#include <linux/list.h>
#include <linux/delay.h>
#include <linux/sched.h>
+#include <linux/idr.h>
#include <net/net_namespace.h>
+#include <net/netns/generic.h>
/*
* Our network namespace constructor/destructor lists
static DEFINE_MUTEX(net_mutex);
LIST_HEAD(net_namespace_list);
+EXPORT_SYMBOL_GPL(net_namespace_list);
struct net init_net;
EXPORT_SYMBOL(init_net);
+#define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */
+
/*
* setup_net runs the initializers for the network namespace object.
*/
{
/* Must be called with net_mutex held */
struct pernet_operations *ops;
- int error;
+ int error = 0;
atomic_set(&net->count, 1);
+
+#ifdef NETNS_REFCNT_DEBUG
atomic_set(&net->use_count, 0);
+#endif
- error = 0;
list_for_each_entry(ops, &pernet_list, list) {
if (ops->init) {
error = ops->init(net);
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",
atomic_read(&net->use_count));
return;
}
-
+#endif
+ kfree(net->gen);
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(&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)
static int __init net_ns_init(void)
{
+ struct net_generic *ng;
int err;
printk(KERN_INFO "net_namespace: %zd bytes\n", sizeof(struct net));
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);
}
#endif
+static DEFINE_IDA(net_generic_ids);
+
/**
* register_pernet_subsys - register a network namespace subsystem
* @ops: pernet operations structure for the subsystem
}
EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
+int register_pernet_gen_subsys(int *id, struct pernet_operations *ops)
+{
+ int rv;
+
+ mutex_lock(&net_mutex);
+again:
+ rv = ida_get_new_above(&net_generic_ids, 1, id);
+ if (rv < 0) {
+ if (rv == -EAGAIN) {
+ ida_pre_get(&net_generic_ids, GFP_KERNEL);
+ goto again;
+ }
+ goto out;
+ }
+ rv = register_pernet_operations(first_device, ops);
+ if (rv < 0)
+ ida_remove(&net_generic_ids, *id);
+out:
+ mutex_unlock(&net_mutex);
+ return rv;
+}
+EXPORT_SYMBOL_GPL(register_pernet_gen_subsys);
+
+void unregister_pernet_gen_subsys(int id, struct pernet_operations *ops)
+{
+ mutex_lock(&net_mutex);
+ unregister_pernet_operations(ops);
+ ida_remove(&net_generic_ids, id);
+ mutex_unlock(&net_mutex);
+}
+EXPORT_SYMBOL_GPL(unregister_pernet_gen_subsys);
+
/**
* register_pernet_device - register a network namespace device
* @ops: pernet operations structure for the subsystem
}
EXPORT_SYMBOL_GPL(register_pernet_device);
+int register_pernet_gen_device(int *id, struct pernet_operations *ops)
+{
+ int error;
+ mutex_lock(&net_mutex);
+again:
+ error = ida_get_new_above(&net_generic_ids, 1, id);
+ if (error) {
+ if (error == -EAGAIN) {
+ ida_pre_get(&net_generic_ids, GFP_KERNEL);
+ goto again;
+ }
+ goto out;
+ }
+ error = register_pernet_operations(&pernet_list, ops);
+ if (error)
+ ida_remove(&net_generic_ids, *id);
+ else if (first_device == &pernet_list)
+ first_device = &ops->list;
+out:
+ mutex_unlock(&net_mutex);
+ return error;
+}
+EXPORT_SYMBOL_GPL(register_pernet_gen_device);
+
/**
* unregister_pernet_device - unregister a network namespace netdevice
* @ops: pernet operations structure to manipulate
mutex_unlock(&net_mutex);
}
EXPORT_SYMBOL_GPL(unregister_pernet_device);
+
+void unregister_pernet_gen_device(int id, struct pernet_operations *ops)
+{
+ mutex_lock(&net_mutex);
+ if (&ops->list == first_device)
+ first_device = first_device->next;
+ unregister_pernet_operations(ops);
+ ida_remove(&net_generic_ids, id);
+ mutex_unlock(&net_mutex);
+}
+EXPORT_SYMBOL_GPL(unregister_pernet_gen_device);
+
+static void net_generic_release(struct rcu_head *rcu)
+{
+ struct net_generic *ng;
+
+ ng = container_of(rcu, struct net_generic, rcu);
+ kfree(ng);
+}
+
+int net_assign_generic(struct net *net, int id, void *data)
+{
+ struct net_generic *ng, *old_ng;
+
+ BUG_ON(!mutex_is_locked(&net_mutex));
+ BUG_ON(id == 0);
+
+ ng = old_ng = net->gen;
+ if (old_ng->len >= id)
+ goto assign;
+
+ ng = kzalloc(sizeof(struct net_generic) +
+ id * sizeof(void *), GFP_KERNEL);
+ if (ng == NULL)
+ return -ENOMEM;
+
+ /*
+ * Some synchronisation notes:
+ *
+ * The net_generic explores the net->gen array inside rcu
+ * read section. Besides once set the net->gen->ptr[x]
+ * pointer never changes (see rules in netns/generic.h).
+ *
+ * That said, we simply duplicate this array and schedule
+ * the old copy for kfree after a grace period.
+ */
+
+ ng->len = id;
+ memcpy(&ng->ptr, &old_ng->ptr, old_ng->len);
+
+ rcu_assign_pointer(net->gen, ng);
+ call_rcu(&old_ng->rcu, net_generic_release);
+assign:
+ ng->ptr[id - 1] = data;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(net_assign_generic);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff