xref: /openbmc/linux/include/net/net_namespace.h (revision b34e08d5)
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/netns/core.h>
13 #include <net/netns/mib.h>
14 #include <net/netns/unix.h>
15 #include <net/netns/packet.h>
16 #include <net/netns/ipv4.h>
17 #include <net/netns/ipv6.h>
18 #include <net/netns/ieee802154_6lowpan.h>
19 #include <net/netns/sctp.h>
20 #include <net/netns/dccp.h>
21 #include <net/netns/netfilter.h>
22 #include <net/netns/x_tables.h>
23 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
24 #include <net/netns/conntrack.h>
25 #endif
26 #include <net/netns/nftables.h>
27 #include <net/netns/xfrm.h>
28 
29 struct user_namespace;
30 struct proc_dir_entry;
31 struct net_device;
32 struct sock;
33 struct ctl_table_header;
34 struct net_generic;
35 struct sock;
36 struct netns_ipvs;
37 
38 
39 #define NETDEV_HASHBITS    8
40 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
41 
42 struct net {
43 	atomic_t		passive;	/* To decided when the network
44 						 * namespace should be freed.
45 						 */
46 	atomic_t		count;		/* To decided when the network
47 						 *  namespace should be shut down.
48 						 */
49 #ifdef NETNS_REFCNT_DEBUG
50 	atomic_t		use_count;	/* To track references we
51 						 * destroy on demand
52 						 */
53 #endif
54 	spinlock_t		rules_mod_lock;
55 
56 	struct list_head	list;		/* list of network namespaces */
57 	struct list_head	cleanup_list;	/* namespaces on death row */
58 	struct list_head	exit_list;	/* Use only net_mutex */
59 
60 	struct user_namespace   *user_ns;	/* Owning user namespace */
61 
62 	unsigned int		proc_inum;
63 
64 	struct proc_dir_entry 	*proc_net;
65 	struct proc_dir_entry 	*proc_net_stat;
66 
67 #ifdef CONFIG_SYSCTL
68 	struct ctl_table_set	sysctls;
69 #endif
70 
71 	struct sock 		*rtnl;			/* rtnetlink socket */
72 	struct sock		*genl_sock;
73 
74 	struct list_head 	dev_base_head;
75 	struct hlist_head 	*dev_name_head;
76 	struct hlist_head	*dev_index_head;
77 	unsigned int		dev_base_seq;	/* protected by rtnl_mutex */
78 	int			ifindex;
79 	unsigned int		dev_unreg_count;
80 
81 	/* core fib_rules */
82 	struct list_head	rules_ops;
83 
84 
85 	struct net_device       *loopback_dev;          /* The loopback */
86 	struct netns_core	core;
87 	struct netns_mib	mib;
88 	struct netns_packet	packet;
89 	struct netns_unix	unx;
90 	struct netns_ipv4	ipv4;
91 #if IS_ENABLED(CONFIG_IPV6)
92 	struct netns_ipv6	ipv6;
93 #endif
94 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
95 	struct netns_ieee802154_lowpan	ieee802154_lowpan;
96 #endif
97 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
98 	struct netns_sctp	sctp;
99 #endif
100 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
101 	struct netns_dccp	dccp;
102 #endif
103 #ifdef CONFIG_NETFILTER
104 	struct netns_nf		nf;
105 	struct netns_xt		xt;
106 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
107 	struct netns_ct		ct;
108 #endif
109 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
110 	struct netns_nftables	nft;
111 #endif
112 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
113 	struct netns_nf_frag	nf_frag;
114 #endif
115 	struct sock		*nfnl;
116 	struct sock		*nfnl_stash;
117 #endif
118 #ifdef CONFIG_WEXT_CORE
119 	struct sk_buff_head	wext_nlevents;
120 #endif
121 	struct net_generic __rcu	*gen;
122 
123 	/* Note : following structs are cache line aligned */
124 #ifdef CONFIG_XFRM
125 	struct netns_xfrm	xfrm;
126 #endif
127 #if IS_ENABLED(CONFIG_IP_VS)
128 	struct netns_ipvs	*ipvs;
129 #endif
130 	struct sock		*diag_nlsk;
131 	atomic_t		fnhe_genid;
132 };
133 
134 /*
135  * ifindex generation is per-net namespace, and loopback is
136  * always the 1st device in ns (see net_dev_init), thus any
137  * loopback device should get ifindex 1
138  */
139 
140 #define LOOPBACK_IFINDEX	1
141 
142 #include <linux/seq_file_net.h>
143 
144 /* Init's network namespace */
