gss_krb5: Introduce encryption type framework
[safe/jmp/linux-2.6] / net / core / net_namespace.c
index 4488010..bd8c471 100644 (file)
@@ -6,6 +6,8 @@
 #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>
 
@@ -25,14 +27,64 @@ EXPORT_SYMBOL(init_net);
 
 #define INITIAL_NET_GEN_PTRS   13 /* +1 for len +2 for rcu_head */
 
+static int ops_init(const struct pernet_operations *ops, struct net *net)
+{
+       int err;
+       if (ops->id && ops->size) {
+               void *data = kzalloc(ops->size, GFP_KERNEL);
+               if (!data)
+                       return -ENOMEM;
+
+               err = net_assign_generic(net, *ops->id, data);
+               if (err) {
+                       kfree(data);
+                       return err;
+               }
+       }
+       if (ops->init)
+               return ops->init(net);
+       return 0;
+}
+
+static void ops_free(const struct pernet_operations *ops, struct net *net)
+{
+       if (ops->id && ops->size) {
+               int id = *ops->id;
+               kfree(net_generic(net, id));
+       }
+}
+
+static void ops_exit_list(const struct pernet_operations *ops,
+                         struct list_head *net_exit_list)
+{
+       struct net *net;
+       if (ops->exit) {
+               list_for_each_entry(net, net_exit_list, exit_list)
+                       ops->exit(net);
+       }
+       if (ops->exit_batch)
+               ops->exit_batch(net_exit_list);
+}
+
+static void ops_free_list(const struct pernet_operations *ops,
+                         struct list_head *net_exit_list)
+{
+       struct net *net;
+       if (ops->size && ops->id) {
+               list_for_each_entry(net, net_exit_list, exit_list)
+                       ops_free(ops, net);
+       }
+}
+
 /*
  * setup_net runs the initializers for the network namespace object.
  */
 static __net_init int setup_net(struct net *net)
 {
        /* Must be called with net_mutex held */
-       struct pernet_operations *ops;
+       const struct pernet_operations *ops, *saved_ops;
        int error = 0;
+       LIST_HEAD(net_exit_list);
 
        atomic_set(&net->count, 1);
 
@@ -41,11 +93,9 @@ static __net_init int setup_net(struct net *net)
 #endif
 
        list_for_each_entry(ops, &pernet_list, list) {
-               if (ops->init) {
-                       error = ops->init(net);
-                       if (error < 0)
-                               goto out_undo;
-               }
+               error = ops_init(ops, net);
+               if (error < 0)
+                       goto out_undo;
        }
 out:
        return error;
@@ -54,10 +104,14 @@ out_undo:
        /* Walk through the list backwards calling the exit functions
         * for the pernet modules whose init functions did not fail.
         */
-       list_for_each_entry_continue_reverse(ops, &pernet_list, list) {
-               if (ops->exit)
-                       ops->exit(net);
-       }
+       list_add(&net->exit_list, &net_exit_list);
+       saved_ops = ops;
+       list_for_each_entry_continue_reverse(ops, &pernet_list, list)
+               ops_exit_list(ops, &net_exit_list);
+
+       ops = saved_ops;
+       list_for_each_entry_continue_reverse(ops, &pernet_list, list)
+               ops_free_list(ops, &net_exit_list);
 
        rcu_barrier();
        goto out;
@@ -115,59 +169,75 @@ static void net_free(struct net *net)
        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 DEFINE_SPINLOCK(cleanup_list_lock);
+static LIST_HEAD(cleanup_list);  /* Must hold cleanup_list_lock to touch */
+
 static void cleanup_net(struct work_struct *work)
 {
-       struct pernet_operations *ops;
-       struct net *net;
+       const struct pernet_operations *ops;
+       struct net *net, *tmp;
+       LIST_HEAD(net_kill_list);
+       LIST_HEAD(net_exit_list);
 
-       net = container_of(work, struct net, work);
+       /* Atomically snapshot the list of namespaces to cleanup */
+       spin_lock_irq(&cleanup_list_lock);
+       list_replace_init(&cleanup_list, &net_kill_list);
+       spin_unlock_irq(&cleanup_list_lock);
 
        mutex_lock(&net_mutex);
 
        /* Don't let anyone else find us. */
        rtnl_lock();
-       list_del(&net->list);
+       list_for_each_entry(net, &net_kill_list, cleanup_list) {
+               list_del_rcu(&net->list);
+               list_add_tail(&net->exit_list, &net_exit_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)
-                       ops->exit(net);
-       }
+       list_for_each_entry_reverse(ops, &pernet_list, list)
+               ops_exit_list(ops, &net_exit_list);
+
+       /* Free the net generic variables */
+       list_for_each_entry_reverse(ops, &pernet_list, list)
+               ops_free_list(ops, &net_exit_list);
 
        mutex_unlock(&net_mutex);
 
@@ -177,14 +247,23 @@ static void cleanup_net(struct work_struct *work)
        rcu_barrier();
 
