taglinefilesource code
ip_route_saddr175include/net/sock.hunsigned long      ip_route_saddr;    /* Source address      */
ip_route_saddr2398net/ipv4/ip.csaddr=sk->ip_route_saddr;   
ip_route_saddr2399net/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_saddr2407net/ipv4/ip.csk->ip_route_saddr=saddr;