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/netns/core.h>
13 #include <net/netns/mib.h>
14 #include <net/netns/unix.h>
15 #include <net/netns/packet.h>
16 #include <net/netns/ipv4.h>
17 #include <net/netns/ipv6.h>
18 #include <net/netns/dccp.h>
19 #include <net/netns/x_tables.h>
20 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
21 #include <net/netns/conntrack.h>
22 #endif
23 #include <net/netns/xfrm.h>
24
25 struct proc_dir_entry;
26 struct net_device;
27 struct sock;
28 struct ctl_table_header;
29 struct net_generic;
30 struct sock;
31 struct netns_ipvs;
32
33
34 #define NETDEV_HASHBITS 8
35 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
36
37 struct net {
38 atomic_t passive; /* To decided when the network
39 * namespace should be freed.
40 */
41 atomic_t count; /* To decided when the network
42 * namespace should be shut down.
43 */
44 #ifdef NETNS_REFCNT_DEBUG
45 atomic_t use_count; /* To track references we
46 * destroy on demand
47 */
48 #endif
49 spinlock_t rules_mod_lock;
50
51 struct list_head list; /* list of network namespaces */
52 struct list_head cleanup_list; /* namespaces on death row */
53 struct list_head exit_list; /* Use only net_mutex */
54
55 struct proc_dir_entry *proc_net;
56 struct proc_dir_entry *proc_net_stat;
57
58 #ifdef CONFIG_SYSCTL
59 struct ctl_table_set sysctls;
60 #endif
61
62 struct sock *rtnl; /* rtnetlink socket */
63 struct sock *genl_sock;
64
65 struct list_head dev_base_head;
66 struct hlist_head *dev_name_head;
67 struct hlist_head *dev_index_head;
68 unsigned int dev_base_seq; /* protected by rtnl_mutex */
69
70 /* core fib_rules */
71 struct list_head rules_ops;
72
73
74 struct net_device *loopback_dev; /* The loopback */
75 struct netns_core core;
76 struct netns_mib mib;
77 struct netns_packet packet;
78 struct netns_unix unx;
79 struct netns_ipv4 ipv4;
80 #if IS_ENABLED(CONFIG_IPV6)
81 struct netns_ipv6 ipv6;
82 #endif
83 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
84 struct netns_dccp dccp;
85 #endif
86 #ifdef CONFIG_NETFILTER
87 struct netns_xt xt;
88 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
89 struct netns_ct ct;
90 #endif
91 struct sock *nfnl;
92 struct sock *nfnl_stash;
93 #endif
94 #ifdef CONFIG_WEXT_CORE
95 struct sk_buff_head wext_nlevents;
96 #endif
97 struct net_generic __rcu *gen;
98
99 /* Note : following structs are cache line aligned */
100 #ifdef CONFIG_XFRM
101 struct netns_xfrm xfrm;
102 #endif
103 struct netns_ipvs *ipvs;
104 };
105
106
107 #include <linux/seq_file_net.h>
108
109 /* Init's network namespace */
110 extern struct net init_net;
111
112 #ifdef CONFIG_NET
113 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
114
115 #else /* CONFIG_NET */
copy_net_ns(unsigned long flags,struct net * net_ns)116 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
117 {
118 /* There is nothing to copy so this is a noop */
119 return net_ns;
120 }
121 #endif /* CONFIG_NET */
122
123
124 extern struct list_head net_namespace_list;
125
126 extern struct net *get_net_ns_by_pid(pid_t pid);
127 extern struct net *get_net_ns_by_fd(int pid);
128
129 #ifdef CONFIG_NET_NS
130 extern void __put_net(struct net *net);
131
get_net(struct net * net)132 static inline struct net *get_net(struct net *net)
133 {
134 atomic_inc(&net->count);
135 return net;
136 }
137
maybe_get_net(struct net * net)138 static inline struct net *maybe_get_net(struct net *net)
139 {
140 /* Used when we know struct net exists but we
141 * aren't guaranteed a previous reference count
142 * exists. If the reference count is zero this
143 * function fails and returns NULL.
