cvs commit: src/sys/net if_bridge.c

[Christian S.J. Peron]

csjp        2006-03-03 05:58:18 UTC

  FreeBSD src repository

  Modified files:
    sys/net              if_bridge.c 
  Log:
  Slightly re-worked bpf(4) code associated with bridging: if we have a
  destination interface as a member of our bridge or this is a unicast packet,
  push it through the bpf(4) machinery.
  
  For broadcast or multicast packets, don't bother with the bpf(4) because it will
  be re-injected into ether_input. We do this before we pass the packets through
  the pfil(9) framework, as it is possible that pfil(9) will drop the packet or
  possibly modify it, making it very difficult to debug firewall issues on the
  bridge.
  
  Further, implemented IFF_MONITOR for bridge interfaces. This does much the same
  thing that it does for regular network interfaces: it pushes the packet to any
  bpf(4) peers and then returns. This bypasses all of the bridge machinery,
  saving mutex acquisitions, list traversals, and other operations performed by
  the bridging code.
  
  This change to the bridging code is useful in situations where individuals use a
  bridge to multiplex RX/TX signals from two interfaces, as is required by some
  network taps for de-multiplexing links and transmitting the RX/TX signals
  out through two separate interfaces. This behaviour is quite common for network
  taps monitoring links, especially for certain manufacturers.
  
  Reviewed by:    thompsa
  MFC after:      1 month
  Sponsored by:   Seccuris Labs
  
  Revision  Changes    Path
  1.55      +26 -10    src/sys/net/if_bridge.c