letting you filter based on the VLAN to which a packet belongs, and an
improvement to the printing of VLAN packets (adding an extra space to
separate the VLAN priority and flags from the next stuff printed).
core if the YY_FLUSH_BUFFER macro is called when there's no current
buffer (e.g., before any scanning has been done).
So, instead, when using Flex, we use "yy_scan_string()" to specify that
the scanner should read from the filter expression string, rather than
defining our own YY_INPUT macro, and we add a "lex_cleanup()" routine,
called after parsing is complete, to delete the buffer allocated by
"yy_scan_string()", which arranges that, when we next hand the scanner a
string, it doesn't then return to the parser cruft left over from the
previous parse.
./configure --enable-ipv6 (requires getaddrinfo(3) and getnameinfo(3)).
TODO: make it work even without getaddrinfo(3) or getnameinfo(3)
(or, tcpdump/configure.in should provide alternative version by
AC_REPLACE_FUNCS)
TODO: make IPv6 filtering code work by default
TODO: make "protochain" friendly with optimization
guy