Subject: Re: [PATCH 04/17] netfilter: add namespace support for l4proto_generic

From: Pablo Neira Ayuso <[email-masked]>
Date: Wed, 23 May 2012 12:32:32 +0200

On Mon, May 14, 2012 at 04:52:14PM +0800, Gao feng wrote:
> implement and export nf_conntrack_proto_generic_[init,fini],
> nf_conntrack_[init,cleanup]_net call them to register or unregister
> the sysctl of generic proto.
> 
> implement generic_net_init,it's used to initial the pernet
> data for generic proto.
> 
> and use nf_generic_net.timeout to replace nf_ct_generic_timeout in
> get_timeouts function.
> 
> Acked-by: Eric W. Biederman <[email-masked]>
> Signed-off-by: Gao feng <[email-masked]>
> ---
>  include/net/netfilter/nf_conntrack_l4proto.h |    2 +
>  include/net/netns/conntrack.h                |    6 +++
>  net/netfilter/nf_conntrack_core.c            |    8 +++-
>  net/netfilter/nf_conntrack_proto.c           |   21 +++++-----
>  net/netfilter/nf_conntrack_proto_generic.c   |   55 ++++++++++++++++++++++++-
>  5 files changed, 76 insertions(+), 16 deletions(-)
> 
> diff --git a/include/net/netfilter/nf_conntrack_l4proto.h b/include/net/netfilter/nf_conntrack_l4proto.h
> index a93dcd5..0d329b9 100644
> --- a/include/net/netfilter/nf_conntrack_l4proto.h
> +++ b/include/net/netfilter/nf_conntrack_l4proto.h
> @@ -118,6 +118,8 @@ struct nf_conntrack_l4proto {
>  
>  /* Existing built-in generic protocol */
>  extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
> +extern int nf_conntrack_proto_generic_init(struct net *net);
> +extern void nf_conntrack_proto_generic_fini(struct net *net);
>  
>  #define MAX_NF_CT_PROTO 256
>  
> diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h
> index 94992e9..3381b80 100644
> --- a/include/net/netns/conntrack.h
> +++ b/include/net/netns/conntrack.h
> @@ -20,7 +20,13 @@ struct nf_proto_net {
>  	unsigned int		users;
>  };
>  
> +struct nf_generic_net {
> +	struct nf_proto_net pn;
> +	unsigned int timeout;
> +};
> +
>  struct nf_ip_net {
> +	struct nf_generic_net   generic;
>  #if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
>  	struct ctl_table_header *ctl_table_header;
>  	struct ctl_table	*ctl_table;
> diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
> index 32c5909..fd33e91 100644
> --- a/net/netfilter/nf_conntrack_core.c
> +++ b/net/netfilter/nf_conntrack_core.c
> @@ -1353,6 +1353,7 @@ static void nf_conntrack_cleanup_net(struct net *net)
>  	}
>  
>  	nf_ct_free_hashtable(net->ct.hash, net->ct.htable_size);
> +	nf_conntrack_proto_generic_fini(net);
>  	nf_conntrack_helper_fini(net);
>  	nf_conntrack_timeout_fini(net);
>  	nf_conntrack_ecache_fini(net);
> @@ -1586,9 +1587,12 @@ static int nf_conntrack_init_net(struct net *net)
>  	ret = nf_conntrack_helper_init(net);
>  	if (ret < 0)
>  		goto err_helper;
> -
> +	ret = nf_conntrack_proto_generic_init(net);
> +	if (ret < 0)
> +		goto err_generic;
>  	return 0;
> -
> +err_generic:
> +	nf_conntrack_helper_fini(net);
>  err_helper:
>  	nf_conntrack_timeout_fini(net);
>  err_timeout:
> diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c
> index 7ee6653..9b4bf6d 100644
> --- a/net/netfilter/nf_conntrack_proto.c
> +++ b/net/netfilter/nf_conntrack_proto.c
> @@ -287,10 +287,16 @@ EXPORT_SYMBOL_GPL(nf_conntrack_l3proto_unregister);
>  static struct nf_proto_net *nf_ct_l4proto_net(struct net *net,
>  					      struct nf_conntrack_l4proto *l4proto)
>  {
> -	if (l4proto->net_id)
> -		return net_generic(net, *l4proto->net_id);
> -	else
> -		return NULL;
> +	switch (l4proto->l4proto) {
> +	case 255: /* l4proto_generic */
> +		return (struct nf_proto_net *)&net->ct.proto.generic;
> +	default:
> +		if (l4proto->net_id)
> +			return net_generic(net, *l4proto->net_id);
> +		else
> +			return NULL;
> +	}
> +	return NULL;
>  }
>  
>  int nf_ct_l4proto_register_sysctl(struct net *net,
> @@ -457,11 +463,6 @@ EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_unregister);
>  int nf_conntrack_proto_init(void)
>  {
>  	unsigned int i;
> -	int err;
> -
> -	err = nf_ct_l4proto_register_sysctl(&init_net, &nf_conntrack_l4proto_generic);
> -	if (err < 0)
> -		return err;

I like that all protocols sysctl are registered by
nf_conntrack_proto_init. Can you keep using that?

