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 
96 	struct list_head 	dev_base_head;
97 	struct proc_dir_entry 	*proc_net;
98 	struct proc_dir_entry 	*proc_net_stat;
99 
100 #ifdef CONFIG_SYSCTL
101 	struct ctl_table_set	sysctls;
102 #endif
103 
104 	struct sock 		*rtnl;			/* rtnetlink socket */
105 	struct sock		*genl_sock;
106 
107 	struct uevent_sock	*uevent_sock;		/* uevent socket */
108 
109 	struct hlist_head 	*dev_name_head;
110 	struct hlist_head	*dev_index_head;
111 	struct raw_notifier_head	netdev_chain;
112 
113 	/* Note that @hash_mix can be read millions times per second,
114 	 * it is critical that it is on a read_mostly cache line.
115 	 */
116 	u32			hash_mix;
117 
118 	struct net_device       *loopback_dev;          /* The loopback */
119 
120 	/* core fib_rules */
121 	struct list_head	rules_ops;
122 
123 	struct netns_core	core;
124 	struct netns_mib	mib;
125 	struct netns_packet	packet;
126 #if IS_ENABLED(CONFIG_UNIX)
127 	struct netns_unix	unx;
128 #endif
129 	struct netns_nexthop	nexthop;
130 	struct netns_ipv4	ipv4;
131 #if IS_ENABLED(CONFIG_IPV6)
132 	struct netns_ipv6	ipv6;
133 #endif
134 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
135 	struct netns_ieee802154_lowpan	ieee802154_lowpan;
136 #endif
137 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
138 	struct netns_sctp	sctp;
139 #endif
140 #ifdef CONFIG_NETFILTER
141 	struct netns_nf		nf;
142 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
143 	struct netns_ct		ct;
144 #endif
145 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
146 	struct netns_nftables	nft;
147 #endif
148 #if IS_ENABLED(CONFIG_NF_FLOW_TABLE)
149 	struct netns_ft ft;
150 #endif
151 #endif
152 #ifdef CONFIG_WEXT_CORE
153 	struct sk_buff_head	wext_nlevents;
154 #endif
155 	struct net_generic __rcu	*gen;
156 
157 	/* Used to store attached BPF programs */
158 	struct netns_bpf	bpf;
159 
160 	/* Note : following structs are cache line aligned */
161 #ifdef CONFIG_XFRM
162 	struct netns_xfrm	xfrm;
163 #endif
164 
165 	u64			net_cookie; /* written once */
166 
167 #if IS_ENABLED(CONFIG_IP_VS)
168 	struct netns_ipvs	*ipvs;
169 #endif
170 #if IS_ENABLED(CONFIG_MPLS)
171 	struct netns_mpls	mpls;
172 #endif
173 #if IS_ENABLED(CONFIG_CAN)
174 	struct netns_can	can;
175 #endif
176 #ifdef CONFIG_XDP_SOCKETS
177 	struct netns_xdp	xdp;
178 #endif
179 #if IS_ENABLED(CONFIG_MCTP)
180 	struct netns_mctp	mctp;
181 #endif
182 #if IS_ENABLED(CONFIG_CRYPTO_USER)
183 	struct sock		*crypto_nlsk;
184 #endif
185 	struct sock		*diag_nlsk;
186 #if IS_ENABLED(CONFIG_SMC)
187 	struct netns_smc	smc;
188 #endif
189 } __randomize_layout;
190 
191 #include <linux/seq_file_net.h>
192 
193 /* Init's network namespace */
194 extern struct net init_net;
195 
196 #ifdef CONFIG_NET_NS
197 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
198 			struct net *old_net);
199 
200 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
201 
202 void net_ns_barrier(void);
203 
204 struct ns_common *get_net_ns(struct ns_common *ns);
205 struct net *get_net_ns_by_fd(int fd);
206 #else /* CONFIG_NET_NS */
207 #include <linux/sched.h>
208 #include <linux/nsproxy.h>
copy_net_ns(unsigned long flags,struct user_namespace * user_ns,struct net * old_net)209 static inline struct net *copy_net_ns(unsigned long flags,
210 	struct user_namespace *user_ns, struct net *old_net)
211 {
212 	if (flags & CLONE_NEWNET)
213 		return ERR_PTR(-EINVAL);
214 	return old_net;
