aboutsummaryrefslogtreecommitdiff
path: root/core/vm/contracts_stateful.go
blob: b91acfb4b083d65c8fd1f6c9718a9bf5eccae37b (plain) (blame)
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
package vm

import (
	"errors"
	"fmt"
	"math/big"

	"github.com/ava-labs/coreth/params"
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/log"
	"github.com/holiman/uint256"
)

// PrecompiledContractsApricot contains the default set of pre-compiled Ethereum
// contracts used in the Istanbul release and the stateful precompiled contracts
// added for the Avalanche Apricot release.
// Apricot is incompatible with the YoloV1 Release since it does not include the
// BLS12-381 Curve Operations added to the set of precompiled contracts
var PrecompiledContractsApricot = map[common.Address]StatefulPrecompiledContract{
	common.BytesToAddress([]byte{1}):                                  newWrappedPrecompiledContract(&ecrecover{}),
	common.BytesToAddress([]byte{2}):                                  newWrappedPrecompiledContract(&sha256hash{}),
	common.BytesToAddress([]byte{3}):                                  newWrappedPrecompiledContract(&ripemd160hash{}),
	common.BytesToAddress([]byte{4}):                                  newWrappedPrecompiledContract(&dataCopy{}),
	common.BytesToAddress([]byte{5}):                                  newWrappedPrecompiledContract(&bigModExp{}),
	common.BytesToAddress([]byte{6}):                                  newWrappedPrecompiledContract(&bn256AddIstanbul{}),
	common.BytesToAddress([]byte{7}):                                  newWrappedPrecompiledContract(&bn256ScalarMulIstanbul{}),
	common.BytesToAddress([]byte{8}):                                  newWrappedPrecompiledContract(&bn256PairingIstanbul{}),
	common.BytesToAddress([]byte{9}):                                  newWrappedPrecompiledContract(&blake2F{}),
	common.HexToAddress("0x0100000000000000000000000000000000000000"): &deprecatedContract{msg: "hardcoded genesis contract has been deprecated"},
	common.HexToAddress("0x0100000000000000000000000000000000000001"): &nativeAssetBalance{gasCost: params.AssetBalanceApricot},
	common.HexToAddress("0x0100000000000000000000000000000000000002"): &nativeAssetCall{gasCost: params.AssetCallApricot},
}

// StatefulPrecompiledContract is the interface for executing a precompiled contract
// This wraps the PrecompiledContracts native to Ethereum and allows adding in stateful
// precompiled contracts to support native Avalanche asset transfers.
type StatefulPrecompiledContract interface {
	// Run executes a precompiled contract in the current state
	// assumes that it has already been verified that [caller] can
	// transfer [value].
	Run(evm *EVM, caller ContractRef, addr common.Address, value *big.Int, input []byte, suppliedGas uint64, readOnly bool) (ret []byte, remainingGas uint64, err error)
}

// wrappedPrecompiledContract implements StatefulPrecompiledContract by wrapping stateless native precompiled contracts
// in Ethereum.
type wrappedPrecompiledContract struct {
	p PrecompiledContract
}

func newWrappedPrecompiledContract(p PrecompiledContract) StatefulPrecompiledContract {
	return &wrappedPrecompiledContract{p: p}
}

// Run ...
func (w *wrappedPrecompiledContract) Run(evm *EVM, caller ContractRef, addr common.Address, value *big.Int, input []byte, suppliedGas uint64, readOnly bool) (ret []byte, remainingGas uint64, err error) {
	evm.Transfer(evm.StateDB, caller.Address(), addr, value)
	return RunPrecompiledContract(w.p, input, suppliedGas)
}

// nativeAssetBalance is a precompiled contract used to retrieve the native asset balance
type nativeAssetBalance struct {
	gasCost uint64
}

// Run implements StatefulPrecompiledContract
func (b *nativeAssetBalance) Run(evm *EVM, caller ContractRef, addr common.Address, value *big.Int, input []byte, suppliedGas uint64, readOnly bool) (ret []byte, remainingGas uint64, err error) {
	// input: encodePacked(address 20 bytes, assetID 32 bytes)
	if value.Sign() != 0 {
		return nil, suppliedGas, errors.New("cannot transfer value to native asset balance pre-compiled contract")
	}

	if suppliedGas < b.gasCost {
		return nil, 0, ErrOutOfGas
	}
	remainingGas = suppliedGas - b.gasCost

	if len(input) != 52 {
		return nil, remainingGas, fmt.Errorf("input to native asset balance must be 52 bytes, containing address [20 bytes] and assetID [32 bytes], but found length: %d", len(input))
	}
	address := common.BytesToAddress(input[:20])
	assetID := new(common.Hash)
	assetID.SetBytes(input[20:52])

	res, overflow := uint256.FromBig(evm.StateDB.GetBalanceMultiCoin(address, *assetID))
	log.Info("nativeAssetBalance", "address", address, "assetID", assetID.Hex(), "res", res, "overflow", overflow)
	if overflow {
		return nil, remainingGas, errors.New("balance overflow")
	}
	return common.LeftPadBytes(res.Bytes(), 32), remainingGas, nil
}

// nativeAssetCall atomically transfers a native asset to a recipient address as well as calling that
// address
type nativeAssetCall struct {
	gasCost uint64
}

// Run implements StatefulPrecompiledContract
func (c *nativeAssetCall) Run(evm *EVM, caller ContractRef, addr common.Address, value *big.Int, input []byte, suppliedGas uint64, readOnly bool) (ret []byte, remainingGas uint64, err error) {
	// input: encodePacked(address 20 bytes, assetID 32 bytes, assetAmount 32 bytes, callData variable length bytes)
	if suppliedGas < c.gasCost {
		return nil, 0, ErrOutOfGas
	}
	remainingGas = suppliedGas - c.gasCost

	if readOnly {
		return nil, remainingGas, errors.New("cannot execute native asset transfer within read only call")
	}

	if len(input) < 84 {
		return nil, remainingGas, fmt.Errorf("missing inputs to native asset transfer, expected input of length at least 84, but found %d", len(input))
	}
	to := common.BytesToAddress(input[:20])
	assetID := new(common.Hash)
	assetID.SetBytes(input[20:52])
	assetAmount := new(big.Int).SetBytes(input[52:84])
	callData := input[84:]
	log.Info("nativeAssetCall", "input", fmt.Sprintf("0x%x", input), "to", to.Hex(), "assetID", assetID.Hex(), "assetAmount", assetAmount, "callData", fmt.Sprintf("0x%x", callData))

	mcerr := evm.Context.CanTransferMC(evm.StateDB, caller.Address(), to, assetID, assetAmount)
	if mcerr == 1 {
		log.Info("Insufficient balance for mc transfer")
		return nil, remainingGas, ErrInsufficientBalance
	} else if mcerr != 0 {
		log.Info("incompatible account for mc transfer")
		return nil, remainingGas, ErrIncompatibleAccount
	}

	snapshot := evm.StateDB.Snapshot()

	if !evm.StateDB.Exist(to) {
		log.Info("Creating account entry", "address", to.Hex())
		remainingGas -= params.CallNewAccountGas
		evm.StateDB.CreateAccount(to)
	}

	// Send [value] to [to] address
	evm.Transfer(evm.StateDB, caller.Address(), to, value)
	evm.TransferMultiCoin(evm.StateDB, caller.Address(), to, assetID, assetAmount)
	ret, remainingGas, err = evm.Call(caller, to, callData, remainingGas, big.NewInt(0))
	log.Info("Finished TransferMultiCoin and call", "return", ret, "remainingGas", remainingGas, "error", err)

	// When an error was returned by the EVM or when setting the creation code
	// above we revert to the snapshot and consume any gas remaining. Additionally
	// when we're in homestead this also counts for code storage gas errors.
	if err != nil {
		evm.StateDB.RevertToSnapshot(snapshot)
		if err != ErrExecutionReverted {
			remainingGas = 0
		}
		// TODO: consider clearing up unused snapshots:
		//} else {
		//	evm.StateDB.DiscardSnapshot(snapshot)
	}
	return ret, remainingGas, err
}

type deprecatedContract struct {
	msg string
}

// Run ...
func (d *deprecatedContract) Run(evm *EVM, caller ContractRef, addr common.Address, value *big.Int, input []byte, suppliedGas uint64, readOnly bool) (ret []byte, remainingGas uint64, err error) {
	return nil, suppliedGas, errors.New(d.msg)
}