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(u64 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(u64 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 static inline struct net *to_net_ns(struct ns_common *ns) 266 { 267 return container_of(ns, struct net, ns); 268 } 269 270 /* Try using get_net_track() instead */ 271 static inline struct net *get_net(struct net *net) 272 { 273 ns_ref_inc(net); 274 return net; 275 } 276 277 static inline struct net *maybe_get_net(struct net *net) 278 { 279 /* Used when we know struct net exists but we 280 * aren't guaranteed a previous reference count 281 * exists. If the reference count is zero this 282 * function fails and returns NULL. 283 */ 284 if (!ns_ref_get(net)) 285 net = NULL; 286 return net; 287 } 288 289 /* Try using put_net_track() instead */ 290 static inline void put_net(struct net *net) 291 { 292 if (ns_ref_put(net)) 293 __put_net(net); 294 } 295 296 static inline 297 int net_eq(const struct net *net1, const struct net *net2) 298 { 299 return net1 == net2; 300 } 301 302 static inline int check_net(const struct net *net) 303 { 304 return ns_ref_read(net) != 0; 305 } 306 307 void net_drop_ns(void *); 308 void net_passive_dec(struct net *net); 309 310 #else 311 312 static inline struct net *get_net(struct net *net) 313 { 314 return net; 315 } 316 317 static inline void put_net(struct net *net) 318 { 319 } 320 321 static inline struct net *maybe_get_net(struct net *net) 322 { 323 return net; 324 } 325 326 static inline 327 int net_eq(const struct net *net1, const struct net *net2) 328 { 329 return 1; 330 } 331 332 static inline int check_net(const struct net *net) 333 { 334 return 1; 335 } 336 337 #define net_drop_ns NULL 338 339 static inline void net_passive_dec(struct net *net) 340 { 341 refcount_dec(&net->passive); 342 } 343 #endif 344 345 static inline void net_passive_inc(struct net *net) 346 { 347 refcount_inc(&net->passive); 348 } 349 350 /* Returns true if the netns initialization is completed successfully */ 351 static inline bool net_initialized(const struct net *net) 352 { 353 return READ_ONCE(net->list.next); 354 } 355 356 static inline void __netns_tracker_alloc(struct net *net, 357 netns_tracker *tracker, 358 bool refcounted, 359 gfp_t gfp) 360 { 361 #ifdef CONFIG_NET_NS_REFCNT_TRACKER 362 ref_tracker_alloc(refcounted ? &net->refcnt_tracker : 363 &net->notrefcnt_tracker, 364 tracker, gfp); 365 #endif 366 } 367 368 static inline void netns_tracker_alloc(struct net *net, netns_tracker *tracker, 369 gfp_t gfp) 370 { 371 __netns_tracker_alloc(net, tracker, true, gfp); 372 } 373 374 static inline void __netns_tracker_free(struct net *net, 375 netns_tracker *tracker, 376 bool refcounted) 377 { 378 #ifdef CONFIG_NET_NS_REFCNT_TRACKER 379 ref_tracker_free(refcounted ? &net->refcnt_tracker : 380 &net->notrefcnt_tracker, tracker); 381 #endif 382 } 383 384 static inline struct net *get_net_track(struct net *net, 385 netns_tracker *tracker, gfp_t gfp) 386 { 387 get_net(net); 388 netns_tracker_alloc(net, tracker, gfp); 389 return net; 390 } 391 392 static inline void put_net_track(struct net *net, netns_tracker *tracker) 393 { 394 __netns_tracker_free(net, tracker, true); 395 put_net(net); 396 } 397 398 typedef struct { 399 #ifdef CONFIG_NET_NS 400 struct net __rcu *net; 401 #endif 402 } possible_net_t; 403 404 static inline void write_pnet(possible_net_t *pnet, struct net *net) 405 { 406 #ifdef CONFIG_NET_NS 407 rcu_assign_pointer(pnet->net, net); 408 #endif 409 } 410 411 static inline struct net *read_pnet(const possible_net_t *pnet) 412 { 413 #ifdef CONFIG_NET_NS 414 return rcu_dereference_protected(pnet->net, true); 415 #else 416 return &init_net; 417 #endif 418 } 419 420 static inline struct net *read_pnet_rcu(const possible_net_t *pnet) 421 { 422 #ifdef CONFIG_NET_NS 423 return rcu_dereference(pnet->net); 424 #else 425 return &init_net; 426 #endif 427 } 428 429 /* Protected by net_rwsem */ 430 #define for_each_net(VAR) \ 431 list_for_each_entry(VAR, &net_namespace_list, list) 432 #define for_each_net_continue_reverse(VAR) \ 433 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list) 434 #define for_each_net_rcu(VAR) \ 435 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 436 437 #ifdef CONFIG_NET_NS 438 #define __net_init 439 #define __net_exit 440 #define __net_initdata 441 #define __net_initconst 442 #else 443 #define __net_init __init 444 #define __net_exit __ref 445 #define __net_initdata __initdata 446 #define __net_initconst __initconst 447 #endif 448 449 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp); 450 int peernet2id(const struct net *net, struct net *peer); 451 bool peernet_has_id(const struct net *net, struct net *peer); 452 struct net *get_net_ns_by_id(const struct net *net, int id); 453 454 struct pernet_operations { 455 struct list_head list; 456 /* 457 * Below methods are called without any exclusive locks. 