private async Task ProcessSelectIceCandidateAsync(string iceUserLocal, WSPayload clientReq)
{
var sdpParser = new SdpParser();
var clientSdp = sdpParser.Parse(clientReq.sdp);
var iceCandidate = clientSdp.MediaDescriptions
.SelectMany(l => l.IceCandidates)
.FirstOrDefault(l => l.CandidateType == "host");
var iceAttributes = clientSdp.MediaDescriptions
.Select(l => l.IceAttributes)
.FirstOrDefault();
if (iceCandidate != null && iceAttributes != null)
{
try
{
var iceClientIps = await Dns.GetHostEntryAsync(iceCandidate.ConnectionAddress);
var iceClientIp = iceClientIps.AddressList.First();
var clientIceEndpoint = new IPEndPoint(iceClientIp, iceCandidate.Port);
await SendIceCandidateAsync(clientIceEndpoint, iceUserLocal, iceCandidate, iceAttributes);
}
catch (SocketException e) when(e.SocketErrorCode == SocketError.HostNotFound)
{
_logger.LogInformation("Unable to resolve ice host {ConnectionAddress} to an IP Address", iceCandidate.ConnectionAddress);
}
}
}
private async Task ProcessCreateSdpOfferAsync(WebSocket webSocket, IPEndPoint clientIp, string host, string iceUserLocal, string iceLocalPassword)
{
var serverAddr = (await Dns.GetHostAddressesAsync(host)).First(l => l.AddressFamily == AddressFamily.InterNetwork);
var sdp = _rtspProxyService.BuildSdp(serverAddr, iceUserLocal, iceLocalPassword);
var response = new WSPayload
{
action = WSAction.CreateSdpOffer,
type = "offer",
sdp = sdp
};
await SendResponseAsync(webSocket, clientIp, response);
}
private async Task ProcessPlayStreamAsync(WebSocket webSocket, IPEndPoint clientIp, WSPayload clientReq)
{
try
{
await _rtspProxyService.PlayStreamAsync(clientReq.rtspUrl);
}
catch (Exception e)
{
await SendResponseAsync(webSocket, clientIp,
new WSPayload
{
action = clientReq.action,
errorMessage = e.Message,
error = true
});
}
}
private async Task SendResponseAsync(WebSocket webSocket, IPEndPoint clientIp, WSPayload response)
{
var responseData = JsonSerializer.Serialize(response);
_logger.LogDebug("[{clientIp}] Sending response", clientIp);
_logger.LogTrace("[{clientIp}] {responseData}", clientIp, responseData);
await webSocket.SendAsync(Encoding.UTF8.GetBytes(responseData), WebSocketMessageType.Text, endOfMessage : true, CancellationToken.None);
}
