Compiling ip_set_iptree.o as module get this error :- CC [M] net/ipv4/netfilter/ip_set_iptree.o net/ipv4/netfilter/ip_set_iptree.c:123: error: parse error before "flags" net/ipv4/netfilter/ip_set_iptree.c:124: warning: function declaration isn't a prototype net/ipv4/netfilter/ip_set_iptree.c: In function `__addip': net/ipv4/netfilter/ip_set_iptree.c:125: error: `set' undeclared (first use in this function) net/ipv4/netfilter/ip_set_iptree.c:125: error: (Each undeclared identifier is reported only once net/ipv4/netfilter/ip_set_iptree.c:125: error: for each function it appears in.) net/ipv4/netfilter/ip_set_iptree.c:132: error: `hash_ip' undeclared (first use in this function) net/ipv4/netfilter/ip_set_iptree.c:132: error: `ip' undeclared (first use in this function) net/ipv4/netfilter/ip_set_iptree.c:135: error: `flags' undeclared (first use in this function) net/ipv4/netfilter/ip_set_iptree.c:141: error: `timeout' undeclared (first use in this function) make[4]: *** [net/ipv4/netfilter/ip_set_iptree.o] Error 1 Regards.