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
47 struct user_namespace;
48 struct proc_dir_entry;
49 struct net_device;
50 struct sock;
51 struct ctl_table_header;
52 struct net_generic;
53 struct uevent_sock;
54 struct netns_ipvs;
55 struct bpf_prog;
56
57
58 #define NETDEV_HASHBITS 8
59 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
60
61 struct 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 */
201 extern struct net init_net;
202
203 #ifdef CONFIG_NET_NS
204 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
205 struct net *old_net);
206
207 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
208
209 void net_ns_barrier(void);
210
211 struct ns_common *get_net_ns(struct ns_common *ns);
212 struct net *get_net_ns_by_fd(int fd);
213 #else /* CONFIG_NET_NS */
214 #include <linux/sched.h>
215 #include <linux/nsproxy.h>
copy_net_ns(unsigned long flags,struct user_namespace * user_ns,struct net * old_net)216 static 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
net_ns_get_ownership(const struct net * net,kuid_t * uid,kgid_t * gid)224 static 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
net_ns_barrier(void)231 static inline void net_ns_barrier(void) {}
232
get_net_ns(struct ns_common * ns)233 static inline struct ns_common *get_net_ns(struct ns_common *ns)
234 {
235 return ERR_PTR(-EINVAL);
236 }
237
get_net_ns_by_fd(int fd)238 static inline struct net *get_net_ns_by_fd(int fd)
239 {
240 return ERR_PTR(-EINVAL);
241 }
242 #endif /* CONFIG_NET_NS */
243
244
245 extern struct list_head net_namespace_list;
246
247 struct net *get_net_ns_by_pid(pid_t pid);
248
249 #ifdef CONFIG_SYSCTL
250 void ipx_register_sysctl(void);
251 void ipx_unregister_sysctl(void);
252 #else
253 #define ipx_register_sysctl()
254 #define ipx_unregister_sysctl()
255 #endif
256
257 #ifdef CONFIG_NET_NS
258 void __put_net(struct net *net);
259
260 /* Try using get_net_track() instead */
get_net(struct net * net)261 static inline struct net *get_net(struct net *net)
262 {
263 refcount_inc(&net->ns.count);
264 return net;
265 }
266
maybe_get_net(struct net * net)267 static 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 */
put_net(struct net * net)280 static inline void put_net(struct net *net)
281 {
282 if (refcount_dec_and_test(&net->ns.count))
283 __put_net(net);
284 }
285
286 static inline
net_eq(const struct net * net1,const struct net * net2)287 int net_eq(const struct net *net1, const struct net *net2)
288 {
289 return net1 == net2;
290 }
291
check_net(const struct net * net)292 static inline int check_net(const struct net *net)
293 {
294 return refcount_read(&net->ns.count) != 0;
295 }
296
297 void net_drop_ns(void *);
298
299 #else
300
get_net(struct net * net)301 static inline struct net *get_net(struct net *net)
302 {
303 return net;
304 }
305
put_net(struct net * net)306 static inline void put_net(struct net *net)
307 {
308 }
309
maybe_get_net(struct net * net)310 static inline struct net *maybe_get_net(struct net *net)
311 {
312 return net;
313 }
314
315 static inline
net_eq(const struct net * net1,const struct net * net2)316 int net_eq(const struct net *net1, const struct net *net2)
317 {
318 return 1;
319 }
320
check_net(const struct net * net)321 static inline int check_net(const struct net *net)
322 {
323 return 1;
324 }
325
326 #define net_drop_ns NULL
327 #endif
328
329 /* Returns true if the netns initialization is completed successfully */
net_initialized(const struct net * net)330 static inline bool net_initialized(const struct net *net)
331 {
332 return READ_ONCE(net->list.next);
333 }
334
__netns_tracker_alloc(struct net * net,netns_tracker * tracker,bool refcounted,gfp_t gfp)335 static inline void __netns_tracker_alloc(struct net *net,
336 netns_tracker *tracker,
337 bool refcounted,
338 gfp_t gfp)
339 {
340 #ifdef CONFIG_NET_NS_REFCNT_TRACKER
341 ref_tracker_alloc(refcounted ? &net->refcnt_tracker :
