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v4.6
 
  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
 34struct user_namespace;
 35struct proc_dir_entry;
 36struct net_device;
 37struct sock;
 38struct ctl_table_header;
 39struct net_generic;
 40struct sock;
 41struct netns_ipvs;
 
 42
 43
 44#define NETDEV_HASHBITS    8
 45#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
 46
 47struct 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#if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
122	struct list_head        nfnl_acct_list;
123#endif
124#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
125	struct list_head	nfct_timeout_list;
126#endif
127#endif
128#ifdef CONFIG_WEXT_CORE
129	struct sk_buff_head	wext_nlevents;
130#endif
131	struct net_generic __rcu	*gen;
132
 
 
 
133	/* Note : following structs are cache line aligned */
134#ifdef CONFIG_XFRM
135	struct netns_xfrm	xfrm;
136#endif
 
 
 
137#if IS_ENABLED(CONFIG_IP_VS)
138	struct netns_ipvs	*ipvs;
139#endif
140#if IS_ENABLED(CONFIG_MPLS)
141	struct netns_mpls	mpls;
142#endif
 
 
 
 
 
 
 
 
 
143	struct sock		*diag_nlsk;
144	atomic_t		fnhe_genid;
145};
 
 
146
147#include <linux/seq_file_net.h>
148
149/* Init's network namespace */
150extern struct net init_net;
151
152#ifdef CONFIG_NET_NS
153struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
154			struct net *old_net);
155
 
 
 
 
 
 
156#else /* CONFIG_NET_NS */
157#include <linux/sched.h>
158#include <linux/nsproxy.h>
159static inline struct net *copy_net_ns(unsigned long flags,
160	struct user_namespace *user_ns, struct net *old_net)
161{
162	if (flags & CLONE_NEWNET)
163		return ERR_PTR(-EINVAL);
164	return old_net;
165}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
166#endif /* CONFIG_NET_NS */
167
168
169extern struct list_head net_namespace_list;
170
171struct net *get_net_ns_by_pid(pid_t pid);
172struct net *get_net_ns_by_fd(int pid);
173
174#ifdef CONFIG_SYSCTL
175void ipx_register_sysctl(void);
176void ipx_unregister_sysctl(void);
177#else
178#define ipx_register_sysctl()
179#define ipx_unregister_sysctl()
180#endif
181
182#ifdef CONFIG_NET_NS
183void __put_net(struct net *net);
184
185static inline struct net *get_net(struct net *net)
186{
187	atomic_inc(&net->count);
188	return net;
189}
190
191static inline struct net *maybe_get_net(struct net *net)
192{
193	/* Used when we know struct net exists but we
194	 * aren't guaranteed a previous reference count
195	 * exists.  If the reference count is zero this
196	 * function fails and returns NULL.
197	 */
198	if (!atomic_inc_not_zero(&net->count))
199		net = NULL;
200	return net;
201}
202
203static inline void put_net(struct net *net)
204{
205	if (atomic_dec_and_test(&net->count))
206		__put_net(net);
207}
208
209static inline
210int net_eq(const struct net *net1, const struct net *net2)
211{
212	return net1 == net2;
213}
214
 
 
 
 
 
215void net_drop_ns(void *);
216
217#else
218
219static inline struct net *get_net(struct net *net)
220{
221	return net;
222}
223
224static inline void put_net(struct net *net)
225{
226}
227
228static inline struct net *maybe_get_net(struct net *net)
229{
230	return net;
231}
232
233static inline
234int net_eq(const struct net *net1, const struct net *net2)
235{
236	return 1;
237}
238
 
 
 
 
 
