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/mib.h>
  13 #include <net/netns/unix.h>
  14 #include <net/netns/packet.h>
  15 #include <net/netns/ipv4.h>
  16 #include <net/netns/ipv6.h>
  17 #include <net/netns/dccp.h>
  18 #include <net/netns/x_tables.h>
  19 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  20 #include <net/netns/conntrack.h>
  21 #endif
  22 #include <net/netns/xfrm.h>
  23
  24 struct proc_dir_entry;
  25 struct net_device;
  26 struct sock;
  27 struct ctl_table_header;
  28 struct net_generic;
  29 struct sock;
  30
  31
  32 #define NETDEV_HASHBITS    8
  33 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  34
  35 struct net {
  36         atomic_t                count;          /* To decided when the network
  37                                                  *  namespace should be freed.
  38                                                  */
  39 #ifdef NETNS_REFCNT_DEBUG
  40         atomic_t                use_count;      /* To track references we
  41                                                  * destroy on demand
  42                                                  */
  43 #endif
  44         struct list_head        list;           /* list of network namespaces */
  45         struct work_struct      work;           /* work struct for freeing */
  46
  47         struct proc_dir_entry   *proc_net;
  48         struct proc_dir_entry   *proc_net_stat;
  49
  50 #ifdef CONFIG_SYSCTL
  51         struct ctl_table_set    sysctls;
  52 #endif
  53
  54         struct net_device       *loopback_dev;          /* The loopback */
  55
  56         struct list_head        dev_base_head;
  57         struct hlist_head       *dev_name_head;
  58         struct hlist_head       *dev_index_head;
  59
  60         /* core fib_rules */
  61         struct list_head        rules_ops;
  62         spinlock_t              rules_mod_lock;
  63
  64         struct sock             *rtnl;                  /* rtnetlink socket */
  65         struct sock             *genl_sock;
  66
  67         struct netns_core       core;
  68         struct netns_mib        mib;
  69         struct netns_packet     packet;
  70         struct netns_unix       unx;
  71         struct netns_ipv4       ipv4;
  72 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  73         struct netns_ipv6       ipv6;
  74 #endif
  75 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
  76         struct netns_dccp       dccp;
  77 #endif
  78 #ifdef CONFIG_NETFILTER
  79         struct netns_xt         xt;
  80 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  81         struct netns_ct         ct;
  82 #endif
  83 #endif
  84 #ifdef CONFIG_XFRM
  85         struct netns_xfrm       xfrm;
  86 #endif
  87 #ifdef CONFIG_WEXT_CORE
  88         struct sk_buff_head     wext_nlevents;
  89 #endif
  90         struct net_generic      *gen;
  91 };
  92
  93
  94 #include <linux/seq_file_net.h>
  95
  96 /* Init's network namespace */
  97 extern struct net init_net;
  98
  99 #ifdef CONFIG_NET
 100 #define INIT_NET_NS(net_ns) .net_ns = &init_net,
 101
 102 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
 103
 104 #else /* CONFIG_NET */
 105
 106 #define INIT_NET_NS(net_ns)
 107
 108 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
 109 {
 110         /* There is nothing to copy so this is a noop */
 111         return net_ns;
 112 }
 113 #endif /* CONFIG_NET */
 114
 115
 116 extern struct list_head net_namespace_list;
 117
 118 extern struct net *get_net_ns_by_pid(pid_t pid);
 119
 120 #ifdef CONFIG_NET_NS
 121 extern void __put_net(struct net *net);
 122
 123 static inline struct net *get_net(struct net *net)
 124 {
 125         atomic_inc(&net->count);
 126         return net;
 127 }
 128
 129 static inline struct net *maybe_get_net(struct net *net)
 130 {
 131         /* Used when we know struct net exists but we
 132          * aren't guaranteed a previous reference count
 133          * exists.  If the reference count is zero this
 134          * function fails and returns NULL.
