Line data Source code
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 :
46 : struct user_namespace;
47 : struct proc_dir_entry;
48 : struct net_device;
49 : struct sock;
50 : struct ctl_table_header;
51 : struct net_generic;
52 : struct uevent_sock;
53 : struct netns_ipvs;
54 : struct bpf_prog;
55 :
56 :
57 : #define NETDEV_HASHBITS 8
58 : #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
59 :
60 : struct net {
61 : /* First cache line can be often dirtied.
62 : * Do not place here read-mostly fields.
63 : */
64 : refcount_t passive; /* To decide when the network
65 : * namespace should be freed.
66 : */
67 : spinlock_t rules_mod_lock;
68 :
69 : atomic_t dev_unreg_count;
70 :
71 : unsigned int dev_base_seq; /* protected by rtnl_mutex */
72 : int ifindex;
73 :
74 : spinlock_t nsid_lock;
75 : atomic_t fnhe_genid;
76 :
77 : struct list_head list; /* list of network namespaces */
78 : struct list_head exit_list; /* To linked to call pernet exit
79 : * methods on dead net (
80 : * pernet_ops_rwsem read locked),
81 : * or to unregister pernet ops
82 : * (pernet_ops_rwsem write locked).
83 : */
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 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 */
196 : extern struct net init_net;
197 :
198 : #ifdef CONFIG_NET_NS
199 : struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
200 : struct net *old_net);
201 :
202 : void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
203 :
204 : void net_ns_barrier(void);
205 :
206 : struct ns_common *get_net_ns(struct ns_common *ns);
207 : struct net *get_net_ns_by_fd(int fd);
208 : #else /* CONFIG_NET_NS */
209 : #include <linux/sched.h>
210 : #include <linux/nsproxy.h>
211 : static inline struct net *copy_net_ns(unsigned long flags,
212 : struct user_namespace *user_ns, struct net *old_net)
213 : {
214 0 : if (flags & CLONE_NEWNET)
215 : return ERR_PTR(-EINVAL);
216 : return old_net;
217 : }
218 :
219 : static 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 :
226 : static inline void net_ns_barrier(void) {}
227 :
228 : static inline struct ns_common *get_net_ns(struct ns_common *ns)
229 : {
230 : return ERR_PTR(-EINVAL);
231 : }
232 :
233 : static inline struct net *get_net_ns_by_fd(int fd)
234 : {
235 : return ERR_PTR(-EINVAL);
236 : }
237 : #endif /* CONFIG_NET_NS */
238 :
239 :
240 : extern struct list_head net_namespace_list;
241 :
242 : struct net *get_net_ns_by_pid(pid_t pid);
243 :
244 : #ifdef CONFIG_SYSCTL
245 : void ipx_register_sysctl(void);
246 : void ipx_unregister_sysctl(void);
247 : #else
248 : #define ipx_register_sysctl()
249 : #define ipx_unregister_sysctl()
250 : #endif
251 :
252 : #ifdef CONFIG_NET_NS
253 : void __put_net(struct net *net);
254 :
255 : /* Try using get_net_track() instead */
256 : static inline struct net *get_net(struct net *net)
257 : {
258 : refcount_inc(&net->ns.count);
259 : return net;
260 : }
261 :
262 : static 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 */
275 : static inline void put_net(struct net *net)
276 : {
277 : if (refcount_dec_and_test(&net->ns.count))
278 : __put_net(net);
279 : }
280 :
281 : static inline
282 : int net_eq(const struct net *net1, const struct net *net2)
283 : {
284 : return net1 == net2;
285 : }
286 :
287 : static inline int check_net(const struct net *net)
288 : {
289 : return refcount_read(&net->ns.count) != 0;
290 : }
291 :
292 : void net_drop_ns(void *);
293 :
294 : #else
295 :
296 : static inline struct net *get_net(struct net *net)
297 : {
298 : return net;
299 : }
300 :
301 : static inline void put_net(struct net *net)
302 : {
303 : }
304 :
305 : static inline struct net *maybe_get_net(struct net *net)
306 : {
307 : return net;
308 : }
309 :
310 : static inline
311 : int net_eq(const struct net *net1, const struct net *net2)
312 : {
313 : return 1;
314 : }
315 :
316 : static inline int check_net(const struct net *net)
317 : {
318 : return 1;
319 : }
320 :
321 : #define net_drop_ns NULL
322 : #endif
323 :
324 :
325 : static 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 :
337 : static 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 :
343 : static 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 :
353 : static 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 :
361 : static 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 :
367 : typedef struct {
368 : #ifdef CONFIG_NET_NS
369 : struct net *net;
370 : #endif
371 : } possible_net_t;
372 :
373 : static inline void write_pnet(possible_net_t *pnet, struct net *net)
374 : {
375 : #ifdef CONFIG_NET_NS
376 : pnet->net = net;
377 : #endif
378 : }
379 :
380 : static inline struct net *read_pnet(const possible_net_t *pnet)
381 : {
382 : #ifdef CONFIG_NET_NS
383 : return pnet->net;
384 : #else
385 : return &init_net;
386 : #endif
387 : }
388 :
389 : /* Protected by net_rwsem */
390 : #define for_each_net(VAR) \
391 : list_for_each_entry(VAR, &net_namespace_list, list)
392 : #define for_each_net_continue_reverse(VAR) \
393 : list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list)
394 : #define for_each_net_rcu(VAR) \
395 : list_for_each_entry_rcu(VAR, &net_namespace_list, list)
396 :
397 : #ifdef CONFIG_NET_NS
398 : #define __net_init
399 : #define __net_exit
400 : #define __net_initdata
401 : #define __net_initconst
402 : #else
403 : #define __net_init __init
404 : #define __net_exit __ref
405 : #define __net_initdata __initdata
406 : #define __net_initconst __initconst
407 : #endif
408 :
409 : int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
410 : int peernet2id(const struct net *net, struct net *peer);
411 : bool peernet_has_id(const struct net *net, struct net *peer);
412 : struct net *get_net_ns_by_id(const struct net *net, int id);
413 :
414 : struct pernet_operations {
415 : struct list_head list;
416 : /*
417 : * Below methods are called without any exclusive locks.
