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 : #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 <net/netns/xdp.h>
34 : #include <net/netns/smc.h>
35 : #include <net/netns/bpf.h>
36 : #include <net/netns/mctp.h>
37 : #include <net/net_trackers.h>
38 : #include <linux/ns_common.h>
39 : #include <linux/idr.h>
40 : #include <linux/skbuff.h>
41 : #include <linux/notifier.h>
42 :
43 : struct user_namespace;
44 : struct proc_dir_entry;
45 : struct net_device;
46 : struct sock;
47 : struct ctl_table_header;
48 : struct net_generic;
49 : struct uevent_sock;
50 : struct netns_ipvs;
51 : struct bpf_prog;
52 :
53 :
54 : #define NETDEV_HASHBITS 8
55 : #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
56 :
57 : struct net {
58 : /* First cache line can be often dirtied.
59 : * Do not place here read-mostly fields.
60 : */
61 : refcount_t passive; /* To decide when the network
62 : * namespace should be freed.
63 : */
64 : spinlock_t rules_mod_lock;
65 :
66 : atomic_t dev_unreg_count;
67 :
68 : unsigned int dev_base_seq; /* protected by rtnl_mutex */
69 : int ifindex;
70 :
71 : spinlock_t nsid_lock;
72 : atomic_t fnhe_genid;
73 :
74 : struct list_head list; /* list of network namespaces */
75 : struct list_head exit_list; /* To linked to call pernet exit
76 : * methods on dead net (
77 : * pernet_ops_rwsem read locked),
78 : * or to unregister pernet ops
79 : * (pernet_ops_rwsem write locked).
80 : */
81 : struct llist_node cleanup_list; /* namespaces on death row */
82 :
83 : #ifdef CONFIG_KEYS
84 : struct key_tag *key_domain; /* Key domain of operation tag */
85 : #endif
86 : struct user_namespace *user_ns; /* Owning user namespace */
87 : struct ucounts *ucounts;
88 : struct idr netns_ids;
89 :
90 : struct ns_common ns;
91 : struct ref_tracker_dir refcnt_tracker;
92 :
93 : struct list_head dev_base_head;
94 : struct proc_dir_entry *proc_net;
95 : struct proc_dir_entry *proc_net_stat;
96 :
97 : #ifdef CONFIG_SYSCTL
98 : struct ctl_table_set sysctls;
99 : #endif
100 :
101 : struct sock *rtnl; /* rtnetlink socket */
102 : struct sock *genl_sock;
103 :
104 : struct uevent_sock *uevent_sock; /* uevent socket */
105 :
106 : struct hlist_head *dev_name_head;
107 : struct hlist_head *dev_index_head;
108 : struct raw_notifier_head netdev_chain;
109 :
110 : /* Note that @hash_mix can be read millions times per second,
111 : * it is critical that it is on a read_mostly cache line.
112 : */
113 : u32 hash_mix;
114 :
115 : struct net_device *loopback_dev; /* The loopback */
116 :
117 : /* core fib_rules */
118 : struct list_head rules_ops;
119 :
120 : struct netns_core core;
121 : struct netns_mib mib;
122 : struct netns_packet packet;
123 : struct netns_unix unx;
124 : struct netns_nexthop nexthop;
125 : struct netns_ipv4 ipv4;
126 : #if IS_ENABLED(CONFIG_IPV6)
127 : struct netns_ipv6 ipv6;
128 : #endif
129 : #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
130 : struct netns_ieee802154_lowpan ieee802154_lowpan;
131 : #endif
132 : #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
133 : struct netns_sctp sctp;
134 : #endif
135 : #ifdef CONFIG_NETFILTER
136 : struct netns_nf nf;
137 : #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
138 : struct netns_ct ct;
139 : #endif
