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