protobuf-go/internal/impl/codec_map.go
Damien Neil b5523e32b3 all: return less-specific, but more informative wire unmarshal errors
When proto.Unmarshal fails, it is almost always due to being passed
input which is not a wire-format message. (A text-format message, a
message with framing left intact, and so forth.) An error like
"variable length integer overflow" can be confusing in this case, since
it implies the problem is the varint rather than the input being
entirely wrong.

Replace all Unmarshal parse errors with "cannot parse invalid
wire-format data".

Change-Id: Id97253bd39ac604e569df71778194f37b3c86c28
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/244297
Reviewed-by: Joe Tsai <joetsai@google.com>
2020-07-23 20:09:00 +00:00

389 lines
10 KiB
Go

// Copyright 2019 The Go 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 impl
import (
"reflect"
"sort"
"google.golang.org/protobuf/encoding/protowire"
"google.golang.org/protobuf/internal/genid"
pref "google.golang.org/protobuf/reflect/protoreflect"
)
type mapInfo struct {
goType reflect.Type
keyWiretag uint64
valWiretag uint64
keyFuncs valueCoderFuncs
valFuncs valueCoderFuncs
keyZero pref.Value
keyKind pref.Kind
conv *mapConverter
}
func encoderFuncsForMap(fd pref.FieldDescriptor, ft reflect.Type) (valueMessage *MessageInfo, funcs pointerCoderFuncs) {
// TODO: Consider generating specialized map coders.
keyField := fd.MapKey()
valField := fd.MapValue()
keyWiretag := protowire.EncodeTag(1, wireTypes[keyField.Kind()])
valWiretag := protowire.EncodeTag(2, wireTypes[valField.Kind()])
keyFuncs := encoderFuncsForValue(keyField)
valFuncs := encoderFuncsForValue(valField)
conv := newMapConverter(ft, fd)
mapi := &mapInfo{
goType: ft,
keyWiretag: keyWiretag,
valWiretag: valWiretag,
keyFuncs: keyFuncs,
valFuncs: valFuncs,
keyZero: keyField.Default(),
keyKind: keyField.Kind(),
conv: conv,
}
if valField.Kind() == pref.MessageKind {
valueMessage = getMessageInfo(ft.Elem())
}
funcs = pointerCoderFuncs{
size: func(p pointer, f *coderFieldInfo, opts marshalOptions) int {
return sizeMap(p.AsValueOf(ft).Elem(), mapi, f, opts)
},
marshal: func(b []byte, p pointer, f *coderFieldInfo, opts marshalOptions) ([]byte, error) {
return appendMap(b, p.AsValueOf(ft).Elem(), mapi, f, opts)
},
unmarshal: func(b []byte, p pointer, wtyp protowire.Type, f *coderFieldInfo, opts unmarshalOptions) (unmarshalOutput, error) {
mp := p.AsValueOf(ft)
if mp.Elem().IsNil() {
mp.Elem().Set(reflect.MakeMap(mapi.goType))
}
if f.mi == nil {
return consumeMap(b, mp.Elem(), wtyp, mapi, f, opts)
} else {
return consumeMapOfMessage(b, mp.Elem(), wtyp, mapi, f, opts)
}
},
}
switch valField.Kind() {
case pref.MessageKind:
funcs.merge = mergeMapOfMessage
case pref.BytesKind:
funcs.merge = mergeMapOfBytes
default:
funcs.merge = mergeMap
}
if valFuncs.isInit != nil {
funcs.isInit = func(p pointer, f *coderFieldInfo) error {
return isInitMap(p.AsValueOf(ft).Elem(), mapi, f)
}
}
return valueMessage, funcs
}
const (
mapKeyTagSize = 1 // field 1, tag size 1.
mapValTagSize = 1 // field 2, tag size 2.