>  	for (i = 0; i < AF_MAX; i++)
>  		rcu_assign_pointer(nf_ct_l3protos[i],
> @@ -473,8 +474,6 @@ void nf_conntrack_proto_fini(void)
>  {
>  	unsigned int i;
>  
> -	nf_ct_l4proto_unregister_sysctl(&init_net, &nf_conntrack_l4proto_generic);
> -
>  	/* free l3proto protocol tables */
>  	for (i = 0; i < PF_MAX; i++)
>  		kfree(nf_ct_protos[i]);
> diff --git a/net/netfilter/nf_conntrack_proto_generic.c b/net/netfilter/nf_conntrack_proto_generic.c
> index d8923d5..7976a64 100644
> --- a/net/netfilter/nf_conntrack_proto_generic.c
> +++ b/net/netfilter/nf_conntrack_proto_generic.c
> @@ -14,6 +14,11 @@
>  
>  static unsigned int nf_ct_generic_timeout __read_mostly = 600*HZ;
>  
> +static inline struct nf_generic_net *generic_pernet(struct net *net)
> +{
> +	return &net->ct.proto.generic;
> +}
> +
>  static bool generic_pkt_to_tuple(const struct sk_buff *skb,
>  				 unsigned int dataoff,
>  				 struct nf_conntrack_tuple *tuple)
> @@ -42,7 +47,7 @@ static int generic_print_tuple(struct seq_file *s,
>  
>  static unsigned int *generic_get_timeouts(struct net *net)
>  {
> -	return &nf_ct_generic_timeout;
> +	return &(generic_pernet(net)->timeout);
>  }
>  
>  /* Returns verdict for packet, or -1 for invalid. */
> @@ -110,7 +115,6 @@ static struct ctl_table_header *generic_sysctl_header;
>  static struct ctl_table generic_sysctl_table[] = {
>  	{
>  		.procname	= "nf_conntrack_generic_timeout",
> -		.data		= &nf_ct_generic_timeout,
>  		.maxlen		= sizeof(unsigned int),
>  		.mode		= 0644,
>  		.proc_handler	= proc_dointvec_jiffies,
> @@ -121,7 +125,6 @@ static struct ctl_table generic_sysctl_table[] = {
>  static struct ctl_table generic_compat_sysctl_table[] = {
>  	{
>  		.procname	= "ip_conntrack_generic_timeout",
> -		.data		= &nf_ct_generic_timeout,
>  		.maxlen		= sizeof(unsigned int),
>  		.mode		= 0644,
>  		.proc_handler	= proc_dointvec_jiffies,
> @@ -131,10 +134,39 @@ static struct ctl_table generic_compat_sysctl_table[] = {
>  #endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
>  #endif /* CONFIG_SYSCTL */
>  
> +static int generic_init_net(struct net *net, u_int8_t compat)
> +{
> +	struct nf_generic_net *gn = generic_pernet(net);
> +	struct nf_proto_net *pn = (struct nf_proto_net *)gn;
> +	gn->timeout = nf_ct_generic_timeout;
> +#ifdef CONFIG_SYSCTL
> +	pn->ctl_table = kmemdup(generic_sysctl_table,
> +				sizeof(generic_sysctl_table),
> +				GFP_KERNEL);
> +	if (!pn->ctl_table)
> +		return -ENOMEM;
> +	pn->ctl_table[0].data = &gn->timeout;
> +
> +#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
> +	pn->ctl_compat_table = kmemdup(generic_compat_sysctl_table,
> +				       sizeof(generic_compat_sysctl_table),
> +				       GFP_KERNEL);
> +	if (!pn->ctl_compat_table) {
> +		kfree(pn->ctl_table);
> +		pn->ctl_table = NULL;
> +		return -ENOMEM;
> +	}
> +	pn->ctl_compat_table[0].data = &gn->timeout;
> +#endif
> +#endif
> +	return 0;
> +}
> +
>  struct nf_conntrack_l4proto nf_conntrack_l4proto_generic __read_mostly =
>  {
>  	.l3proto		= PF_UNSPEC,
>  	.l4proto		= 255,
> +	.compat			= 1,
>  	.name			= "unknown",
>  	.pkt_to_tuple		= generic_pkt_to_tuple,
>  	.invert_tuple		= generic_invert_tuple,
> @@ -158,4 +190,21 @@ struct nf_conntrack_l4proto nf_conntrack_l4proto_generic __read_mostly =
>  	.ctl_compat_table	= generic_compat_sysctl_table,
>  #endif
>  #endif
> +	.init_net		= generic_init_net,
>  };
> +
> +int nf_conntrack_proto_generic_init(struct net *net)
> +{
> +	int ret = 0;
> +	ret = generic_init_net(net, nf_conntrack_l4proto_generic.compat);
> +	if (ret < 0)
> +		return ret;
> +	return nf_ct_l4proto_register_sysctl(net,
> +					     &nf_conntrack_l4proto_generic);
> +}
> +
> +void nf_conntrack_proto_generic_fini(struct net *net)
> +{
> +	nf_ct_l4proto_unregister_sysctl(net,
> +					&nf_conntrack_l4proto_generic);
> +}
> -- 
> 1.7.7.6
>