root/include/net/net_namespace.h

INCLUDED FROM

DEFINITIONS

1. copy_net_ns
2. net_ns_get_ownership
3. net_ns_barrier
4. get_net
5. maybe_get_net
6. put_net
7. net_eq
8. check_net
9. get_net
10. put_net
11. maybe_get_net
12. net_eq
13. check_net
14. write_pnet
15. read_pnet
16. net_sysctl_init
17. register_net_sysctl
18. unregister_net_sysctl_table
19. rt_genid_ipv4
20. rt_genid_ipv6
21. rt_genid_bump_ipv4
22. rt_genid_bump_ipv6
23. net_ieee802154_lowpan
24. rt_genid_bump_all
25. fnhe_genid
26. fnhe_genid_bump

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Operations on the network namespace
   4  */
   5 #ifndef __NET_NET_NAMESPACE_H
   6 #define __NET_NET_NAMESPACE_H
   7 
   8 #include <linux/atomic.h>
   9 #include <linux/refcount.h>
  10 #include <linux/workqueue.h>
  11 #include <linux/list.h>
  12 #include <linux/sysctl.h>
  13 #include <linux/uidgid.h>
  14 
  15 #include <net/flow.h>
  16 #include <net/netns/core.h>
  17 #include <net/netns/mib.h>
  18 #include <net/netns/unix.h>
  19 #include <net/netns/packet.h>
  20 #include <net/netns/ipv4.h>
  21 #include <net/netns/ipv6.h>
  22 #include <net/netns/nexthop.h>
  23 #include <net/netns/ieee802154_6lowpan.h>
  24 #include <net/netns/sctp.h>
  25 #include <net/netns/dccp.h>
  26 #include <net/netns/netfilter.h>
  27 #include <net/netns/x_tables.h>
  28 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  29 #include <net/netns/conntrack.h>
  30 #endif
  31 #include <net/netns/nftables.h>
  32 #include <net/netns/xfrm.h>
  33 #include <net/netns/mpls.h>
  34 #include <net/netns/can.h>
  35 #include <net/netns/xdp.h>
  36 #include <linux/ns_common.h>
  37 #include <linux/idr.h>
  38 #include <linux/skbuff.h>
  39 
  40 struct user_namespace;
  41 struct proc_dir_entry;
  42 struct net_device;
  43 struct sock;
  44 struct ctl_table_header;
  45 struct net_generic;
  46 struct uevent_sock;
  47 struct netns_ipvs;
  48 struct bpf_prog;
  49 
  50 
  51 #define NETDEV_HASHBITS    8
  52 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  53 
  54 struct net {
  55         /* First cache line can be often dirtied.
  56          * Do not place here read-mostly fields.
  57          */
  58         refcount_t              passive;        /* To decide when the network
  59                                                  * namespace should be freed.
  60                                                  */
  61         refcount_t              count;          /* To decided when the network
  62                                                  *  namespace should be shut down.
  63                                                  */
  64         spinlock_t              rules_mod_lock;
  65 
  66         unsigned int            dev_unreg_count;
  67 
  68         unsigned int            dev_base_seq;   /* protected by rtnl_mutex */
  69         int                     ifindex;
  70 
  71         spinlock_t              nsid_lock;
  72         atomic_t                fnhe_genid;
  73 
  74         struct list_head        list;           /* list of network namespaces */
  75         struct list_head        exit_list;      /* To linked to call pernet exit
  76                                                  * methods on dead net (
  77                                                  * pernet_ops_rwsem read locked),
  78                                                  * or to unregister pernet ops
  79                                                  * (pernet_ops_rwsem write locked).
  80                                                  */
  81         struct llist_node       cleanup_list;   /* namespaces on death row */
  82 
  83 #ifdef CONFIG_KEYS
  84         struct key_tag          *key_domain;    /* Key domain of operation tag */
  85 #endif
  86         struct user_namespace   *user_ns;       /* Owning user namespace */
  87         struct ucounts          *ucounts;
  88         struct idr              netns_ids;
  89 
  90         struct ns_common        ns;
  91 
  92         struct list_head        dev_base_head;
  93         struct proc_dir_entry   *proc_net;
  94         struct proc_dir_entry   *proc_net_stat;
  95 
  96 #ifdef CONFIG_SYSCTL
  97         struct ctl_table_set    sysctls;
  98 #endif
  99 
 100         struct sock             *rtnl;                  /* rtnetlink socket */
 101         struct sock             *genl_sock;
 102 
 103         struct uevent_sock      *uevent_sock;           /* uevent socket */
 104 
 105         struct hlist_head       *dev_name_head;
 106         struct hlist_head       *dev_index_head;
 107         /* Note that @hash_mix can be read millions times per second,
 108          * it is critical that it is on a read_mostly cache line.
