forked from ethereum/go-ethereum
-
Notifications
You must be signed in to change notification settings - Fork 1
/
unpack.go
235 lines (215 loc) · 7.58 KB
/
unpack.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package abi
import (
"encoding/binary"
"fmt"
"math/big"
"reflect"
"github.com/ethereum/go-ethereum/common"
)
// toGoSliceType parses the input and casts it to the proper slice defined by the ABI
// argument in T.
func toGoSlice(i int, t Argument, output []byte) (interface{}, error) {
index := i * 32
// The slice must, at very least be large enough for the index+32 which is exactly the size required
// for the [offset in output, size of offset].
if index+32 > len(output) {
return nil, fmt.Errorf("abi: cannot marshal in to go slice: insufficient size output %d require %d", len(output), index+32)
}
elem := t.Type.Elem
// first we need to create a slice of the type
var refSlice reflect.Value
switch elem.T {
case IntTy, UintTy, BoolTy:
// create a new reference slice matching the element type
switch t.Type.Kind {
case reflect.Bool:
refSlice = reflect.ValueOf([]bool(nil))
case reflect.Uint8:
refSlice = reflect.ValueOf([]uint8(nil))
case reflect.Uint16:
refSlice = reflect.ValueOf([]uint16(nil))
case reflect.Uint32:
refSlice = reflect.ValueOf([]uint32(nil))
case reflect.Uint64:
refSlice = reflect.ValueOf([]uint64(nil))
case reflect.Int8:
refSlice = reflect.ValueOf([]int8(nil))
case reflect.Int16:
refSlice = reflect.ValueOf([]int16(nil))
case reflect.Int32:
refSlice = reflect.ValueOf([]int32(nil))
case reflect.Int64:
refSlice = reflect.ValueOf([]int64(nil))
default:
refSlice = reflect.ValueOf([]*big.Int(nil))
}
case AddressTy: // address must be of slice Address
refSlice = reflect.ValueOf([]common.Address(nil))
case HashTy: // hash must be of slice hash
refSlice = reflect.ValueOf([]common.Hash(nil))
case FixedBytesTy:
refSlice = reflect.ValueOf([][]byte(nil))
default: // no other types are supported
return nil, fmt.Errorf("abi: unsupported slice type %v", elem.T)
}
var slice []byte
var size int
var offset int
if t.Type.IsSlice {
// get the offset which determines the start of this array ...
offset = int(binary.BigEndian.Uint64(output[index+24 : index+32]))
if offset+32 > len(output) {
return nil, fmt.Errorf("abi: cannot marshal in to go slice: offset %d would go over slice boundary (len=%d)", len(output), offset+32)
}
slice = output[offset:]
// ... starting with the size of the array in elements ...
size = int(binary.BigEndian.Uint64(slice[24:32]))
slice = slice[32:]
// ... and make sure that we've at the very least the amount of bytes
// available in the buffer.
if size*32 > len(slice) {
return nil, fmt.Errorf("abi: cannot marshal in to go slice: insufficient size output %d require %d", len(output), offset+32+size*32)
}
// reslice to match the required size
slice = slice[:size*32]
} else if t.Type.IsArray {
//get the number of elements in the array
size = t.Type.SliceSize
//check to make sure array size matches up
if index+32*size > len(output) {
return nil, fmt.Errorf("abi: cannot marshal in to go array: offset %d would go over slice boundary (len=%d)", len(output), index+32*size)
}
//slice is there for a fixed amount of times
slice = output[index : index+size*32]
}
for i := 0; i < size; i++ {
var (
inter interface{} // interface type
returnOutput = slice[i*32 : i*32+32] // the return output
err error
)
// set inter to the correct type (cast)
switch elem.T {
case IntTy, UintTy:
inter = readInteger(t.Type.Kind, returnOutput)
case BoolTy:
inter, err = readBool(returnOutput)
if err != nil {
return nil, err
}
case AddressTy:
inter = common.BytesToAddress(returnOutput)
case HashTy:
inter = common.BytesToHash(returnOutput)
case FixedBytesTy:
inter = returnOutput
}
// append the item to our reflect slice
refSlice = reflect.Append(refSlice, reflect.ValueOf(inter))
}
// return the interface
return refSlice.Interface(), nil
}
func readInteger(kind reflect.Kind, b []byte) interface{} {
switch kind {
case reflect.Uint8:
return uint8(b[len(b)-1])
case reflect.Uint16:
return binary.BigEndian.Uint16(b[len(b)-2:])
case reflect.Uint32:
return binary.BigEndian.Uint32(b[len(b)-4:])
case reflect.Uint64:
return binary.BigEndian.Uint64(b[len(b)-8:])
case reflect.Int8:
return int8(b[len(b)-1])
case reflect.Int16:
return int16(binary.BigEndian.Uint16(b[len(b)-2:]))
case reflect.Int32:
return int32(binary.BigEndian.Uint32(b[len(b)-4:]))
case reflect.Int64:
return int64(binary.BigEndian.Uint64(b[len(b)-8:]))
default:
return new(big.Int).SetBytes(b)
}
}
func readBool(word []byte) (bool, error) {
if len(word) != 32 {
return false, fmt.Errorf("abi: fatal error: incorrect word length")
}
for i, b := range word {
if b != 0 && i != 31 {
return false, errBadBool
}
}
switch word[31] {
case 0:
return false, nil
case 1:
return true, nil
default:
return false, errBadBool
}
}
// toGoType parses the input and casts it to the proper type defined by the ABI
// argument in T.
func toGoType(i int, t Argument, output []byte) (interface{}, error) {
// we need to treat slices differently
if (t.Type.IsSlice || t.Type.IsArray) && t.Type.T != BytesTy && t.Type.T != StringTy && t.Type.T != FixedBytesTy && t.Type.T != FunctionTy {
return toGoSlice(i, t, output)
}
index := i * 32
if index+32 > len(output) {
return nil, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), index+32)
}
// Parse the given index output and check whether we need to read
// a different offset and length based on the type (i.e. string, bytes)
var returnOutput []byte
switch t.Type.T {
case StringTy, BytesTy: // variable arrays are written at the end of the return bytes
// parse offset from which we should start reading
offset := int(binary.BigEndian.Uint64(output[index+24 : index+32]))
if offset+32 > len(output) {
return nil, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), offset+32)
}
// parse the size up until we should be reading
size := int(binary.BigEndian.Uint64(output[offset+24 : offset+32]))
if offset+32+size > len(output) {
return nil, fmt.Errorf("abi: cannot marshal in to go type: length insufficient %d require %d", len(output), offset+32+size)
}
// get the bytes for this return value
returnOutput = output[offset+32 : offset+32+size]
default:
returnOutput = output[index : index+32]
}
// convert the bytes to whatever is specified by the ABI.
switch t.Type.T {
case IntTy, UintTy:
return readInteger(t.Type.Kind, returnOutput), nil
case BoolTy:
return readBool(returnOutput)
case AddressTy:
return common.BytesToAddress(returnOutput), nil
case HashTy:
return common.BytesToHash(returnOutput), nil
case BytesTy, FixedBytesTy, FunctionTy:
return returnOutput, nil
case StringTy:
return string(returnOutput), nil
}
return nil, fmt.Errorf("abi: unknown type %v", t.Type.T)
}