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