fix!: allow opening remote streams (#126)

Updates client/server code in line with go implementation to open and read remote streams.

Also updates all deps.

BREAKING CHANGE: the stream type returned by `client.openStream` has changed

Author: achingbrain

packages/libp2p-daemon-client/package.json

@@ -143,7 +143,8 @@
     "@multiformats/multiaddr": "^10.1.8",
     "err-code": "^3.0.1",
     "it-stream-types": "^1.0.4",
-    "multiformats": "^9.6.4"
+    "multiformats": "^9.6.4",
+    "uint8arraylist": "^2.3.2"
   },
   "devDependencies": {
     "@libp2p/components": "^2.0.0",

packages/libp2p-daemon-client/src/index.ts

@@ -1,6 +1,6 @@
 import errcode from 'err-code'
 import { TCP } from '@libp2p/tcp'
-import { PSMessage, Request, Response } from '@libp2p/daemon-protocol'
+import { PSMessage, Request, Response, StreamInfo } from '@libp2p/daemon-protocol'
 import { StreamHandler } from '@libp2p/daemon-protocol/stream-handler'
 import { Multiaddr } from '@multiformats/multiaddr'
 import { DHT } from './dht.js'
@@ -12,6 +12,10 @@ import type { Duplex } from 'it-stream-types'
 import type { CID } from 'multiformats/cid'
 import type { PeerInfo } from '@libp2p/interface-peer-info'
 import type { MultiaddrConnection } from '@libp2p/interface-connection'
+import type { Uint8ArrayList } from 'uint8arraylist'
+import { logger } from '@libp2p/logger'
+
+const log = logger('libp2p:daemon-client')
 
 class Client implements DaemonClient {
   private readonly multiaddr: Multiaddr
@@ -22,7 +26,6 @@ class Client implements DaemonClient {
   constructor (addr: Multiaddr) {
     this.multiaddr = addr
     this.tcp = new TCP()
-
     this.dht = new DHT(this)
     this.pubsub = new Pubsub(this)
   }
@@ -150,7 +153,7 @@ class Client implements DaemonClient {
   /**
    * Initiate an outbound stream to a peer on one of a set of protocols.
    */
-  async openStream (peerId: PeerId, protocol: string): Promise<Duplex<Uint8Array>> {
+  async openStream (peerId: PeerId, protocol: string): Promise<Duplex<Uint8ArrayList, Uint8Array>> {
     if (!isPeerId(peerId)) {
       throw errcode(new Error('invalid peer id received'), 'ERR_INVALID_PEER_ID')
     }
@@ -181,20 +184,58 @@ class Client implements DaemonClient {
   /**
    * Register a handler for inbound streams on a given protocol
    */
-  async registerStreamHandler (addr: Multiaddr, protocol: string) {
-    if (!Multiaddr.isMultiaddr(addr)) {
-      throw errcode(new Error('invalid multiaddr received'), 'ERR_INVALID_MULTIADDR')
-    }
-
+  async registerStreamHandler (protocol: string, handler: StreamHandlerFunction): Promise<void> {
     if (typeof protocol !== 'string') {
       throw errcode(new Error('invalid protocol received'), 'ERR_INVALID_PROTOCOL')
     }
 
+    // open a tcp port, pipe any data from it to the handler function
+    const listener = this.tcp.createListener({
+      upgrader: passThroughUpgrader,
+      handler: (connection) => {
+        Promise.resolve()
+          .then(async () => {
+            const sh = new StreamHandler({
+              // @ts-expect-error because we are using a passthrough upgrader, this is a MultiaddrConnection
+              stream: connection
+            })
+            const message = await sh.read()
+
+            if (message == null) {
+              throw errcode(new Error('Could not read open stream response'), 'ERR_OPEN_STREAM_FAILED')
+            }
+
+            const response = StreamInfo.decode(message)
+
+            if (response.proto !== protocol) {
+              throw errcode(new Error('Incorrect protocol'), 'ERR_OPEN_STREAM_FAILED')
+            }
+
+            await handler(sh.rest())
+          })
+          .finally(() => {
+            connection.close()
+              .catch(err => {
+                log.error(err)
+              })
+            listener.close()
+              .catch(err => {
+                log.error(err)
+              })
+          })
+      }
+    })
+    await listener.listen(new Multiaddr('/ip4/127.0.0.1/tcp/0'))
+    const address = listener.getAddrs()[0]
+
+    if (address == null) {
+      throw errcode(new Error('Could not listen on port'), 'ERR_REGISTER_STREAM_HANDLER_FAILED')
+    }
+
     const sh = await this.send({
       type: Request.Type.STREAM_HANDLER,
-      streamOpen: undefined,
       streamHandler: {
-        addr: addr.bytes,
+        addr: address.bytes,
         proto: [protocol]
       }
     })
@@ -215,6 +256,10 @@ export interface IdentifyResult {
   addrs: Multiaddr[]
 }
 
