Rsyslog.prototype.log() file descriptor leak using protocol U (UDP)

[syndr0m]

Rsyslog.prototype.log = function (level, msg, meta, callback) {
(...)
client.send(_buffer, 0, _buffer.length, this.port, this.host, function(err, bytes) {
      if (err)
      {
        // Should call client.close() before throwing error.
        // (can be a DNS error)
        throw err;
      }
(...)

simplified example of using udp socket.send() without close()

marc@marc:~/tmp$ cat > udp.js
for (var i = 0; i < 5; ++i) {
  require('dgram').createSocket("udp4").send(new Buffer("toto"), 0, 4, 4242, "127.0.0.1", function () { });
}
marc@marc:~/tmp$ node udp.js &
[1] 27644
marc@marc:~/tmp$ sudo lsof -n -i -P | grep node
node      27644      marc    9u  IPv4 8889835      0t0  UDP *:60787 
node      27644      marc   10u  IPv4 8889836      0t0  UDP *:60167 
node      27644      marc   11u  IPv4 8889837      0t0  UDP *:34401 
node      27644      marc   12u  IPv4 8889838      0t0  UDP *:58187 
node      27644      marc   13u  IPv4 8889839      0t0  UDP *:38581

[markstos]

This looks very related to #8 which suggests that winston-rsyslog is making a new TCP connection for each logging event when a single persistent connection might do.