[lwip-devel] [patch #6865] SO_REUSEADDR for TCP

[Jeff Barber]

URL:
  <http://savannah.nongnu.org/patch/?6865>

                 Summary: SO_REUSEADDR for TCP
                 Project: lwIP - A Lightweight TCP/IP stack
            Submitted by: jeffbabar
            Submitted on: Tue 14 Jul 2009 03:22:04 PM GMT
                Category: None
                Priority: 5 - Normal
                  Status: None
                 Privacy: Public
             Assigned to: None
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
         Planned Release: None

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Details:

In developing an FTP server (for example) it is necessary to bind each
outgoing PORT connection to the well-known FTP-data port (20).  Back-to-back
transfers usually mean that the second and subsequent connections need to be
bound to port 20 while the previous PCB is still in TIME_WAIT.  Hence, the
equivalent of SO_REUSEADDR required in order to implement the server.

This patch provides a new TCP flag "TF_REUSEADDR" that, when set during the
processing of tcp_bind, bypasses the checking of the PCBs still in TIME_WAIT.

Applies cleanly to top-of-tree and 1.3.1-RC1.  It does not apply cleanly to
1.3.0 but the sole failure is the one line definition of the new flag and is
trivial to fix.

Usage:
    pcb = tcp_new();
    pcb->flags |= TF_REUSEADDR;
    status = tcp_bind(pcb, &in_addr_any, FTP_DATA_PORT);
    ...

Sorry, I only use the raw API with NO_SYS=1 so I can't provide a patch that
works for other APIs.




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File Attachments:


-------------------------------------------------------
Date: Tue 14 Jul 2009 03:22:04 PM GMT  Name: tcp_reuseaddr.patch  Size: 2kB  
By: jeffbabar

<http://savannah.nongnu.org/patch/download.php?file_id=18422>

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