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