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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/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 defer_free_list;
84 struct llist_node cleanup_list; /* namespaces on death row */
85
86#ifdef CONFIG_KEYS
87 struct key_tag *key_domain; /* Key domain of operation tag */
88#endif
89 struct user_namespace *user_ns; /* Owning user namespace */
90 struct ucounts *ucounts;
91 struct idr netns_ids;
92
93 struct ns_common ns;
94 struct ref_tracker_dir refcnt_tracker;
95 struct ref_tracker_dir notrefcnt_tracker; /* tracker for objects not
96 * refcounted against netns
97 */
98 struct list_head dev_base_head;
99 struct proc_dir_entry *proc_net;
100 struct proc_dir_entry *proc_net_stat;
101
102#ifdef CONFIG_SYSCTL
103 struct ctl_table_set sysctls;
104#endif
105
106 struct sock *rtnl; /* rtnetlink socket */
107 struct sock *genl_sock;
108
109 struct uevent_sock *uevent_sock; /* uevent socket */
110
111 struct hlist_head *dev_name_head;
112 struct hlist_head *dev_index_head;
113 struct xarray dev_by_index;
114 struct raw_notifier_head netdev_chain;
115
116 /* Note that @hash_mix can be read millions times per second,
117 * it is critical that it is on a read_mostly cache line.
118 */
119 u32 hash_mix;
120
121 struct net_device *loopback_dev; /* The loopback */
122
123 /* core fib_rules */
124 struct list_head rules_ops;
125
126 struct netns_core core;
127 struct netns_mib mib;
128 struct netns_packet packet;
129#if IS_ENABLED(CONFIG_UNIX)
130 struct netns_unix unx;
131#endif
132 struct netns_nexthop nexthop;
133 struct netns_ipv4 ipv4;
134#if IS_ENABLED(CONFIG_IPV6)
135 struct netns_ipv6 ipv6;
136#endif
137#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
138 struct netns_ieee802154_lowpan ieee802154_lowpan;
139#endif
140#if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
141 struct netns_sctp sctp;
142#endif
143#ifdef CONFIG_NETFILTER
144 struct netns_nf nf;
145#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
146 struct netns_ct ct;
147#endif
148#if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
149 struct netns_nftables nft;
150#endif
151#if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
152 struct netns_ft ft;
153#endif
154#endif
155#ifdef CONFIG_WEXT_CORE
156 struct sk_buff_head wext_nlevents;
157#endif
158 struct net_generic __rcu *gen;
159
160 /* Used to store attached BPF programs */
161 struct netns_bpf bpf;
162
163 /* Note : following structs are cache line aligned */
164#ifdef CONFIG_XFRM
165 struct netns_xfrm xfrm;
166#endif
167
168 u64 net_cookie; /* written once */
169
170#if IS_ENABLED(CONFIG_IP_VS)
171 struct netns_ipvs *ipvs;
172#endif
173#if IS_ENABLED(CONFIG_MPLS)
174 struct netns_mpls mpls;
175#endif
176#if IS_ENABLED(CONFIG_CAN)
177 struct netns_can can;
178#endif
179#ifdef CONFIG_XDP_SOCKETS
180 struct netns_xdp xdp;
181#endif
182#if IS_ENABLED(CONFIG_MCTP)
183 struct netns_mctp mctp;
184#endif
185#if IS_ENABLED(CONFIG_CRYPTO_USER)
186 struct sock *crypto_nlsk;
187#endif
188 struct sock *diag_nlsk;
189#if IS_ENABLED(CONFIG_SMC)
190 struct netns_smc smc;
191#endif
192#ifdef CONFIG_DEBUG_NET_SMALL_RTNL
193 /* Move to a better place when the config guard is removed. */
194 struct mutex rtnl_mutex;
195#endif
196} __randomize_layout;
197
198#include <linux/seq_file_net.h>
199
200/* Init's network namespace */
201extern struct net init_net;
202
203#ifdef CONFIG_NET_NS
204struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
205 struct net *old_net);
206
207void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
208
209void net_ns_barrier(void);
210
211struct ns_common *get_net_ns(struct ns_common *ns);
212struct net *get_net_ns_by_fd(int fd);
213#else /* CONFIG_NET_NS */
214#include <linux/sched.h>
215#include <linux/nsproxy.h>
216static inline struct net *copy_net_ns(unsigned long flags,
217 struct user_namespace *user_ns, struct net *old_net)
218{
219 if (flags & CLONE_NEWNET)
220 return ERR_PTR(-EINVAL);
221 return old_net;
222}
223
224static inline void net_ns_get_ownership(const struct net *net,
225 kuid_t *uid, kgid_t *gid)
226{
227 *uid = GLOBAL_ROOT_UID;
228 *gid = GLOBAL_ROOT_GID;
229}
230
231static inline void net_ns_barrier(void) {}
232
233static inline struct ns_common *get_net_ns(struct ns_common *ns)
234{
235 return ERR_PTR(-EINVAL);
236}
237
238static inline struct net *get_net_ns_by_fd(int fd)
239{
240 return ERR_PTR(-EINVAL);
241}
242#endif /* CONFIG_NET_NS */
243
244
245extern struct list_head net_namespace_list;
246
247struct net *get_net_ns_by_pid(pid_t pid);
248
249#ifdef CONFIG_SYSCTL
250void ipx_register_sysctl(void);
251void ipx_unregister_sysctl(void);
252#else
253#define ipx_register_sysctl()
254#define ipx_unregister_sysctl()
255#endif
256
257#ifdef CONFIG_NET_NS
258void __put_net(struct net *net);
259
260/* Try using get_net_track() instead */
261static inline struct net *get_net(struct net *net)
262{
263 refcount_inc(&net->ns.count);
264 return net;
265}
266
267static inline struct net *maybe_get_net(struct net *net)
268{
269 /* Used when we know struct net exists but we
270 * aren't guaranteed a previous reference count
271 * exists. If the reference count is zero this
272 * function fails and returns NULL.
