feat: support custom DNS resolvers (#2435)

Adds a `dns` config key that lets users specify an instance of the `DNS` interface from `@multiformats/dns`. This instance will be passed through to DNSADDR `multiaddr`s for use when the DNSLink TXT record is resolved.
libp2p · Mar 12, 2024 · f39ce5f · f39ce5f
1 parent 25c8f93
commit f39ce5f
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Showing 8 changed files with 66 additions and 119 deletions.
diff --git a/packages/libp2p/package.json b/packages/libp2p/package.json
@@ -95,7 +95,8 @@
     "@libp2p/peer-id-factory": "^4.0.7",
     "@libp2p/peer-store": "^10.0.11",
     "@libp2p/utils": "^5.2.6",
-    "@multiformats/multiaddr": "^12.1.14",
+    "@multiformats/dns": "^1.0.1",
+    "@multiformats/multiaddr": "^12.2.0",
     "any-signal": "^4.1.1",
     "datastore-core": "^9.2.8",
     "interface-datastore": "^8.2.11",

diff --git a/packages/libp2p/src/components.ts b/packages/libp2p/src/components.ts
@@ -2,6 +2,7 @@ import { CodeError } from '@libp2p/interface'
 import { isStartable, type Startable, type Libp2pEvents, type ComponentLogger, type NodeInfo, type ConnectionProtector, type ConnectionGater, type ContentRouting, type TypedEventTarget, type Metrics, type PeerId, type PeerRouting, type PeerStore, type PrivateKey, type Upgrader } from '@libp2p/interface'
 import { defaultLogger } from '@libp2p/logger'
 import type { AddressManager, ConnectionManager, Registrar, TransportManager } from '@libp2p/interface-internal'
+import type { DNS } from '@multiformats/dns'
 import type { Datastore } from 'interface-datastore'
 
 export interface Components extends Record<string, any>, Startable {
@@ -22,6 +23,7 @@ export interface Components extends Record<string, any>, Startable {
   datastore: Datastore
   connectionProtector?: ConnectionProtector
   metrics?: Metrics
+  dns?: DNS
 }
 
 export interface ComponentsInit {
@@ -42,6 +44,7 @@ export interface ComponentsInit {
   peerRouting?: PeerRouting
   datastore?: Datastore
   connectionProtector?: ConnectionProtector
+  dns?: DNS
 }
 
 class DefaultComponents implements Startable {
@@ -103,7 +106,8 @@ class DefaultComponents implements Startable {
 
 const OPTIONAL_SERVICES = [
   'metrics',
-  'connectionProtector'
+  'connectionProtector',
+  'dns'
 ]
 
 const NON_SERVICE_PROPERTIES = [

diff --git a/packages/libp2p/src/connection-manager/dial-queue.ts b/packages/libp2p/src/connection-manager/dial-queue.ts
@@ -18,6 +18,7 @@ import {
 import { resolveMultiaddrs } from './utils.js'
 import type { AddressSorter, AbortOptions, ComponentLogger, Logger, Connection, ConnectionGater, Metrics, PeerId, Address, PeerStore, PeerRouting } from '@libp2p/interface'
 import type { TransportManager } from '@libp2p/interface-internal'
+import type { DNS } from '@multiformats/dns'
 
 export interface PendingDialTarget {
   resolve(value: any): void
@@ -61,6 +62,7 @@ interface DialQueueComponents {
   transportManager: TransportManager
   connectionGater: ConnectionGater
   logger: ComponentLogger
+  dns?: DNS
 }
 
 export class DialQueue {
@@ -344,6 +346,7 @@ export class DialQueue {
     let resolvedAddresses = (await Promise.all(
       addrs.map(async addr => {
         const result = await resolveMultiaddrs(addr.multiaddr, {
+          dns: this.components.dns,
           ...options,
           log: this.log
         })

diff --git a/packages/libp2p/src/connection-manager/utils.ts b/packages/libp2p/src/connection-manager/utils.ts
@@ -1,47 +1,30 @@
-import { type AbortOptions, multiaddr, type Multiaddr } from '@multiformats/multiaddr'
+import { resolvers } from '@multiformats/multiaddr'
 import type { LoggerOptions } from '@libp2p/interface'
+import type { Multiaddr, ResolveOptions } from '@multiformats/multiaddr'
 
