1 /*
2 * Operations on the network namespace
3 */
4 #ifndef __NET_NET_NAMESPACE_H
5 #define __NET_NET_NAMESPACE_H
6
7 #include <asm/atomic.h>
8 #include <linux/workqueue.h>
9 #include <linux/list.h>
10
11 #include <net/netns/core.h>
12 #include <net/netns/mib.h>
13 #include <net/netns/unix.h>
14 #include <net/netns/packet.h>
15 #include <net/netns/ipv4.h>
16 #include <net/netns/ipv6.h>
17 #include <net/netns/dccp.h>
18 #include <net/netns/x_tables.h>
19 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
20 #include <net/netns/conntrack.h>
21 #endif
22 #include <net/netns/xfrm.h>
23
24 struct proc_dir_entry;
25 struct net_device;
26 struct sock;
27 struct ctl_table_header;
28 struct net_generic;
29 struct sock;
30 struct netns_ipvs;
31
32
33 #define NETDEV_HASHBITS 8
34 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
35
36 struct net {
37 atomic_t count; /* To decided when the network
38 * namespace should be freed.
39 */
40 #ifdef NETNS_REFCNT_DEBUG
41 atomic_t use_count; /* To track references we
42 * destroy on demand
43 */
44 #endif
45 spinlock_t rules_mod_lock;
46
47 struct list_head list; /* list of network namespaces */
48 struct list_head cleanup_list; /* namespaces on death row */
49 struct list_head exit_list; /* Use only net_mutex */
50
51 struct proc_dir_entry *proc_net;
52 struct proc_dir_entry *proc_net_stat;
53
54 #ifdef CONFIG_SYSCTL
55 struct ctl_table_set sysctls;
56 #endif
57
58 struct sock *rtnl; /* rtnetlink socket */
59 struct sock *genl_sock;
60
61 struct list_head dev_base_head;
62 struct hlist_head *dev_name_head;
63 struct hlist_head *dev_index_head;
64
65 /* core fib_rules */
66 struct list_head rules_ops;
67
68
69 struct net_device *loopback_dev; /* The loopback */
70 struct netns_core core;
71 struct netns_mib mib;
72 struct netns_packet packet;
73 struct netns_unix unx;
74 struct netns_ipv4 ipv4;
75 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
76 struct netns_ipv6 ipv6;
77 #endif
78 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
79 struct netns_dccp dccp;
80 #endif
81 #ifdef CONFIG_NETFILTER
82 struct netns_xt xt;
83 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
84 struct netns_ct ct;
85 #endif
86 struct sock *nfnl;
87 struct sock *nfnl_stash;
88 #endif
89 #ifdef CONFIG_WEXT_CORE
90 struct sk_buff_head wext_nlevents;
91 #endif
92 struct net_generic __rcu *gen;
93
94 /* Note : following structs are cache line aligned */
95 #ifdef CONFIG_XFRM
96 struct netns_xfrm xfrm;
97 #endif
98 struct netns_ipvs *ipvs;
99 };
100
101
102 #include <linux/seq_file_net.h>
103
104 /* Init's network namespace */
105 extern struct net init_net;
106
107 #ifdef CONFIG_NET
108 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
109
110 #else /* CONFIG_NET */
copy_net_ns(unsigned long flags,struct net * net_ns)111 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
112 {
113 /* There is nothing to copy so this is a noop */
114 return net_ns;
115 }
116 #endif /* CONFIG_NET */
117
118
119 extern struct list_head net_namespace_list;
120
121 extern struct net *get_net_ns_by_pid(pid_t pid);
122
123 #ifdef CONFIG_NET_NS
124 extern void __put_net(struct net *net);
125
get_net(struct net * net)126 static inline struct net *get_net(struct net *net)
127 {
128 atomic_inc(&net->count);
129 return net;
130 }
131
maybe_get_net(struct net * net)132 static inline struct net *maybe_get_net(struct net *net)
133 {
134 /* Used when we know struct net exists but we
135 * aren't guaranteed a previous reference count
136 * exists. If the reference count is zero this
137 * function fails and returns NULL.
