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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-11 19:40:14 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-11 19:40:14 -0700
commit038a5008b2f395c85e6e71d6ddf3c684e7c405b0 (patch)
tree4735eab577e97e5a22c3141e3f60071c8065585e /net/core/net_namespace.c
parentdd6d1844af33acb4edd0a40b1770d091a22c94be (diff)
parent266918303226cceac7eca38ced30f15f277bd89c (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (867 commits) [SKY2]: status polling loop (post merge) [NET]: Fix NAPI completion handling in some drivers. [TCP]: Limit processing lost_retrans loop to work-to-do cases [TCP]: Fix lost_retrans loop vs fastpath problems [TCP]: No need to re-count fackets_out/sacked_out at RTO [TCP]: Extract tcp_match_queue_to_sack from sacktag code [TCP]: Kill almost unused variable pcount from sacktag [TCP]: Fix mark_head_lost to ignore R-bit when trying to mark L [TCP]: Add bytes_acked (ABC) clearing to FRTO too [IPv6]: Update setsockopt(IPV6_MULTICAST_IF) to support RFC 3493, try2 [NETFILTER]: x_tables: add missing ip6t_modulename aliases [NETFILTER]: nf_conntrack_tcp: fix connection reopening [QETH]: fix qeth_main.c [NETLINK]: fib_frontend build fixes [IPv6]: Export userland ND options through netlink (RDNSS support) [9P]: build fix with !CONFIG_SYSCTL [NET]: Fix dev_put() and dev_hold() comments [NET]: make netlink user -> kernel interface synchronious [NET]: unify netlink kernel socket recognition [NET]: cleanup 3rd argument in netlink_sendskb ... Fix up conflicts manually in Documentation/feature-removal-schedule.txt and my new least favourite crap, the "mod_devicetable" support in the files include/linux/mod_devicetable.h and scripts/mod/file2alias.c. (The latter files seem to be explicitly _designed_ to get conflicts when different subsystems work with them - that have an absolutely horrid lack of subsystem separation!) Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'net/core/net_namespace.c')
-rw-r--r--net/core/net_namespace.c317
1 files changed, 317 insertions, 0 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
new file mode 100644
index 00000000000..6f71db8c442
--- /dev/null
+++ b/net/core/net_namespace.c
@@ -0,0 +1,317 @@
+#include <linux/workqueue.h>
+#include <linux/rtnetlink.h>
+#include <linux/cache.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <net/net_namespace.h>
+
+/*
+ * Our network namespace constructor/destructor lists
+ */
+
+static LIST_HEAD(pernet_list);
+static struct list_head *first_device = &pernet_list;
+static DEFINE_MUTEX(net_mutex);
+
+LIST_HEAD(net_namespace_list);
+
+static struct kmem_cache *net_cachep;
+
+struct net init_net;
+EXPORT_SYMBOL_GPL(init_net);
+
+static struct net *net_alloc(void)
+{
+ return kmem_cache_zalloc(net_cachep, GFP_KERNEL);
+}
+
+static void net_free(struct net *net)
+{
+ if (!net)
+ return;
+
+ if (unlikely(atomic_read(&net->use_count) != 0)) {
+ printk(KERN_EMERG "network namespace not free! Usage: %d\n",
+ atomic_read(&net->use_count));
+ return;
+ }
+
+ kmem_cache_free(net_cachep, net);
+}
+
+static void cleanup_net(struct work_struct *work)
+{
+ struct pernet_operations *ops;
+ struct net *net;
+
+ net = container_of(work, struct net, work);
+
+ mutex_lock(&net_mutex);
+
+ /* Don't let anyone else find us. */
+ rtnl_lock();
+ list_del(&net->list);
+ rtnl_unlock();
+
+ /* Run all of the network namespace exit methods */
+ list_for_each_entry_reverse(ops, &pernet_list, list) {
+ if (ops->exit)
+ ops->exit(net);
+ }
+
+ mutex_unlock(&net_mutex);
+
+ /* Ensure there are no outstanding rcu callbacks using this
+ * network namespace.
+ */
+ rcu_barrier();
+
+ /* Finally it is safe to free my network namespace structure */
+ net_free(net);
+}
+
+
+void __put_net(struct net *net)
+{
+ /* Cleanup the network namespace in process context */
+ INIT_WORK(&net->work, cleanup_net);
+ schedule_work(&net->work);
+}
+EXPORT_SYMBOL_GPL(__put_net);
+
+/*
+ * setup_net runs the initializers for the network namespace object.
