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