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/dccp.h>
26 #include <net/netns/netfilter.h>
27 #include <net/netns/x_tables.h>
28 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
29 #include <net/netns/conntrack.h>
30 #endif
31 #include <net/netns/nftables.h>
32 #include <net/netns/xfrm.h>
33 #include <net/netns/mpls.h>
34 #include <net/netns/can.h>
35 #include <net/netns/xdp.h>
36 #include <net/netns/bpf.h>
37 #include <linux/ns_common.h>
38 #include <linux/idr.h>
39 #include <linux/skbuff.h>
40 #include <linux/notifier.h>
41 #ifdef CONFIG_NEWIP
42 #include <net/netns/nip.h>
43 #endif
44
45 struct user_namespace;
46 struct proc_dir_entry;
47 struct net_device;
48 struct sock;
49 struct ctl_table_header;
50 struct net_generic;
51 struct uevent_sock;
52 struct netns_ipvs;
53 struct bpf_prog;
54
55
56 #define NETDEV_HASHBITS 8
57 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
58
59 struct net {
60 /* First cache line can be often dirtied.
61 * Do not place here read-mostly fields.
62 */
63 refcount_t passive; /* To decide when the network
64 * namespace should be freed.
65 */
66 refcount_t count; /* To decided when the network
67 * namespace should be shut down.
68 */
69 spinlock_t rules_mod_lock;
70
71 unsigned int dev_unreg_count;
72
73 unsigned int dev_base_seq; /* protected by rtnl_mutex */
74 int ifindex;
75
76 spinlock_t nsid_lock;
77 atomic_t fnhe_genid;
78
79 struct list_head list; /* list of network namespaces */
80 struct list_head exit_list; /* To linked to call pernet exit
81 * methods on dead net (
82 * pernet_ops_rwsem read locked),
83 * or to unregister pernet ops
84 * (pernet_ops_rwsem write locked).
85 */
86 struct llist_node cleanup_list; /* namespaces on death row */
87
88 #ifdef CONFIG_KEYS
89 struct key_tag *key_domain; /* Key domain of operation tag */
90 #endif
91 struct user_namespace *user_ns; /* Owning user namespace */
92 struct ucounts *ucounts;
93 struct idr netns_ids;
94
95 struct ns_common ns;
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 raw_notifier_head netdev_chain;
113
114 /* Note that @hash_mix can be read millions times per second,
115 * it is critical that it is on a read_mostly cache line.
116 */
117 u32 hash_mix;
118
119 struct net_device *loopback_dev; /* The loopback */
120
121 /* core fib_rules */
122 struct list_head rules_ops;
123
124 struct netns_core core;
125 struct netns_mib mib;
126 struct netns_packet packet;
127 struct netns_unix unx;
128 struct netns_nexthop nexthop;
129 struct netns_ipv4 ipv4;
130 #if IS_ENABLED(CONFIG_IPV6)
131 struct netns_ipv6 ipv6;
132 #endif
133 #if IS_ENABLED(CONFIG_NEWIP)
134 struct netns_newip newip; /* NIP */
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 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
143 struct netns_dccp dccp;
144 #endif
145 #ifdef CONFIG_NETFILTER
146 struct netns_nf nf;
147 struct netns_xt xt;
148 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
149 struct netns_ct ct;
150 #endif
151 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
152 struct netns_nftables nft;
153 #endif
154 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
155 struct netns_nf_frag nf_frag;
156 struct ctl_table_header *nf_frag_frags_hdr;
157 #endif
158 struct sock *nfnl;
159 struct sock *nfnl_stash;
160 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
161 struct list_head nfnl_acct_list;
162 #endif
163 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
164 struct list_head nfct_timeout_list;
165 #endif
166 #endif
167 #ifdef CONFIG_WEXT_CORE
168 struct sk_buff_head wext_nlevents;
169 #endif
170 struct net_generic __rcu *gen;
171
172 /* Used to store attached BPF programs */
173 struct netns_bpf bpf;
174
175 /* Note : following structs are cache line aligned */
176 #ifdef CONFIG_XFRM
177 struct netns_xfrm xfrm;
178 #endif
179
180 atomic64_t net_cookie; /* written once */
181
182 #if IS_ENABLED(CONFIG_IP_VS)
183 struct netns_ipvs *ipvs;
184 #endif
185 #if IS_ENABLED(CONFIG_MPLS)
186 struct netns_mpls mpls;
187 #endif
188 #if IS_ENABLED(CONFIG_CAN)
189 struct netns_can can;
190 #endif
191 #ifdef CONFIG_XDP_SOCKETS
192 struct netns_xdp xdp;
193 #endif
194 #if IS_ENABLED(CONFIG_CRYPTO_USER)
195 struct sock *crypto_nlsk;
196 #endif
197 struct sock *diag_nlsk;
198 } __randomize_layout;
199
200 #include <linux/seq_file_net.h>
201
202 /* Init's network namespace */
203 extern struct net init_net;
204
205 #ifdef CONFIG_NET_NS
206 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
207 struct net *old_net);
208
209 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
210
211 void net_ns_barrier(void);
212