215 }
216 
net_ns_get_ownership(const struct net * net,kuid_t * uid,kgid_t * gid)217 static inline void net_ns_get_ownership(const struct net *net,
218 					kuid_t *uid, kgid_t *gid)
219 {
220 	*uid = GLOBAL_ROOT_UID;
221 	*gid = GLOBAL_ROOT_GID;
222 }
223 
net_ns_barrier(void)224 static inline void net_ns_barrier(void) {}
225 
get_net_ns(struct ns_common * ns)226 static inline struct ns_common *get_net_ns(struct ns_common *ns)
227 {
228 	return ERR_PTR(-EINVAL);
229 }
230 
get_net_ns_by_fd(int fd)231 static inline struct net *get_net_ns_by_fd(int fd)
232 {
233 	return ERR_PTR(-EINVAL);
234 }
235 #endif /* CONFIG_NET_NS */
236 
237 
238 extern struct list_head net_namespace_list;
239 
240 struct net *get_net_ns_by_pid(pid_t pid);
241 
242 #ifdef CONFIG_SYSCTL
243 void ipx_register_sysctl(void);
244 void ipx_unregister_sysctl(void);
245 #else
246 #define ipx_register_sysctl()
247 #define ipx_unregister_sysctl()
248 #endif
249 
250 #ifdef CONFIG_NET_NS
251 void __put_net(struct net *net);
252 
253 /* Try using get_net_track() instead */
get_net(struct net * net)254 static inline struct net *get_net(struct net *net)
255 {
256 	refcount_inc(&net->ns.count);
257 	return net;
258 }
259 
maybe_get_net(struct net * net)260 static inline struct net *maybe_get_net(struct net *net)
261 {
262 	/* Used when we know struct net exists but we
263 	 * aren't guaranteed a previous reference count
264 	 * exists.  If the reference count is zero this
265 	 * function fails and returns NULL.
266 	 */
267 	if (!refcount_inc_not_zero(&net->ns.count))
268 		net = NULL;
269 	return net;
270 }
271 
272 /* Try using put_net_track() instead */
put_net(struct net * net)273 static inline void put_net(struct net *net)
274 {
275 	if (refcount_dec_and_test(&net->ns.count))
276 		__put_net(net);
277 }
278 
279 static inline
net_eq(const struct net * net1,const struct net * net2)280 int net_eq(const struct net *net1, const struct net *net2)
281 {
282 	return net1 == net2;
283 }
284 
check_net(const struct net * net)285 static inline int check_net(const struct net *net)
286 {
287 	return refcount_read(&net->ns.count) != 0;
288 }
289 
290 void net_drop_ns(void *);
291 
292 #else
293 
get_net(struct net * net)294 static inline struct net *get_net(struct net *net)
295 {
296 	return net;
297 }
298 
put_net(struct net * net)299 static inline void put_net(struct net *net)
300 {
301 }
302 
maybe_get_net(struct net * net)303 static inline struct net *maybe_get_net(struct net *net)
304 {
305 	return net;
306 }
307 
308 static inline
net_eq(const struct net * net1,const struct net * net2)309 int net_eq(const struct net *net1, const struct net *net2)
310 {
311 	return 1;
312 }
313 
check_net(const struct net * net)314 static inline int check_net(const struct net *net)
315 {
316 	return 1;
317 }
318 
319 #define net_drop_ns NULL
320 #endif
321 
322 
netns_tracker_alloc(struct net * net,netns_tracker * tracker,gfp_t gfp)323 static inline void netns_tracker_alloc(struct net *net,
324 				       netns_tracker *tracker, gfp_t gfp)
325 {
326 #ifdef CONFIG_NET_NS_REFCNT_TRACKER
327 	ref_tracker_alloc(&net->refcnt_tracker, tracker, gfp);
328 #endif
329 }
330 
netns_tracker_free(struct net * net,netns_tracker * tracker)331 static inline void netns_tracker_free(struct net *net,
332 				      netns_tracker *tracker)
333 {
334 #ifdef CONFIG_NET_NS_REFCNT_TRACKER
335        ref_tracker_free(&net->refcnt_tracker, tracker);
336 #endif