273 */
274 if (!refcount_inc_not_zero(&net->ns.count))
275 net = NULL;
276 return net;
277}
278
279/* Try using put_net_track() instead */
280static inline void put_net(struct net *net)
281{
282 if (refcount_dec_and_test(&net->ns.count))
283 __put_net(net);
284}
285
286static inline
287int net_eq(const struct net *net1, const struct net *net2)
288{
289 return net1 == net2;
290}
291
292static inline int check_net(const struct net *net)
293{
294 return refcount_read(&net->ns.count) != 0;
295}
296
297void net_drop_ns(void *);
298void net_passive_dec(struct net *net);
299
300#else
301
302static inline struct net *get_net(struct net *net)
303{
304 return net;
305}
306
307static inline void put_net(struct net *net)
308{
309}
310
311static inline struct net *maybe_get_net(struct net *net)
312{
313 return net;
314}
315
316static inline
317int net_eq(const struct net *net1, const struct net *net2)
318{
319 return 1;
320}
321
322static inline int check_net(const struct net *net)
323{
324 return 1;
325}
326
327#define net_drop_ns NULL
328
329static inline void net_passive_dec(struct net *net)
330{
331 refcount_dec(&net->passive);
332}
333#endif
334
335static inline void net_passive_inc(struct net *net)
336{
337 refcount_inc(&net->passive);
338}
339
340/* Returns true if the netns initialization is completed successfully */
341static inline bool net_initialized(const struct net *net)
342{
343 return READ_ONCE(net->list.next);
344}
345
346static inline void __netns_tracker_alloc(struct net *net,
347 netns_tracker *tracker,
348 bool refcounted,
349 gfp_t gfp)
350{
351#ifdef CONFIG_NET_NS_REFCNT_TRACKER
352 ref_tracker_alloc(refcounted ? &net->refcnt_tracker :
353 &net->notrefcnt_tracker,
354 tracker, gfp);
355#endif
356}
357
358static inline void netns_tracker_alloc(struct net *net, netns_tracker *tracker,
359 gfp_t gfp)
360{
361 __netns_tracker_alloc(net, tracker, true, gfp);
362}
363
364static inline void __netns_tracker_free(struct net *net,
365 netns_tracker *tracker,
366 bool refcounted)
367{
368#ifdef CONFIG_NET_NS_REFCNT_TRACKER
369 ref_tracker_free(refcounted ? &net->refcnt_tracker :
370 &net->notrefcnt_tracker, tracker);
371#endif
372}
373
374static inline struct net *get_net_track(struct net *net,
375 netns_tracker *tracker, gfp_t gfp)
376{
377 get_net(net);
378 netns_tracker_alloc(net, tracker, gfp);
379 return net;
380}
381
382static inline void put_net_track(struct net *net, netns_tracker *tracker)
383{
384 __netns_tracker_free(net, tracker, true);
385 put_net(net);
386}
387
388typedef struct {
389#ifdef CONFIG_NET_NS
390 struct net __rcu *net;
391#endif
392} possible_net_t;
393
394static inline void write_pnet(possible_net_t *pnet, struct net *net)
395{
396#ifdef CONFIG_NET_NS
397 rcu_assign_pointer(pnet->net, net);
398#endif
399}
400
401static inline struct net *read_pnet(const possible_net_t *pnet)
402{
403#ifdef CONFIG_NET_NS
404 return rcu_dereference_protected(pnet->net, true);
405#else
406 return &init_net;
407#endif
408}
409
410static inline struct net *read_pnet_rcu(const possible_net_t *pnet)
411{
412#ifdef CONFIG_NET_NS
413 return rcu_dereference(pnet->net);
414#else
415 return &init_net;
416#endif
417}
418
419/* Protected by net_rwsem */
420#define for_each_net(VAR) \
421 list_for_each_entry(VAR, &net_namespace_list, list)
422#define for_each_net_continue_reverse(VAR) \
423 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list)
424#define for_each_net_rcu(VAR) \
425 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
426
427#ifdef CONFIG_NET_NS
428#define __net_init
429#define __net_exit
430#define __net_initdata
431#define __net_initconst
432#else
433#define __net_init __init
434#define __net_exit __ref
435#define __net_initdata __initdata
436#define __net_initconst __initconst
437#endif
438
439int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
440int peernet2id(const struct net *net, struct net *peer);
441bool peernet_has_id(const struct net *net, struct net *peer);
442struct net *get_net_ns_by_id(const struct net *net, int id);
443
444struct pernet_operations {
445 struct list_head list;
446 /*
447 * Below methods are called without any exclusive locks.
