Loading...
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#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
27#include <net/netns/conntrack.h>
28#endif
29#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
30#include <net/netns/flow_table.h>
31#endif
32#include <net/netns/nftables.h>
33#include <net/netns/xfrm.h>
34#include <net/netns/mpls.h>
35#include <net/netns/can.h>
36#include <net/netns/xdp.h>
37#include <net/netns/smc.h>
38#include <net/netns/bpf.h>
39#include <net/netns/mctp.h>
40#include <net/net_trackers.h>
41#include <linux/ns_common.h>
42#include <linux/idr.h>
43#include <linux/skbuff.h>
44#include <linux/notifier.h>
45#include <linux/xarray.h>
46
47struct user_namespace;
48struct proc_dir_entry;
49struct net_device;
50struct sock;
51struct ctl_table_header;
52struct net_generic;
53struct uevent_sock;
54struct netns_ipvs;
55struct bpf_prog;
56
57
58#define NETDEV_HASHBITS 8
59#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
60
61struct net {
62 /* First cache line can be often dirtied.
63 * Do not place here read-mostly fields.
64 */
65 refcount_t passive; /* To decide when the network
66 * namespace should be freed.
67 */
68 spinlock_t rules_mod_lock;
69
70 unsigned int dev_base_seq; /* protected by rtnl_mutex */
71 u32 ifindex;
72
73 spinlock_t nsid_lock;
74 atomic_t fnhe_genid;
75
76 struct list_head list; /* list of network namespaces */
77 struct list_head exit_list; /* To linked to call pernet exit
78 * methods on dead net (
79 * pernet_ops_rwsem read locked),
80 * or to unregister pernet ops
81 * (pernet_ops_rwsem write locked).
82 */
83 struct llist_node cleanup_list; /* namespaces on death row */
84
85#ifdef CONFIG_KEYS
86 struct key_tag *key_domain; /* Key domain of operation tag */
87#endif
88 struct user_namespace *user_ns; /* Owning user namespace */
89 struct ucounts *ucounts;
90 struct idr netns_ids;
91
92 struct ns_common ns;
93 struct ref_tracker_dir refcnt_tracker;
94 struct ref_tracker_dir notrefcnt_tracker; /* tracker for objects not
95 * refcounted against netns
96 */
97 struct list_head dev_base_head;
98 struct proc_dir_entry *proc_net;
99 struct proc_dir_entry *proc_net_stat;
100
101#ifdef CONFIG_SYSCTL
102 struct ctl_table_set sysctls;
103#endif
104
105 struct sock *rtnl; /* rtnetlink socket */
106 struct sock *genl_sock;
107
108 struct uevent_sock *uevent_sock; /* uevent socket */
109
110 struct hlist_head *dev_name_head;
111 struct hlist_head *dev_index_head;
112 struct xarray dev_by_index;
113 struct raw_notifier_head netdev_chain;
114
115 /* Note that @hash_mix can be read millions times per second,
116 * it is critical that it is on a read_mostly cache line.
