bug in tcp?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



I'm seeing some weird behavior in TCP.  The issue is perfectly
reproducible using netcat and other programs.  This is what I do:

    1.  Open a TCP connection over the loopback (over IPv4).

    2.  Send a couple of bytes of data each way.  No problems.

    3.  Wait about 120 hours with no writes on either side of the
        connection.

    4.  write() a few bytes to the server's socket.  I'd expect the data
        to go through, but it doesnt.  I see the TCP frame from the
        server to the client, but instead of an ACK, the client sends
        back a RST.  netstat shows the bytes sitting in the server's
        socket's send-buffer.

    5.  write a few bytes to the client's socket.  The server gets
        these immediately.

    6.  On the next server-to-client retransmit, the client gets the
        bytes from the server.  After this, the connection works normally.


The libpcap capture file is here:  http://highlab.com/~seb/tcp-idleness-bug


The behavior is reproducible on all kernels I've tried: 2.4.32, 2.6.19.1,
and 2.6.20.4.  I dont think it's iptables-related, though I'm rerunning
the tests on a machine without iptables to be sure.  I'll have results
for you in 120 hours.  ;-)


-- 
Sebastian Kuzminsky
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux