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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/dccp.h>
26#include <net/netns/netfilter.h>
27#include <net/netns/x_tables.h>
28#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
29#include <net/netns/conntrack.h>
30#endif
31#include <net/netns/nftables.h>
32#include <net/netns/xfrm.h>
33#include <net/netns/mpls.h>
34#include <net/netns/can.h>
35#include <net/netns/xdp.h>
36#include <linux/ns_common.h>
37#include <linux/idr.h>
38#include <linux/skbuff.h>
39
40struct user_namespace;
41struct proc_dir_entry;
42struct net_device;
43struct sock;
44struct ctl_table_header;
45struct net_generic;
46struct uevent_sock;
47struct netns_ipvs;
48struct bpf_prog;
49
50
51#define NETDEV_HASHBITS 8
52#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
53
54struct net {
55 /* First cache line can be often dirtied.
56 * Do not place here read-mostly fields.
57 */
58 refcount_t passive; /* To decide when the network
59 * namespace should be freed.
60 */
61 refcount_t count; /* To decided when the network
62 * namespace should be shut down.
63 */
64 spinlock_t rules_mod_lock;
65
66 unsigned int dev_unreg_count;
67
68 unsigned int dev_base_seq; /* protected by rtnl_mutex */
69 int ifindex;
70
71 spinlock_t nsid_lock;
72 atomic_t fnhe_genid;
73
74 struct list_head list; /* list of network namespaces */
75 struct list_head exit_list; /* To linked to call pernet exit
76 * methods on dead net (
77 * pernet_ops_rwsem read locked),
78 * or to unregister pernet ops
79 * (pernet_ops_rwsem write locked).
80 */
81 struct llist_node cleanup_list; /* namespaces on death row */
82
83#ifdef CONFIG_KEYS
84 struct key_tag *key_domain; /* Key domain of operation tag */
85#endif
86 struct user_namespace *user_ns; /* Owning user namespace */
87 struct ucounts *ucounts;
88 struct idr netns_ids;
89
90 struct ns_common ns;
91
92 struct list_head dev_base_head;
93 struct proc_dir_entry *proc_net;
94 struct proc_dir_entry *proc_net_stat;
95
96#ifdef CONFIG_SYSCTL
97 struct ctl_table_set sysctls;
98#endif
99
100 struct sock *rtnl; /* rtnetlink socket */
101 struct sock *genl_sock;
102
103 struct uevent_sock *uevent_sock; /* uevent socket */
104
105 struct hlist_head *dev_name_head;
106 struct hlist_head *dev_index_head;
107 /* Note that @hash_mix can be read millions times per second,
108 * it is critical that it is on a read_mostly cache line.
109 */
110 u32 hash_mix;
111
112 struct net_device *loopback_dev; /* The loopback */
113
114 /* core fib_rules */
115 struct list_head rules_ops;
116
117 struct netns_core core;
118 struct netns_mib mib;
119 struct netns_packet packet;
120 struct netns_unix unx;
121 struct netns_nexthop nexthop;
122 struct netns_ipv4 ipv4;
123#if IS_ENABLED(CONFIG_IPV6)
124 struct netns_ipv6 ipv6;
125#endif
126#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
127 struct netns_ieee802154_lowpan ieee802154_lowpan;
128#endif
129#if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
130 struct netns_sctp sctp;
131#endif
132#if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
133 struct netns_dccp dccp;
134#endif
135#ifdef CONFIG_NETFILTER
136 struct netns_nf nf;
137 struct netns_xt xt;
138#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
139 struct netns_ct ct;
140#endif
141#if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
142 struct netns_nftables nft;
143#endif
144#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
145 struct netns_nf_frag nf_frag;
146 struct ctl_table_header *nf_frag_frags_hdr;
147#endif
148 struct sock *nfnl;
149 struct sock *nfnl_stash;
150#if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
151 struct list_head nfnl_acct_list;
152#endif
153#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
154 struct list_head nfct_timeout_list;
155#endif
156#endif
157#ifdef CONFIG_WEXT_CORE
158 struct sk_buff_head wext_nlevents;
159#endif
160 struct net_generic __rcu *gen;
161
162 struct bpf_prog __rcu *flow_dissector_prog;
163
164 /* Note : following structs are cache line aligned */
165#ifdef CONFIG_XFRM
166 struct netns_xfrm xfrm;
167#endif
168#if IS_ENABLED(CONFIG_IP_VS)
169 struct netns_ipvs *ipvs;
170#endif
