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 <linux/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         unsigned int            dev_base_seq;   /* protected by rtnl_mutex */
  69
  70         /* core fib_rules */
  71         struct list_head        rules_ops;
  72
  73
  74         struct net_device       *loopback_dev;          /* The loopback */
  75         struct netns_core       core;
  76         struct netns_mib        mib;
  77         struct netns_packet     packet;
  78         struct netns_unix       unx;
  79         struct netns_ipv4       ipv4;
  80 #if IS_ENABLED(CONFIG_IPV6)
  81         struct netns_ipv6       ipv6;
  82 #endif
  83 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
  84         struct netns_dccp       dccp;
  85 #endif
  86 #ifdef CONFIG_NETFILTER
  87         struct netns_xt         xt;
  88 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  89         struct netns_ct         ct;
  90 #endif
  91         struct sock             *nfnl;
  92         struct sock             *nfnl_stash;
  93 #endif
  94 #ifdef CONFIG_WEXT_CORE
  95         struct sk_buff_head     wext_nlevents;
  96 #endif
  97         struct net_generic __rcu        *gen;
  98
  99         /* Note : following structs are cache line aligned */
 100 #ifdef CONFIG_XFRM
 101         struct netns_xfrm       xfrm;
 102 #endif
 103         struct netns_ipvs       *ipvs;
 104 };
 105
 106
 107 #include <linux/seq_file_net.h>
 108
 109 /* Init's network namespace */
 110 extern struct net init_net;
 111
 112 #ifdef CONFIG_NET
 113 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
 114
 115 #else /* CONFIG_NET */
 116 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
 117 {
 118         /* There is nothing to copy so this is a noop */
 119         return net_ns;
 120 }
 121 #endif /* CONFIG_NET */
 122
 123
 124 extern struct list_head net_namespace_list;
 125
 126 extern struct net *get_net_ns_by_pid(pid_t pid);
 127 extern struct net *get_net_ns_by_fd(int pid);
 128
 129 #ifdef CONFIG_NET_NS
 130 extern void __put_net(struct net *net);
 131
 132 static inline struct net *get_net(struct net *net)
 133 {
 134         atomic_inc(&net->count);
 135         return net;
 136 }
 137
 138 static inline struct net *maybe_get_net(struct net *net)
 139 {
 140         /* Used when we know struct net exists but we
 141          * aren't guaranteed a previous reference count
 142          * exists.  If the reference count is zero this
 143          * function fails and returns NULL.
 144          */
 145         if (!atomic_inc_not_zero(&net->count))
 146                 net = NULL;
 147         return net;
 148 }
 149
 150 static inline void put_net(struct net *net)
 151 {
 152         if (atomic_dec_and_test(&net->count))
 153                 __put_net(net);
 154 }
 155
 156 static inline
 157 int net_eq(const struct net *net1, const struct net *net2)
 158 {
 159         return net1 == net2;
 160 }
 161
 162 extern void net_drop_ns(void *);
 163
 164 #else
 165
 166 static inline struct net *get_net(struct net *net)
 167 {
 168         return net;
 169 }
 170
 171 static inline void put_net(struct net *net)
 172 {
 173 }
 174
 175 static inline struct net *maybe_get_net(struct net *net)
 176 {
 177         return net;
 178 }
 179
 180 static inline
 181 int net_eq(const struct net *net1, const struct net *net2)
 182 {
 183         return 1;
 184 }
 185
 186 #define net_drop_ns NULL
 187 #endif
 188
 189
 190 #ifdef NETNS_REFCNT_DEBUG
 191 static inline struct net *hold_net(struct net *net)
 192 {
 193         if (net)
 194                 atomic_inc(&net->use_count);
 195         return net;
 196 }
 197
 198 static inline void release_net(struct net *net)
 199 {
 200         if (net)
 201                 atomic_dec(&net->use_count);
 202 }
 203 #else
 204 static inline struct net *hold_net(struct net *net)
 205 {
 206         return net;
 207 }
 208
 209 static inline void release_net(struct net *net)
 210 {
 211 }
 212 #endif
 213
 214 #ifdef CONFIG_NET_NS
 215
 216 static inline void write_pnet(struct net **pnet, struct net *net)
 217 {
 218         *pnet = net;
 219 }
 220
 221 static inline struct net *read_pnet(struct net * const *pnet)
 222 {
 223         return *pnet;
 224 }
 225
 226 #else
 227
 228 #define write_pnet(pnet, net)   do { (void)(net);} while (0)
 229 #define read_pnet(pnet)         (&init_net)
 230
 231 #endif
 232
 233 #define for_each_net(VAR)                               \
 234         list_for_each_entry(VAR, &net_namespace_list, list)
 235
 236 #define for_each_net_rcu(VAR)                           \
 237         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 238
 239 #ifdef CONFIG_NET_NS
 240 #define __net_init
 241 #define __net_exit
 242 #define __net_initdata
 243 #else
 244 #define __net_init      __init
 245 #define __net_exit      __exit_refok
 246 #define __net_initdata  __initdata
 247 #endif
 248
 249 struct pernet_operations {
 250         struct list_head list;
 251         int (*init)(struct net *net);
 252         void (*exit)(struct net *net);
 253         void (*exit_batch)(struct list_head *net_exit_list);
 254         int *id;
 255         size_t size;
 256 };
 257
 258 /*
 259  * Use these carefully.  If you implement a network device and it
 260  * needs per network namespace operations use device pernet operations,
 261  * otherwise use pernet subsys operations.
 262  *
 263  * Network interfaces need to be removed from a dying netns _before_
 264  * subsys notifiers can be called, as most of the network code cleanup
 265  * (which is done from subsys notifiers) runs with the assumption that
 266  * dev_remove_pack has been called so no new packets will arrive during
 267  * and after the cleanup functions have been called.  dev_remove_pack
 268  * is not per namespace so instead the guarantee of no more packets
 269  * arriving in a network namespace is provided by ensuring that all
 270  * network devices and all sockets have left the network namespace
 271  * before the cleanup methods are called.
 272  *
 273  * For the longest time the ipv4 icmp code was registered as a pernet
 274  * device which caused kernel oops, and panics during network
 275  * namespace cleanup.   So please don't get this wrong.
 276  */
 277 extern int register_pernet_subsys(struct pernet_operations *);
 278 extern void unregister_pernet_subsys(struct pernet_operations *);
 279 extern int register_pernet_device(struct pernet_operations *);
 280 extern void unregister_pernet_device(struct pernet_operations *);
 281
 282 struct ctl_table;
 283 struct ctl_table_header;
 284
 285 #ifdef CONFIG_SYSCTL
 286 extern int net_sysctl_init(void);
 287 extern struct ctl_table_header *register_net_sysctl(struct net *net,
 288         const char *path, struct ctl_table *table);
 289 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
 290 #else
 291 static inline int net_sysctl_init(void) { return 0; }
 292 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 293         const char *path, struct ctl_table *table)
 294 {
 295         return NULL;
 296 }
 297 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 298 {
 299 }
 300 #endif
 301
 302
 303 #endif /* __NET_NET_NAMESPACE_H */