1 /*
2 * Operations on the network namespace
3 */
4 #ifndef __NET_NET_NAMESPACE_H
5 #define __NET_NET_NAMESPACE_H
6
7 #include <linux/atomic.h>
8 #include <linux/workqueue.h>
9 #include <linux/list.h>
10 #include <linux/sysctl.h>
11
12 #include <net/flow.h>
13 #include <net/netns/core.h>
14 #include <net/netns/mib.h>
15 #include <net/netns/unix.h>
16 #include <net/netns/packet.h>
17 #include <net/netns/ipv4.h>
18 #include <net/netns/ipv6.h>
19 #include <net/netns/sctp.h>
20 #include <net/netns/dccp.h>
21 #include <net/netns/netfilter.h>
22 #include <net/netns/x_tables.h>
23 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
24 #include <net/netns/conntrack.h>
25 #endif
26 #include <net/netns/xfrm.h>
27 #include <linux/idr.h>
28 #include <linux/skbuff.h>
29
30 struct user_namespace;
31 struct proc_dir_entry;
32 struct net_device;
33 struct sock;
34 struct ctl_table_header;
35 struct net_generic;
36 struct sock;
37 struct netns_ipvs;
38
39
40 #define NETDEV_HASHBITS 8
41 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
42
43 struct net {
44 atomic_t passive; /* To decided when the network
45 * namespace should be freed.
46 */
47 atomic_t count; /* To decided when the network
48 * namespace should be shut down.
49 */
50 #ifdef NETNS_REFCNT_DEBUG
51 atomic_t use_count; /* To track references we
52 * destroy on demand
53 */
54 #endif
55 spinlock_t rules_mod_lock;
56
57 struct list_head list; /* list of network namespaces */
58 struct list_head cleanup_list; /* namespaces on death row */
59 struct list_head exit_list; /* Use only net_mutex */
60
61 struct user_namespace *user_ns; /* Owning user namespace */
62 struct idr netns_ids;
63
64 unsigned int proc_inum;
65
66 struct proc_dir_entry *proc_net;
67 struct proc_dir_entry *proc_net_stat;
68
69 #ifdef CONFIG_SYSCTL
70 struct ctl_table_set sysctls;
71 #endif
72
73 struct sock *rtnl; /* rtnetlink socket */
74 struct sock *genl_sock;
75
76 struct list_head dev_base_head;
77 struct hlist_head *dev_name_head;
78 struct hlist_head *dev_index_head;
79 unsigned int dev_base_seq; /* protected by rtnl_mutex */
80 int ifindex;
81
82 /* core fib_rules */
83 struct list_head rules_ops;
84
85
86 struct net_device *loopback_dev; /* The loopback */
87 struct netns_core core;
88 struct netns_mib mib;
89 struct netns_packet packet;
90 struct netns_unix unx;
91 struct netns_ipv4 ipv4;
92 #if IS_ENABLED(CONFIG_IPV6)
93 struct netns_ipv6 ipv6;
94 #endif
95 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
96 struct netns_sctp sctp;
97 #endif
98 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
99 struct netns_dccp dccp;
100 #endif
101 #ifdef CONFIG_NETFILTER
102 struct netns_nf nf;
103 struct netns_xt xt;
104 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
105 struct netns_ct ct;
106 #endif
107 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
108 struct netns_nf_frag nf_frag;
109 #endif
110 struct sock *nfnl;
111 struct sock *nfnl_stash;
112 #endif
113 #ifdef CONFIG_WEXT_CORE
114 struct sk_buff_head wext_nlevents;
115 #endif
116 struct net_generic __rcu *gen;
117
118 /* Note : following structs are cache line aligned */
119 #ifdef CONFIG_XFRM
120 struct netns_xfrm xfrm;
121 #endif
122 struct netns_ipvs *ipvs;
123 struct sock *diag_nlsk;
124 atomic_t rt_genid;
125 };
126
127 #include <linux/seq_file_net.h>
128
129 /* Init's network namespace */
130 extern struct net init_net;
131
132 #ifdef CONFIG_NET_NS
133 extern struct net *copy_net_ns(unsigned long flags,
134 struct user_namespace *user_ns, struct net *old_net);
135
136 #else /* CONFIG_NET_NS */
137 #include <linux/sched.h>
138 #include <linux/nsproxy.h>
copy_net_ns(unsigned long flags,struct user_namespace * user_ns,struct net * old_net)139 static inline struct net *copy_net_ns(unsigned long flags,
140 struct user_namespace *user_ns, struct net *old_net)
141 {
142 if (flags & CLONE_NEWNET)
143 return ERR_PTR(-EINVAL);
144 return old_net;
145 }
146 #endif /* CONFIG_NET_NS */
147
148
149 extern struct list_head net_namespace_list;
150
151 extern struct net *get_net_ns_by_pid(pid_t pid);
152 extern struct net *get_net_ns_by_fd(int pid);
153
154 #ifdef CONFIG_NET_NS
155 extern void __put_net(struct net *net);
156
get_net(struct net * net)157 static inline struct net *get_net(struct net *net)
158 {
159 atomic_inc(&net->count);
160 return net;
161 }
162
maybe_get_net(struct net * net)163 static inline struct net *maybe_get_net(struct net *net)
164 {
165 /* Used when we know struct net exists but we
166 * aren't guaranteed a previous reference count
167 * exists. If the reference count is zero this
168 * function fails and returns NULL.
