x00\x00\x00\x00\x00\x00foo",
},
{
name: "string_slice",
val: []string{"foo", "bar"},
out: "\x02\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00foo\x03\x00\x00\x00\x00\x00\x00\x00bar",
},
{
name: "int_slice",
val: []int{1, 0, -1},
out: "\x03\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\xff\xff\xff\xff\xff",
out32: "\x03\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\xff",
},
{
name: "struct",
val: struct {
a, b int
c uint16
}{1, -1, 2},
out: "\x01\x00\x00\x00\x00\x00\x00\x00\xff\xff\xff\xff\xff\xff\xff\xff\x02\x00",
out32: "\x01\x00\x00\x00\xff\xff\xff\xff\x02\x00",
},
{
name: "nil_int_ptr",
val: (*int)(nil),
out: "\x00",
},
{
name: "int_ptr",
val: &someInt,
out: "\x01A\x00\x00\x00\x00\x00\x00\x00",
out32: "\x01A\x00\x00\x00",
},
{
name: "nil_uint32_ptr",
val: (*uint32)(nil),
out: "\x00",
},
{
name: "complex128_ptr",
val: &someComplex128,
out: "\x01\x00\x00\x00\x00\x00\x00\xf0?\x00\x00\x00\x00\x00\x00\x00@",
},
{
name: "packet_filter",
val: filterRules,
out: "\x04\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00*\v\x00\x00\x00\x00\x00\x00\x0010.1.3.4/32\v\x00\x00\x00\x00\x00\x00\x0010.0.0.0/24\x03\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\n\x00\x00\x00\x00\x00\x00\x001.2.3.4/32\x01 \x00\x00\x00\x00\x00\x00\x00\x01\x00\x02\x00\x04\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x02\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\n\x00\x00\x00\x00\x00\x00\x001.2.3.4/32\x01\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00foo\x01\x00\x00\x00\x00\x00\x00\x00\v\x00\x00\x00\x00\x00\x00\x00foooooooooo\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\f\x00\x00\x00\x00\x00\x00\x00baaaaaarrrrr\x00\x01\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\v\x00\x00\x00\x00\x00\x00\x00foooooooooo\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\f\x00\x00\x00\x00\x00\x00\x00baaaaaarrrrr\x00\x01\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\v\x00\x00\x00\x00\x00\x00\x00foooooooooo\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\f\x00\x00\x00\x00\x00\x00\x00baaaaaarrrrr\x00\x01\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
out32: "\x04\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00*\v\x00\x00\x00\x00\x00\x00\x0010.1.3.4/32\v\x00\x00\x00\x00\x00\x00\x0010.0.0.0/24\x03\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x02\x00\x00\x00\x03\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\n\x00\x00\x00\x00\x00\x00\x001.2.3.4/32\x01 \x00\x00\x00\x01\x00\x02\x00\x04\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x02\x00\x00\x00\x03\x00\x00\x00\x04\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\n\x00\x00\x00\x00\x00\x00\x001.2.3.4/32\x01\x00\x00\x00\x00\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00foo\x01\x00\x00\x00\x00\x00\x00\x00\v\x00\x00\x00\x00\x00\x00\x00foooooooooo\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\f\x00\x00\x00\x00\x00\x00\x00baaaaaarrrrr\x00\x01\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\v\x00\x00\x00\x00\x00\x00\x00foooooooooo\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\f\x00\x00\x00\x00\x00\x00\x00baaaaaarrrrr\x00\x01\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\v\x00\x00\x00\x00\x00\x00\x00foooooooooo\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\f\x00\x00\x00\x00\x00\x00\x00baaaaaarrrrr\x00\x01\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
},
{
name: "netip.Addr",
val: netip.MustParseAddr("fe80::123%foo"),
out: "\r\x00\x00\x00\x00\x00\x00\x00fe80::123%foo",
},
{
name: "ptr-netip.Addr",
val: &someIP,
out: "\x01\a\x00\x00\x00\x00\x00\x00\x001.2.3.4",
},
{
name: "ptr-nil-netip.Addr",
val: (*netip.Addr)(nil),
out: "\x00",
},
{
name: "time",
val: time.Unix(0, 0).In(time.UTC),
out: "\x141970-01-01T00:00:00Z",
},
{
name: "time_ptr", // addressable, as opposed to "time" test above
val: ptrTo(time.Unix(0, 0).In(time.UTC)),
out: "\x01\x141970-01-01T00:00:00Z",
},
{
name: "time_ptr_via_unexported",
val: testtype.NewUnexportedAddressableTime(time.Unix(0, 0).In(time.UTC)),
out: "\x01\x141970-01-01T00:00:00Z",
},
{
name: "time_ptr_via_unexported_value",
val: *testtype.NewUnexportedAddressableTime(time.Unix(0, 0).In(time.UTC)),
out: "\x141970-01-01T00:00:00Z",
},
{
name: "time_custom_zone",
val: time.Unix(1655311822, 0).In(time.FixedZone("FOO", -60*60)),
out: "\x192022-06-15T15:50:22-01:00",
},
{
name: "time_nil",
val: (*time.Time)(nil),
out: "\x00",
},
{
name: "array_memhash",
val: [4]byte{1, 2, 3, 4},
out: "\x01\x02\x03\x04",
},
{
name: "array_ptr_memhash",
val: ptrTo([4]byte{1, 2, 3, 4}),
out: "\x01\x01\x02\x03\x04",
},
{
name: "ptr_to_struct_partially_memhashable",
val: &struct {
