On Wednesday, 2 April 2014 at 21:54:58 UTC, FreeSlave wrote:
> It's only server. Maybe problem is on client side.
>

Yes, it is only a server which needs to answer back the client;
And there was the problem: I was not fetching the client's
address, and since UDP is an unconnected protocol, I couldn't
send it back with just "send".

So what I had to do was to create a client address and pass it in
receiveFrom(), and then use sendTo(in data, in clientAddr). Once
this was fixed, the server was able to answer my client.

N.b. auto addr_client = new InternetAddress didn't seem to work,
like if InternetAddress wasn't right for the Address parameter. I
explicitely needed Address.

Here's the code:

module main;

import std.stdio;
import std.socket;
import std.string;
import std.conv;

int main()
{
	auto s = new UdpSocket();

	auto addr = new InternetAddress("127.0.0.1", 6666);
	s.setOption(SocketOptionLevel.IP, SocketOption.REUSEADDR, true);
	s.bind(addr);
	Address addr_client = new InternetAddress(6666);

	while (true)
	{
		ubyte[2048] recv_buf;
		immutable count = s.receiveFrom(recv_buf, addr_client);
		char[] test = cast(char[])(recv_buf[0..count-1]); // -1 pour
compatibilité avec C string...

		writefln("Received: %s\n", test);

		auto rep = toStringz("Hello");
		s.sendTo(rep[0..6], addr_client);
	}

	return 0;
}

Thanks all for your help, much appreciated!

Alexandre