145 extern struct net init_net;
146 
147 #ifdef CONFIG_NET_NS
148 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
149 			struct net *old_net);
150 
151 #else /* CONFIG_NET_NS */
152 #include <linux/sched.h>
153 #include <linux/nsproxy.h>
154 static inline struct net *copy_net_ns(unsigned long flags,
155 	struct user_namespace *user_ns, struct net *old_net)
156 {
157 	if (flags & CLONE_NEWNET)
158 		return ERR_PTR(-EINVAL);
159 	return old_net;
160 }
161 #endif /* CONFIG_NET_NS */
162 
163 
164 extern struct list_head net_namespace_list;
165 
166 struct net *get_net_ns_by_pid(pid_t pid);
167 struct net *get_net_ns_by_fd(int pid);
168 
169 #ifdef CONFIG_SYSCTL
170 void ipx_register_sysctl(void);
171 void ipx_unregister_sysctl(void);
172 #else
173 #define ipx_register_sysctl()
174 #define ipx_unregister_sysctl()
175 #endif
176 
177 #ifdef CONFIG_NET_NS
178 void __put_net(struct net *net);
179 
180 static inline struct net *get_net(struct net *net)
181 {
182 	atomic_inc(&net->count);
183 	return net;
184 }
185 
186 static inline struct net *maybe_get_net(struct net *net)
187 {
188 	/* Used when we know struct net exists but we
189 	 * aren't guaranteed a previous reference count
190 	 * exists.  If the reference count is zero this
191 	 * function fails and returns NULL.
192 	 */
193 	if (!atomic_inc_not_zero(&net->count))
194 		net = NULL;
195 	return net;
196 }
197 
198 static inline void put_net(struct net *net)
199 {
200 	if (atomic_dec_and_test(&net->count))
201 		__put_net(net);
202 }
203 
204 static inline
205 int net_eq(const struct net *net1, const struct net *net2)
206 {
207 	return net1 == net2;
208 }
209 
210 void net_drop_ns(void *);
211 
212 #else
213 
214 static inline struct net *get_net(struct net *net)
215 {
216 	return net;
217 }
218 
219 static inline void put_net(struct net *net)
220 {
221 }
222 
223 static inline struct net *maybe_get_net(struct net *net)
224 {
225 	return net;
226 }
227 
228 static inline
229 int net_eq(const struct net *net1, const struct net *net2)
230 {
231 	return 1;
232 }
233 
234 #define net_drop_ns NULL
235 #endif
236 
237 
238 #ifdef NETNS_REFCNT_DEBUG
239 static inline struct net *hold_net(struct net *net)
240 {
241 	if (net)
242 		atomic_inc(&net->use_count);
243 	return net;
244 }
245 
246 static inline void release_net(struct net *net)
247 {
248 	if (net)
249 		atomic_dec(&net->use_count);
250 }
251 #else
252 static inline struct net *hold_net(struct net *net)
253 {
254 	return net;
255 }
256 
257 static inline void release_net(struct net *net)
258 {
259 }
260 #endif
261 
262 #ifdef CONFIG_NET_NS
263 
264 static inline void write_pnet(struct net **pnet, struct net *net)
265 {
266 	*pnet = net;
267 }
268 
269 static inline struct net *read_pnet(struct net * const *pnet)
270 {
271 	return *pnet;
272 }
273 
274 #else
275 
276 #define write_pnet(pnet, net)	do { (void)(net);} while (0)
277 #define read_pnet(pnet)		(&init_net)
278 
279 #endif
280 
281 #define for_each_net(VAR)				\
282 	list_for_each_entry(VAR, &net_namespace_list, list)
283 
284 #define for_each_net_rcu(VAR)				\
285 	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
286 
287 #ifdef CONFIG_NET_NS
288 #define __net_init
289 #define __net_exit
290 #define __net_initdata
291 #define __net_initconst
292 #else
293 #define __net_init	__init
294 #define __net_exit	__exit_refok
295 #define __net_initdata	__initdata
296 #define __net_initconst	__initconst
297 #endif
298 
299 struct pernet_operations {
300 	struct list_head list;
301 	int (*init)(struct net *net);
302 	void (*exit)(struct net *net);
303 	void (*exit_batch)(struct list_head *net_exit_list);
304 	int *id;
305 	size_t size;
306 };
307 
308 /*
309  * Use these carefully.  If you implement a network device and it
310  * needs per network namespace operations use device pernet operations,
311  * otherwise use pernet subsys operations.
