taglinefilesource code
RTF_GATEWAY975net/inet/dev.crt_add(RTF_GATEWAY, ipc.paddr, ipc.router, dev);
RTF_GATEWAY162net/inet/route.crt->rt_flags&=~RTF_GATEWAY;
RTF_GATEWAY166net/inet/route.crt->rt_flags |= RTF_GATEWAY;
RTF_GATEWAY257net/inet/route.cif (! (r->rt_dst & mask) && (gw==0 || r->rt_flags&RTF_GATEWAY)) 
RTF_GATEWAY305net/inet/route.cif (!(r->rt_flags & RTF_GATEWAY))