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