458 * More than one net may be constructed and destructed 459 * in parallel on several cpus. Every pernet_operations 460 * have to keep in mind all other pernet_operations and 461 * to introduce a locking, if they share common resources. 462 * 463 * The only time they are called with exclusive lock is 464 * from register_pernet_subsys(), unregister_pernet_subsys() 465 * register_pernet_device() and unregister_pernet_device(). 466 * 467 * Exit methods using blocking RCU primitives, such as 468 * synchronize_rcu(), should be implemented via exit_batch. 469 * Then, destruction of a group of net requires single 470 * synchronize_rcu() related to these pernet_operations, 471 * instead of separate synchronize_rcu() for every net. 472 * Please, avoid synchronize_rcu() at all, where it's possible. 473 * 474 * Note that a combination of pre_exit() and exit() can 475 * be used, since a synchronize_rcu() is guaranteed between 476 * the calls. 477 */ 478 int (*init)(struct net *net); 479 void (*pre_exit)(struct net *net); 480 void (*exit)(struct net *net); 481 void (*exit_batch)(struct list_head *net_exit_list); 482 /* Following method is called with RTNL held. */ 483 void (*exit_rtnl)(struct net *net, 484 struct list_head *dev_kill_list); 485 unsigned int * const id; 486 const size_t size; 487 }; 488 489 /* 490 * Use these carefully. If you implement a network device and it 491 * needs per network namespace operations use device pernet operations, 492 * otherwise use pernet subsys operations. 493 * 494 * Network interfaces need to be removed from a dying netns _before_ 495 * subsys notifiers can be called, as most of the network code cleanup 496 * (which is done from subsys notifiers) runs with the assumption that 497 * dev_remove_pack has been called so no new packets will arrive during 498 * and after the cleanup functions have been called. dev_remove_pack 499 * is not per namespace so instead the guarantee of no more packets 500 * arriving in a network namespace is provided by ensuring that all 501 * network devices and all sockets have left the network namespace 502 * before the cleanup methods are called. 503 * 504 * For the longest time the ipv4 icmp code was registered as a pernet 505 * device which caused kernel oops, and panics during network 506 * namespace cleanup. So please don't get this wrong. 507 */ 508 int register_pernet_subsys(struct pernet_operations *); 509 void unregister_pernet_subsys(struct pernet_operations *); 510 int register_pernet_device(struct pernet_operations *); 511 void unregister_pernet_device(struct pernet_operations *); 512 513 struct ctl_table; 514 515 #define register_net_sysctl(net, path, table) \ 516 register_net_sysctl_sz(net, path, table, ARRAY_SIZE(table)) 517 #ifdef CONFIG_SYSCTL 518 int net_sysctl_init(void); 519 struct ctl_table_header *register_net_sysctl_sz(struct net *net, const char *path, 520 struct ctl_table *table, size_t table_size); 521 void unregister_net_sysctl_table(struct ctl_table_header *header); 522 #else 523 static inline int net_sysctl_init(void) { return 0; } 524 static inline struct ctl_table_header *register_net_sysctl_sz(struct net *net, 525 const char *path, struct ctl_table *table, size_t table_size) 526 { 527 return NULL; 528 } 529 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 530 { 531 } 532 #endif 533 534 static inline int rt_genid_ipv4(const struct net *net) 535 { 536 return atomic_read(&net->ipv4.rt_genid); 537 } 538 539 #if IS_ENABLED(CONFIG_IPV6) 540 static inline int rt_genid_ipv6(const struct net *net) 541 { 542 return atomic_read(&net->ipv6.fib6_sernum); 543 } 544 #endif 545 546 static inline void rt_genid_bump_ipv4(struct net *net) 547 { 548 atomic_inc(&net->ipv4.rt_genid); 549 } 550 551 extern void (*__fib6_flush_trees)(struct net *net); 552 static inline void rt_genid_bump_ipv6(struct net *net) 553 { 554 if (__fib6_flush_trees) 555 __fib6_flush_trees(net); 556 } 557 558 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 559 static inline struct netns_ieee802154_lowpan * 560 net_ieee802154_lowpan(struct net *net) 561 { 562 return &net->ieee802154_lowpan; 563 } 564 #endif 565 566 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 567 static inline void rt_genid_bump_all(struct net *net) 568 { 569 rt_genid_bump_ipv4(net); 570 rt_genid_bump_ipv6(net); 571 } 572 573 static inline int fnhe_genid(const struct net *net) 574 { 575 return atomic_read(&net->fnhe_genid); 576 } 577 578 static inline void fnhe_genid_bump(struct net *net) 579 { 580 atomic_inc(&net->fnhe_genid); 581 } 582 583 #ifdef CONFIG_NET 584 void net_ns_init(void); 585 #else 586 static inline void net_ns_init(void) {} 587 #endif 588 589 #endif /* __NET_NET_NAMESPACE_H */ 590