dissector, it's looking for Q.931 encapsulated inside TPKT, so it
shouldn't check whether the first byte is NLPID_Q_931 or not, as it
*won't* be NLPID_Q_931, it'll be 3, for the TPKT version. It should
first check whether "is_tpkt()" thinks it's a TPKT packet, and then
check that the packet has at least 3 bytes past the TPKT header, then
check the first byte in the payload to see whether it's NLPID_Q_931. If
that all succeeds, treat it as Q.931 inside TPKT.
Make "is_tpkt()" return the length from the TPKT header on success, and
-1 on failure, and return the offset past the TPKT header via a pointer
(so clients don't have to know that the TPKT header is 4 bytes long).
svn path=/trunk/; revision=4669
containing OSI transport layer PDUs).
Enable the Q.931-inside-TPKT code (but not the H.225 stuff, as that
requires Andreas Sikkema's H.225 dissector). Update it to match his
current modified Q.931 dissector.
svn path=/trunk/; revision=3199