171#if IS_ENABLED(CONFIG_MPLS)
172 struct netns_mpls mpls;
173#endif
174#if IS_ENABLED(CONFIG_CAN)
175 struct netns_can can;
176#endif
177#ifdef CONFIG_XDP_SOCKETS
178 struct netns_xdp xdp;
179#endif
180#if IS_ENABLED(CONFIG_CRYPTO_USER)
181 struct sock *crypto_nlsk;
182#endif
183 struct sock *diag_nlsk;
184} __randomize_layout;
185
186#include <linux/seq_file_net.h>
187
188/* Init's network namespace */
189extern struct net init_net;
190
191#ifdef CONFIG_NET_NS
192struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
193 struct net *old_net);
194
195void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
196
197void net_ns_barrier(void);
198#else /* CONFIG_NET_NS */
199#include <linux/sched.h>
200#include <linux/nsproxy.h>
201static inline struct net *copy_net_ns(unsigned long flags,
202 struct user_namespace *user_ns, struct net *old_net)
203{
204 if (flags & CLONE_NEWNET)
205 return ERR_PTR(-EINVAL);
206 return old_net;
207}
208
209static inline void net_ns_get_ownership(const struct net *net,
210 kuid_t *uid, kgid_t *gid)
211{
212 *uid = GLOBAL_ROOT_UID;
213 *gid = GLOBAL_ROOT_GID;
214}
215
216static inline void net_ns_barrier(void) {}
217#endif /* CONFIG_NET_NS */
218
219
220extern struct list_head net_namespace_list;
221
222struct net *get_net_ns_by_pid(pid_t pid);
223struct net *get_net_ns_by_fd(int fd);
224
225#ifdef CONFIG_SYSCTL
226void ipx_register_sysctl(void);
227void ipx_unregister_sysctl(void);
228#else
229#define ipx_register_sysctl()
230#define ipx_unregister_sysctl()
231#endif
232
233#ifdef CONFIG_NET_NS
234void __put_net(struct net *net);
235
236static inline struct net *get_net(struct net *net)
237{
238 refcount_inc(&net->count);
239 return net;
240}
241
242static inline struct net *maybe_get_net(struct net *net)
243{
244 /* Used when we know struct net exists but we
245 * aren't guaranteed a previous reference count
246 * exists. If the reference count is zero this
247 * function fails and returns NULL.
248 */
249 if (!refcount_inc_not_zero(&net->count))
250 net = NULL;
251 return net;
252}
253
254static inline void put_net(struct net *net)
255{
256 if (refcount_dec_and_test(&net->count))
257 __put_net(net);
258}
259
260static inline
261int net_eq(const struct net *net1, const struct net *net2)
262{
263 return net1 == net2;
264}
265
266static inline int check_net(const struct net *net)
267{
268 return refcount_read(&net->count) != 0;
269}
270
271void net_drop_ns(void *);
272
273#else
274
275static inline struct net *get_net(struct net *net)
276{
277 return net;
278}
279
280static inline void put_net(struct net *net)
281{
282}
283
284static inline struct net *maybe_get_net(struct net *net)
285{
286 return net;
287}
288
289static inline
290int net_eq(const struct net *net1, const struct net *net2)
291{
292 return 1;
293}
294
295static inline int check_net(const struct net *net)
296{
297 return 1;
298}
299
300#define net_drop_ns NULL
301#endif
302
303
304typedef struct {
305#ifdef CONFIG_NET_NS
306 struct net *net;
307#endif
308} possible_net_t;
309
310static inline void write_pnet(possible_net_t *pnet, struct net *net)
311{
312#ifdef CONFIG_NET_NS
313 pnet->net = net;
314#endif
315}
316
317static inline struct net *read_pnet(const possible_net_t *pnet)
318{
319#ifdef CONFIG_NET_NS
320 return pnet->net;
321#else
322 return &init_net;
323#endif
324}
325
326/* Protected by net_rwsem */
327#define for_each_net(VAR) \
328 list_for_each_entry(VAR, &net_namespace_list, list)
329
330#define for_each_net_rcu(VAR) \
331 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
332
333#ifdef CONFIG_NET_NS
334#define __net_init
335#define __net_exit
336#define __net_initdata
337#define __net_initconst
338#else
339#define __net_init __init
340#define __net_exit __ref
341#define __net_initdata __initdata
342#define __net_initconst __initconst
343#endif
344
345int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
346int peernet2id(struct net *net, struct net *peer);
347bool peernet_has_id(struct net *net, struct net *peer);
348struct net *get_net_ns_by_id(struct net *net, int id);
349
350struct pernet_operations {
351 struct list_head list;
352 /*
353 * Below methods are called without any exclusive locks.
