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
14 #include <net/flow.h>
15 #include <net/netns/core.h>
16 #include <net/netns/mib.h>
17 #include <net/netns/unix.h>
18 #include <net/netns/packet.h>
19 #include <net/netns/ipv4.h>
20 #include <net/netns/ipv6.h>
21 #include <net/netns/ieee802154_6lowpan.h>
22 #include <net/netns/sctp.h>
23 #include <net/netns/dccp.h>
24 #include <net/netns/netfilter.h>
25 #include <net/netns/x_tables.h>
26 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
27 #include <net/netns/conntrack.h>
28 #endif
29 #include <net/netns/nftables.h>
30 #include <net/netns/xfrm.h>
31 #include <net/netns/mpls.h>
32 #include <net/netns/can.h>
33 #include <linux/ns_common.h>
34 #include <linux/idr.h>
35 #include <linux/skbuff.h>
36
37 struct user_namespace;
38 struct proc_dir_entry;
39 struct net_device;
40 struct sock;
41 struct ctl_table_header;
42 struct net_generic;
43 struct sock;
44 struct netns_ipvs;
45
46
47 #define NETDEV_HASHBITS 8
48 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
49
50 struct net {
51 refcount_t passive; /* To decided when the network
52 * namespace should be freed.
53 */
54 atomic_t count; /* To decided when the network
55 * namespace should be shut down.
56 */
57 spinlock_t rules_mod_lock;
58
59 u32 hash_mix;
60 atomic64_t cookie_gen;
61
62 struct list_head list; /* list of network namespaces */
63 struct list_head cleanup_list; /* namespaces on death row */
64 struct list_head exit_list; /* Use only net_mutex */
65
66 struct user_namespace *user_ns; /* Owning user namespace */
67 struct ucounts *ucounts;
68 spinlock_t nsid_lock;
69 struct idr netns_ids;
70
71 struct ns_common ns;
72
73 struct proc_dir_entry *proc_net;
74 struct proc_dir_entry *proc_net_stat;
75
76 #ifdef CONFIG_SYSCTL
77 struct ctl_table_set sysctls;
78 #endif
79
80 struct sock *rtnl; /* rtnetlink socket */
81 struct sock *genl_sock;
82
83 struct list_head dev_base_head;
84 struct hlist_head *dev_name_head;
85 struct hlist_head *dev_index_head;
86 unsigned int dev_base_seq; /* protected by rtnl_mutex */
87 int ifindex;
88 unsigned int dev_unreg_count;
89
90 /* core fib_rules */
91 struct list_head rules_ops;
92
93 struct list_head fib_notifier_ops; /* protected by net_mutex */
94
95 struct net_device *loopback_dev; /* The loopback */
96 struct netns_core core;
97 struct netns_mib mib;
98 struct netns_packet packet;
99 struct netns_unix unx;
100 struct netns_ipv4 ipv4;
101 #if IS_ENABLED(CONFIG_IPV6)
102 struct netns_ipv6 ipv6;
103 #endif
104 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
105 struct netns_ieee802154_lowpan ieee802154_lowpan;
106 #endif
107 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
108 struct netns_sctp sctp;
109 #endif
110 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
111 struct netns_dccp dccp;
112 #endif
113 #ifdef CONFIG_NETFILTER
114 struct netns_nf nf;
115 struct netns_xt xt;
116 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
117 struct netns_ct ct;
118 #endif
119 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
120 struct netns_nftables nft;
121 #endif
122 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
123 struct netns_nf_frag nf_frag;
124 struct ctl_table_header *nf_frag_frags_hdr;
125 #endif
126 struct sock *nfnl;
127 struct sock *nfnl_stash;
128 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
129 struct list_head nfnl_acct_list;
130 #endif
131 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
132 struct list_head nfct_timeout_list;
133 #endif
134 #endif
135 #ifdef CONFIG_WEXT_CORE
136 struct sk_buff_head wext_nlevents;
137 #endif
138 struct net_generic __rcu *gen;
139
140 /* Note : following structs are cache line aligned */
141 #ifdef CONFIG_XFRM
142 struct netns_xfrm xfrm;
143 #endif
144 #if IS_ENABLED(CONFIG_IP_VS)
145 struct netns_ipvs *ipvs;
146 #endif
147 #if IS_ENABLED(CONFIG_MPLS)
148 struct netns_mpls mpls;
149 #endif
150 #if IS_ENABLED(CONFIG_CAN)
151 struct netns_can can;
152 #endif
153 struct sock *diag_nlsk;
154 atomic_t fnhe_genid;
155 } __randomize_layout;
156
157 #include <linux/seq_file_net.h>
158
159 /* Init's network namespace */
160 extern struct net init_net;
161
162 #ifdef CONFIG_NET_NS
163 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
164 struct net *old_net);
165
