This is the linux port of tcpdump version 3.0.

Port by: Adam Caldwell (acaldwel@ace.cs.ohiou.edu)

NOTES:
  1) Linux doesn't have a lot of the include files that tcpdump expects...
     and when it does have them, the linux includes use different names,
     so I had to include a special directory especially for linux, which
     contained the needed definitions.
  2) This program compiles using gcc 2.5.8, flex 2.4.6, bison 1.22, 
     whatever include files came with Slackware 1.2.0 (presumably the ones
     that go with gcc 2.5.8), and kernel version 1.0.8 (and 1.1.33)
  3) The kernel keeps track of the exact time a packet was received.
     the newer kernels provide a way to get to this, so I put in a modification
     to ask for it.... If it the newer interface doesn't exist (ie old kernel)
     it will revert back to using gettimeofday().
  4) I put in a hook so that it can clean up after itself (ie turn off promisc
     mode if it turned it on.

Changes for 3.0.3
  -- Added loopback support (everything shows up twice because the machine
     is both the sender and the reciever)
  -- Fixed a bug in pcap-linux that would cause it to fail if used in another
     program.

Things to do:
  1) The kernel keeps track of interface statistics... I took the easy way
     out and didn't ask for them.
