#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>
{
/* Must be called with net_mutex held */
struct pernet_operations *ops;
- int error;
- struct net_generic *ng;
+ int error = 0;
atomic_set(&net->count, 1);
+
#ifdef NETNS_REFCNT_DEBUG
atomic_set(&net->use_count, 0);
#endif
- error = -ENOMEM;
- ng = kzalloc(sizeof(struct net_generic) +
- INITIAL_NET_GEN_PTRS * sizeof(void *), GFP_KERNEL);
- if (ng == NULL)
- goto out;
-
- ng->len = INITIAL_NET_GEN_PTRS;
- rcu_assign_pointer(net->gen, ng);
-
- error = 0;
list_for_each_entry(ops, &pernet_list, list) {
if (ops->init) {
error = ops->init(net);
}
rcu_barrier();
- kfree(ng);
goto out;
}
+static struct net_generic *net_alloc_generic(void)
+{
+ struct net_generic *ng;
+ size_t generic_size = sizeof(struct net_generic) +
+ INITIAL_NET_GEN_PTRS * sizeof(void *);
+
+ ng = kzalloc(generic_size, GFP_KERNEL);
+ if (ng)
+ ng->len = INITIAL_NET_GEN_PTRS;
+
+ return ng;
+}
+
#ifdef CONFIG_NET_NS
static struct kmem_cache *net_cachep;
static struct workqueue_struct *netns_wq;
static struct net *net_alloc(void)
{
- return kmem_cache_zalloc(net_cachep, GFP_KERNEL);
+ struct net *net = NULL;
+ struct net_generic *ng;
+
+ ng = net_alloc_generic();
+ if (!ng)
+ goto out;
+
+ net = kmem_cache_zalloc(net_cachep, GFP_KERNEL);
+ if (!net)
+ goto out_free;
+
+ rcu_assign_pointer(net->gen, ng);
+out:
+ return net;
+
+out_free:
+ kfree(ng);
+ goto out;
}
static void net_free(struct net *net)
{
- if (!net)
- return;
-
#ifdef NETNS_REFCNT_DEBUG
if (unlikely(atomic_read(&net->use_count) != 0)) {
printk(KERN_EMERG "network namespace not free! Usage: %d\n",
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;
-
- get_net(old_net);
-
- if (!(flags & CLONE_NEWNET))
- return old_net;
-
- err = -ENOMEM;
- new_net = net_alloc();
- if (!new_net)
- goto out;
+ 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)
- goto out_unlock;
-
- rtnl_lock();
- list_add_tail(&new_net->list, &net_namespace_list);
- rtnl_unlock();
-
-
-out_unlock:
+ rv = setup_net(net);
+ if (rv == 0) {
+ rtnl_lock();
+ list_add_tail_rcu(&net->list, &net_namespace_list);
+ rtnl_unlock();
+ }
mutex_unlock(&net_mutex);
-out:
- put_net(old_net);
- if (err) {
- net_free(new_net);
- new_net = ERR_PTR(err);
+ if (rv < 0) {
+ net_free(net);
+ return ERR_PTR(rv);
}
- return new_net;
+ return net;
+}
+
+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)
struct pernet_operations *ops;
struct net *net;
- /* Be very certain incoming network packets will not find us */
- rcu_barrier();
-
net = container_of(work, struct net, work);
mutex_lock(&net_mutex);
/* 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)
{
- int err;
+ struct net_generic *ng;
- 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,
panic("Could not create netns workq");
#endif
+ ng = net_alloc_generic();
+ if (!ng)
+ panic("Could not allocate generic netns");
+
+ 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;
}
rv = register_pernet_operations(first_device, ops);
if (rv < 0)
ida_remove(&net_generic_ids, *id);
- mutex_unlock(&net_mutex);
out:
+ mutex_unlock(&net_mutex);
return rv;
}
EXPORT_SYMBOL_GPL(register_pernet_gen_subsys);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff