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 #include <linux/sysctl.h>
  11
  12 #include <net/netns/core.h>
  13 #include <net/netns/mib.h>
  14 #include <net/netns/unix.h>
  15 #include <net/netns/packet.h>
  16 #include <net/netns/ipv4.h>
  17 #include <net/netns/ipv6.h>
  18 #include <net/netns/dccp.h>
  19 #include <net/netns/x_tables.h>
  20 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  21 #include <net/netns/conntrack.h>
  22 #endif
  23 #include <net/netns/xfrm.h>
  24
  25 struct proc_dir_entry;
  26 struct net_device;
  27 struct sock;
  28 struct ctl_table_header;
  29 struct net_generic;
  30 struct sock;
  31 struct netns_ipvs;
  32
  33
  34 #define NETDEV_HASHBITS    8
  35 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  36
  37 struct net {
  38         atomic_t                passive;        /* To decided when the network
  39                                                  * namespace should be freed.
  40                                                  */
  41         atomic_t                count;          /* To decided when the network
  42                                                  *  namespace should be shut down.
  43                                                  */
  44 #ifdef NETNS_REFCNT_DEBUG
  45         atomic_t                use_count;      /* To track references we
  46                                                  * destroy on demand
  47                                                  */
  48 #endif
  49         spinlock_t              rules_mod_lock;
  50
  51         struct list_head        list;           /* list of network namespaces */
  52         struct list_head        cleanup_list;   /* namespaces on death row */
  53         struct list_head        exit_list;      /* Use only net_mutex */
  54
  55         struct proc_dir_entry   *proc_net;
  56         struct proc_dir_entry   *proc_net_stat;
  57
  58 #ifdef CONFIG_SYSCTL
  59         struct ctl_table_set    sysctls;
  60 #endif
  61
  62         struct sock             *rtnl;                  /* rtnetlink socket */
  63         struct sock             *genl_sock;
  64
  65         struct list_head        dev_base_head;
  66         struct hlist_head       *dev_name_head;
  67         struct hlist_head       *dev_index_head;
  68
  69         /* core fib_rules */
  70         struct list_head        rules_ops;
  71
  72
  73         struct net_device       *loopback_dev;          /* The loopback */
  74         struct netns_core       core;
  75         struct netns_mib        mib;
  76         struct netns_packet     packet;
  77         struct netns_unix       unx;
  78         struct netns_ipv4       ipv4;
  79 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
  80         struct netns_ipv6       ipv6;
  81 #endif
  82 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
  83         struct netns_dccp       dccp;
  84 #endif
  85 #ifdef CONFIG_NETFILTER
  86         struct netns_xt         xt;
  87 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  88         struct netns_ct         ct;
  89 #endif
  90         struct sock             *nfnl;
  91         struct sock             *nfnl_stash;
  92 #endif
  93 #ifdef CONFIG_WEXT_CORE
  94         struct sk_buff_head     wext_nlevents;
  95 #endif
  96         struct net_generic __rcu        *gen;
  97
  98         /* Note : following structs are cache line aligned */
  99 #ifdef CONFIG_XFRM
 100         struct netns_xfrm       xfrm;
 101 #endif
 102         struct netns_ipvs       *ipvs;
 103 };
 104
 105
 106 #include <linux/seq_file_net.h>
 107
 108 /* Init's network namespace */
 109 extern struct net init_net;
 110
 111 #ifdef CONFIG_NET
 112 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
 113
 114 #else /* CONFIG_NET */
 115 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
 116 {
 117         /* There is nothing to copy so this is a noop */
 118         return net_ns;
 119 }
 120 #endif /* CONFIG_NET */
 121
 122
 123 extern struct list_head net_namespace_list;
 124
 125 extern struct net *get_net_ns_by_pid(pid_t pid);
 126 extern struct net *get_net_ns_by_fd(int pid);
 127
 128 #ifdef CONFIG_NET_NS
 129 extern void __put_net(struct net *net);
 130
 131 static inline struct net *get_net(struct net *net)
 132 {
 133         atomic_inc(&net->count);
 134         return net;
 135 }
 136
 137 static inline struct net *maybe_get_net(struct net *net)
 138 {
 139         /* Used when we know struct net exists but we
 140          * aren't guaranteed a previous reference count
 141          * exists.  If the reference count is zero this
 142          * function fails and returns NULL.
