0 means "there is no FCS in the packet data", 4 means "there is an FCS
in the packet data", -1 means "I don't know whether there's an FCS in
the packet data, guess based on the packet size".
Assume that Ethernet encapsulated inside other protocols has no FCS, by
having the "eth" dissector assume that (and not check for an Ethernet
pseudo-header).
Have "ethertype()" take an argument giving the FCS size; pass 0 when
appropriate.
Fix up Wiretap routines to set the pseudo-header. This means we no
longer use the "generic" seek-and-read routine, so get rid of it.
svn path=/trunk/; revision=8574
use WTAP_ENCAP_ATM_PDUS as the default encapsulation for ATM;
don't use ULL constants, as not all C compilers that support
gint64 support them, and as there's no need to make them ULL
constants.
svn path=/trunk/; revision=8278
Guy Harris