diff options
Diffstat (limited to 'net/core/net_namespace.c')
| -rw-r--r-- | net/core/net_namespace.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 7b660834a4c2..72b4c184dd84 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -5,7 +5,9 @@ #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 @@ -20,6 +22,8 @@ LIST_HEAD(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. */ @@ -28,9 +32,22 @@ static __net_init int setup_net(struct net *net) /* Must be called with net_mutex held */ struct pernet_operations *ops; int error; + struct net_generic *ng; 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; + INIT_RCU_HEAD(&ng->rcu); + rcu_assign_pointer(net->gen, ng); error = 0; list_for_each_entry(ops, &pernet_list, list) { @@ -53,6 +70,7 @@ out_undo: } rcu_barrier(); + kfree(ng); goto out; } @@ -70,11 +88,13 @@ 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 kmem_cache_free(net_cachep, net); } @@ -253,6 +273,8 @@ static void unregister_pernet_operations(struct pernet_operations *ops) } #endif +static DEFINE_IDA(net_generic_ids); + /** * register_pernet_subsys - register a network namespace subsystem * @ops: pernet operations structure for the subsystem @@ -330,6 +352,30 @@ int register_pernet_device(struct pernet_operations *ops) } 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 @@ -348,3 +394,61 @@ void unregister_pernet_device(struct pernet_operations *ops) 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; + INIT_RCU_HEAD(&ng->rcu); + 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); |