138 */
139 if (!atomic_inc_not_zero(&net->count))
140 net = NULL;
141 return net;
142 }
143
put_net(struct net * net)144 static inline void put_net(struct net *net)
145 {
146 if (atomic_dec_and_test(&net->count))
147 __put_net(net);
148 }
149
150 static inline
net_eq(const struct net * net1,const struct net * net2)151 int net_eq(const struct net *net1, const struct net *net2)
152 {
153 return net1 == net2;
154 }
155 #else
156
get_net(struct net * net)157 static inline struct net *get_net(struct net *net)
158 {
159 return net;
160 }
161
put_net(struct net * net)162 static inline void put_net(struct net *net)
163 {
164 }
165
maybe_get_net(struct net * net)166 static inline struct net *maybe_get_net(struct net *net)
167 {
168 return net;
169 }
170
171 static inline
net_eq(const struct net * net1,const struct net * net2)172 int net_eq(const struct net *net1, const struct net *net2)
173 {
174 return 1;
175 }
176 #endif
177
178
179 #ifdef NETNS_REFCNT_DEBUG
hold_net(struct net * net)180 static inline struct net *hold_net(struct net *net)
181 {
182 if (net)
183 atomic_inc(&net->use_count);
184 return net;
185 }
186
release_net(struct net * net)187 static inline void release_net(struct net *net)
188 {
189 if (net)
190 atomic_dec(&net->use_count);
191 }
192 #else
hold_net(struct net * net)193 static inline struct net *hold_net(struct net *net)
194 {
195 return net;
196 }
197
release_net(struct net * net)198 static inline void release_net(struct net *net)
199 {
200 }
201 #endif
202
203 #ifdef CONFIG_NET_NS
204
write_pnet(struct net ** pnet,struct net * net)205 static inline void write_pnet(struct net **pnet, struct net *net)
206 {
207 *pnet = net;
208 }
209
read_pnet(struct net * const * pnet)210 static inline struct net *read_pnet(struct net * const *pnet)
211 {
212 return *pnet;
213 }
214
215 #else
216
217 #define write_pnet(pnet, net) do { (void)(net);} while (0)
218 #define read_pnet(pnet) (&init_net)
219
220 #endif
221
222 #define for_each_net(VAR) \
223 list_for_each_entry(VAR, &net_namespace_list, list)
224
225 #define for_each_net_rcu(VAR) \
226 list_for_each_entry_rcu(VAR, &net_namespace_list, list)
227
228 #ifdef CONFIG_NET_NS
229 #define __net_init
230 #define __net_exit
231 #define __net_initdata
232 #else
233 #define __net_init __init
234 #define __net_exit __exit_refok
235 #define __net_initdata __initdata
236 #endif
237
238 struct pernet_operations {
239 struct list_head list;
240 int (*init)(struct net *net);
241 void (*exit)(struct net *net);
242 void (*exit_batch)(struct list_head *net_exit_list);
243 int *id;
244 size_t size;
245 };
246
247 /*
248 * Use these carefully. If you implement a network device and it
249 * needs per network namespace operations use device pernet operations,
250 * otherwise use pernet subsys operations.
251 *
252 * Network interfaces need to be removed from a dying netns _before_
253 * subsys notifiers can be called, as most of the network code cleanup
254 * (which is done from subsys notifiers) runs with the assumption that
255 * dev_remove_pack has been called so no new packets will arrive during
256 * and after the cleanup functions have been called. dev_remove_pack
257 * is not per namespace so instead the guarantee of no more packets
258 * arriving in a network namespace is provided by ensuring that all
259 * network devices and all sockets have left the network namespace
260 * before the cleanup methods are called.
261 *
262 * For the longest time the ipv4 icmp code was registered as a pernet
263 * device which caused kernel oops, and panics during network
264 * namespace cleanup. So please don't get this wrong.
265 */
266 extern int register_pernet_subsys(struct pernet_operations *);
267 extern void unregister_pernet_subsys(struct pernet_operations *);
268 extern int register_pernet_device(struct pernet_operations *);
269 extern void unregister_pernet_device(struct pernet_operations *);
270
271 struct ctl_path;
272 struct ctl_table;
273 struct ctl_table_header;
274
275 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
276 const struct ctl_path *path, struct ctl_table *table);
277 extern struct ctl_table_header *register_net_sysctl_rotable(
278 const struct ctl_path *path, struct ctl_table *table);
279 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
280
281 #endif /* __NET_NET_NAMESPACE_H */
282