117 */
118 u32 hash_mix;
119
120 struct net_device *loopback_dev; /* The loopback */
121
122 /* core fib_rules */
123 struct list_head rules_ops;
124
125 struct netns_core core;
126 struct netns_mib mib;
127 struct netns_packet packet;
128#if IS_ENABLED(CONFIG_UNIX)
129 struct netns_unix unx;
130#endif
131 struct netns_nexthop nexthop;
132 struct netns_ipv4 ipv4;
133#if IS_ENABLED(CONFIG_IPV6)
134 struct netns_ipv6 ipv6;
135#endif
136#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
137 struct netns_ieee802154_lowpan ieee802154_lowpan;
138#endif
139#if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
140 struct netns_sctp sctp;
141#endif
142#ifdef CONFIG_NETFILTER
143 struct netns_nf nf;
144#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
145 struct netns_ct ct;
146#endif
147#if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
148 struct netns_nftables nft;
149#endif
150#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
151 struct netns_ft ft;
152#endif
153#endif
154#ifdef CONFIG_WEXT_CORE
155 struct sk_buff_head wext_nlevents;
156#endif
157 struct net_generic __rcu *gen;
158
159 /* Used to store attached BPF programs */
160 struct netns_bpf bpf;
161
162 /* Note : following structs are cache line aligned */
163#ifdef CONFIG_XFRM
164 struct netns_xfrm xfrm;
165#endif
166
167 u64 net_cookie; /* written once */
168
169#if IS_ENABLED(CONFIG_IP_VS)
170 struct netns_ipvs *ipvs;
171#endif
172#if IS_ENABLED(CONFIG_MPLS)
173 struct netns_mpls mpls;
174#endif
175#if IS_ENABLED(CONFIG_CAN)
176 struct netns_can can;
177#endif
178#ifdef CONFIG_XDP_SOCKETS
179 struct netns_xdp xdp;
180#endif
181#if IS_ENABLED(CONFIG_MCTP)
182 struct netns_mctp mctp;
183#endif
184#if IS_ENABLED(CONFIG_CRYPTO_USER)
185 struct sock *crypto_nlsk;
186#endif
187 struct sock *diag_nlsk;
188#if IS_ENABLED(CONFIG_SMC)
189 struct netns_smc smc;
190#endif
191} __randomize_layout;
192
193#include <linux/seq_file_net.h>
194
195/* Init's network namespace */
196extern struct net init_net;
197
198#ifdef CONFIG_NET_NS
199struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
200 struct net *old_net);
201
202void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
203
204void net_ns_barrier(void);
205
206struct ns_common *get_net_ns(struct ns_common *ns);
207struct net *get_net_ns_by_fd(int fd);
208#else /* CONFIG_NET_NS */
209#include <linux/sched.h>
210#include <linux/nsproxy.h>
211static inline struct net *copy_net_ns(unsigned long flags,
212 struct user_namespace *user_ns, struct net *old_net)
213{
214 if (flags & CLONE_NEWNET)
215 return ERR_PTR(-EINVAL);
216 return old_net;
217}
218
219static inline void net_ns_get_ownership(const struct net *net,
220 kuid_t *uid, kgid_t *gid)
221{
222 *uid = GLOBAL_ROOT_UID;
223 *gid = GLOBAL_ROOT_GID;
224}
225
226static inline void net_ns_barrier(void) {}
227
228static inline struct ns_common *get_net_ns(struct ns_common *ns)
229{
230 return ERR_PTR(-EINVAL);
231}
232
233static inline struct net *get_net_ns_by_fd(int fd)
234{
235 return ERR_PTR(-EINVAL);
236}
237#endif /* CONFIG_NET_NS */
238
239
240extern struct list_head net_namespace_list;
241
242struct net *get_net_ns_by_pid(pid_t pid);
243
244#ifdef CONFIG_SYSCTL
245void ipx_register_sysctl(void);
246void ipx_unregister_sysctl(void);
247#else
248#define ipx_register_sysctl()
249#define ipx_unregister_sysctl()
250#endif
251
252#ifdef CONFIG_NET_NS
253void __put_net(struct net *net);
254
255/* Try using get_net_track() instead */
256static inline struct net *get_net(struct net *net)
257{
258 refcount_inc(&net->ns.count);
259 return net;
260}
261
262static inline struct net *maybe_get_net(struct net *net)
263{
264 /* Used when we know struct net exists but we
265 * aren't guaranteed a previous reference count
266 * exists. If the reference count is zero this
267 * function fails and returns NULL.