239#define net_drop_ns NULL
240#endif
241
242
243typedef struct {
244#ifdef CONFIG_NET_NS
245	struct net *net;
246#endif
247} possible_net_t;
248
249static inline void write_pnet(possible_net_t *pnet, struct net *net)
250{
251#ifdef CONFIG_NET_NS
252	pnet->net = net;
253#endif
254}
255
256static inline struct net *read_pnet(const possible_net_t *pnet)
257{
258#ifdef CONFIG_NET_NS
259	return pnet->net;
260#else
261	return &init_net;
262#endif
263}
264
 
265#define for_each_net(VAR)				\
266	list_for_each_entry(VAR, &net_namespace_list, list)
267
 
268#define for_each_net_rcu(VAR)				\
269	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
270
271#ifdef CONFIG_NET_NS
272#define __net_init
273#define __net_exit
274#define __net_initdata
275#define __net_initconst
276#else
277#define __net_init	__init
278#define __net_exit	__exit_refok
279#define __net_initdata	__initdata
280#define __net_initconst	__initconst
281#endif
282
283int peernet2id_alloc(struct net *net, struct net *peer);
284int peernet2id(struct net *net, struct net *peer);
285bool peernet_has_id(struct net *net, struct net *peer);
286struct net *get_net_ns_by_id(struct net *net, int id);
287
288struct pernet_operations {
289	struct list_head list;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
290	int (*init)(struct net *net);
 
291	void (*exit)(struct net *net);
292	void (*exit_batch)(struct list_head *net_exit_list);
293	int *id;
294	size_t size;
295};
296
297/*
298 * Use these carefully.  If you implement a network device and it
299 * needs per network namespace operations use device pernet operations,
300 * otherwise use pernet subsys operations.
301 *
302 * Network interfaces need to be removed from a dying netns _before_
303 * subsys notifiers can be called, as most of the network code cleanup
304 * (which is done from subsys notifiers) runs with the assumption that
305 * dev_remove_pack has been called so no new packets will arrive during
306 * and after the cleanup functions have been called.  dev_remove_pack
307 * is not per namespace so instead the guarantee of no more packets
308 * arriving in a network namespace is provided by ensuring that all
309 * network devices and all sockets have left the network namespace
310 * before the cleanup methods are called.
311 *
312 * For the longest time the ipv4 icmp code was registered as a pernet
313 * device which caused kernel oops, and panics during network
314 * namespace cleanup.   So please don't get this wrong.
315 */
316int register_pernet_subsys(struct pernet_operations *);
317void unregister_pernet_subsys(struct pernet_operations *);
318int register_pernet_device(struct pernet_operations *);
319void unregister_pernet_device(struct pernet_operations *);
320
321struct ctl_table;
322struct ctl_table_header;
323
324#ifdef CONFIG_SYSCTL
325int net_sysctl_init(void);
326struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
327					     struct ctl_table *table);
328void unregister_net_sysctl_table(struct ctl_table_header *header);
329#else
330static inline int net_sysctl_init(void) { return 0; }
331static inline struct ctl_table_header *register_net_sysctl(struct net *net,
332	const char *path, struct ctl_table *table)
333{
334	return NULL;
335}
336static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
337{
338}
339#endif
340
341static inline int rt_genid_ipv4(struct net *net)
342{
343	return atomic_read(&net->ipv4.rt_genid);
344}
345
 
 
 
 
 
 
 