354 * More than one net may be constructed and destructed
355 * in parallel on several cpus. Every pernet_operations
356 * have to keep in mind all other pernet_operations and
357 * to introduce a locking, if they share common resources.
358 *
359 * The only time they are called with exclusive lock is
360 * from register_pernet_subsys(), unregister_pernet_subsys()
361 * register_pernet_device() and unregister_pernet_device().
362 *
363 * Exit methods using blocking RCU primitives, such as
364 * synchronize_rcu(), should be implemented via exit_batch.
365 * Then, destruction of a group of net requires single
366 * synchronize_rcu() related to these pernet_operations,
367 * instead of separate synchronize_rcu() for every net.
368 * Please, avoid synchronize_rcu() at all, where it's possible.
369 *
370 * Note that a combination of pre_exit() and exit() can
371 * be used, since a synchronize_rcu() is guaranteed between
372 * the calls.
373 */
374 int (*init)(struct net *net);
375 void (*pre_exit)(struct net *net);
376 void (*exit)(struct net *net);
377 void (*exit_batch)(struct list_head *net_exit_list);
378 unsigned int *id;
379 size_t size;
380};
381
382/*
383 * Use these carefully. If you implement a network device and it
384 * needs per network namespace operations use device pernet operations,
385 * otherwise use pernet subsys operations.
386 *
387 * Network interfaces need to be removed from a dying netns _before_
388 * subsys notifiers can be called, as most of the network code cleanup
389 * (which is done from subsys notifiers) runs with the assumption that
390 * dev_remove_pack has been called so no new packets will arrive during
391 * and after the cleanup functions have been called. dev_remove_pack
392 * is not per namespace so instead the guarantee of no more packets
393 * arriving in a network namespace is provided by ensuring that all
394 * network devices and all sockets have left the network namespace
395 * before the cleanup methods are called.
396 *
397 * For the longest time the ipv4 icmp code was registered as a pernet
398 * device which caused kernel oops, and panics during network
399 * namespace cleanup. So please don't get this wrong.
400 */
401int register_pernet_subsys(struct pernet_operations *);
402void unregister_pernet_subsys(struct pernet_operations *);
403int register_pernet_device(struct pernet_operations *);
404void unregister_pernet_device(struct pernet_operations *);
405
406struct ctl_table;
407struct ctl_table_header;
408
409#ifdef CONFIG_SYSCTL
410int net_sysctl_init(void);
411struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
412 struct ctl_table *table);
413void unregister_net_sysctl_table(struct ctl_table_header *header);
414#else
415static inline int net_sysctl_init(void) { return 0; }
416static inline struct ctl_table_header *register_net_sysctl(struct net *net,
417 const char *path, struct ctl_table *table)
418{
419 return NULL;
420}
421static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
422{
423}
424#endif
425
426static inline int rt_genid_ipv4(struct net *net)
427{
428 return atomic_read(&net->ipv4.rt_genid);
429}
430
431static inline void rt_genid_bump_ipv4(struct net *net)
432{
433 atomic_inc(&net->ipv4.rt_genid);
434}
435
436extern void (*__fib6_flush_trees)(struct net *net);
437static inline void rt_genid_bump_ipv6(struct net *net)
438{
439 if (__fib6_flush_trees)
440 __fib6_flush_trees(net);
441}
442
443#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
444static inline struct netns_ieee802154_lowpan *
445net_ieee802154_lowpan(struct net *net)
446{
447 return &net->ieee802154_lowpan;
448}
449#endif
450
451/* For callers who don't really care about whether it's IPv4 or IPv6 */
452static inline void rt_genid_bump_all(struct net *net)
453{
454 rt_genid_bump_ipv4(net);
455 rt_genid_bump_ipv6(net);
456}
457
458static inline int fnhe_genid(struct net *net)
459{
460 return atomic_read(&net->fnhe_genid);
461}
462
