xref: /linux/include/net/net_namespace.h (revision 2ba9268dd603d23e17643437b2246acb6844953b)
1 /*
2  * Operations on the network namespace
3  */
4 #ifndef __NET_NET_NAMESPACE_H
5 #define __NET_NET_NAMESPACE_H
6 
7 #include <linux/atomic.h>
8 #include <linux/workqueue.h>
9 #include <linux/list.h>
10 #include <linux/sysctl.h>
11 
12 #include <net/flow.h>
13 #include <net/netns/core.h>
14 #include <net/netns/mib.h>
15 #include <net/netns/unix.h>
16 #include <net/netns/packet.h>
17 #include <net/netns/ipv4.h>
18 #include <net/netns/ipv6.h>
19 #include <net/netns/ieee802154_6lowpan.h>
20 #include <net/netns/sctp.h>
21 #include <net/netns/dccp.h>
22 #include <net/netns/netfilter.h>
23 #include <net/netns/x_tables.h>
24 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
25 #include <net/netns/conntrack.h>
26 #endif
27 #include <net/netns/nftables.h>
28 #include <net/netns/xfrm.h>
29 #include <linux/ns_common.h>
30 
31 struct user_namespace;
32 struct proc_dir_entry;
33 struct net_device;
34 struct sock;
35 struct ctl_table_header;
36 struct net_generic;
37 struct sock;
38 struct netns_ipvs;
39 
40 
41 #define NETDEV_HASHBITS    8
42 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
43 
44 struct net {
45 	atomic_t		passive;	/* To decided when the network
46 						 * namespace should be freed.
47 						 */
48 	atomic_t		count;		/* To decided when the network
49 						 *  namespace should be shut down.
50 						 */
51 #ifdef NETNS_REFCNT_DEBUG
52 	atomic_t		use_count;	/* To track references we
53 						 * destroy on demand
54 						 */
55 #endif
56 	spinlock_t		rules_mod_lock;
57 
58 	struct list_head	list;		/* list of network namespaces */
59 	struct list_head	cleanup_list;	/* namespaces on death row */
60 	struct list_head	exit_list;	/* Use only net_mutex */
61 
62 	struct user_namespace   *user_ns;	/* Owning user namespace */
63 	struct idr		netns_ids;
64 
65 	struct ns_common	ns;
66 
67 	struct proc_dir_entry 	*proc_net;
68 	struct proc_dir_entry 	*proc_net_stat;
69 
70 #ifdef CONFIG_SYSCTL
71 	struct ctl_table_set	sysctls;
72 #endif
73 
74 	struct sock 		*rtnl;			/* rtnetlink socket */
75 	struct sock		*genl_sock;
76 
77 	struct list_head 	dev_base_head;
78 	struct hlist_head 	*dev_name_head;
79 	struct hlist_head	*dev_index_head;
80 	unsigned int		dev_base_seq;	/* protected by rtnl_mutex */
81 	int			ifindex;
82 	unsigned int		dev_unreg_count;
83 
84 	/* core fib_rules */
85 	struct list_head	rules_ops;
86 
87 
88 	struct net_device       *loopback_dev;          /* The loopback */
89 	struct netns_core	core;
90 	struct netns_mib	mib;
91 	struct netns_packet	packet;
92 	struct netns_unix	unx;
93 	struct netns_ipv4	ipv4;
94 #if IS_ENABLED(CONFIG_IPV6)
95 	struct netns_ipv6	ipv6;
96 #endif
97 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
98 	struct netns_ieee802154_lowpan	ieee802154_lowpan;
99 #endif
100 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
101 	struct netns_sctp	sctp;
102 #endif
103 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
104 	struct netns_dccp	dccp;
105 #endif
106 #ifdef CONFIG_NETFILTER
107 	struct netns_nf		nf;
108 	struct netns_xt		xt;
109 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
110 	struct netns_ct		ct;
111 #endif
112 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
113 	struct netns_nftables	nft;
114 #endif
115 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
116 	struct netns_nf_frag	nf_frag;
117 #endif
118 	struct sock		*nfnl;
119 	struct sock		*nfnl_stash;
120 #endif
121 #ifdef CONFIG_WEXT_CORE
122 	struct sk_buff_head	wext_nlevents;
123 #endif