 135          */
 136         if (!atomic_inc_not_zero(&net->count))
 137                 net = NULL;
 138         return net;
 139 }
 140
 141 static inline void put_net(struct net *net)
 142 {
 143         if (atomic_dec_and_test(&net->count))
 144                 __put_net(net);
 145 }
 146
 147 static inline
 148 int net_eq(const struct net *net1, const struct net *net2)
 149 {
 150         return net1 == net2;
 151 }
 152 #else
 153
 154 static inline struct net *get_net(struct net *net)
 155 {
 156         return net;
 157 }
 158
 159 static inline void put_net(struct net *net)
 160 {
 161 }
 162
 163 static inline struct net *maybe_get_net(struct net *net)
 164 {
 165         return net;
 166 }
 167
 168 static inline
 169 int net_eq(const struct net *net1, const struct net *net2)
 170 {
 171         return 1;
 172 }
 173 #endif
 174
 175
 176 #ifdef NETNS_REFCNT_DEBUG
 177 static inline struct net *hold_net(struct net *net)
 178 {
 179         if (net)
 180                 atomic_inc(&net->use_count);
 181         return net;
 182 }
 183
 184 static inline void release_net(struct net *net)
 185 {
 186         if (net)
 187                 atomic_dec(&net->use_count);
 188 }
 189 #else
 190 static inline struct net *hold_net(struct net *net)
 191 {
 192         return net;
 193 }
 194
 195 static inline void release_net(struct net *net)
 196 {
 197 }
 198 #endif
 199
 200 #ifdef CONFIG_NET_NS
 201
 202 static inline void write_pnet(struct net **pnet, struct net *net)
 203 {
 204         *pnet = net;
 205 }
 206
 207 static inline struct net *read_pnet(struct net * const *pnet)
 208 {
 209         return *pnet;
 210 }
 211
 212 #else
 213
 214 #define write_pnet(pnet, net)   do { (void)(net);} while (0)
 215 #define read_pnet(pnet)         (&init_net)
 216
 217 #endif
 218
 219 #define for_each_net(VAR)                               \
 220         list_for_each_entry(VAR, &net_namespace_list, list)
 221
 222 #define for_each_net_rcu(VAR)                           \
 223         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 224
 225 #ifdef CONFIG_NET_NS
 226 #define __net_init
 227 #define __net_exit
 228 #define __net_initdata
 229 #else
 230 #define __net_init      __init
 231 #define __net_exit      __exit_refok
 232 #define __net_initdata  __initdata
 233 #endif
 234
 235 struct pernet_operations {
 236         struct list_head list;
 237         int (*init)(struct net *net);
 238         void (*exit)(struct net *net);
 239 };
 240
 241 /*
 242  * Use these carefully.  If you implement a network device and it
 243  * needs per network namespace operations use device pernet operations,
 244  * otherwise use pernet subsys operations.
 245  *
 246  * Network interfaces need to be removed from a dying netns _before_
 247  * subsys notifiers can be called, as most of the network code cleanup
 248  * (which is done from subsys notifiers) runs with the assumption that
 249  * dev_remove_pack has been called so no new packets will arrive during
 250  * and after the cleanup functions have been called.  dev_remove_pack
 251  * is not per namespace so instead the guarantee of no more packets
 252  * arriving in a network namespace is provided by ensuring that all
 253  * network devices and all sockets have left the network namespace
 254  * before the cleanup methods are called.
 255  *
 256  * For the longest time the ipv4 icmp code was registered as a pernet
 257  * device which caused kernel oops, and panics during network
 258  * namespace cleanup.   So please don't get this wrong.
 259  */
 260 extern int register_pernet_subsys(struct pernet_operations *);
 261 extern void unregister_pernet_subsys(struct pernet_operations *);
 262 extern int register_pernet_gen_subsys(int *id, struct pernet_operations *);
 263 extern void unregister_pernet_gen_subsys(int id, struct pernet_operations *);
 264 extern int register_pernet_device(struct pernet_operations *);
 265 extern void unregister_pernet_device(struct pernet_operations *);
 266 extern int register_pernet_gen_device(int *id, struct pernet_operations *);
 267 extern void unregister_pernet_gen_device(int id, struct pernet_operations *);
 268
 269 struct ctl_path;
 270 struct ctl_table;
 271 struct ctl_table_header;
 272
 273 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
 274         const struct ctl_path *path, struct ctl_table *table);
 275 extern struct ctl_table_header *register_net_sysctl_rotable(
 276         const struct ctl_path *path, struct ctl_table *table);
 277 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
 278
 279 #endif /* __NET_NET_NAMESPACE_H */