Files
mev-beta/pkg/events/parser.go
Krypto Kajun 850223a953 fix(multicall): resolve critical multicall parsing corruption issues
- Added comprehensive bounds checking to prevent buffer overruns in multicall parsing
- Implemented graduated validation system (Strict/Moderate/Permissive) to reduce false positives
- Added LRU caching system for address validation with 10-minute TTL
- Enhanced ABI decoder with missing Universal Router and Arbitrum-specific DEX signatures
- Fixed duplicate function declarations and import conflicts across multiple files
- Added error recovery mechanisms with multiple fallback strategies
- Updated tests to handle new validation behavior for suspicious addresses
- Fixed parser test expectations for improved validation system
- Applied gofmt formatting fixes to ensure code style compliance
- Fixed mutex copying issues in monitoring package by introducing MetricsSnapshot
- Resolved critical security vulnerabilities in heuristic address extraction
- Progress: Updated TODO audit from 10% to 35% complete

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
2025-10-17 00:12:55 -05:00

1003 lines
32 KiB
Go

package events
import (
"fmt"
"math/big"
"strings"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/crypto"
"github.com/holiman/uint256"
"github.com/fraktal/mev-beta/pkg/calldata"
"github.com/fraktal/mev-beta/pkg/uniswap"
)
// EventType represents the type of DEX event
type EventType int
const (
Unknown EventType = iota
Swap
AddLiquidity
RemoveLiquidity
NewPool
)
// String returns a string representation of the event type
func (et EventType) String() string {
switch et {
case Unknown:
return "Unknown"
case Swap:
return "Swap"
case AddLiquidity:
return "AddLiquidity"
case RemoveLiquidity:
return "RemoveLiquidity"
case NewPool:
return "NewPool"
default:
return "Unknown"
}
}
type Event struct {
Type EventType
Protocol string // UniswapV2, UniswapV3, SushiSwap, etc.
PoolAddress common.Address
Token0 common.Address
Token1 common.Address
Amount0 *big.Int
Amount1 *big.Int
SqrtPriceX96 *uint256.Int
Liquidity *uint256.Int
Tick int
Timestamp uint64
TransactionHash common.Hash
BlockNumber uint64
}
// EventParser parses DEX events from Ethereum transactions
type EventParser struct {
// Known DEX contract addresses
UniswapV2Factory common.Address
UniswapV3Factory common.Address
SushiSwapFactory common.Address
// Router addresses
UniswapV2Router01 common.Address
UniswapV2Router02 common.Address
UniswapV3Router common.Address
SushiSwapRouter common.Address
// Known pool addresses (for quick lookup)
knownPools map[common.Address]string
// Event signatures for parsing logs
swapEventV2Sig common.Hash
swapEventV3Sig common.Hash
mintEventV2Sig common.Hash
mintEventV3Sig common.Hash
burnEventV2Sig common.Hash
burnEventV3Sig common.Hash
}
// NewEventParser creates a new event parser with official Arbitrum deployment addresses
func NewEventParser() *EventParser {
parser := &EventParser{
// Official Arbitrum DEX Factory Addresses
UniswapV2Factory: common.HexToAddress("0xf1D7CC64Fb4452F05c498126312eBE29f30Fbcf9"), // Official Uniswap V2 Factory on Arbitrum
UniswapV3Factory: common.HexToAddress("0x1F98431c8aD98523631AE4a59f267346ea31F984"), // Official Uniswap V3 Factory on Arbitrum
SushiSwapFactory: common.HexToAddress("0xc35DADB65012eC5796536bD9864eD8773aBc74C4"), // Official SushiSwap V2 Factory on Arbitrum
// Official Arbitrum DEX Router Addresses
UniswapV2Router01: common.HexToAddress("0x0000000000000000000000000000000000000000"), // V2Router01 not deployed on Arbitrum
UniswapV2Router02: common.HexToAddress("0x4752ba5dbc23f44d87826276bf6fd6b1c372ad24"), // Official Uniswap V2 Router02 on Arbitrum
UniswapV3Router: common.HexToAddress("0xE592427A0AEce92De3Edee1F18E0157C05861564"), // Official Uniswap V3 SwapRouter on Arbitrum
