xref: /openbmc/linux/include/net/net_namespace.h (revision bbde9fc1824aab58bc78c084163007dd6c03fe5b)
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 	spinlock_t		nsid_lock;
64 	struct idr		netns_ids;
65 
66 	struct ns_common	ns;
67 
68 	struct proc_dir_entry 	*proc_net;
69 	struct proc_dir_entry 	*proc_net_stat;
70 
71 #ifdef CONFIG_SYSCTL
72 	struct ctl_table_set	sysctls;
73 #endif
74 
75 	struct sock 		*rtnl;			/* rtnetlink socket */
76 	struct sock		*genl_sock;
77 
78 	struct list_head 	dev_base_head;
79 	struct hlist_head 	*dev_name_head;
80 	struct hlist_head	*dev_index_head;
81 	unsigned int		dev_base_seq;	/* protected by rtnl_mutex */
82 	int			ifindex;
83 	unsigned int		dev_unreg_count;
84 
85 	/* core fib_rules */
86 	struct list_head	rules_ops;
87 
88 
89 	struct net_device       *loopback_dev;          /* The loopback */
90 	struct netns_core	core;
91 	struct netns_mib	mib;
92 	struct netns_packet	packet;
93 	struct netns_unix	unx;
94 	struct netns_ipv4	ipv4;
95 #if IS_ENABLED(CONFIG_IPV6)
96 	struct netns_ipv6	ipv6;
97 #endif
98 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
99 	struct netns_ieee802154_lowpan	ieee802154_lowpan;
100 #endif
101 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
102 	struct netns_sctp	sctp;
103 #endif
104 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
105 	struct netns_dccp	dccp;
106 #endif
107 #ifdef CONFIG_NETFILTER
108 	struct netns_nf		nf;
109 	struct netns_xt		xt;
110 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
111 	struct netns_ct		ct;
112 #endif
113 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
114 	struct netns_nftables	nft;
115 #endif
116 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
117 	struct netns_nf_frag	nf_frag;
118 #endif
119 	struct sock		*nfnl;
120 	struct sock		*nfnl_stash;
121 #endif
122 #ifdef CONFIG_WEXT_CORE
123 	struct sk_buff_head	wext_nlevents;
124 #endif
125 	struct net_generic __rcu	*gen;
126 
127 	/* Note : following structs are cache line aligned */
128 #ifdef CONFIG_XFRM
129 	struct netns_xfrm	xfrm;
130 #endif
131 #if IS_ENABLED(CONFIG_IP_VS)
132 	struct netns_ipvs	*ipvs;
133 #endif
134 #if IS_ENABLED(CONFIG_MPLS)
135 	struct netns_mpls	mpls;
136 #endif
137 	struct sock		*diag_nlsk;
138 	atomic_t		fnhe_genid;
139 };
140 
141 #include <linux/seq_file_net.h>
142 
143 /* Init's network namespace */
144 extern struct net init_net;
145 
146 #ifdef CONFIG_NET_NS
147 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
148 			struct net *old_net);
149 
150 #else /* CONFIG_NET_NS */
151 #include <linux/sched.h>
152 #include <linux/nsproxy.h>
153 static inline struct net *copy_net_ns(unsigned long flags,
154 	struct user_namespace *user_ns, struct net *old_net)
155 {
156 	if (flags & CLONE_NEWNET)
157 		return ERR_PTR(-EINVAL);
158 	return old_net;
159 }
160 #endif /* CONFIG_NET_NS */
161 
162 
163 extern struct list_head net_namespace_list;
164 
165 struct net *get_net_ns_by_pid(pid_t pid);
166 struct net *get_net_ns_by_fd(int pid);
167 
168 #ifdef CONFIG_SYSCTL
169 void ipx_register_sysctl(void);
170 void ipx_unregister_sysctl(void);
171 #else
172 #define ipx_register_sysctl()
173 #define ipx_unregister_sysctl()
174 #endif
175 
176 #ifdef CONFIG_NET_NS
177 void __put_net(struct net *net);
178 
179 static inline struct net *get_net(struct net *net)
180 {
181 	atomic_inc(&net->count);
182 	return net;
183 }
184 
185 static inline struct net *maybe_get_net(struct net *net)
186 {
187 	/* Used when we know struct net exists but we
188 	 * aren't guaranteed a previous reference count
189 	 * exists.  If the reference count is zero this
190 	 * function fails and returns NULL.