 109          */
 110         u32                     hash_mix;
 111 
 112         struct net_device       *loopback_dev;          /* The loopback */
 113 
 114         /* core fib_rules */
 115         struct list_head        rules_ops;
 116 
 117         struct netns_core       core;
 118         struct netns_mib        mib;
 119         struct netns_packet     packet;
 120         struct netns_unix       unx;
 121         struct netns_nexthop    nexthop;
 122         struct netns_ipv4       ipv4;
 123 #if IS_ENABLED(CONFIG_IPV6)
 124         struct netns_ipv6       ipv6;
 125 #endif
 126 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 127         struct netns_ieee802154_lowpan  ieee802154_lowpan;
 128 #endif
 129 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
 130         struct netns_sctp       sctp;
 131 #endif
 132 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
 133         struct netns_dccp       dccp;
 134 #endif
 135 #ifdef CONFIG_NETFILTER
 136         struct netns_nf         nf;
 137         struct netns_xt         xt;
 138 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 139         struct netns_ct         ct;
 140 #endif
 141 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
 142         struct netns_nftables   nft;
 143 #endif
 144 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 145         struct netns_nf_frag    nf_frag;
 146         struct ctl_table_header *nf_frag_frags_hdr;
 147 #endif
 148         struct sock             *nfnl;
 149         struct sock             *nfnl_stash;
 150 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
 151         struct list_head        nfnl_acct_list;
 152 #endif
 153 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 154         struct list_head        nfct_timeout_list;
 155 #endif
 156 #endif
 157 #ifdef CONFIG_WEXT_CORE
 158         struct sk_buff_head     wext_nlevents;
 159 #endif
 160         struct net_generic __rcu        *gen;
 161 
 162         struct bpf_prog __rcu   *flow_dissector_prog;
 163 
 164         /* Note : following structs are cache line aligned */
 165 #ifdef CONFIG_XFRM
 166         struct netns_xfrm       xfrm;
 167 #endif
 168 #if IS_ENABLED(CONFIG_IP_VS)
 169         struct netns_ipvs       *ipvs;
 170 #endif
 171 #if IS_ENABLED(CONFIG_MPLS)
 172         struct netns_mpls       mpls;
 173 #endif
 174 #if IS_ENABLED(CONFIG_CAN)
 175         struct netns_can        can;
 176 #endif
 177 #ifdef CONFIG_XDP_SOCKETS
 178         struct netns_xdp        xdp;
 179 #endif
 180 #if IS_ENABLED(CONFIG_CRYPTO_USER)
 181         struct sock             *crypto_nlsk;
 182 #endif
 183         struct sock             *diag_nlsk;
 184 } __randomize_layout;
 185 
 186 #include <linux/seq_file_net.h>
 187 
 188 /* Init's network namespace */
 189 extern struct net init_net;
 190 
 191 #ifdef CONFIG_NET_NS
 192 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
 193                         struct net *old_net);
 194 
 195 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
 196 
 197 void net_ns_barrier(void);
 198 #else /* CONFIG_NET_NS */
 199 #include <linux/sched.h>
 200 #include <linux/nsproxy.h>
 201 static inline struct net *copy_net_ns(unsigned long flags,
 202         struct user_namespace *user_ns, struct net *old_net)
 203 {
 204         if (flags & CLONE_NEWNET)
 205                 return ERR_PTR(-EINVAL);
 206         return old_net;
 207 }
 208 
 209 static inline void net_ns_get_ownership(const struct net *net,
 210                                         kuid_t *uid, kgid_t *gid)
 211 {
 212         *uid = GLOBAL_ROOT_UID;
 213         *gid = GLOBAL_ROOT_GID;
 214 }
 215 
 216 static inline void net_ns_barrier(void) {}
 217 #endif /* CONFIG_NET_NS */
 218 
 219 
 220 extern struct list_head net_namespace_list;
 221 
 222 struct net *get_net_ns_by_pid(pid_t pid);
 223 struct net *get_net_ns_by_fd(int fd);
 224 
 225 #ifdef CONFIG_SYSCTL
 226 void ipx_register_sysctl(void);
 227 void ipx_unregister_sysctl(void);
 228 #else
 229 #define ipx_register_sysctl()
 230 #define ipx_unregister_sysctl()
 231 #endif
 232 
 233 #ifdef CONFIG_NET_NS
 234 void __put_net(struct net *net);
 235 
 236 static inline struct net *get_net(struct net *net)
 237 {
 238         refcount_inc(&net->count);
 239         return net;
 240 }
 241 
 242 static inline struct net *maybe_get_net(struct net *net)
 243 {
 244         /* Used when we know struct net exists but we
 245          * aren't guaranteed a previous reference count
 246          * exists.  If the reference count is zero this
 247          * function fails and returns NULL.
