xref: /openbmc/linux/include/net/net_namespace.h (revision 6774def6)
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 
30 struct user_namespace;
31 struct proc_dir_entry;
32 struct net_device;
33 struct sock;
34 struct ctl_table_header;
35 struct net_generic;
36 struct sock;
37 struct netns_ipvs;
38 
39 
40 #define NETDEV_HASHBITS    8
41 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
42 
43 struct net {
44 	atomic_t		passive;	/* To decided when the network
45 						 * namespace should be freed.
46 						 */
47 	atomic_t		count;		/* To decided when the network
48 						 *  namespace should be shut down.
49 						 */
50 #ifdef NETNS_REFCNT_DEBUG
51 	atomic_t		use_count;	/* To track references we
52 						 * destroy on demand
53 						 */
54 #endif
55 	spinlock_t		rules_mod_lock;
56 
57 	struct list_head	list;		/* list of network namespaces */
58 	struct list_head	cleanup_list;	/* namespaces on death row */
59 	struct list_head	exit_list;	/* Use only net_mutex */
60 
61 	struct user_namespace   *user_ns;	/* Owning user namespace */
62 
63 	unsigned int		proc_inum;
64 
65 	struct proc_dir_entry 	*proc_net;
66 	struct proc_dir_entry 	*proc_net_stat;
67 
68 #ifdef CONFIG_SYSCTL
69 	struct ctl_table_set	sysctls;
70 #endif
71 
72 	struct sock 		*rtnl;			/* rtnetlink socket */
73 	struct sock		*genl_sock;
74 
75 	struct list_head 	dev_base_head;
76 	struct hlist_head 	*dev_name_head;
77 	struct hlist_head	*dev_index_head;
78 	unsigned int		dev_base_seq;	/* protected by rtnl_mutex */
79 	int			ifindex;
80 	unsigned int		dev_unreg_count;
81 
82 	/* core fib_rules */
83 	struct list_head	rules_ops;
84 
85 
86 	struct net_device       *loopback_dev;          /* The loopback */
87 	struct netns_core	core;
88 	struct netns_mib	mib;
89 	struct netns_packet	packet;
90 	struct netns_unix	unx;
91 	struct netns_ipv4	ipv4;
92 #if IS_ENABLED(CONFIG_IPV6)
93 	struct netns_ipv6	ipv6;
94 #endif
95 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
96 	struct netns_ieee802154_lowpan	ieee802154_lowpan;
97 #endif
98 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
99 	struct netns_sctp	sctp;
100 #endif
101 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
102 	struct netns_dccp	dccp;
103 #endif
104 #ifdef CONFIG_NETFILTER
105 	struct netns_nf		nf;
106 	struct netns_xt		xt;
107 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
108 	struct netns_ct		ct;
109 #endif
110 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
111 	struct netns_nftables	nft;
112 #endif
113 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
114 	struct netns_nf_frag	nf_frag;
115 #endif
116 	struct sock		*nfnl;
117 	struct sock		*nfnl_stash;
118 #endif
119 #ifdef CONFIG_WEXT_CORE
120 	struct sk_buff_head	wext_nlevents;
121 #endif
122 	struct net_generic __rcu	*gen;
123 
124 	/* Note : following structs are cache line aligned */
125 #ifdef CONFIG_XFRM
126 	struct netns_xfrm	xfrm;
127 #endif
128 #if IS_ENABLED(CONFIG_IP_VS)
129 	struct netns_ipvs	*ipvs;
130 #endif
131 	struct sock		*diag_nlsk;
132 	atomic_t		fnhe_genid;
133 };
134 
135 #include <linux/seq_file_net.h>
136 
137 /* Init's network namespace */
138 extern struct net init_net;
139 
140 #ifdef CONFIG_NET_NS
141 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
142 			struct net *old_net);
143 
144 #else /* CONFIG_NET_NS */
145 #include <linux/sched.h>
146 #include <linux/nsproxy.h>
147 static inline struct net *copy_net_ns(unsigned long flags,
148 	struct user_namespace *user_ns, struct net *old_net)
149 {
150 	if (flags & CLONE_NEWNET)
151 		return ERR_PTR(-EINVAL);
152 	return old_net;
153 }
154 #endif /* CONFIG_NET_NS */
155 
156 
157 extern struct list_head net_namespace_list;
158 
159 struct net *get_net_ns_by_pid(pid_t pid);
160 struct net *get_net_ns_by_fd(int pid);
161 
162 #ifdef CONFIG_SYSCTL
163 void ipx_register_sysctl(void);
164 void ipx_unregister_sysctl(void);
165 #else
166 #define ipx_register_sysctl()
167 #define ipx_unregister_sysctl()
168 #endif
169 
170 #ifdef CONFIG_NET_NS
171 void __put_net(struct net *net);
172 
173 static inline struct net *get_net(struct net *net)
174 {
175 	atomic_inc(&net->count);
176 	return net;
177 }
178 
179 static inline struct net *maybe_get_net(struct net *net)
180 {
181 	/* Used when we know struct net exists but we
182 	 * aren't guaranteed a previous reference count
183 	 * exists.  If the reference count is zero this
184 	 * function fails and returns NULL.