463static inline void fnhe_genid_bump(struct net *net)
464{
465 atomic_inc(&net->fnhe_genid);
466}
467
468#endif /* __NET_NET_NAMESPACE_H */
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
14#include <net/flow.h>
15#include <net/netns/core.h>
16#include <net/netns/mib.h>
17#include <net/netns/unix.h>
18#include <net/netns/packet.h>
19#include <net/netns/ipv4.h>
20#include <net/netns/ipv6.h>
21#include <net/netns/ieee802154_6lowpan.h>
22#include <net/netns/sctp.h>
23#include <net/netns/dccp.h>
24#include <net/netns/netfilter.h>
25#include <net/netns/x_tables.h>
26#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
27#include <net/netns/conntrack.h>
28#endif
29#include <net/netns/nftables.h>
30#include <net/netns/xfrm.h>
31#include <net/netns/mpls.h>
32#include <net/netns/can.h>
33#include <linux/ns_common.h>
34#include <linux/idr.h>
35#include <linux/skbuff.h>
36
37struct user_namespace;
38struct proc_dir_entry;
39struct net_device;
40struct sock;
41struct ctl_table_header;
42struct net_generic;
43struct uevent_sock;
44struct netns_ipvs;
45
46
47#define NETDEV_HASHBITS 8
48#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
49
50struct net {
51 refcount_t passive; /* To decided when the network
52 * namespace should be freed.
53 */
54 refcount_t count; /* To decided when the network
55 * namespace should be shut down.
56 */
57 spinlock_t rules_mod_lock;
58
59 atomic64_t cookie_gen;
60
61 struct list_head list; /* list of network namespaces */
62 struct list_head exit_list; /* To linked to call pernet exit
63 * methods on dead net (
64 * pernet_ops_rwsem read locked),
65 * or to unregister pernet ops
66 * (pernet_ops_rwsem write locked).
67 */
68 struct llist_node cleanup_list; /* namespaces on death row */
69
70 struct user_namespace *user_ns; /* Owning user namespace */
71 struct ucounts *ucounts;
72 spinlock_t nsid_lock;
73 struct idr netns_ids;
74
75 struct ns_common ns;
76
77 struct proc_dir_entry *proc_net;
78 struct proc_dir_entry *proc_net_stat;
79
80#ifdef CONFIG_SYSCTL
81 struct ctl_table_set sysctls;
82#endif
83
84 struct sock *rtnl; /* rtnetlink socket */
85 struct sock *genl_sock;
86
87 struct uevent_sock *uevent_sock; /* uevent socket */
88
89 struct list_head dev_base_head;
90 struct hlist_head *dev_name_head;
91 struct hlist_head *dev_index_head;
92 unsigned int dev_base_seq; /* protected by rtnl_mutex */
93 int ifindex;
94 unsigned int dev_unreg_count;
95
96 /* core fib_rules */
97 struct list_head rules_ops;
98
99 struct list_head fib_notifier_ops; /* Populated by
100 * register_pernet_subsys()
101 */
102 struct net_device *loopback_dev; /* The loopback */
103 struct netns_core core;
104 struct netns_mib mib;
105 struct netns_packet packet;
106 struct netns_unix unx;
107 struct netns_ipv4 ipv4;
108#if IS_ENABLED(CONFIG_IPV6)
109 struct netns_ipv6 ipv6;
110#endif
111#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
112 struct netns_ieee802154_lowpan ieee802154_lowpan;
113#endif
114#if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
115 struct netns_sctp sctp;
116#endif
117#if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
118 struct netns_dccp dccp;
119#endif
120#ifdef CONFIG_NETFILTER
121 struct netns_nf nf;
122 struct netns_xt xt;
123#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
124 struct netns_ct ct;
125#endif
126#if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
127 struct netns_nftables nft;
128#endif
129#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
130 struct netns_nf_frag nf_frag;
131#endif
132 struct sock *nfnl;
133 struct sock *nfnl_stash;
134#if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
135 struct list_head nfnl_acct_list;
136#endif
137#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
138 struct list_head nfct_timeout_list;
139#endif
140#endif
141#ifdef CONFIG_WEXT_CORE
142 struct sk_buff_head wext_nlevents;
143#endif
144 struct net_generic __rcu *gen;
145
146 /* Note : following structs are cache line aligned */