213 struct ns_common *get_net_ns(struct ns_common *ns);
214 #else /* CONFIG_NET_NS */
215 #include <linux/sched.h>
216 #include <linux/nsproxy.h>
copy_net_ns(unsigned long flags,struct user_namespace * user_ns,struct net * old_net)217 static inline struct net *copy_net_ns(unsigned long flags,
218 struct user_namespace *user_ns, struct net *old_net)
219 {
220 if (flags & CLONE_NEWNET)
221 return ERR_PTR(-EINVAL);
222 return old_net;
223 }
224
net_ns_get_ownership(const struct net * net,kuid_t * uid,kgid_t * gid)225 static inline void net_ns_get_ownership(const struct net *net,
226 kuid_t *uid, kgid_t *gid)
227 {
228 *uid = GLOBAL_ROOT_UID;
229 *gid = GLOBAL_ROOT_GID;
230 }
231
net_ns_barrier(void)232 static inline void net_ns_barrier(void) {}
233
get_net_ns(struct ns_common * ns)234 static inline struct ns_common *get_net_ns(struct ns_common *ns)
235 {
236 return ERR_PTR(-EINVAL);
237 }
238 #endif /* CONFIG_NET_NS */
239
240
241 extern struct list_head net_namespace_list;
242
243 struct net *get_net_ns_by_pid(pid_t pid);
244 struct net *get_net_ns_by_fd(int fd);
245
246 u64 __net_gen_cookie(struct net *net);
247
248 #ifdef CONFIG_SYSCTL
249 void ipx_register_sysctl(void);
250 void ipx_unregister_sysctl(void);
251 #else
252 #define ipx_register_sysctl()
253 #define ipx_unregister_sysctl()
254 #endif
255
256 #ifdef CONFIG_NET_NS
257 void __put_net(struct net *net);
258
get_net(struct net * net)259 static inline struct net *get_net(struct net *net)
260 {
261 refcount_inc(&net->count);
262 return net;
263 }
264
maybe_get_net(struct net * net)265 static inline struct net *maybe_get_net(struct net *net)
266 {
267 /* Used when we know struct net exists but we
268 * aren't guaranteed a previous reference count
269 * exists. If the reference count is zero this
270 * function fails and returns NULL.
271 */
272 if (!refcount_inc_not_zero(&net->count))
273 net = NULL;
274 return net;
275 }
276
put_net(struct net * net)277 static inline void put_net(struct net *net)
278 {
279 if (refcount_dec_and_test(&net->count))
280 __put_net(net);
281 }
282
283 static inline
net_eq(const struct net * net1,const struct net * net2)284 int net_eq(const struct net *net1, const struct net *net2)
285 {
286 return net1 == net2;
287 }
288
check_net(const struct net * net)289 static inline int check_net(const struct net *net)
290 {
291 return refcount_read(&net->count) != 0;
292 }
293
294 void net_drop_ns(void *);
295
296 #else
297
get_net(struct net * net)298 static inline struct net *get_net(struct net *net)
299 {
300 return net;
301 }
302
put_net(struct net * net)303 static inline void put_net(struct net *net)
304 {
305 }
306
maybe_get_net(struct net * net)307 static inline struct net *maybe_get_net(struct net *net)
308 {
309 return net;
310 }
311
312 static inline
net_eq(const struct net * net1,const struct net * net2)313 int net_eq(const struct net *net1, const struct net *net2)
314 {
315 return 1;
316 }
317
check_net(const struct net * net)318 static inline int check_net(const struct net *net)
319 {
320 return 1;
321 }
322
323 #define net_drop_ns NULL
324 #endif
325
326
327 typedef struct {
328 #ifdef CONFIG_NET_NS
329 struct net *net;
330 #endif
331 } possible_net_t;
332
write_pnet(possible_net_t * pnet,struct net * net)333 static inline void write_pnet(possible_net_t *pnet, struct net *net)
334 {
335 #ifdef CONFIG_NET_NS
336 pnet->net = net;
337 #endif
338 }
339
read_pnet(const possible_net_t * pnet)340 static inline struct net *read_pnet(const possible_net_t *pnet)
341 {
342 #ifdef CONFIG_NET_NS
343 return pnet->net;
344 #else
345 return &init_net;
346 #endif
347 }
348
349 /* Protected by net_rwsem */
350 #define for_each_net(VAR) \
351 list_for_each_entry(VAR, &net_namespace_list, list)
352 #define for_each_net_continue_reverse(VAR) \
353 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list)
354 #define for_each_net_rcu(VAR) \
355 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
356
357 #ifdef CONFIG_NET_NS
358 #define __net_init
359 #define __net_exit
360 #define __net_initdata
361 #define __net_initconst
362 #else
363 #define __net_init __init
364 #define __net_exit __ref
365 #define __net_initdata __initdata
366 #define __net_initconst __initconst
367 #endif
368
369 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
370 int peernet2id(const struct net *net, struct net *peer);
371 bool peernet_has_id(const struct net *net, struct net *peer);
372 struct net *get_net_ns_by_id(const struct net *net, int id);
373
374 struct pernet_operations {
375 struct list_head list;
376 /*
377 * Below methods are called without any exclusive locks.