124 	struct net_generic __rcu	*gen;
125 
126 	/* Note : following structs are cache line aligned */
127 #ifdef CONFIG_XFRM
128 	struct netns_xfrm	xfrm;
129 #endif
130 #if IS_ENABLED(CONFIG_IP_VS)
131 	struct netns_ipvs	*ipvs;
132 #endif
133 	struct sock		*diag_nlsk;
134 	atomic_t		fnhe_genid;
135 };
136 
137 #include <linux/seq_file_net.h>
138 
139 /* Init's network namespace */
140 extern struct net init_net;
141 
142 #ifdef CONFIG_NET_NS
143 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
144 			struct net *old_net);
145 
146 #else /* CONFIG_NET_NS */
147 #include <linux/sched.h>
148 #include <linux/nsproxy.h>
149 static inline struct net *copy_net_ns(unsigned long flags,
150 	struct user_namespace *user_ns, struct net *old_net)
151 {
152 	if (flags & CLONE_NEWNET)
153 		return ERR_PTR(-EINVAL);
154 	return old_net;
155 }
156 #endif /* CONFIG_NET_NS */
157 
158 
159 extern struct list_head net_namespace_list;
160 
161 struct net *get_net_ns_by_pid(pid_t pid);
162 struct net *get_net_ns_by_fd(int pid);
163 
164 #ifdef CONFIG_SYSCTL
165 void ipx_register_sysctl(void);
166 void ipx_unregister_sysctl(void);
167 #else
168 #define ipx_register_sysctl()
169 #define ipx_unregister_sysctl()
170 #endif
171 
172 #ifdef CONFIG_NET_NS
173 void __put_net(struct net *net);
174 
175 static inline struct net *get_net(struct net *net)
176 {
177 	atomic_inc(&net->count);
178 	return net;
179 }
180 
181 static inline struct net *maybe_get_net(struct net *net)
182 {
183 	/* Used when we know struct net exists but we
184 	 * aren't guaranteed a previous reference count
185 	 * exists.  If the reference count is zero this
186 	 * function fails and returns NULL.
187 	 */
188 	if (!atomic_inc_not_zero(&net->count))
189 		net = NULL;
190 	return net;
191 }
192 
193 static inline void put_net(struct net *net)
194 {
195 	if (atomic_dec_and_test(&net->count))
196 		__put_net(net);
197 }
198 
199 static inline
200 int net_eq(const struct net *net1, const struct net *net2)
201 {
202 	return net1 == net2;
203 }
204 
205 void net_drop_ns(void *);
206 
207 #else
208 
209 static inline struct net *get_net(struct net *net)
210 {
211 	return net;
212 }
213 
214 static inline void put_net(struct net *net)
215 {
216 }
217 
218 static inline struct net *maybe_get_net(struct net *net)
219 {
220 	return net;
221 }
222 
223 static inline
224 int net_eq(const struct net *net1, const struct net *net2)
225 {
226 	return 1;
227 }
228 
229 #define net_drop_ns NULL
230 #endif
231 
232 
233 #ifdef NETNS_REFCNT_DEBUG
234 static inline struct net *hold_net(struct net *net)
235 {
236 	if (net)
237 		atomic_inc(&net->use_count);
238 	return net;
239 }
240 
241 static inline void release_net(struct net *net)
242 {
243 	if (net)
244 		atomic_dec(&net->use_count);
245 }
246 #else
247 static inline struct net *hold_net(struct net *net)
248 {
249 	return net;
250 }
251 
252 static inline void release_net(struct net *net)
253 {
254 }
255 #endif
256 
257 #ifdef CONFIG_NET_NS
258 
259 static inline void write_pnet(struct net **pnet, struct net *net)
260 {
261 	*pnet = net;
262 }
263 
264 static inline struct net *read_pnet(struct net * const *pnet)
265 {
266 	return *pnet;
267 }
268 
269 #else
270 
271 #define write_pnet(pnet, net)	do { (void)(net);} while (0)
272 #define read_pnet(pnet)		(&init_net)
273 
274 #endif
275 
276 #define for_each_net(VAR)				\
277 	list_for_each_entry(VAR, &net_namespace_list, list)
278 
279 #define for_each_net_rcu(VAR)				\
280 	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
281 
282 #ifdef CONFIG_NET_NS
283 #define __net_init
