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 #ifdef CONFIG_DEBUG_NET_SMALL_RTNL 192 /* Move to a better place when the config guard is removed. */ 193 struct mutex rtnl_mutex; 194 #endif 195 } __randomize_layout; 196 197 #include <linux/seq_file_net.h> 198 199 /* Init's network namespace */ 200 extern struct net init_net; 201 202 #ifdef CONFIG_NET_NS 203 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 204 struct net *old_net); 205 206 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 207 208 void net_ns_barrier(void); 209 210 struct ns_common *get_net_ns(struct ns_common *ns); 211 struct net *get_net_ns_by_fd(int fd); 212 #else /* CONFIG_NET_NS */ 213 #include <linux/sched.h> 214 #include <linux/nsproxy.h> 215 static inline struct net *copy_net_ns(unsigned long flags, 216 struct user_namespace *user_ns, struct net *old_net) 217 { 218 if (flags & CLONE_NEWNET) 219 return ERR_PTR(-EINVAL); 220 return old_net; 221 } 222 223 static inline void net_ns_get_ownership(const struct net *net, 224 kuid_t *uid, kgid_t *gid) 225 { 226 *uid = GLOBAL_ROOT_UID; 227 *gid = GLOBAL_ROOT_GID; 228 } 229 230 static inline void net_ns_barrier(void) {} 231 232 static inline struct ns_common *get_net_ns(struct ns_common *ns) 233 { 234 return ERR_PTR(-EINVAL); 235 } 236 237 static inline struct net *get_net_ns_by_fd(int fd) 238 { 239 return ERR_PTR(-EINVAL); 240 } 241 #endif /* CONFIG_NET_NS */ 242 243 244 extern struct list_head net_namespace_list; 245 246 struct net *get_net_ns_by_pid(pid_t pid); 247 248 #ifdef CONFIG_SYSCTL 249 void ipx_register_sysctl(void); 250 void ipx_unregister_sysctl(void); 251 #else 252 #define ipx_register_sysctl() 253 #define ipx_unregister_sysctl() 254 #endif 255 256 #ifdef CONFIG_NET_NS 257 void __put_net(struct net *net); 258 259 /* Try using get_net_track() instead */ 260 static inline struct net *get_net(struct net *net) 261 { 262 refcount_inc(&net->ns.count); 263 return net; 264 } 265 266 static inline struct net *maybe_get_net(struct net *net) 267 { 268 /* Used when we know struct net exists but we 269 * aren't guaranteed a previous reference count 270 * exists. If the reference count is zero this 271 * function fails and returns NULL. 272 */ 273 if (!refcount_inc_not_zero(&net->ns.count)) 274 net = NULL; 275 return net; 276 } 277 278 /* Try using put_net_track() instead */ 279 static inline void put_net(struct net *net) 280 { 281 if (refcount_dec_and_test(&net->ns.count)) 282 __put_net(net); 283 } 284 285 static inline 286 int net_eq(const struct net *net1, const struct net *net2) 287 { 288 return net1 == net2; 289 } 290 291 static inline int check_net(const struct net *net) 292 { 293 return refcount_read(&net->ns.count) != 0; 294 } 295 296 void net_drop_ns(void *); 297 298 #else 299 300 static inline struct net *get_net(struct net *net) 301 { 302 return net; 303 } 304 305 static inline void put_net(struct net *net) 306 { 307 } 308 309 static inline struct net *maybe_get_net(struct net *net) 310 { 311 return net; 312 } 313 314 static inline 315 int net_eq(const struct net *net1, const struct net *net2) 316 { 317 return 1; 318 } 319 320 static inline int check_net(const struct net *net) 321 { 322 return 1; 323 } 324 325 #define net_drop_ns NULL 326 #endif 327 328 329 static inline void __netns_tracker_alloc(struct net *net, 330 netns_tracker *tracker, 331 bool refcounted, 332 gfp_t gfp) 333 { 334 #ifdef CONFIG_NET_NS_REFCNT_TRACKER 335 ref_tracker_alloc(refcounted ? &net->refcnt_tracker : 336 &net->notrefcnt_tracker, 337 tracker, gfp); 338 #endif 339 } 340 341 static inline void