346static inline void rt_genid_bump_ipv4(struct net *net)
347{
348	atomic_inc(&net->ipv4.rt_genid);
349}
350
351extern void (*__fib6_flush_trees)(struct net *net);
352static inline void rt_genid_bump_ipv6(struct net *net)
353{
354	if (__fib6_flush_trees)
355		__fib6_flush_trees(net);
356}
357
358#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
359static inline struct netns_ieee802154_lowpan *
360net_ieee802154_lowpan(struct net *net)
361{
362	return &net->ieee802154_lowpan;
363}
364#endif
365
366/* For callers who don't really care about whether it's IPv4 or IPv6 */
367static inline void rt_genid_bump_all(struct net *net)
368{
369	rt_genid_bump_ipv4(net);
370	rt_genid_bump_ipv6(net);
371}
372
373static inline int fnhe_genid(struct net *net)
374{
375	return atomic_read(&net->fnhe_genid);
376}
377
378static inline void fnhe_genid_bump(struct net *net)
379{
380	atomic_inc(&net->fnhe_genid);
381}
382
383#endif /* __NET_NET_NAMESPACE_H */
v5.14.15
  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * Operations on the network namespace
  4 */
  5#ifndef __NET_NET_NAMESPACE_H
  6#define __NET_NET_NAMESPACE_H
  7
  8#include <linux/atomic.h>
  9#include <linux/refcount.h>
 10#include <linux/workqueue.h>
 11#include <linux/list.h>
 12#include <linux/sysctl.h>
 13#include <linux/uidgid.h>
 14
 15#include <net/flow.h>
 16#include <net/netns/core.h>
 17#include <net/netns/mib.h>
 18#include <net/netns/unix.h>
 19#include <net/netns/packet.h>
 20#include <net/netns/ipv4.h>
 21#include <net/netns/ipv6.h>
 22#include <net/netns/nexthop.h>
 23#include <net/netns/ieee802154_6lowpan.h>
 24#include <net/netns/sctp.h>
 
 25#include <net/netns/netfilter.h>
 26#include <net/netns/x_tables.h>
 27#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 28#include <net/netns/conntrack.h>
 29#endif
 30#include <net/netns/nftables.h>
 31#include <net/netns/xfrm.h>
 32#include <net/netns/mpls.h>
 33#include <net/netns/can.h>
 34#include <net/netns/xdp.h>
 35#include <net/netns/smc.h>
 36#include <net/netns/bpf.h>
 37#include <linux/ns_common.h>
 38#include <linux/idr.h>
 39#include <linux/skbuff.h>
 40#include <linux/notifier.h>
 41
 42struct user_namespace;
 43struct proc_dir_entry;
 44struct net_device;
 45struct sock;
 46struct ctl_table_header;
 47struct net_generic;
 48struct uevent_sock;
 49struct netns_ipvs;
 50struct bpf_prog;
 51
 52
 53#define NETDEV_HASHBITS    8
 54#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
 55
 56struct net {
 57	/* First cache line can be often dirtied.
 58	 * Do not place here read-mostly fields.
 59	 */
 60	refcount_t		passive;	/* To decide when the network
 61						 * namespace should be freed.
 62						 */
 
 
 
 63	spinlock_t		rules_mod_lock;
 64
 65	unsigned int		dev_unreg_count;
 66
 67	unsigned int		dev_base_seq;	/* protected by rtnl_mutex */
 68	int			ifindex;
 69
 70	spinlock_t		nsid_lock;
 71	atomic_t		fnhe_genid;
 72
 73	struct list_head	list;		/* list of network namespaces */
 74	struct list_head	exit_list;	/* To linked to call pernet exit
 75						 * methods on dead net (
 76						 * pernet_ops_rwsem read locked),
 77						 * or to unregister pernet ops
 78						 * (pernet_ops_rwsem write locked).
 79						 */
 80	struct llist_node	cleanup_list;	/* namespaces on death row */
 81
 82#ifdef CONFIG_KEYS
 83	struct key_tag		*key_domain;	/* Key domain of operation tag */
 84#endif
 85	struct user_namespace   *user_ns;	/* Owning user namespace */
 86	struct ucounts		*ucounts;
 87	struct idr		netns_ids;
 88
 89	struct ns_common	ns;
 90
 91	struct list_head 	dev_base_head;
 92	struct proc_dir_entry 	*proc_net;
 93	struct proc_dir_entry 	*proc_net_stat;
 94
 95#ifdef CONFIG_SYSCTL
 96	struct ctl_table_set	sysctls;
 97#endif
 98
 99	struct sock 		*rtnl;			/* rtnetlink socket */
100	struct sock		*genl_sock;
101
102	struct uevent_sock	*uevent_sock;		/* uevent socket */
103
104	struct hlist_head 	*dev_name_head;
105	struct hlist_head	*dev_index_head;
106	struct raw_notifier_head	netdev_chain;
107
108	/* Note that @hash_mix can be read millions times per second,
109	 * it is critical that it is on a read_mostly cache line.
110	 */
111	u32			hash_mix;
112
113	struct net_device       *loopback_dev;          /* The loopback */
114
115	/* core fib_rules */
116	struct list_head	rules_ops;
117
 
