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