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 extern void __put_net(struct net *net); 55 56 static inline struct net *get_net(struct net *net) 57 { 58 #ifdef CONFIG_NET 59 atomic_inc(&net->count); 60 #endif 61 return net; 62 } 63 64 static inline struct net *maybe_get_net(struct net *net) 65 { 66 /* Used when we know struct net exists but we 67 * aren't guaranteed a previous reference count 68 * exists. If the reference count is zero this 69 * function fails and returns NULL. 70 */ 71 if (!atomic_inc_not_zero(&net->count)) 72 net = NULL; 73 return net; 74 } 75 76 static inline void put_net(struct net *net) 77 { 78 #ifdef CONFIG_NET 79 if (atomic_dec_and_test(&net->count)) 80 __put_net(net); 81 #endif 82 } 83 84 static inline struct net *hold_net(struct net *net) 85 { 86 #ifdef CONFIG_NET 87 atomic_inc(&net->use_count); 88 #endif 89 return net; 90 } 91 92 static inline void release_net(struct net *net) 93 { 94 #ifdef CONFIG_NET 95 atomic_dec(&net->use_count); 96 #endif 97 } 98 99 #define for_each_net(VAR) \ 100 list_for_each_entry(VAR, &net_namespace_list, list) 101 102 #ifdef CONFIG_NET_NS 103 #define __net_init 104 #define __net_exit 105 #define __net_initdata 106 #else 107 #define __net_init __init 108 #define __net_exit __exit_refok 109 #define __net_initdata __initdata 110 #endif 111 112 struct pernet_operations { 113 struct list_head list; 114 int (*init)(struct net *net); 115 void (*exit)(struct net *net); 116 }; 117 118 extern int register_pernet_subsys(struct pernet_operations *); 119 extern void unregister_pernet_subsys(struct pernet_operations *); 120 extern int register_pernet_device(struct pernet_operations *); 121 extern void unregister_pernet_device(struct pernet_operations *); 122 123 #endif /* __NET_NET_NAMESPACE_H */ 124