taglinefilesource code
vifi88include/linux/mroute.hvifi_t  vifi;    /* Which iface */
vifi245net/ipv4/ipmr.cif(vr.vifi>=MAXVIFS)
vifi247net/ipv4/ipmr.cvif=&vif_table[vr.vifi];
vifi248net/ipv4/ipmr.cif(vifc_map&(1<<vr.vifi))