Re: Fw: F_SETSIG broken/changed in 2.6 for UDP and TCP sockets?

From: Russell Leighton (russ_at_elegant-software.com)
Date: 06/05/04

  • Next message: Dominik Brodowski: "Re: Too much error in __const_udelay() ?"
    Date:	Sat, 05 Jun 2004 11:14:11 -0400
    To: netdev@oss.sgi.com, linux-kernel@vger.kernel.org
    
    

    Last issue resolved. I am posting so there is a complete thread for
    anyone that stumbles on this in the future.

    F_SETSIG IS working...what is NOT working (as it did in 2.4) is the
    interaction between clone() and getpid() in child processes.
    This issue altered the control of my program and made it look like I was
    not receiving signals.

    I'll send another email to the kernel mailing list w/a test program that
    demonstrates this.

    Russell Leighton wrote:

    >
    > Thanks to all that helped me troubleshoot.
    >
    > Of the 2 issues I had with FedoraCore2, one problem is solved:
    >
    > * Multicast issues were solved by using another NIC. It seems that
    > the driver for the NatSemi DP8381[56] does not receive mutlicast
    > properly.
    > * F_SETSIG still seems broken for TCP for me when my process sets up
    > more than a few fd's...I will try the latest kernel to see if this
    > goes away
    >
    >
    > Russ
    >
    > Andrew Morton wrote:
    >
    >> Begin forwarded message:
    >>
    >> Date: Mon, 31 May 2004 14:45:08 -0400
    >> From: Russell Leighton <russ@elegant-software.com>
    >> To: linux-kernel@vger.kernel.org
    >> Subject: F_SETSIG broken/changed in 2.6 for UDP and TCP sockets?
    >>
    >>
    >>
    >> I have a program that works fine under stock rh9 (2.4.2-8) but has
    >> issues getting signaled under FedoraCore2 (2.6.5-1.358)
    >> using SETSIG to a Posix RT signal.
    >>
    >> The program does the standard:
    >>
    >> /* hook to process */
    >> if ( fcntl(fdcallback->fd, F_SETOWN, mon->handler_q.thread->pid) ==
    >> -1 ) {
    >> aw_log(fdcallback->handler->logger, AW_ERROR_LOG_LEVEL,
    >> "cannot set owner on fd (%s)",
    >> strerror(errno));
    >> }/* end if */
    >>
    >> /* make async */
    >> if ( fcntl(fdcallback->fd, F_SETFL, (O_NONBLOCK | O_ASYNC) ) == -1 ) {
    >> aw_log(fdcallback->handler->logger, AW_ERROR_LOG_LEVEL,
    >> "cannot set async on fd (%s)",
    >> strerror(errno));
    >> }/* end if */
    >>
    >> /* hook to signal */
    >> if ( fcntl(fdcallback->fd, F_SETSIG, AW_SIG_FD) == -1 ) {
    >> aw_log(fdcallback->handler->logger, AW_ERROR_LOG_LEVEL,
    >> "cannot set signal on fd (%s)",
    >> strerror(errno));
    >> }/* end if */
    >>
    >> Under Fedora things work well for raw sockets (much lower latency
    >> than in 2.4!) but are inconsistent with udp or tcp sockets.
    >>
    >> In the udp case, I when I listen for multicast packets my app only
    >> receives them when I am running a tcpdump (bizarre!).
    >>
    >> In the tcp case, I don't get signaled if I do the F_SETSIG on more
    >> than 1 fd.
    >>
    >> Any tips on tracking this down would be much appreciated.
    >>
    >> Thx
    >>
    >> Russ
    >>
    >> -
    >> To unsubscribe from this list: send the line "unsubscribe
    >> linux-kernel" in
    >> the body of a message to majordomo@vger.kernel.org
    >> More majordomo info at http://vger.kernel.org/majordomo-info.html
    >> Please read the FAQ at http://www.tux.org/lkml/
    >>
    >>
    >>
    >>
    >
    >

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


  • Next message: Dominik Brodowski: "Re: Too much error in __const_udelay() ?"

    Relevant Pages

    • Re: raw sockets: question about sending IP + UDP header
      ... > the UDP datagram through a raw socket client to a UDP socket server. ... > to test if my IP header and IP checksum is correct plus of course my UDP ... There's a chapter on Raw Sockets in Unix Network Programming, ...
      (comp.unix.programmer)
    • Re: UDP recvmsg blocks after select(), 2.6 bug?
      ... > currently we could get precise behaviour - by halving performance of UDP ... pkts could be dropped even for TCP sockets. ... send the line "unsubscribe linux-kernel" in ...
      (Linux-Kernel)
    • Re: Sending packet with spoofed IP address
      ... >From XP SP2 you can't use raw sockets for TCP and for UDP only with correct ... > Are these going to be UDP packets? ... > way to create a TCP connection without a correct source IP address. ... >> use a protocol driver. ...
      (microsoft.public.development.device.drivers)
    • Re: UDP recvmsg blocks after select(), 2.6 bug?
      ... On Iau, 2004-10-07 at 15:07, Martijn Sipkema wrote: ... >> kernel control too, ... currently we could get precise behaviour - by halving performance of UDP ... send the line "unsubscribe linux-kernel" in ...
      (Linux-Kernel)
    • Re: Ping abschicken?
      ... - RAW sockets können keine UDP frames senden, ... Da aber die Ping-Frames weder TCP noch UDP sind, ... Next by Date: ...
      (microsoft.public.de.vc)