SushiSwapRouter: common.HexToAddress("0x1b02dA8Cb0d097eB8D57A175b88c7D8b47997506"), // Official SushiSwap Router on Arbitrum
knownPools: make(map[common.Address]string),
}
// Initialize event signatures
parser.swapEventV2Sig = crypto.Keccak256Hash([]byte("Swap(address,uint256,uint256,uint256,uint256,address)"))
parser.swapEventV3Sig = crypto.Keccak256Hash([]byte("Swap(address,address,int256,int256,uint160,uint128,int24)"))
parser.mintEventV2Sig = crypto.Keccak256Hash([]byte("Mint(address,uint256,uint256)"))
parser.mintEventV3Sig = crypto.Keccak256Hash([]byte("Mint(address,address,int24,int24,uint128,uint256,uint256)"))
parser.burnEventV2Sig = crypto.Keccak256Hash([]byte("Burn(address,uint256,uint256)"))
parser.burnEventV3Sig = crypto.Keccak256Hash([]byte("Burn(address,int24,int24,uint128,uint256,uint256)"))
// Pre-populate known Arbitrum pools (high volume pools)
parser.knownPools[common.HexToAddress("0xC6962004f452bE9203591991D15f6b388e09E8D0")] = "UniswapV3" // USDC/WETH 0.05%
parser.knownPools[common.HexToAddress("0x88e6A0c2dDD26FEEb64F039a2c41296FcB3f5640")] = "UniswapV3" // USDC/WETH 0.3%
parser.knownPools[common.HexToAddress("0xC31E54c7a869B9FcBEcc14363CF510d1c41fa443")] = "UniswapV3" // WETH/USDT 0.05%
parser.knownPools[common.HexToAddress("0x641C00A822e8b671738d32a431a4Fb6074E5c79d")] = "UniswapV3" // WETH/USDT 0.3%
// Add test addresses to known pools
parser.knownPools[common.HexToAddress("0x905dfCD5649217c42684f23958568e533C711Aa3")] = "SushiSwap" // Test SushiSwap pool
parser.knownPools[common.HexToAddress("0x84652bb2539513BAf36e225c930Fdd8eaa63CE27")] = "Camelot" // Test Camelot pool
parser.knownPools[common.HexToAddress("0x32dF62dc3aEd2cD6224193052Ce665DC18165841")] = "Balancer" // Test Balancer pool
parser.knownPools[common.HexToAddress("0x7f90122BF0700F9E7e1F688fe926940E8839F353")] = "Curve" // Test Curve pool
return parser
}
// ParseTransactionReceipt parses events from a transaction receipt
func (ep *EventParser) ParseTransactionReceipt(receipt *types.Receipt, blockNumber uint64, timestamp uint64) ([]*Event, error) {
events := make([]*Event, 0)
// Parse logs for DEX events
for _, log := range receipt.Logs {
// Skip anonymous logs
if len(log.Topics) == 0 {
continue
}
// Check if this is a DEX event based on the topic signature
eventSig := log.Topics[0]
var event *Event
var err error
switch eventSig {
case ep.swapEventV2Sig:
event, err = ep.parseUniswapV2Swap(log, blockNumber, timestamp, receipt.TxHash)
case ep.swapEventV3Sig:
event, err = ep.parseUniswapV3Swap(log, blockNumber, timestamp, receipt.TxHash)
case ep.mintEventV2Sig:
event, err = ep.parseUniswapV2Mint(log, blockNumber, timestamp, receipt.TxHash)
case ep.mintEventV3Sig:
event, err = ep.parseUniswapV3Mint(log, blockNumber, timestamp, receipt.TxHash)
case ep.burnEventV2Sig:
event, err = ep.parseUniswapV2Burn(log, blockNumber, timestamp, receipt.TxHash)
case ep.burnEventV3Sig:
event, err = ep.parseUniswapV3Burn(log, blockNumber, timestamp, receipt.TxHash)
}
if err != nil {
// Log error but continue parsing other logs
continue
}
if event != nil {
events = append(events, event)
}
}
return events, nil
}
// IsDEXInteraction checks if a transaction interacts with a known DEX contract
func (ep *EventParser) IsDEXInteraction(tx *types.Transaction) bool {
if tx.To() == nil {
return false
}
to := *tx.To()
// Check factory contracts
if to == ep.UniswapV2Factory ||
to == ep.UniswapV3Factory ||
to == ep.SushiSwapFactory {
return true
}
// Check router contracts
if to == ep.UniswapV2Router01 ||
to == ep.UniswapV2Router02 ||
to == ep.UniswapV3Router ||
to == ep.SushiSwapRouter {
return true
}
// Check known pools
if _, exists := ep.knownPools[to]; exists {
return true
}
return false
}
// identifyProtocol identifies which DEX protocol a transaction is interacting with
func (ep *EventParser) identifyProtocol(tx *types.Transaction) string {
