feat(libp2p): direct connection through relay protocol (DCUtR) (#1928)

Implements the [DCUtR protocol](https://github.com/libp2p/specs/blob/master/relay/DCUtR.md).

Only supports TCP Simultaneous Connect since there is no QUIC support yet

Author: achingbrain

packages/interface-internal/src/connection-manager/index.ts

@@ -4,6 +4,21 @@ import type { PeerId } from '@libp2p/interface/peer-id'
 import type { PeerMap } from '@libp2p/peer-collections'
 import type { Multiaddr } from '@multiformats/multiaddr'
 
+export interface OpenConnectionOptions extends AbortOptions {
+  /**
+   * Connection requests with a higher priority will be executed before those
+   * with a lower priority. (default: 50)
+   */
+  priority?: number
+
+  /**
+   * When opening a connection to a remote peer, if a connection already exists
+   * it will be returned instead of creating a new connection. Pass true here
+   * to override that and dial a new connection anyway. (default: false)
+   */
+  force?: boolean
+}
+
 export interface ConnectionManager {
   /**
    * Return connections, optionally filtering by a PeerId
@@ -37,7 +52,7 @@ export interface ConnectionManager {
    * const connection = await libp2p.connectionManager.openConnection(peerId)
    * ```
    */
-  openConnection: (peer: PeerId | Multiaddr | Multiaddr[], options?: AbortOptions) => Promise<Connection>
+  openConnection: (peer: PeerId | Multiaddr | Multiaddr[], options?: OpenConnectionOptions) => Promise<Connection>
 
   /**
    * Close our connections to a peer

packages/libp2p/package.json

@@ -56,6 +56,10 @@
       "types": "./dist/src/circuit-relay/index.d.ts",
       "import": "./dist/src/circuit-relay/index.js"
     },
+    "./dcutr": {
+      "types": "./dist/src/dcutr/index.d.ts",
+      "import": "./dist/src/dcutr/index.js"
+    },
     "./fetch": {
       "types": "./dist/src/fetch/index.d.ts",
       "import": "./dist/src/fetch/index.js"
@@ -100,7 +104,8 @@
     "build": "aegir build",
     "generate": "run-s generate:proto:*",
     "generate:proto:autonat": "protons ./src/autonat/pb/index.proto",
-    "generate:proto:circuit": "protons ./src/circuit/pb/index.proto",
+    "generate:proto:circuit-relay": "protons ./src/circuit-relay/pb/index.proto",
+    "generate:proto:dcutr": "protons ./src/dcutr/pb/message.proto",
     "generate:proto:fetch": "protons ./src/fetch/pb/proto.proto",
     "generate:proto:identify": "protons ./src/identify/pb/message.proto",
     "generate:proto:plaintext": "protons ./src/insecure/pb/proto.proto",
@@ -129,6 +134,7 @@
     "@libp2p/utils": "^4.0.2",
     "@multiformats/mafmt": "^12.1.2",
     "@multiformats/multiaddr": "^12.1.5",
+    "@multiformats/multiaddr-matcher": "^1.0.0",
     "abortable-iterator": "^5.0.1",
     "any-signal": "^4.1.1",
     "datastore-core": "^9.0.1",

packages/libp2p/src/connection-manager/auto-dial.ts

@@ -222,7 +222,6 @@ export class AutoDial implements Startable {
 
         log('connecting to a peerStore stored peer %p', peer.id)
         await this.connectionManager.openConnection(peer.id, {
-          // @ts-expect-error needs adding to the ConnectionManager interface
           priority: this.autoDialPriority
         })
       }, {

packages/libp2p/src/connection-manager/index.ts

@@ -20,7 +20,7 @@ import type { Metrics } from '@libp2p/interface/metrics'
 import type { PeerId } from '@libp2p/interface/peer-id'
 import type { Peer, PeerStore } from '@libp2p/interface/peer-store'
 import type { Startable } from '@libp2p/interface/startable'
-import type { ConnectionManager } from '@libp2p/interface-internal/connection-manager'
+import type { ConnectionManager, OpenConnectionOptions } from '@libp2p/interface-internal/connection-manager'
 import type { TransportManager } from '@libp2p/interface-internal/transport-manager'
 
 const log = logger('libp2p:connection-manager')
@@ -154,10 +154,6 @@ export interface DefaultConnectionManagerComponents {
   events: EventEmitter<Libp2pEvents>
 }
 
-export interface OpenConnectionOptions extends AbortOptions {
-  priority?: number
-}
-
 /**
  * Responsible for managing known connections.
  */
@@ -492,7 +488,7 @@ export class DefaultConnectionManager implements ConnectionManager, Startable {
 
     const { peerId } = getPeerAddress(peerIdOrMultiaddr)
 
-    if (peerId != null) {
+    if (peerId != null && options.force !== true) {
       log('dial %p', peerId)
       const existingConnections = this.getConnections(peerId)