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/netfilter.h> 26 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 27 #include <net/netns/conntrack.h> 28 #endif 29 #if IS_ENABLED(CONFIG_NF_FLOW_TABLE) 30 #include <net/netns/flow_table.h> 31 #endif 32 #include <net/netns/nftables.h> 33 #include <net/netns/xfrm.h> 34 #include <net/netns/mpls.h> 35 #include <net/netns/can.h> 36 #include <net/netns/xdp.h> 37 #include <net/netns/smc.h> 38 #include <net/netns/bpf.h> 39 #include <net/netns/mctp.h> 40 #include <net/net_trackers.h> 41 #include <linux/ns_common.h> 42 #include <linux/idr.h> 43 #include <linux/skbuff.h> 44 #include <linux/notifier.h> 45 #include <linux/xarray.h> 46 47 struct user_namespace; 48 struct proc_dir_entry; 49 struct net_device; 50 struct sock; 51 struct ctl_table_header; 52 struct net_generic; 53 struct uevent_sock; 54 struct netns_ipvs; 55 struct bpf_prog; 56 57 58 #define NETDEV_HASHBITS 8 59 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 60 61 struct net { 62 /* First cache line can be often dirtied. 63 * Do not place here read-mostly fields. 64 */ 65 refcount_t passive; /* To decide when the network 66 * namespace should be freed. 67 */ 68 spinlock_t rules_mod_lock; 69 70 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 71 u32 ifindex; 72 73 spinlock_t nsid_lock; 74 atomic_t fnhe_genid; 75 76 struct list_head list; /* list of network namespaces */ 77 struct list_head exit_list; /* To linked to call pernet exit 78 * methods on dead net ( 79 * pernet_ops_rwsem read locked), 80 * or to unregister pernet ops 81 * (pernet_ops_rwsem write locked). 82 */ 83 struct llist_node defer_free_list; 84 struct llist_node cleanup_list; /* namespaces on death row */ 85 86 struct list_head ptype_all; 87 struct list_head ptype_specific; 88 89 #ifdef CONFIG_KEYS 90 struct key_tag *key_domain; /* Key domain of operation tag */ 91 #endif 92 struct user_namespace *user_ns; /* Owning user namespace */ 93 struct ucounts *ucounts; 94 struct idr netns_ids; 95 96 struct ns_common ns; 97 struct ref_tracker_dir refcnt_tracker; 98 struct ref_tracker_dir notrefcnt_tracker; /* tracker for objects not 99 * refcounted against netns 100 */ 101 struct list_head dev_base_head; 102 struct proc_dir_entry *proc_net; 103 struct proc_dir_entry *proc_net_stat; 104 105 #ifdef CONFIG_SYSCTL 106 struct ctl_table_set sysctls; 107 #endif 108 109 struct sock *rtnl; /* rtnetlink socket */ 110 struct sock *genl_sock; 111 112 struct uevent_sock *uevent_sock; /* uevent socket */ 113 114 struct hlist_head *dev_name_head; 115 struct hlist_head *dev_index_head; 116 struct xarray dev_by_index; 117 struct raw_notifier_head netdev_chain; 118 119 /* Note that @hash_mix can be read millions times per second, 120 * it is critical that it is on a read_mostly cache line. 121 */ 122 u32 hash_mix; 123 124 struct net_device *loopback_dev; /* The loopback */ 125 126 /* core fib_rules */ 127 struct list_head rules_ops; 128 129 struct netns_core core; 130 struct netns_mib mib; 131 struct netns_packet packet; 132 #if IS_ENABLED(CONFIG_UNIX) 133 struct netns_unix unx; 134 #endif 135 struct netns_nexthop nexthop; 136 struct netns_ipv4 ipv4; 137 #if IS_ENABLED(CONFIG_IPV6) 138 struct netns_ipv6 ipv6; 139 #endif 140 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 141 struct netns_ieee802154_lowpan ieee802154_lowpan; 142 #endif 143 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 144 struct netns_sctp sctp; 145 #endif 146 #ifdef CONFIG_NETFILTER 147 struct netns_nf nf; 148 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 149 struct netns_ct ct; 150 #endif 151 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 152 struct netns_nftables nft; 153 #endif 154 #if IS_ENABLED(CONFIG_NF_FLOW_TABLE) 155 struct netns_ft ft; 156 #endif 157 #endif 158 #ifdef CONFIG_WEXT_CORE 159 struct sk_buff_head wext_nlevents; 160 #endif 161 struct net_generic __rcu *gen; 162 163 /* Used to store attached BPF programs */ 164 struct