netns_tracker_alloc(struct net *net, netns_tracker *tracker, 342 gfp_t gfp) 343 { 344 __netns_tracker_alloc(net, tracker, true, gfp); 345 } 346 347 static inline void __netns_tracker_free(struct net *net, 348 netns_tracker *tracker, 349 bool refcounted) 350 { 351 #ifdef CONFIG_NET_NS_REFCNT_TRACKER 352 ref_tracker_free(refcounted ? &net->refcnt_tracker : 353 &net->notrefcnt_tracker, tracker); 354 #endif 355 } 356 357 static inline struct net *get_net_track(struct net *net, 358 netns_tracker *tracker, gfp_t gfp) 359 { 360 get_net(net); 361 netns_tracker_alloc(net, tracker, gfp); 362 return net; 363 } 364 365 static inline void put_net_track(struct net *net, netns_tracker *tracker) 366 { 367 __netns_tracker_free(net, tracker, true); 368 put_net(net); 369 } 370 371 typedef struct { 372 #ifdef CONFIG_NET_NS 373 struct net __rcu *net; 374 #endif 375 } possible_net_t; 376 377 static inline void write_pnet(possible_net_t *pnet, struct net *net) 378 { 379 #ifdef CONFIG_NET_NS 380 rcu_assign_pointer(pnet->net, net); 381 #endif 382 } 383 384 static inline struct net *read_pnet(const possible_net_t *pnet) 385 { 386 #ifdef CONFIG_NET_NS 387 return rcu_dereference_protected(pnet->net, true); 388 #else 389 return &init_net; 390 #endif 391 } 392 393 static inline struct net *read_pnet_rcu(possible_net_t *pnet) 394 { 395 #ifdef CONFIG_NET_NS 396 return rcu_dereference(pnet->net); 397 #else 398 return &init_net; 399 #endif 400 } 401 402 /* Protected by net_rwsem */ 403 #define for_each_net(VAR) \ 404 list_for_each_entry(VAR, &net_namespace_list, list) 405 #define for_each_net_continue_reverse(VAR) \ 406 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list) 407 #define for_each_net_rcu(VAR) \ 408 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 409 410 #ifdef CONFIG_NET_NS 411 #define __net_init 412 #define __net_exit 413 #define __net_initdata 414 #define __net_initconst 415 #else 416 #define __net_init __init 417 #define __net_exit __ref 418 #define __net_initdata __initdata 419 #define __net_initconst __initconst 420 #endif 421 422 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp); 423 int peernet2id(const struct net *net, struct net *peer); 424 bool peernet_has_id(const struct net *net, struct net *peer); 425 struct net *get_net_ns_by_id(const struct net *net, int id); 426 427 struct pernet_operations { 428 struct list_head list; 429 /* 430 * Below methods are called without any exclusive locks. 431 * More than one net may be constructed and destructed 432 * in parallel on several cpus. Every pernet_operations 433 * have to keep in mind all other pernet_operations and 434 * to introduce a locking, if they share common resources. 435 * 436 * The only time they are called with exclusive lock is 437 * from register_pernet_subsys(), unregister_pernet_subsys() 438 * register_pernet_device() and unregister_pernet_device(). 439 * 440 * Exit methods using blocking RCU primitives, such as 441 * synchronize_rcu(), should be implemented via exit_batch. 442 * Then, destruction of a group of net requires single 443 * synchronize_rcu() related to these pernet_operations, 444 * instead of separate synchronize_rcu() for every net. 445 * Please, avoid synchronize_rcu() at all, where it's possible. 446 * 447 * Note that a combination of pre_exit() and exit() can 448 * be used, since a synchronize_rcu() is guaranteed between 449 * the calls. 