Initiate connection handshake from server

This way the connection can be initiated by either side. It looks like
sometimes the initial message from the client is lost (it never makes it
into the onControlMessage callback) but I'm still not sure why or if
that is preventable.

Also added a timeout on the server end to clean things up in case the
client never responds.

ci/dev/vscode.patch

@@ -2478,10 +2478,10 @@ index 0000000000000000000000000000000000000000..3d428a57d31f29c40f9c3ce45f715b44
 +};
 diff --git a/src/vs/server/node/protocol.ts b/src/vs/server/node/protocol.ts
 new file mode 100644
-index 0000000000000000000000000000000000000000..523fcd3186d92799bc50e33a72832bd443b2945b
+index 0000000000000000000000000000000000000000..0d9310038c0ca378579652d89bc8ac84924213db
 --- /dev/null
 +++ b/src/vs/server/node/protocol.ts
-@@ -0,0 +1,80 @@
+@@ -0,0 +1,91 @@
 +import { field } from '@coder/logger';
 +import * as net from 'net';
 +import { VSBuffer } from 'vs/base/common/buffer';
@@ -2518,6 +2518,11 @@ index 0000000000000000000000000000000000000000..523fcd3186d92799bc50e33a72832bd4
 +	public handshake(): Promise<ConnectionTypeRequest> {
 +		logger.trace('Protocol handshake', field('token', this.options.reconnectionToken));
 +		return new Promise((resolve, reject) => {
++			const timeout = setTimeout(() => {
++				logger.error('Handshake timed out', field('token', this.options.reconnectionToken));
++				reject(new Error("timed out"));
++			}, 10000); // Matches the client timeout.
++
 +			const handler = this.onControlMessage((rawMessage) => {
 +				try {
 +					const raw = rawMessage.toString();
@@ -2528,15 +2533,21 @@ index 0000000000000000000000000000000000000000..523fcd3186d92799bc50e33a72832bd4
 +							return this.authenticate(message);
 +						case 'connectionType':
 +							handler.dispose();
++							clearTimeout(timeout);
 +							return resolve(message);
 +						default:
 +							throw new Error('Unrecognized message type');
 +					}
 +				} catch (error) {
 +					handler.dispose();
++					clearTimeout(timeout);
 +					reject(error);
 +				}
 +			});
++
++			// Kick off the handshake in case we missed the client's opening shot.
++			// TODO: Investigate why that message seems to get lost.
++			this.authenticate();
 +		});
 +	}
 +