144 */
145 if (!atomic_inc_not_zero(&net->count))
146 net = NULL;
147 return net;
148 }
149
put_net(struct net * net)150 static inline void put_net(struct net *net)
151 {
152 if (atomic_dec_and_test(&net->count))
153 __put_net(net);
154 }
155
156 static inline
net_eq(const struct net * net1,const struct net * net2)157 int net_eq(const struct net *net1, const struct net *net2)
158 {
159 return net1 == net2;
160 }
161
162 extern void net_drop_ns(void *);
163
164 #else
165
get_net(struct net * net)166 static inline struct net *get_net(struct net *net)
167 {
168 return net;
169 }
170
put_net(struct net * net)171 static inline void put_net(struct net *net)
172 {
173 }
174
maybe_get_net(struct net * net)175 static inline struct net *maybe_get_net(struct net *net)
176 {
177 return net;
178 }
179
180 static inline
net_eq(const struct net * net1,const struct net * net2)181 int net_eq(const struct net *net1, const struct net *net2)
182 {
183 return 1;
184 }
185
186 #define net_drop_ns NULL
187 #endif
188
189
190 #ifdef NETNS_REFCNT_DEBUG
hold_net(struct net * net)191 static inline struct net *hold_net(struct net *net)
192 {
193 if (net)
194 atomic_inc(&net->use_count);
195 return net;
196 }
197
release_net(struct net * net)198 static inline void release_net(struct net *net)
199 {
200 if (net)
201 atomic_dec(&net->use_count);
202 }
203 #else
hold_net(struct net * net)204 static inline struct net *hold_net(struct net *net)
205 {
206 return net;
207 }
208
release_net(struct net * net)209 static inline void release_net(struct net *net)
210 {
211 }
212 #endif
213
214 #ifdef CONFIG_NET_NS
215
write_pnet(struct net ** pnet,struct net * net)216 static inline void write_pnet(struct net **pnet, struct net *net)
217 {
218 *pnet = net;
219 }
220
read_pnet(struct net * const * pnet)221 static inline struct net *read_pnet(struct net * const *pnet)
222 {
223 return *pnet;
224 }
225
226 #else
227
228 #define write_pnet(pnet, net) do { (void)(net);} while (0)
229 #define read_pnet(pnet) (&init_net)
230
231 #endif
232
233 #define for_each_net(VAR) \
234 list_for_each_entry(VAR, &net_namespace_list, list)
235
236 #define for_each_net_rcu(VAR) \
237 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
238
239 #ifdef CONFIG_NET_NS
240 #define __net_init
241 #define __net_exit
242 #define __net_initdata
243 #else
244 #define __net_init __init
245 #define __net_exit __exit_refok
246 #define __net_initdata __initdata
247 #endif
248
249 struct pernet_operations {
250 struct list_head list;
251 int (*init)(struct net *net);
252 void (*exit)(struct net *net);
253 void (*exit_batch)(struct list_head *net_exit_list);
254 int *id;
255 size_t size;
256 };
257
258 /*
259 * Use these carefully. If you implement a network device and it
260 * needs per network namespace operations use device pernet operations,
261 * otherwise use pernet subsys operations.
262 *
263 * Network interfaces need to be removed from a dying netns _before_
264 * subsys notifiers can be called, as most of the network code cleanup
265 * (which is done from subsys notifiers) runs with the assumption that
266 * dev_remove_pack has been called so no new packets will arrive during
267 * and after the cleanup functions have been called. dev_remove_pack
268 * is not per namespace so instead the guarantee of no more packets
269 * arriving in a network namespace is provided by ensuring that all
270 * network devices and all sockets have left the network namespace
271 * before the cleanup methods are called.
272 *
273 * For the longest time the ipv4 icmp code was registered as a pernet
274 * device which caused kernel oops, and panics during network
275 * namespace cleanup. So please don't get this wrong.
276 */
277 extern int register_pernet_subsys(struct pernet_operations *);
278 extern void unregister_pernet_subsys(struct pernet_operations *);
279 extern int register_pernet_device(struct pernet_operations *);
280 extern void unregister_pernet_device(struct pernet_operations *);
281
282 struct ctl_path;
283 struct ctl_table;
284 struct ctl_table_header;
285
286 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
287 const struct ctl_path *path, struct ctl_table *table);
288 extern struct ctl_table_header *register_net_sysctl_rotable(
289 const struct ctl_path *path, struct ctl_table *table);
290 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
291
292 #endif /* __NET_NET_NAMESPACE_H */
293