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/ieee802154_6lowpan.h>
23#include <net/netns/sctp.h>
24#include <net/netns/dccp.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 <linux/ns_common.h>
36#include <linux/idr.h>
37#include <linux/skbuff.h>
38
39struct user_namespace;
40struct proc_dir_entry;
41struct net_device;
42struct sock;
43struct ctl_table_header;
44struct net_generic;
45struct uevent_sock;
46struct netns_ipvs;
47struct bpf_prog;
48
49
50#define NETDEV_HASHBITS 8
51#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
52
53struct net {
54 refcount_t passive; /* To decided when the network
55 * namespace should be freed.
56 */
57 refcount_t count; /* To decided when the network
58 * namespace should be shut down.
59 */
60 spinlock_t rules_mod_lock;
61
62 atomic64_t cookie_gen;
63
64 struct list_head list; /* list of network namespaces */
65 struct list_head exit_list; /* To linked to call pernet exit
66 * methods on dead net (
67 * pernet_ops_rwsem read locked),
68 * or to unregister pernet ops
69 * (pernet_ops_rwsem write locked).
70 */
71 struct llist_node cleanup_list; /* namespaces on death row */
72
73 struct user_namespace *user_ns; /* Owning user namespace */
74 struct ucounts *ucounts;
75 spinlock_t nsid_lock;
76 struct idr netns_ids;
77
78 struct ns_common ns;
79
80 struct proc_dir_entry *proc_net;
81 struct proc_dir_entry *proc_net_stat;
82
83#ifdef CONFIG_SYSCTL
84 struct ctl_table_set sysctls;
85#endif
86
87 struct sock *rtnl; /* rtnetlink socket */
88 struct sock *genl_sock;
89
90 struct uevent_sock *uevent_sock; /* uevent socket */
91
92 struct list_head dev_base_head;
93 struct hlist_head *dev_name_head;
94 struct hlist_head *dev_index_head;
95 unsigned int dev_base_seq; /* protected by rtnl_mutex */
96 int ifindex;
97 unsigned int dev_unreg_count;
98
99 /* core fib_rules */
100 struct list_head rules_ops;
101
102 struct list_head fib_notifier_ops; /* Populated by
103 * register_pernet_subsys()
104 */
105 struct net_device *loopback_dev; /* The loopback */
106 struct netns_core core;
107 struct netns_mib mib;
108 struct netns_packet packet;
109 struct netns_unix unx;
110 struct netns_ipv4 ipv4;
111#if IS_ENABLED(CONFIG_IPV6)
112 struct netns_ipv6 ipv6;
113#endif
114#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
115 struct netns_ieee802154_lowpan ieee802154_lowpan;
116#endif
117#if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
118 struct netns_sctp sctp;
119#endif
120#if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
121 struct netns_dccp dccp;
122#endif
123#ifdef CONFIG_NETFILTER
124 struct netns_nf nf;
125 struct netns_xt xt;
126#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
127 struct netns_ct ct;
128#endif
129#if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
130 struct netns_nftables nft;
131#endif
132#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
133 struct netns_nf_frag nf_frag;
134 struct ctl_table_header *nf_frag_frags_hdr;
135#endif
136 struct sock *nfnl;
137 struct sock *nfnl_stash;
138#if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
139 struct list_head nfnl_acct_list;
140#endif
141#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
142 struct list_head nfct_timeout_list;
143#endif
144#endif
145#ifdef CONFIG_WEXT_CORE
146 struct sk_buff_head wext_nlevents;
147#endif
148 struct net_generic __rcu *gen;
149
150 struct bpf_prog __rcu *flow_dissector_prog;
151
152 /* Note : following structs are cache line aligned */
153#ifdef CONFIG_XFRM
154 struct netns_xfrm xfrm;
155#endif
156#if IS_ENABLED(CONFIG_IP_VS)
157 struct netns_ipvs *ipvs;
158#endif
159#if IS_ENABLED(CONFIG_MPLS)
160 struct netns_mpls mpls;
161#endif
162#if IS_ENABLED(CONFIG_CAN)
163 struct netns_can can;
164#endif
165#ifdef CONFIG_XDP_SOCKETS
166 struct netns_xdp xdp;
167#endif
168 struct sock *diag_nlsk;
169 atomic_t fnhe_genid;
