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5f256bec EB |
1 | #include <linux/workqueue.h> |
2 | #include <linux/rtnetlink.h> | |
3 | #include <linux/cache.h> | |
4 | #include <linux/slab.h> | |
5 | #include <linux/list.h> | |
6 | #include <linux/delay.h> | |
9dd776b6 | 7 | #include <linux/sched.h> |
5f256bec EB |
8 | #include <net/net_namespace.h> |
9 | ||
10 | /* | |
11 | * Our network namespace constructor/destructor lists | |
12 | */ | |
13 | ||
14 | static LIST_HEAD(pernet_list); | |
15 | static struct list_head *first_device = &pernet_list; | |
16 | static DEFINE_MUTEX(net_mutex); | |
17 | ||
5f256bec EB |
18 | LIST_HEAD(net_namespace_list); |
19 | ||
5f256bec EB |
20 | struct net init_net; |
21 | EXPORT_SYMBOL_GPL(init_net); | |
22 | ||
5f256bec EB |
23 | /* |
24 | * setup_net runs the initializers for the network namespace object. | |
25 | */ | |
1a2ee93d | 26 | static __net_init int setup_net(struct net *net) |
5f256bec EB |
27 | { |
28 | /* Must be called with net_mutex held */ | |
29 | struct pernet_operations *ops; | |
5f256bec EB |
30 | int error; |
31 | ||
5f256bec EB |
32 | atomic_set(&net->count, 1); |
33 | atomic_set(&net->use_count, 0); | |
34 | ||
35 | error = 0; | |
768f3591 | 36 | list_for_each_entry(ops, &pernet_list, list) { |
5f256bec EB |
37 | if (ops->init) { |
38 | error = ops->init(net); | |
39 | if (error < 0) | |
40 | goto out_undo; | |
41 | } | |
42 | } | |
43 | out: | |
44 | return error; | |
768f3591 | 45 | |
5f256bec EB |
46 | out_undo: |
47 | /* Walk through the list backwards calling the exit functions | |
48 | * for the pernet modules whose init functions did not fail. | |
49 | */ | |
768f3591 | 50 | list_for_each_entry_continue_reverse(ops, &pernet_list, list) { |
5f256bec EB |
51 | if (ops->exit) |
52 | ops->exit(net); | |
53 | } | |
310928d9 DL |
54 | |
55 | rcu_barrier(); | |
5f256bec EB |
56 | goto out; |
57 | } | |
58 | ||
6a1a3b9f | 59 | #ifdef CONFIG_NET_NS |
d57a9212 PE |
60 | static struct kmem_cache *net_cachep; |
61 | ||
6a1a3b9f PE |
62 | static struct net *net_alloc(void) |
63 | { | |
64 | return kmem_cache_zalloc(net_cachep, GFP_KERNEL); | |
65 | } | |
66 | ||
45a19b0a JFS |
67 | static void net_free(struct net *net) |
68 | { | |
69 | if (!net) | |
70 | return; | |
71 | ||
72 | if (unlikely(atomic_read(&net->use_count) != 0)) { | |
73 | printk(KERN_EMERG "network namespace not free! Usage: %d\n", | |
74 | atomic_read(&net->use_count)); | |
75 | return; | |
76 | } | |
77 | ||
78 | kmem_cache_free(net_cachep, net); | |
79 | } | |
80 | ||
9dd776b6 EB |
81 | struct net *copy_net_ns(unsigned long flags, struct net *old_net) |
82 | { | |
83 | struct net *new_net = NULL; | |
84 | int err; | |
85 | ||
86 | get_net(old_net); | |
87 | ||
88 | if (!(flags & CLONE_NEWNET)) | |
89 | return old_net; | |
90 | ||
9dd776b6 EB |
91 | err = -ENOMEM; |
92 | new_net = net_alloc(); | |
93 | if (!new_net) | |
94 | goto out; | |
95 | ||
96 | mutex_lock(&net_mutex); | |
97 | err = setup_net(new_net); | |
98 | if (err) | |
99 | goto out_unlock; | |
100 | ||
f4618d39 | 101 | rtnl_lock(); |
9dd776b6 | 102 | list_add_tail(&new_net->list, &net_namespace_list); |
f4618d39 | 103 | rtnl_unlock(); |
9dd776b6 EB |
104 | |
105 | ||
106 | out_unlock: | |
107 | mutex_unlock(&net_mutex); | |
108 | out: | |
109 | put_net(old_net); | |
110 | if (err) { | |
111 | net_free(new_net); | |
112 | new_net = ERR_PTR(err); | |
113 | } | |
114 | return new_net; | |
115 | } | |
116 | ||
6a1a3b9f PE |
117 | static void cleanup_net(struct work_struct *work) |
118 | { | |
119 | struct pernet_operations *ops; | |
120 | struct net *net; | |
121 | ||
122 | net = container_of(work, struct net, work); | |
123 | ||
124 | mutex_lock(&net_mutex); | |
125 | ||
126 | /* Don't let anyone else find us. */ | |
127 | rtnl_lock(); | |
128 | list_del(&net->list); | |
