xref: /linux/include/net/net_namespace.h (revision b233b28eac0cc37d07c2d007ea08c86c778c5af4)
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 
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 
112 static inline int net_alive(struct net *net)
113 {
114 	return net && atomic_read(&net->count);
115 }
116 
117 static inline struct net *get_net(struct net *net)
118 {
119 	atomic_inc(&net->count);
120 	return net;
121 }
122 
123 static inline struct net *maybe_get_net(struct net *net)
124 {
125 	/* Used when we know struct net exists but we
126 	 * aren't guaranteed a previous reference count
127 	 * exists.  If the reference count is zero this
128 	 * function fails and returns NULL.
129 	 */
130 	if (!atomic_inc_not_zero(&net->count))
131 		net = NULL;
132 	return net;
133 }
134 
135 static inline void put_net(struct net *net)
136 {
137 	if (atomic_dec_and_test(&net->count))
138 		__put_net(net);
139 }
140 
141 static inline
142 int net_eq(const struct net *net1, const struct net *net2)
143 {
144 	return net1 == net2;
145 }
146 #else
147 
148 static inline int net_alive(struct net *net)
149 {
150 	return 1;
151 }
152 
153 static inline struct net *get_net(struct net *net)
154 {
155 	return net;
156 }
157 
158 static inline void put_net(struct net *net)
159 {
160 }
161 
162 static inline struct net *maybe_get_net(struct net *net)
163 {
164 	return net;
165 }
166 
167 static inline
168 int net_eq(const struct net *net1, const struct net *net2)
169 {
170 	return 1;
171 }
172 #endif
173 
174 
175 #ifdef NETNS_REFCNT_DEBUG
176 static inline struct net *hold_net(struct net *net)
177 {
178 	if (net)
179 		atomic_inc(&net->use_count);
180 	return net;
181 }
182 
183 static inline void release_net(struct net *net)
184 {
185 	if (net)
186 		atomic_dec(&net->use_count);
187 }
188 #else
189 static inline struct net *hold_net(struct net *net)
190 {
191 	return net;
192 }
193 
194 static inline void release_net(struct net *net)
195 {
196 }
197 #endif
198 
199 #ifdef CONFIG_NET_NS
200 
201 static inline void write_pnet(struct net **pnet, struct net *net)
202 {
203 	*pnet = net;
204 }
205 
206 static inline struct net *read_pnet(struct net * const *pnet)
207 {
208 	return *pnet;
209 }
210 
211 #else
212 
213 #define write_pnet(pnet, net)	do { (void)(net);} while (0)
214 #define read_pnet(pnet)		(&init_net)
215 
216 #endif
217 
218 #define for_each_net(VAR)				\
219 	list_for_each_entry(VAR, &net_namespace_list, list)
220 
221 #ifdef CONFIG_NET_NS
222 #define __net_init
223 #define __net_exit
224 #define __net_initdata
225 #else
226 #define __net_init	__init
227 #define __net_exit	__exit_refok
228 #define __net_initdata	__initdata
229 #endif
230 
231 struct pernet_operations {
232 	struct list_head list;
233 	int (*init)(struct net *net);
234 	void (*exit)(struct net *net);
235 };
236 
237 extern int register_pernet_subsys(struct pernet_operations *);
238 extern void unregister_pernet_subsys(struct pernet_operations *);
239 extern int register_pernet_gen_subsys(int *id, struct pernet_operations *);
240 extern void unregister_pernet_gen_subsys(int id, struct pernet_operations *);
241 extern int register_pernet_device(struct pernet_operations *);
242 extern void unregister_pernet_device(struct pernet_operations *);
243 extern int register_pernet_gen_device(int *id, struct pernet_operations *);
244 extern void unregister_pernet_gen_device(int id, struct pernet_operations *);
245 
246 struct ctl_path;
247 struct ctl_table;
248 struct ctl_table_header;
249 
250 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
251 	const struct ctl_path *path, struct ctl_table *table);
252 extern struct ctl_table_header *register_net_sysctl_rotable(
253 	const struct ctl_path *path, struct ctl_table *table);
254 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
255 
256 #endif /* __NET_NET_NAMESPACE_H */
257