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