448 * More than one net may be constructed and destructed
449 * in parallel on several cpus. Every pernet_operations
450 * have to keep in mind all other pernet_operations and
451 * to introduce a locking, if they share common resources.
452 *
453 * The only time they are called with exclusive lock is
454 * from register_pernet_subsys(), unregister_pernet_subsys()
455 * register_pernet_device() and unregister_pernet_device().
456 *
457 * Exit methods using blocking RCU primitives, such as
458 * synchronize_rcu(), should be implemented via exit_batch.
459 * Then, destruction of a group of net requires single
460 * synchronize_rcu() related to these pernet_operations,
461 * instead of separate synchronize_rcu() for every net.
462 * Please, avoid synchronize_rcu() at all, where it's possible.
463 *
464 * Note that a combination of pre_exit() and exit() can
465 * be used, since a synchronize_rcu() is guaranteed between
466 * the calls.
467 */
468 int (*init)(struct net *net);
469 void (*pre_exit)(struct net *net);
470 void (*exit)(struct net *net);
471 void (*exit_batch)(struct list_head *net_exit_list);
472 /* Following method is called with RTNL held. */
473 void (*exit_batch_rtnl)(struct list_head *net_exit_list,
474 struct list_head *dev_kill_list);
475 unsigned int * const id;
476 const size_t size;
477};
478
479/*
480 * Use these carefully. If you implement a network device and it
481 * needs per network namespace operations use device pernet operations,
482 * otherwise use pernet subsys operations.
483 *
484 * Network interfaces need to be removed from a dying netns _before_
485 * subsys notifiers can be called, as most of the network code cleanup
486 * (which is done from subsys notifiers) runs with the assumption that
487 * dev_remove_pack has been called so no new packets will arrive during
488 * and after the cleanup functions have been called. dev_remove_pack
489 * is not per namespace so instead the guarantee of no more packets
490 * arriving in a network namespace is provided by ensuring that all
491 * network devices and all sockets have left the network namespace
492 * before the cleanup methods are called.
493 *
494 * For the longest time the ipv4 icmp code was registered as a pernet
495 * device which caused kernel oops, and panics during network
496 * namespace cleanup. So please don't get this wrong.
497 */
498int register_pernet_subsys(struct pernet_operations *);
499void unregister_pernet_subsys(struct pernet_operations *);
500int register_pernet_device(struct pernet_operations *);
501void unregister_pernet_device(struct pernet_operations *);
502
503struct ctl_table;
504
505#define register_net_sysctl(net, path, table) \
506 register_net_sysctl_sz(net, path, table, ARRAY_SIZE(table))
507#ifdef CONFIG_SYSCTL
508int net_sysctl_init(void);
509struct ctl_table_header *register_net_sysctl_sz(struct net *net, const char *path,
510 struct ctl_table *table, size_t table_size);
511void unregister_net_sysctl_table(struct ctl_table_header *header);
512#else
513static inline int net_sysctl_init(void) { return 0; }
514static inline struct ctl_table_header *register_net_sysctl_sz(struct net *net,
515 const char *path, struct ctl_table *table, size_t table_size)
516{
517 return NULL;
518}
519static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
520{
521}
522#endif
523
524static inline int rt_genid_ipv4(const struct net *net)
525{
526 return atomic_read(&net->ipv4.rt_genid);
527}
528
529#if IS_ENABLED(CONFIG_IPV6)
530static inline int rt_genid_ipv6(const struct net *net)
531{
532 return atomic_read(&net->ipv6.fib6_sernum);
533}
534#endif
535
536static inline void rt_genid_bump_ipv4(struct net *net)
537{
538 atomic_inc(&net->ipv4.rt_genid);
539}
540
541extern void (*__fib6_flush_trees)(struct net *net);
542static inline void rt_genid_bump_ipv6(struct net *net)
543{
544 if (__fib6_flush_trees)
545 __fib6_flush_trees(net);
546}
547
548#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
549static inline struct netns_ieee802154_lowpan *
550net_ieee802154_lowpan(struct net *net)
551{
552 return &net->ieee802154_lowpan;
553}
554#endif
555
556/* For callers who don't really care about whether it's IPv4 or IPv6 */
557static inline void rt_genid_bump_all(struct net *net)
558{
559 rt_genid_bump_ipv4(net);
560 rt_genid_bump_ipv6(net);
561}
562
563static inline int fnhe_genid(const struct net *net)
564{
565 return atomic_read(&net->fnhe_genid);
566}
567
568static inline void fnhe_genid_bump(struct net *net)
569{
570 atomic_inc(&net->fnhe_genid);
571}
572
573#ifdef CONFIG_NET
574void net_ns_init(void);
575#else
576static inline void net_ns_init(void) {}
577#endif
578
579#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 */