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Commit d62c612e authored by Pavel Emelyanov's avatar Pavel Emelyanov Committed by David S. Miller
Browse files

netns: Introduce sysctl root for read-only net sysctls. 



This one stores all ctl-heads in one list and restricts the
permissions not give write access to non-init net namespaces.

Signed-off-by: default avatarPavel Emelyanov <xemul@openvz.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 5b06c85c

include/net/net_namespace.h

+3 −0
Original line number Diff line number Diff line
@@ -201,8 +201,11 @@ extern void unregister_pernet_gen_device(int id, struct pernet_operations *); 
struct ctl_path;

struct ctl_table;

struct ctl_table_header;



extern struct ctl_table_header *register_net_sysctl_table(struct net *net,

	const struct ctl_path *path, struct ctl_table *table);

extern struct ctl_table_header *register_net_sysctl_rotable(

	const struct ctl_path *path, struct ctl_table *table);

extern void unregister_net_sysctl_table(struct ctl_table_header *header);



#endif /* __NET_NET_NAMESPACE_H */

net/sysctl_net.c

+30 −0
Original line number Diff line number Diff line
@@ -40,6 +40,27 @@ static struct ctl_table_root net_sysctl_root = { 
	.lookup = net_ctl_header_lookup,

};



static LIST_HEAD(net_sysctl_ro_tables);

static struct list_head *net_ctl_ro_header_lookup(struct ctl_table_root *root,

		struct nsproxy *namespaces)

{

	return &net_sysctl_ro_tables;

}



static int net_ctl_ro_header_perms(struct ctl_table_root *root,

		struct nsproxy *namespaces, struct ctl_table *table)

{

	if (namespaces->net_ns == &init_net)

		return table->mode;

	else

		return table->mode & ~0222;

}



static struct ctl_table_root net_sysctl_ro_root = {

	.lookup = net_ctl_ro_header_lookup,

	.permissions = net_ctl_ro_header_perms,

};



static int sysctl_net_init(struct net *net)

{

	INIT_LIST_HEAD(&net->sysctl_table_headers);
@@ -64,6 +85,7 @@ static __init int sysctl_init(void) 
	if (ret)

		goto out;

	register_sysctl_root(&net_sysctl_root);

	register_sysctl_root(&net_sysctl_ro_root);

out:

	return ret;

}
@@ -80,6 +102,14 @@ struct ctl_table_header *register_net_sysctl_table(struct net *net, 
}

EXPORT_SYMBOL_GPL(register_net_sysctl_table);



struct ctl_table_header *register_net_sysctl_rotable(const

		struct ctl_path *path, struct ctl_table *table)

{

	return __register_sysctl_paths(&net_sysctl_ro_root,

			&init_nsproxy, path, table);

}

EXPORT_SYMBOL_GPL(register_net_sysctl_rotable);



void unregister_net_sysctl_table(struct ctl_table_header *header)

{

	unregister_sysctl_table(header);