if tx.To() == nil {
return "Unknown"
}
to := *tx.To()
// Check factory contracts
if to == ep.UniswapV2Factory {
return "UniswapV2"
}
if to == ep.UniswapV3Factory {
return "UniswapV3"
}
if to == ep.SushiSwapFactory {
return "SushiSwap"
}
// Check router contracts
if to == ep.UniswapV2Router01 || to == ep.UniswapV2Router02 {
return "UniswapV2"
}
if to == ep.UniswapV3Router {
return "UniswapV3"
}
if to == ep.SushiSwapRouter {
return "SushiSwap"
}
// Check known pools
if protocol, exists := ep.knownPools[to]; exists {
return protocol
}
// Try to identify from function signature in transaction data
if len(tx.Data()) >= 4 {
sig := common.Bytes2Hex(tx.Data()[:4])
switch sig {
case "0xac9650d8": // multicall (Uniswap V3)
return "UniswapV3"
case "0x1f0464d1": // multicall with blockhash (Uniswap V3)
return "UniswapV3"
case "0x88316456": // swap (Uniswap V2)
return "UniswapV2"
case "0x128acb08": // swap (SushiSwap)
return "SushiSwap"
case "0x38ed1739": // swapExactTokensForTokens (Uniswap V2)
return "UniswapV2"
case "0x8803dbee": // swapTokensForExactTokens (Uniswap V2)
return "UniswapV2"
case "0x7ff36ab5": // swapExactETHForTokens (Uniswap V2)
return "UniswapV2"
case "0xb6f9de95": // swapExactTokensForETH (Uniswap V2)
return "UniswapV2"
case "0x414bf389": // exactInputSingle (Uniswap V3)
return "UniswapV3"
case "0xdb3e2198": // exactInput (Uniswap V3)
return "UniswapV3"
case "0xf305d719": // exactOutputSingle (Uniswap V3)
return "UniswapV3"
case "0x04e45aaf": // exactOutput (Uniswap V3)
return "UniswapV3"
case "0x18cbafe5": // swapExactTokensForTokensSupportingFeeOnTransferTokens (Uniswap V2)
return "UniswapV2"
case "0x18cffa1c": // swapExactETHForTokensSupportingFeeOnTransferTokens (Uniswap V2)
return "UniswapV2"
case "0x791ac947": // swapExactTokensForETHSupportingFeeOnTransferTokens (Uniswap V2)
return "UniswapV2"
case "0x5ae401dc": // multicall (Uniswap V3)
return "UniswapV3"
}
}
return "Unknown"
}
// parseUniswapV2Swap parses a Uniswap V2 Swap event
func (ep *EventParser) parseUniswapV2Swap(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
if len(log.Topics) != 2 || len(log.Data) != 32*4 {
return nil, fmt.Errorf("invalid Uniswap V2 Swap event log")
}
// Parse the data fields
amount0In := new(big.Int).SetBytes(log.Data[0:32])
amount1In := new(big.Int).SetBytes(log.Data[32:64])
amount0Out := new(big.Int).SetBytes(log.Data[64:96])
amount1Out := new(big.Int).SetBytes(log.Data[96:128])
// Determine which token is being swapped in/out
var amount0, amount1 *big.Int
if amount0In.Cmp(big.NewInt(0)) > 0 {
amount0 = amount0In
} else {
amount0 = new(big.Int).Neg(amount0Out)
}
if amount1In.Cmp(big.NewInt(0)) > 0 {
amount1 = amount1In
} else {
amount1 = new(big.Int).Neg(amount1Out)
}
// DEBUG: Log details about this event creation
if log.Address == (common.Address{}) {
fmt.Printf("ZERO ADDRESS DEBUG [EVENTS-1]: Creating Event with zero address - BlockNumber: %d, LogIndex: %d, LogTopics: %d, LogData: %d bytes\n",
blockNumber, log.Index, len(log.Topics), len(log.Data))
}
event := &Event{
Type: Swap,
Protocol: "UniswapV2",
PoolAddress: log.Address,
Amount0: amount0,
Amount1: amount1,
Timestamp: timestamp,
TransactionHash: txHash,
BlockNumber: blockNumber,
}
return event, nil
}
// parseUniswapV3Swap parses a Uniswap V3 Swap event
func (ep *EventParser) parseUniswapV3Swap(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
if len(log.Topics) != 3 || len(log.Data) != 32*5 {
return nil, fmt.Errorf("invalid Uniswap V3 Swap event log")
}
// Parse the data fields
amount0 := new(big.Int).SetBytes(log.Data[0:32])
amount1 := new(big.Int).SetBytes(log.Data[32:64])
sqrtPriceX96 := new(big.Int).SetBytes(log.Data[64:96])
liquidity := new(big.Int).SetBytes(log.Data[96:128])
tick := new(big.Int).SetBytes(log.Data[128:160])
// Convert to signed values if needed
if amount0.Cmp(big.NewInt(0)) > 0x7fffffffffffffff {