342 &net->notrefcnt_tracker,
343 tracker, gfp);
344 #endif
345 }
346
netns_tracker_alloc(struct net * net,netns_tracker * tracker,gfp_t gfp)347 static inline void netns_tracker_alloc(struct net *net, netns_tracker *tracker,
348 gfp_t gfp)
349 {
350 __netns_tracker_alloc(net, tracker, true, gfp);
351 }
352
__netns_tracker_free(struct net * net,netns_tracker * tracker,bool refcounted)353 static inline void __netns_tracker_free(struct net *net,
354 netns_tracker *tracker,
355 bool refcounted)
356 {
357 #ifdef CONFIG_NET_NS_REFCNT_TRACKER
358 ref_tracker_free(refcounted ? &net->refcnt_tracker :
359 &net->notrefcnt_tracker, tracker);
360 #endif
361 }
362
get_net_track(struct net * net,netns_tracker * tracker,gfp_t gfp)363 static inline struct net *get_net_track(struct net *net,
364 netns_tracker *tracker, gfp_t gfp)
365 {
366 get_net(net);
367 netns_tracker_alloc(net, tracker, gfp);
368 return net;
369 }
370
put_net_track(struct net * net,netns_tracker * tracker)371 static inline void put_net_track(struct net *net, netns_tracker *tracker)
372 {
373 __netns_tracker_free(net, tracker, true);
374 put_net(net);
375 }
376
377 typedef struct {
378 #ifdef CONFIG_NET_NS
379 struct net __rcu *net;
380 #endif
381 } possible_net_t;
382
write_pnet(possible_net_t * pnet,struct net * net)383 static inline void write_pnet(possible_net_t *pnet, struct net *net)
384 {
385 #ifdef CONFIG_NET_NS
386 rcu_assign_pointer(pnet->net, net);
387 #endif
388 }
389
read_pnet(const possible_net_t * pnet)390 static inline struct net *read_pnet(const possible_net_t *pnet)
391 {
392 #ifdef CONFIG_NET_NS
393 return rcu_dereference_protected(pnet->net, true);
394 #else
395 return &init_net;
396 #endif
397 }
398
read_pnet_rcu(possible_net_t * pnet)399 static inline struct net *read_pnet_rcu(possible_net_t *pnet)
400 {
401 #ifdef CONFIG_NET_NS
402 return rcu_dereference(pnet->net);
403 #else
404 return &init_net;
405 #endif
406 }
407
408 /* Protected by net_rwsem */
409 #define for_each_net(VAR) \
410 list_for_each_entry(VAR, &net_namespace_list, list)
411 #define for_each_net_continue_reverse(VAR) \
412 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list)
413 #define for_each_net_rcu(VAR) \
414 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
415
416 #ifdef CONFIG_NET_NS
417 #define __net_init
418 #define __net_exit
419 #define __net_initdata
420 #define __net_initconst
421 #else
422 #define __net_init __init
423 #define __net_exit __ref
424 #define __net_initdata __initdata
425 #define __net_initconst __initconst
426 #endif
427
428 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
429 int peernet2id(const struct net *net, struct net *peer);
430 bool peernet_has_id(const struct net *net, struct net *peer);
431 struct net *get_net_ns_by_id(const struct net *net, int id);
432
433 struct pernet_operations {
434 struct list_head list;
435 /*
436 * Below methods are called without any exclusive locks.
437 * More than one net may be constructed and destructed
438 * in parallel on several cpus. Every pernet_operations
439 * have to keep in mind all other pernet_operations and
440 * to introduce a locking, if they share common resources.
441 *
442 * The only time they are called with exclusive lock is
443 * from register_pernet_subsys(), unregister_pernet_subsys()
444 * register_pernet_device() and unregister_pernet_device().
445 *
446 * Exit methods using blocking RCU primitives, such as
447 * synchronize_rcu(), should be implemented via exit_batch.
448 * Then, destruction of a group of net requires single
449 * synchronize_rcu() related to these pernet_operations,
450 * instead of separate synchronize_rcu() for every net.
451 * Please, avoid synchronize_rcu() at all, where it's possible.
452 *
453 * Note that a combination of pre_exit() and exit() can
454 * be used, since a synchronize_rcu() is guaranteed between
455 * the calls.
