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
  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 */