191 	 */
192 	if (!atomic_inc_not_zero(&net->count))
193 		net = NULL;
194 	return net;
195 }
196 
197 static inline void put_net(struct net *net)
198 {
199 	if (atomic_dec_and_test(&net->count))
200 		__put_net(net);
201 }
202 
203 static inline
204 int net_eq(const struct net *net1, const struct net *net2)
205 {
206 	return net1 == net2;
207 }
208 
209 void net_drop_ns(void *);
210 
211 #else
212 
213 static inline struct net *get_net(struct net *net)
214 {
215 	return net;
216 }
217 
218 static inline void put_net(struct net *net)
219 {
220 }
221 
222 static inline struct net *maybe_get_net(struct net *net)
223 {
224 	return net;
225 }
226 
227 static inline
228 int net_eq(const struct net *net1, const struct net *net2)
229 {
230 	return 1;
231 }
232 
233 #define net_drop_ns NULL
234 #endif
235 
236 
237 typedef struct {
238 #ifdef CONFIG_NET_NS
239 	struct net *net;
240 #endif
241 } possible_net_t;
242 
243 static inline void write_pnet(possible_net_t *pnet, struct net *net)
244 {
245 #ifdef CONFIG_NET_NS
246 	pnet->net = net;
247 #endif
248 }
249 
250 static inline struct net *read_pnet(const possible_net_t *pnet)
251 {
252 #ifdef CONFIG_NET_NS
253 	return pnet->net;
254 #else
255 	return &init_net;
256 #endif
257 }
258 
259 #define for_each_net(VAR)				\
260 	list_for_each_entry(VAR, &net_namespace_list, list)
261 
262 #define for_each_net_rcu(VAR)				\
263 	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
264 
265 #ifdef CONFIG_NET_NS
266 #define __net_init
267 #define __net_exit
268 #define __net_initdata
269 #define __net_initconst
270 #else
271 #define __net_init	__init
272 #define __net_exit	__exit_refok
273 #define __net_initdata	__initdata
274 #define __net_initconst	__initconst
275 #endif
276 
277 int peernet2id_alloc(struct net *net, struct net *peer);
278 int peernet2id(struct net *net, struct net *peer);
279 bool peernet_has_id(struct net *net, struct net *peer);
280 struct net *get_net_ns_by_id(struct net *net, int id);
281 
282 struct pernet_operations {
283 	struct list_head list;
284 	int (*init)(struct net *net);
285 	void (*exit)(struct net *net);
286 	void (*exit_batch)(struct list_head *net_exit_list);
287 	int *id;
288 	size_t size;
289 };
290 
291 /*
292  * Use these carefully.  If you implement a network device and it
293  * needs per network namespace operations use device pernet operations,
294  * otherwise use pernet subsys operations.
295  *
296  * Network interfaces need to be removed from a dying netns _before_
297  * subsys notifiers can be called, as most of the network code cleanup
298  * (which is done from subsys notifiers) runs with the assumption that
299  * dev_remove_pack has been called so no new packets will arrive during
300  * and after the cleanup functions have been called.  dev_remove_pack
301  * is not per namespace so instead the guarantee of no more packets
302  * arriving in a network namespace is provided by ensuring that all
303  * network devices and all sockets have left the network namespace
304  * before the cleanup methods are called.
305  *
306  * For the longest time the ipv4 icmp code was registered as a pernet
307  * device which caused kernel oops, and panics during network
308  * namespace cleanup.   So please don't get this wrong.
309  */
310 int register_pernet_subsys(struct pernet_operations *);
311 void unregister_pernet_subsys(struct pernet_operations *);
312 int register_pernet_device(struct pernet_operations *);
313 void unregister_pernet_device(struct pernet_operations *);
314 
315 struct ctl_table;
316 struct ctl_table_header;
317 
318 #ifdef CONFIG_SYSCTL
319 int net_sysctl_init(void);
320 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
321 					     struct ctl_table *table);
322 void unregister_net_sysctl_table(struct ctl_table_header *header);
323 #else
324 static inline int net_sysctl_init(void) { return 0; }
325 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
326 	const char *path, struct ctl_table *table)
327 {
328 	return NULL;
329 }
330 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
331 {
332 }
333 #endif
334 
335 static inline int rt_genid_ipv4(struct net *net)
336 {
337 	return atomic_read(&net->ipv4.rt_genid);
338 }
339 
340 static inline void rt_genid_bump_ipv4(struct net *net)
341 {
342 	atomic_inc(&net->ipv4.rt_genid);
343 }
344 
345 extern void (*__fib6_flush_trees)(struct net *net);
346 static inline void rt_genid_bump_ipv6(struct net *net)
347 {
348 	if (__fib6_flush_trees)
349 		__fib6_flush_trees(net);
350 }
351 
352 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
353 static inline struct netns_ieee802154_lowpan *
354 net_ieee802154_lowpan(struct net *net)
355 {
356 	return &net->ieee802154_lowpan;
357 }
358 #endif
359 
360 /* For callers who don't really care about whether it's IPv4 or IPv6 */
361 static inline void rt_genid_bump_all(struct net *net)
362 {
363 	rt_genid_bump_ipv4(net);
364 	rt_genid_bump_ipv6(net);
365 }
366 
367 static inline int fnhe_genid(struct net *net)
368 {
369 	return atomic_read(&net->fnhe_genid);
370 }
371 
372 static inline void fnhe_genid_bump(struct net *net)
373 {
374 	atomic_inc(&net->fnhe_genid);
375 }
376 
377 #endif /* __NET_NET_NAMESPACE_H */
378