147#ifdef CONFIG_XFRM
148 struct netns_xfrm xfrm;
149#endif
150#if IS_ENABLED(CONFIG_IP_VS)
151 struct netns_ipvs *ipvs;
152#endif
153#if IS_ENABLED(CONFIG_MPLS)
154 struct netns_mpls mpls;
155#endif
156#if IS_ENABLED(CONFIG_CAN)
157 struct netns_can can;
158#endif
159 struct sock *diag_nlsk;
160 atomic_t fnhe_genid;
161} __randomize_layout;
162
163#include <linux/seq_file_net.h>
164
165/* Init's network namespace */
166extern struct net init_net;
167
168#ifdef CONFIG_NET_NS
169struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
170 struct net *old_net);
171
172void net_ns_barrier(void);
173#else /* CONFIG_NET_NS */
174#include <linux/sched.h>
175#include <linux/nsproxy.h>
176static inline struct net *copy_net_ns(unsigned long flags,
177 struct user_namespace *user_ns, struct net *old_net)
178{
179 if (flags & CLONE_NEWNET)
180 return ERR_PTR(-EINVAL);
181 return old_net;
182}
183
184static inline void net_ns_barrier(void) {}
185#endif /* CONFIG_NET_NS */
186
187
188extern struct list_head net_namespace_list;
189
190struct net *get_net_ns_by_pid(pid_t pid);
191struct net *get_net_ns_by_fd(int fd);
192
193#ifdef CONFIG_SYSCTL
194void ipx_register_sysctl(void);
195void ipx_unregister_sysctl(void);
196#else
197#define ipx_register_sysctl()
198#define ipx_unregister_sysctl()
199#endif
200
201#ifdef CONFIG_NET_NS
202void __put_net(struct net *net);
203
204static inline struct net *get_net(struct net *net)
205{
206 refcount_inc(&net->count);
207 return net;
208}
209
210static inline struct net *maybe_get_net(struct net *net)
211{
212 /* Used when we know struct net exists but we
213 * aren't guaranteed a previous reference count
214 * exists. If the reference count is zero this
215 * function fails and returns NULL.
216 */
217 if (!refcount_inc_not_zero(&net->count))
218 net = NULL;
219 return net;
220}
221
222static inline void put_net(struct net *net)
223{
224 if (refcount_dec_and_test(&net->count))
225 __put_net(net);
226}
227
228static inline
229int net_eq(const struct net *net1, const struct net *net2)
230{
231 return net1 == net2;
232}
233
234static inline int check_net(const struct net *net)
235{
236 return refcount_read(&net->count) != 0;
237}
238
239void net_drop_ns(void *);
240
241#else
242
243static inline struct net *get_net(struct net *net)
244{
245 return net;
246}
247
248static inline void put_net(struct net *net)
249{
250}
251
252static inline struct net *maybe_get_net(struct net *net)
253{
254 return net;
255}
256
257static inline
258int net_eq(const struct net *net1, const struct net *net2)
259{
260 return 1;
261}
262
263static inline int check_net(const struct net *net)
264{
265 return 1;
266}
267
268#define net_drop_ns NULL
269#endif
270
271
272typedef struct {
273#ifdef CONFIG_NET_NS
274 struct net *net;
275#endif
276} possible_net_t;
277
278static inline void write_pnet(possible_net_t *pnet, struct net *net)
279{
280#ifdef CONFIG_NET_NS
281 pnet->net = net;
282#endif
283}
284
285static inline struct net *read_pnet(const possible_net_t *pnet)
286{
287#ifdef CONFIG_NET_NS
288 return pnet->net;
289#else
290 return &init_net;
291#endif
292}
293
294/* Protected by net_rwsem */
295#define for_each_net(VAR) \
296 list_for_each_entry(VAR, &net_namespace_list, list)
297
298#define for_each_net_rcu(VAR) \
299 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
300
301#ifdef CONFIG_NET_NS
302#define __net_init
303#define __net_exit
304#define __net_initdata
305#define __net_initconst
306#else
307#define __net_init __init
308#define __net_exit __ref
309#define __net_initdata __initdata
310#define __net_initconst __initconst
311#endif
312
313int peernet2id_alloc(struct net *net, struct net *peer);
314int peernet2id(struct net *net, struct net *peer);
315bool peernet_has_id(struct net *net, struct net *peer);
316struct net *get_net_ns_by_id(struct net *net, int id);
317
318struct pernet_operations {
319 struct list_head list;
320 /*
321 * Below methods are called without any exclusive locks.