 /**
- * Resolve multiaddr recursively
+ * Recursively resolve DNSADDR multiaddrs
  */
-export async function resolveMultiaddrs (ma: Multiaddr, options: AbortOptions & LoggerOptions): Promise<Multiaddr[]> {
-  // TODO: recursive logic should live in multiaddr once dns4/dns6 support is in place
-  // Now only supporting resolve for dnsaddr
-  const resolvableProto = ma.protoNames().includes('dnsaddr')
+export async function resolveMultiaddrs (ma: Multiaddr, options: ResolveOptions & LoggerOptions): Promise<Multiaddr[]> {
+  // check multiaddr resolvers
+  let resolvable = false
 
-  // Multiaddr is not resolvable? End recursion!
-  if (!resolvableProto) {
-    return [ma]
+  for (const key of resolvers.keys()) {
+    resolvable = ma.protoNames().includes(key)
+
+    if (resolvable) {
+      break
+    }
   }
 
-  const resolvedMultiaddrs = await resolveRecord(ma, options)
-  const recursiveMultiaddrs = await Promise.all(resolvedMultiaddrs.map(async (nm) => {
-    return resolveMultiaddrs(nm, options)
-  }))
+  // return multiaddr if it is not resolvable
+  if (!resolvable) {
+    return [ma]
+  }
 
-  const addrs = recursiveMultiaddrs.flat()
-  const output = addrs.reduce<Multiaddr[]>((array, newM) => {
-    if (array.find(m => m.equals(newM)) == null) {
-      array.push(newM)
-    }
-    return array
-  }, ([]))
+  const output = await ma.resolve(options)
 
   options.log('resolved %s to', ma, output.map(ma => ma.toString()))
 
   return output
 }
-
-/**
- * Resolve a given multiaddr. If this fails, an empty array will be returned
- */
-async function resolveRecord (ma: Multiaddr, options: AbortOptions & LoggerOptions): Promise<Multiaddr[]> {
-  try {
-    ma = multiaddr(ma.toString()) // Use current multiaddr module
-    const multiaddrs = await ma.resolve(options)
-    return multiaddrs
-  } catch (err) {
-    options.log.error(`multiaddr ${ma.toString()} could not be resolved`, err)
-    return []
-  }
-}
diff --git a/packages/libp2p/src/index.ts b/packages/libp2p/src/index.ts
@@ -21,6 +21,7 @@ import type { ConnectionManagerInit } from './connection-manager/index.js'
 import type { TransportManagerInit } from './transport-manager.js'
 import type { Libp2p, ServiceMap, RecursivePartial, ComponentLogger, NodeInfo, ConnectionProtector, ConnectionEncrypter, ConnectionGater, ContentRouting, Metrics, PeerDiscovery, PeerId, PeerRouting, StreamMuxerFactory, Transport, PrivateKey } from '@libp2p/interface'
 import type { PersistentPeerStoreInit } from '@libp2p/peer-store'
+import type { DNS } from '@multiformats/dns'
 import type { Datastore } from 'interface-datastore'
 
 export type ServiceFactoryMap<T extends Record<string, unknown> = Record<string, unknown>> = {
@@ -123,6 +124,13 @@ export interface Libp2pInit<T extends ServiceMap = { x: Record<string, unknown>
    * ```
    */
   logger?: ComponentLogger
+
+  /**
+   * An optional DNS resolver configuration. If omitted the default DNS resolver
+   * for the platform will be used which means `node:dns` on Node.js and
+   * DNS-JSON-over-HTTPS for browsers using Google and Cloudflare servers.
+   */
+  dns?: DNS
 }
 
