Node.js how to handle packet fragmentation with net.Server

Question

When a net.Server receives data that exceeds 1500 bytes (default mtu), the 'on data' event is executed with each fragment of the packet. Is there a way to receive the whole packet in a single 'on data' call?

Thanks.

Why ? Just concatenate the chunks if you need it in one piece. — Denys Séguret
– Denys Séguret, Commented Jul 21, 2014 at 6:39
There are hundred of sources sending data, the source_id is in the begin of packet. If a packet is fragmented, I can't identify the source of the following chunks. — Danilo Aburto Vivians
– Danilo Aburto Vivians, Commented Jul 21, 2014 at 6:47
Can you show your code ? Usually you work on sockets, you don't handle packets just like this... — Denys Séguret
– Denys Séguret, Commented Jul 21, 2014 at 6:49
The code is too large. The socket passed to "onconnection" event have to handle several event types. I can't simply concatenate the events after receive them. — Danilo Aburto Vivians
– Danilo Aburto Vivians, Commented Jul 21, 2014 at 7:15

Kokin Lin · Accepted Answer · 2015-05-22 09:16:22Z

2

Try this

var sys     = require('sys');
var net     = require('net');;

var socktimeout = 600000;
var svrport = your_port;

var svr = net.createServer(function(sock) {
  var mdata = new Buffer(0);
    //sys.puts('Connected: ' + sock.remoteAddress + ':' + sock.remotePort); 
     sock.setTimeout(socktimeout,function(){
            sock.end("timeout");
            sock.destroy();
        });

    sock.on('data', function(data) {  


        if(mdata.length != 0)
        {
          var tempBuf = Buffer.concat([mdata, data]);
          mdata = tempBuf;
        }
        else
        {
          mdata = data;
        }

        var len=got_your_Packget_length(mdata);
         
      if(mdata.length == len)
      {
        do_your_job(mdata)
        mdata = new Buffer(0);
      }


    });
 


    sock.on('error', function(err) { // Handle the connection error.
        sys.puts('error: ' + err +'\n');
    });
});
 
svr.listen(svrport);

answered May 22, 2015 at 9:16

Kokin Lin

212 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Sander Over a year ago

I believe this is useless if you got no idea how large the data package is. I think it should be possible to check the datagram's ethernet fragment length, frag_flag and offset. For a better understanding: stackoverflow.com/questions/15999739/…

Collectives™ on Stack Overflow

Node.js how to handle packet fragmentation with net.Server

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related