On 02/18/2016 09:37 PM, David Miller wrote: > From: Nikolay Aleksandrov <ra...@blackwall.org> > Date: Tue, 16 Feb 2016 12:46:52 +0100 > >> Note that the reason we can't simply add an attribute after >> MDBA_MDB_ENTRY_INFO is that current users (e.g. iproute2) walk over >> the attribute list directly without checking for the attribute type. > > Honestly that sounds like a bug in iproute2 to me... >
I agree, but changing this in the kernel would make older iproute2 versions incompatible with newer kernels, possibly outputting garbage from the additional attributes, besides we still will have to turn MDBA_MDB_ENTRY_INFO into a nested attribute and insert the struct with a header as that's the per-mdb entry attribute currently. Alternatively I have a version that uses a request flag in the dump request and sends back an alternative/"extended" version of the mdbs where every field is a netlink attribute and is extensible, thus keeping the old format in place and offering extended attribute support to anyone who requests it. I just thought this version is a middle ground between the two solutions and still doesn't break user-space while being extensible. There're no more holes in the mdb entry struct to reuse.. :-) Cheers, Nik