 export type { Libp2p }

diff --git a/packages/libp2p/src/libp2p.ts b/packages/libp2p/src/libp2p.ts
@@ -75,7 +75,8 @@ export class Libp2pNode<T extends ServiceMap = Record<string, unknown>> extends
       logger: this.logger,
       events,
       datastore: init.datastore ?? new MemoryDatastore(),
-      connectionGater: connectionGater(init.connectionGater)
+      connectionGater: connectionGater(init.connectionGater),
+      dns: init.dns
     })
 
     this.peerStore = this.configureComponent('peerStore', new PersistentPeerStore(components, {

diff --git a/packages/libp2p/test/connection-manager/index.node.ts b/packages/libp2p/test/connection-manager/index.node.ts
@@ -3,6 +3,8 @@
 import { TypedEventEmitter, start } from '@libp2p/interface'
 import { mockConnection, mockDuplex, mockMultiaddrConnection } from '@libp2p/interface-compliance-tests/mocks'
 import { createEd25519PeerId } from '@libp2p/peer-id-factory'
+import { dns } from '@multiformats/dns'
+import { multiaddr } from '@multiformats/multiaddr'
 import { expect } from 'aegir/chai'
 import delay from 'delay'
 import all from 'it-all'
@@ -390,6 +392,30 @@ describe('libp2p.connections', () => {
       })
       expect(libp2p.components.connectionManager.getConnections()).to.have.lengthOf(2)
     })
+
+    it('should use custom DNS resolver', async () => {
+      const resolver = sinon.stub()
+
+      libp2p = await createNode({
+        config: createBaseOptions({
+          addresses: {
+            listen: ['/ip4/127.0.0.1/tcp/0/ws']
+          },
+          dns: dns({
+            resolvers: {
+              '.': resolver
+            }
+          })
+        })
+      })
+
+      const ma = multiaddr('/dnsaddr/example.com/tcp/12345')
+      const err = new Error('Could not resolve')
+
+      resolver.withArgs('_dnsaddr.example.com').rejects(err)
+
+      await expect(libp2p.dial(ma)).to.eventually.be.rejectedWith(err)
+    })
   })
 
   describe('connection gater', () => {

diff --git a/packages/libp2p/test/connection-manager/resolver.spec.ts b/packages/libp2p/test/connection-manager/resolver.spec.ts
@@ -14,22 +14,12 @@ import { multiaddr } from '@multiformats/multiaddr'
 import { expect } from 'aegir/chai'
 import pDefer from 'p-defer'
 import sinon from 'sinon'
-import { codes as ErrorCodes } from '../../src/errors.js'
 import { createLibp2pNode, type Libp2pNode } from '../../src/libp2p.js'
 import type { PeerId, Transport } from '@libp2p/interface'
 import type { Multiaddr } from '@multiformats/multiaddr'
 
 const relayAddr = multiaddr(process.env.RELAY_MULTIADDR)
 
-const getDnsaddrStub = (peerId: PeerId): string[] => [
-  `/dnsaddr/ams-1.bootstrap.libp2p.io/p2p/${peerId.toString()}`,
-  `/dnsaddr/ams-2.bootstrap.libp2p.io/p2p/${peerId.toString()}`,
-  `/dnsaddr/lon-1.bootstrap.libp2p.io/p2p/${peerId.toString()}`,
-  `/dnsaddr/nrt-1.bootstrap.libp2p.io/p2p/${peerId.toString()}`,
-  `/dnsaddr/nyc-1.bootstrap.libp2p.io/p2p/${peerId.toString()}`,
-  `/dnsaddr/sfo-2.bootstrap.libp2p.io/p2p/${peerId.toString()}`
-]
-
 const relayedAddr = (peerId: PeerId): string => `${relayAddr.toString()}/p2p-circuit/p2p/${peerId.toString()}`
 
 const getDnsRelayedAddrStub = (peerId: PeerId): string[] => [
@@ -140,41 +130,6 @@ describe('dialing (resolvable addresses)', () => {
     expect(dialArgs[0].equals(relayedAddrFetched)).to.eql(true)
   })
 