284 #define __net_exit
285 #define __net_initdata
286 #define __net_initconst
287 #else
288 #define __net_init	__init
289 #define __net_exit	__exit_refok
290 #define __net_initdata	__initdata
291 #define __net_initconst	__initconst
292 #endif
293 
294 int peernet2id(struct net *net, struct net *peer);
295 struct net *get_net_ns_by_id(struct net *net, int id);
296 
297 struct pernet_operations {
298 	struct list_head list;
299 	int (*init)(struct net *net);
300 	void (*exit)(struct net *net);
301 	void (*exit_batch)(struct list_head *net_exit_list);
302 	int *id;
303 	size_t size;
304 };
305 
306 /*
307  * Use these carefully.  If you implement a network device and it
308  * needs per network namespace operations use device pernet operations,
309  * otherwise use pernet subsys operations.
310  *
311  * Network interfaces need to be removed from a dying netns _before_
312  * subsys notifiers can be called, as most of the network code cleanup
313  * (which is done from subsys notifiers) runs with the assumption that
314  * dev_remove_pack has been called so no new packets will arrive during
315  * and after the cleanup functions have been called.  dev_remove_pack
316  * is not per namespace so instead the guarantee of no more packets
317  * arriving in a network namespace is provided by ensuring that all
318  * network devices and all sockets have left the network namespace
319  * before the cleanup methods are called.
320  *
321  * For the longest time the ipv4 icmp code was registered as a pernet
322  * device which caused kernel oops, and panics during network
323  * namespace cleanup.   So please don't get this wrong.
324  */
325 int register_pernet_subsys(struct pernet_operations *);
326 void unregister_pernet_subsys(struct pernet_operations *);
327 int register_pernet_device(struct pernet_operations *);
328 void unregister_pernet_device(struct pernet_operations *);
329 
330 struct ctl_table;
331 struct ctl_table_header;
332 
333 #ifdef CONFIG_SYSCTL
334 int net_sysctl_init(void);
335 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
336 					     struct ctl_table *table);
337 void unregister_net_sysctl_table(struct ctl_table_header *header);
338 #else
339 static inline int net_sysctl_init(void) { return 0; }
340 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
341 	const char *path, struct ctl_table *table)
342 {
343 	return NULL;
344 }
345 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
346 {
347 }
348 #endif
349 
350 static inline int rt_genid_ipv4(struct net *net)
351 {
352 	return atomic_read(&net->ipv4.rt_genid);
353 }
354 
355 static inline void rt_genid_bump_ipv4(struct net *net)
356 {
357 	atomic_inc(&net->ipv4.rt_genid);
358 }
359 
360 extern void (*__fib6_flush_trees)(struct net *net);
361 static inline void rt_genid_bump_ipv6(struct net *net)
362 {
363 	if (__fib6_flush_trees)
364 		__fib6_flush_trees(net);
365 }
366 
367 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
368 static inline struct netns_ieee802154_lowpan *
369 net_ieee802154_lowpan(struct net *net)
370 {
371 	return &net->ieee802154_lowpan;
372 }
373 #endif
374 
375 /* For callers who don't really care about whether it's IPv4 or IPv6 */
376 static inline void rt_genid_bump_all(struct net *net)
377 {
378 	rt_genid_bump_ipv4(net);
379 	rt_genid_bump_ipv6(net);
380 }
381 
382 static inline int fnhe_genid(struct net *net)
383 {
384 	return atomic_read(&net->fnhe_genid);
385 }
386 
387 static inline void fnhe_genid_bump(struct net *net)
388 {
389 	atomic_inc(&net->fnhe_genid);
390 }
391 
392 #endif /* __NET_NET_NAMESPACE_H */
393