[NET]: Implement the per network namespace sysctl infrastructure
The user interface is: register_net_sysctl_table and
unregister_net_sysctl_table. Very much like the current
interface except there is a network namespace parameter.
With this any sysctl registered with register_net_sysctl_table
will only show up to tasks in the same network namespace.
All other sysctls continue to be globally visible.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Daniel Lezcano <dlezcano@fr.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sysctl_net.c b/net/sysctl_net.c
index cd4eafb..c50c793 100644
--- a/net/sysctl_net.c
+++ b/net/sysctl_net.c
@@ -14,6 +14,7 @@
#include <linux/mm.h>
#include <linux/sysctl.h>
+#include <linux/nsproxy.h>
#include <net/sock.h>
@@ -54,3 +55,59 @@
#endif
{ 0 },
};
+
+static struct list_head *
+net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces)
+{
+ return &namespaces->net_ns->sysctl_table_headers;
+}
+
+static struct ctl_table_root net_sysctl_root = {
+ .lookup = net_ctl_header_lookup,
+};
+
+static int sysctl_net_init(struct net *net)
+{
+ INIT_LIST_HEAD(&net->sysctl_table_headers);
+ return 0;
+}
+
+static void sysctl_net_exit(struct net *net)
+{
+ WARN_ON(!list_empty(&net->sysctl_table_headers));
+ return;
+}
+
+static struct pernet_operations sysctl_pernet_ops = {
+ .init = sysctl_net_init,
+ .exit = sysctl_net_exit,
+};
+
+static __init int sysctl_init(void)
+{
+ int ret;
+ ret = register_pernet_subsys(&sysctl_pernet_ops);
+ if (ret)
+ goto out;
+ register_sysctl_root(&net_sysctl_root);
+out:
+ return ret;
+}
+subsys_initcall(sysctl_init);
+
+struct ctl_table_header *register_net_sysctl_table(struct net *net,
+ const struct ctl_path *path, struct ctl_table *table)
+{
+ struct nsproxy namespaces;
+ namespaces = *current->nsproxy;
+ namespaces.net_ns = net;
+ return __register_sysctl_paths(&net_sysctl_root,
+ &namespaces, path, table);
+}
+EXPORT_SYMBOL_GPL(register_net_sysctl_table);
+
+void unregister_net_sysctl_table(struct ctl_table_header *header)
+{
+ return unregister_sysctl_table(header);
+}
+EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);