 143          */
 144         if (!atomic_inc_not_zero(&net->count))
 145                 net = NULL;
 146         return net;
 147 }
 148
 149 static inline void put_net(struct net *net)
 150 {
 151         if (atomic_dec_and_test(&net->count))
 152                 __put_net(net);
 153 }
 154
 155 static inline
 156 int net_eq(const struct net *net1, const struct net *net2)
 157 {
 158         return net1 == net2;
 159 }
 160
 161 extern void net_drop_ns(void *);
 162
 163 #else
 164
 165 static inline struct net *get_net(struct net *net)
 166 {
 167         return net;
 168 }
 169
 170 static inline void put_net(struct net *net)
 171 {
 172 }
 173
 174 static inline struct net *maybe_get_net(struct net *net)
 175 {
 176         return net;
 177 }
 178
 179 static inline
 180 int net_eq(const struct net *net1, const struct net *net2)
 181 {
 182         return 1;
 183 }
 184
 185 #define net_drop_ns NULL
 186 #endif
 187
 188
 189 #ifdef NETNS_REFCNT_DEBUG
 190 static inline struct net *hold_net(struct net *net)
 191 {
 192         if (net)
 193                 atomic_inc(&net->use_count);
 194         return net;
 195 }
 196
 197 static inline void release_net(struct net *net)
 198 {
 199         if (net)
 200                 atomic_dec(&net->use_count);
 201 }
 202 #else
 203 static inline struct net *hold_net(struct net *net)
 204 {
 205         return net;
 206 }
 207
 208 static inline void release_net(struct net *net)
 209 {
 210 }
 211 #endif
 212
 213 #ifdef CONFIG_NET_NS
 214
 215 static inline void write_pnet(struct net **pnet, struct net *net)
 216 {
 217         *pnet = net;
 218 }
 219
 220 static inline struct net *read_pnet(struct net * const *pnet)
 221 {
 222         return *pnet;
 223 }
 224
 225 #else
 226
 227 #define write_pnet(pnet, net)   do { (void)(net);} while (0)
 228 #define read_pnet(pnet)         (&init_net)
 229
 230 #endif
 231
 232 #define for_each_net(VAR)                               \
 233         list_for_each_entry(VAR, &net_namespace_list, list)
 234
 235 #define for_each_net_rcu(VAR)                           \
 236         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 237
 238 #ifdef CONFIG_NET_NS
 239 #define __net_init
 240 #define __net_exit
 241 #define __net_initdata
 242 #else
 243 #define __net_init      __init
 244 #define __net_exit      __exit_refok
 245 #define __net_initdata  __initdata
 246 #endif
 247
 248 struct pernet_operations {
 249         struct list_head list;
 250         int (*init)(struct net *net);
 251         void (*exit)(struct net *net);
 252         void (*exit_batch)(struct list_head *net_exit_list);
 253         int *id;
 254         size_t size;
 255 };
 256
 257 /*
 258  * Use these carefully.  If you implement a network device and it
 259  * needs per network namespace operations use device pernet operations,
 260  * otherwise use pernet subsys operations.
 261  *
 262  * Network interfaces need to be removed from a dying netns _before_
 263  * subsys notifiers can be called, as most of the network code cleanup
 264  * (which is done from subsys notifiers) runs with the assumption that
 265  * dev_remove_pack has been called so no new packets will arrive during
 266  * and after the cleanup functions have been called.  dev_remove_pack
 267  * is not per namespace so instead the guarantee of no more packets
 268  * arriving in a network namespace is provided by ensuring that all
 269  * network devices and all sockets have left the network namespace
 270  * before the cleanup methods are called.
 271  *
 272  * For the longest time the ipv4 icmp code was registered as a pernet
 273  * device which caused kernel oops, and panics during network
 274  * namespace cleanup.   So please don't get this wrong.
 275  */
 276 extern int register_pernet_subsys(struct pernet_operations *);
 277 extern void unregister_pernet_subsys(struct pernet_operations *);
 278 extern int register_pernet_device(struct pernet_operations *);
 279 extern void unregister_pernet_device(struct pernet_operations *);
 280
 281 struct ctl_path;
 282 struct ctl_table;
 283 struct ctl_table_header;
 284
 285 extern struct ctl_table_header *register_net_sysctl_table(struct net *net,
 286         const struct ctl_path *path, struct ctl_table *table);
 287 extern struct ctl_table_header *register_net_sysctl_rotable(
 288         const struct ctl_path *path, struct ctl_table *table);
 289 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
 290
 291 #endif /* __NET_NET_NAMESPACE_H */