 248          */
 249         if (!refcount_inc_not_zero(&net->count))
 250                 net = NULL;
 251         return net;
 252 }
 253 
 254 static inline void put_net(struct net *net)
 255 {
 256         if (refcount_dec_and_test(&net->count))
 257                 __put_net(net);
 258 }
 259 
 260 static inline
 261 int net_eq(const struct net *net1, const struct net *net2)
 262 {
 263         return net1 == net2;
 264 }
 265 
 266 static inline int check_net(const struct net *net)
 267 {
 268         return refcount_read(&net->count) != 0;
 269 }
 270 
 271 void net_drop_ns(void *);
 272 
 273 #else
 274 
 275 static inline struct net *get_net(struct net *net)
 276 {
 277         return net;
 278 }
 279 
 280 static inline void put_net(struct net *net)
 281 {
 282 }
 283 
 284 static inline struct net *maybe_get_net(struct net *net)
 285 {
 286         return net;
 287 }
 288 
 289 static inline
 290 int net_eq(const struct net *net1, const struct net *net2)
 291 {
 292         return 1;
 293 }
 294 
 295 static inline int check_net(const struct net *net)
 296 {
 297         return 1;
 298 }
 299 
 300 #define net_drop_ns NULL
 301 #endif
 302 
 303 
 304 typedef struct {
 305 #ifdef CONFIG_NET_NS
 306         struct net *net;
 307 #endif
 308 } possible_net_t;
 309 
 310 static inline void write_pnet(possible_net_t *pnet, struct net *net)
 311 {
 312 #ifdef CONFIG_NET_NS
 313         pnet->net = net;
 314 #endif
 315 }
 316 
 317 static inline struct net *read_pnet(const possible_net_t *pnet)
 318 {
 319 #ifdef CONFIG_NET_NS
 320         return pnet->net;
 321 #else
 322         return &init_net;
 323 #endif
 324 }
 325 
 326 /* Protected by net_rwsem */
 327 #define for_each_net(VAR)                               \
 328         list_for_each_entry(VAR, &net_namespace_list, list)
 329 
 330 #define for_each_net_rcu(VAR)                           \
 331         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 332 
 333 #ifdef CONFIG_NET_NS
 334 #define __net_init
 335 #define __net_exit
 336 #define __net_initdata
 337 #define __net_initconst
 338 #else
 339 #define __net_init      __init
 340 #define __net_exit      __ref
 341 #define __net_initdata  __initdata
 342 #define __net_initconst __initconst
 343 #endif
 344 
 345 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
 346 int peernet2id(struct net *net, struct net *peer);
 347 bool peernet_has_id(struct net *net, struct net *peer);
 348 struct net *get_net_ns_by_id(struct net *net, int id);
 349 
 350 struct pernet_operations {
 351         struct list_head list;
 352         /*
 353          * Below methods are called without any exclusive locks.
 354          * More than one net may be constructed and destructed
 355          * in parallel on several cpus. Every pernet_operations
 356          * have to keep in mind all other pernet_operations and
 357          * to introduce a locking, if they share common resources.
 358          *
 359          * The only time they are called with exclusive lock is
 360          * from register_pernet_subsys(), unregister_pernet_subsys()
 361          * register_pernet_device() and unregister_pernet_device().