netns_bpf bpf; 165 166 /* Note : following structs are cache line aligned */ 167 #ifdef CONFIG_XFRM 168 struct netns_xfrm xfrm; 169 #endif 170 171 u64 net_cookie; /* written once */ 172 173 #if IS_ENABLED(CONFIG_IP_VS) 174 struct netns_ipvs *ipvs; 175 #endif 176 #if IS_ENABLED(CONFIG_MPLS) 177 struct netns_mpls mpls; 178 #endif 179 #if IS_ENABLED(CONFIG_CAN) 180 struct netns_can can; 181 #endif 182 #ifdef CONFIG_XDP_SOCKETS 183 struct netns_xdp xdp; 184 #endif 185 #if IS_ENABLED(CONFIG_MCTP) 186 struct netns_mctp mctp; 187 #endif 188 #if IS_ENABLED(CONFIG_CRYPTO_USER) 189 struct sock *crypto_nlsk; 190 #endif 191 struct sock *diag_nlsk; 192 #if IS_ENABLED(CONFIG_SMC) 193 struct netns_smc smc; 194 #endif 195 #ifdef CONFIG_DEBUG_NET_SMALL_RTNL 196 /* Move to a better place when the config guard is removed. */ 197 struct mutex rtnl_mutex; 198 #endif 199 } __randomize_layout; 200 201 #include <linux/seq_file_net.h> 202 203 /* Init's network namespace */ 204 extern struct net init_net; 205 206 #ifdef CONFIG_NET_NS 207 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 208 struct net *old_net); 209 210 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 211 212 void net_ns_barrier(void); 213 214 struct ns_common *get_net_ns(struct ns_common *ns); 215 struct net *get_net_ns_by_fd(int fd); 216 extern struct task_struct *cleanup_net_task; 217 218 #else /* CONFIG_NET_NS */ 219 #include <linux/sched.h> 220 #include <linux/nsproxy.h> 221 static inline struct net *copy_net_ns(unsigned long flags, 222 struct user_namespace *user_ns, struct net *old_net) 223 { 224 if (flags & CLONE_NEWNET) 225 return ERR_PTR(-EINVAL); 226 return old_net; 227 } 228 229 static inline void net_ns_get_ownership(const struct net *net, 230 kuid_t *uid, kgid_t *gid) 231 { 232 *uid = GLOBAL_ROOT_UID; 233 *gid = GLOBAL_ROOT_GID; 234 } 235 236 static inline void net_ns_barrier(void) {} 237 238 static inline struct ns_common *get_net_ns(struct ns_common *ns) 239 { 240 return ERR_PTR(-EINVAL); 241 } 242 243 static inline struct net *get_net_ns_by_fd(int fd) 244 { 245 return ERR_PTR(-EINVAL); 246 } 247 #endif /* CONFIG_NET_NS */ 248 249 250 extern struct list_head net_namespace_list; 251 252 struct net *get_net_ns_by_pid(pid_t pid); 253 254 #ifdef CONFIG_SYSCTL 255 void ipx_register_sysctl(void); 256 void ipx_unregister_sysctl(void); 257 #else 258 #define ipx_register_sysctl() 259 #define ipx_unregister_sysctl() 260 #endif 261 262 #ifdef CONFIG_NET_NS 263 void __put_net(struct net *net); 264 265 /* Try using get_net_track() instead */ 266 static inline struct net *get_net(struct net *net) 267 { 268 refcount_inc(&net->ns.count); 269 return net; 270 } 271 272 static inline struct net *maybe_get_net(struct net *net) 273 { 274 /* Used when we know struct net exists but we 275 * aren't guaranteed a previous reference count 276 * exists. If the reference count is zero this 277 * function fails and returns NULL. 278 */ 279 if (!refcount_inc_not_zero(&net->ns.count)) 280 net = NULL; 281 return net; 282 } 283 284 /* Try using put_net_track() instead */ 285 static inline void put_net(struct net *net) 286 { 287 if (refcount_dec_and_test(&net->ns.count)) 288 __put_net(net); 289 } 290 291 static inline 292 int net_eq(const struct net *net1, const struct net *net2) 293 { 294 return net1 == net2; 295 } 296 297 static inline int check_net(const struct net *net) 298 { 299 return refcount_read(&net->ns.count) != 0; 300 } 301 302 void net_drop_ns(void *); 303 void net_passive_dec(struct net *net); 304 305 #else 306 307 static inline struct net *get_net(struct net *net) 308 { 309 return net; 310 } 311 312 static inline void put_net(struct net *net) 313 { 314 } 315 316 static inline struct net *maybe_get_net(struct net *net) 317 { 318 return net; 319 } 320 321 static inline 322 int net_eq(const struct net *net1, const struct net *net2) 323 { 324 return 1; 325 } 326 327 static inline int check_net(const struct net *net) 328 { 329 return 1; 330 } 331 332 #define