 
118	struct netns_core	core;
119	struct netns_mib	mib;
120	struct netns_packet	packet;
121	struct netns_unix	unx;
122	struct netns_nexthop	nexthop;
123	struct netns_ipv4	ipv4;
124#if IS_ENABLED(CONFIG_IPV6)
125	struct netns_ipv6	ipv6;
126#endif
127#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
128	struct netns_ieee802154_lowpan	ieee802154_lowpan;
129#endif
130#if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
131	struct netns_sctp	sctp;
132#endif
 
 
 
133#ifdef CONFIG_NETFILTER
134	struct netns_nf		nf;
135	struct netns_xt		xt;
136#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
137	struct netns_ct		ct;
138#endif
139#if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
140	struct netns_nftables	nft;
141#endif
 
 
 
 
 
 
 
 
 
 
 
142#endif
143#ifdef CONFIG_WEXT_CORE
144	struct sk_buff_head	wext_nlevents;
145#endif
146	struct net_generic __rcu	*gen;
147
148	/* Used to store attached BPF programs */
149	struct netns_bpf	bpf;
150
151	/* Note : following structs are cache line aligned */
152#ifdef CONFIG_XFRM
153	struct netns_xfrm	xfrm;
154#endif
155
156	u64			net_cookie; /* written once */
157
158#if IS_ENABLED(CONFIG_IP_VS)
159	struct netns_ipvs	*ipvs;
160#endif
161#if IS_ENABLED(CONFIG_MPLS)
162	struct netns_mpls	mpls;
163#endif
164#if IS_ENABLED(CONFIG_CAN)
165	struct netns_can	can;
166#endif
167#ifdef CONFIG_XDP_SOCKETS
168	struct netns_xdp	xdp;
169#endif
170#if IS_ENABLED(CONFIG_CRYPTO_USER)
171	struct sock		*crypto_nlsk;
172#endif
173	struct sock		*diag_nlsk;
174#if IS_ENABLED(CONFIG_SMC)
175	struct netns_smc	smc;
176#endif
177} __randomize_layout;
178
179#include <linux/seq_file_net.h>
180
181/* Init's network namespace */
182extern struct net init_net;
183
184#ifdef CONFIG_NET_NS
185struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
186			struct net *old_net);
187
188void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
189
190void net_ns_barrier(void);
191
192struct ns_common *get_net_ns(struct ns_common *ns);
193struct net *get_net_ns_by_fd(int fd);
194#else /* CONFIG_NET_NS */
195#include <linux/sched.h>
196#include <linux/nsproxy.h>
197static inline struct net *copy_net_ns(unsigned long flags,
198	struct user_namespace *user_ns, struct net *old_net)
199{
200	if (flags & CLONE_NEWNET)
201		return ERR_PTR(-EINVAL);
202	return old_net;
203}
204
205static inline void net_ns_get_ownership(const struct net *net,
206					kuid_t *uid, kgid_t *gid)
207{
208	*uid = GLOBAL_ROOT_UID;
209	*gid = GLOBAL_ROOT_GID;
210}
211
212static inline void net_ns_barrier(void) {}
213
214static inline struct ns_common *get_net_ns(struct ns_common *ns)
215{
216	return ERR_PTR(-EINVAL);
217}
218
219static inline struct net *get_net_ns_by_fd(int fd)
220{
221	return ERR_PTR(-EINVAL);
222}
223#endif /* CONFIG_NET_NS */
224
225
226extern struct list_head net_namespace_list;
227
228struct net *get_net_ns_by_pid(pid_t pid);
 
