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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
30struct user_namespace;
31struct proc_dir_entry;
32struct net_device;
33struct sock;
34struct ctl_table_header;
35struct net_generic;
36struct sock;
37struct netns_ipvs;
38
39
40#define NETDEV_HASHBITS 8
41#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
42
43struct net {
44 atomic_t passive; /* To decided when the network
45 * namespace should be freed.
46 */
47 atomic_t count; /* To decided when the network
48 * namespace should be shut down.
49 */
50#ifdef NETNS_REFCNT_DEBUG
51 atomic_t use_count; /* To track references we
52 * destroy on demand
53 */
54#endif
55 spinlock_t rules_mod_lock;
56
57 struct list_head list; /* list of network namespaces */
58 struct list_head cleanup_list; /* namespaces on death row */
59 struct list_head exit_list; /* Use only net_mutex */
60
61 struct user_namespace *user_ns; /* Owning user namespace */
62
63 unsigned int proc_inum;
64
65 struct proc_dir_entry *proc_net;
66 struct proc_dir_entry *proc_net_stat;
67
68#ifdef CONFIG_SYSCTL
69 struct ctl_table_set sysctls;
70#endif
71
72 struct sock *rtnl; /* rtnetlink socket */
73 struct sock *genl_sock;
74
75 struct list_head dev_base_head;
76 struct hlist_head *dev_name_head;
77 struct hlist_head *dev_index_head;
78 unsigned int dev_base_seq; /* protected by rtnl_mutex */
79 int ifindex;
80 unsigned int dev_unreg_count;
81
82 /* core fib_rules */
83 struct list_head rules_ops;
84
85
86 struct net_device *loopback_dev; /* The loopback */
87 struct netns_core core;
88 struct netns_mib mib;
89 struct netns_packet packet;
90 struct netns_unix unx;
91 struct netns_ipv4 ipv4;
92#if IS_ENABLED(CONFIG_IPV6)
93 struct netns_ipv6 ipv6;
94#endif
95#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
96 struct netns_ieee802154_lowpan ieee802154_lowpan;
97#endif
98#if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
99 struct netns_sctp sctp;
100#endif
101#if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
102 struct netns_dccp dccp;
103#endif
104#ifdef CONFIG_NETFILTER
105 struct netns_nf nf;
106 struct netns_xt xt;
107#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
108 struct netns_ct ct;
109#endif
110#if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
111 struct netns_nftables nft;
112#endif
113#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
114 struct netns_nf_frag nf_frag;
115#endif
116 struct sock *nfnl;
117 struct sock *nfnl_stash;
118#endif
119#ifdef CONFIG_WEXT_CORE
120 struct sk_buff_head wext_nlevents;
121#endif
122 struct net_generic __rcu *gen;
123
124 /* Note : following structs are cache line aligned */
125#ifdef CONFIG_XFRM
126 struct netns_xfrm xfrm;
127#endif
128#if IS_ENABLED(CONFIG_IP_VS)
129 struct netns_ipvs *ipvs;
130#endif
131 struct sock *diag_nlsk;
132 atomic_t fnhe_genid;
133};
134
135#include <linux/seq_file_net.h>
136
137/* Init's network namespace */
138extern struct net init_net;
139
140#ifdef CONFIG_NET_NS
141struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
142 struct net *old_net);
143
144#else /* CONFIG_NET_NS */
145#include <linux/sched.h>
146#include <linux/nsproxy.h>
147static inline struct net *copy_net_ns(unsigned long flags,
148 struct user_namespace *user_ns, struct net *old_net)
149{
150 if (flags & CLONE_NEWNET)
151 return ERR_PTR(-EINVAL);
152 return old_net;
153}
154#endif /* CONFIG_NET_NS */
155
156
157extern struct list_head net_namespace_list;
158
159struct net *get_net_ns_by_pid(pid_t pid);
160struct net *get_net_ns_by_fd(int pid);
161
162#ifdef CONFIG_SYSCTL
163void ipx_register_sysctl(void);
164void ipx_unregister_sysctl(void);
165#else
166#define ipx_register_sysctl()
167#define ipx_unregister_sysctl()
168#endif
169
170#ifdef CONFIG_NET_NS
171void __put_net(struct net *net);
172
173static inline struct net *get_net(struct net *net)
174{
175 atomic_inc(&net->count);
176 return net;
177}
178
179static inline struct net *maybe_get_net(struct net *net)
180{
181 /* Used when we know struct net exists but we
182 * aren't guaranteed a previous reference count
183 * exists. If the reference count is zero this
184 * function fails and returns NULL.
