More v2 stuff (#1141)

* More v2 stuff

- Adding `Trickle` to client -> server message. There should not be any
  tricklw from server -> client in v2. So, not adding it. Will add if
  needed later.
- Some utils to parse envelopes as we are moving in the direction of
  having an envelope of messages in the initial connect request to keep
  it modular. May change again later, but today's state is this.
- change relay signal to pass wire message back and forth.

* generated protobuf

* add utils

---------

Co-authored-by: github-actions <41898282+github-actions[bot]@users.noreply.github.com>

Author: boks1971

livekit/livekit_rtc_v2.pb.go

@@ -52,6 +52,7 @@ message Signalv2ClientMessage {
     ConnectRequest connect_request = 2;
     SessionDescription publisher_sdp = 3; // SDP offer for publisher peer connection
     SessionDescription subscriber_sdp = 4; // SDP answer for subscriber peer connection
+    TrickleRequest trickle = 5;
   }
 }
 

protobufs/livekit_rtc_v2.proto

@@ -25,11 +25,11 @@ message RelaySignalv2ConnectRequest {
   // A user's ClaimGrants serialized in JSON
   string grants_json = 1;
   livekit.CreateRoomRequest create_room = 2;
-  livekit.ConnectRequest connect_request = 3;
+  livekit.Signalv2WireMessage wire_message = 3; // livekit.ConnectRequest is the first message in the envelope
 }
 
 message RelaySignalv2ConnectResponse {
-  livekit.ConnectResponse connect_response = 1;
+  livekit.Signalv2WireMessage wire_message = 1; // livekit.ConnectResponse is the first message in the envelope
 }
 
 message RelaySignalv2ParticipantRequest {

protobufs/rpc/signalv2_types.proto

@@ -0,0 +1,84 @@
+// Copyright 2023 LiveKit, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package signalling
+
+import (
+	"github.com/livekit/protocol/livekit"
+)
+
+func GetConnectRequest(wireMessage *livekit.Signalv2WireMessage) *livekit.ConnectRequest {
+	if wireMessage != nil {
+		switch msg := wireMessage.GetMessage().(type) {
+		case *livekit.Signalv2WireMessage_Envelope:
+			for _, innerMsg := range msg.Envelope.GetClientMessages() {
+				switch clientMessage := innerMsg.GetMessage().(type) {
+				case *livekit.Signalv2ClientMessage_ConnectRequest:
+					return clientMessage.ConnectRequest
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+func WithoutConnectRequest(wireMessage *livekit.Signalv2WireMessage) *livekit.Signalv2WireMessage {
+	var strippedWireMessage *livekit.Signalv2WireMessage
+	if wireMessage != nil {
+		switch msg := wireMessage.GetMessage().(type) {
+		case *livekit.Signalv2WireMessage_Envelope:
+			clientMessages := make(
+				[]*livekit.Signalv2ClientMessage,
+				0,
+				len(msg.Envelope.GetClientMessages()),
+			)
+			for _, clientMessage := range msg.Envelope.GetClientMessages() {
+				switch clientMessage.GetMessage().(type) {
+				case *livekit.Signalv2ClientMessage_ConnectRequest:
+				default:
+					clientMessages = append(clientMessages, clientMessage)
+				}
+			}
+
+			if len(clientMessages) != 0 {
+				strippedWireMessage = &livekit.Signalv2WireMessage{
+					Message: &livekit.Signalv2WireMessage_Envelope{
+						Envelope: &livekit.Envelope{
+							ClientMessages: clientMessages,
+						},
+					},
+				}
+			}
+		}
+	}
+
+	return strippedWireMessage
+}
+
+func GetConnectResponse(wireMessage *livekit.Signalv2WireMessage) *livekit.ConnectResponse {
+	if wireMessage != nil {
+		switch msg := wireMessage.GetMessage().(type) {
+		case *livekit.Signalv2WireMessage_Envelope:
+			for _, innerMsg := range msg.Envelope.GetServerMessages() {
+				switch serverMessage := innerMsg.GetMessage().(type) {
+				case *livekit.Signalv2ServerMessage_ConnectResponse:
+					return serverMessage.ConnectResponse
+				}
+			}
+		}
+	}
+
+	return nil
+}