Fix handling of Compound related Transfer events (#595)

e2e-commons/constants.json

@@ -38,7 +38,7 @@
   "ercToNativeBridge": {
     "home": "0x5118AC62AE912Dd5B51EEfF7338c4fcb0248Ba8c",
     "foreign": "0x32198D570fffC7033641F8A9094FFDCaAEF42624",
-    "foreignToken": "0x7cc4b1851c35959d34e635a470f6b5c43ba3c9c9",
+    "foreignToken": "0x6B175474E89094C44Da98b954EedeAC495271d0F",
     "monitor": "http://monitor-erc20-native:3012/bridge"
   },
   "amb": {

e2e-commons/contracts-envs/erc-to-native.env

@@ -32,7 +32,7 @@ FOREIGN_GAS_PRICE=10000000000
 FOREIGN_REWARDABLE=false
 
 BLOCK_REWARD_ADDRESS=0xdbeE25CbE97e4A5CC6c499875774dc7067E9426B
-ERC20_TOKEN_ADDRESS=0x7cc4b1851c35959d34e635a470f6b5c43ba3c9c9
+ERC20_TOKEN_ADDRESS=0x6B175474E89094C44Da98b954EedeAC495271d0F
 
 REQUIRED_NUMBER_OF_VALIDATORS=1
 VALIDATORS="0xaaB52d66283F7A1D5978bcFcB55721ACB467384b 0xdCC784657C78054aa61FbcFFd2605F32374816A4 0xDcef88209a20D52165230104B245803C3269454d"

monitor/getBalances.js

@@ -46,24 +46,6 @@ async function main(bridgeMode, eventsInfo) {
     const foreignBridge = new web3Foreign.eth.Contract(FOREIGN_ERC_TO_NATIVE_ABI, COMMON_FOREIGN_BRIDGE_ADDRESS)
     const erc20Address = await foreignBridge.methods.erc20token().call()
     const erc20Contract = new web3Foreign.eth.Contract(ERC20_ABI, erc20Address)
-    let investedAmountInDai = 0
-    let bridgeDsrBalance = 0
-    let displayChaiToken = false
-
-    try {
-      logger.debug('calling foreignBridge.methods.isChaiTokenEnabled')
-      if (await foreignBridge.methods.isChaiTokenEnabled().call()) {
-        displayChaiToken = true
-        logger.debug('calling foreignBridge.methods.investedAmountInDai')
-        investedAmountInDai = await foreignBridge.methods.investedAmountInDai().call()
-        logger.debug('calling foreignBridge.methods.dsrBalance')
-        bridgeDsrBalance = await foreignBridge.methods.dsrBalance().call()
-      } else {
-        logger.debug('Chai token is currently disabled')
-      }
-    } catch (e) {
-      logger.debug('Methods for chai token are not present')
-    }
 
     logger.debug('calling erc20Contract.methods.balanceOf')
     const foreignErc20Balance = await erc20Contract.methods
@@ -85,29 +67,16 @@ async function main(bridgeMode, eventsInfo) {
     const burntCoinsBN = new BN(burntCoins)
     const totalSupplyBN = mintedCoinsBN.minus(burntCoinsBN)
     const foreignErc20BalanceBN = new BN(foreignErc20Balance).plus(lateForeignConfirmationsTotalValue)
-    const investedAmountInDaiBN = new BN(investedAmountInDai)
-    const bridgeDsrBalanceBN = new BN(bridgeDsrBalance)
-
-    const diff = foreignErc20BalanceBN
-      .plus(investedAmountInDaiBN)
-      .minus(totalSupplyBN)
-      .toFixed()
-
-    const foreign = {
-      erc20Balance: Web3Utils.fromWei(foreignErc20Balance)
-    }
-
-    if (displayChaiToken) {
-      foreign.investedErc20Balance = Web3Utils.fromWei(investedAmountInDai)
-      foreign.accumulatedInterest = Web3Utils.fromWei(bridgeDsrBalanceBN.minus(investedAmountInDaiBN).toString(10))
-    }
 