268 */
269 if (!refcount_inc_not_zero(&net->ns.count))
270 net = NULL;
271 return net;
272}
273
274/* Try using put_net_track() instead */
275static inline void put_net(struct net *net)
276{
277 if (refcount_dec_and_test(&net->ns.count))
278 __put_net(net);
279}
280
281static inline
282int net_eq(const struct net *net1, const struct net *net2)
283{
284 return net1 == net2;
285}
286
287static inline int check_net(const struct net *net)
288{
289 return refcount_read(&net->ns.count) != 0;
290}
291
292void net_drop_ns(void *);
293
294#else
295
296static inline struct net *get_net(struct net *net)
297{
298 return net;
299}
300
301static inline void put_net(struct net *net)
302{
303}
304
305static inline struct net *maybe_get_net(struct net *net)
306{
307 return net;
308}
309
310static inline
311int net_eq(const struct net *net1, const struct net *net2)
312{
313 return 1;
314}
315
316static inline int check_net(const struct net *net)
317{
318 return 1;
319}
320
321#define net_drop_ns NULL
322#endif
323
324
325static inline void __netns_tracker_alloc(struct net *net,
326 netns_tracker *tracker,
327 bool refcounted,
328 gfp_t gfp)
329{
330#ifdef CONFIG_NET_NS_REFCNT_TRACKER
331 ref_tracker_alloc(refcounted ? &net->refcnt_tracker :
332 &net->notrefcnt_tracker,
333 tracker, gfp);
334#endif
335}
336
337static inline void netns_tracker_alloc(struct net *net, netns_tracker *tracker,
338 gfp_t gfp)
339{
340 __netns_tracker_alloc(net, tracker, true, gfp);
341}
342
343static inline void __netns_tracker_free(struct net *net,
344 netns_tracker *tracker,
345 bool refcounted)
346{
347#ifdef CONFIG_NET_NS_REFCNT_TRACKER
348 ref_tracker_free(refcounted ? &net->refcnt_tracker :
349 &net->notrefcnt_tracker, tracker);
350#endif
351}
352
353static inline struct net *get_net_track(struct net *net,
354 netns_tracker *tracker, gfp_t gfp)
355{
356 get_net(net);
357 netns_tracker_alloc(net, tracker, gfp);
358 return net;
359}
360
361static inline void put_net_track(struct net *net, netns_tracker *tracker)
362{
363 __netns_tracker_free(net, tracker, true);
364 put_net(net);
365}
366
367typedef struct {
368#ifdef CONFIG_NET_NS
369 struct net __rcu *net;
370#endif
371} possible_net_t;
372
373static inline void write_pnet(possible_net_t *pnet, struct net *net)
374{
375#ifdef CONFIG_NET_NS
376 rcu_assign_pointer(pnet->net, net);
377#endif
378}
379
380static inline struct net *read_pnet(const possible_net_t *pnet)
381{
382#ifdef CONFIG_NET_NS
383 return rcu_dereference_protected(pnet->net, true);
384#else
385 return &init_net;
386#endif
387}
388
389static inline struct net *read_pnet_rcu(possible_net_t *pnet)
390{
391#ifdef CONFIG_NET_NS
392 return rcu_dereference(pnet->net);
393#else
394 return &init_net;
395#endif
396}
397
398/* Protected by net_rwsem */
399#define for_each_net(VAR) \
400 list_for_each_entry(VAR, &net_namespace_list, list)
401#define for_each_net_continue_reverse(VAR) \
402 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list)
403#define for_each_net_rcu(VAR) \
404 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
405
406#ifdef CONFIG_NET_NS
407#define __net_init
408#define __net_exit
409#define __net_initdata
410#define __net_initconst
411#else
412#define __net_init __init
413#define __net_exit __ref
414#define __net_initdata __initdata
415#define __net_initconst __initconst
416#endif
417
418int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
419int peernet2id(const struct net *net, struct net *peer);
420bool peernet_has_id(const struct net *net, struct net *peer);
421struct net *get_net_ns_by_id(const struct net *net, int id);
422
423struct pernet_operations {
424 struct list_head list;
425 /*
426 * Below methods are called without any exclusive locks.
427 * More than one net may be constructed and destructed
428 * in parallel on several cpus. Every pernet_operations
429 * have to keep in mind all other pernet_operations and
430 * to introduce a locking, if they share common resources.
431 *
432 * The only time they are called with exclusive lock is
433 * from register_pernet_subsys(), unregister_pernet_subsys()
434 * register_pernet_device() and unregister_pernet_device().
435 *
436 * Exit methods using blocking RCU primitives, such as
437 * synchronize_rcu(), should be implemented via exit_batch.