net_drop_ns NULL 333 334 static inline void net_passive_dec(struct net *net) 335 { 336 refcount_dec(&net->passive); 337 } 338 #endif 339 340 static inline void net_passive_inc(struct net *net) 341 { 342 refcount_inc(&net->passive); 343 } 344 345 /* Returns true if the netns initialization is completed successfully */ 346 static inline bool net_initialized(const struct net *net) 347 { 348 return READ_ONCE(net->list.next); 349 } 350 351 static inline void __netns_tracker_alloc(struct net *net, 352 netns_tracker *tracker, 353 bool refcounted, 354 gfp_t gfp) 355 { 356 #ifdef CONFIG_NET_NS_REFCNT_TRACKER 357 ref_tracker_alloc(refcounted ? &net->refcnt_tracker : 358 &net->notrefcnt_tracker, 359 tracker, gfp); 360 #endif 361 } 362 363 static inline void netns_tracker_alloc(struct net *net, netns_tracker *tracker, 364 gfp_t gfp) 365 { 366 __netns_tracker_alloc(net, tracker, true, gfp); 367 } 368 369 static inline void __netns_tracker_free(struct net *net, 370 netns_tracker *tracker, 371 bool refcounted) 372 { 373 #ifdef CONFIG_NET_NS_REFCNT_TRACKER 374 ref_tracker_free(refcounted ? &net->refcnt_tracker : 375 &net->notrefcnt_tracker, tracker); 376 #endif 377 } 378 379 static inline struct net *get_net_track(struct net *net, 380 netns_tracker *tracker, gfp_t gfp) 381 { 382 get_net(net); 383 netns_tracker_alloc(net, tracker, gfp); 384 return net; 385 } 386 387 static inline void put_net_track(struct net *net, netns_tracker *tracker) 388 { 389 __netns_tracker_free(net, tracker, true); 390 put_net(net); 391 } 392 393 typedef struct { 394 #ifdef CONFIG_NET_NS 395 struct net __rcu *net; 396 #endif 397 } possible_net_t; 398 399 static inline void write_pnet(possible_net_t *pnet, struct net *net) 400 { 401 #ifdef CONFIG_NET_NS 402 rcu_assign_pointer(pnet->net, net); 403 #endif 404 } 405 406 static inline struct net *read_pnet(const possible_net_t *pnet) 407 { 408 #ifdef CONFIG_NET_NS 409 return rcu_dereference_protected(pnet->net, true); 410 #else 411 return &init_net; 412 #endif 413 } 414 415 static inline struct net *read_pnet_rcu(const possible_net_t *pnet) 416 { 417 #ifdef CONFIG_NET_NS 418 return rcu_dereference(pnet->net); 419 #else 420 return &init_net; 421 #endif 422 } 423 424 /* Protected by net_rwsem */ 425 #define for_each_net(VAR) \ 426 list_for_each_entry(VAR, &net_namespace_list, list) 427 #define for_each_net_continue_reverse(VAR) \ 428 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list) 429 #define for_each_net_rcu(VAR) \ 430 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 431 432 #ifdef CONFIG_NET_NS 433 #define __net_init 434 #define __net_exit 435 #define __net_initdata 436 #define __net_initconst 437 #else 438 #define __net_init __init 439 #define __net_exit __ref 440 #define __net_initdata __initdata 441 #define __net_initconst __initconst 442 #endif 443 444 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp); 445 int peernet2id(const struct net *net, struct net *peer); 446 bool peernet_has_id(const struct net *net, struct net *peer); 447 struct net *get_net_ns_by_id(const struct net *net, int id); 448 449 struct pernet_operations { 450 struct list_head list; 451 /* 452 * Below methods are called without any exclusive locks. 453 * More than one net may be constructed and destructed 454 * in parallel on several cpus. Every pernet_operations 455 * have to keep in mind all other pernet_operations and 456 * to introduce a locking, if they share common resources. 457 * 458 * The only time they are called with exclusive lock is 459 * from register_pernet_subsys(), unregister_pernet_subsys() 460 * register_pernet_device() and unregister_pernet_device(). 461 * 462 * Exit methods using blocking RCU primitives, such as 463 * synchronize_rcu(), should be implemented via exit_batch. 464 * Then, destruction of a group of net requires single 465 * synchronize_rcu() related to these pernet_operations, 466 * instead of separate synchronize_rcu() for every net. 467 * Please, avoid synchronize_rcu() at all, where it's possible. 