129 | rtnl_unlock(); | |
130 | ||
131 | /* Run all of the network namespace exit methods */ | |
132 | list_for_each_entry_reverse(ops, &pernet_list, list) { | |
133 | if (ops->exit) | |
134 | ops->exit(net); | |
135 | } | |
136 | ||
137 | mutex_unlock(&net_mutex); | |
138 | ||
139 | /* Ensure there are no outstanding rcu callbacks using this | |
140 | * network namespace. | |
141 | */ | |
142 | rcu_barrier(); | |
143 | ||
144 | /* Finally it is safe to free my network namespace structure */ | |
145 | net_free(net); | |
146 | } | |
147 | ||
148 | void __put_net(struct net *net) | |
149 | { | |
150 | /* Cleanup the network namespace in process context */ | |
151 | INIT_WORK(&net->work, cleanup_net); | |
152 | schedule_work(&net->work); | |
153 | } | |
154 | EXPORT_SYMBOL_GPL(__put_net); | |
155 | ||
156 | #else | |
157 | struct net *copy_net_ns(unsigned long flags, struct net *old_net) | |
158 | { | |
159 | if (flags & CLONE_NEWNET) | |
160 | return ERR_PTR(-EINVAL); | |
161 | return old_net; | |
162 | } | |
163 | #endif | |
164 | ||
5f256bec EB |
165 | static int __init net_ns_init(void) |
166 | { | |
167 | int err; | |
168 | ||
169 | printk(KERN_INFO "net_namespace: %zd bytes\n", sizeof(struct net)); | |
d57a9212 | 170 | #ifdef CONFIG_NET_NS |
5f256bec EB |
171 | net_cachep = kmem_cache_create("net_namespace", sizeof(struct net), |
172 | SMP_CACHE_BYTES, | |
173 | SLAB_PANIC, NULL); | |
d57a9212 | 174 | #endif |
5f256bec EB |
175 | mutex_lock(&net_mutex); |
176 | err = setup_net(&init_net); | |
177 | ||
f4618d39 | 178 | rtnl_lock(); |
5f256bec | 179 | list_add_tail(&init_net.list, &net_namespace_list); |
f4618d39 | 180 | rtnl_unlock(); |
5f256bec EB |
181 | |
182 | mutex_unlock(&net_mutex); | |
183 | if (err) | |
184 | panic("Could not setup the initial network namespace"); | |
185 | ||
186 | return 0; | |
187 | } | |
188 | ||
189 | pure_initcall(net_ns_init); | |
190 | ||
ed160e83 | 191 | #ifdef CONFIG_NET_NS |
5f256bec EB |
192 | static int register_pernet_operations(struct list_head *list, |
193 | struct pernet_operations *ops) | |
194 | { | |
195 | struct net *net, *undo_net; | |
196 | int error; | |
197 | ||
5f256bec | 198 | list_add_tail(&ops->list, list); |
1dba323b PE |
199 | if (ops->init) { |
200 | for_each_net(net) { | |
5f256bec EB |
201 | error = ops->init(net); |
202 | if (error) | |
203 | goto out_undo; | |
204 | } | |
205 | } | |
1dba323b | 206 | return 0; |
5f256bec EB |
207 | |
208 | out_undo: | |
209 | /* If I have an error cleanup all namespaces I initialized */ | |
210 | list_del(&ops->list); | |
1dba323b PE |
211 | if (ops->exit) { |
212 | for_each_net(undo_net) { | |
213 | if (undo_net == net) | |
214 | goto undone; | |
5f256bec | 215 | ops->exit(undo_net); |
1dba323b | 216 | } |
5f256bec EB |
217 | } |
218 | undone: | |
1dba323b | 219 | return error; |
5f256bec EB |
220 | } |
221 | ||
222 | static void unregister_pernet_operations(struct pernet_operations *ops) | |
223 | { | |
224 | struct net *net; | |
225 | ||
226 | list_del(&ops->list); | |
1dba323b PE |
227 | if (ops->exit) |
228 | for_each_net(net) | |
5f256bec EB |
229 | ops->exit(net); |
230 | } | |
231 | ||
ed160e83 DL |
232 | #else |
233 | ||
234 | static int register_pernet_operations(struct list_head *list, | |
235 | struct pernet_operations *ops) | |
236 | { | |
237 | if (ops->init == NULL) | |
238 | return 0; | |
239 | return ops->init(&init_net); | |
240 | } | |
241 | ||
242 | static void unregister_pernet_operations(struct pernet_operations *ops) | |
243 | { | |
244 | if (ops->exit) | |
245 | ops->exit(&init_net); | |
246 | } | |
247 | #endif | |
248 | ||
5f256bec EB |
249 | /** |
250 | * register_pernet_subsys - register a network namespace subsystem | |
251 | * @ops: pernet operations structure for the subsystem | |
252 | * | |
253 | * Register a subsystem which has init and exit functions | |
