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