-  it('resolves a dnsaddr recursively', async () => {
-    const remoteId = remoteLibp2p.peerId
-    const dialAddr = multiaddr(`/dnsaddr/remote.libp2p.io/p2p/${remoteId.toString()}`)
-    const relayedAddrFetched = multiaddr(relayedAddr(remoteId))
-
-    const relayId = await createEd25519PeerId()
-    // ensure remote libp2p creates reservation on relay
-    await remoteLibp2p.peerStore.merge(relayId, {
-      protocols: [RELAY_V2_HOP_CODEC]
-    })
-
-    // Transport spy
-    const transport = getTransport(libp2p, 'libp2p/circuit-relay-v2')
-    const transportDialSpy = sinon.spy(transport, 'dial')
-
-    // Resolver stub
-    let firstCall = false
-    resolver.callsFake(async () => {
-      if (!firstCall) {
-        firstCall = true
-        // Return an array of dnsaddr
-        return Promise.resolve(getDnsaddrStub(remoteId))
-      }
-      return Promise.resolve(getDnsRelayedAddrStub(remoteId))
-    })
-
-    // Dial with address resolve
-    const connection = await libp2p.dial(dialAddr)
-    expect(connection).to.exist()
-    expect(connection.remoteAddr.equals(relayedAddrFetched))
-
-    const dialArgs = transportDialSpy.firstCall.args
-    expect(dialArgs[0].equals(relayedAddrFetched)).to.eql(true)
-  })
-
   // TODO: Temporary solution does not resolve dns4/dns6
   // Resolver just returns the received multiaddrs
   it('stops recursive resolve if finds dns4/dns6 and dials it', async () => {
@@ -205,50 +160,16 @@ describe('dialing (resolvable addresses)', () => {
     await deferred.promise
   })
 
-  it('resolves a dnsaddr recursively not failing if one address fails to resolve', async () => {
-    const remoteId = remoteLibp2p.peerId
-    const dialAddr = multiaddr(`/dnsaddr/remote.libp2p.io/p2p/${remoteId.toString()}`)
-    const relayedAddrFetched = multiaddr(relayedAddr(remoteId))
-
-    const relayId = await createEd25519PeerId()
-    // ensure remote libp2p creates reservation on relay
-    await remoteLibp2p.peerStore.merge(relayId, {
-      protocols: [RELAY_V2_HOP_CODEC]
-    })
-
-    // Transport spy
-    const transport = getTransport(libp2p, 'libp2p/circuit-relay-v2')
-    const transportDialSpy = sinon.spy(transport, 'dial')
-
-    // Resolver stub
-    resolver.onCall(0).callsFake(async () => Promise.resolve(getDnsaddrStub(remoteId)))
-    resolver.onCall(1).callsFake(async () => Promise.reject(new Error()))
-    resolver.callsFake(async () => Promise.resolve(getDnsRelayedAddrStub(remoteId)))
-
-    // Dial with address resolve
-    const connection = await libp2p.dial(dialAddr)
-    expect(connection).to.exist()
-    expect(connection.remoteAddr.equals(relayedAddrFetched))
-
-    const dialArgs = transportDialSpy.firstCall.args
-    expect(dialArgs[0].equals(relayedAddrFetched)).to.eql(true)
-  })
-
   it('fails to dial if resolve fails and there are no addresses to dial', async () => {
     const remoteId = remoteLibp2p.peerId
     const dialAddr = multiaddr(`/dnsaddr/remote.libp2p.io/p2p/${remoteId.toString()}`)
+    const err = new Error()
 
     // Stub resolver
-    resolver.returns(Promise.reject(new Error()))
-
-    // Stub transport
-    const transport = getTransport(libp2p, '@libp2p/websockets')
-    const spy = sinon.spy(transport, 'dial')
+    resolver.returns(Promise.reject(err))
 
     await expect(libp2p.dial(dialAddr))
-      .to.eventually.be.rejectedWith(Error)
-      .and.to.have.nested.property('.code', ErrorCodes.ERR_NO_VALID_ADDRESSES)
-    expect(spy.callCount).to.eql(0)
+      .to.eventually.be.rejectedWith(err)
   })
 })