amount0 = amount0.Sub(amount0, new(big.Int).Lsh(big.NewInt(1), 256))
}
if amount1.Cmp(big.NewInt(0)) > 0x7fffffffffffffff {
amount1 = amount1.Sub(amount1, new(big.Int).Lsh(big.NewInt(1), 256))
}
event := &Event{
Type: Swap,
Protocol: "UniswapV3",
PoolAddress: log.Address,
Amount0: amount0,
Amount1: amount1,
SqrtPriceX96: uint256.MustFromBig(sqrtPriceX96),
Liquidity: uint256.MustFromBig(liquidity),
Tick: int(tick.Int64()),
Timestamp: timestamp,
TransactionHash: txHash,
BlockNumber: blockNumber,
}
return event, nil
}
// parseUniswapV2Mint parses a Uniswap V2 Mint event
func (ep *EventParser) parseUniswapV2Mint(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
if len(log.Topics) != 2 || len(log.Data) != 32*2 {
return nil, fmt.Errorf("invalid Uniswap V2 Mint event log")
}
// Parse the data fields
amount0 := new(big.Int).SetBytes(log.Data[0:32])
amount1 := new(big.Int).SetBytes(log.Data[32:64])
event := &Event{
Type: AddLiquidity,
Protocol: "UniswapV2",
PoolAddress: log.Address,
Amount0: amount0,
Amount1: amount1,
Timestamp: timestamp,
TransactionHash: txHash,
BlockNumber: blockNumber,
}
return event, nil
}
// parseUniswapV3Mint parses a Uniswap V3 Mint event
func (ep *EventParser) parseUniswapV3Mint(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
if len(log.Topics) != 3 || len(log.Data) != 32*4 {
return nil, fmt.Errorf("invalid Uniswap V3 Mint event log")
}
// Parse the data fields
amount0 := new(big.Int).SetBytes(log.Data[0:32])
amount1 := new(big.Int).SetBytes(log.Data[32:64])
event := &Event{
Type: AddLiquidity,
Protocol: "UniswapV3",
PoolAddress: log.Address,
Amount0: amount0,
Amount1: amount1,
Timestamp: timestamp,
TransactionHash: txHash,
BlockNumber: blockNumber,
}
return event, nil
}
// parseUniswapV2Burn parses a Uniswap V2 Burn event
func (ep *EventParser) parseUniswapV2Burn(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
if len(log.Topics) != 2 || len(log.Data) != 32*2 {
return nil, fmt.Errorf("invalid Uniswap V2 Burn event log")
}
// Parse the data fields
amount0 := new(big.Int).SetBytes(log.Data[0:32])
amount1 := new(big.Int).SetBytes(log.Data[32:64])
event := &Event{
Type: RemoveLiquidity,
Protocol: "UniswapV2",
PoolAddress: log.Address,
Amount0: amount0,
Amount1: amount1,
Timestamp: timestamp,
TransactionHash: txHash,
BlockNumber: blockNumber,
}
return event, nil
}
// parseUniswapV3Burn parses a Uniswap V3 Burn event
func (ep *EventParser) parseUniswapV3Burn(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
if len(log.Topics) != 3 || len(log.Data) != 32*4 {
return nil, fmt.Errorf("invalid Uniswap V3 Burn event log")
}
// Parse the data fields
amount0 := new(big.Int).SetBytes(log.Data[0:32])
amount1 := new(big.Int).SetBytes(log.Data[32:64])
event := &Event{
Type: RemoveLiquidity,
Protocol: "UniswapV3",
PoolAddress: log.Address,
Amount0: amount0,
Amount1: amount1,
Timestamp: timestamp,
TransactionHash: txHash,
BlockNumber: blockNumber,
}
return event, nil
}
// ParseTransaction parses events from a transaction by decoding the function call data
func (ep *EventParser) ParseTransaction(tx *types.Transaction, blockNumber uint64, timestamp uint64) ([]*Event, error) {
// Check if this is a DEX interaction
if !ep.IsDEXInteraction(tx) {
// Return empty slice for non-DEX transactions
return []*Event{}, nil
}
if tx.To() == nil {
return []*Event{}, nil
}
// Determine the protocol
protocol := ep.identifyProtocol(tx)
// Parse transaction data to extract swap details
data := tx.Data()
if len(data) < 4 {
return []*Event{}, fmt.Errorf("insufficient transaction data")
}
// Get function selector (first 4 bytes)
selector := common.Bytes2Hex(data[:4])
events := make([]*Event, 0)
switch selector {
case "38ed1739": // swapExactTokensForTokens
event, err := ep.parseSwapExactTokensForTokensFromTx(tx, protocol, blockNumber, timestamp)
if err != nil {
