xref: /linux/include/net/net_namespace.h (revision a1e58bbdc969c3fe60addca7f2729779d22a83c1)
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/unix.h>
12 #include <net/netns/packet.h>
13 #include <net/netns/ipv4.h>
14 #include <net/netns/ipv6.h>
15 #include <net/netns/x_tables.h>
16 
17 struct proc_dir_entry;
18 struct net_device;
19 struct sock;
20 struct ctl_table_header;
21 
22 struct net {
23 	atomic_t		count;		/* To decided when the network
24 						 *  namespace should be freed.
25 						 */
26 	atomic_t		use_count;	/* To track references we
27 						 * destroy on demand
28 						 */
29 	struct list_head	list;		/* list of network namespaces */
30 	struct work_struct	work;		/* work struct for freeing */
31 
32 	struct proc_dir_entry 	*proc_net;
33 	struct proc_dir_entry 	*proc_net_stat;
34 
35 	struct list_head	sysctl_table_headers;
36 
37 	struct net_device       *loopback_dev;          /* The loopback */
38 
39 	struct list_head 	dev_base_head;
40 	struct hlist_head 	*dev_name_head;
41 	struct hlist_head	*dev_index_head;
42 
43 	/* core fib_rules */
44 	struct list_head	rules_ops;
45 	spinlock_t		rules_mod_lock;
46 
47 	struct sock 		*rtnl;			/* rtnetlink socket */
48 
49 	/* core sysctls */
50 	struct ctl_table_header	*sysctl_core_hdr;
51 	int			sysctl_somaxconn;
52 
53 	struct netns_packet	packet;
54 	struct netns_unix	unx;
55 	struct netns_ipv4	ipv4;
56 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
57 	struct netns_ipv6	ipv6;
58 #endif
59 #ifdef CONFIG_NETFILTER
60 	struct netns_xt		xt;
61 #endif
62 };
63 
64 #ifdef CONFIG_NET
65 /* Init's network namespace */
66 extern struct net init_net;
67 #define INIT_NET_NS(net_ns) .net_ns = &init_net,
68 #else
69 #define INIT_NET_NS(net_ns)
70 #endif
71 
72 extern struct list_head net_namespace_list;
73 
74 #ifdef CONFIG_NET
75 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
76 #else
77 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
78 {
79 	/* There is nothing to copy so this is a noop */
80 	return net_ns;
81 }
82 #endif
83 
84 #ifdef CONFIG_NET_NS
85 extern void __put_net(struct net *net);
86 
87 static inline struct net *get_net(struct net *net)
88 {
89 	atomic_inc(&net->count);
90 	return net;
91 }
92 
93 static inline struct net *maybe_get_net(struct net *net)
94 {
95 	/* Used when we know struct net exists but we
96 	 * aren't guaranteed a previous reference count
97 	 * exists.  If the reference count is zero this
98 	 * function fails and returns NULL.
99 	 */
100 	if (!atomic_inc_not_zero(&net->count))
101 		net = NULL;
102 	return net;
103 }
104 
105 static inline void put_net(struct net *net)
106 {
107 	if (atomic_dec_and_test(&net->count))
108 		__put_net(net);
109 }
110 
111 static inline struct net *hold_net(struct net *net)
112 {
113 	atomic_inc(&net->use_count);
114 	return net;
115 }
116 
117 static inline void release_net(struct net *net)
118 {
119 	atomic_dec(&net->use_count);
120 }
121 #else
122 static inline struct net *get_net(struct net *net)
123 {
124 	return net;
125 }
126 
127 static inline void put_net(struct net *net)
128 {
129 }
130 
131 static inline struct net *hold_net(struct net *net)
132 {
133 	return net;
134 }
135 
136 static inline void release_net(struct net *net)
137 {
138 }
139 
140 static inline struct net *maybe_get_net(struct net *net)
141 {
142 	return net;
143 }
144 #endif
145 
146 #define for_each_net(VAR)				\
147 	list_for_each_entry(VAR, &net_namespace_list, list)
148 
149 #ifdef CONFIG_NET_NS
150 #define __net_init
151 #define __net_exit
152 #define __net_initdata
153 #else
154 #define __net_init	__init
155 #define __net_exit	__exit_refok
156 #define __net_initdata	__initdata
157 #endif
158 
159 struct pernet_operations {
160 	struct list_head list;
161 	int (*init)(struct net *net);
162 	void (*exit)(struct net *net);
163 };
164 
165 extern int register_pernet_subsys(struct pernet_operations *);
166 extern void unregister_pernet_subsys(struct pernet_operations *);
167 extern int register_pernet_device(struct pernet_operations *);
168 extern void unregister_pernet_device(struct pernet_operations *);
169 
170 struct ctl_path;
171 struct ctl_table;
172 struct ctl_table_header;
173 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
174 	const struct ctl_path *path, struct ctl_table *table);
175 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
176 
177 #endif /* __NET_NET_NAMESPACE_H */
178