+export interface StreamHandlerFunction {
+  (stream: Duplex<Uint8ArrayList, Uint8Array>): Promise<void>
+}
+
 export interface DHTClient {
   put: (key: Uint8Array, value: Uint8Array) => Promise<void>
   get: (key: Uint8Array) => Promise<Uint8Array>
@@ -238,7 +283,8 @@ export interface DaemonClient {
   pubsub: PubSubClient
 
   send: (request: Request) => Promise<StreamHandler>
-  openStream: (peerId: PeerId, protocol: string) => Promise<Duplex<Uint8Array>>
+  openStream: (peerId: PeerId, protocol: string) => Promise<Duplex<Uint8ArrayList, Uint8Array>>
+  registerStreamHandler: (protocol: string, handler: StreamHandlerFunction) => Promise<void>
 }
 
 export function createClient (multiaddr: Multiaddr): DaemonClient {

packages/libp2p-daemon-client/test/stream.spec.ts

@@ -86,6 +86,6 @@ describe('daemon stream client', function () {
     )
 
     expect(data).to.have.lengthOf(1)
-    expect(uint8ArrayToString(data[0])).to.equal('hello world')
+    expect(uint8ArrayToString(data[0].subarray())).to.equal('hello world')
   })
 })

packages/libp2p-daemon-protocol/src/stream-handler.ts

@@ -14,7 +14,7 @@ export interface StreamHandlerOptions {
 
 export class StreamHandler {
   private readonly stream: Duplex<Uint8Array>
-  private readonly shake: Handshake
+  private readonly shake: Handshake<Uint8Array>
   public decoder: Source<Uint8ArrayList>
   /**
    * Create a stream handler for connection
@@ -34,7 +34,7 @@ export class StreamHandler {
     // @ts-expect-error decoder is really a generator
     const msg = await this.decoder.next()
     if (msg.value != null) {
-      return msg.value.slice()
+      return msg.value.subarray()
     }
 
     log('read received no value, closing stream')

packages/libp2p-daemon-server/src/index.ts

@@ -15,7 +15,7 @@ import {
   StreamInfo
 } from '@libp2p/daemon-protocol'
 import type { Listener } from '@libp2p/interface-transport'
-import type { Connection, Stream } from '@libp2p/interface-connection'
+import type { Connection, MultiaddrConnection, Stream } from '@libp2p/interface-connection'
 import type { PeerId } from '@libp2p/interface-peer-id'
 import type { AbortOptions } from '@libp2p/interfaces'
 import type { StreamHandler as StreamCallback } from '@libp2p/interface-registrar'
@@ -67,7 +67,6 @@ export class Server implements Libp2pServer {
   private readonly libp2p: Libp2p
   private readonly tcp: TCP
   private readonly listener: Listener
-  private readonly streamHandlers: Record<string, StreamHandler>
   private readonly dhtOperations?: DHTOperations
   private readonly pubsubOperations?: PubSubOperations
 
@@ -81,7 +80,6 @@ export class Server implements Libp2pServer {
       handler: this.handleConnection.bind(this),
       upgrader: passThroughUpgrader
     })
-    this.streamHandlers = {}
     this._onExit = this._onExit.bind(this)
 
     if (libp2pNode.dht != null) {
@@ -118,9 +116,7 @@ export class Server implements Libp2pServer {
     }
 
     const { peer, proto } = request.streamOpen
-
     const peerId = peerIdFromBytes(peer)
-
     const connection = await this.libp2p.dial(peerId)
     const stream = await connection.newStream(proto)
 
@@ -146,18 +142,18 @@ export class Server implements Libp2pServer {
 
     const protocols = request.streamHandler.proto
     const addr = new Multiaddr(request.streamHandler.addr)
-    const addrString = addr.toString()
-
-    // If we have a handler, end it
-    if (this.streamHandlers[addrString] != null) {
-      await this.streamHandlers[addrString].close()
-      delete this.streamHandlers[addrString] // eslint-disable-line @typescript-eslint/no-dynamic-delete
-    }
+    let conn: MultiaddrConnection
+
+    await this.libp2p.handle(protocols, ({ connection, stream }) => {
+      Promise.resolve()
+        .then(async () => {
+          // Connect the client socket with the libp2p connection
+          // @ts-expect-error because we use a passthrough upgrader,
+          // this is actually a MultiaddrConnection and not a Connection
+          conn = await this.tcp.dial(addr, {
+            upgrader: passThroughUpgrader
+          })
 
-    await Promise.all(
-      protocols.map(async (proto) => {
-        // Connect the client socket with the libp2p connection
-        await this.libp2p.handle(proto, ({ connection, stream }) => {
           const message = StreamInfo.encode({
             peer: connection.remotePeer.toBytes(),
             addr: connection.remoteAddr.bytes,
@@ -167,21 +163,36 @@ export class Server implements Libp2pServer {
 
           // Tell the client about the new connection
           // And then begin piping the client and peer connection
-          void pipe(
-            [encodedMessage, stream.source],
-            // @ts-expect-error because we use a passthrough upgrader,
-            // this is actually a MultiaddrConnection and not a Connection
-            clientConnection,
+          await pipe(
+            (async function * () {
+              yield encodedMessage
+              yield * stream.source
+            }()),
+            async function * (source) {
+              for await (const list of source) {
+                // convert Uint8ArrayList to Uint8Arrays for the socket
+                yield * list
+              }
+            },
+            conn,
             stream.sink
-          ).catch(err => {
-            log.error(err)
-          })
+          )
         })
-      })
-    )
+        .catch(async err => {
+          log.error(err)
 
-    const clientConnection = await this.tcp.dial(addr, {
-      upgrader: passThroughUpgrader
+          if (conn != null) {
+            await conn.close(err)
+          }
+        })
+        .finally(() => {
+          if (conn != null) {
+            conn.close()
+              .catch(err => {
+                log.error(err)
+              })
+          }
+        })
     })
   }