return []*Event{}, fmt.Errorf("failed to parse swapExactTokensForTokens: %w", err)
}
if event != nil {
events = append(events, event)
}
case "414bf389": // exactInputSingle (Uniswap V3)
event, err := ep.parseExactInputSingleFromTx(tx, protocol, blockNumber, timestamp)
if err != nil {
return []*Event{}, fmt.Errorf("failed to parse exactInputSingle: %w", err)
}
if event != nil {
events = append(events, event)
}
case "db3e2198": // exactInput (Uniswap V3)
event, err := ep.parseExactInputFromTx(tx, protocol, blockNumber, timestamp)
if err != nil {
return []*Event{}, fmt.Errorf("failed to parse exactInput: %w", err)
}
if event != nil {
events = append(events, event)
}
case "7ff36ab5", "18cffa1c": // swapExactETHForTokens variants
event, err := ep.parseSwapExactETHForTokensFromTx(tx, protocol, blockNumber, timestamp)
if err != nil {
return []*Event{}, fmt.Errorf("failed to parse swapExactETHForTokens: %w", err)
}
if event != nil {
events = append(events, event)
}
case "ac9650d8": // multicall (Uniswap V3)
event, err := ep.parseMulticallFromTx(tx, protocol, blockNumber, timestamp)
if err != nil {
return []*Event{}, fmt.Errorf("failed to parse multicall: %w", err)
}
if event != nil {
events = append(events, event)
}
case "f305d719": // exactOutputSingle (Uniswap V3)
event, err := ep.parseExactOutputSingleFromTx(tx, protocol, blockNumber, timestamp)
if err != nil {
return []*Event{}, fmt.Errorf("failed to parse exactOutputSingle: %w", err)
}
if event != nil {
events = append(events, event)
}
default:
// For unknown functions, create a basic event
// Use router address as fallback since we can't extract tokens
event := &Event{
Type: Swap,
Protocol: protocol,
PoolAddress: *tx.To(), // Router address as fallback for unknown functions
Token0: common.Address{}, // Will be determined from logs
Token1: common.Address{}, // Will be determined from logs
Amount0: tx.Value(), // Use transaction value as fallback
Amount1: big.NewInt(0),
SqrtPriceX96: uint256.NewInt(0),
Liquidity: uint256.NewInt(0),
Tick: 0,
Timestamp: timestamp,
TransactionHash: tx.Hash(),
BlockNumber: blockNumber,
}
events = append(events, event)
}
return events, nil
}
// parseSwapExactTokensForTokensFromTx parses swapExactTokensForTokens from transaction data
func (ep *EventParser) parseSwapExactTokensForTokensFromTx(tx *types.Transaction, protocol string, blockNumber uint64, timestamp uint64) (*Event, error) {
data := tx.Data()[4:] // Skip function selector
if len(data) < 160 { // 5 parameters * 32 bytes
return nil, fmt.Errorf("insufficient data for swapExactTokensForTokens")
}
// Parse ABI-encoded parameters
amountIn := new(big.Int).SetBytes(data[0:32])
amountOutMin := new(big.Int).SetBytes(data[32:64])
// Extract path array from ABI-encoded data
// Path is at offset 96 (64 + 32), and its length is at that position
var token0, token1 common.Address
if len(data) >= 128 { // Ensure we have enough data
pathOffset := new(big.Int).SetBytes(data[64:96]).Uint64()
if pathOffset < uint64(len(data)) && pathOffset+32 < uint64(len(data)) {
pathLength := new(big.Int).SetBytes(data[pathOffset : pathOffset+32]).Uint64()
if pathLength >= 40 { // At least 2 addresses (20 bytes each)
// First token (token0)
token0 = common.BytesToAddress(data[pathOffset+32 : pathOffset+52])
// Last token (token1) - assuming simple path with 2 tokens
if pathLength >= 40 {
token1 = common.BytesToAddress(data[pathOffset+52 : pathOffset+72])
}
}
}
}
// Derive actual pool address from token pair
poolAddress := ep.derivePoolAddress(token0, token1, protocol)
event := &Event{
Type: Swap,
Protocol: protocol,
PoolAddress: poolAddress,
Token0: token0,
Token1: token1,
Amount0: amountIn,
Amount1: amountOutMin,
SqrtPriceX96: uint256.NewInt(0),
Liquidity: uint256.NewInt(0),
Tick: 0,
Timestamp: timestamp,
TransactionHash: tx.Hash(),
BlockNumber: blockNumber,
}
return event, nil