)
func sizeMap(mapv reflect.Value, mapi *mapInfo, f *coderFieldInfo, opts marshalOptions) int {
if mapv.Len() == 0 {
return 0
}
n := 0
iter := mapRange(mapv)
for iter.Next() {
key := mapi.conv.keyConv.PBValueOf(iter.Key()).MapKey()
keySize := mapi.keyFuncs.size(key.Value(), mapKeyTagSize, opts)
var valSize int
value := mapi.conv.valConv.PBValueOf(iter.Value())
if f.mi == nil {
valSize = mapi.valFuncs.size(value, mapValTagSize, opts)
} else {
p := pointerOfValue(iter.Value())
valSize += mapValTagSize
valSize += protowire.SizeBytes(f.mi.sizePointer(p, opts))
}
n += f.tagsize + protowire.SizeBytes(keySize+valSize)
}
return n
}
func consumeMap(b []byte, mapv reflect.Value, wtyp protowire.Type, mapi *mapInfo, f *coderFieldInfo, opts unmarshalOptions) (out unmarshalOutput, err error) {
if wtyp != protowire.BytesType {
return out, errUnknown
}
b, n := protowire.ConsumeBytes(b)
if n < 0 {
return out, errDecode
}
var (
key = mapi.keyZero
val = mapi.conv.valConv.New()
)
for len(b) > 0 {
num, wtyp, n := protowire.ConsumeTag(b)
if n < 0 {
return out, errDecode
}
if num > protowire.MaxValidNumber {
return out, errDecode
}
b = b[n:]
err := errUnknown
switch num {
case genid.MapEntry_Key_field_number:
var v pref.Value
var o unmarshalOutput
v, o, err = mapi.keyFuncs.unmarshal(b, key, num, wtyp, opts)
if err != nil {
break
}
key = v
n = o.n
case genid.MapEntry_Value_field_number:
var v pref.Value
var o unmarshalOutput
v, o, err = mapi.valFuncs.unmarshal(b, val, num, wtyp, opts)
if err != nil {
break
}
val = v
n = o.n
}
if err == errUnknown {
n = protowire.ConsumeFieldValue(num, wtyp, b)
if n < 0 {
return out, errDecode
}
} else if err != nil {
return out, err
}
b = b[n:]
}
mapv.SetMapIndex(mapi.conv.keyConv.GoValueOf(key), mapi.conv.valConv.GoValueOf(val))
out.n = n
return out, nil
}
func consumeMapOfMessage(b []byte, mapv reflect.Value, wtyp protowire.Type, mapi *mapInfo, f *coderFieldInfo, opts unmarshalOptions) (out unmarshalOutput, err error) {
if wtyp != protowire.BytesType {
return out, errUnknown
}
b, n := protowire.ConsumeBytes(b)
if n < 0 {
return out, errDecode
}
var (
key = mapi.keyZero
val = reflect.New(f.mi.GoReflectType.Elem())
)
for len(b) > 0 {
num, wtyp, n := protowire.ConsumeTag(b)
if n < 0 {
return out, errDecode
}
if num > protowire.MaxValidNumber {
return out, errDecode
}
b = b[n:]
err := errUnknown
switch num {
case 1:
var v pref.Value
var o unmarshalOutput
v, o, err = mapi.keyFuncs.unmarshal(b, key, num, wtyp, opts)
if err != nil {
break
}
key = v
n = o.n
case 2:
if wtyp != protowire.BytesType {
break
}
var v []byte
v, n = protowire.ConsumeBytes(b)
if n < 0 {
return out, errDecode
}
var o unmarshalOutput
o, err = f.mi.unmarshalPointer(v, pointerOfValue(val), 0, opts)
if o.initialized {
// Consider this map item initialized so long as we see
// an initialized value.
out.initialized = true
}
}
if err == errUnknown {
n = protowire.ConsumeFieldValue(num, wtyp, b)
if n < 0 {
return out, errDecode
}
} else if err != nil {
return out, err
}
b = b[n:]
}
mapv.SetMapIndex(mapi.conv.keyConv.GoValueOf(key), val)
out.n = n
return out, nil
}
func appendMapItem(b []byte, keyrv, valrv reflect.Value, mapi *mapInfo, f *coderFieldInfo, opts marshalOptions) ([]byte, error) {
if f.mi == nil {
key := mapi.conv.keyConv.PBValueOf(keyrv).MapKey()
val := mapi.conv.valConv.PBValueOf(valrv)
size := 0
size += mapi.keyFuncs.size(key.Value(), mapKeyTagSize, opts)
size += mapi.valFuncs.size(val, mapValTagSize, opts)
b = protowire.AppendVarint(b, uint64(size))
b, err := mapi.keyFuncs.marshal(b, key.Value(), mapi.keyWiretag, opts)
if err != nil {
return nil, err