185 */
186 if (!atomic_inc_not_zero(&net->count))
187 net = NULL;
188 return net;
189}
190
191static inline void put_net(struct net *net)
192{
193 if (atomic_dec_and_test(&net->count))
194 __put_net(net);
195}
196
197static inline
198int net_eq(const struct net *net1, const struct net *net2)
199{
200 return net1 == net2;
201}
202
203void net_drop_ns(void *);
204
205#else
206
207static inline struct net *get_net(struct net *net)
208{
209 return net;
210}
211
212static inline void put_net(struct net *net)
213{
214}
215
216static inline struct net *maybe_get_net(struct net *net)
217{
218 return net;
219}
220
221static inline
222int net_eq(const struct net *net1, const struct net *net2)
223{
224 return 1;
225}
226
227#define net_drop_ns NULL
228#endif
229
230
231#ifdef NETNS_REFCNT_DEBUG
232static inline struct net *hold_net(struct net *net)
233{
234 if (net)
235 atomic_inc(&net->use_count);
236 return net;
237}
238
239static inline void release_net(struct net *net)
240{
241 if (net)
242 atomic_dec(&net->use_count);
243}
244#else
245static inline struct net *hold_net(struct net *net)
246{
247 return net;
248}
249
250static inline void release_net(struct net *net)
251{
252}
253#endif
254
255#ifdef CONFIG_NET_NS
256
257static inline void write_pnet(struct net **pnet, struct net *net)
258{
259 *pnet = net;
260}
261
262static inline struct net *read_pnet(struct net * const *pnet)
263{
264 return *pnet;
265}
266
267#else
268
269#define write_pnet(pnet, net) do { (void)(net);} while (0)
270#define read_pnet(pnet) (&init_net)
271
272#endif
273
274#define for_each_net(VAR) \
275 list_for_each_entry(VAR, &net_namespace_list, list)
276
277#define for_each_net_rcu(VAR) \
278 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
279
280#ifdef CONFIG_NET_NS
281#define __net_init
282#define __net_exit
283#define __net_initdata
284#define __net_initconst
285#else
286#define __net_init __init
287#define __net_exit __exit_refok
288#define __net_initdata __initdata
289#define __net_initconst __initconst
290#endif
291
292struct pernet_operations {
293 struct list_head list;
294 int (*init)(struct net *net);
295 void (*exit)(struct net *net);
296 void (*exit_batch)(struct list_head *net_exit_list);
297 int *id;
298 size_t size;
299};
300
301/*
302 * Use these carefully. If you implement a network device and it
303 * needs per network namespace operations use device pernet operations,
304 * otherwise use pernet subsys operations.
305 *
306 * Network interfaces need to be removed from a dying netns _before_
307 * subsys notifiers can be called, as most of the network code cleanup
308 * (which is done from subsys notifiers) runs with the assumption that
309 * dev_remove_pack has been called so no new packets will arrive during
310 * and after the cleanup functions have been called. dev_remove_pack
311 * is not per namespace so instead the guarantee of no more packets
312 * arriving in a network namespace is provided by ensuring that all
313 * network devices and all sockets have left the network namespace
314 * before the cleanup methods are called.
315 *
316 * For the longest time the ipv4 icmp code was registered as a pernet
317 * device which caused kernel oops, and panics during network
318 * namespace cleanup. So please don't get this wrong.
319 */
320int register_pernet_subsys(struct pernet_operations *);
321void unregister_pernet_subsys(struct pernet_operations *);
322int register_pernet_device(struct pernet_operations *);
323void unregister_pernet_device(struct pernet_operations *);
324
325struct ctl_table;
326struct ctl_table_header;
327
328#ifdef CONFIG_SYSCTL
329int net_sysctl_init(void);
330struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
331 struct ctl_table *table);
332void unregister_net_sysctl_table(struct ctl_table_header *header);
333#else
334static inline int net_sysctl_init(void) { return 0; }
335static inline struct ctl_table_header *register_net_sysctl(struct net *net,
336 const char *path, struct ctl_table *table)
337{
338 return NULL;
339}
340static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
341{
342}
343#endif
344
345static inline int rt_genid_ipv4(struct net *net)
346{
347 return atomic_read(&net->ipv4.rt_genid);
348}
349
350static inline void rt_genid_bump_ipv4(struct net *net)
351{
352 atomic_inc(&net->ipv4.rt_genid);
353}
354
355#if IS_ENABLED(CONFIG_IPV6)
356static inline int rt_genid_ipv6(struct net *net)
357{
358 return atomic_read(&net->ipv6.rt_genid);
359}
360
361static inline void rt_genid_bump_ipv6(struct net *net)
362{
363 atomic_inc(&net->ipv6.rt_genid);
364}
365#else
366static inline int rt_genid_ipv6(struct net *net)
367{
368 return 0;
369}
370
371static inline void rt_genid_bump_ipv6(struct net *net)
372{
373}
374#endif
375
376/* For callers who don't really care about whether it's IPv4 or IPv6 */
377static inline void rt_genid_bump_all(struct net *net)
378{
379 rt_genid_bump_ipv4(net);
380 rt_genid_bump_ipv6(net);
381}
382
383static inline int fnhe_genid(struct net *net)
384{
385 return atomic_read(&net->fnhe_genid);
386}
387
388static inline void fnhe_genid_bump(struct net *net)
389{
390 atomic_inc(&net->fnhe_genid);
391}
392
393#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#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 */