170} __randomize_layout;
171
172#include <linux/seq_file_net.h>
173
174/* Init's network namespace */
175extern struct net init_net;
176
177#ifdef CONFIG_NET_NS
178struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
179 struct net *old_net);
180
181void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
182
183void net_ns_barrier(void);
184#else /* CONFIG_NET_NS */
185#include <linux/sched.h>
186#include <linux/nsproxy.h>
187static inline struct net *copy_net_ns(unsigned long flags,
188 struct user_namespace *user_ns, struct net *old_net)
189{
190 if (flags & CLONE_NEWNET)
191 return ERR_PTR(-EINVAL);
192 return old_net;
193}
194
195static inline void net_ns_get_ownership(const struct net *net,
196 kuid_t *uid, kgid_t *gid)
197{
198 *uid = GLOBAL_ROOT_UID;
199 *gid = GLOBAL_ROOT_GID;
200}
201
202static inline void net_ns_barrier(void) {}
203#endif /* CONFIG_NET_NS */
204
205
206extern struct list_head net_namespace_list;
207
208struct net *get_net_ns_by_pid(pid_t pid);
209struct net *get_net_ns_by_fd(int fd);
210
211#ifdef CONFIG_SYSCTL
212void ipx_register_sysctl(void);
213void ipx_unregister_sysctl(void);
214#else
215#define ipx_register_sysctl()
216#define ipx_unregister_sysctl()
217#endif
218
219#ifdef CONFIG_NET_NS
220void __put_net(struct net *net);
221
222static inline struct net *get_net(struct net *net)
223{
224 refcount_inc(&net->count);
225 return net;
226}
227
228static inline struct net *maybe_get_net(struct net *net)
229{
230 /* Used when we know struct net exists but we
231 * aren't guaranteed a previous reference count
232 * exists. If the reference count is zero this
233 * function fails and returns NULL.
234 */
235 if (!refcount_inc_not_zero(&net->count))
236 net = NULL;
237 return net;
238}
239
240static inline void put_net(struct net *net)
241{
242 if (refcount_dec_and_test(&net->count))
243 __put_net(net);
244}
245
246static inline
247int net_eq(const struct net *net1, const struct net *net2)
248{
249 return net1 == net2;
250}
251
252static inline int check_net(const struct net *net)
253{
254 return refcount_read(&net->count) != 0;
255}
256
257void net_drop_ns(void *);
258
259#else
260
261static inline struct net *get_net(struct net *net)
262{
263 return net;
264}
265
266static inline void put_net(struct net *net)
267{
268}
269
270static inline struct net *maybe_get_net(struct net *net)
271{
272 return net;
273}
274
275static inline
276int net_eq(const struct net *net1, const struct net *net2)
277{
278 return 1;
279}
280
281static inline int check_net(const struct net *net)
282{
283 return 1;
284}
285
286#define net_drop_ns NULL
287#endif
288
289
290typedef struct {
291#ifdef CONFIG_NET_NS
292 struct net *net;
293#endif
294} possible_net_t;
295
296static inline void write_pnet(possible_net_t *pnet, struct net *net)
297{
298#ifdef CONFIG_NET_NS
299 pnet->net = net;
300#endif
301}
302
303static inline struct net *read_pnet(const possible_net_t *pnet)
304{
305#ifdef CONFIG_NET_NS
306 return pnet->net;
307#else
308 return &init_net;
309#endif
310}
311
312/* Protected by net_rwsem */
313#define for_each_net(VAR) \
314 list_for_each_entry(VAR, &net_namespace_list, list)
315
316#define for_each_net_rcu(VAR) \
317 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
318
319#ifdef CONFIG_NET_NS
320#define __net_init
321#define __net_exit
322#define __net_initdata
323#define __net_initconst
324#else
325#define __net_init __init
326#define __net_exit __ref
327#define __net_initdata __initdata
328#define __net_initconst __initconst
329#endif
330
331int peernet2id_alloc(struct net *net, struct net *peer);
332int peernet2id(struct net *net, struct net *peer);
333bool peernet_has_id(struct net *net, struct net *peer);
334struct net *get_net_ns_by_id(struct net *net, int id);
335
336struct pernet_operations {
337 struct list_head list;
338 /*
339 * Below methods are called without any exclusive locks.
