Subject: Re: net/netfilter/nf_conntrack_proto_tcp.c:1606:9: error: ‘struct nf_proto_net’ has no member named ‘user’

From: Gao feng <[email-masked]>
Date: Wed, 13 Jun 2012 16:51:03 +0800

于 2012年06月13日 00:03, Pablo Neira Ayuso 写道:
> Still, we have that pn->users thing:
> 
>         if (!pn->users++) {
>                 for (i = 0; i < TCP_CONNTRACK_TIMEOUT_MAX; i++)
>                         tn->timeouts[i] = tcp_timeouts[i];
> 
>                 tn->tcp_loose = nf_ct_tcp_loose;
>                 tn->tcp_be_liberal = nf_ct_tcp_be_liberal;
>                 tn->tcp_max_retrans = nf_ct_tcp_max_retrans;
>         }
> 
> Define some pn->initialized boolean. Set it to true at the end of
> the new tcp_init_net.

It should not be boolean,because We don't know what's the right time to set it false.
Just like nf_conntrack_l4proto_tcp(4,6), they both use nf_tcp_net,we can set it false
only when tcp4 and tcp6 are unregistered, so we need a referenct count here to point
out if one proto has initialied the nf_tcp_net, or if there are no protos use nf_tcp_net.

Though it maybe confusing,we can regard it as the reference count of nf_proto_net(how
many protos are using nf_proto_net), and this reference count is increased when
l4proto being registered success(no matter sysctl is enabled or disabled).