feat(raiden): check direct channel before swap

This adds logic to check that we have a direct channel with a peer with
sufficient balance for raiden currencies before accepting or proposing a
swap. Currently multi-hop Raiden payments are not well supported, and
failed payments are not handled well in Raiden. This will prevent any
attempts to swap Raiden tokens without a direct channel.

Closes #1027.

bin/xud

@@ -72,6 +72,11 @@ const { argv } = require('yargs')
       type: 'string',
       alias: 'x',
     },
+    'debug.raidenDirectChannelChecks': {
+      describe: 'Whether to require direct channels for raiden payments',
+      type: 'boolean',
+      default: undefined,
+    },
     'http.port': {
       describe: 'Port to listen for http requests',
       type: 'number',

lib/Config.ts

@@ -23,6 +23,7 @@ class Config {
   public raiden: RaidenClientConfig;
   public orderthresholds: OrderBookThresholds;
   public webproxy: { port: number, disable: boolean };
+  public debug: { raidenDirectChannelChecks: boolean };
   public instanceid = 0;
   /** Whether to intialize a new database with default values. */
   public initdb = true;
@@ -96,6 +97,9 @@ class Config {
       disable: true,
       port: 8080,
     };
+    this.debug = {
+      raidenDirectChannelChecks: true,
+    };
     // TODO: add dynamic max/min price limits
     this.orderthresholds = {
       minQuantity: 0, // 0 = disabled

lib/lndclient/LndClient.ts

@@ -496,7 +496,7 @@ class LndClient extends SwapClient {
     return this.unaryCall<lndrpc.ListChannelsRequest, lndrpc.ListChannelsResponse>('listChannels', new lndrpc.ListChannelsRequest());
   }
 
-  public getRoutes =  async (amount: number, destination: string, finalCltvDelta = this.cltvDelta): Promise<lndrpc.Route[]> => {
+  public getRoutes =  async (amount: number, destination: string, _currency: string, finalCltvDelta = this.cltvDelta): Promise<lndrpc.Route[]> => {
     const request = new lndrpc.QueryRoutesRequest();
     request.setAmt(amount);
     request.setFinalCltvDelta(finalCltvDelta);

lib/orderbook/OrderBook.ts

@@ -129,7 +129,7 @@ class OrderBook extends EventEmitter {
     return order.quantity >= minQuantity;
   }
   /**
-   * Checks that a currency advertised by a peer are known to us, have a swap client identifier,
+   * Checks that a currency advertised by a peer is known to us, has a swap client identifier,
    * and that their token identifier matches ours.
    */
   private isPeerCurrencySupported = (peer: Peer, currency: string) => {

lib/p2p/Peer.ts

@@ -64,10 +64,10 @@ class Peer extends EventEmitter {
   public active = false;
   /** Timer to periodically call getNodes #402 */
   public discoverTimer?: NodeJS.Timer;
-  /** Currencies that we have verified that we can swap for this peer. */
+  /** Currencies that we have verified we can swap with this peer. */
   public verifiedCurrencies = new Set<string>();
   /**
-   * Currencies that we cannot swap because we are missing a swap client identifier or because our
+   * Currencies that we cannot swap because we are missing a swap client identifier or because the
    * peer's token identifier for this currency does not match ours - for example this may happen
    * because a peer is using a different raiden token contract address for a currency than we are.
    */
@@ -130,6 +130,10 @@ class Peer extends EventEmitter {
     return this.nodeState ? this.nodeState.addresses : undefined;
   }
 
+  public get raidenAddress(): string | undefined {
+    return this.nodeState ? this.nodeState.raidenAddress : undefined;
+  }
+
   /** Returns a list of trading pairs advertised by this peer. */
   public get advertisedPairs(): string[] {
     if (this.nodeState) {

lib/raidenclient/RaidenClient.ts

@@ -51,13 +51,14 @@ class RaidenClient extends SwapClient {
   private disable: boolean;
   private unitConverter: UnitConverter;
   private maximumOutboundAmounts = new Map<string, number>();
+  private directChannelChecks: boolean;
 
   /**
    * Creates a raiden client.
    */
   constructor(
-    { config, logger, unitConverter }:
-    { config: RaidenClientConfig, logger: Logger, unitConverter: UnitConverter },
+    { config, logger, unitConverter, directChannelChecks = false }:
+    { config: RaidenClientConfig, logger: Logger, unitConverter: UnitConverter, directChannelChecks: boolean },
   ) {
     super(logger);
     const { disable, host, port } = config;
@@ -66,6 +67,7 @@ class RaidenClient extends SwapClient {
     this.host = host;
     this.disable = disable;
     this.unitConverter = unitConverter;
+    this.directChannelChecks = directChannelChecks;
   }
 
   /**
@@ -201,12 +203,35 @@ class RaidenClient extends SwapClient {
     // not implemented, raiden does not use invoices
   }
 