337 }
338 
get_net_track(struct net * net,netns_tracker * tracker,gfp_t gfp)339 static inline struct net *get_net_track(struct net *net,
340 					netns_tracker *tracker, gfp_t gfp)
341 {
342 	get_net(net);
343 	netns_tracker_alloc(net, tracker, gfp);
344 	return net;
345 }
346 
put_net_track(struct net * net,netns_tracker * tracker)347 static inline void put_net_track(struct net *net, netns_tracker *tracker)
348 {
349 	netns_tracker_free(net, tracker);
350 	put_net(net);
351 }
352 
353 typedef struct {
354 #ifdef CONFIG_NET_NS
355 	struct net *net;
356 #endif
357 } possible_net_t;
358 
write_pnet(possible_net_t * pnet,struct net * net)359 static inline void write_pnet(possible_net_t *pnet, struct net *net)
360 {
361 #ifdef CONFIG_NET_NS
362 	pnet->net = net;
363 #endif
364 }
365 
read_pnet(const possible_net_t * pnet)366 static inline struct net *read_pnet(const possible_net_t *pnet)
367 {
368 #ifdef CONFIG_NET_NS
369 	return pnet->net;
370 #else
371 	return &init_net;
372 #endif
373 }
374 
375 /* Protected by net_rwsem */
376 #define for_each_net(VAR)				\
377 	list_for_each_entry(VAR, &net_namespace_list, list)
378 #define for_each_net_continue_reverse(VAR)		\
379 	list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list)
380 #define for_each_net_rcu(VAR)				\
381 	list_for_each_entry_rcu(VAR, &net_namespace_list, list)
382 
383 #ifdef CONFIG_NET_NS
384 #define __net_init
385 #define __net_exit
386 #define __net_initdata
387 #define __net_initconst
388 #else
389 #define __net_init	__init
390 #define __net_exit	__ref
391 #define __net_initdata	__initdata
392 #define __net_initconst	__initconst
393 #endif
394 
395 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
396 int peernet2id(const struct net *net, struct net *peer);
397 bool peernet_has_id(const struct net *net, struct net *peer);
398 struct net *get_net_ns_by_id(const struct net *net, int id);
399 
400 struct pernet_operations {
401 	struct list_head list;
402 	/*
403 	 * Below methods are called without any exclusive locks.
404 	 * More than one net may be constructed and destructed
405 	 * in parallel on several cpus. Every pernet_operations
406 	 * have to keep in mind all other pernet_operations and
407 	 * to introduce a locking, if they share common resources.
408 	 *
409 	 * The only time they are called with exclusive lock is
410 	 * from register_pernet_subsys(), unregister_pernet_subsys()
411 	 * register_pernet_device() and unregister_pernet_device().
412 	 *
413 	 * Exit methods using blocking RCU primitives, such as
414 	 * synchronize_rcu(), should be implemented via exit_batch.
415 	 * Then, destruction of a group of net requires single
416 	 * synchronize_rcu() related to these pernet_operations,
417 	 * instead of separate synchronize_rcu() for every net.
418 	 * Please, avoid synchronize_rcu() at all, where it's possible.
419 	 *
420 	 * Note that a combination of pre_exit() and exit() can
421 	 * be used, since a synchronize_rcu() is guaranteed between
422 	 * the calls.
423 	 */
424 	int (*init)(struct net *net);
425 	void (*pre_exit)(struct net *net);
426 	void (*exit)(struct net *net);
427 	void (*exit_batch)(struct list_head *net_exit_list);
428 	unsigned int *id;
429 	size_t size;
430 };
431 
432 /*
433  * Use these carefully.  If you implement a network device and it
434  * needs per network namespace operations use device pernet operations,
435  * otherwise use pernet subsys operations.
