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/flow.h>
  13 #include <net/netns/core.h>
  14 #include <net/netns/mib.h>
  15 #include <net/netns/unix.h>
  16 #include <net/netns/packet.h>
  17 #include <net/netns/ipv4.h>
  18 #include <net/netns/ipv6.h>
  19 #include <net/netns/ieee802154_6lowpan.h>
  20 #include <net/netns/sctp.h>
  21 #include <net/netns/dccp.h>
  22 #include <net/netns/netfilter.h>
  23 #include <net/netns/x_tables.h>
  24 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  25 #include <net/netns/conntrack.h>
  26 #endif
  27 #include <net/netns/nftables.h>
  28 #include <net/netns/xfrm.h>
  29 #include <linux/ns_common.h>
  30
  31 struct user_namespace;
  32 struct proc_dir_entry;
  33 struct net_device;
  34 struct sock;
  35 struct ctl_table_header;
  36 struct net_generic;
  37 struct sock;
  38 struct netns_ipvs;
  39
  40
  41 #define NETDEV_HASHBITS    8
  42 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  43
  44 struct net {
  45         atomic_t                passive;        /* To decided when the network
  46                                                  * namespace should be freed.
  47                                                  */
  48         atomic_t                count;          /* To decided when the network
  49                                                  *  namespace should be shut down.
  50                                                  */
  51 #ifdef NETNS_REFCNT_DEBUG
  52         atomic_t                use_count;      /* To track references we
  53                                                  * destroy on demand
  54                                                  */
  55 #endif
  56         spinlock_t              rules_mod_lock;
  57
  58         struct list_head        list;           /* list of network namespaces */
  59         struct list_head        cleanup_list;   /* namespaces on death row */
  60         struct list_head        exit_list;      /* Use only net_mutex */
  61
  62         struct user_namespace   *user_ns;       /* Owning user namespace */
  63
  64         struct ns_common        ns;
  65
  66         struct proc_dir_entry   *proc_net;
  67         struct proc_dir_entry   *proc_net_stat;
  68
  69 #ifdef CONFIG_SYSCTL
  70         struct ctl_table_set    sysctls;
  71 #endif
  72
  73         struct sock             *rtnl;                  /* rtnetlink socket */
  74         struct sock             *genl_sock;
  75
  76         struct list_head        dev_base_head;
  77         struct hlist_head       *dev_name_head;
  78         struct hlist_head       *dev_index_head;
  79         unsigned int            dev_base_seq;   /* protected by rtnl_mutex */
  80         int                     ifindex;
  81         unsigned int            dev_unreg_count;
  82
  83         /* core fib_rules */
  84         struct list_head        rules_ops;
  85
  86
  87         struct net_device       *loopback_dev;          /* The loopback */
  88         struct netns_core       core;
  89         struct netns_mib        mib;
  90         struct netns_packet     packet;
  91         struct netns_unix       unx;
  92         struct netns_ipv4       ipv4;
  93 #if IS_ENABLED(CONFIG_IPV6)
  94         struct netns_ipv6       ipv6;
  95 #endif
  96 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
  97         struct netns_ieee802154_lowpan  ieee802154_lowpan;
  98 #endif
  99 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
 100         struct netns_sctp       sctp;
 101 #endif
 102 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
 103         struct netns_dccp       dccp;
 104 #endif
 105 #ifdef CONFIG_NETFILTER
 106         struct netns_nf         nf;
 107         struct netns_xt         xt;
 108 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 109         struct netns_ct         ct;
 110 #endif
 111 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
 112         struct netns_nftables   nft;
 113 #endif
 114 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 115         struct netns_nf_frag    nf_frag;
 116 #endif
 117         struct sock             *nfnl;
 118         struct sock             *nfnl_stash;
 119 #endif
 120 #ifdef CONFIG_WEXT_CORE
 121         struct sk_buff_head     wext_nlevents;
 122 #endif
 123         struct net_generic __rcu        *gen;
 124
 125         /* Note : following structs are cache line aligned */
 126 #ifdef CONFIG_XFRM
 127         struct netns_xfrm       xfrm;
 128 #endif
 129 #if IS_ENABLED(CONFIG_IP_VS)
 130         struct netns_ipvs       *ipvs;
