Re: sendmsg and IP_PKTINFO

[David S. Miller]

   From: Neil Brown <[e-mail]>
   Date: Fri, 21 Feb 2003 14:51:07 +1100
   
   As far as I can tell, control message are currently defined for:
      IPv4,
      IPv6,
      SOL_HCI - some bluetooth thing
      SOL_SOCKET (which don't seem to be clearly documented in socket(7))
   
Also, control messages are used for AF_UNIX to pass file descriptors
around.