438 * Then, destruction of a group of net requires single
439 * synchronize_rcu() related to these pernet_operations,
440 * instead of separate synchronize_rcu() for every net.
441 * Please, avoid synchronize_rcu() at all, where it's possible.
442 *
443 * Note that a combination of pre_exit() and exit() can
444 * be used, since a synchronize_rcu() is guaranteed between
445 * the calls.
446 */
447 int (*init)(struct net *net);
448 void (*pre_exit)(struct net *net);
449 void (*exit)(struct net *net);
450 void (*exit_batch)(struct list_head *net_exit_list);
451 /* Following method is called with RTNL held. */
452 void (*exit_batch_rtnl)(struct list_head *net_exit_list,
453 struct list_head *dev_kill_list);
454 unsigned int *id;
455 size_t size;
456};
457
458/*
459 * Use these carefully. If you implement a network device and it
460 * needs per network namespace operations use device pernet operations,
461 * otherwise use pernet subsys operations.
462 *
463 * Network interfaces need to be removed from a dying netns _before_
464 * subsys notifiers can be called, as most of the network code cleanup
465 * (which is done from subsys notifiers) runs with the assumption that
466 * dev_remove_pack has been called so no new packets will arrive during
467 * and after the cleanup functions have been called. dev_remove_pack
468 * is not per namespace so instead the guarantee of no more packets
469 * arriving in a network namespace is provided by ensuring that all
470 * network devices and all sockets have left the network namespace
471 * before the cleanup methods are called.
472 *
473 * For the longest time the ipv4 icmp code was registered as a pernet
474 * device which caused kernel oops, and panics during network
475 * namespace cleanup. So please don't get this wrong.
476 */
477int register_pernet_subsys(struct pernet_operations *);
478void unregister_pernet_subsys(struct pernet_operations *);
479int register_pernet_device(struct pernet_operations *);
480void unregister_pernet_device(struct pernet_operations *);
481
482struct ctl_table;
483
484#define register_net_sysctl(net, path, table) \
485 register_net_sysctl_sz(net, path, table, ARRAY_SIZE(table))
486#ifdef CONFIG_SYSCTL
487int net_sysctl_init(void);
488struct ctl_table_header *register_net_sysctl_sz(struct net *net, const char *path,
489 struct ctl_table *table, size_t table_size);
490void unregister_net_sysctl_table(struct ctl_table_header *header);
491#else
492static inline int net_sysctl_init(void) { return 0; }
493static inline struct ctl_table_header *register_net_sysctl_sz(struct net *net,
494 const char *path, struct ctl_table *table, size_t table_size)
495{
496 return NULL;
497}
498static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
499{
500}
501#endif
502
503static inline int rt_genid_ipv4(const struct net *net)
504{
505 return atomic_read(&net->ipv4.rt_genid);
506}
507
508#if IS_ENABLED(CONFIG_IPV6)
509static inline int rt_genid_ipv6(const struct net *net)
510{
511 return atomic_read(&net->ipv6.fib6_sernum);
512}
513#endif
514
515static inline void rt_genid_bump_ipv4(struct net *net)
516{
517 atomic_inc(&net->ipv4.rt_genid);
518}
519
520extern void (*__fib6_flush_trees)(struct net *net);
521static inline void rt_genid_bump_ipv6(struct net *net)
522{
523 if (__fib6_flush_trees)
524 __fib6_flush_trees(net);
525}
526
527#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
528static inline struct netns_ieee802154_lowpan *
529net_ieee802154_lowpan(struct net *net)
530{
531 return &net->ieee802154_lowpan;
532}
533#endif
534
535/* For callers who don't really care about whether it's IPv4 or IPv6 */
536static inline void rt_genid_bump_all(struct net *net)
537{
538 rt_genid_bump_ipv4(net);
539 rt_genid_bump_ipv6(net);
540}
541
542static inline int fnhe_genid(const struct net *net)
543{
544 return atomic_read(&net->fnhe_genid);
545}
546
547static inline void fnhe_genid_bump(struct net *net)
548{
549 atomic_inc(&net->fnhe_genid);
550}
551
552#ifdef CONFIG_NET
553void net_ns_init(void);
554#else
555static inline void net_ns_init(void) {}
556#endif
557
558#endif /* __NET_NET_NAMESPACE_H */
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/dccp.h>
19#include <net/netns/x_tables.h>
20#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
21#include <net/netns/conntrack.h>
22#endif
23#include <net/netns/xfrm.h>
24
25struct proc_dir_entry;
26struct net_device;
27struct sock;
28struct ctl_table_header;
29struct net_generic;
30struct sock;
31struct netns_ipvs;
32
33
34#define NETDEV_HASHBITS 8
35#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
36
37struct net {
38 atomic_t passive; /* To decided when the network
39 * namespace should be freed.
