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