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 46 struct user_namespace; 47 struct proc_dir_entry; 48 struct net_device; 49 struct sock; 50 struct ctl_table_header; 51 struct net_generic; 52 struct uevent_sock; 53 struct netns_ipvs; 54 struct bpf_prog; 55 56 57 #define NETDEV_HASHBITS 8 58 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 59 60 struct net { 61 /* First cache line can be often dirtied. 62 * Do not place here read-mostly fields. 63 */ 64 refcount_t passive; /* To decide when the network 65 * namespace should be freed. 66 */ 67 spinlock_t rules_mod_lock; 68 69 atomic_t dev_unreg_count; 70 71 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 72 int ifindex; 73 74 spinlock_t nsid_lock; 75 atomic_t fnhe_genid; 76 77 struct list_head list; /* list of network namespaces */ 78 struct list_head exit_list; /* To linked to call pernet exit 79 * methods on dead net ( 80 * pernet_ops_rwsem read locked), 81 * or to unregister pernet ops 82 * (pernet_ops_rwsem write locked). 83 */ 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 96 struct list_head dev_base_head; 97 struct proc_dir_entry *proc_net; 98 struct proc_dir_entry *proc_net_stat; 99 100 #ifdef CONFIG_SYSCTL 101 struct ctl_table_set sysctls; 102 #endif 103 104 struct sock *rtnl; /* rtnetlink socket */ 105 struct sock *genl_sock; 106 107 struct uevent_sock *uevent_sock; /* uevent socket */ 108 109 struct hlist_head *dev_name_head; 110 struct hlist_head *dev_index_head; 111 struct raw_notifier_head netdev_chain; 112 113 /* Note that @hash_mix can be read millions times per second, 114 * it is critical that it is on a read_mostly cache line. 115 */ 116 u32 hash_mix; 117 118 struct net_device *loopback_dev; /* The loopback */ 119 120 /* core fib_rules */ 121 struct list_head rules_ops; 122 123 struct netns_core core; 124 struct netns_mib mib; 125 struct netns_packet packet; 126 #if IS_ENABLED(CONFIG_UNIX) 127 struct netns_unix unx; 128 #endif 129 struct netns_nexthop nexthop; 130 struct netns_ipv4 ipv4; 131 #if IS_ENABLED(CONFIG_IPV6) 132 struct netns_ipv6 ipv6; 133 #endif 134 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 135 struct netns_ieee802154_lowpan ieee802154_lowpan; 136 #endif 137 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 138 struct netns_sctp sctp; 139 #endif 140 #ifdef CONFIG_NETFILTER 141 struct netns_nf nf; 142 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 143 struct netns_ct ct; 144 #endif 145 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 146 struct netns_nftables nft; 147 #endif 148 #if IS_ENABLED(CONFIG_NF_FLOW_TABLE) 149 struct netns_ft ft; 150 #endif 151 #endif 152 #ifdef CONFIG_WEXT_CORE 153 struct sk_buff_head wext_nlevents; 154 #endif 155 struct net_generic __rcu *gen; 156 157 /* Used to store attached BPF programs */ 158 struct netns_bpf bpf; 159 160 /* Note : following structs are cache line aligned */ 161 #ifdef CONFIG_XFRM 162 struct netns_xfrm xfrm; 163 #endif 164 165 u64 net_cookie; /* written once */ 166 167 #if IS_ENABLED(CONFIG_IP_VS) 168 struct netns_ipvs *ipvs; 169 #endif 170 #if IS_ENABLED(CONFIG_MPLS) 171 struct netns_mpls mpls; 172 #endif 173 #if IS_ENABLED(CONFIG_CAN) 174 struct netns_can can; 175 #endif 176 #ifdef CONFIG_XDP_SOCKETS 177 struct netns_xdp xdp; 178 #endif 179 #if IS_ENABLED(CONFIG_MCTP) 180 struct netns_mctp mctp; 181 #endif 182 #if IS_ENABLED(CONFIG_CRYPTO_USER) 183 struct sock *crypto_nlsk; 184 #endif 185 struct sock *diag_nlsk; 186 #if IS_ENABLED(CONFIG_SMC) 187 struct netns_smc smc; 188 #endif 189 } __randomize_layout; 190 191 #include <linux/seq_file_net.h> 192 193 /* Init's network namespace */ 194 extern struct net init_net; 195 196 #ifdef CONFIG_NET_NS 197 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 198 struct net *old_net); 199 200 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 201 202 void net_ns_barrier(void); 203 204 struct ns_common *get_net_ns(struct ns_common *ns); 205 struct net *get_net_ns_by_fd(int fd); 206 #else /* CONFIG_NET_NS */ 207 #include <linux/sched.h> 208 #include <linux/nsproxy.h> 209 static inline struct net *copy_net_ns(unsigned long flags, 210 struct user_namespace *user_ns, struct net *old_net) 211 { 212 if (flags & CLONE_NEWNET) 213 return ERR_PTR(-EINVAL); 214 return old_net; 215 } 216 217 static inline void net_ns_get_ownership(const struct net *net, 218 kuid_t *uid, kgid_t *gid) 219 { 220 *uid = GLOBAL_ROOT_UID; 221 *gid = GLOBAL_ROOT_GID; 222 } 223 224 static inline void net_ns_barrier(void) {} 225 226 static inline struct ns_common *get_net_ns(struct ns_common *ns) 227 { 228 return ERR_PTR(-EINVAL); 229 } 230 231 static inline struct net *get_net_ns_by_fd(int fd) 232 { 233 return ERR_PTR(-EINVAL); 234 } 235 #endif /* CONFIG_NET_NS */ 236 237 238 extern struct list_head net_namespace_list; 239 240 struct net *get_net_ns_by_pid(pid_t pid); 241 242 #ifdef CONFIG_SYSCTL 243 void ipx_register_sysctl(void); 244 void ipx_unregister_sysctl(void); 245 #else 246 #define ipx_register_sysctl() 247 #define ipx_unregister_sysctl() 248 #endif 249 250 #ifdef CONFIG_NET_NS 251 void __put_net(struct net *net); 252 253 /* Try using get_net_track() instead */ 254 static inline struct net *get_net(struct net *net) 255 { 256 refcount_inc(&net->ns.count); 257 return net; 258 } 259 260 static inline struct net *maybe_get_net(struct net *net) 261 { 262 /* Used when we know struct net exists but we 263 * aren't guaranteed a previous reference count 264 * exists. If the reference count is zero this 265 * function fails and returns NULL. 266 */ 267 if (!refcount_inc_not_zero(&net->ns.count)) 268 net = NULL; 269 return net; 270 } 271 272 /* Try using put_net_track() instead */ 273 static inline void put_net(struct net *net) 274 { 275 if (refcount_dec_and_test(&net->ns.count)) 276 __put_net(net); 277 } 278 279 static inline 280 int net_eq(const struct net *net1, const struct net *net2) 281 { 282 return net1 == net2; 283 } 284 285 static inline int check_net(const struct net *net) 286 { 287 return refcount_read(&net->ns.count) != 0; 288 } 289 290 void net_drop_ns(void *); 291 292 #else 293 294 static inline struct net *get_net(struct net *net) 295 { 296 return net; 297 } 298 299 static inline void put_net(struct net *net) 300 { 301 } 302 303 static inline struct net *maybe_get_net(struct net *net) 304 { 305 return net; 306 } 307 308 static inline 309 int net_eq(const struct net *net1, const struct net *net2) 310 { 311 return 1; 312 } 313 314 static inline int check_net(const struct net *net) 315 { 316 return 1; 317 } 318 319 #define net_drop_ns NULL 320 #endif 321 322 323 static inline void netns_tracker_alloc(struct net *net, 324 netns_tracker *tracker, gfp_t gfp) 325 { 326 #ifdef CONFIG_NET_NS_REFCNT_TRACKER 327 ref_tracker_alloc(&net->refcnt_tracker, tracker, gfp); 328 #endif 329 } 330 331 static inline void netns_tracker_free(struct net *net, 332 netns_tracker *tracker) 333 { 334 #ifdef CONFIG_NET_NS_REFCNT_TRACKER 335 ref_tracker_free(&net->refcnt_tracker, tracker); 336 #endif 337 } 338 339 static inline struct net *get_net_track(struct net *net, 340 netns_tracker *tracker, gfp_t gfp) 341 { 342 get_net(net); 343 netns_tracker_alloc(net, tracker, gfp); 344 return net; 345 } 346 347 static inline void put_net_track(struct net *net, netns_tracker *tracker) 348 { 349 netns_tracker_free(net, tracker); 350 put_net(net); 351 } 352 353 typedef struct { 354 #ifdef CONFIG_NET_NS 355 struct net *net; 356 #endif 357 } possible_net_t; 358 359 static inline void write_pnet(possible_net_t *pnet, struct net *net) 360 { 361 #ifdef CONFIG_NET_NS 362 pnet->net = net; 363 #endif 364 } 365 366 static inline struct net *read_pnet(const possible_net_t *pnet) 367 { 368 #ifdef CONFIG_NET_NS 369 return pnet->net; 370 #else 371 return &init_net; 372 #endif 373 } 374 375 /* Protected by net_rwsem */ 376 #define for_each_net(VAR) \ 377 list_for_each_entry(VAR, &net_namespace_list, list) 378 #define for_each_net_continue_reverse(VAR) \ 379 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list) 380 #define for_each_net_rcu(VAR) \ 381 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 382 383 #ifdef CONFIG_NET_NS 384 #define __net_init 385 #define __net_exit 386 #define __net_initdata 387 #define __net_initconst 388 #else 389 #define __net_init __init 390 #define __net_exit __ref 391 #define __net_initdata __initdata 392 #define __net_initconst __initconst 393 #endif 394 395 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp); 396 int peernet2id(const struct net *net, struct net *peer); 397 bool peernet_has_id(const struct net *net, struct net *peer); 398 struct net *get_net_ns_by_id(const struct net *net, int id); 399 400 struct pernet_operations { 401 struct list_head list; 402 /* 403 * Below methods are called without any exclusive locks. 