}
return mapi.valFuncs.marshal(b, val, mapi.valWiretag, opts)
} else {
key := mapi.conv.keyConv.PBValueOf(keyrv).MapKey()
val := pointerOfValue(valrv)
valSize := f.mi.sizePointer(val, opts)
size := 0
size += mapi.keyFuncs.size(key.Value(), mapKeyTagSize, opts)
size += mapValTagSize + protowire.SizeBytes(valSize)
b = protowire.AppendVarint(b, uint64(size))
b, err := mapi.keyFuncs.marshal(b, key.Value(), mapi.keyWiretag, opts)
if err != nil {
return nil, err
}
b = protowire.AppendVarint(b, mapi.valWiretag)
b = protowire.AppendVarint(b, uint64(valSize))
return f.mi.marshalAppendPointer(b, val, opts)
}
}
func appendMap(b []byte, mapv reflect.Value, mapi *mapInfo, f *coderFieldInfo, opts marshalOptions) ([]byte, error) {
if mapv.Len() == 0 {
return b, nil
}
if opts.Deterministic() {
return appendMapDeterministic(b, mapv, mapi, f, opts)
}
iter := mapRange(mapv)
for iter.Next() {
var err error
b = protowire.AppendVarint(b, f.wiretag)
b, err = appendMapItem(b, iter.Key(), iter.Value(), mapi, f, opts)
if err != nil {
return b, err
}
}
return b, nil
}
func appendMapDeterministic(b []byte, mapv reflect.Value, mapi *mapInfo, f *coderFieldInfo, opts marshalOptions) ([]byte, error) {
keys := mapv.MapKeys()
sort.Slice(keys, func(i, j int) bool {
switch keys[i].Kind() {
case reflect.Bool:
return !keys[i].Bool() && keys[j].Bool()
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return keys[i].Int() < keys[j].Int()
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return keys[i].Uint() < keys[j].Uint()
case reflect.Float32, reflect.Float64:
return keys[i].Float() < keys[j].Float()
case reflect.String:
return keys[i].String() < keys[j].String()
default:
panic("invalid kind: " + keys[i].Kind().String())
}
})
for _, key := range keys {
var err error
b = protowire.AppendVarint(b, f.wiretag)
b, err = appendMapItem(b, key, mapv.MapIndex(key), mapi, f, opts)
if err != nil {
return b, err
}
}
return b, nil
}
func isInitMap(mapv reflect.Value, mapi *mapInfo, f *coderFieldInfo) error {
if mi := f.mi; mi != nil {
mi.init()
if !mi.needsInitCheck {
return nil
}
iter := mapRange(mapv)
for iter.Next() {
val := pointerOfValue(iter.Value())
if err := mi.checkInitializedPointer(val); err != nil {
return err
}
}
} else {
iter := mapRange(mapv)
for iter.Next() {
val := mapi.conv.valConv.PBValueOf(iter.Value())
if err := mapi.valFuncs.isInit(val); err != nil {
return err
}
}
}
return nil
}
func mergeMap(dst, src pointer, f *coderFieldInfo, opts mergeOptions) {
dstm := dst.AsValueOf(f.ft).Elem()
srcm := src.AsValueOf(f.ft).Elem()
if srcm.Len() == 0 {
return
}
if dstm.IsNil() {
dstm.Set(reflect.MakeMap(f.ft))
}
iter := mapRange(srcm)
for iter.Next() {
dstm.SetMapIndex(iter.Key(), iter.Value())
}
}
func mergeMapOfBytes(dst, src pointer, f *coderFieldInfo, opts mergeOptions) {
dstm := dst.AsValueOf(f.ft).Elem()
srcm := src.AsValueOf(f.ft).Elem()
if srcm.Len() == 0 {
return
}
if dstm.IsNil() {
dstm.Set(reflect.MakeMap(f.ft))
}
iter := mapRange(srcm)
for iter.Next() {
dstm.SetMapIndex(iter.Key(), reflect.ValueOf(append(emptyBuf[:], iter.Value().Bytes()...)))
}
}
func mergeMapOfMessage(dst, src pointer, f *coderFieldInfo, opts mergeOptions) {
dstm := dst.AsValueOf(f.ft).Elem()
srcm := src.AsValueOf(f.ft).Elem()
if srcm.Len() == 0 {
return
}
if dstm.IsNil() {
dstm.Set(reflect.MakeMap(f.ft))
}
iter := mapRange(srcm)
for iter.Next() {
val := reflect.New(f.ft.Elem().Elem())
if f.mi != nil {
f.mi.mergePointer(pointerOfValue(val), pointerOfValue(iter.Value()), opts)
} else {
opts.Merge(asMessage(val), asMessage(iter.Value()))
}
dstm.SetMapIndex(iter.Key(), val)
}
}