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: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pavel Emelyanov 2008-05-19 13:45:33 -07:00 committed by David S. Miller
parent 5b06c85c3b
commit d62c612ef8
2 changed files with 33 additions and 0 deletions

View File

@ -201,8 +201,11 @@ extern void unregister_pernet_gen_device(int id, struct pernet_operations *);
struct ctl_path; struct ctl_path;
struct ctl_table; struct ctl_table;
struct ctl_table_header; struct ctl_table_header;
extern struct ctl_table_header *register_net_sysctl_table(struct net *net, extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
const struct ctl_path *path, struct ctl_table *table); 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); extern void unregister_net_sysctl_table(struct ctl_table_header *header);
#endif /* __NET_NET_NAMESPACE_H */ #endif /* __NET_NET_NAMESPACE_H */

View File

@ -40,6 +40,27 @@ static struct ctl_table_root net_sysctl_root = {
.lookup = net_ctl_header_lookup, .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) static int sysctl_net_init(struct net *net)
{ {
INIT_LIST_HEAD(&net->sysctl_table_headers); INIT_LIST_HEAD(&net->sysctl_table_headers);
@ -64,6 +85,7 @@ static __init int sysctl_init(void)
if (ret) if (ret)
goto out; goto out;
register_sysctl_root(&net_sysctl_root); register_sysctl_root(&net_sysctl_root);
register_sysctl_root(&net_sysctl_ro_root);
out: out:
return ret; return ret;
} }
@ -80,6 +102,14 @@ struct ctl_table_header *register_net_sysctl_table(struct net *net,
} }
EXPORT_SYMBOL_GPL(register_net_sysctl_table); 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) void unregister_net_sysctl_table(struct ctl_table_header *header)
{ {
unregister_sysctl_table(header); unregister_sysctl_table(header);