 362          *
 363          * Exit methods using blocking RCU primitives, such as
 364          * synchronize_rcu(), should be implemented via exit_batch.
 365          * Then, destruction of a group of net requires single
 366          * synchronize_rcu() related to these pernet_operations,
 367          * instead of separate synchronize_rcu() for every net.
 368          * Please, avoid synchronize_rcu() at all, where it's possible.
 369          *
 370          * Note that a combination of pre_exit() and exit() can
 371          * be used, since a synchronize_rcu() is guaranteed between
 372          * the calls.
 373          */
 374         int (*init)(struct net *net);
 375         void (*pre_exit)(struct net *net);
 376         void (*exit)(struct net *net);
 377         void (*exit_batch)(struct list_head *net_exit_list);
 378         unsigned int *id;
 379         size_t size;
 380 };
 381 
 382 /*
 383  * Use these carefully.  If you implement a network device and it
 384  * needs per network namespace operations use device pernet operations,
 385  * otherwise use pernet subsys operations.
 386  *
 387  * Network interfaces need to be removed from a dying netns _before_
 388  * subsys notifiers can be called, as most of the network code cleanup
 389  * (which is done from subsys notifiers) runs with the assumption that
 390  * dev_remove_pack has been called so no new packets will arrive during
 391  * and after the cleanup functions have been called.  dev_remove_pack
 392  * is not per namespace so instead the guarantee of no more packets
 393  * arriving in a network namespace is provided by ensuring that all
 394  * network devices and all sockets have left the network namespace
 395  * before the cleanup methods are called.
 396  *
 397  * For the longest time the ipv4 icmp code was registered as a pernet
 398  * device which caused kernel oops, and panics during network
 399  * namespace cleanup.   So please don't get this wrong.
 400  */
 401 int register_pernet_subsys(struct pernet_operations *);
 402 void unregister_pernet_subsys(struct pernet_operations *);
 403 int register_pernet_device(struct pernet_operations *);
 404 void unregister_pernet_device(struct pernet_operations *);
 405 
 406 struct ctl_table;
 407 struct ctl_table_header;
 408 
 409 #ifdef CONFIG_SYSCTL
 410 int net_sysctl_init(void);
 411 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
 412                                              struct ctl_table *table);
 413 void unregister_net_sysctl_table(struct ctl_table_header *header);
 414 #else
 415 static inline int net_sysctl_init(void) { return 0; }
 416 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 417         const char *path, struct ctl_table *table)
 418 {
 419         return NULL;
 420 }
 421 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 422 {
 423 }
 424 #endif
 425 
 426 static inline int rt_genid_ipv4(struct net *net)
 427 {
 428         return atomic_read(&net->ipv4.rt_genid);
 429 }
 430 
 431 #if IS_ENABLED(CONFIG_IPV6)
 432 static inline int rt_genid_ipv6(const struct net *net)
 433 {
 434         return atomic_read(&net->ipv6.fib6_sernum);
 435 }
 436 #endif
 437 
 438 static inline void rt_genid_bump_ipv4(struct net *net)
 439 {
 440         atomic_inc(&net->ipv4.rt_genid);
 441 }
 442 
 443 extern void (*__fib6_flush_trees)(struct net *net);
 444 static inline void rt_genid_bump_ipv6(struct net *net)
 445 {
 446         if (__fib6_flush_trees)
 447                 __fib6_flush_trees(net);
 448 }
 449 
 450 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 451 static inline struct netns_ieee802154_lowpan *
 452 net_ieee802154_lowpan(struct net *net)
 453 {
 454         return &net->ieee802154_lowpan;
 455 }
 456 #endif
 457 
 458 /* For callers who don't really care about whether it's IPv4 or IPv6 */
 459 static inline void rt_genid_bump_all(struct net *net)
 460 {
 461         rt_genid_bump_ipv4(net);
 462         rt_genid_bump_ipv6(net);
 463 }
 464 
 465 static inline int fnhe_genid(struct net *net)
 466 {
 467         return atomic_read(&net->fnhe_genid);
 468 }
 469 
 470 static inline void fnhe_genid_bump(struct net *net)
 471 {
 472         atomic_inc(&net->fnhe_genid);
 473 }
 474 
 475 #endif /* __NET_NET_NAMESPACE_H */