185 	 */
186 	if (!atomic_inc_not_zero(&net->count))
187 		net = NULL;
188 	return net;
189 }
190 
191 static inline void put_net(struct net *net)
192 {
193 	if (atomic_dec_and_test(&net->count))
194 		__put_net(net);
195 }
196 
197 static inline
198 int net_eq(const struct net *net1, const struct net *net2)
199 {
200 	return net1 == net2;
201 }
202 
203 void net_drop_ns(void *);
204 
205 #else
206 
207 static inline struct net *get_net(struct net *net)
208 {
209 	return net;
210 }
211 
212 static inline void put_net(struct net *net)
213 {
214 }
215 
216 static inline struct net *maybe_get_net(struct net *net)
217 {
218 	return net;
219 }
220 
221 static inline
222 int net_eq(const struct net *net1, const struct net *net2)
223 {
224 	return 1;
225 }
226 
227 #define net_drop_ns NULL
228 #endif
229 
230 
231 #ifdef NETNS_REFCNT_DEBUG
232 static inline struct net *hold_net(struct net *net)
233 {
234 	if (net)
235 		atomic_inc(&net->use_count);
236 	return net;
237 }
238 
239 static inline void release_net(struct net *net)
240 {
241 	if (net)
242 		atomic_dec(&net->use_count);
243 }
244 #else
245 static inline struct net *hold_net(struct net *net)
246 {
247 	return net;
248 }
249 
250 static inline void release_net(struct net *net)
251 {
252 }
253 #endif
254 
255 #ifdef CONFIG_NET_NS
256 
257 static inline void write_pnet(struct net **pnet, struct net *net)
258 {
259 	*pnet = net;
260 }
261 
262 static inline struct net *read_pnet(struct net * const *pnet)
263 {
264 	return *pnet;
265 }
266 
267 #else
268 
269 #define write_pnet(pnet, net)	do { (void)(net);} while (0)
270 #define read_pnet(pnet)		(&init_net)
271 
272 #endif
273 
274 #define for_each_net(VAR)				\
275 	list_for_each_entry(VAR, &net_namespace_list, list)
276 
277 #define for_each_net_rcu(VAR)				\
278 	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
279 
280 #ifdef CONFIG_NET_NS
281 #define __net_init
282 #define __net_exit
283 #define __net_initdata
284 #define __net_initconst
285 #else
286 #define __net_init	__init
287 #define __net_exit	__exit_refok
288 #define __net_initdata	__initdata
289 #define __net_initconst	__initconst
290 #endif
291 
292 struct pernet_operations {
293 	struct list_head list;
294 	int (*init)(struct net *net);
295 	void (*exit)(struct net *net);
296 	void (*exit_batch)(struct list_head *net_exit_list);
297 	int *id;
298 	size_t size;
299 };
300 
301 /*
302  * Use these carefully.  If you implement a network device and it
303  * needs per network namespace operations use device pernet operations,
304  * otherwise use pernet subsys operations.
305  *
306  * Network interfaces need to be removed from a dying netns _before_
307  * subsys notifiers can be called, as most of the network code cleanup
308  * (which is done from subsys notifiers) runs with the assumption that
309  * dev_remove_pack has been called so no new packets will arrive during
310  * and after the cleanup functions have been called.  dev_remove_pack
311  * is not per namespace so instead the guarantee of no more packets
312  * arriving in a network namespace is provided by ensuring that all
313  * network devices and all sockets have left the network namespace
314  * before the cleanup methods are called.
315  *
316  * For the longest time the ipv4 icmp code was registered as a pernet
317  * device which caused kernel oops, and panics during network
318  * namespace cleanup.   So please don't get this wrong.
319  */
320 int register_pernet_subsys(struct pernet_operations *);
321 void unregister_pernet_subsys(struct pernet_operations *);
322 int register_pernet_device(struct pernet_operations *);
323 void unregister_pernet_device(struct pernet_operations *);
324 
325 struct ctl_table;
326 struct ctl_table_header;
327 
328 #ifdef CONFIG_SYSCTL
329 int net_sysctl_init(void);
330 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
331 					     struct ctl_table *table);
332 void unregister_net_sysctl_table(struct ctl_table_header *header);
333 #else
334 static inline int net_sysctl_init(void) { return 0; }
335 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
336 	const char *path, struct ctl_table *table)
337 {
338 	return NULL;
339 }
340 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
341 {
342 }
343 #endif
344 
345 static inline int rt_genid_ipv4(struct net *net)
346 {
347 	return atomic_read(&net->ipv4.rt_genid);
348 }
349 
350 static inline void rt_genid_bump_ipv4(struct net *net)
351 {
352 	atomic_inc(&net->ipv4.rt_genid);
353 }
354 
355 extern void (*__fib6_flush_trees)(struct net *net);
356 static inline void rt_genid_bump_ipv6(struct net *net)
357 {
358 	if (__fib6_flush_trees)
359 		__fib6_flush_trees(net);
360 }
361 
362 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
363 static inline struct netns_ieee802154_lowpan *
364 net_ieee802154_lowpan(struct net *net)
365 {
366 	return &net->ieee802154_lowpan;
367 }
368 #endif
369 
370 /* For callers who don't really care about whether it's IPv4 or IPv6 */
371 static inline void rt_genid_bump_all(struct net *net)
372 {
373 	rt_genid_bump_ipv4(net);
374 	rt_genid_bump_ipv6(net);
375 }
376 
377 static inline int fnhe_genid(struct net *net)
378 {
379 	return atomic_read(&net->fnhe_genid);
380 }
381 
382 static inline void fnhe_genid_bump(struct net *net)
383 {
384 	atomic_inc(&net->fnhe_genid);
385 }
386 
387 #endif /* __NET_NET_NAMESPACE_H */
388