support status code for closing websocket

[brucekim]

Current WebSocketTransport.close() only returns code number '100' regardless of any specific reason of websocket closed.

Why not to support correct status code in order for the module relying on go-protoo package to properly handle error situation happened to websocket?

RFC6455 specifies several websocket close codes. I think it would be better to comply with it for better project. I checked 'gollira/websocket' also supports/return websocket close code as specified in RFC6455.

• https://pkg.go.dev/github.com/gorilla/websocket

In addition, one of project that relies on go-protoo has a defect due to the lack of status code for websocket close as below

• https://github.com/pion/ion/blob/master/pkg/signal/handle.go
• It could only handle peer-leave in case of the status code higher than 1000, which means it considers abnormal websocket close situation except normal closure.
• Thus, the code snippet from that project below is currently dead code for now.

It would be enough to keep status code with description delivered by gollira/websocket and send it through transport.onClose channel.

Please review my feedback.

` handleClose := func(code int, err string) { if allowClientDisconnect { log.Infof("signal.in handleClose.AllowDisconnected => peer (%s)", peer.ID()) return }

    roomLock.RLock()
    defer roomLock.RUnlock()
    rooms := GetRoomsByPeer(peer.ID())
    log.Infof("signal.in handleClose [%d] %s rooms=%v", code, err, rooms)
    for _, room := range rooms {
        if room != nil {
            oldPeer := room.GetPeer(peer.ID())
            // only remove if its the same peer. If newer peer joined before the cleanup, leave it.
            if oldPeer == &peer.Peer {
                if code > 1000 {
                    msg := proto.LeaveMsg{
                        RoomInfo: proto.RoomInfo{RID: room.ID()},
                    }
                    msgStr, _ := json.Marshal(msg)
                    bizCall(proto.ClientLeave, peer, msgStr, connectionClaims, emptyAccept, reject)
                }
                log.Infof("signal.in handleClose removing peer (%s) from room (%s)", peer.ID(), room.ID())
                room.RemovePeer(peer.ID())
            }
        }
    }
    log.Infof("signal.in handleClose => peer (%s) ", peer.ID())
}

`

Is there any reason to use code number '100' returning in close()?

 |Status Code | Meaning         | Contact       | Reference |
-+------------+-----------------+---------------+-----------|
 | 1000       | Normal Closure  | hybi@ietf.org | RFC 6455  |
-+------------+-----------------+---------------+-----------|
 | 1001       | Going Away      | hybi@ietf.org | RFC 6455  |
-+------------+-----------------+---------------+-----------|
 | 1002       | Protocol error  | hybi@ietf.org | RFC 6455  |
-+------------+-----------------+---------------+-----------|
 | 1003       | Unsupported Data| hybi@ietf.org | RFC 6455  |
-+------------+-----------------+---------------+-----------|
 | 1004       | ---Reserved---- | hybi@ietf.org | RFC 6455  |
-+------------+-----------------+---------------+-----------|
 | 1005       | No Status Rcvd  | hybi@ietf.org | RFC 6455  |
-+------------+-----------------+---------------+-----------|
 | 1006       | Abnormal Closure| hybi@ietf.org | RFC 6455  |
-+------------+-----------------+---------------+-----------|
 | 1007       | Invalid frame   | hybi@ietf.org | RFC 6455  |
 |            | payload data    |               |           |
-+------------+-----------------+---------------+-----------|
 | 1008       | Policy Violation| hybi@ietf.org | RFC 6455  |
-+------------+-----------------+---------------+-----------|
 | 1009       | Message Too Big | hybi@ietf.org | RFC 6455  |
-+------------+-----------------+---------------+-----------|
 | 1010       | Mandatory Ext.  | hybi@ietf.org | RFC 6455  |
-+------------+-----------------+---------------+-----------|
 | 1011       | Internal Server | hybi@ietf.org | RFC 6455  |
 |            | Error           |               |           |
-+------------+-----------------+---------------+-----------|
 | 1015       | TLS handshake   | hybi@ietf.org | RFC 6455  |
-+------------+-----------------+---------------+-----------|