none
TCP filter driver RRS feed

  • Question

  • Hi,

    we need to issue socket-related IOCTL to some of the connections. In early versions of Windows we used to layer our filter directly over \\.\Tcp and hand-craft IOCTLs. Since a lot of things have been changed we'd like to know 1) Is this approach still valid (don't have source of THAT driver any more so it will take time to write it again) and 2) Is there any way to do it from user mode with say new filtering API or whatever. Sorry, failed to answer the question Google-ing :(

    Thanks!

    -nismo

    Sunday, October 14, 2012 10:35 AM

Answers

All replies

  • what IOCTL are you sending? what bigger problem are you trying to solve?

    d -- This posting is provided "AS IS" with no warranties, and confers no rights.

    Sunday, October 14, 2012 11:48 PM
  • what IOCTL are you sending? what bigger problem are you trying to solve?

    d -- This posting is provided "AS IS" with no warranties, and confers no rights.

    SIO_LOOPBACK_FAST_PATH

    MS had represented this call with Windows Server 2012 and it does work but unfortunately you need to set it on both sides (client & server).

    We do control server as it's our application but unfortunately we don't have access to client's source to modify it... So test application issuing this call

    DOES work 6-7 times faster compared to "generic" loopback so now we need to fake this call on a client. Do you think layering on top of \\.\Tcp is a way to go?

    Thanks!

    -nismo

    Monday, October 15, 2012 8:09 AM
  • Nismo,

        There SIO_LOOPBACK_FAST_PATH IOCTL is available on a per-socket basis in Windows Server 2012 and Windows 8.  There is currently no architected way to apply the IOCTL to an application which does not set the IOCTL itself.  I've just posted a blog about the use of SIO_LOOPBACK_FAST_PATH for anyone looking for additional information here:

      http://blogs.technet.com/b/wincat/archive/2012/12/05/fast-tcp-loopback-performance-and-low-latency-with-windows-server-2012-tcp-loopback-fast-path.aspx

    Ed Briggs

    Microsoft Corporation

    Wednesday, December 5, 2012 5:20 PM