169 */
170 if (!atomic_inc_not_zero(&net->count))
171 net = NULL;
172 return net;
173 }
174
put_net(struct net * net)175 static inline void put_net(struct net *net)
176 {
177 if (atomic_dec_and_test(&net->count))
178 __put_net(net);
179 }
180
181 static inline
net_eq(const struct net * net1,const struct net * net2)182 int net_eq(const struct net *net1, const struct net *net2)
183 {
184 return net1 == net2;
185 }
186
187 extern void net_drop_ns(void *);
188
189 #else
190
get_net(struct net * net)191 static inline struct net *get_net(struct net *net)
192 {
193 return net;
194 }
195
put_net(struct net * net)196 static inline void put_net(struct net *net)
197 {
198 }
199
maybe_get_net(struct net * net)200 static inline struct net *maybe_get_net(struct net *net)
201 {
202 return net;
203 }
204
205 static inline
net_eq(const struct net * net1,const struct net * net2)206 int net_eq(const struct net *net1, const struct net *net2)
207 {
208 return 1;
209 }
210
211 #define net_drop_ns NULL
212 #endif
213
214
215 #ifdef NETNS_REFCNT_DEBUG
hold_net(struct net * net)216 static inline struct net *hold_net(struct net *net)
217 {
218 if (net)
219 atomic_inc(&net->use_count);
220 return net;
221 }
222
release_net(struct net * net)223 static inline void release_net(struct net *net)
224 {
225 if (net)
226 atomic_dec(&net->use_count);
227 }
228 #else
hold_net(struct net * net)229 static inline struct net *hold_net(struct net *net)
230 {
231 return net;
232 }
233
release_net(struct net * net)234 static inline void release_net(struct net *net)
235 {
236 }
237 #endif
238
239 #ifdef CONFIG_NET_NS
240
write_pnet(struct net ** pnet,struct net * net)241 static inline void write_pnet(struct net **pnet, struct net *net)
242 {
243 *pnet = net;
244 }
245
read_pnet(struct net * const * pnet)246 static inline struct net *read_pnet(struct net * const *pnet)
247 {
248 return *pnet;
249 }
250
251 #else
252
253 #define write_pnet(pnet, net) do { (void)(net);} while (0)
254 #define read_pnet(pnet) (&init_net)
255
256 #endif
257
258 #define for_each_net(VAR) \
259 list_for_each_entry(VAR, &net_namespace_list, list)
260
261 #define for_each_net_rcu(VAR) \
262 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
263
264 #ifdef CONFIG_NET_NS
265 #define __net_init
266 #define __net_exit
267 #define __net_initdata
268 #define __net_initconst
269 #else
270 #define __net_init __init
271 #define __net_exit __exit_refok
272 #define __net_initdata __initdata
273 #define __net_initconst __initconst
274 #endif
275
276 int peernet2id(struct net *net, struct net *peer);
277 struct net *get_net_ns_by_id(struct net *net, int id);
278
279 struct pernet_operations {
280 struct list_head list;
281 int (*init)(struct net *net);
282 void (*exit)(struct net *net);
283 void (*exit_batch)(struct list_head *net_exit_list);
284 int *id;
285 size_t size;
286 };
287
288 /*
289 * Use these carefully. If you implement a network device and it
290 * needs per network namespace operations use device pernet operations,
291 * otherwise use pernet subsys operations.
292 *
293 * Network interfaces need to be removed from a dying netns _before_
294 * subsys notifiers can be called, as most of the network code cleanup
295 * (which is done from subsys notifiers) runs with the assumption that
296 * dev_remove_pack has been called so no new packets will arrive during
297 * and after the cleanup functions have been called. dev_remove_pack
298 * is not per namespace so instead the guarantee of no more packets
299 * arriving in a network namespace is provided by ensuring that all
300 * network devices and all sockets have left the network namespace
301 * before the cleanup methods are called.
302 *
303 * For the longest time the ipv4 icmp code was registered as a pernet
304 * device which caused kernel oops, and panics during network
305 * namespace cleanup. So please don't get this wrong.
306 */
307 extern int register_pernet_subsys(struct pernet_operations *);
308 extern void unregister_pernet_subsys(struct pernet_operations *);
309 extern int register_pernet_device(struct pernet_operations *);
310 extern void unregister_pernet_device(struct pernet_operations *);
311
312 struct ctl_table;
313 struct ctl_table_header;
314
315 #ifdef CONFIG_SYSCTL
316 extern int net_sysctl_init(void);
317 extern struct ctl_table_header *register_net_sysctl(struct net *net,
318 const char *path, struct ctl_table *table);
319 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
320 #else
net_sysctl_init(void)321 static inline int net_sysctl_init(void) { return 0; }
register_net_sysctl(struct net * net,const char * path,struct ctl_table * table)322 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
323 const char *path, struct ctl_table *table)
324 {
325 return NULL;
326 }
unregister_net_sysctl_table(struct ctl_table_header * header)327 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
328 {
329 }
330 #endif
331
rt_genid(struct net * net)332 static inline int rt_genid(struct net *net)
333 {
334 return atomic_read(&net->rt_genid);
335 }
336
rt_genid_bump(struct net * net)337 static inline void rt_genid_bump(struct net *net)
338 {
339 atomic_inc(&net->rt_genid);
340 }
341
342 #endif /* __NET_NET_NAMESPACE_H */
343