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 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 */
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>
copy_net_ns(unsigned long flags,struct user_namespace * user_ns,struct net * old_net)211 static 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
net_ns_get_ownership(const struct net * net,kuid_t * uid,kgid_t * gid)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
net_ns_barrier(void)226 static inline void net_ns_barrier(void) {}
227
get_net_ns(struct ns_common * ns)228 static inline struct ns_common *get_net_ns(struct ns_common *ns)
229 {
230 return ERR_PTR(-EINVAL);
231 }
232
get_net_ns_by_fd(int fd)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 */
get_net(struct net * net)256 static inline struct net *get_net(struct net *net)
257 {
258 refcount_inc(&net->ns.count);
259 return net;
260 }
261
maybe_get_net(struct net * net)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 */
put_net(struct net * net)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
net_eq(const struct net * net1,const struct net * net2)282 int net_eq(const struct net *net1, const struct net *net2)
283 {
284 return net1 == net2;
285 }
286
check_net(const struct net * net)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
get_net(struct net * net)296 static inline struct net *get_net(struct net *net)
297 {
298 return net;
299 }
300
put_net(struct net * net)301 static inline void put_net(struct net *net)
302 {
303 }
304
maybe_get_net(struct net * net)305 static inline struct net *maybe_get_net(struct net *net)
306 {
307 return net;
308 }
309
310 static inline
net_eq(const struct net * net1,const struct net * net2)311 int net_eq(const struct net *net1, const struct net *net2)
312 {
313 return 1;
314 }
315
check_net(const struct net * net)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
__netns_tracker_alloc(struct net * net,netns_tracker * tracker,bool refcounted,gfp_t gfp)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
netns_tracker_alloc(struct net * net,netns_tracker * tracker,gfp_t gfp)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
__netns_tracker_free(struct net * net,netns_tracker * tracker,bool refcounted)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
get_net_track(struct net * net,netns_tracker * tracker,gfp_t gfp)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
put_net_track(struct net * net,netns_tracker * tracker)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 __rcu *net;
370 #endif
371 } possible_net_t;
372
write_pnet(possible_net_t * pnet,struct net * net)373 static 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
read_pnet(const possible_net_t * pnet)380 static 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
read_pnet_rcu(possible_net_t * pnet)389 static 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
418 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
419 int peernet2id(const struct net *net, struct net *peer);
420 bool peernet_has_id(const struct net *net, struct net *peer);
421 struct net *get_net_ns_by_id(const struct net *net, int id);
422
423 struct 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 * const id;
455 const 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 */
477 int register_pernet_subsys(struct pernet_operations *);
478 void unregister_pernet_subsys(struct pernet_operations *);
479 int register_pernet_device(struct pernet_operations *);
480 void unregister_pernet_device(struct pernet_operations *);
481
482 struct 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
487 int net_sysctl_init(void);
488 struct ctl_table_header *register_net_sysctl_sz(struct net *net, const char *path,
489 struct ctl_table *table, size_t table_size);
490 void unregister_net_sysctl_table(struct ctl_table_header *header);
491 #else
net_sysctl_init(void)492 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)493 static 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 }
unregister_net_sysctl_table(struct ctl_table_header * header)498 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
499 {
500 }
501 #endif
502
rt_genid_ipv4(const struct net * net)503 static 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)
rt_genid_ipv6(const struct net * net)509 static inline int rt_genid_ipv6(const struct net *net)
510 {
511 return atomic_read(&net->ipv6.fib6_sernum);
512 }
513 #endif
514
rt_genid_bump_ipv4(struct net * net)515 static inline void rt_genid_bump_ipv4(struct net *net)
516 {
517 atomic_inc(&net->ipv4.rt_genid);
518 }
519
520 extern void (*__fib6_flush_trees)(struct net *net);
rt_genid_bump_ipv6(struct net * net)521 static 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)
528 static inline struct netns_ieee802154_lowpan *
net_ieee802154_lowpan(struct net * net)529 net_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 */
rt_genid_bump_all(struct net * net)536 static inline void rt_genid_bump_all(struct net *net)
537 {
538 rt_genid_bump_ipv4(net);
539 rt_genid_bump_ipv6(net);
540 }
541
fnhe_genid(const struct net * net)542 static inline int fnhe_genid(const struct net *net)
543 {
544 return atomic_read(&net->fnhe_genid);
545 }
546
fnhe_genid_bump(struct net * net)547 static inline void fnhe_genid_bump(struct net *net)
548 {
549 atomic_inc(&net->fnhe_genid);
550 }
551
552 #ifdef CONFIG_NET
553 void net_ns_init(void);
554 #else
net_ns_init(void)555 static inline void net_ns_init(void) {}
556 #endif
557
558 #endif /* __NET_NET_NAMESPACE_H */
559