int buff_length = 8192;
ifstream stream;
char* buffer = new char[buff_length];

stream.open( path.string().c_str(), ios::binary );

boost::system::error_code ignored_error;

while (stream)
{
    stream.read(buffer, buff_length);
    boost::asio::write(*socket, boost::asio::buffer(buffer, stream.gcount()),
                            boost::asio::transfer_all(), ignored_error);
}