229
230#ifdef CONFIG_SYSCTL
231void ipx_register_sysctl(void);
232void ipx_unregister_sysctl(void);
233#else
234#define ipx_register_sysctl()
235#define ipx_unregister_sysctl()
236#endif
237
238#ifdef CONFIG_NET_NS
239void __put_net(struct net *net);
240
241static inline struct net *get_net(struct net *net)
242{
243	refcount_inc(&net->ns.count);
244	return net;
245}
246
247static inline struct net *maybe_get_net(struct net *net)
248{
249	/* Used when we know struct net exists but we
250	 * aren't guaranteed a previous reference count
251	 * exists.  If the reference count is zero this
252	 * function fails and returns NULL.
253	 */
254	if (!refcount_inc_not_zero(&net->ns.count))
255		net = NULL;
256	return net;
257}
258
259static inline void put_net(struct net *net)
260{
261	if (refcount_dec_and_test(&net->ns.count))
262		__put_net(net);
263}
264
265static inline
266int net_eq(const struct net *net1, const struct net *net2)
267{
268	return net1 == net2;
269}
270
271static inline int check_net(const struct net *net)
272{
273	return refcount_read(&net->ns.count) != 0;
274}
275
276void net_drop_ns(void *);
277
278#else
279
280static inline struct net *get_net(struct net *net)
281{
282	return net;
283}
284
285static inline void put_net(struct net *net)
286{
287}
288
289static inline struct net *maybe_get_net(struct net *net)
290{
291	return net;
292}
293
294static inline
295int net_eq(const struct net *net1, const struct net *net2)
296{
297	return 1;
298}
299
300static inline int check_net(const struct net *net)
301{
302	return 1;
303}
304
305#define net_drop_ns NULL
306#endif
307
308
309typedef struct {
310#ifdef CONFIG_NET_NS
311	struct net *net;
312#endif
313} possible_net_t;
314
315static inline void write_pnet(possible_net_t *pnet, struct net *net)
316{
317#ifdef CONFIG_NET_NS
318	pnet->net = net;
319#endif
320}
321
322static inline struct net *read_pnet(const possible_net_t *pnet)
323{
324#ifdef CONFIG_NET_NS
325	return pnet->net;
326#else
327	return &init_net;
328#endif
329}
330
331/* Protected by net_rwsem */
332#define for_each_net(VAR)				\
333	list_for_each_entry(VAR, &net_namespace_list, list)
334#define for_each_net_continue_reverse(VAR)		\
335	list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list)
336#define for_each_net_rcu(VAR)				\
337	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
338
339#ifdef CONFIG_NET_NS
340#define __net_init
341#define __net_exit
342#define __net_initdata
343#define __net_initconst
344#else
345#define __net_init	__init
346#define __net_exit	__ref
347#define __net_initdata	__initdata
348#define __net_initconst	__initconst
349#endif
350
351int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
352int peernet2id(const struct net *net, struct net *peer);
353bool peernet_has_id(const struct net *net, struct net *peer);
354struct net *get_net_ns_by_id(const struct net *net, int id);
355
356struct pernet_operations {
357	struct list_head list;
358	/*
359	 * Below methods are called without any exclusive locks.
360	 * More than one net may be constructed and destructed
361	 * in parallel on several cpus. Every pernet_operations
362	 * have to keep in mind all other pernet_operations and
363	 * to introduce a locking, if they share common resources.
364	 *
365	 * The only time they are called with exclusive lock is
366	 * from register_pernet_subsys(), unregister_pernet_subsys()
367	 * register_pernet_device() and unregister_pernet_device().
368	 *
369	 * Exit methods using blocking RCU primitives, such as
370	 * synchronize_rcu(), should be implemented via exit_batch.
371	 * Then, destruction of a group of net requires single
372	 * synchronize_rcu() related to these pernet_operations,
373	 * instead of separate synchronize_rcu() for every net.
374	 * Please, avoid synchronize_rcu() at all, where it's possible.
375	 *
376	 * Note that a combination of pre_exit() and exit() can
377	 * be used, since a synchronize_rcu() is guaranteed between
378	 * the calls.
379	 */
380	int (*init)(struct net *net);
381	void (*pre_exit)(struct net *net);
382	void (*exit)(struct net *net);
383	void (*exit_batch)(struct list_head *net_exit_list);
384	unsigned int *id;
385	size_t size;
386};
387
388/*
389 * Use these carefully.  If you implement a network device and it
390 * needs per network namespace operations use device pernet operations,
391 * otherwise use pernet subsys operations.
392 *
393 * Network interfaces need to be removed from a dying netns _before_
394 * subsys notifiers can be called, as most of the network code cleanup
395 * (which is done from subsys notifiers) runs with the assumption that
396 * dev_remove_pack has been called so no new packets will arrive during
397 * and after the cleanup functions have been called.  dev_remove_pack
398 * is not per namespace so instead the guarantee of no more packets
399 * arriving in a network namespace is provided by ensuring that all
400 * network devices and all sockets have left the network namespace
401 * before the cleanup methods are called.
402 *
403 * For the longest time the ipv4 icmp code was registered as a pernet
404 * device which caused kernel oops, and panics during network
405 * namespace cleanup.   So please don't get this wrong.
406 */
407int register_pernet_subsys(struct pernet_operations *);
408void unregister_pernet_subsys(struct pernet_operations *);
409int register_pernet_device(struct pernet_operations *);
410void unregister_pernet_device(struct pernet_operations *);
411
412struct ctl_table;
 
