#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/idr.h>
+#include <linux/rculist.h>
+#include <linux/nsproxy.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
kmem_cache_free(net_cachep, net);
}
-struct net *copy_net_ns(unsigned long flags, struct net *old_net)
+static struct net *net_create(void)
{
- struct net *new_net = NULL;
- int err;
-
- if (!(flags & CLONE_NEWNET))
- return get_net(old_net);
-
- err = -ENOMEM;
- new_net = net_alloc();
- if (!new_net)
- goto out_err;
+ struct net *net;
+ int rv;
+ net = net_alloc();
+ if (!net)
+ return ERR_PTR(-ENOMEM);
mutex_lock(&net_mutex);
- err = setup_net(new_net);
- if (!err) {
+ rv = setup_net(net);
+ if (rv == 0) {
rtnl_lock();
- list_add_tail(&new_net->list, &net_namespace_list);
+ list_add_tail_rcu(&net->list, &net_namespace_list);
rtnl_unlock();
}
mutex_unlock(&net_mutex);
+ if (rv < 0) {
+ net_free(net);
+ return ERR_PTR(rv);
+ }
+ return net;
+}
- if (err)
- goto out_free;
-out:
- return new_net;
-
-out_free:
- net_free(new_net);
-out_err:
- new_net = ERR_PTR(err);
- goto out;
+struct net *copy_net_ns(unsigned long flags, struct net *old_net)
+{
+ if (!(flags & CLONE_NEWNET))
+ return get_net(old_net);
+ return net_create();
}
static void cleanup_net(struct work_struct *work)
/* Don't let anyone else find us. */
rtnl_lock();
- list_del(&net->list);
+ list_del_rcu(&net->list);
rtnl_unlock();
+ /*
+ * Another CPU might be rcu-iterating the list, wait for it.
+ * This needs to be before calling the exit() notifiers, so
+ * the rcu_barrier() below isn't sufficient alone.
+ */
+ synchronize_rcu();
+
/* Run all of the network namespace exit methods */
list_for_each_entry_reverse(ops, &pernet_list, list) {
if (ops->exit)
}
#endif
+struct net *get_net_ns_by_pid(pid_t pid)
+{
+ struct task_struct *tsk;
+ struct net *net;
+
+ /* Lookup the network namespace */
+ net = ERR_PTR(-ESRCH);
+ rcu_read_lock();
+ tsk = find_task_by_vpid(pid);
+ if (tsk) {
+ struct nsproxy *nsproxy;
+ nsproxy = task_nsproxy(tsk);
+ if (nsproxy)
+ net = get_net(nsproxy->net_ns);
+ }
+ rcu_read_unlock();
+ return net;
+}
+EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
+
static int __init net_ns_init(void)
{
struct net_generic *ng;
- int err;
- printk(KERN_INFO "net_namespace: %zd bytes\n", sizeof(struct net));
#ifdef CONFIG_NET_NS
net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
SMP_CACHE_BYTES,
rcu_assign_pointer(init_net.gen, ng);
mutex_lock(&net_mutex);
- err = setup_net(&init_net);
+ if (setup_net(&init_net))
+ panic("Could not setup the initial network namespace");
rtnl_lock();
- list_add_tail(&init_net.list, &net_namespace_list);
+ list_add_tail_rcu(&init_net.list, &net_namespace_list);
rtnl_unlock();
mutex_unlock(&net_mutex);
- if (err)
- panic("Could not setup the initial network namespace");
return 0;
}