MASTER HANDSHAKER PATCH

> Do you think it'll not happen only with ns-3 scenario (without dce) ? I will look at and try the script and patch. > (In reply to MatГas Richart from comment #2) (In reply to Hajime Tazaki from comment #5)

If yes, it would be nice to have a pure ns-3 script (example/test-case) to reproduce this issue. I will look at and try the script and patch.Дo you think it'll not happen only with ns-3 scenario (without dce) ? > when the connection fail and then the select unblocks and the accept fails. > The problem is, as I said in the report, that the master socket is closed > The applications consist on a client and a server, where the server makes a > move nodes so as to be able to receive the SYN packet but not the other

> reproducible simulation scenario of the issue.

MASTER HANDSHAKER PATCH

> Is it possible to provide 1) a patch (you're not sure), and 2) a minimum > (In reply to Hajime Tazaki from comment #1) (In reply to MatГas Richart from comment #2) It appears to be a problem of dce and not of ns3. This patch is simple but we are not sure if it is the best solution. We make the CloseAndNotify not to invoke the callback if it was caused by a SYN+ACK failed retransmissions and it works, the master socket is not closed. This callback is used by dce to deallocate its sockets (see CloseSucces() in unix-stream-socket-fd), but as the associated socket is the master, the master is closed. This function deallocates memory and invokes a close callback. Then if the connection fails, the function CloseAndNotify() is called. Only after the final ACK is received, the function ConnectionSucceeded is called, which makes dce to wakeup the Accept and then create a new dce socket. What is happening is that ns3 when imitating a new connection, after the arrival of a SYN packet, it forks a new socket (see ProcessListen() and CompleteFork()) for that connection but in dce no socket is allocated yet. We trace the problem to the file of ns3. In summary the bug consists in that, when using a socket in mode LISTEN (waiting for connection requests) if the packet with the SYN+ACK is lost for every retransmission attempt the master socket is closed.

Master handshaker