254 | * that are called when network namespaces are created and | |
255 | * destroyed respectively. | |
256 | * | |
257 | * When registered all network namespace init functions are | |
258 | * called for every existing network namespace. Allowing kernel | |
259 | * modules to have a race free view of the set of network namespaces. | |
260 | * | |
261 | * When a new network namespace is created all of the init | |
262 | * methods are called in the order in which they were registered. | |
263 | * | |
264 | * When a network namespace is destroyed all of the exit methods | |
265 | * are called in the reverse of the order with which they were | |
266 | * registered. | |
267 | */ | |
268 | int register_pernet_subsys(struct pernet_operations *ops) | |
269 | { | |
270 | int error; | |
271 | mutex_lock(&net_mutex); | |
272 | error = register_pernet_operations(first_device, ops); | |
273 | mutex_unlock(&net_mutex); | |
274 | return error; | |
275 | } | |
276 | EXPORT_SYMBOL_GPL(register_pernet_subsys); | |
277 | ||
278 | /** | |
279 | * unregister_pernet_subsys - unregister a network namespace subsystem | |
280 | * @ops: pernet operations structure to manipulate | |
281 | * | |
282 | * Remove the pernet operations structure from the list to be | |
283 | * used when network namespaces are created or destoryed. In | |
284 | * addition run the exit method for all existing network | |
285 | * namespaces. | |
286 | */ | |
287 | void unregister_pernet_subsys(struct pernet_operations *module) | |
288 | { | |
289 | mutex_lock(&net_mutex); | |
290 | unregister_pernet_operations(module); | |
291 | mutex_unlock(&net_mutex); | |
292 | } | |
293 | EXPORT_SYMBOL_GPL(unregister_pernet_subsys); | |
294 | ||
295 | /** | |
296 | * register_pernet_device - register a network namespace device | |
297 | * @ops: pernet operations structure for the subsystem | |
298 | * | |
299 | * Register a device which has init and exit functions | |
300 | * that are called when network namespaces are created and | |
301 | * destroyed respectively. | |
302 | * | |
303 | * When registered all network namespace init functions are | |
304 | * called for every existing network namespace. Allowing kernel | |
305 | * modules to have a race free view of the set of network namespaces. | |
306 | * | |
307 | * When a new network namespace is created all of the init | |
308 | * methods are called in the order in which they were registered. | |
309 | * | |
310 | * When a network namespace is destroyed all of the exit methods | |
311 | * are called in the reverse of the order with which they were | |
312 | * registered. | |
313 | */ | |
314 | int register_pernet_device(struct pernet_operations *ops) | |
315 | { | |
316 | int error; | |
317 | mutex_lock(&net_mutex); | |
318 | error = register_pernet_operations(&pernet_list, ops); | |
319 | if (!error && (first_device == &pernet_list)) | |
320 | first_device = &ops->list; | |
321 | mutex_unlock(&net_mutex); | |
322 | return error; | |
323 | } | |
324 | EXPORT_SYMBOL_GPL(register_pernet_device); | |
325 | ||
326 | /** | |
327 | * unregister_pernet_device - unregister a network namespace netdevice | |
328 | * @ops: pernet operations structure to manipulate | |
329 | * | |
330 | * Remove the pernet operations structure from the list to be | |
331 | * used when network namespaces are created or destoryed. In | |
332 | * addition run the exit method for all existing network | |
333 | * namespaces. | |
334 | */ | |
335 | void unregister_pernet_device(struct pernet_operations *ops) | |
336 | { | |
337 | mutex_lock(&net_mutex); | |
338 | if (&ops->list == first_device) | |
339 | first_device = first_device->next; | |
340 | unregister_pernet_operations(ops); | |
341 | mutex_unlock(&net_mutex); | |
342 | } | |
343 | EXPORT_SYMBOL_GPL(unregister_pernet_device); |