468 * 469 * Note that a combination of pre_exit() and exit() can 470 * be used, since a synchronize_rcu() is guaranteed between 471 * the calls. 472 */ 473 int (*init)(struct net *net); 474 void (*pre_exit)(struct net *net); 475 void (*exit)(struct net *net); 476 void (*exit_batch)(struct list_head *net_exit_list); 477 /* Following method is called with RTNL held. */ 478 void (*exit_batch_rtnl)(struct list_head *net_exit_list, 479 struct list_head *dev_kill_list); 480 unsigned int * const id; 481 const size_t size; 482 }; 483 484 /* 485 * Use these carefully. If you implement a network device and it 486 * needs per network namespace operations use device pernet operations, 487 * otherwise use pernet subsys operations. 488 * 489 * Network interfaces need to be removed from a dying netns _before_ 490 * subsys notifiers can be called, as most of the network code cleanup 491 * (which is done from subsys notifiers) runs with the assumption that 492 * dev_remove_pack has been called so no new packets will arrive during 493 * and after the cleanup functions have been called. dev_remove_pack 494 * is not per namespace so instead the guarantee of no more packets 495 * arriving in a network namespace is provided by ensuring that all 496 * network devices and all sockets have left the network namespace 497 * before the cleanup methods are called. 498 * 499 * For the longest time the ipv4 icmp code was registered as a pernet 500 * device which caused kernel oops, and panics during network 501 * namespace cleanup. So please don't get this wrong. 502 */ 503 int register_pernet_subsys(struct pernet_operations *); 504 void unregister_pernet_subsys(struct pernet_operations *); 505 int register_pernet_device(struct pernet_operations *); 506 void unregister_pernet_device(struct pernet_operations *); 507 508 struct ctl_table; 509 510 #define register_net_sysctl(net, path, table) \ 511 register_net_sysctl_sz(net, path, table, ARRAY_SIZE(table)) 512 #ifdef CONFIG_SYSCTL 513 int net_sysctl_init(void); 514 struct ctl_table_header *register_net_sysctl_sz(struct net *net, const char *path, 515 struct ctl_table *table, size_t table_size); 516 void unregister_net_sysctl_table(struct ctl_table_header *header); 517 #else 518 static inline int net_sysctl_init(void) { return 0; } 519 static inline struct ctl_table_header *register_net_sysctl_sz(struct net *net, 520 const char *path, struct ctl_table *table, size_t table_size) 521 { 522 return NULL; 523 } 524 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 525 { 526 } 527 #endif 528 529 static inline int rt_genid_ipv4(const struct net *net) 530 { 531 return atomic_read(&net->ipv4.rt_genid); 532 } 533 534 #if IS_ENABLED(CONFIG_IPV6) 535 static inline int rt_genid_ipv6(const struct net *net) 536 { 537 return atomic_read(&net->ipv6.fib6_sernum); 538 } 539 #endif 540 541 static inline void rt_genid_bump_ipv4(struct net *net) 542 { 543 atomic_inc(&net->ipv4.rt_genid); 544 } 545 546 extern void (*__fib6_flush_trees)(struct net *net); 547 static inline void rt_genid_bump_ipv6(struct net *net) 548 { 549 if (__fib6_flush_trees) 550 __fib6_flush_trees(net); 551 } 552 553 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 554 static inline struct netns_ieee802154_lowpan * 555 net_ieee802154_lowpan(struct net *net) 556 { 557 return &net->ieee802154_lowpan; 558 } 559 #endif 560 561 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 562 static inline void rt_genid_bump_all(struct net *net) 563 { 564 rt_genid_bump_ipv4(net); 565 rt_genid_bump_ipv6(net); 566 } 567 568 static inline int fnhe_genid(const struct net *net) 569 { 570 return atomic_read(&net->fnhe_genid); 571 } 572 573 static inline void fnhe_genid_bump(struct net *net) 574 { 575 atomic_inc(&net->fnhe_genid); 576 } 577 578 #ifdef CONFIG_NET 579 void net_ns_init(void); 580 #else 581 static inline void net_ns_init(void) {} 582 #endif 583 584 #endif /* __NET_NET_NAMESPACE_H */ 585