// Create our UDP socket.

auto socket = sfn::UdpSocket::Create();

// Our soon-to-be DNS request.

std::string request;

// Transaction ID

request += { 0x13, 0x37 };

// Standard recursive query flags

request += { 0x01, 0x00 };

// Questions

request += { 0x00, 0x01 };

// RRs

request += { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };

// Name part 1

request += static_cast<char>( 4 ); // Length

request += "ietf";

// Name part 2

request += static_cast<char>( 3 ); // Length

request += "org";

// Name terminator

request += static_cast<char>( 0x00 );

// Type: A Class: IN

request += { 0x00, 0x01, 0x00, 0x01 };

// Google DNS server endpoint.

sfn::Endpoint google_dns{ sfn::IpAddress{ "8.8.8.8" }, 53 };

// Bind the socket to a local endpoint so we are able to receive data.

socket->Bind( sfn::Endpoint{ sfn::IpAddress{ "0.0.0.0" }, 1337 } );

// Send the DNS request to the Google DNS server endpoint.

socket->SendTo( request.c_str(), request.size(), google_dns );

// Start a network processing thread.

sfn::Start();

while( true ) {

std::array<char, 1024> reply;

// Dequeue any data we receive from the Google DNS server.

std::size_t reply_size = socket->ReceiveFrom( reply.data(), reply.size(), google_dns );

// Display the IP address so everybody believes this works.

if( reply_size >= 4 ) {

std::cout << "Address: " << static_cast<unsigned short>( reply[reply_size - 4] & 0xff ) << "."

<< static_cast<unsigned short>( reply[reply_size - 3] & 0xff ) << "."

<< static_cast<unsigned short>( reply[reply_size - 2] & 0xff ) << "."

<< static_cast<unsigned short>( reply[reply_size - 1] & 0xff ) << "\n";

break;

}

}

// Close the socket.

socket->Close();

// Stop all network processing threads.

sfn::Stop();

return 0;