166 void net_ns_barrier(void);
167 #else /* CONFIG_NET_NS */
168 #include <linux/sched.h>
169 #include <linux/nsproxy.h>
copy_net_ns(unsigned long flags,struct user_namespace * user_ns,struct net * old_net)170 static inline struct net *copy_net_ns(unsigned long flags,
171 struct user_namespace *user_ns, struct net *old_net)
172 {
173 if (flags & CLONE_NEWNET)
174 return ERR_PTR(-EINVAL);
175 return old_net;
176 }
177
net_ns_barrier(void)178 static inline void net_ns_barrier(void) {}
179 #endif /* CONFIG_NET_NS */
180
181
182 extern struct list_head net_namespace_list;
183
184 struct net *get_net_ns_by_pid(pid_t pid);
185 struct net *get_net_ns_by_fd(int fd);
186
187 #ifdef CONFIG_SYSCTL
188 void ipx_register_sysctl(void);
189 void ipx_unregister_sysctl(void);
190 #else
191 #define ipx_register_sysctl()
192 #define ipx_unregister_sysctl()
193 #endif
194
195 #ifdef CONFIG_NET_NS
196 void __put_net(struct net *net);
197
get_net(struct net * net)198 static inline struct net *get_net(struct net *net)
199 {
200 atomic_inc(&net->count);
201 return net;
202 }
203
maybe_get_net(struct net * net)204 static inline struct net *maybe_get_net(struct net *net)
205 {
206 /* Used when we know struct net exists but we
207 * aren't guaranteed a previous reference count
208 * exists. If the reference count is zero this
209 * function fails and returns NULL.
210 */
211 if (!atomic_inc_not_zero(&net->count))
212 net = NULL;
213 return net;
214 }
215
put_net(struct net * net)216 static inline void put_net(struct net *net)
217 {
218 if (atomic_dec_and_test(&net->count))
219 __put_net(net);
220 }
221
222 static inline
net_eq(const struct net * net1,const struct net * net2)223 int net_eq(const struct net *net1, const struct net *net2)
224 {
225 return net1 == net2;
226 }
227
check_net(const struct net * net)228 static inline int check_net(const struct net *net)
229 {
230 return atomic_read(&net->count) != 0;
231 }
232
233 void net_drop_ns(void *);
234
235 #else
236
get_net(struct net * net)237 static inline struct net *get_net(struct net *net)
238 {
239 return net;
240 }
241
put_net(struct net * net)242 static inline void put_net(struct net *net)
243 {
244 }
245
maybe_get_net(struct net * net)246 static inline struct net *maybe_get_net(struct net *net)
247 {
248 return net;
249 }
250
251 static inline
net_eq(const struct net * net1,const struct net * net2)252 int net_eq(const struct net *net1, const struct net *net2)
253 {
254 return 1;
255 }
256
check_net(const struct net * net)257 static inline int check_net(const struct net *net)
258 {
259 return 1;
260 }
261
262 #define net_drop_ns NULL
263 #endif
264
265
266 typedef struct {
267 #ifdef CONFIG_NET_NS
268 struct net *net;
269 #endif
270 } possible_net_t;
271
write_pnet(possible_net_t * pnet,struct net * net)272 static inline void write_pnet(possible_net_t *pnet, struct net *net)
273 {
274 #ifdef CONFIG_NET_NS
275 pnet->net = net;
276 #endif
277 }
278
read_pnet(const possible_net_t * pnet)279 static inline struct net *read_pnet(const possible_net_t *pnet)
280 {
281 #ifdef CONFIG_NET_NS
282 return pnet->net;
283 #else
284 return &init_net;
285 #endif
286 }
287
288 #define for_each_net(VAR) \
289 list_for_each_entry(VAR, &net_namespace_list, list)
290
291 #define for_each_net_rcu(VAR) \
292 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
293
294 #ifdef CONFIG_NET_NS
295 #define __net_init
296 #define __net_exit
297 #define __net_initdata
298 #define __net_initconst
299 #else
300 #define __net_init __init
301 #define __net_exit __ref
302 #define __net_initdata __initdata
303 #define __net_initconst __initconst
304 #endif
305
306 int peernet2id_alloc(struct net *net, struct net *peer);
307 int peernet2id(struct net *net, struct net *peer);
308 bool peernet_has_id(struct net *net, struct net *peer);
309 struct net *get_net_ns_by_id(struct net *net, int id);
310
311 struct pernet_operations {
312 struct list_head list;
313 int (*init)(struct net *net);
314 void (*exit)(struct net *net);
315 void (*exit_batch)(struct list_head *net_exit_list);
316 unsigned int *id;
317 size_t size;
318 };
319
320 /*
321 * Use these carefully. If you implement a network device and it
322 * needs per network namespace operations use device pernet operations,
323 * otherwise use pernet subsys operations.
