RFC: removing redundant checks in ether_input_internal()

[John Baldwin]

On Wednesday, May 22, 2013 10:53:29 am Andre Oppermann wrote:
> On 22.05.2013 14:58, Luigi Rizzo wrote:
> > if_ethersubr.c :: ether_input_internal() is only called as follows:
> >
> >      static void
> >      ether_nh_input(struct mbuf *m)
> >      {
> >
> >          ether_input_internal(m->m_pkthdr.rcvif, m);
> >      }
> >
> > hence the following checks in the body are unnecessary:
> >
> >          if (m->m_pkthdr.rcvif == NULL) {
> >                  if_printf(ifp, "discard frame w/o interface pointer\n");
> >                  ifp->if_ierrors++;
> >                  m_freem(m);
> >                  return;
> >          }
> >      #ifdef DIAGNOSTIC
> >          if (m->m_pkthdr.rcvif != ifp) {
> >                  if_printf(ifp, "Warning, frame marked as received on 
%s\n",
> >                          m->m_pkthdr.rcvif->if_xname);
> >          }
> >      #endif
> >
> > Any objection if i remove them ?
> 
> No, but they should remain as KASSERTs.  None of these should trigger in
> production and all of them are an indication that something is very wrong
> with the packet or the caller.

Eh, but if the only caller is ether_nh_input() then by definition you know
that m->m_pkthdr.rcvif == ifp.

-- 
John Baldwin