}
// parseExactInputSingleFromTx parses exactInputSingle from transaction data
func (ep *EventParser) parseExactInputSingleFromTx(tx *types.Transaction, protocol string, blockNumber uint64, timestamp uint64) (*Event, error) {
data := tx.Data()[4:] // Skip function selector
if len(data) < 256 { // 8 parameters * 32 bytes
return nil, fmt.Errorf("insufficient data for exactInputSingle")
}
// Parse ExactInputSingleParams struct
tokenIn := common.BytesToAddress(data[12:32])
tokenOut := common.BytesToAddress(data[44:64])
fee := new(big.Int).SetBytes(data[64:96]).Uint64()
amountIn := new(big.Int).SetBytes(data[160:192])
amountOutMin := new(big.Int).SetBytes(data[192:224])
// Derive actual pool address from token pair
poolAddress := ep.derivePoolAddress(tokenIn, tokenOut, protocol)
event := &Event{
Type: Swap,
Protocol: protocol,
PoolAddress: poolAddress,
Token0: tokenIn,
Token1: tokenOut,
Amount0: amountIn,
Amount1: amountOutMin,
SqrtPriceX96: uint256.NewInt(0),
Liquidity: uint256.NewInt(0),
Tick: 0,
Timestamp: timestamp,
TransactionHash: tx.Hash(),
BlockNumber: blockNumber,
}
// Store fee information for later use
event.Protocol = fmt.Sprintf("%s_fee_%d", protocol, fee)
return event, nil
}
// parseExactInputFromTx parses exactInput (multi-hop) from transaction data
func (ep *EventParser) parseExactInputFromTx(tx *types.Transaction, protocol string, blockNumber uint64, timestamp uint64) (*Event, error) {
data := tx.Data()[4:] // Skip function selector
if len(data) < 160 { // 5 parameters * 32 bytes
return nil, fmt.Errorf("insufficient data for exactInput")
}
// Parse ExactInputParams struct
amountIn := new(big.Int).SetBytes(data[96:128])
amountOutMin := new(big.Int).SetBytes(data[128:160])
// Extract path from encoded path bytes (first parameter)
// Path is encoded at offset 0, and its length is at offset 32
var token0, token1 common.Address
if len(data) >= 96 {
pathOffset := new(big.Int).SetBytes(data[0:32]).Uint64()
if pathOffset < uint64(len(data)) && pathOffset+32 < uint64(len(data)) {
pathLength := new(big.Int).SetBytes(data[pathOffset : pathOffset+32]).Uint64()
if pathLength >= 23 { // At least tokenA(20) + fee(3) for Uniswap V3 encoded path
// First token (20 bytes)
token0 = common.BytesToAddress(data[pathOffset+32 : pathOffset+52])
// For multi-hop paths, find the last token
// Uniswap V3 path format: tokenA(20) + fee(3) + tokenB(20) + fee(3) + tokenC(20)...
if pathLength >= 43 { // tokenA(20) + fee(3) + tokenB(20)
token1 = common.BytesToAddress(data[pathOffset+32+20+3 : pathOffset+32+20+3+20]) // Skip token0(20) + fee(3)
}
}
}
}
// Derive actual pool address from token pair
poolAddress := ep.derivePoolAddress(token0, token1, protocol)
event := &Event{
Type: Swap,
Protocol: protocol,
PoolAddress: poolAddress,
Token0: token0,
Token1: token1,
Amount0: amountIn,
Amount1: amountOutMin,
SqrtPriceX96: uint256.NewInt(0),
Liquidity: uint256.NewInt(0),
Tick: 0,
Timestamp: timestamp,
TransactionHash: tx.Hash(),
BlockNumber: blockNumber,
}
return event, nil
}
// parseSwapExactETHForTokensFromTx parses swapExactETHForTokens from transaction data
func (ep *EventParser) parseSwapExactETHForTokensFromTx(tx *types.Transaction, protocol string, blockNumber uint64, timestamp uint64) (*Event, error) {
data := tx.Data()[4:] // Skip function selector
if len(data) < 128 { // 4 parameters * 32 bytes
return nil, fmt.Errorf("insufficient data for swapExactETHForTokens")
}
amountOutMin := new(big.Int).SetBytes(data[0:32])
// Extract path array to get the output token
// Path offset is at position 32
var token1 common.Address
if len(data) >= 96 {
pathOffset := new(big.Int).SetBytes(data[32:64]).Uint64()
if pathOffset < uint64(len(data)) && pathOffset+32 < uint64(len(data)) {
pathLength := new(big.Int).SetBytes(data[pathOffset : pathOffset+32]).Uint64()
if pathLength >= 40 { // At least 2 addresses (20 bytes each)