324 *
325 * Network interfaces need to be removed from a dying netns _before_
326 * subsys notifiers can be called, as most of the network code cleanup
327 * (which is done from subsys notifiers) runs with the assumption that
328 * dev_remove_pack has been called so no new packets will arrive during
329 * and after the cleanup functions have been called. dev_remove_pack
330 * is not per namespace so instead the guarantee of no more packets
331 * arriving in a network namespace is provided by ensuring that all
332 * network devices and all sockets have left the network namespace
333 * before the cleanup methods are called.
334 *
335 * For the longest time the ipv4 icmp code was registered as a pernet
336 * device which caused kernel oops, and panics during network
337 * namespace cleanup. So please don't get this wrong.
338 */
339 int register_pernet_subsys(struct pernet_operations *);
340 void unregister_pernet_subsys(struct pernet_operations *);
341 int register_pernet_device(struct pernet_operations *);
342 void unregister_pernet_device(struct pernet_operations *);
343
344 struct ctl_table;
345 struct ctl_table_header;
346
347 #ifdef CONFIG_SYSCTL
348 int net_sysctl_init(void);
349 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
350 struct ctl_table *table);
351 void unregister_net_sysctl_table(struct ctl_table_header *header);
352 #else
net_sysctl_init(void)353 static inline int net_sysctl_init(void) { return 0; }
register_net_sysctl(struct net * net,const char * path,struct ctl_table * table)354 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
355 const char *path, struct ctl_table *table)
356 {
357 return NULL;
358 }
unregister_net_sysctl_table(struct ctl_table_header * header)359 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
360 {
361 }
362 #endif
363
rt_genid_ipv4(struct net * net)364 static inline int rt_genid_ipv4(struct net *net)
365 {
366 return atomic_read(&net->ipv4.rt_genid);
367 }
368
rt_genid_bump_ipv4(struct net * net)369 static inline void rt_genid_bump_ipv4(struct net *net)
370 {
371 atomic_inc(&net->ipv4.rt_genid);
372 }
373
374 extern void (*__fib6_flush_trees)(struct net *net);
rt_genid_bump_ipv6(struct net * net)375 static inline void rt_genid_bump_ipv6(struct net *net)
376 {
377 if (__fib6_flush_trees)
378 __fib6_flush_trees(net);
379 }
380
381 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
382 static inline struct netns_ieee802154_lowpan *
net_ieee802154_lowpan(struct net * net)383 net_ieee802154_lowpan(struct net *net)
384 {
385 return &net->ieee802154_lowpan;
386 }
387 #endif
388
389 /* For callers who don't really care about whether it's IPv4 or IPv6 */
rt_genid_bump_all(struct net * net)390 static inline void rt_genid_bump_all(struct net *net)
391 {
392 rt_genid_bump_ipv4(net);
393 rt_genid_bump_ipv6(net);
394 }
395
fnhe_genid(struct net * net)396 static inline int fnhe_genid(struct net *net)
397 {
398 return atomic_read(&net->fnhe_genid);
399 }
400
fnhe_genid_bump(struct net * net)401 static inline void fnhe_genid_bump(struct net *net)
402 {
403 atomic_inc(&net->fnhe_genid);
404 }
405
406 #endif /* __NET_NET_NAMESPACE_H */
407