问题
I'm new at SSDP/UPNP/Sockets and all that jazz. I'm playing around with it a bit and I just want to see what a generic SSDP search on my network will bring up.
Using this SSDP Sniffer app, I get a lot of results so I'm attempting to recreate this.
I'm using the following code, which I've found various versions of, but all the tweaking I do doesn't appear to bring back any results. I pretty much at a loss here and would appreciate any guidance.
thanks!
private const string SSDP_IP = "239.255.255.250";
private const string SSDP_PORT = "1900";
private const string SSDP_QUERY = "M-SEARCH * HTTP/1.1\r\n" +
"Host: " + SSDP_IP + ":" + SSDP_PORT + "\r\n" +
"Man: ssdp:discover\r\n" +
"ST: ssdp:all\r\n";
DataGramSocket socket;
async public void SsdpQueryAsync()
{
var remoteIP = new Windows.Networking.HostName(SSDP_IP);
var reqBuff = Encoding.UTF8.GetBytes(SSDP_QUERY);
socket = new DatagramSocket();
socket.MessageReceived += (sender, args) =>
{
// This is invoked for each device that responds to the query...
Task.Run(() =>
{
// do something useful
});
};
await socket.BindEndpointAsync(null, "");
socket.JoinMulticastGroup(remoteIP);
using (var stream = await socket.GetOutputStreamAsync(remoteIP, SSDP_PORT))
{
await stream.WriteAsync(reqBuff.AsBuffer());
}
await Task.Delay(5000);
}
回答1:
I'm not familiar with C# or dotnet APIs, but I can see some details wrong with the M-SEARCH message:
- MAN header must be enclosed in double quotes, so
MAN: "ssdp:discover"\r\n
- MX header is missing (required for multicast)
- USER-AGENT header is missing
- missing an empty line in the end
- Header names are supposedly case insensitive, but I'd use upper case just in case...
See the Device Architecture reference pdf for more details
来源:https://stackoverflow.com/questions/18834893/ssdp-search-in-windows-phone-8