-  public getRoutes =  async (_amount: number, _destination: string) => {
-    // stub placeholder, query routes not currently implemented in raiden
-    // assume a fixed lock time of 100 Raiden's blocks
-    return [{
+  public getRoutes = async (amount: number, destination: string, currency: string) => {
+    // a query routes call is not currently provided by raiden
+
+    /** A placeholder route value that assumes a fixed lock time of 100 Raiden's blocks. */
+    const placeholderRoute = {
       getTotalTimeLock: () => 101,
-    }];
+    };
+
+    if (this.directChannelChecks) {
+      // temporary check for a direct channel in raiden
+      const tokenAddress = this.tokenAddresses.get(currency);
+      const channels = await this.getChannels(tokenAddress);
+      for (const channel of channels) {
+        if (channel.partner_address && channel.partner_address === destination) {
+          const balance = channel.balance;
+          if (balance >= amount) {
+            this.logger.debug(`found a direct channel for ${currency} to ${destination} with ${balance} balance`);
+            return [placeholderRoute];
+          } else {
+            this.logger.warn(`direct channel found for ${currency} to ${destination} with balance of ${balance} is insufficient for ${amount})`);
+            return []; // we have a direct channel but it doesn't have enough balance, return no routes
+          }
+        }
+      }
+      this.logger.warn(`no direct channel found for ${currency} to ${destination}`);
+      return []; // no direct channels, return no routes
+    } else {
+      return [placeholderRoute];
+    }
   }
 
   public getHeight = async () => {

lib/raidenclient/types.ts

@@ -32,6 +32,7 @@ export type Channel = OpenChannelPayload & {
   channel_address: string;
   token_network_identifier: string;
   channel_identifier: number;
+  /** The balance of the channel denominated in the smallest units supported by the token. */
   balance: number
   state: string;
 };
@@ -49,6 +50,7 @@ export type TokenPaymentResponse = TokenPaymentRequest & {
 export type TokenPaymentRequest = {
   token_address: string,
   target_address: string,
+  /** The amount of the payment request denominated in the smallest units supported by the token. */
   amount: number,
   secret_hash: string,
   identifier?: number,

lib/swaps/SwapClient.ts

@@ -13,7 +13,9 @@ enum ClientStatus {
 }
 
 type ChannelBalance = {
+  /** The cumulative balance of open channels denominated in satoshis. */
   balance: number,
+  /** The cumulative balance of pending channels denominated in satoshis. */
   pendingOpenBalance: number,
 };
 
@@ -107,12 +109,12 @@ abstract class SwapClient extends EventEmitter {
   public abstract async sendSmallestAmount(rHash: string, destination: string, currency: string): Promise<string>;
 
   /**
-   * Gets routes for the given currency, amount and peerPubKey.
-   * @param amount the capacity of the route
-   * @param destination target node for the route
+   * Gets routes for the given currency, amount, and swap identifier.
+   * @param amount the capacity the route must support denominated in the smallest units supported by its currency
+   * @param destination the identifier for the receiving node
    * @returns routes
    */
-  public abstract async getRoutes(amount: number, destination: string, finalCltvDelta?: number): Promise<Route[]>;
+  public abstract async getRoutes(amount: number, destination: string, currency: string, finalCltvDelta?: number): Promise<Route[]>;
 
   public abstract async addInvoice(rHash: string, amount: number, cltvExpiry: number): Promise<void>;
 

lib/swaps/SwapClientManager.ts

@@ -52,6 +52,7 @@ class SwapClientManager extends EventEmitter {
       unitConverter,
       config: config.raiden,
       logger: loggers.raiden,
+      directChannelChecks: config.debug.raidenDirectChannelChecks,
     });
   }
 

lib/swaps/Swaps.ts

@@ -265,7 +265,7 @@ class Swaps extends EventEmitter {
 
     let routes;
     try {
-      routes = await swapClient.getRoutes(makerUnits, destination);
+      routes = await swapClient.getRoutes(makerUnits, destination, makerCurrency);
     } catch (err) {
       throw SwapFailureReason.UnexpectedClientError;
     }
@@ -484,11 +484,10 @@ class Swaps extends EventEmitter {
       return false;
     }
 