 131 #endif
 132         struct sock             *diag_nlsk;
 133         atomic_t                fnhe_genid;
 134 };
 135
 136 #include <linux/seq_file_net.h>
 137
 138 /* Init's network namespace */
 139 extern struct net init_net;
 140
 141 #ifdef CONFIG_NET_NS
 142 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
 143                         struct net *old_net);
 144
 145 #else /* CONFIG_NET_NS */
 146 #include <linux/sched.h>
 147 #include <linux/nsproxy.h>
 148 static inline struct net *copy_net_ns(unsigned long flags,
 149         struct user_namespace *user_ns, struct net *old_net)
 150 {
 151         if (flags & CLONE_NEWNET)
 152                 return ERR_PTR(-EINVAL);
 153         return old_net;
 154 }
 155 #endif /* CONFIG_NET_NS */
 156
 157
 158 extern struct list_head net_namespace_list;
 159
 160 struct net *get_net_ns_by_pid(pid_t pid);
 161 struct net *get_net_ns_by_fd(int pid);
 162
 163 #ifdef CONFIG_SYSCTL
 164 void ipx_register_sysctl(void);
 165 void ipx_unregister_sysctl(void);
 166 #else
 167 #define ipx_register_sysctl()
 168 #define ipx_unregister_sysctl()
 169 #endif
 170
 171 #ifdef CONFIG_NET_NS
 172 void __put_net(struct net *net);
 173
 174 static inline struct net *get_net(struct net *net)
 175 {
 176         atomic_inc(&net->count);
 177         return net;
 178 }
 179
 180 static inline struct net *maybe_get_net(struct net *net)
 181 {
 182         /* Used when we know struct net exists but we
 183          * aren't guaranteed a previous reference count
 184          * exists.  If the reference count is zero this
 185          * function fails and returns NULL.
 186          */
 187         if (!atomic_inc_not_zero(&net->count))
 188                 net = NULL;
 189         return net;
 190 }
 191
 192 static inline void put_net(struct net *net)
 193 {
 194         if (atomic_dec_and_test(&net->count))
 195                 __put_net(net);
 196 }
 197
 198 static inline
 199 int net_eq(const struct net *net1, const struct net *net2)
 200 {
 201         return net1 == net2;
 202 }
 203
 204 void net_drop_ns(void *);
 205
 206 #else
 207
 208 static inline struct net *get_net(struct net *net)
 209 {
 210         return net;
 211 }
 212
 213 static inline void put_net(struct net *net)
 214 {
 215 }
 216
 217 static inline struct net *maybe_get_net(struct net *net)
 218 {
 219         return net;
 220 }
 221
 222 static inline
 223 int net_eq(const struct net *net1, const struct net *net2)
 224 {
 225         return 1;
 226 }
 227
 228 #define net_drop_ns NULL
 229 #endif
 230
 231
 232 #ifdef NETNS_REFCNT_DEBUG
 233 static inline struct net *hold_net(struct net *net)
 234 {
 235         if (net)
 236                 atomic_inc(&net->use_count);
 237         return net;
 238 }
 239
 240 static inline void release_net(struct net *net)
 241 {
 242         if (net)
 243                 atomic_dec(&net->use_count);
 244 }
 245 #else
 246 static inline struct net *hold_net(struct net *net)
 247 {
 248         return net;
 249 }
 250
 251 static inline void release_net(struct net *net)
 252 {
 253 }
 254 #endif
 255
 256 #ifdef CONFIG_NET_NS
 257
 258 static inline void write_pnet(struct net **pnet, struct net *net)
 259 {
 260         *pnet = net;
 261 }
 262
 263 static inline struct net *read_pnet(struct net * const *pnet)
 264 {
 265         return *pnet;
 266 }
 267
 268 #else
 269
 270 #define write_pnet(pnet, net)   do { (void)(net);} while (0)
 271 #define read_pnet(pnet)         (&init_net)
 272
 273 #endif
 274
 275 #define for_each_net(VAR)                               \
 276         list_for_each_entry(VAR, &net_namespace_list, list)
 277
 278 #define for_each_net_rcu(VAR)                           \
 279         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 280
 281 #ifdef CONFIG_NET_NS
 282 #define __net_init
 283 #define __net_exit
 284 #define __net_initdata
 285 #define __net_initconst
 286 #else
 287 #define __net_init      __init
 288 #define __net_exit      __exit_refok
 289 #define __net_initdata  __initdata
 290 #define __net_initconst __initconst
 291 #endif
 292
 293 struct pernet_operations {
 294         struct list_head list;
 295         int (*init)(struct net *net);
 296         void (*exit)(struct net *net);
 297         void (*exit_batch)(struct list_head *net_exit_list);
 298         int *id;
 299         size_t size;
 300 };
 301
 302 /*
 303  * Use these carefully.  If you implement a network device and it
 304  * needs per network namespace operations use device pernet operations,
 305  * otherwise use pernet subsys operations.
