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