322 * More than one net may be constructed and destructed
323 * in parallel on several cpus. Every pernet_operations
324 * have to keep in mind all other pernet_operations and
325 * to introduce a locking, if they share common resources.
326 *
327 * The only time they are called with exclusive lock is
328 * from register_pernet_subsys(), unregister_pernet_subsys()
329 * register_pernet_device() and unregister_pernet_device().
330 *
331 * Exit methods using blocking RCU primitives, such as
332 * synchronize_rcu(), should be implemented via exit_batch.
333 * Then, destruction of a group of net requires single
334 * synchronize_rcu() related to these pernet_operations,
335 * instead of separate synchronize_rcu() for every net.
336 * Please, avoid synchronize_rcu() at all, where it's possible.
337 */
338 int (*init)(struct net *net);
339 void (*exit)(struct net *net);
340 void (*exit_batch)(struct list_head *net_exit_list);
341 unsigned int *id;
342 size_t size;
343};
344
345/*
346 * Use these carefully. If you implement a network device and it
347 * needs per network namespace operations use device pernet operations,
348 * otherwise use pernet subsys operations.
349 *
350 * Network interfaces need to be removed from a dying netns _before_
351 * subsys notifiers can be called, as most of the network code cleanup
352 * (which is done from subsys notifiers) runs with the assumption that
353 * dev_remove_pack has been called so no new packets will arrive during
354 * and after the cleanup functions have been called. dev_remove_pack
355 * is not per namespace so instead the guarantee of no more packets
356 * arriving in a network namespace is provided by ensuring that all
357 * network devices and all sockets have left the network namespace
358 * before the cleanup methods are called.
359 *
360 * For the longest time the ipv4 icmp code was registered as a pernet
361 * device which caused kernel oops, and panics during network
362 * namespace cleanup. So please don't get this wrong.
363 */
364int register_pernet_subsys(struct pernet_operations *);
365void unregister_pernet_subsys(struct pernet_operations *);
366int register_pernet_device(struct pernet_operations *);
367void unregister_pernet_device(struct pernet_operations *);
368
369struct ctl_table;
370struct ctl_table_header;
371
372#ifdef CONFIG_SYSCTL
373int net_sysctl_init(void);
374struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
375 struct ctl_table *table);
376void unregister_net_sysctl_table(struct ctl_table_header *header);
377#else
378static inline int net_sysctl_init(void) { return 0; }
379static inline struct ctl_table_header *register_net_sysctl(struct net *net,
380 const char *path, struct ctl_table *table)
381{
382 return NULL;
383}
384static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
385{
386}
387#endif
388
389static inline int rt_genid_ipv4(struct net *net)
390{
391 return atomic_read(&net->ipv4.rt_genid);
392}
393
394static inline void rt_genid_bump_ipv4(struct net *net)
395{
396 atomic_inc(&net->ipv4.rt_genid);
397}
398
399extern void (*__fib6_flush_trees)(struct net *net);
400static inline void rt_genid_bump_ipv6(struct net *net)
401{
402 if (__fib6_flush_trees)
403 __fib6_flush_trees(net);
404}
405
406#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
407static inline struct netns_ieee802154_lowpan *
408net_ieee802154_lowpan(struct net *net)
409{
410 return &net->ieee802154_lowpan;
411}
412#endif
413
414/* For callers who don't really care about whether it's IPv4 or IPv6 */
415static inline void rt_genid_bump_all(struct net *net)
416{
417 rt_genid_bump_ipv4(net);
418 rt_genid_bump_ipv6(net);
419}
420
421static inline int fnhe_genid(struct net *net)
422{
423 return atomic_read(&net->fnhe_genid);
424}
425
426static inline void fnhe_genid_bump(struct net *net)
427{
428 atomic_inc(&net->fnhe_genid);
429}
430
431#endif /* __NET_NET_NAMESPACE_H */