IP_REASS_START
offset = IP_REASS_START(mp1);
IP_REASS_START(mp1->b_cont) &&
end >= IP_REASS_START(mp1->b_cont)) ||
offset = IP_REASS_START(mp1);
if (start >= IP_REASS_START(mp1->b_cont))
offset = IP_REASS_START(mp1);
!= IP_REASS_START(mp1->b_cont) &&
IP_REASS_START(mp1->b_cont)) ||
offset = IP_REASS_START(mp1);