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