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
45struct user_namespace;
46struct proc_dir_entry;
47struct net_device;
48struct sock;
49struct ctl_table_header;
50struct net_generic;
51struct uevent_sock;
52struct netns_ipvs;
53struct bpf_prog;
54
55
56#define NETDEV_HASHBITS    8
57#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
58
59struct 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 */
203extern struct net init_net;
204
205#ifdef CONFIG_NET_NS
206struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
207			struct net *old_net);
208
209void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
210
211void net_ns_barrier(void);
212
213struct ns_common *get_net_ns(struct ns_common *ns);
214#else /* CONFIG_NET_NS */
215#include <linux/sched.h>
216#include <linux/nsproxy.h>
217static 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
225static 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
232static inline void net_ns_barrier(void) {}
233
234static 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
241extern struct list_head net_namespace_list;
242
243struct net *get_net_ns_by_pid(pid_t pid);
244struct net *get_net_ns_by_fd(int fd);
245
246u64 __net_gen_cookie(struct net *net);
247
248#ifdef CONFIG_SYSCTL
249void ipx_register_sysctl(void);
250void ipx_unregister_sysctl(void);
251#else
252#define ipx_register_sysctl()
253#define ipx_unregister_sysctl()
254#endif
255
256#ifdef CONFIG_NET_NS
257void __put_net(struct net *net);
258
259static inline struct net *get_net(struct net *net)
260{
261	refcount_inc(&net->count);
262	return net;
263}
264
265static 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
277static inline void put_net(struct net *net)
278{
279	if (refcount_dec_and_test(&net->count))
280		__put_net(net);
281}
282
283static inline
284int net_eq(const struct net *net1, const struct net *net2)
285{
286	return net1 == net2;
287}
288
289static inline int check_net(const struct net *net)
290{
291	return refcount_read(&net->count) != 0;
292}
293
294void net_drop_ns(void *);
295
296#else
297
298static inline struct net *get_net(struct net *net)
299{
300	return net;
301}
302
303static inline void put_net(struct net *net)
304{
305}
306
307static inline struct net *maybe_get_net(struct net *net)
308{
309	return net;
310}
311
312static inline
313int net_eq(const struct net *net1, const struct net *net2)
314{
315	return 1;
316}
317
318static inline int check_net(const struct net *net)
319{
320	return 1;
321}
322
323#define net_drop_ns NULL
324#endif
325
326
327typedef struct {
328#ifdef CONFIG_NET_NS
329	struct net *net;
330#endif
331} possible_net_t;
332
333static 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
340static 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
369int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
370int peernet2id(const struct net *net, struct net *peer);
371bool peernet_has_id(const struct net *net, struct net *peer);
372struct net *get_net_ns_by_id(const struct net *net, int id);
373
374struct 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 */
425int register_pernet_subsys(struct pernet_operations *);
426void unregister_pernet_subsys(struct pernet_operations *);
427int register_pernet_device(struct pernet_operations *);
428void unregister_pernet_device(struct pernet_operations *);
429
430struct ctl_table;
431struct ctl_table_header;
432
433#ifdef CONFIG_SYSCTL
434int net_sysctl_init(void);
435struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
436					     struct ctl_table *table);
437void unregister_net_sysctl_table(struct ctl_table_header *header);
438#else
439static inline int net_sysctl_init(void) { return 0; }
440static inline struct ctl_table_header *register_net_sysctl(struct net *net,
441	const char *path, struct ctl_table *table)
442{
443	return NULL;
444}
445static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
446{
447}
448#endif
449
450static 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)
456static inline int rt_genid_ipv6(const struct net *net)
457{
458	return atomic_read(&net->ipv6.fib6_sernum);
459}
460#endif
461
462static inline void rt_genid_bump_ipv4(struct net *net)
463{
464	atomic_inc(&net->ipv4.rt_genid);
465}
466
467extern void (*__fib6_flush_trees)(struct net *net);
468static 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)
475static inline struct netns_ieee802154_lowpan *
476net_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 */
483static inline void rt_genid_bump_all(struct net *net)
484{
485	rt_genid_bump_ipv4(net);
486	rt_genid_bump_ipv6(net);
487}
488
489static inline int fnhe_genid(const struct net *net)
490{
491	return atomic_read(&net->fnhe_genid);
492}
493
494static inline void fnhe_genid_bump(struct net *net)
495{
496	atomic_inc(&net->fnhe_genid);
497}
498
499#endif /* __NET_NET_NAMESPACE_H */
500