312  *
313  * Network interfaces need to be removed from a dying netns _before_
314  * subsys notifiers can be called, as most of the network code cleanup
315  * (which is done from subsys notifiers) runs with the assumption that
316  * dev_remove_pack has been called so no new packets will arrive during
317  * and after the cleanup functions have been called.  dev_remove_pack
318  * is not per namespace so instead the guarantee of no more packets
319  * arriving in a network namespace is provided by ensuring that all
320  * network devices and all sockets have left the network namespace
321  * before the cleanup methods are called.
322  *
323  * For the longest time the ipv4 icmp code was registered as a pernet
324  * device which caused kernel oops, and panics during network
325  * namespace cleanup.   So please don't get this wrong.
326  */
327 int register_pernet_subsys(struct pernet_operations *);
328 void unregister_pernet_subsys(struct pernet_operations *);
329 int register_pernet_device(struct pernet_operations *);
330 void unregister_pernet_device(struct pernet_operations *);
331 
332 struct ctl_table;
333 struct ctl_table_header;
334 
335 #ifdef CONFIG_SYSCTL
336 int net_sysctl_init(void);
337 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
338 					     struct ctl_table *table);
339 void unregister_net_sysctl_table(struct ctl_table_header *header);
340 #else
341 static inline int net_sysctl_init(void) { return 0; }
342 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
343 	const char *path, struct ctl_table *table)
344 {
345 	return NULL;
346 }
347 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
348 {
349 }
350 #endif
351 
352 static inline int rt_genid_ipv4(struct net *net)
353 {
354 	return atomic_read(&net->ipv4.rt_genid);
355 }
356 
357 static inline void rt_genid_bump_ipv4(struct net *net)
358 {
359 	atomic_inc(&net->ipv4.rt_genid);
360 }
361 
362 #if IS_ENABLED(CONFIG_IPV6)
363 static inline int rt_genid_ipv6(struct net *net)
364 {
365 	return atomic_read(&net->ipv6.rt_genid);
366 }
367 
368 static inline void rt_genid_bump_ipv6(struct net *net)
369 {
370 	atomic_inc(&net->ipv6.rt_genid);
371 }
372 #else
373 static inline int rt_genid_ipv6(struct net *net)
374 {
375 	return 0;
376 }
377 
378 static inline void rt_genid_bump_ipv6(struct net *net)
379 {
380 }
381 #endif
382 
383 /* For callers who don't really care about whether it's IPv4 or IPv6 */
384 static inline void rt_genid_bump_all(struct net *net)
385 {
386 	rt_genid_bump_ipv4(net);
387 	rt_genid_bump_ipv6(net);
388 }
389 
390 static inline int fnhe_genid(struct net *net)
391 {
392 	return atomic_read(&net->fnhe_genid);
393 }
394 
395 static inline void fnhe_genid_bump(struct net *net)
396 {
397 	atomic_inc(&net->fnhe_genid);
398 }
399 
400 #endif /* __NET_NET_NAMESPACE_H */
401