40 */
41 atomic_t count; /* To decided when the network
42 * namespace should be shut down.
43 */
44#ifdef NETNS_REFCNT_DEBUG
45 atomic_t use_count; /* To track references we
46 * destroy on demand
47 */
48#endif
49 spinlock_t rules_mod_lock;
50
51 struct list_head list; /* list of network namespaces */
52 struct list_head cleanup_list; /* namespaces on death row */
53 struct list_head exit_list; /* Use only net_mutex */
54
55 struct proc_dir_entry *proc_net;
56 struct proc_dir_entry *proc_net_stat;
57
58#ifdef CONFIG_SYSCTL
59 struct ctl_table_set sysctls;
60#endif
61
62 struct sock *rtnl; /* rtnetlink socket */
63 struct sock *genl_sock;
64
65 struct list_head dev_base_head;
66 struct hlist_head *dev_name_head;
67 struct hlist_head *dev_index_head;
68 unsigned int dev_base_seq; /* protected by rtnl_mutex */
69
70 /* core fib_rules */
71 struct list_head rules_ops;
72
73
74 struct net_device *loopback_dev; /* The loopback */
75 struct netns_core core;
76 struct netns_mib mib;
77 struct netns_packet packet;
78 struct netns_unix unx;
79 struct netns_ipv4 ipv4;
80#if IS_ENABLED(CONFIG_IPV6)
81 struct netns_ipv6 ipv6;
82#endif
83#if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
84 struct netns_dccp dccp;
85#endif
86#ifdef CONFIG_NETFILTER
87 struct netns_xt xt;
88#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
89 struct netns_ct ct;
90#endif
91 struct sock *nfnl;
92 struct sock *nfnl_stash;
93#endif
94#ifdef CONFIG_WEXT_CORE
95 struct sk_buff_head wext_nlevents;
96#endif
97 struct net_generic __rcu *gen;
98
99 /* Note : following structs are cache line aligned */
100#ifdef CONFIG_XFRM
101 struct netns_xfrm xfrm;
102#endif
103 struct netns_ipvs *ipvs;
104};
105
106
107#include <linux/seq_file_net.h>
108
109/* Init's network namespace */
110extern struct net init_net;
111
112#ifdef CONFIG_NET
113extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
114
115#else /* CONFIG_NET */
116static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
117{
118 /* There is nothing to copy so this is a noop */
119 return net_ns;
120}
121#endif /* CONFIG_NET */
122
123
124extern struct list_head net_namespace_list;
125
126extern struct net *get_net_ns_by_pid(pid_t pid);
127extern struct net *get_net_ns_by_fd(int pid);
128
129#ifdef CONFIG_NET_NS
130extern void __put_net(struct net *net);
131
132static inline struct net *get_net(struct net *net)
133{
134 atomic_inc(&net->count);
135 return net;
136}
137
138static inline struct net *maybe_get_net(struct net *net)
139{
140 /* Used when we know struct net exists but we
141 * aren't guaranteed a previous reference count
142 * exists. If the reference count is zero this
143 * function fails and returns NULL.
