include/net/net_namespace.h

   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
  16 struct proc_dir_entry;
  17 struct net_device;
  18 struct sock;
  19 struct ctl_table_header;
  20
  21 struct net {
  22         atomic_t                count;          /* To decided when the network
  23                                                  *  namespace should be freed.
  24                                                  */
  25         atomic_t                use_count;      /* To track references we
  26                                                  * destroy on demand
  27                                                  */
  28         struct list_head        list;           /* list of network namespaces */
  29         struct work_struct      work;           /* work struct for freeing */
  30
  31         struct proc_dir_entry   *proc_net;
  32         struct proc_dir_entry   *proc_net_stat;
  33         struct proc_dir_entry   *proc_net_root;
  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 };
  60
  61 #ifdef CONFIG_NET
  62 /* Init's network namespace */
  63 extern struct net init_net;
  64 #define INIT_NET_NS(net_ns) .net_ns = &init_net,
  65 #else
  66 #define INIT_NET_NS(net_ns)
  67 #endif
  68
  69 extern struct list_head net_namespace_list;
  70
  71 #ifdef CONFIG_NET
  72 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
  73 #else
  74 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
  75 {
  76         /* There is nothing to copy so this is a noop */
  77         return net_ns;
  78 }
  79 #endif
  80
  81 #ifdef CONFIG_NET_NS
  82 extern void __put_net(struct net *net);
  83
  84 static inline struct net *get_net(struct net *net)
  85 {
  86         atomic_inc(&net->count);
  87         return net;
  88 }
  89
  90 static inline struct net *maybe_get_net(struct net *net)
  91 {
  92         /* Used when we know struct net exists but we
  93          * aren't guaranteed a previous reference count
  94          * exists.  If the reference count is zero this
  95          * function fails and returns NULL.
  96          */
  97         if (!atomic_inc_not_zero(&net->count))
  98                 net = NULL;
  99         return net;
 100 }
 101
 102 static inline void put_net(struct net *net)
 103 {
 104         if (atomic_dec_and_test(&net->count))
 105                 __put_net(net);
 106 }
 107
 108 static inline struct net *hold_net(struct net *net)
 109 {
 110         atomic_inc(&net->use_count);
 111         return net;
 112 }
 113
 114 static inline void release_net(struct net *net)
 115 {
 116         atomic_dec(&net->use_count);
 117 }
 118 #else
 119 static inline struct net *get_net(struct net *net)
 120 {
 121         return net;
 122 }
 123
 124 static inline void put_net(struct net *net)
 125 {
 126 }
 127
 128 static inline struct net *hold_net(struct net *net)
 129 {
 130         return net;
 131 }
 132
 133 static inline void release_net(struct net *net)
 134 {
 135 }
 136
 137 static inline struct net *maybe_get_net(struct net *net)
 138 {
 139         return net;
 140 }
 141 #endif
 142
 143 #define for_each_net(VAR)                               \
 144         list_for_each_entry(VAR, &net_namespace_list, list)
 145
 146 #ifdef CONFIG_NET_NS
 147 #define __net_init
 148 #define __net_exit
 149 #define __net_initdata
 150 #else
 151 #define __net_init      __init
 152 #define __net_exit      __exit_refok
 153 #define __net_initdata  __initdata
 154 #endif
 155
 156 struct pernet_operations {
 157         struct list_head list;
 158         int (*init)(struct net *net);
 159         void (*exit)(struct net *net);
 160 };
 161
 162 extern int register_pernet_subsys(struct pernet_operations *);
 163 extern void unregister_pernet_subsys(struct pernet_operations *);
 164 extern int register_pernet_device(struct pernet_operations *);
 165 extern void unregister_pernet_device(struct pernet_operations *);
 166
 167 struct ctl_path;
 168 struct ctl_table;
 169 struct ctl_table_header;
 170 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
 171         const struct ctl_path *path, struct ctl_table *table);
 172 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
 173
 174 #endif /* __NET_NET_NAMESPACE_H */