xref: /linux/include/net/net_namespace.h (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
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 <linux/ns_common.h>
31 #include <linux/idr.h>
32 #include <linux/skbuff.h>
33 
34 struct user_namespace;
35 struct proc_dir_entry;
36 struct net_device;
37 struct sock;
38 struct ctl_table_header;
39 struct net_generic;
40 struct sock;
41 struct netns_ipvs;
42 
43 
44 #define NETDEV_HASHBITS    8
45 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
46 
47 struct net {
48 	atomic_t		passive;	/* To decided when the network
49 						 * namespace should be freed.
50 						 */
51 	atomic_t		count;		/* To decided when the network
52 						 *  namespace should be shut down.
53 						 */
54 	spinlock_t		rules_mod_lock;
55 
56 	atomic64_t		cookie_gen;
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 ucounts		*ucounts;
64 	spinlock_t		nsid_lock;
65 	struct idr		netns_ids;
66 
67 	struct ns_common	ns;
68 
69 	struct proc_dir_entry 	*proc_net;
70 	struct proc_dir_entry 	*proc_net_stat;
71 
72 #ifdef CONFIG_SYSCTL
73 	struct ctl_table_set	sysctls;
74 #endif
75 
76 	struct sock 		*rtnl;			/* rtnetlink socket */
77 	struct sock		*genl_sock;
78 
79 	struct list_head 	dev_base_head;
80 	struct hlist_head 	*dev_name_head;
81 	struct hlist_head	*dev_index_head;
82 	unsigned int		dev_base_seq;	/* protected by rtnl_mutex */
83 	int			ifindex;
84 	unsigned int		dev_unreg_count;
85 
86 	/* core fib_rules */
87 	struct list_head	rules_ops;
88 
89 
90 	struct net_device       *loopback_dev;          /* The loopback */
91 	struct netns_core	core;
92 	struct netns_mib	mib;
93 	struct netns_packet	packet;
94 	struct netns_unix	unx;
95 	struct netns_ipv4	ipv4;
96 #if IS_ENABLED(CONFIG_IPV6)
97 	struct netns_ipv6	ipv6;
98 #endif
99 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
100 	struct netns_ieee802154_lowpan	ieee802154_lowpan;
101 #endif
102 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
103 	struct netns_sctp	sctp;
104 #endif
105 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
106 	struct netns_dccp	dccp;
107 #endif
108 #ifdef CONFIG_NETFILTER
109 	struct netns_nf		nf;
110 	struct netns_xt		xt;
111 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
112 	struct netns_ct		ct;
113 #endif
114 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
115 	struct netns_nftables	nft;
116 #endif
117 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
118 	struct netns_nf_frag	nf_frag;
119 #endif
120 	struct sock		*nfnl;
121 	struct sock		*nfnl_stash;
122 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
123 	struct list_head        nfnl_acct_list;
124 #endif
125 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
126 	struct list_head	nfct_timeout_list;
127 #endif
128 #endif
129 #ifdef CONFIG_WEXT_CORE
130 	struct sk_buff_head	wext_nlevents;
131 #endif
132 	struct net_generic __rcu	*gen;
133 
134 	/* Note : following structs are cache line aligned */
135 #ifdef CONFIG_XFRM
136 	struct netns_xfrm	xfrm;
137 #endif
138 #if IS_ENABLED(CONFIG_IP_VS)
139 	struct netns_ipvs	*ipvs;
140 #endif
141 #if IS_ENABLED(CONFIG_MPLS)
142 	struct netns_mpls	mpls;
143 #endif
144 	struct sock		*diag_nlsk;
145 	atomic_t		fnhe_genid;
146 };
147 
148 #include <linux/seq_file_net.h>
149 
150 /* Init's network namespace */
151 extern struct net init_net;
152 
153 #ifdef CONFIG_NET_NS
154 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
155 			struct net *old_net);
156 
157 #else /* CONFIG_NET_NS */
158 #include <linux/sched.h>
159 #include <linux/nsproxy.h>
160 static inline struct net *copy_net_ns(unsigned long flags,
161 	struct user_namespace *user_ns, struct net *old_net)
162 {
163 	if (flags & CLONE_NEWNET)
164 		return ERR_PTR(-EINVAL);
165 	return old_net;
166 }
167 #endif /* CONFIG_NET_NS */
168 
169 
170 extern struct list_head net_namespace_list;
171 
172 struct net *get_net_ns_by_pid(pid_t pid);
173 struct net *get_net_ns_by_fd(int pid);
174 
175 #ifdef CONFIG_SYSCTL
176 void ipx_register_sysctl(void);
177 void ipx_unregister_sysctl(void);
178 #else
179 #define ipx_register_sysctl()
180 #define ipx_unregister_sysctl()
181 #endif
182 
183 #ifdef CONFIG_NET_NS
184 void __put_net(struct net *net);
185 
186 static inline struct net *get_net(struct net *net)
187 {
188 	atomic_inc(&net->count);
189 	return net;
190 }
191 
192 static inline struct net *maybe_get_net(struct net *net)
193 {
194 	/* Used when we know struct net exists but we
195 	 * aren't guaranteed a previous reference count
196 	 * exists.  If the reference count is zero this
197 	 * function fails and returns NULL.
