rip6_input
rv = rip6_input(mp, offp, proto);
rv = rip6_input(mp, offp, proto);
PR_WRAP_INPUT6(rip6_input)
.pr_input = rip6_input,
.pr_input = rip6_input,
rip6_input(&m, offp, proto);
int rip6_input(struct mbuf **, int *, int);