xref: /linux/include/net/net_namespace.h (revision 905e46acd3272d04566fec49afbd7ad9e2ed9ae3)
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 <net/netns/mpls.h>
30 #include <net/netns/can.h>
31 #include <linux/ns_common.h>
32 #include <linux/idr.h>
33 #include <linux/skbuff.h>
34 
35 struct user_namespace;
36 struct proc_dir_entry;
37 struct net_device;
38 struct sock;
39 struct ctl_table_header;
40 struct net_generic;
41 struct sock;
42 struct netns_ipvs;
43 
44 
45 #define NETDEV_HASHBITS    8
46 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
47 
48 struct net {
49 	atomic_t		passive;	/* To decided when the network
50 						 * namespace should be freed.
51 						 */
52 	atomic_t		count;		/* To decided when the network
53 						 *  namespace should be shut down.
54 						 */
55 	spinlock_t		rules_mod_lock;
56 
57 	atomic64_t		cookie_gen;
58 
59 	struct list_head	list;		/* list of network namespaces */
60 	struct list_head	cleanup_list;	/* namespaces on death row */
61 	struct list_head	exit_list;	/* Use only net_mutex */
62 
63 	struct user_namespace   *user_ns;	/* Owning user namespace */
64 	struct ucounts		*ucounts;
65 	spinlock_t		nsid_lock;
66 	struct idr		netns_ids;
67 
68 	struct ns_common	ns;
69 
70 	struct proc_dir_entry 	*proc_net;
71 	struct proc_dir_entry 	*proc_net_stat;
72 
73 #ifdef CONFIG_SYSCTL
74 	struct ctl_table_set	sysctls;
75 #endif
76 
77 	struct sock 		*rtnl;			/* rtnetlink socket */
78 	struct sock		*genl_sock;
79 
80 	struct list_head 	dev_base_head;
81 	struct hlist_head 	*dev_name_head;
82 	struct hlist_head	*dev_index_head;
83 	unsigned int		dev_base_seq;	/* protected by rtnl_mutex */
84 	int			ifindex;
85 	unsigned int		dev_unreg_count;
86 
87 	/* core fib_rules */
88 	struct list_head	rules_ops;
89 
90 
91 	struct net_device       *loopback_dev;          /* The loopback */
92 	struct netns_core	core;
93 	struct netns_mib	mib;
94 	struct netns_packet	packet;
95 	struct netns_unix	unx;
96 	struct netns_ipv4	ipv4;
97 #if IS_ENABLED(CONFIG_IPV6)
98 	struct netns_ipv6	ipv6;
99 #endif
100 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
101 	struct netns_ieee802154_lowpan	ieee802154_lowpan;
102 #endif
103 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
104 	struct netns_sctp	sctp;
105 #endif
106 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
107 	struct netns_dccp	dccp;
108 #endif
109 #ifdef CONFIG_NETFILTER
110 	struct netns_nf		nf;
111 	struct netns_xt		xt;
112 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
113 	struct netns_ct		ct;
114 #endif
115 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
116 	struct netns_nftables	nft;
117 #endif
118 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
119 	struct netns_nf_frag	nf_frag;
120 #endif
121 	struct sock		*nfnl;
122 	struct sock		*nfnl_stash;
123 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
124 	struct list_head        nfnl_acct_list;
125 #endif
126 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
127 	struct list_head	nfct_timeout_list;
128 #endif
129 #endif
130 #ifdef CONFIG_WEXT_CORE
131 	struct sk_buff_head	wext_nlevents;
132 #endif
133 	struct net_generic __rcu	*gen;
134 
135 	/* Note : following structs are cache line aligned */
136 #ifdef CONFIG_XFRM
137 	struct netns_xfrm	xfrm;
138 #endif
139 #if IS_ENABLED(CONFIG_IP_VS)
140 	struct netns_ipvs	*ipvs;
141 #endif
142 #if IS_ENABLED(CONFIG_MPLS)
143 	struct netns_mpls	mpls;
144 #endif
145 #if IS_ENABLED(CONFIG_CAN)
146 	struct netns_can	can;
147 #endif
148 	struct sock		*diag_nlsk;
149 	atomic_t		fnhe_genid;
150 };
151 
152 #include <linux/seq_file_net.h>
153 
154 /* Init's network namespace */
155 extern struct net init_net;
156 
157 #ifdef CONFIG_NET_NS
158 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
159 			struct net *old_net);
160 
161 #else /* CONFIG_NET_NS */
162 #include <linux/sched.h>
163 #include <linux/nsproxy.h>
164 static inline struct net *copy_net_ns(unsigned long flags,
165 	struct user_namespace *user_ns, struct net *old_net)
166 {
167 	if (flags & CLONE_NEWNET)
168 		return ERR_PTR(-EINVAL);
169 	return old_net;
170 }
171 #endif /* CONFIG_NET_NS */
172 
173 
174 extern struct list_head net_namespace_list;
175 
176 struct net *get_net_ns_by_pid(pid_t pid);
177 struct net *get_net_ns_by_fd(int fd);
178 
179 #ifdef CONFIG_SYSCTL
180 void ipx_register_sysctl(void);
181 void ipx_unregister_sysctl(void);
182 #else
183 #define ipx_register_sysctl()
184 #define ipx_unregister_sysctl()
185 #endif
186 
187 #ifdef CONFIG_NET_NS
188 void __put_net(struct net *net);
189 
190 static inline struct net *get_net(struct net *net)
191 {
192 	atomic_inc(&net->count);
193 	return net;
194 }
195 
196 static inline struct net *maybe_get_net(struct net *net)
197 {
198 	/* Used when we know struct net exists but we
199 	 * aren't guaranteed a previous reference count
200 	 * exists.  If the reference count is zero this
201 	 * function fails and returns NULL.
