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 struct proc_dir_entry; 12 struct net_device; 13 struct net { 14 atomic_t count; /* To decided when the network 15 * namespace should be freed. 16 */ 17 atomic_t use_count; /* To track references we 18 * destroy on demand 19 */ 20 struct list_head list; /* list of network namespaces */ 21 struct work_struct work; /* work struct for freeing */ 22 23 struct proc_dir_entry *proc_net; 24 struct proc_dir_entry *proc_net_stat; 25 struct proc_dir_entry *proc_net_root; 26 27 struct net_device *loopback_dev; /* The loopback */ 28 29 struct list_head dev_base_head; 30 struct hlist_head *dev_name_head; 31 struct hlist_head *dev_index_head; 32 }; 33 34 #ifdef CONFIG_NET 35 /* Init's network namespace */ 36 extern struct net init_net; 37 #define INIT_NET_NS(net_ns) .net_ns = &init_net, 38 #else 39 #define INIT_NET_NS(net_ns) 40 #endif 41 42 extern struct list_head net_namespace_list; 43 44 #ifdef CONFIG_NET 45 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns); 46 #else 47 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns) 48 { 49 /* There is nothing to copy so this is a noop */ 50 return net_ns; 51 } 52 #endif 53 54 #ifdef CONFIG_NET_NS 55 extern void __put_net(struct net *net); 56 57 static inline struct net *get_net(struct net *net) 58 { 59 atomic_inc(&net->count); 60 return net; 61 } 62 63 static inline struct net *maybe_get_net(struct net *net) 64 { 65 /* Used when we know struct net exists but we 66 * aren't guaranteed a previous reference count 67 * exists. If the reference count is zero this 68 * function fails and returns NULL. 69 */ 70 if (!atomic_inc_not_zero(&net->count)) 71 net = NULL; 72 return net; 73 } 74 75 static inline void put_net(struct net *net) 76 { 77 if (atomic_dec_and_test(&net->count)) 78 __put_net(net); 79 } 80 81 static inline struct net *hold_net(struct net *net) 82 { 83 atomic_inc(&net->use_count); 84 return net; 85 } 86 87 static inline void release_net(struct net *net) 88 { 89 atomic_dec(&net->use_count); 90 } 91 #else 92 static inline struct net *get_net(struct net *net) 93 { 94 return net; 95 } 96 97 static inline void put_net(struct net *net) 98 { 99 } 100 101 static inline struct net *hold_net(struct net *net) 102 { 103 return net; 104 } 105 106 static inline void release_net(struct net *net) 107 { 108 } 109 110 static inline struct net *maybe_get_net(struct net *net) 111 { 112 return net; 113 } 114 #endif 115 116 #define for_each_net(VAR) \ 117 list_for_each_entry(VAR, &net_namespace_list, list) 118 119 #ifdef CONFIG_NET_NS 120 #define __net_init 121 #define __net_exit 122 #define __net_initdata 123 #else 124 #define __net_init __init 125 #define __net_exit __exit_refok 126 #define __net_initdata __initdata 127 #endif 128 129 struct pernet_operations { 130 struct list_head list; 131 int (*init)(struct net *net); 132 void (*exit)(struct net *net); 133 }; 134 135 extern int register_pernet_subsys(struct pernet_operations *); 136 extern void unregister_pernet_subsys(struct pernet_operations *); 137 extern int register_pernet_device(struct pernet_operations *); 138 extern void unregister_pernet_device(struct pernet_operations *); 139 140 #endif /* __NET_NET_NAMESPACE_H */ 141