140 : #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
141 : struct netns_nftables nft;
142 : #endif
143 : #endif
144 : #ifdef CONFIG_WEXT_CORE
145 : struct sk_buff_head wext_nlevents;
146 : #endif
147 : struct net_generic __rcu *gen;
148 :
149 : /* Used to store attached BPF programs */
150 : struct netns_bpf bpf;
151 :
152 : /* Note : following structs are cache line aligned */
153 : #ifdef CONFIG_XFRM
154 : struct netns_xfrm xfrm;
155 : #endif
156 :
157 : u64 net_cookie; /* written once */
158 :
159 : #if IS_ENABLED(CONFIG_IP_VS)
160 : struct netns_ipvs *ipvs;
161 : #endif
162 : #if IS_ENABLED(CONFIG_MPLS)
163 : struct netns_mpls mpls;
164 : #endif
165 : #if IS_ENABLED(CONFIG_CAN)
166 : struct netns_can can;
167 : #endif
168 : #ifdef CONFIG_XDP_SOCKETS
169 : struct netns_xdp xdp;
170 : #endif
171 : #if IS_ENABLED(CONFIG_MCTP)
172 : struct netns_mctp mctp;
173 : #endif
174 : #if IS_ENABLED(CONFIG_CRYPTO_USER)
175 : struct sock *crypto_nlsk;
176 : #endif
177 : struct sock *diag_nlsk;
178 : #if IS_ENABLED(CONFIG_SMC)
179 : struct netns_smc smc;
180 : #endif
181 : } __randomize_layout;
182 :
183 : #include <linux/seq_file_net.h>
184 :
185 : /* Init's network namespace */
186 : extern struct net init_net;
187 :
188 : #ifdef CONFIG_NET_NS
189 : struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
190 : struct net *old_net);
191 :
192 : void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
193 :
194 : void net_ns_barrier(void);
195 :
196 : struct ns_common *get_net_ns(struct ns_common *ns);
197 : struct net *get_net_ns_by_fd(int fd);
198 : #else /* CONFIG_NET_NS */
199 : #include <linux/sched.h>
200 : #include <linux/nsproxy.h>
201 : static inline struct net *copy_net_ns(unsigned long flags,
202 : struct user_namespace *user_ns, struct net *old_net)
203 : {
204 0 : if (flags & CLONE_NEWNET)
205 : return ERR_PTR(-EINVAL);
206 : return old_net;
207 : }
208 :
209 : static inline void net_ns_get_ownership(const struct net *net,
210 : kuid_t *uid, kgid_t *gid)
211 : {
212 : *uid = GLOBAL_ROOT_UID;
213 : *gid = GLOBAL_ROOT_GID;
214 : }
215 :
216 : static inline void net_ns_barrier(void) {}
217 :
218 : static inline struct ns_common *get_net_ns(struct ns_common *ns)
219 : {
220 : return ERR_PTR(-EINVAL);
221 : }
222 :
223 : static inline struct net *get_net_ns_by_fd(int fd)
224 : {
225 : return ERR_PTR(-EINVAL);
226 : }
227 : #endif /* CONFIG_NET_NS */
228 :
229 :
230 : extern struct list_head net_namespace_list;
231 :
232 : struct net *get_net_ns_by_pid(pid_t pid);
233 :
234 : #ifdef CONFIG_SYSCTL
235 : void ipx_register_sysctl(void);
236 : void ipx_unregister_sysctl(void);
237 : #else
238 : #define ipx_register_sysctl()
239 : #define ipx_unregister_sysctl()
240 : #endif
241 :
242 : #ifdef CONFIG_NET_NS
243 : void __put_net(struct net *net);
244 :
245 : /* Try using get_net_track() instead */
246 : static inline struct net *get_net(struct net *net)
247 : {
248 : refcount_inc(&net->ns.count);
249 : return net;
250 : }
251 :
252 : static inline struct net *maybe_get_net(struct net *net)
253 : {
254 : /* Used when we know struct net exists but we
255 : * aren't guaranteed a previous reference count
256 : * exists. If the reference count is zero this
257 : * function fails and returns NULL.
