On Sat, 2020-06-20 at 17:44 -0700, David Miller wrote: > From: Paolo Abeni <pab...@redhat.com> > Date: Fri, 19 Jun 2020 12:54:40 +0200 > > > IPPROTO_MPTCP value (0x106) can't be represented using the current sock > > diag uAPI, as the 'sdiag_protocol' field is 8 bits wide. > > > > To implement diag support for MPTCP socket, we will likely need a > > 'inet_diag_req_v3' with a wider 'sdiag_protocol' > > field. inet_diag_handler_cmd() could detect the version of > > the inet_diag_req_v* provided by user-space checking nlmsg_len() and > > convert _v2 reqs to _v3. > > > > This change will be a bit invasive, as all in kernel diag users will > > then operate only on 'inet_diag_req_v3' (many functions' signature > > change required), but the code-related changes will be encapsulated > > by inet_diag_handler_cmd(). > > Another way to extend the size of a field is to add an attribute which > supercedes the header structure field when present. > > We did this when we needed to make the fib rule table ID number larger, > see FRA_TABLE. > > You'd only need to specify this when using protocol values larger than > 8 bits in size.
Thank you very much for the directions! This looks like a better, more encapsulated solution. I'll try to give it a shot. Thanks! Paolo
