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