258 : */
259 : if (!refcount_inc_not_zero(&net->ns.count))
260 : net = NULL;
261 : return net;
262 : }
263 :
264 : /* Try using put_net_track() instead */
265 : static inline void put_net(struct net *net)
266 : {
267 : if (refcount_dec_and_test(&net->ns.count))
268 : __put_net(net);
269 : }
270 :
271 : static inline
272 : int net_eq(const struct net *net1, const struct net *net2)
273 : {
274 : return net1 == net2;
275 : }
276 :
277 : static inline int check_net(const struct net *net)
278 : {
279 : return refcount_read(&net->ns.count) != 0;
280 : }
281 :
282 : void net_drop_ns(void *);
283 :
284 : #else
285 :
286 : static inline struct net *get_net(struct net *net)
287 : {
288 : return net;
289 : }
290 :
291 : static inline void put_net(struct net *net)
292 : {
293 : }
294 :
295 : static inline struct net *maybe_get_net(struct net *net)
296 : {
297 : return net;
298 : }
299 :
300 : static inline
301 : int net_eq(const struct net *net1, const struct net *net2)
302 : {
303 : return 1;
304 : }
305 :
306 : static inline int check_net(const struct net *net)
307 : {
308 : return 1;
309 : }
310 :
311 : #define net_drop_ns NULL
312 : #endif
313 :
314 :
315 : static inline void netns_tracker_alloc(struct net *net,
316 : netns_tracker *tracker, gfp_t gfp)
317 : {
318 : #ifdef CONFIG_NET_NS_REFCNT_TRACKER
319 : ref_tracker_alloc(&net->refcnt_tracker, tracker, gfp);
320 : #endif
321 : }
322 :
323 : static inline void netns_tracker_free(struct net *net,
324 : netns_tracker *tracker)
325 : {
326 : #ifdef CONFIG_NET_NS_REFCNT_TRACKER
327 : ref_tracker_free(&net->refcnt_tracker, tracker);
328 : #endif
329 : }
330 :
331 : static inline struct net *get_net_track(struct net *net,
332 : netns_tracker *tracker, gfp_t gfp)
333 : {
334 : get_net(net);
335 : netns_tracker_alloc(net, tracker, gfp);
336 : return net;
337 : }
338 :
339 : static inline void put_net_track(struct net *net, netns_tracker *tracker)
340 : {
341 : netns_tracker_free(net, tracker);
342 : put_net(net);
343 : }
344 :
345 : typedef struct {
346 : #ifdef CONFIG_NET_NS
347 : struct net *net;
348 : #endif
349 : } possible_net_t;
350 :
351 : static inline void write_pnet(possible_net_t *pnet, struct net *net)
352 : {
353 : #ifdef CONFIG_NET_NS
354 : pnet->net = net;
355 : #endif
356 : }
357 :
358 : static inline struct net *read_pnet(const possible_net_t *pnet)
359 : {
360 : #ifdef CONFIG_NET_NS
361 : return pnet->net;
362 : #else
363 : return &init_net;
364 : #endif
365 : }
366 :
367 : /* Protected by net_rwsem */
368 : #define for_each_net(VAR) \
369 : list_for_each_entry(VAR, &net_namespace_list, list)
370 : #define for_each_net_continue_reverse(VAR) \
371 : list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list)
372 : #define for_each_net_rcu(VAR) \
373 : list_for_each_entry_rcu(VAR, &net_namespace_list, list)
374 :
375 : #ifdef CONFIG_NET_NS
376 : #define __net_init
377 : #define __net_exit
378 : #define __net_initdata
379 : #define __net_initconst
380 : #else
381 : #define __net_init __init
382 : #define __net_exit __ref
383 : #define __net_initdata __initdata
384 : #define __net_initconst __initconst
385 : #endif
386 :
387 : int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
388 : int peernet2id(const struct net *net, struct net *peer);
389 : bool peernet_has_id(const struct net *net, struct net *peer);
390 : struct net *get_net_ns_by_id(const struct net *net, int id);
391 :
392 : struct pernet_operations {
393 : struct list_head list;
394 : /*
395 : * Below methods are called without any exclusive locks.
396 : * More than one net may be constructed and destructed
397 : * in parallel on several cpus. Every pernet_operations
398 : * have to keep in mind all other pernet_operations and
399 : * to introduce a locking, if they share common resources.
400 : *
401 : * The only time they are called with exclusive lock is
402 : * from register_pernet_subsys(), unregister_pernet_subsys()
403 : * register_pernet_device() and unregister_pernet_device().
404 : *
405 : * Exit methods using blocking RCU primitives, such as
406 : * synchronize_rcu(), should be implemented via exit_batch.
407 : * Then, destruction of a group of net requires single
408 : * synchronize_rcu() related to these pernet_operations,
409 : * instead of separate synchronize_rcu() for every net.
