Socket LocalEndPoint not updated in SendToAsync(SocketAsyncEventArgs e) #915
Description
The SocketAsyncEventArgs version of SendToAsync does not properly set _rightEndPoint, while it creates the endPointSnapshot variable that is used to set _rightEndPoint in SendTo, BeginSendTo and SendToAsync (task) methods.
According to remarks section of the documentation on recvfrom method, all of sendto, WSASendTo and WSAJoinLeaf implicitly binds to a local address which is reflected by calling getsockname.
Here is a reference link for Socket.cs with line number.
https://github.com/dotnet/corefx/blob/master/src/System.Net.Sockets/src/System/Net/Sockets/Socket.cs#L4213
Otherwise it is in public bool SendToAsync(SocketAsyncEventArgs e) method.
Example code for reproducing issue
static void Main(string[] args)
{
using (var socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp))
{
var destinationEndPoint = new IPEndPoint(IPAddress.Parse("10.20.30.40"), 1234);
var socketAsyncEventArgs = new SocketAsyncEventArgs();
socketAsyncEventArgs.RemoteEndPoint = destinationEndPoint;
socketAsyncEventArgs.SetBuffer(new byte[32], 0, 32); // 32 bytes of zeros
socketAsyncEventArgs.Completed += (sender, e) => SendCompleted(e);
if (!socket.SendToAsync(socketAsyncEventArgs))
SendCompleted(socketAsyncEventArgs);
Debug.Assert(socket.LocalEndPoint != null); // LocalEndPoint should not be null
}
Console.ReadLine();
}
static void SendCompleted(SocketAsyncEventArgs args)
{
args.Dispose();
}