456 */
457 int (*init)(struct net *net);
458 void (*pre_exit)(struct net *net);
459 void (*exit)(struct net *net);
460 void (*exit_batch)(struct list_head *net_exit_list);
461 /* Following method is called with RTNL held. */
462 void (*exit_batch_rtnl)(struct list_head *net_exit_list,
463 struct list_head *dev_kill_list);
464 unsigned int * const id;
465 const size_t size;
466 };
467
468 /*
469 * Use these carefully. If you implement a network device and it
470 * needs per network namespace operations use device pernet operations,
471 * otherwise use pernet subsys operations.
472 *
473 * Network interfaces need to be removed from a dying netns _before_
474 * subsys notifiers can be called, as most of the network code cleanup
475 * (which is done from subsys notifiers) runs with the assumption that
476 * dev_remove_pack has been called so no new packets will arrive during
477 * and after the cleanup functions have been called. dev_remove_pack
478 * is not per namespace so instead the guarantee of no more packets
479 * arriving in a network namespace is provided by ensuring that all
480 * network devices and all sockets have left the network namespace
481 * before the cleanup methods are called.
482 *
483 * For the longest time the ipv4 icmp code was registered as a pernet
484 * device which caused kernel oops, and panics during network
485 * namespace cleanup. So please don't get this wrong.
486 */
487 int register_pernet_subsys(struct pernet_operations *);
488 void unregister_pernet_subsys(struct pernet_operations *);
489 int register_pernet_device(struct pernet_operations *);
490 void unregister_pernet_device(struct pernet_operations *);
491
492 struct ctl_table;
493
494 #define register_net_sysctl(net, path, table) \
495 register_net_sysctl_sz(net, path, table, ARRAY_SIZE(table))
496 #ifdef CONFIG_SYSCTL
497 int net_sysctl_init(void);
498 struct ctl_table_header *register_net_sysctl_sz(struct net *net, const char *path,
499 struct ctl_table *table, size_t table_size);
500 void unregister_net_sysctl_table(struct ctl_table_header *header);
501 #else
net_sysctl_init(void)502 static inline int net_sysctl_init(void) { return 0; }
register_net_sysctl_sz(struct net * net,const char * path,struct ctl_table * table,size_t table_size)503 static inline struct ctl_table_header *register_net_sysctl_sz(struct net *net,
504 const char *path, struct ctl_table *table, size_t table_size)
505 {
506 return NULL;
507 }
unregister_net_sysctl_table(struct ctl_table_header * header)508 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
509 {
510 }
511 #endif
512
rt_genid_ipv4(const struct net * net)513 static inline int rt_genid_ipv4(const struct net *net)
514 {
515 return atomic_read(&net->ipv4.rt_genid);
516 }
517
518 #if IS_ENABLED(CONFIG_IPV6)
rt_genid_ipv6(const struct net * net)519 static inline int rt_genid_ipv6(const struct net *net)
520 {
521 return atomic_read(&net->ipv6.fib6_sernum);
522 }
523 #endif
524
rt_genid_bump_ipv4(struct net * net)525 static inline void rt_genid_bump_ipv4(struct net *net)
526 {
527 atomic_inc(&net->ipv4.rt_genid);
528 }
529
530 extern void (*__fib6_flush_trees)(struct net *net);
rt_genid_bump_ipv6(struct net * net)531 static inline void rt_genid_bump_ipv6(struct net *net)
532 {
533 if (__fib6_flush_trees)
534 __fib6_flush_trees(net);
535 }
536
537 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
538 static inline struct netns_ieee802154_lowpan *
net_ieee802154_lowpan(struct net * net)539 net_ieee802154_lowpan(struct net *net)
540 {
541 return &net->ieee802154_lowpan;
542 }
543 #endif
544
545 /* For callers who don't really care about whether it's IPv4 or IPv6 */
rt_genid_bump_all(struct net * net)546 static inline void rt_genid_bump_all(struct net *net)
547 {
548 rt_genid_bump_ipv4(net);
549 rt_genid_bump_ipv6(net);
550 }
551
fnhe_genid(const struct net * net)552 static inline int fnhe_genid(const struct net *net)
553 {
554 return atomic_read(&net->fnhe_genid);
555 }
556
fnhe_genid_bump(struct net * net)557 static inline void fnhe_genid_bump(struct net *net)
558 {
559 atomic_inc(&net->fnhe_genid);
560 }
561
562 #ifdef CONFIG_NET
563 void net_ns_init(void);
564 #else
net_ns_init(void)565 static inline void net_ns_init(void) {}
566 #endif
567
568 #endif /* __NET_NET_NAMESPACE_H */
569