293 lines
7.0 KiB
C
293 lines
7.0 KiB
C
#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 <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);
|
|
|
|
static DEFINE_MUTEX(net_list_mutex);
|
|
LIST_HEAD(net_namespace_list);
|
|
|
|
static struct kmem_cache *net_cachep;
|
|
|
|
struct net init_net;
|
|
EXPORT_SYMBOL_GPL(init_net);
|
|
|
|
void net_lock(void)
|
|
{
|
|
mutex_lock(&net_list_mutex);
|
|
}
|
|
|
|
void net_unlock(void)
|
|
{
|
|
mutex_unlock(&net_list_mutex);
|
|
}
|
|
|
|
static struct net *net_alloc(void)
|
|
{
|
|
return kmem_cache_alloc(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 list_head *ptr;
|
|
struct net *net;
|
|
|
|
net = container_of(work, struct net, work);
|
|
|
|
mutex_lock(&net_mutex);
|
|
|
|
/* Don't let anyone else find us. */
|
|
net_lock();
|
|
list_del(&net->list);
|
|
net_unlock();
|
|
|
|
/* Run all of the network namespace exit methods */
|
|
list_for_each_prev(ptr, &pernet_list) {
|
|
ops = list_entry(ptr, struct pernet_operations, 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;
|
|
struct list_head *ptr;
|
|
int error;
|
|
|
|
memset(net, 0, sizeof(struct net));
|
|
atomic_set(&net->count, 1);
|
|
atomic_set(&net->use_count, 0);
|
|
|
|
error = 0;
|
|
list_for_each(ptr, &pernet_list) {
|
|
ops = list_entry(ptr, struct pernet_operations, 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.
|
|
*/
|
|
for (ptr = ptr->prev; ptr != &pernet_list; ptr = ptr->prev) {
|
|
ops = list_entry(ptr, struct pernet_operations, list);
|
|
if (ops->exit)
|
|
ops->exit(net);
|
|
}
|
|
goto out;
|
|
}
|
|
|
|
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);
|
|
|
|
net_lock();
|
|
list_add_tail(&init_net.list, &net_namespace_list);
|
|
net_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);
|