when packet comes into PREROUTING HOOK , at the first conntrack module handle it. At this point, ip_conntrack_in() function handle it , finding protocol , finding former relative connection in conntrack hash table using resolve_normal_ct() function. What I ask like this How the related packet which is answerd by resolve_normal_ct() in PREROUTING HOOK pass through the filter module in FORWARD HOOK? i wanna know about mechanism in ip_conntrack_ftp.c but, When Helper module register new connection track table entry properly after finding data session requesting pattern , How expected packet related in ftp data session go though iptable in FORWARD HOOK ? if iptable in FORWARD HOOK only commit the packet which is relate in ftp control session.. newbie .Seo ..
