taglinefilesource code
ip_route_stamp199include/net/sock.hunsigned long    ip_route_stamp;    /* Route cache stamp */
ip_route_stamp2413net/ipv4/ip.cif(!rt || sk->ip_route_stamp != rt_stamp || daddr!=sk->ip_route_daddr || sk->ip_route_local!=local || sk->saddr!=sk->ip_route_saddr)
ip_route_stamp2422net/ipv4/ip.csk->ip_route_stamp=rt_stamp;
ip_route_stamp546net/ipv4/udp.csk->ip_route_stamp = rt_stamp;