 306  *
 307  * Network interfaces need to be removed from a dying netns _before_
 308  * subsys notifiers can be called, as most of the network code cleanup
 309  * (which is done from subsys notifiers) runs with the assumption that
 310  * dev_remove_pack has been called so no new packets will arrive during
 311  * and after the cleanup functions have been called.  dev_remove_pack
 312  * is not per namespace so instead the guarantee of no more packets
 313  * arriving in a network namespace is provided by ensuring that all
 314  * network devices and all sockets have left the network namespace
 315  * before the cleanup methods are called.
 316  *
 317  * For the longest time the ipv4 icmp code was registered as a pernet
 318  * device which caused kernel oops, and panics during network
 319  * namespace cleanup.   So please don't get this wrong.
 320  */
 321 int register_pernet_subsys(struct pernet_operations *);
 322 void unregister_pernet_subsys(struct pernet_operations *);
 323 int register_pernet_device(struct pernet_operations *);
 324 void unregister_pernet_device(struct pernet_operations *);
 325
 326 struct ctl_table;
 327 struct ctl_table_header;
 328
 329 #ifdef CONFIG_SYSCTL
 330 int net_sysctl_init(void);
 331 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
 332                                              struct ctl_table *table);
 333 void unregister_net_sysctl_table(struct ctl_table_header *header);
 334 #else
 335 static inline int net_sysctl_init(void) { return 0; }
 336 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 337         const char *path, struct ctl_table *table)
 338 {
 339         return NULL;
 340 }
 341 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 342 {
 343 }
 344 #endif
 345
 346 static inline int rt_genid_ipv4(struct net *net)
 347 {
 348         return atomic_read(&net->ipv4.rt_genid);
 349 }
 350
 351 static inline void rt_genid_bump_ipv4(struct net *net)
 352 {
 353         atomic_inc(&net->ipv4.rt_genid);
 354 }
 355
 356 extern void (*__fib6_flush_trees)(struct net *net);
 357 static inline void rt_genid_bump_ipv6(struct net *net)
 358 {
 359         if (__fib6_flush_trees)
 360                 __fib6_flush_trees(net);
 361 }
 362
 363 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 364 static inline struct netns_ieee802154_lowpan *
 365 net_ieee802154_lowpan(struct net *net)
 366 {
 367         return &net->ieee802154_lowpan;
 368 }
 369 #endif
 370
 371 /* For callers who don't really care about whether it's IPv4 or IPv6 */
 372 static inline void rt_genid_bump_all(struct net *net)
 373 {
 374         rt_genid_bump_ipv4(net);
 375         rt_genid_bump_ipv6(net);
 376 }
 377
 378 static inline int fnhe_genid(struct net *net)
 379 {
 380         return atomic_read(&net->fnhe_genid);
 381 }
 382
 383 static inline void fnhe_genid_bump(struct net *net)
 384 {
 385         atomic_inc(&net->fnhe_genid);
 386 }
 387
 388 #endif /* __NET_NET_NAMESPACE_H */