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

source code of linux/include/net/net_namespace.h