taglinefilesource code
ip_route_daddr174include/net/sock.hunsigned long      ip_route_daddr;    /* Target address       */
ip_route_daddr2374net/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_daddr2381net/ipv4/ip.csk->ip_route_daddr=daddr;