378 * More than one net may be constructed and destructed
379 * in parallel on several cpus. Every pernet_operations
380 * have to keep in mind all other pernet_operations and
381 * to introduce a locking, if they share common resources.
382 *
383 * The only time they are called with exclusive lock is
384 * from register_pernet_subsys(), unregister_pernet_subsys()
385 * register_pernet_device() and unregister_pernet_device().
386 *
387 * Exit methods using blocking RCU primitives, such as
388 * synchronize_rcu(), should be implemented via exit_batch.
389 * Then, destruction of a group of net requires single
390 * synchronize_rcu() related to these pernet_operations,
391 * instead of separate synchronize_rcu() for every net.
392 * Please, avoid synchronize_rcu() at all, where it's possible.
393 *
394 * Note that a combination of pre_exit() and exit() can
395 * be used, since a synchronize_rcu() is guaranteed between
396 * the calls.
397 */
398 int (*init)(struct net *net);
399 void (*pre_exit)(struct net *net);
400 void (*exit)(struct net *net);
401 void (*exit_batch)(struct list_head *net_exit_list);
402 unsigned int *id;
403 size_t size;
404 };
405
406 /*
407 * Use these carefully. If you implement a network device and it
408 * needs per network namespace operations use device pernet operations,
409 * otherwise use pernet subsys operations.
410 *
411 * Network interfaces need to be removed from a dying netns _before_
412 * subsys notifiers can be called, as most of the network code cleanup
413 * (which is done from subsys notifiers) runs with the assumption that
414 * dev_remove_pack has been called so no new packets will arrive during
415 * and after the cleanup functions have been called. dev_remove_pack
416 * is not per namespace so instead the guarantee of no more packets
417 * arriving in a network namespace is provided by ensuring that all
418 * network devices and all sockets have left the network namespace
419 * before the cleanup methods are called.
420 *
421 * For the longest time the ipv4 icmp code was registered as a pernet
422 * device which caused kernel oops, and panics during network
423 * namespace cleanup. So please don't get this wrong.
424 */
425 int register_pernet_subsys(struct pernet_operations *);
426 void unregister_pernet_subsys(struct pernet_operations *);
427 int register_pernet_device(struct pernet_operations *);
428 void unregister_pernet_device(struct pernet_operations *);
429
430 struct ctl_table;
431 struct ctl_table_header;
432
433 #ifdef CONFIG_SYSCTL
434 int net_sysctl_init(void);
435 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
436 struct ctl_table *table);
437 void unregister_net_sysctl_table(struct ctl_table_header *header);
438 #else
net_sysctl_init(void)439 static inline int net_sysctl_init(void) { return 0; }
register_net_sysctl(struct net * net,const char * path,struct ctl_table * table)440 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
441 const char *path, struct ctl_table *table)
442 {
443 return NULL;
444 }
unregister_net_sysctl_table(struct ctl_table_header * header)445 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
446 {
447 }
448 #endif
449
rt_genid_ipv4(const struct net * net)450 static inline int rt_genid_ipv4(const struct net *net)
451 {
452 return atomic_read(&net->ipv4.rt_genid);
453 }
454
455 #if IS_ENABLED(CONFIG_IPV6)
rt_genid_ipv6(const struct net * net)456 static inline int rt_genid_ipv6(const struct net *net)
457 {
458 return atomic_read(&net->ipv6.fib6_sernum);
459 }
460 #endif
461
rt_genid_bump_ipv4(struct net * net)462 static inline void rt_genid_bump_ipv4(struct net *net)
463 {
464 atomic_inc(&net->ipv4.rt_genid);
465 }
466
467 extern void (*__fib6_flush_trees)(struct net *net);
rt_genid_bump_ipv6(struct net * net)468 static inline void rt_genid_bump_ipv6(struct net *net)
469 {
470 if (__fib6_flush_trees)
471 __fib6_flush_trees(net);
472 }
473
474 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
475 static inline struct netns_ieee802154_lowpan *
net_ieee802154_lowpan(struct net * net)476 net_ieee802154_lowpan(struct net *net)
477 {
478 return &net->ieee802154_lowpan;
479 }
480 #endif
481
482 /* For callers who don't really care about whether it's IPv4 or IPv6 */
rt_genid_bump_all(struct net * net)483 static inline void rt_genid_bump_all(struct net *net)
484 {
485 rt_genid_bump_ipv4(net);
486 rt_genid_bump_ipv6(net);
487 }
488
fnhe_genid(const struct net * net)489 static inline int fnhe_genid(const struct net *net)
490 {
491 return atomic_read(&net->fnhe_genid);
492 }
493
fnhe_genid_bump(struct net * net)494 static inline void fnhe_genid_bump(struct net *net)
495 {
496 atomic_inc(&net->fnhe_genid);
497 }
498
499 #endif /* __NET_NET_NAMESPACE_H */
500