+ */
+static int setup_net(struct net *net)
+{
+ /* Must be called with net_mutex held */
+ struct pernet_operations *ops;
+ int error;
+
+ atomic_set(&net->count, 1);
+ atomic_set(&net->use_count, 0);
+
+ error = 0;
+ list_for_each_entry(ops, &pernet_list, list) {
+ if (ops->init) {
+ error = ops->init(net);
+ if (error < 0)
+ goto out_undo;
+ }
+ }
+out:
+ return error;
+
+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);
+ }
+ goto out;
+}
+
+struct net *copy_net_ns(unsigned long flags, struct net *old_net)
+{
+ struct net *new_net = NULL;
+ int err;
+
+ get_net(old_net);
+
+ if (!(flags & CLONE_NEWNET))
+ return old_net;
+
+#ifndef CONFIG_NET_NS
+ return ERR_PTR(-EINVAL);
+#endif
+
+ err = -ENOMEM;
+ new_net = net_alloc();
+ if (!new_net)
+ goto out;
+
+ 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:
+ mutex_unlock(&net_mutex);
+out:
+ put_net(old_net);
+ if (err) {
+ net_free(new_net);
+ new_net = ERR_PTR(err);
+ }
+ return new_net;
+}
+
+static int __init net_ns_init(void)
+{
+ int err;
+
+ printk(KERN_INFO "net_namespace: %zd bytes\n", sizeof(struct net));
+ net_cachep = kmem_cache_create("net_namespace", sizeof(struct net),
+ SMP_CACHE_BYTES,
+ SLAB_PANIC, NULL);
+ mutex_lock(&net_mutex);
+ err = setup_net(&init_net);
+
+ rtnl_lock();
+ list_add_tail(&init_net.list, &net_namespace_list);
+ rtnl_unlock();
+
+ mutex_unlock(&net_mutex);
+ if (err)
+ panic("Could not setup the initial network namespace");
+
+ return 0;
+}
+
+pure_initcall(net_ns_init);
+
+static int register_pernet_operations(struct list_head *list,
+ struct pernet_operations *ops)
+{
+ struct net *net, *undo_net;
+ int error;
+
+ error = 0;
+ list_add_tail(&ops->list, list);
+ for_each_net(net) {
+ if (ops->init) {
+ error = ops->init(net);
+ if (error)
+ goto out_undo;
+ }
+ }
+out:
+ return error;
+
+out_undo:
+ /* If I have an error cleanup all namespaces I initialized */
+ list_del(&ops->list);
+ for_each_net(undo_net) {
+ if (undo_net == net)
+ goto undone;
+ if (ops->exit)
+ ops->exit(undo_net);
+ }
+undone:
+ goto out;
+}
+
+static void unregister_pernet_operations(struct pernet_operations *ops)
+{
+ struct net *net;
+
+ list_del(&ops->list);
+ for_each_net(net)
+ if (ops->exit)
+ ops->exit(net);
+}
+
+/**
+ * register_pernet_subsys - register a network namespace subsystem
+ * @ops: pernet operations structure for the subsystem
+ *
+ * Register a subsystem which has init and exit functions
+ * that are called when network namespaces are created and
+ * destroyed respectively.
+ *
+ * When registered all network namespace init functions are
+ * called for every existing network namespace. Allowing kernel
+ * modules to have a race free view of the set of network namespaces.
+ *
+ * When a new network namespace is created all of the init
+ * methods are called in the order in which they were registered.
+ *
+ * When a network namespace is destroyed all of the exit methods
+ * are called in the reverse of the order with which they were
+ * registered.
+ */
+int register_pernet_subsys(struct pernet_operations *ops)
+{
+ int error;
+ mutex_lock(&net_mutex);
+ error = register_pernet_operations(first_device, ops);
+ mutex_unlock(&net_mutex);
+ return error;
+}
+EXPORT_SYMBOL_GPL(register_pernet_subsys);
+
+/**
+ * unregister_pernet_subsys - unregister a network namespace subsystem
+ * @ops: pernet operations structure to manipulate
+ *
+ * Remove the pernet operations structure from the list to be
+ * used when network namespaces are created or destoryed. In
+ * addition run the exit method for all existing network
+ * namespaces.
+ */
+void unregister_pernet_subsys(struct pernet_operations *module)
+{
+ mutex_lock(&net_mutex);
+ unregister_pernet_operations(module);
+ mutex_unlock(&net_mutex);
+}
+EXPORT_SYMBOL_GPL(unregister_pernet_subsys);
+
+/**
+ * register_pernet_device - register a network namespace device
+ * @ops: pernet operations structure for the subsystem
+ *
+ * Register a device which has init and exit functions
+ * that are called when network namespaces are created and
+ * destroyed respectively.
+ *
+ * When registered all network namespace init functions are
+ * called for every existing network namespace. Allowing kernel
+ * modules to have a race free view of the set of network namespaces.
+ *
+ * When a new network namespace is created all of the init
+ * methods are called in the order in which they were registered.
+ *
+ * When a network namespace is destroyed all of the exit methods
+ * are called in the reverse of the order with which they were
+ * registered.
+ */
+int register_pernet_device(struct pernet_operations *ops)
+{
+ int error;
+ mutex_lock(&net_mutex);
+ error = register_pernet_operations(&pernet_list, ops);
+ if (!error && (first_device == &pernet_list))
+ first_device = &ops->list;
+ mutex_unlock(&net_mutex);
+ return error;
+}
+EXPORT_SYMBOL_GPL(register_pernet_device);
+
+/**
+ * unregister_pernet_device - unregister a network namespace netdevice
+ * @ops: pernet operations structure to manipulate
+ *
+ * Remove the pernet operations structure from the list to be
+ * used when network namespaces are created or destoryed. In
+ * addition run the exit method for all existing network
+ * namespaces.
+ */
+void unregister_pernet_device(struct pernet_operations *ops)
+{
+ mutex_lock(&net_mutex);
+ if (&ops->list == first_device)
+ first_device = first_device->next;
+ unregister_pernet_operations(ops);
+ mutex_unlock(&net_mutex);
+}
+EXPORT_SYMBOL_GPL(unregister_pernet_device);