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