+    const diff = foreignErc20BalanceBN.minus(totalSupplyBN).toFixed()
     logger.debug('Done')
     return {
       home: {
         totalSupply: Web3Utils.fromWei(totalSupplyBN.toFixed())
       },
-      foreign,
+      foreign: {
+        erc20Balance: Web3Utils.fromWei(foreignErc20Balance)
+      },
       balanceDiff: Number(Web3Utils.fromWei(diff)),
       ...blockRanges,
       lastChecked: Math.floor(Date.now() / 1000)

monitor/utils/events.js

@@ -11,7 +11,6 @@ const {
   OLD_AMB_USER_REQUEST_FOR_AFFIRMATION_ABI
 } = require('../../commons')
 const { normalizeEventInformation } = require('./message')
-const { filterTransferBeforeES } = require('./tokenUtils')
 const { writeFile, readCacheFile } = require('./file')
 const { web3Home, web3Foreign, getHomeBlockNumber, getForeignBlockNumber } = require('./web3')
 const { getPastEvents } = require('./web3Cache')
@@ -160,80 +159,32 @@ async function main(mode) {
         filter: { to: COMMON_FOREIGN_BRIDGE_ADDRESS }
       },
       chain: 'foreign'
+    }))
+      .map(normalizeEvent)
+      .filter(e => e.recipient !== ZERO_ADDRESS) // filter mint operation during SCD-to-MCD swaps
+      .filter(e => e.recipient.toLowerCase() !== '0x5d3a536e4d6dbd6114cc1ead35777bab948e3643') // filter cDai withdraws during compounding
+
+    // Get transfer events for each previously used Sai token
+    const saiTokenAddress = '0x89d24A6b4CcB1B6fAA2625fE562bDD9a23260359'
+    const halfDuplexTokenContract = new web3Foreign.eth.Contract(ERC20_ABI, saiTokenAddress)
+    logger.debug('Half duplex token:', saiTokenAddress)
+    logger.debug("calling halfDuplexTokenContract.getPastEvents('Transfer')")
+    // https://etherscan.io/tx/0xd0c3c92c94e05bc71256055ce8c4c993e047f04e04f3283a04e4cb077b71f6c6
+    const blockNumberHalfDuplexDisabled = 9884448
+    const halfDuplexTransferEvents = (await getPastEvents(halfDuplexTokenContract, {
+      event: 'Transfer',
+      fromBlock: MONITOR_FOREIGN_START_BLOCK,
+      toBlock: Math.min(blockNumberHalfDuplexDisabled, foreignDelayedBlockNumber),
+      options: {
+        filter: { to: COMMON_FOREIGN_BRIDGE_ADDRESS }
+      },
+      chain: 'foreign'
     })).map(normalizeEvent)
 