418 : * More than one net may be constructed and destructed
419 : * in parallel on several cpus. Every pernet_operations
420 : * have to keep in mind all other pernet_operations and
421 : * to introduce a locking, if they share common resources.
422 : *
423 : * The only time they are called with exclusive lock is
424 : * from register_pernet_subsys(), unregister_pernet_subsys()
425 : * register_pernet_device() and unregister_pernet_device().
426 : *
427 : * Exit methods using blocking RCU primitives, such as
428 : * synchronize_rcu(), should be implemented via exit_batch.
429 : * Then, destruction of a group of net requires single
430 : * synchronize_rcu() related to these pernet_operations,
431 : * instead of separate synchronize_rcu() for every net.
432 : * Please, avoid synchronize_rcu() at all, where it's possible.
433 : *
434 : * Note that a combination of pre_exit() and exit() can
435 : * be used, since a synchronize_rcu() is guaranteed between
436 : * the calls.
437 : */
438 : int (*init)(struct net *net);
439 : void (*pre_exit)(struct net *net);
440 : void (*exit)(struct net *net);
441 : void (*exit_batch)(struct list_head *net_exit_list);
442 : unsigned int *id;
443 : size_t size;
444 : };
445 :
446 : /*
447 : * Use these carefully. If you implement a network device and it
448 : * needs per network namespace operations use device pernet operations,
449 : * otherwise use pernet subsys operations.
450 : *
451 : * Network interfaces need to be removed from a dying netns _before_
452 : * subsys notifiers can be called, as most of the network code cleanup
453 : * (which is done from subsys notifiers) runs with the assumption that
454 : * dev_remove_pack has been called so no new packets will arrive during
455 : * and after the cleanup functions have been called. dev_remove_pack
456 : * is not per namespace so instead the guarantee of no more packets
457 : * arriving in a network namespace is provided by ensuring that all
458 : * network devices and all sockets have left the network namespace
459 : * before the cleanup methods are called.
460 : *
461 : * For the longest time the ipv4 icmp code was registered as a pernet
462 : * device which caused kernel oops, and panics during network
463 : * namespace cleanup. So please don't get this wrong.
464 : */
465 : int register_pernet_subsys(struct pernet_operations *);
466 : void unregister_pernet_subsys(struct pernet_operations *);
467 : int register_pernet_device(struct pernet_operations *);
468 : void unregister_pernet_device(struct pernet_operations *);
469 :
470 : struct ctl_table;
471 :
472 : #ifdef CONFIG_SYSCTL
473 : int net_sysctl_init(void);
474 : struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
475 : struct ctl_table *table);
476 : void unregister_net_sysctl_table(struct ctl_table_header *header);
477 : #else
478 : static inline int net_sysctl_init(void) { return 0; }
479 : static inline struct ctl_table_header *register_net_sysctl(struct net *net,
480 : const char *path, struct ctl_table *table)
481 : {
482 : return NULL;
483 : }
484 : static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
485 : {
486 : }
487 : #endif
488 :
489 : static inline int rt_genid_ipv4(const struct net *net)
490 : {
491 : return atomic_read(&net->ipv4.rt_genid);
492 : }
493 :
494 : #if IS_ENABLED(CONFIG_IPV6)
495 : static inline int rt_genid_ipv6(const struct net *net)
496 : {
497 : return atomic_read(&net->ipv6.fib6_sernum);
498 : }
499 : #endif
500 :
501 : static inline void rt_genid_bump_ipv4(struct net *net)
502 : {
503 : atomic_inc(&net->ipv4.rt_genid);
504 : }
505 :
506 : extern void (*__fib6_flush_trees)(struct net *net);
507 : static inline void rt_genid_bump_ipv6(struct net *net)
508 : {
509 : if (__fib6_flush_trees)
510 : __fib6_flush_trees(net);
511 : }
512 :
513 : #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
514 : static inline struct netns_ieee802154_lowpan *
515 : net_ieee802154_lowpan(struct net *net)
516 : {
517 : return &net->ieee802154_lowpan;
518 : }
519 : #endif
520 :
521 : /* For callers who don't really care about whether it's IPv4 or IPv6 */
522 : static inline void rt_genid_bump_all(struct net *net)
523 : {
524 : rt_genid_bump_ipv4(net);
525 : rt_genid_bump_ipv6(net);
526 : }
527 :
528 : static inline int fnhe_genid(const struct net *net)
529 : {
530 : return atomic_read(&net->fnhe_genid);
531 : }
532 :
533 : static inline void fnhe_genid_bump(struct net *net)
534 : {
535 : atomic_inc(&net->fnhe_genid);
536 : }
537 :
538 : #ifdef CONFIG_NET
539 : void net_ns_init(void);
540 : #else
541 : static inline void net_ns_init(void) {}
542 : #endif
543 :
544 : #endif /* __NET_NET_NAMESPACE_H */
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