404 * More than one net may be constructed and destructed 405 * in parallel on several cpus. Every pernet_operations 406 * have to keep in mind all other pernet_operations and 407 * to introduce a locking, if they share common resources. 408 * 409 * The only time they are called with exclusive lock is 410 * from register_pernet_subsys(), unregister_pernet_subsys() 411 * register_pernet_device() and unregister_pernet_device(). 412 * 413 * Exit methods using blocking RCU primitives, such as 414 * synchronize_rcu(), should be implemented via exit_batch. 415 * Then, destruction of a group of net requires single 416 * synchronize_rcu() related to these pernet_operations, 417 * instead of separate synchronize_rcu() for every net. 418 * Please, avoid synchronize_rcu() at all, where it's possible. 419 * 420 * Note that a combination of pre_exit() and exit() can 421 * be used, since a synchronize_rcu() is guaranteed between 422 * the calls. 423 */ 424 int (*init)(struct net *net); 425 void (*pre_exit)(struct net *net); 426 void (*exit)(struct net *net); 427 void (*exit_batch)(struct list_head *net_exit_list); 428 unsigned int *id; 429 size_t size; 430 }; 431 432 /* 433 * Use these carefully. If you implement a network device and it 434 * needs per network namespace operations use device pernet operations, 435 * otherwise use pernet subsys operations. 436 * 437 * Network interfaces need to be removed from a dying netns _before_ 438 * subsys notifiers can be called, as most of the network code cleanup 439 * (which is done from subsys notifiers) runs with the assumption that 440 * dev_remove_pack has been called so no new packets will arrive during 441 * and after the cleanup functions have been called. dev_remove_pack 442 * is not per namespace so instead the guarantee of no more packets 443 * arriving in a network namespace is provided by ensuring that all 444 * network devices and all sockets have left the network namespace 445 * before the cleanup methods are called. 446 * 447 * For the longest time the ipv4 icmp code was registered as a pernet 448 * device which caused kernel oops, and panics during network 449 * namespace cleanup. So please don't get this wrong. 450 */ 451 int register_pernet_subsys(struct pernet_operations *); 452 void unregister_pernet_subsys(struct pernet_operations *); 453 int register_pernet_device(struct pernet_operations *); 454 void unregister_pernet_device(struct pernet_operations *); 455 456 struct ctl_table; 457 458 #ifdef CONFIG_SYSCTL 459 int net_sysctl_init(void); 460 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 461 struct ctl_table *table); 462 void unregister_net_sysctl_table(struct ctl_table_header *header); 463 #else 464 static inline int net_sysctl_init(void) { return 0; } 465 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 466 const char *path, struct ctl_table *table) 467 { 468 return NULL; 469 } 470 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 471 { 472 } 473 #endif 474 475 static inline int rt_genid_ipv4(const struct net *net) 476 { 477 return atomic_read(&net->ipv4.rt_genid); 478 } 479 480 #if IS_ENABLED(CONFIG_IPV6) 481 static inline int rt_genid_ipv6(const struct net *net) 482 { 483 return atomic_read(&net->ipv6.fib6_sernum); 484 } 485 #endif 486 487 static inline void rt_genid_bump_ipv4(struct net *net) 488 { 489 atomic_inc(&net->ipv4.rt_genid); 490 } 491 492 extern void (*__fib6_flush_trees)(struct net *net); 493 static inline void rt_genid_bump_ipv6(struct net *net) 494 { 495 if (__fib6_flush_trees) 496 __fib6_flush_trees(net); 497 } 498 499 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 500 static inline struct netns_ieee802154_lowpan * 501 net_ieee802154_lowpan(struct net *net) 502 { 503 return &net->ieee802154_lowpan; 504 } 505 #endif 506 507 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 508 static inline void rt_genid_bump_all(struct net *net) 509 { 510 rt_genid_bump_ipv4(net); 511 rt_genid_bump_ipv6(net); 512 } 513 514 static inline int fnhe_genid(const struct net *net) 515 { 516 return atomic_read(&net->fnhe_genid); 517 } 518 519 static inline void fnhe_genid_bump(struct net *net) 520 { 521 atomic_inc(&net->fnhe_genid); 522 } 523 524 #ifdef CONFIG_NET 525 void net_ns_init(void); 526 #else 527 static inline void net_ns_init(void) {} 528 #endif 529 530 #endif /* __NET_NET_NAMESPACE_H */ 531