-    let directTransfers = transferEvents
+    transferEvents = [...halfDuplexTransferEvents, ...transferEvents]
-    const tokensSwappedAbiExists = FOREIGN_ABI.filter(e => e.type === 'event' && e.name === 'TokensSwapped')[0]
-    if (tokensSwappedAbiExists) {
-      logger.debug('collecting half duplex tokens participated in the bridge balance')
-      logger.debug("calling foreignBridge.getPastEvents('TokensSwapped')")
-      const tokensSwappedEvents = await getPastEvents(foreignBridge, {
-        event: 'TokensSwapped',
-        fromBlock: MONITOR_FOREIGN_START_BLOCK,
-        toBlock: foreignBlockNumber,
-        chain: 'foreign',
-        safeToBlock: foreignDelayedBlockNumber
-      })
-
-      // Get token swap events emitted by foreign bridge
-      const bridgeTokensSwappedEvents = tokensSwappedEvents.filter(e => e.address === COMMON_FOREIGN_BRIDGE_ADDRESS)
-
-      // Get transfer events for each previous erc20
-      const uniqueTokenAddressesSet = new Set(bridgeTokensSwappedEvents.map(e => e.returnValues.from))
-
-      // Exclude chai token from previous erc20
-      try {
-        logger.debug('calling foreignBridge.chaiToken() to remove it from half duplex tokens list')
-        const chaiToken = await foreignBridge.methods.chaiToken().call()
-        uniqueTokenAddressesSet.delete(chaiToken)
-      } catch (e) {
-        logger.debug('call to foreignBridge.chaiToken() failed')
-      }
-      // Exclude dai token from previous erc20
-      try {
-        logger.debug('calling foreignBridge.erc20token()  to remove it from half duplex tokens list')
-        const daiToken = await foreignBridge.methods.erc20token().call()
-        uniqueTokenAddressesSet.delete(daiToken)
-      } catch (e) {
-        logger.debug('call to foreignBridge.erc20token() failed')
-      }
-
-      const uniqueTokenAddresses = [...uniqueTokenAddressesSet]
-      await Promise.all(
-        uniqueTokenAddresses.map(async tokenAddress => {
-          const halfDuplexTokenContract = new web3Foreign.eth.Contract(ERC20_ABI, tokenAddress)
-
-          logger.debug('Half duplex token:', tokenAddress)
-          logger.debug("calling halfDuplexTokenContract.getPastEvents('Transfer')")
-          const halfDuplexTransferEvents = (await getPastEvents(halfDuplexTokenContract, {
-            event: 'Transfer',
-            fromBlock: MONITOR_FOREIGN_START_BLOCK,
-            toBlock: foreignDelayedBlockNumber,
-            options: {
-              filter: { to: COMMON_FOREIGN_BRIDGE_ADDRESS }
-            },
-            chain: 'foreign'
-          })).map(normalizeEvent)
-
-          // Remove events after the ES
-          logger.debug('filtering half duplex transfers happened before ES')
-          const validHalfDuplexTransfers = await filterTransferBeforeES(halfDuplexTransferEvents)
-
-          transferEvents = [...validHalfDuplexTransfers, ...transferEvents]
-        })
-      )
-
-      // filter transfer that is part of a token swap
-      directTransfers = transferEvents.filter(
-        e =>
-          bridgeTokensSwappedEvents.findIndex(
-            t => t.transactionHash === e.referenceTx && e.recipient === ZERO_ADDRESS
-          ) === -1
-      )
-    }
 
     // Get transfer events that didn't have a UserRequestForAffirmation event in the same transaction
-    directTransfers = directTransfers.filter(
+    const directTransfers = transferEvents.filter(
       e => foreignToHomeRequests.findIndex(t => t.referenceTx === e.referenceTx) === -1
     )
 

monitor/utils/tokenUtils.js

@@ -1,27 +0,0 @@
-// https://etherscan.io/tx/0xd0c3c92c94e05bc71256055ce8c4c993e047f04e04f3283a04e4cb077b71f6c6
-const blockNumberHalfDuplexDisabled = 9884448
-
-/**
- * Returns true if the event was before the bridge stopped supporting half duplex transfers.
- */
-async function transferBeforeES(event) {
-  return event.blockNumber < blockNumberHalfDuplexDisabled
-}
-
-async function filterTransferBeforeES(array) {
-  const newArray = []
-  // Iterate events from newer to older
-  for (let i = array.length - 1; i >= 0; i--) {
-    const beforeES = await transferBeforeES(array[i])
-    if (beforeES) {
-      // add element to first position so the new array will have the same order
-      newArray.unshift(array[i])
-    }
-  }
-  return newArray
-}
-
-module.exports = {
-  filterTransferBeforeES,
-  blockNumberHalfDuplexDisabled
-}

oracle-e2e/test/ercToNative.js

@@ -33,6 +33,10 @@ const homeBridge = new homeWeb3.eth.Contract(HOME_ERC_TO_NATIVE_ABI, COMMON_HOME
 
 describe('erc to native', () => {
   before(async () => {
+    console.log('Initializing interest')
+    await foreignBridge.methods
+      .initializeInterest(ercToNativeBridge.foreignToken, 1, 1, validator.address)
+      .send({ from: validator.address, gas: '4000000' })
     if (process.env.ULTIMATE === 'true') {
       return
     }
@@ -112,6 +116,7 @@ describe('erc to native', () => {
       .catch(e => {
         console.error(e)
       })
+    await foreignBridge.methods.investDai().send({ from: validator.address, gas: '4000000' })
 
