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/core.h>
  12 #include <net/netns/unix.h>
  13 #include <net/netns/packet.h>
  14 #include <net/netns/ipv4.h>
  15 #include <net/netns/ipv6.h>
  16 #include <net/netns/dccp.h>
  17 #include <net/netns/x_tables.h>
  18
  19 struct proc_dir_entry;
  20 struct net_device;
  21 struct sock;
  22 struct ctl_table_header;
  23 struct net_generic;
  24
  25 struct net {
  26         atomic_t                count;          /* To decided when the network
  27                                                  *  namespace should be freed.
  28                                                  */
  29 #ifdef NETNS_REFCNT_DEBUG
  30         atomic_t                use_count;      /* To track references we
  31                                                  * destroy on demand
  32                                                  */
  33 #endif
  34         struct list_head        list;           /* list of network namespaces */
  35         struct work_struct      work;           /* work struct for freeing */
  36
  37         struct proc_dir_entry   *proc_net;
  38         struct proc_dir_entry   *proc_net_stat;
  39
  40         struct list_head        sysctl_table_headers;
  41
  42         struct net_device       *loopback_dev;          /* The loopback */
  43
  44         struct list_head        dev_base_head;
  45         struct hlist_head       *dev_name_head;
  46         struct hlist_head       *dev_index_head;
  47
  48         /* core fib_rules */
  49         struct list_head        rules_ops;
  50         spinlock_t              rules_mod_lock;
  51
  52         struct sock             *rtnl;                  /* rtnetlink socket */
  53
  54         struct netns_core       core;
  55         struct netns_packet     packet;
  56         struct netns_unix       unx;
  57         struct netns_ipv4       ipv4;
  58 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  59         struct netns_ipv6       ipv6;
  60 #endif
  61 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
  62         struct netns_dccp       dccp;
  63 #endif
  64 #ifdef CONFIG_NETFILTER
  65         struct netns_xt         xt;
  66 #endif
  67         struct net_generic      *gen;
  68 };
  69
  70
  71 #include <linux/seq_file_net.h>
  72
  73 /* Init's network namespace */
  74 extern struct net init_net;
  75
  76 #ifdef CONFIG_NET
  77 #define INIT_NET_NS(net_ns) .net_ns = &init_net,
  78
  79 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
  80
  81 #else /* CONFIG_NET */
  82
  83 #define INIT_NET_NS(net_ns)
  84
  85 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
  86 {
  87         /* There is nothing to copy so this is a noop */
  88         return net_ns;
  89 }
  90 #endif /* CONFIG_NET */
  91
  92
  93 extern struct list_head net_namespace_list;
  94
  95 #ifdef CONFIG_NET_NS
  96 extern void __put_net(struct net *net);
  97
  98 static inline int net_alive(struct net *net)
  99 {
 100         return net && atomic_read(&net->count);
 101 }
 102
 103 static inline struct net *get_net(struct net *net)
 104 {
 105         atomic_inc(&net->count);
 106         return net;
 107 }
 108
 109 static inline struct net *maybe_get_net(struct net *net)
 110 {
 111         /* Used when we know struct net exists but we
 112          * aren't guaranteed a previous reference count
 113          * exists.  If the reference count is zero this
 114          * function fails and returns NULL.
 115          */
 116         if (!atomic_inc_not_zero(&net->count))
 117                 net = NULL;
 118         return net;
 119 }
 120
 121 static inline void put_net(struct net *net)
 122 {
 123         if (atomic_dec_and_test(&net->count))
 124                 __put_net(net);
 125 }
 126
 127 static inline
 128 int net_eq(const struct net *net1, const struct net *net2)
 129 {
 130         return net1 == net2;
 131 }
 132 #else
 133
 134 static inline int net_alive(struct net *net)
 135 {
 136         return 1;
 137 }
 138
 139 static inline struct net *get_net(struct net *net)
 140 {
 141         return net;
 142 }
 143
 144 static inline void put_net(struct net *net)
 145 {
 146 }
 147
 148 static inline struct net *maybe_get_net(struct net *net)
 149 {
 150         return net;
 151 }
 152
 153 static inline
 154 int net_eq(const struct net *net1, const struct net *net2)
 155 {
 156         return 1;
 157 }
 158 #endif
 159
 160
 161 #ifdef NETNS_REFCNT_DEBUG
 162 static inline struct net *hold_net(struct net *net)
 163 {
 164         if (net)
 165                 atomic_inc(&net->use_count);
 166         return net;
 167 }
 168
 169 static inline void release_net(struct net *net)
 170 {
 171         if (net)
 172                 atomic_dec(&net->use_count);
 173 }
 174 #else
 175 static inline struct net *hold_net(struct net *net)
 176 {
 177         return net;
 178 }
 179
 180 static inline void release_net(struct net *net)
 181 {
 182 }
 183 #endif
 184
 185
 186 #define for_each_net(VAR)                               \
 187         list_for_each_entry(VAR, &net_namespace_list, list)
 188
 189 #ifdef CONFIG_NET_NS
 190 #define __net_init
 191 #define __net_exit
 192 #define __net_initdata
 193 #else
 194 #define __net_init      __init
 195 #define __net_exit      __exit_refok
 196 #define __net_initdata  __initdata
 197 #endif
 198
 199 struct pernet_operations {
 200         struct list_head list;
 201         int (*init)(struct net *net);
 202         void (*exit)(struct net *net);
 203 };
 204
 205 extern int register_pernet_subsys(struct pernet_operations *);
 206 extern void unregister_pernet_subsys(struct pernet_operations *);
 207 extern int register_pernet_device(struct pernet_operations *);
 208 extern void unregister_pernet_device(struct pernet_operations *);
 209 extern int register_pernet_gen_device(int *id, struct pernet_operations *);
 210 extern void unregister_pernet_gen_device(int id, struct pernet_operations *);
 211
 212 struct ctl_path;
 213 struct ctl_table;
 214 struct ctl_table_header;
 215 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
 216         const struct ctl_path *path, struct ctl_table *table);
 217 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
 218
 219 #endif /* __NET_NET_NAMESPACE_H */