        /* Finally it is safe to free my network namespace structure */
-       net_free(net);
+       list_for_each_entry_safe(net, tmp, &net_exit_list, exit_list) {
+               list_del_init(&net->exit_list);
+               net_free(net);
+       }
 }
+static DECLARE_WORK(net_cleanup_work, cleanup_net);
 
 void __put_net(struct net *net)
 {
        /* Cleanup the network namespace in process context */
-       INIT_WORK(&net->work, cleanup_net);
-       queue_work(netns_wq, &net->work);
+       unsigned long flags;
+
+       spin_lock_irqsave(&cleanup_list_lock, flags);
+       list_add(&net->cleanup_list, &cleanup_list);
+       spin_unlock_irqrestore(&cleanup_list_lock, flags);
+
+       queue_work(netns_wq, &net_cleanup_work);
 }
 EXPORT_SYMBOL_GPL(__put_net);
 
@@ -197,12 +276,30 @@ struct net *copy_net_ns(unsigned long flags, struct net *old_net)
 }
 #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,
@@ -221,15 +318,14 @@ static int __init net_ns_init(void)
        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;
 }
@@ -237,18 +333,20 @@ static int __init net_ns_init(void)
 pure_initcall(net_ns_init);
 
 #ifdef CONFIG_NET_NS
-static int register_pernet_operations(struct list_head *list,
-                                     struct pernet_operations *ops)
+static int __register_pernet_operations(struct list_head *list,
+                                       struct pernet_operations *ops)
 {
-       struct net *net, *undo_net;
+       struct net *net;
        int error;
+       LIST_HEAD(net_exit_list);
 
        list_add_tail(&ops->list, list);
-       if (ops->init) {
+       if (ops->init || (ops->id && ops->size)) {
                for_each_net(net) {
-                       error = ops->init(net);
+                       error = ops_init(ops, net);
                        if (error)
                                goto out_undo;
+                       list_add_tail(&net->exit_list, &net_exit_list);
                }
        }
        return 0;
@@ -256,45 +354,82 @@ static int register_pernet_operations(struct list_head *list,
 out_undo:
        /* If I have an error cleanup all namespaces I initialized */
        list_del(&ops->list);
-       if (ops->exit) {
-               for_each_net(undo_net) {
-                       if (undo_net == net)
-                               goto undone;
-                       ops->exit(undo_net);
-               }
-       }
-undone:
+       ops_exit_list(ops, &net_exit_list);
+       ops_free_list(ops, &net_exit_list);
        return error;
 }
 
-static void unregister_pernet_operations(struct pernet_operations *ops)
+static void __unregister_pernet_operations(struct pernet_operations *ops)
 {
        struct net *net;
+       LIST_HEAD(net_exit_list);
 
        list_del(&ops->list);
-       if (ops->exit)
-               for_each_net(net)
-                       ops->exit(net);
+       for_each_net(net)
+               list_add_tail(&net->exit_list, &net_exit_list);
+       ops_exit_list(ops, &net_exit_list);
+       ops_free_list(ops, &net_exit_list);
 }
 
 #else
 
+static int __register_pernet_operations(struct list_head *list,
+                                       struct pernet_operations *ops)
+{
+       int err = 0;
+       err = ops_init(ops, &init_net);
+       if (err)
+               ops_free(ops, &init_net);
+       return err;
+       
+}
+
+static void __unregister_pernet_operations(struct pernet_operations *ops)
+{
+       LIST_HEAD(net_exit_list);
+       list_add(&init_net.exit_list, &net_exit_list);
+       ops_exit_list(ops, &net_exit_list);
+       ops_free_list(ops, &net_exit_list);
+}
+
+#endif /* CONFIG_NET_NS */
+
+static DEFINE_IDA(net_generic_ids);
+
 static int register_pernet_operations(struct list_head *list,
                                      struct pernet_operations *ops)
 {
-       if (ops->init == NULL)
-               return 0;
-       return ops->init(&init_net);
+       int error;
+
+       if (ops->id) {
+again:
+               error = ida_get_new_above(&net_generic_ids, 1, ops->id);
+               if (error < 0) {
+                       if (error == -EAGAIN) {
+                               ida_pre_get(&net_generic_ids, GFP_KERNEL);
+                               goto again;
+                       }
+                       return error;
+               }
+       }
+       error = __register_pernet_operations(list, ops);
+       if (error) {
+               rcu_barrier();
+               if (ops->id)
+                       ida_remove(&net_generic_ids, *ops->id);
+       }
+
+       return error;
 }
 
 static void unregister_pernet_operations(struct pernet_operations *ops)
 {
-       if (ops->exit)
-               ops->exit(&init_net);
+       
+       __unregister_pernet_operations(ops);
+       rcu_barrier();
+       if (ops->id)
+               ida_remove(&net_generic_ids, *ops->id);
 }
-#endif
-
-static DEFINE_IDA(net_generic_ids);
 
 /**
  *      register_pernet_subsys - register a network namespace subsystem
@@ -342,38 +477,6 @@ void unregister_pernet_subsys(struct pernet_operations *module)
 }
 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
@@ -405,30 +508,6 @@ 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
@@ -448,17 +527,6 @@ void unregister_pernet_device(struct pernet_operations *ops)
 }
 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;
@@ -495,7 +563,7 @@ int net_assign_generic(struct net *net, int id, void *data)
         */
 
        ng->len = id;
-       memcpy(&ng->ptr, &old_ng->ptr, old_ng->len);
+       memcpy(&ng->ptr, &old_ng->ptr, old_ng->len * sizeof(void*));
 
        rcu_assign_pointer(net->gen, ng);
        call_rcu(&old_ng->rcu, net_generic_release);