     // check that balance increases
     await uniformRetry(async retry => {

oracle/src/confirmRelay.js

@@ -6,6 +6,7 @@ const logger = require('./services/logger')
 const GasPrice = require('./services/gasPrice')
 const { getNonce, getChainId, getEventsFromTx } = require('./tx/web3')
 const { sendTx } = require('./tx/sendTx')
+const { getTokensState } = require('./utils/tokenState')
 const { checkHTTPS, watchdog, syncForEach, addExtraGas } = require('./utils/utils')
 const { EXIT_CODES, EXTRA_GAS_PERCENTAGE, MAX_GAS_LIMIT } = require('./utils/constants')
 
@@ -17,7 +18,7 @@ if (process.argv.length < 4) {
 }
 
 const config = require(path.join('../config/', process.argv[2]))
-const { web3, eventContract, chain } = config.main
+const { web3, eventContract, chain, bridgeContract } = config.main
 
 const isTxHash = txHash => txHash.length === 66 && web3.utils.isHexStrict(txHash)
 function readTxHashes(filePath) {
@@ -114,6 +115,12 @@ function processEvents(events) {
 }
 
 async function main({ sendJob, txHashes }) {
+  if (config.id === 'erc-native-transfer') {
+    logger.debug('Getting token address to listen Transfer events')
+    const state = await getTokensState(bridgeContract, logger)
+    eventContract.options.address = state.bridgeableTokenAddress
+  }
+
   logger.info(`Processing ${txHashes.length} input transactions`)
   for (const txHash of txHashes) {
     try {

oracle/src/events/processTransfers/index.js

@@ -13,12 +13,25 @@ const limit = promiseLimit(MAX_CONCURRENT_EVENTS)
 function processTransfersBuilder(config) {
   const { bridgeContract, web3 } = config.home
 
-  const userRequestForAffirmationAbi = config.foreign.bridgeABI.find(
+  const userRequestForAffirmationHash = web3.eth.abi.encodeEventSignature('UserRequestForAffirmation(address,uint256)')
-    e => e.type === 'event' && e.name === 'UserRequestForAffirmation'
+  const redeemHash = web3.eth.abi.encodeEventSignature('Redeem(address,uint256,uint256)')
-  )
+  const transferHash = web3.eth.abi.encodeEventSignature('Transfer(address,address,uint256)')
-  const tokensSwappedAbi = config.foreign.bridgeABI.find(e => e.type === 'event' && e.name === 'TokensSwapped')
+
-  const userRequestForAffirmationHash = web3.eth.abi.encodeEventSignature(userRequestForAffirmationAbi)
+  const foreignBridgeAddress = config.foreign.bridgeAddress
-  const tokensSwappedHash = tokensSwappedAbi ? web3.eth.abi.encodeEventSignature(tokensSwappedAbi) : '0x'
+
+  const decodeAddress = data => web3.eth.abi.decodeParameter('address', data)
+
+  const isUserRequestForAffirmation = e =>
+    e.address.toLowerCase() === foreignBridgeAddress.toLowerCase() && e.topics[0] === userRequestForAffirmationHash
+  const isRedeem = cTokenAddress => e =>
+    e.address.toLowerCase() === cTokenAddress.toLowerCase() &&
+    e.topics[0] === redeemHash &&
+    decodeAddress(e.data.slice(0, 66)).toLowerCase() === foreignBridgeAddress.toLowerCase()
+  const isCTokenTransfer = cTokenAddress => e =>
+    e.address.toLowerCase() === cTokenAddress.toLowerCase() &&
+    e.topics[0] === transferHash &&
+    decodeAddress(e.topics[1]).toLowerCase() === foreignBridgeAddress.toLowerCase() &&
+    decodeAddress(e.topics[2]).toLowerCase() === cTokenAddress.toLowerCase()
 
   let validatorContract = null
 
@@ -32,37 +45,35 @@ function processTransfersBuilder(config) {
     rootLogger.debug(`Processing ${transfers.length} Transfer events`)
     const callbacks = transfers
       .map(transfer => async () => {
-        const { from, value } = transfer.returnValues
+        const { from, to, value } = transfer.returnValues
 
         const logger = rootLogger.child({
-          eventTransactionHash: transfer.transactionHash
+          eventTransactionHash: transfer.transactionHash,
+          from,
+          to,
+          value
         })
 
-        logger.info({ from, value }, `Processing transfer ${transfer.transactionHash}`)
+        logger.info('Processing transfer')
 
         const receipt = await config.foreign.web3.eth.getTransactionReceipt(transfer.transactionHash)
 
-        const existsAffirmationEvent = receipt.logs.some(
+        if (receipt.logs.some(isUserRequestForAffirmation)) {
-          e => e.address === config.foreign.bridgeAddress && e.topics[0] === userRequestForAffirmationHash
+          logger.info('Transfer event discarded because affirmation is detected in the same transaction')
-        )
-
-        if (existsAffirmationEvent) {
-          logger.info(
-            `Transfer event discarded because a transaction with alternative receiver detected in transaction ${
-              transfer.transactionHash
-            }`
-          )
           return
         }
 
-        const existsTokensSwappedEvent = tokensSwappedAbi
+        if (from === ZERO_ADDRESS) {
-          ? receipt.logs.some(e => e.address === config.foreign.bridgeAddress && e.topics[0] === tokensSwappedHash)
+          logger.info('Mint-like transfers from zero address are not processed')
-          : false
+          return
+        }
 
-        if (from === ZERO_ADDRESS && existsTokensSwappedEvent) {
+        // when bridge performs a withdrawal from Compound, the following three events occur
-          logger.info(
+        // * token.Transfer(from=cToken, to=bridge, amount=X)
-            `Transfer event discarded because token swap is detected in transaction ${transfer.transactionHash}`
+        // * cToken.Redeem(redeemer=bridge, amount=X, tokens=Y)
-          )
+        // * cToken.Transfer(from=bridge, to=cToken, amount=Y)
+        if (receipt.logs.some(isRedeem(from)) && receipt.logs.some(isCTokenTransfer(from))) {
+          logger.info('Transfer event discarded because cToken redeem is detected in the same transaction')
           return
         }
 

oracle/src/watcher.js

@@ -156,8 +156,6 @@ async function main({ sendToQueue }) {
       logger.info(`Oracle watcher was unsuspended.`)
     }
 
-    await checkConditions()
-
     const lastBlockToProcess = await getLastBlockToProcess(web3, bridgeContract)
 
     if (lastBlockToProcess <= lastProcessedBlock) {
@@ -165,6 +163,8 @@ async function main({ sendToQueue }) {
       return
     }
 
+    await checkConditions()
+
     const fromBlock = lastProcessedBlock + 1
     const rangeEndBlock = config.blockPollingLimit ? fromBlock + config.blockPollingLimit : lastBlockToProcess
     let toBlock = Math.min(lastBlockToProcess, rangeEndBlock)

parity/foreign_mocks/cDAIMock.sol

@@ -0,0 +1,33 @@
+pragma solidity 0.4.24;
+
+interface IERC20 {
+  function transferFrom(address from,address to,uint256 value) external;
+  function transfer(address to,uint256 value) external;
+}
+
+contract cDaiMock {
+  IERC20 daiToken;
+
+  event Transfer(address indexed from, address indexed to, uint amount);
+  event Mint(address minter, uint mintAmount, uint mintTokens);
+  event Redeem(address redeemer, uint redeemAmount, uint redeemTokens);
+
+
+  function mint(uint256 mintAmount) external returns (uint256) {
+    daiToken.transferFrom(msg.sender, address(this), mintAmount);
+
+    emit Mint(msg.sender, mintAmount, mintAmount);
+    emit Transfer(address(this), msg.sender, mintAmount);
+
+    return 0;
+  }
+
+  function redeemUnderlying(uint256 redeemAmount) external returns (uint256) {
+    daiToken.transfer(msg.sender, redeemAmount);
+
+    emit Transfer(msg.sender, address(this), redeemAmount);
+    emit Redeem(msg.sender, redeemAmount, redeemAmount);
+
+    return 0;
+  }
+}