// Extract the last token from the path (output token)
// For swapExactETHForTokens, we want the second token in the path
if pathLength >= 40 {
token1 = common.BytesToAddress(data[pathOffset+52 : pathOffset+72])
}
}
}
}
event := &Event{
Type: Swap,
Protocol: protocol,
PoolAddress: *tx.To(),
Token0: common.HexToAddress("0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE"), // ETH
Token1: token1,
Amount0: tx.Value(), // ETH amount from transaction value
Amount1: amountOutMin,
SqrtPriceX96: uint256.NewInt(0),
Liquidity: uint256.NewInt(0),
Tick: 0,
Timestamp: timestamp,
TransactionHash: tx.Hash(),
BlockNumber: blockNumber,
}
return event, nil
}
// parseExactOutputSingleFromTx parses exactOutputSingle from transaction data
func (ep *EventParser) parseExactOutputSingleFromTx(tx *types.Transaction, protocol string, blockNumber uint64, timestamp uint64) (*Event, error) {
data := tx.Data()[4:] // Skip function selector
if len(data) < 256 { // 8 parameters * 32 bytes
return nil, fmt.Errorf("insufficient data for exactOutputSingle")
}
// Parse ExactOutputSingleParams struct
tokenIn := common.BytesToAddress(data[12:32])
tokenOut := common.BytesToAddress(data[44:64])
fee := new(big.Int).SetBytes(data[64:96]).Uint64()
amountOut := new(big.Int).SetBytes(data[160:192])
amountInMaximum := new(big.Int).SetBytes(data[192:224])
// Derive actual pool address from token pair
poolAddress := ep.derivePoolAddress(tokenIn, tokenOut, protocol)
event := &Event{
Type: Swap,
Protocol: protocol,
PoolAddress: poolAddress,
Token0: tokenIn,
Token1: tokenOut,
Amount0: amountInMaximum, // Maximum input amount
Amount1: amountOut, // Exact output amount
SqrtPriceX96: uint256.NewInt(0),
Liquidity: uint256.NewInt(0),
Tick: 0,
Timestamp: timestamp,
TransactionHash: tx.Hash(),
BlockNumber: blockNumber,
}
// Store fee information for later use
event.Protocol = fmt.Sprintf("%s_fee_%d", protocol, fee)
return event, nil
}
// parseMulticallFromTx parses multicall transactions to extract token addresses and amounts
func (ep *EventParser) parseMulticallFromTx(tx *types.Transaction, protocol string, blockNumber uint64, timestamp uint64) (*Event, error) {
data := tx.Data()[4:] // Skip function selector
if len(data) < 64 { // Need at least bytes array offset and length
return nil, fmt.Errorf("insufficient data for multicall")
}
// Extract tokens from multicall data using comprehensive scanning
tokenCtx := &calldata.MulticallContext{
TxHash: tx.Hash().Hex(),
Protocol: protocol,
Stage: "events.parser.parseMulticallFromTx",
BlockNumber: blockNumber,
}
swap := ep.extractSwapFromMulticallData(data, tokenCtx)
var (
token0 common.Address
token1 common.Address
amount0 *big.Int
amount1 *big.Int
poolAddress common.Address
)
if swap != nil {
token0 = swap.TokenIn
token1 = swap.TokenOut
amount0 = swap.AmountIn
if swap.AmountOut != nil {
amount1 = new(big.Int).Set(swap.AmountOut)
} else if swap.AmountOutMinimum != nil {
amount1 = new(big.Int).Set(swap.AmountOutMinimum)
}
if swap.PoolAddress != (common.Address{}) {
poolAddress = swap.PoolAddress
}
if protocol == "" {
protocol = swap.Protocol
}
}
if poolAddress == (common.Address{}) {
if token0 != (common.Address{}) && token1 != (common.Address{}) {
poolAddress = ep.derivePoolAddress(token0, token1, protocol)
} else if tx.To() != nil {
poolAddress = *tx.To()
}
}
if amount0 == nil {
amount0 = tx.Value()
}
if amount1 == nil {
amount1 = big.NewInt(0)
}
event := &Event{
Type: Swap,
Protocol: protocol,
PoolAddress: poolAddress,
Token0: token0,
Token1: token1,
Amount0: amount0,
Amount1: amount1,
SqrtPriceX96: uint256.NewInt(0),
Liquidity: uint256.NewInt(0),
Tick: 0,
Timestamp: timestamp,
TransactionHash: tx.Hash(),
BlockNumber: blockNumber,
}
return event, nil
}
// extractSwapFromMulticallData decodes the first viable swap call from multicall payload data.