450 */ 451 int (*init)(struct net *net); 452 void (*pre_exit)(struct net *net); 453 void (*exit)(struct net *net); 454 void (*exit_batch)(struct list_head *net_exit_list); 455 /* Following method is called with RTNL held. */ 456 void (*exit_batch_rtnl)(struct list_head *net_exit_list, 457 struct list_head *dev_kill_list); 458 unsigned int * const id; 459 const size_t size; 460 }; 461 462 /* 463 * Use these carefully. If you implement a network device and it 464 * needs per network namespace operations use device pernet operations, 465 * otherwise use pernet subsys operations. 466 * 467 * Network interfaces need to be removed from a dying netns _before_ 468 * subsys notifiers can be called, as most of the network code cleanup 469 * (which is done from subsys notifiers) runs with the assumption that 470 * dev_remove_pack has been called so no new packets will arrive during 471 * and after the cleanup functions have been called. dev_remove_pack 472 * is not per namespace so instead the guarantee of no more packets 473 * arriving in a network namespace is provided by ensuring that all 474 * network devices and all sockets have left the network namespace 475 * before the cleanup methods are called. 476 * 477 * For the longest time the ipv4 icmp code was registered as a pernet 478 * device which caused kernel oops, and panics during network 479 * namespace cleanup. So please don't get this wrong. 480 */ 481 int register_pernet_subsys(struct pernet_operations *); 482 void unregister_pernet_subsys(struct pernet_operations *); 483 int register_pernet_device(struct pernet_operations *); 484 void unregister_pernet_device(struct pernet_operations *); 485 486 struct ctl_table; 487 488 #define register_net_sysctl(net, path, table) \ 489 register_net_sysctl_sz(net, path, table, ARRAY_SIZE(table)) 490 #ifdef CONFIG_SYSCTL 491 int net_sysctl_init(void); 492 struct ctl_table_header *register_net_sysctl_sz(struct net *net, const char *path, 493 struct ctl_table *table, size_t table_size); 494 void unregister_net_sysctl_table(struct ctl_table_header *header); 495 #else 496 static inline int net_sysctl_init(void) { return 0; } 497 static inline struct ctl_table_header *register_net_sysctl_sz(struct net *net, 498 const char *path, struct ctl_table *table, size_t table_size) 499 { 500 return NULL; 501 } 502 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 503 { 504 } 505 #endif 506 507 static inline int rt_genid_ipv4(const struct net *net) 508 { 509 return atomic_read(&net->ipv4.rt_genid); 510 } 511 512 #if IS_ENABLED(CONFIG_IPV6) 513 static inline int rt_genid_ipv6(const struct net *net) 514 { 515 return atomic_read(&net->ipv6.fib6_sernum); 516 } 517 #endif 518 519 static inline void rt_genid_bump_ipv4(struct net *net) 520 { 521 atomic_inc(&net->ipv4.rt_genid); 522 } 523 524 extern void (*__fib6_flush_trees)(struct net *net); 525 static inline void rt_genid_bump_ipv6(struct net *net) 526 { 527 if (__fib6_flush_trees) 528 __fib6_flush_trees(net); 529 } 530 531 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 532 static inline struct netns_ieee802154_lowpan * 533 net_ieee802154_lowpan(struct net *net) 534 { 535 return &net->ieee802154_lowpan; 536 } 537 #endif 538 539 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 540 static inline void rt_genid_bump_all(struct net *net) 541 { 542 rt_genid_bump_ipv4(net); 543 rt_genid_bump_ipv6(net); 544 } 545 546 static inline int fnhe_genid(const struct net *net) 547 { 548 return atomic_read(&net->fnhe_genid); 549 } 550 551 static inline void fnhe_genid_bump(struct net *net) 552 { 553 atomic_inc(&net->fnhe_genid); 554 } 555 556 #ifdef CONFIG_NET 557 void net_ns_init(void); 558 #else 559 static inline void net_ns_init(void) {} 560 #endif 561 562 #endif /* __NET_NET_NAMESPACE_H */ 563