-    const takerPubKey = peer.getIdentifier(takerSwapClient.type, takerCurrency)!;
+    const takerIdentifier = peer.getIdentifier(takerSwapClient.type, takerCurrency)!;
 
     const deal: SwapDeal = {
       ...requestBody,
-      takerPubKey,
       price,
       isBuy,
       quantity,
@@ -498,7 +497,8 @@ class Swaps extends EventEmitter {
       takerCurrency,
       makerUnits,
       takerUnits,
-      destination: takerPubKey,
+      takerPubKey: takerIdentifier,
+      destination: takerIdentifier,
       peerPubKey: peer.nodePubKey!,
       localId: orderToAccept.localId,
       phase: SwapPhase.SwapCreated,
@@ -526,7 +526,7 @@ class Swaps extends EventEmitter {
     }
 
     try {
-      deal.makerToTakerRoutes = await takerSwapClient.getRoutes(takerUnits, takerPubKey, deal.takerCltvDelta);
+      deal.makerToTakerRoutes = await takerSwapClient.getRoutes(takerUnits, takerIdentifier, deal.takerCurrency, deal.takerCltvDelta);
     } catch (err) {
       this.failDeal(deal, SwapFailureReason.UnexpectedClientError, err.message);
       await this.sendErrorToPeer({

test/jest/RaidenClient.spec.ts

@@ -117,7 +117,7 @@ describe('RaidenClient', () => {
 
   describe('sendPayment', () => {
     test('it removes 0x from secret', async () => {
-      raiden = new RaidenClient({ unitConverter, config, logger: raidenLogger });
+      raiden = new RaidenClient({ unitConverter, config, directChannelChecks: true, logger: raidenLogger });
       await raiden.init(currencyInstances as CurrencyInstance[]);
       const validTokenPaymentResponse: TokenPaymentResponse = getValidTokenPaymentResponse();
       raiden['tokenPayment'] = jest.fn()
@@ -129,7 +129,7 @@ describe('RaidenClient', () => {
     });
 
     test('it rejects in case of empty secret response', async () => {
-      raiden = new RaidenClient({ unitConverter, config, logger: raidenLogger });
+      raiden = new RaidenClient({ unitConverter, config, directChannelChecks: true, logger: raidenLogger });
       await raiden.init(currencyInstances as CurrencyInstance[]);
       const invalidTokenPaymentResponse: TokenPaymentResponse = {
         ...getValidTokenPaymentResponse(),
@@ -157,7 +157,7 @@ describe('RaidenClient', () => {
 
     test('it fails when tokenAddress for currency not found', async () => {
       expect.assertions(1);
-      raiden = new RaidenClient({ unitConverter, config, logger: raidenLogger });
+      raiden = new RaidenClient({ unitConverter, config, directChannelChecks: true, logger: raidenLogger });
       await raiden.init([] as CurrencyInstance[]);
       try {
         await raiden.openChannel({
@@ -172,7 +172,7 @@ describe('RaidenClient', () => {
 
     test('it throws when openChannel fails', async () => {
       expect.assertions(1);
-      raiden = new RaidenClient({ unitConverter, config, logger: raidenLogger });
+      raiden = new RaidenClient({ unitConverter, config, directChannelChecks: true, logger: raidenLogger });
       const peerRaidenAddress = '0x10D8CCAD85C7dc123090B43aA1f98C00a303BFC5';
       const currency = 'WETH';
       const mockTokenAddresses = new Map<string, string>();
@@ -195,7 +195,7 @@ describe('RaidenClient', () => {
 
     test('it opens a channel', async () => {
       expect.assertions(2);
-      raiden = new RaidenClient({ unitConverter, config, logger: raidenLogger });
+      raiden = new RaidenClient({ unitConverter, config, directChannelChecks: true, logger: raidenLogger });
       const peerRaidenAddress = '0x10D8CCAD85C7dc123090B43aA1f98C00a303BFC5';
       const currency = 'WETH';
       const mockTokenAddresses = new Map<string, string>();
@@ -219,7 +219,7 @@ describe('RaidenClient', () => {
   });
 
   test('channelBalance calculates the total balance of open channels for a currency', async () => {
-    raiden = new RaidenClient({ unitConverter, config, logger: raidenLogger });
+    raiden = new RaidenClient({ unitConverter, config, directChannelChecks: true, logger: raidenLogger });
     await raiden.init(currencyInstances as CurrencyInstance[]);
     raiden.tokenAddresses.get = jest.fn().mockReturnValue(channelBalanceTokenAddress);
     raiden['getChannels'] = jest.fn()

test/jest/SwapClientManager.spec.ts

@@ -112,6 +112,9 @@ describe('Swaps.SwapClientManager', () => {
       host: 'localhost',
       port: 1234,
     };
+    config.debug = {
+      raidenDirectChannelChecks: true,
+    };
     db = new DB(loggers.db, config.dbpath);
     unitConverter = new UnitConverter();
     unitConverter.init();

test/jest/integration/Swaps.spec.ts

@@ -260,6 +260,7 @@ describe('Swaps', () => {
       expect(lndBtc.getRoutes).toHaveBeenCalledWith(
         1000,
         peerLndBtcPubKey,
+        takerCurrency,
         swapRequestBody.takerCltvDelta,
       );
       expect(lndLtc.addInvoice).toHaveBeenCalledTimes(1);