lacking it, so use it in some other cases, instead of duplicating its
functionality.
Check, however, whether it succeeds, and fail appropriately when it
fails.
Also, when other mallocs fails, free up any memory allocated for data
structures, so it doesn't leak.
packets (based on the Ethernet type). "pppoes" has the side-effect that
subsequent filter expressions will test the PPP header and headers
in the PPP payload, not the link-layer header and headers in the
link-layer payload.
so that it's not EBUSY if we didn't get an EBUSY in a
DL_ERROR_ACK/DL_SYSERR reply, and our checks for EBUSY only catch that
case.
If we *did* get EBUSY on all the SAPs we tried, supply an error.
Make "dl_dohpuxbind()" always return a value, so we don't fall off the
end and return an error indication by accident.
to -1, set a "we're doing MPLS" flag, and check that flag rather than
checking for an off_linktype of -1; off_linktype can be -1 for reasons
having nothing to do with MPLS (e.g., a DLT_ of DLT_RAW), and those
should be handled as they have traditionally been.
Rename "gen_null()" to "gen_mpls_linktype()" to make it clearer what it
does (it checks the MPLS stack as well as the IP header).
instruction as an unsigned value, and, at least for comparisons, the
value is converted to unsigned anyway, as the A and X registers are
unsigned, and the Usual Arithmetic Conversions of C89 apply to
comparisons. Make ours unsigned as well. (On two's complement machines
- which means all machines we support - that won't be an issue for using
the constant field as an offset, either, as arithmetic in the BPF
virtual machine is 32-bit two's complement.)
centralize the MPLS check into gen_linktype() and backout the
specific checks in gen_proto_abrev(), gen_proto(), gen_host()
this adds as a by-product support for IPv6
values for an HDLC link (MTP2 is what's usually run on those links, with
MTP3 atop it); remove them. Also, boost dlt_count to match the number
of DLT_ values.
if we have a MPLS label stack deeper > 1 then generate a match
for a cleared bottom-of-stack-bit of the previous MPLS shim header
rather than just incrementing the offset;
if there is a compined expression of MPLS and IP like e.g.
"mpls && ip" | "mpls && ip host" | "mpls && ip src net"
then poison the linkoffset to make sure that other code generators
do not try to match link-layer protos like Q_ARP, Q_RARP etc.
introduce a new function gen_null() that matches against the first nibble
of the IP header and matches if the bottom-of-stack bit is set;
TODO: IPv6 stuff i.e. gen_host6() etc.
hannes