198 	 */
199 	if (!atomic_inc_not_zero(&net->count))
200 		net = NULL;
201 	return net;
202 }
203 
204 static inline void put_net(struct net *net)
205 {
206 	if (atomic_dec_and_test(&net->count))
207 		__put_net(net);
208 }
209 
210 static inline
211 int net_eq(const struct net *net1, const struct net *net2)
212 {
213 	return net1 == net2;
214 }
215 
216 void net_drop_ns(void *);
217 
218 #else
219 
220 static inline struct net *get_net(struct net *net)
221 {
222 	return net;
223 }
224 
225 static inline void put_net(struct net *net)
226 {
227 }
228 
229 static inline struct net *maybe_get_net(struct net *net)
230 {
231 	return net;
232 }
233 
234 static inline
235 int net_eq(const struct net *net1, const struct net *net2)
236 {
237 	return 1;
238 }
239 
240 #define net_drop_ns NULL
241 #endif
242 
243 
244 typedef struct {
245 #ifdef CONFIG_NET_NS
246 	struct net *net;
247 #endif
248 } possible_net_t;
249 
250 static inline void write_pnet(possible_net_t *pnet, struct net *net)
251 {
252 #ifdef CONFIG_NET_NS
253 	pnet->net = net;
254 #endif
255 }
256 
257 static inline struct net *read_pnet(const possible_net_t *pnet)
258 {
259 #ifdef CONFIG_NET_NS
260 	return pnet->net;
261 #else
262 	return &init_net;
263 #endif
264 }
265 
266 #define for_each_net(VAR)				\
267 	list_for_each_entry(VAR, &net_namespace_list, list)
268 
269 #define for_each_net_rcu(VAR)				\
270 	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
271 
272 #ifdef CONFIG_NET_NS
273 #define __net_init
274 #define __net_exit
275 #define __net_initdata
276 #define __net_initconst
277 #else
278 #define __net_init	__init
279 #define __net_exit	__ref
280 #define __net_initdata	__initdata
281 #define __net_initconst	__initconst
282 #endif
283 
284 int peernet2id_alloc(struct net *net, struct net *peer);
285 int peernet2id(struct net *net, struct net *peer);
286 bool peernet_has_id(struct net *net, struct net *peer);
287 struct net *get_net_ns_by_id(struct net *net, int id);
288 
289 struct pernet_operations {
290 	struct list_head list;
291 	int (*init)(struct net *net);
292 	void (*exit)(struct net *net);
293 	void (*exit_batch)(struct list_head *net_exit_list);
294 	int *id;
295 	size_t size;
296 };
297 
298 /*
299  * Use these carefully.  If you implement a network device and it
300  * needs per network namespace operations use device pernet operations,
301  * otherwise use pernet subsys operations.
302  *
303  * Network interfaces need to be removed from a dying netns _before_
304  * subsys notifiers can be called, as most of the network code cleanup
305  * (which is done from subsys notifiers) runs with the assumption that
306  * dev_remove_pack has been called so no new packets will arrive during
307  * and after the cleanup functions have been called.  dev_remove_pack
308  * is not per namespace so instead the guarantee of no more packets
309  * arriving in a network namespace is provided by ensuring that all
310  * network devices and all sockets have left the network namespace
311  * before the cleanup methods are called.
312  *
313  * For the longest time the ipv4 icmp code was registered as a pernet
314  * device which caused kernel oops, and panics during network
315  * namespace cleanup.   So please don't get this wrong.
316  */
317 int register_pernet_subsys(struct pernet_operations *);
318 void unregister_pernet_subsys(struct pernet_operations *);
319 int register_pernet_device(struct pernet_operations *);
320 void unregister_pernet_device(struct pernet_operations *);
321 
322 struct ctl_table;
323 struct ctl_table_header;
324 
325 #ifdef CONFIG_SYSCTL
326 int net_sysctl_init(void);
327 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
328 					     struct ctl_table *table);
329 void unregister_net_sysctl_table(struct ctl_table_header *header);
330 #else
331 static inline int net_sysctl_init(void) { return 0; }
332 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
333 	const char *path, struct ctl_table *table)
334 {
335 	return NULL;
336 }
337 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
338 {
339 }
340 #endif
341 
342 static inline int rt_genid_ipv4(struct net *net)
343 {
344 	return atomic_read(&net->ipv4.rt_genid);
345 }
346 
347 static inline void rt_genid_bump_ipv4(struct net *net)
348 {
349 	atomic_inc(&net->ipv4.rt_genid);
350 }
351 
352 extern void (*__fib6_flush_trees)(struct net *net);
353 static inline void rt_genid_bump_ipv6(struct net *net)
354 {
355 	if (__fib6_flush_trees)
356 		__fib6_flush_trees(net);
357 }
358 
359 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
360 static inline struct netns_ieee802154_lowpan *
361 net_ieee802154_lowpan(struct net *net)
362 {
363 	return &net->ieee802154_lowpan;
364 }
365 #endif
366 
367 /* For callers who don't really care about whether it's IPv4 or IPv6 */
368 static inline void rt_genid_bump_all(struct net *net)
369 {
370 	rt_genid_bump_ipv4(net);
371 	rt_genid_bump_ipv6(net);
372 }
373 
374 static inline int fnhe_genid(struct net *net)
375 {
376 	return atomic_read(&net->fnhe_genid);
377 }
378 
379 static inline void fnhe_genid_bump(struct net *net)
380 {
381 	atomic_inc(&net->fnhe_genid);
382 }
383 
384 #endif /* __NET_NET_NAMESPACE_H */
385