340 * More than one net may be constructed and destructed
341 * in parallel on several cpus. Every pernet_operations
342 * have to keep in mind all other pernet_operations and
343 * to introduce a locking, if they share common resources.
344 *
345 * The only time they are called with exclusive lock is
346 * from register_pernet_subsys(), unregister_pernet_subsys()
347 * register_pernet_device() and unregister_pernet_device().
348 *
349 * Exit methods using blocking RCU primitives, such as
350 * synchronize_rcu(), should be implemented via exit_batch.
351 * Then, destruction of a group of net requires single
352 * synchronize_rcu() related to these pernet_operations,
353 * instead of separate synchronize_rcu() for every net.
354 * Please, avoid synchronize_rcu() at all, where it's possible.
355 */
356 int (*init)(struct net *net);
357 void (*exit)(struct net *net);
358 void (*exit_batch)(struct list_head *net_exit_list);
359 unsigned int *id;
360 size_t size;
361};
362
363/*
364 * Use these carefully. If you implement a network device and it
365 * needs per network namespace operations use device pernet operations,
366 * otherwise use pernet subsys operations.
367 *
368 * Network interfaces need to be removed from a dying netns _before_
369 * subsys notifiers can be called, as most of the network code cleanup
370 * (which is done from subsys notifiers) runs with the assumption that
371 * dev_remove_pack has been called so no new packets will arrive during
372 * and after the cleanup functions have been called. dev_remove_pack
373 * is not per namespace so instead the guarantee of no more packets
374 * arriving in a network namespace is provided by ensuring that all
375 * network devices and all sockets have left the network namespace
376 * before the cleanup methods are called.
377 *
378 * For the longest time the ipv4 icmp code was registered as a pernet
379 * device which caused kernel oops, and panics during network
380 * namespace cleanup. So please don't get this wrong.
381 */
382int register_pernet_subsys(struct pernet_operations *);
383void unregister_pernet_subsys(struct pernet_operations *);
384int register_pernet_device(struct pernet_operations *);
385void unregister_pernet_device(struct pernet_operations *);
386
387struct ctl_table;
388struct ctl_table_header;
389
390#ifdef CONFIG_SYSCTL
391int net_sysctl_init(void);
392struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
393 struct ctl_table *table);
394void unregister_net_sysctl_table(struct ctl_table_header *header);
395#else
396static inline int net_sysctl_init(void) { return 0; }
397static inline struct ctl_table_header *register_net_sysctl(struct net *net,
398 const char *path, struct ctl_table *table)
399{
400 return NULL;
401}
402static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
403{
404}
405#endif
406
407static inline int rt_genid_ipv4(struct net *net)
408{
409 return atomic_read(&net->ipv4.rt_genid);
410}
411
412static inline void rt_genid_bump_ipv4(struct net *net)
413{
414 atomic_inc(&net->ipv4.rt_genid);
415}
416
417extern void (*__fib6_flush_trees)(struct net *net);
418static inline void rt_genid_bump_ipv6(struct net *net)
419{
420 if (__fib6_flush_trees)
421 __fib6_flush_trees(net);
422}
423
424#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
425static inline struct netns_ieee802154_lowpan *
426net_ieee802154_lowpan(struct net *net)
427{
428 return &net->ieee802154_lowpan;
429}
430#endif
431
432/* For callers who don't really care about whether it's IPv4 or IPv6 */
433static inline void rt_genid_bump_all(struct net *net)
434{
435 rt_genid_bump_ipv4(net);
436 rt_genid_bump_ipv6(net);
437}
438
439static inline int fnhe_genid(struct net *net)
440{
441 return atomic_read(&net->fnhe_genid);
442}
443
444static inline void fnhe_genid_bump(struct net *net)
445{
446 atomic_inc(&net->fnhe_genid);
447}
448
449#endif /* __NET_NET_NAMESPACE_H */
450