taglinefilesource code
ip_route_stamp173include/net/sock.hunsigned long      ip_route_stamp;    /* Route cache stamp       */
ip_route_stamp2399net/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_stamp2408net/ipv4/ip.csk->ip_route_stamp=rt_stamp;
ip_route_stamp492net/ipv4/udp.csk->ip_route_stamp = rt_stamp;