GUIDELINES FOR WRITING SUMMARY PROTOCOL DECODERS

1. Each frame should be processed individually.  You cannot assume any
state information.

2. Each layer appends its information to a string being written.  Just use
printf or putchar and don't write any linefeeds.

3. Put the following in your decoder for tcpview compatibility:

#ifdef TCPVIEW
#include "tcpview.h"
#endif

4. Insert a call to your decoder in the layer below yours.

See print-ether.c, print-arp.c, or print-udp.c for examples.  You can write a
decoder just using one of these as a framework.