func (ep *EventParser) extractSwapFromMulticallData(data []byte, ctx *calldata.MulticallContext) *calldata.SwapCall {
swaps, err := calldata.DecodeSwapCallsFromMulticall(data, ctx)
if err != nil || len(swaps) == 0 {
return nil
}
for _, swap := range swaps {
if swap == nil {
continue
}
if !ep.isValidTokenAddress(swap.TokenIn) || !ep.isValidTokenAddress(swap.TokenOut) {
continue
}
return swap
}
return nil
}
// isValidTokenAddress checks if an address looks like a valid token address
func (ep *EventParser) isValidTokenAddress(addr common.Address) bool {
// Skip zero address
if addr == (common.Address{}) {
return false
}
// Skip known router and factory addresses
knownRouters := map[common.Address]bool{
ep.UniswapV2Router02: true,
ep.UniswapV3Router: true,
ep.UniswapV2Factory: true,
ep.UniswapV3Factory: true,
ep.SushiSwapFactory: true,
common.HexToAddress("0xA51afAFe0263b40EdaEf0Df8781eA9aa03E381a3"): true, // Universal Router
common.HexToAddress("0x1111111254EEB25477B68fb85Ed929f73A960582"): true, // 1inch Router v5
common.HexToAddress("0xC36442b4a4522E871399CD717aBDD847Ab11FE88"): true, // Uniswap V3 Position Manager
}
if knownRouters[addr] {
return false
}
// Basic heuristic: valid token addresses typically have some non-zero bytes
// and don't end with many zeros (which are often parameter values)
bytes := addr.Bytes()
nonZeroCount := 0
for _, b := range bytes {
if b != 0 {
nonZeroCount++
}
}
// Require at least 8 non-zero bytes for a valid token address
return nonZeroCount >= 8
}
// derivePoolAddress derives the pool address from token pair and protocol
func (ep *EventParser) derivePoolAddress(token0, token1 common.Address, protocol string) common.Address {
// If either token is zero address, we cannot derive a valid pool address
if token0 == (common.Address{}) || token1 == (common.Address{}) {
return common.Address{}
}
// Check if either token is actually a router address (shouldn't happen but safety check)
knownRouters := map[common.Address]bool{
ep.UniswapV2Router02: true,
ep.UniswapV3Router: true,
common.HexToAddress("0xA51afAFe0263b40EdaEf0Df8781eA9aa03E381a3"): true, // Universal Router
common.HexToAddress("0x1111111254EEB25477B68fb85Ed929f73A960582"): true, // 1inch Router v5
common.HexToAddress("0xC36442b4a4522E871399CD717aBDD847Ab11FE88"): true, // Uniswap V3 Position Manager
}
if knownRouters[token0] || knownRouters[token1] {
return common.Address{}
}
protocolLower := strings.ToLower(protocol)
if strings.Contains(protocolLower, "uniswapv3") {
fee := int64(3000)
return uniswap.CalculatePoolAddress(ep.UniswapV3Factory, token0, token1, fee)
}
if strings.Contains(protocolLower, "sushi") {
if addr := calculateUniswapV2Pair(ep.SushiSwapFactory, token0, token1); addr != (common.Address{}) {
return addr
}
}
if strings.Contains(protocolLower, "uniswapv2") || strings.Contains(protocolLower, "camelot") {
if addr := calculateUniswapV2Pair(ep.UniswapV2Factory, token0, token1); addr != (common.Address{}) {
return addr
}
}
return common.Address{}
}
func calculateUniswapV2Pair(factory, token0, token1 common.Address) common.Address {
if factory == (common.Address{}) || token0 == (common.Address{}) || token1 == (common.Address{}) {
return common.Address{}
}
if token0.Big().Cmp(token1.Big()) > 0 {
token0, token1 = token1, token0
}
keccakInput := append(token0.Bytes(), token1.Bytes()...)
salt := crypto.Keccak256(keccakInput)
initCodeHash := common.HexToHash("0x96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f")
data := make([]byte, 0, 85)
data = append(data, 0xff)
data = append(data, factory.Bytes()...)
data = append(data, salt...)
data = append(data, initCodeHash.Bytes()...)
hash := crypto.Keccak256(data)
var addr common.Address
copy(addr[:], hash[12:])
return addr
}
// AddKnownPool adds a pool address to the known pools map
func (ep *EventParser) AddKnownPool(address common.Address, protocol string) {
ep.knownPools[address] = protocol
}
// GetKnownPools returns all known pools
func (ep *EventParser) GetKnownPools() map[common.Address]string {
return ep.knownPools
}