202 	 */
203 	if (!atomic_inc_not_zero(&net->count))
204 		net = NULL;
205 	return net;
206 }
207 
208 static inline void put_net(struct net *net)
209 {
210 	if (atomic_dec_and_test(&net->count))
211 		__put_net(net);
212 }
213 
214 static inline
215 int net_eq(const struct net *net1, const struct net *net2)
216 {
217 	return net1 == net2;
218 }
219 
220 void net_drop_ns(void *);
221 
222 #else
223 
224 static inline struct net *get_net(struct net *net)
225 {
226 	return net;
227 }
228 
229 static inline void put_net(struct net *net)
230 {
231 }
232 
233 static inline struct net *maybe_get_net(struct net *net)
234 {
235 	return net;
236 }
237 
238 static inline
239 int net_eq(const struct net *net1, const struct net *net2)
240 {
241 	return 1;
242 }
243 
244 #define net_drop_ns NULL
245 #endif
246 
247 
248 typedef struct {
249 #ifdef CONFIG_NET_NS
250 	struct net *net;
251 #endif
252 } possible_net_t;
253 
254 static inline void write_pnet(possible_net_t *pnet, struct net *net)
255 {
256 #ifdef CONFIG_NET_NS
257 	pnet->net = net;
258 #endif
259 }
260 
261 static inline struct net *read_pnet(const possible_net_t *pnet)
262 {
263 #ifdef CONFIG_NET_NS
264 	return pnet->net;
265 #else
266 	return &init_net;
267 #endif
268 }
269 
270 #define for_each_net(VAR)				\
271 	list_for_each_entry(VAR, &net_namespace_list, list)
272 
273 #define for_each_net_rcu(VAR)				\
274 	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
275 
276 #ifdef CONFIG_NET_NS
277 #define __net_init
278 #define __net_exit
279 #define __net_initdata
280 #define __net_initconst
281 #else
282 #define __net_init	__init
283 #define __net_exit	__ref
284 #define __net_initdata	__initdata
285 #define __net_initconst	__initconst
286 #endif
287 
288 int peernet2id_alloc(struct net *net, struct net *peer);
289 int peernet2id(struct net *net, struct net *peer);
290 bool peernet_has_id(struct net *net, struct net *peer);
291 struct net *get_net_ns_by_id(struct net *net, int id);
292 
293 struct pernet_operations {
294 	struct list_head list;
295 	int (*init)(struct net *net);
296 	void (*exit)(struct net *net);
297 	void (*exit_batch)(struct list_head *net_exit_list);
298 	unsigned int *id;
299 	size_t size;
300 };
301 
302 /*
303  * Use these carefully.  If you implement a network device and it
304  * needs per network namespace operations use device pernet operations,
305  * otherwise use pernet subsys operations.
306  *
307  * Network interfaces need to be removed from a dying netns _before_
308  * subsys notifiers can be called, as most of the network code cleanup
309  * (which is done from subsys notifiers) runs with the assumption that
310  * dev_remove_pack has been called so no new packets will arrive during
311  * and after the cleanup functions have been called.  dev_remove_pack
312  * is not per namespace so instead the guarantee of no more packets
313  * arriving in a network namespace is provided by ensuring that all
314  * network devices and all sockets have left the network namespace
315  * before the cleanup methods are called.
316  *
317  * For the longest time the ipv4 icmp code was registered as a pernet
318  * device which caused kernel oops, and panics during network
319  * namespace cleanup.   So please don't get this wrong.
320  */
321 int register_pernet_subsys(struct pernet_operations *);
322 void unregister_pernet_subsys(struct pernet_operations *);
323 int register_pernet_device(struct pernet_operations *);
324 void unregister_pernet_device(struct pernet_operations *);
325 
326 struct ctl_table;
327 struct ctl_table_header;
328 
329 #ifdef CONFIG_SYSCTL
330 int net_sysctl_init(void);
331 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
332 					     struct ctl_table *table);
333 void unregister_net_sysctl_table(struct ctl_table_header *header);
334 #else
335 static inline int net_sysctl_init(void) { return 0; }
336 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
337 	const char *path, struct ctl_table *table)
338 {
339 	return NULL;
340 }
341 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
342 {
343 }
344 #endif
345 
346 static inline int rt_genid_ipv4(struct net *net)
347 {
348 	return atomic_read(&net->ipv4.rt_genid);
349 }
350 
351 static inline void rt_genid_bump_ipv4(struct net *net)
352 {
353 	atomic_inc(&net->ipv4.rt_genid);
354 }
355 
356 extern void (*__fib6_flush_trees)(struct net *net);
357 static inline void rt_genid_bump_ipv6(struct net *net)
358 {
359 	if (__fib6_flush_trees)
360 		__fib6_flush_trees(net);
361 }
362 
363 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
364 static inline struct netns_ieee802154_lowpan *
365 net_ieee802154_lowpan(struct net *net)
366 {
367 	return &net->ieee802154_lowpan;
368 }
369 #endif
370 
371 /* For callers who don't really care about whether it's IPv4 or IPv6 */
372 static inline void rt_genid_bump_all(struct net *net)
373 {
374 	rt_genid_bump_ipv4(net);
375 	rt_genid_bump_ipv6(net);
376 }
377 
378 static inline int fnhe_genid(struct net *net)
379 {
380 	return atomic_read(&net->fnhe_genid);
381 }
382 
383 static inline void fnhe_genid_bump(struct net *net)
384 {
385 	atomic_inc(&net->fnhe_genid);
386 }
387 
388 #endif /* __NET_NET_NAMESPACE_H */
389