410 : * Please, avoid synchronize_rcu() at all, where it's possible.
411 : *
412 : * Note that a combination of pre_exit() and exit() can
413 : * be used, since a synchronize_rcu() is guaranteed between
414 : * the calls.
415 : */
416 : int (*init)(struct net *net);
417 : void (*pre_exit)(struct net *net);
418 : void (*exit)(struct net *net);
419 : void (*exit_batch)(struct list_head *net_exit_list);
420 : unsigned int *id;
421 : size_t size;
422 : };
423 :
424 : /*
425 : * Use these carefully. If you implement a network device and it
426 : * needs per network namespace operations use device pernet operations,
427 : * otherwise use pernet subsys operations.
428 : *
429 : * Network interfaces need to be removed from a dying netns _before_
430 : * subsys notifiers can be called, as most of the network code cleanup
431 : * (which is done from subsys notifiers) runs with the assumption that
432 : * dev_remove_pack has been called so no new packets will arrive during
433 : * and after the cleanup functions have been called. dev_remove_pack
434 : * is not per namespace so instead the guarantee of no more packets
435 : * arriving in a network namespace is provided by ensuring that all
436 : * network devices and all sockets have left the network namespace
437 : * before the cleanup methods are called.
438 : *
439 : * For the longest time the ipv4 icmp code was registered as a pernet
440 : * device which caused kernel oops, and panics during network
441 : * namespace cleanup. So please don't get this wrong.
442 : */
443 : int register_pernet_subsys(struct pernet_operations *);
444 : void unregister_pernet_subsys(struct pernet_operations *);
445 : int register_pernet_device(struct pernet_operations *);
446 : void unregister_pernet_device(struct pernet_operations *);
447 :
448 : struct ctl_table;
449 :
450 : #ifdef CONFIG_SYSCTL
451 : int net_sysctl_init(void);
452 : struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
453 : struct ctl_table *table);
454 : void unregister_net_sysctl_table(struct ctl_table_header *header);
455 : #else
456 : static inline int net_sysctl_init(void) { return 0; }
457 : static inline struct ctl_table_header *register_net_sysctl(struct net *net,
458 : const char *path, struct ctl_table *table)
459 : {
460 : return NULL;
461 : }
462 : static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
463 : {
464 : }
465 : #endif
466 :
467 : static inline int rt_genid_ipv4(const struct net *net)
468 : {
469 : return atomic_read(&net->ipv4.rt_genid);
470 : }
471 :
472 : #if IS_ENABLED(CONFIG_IPV6)
473 : static inline int rt_genid_ipv6(const struct net *net)
474 : {
475 : return atomic_read(&net->ipv6.fib6_sernum);
476 : }
477 : #endif
478 :
479 : static inline void rt_genid_bump_ipv4(struct net *net)
480 : {
481 : atomic_inc(&net->ipv4.rt_genid);
482 : }
483 :
484 : extern void (*__fib6_flush_trees)(struct net *net);
485 : static inline void rt_genid_bump_ipv6(struct net *net)
486 : {
487 : if (__fib6_flush_trees)
488 : __fib6_flush_trees(net);
489 : }
490 :
491 : #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
492 : static inline struct netns_ieee802154_lowpan *
493 : net_ieee802154_lowpan(struct net *net)
494 : {
495 : return &net->ieee802154_lowpan;
496 : }
497 : #endif
498 :
499 : /* For callers who don't really care about whether it's IPv4 or IPv6 */
500 : static inline void rt_genid_bump_all(struct net *net)
501 : {
502 : rt_genid_bump_ipv4(net);
503 : rt_genid_bump_ipv6(net);
504 : }
505 :
506 : static inline int fnhe_genid(const struct net *net)
507 : {
508 : return atomic_read(&net->fnhe_genid);
509 : }
510 :
511 : static inline void fnhe_genid_bump(struct net *net)
512 : {
513 : atomic_inc(&net->fnhe_genid);
514 : }
515 :
516 : #ifdef CONFIG_NET
517 : void net_ns_init(void);
518 : #else
519 : static inline void net_ns_init(void) {}
520 : #endif
521 :
522 : #endif /* __NET_NET_NAMESPACE_H */
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