144 */
145 if (!atomic_inc_not_zero(&net->count))
146 net = NULL;
147 return net;
148}
149
150static inline void put_net(struct net *net)
151{
152 if (atomic_dec_and_test(&net->count))
153 __put_net(net);
154}
155
156static inline
157int net_eq(const struct net *net1, const struct net *net2)
158{
159 return net1 == net2;
160}
161
162extern void net_drop_ns(void *);
163
164#else
165
166static inline struct net *get_net(struct net *net)
167{
168 return net;
169}
170
171static inline void put_net(struct net *net)
172{
173}
174
175static inline struct net *maybe_get_net(struct net *net)
176{
177 return net;
178}
179
180static inline
181int net_eq(const struct net *net1, const struct net *net2)
182{
183 return 1;
184}
185
186#define net_drop_ns NULL
187#endif
188
189
190#ifdef NETNS_REFCNT_DEBUG
191static inline struct net *hold_net(struct net *net)
192{
193 if (net)
194 atomic_inc(&net->use_count);
195 return net;
196}
197
198static inline void release_net(struct net *net)
199{
200 if (net)
201 atomic_dec(&net->use_count);
202}
203#else
204static inline struct net *hold_net(struct net *net)
205{
206 return net;
207}
208
209static inline void release_net(struct net *net)
210{
211}
212#endif
213
214#ifdef CONFIG_NET_NS
215
216static inline void write_pnet(struct net **pnet, struct net *net)
217{
218 *pnet = net;
219}
220
221static inline struct net *read_pnet(struct net * const *pnet)
222{
223 return *pnet;
224}
225
226#else
227
228#define write_pnet(pnet, net) do { (void)(net);} while (0)
229#define read_pnet(pnet) (&init_net)
230
231#endif
232
233#define for_each_net(VAR) \
234 list_for_each_entry(VAR, &net_namespace_list, list)
235
236#define for_each_net_rcu(VAR) \
237 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
238
239#ifdef CONFIG_NET_NS
240#define __net_init
241#define __net_exit
242#define __net_initdata
243#else
244#define __net_init __init
245#define __net_exit __exit_refok
246#define __net_initdata __initdata
247#endif
248
249struct pernet_operations {
250 struct list_head list;
251 int (*init)(struct net *net);
252 void (*exit)(struct net *net);
253 void (*exit_batch)(struct list_head *net_exit_list);
254 int *id;
255 size_t size;
256};
257
258/*
259 * Use these carefully. If you implement a network device and it
260 * needs per network namespace operations use device pernet operations,
261 * otherwise use pernet subsys operations.
262 *
263 * Network interfaces need to be removed from a dying netns _before_
264 * subsys notifiers can be called, as most of the network code cleanup
265 * (which is done from subsys notifiers) runs with the assumption that
266 * dev_remove_pack has been called so no new packets will arrive during
267 * and after the cleanup functions have been called. dev_remove_pack
268 * is not per namespace so instead the guarantee of no more packets
269 * arriving in a network namespace is provided by ensuring that all
270 * network devices and all sockets have left the network namespace
271 * before the cleanup methods are called.
272 *
273 * For the longest time the ipv4 icmp code was registered as a pernet
274 * device which caused kernel oops, and panics during network
275 * namespace cleanup. So please don't get this wrong.
276 */
277extern int register_pernet_subsys(struct pernet_operations *);
278extern void unregister_pernet_subsys(struct pernet_operations *);
279extern int register_pernet_device(struct pernet_operations *);
280extern void unregister_pernet_device(struct pernet_operations *);
281
282struct ctl_table;
283struct ctl_table_header;
284
285#ifdef CONFIG_SYSCTL
286extern int net_sysctl_init(void);
287extern struct ctl_table_header *register_net_sysctl(struct net *net,
288 const char *path, struct ctl_table *table);
289extern void unregister_net_sysctl_table(struct ctl_table_header *header);
290#else
291static inline int net_sysctl_init(void) { return 0; }
292static inline struct ctl_table_header *register_net_sysctl(struct net *net,
293 const char *path, struct ctl_table *table)
294{
295 return NULL;
296}
297static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
298{
299}
300#endif
301
302
303#endif /* __NET_NET_NAMESPACE_H */