A int16
B int16
C *int
}{5, 6, nil},
out: "\x01\x05\x00\x06\x00\x00",
},
{
name: "struct_partially_memhashable_but_cant_addr",
val: struct {
A int16
B int16
C *int
}{5, 6, nil},
out: "\x05\x00\x06\x00\x00",
},
{
name: "array_elements",
val: [4]byte{1, 2, 3, 4},
out: "\x01\x02\x03\x04",
},
{
name: "bool",
val: true,
out: "\x01",
},
{
name: "IntIntByteInt",
val: IntIntByteInt{1, 2, 3, 4},
out: "\x01\x00\x00\x00\x02\x00\x00\x00\x03\x04\x00\x00\x00",
},
{
name: "IntIntByteInt-canddr",
val: &IntIntByteInt{1, 2, 3, 4},
out: "\x01\x01\x00\x00\x00\x02\x00\x00\x00\x03\x04\x00\x00\x00",
},
{
name: "array-IntIntByteInt",
val: [2]IntIntByteInt{
{1, 2, 3, 4},
{5, 6, 7, 8},
},
out: "\x01\x00\x00\x00\x02\x00\x00\x00\x03\x04\x00\x00\x00\x05\x00\x00\x00\x06\x00\x00\x00\a\b\x00\x00\x00",
},
{
name: "array-IntIntByteInt-canaddr",
val: &[2]IntIntByteInt{
{1, 2, 3, 4},
{5, 6, 7, 8},
},
out: "\x01\x01\x00\x00\x00\x02\x00\x00\x00\x03\x04\x00\x00\x00\x05\x00\x00\x00\x06\x00\x00\x00\a\b\x00\x00\x00",
},
{
name: "tailcfg.Node",
val: &tailcfg.Node{},
out: "\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\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\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x140001-01-01T00:00:00Z\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\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\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\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x140001-01-01T00:00:00Z\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\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
rv := reflect.ValueOf(tt.val)
va := newAddressableValue(rv.Type())
va.Set(rv)
fn := getTypeInfo(va.Type()).hasher()
var buf bytes.Buffer
h := &hasher{
bw: bufio.NewWriter(&buf),
}
got := fn(h, va)
const ptrSize = 32 << uintptr(^uintptr(0)>>63)
if tt.out32 != "" && ptrSize == 32 {
tt.out = tt.out32
}
if tt.out != "" {
tt.want = true
}
if got != tt.want {
t.Fatalf("func returned %v; want %v", got, tt.want)
}
if err := h.bw.Flush(); err != nil {
t.Fatal(err)
}
if got := buf.String(); got != tt.out {
t.Fatalf("got %q; want %q", got, tt.out)
}
})
}
}
var sink Sum
func BenchmarkHash(b *testing.B) {
b.ReportAllocs()
v := getVal()
for i := 0; i < b.N; i++ {
sink = Hash(v)
}
}
func ptrTo[T any](v T) *T { return &v }
// filterRules is a packet filter that has both everything populated (in its
// first element) and also a few entries that are the typical shape for regular
// packet filters as sent to clients.
var filterRules = []tailcfg.FilterRule{
{
SrcIPs: []string{"*", "10.1.3.4/32", "10.0.0.0/24"},
SrcBits: []int{1, 2, 3},
DstPorts: []tailcfg.NetPortRange{{
IP: "1.2.3.4/32",
Bits: ptrTo(32),
Ports: tailcfg.PortRange{First: 1, Last: 2},
}},
IPProto: []int{1, 2, 3, 4},
CapGrant: []tailcfg.CapGrant{{
Dsts: []netip.Prefix{netip.MustParsePrefix("1.2.3.4/32")},
Caps: []string{"foo"},
}},
},
{
SrcIPs: []string{"foooooooooo"},
DstPorts: []tailcfg.NetPortRange{{
IP: "baaaaaarrrrr",
Ports: tailcfg.PortRange{First: 1, Last: 2},
}},
},
{
SrcIPs: []string{"foooooooooo"},
DstPorts: []tailcfg.NetPortRange{{
IP: "baaaaaarrrrr",
Ports: tailcfg.PortRange{First: 1, Last: 2},
}},
},
{
SrcIPs: []string{"foooooooooo"},
DstPorts: []tailcfg.NetPortRange{{
IP: "baaaaaarrrrr",
Ports: tailcfg.PortRange{First: 1, Last: 2},
}},
},
}
func BenchmarkHashPacketFilter(b *testing.B) {
b.ReportAllocs()
hash := HasherForType[*[]tailcfg.FilterRule]()
for i := 0; i < b.N; i++ {
sink = hash(&filterRules)
}
}
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)
ti := getTypeInfo(reflect.TypeOf(m))
for i := 0; i < 20; i++ {
v := addressableValue{reflect.ValueOf(&m).Elem()}
buf.Reset()
bw.Reset(&buf)
h := &hasher{bw: bw}
h.hashMap(v, ti, false)
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(addressableValue{reflect.ValueOf(&x).Elem()}, false)
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 := addressableValue{reflect.ValueOf(&m).Elem()}
ti := getTypeInfo(v.Type())
h := &hasher{bw: bw}
for i := 0; i < b.N; i++ {
buf.Reset()
bw.Reset(&buf)
h.hashMap(v, ti, false)
}
}
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]any
}
v := &T{
M: map[string]any{},
}
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)
}
}
// Test for http://go/corp/6311 issue.
func TestHashThroughView(t *testing.T) {
type sshPolicyOut struct {
Rules []tailcfg.SSHRuleView
}
type mapResponseOut struct {
SSHPolicy *sshPolicyOut
}
// Just test we don't panic:
_ = Hash(&mapResponseOut{
SSHPolicy: &sshPolicyOut{
Rules: []tailcfg.SSHRuleView{
(&tailcfg.SSHRule{
RuleExpires: ptrTo(time.Unix(123, 0)),
}).View(),
},
},
})
}
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)
}
}