436  *
437  * Network interfaces need to be removed from a dying netns _before_
438  * subsys notifiers can be called, as most of the network code cleanup
439  * (which is done from subsys notifiers) runs with the assumption that
440  * dev_remove_pack has been called so no new packets will arrive during
441  * and after the cleanup functions have been called.  dev_remove_pack
442  * is not per namespace so instead the guarantee of no more packets
443  * arriving in a network namespace is provided by ensuring that all
444  * network devices and all sockets have left the network namespace
445  * before the cleanup methods are called.
446  *
447  * For the longest time the ipv4 icmp code was registered as a pernet
448  * device which caused kernel oops, and panics during network
449  * namespace cleanup.   So please don't get this wrong.
450  */
451 int register_pernet_subsys(struct pernet_operations *);
452 void unregister_pernet_subsys(struct pernet_operations *);
453 int register_pernet_device(struct pernet_operations *);
454 void unregister_pernet_device(struct pernet_operations *);
455 
456 struct ctl_table;
457 
458 #ifdef CONFIG_SYSCTL
459 int net_sysctl_init(void);
460 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
461 					     struct ctl_table *table);
462 void unregister_net_sysctl_table(struct ctl_table_header *header);
463 #else
net_sysctl_init(void)464 static inline int net_sysctl_init(void) { return 0; }
register_net_sysctl(struct net * net,const char * path,struct ctl_table * table)465 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
466 	const char *path, struct ctl_table *table)
467 {
468 	return NULL;
469 }
unregister_net_sysctl_table(struct ctl_table_header * header)470 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
471 {
472 }
473 #endif
474 
rt_genid_ipv4(const struct net * net)475 static inline int rt_genid_ipv4(const struct net *net)
476 {
477 	return atomic_read(&net->ipv4.rt_genid);
478 }
479 
480 #if IS_ENABLED(CONFIG_IPV6)
rt_genid_ipv6(const struct net * net)481 static inline int rt_genid_ipv6(const struct net *net)
482 {
483 	return atomic_read(&net->ipv6.fib6_sernum);
484 }
485 #endif
486 
rt_genid_bump_ipv4(struct net * net)487 static inline void rt_genid_bump_ipv4(struct net *net)
488 {
489 	atomic_inc(&net->ipv4.rt_genid);
490 }
491 
492 extern void (*__fib6_flush_trees)(struct net *net);
rt_genid_bump_ipv6(struct net * net)493 static inline void rt_genid_bump_ipv6(struct net *net)
494 {
495 	if (__fib6_flush_trees)
496 		__fib6_flush_trees(net);
497 }
498 
499 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
500 static inline struct netns_ieee802154_lowpan *
net_ieee802154_lowpan(struct net * net)501 net_ieee802154_lowpan(struct net *net)
502 {
503 	return &net->ieee802154_lowpan;
504 }
505 #endif
506 
507 /* For callers who don't really care about whether it's IPv4 or IPv6 */
rt_genid_bump_all(struct net * net)508 static inline void rt_genid_bump_all(struct net *net)
509 {
510 	rt_genid_bump_ipv4(net);
511 	rt_genid_bump_ipv6(net);
512 }
513 
fnhe_genid(const struct net * net)514 static inline int fnhe_genid(const struct net *net)
515 {
516 	return atomic_read(&net->fnhe_genid);
517 }
518 
fnhe_genid_bump(struct net * net)519 static inline void fnhe_genid_bump(struct net *net)
520 {
521 	atomic_inc(&net->fnhe_genid);
522 }
523 
524 #ifdef CONFIG_NET
525 void net_ns_init(void);
526 #else
net_ns_init(void)527 static inline void net_ns_init(void) {}
528 #endif
529 
530 #endif /* __NET_NET_NAMESPACE_H */
531