xref: /openbmc/linux/include/net/net_namespace.h (revision e8f6f3b4)
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 
64 	struct ns_common	ns;
65 
66 	struct proc_dir_entry 	*proc_net;
67 	struct proc_dir_entry 	*proc_net_stat;
68 
69 #ifdef CONFIG_SYSCTL
70 	struct ctl_table_set	sysctls;
71 #endif
72 
73 	struct sock 		*rtnl;			/* rtnetlink socket */
74 	struct sock		*genl_sock;
75 
76 	struct list_head 	dev_base_head;
77 	struct hlist_head 	*dev_name_head;
78 	struct hlist_head	*dev_index_head;
79 	unsigned int		dev_base_seq;	/* protected by rtnl_mutex */
80 	int			ifindex;
81 	unsigned int		dev_unreg_count;
82 
83 	/* core fib_rules */
84 	struct list_head	rules_ops;
85 
86 
87 	struct net_device       *loopback_dev;          /* The loopback */
88 	struct netns_core	core;
89 	struct netns_mib	mib;
90 	struct netns_packet	packet;
91 	struct netns_unix	unx;
92 	struct netns_ipv4	ipv4;
93 #if IS_ENABLED(CONFIG_IPV6)
94 	struct netns_ipv6	ipv6;
95 #endif
96 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
97 	struct netns_ieee802154_lowpan	ieee802154_lowpan;
98 #endif
99 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
100 	struct netns_sctp	sctp;
101 #endif
102 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
103 	struct netns_dccp	dccp;
104 #endif
105 #ifdef CONFIG_NETFILTER
106 	struct netns_nf		nf;
107 	struct netns_xt		xt;
108 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
109 	struct netns_ct		ct;
110 #endif
111 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
112 	struct netns_nftables	nft;
113 #endif
114 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
115 	struct netns_nf_frag	nf_frag;
116 #endif
117 	struct sock		*nfnl;
118 	struct sock		*nfnl_stash;
119 #endif
120 #ifdef CONFIG_WEXT_CORE
121 	struct sk_buff_head	wext_nlevents;
122 #endif
123 	struct net_generic __rcu	*gen;
124 
125 	/* Note : following structs are cache line aligned */
126 #ifdef CONFIG_XFRM
127 	struct netns_xfrm	xfrm;
128 #endif
129 #if IS_ENABLED(CONFIG_IP_VS)
130 	struct netns_ipvs	*ipvs;
131 #endif
132 	struct sock		*diag_nlsk;
133 	atomic_t		fnhe_genid;
134 };
135 
136 #include <linux/seq_file_net.h>
137 
138 /* Init's network namespace */
139 extern struct net init_net;
140 
141 #ifdef CONFIG_NET_NS
142 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
143 			struct net *old_net);
144 
145 #else /* CONFIG_NET_NS */
146 #include <linux/sched.h>
147 #include <linux/nsproxy.h>
148 static inline struct net *copy_net_ns(unsigned long flags,
149 	struct user_namespace *user_ns, struct net *old_net)
150 {
151 	if (flags & CLONE_NEWNET)
152 		return ERR_PTR(-EINVAL);
153 	return old_net;
154 }
155 #endif /* CONFIG_NET_NS */
156 
157 
158 extern struct list_head net_namespace_list;
159 
160 struct net *get_net_ns_by_pid(pid_t pid);
161 struct net *get_net_ns_by_fd(int pid);
162 
163 #ifdef CONFIG_SYSCTL
164 void ipx_register_sysctl(void);
165 void ipx_unregister_sysctl(void);
166 #else
167 #define ipx_register_sysctl()
168 #define ipx_unregister_sysctl()
169 #endif
170 
171 #ifdef CONFIG_NET_NS
172 void __put_net(struct net *net);
173 
174 static inline struct net *get_net(struct net *net)
175 {
176 	atomic_inc(&net->count);
177 	return net;
178 }
179 
180 static inline struct net *maybe_get_net(struct net *net)
181 {
182 	/* Used when we know struct net exists but we
183 	 * aren't guaranteed a previous reference count
184 	 * exists.  If the reference count is zero this
185 	 * function fails and returns NULL.
186 	 */
187 	if (!atomic_inc_not_zero(&net->count))
188 		net = NULL;
189 	return net;
190 }
191 
192 static inline void put_net(struct net *net)
193 {
194 	if (atomic_dec_and_test(&net->count))
195 		__put_net(net);
196 }
197 
198 static inline
199 int net_eq(const struct net *net1, const struct net *net2)
200 {
201 	return net1 == net2;
202 }
203 
204 void net_drop_ns(void *);
205 
206 #else
207 
208 static inline struct net *get_net(struct net *net)
209 {
210 	return net;
211 }
212 
213 static inline void put_net(struct net *net)
214 {
215 }
216 
217 static inline struct net *maybe_get_net(struct net *net)
218 {
219 	return net;
220 }
221 
222 static inline
223 int net_eq(const struct net *net1, const struct net *net2)
224 {
225 	return 1;
226 }
227 
228 #define net_drop_ns NULL
229 #endif
230 
231 
232 #ifdef NETNS_REFCNT_DEBUG
233 static inline struct net *hold_net(struct net *net)
234 {
235 	if (net)
236 		atomic_inc(&net->use_count);
237 	return net;
238 }
239 
240 static inline void release_net(struct net *net)
241 {
242 	if (net)
243 		atomic_dec(&net->use_count);
244 }
245 #else
246 static inline struct net *hold_net(struct net *net)
247 {
248 	return net;
249 }
250 
251 static inline void release_net(struct net *net)
252 {
253 }
254 #endif
255 
256 #ifdef CONFIG_NET_NS
257 
258 static inline void write_pnet(struct net **pnet, struct net *net)
259 {
260 	*pnet = net;
261 }
262 
263 static inline struct net *read_pnet(struct net * const *pnet)
264 {
265 	return *pnet;
266 }
267 
268 #else
269 
270 #define write_pnet(pnet, net)	do { (void)(net);} while (0)
271 #define read_pnet(pnet)		(&init_net)
272 
273 #endif
274 
275 #define for_each_net(VAR)				\
276 	list_for_each_entry(VAR, &net_namespace_list, list)
277 
278 #define for_each_net_rcu(VAR)				\
279 	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
280 
281 #ifdef CONFIG_NET_NS
282 #define __net_init
283 #define __net_exit
284 #define __net_initdata
285 #define __net_initconst
286 #else
287 #define __net_init	__init
288 #define __net_exit	__exit_refok
289 #define __net_initdata	__initdata
290 #define __net_initconst	__initconst
291 #endif
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 	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