413
414#ifdef CONFIG_SYSCTL
415int net_sysctl_init(void);
416struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
417					     struct ctl_table *table);
418void unregister_net_sysctl_table(struct ctl_table_header *header);
419#else
420static inline int net_sysctl_init(void) { return 0; }
421static inline struct ctl_table_header *register_net_sysctl(struct net *net,
422	const char *path, struct ctl_table *table)
423{
424	return NULL;
425}
426static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
427{
428}
429#endif
430
431static inline int rt_genid_ipv4(const struct net *net)
432{
433	return atomic_read(&net->ipv4.rt_genid);
434}
435
436#if IS_ENABLED(CONFIG_IPV6)
437static inline int rt_genid_ipv6(const struct net *net)
438{
439	return atomic_read(&net->ipv6.fib6_sernum);
440}
441#endif
442
443static inline void rt_genid_bump_ipv4(struct net *net)
444{
445	atomic_inc(&net->ipv4.rt_genid);
446}
447
448extern void (*__fib6_flush_trees)(struct net *net);
449static inline void rt_genid_bump_ipv6(struct net *net)
450{
451	if (__fib6_flush_trees)
452		__fib6_flush_trees(net);
453}
454
455#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
456static inline struct netns_ieee802154_lowpan *
457net_ieee802154_lowpan(struct net *net)
458{
459	return &net->ieee802154_lowpan;
460}
461#endif
462
463/* For callers who don't really care about whether it's IPv4 or IPv6 */
464static inline void rt_genid_bump_all(struct net *net)
465{
466	rt_genid_bump_ipv4(net);
467	rt_genid_bump_ipv6(net);
468}
469
470static inline int fnhe_genid(const struct net *net)
471{
472	return atomic_read(&net->fnhe_genid);
473}
474
475static inline void fnhe_genid_bump(struct net *net)
476{
477	atomic_inc(&net->fnhe_genid);
478}
479
480#endif /* __NET_NET_NAMESPACE_H */