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 #include <net/netns/nftables.h> 30 #include <net/netns/xfrm.h> 31 #include <net/netns/mpls.h> 32 #include <net/netns/can.h> 33 #include <net/netns/xdp.h> 34 #include <net/netns/smc.h> 35 #include <net/netns/bpf.h> 36 #include <net/netns/mctp.h> 37 #include <net/net_trackers.h> 38 #include <linux/ns_common.h> 39 #include <linux/idr.h> 40 #include <linux/skbuff.h> 41 #include <linux/notifier.h> 42 43 struct user_namespace; 44 struct proc_dir_entry; 45 struct net_device; 46 struct sock; 47 struct ctl_table_header; 48 struct net_generic; 49 struct uevent_sock; 50 struct netns_ipvs; 51 struct bpf_prog; 52 53 54 #define NETDEV_HASHBITS 8 55 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 56 57 struct net { 58 /* First cache line can be often dirtied. 59 * Do not place here read-mostly fields. 60 */ 61 refcount_t passive; /* To decide when the network 62 * namespace should be freed. 63 */ 64 spinlock_t rules_mod_lock; 65 66 atomic_t dev_unreg_count; 67 68 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 69 int ifindex; 70 71 spinlock_t nsid_lock; 72 atomic_t fnhe_genid; 73 74 struct list_head list; /* list of network namespaces */ 75 struct list_head exit_list; /* To linked to call pernet exit 76 * methods on dead net ( 77 * pernet_ops_rwsem read locked), 78 * or to unregister pernet ops 79 * (pernet_ops_rwsem write locked). 80 */ 81 struct llist_node cleanup_list; /* namespaces on death row */ 82 83 #ifdef CONFIG_KEYS 84 struct key_tag *key_domain; /* Key domain of operation tag */ 85 #endif 86 struct user_namespace *user_ns; /* Owning user namespace */ 87 struct ucounts *ucounts; 88 struct idr netns_ids; 89 90 struct ns_common ns; 91 struct ref_tracker_dir refcnt_tracker; 92 93 struct list_head dev_base_head; 94 struct proc_dir_entry *proc_net; 95 struct proc_dir_entry *proc_net_stat; 96 97 #ifdef CONFIG_SYSCTL 98 struct ctl_table_set sysctls; 99 #endif 100 101 struct sock *rtnl; /* rtnetlink socket */ 102 struct sock *genl_sock; 103 104 struct uevent_sock *uevent_sock; /* uevent socket */ 105 106 struct hlist_head *dev_name_head; 107 struct hlist_head *dev_index_head; 108 struct raw_notifier_head netdev_chain; 109 110 /* Note that @hash_mix can be read millions times per second, 111 * it is critical that it is on a read_mostly cache line. 112 */ 113 u32 hash_mix; 114 115 struct net_device *loopback_dev; /* The loopback */ 116 117 /* core fib_rules */ 118 struct list_head rules_ops; 119 120 struct netns_core core; 121 struct netns_mib mib; 122 struct netns_packet packet; 123 #if IS_ENABLED(CONFIG_UNIX) 124 struct netns_unix unx; 125 #endif 126 struct netns_nexthop nexthop; 127 struct netns_ipv4 ipv4; 128 #if IS_ENABLED(CONFIG_IPV6) 129 struct netns_ipv6 ipv6; 130 #endif 131 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 132 struct netns_ieee802154_lowpan ieee802154_lowpan; 133 #endif 134 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 135 struct netns_sctp sctp; 136 #endif 137 #ifdef CONFIG_NETFILTER 138 struct netns_nf nf; 139 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 140 struct netns_ct ct; 141 #endif 142 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 143 struct netns_nftables nft; 144 #endif 145 #endif 146 #ifdef CONFIG_WEXT_CORE 147 struct sk_buff_head wext_nlevents; 148 #endif 149 struct net_generic __rcu *gen; 150 151 /* Used to store attached BPF programs */ 152 struct netns_bpf bpf; 153 154 /* Note : following structs are cache line aligned */ 155 #ifdef CONFIG_XFRM 156 struct netns_xfrm xfrm; 157 #endif 158 159 u64 net_cookie; /* written once */ 160 161 #if IS_ENABLED(CONFIG_IP_VS) 162 struct netns_ipvs *ipvs; 163 #endif 164 #if IS_ENABLED(CONFIG_MPLS) 165 struct netns_mpls mpls; 166 #endif 167 #if IS_ENABLED(CONFIG_CAN) 168 struct netns_can can; 169 #endif 170 #ifdef CONFIG_XDP_SOCKETS 171 struct netns_xdp xdp; 172 #endif 173 #if IS_ENABLED(CONFIG_MCTP) 174 struct netns_mctp mctp; 175 #endif 176 #if IS_ENABLED(CONFIG_CRYPTO_USER) 177 struct sock *crypto_nlsk; 178 #endif 179 struct sock *diag_nlsk; 180 #if IS_ENABLED(CONFIG_SMC) 181 struct netns_smc smc; 182 #endif 183 } __randomize_layout; 184 185 #include <linux/seq_file_net.h> 186 187 /* Init's network namespace */ 188 extern struct net init_net; 189 190 #ifdef CONFIG_NET_NS 191 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 192 struct net *old_net); 193 194 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 195 196 void net_ns_barrier(void); 197 198 struct ns_common *get_net_ns(struct ns_common *ns); 199 struct net *get_net_ns_by_fd(int fd); 200 #else /* CONFIG_NET_NS */ 201 #include <linux/sched.h> 202 #include <linux/nsproxy.h> 203 static inline struct net *copy_net_ns(unsigned long flags, 204 struct user_namespace *user_ns, struct net *old_net) 205 { 206 if (flags & CLONE_NEWNET) 207 return ERR_PTR(-EINVAL); 208 return old_net; 209 } 210 211 static inline void net_ns_get_ownership(const struct net *net, 212 kuid_t *uid, kgid_t *gid) 213 { 214 *uid = GLOBAL_ROOT_UID; 215 *gid = GLOBAL_ROOT_GID; 216 } 217 218 static inline void net_ns_barrier(void) {} 219 220 static inline struct ns_common *get_net_ns(struct ns_common *ns) 221 { 222 return ERR_PTR(-EINVAL); 223 } 224 225 static inline struct net *get_net_ns_by_fd(int fd) 226 { 227 return ERR_PTR(-EINVAL); 228 } 229 #endif /* CONFIG_NET_NS */ 230 231 232 extern struct list_head net_namespace_list; 233 234 struct net *get_net_ns_by_pid(pid_t pid); 235 236 #ifdef CONFIG_SYSCTL 237 void ipx_register_sysctl(void); 238 void ipx_unregister_sysctl(void); 239 #else 240 #define ipx_register_sysctl() 241 #define ipx_unregister_sysctl() 242 #endif 243 244 #ifdef CONFIG_NET_NS 245 void __put_net(struct net *net); 246 247 /* Try using get_net_track() instead */ 248 static inline struct net *get_net(struct net *net) 249 { 250 refcount_inc(&net->ns.count); 251 return net; 252 } 253 254 static inline struct net *maybe_get_net(struct net *net) 255 { 256 /* Used when we know struct net exists but we 257 * aren't guaranteed a previous reference count 258 * exists. If the reference count is zero this 259 * function fails and returns NULL. 260 */ 261 if (!refcount_inc_not_zero(&net->ns.count)) 262 net = NULL; 263 return net; 264 } 265 266 /* Try using put_net_track() instead */ 267 static inline void put_net(struct net *net) 268 { 269 if (refcount_dec_and_test(&net->ns.count)) 270 __put_net(net); 271 } 272 273 static inline 274 int net_eq(const struct net *net1, const struct net *net2) 275 { 276 return net1 == net2; 277 } 278 279 static inline int check_net(const struct net *net) 280 { 281 return refcount_read(&net->ns.count) != 0; 282 } 283 284 void net_drop_ns(void *); 285 286 #else 287 288 static inline struct net *get_net(struct net *net) 289 { 290 return net; 291 } 292 293 static inline void put_net(struct net *net) 294 { 295 } 296 297 static inline struct net *maybe_get_net(struct net *net) 298 { 299 return net; 300 } 301 302 static inline 303 int net_eq(const struct net *net1, const struct net *net2) 304 { 305 return 1; 306 } 307 308 static inline int check_net(const struct net *net) 309 { 310 return 1; 311 } 312 313 #define net_drop_ns NULL 314 #endif 315 316 317 static inline void netns_tracker_alloc(struct net *net, 318 netns_tracker *tracker, gfp_t gfp) 319 { 320 #ifdef CONFIG_NET_NS_REFCNT_TRACKER 321 ref_tracker_alloc(&net->refcnt_tracker, tracker, gfp); 322 #endif 323 } 324 325 static inline void netns_tracker_free(struct net *net, 326 netns_tracker *tracker) 327 { 328 #ifdef CONFIG_NET_NS_REFCNT_TRACKER 329 ref_tracker_free(&net->refcnt_tracker, tracker); 330 #endif 331 } 332 333 static inline struct net *get_net_track(struct net *net, 334 netns_tracker *tracker, gfp_t gfp) 335 { 336 get_net(net); 337 netns_tracker_alloc(net, tracker, gfp); 338 return net; 339 } 340 341 static inline void put_net_track(struct net *net, netns_tracker *tracker) 342 { 343 netns_tracker_free(net, tracker); 344 put_net(net); 345 } 346 347 typedef struct { 348 #ifdef CONFIG_NET_NS 349 struct net *net; 350 #endif 351 } possible_net_t; 352 353 static inline void write_pnet(possible_net_t *pnet, struct net *net) 354 { 355 #ifdef CONFIG_NET_NS 356 pnet->net = net; 357 #endif 358 } 359 360 static inline struct net *read_pnet(const possible_net_t *pnet) 361 { 362 #ifdef CONFIG_NET_NS 363 return pnet->net; 364 #else 365 return &init_net; 366 #endif 367 } 368 369 /* Protected by net_rwsem */ 370 #define for_each_net(VAR) \ 371 list_for_each_entry(VAR, &net_namespace_list, list) 372 #define for_each_net_continue_reverse(VAR) \ 373 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list) 374 #define for_each_net_rcu(VAR) \ 375 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 376 377 #ifdef CONFIG_NET_NS 378 #define __net_init 379 #define __net_exit 380 #define __net_initdata 381 #define __net_initconst 382 #else 383 #define __net_init __init 384 #define __net_exit __ref 385 #define __net_initdata __initdata 386 #define __net_initconst __initconst 387 #endif 388 389 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp); 390 int peernet2id(const struct net *net, struct net *peer); 391 bool peernet_has_id(const struct net *net, struct net *peer); 392 struct net *get_net_ns_by_id(const struct net *net, int id); 393 394 struct pernet_operations { 395 struct list_head list; 396 /* 397 * Below methods are called without any exclusive locks. 398 * More than one net may be constructed and destructed 399 * in parallel on several cpus. Every pernet_operations 400 * have to keep in mind all other pernet_operations and 401 * to introduce a locking, if they share common resources. 402 * 403 * The only time they are called with exclusive lock is 404 * from register_pernet_subsys(), unregister_pernet_subsys() 405 * register_pernet_device() and unregister_pernet_device(). 406 * 407 * Exit methods using blocking RCU primitives, such as 408 * synchronize_rcu(), should be implemented via exit_batch. 409 * Then, destruction of a group of net requires single 410 * synchronize_rcu() related to these pernet_operations, 411 * instead of separate synchronize_rcu() for every net. 412 * Please, avoid synchronize_rcu() at all, where it's possible. 413 * 414 * Note that a combination of pre_exit() and exit() can 415 * be used, since a synchronize_rcu() is guaranteed between 416 * the calls. 417 */ 418 int (*init)(struct net *net); 419 void (*pre_exit)(struct net *net); 420 void (*exit)(struct net *net); 421 void (*exit_batch)(struct list_head *net_exit_list); 422 unsigned int *id; 423 size_t size; 424 }; 425 426 /* 427 * Use these carefully. If you implement a network device and it 428 * needs per network namespace operations use device pernet operations, 429 * otherwise use pernet subsys operations. 430 * 431 * Network interfaces need to be removed from a dying netns _before_ 432 * subsys notifiers can be called, as most of the network code cleanup 433 * (which is done from subsys notifiers) runs with the assumption that 434 * dev_remove_pack has been called so no new packets will arrive during 435 * and after the cleanup functions have been called. dev_remove_pack 436 * is not per namespace so instead the guarantee of no more packets 437 * arriving in a network namespace is provided by ensuring that all 438 * network devices and all sockets have left the network namespace 439 * before the cleanup methods are called. 440 * 441 * For the longest time the ipv4 icmp code was registered as a pernet 442 * device which caused kernel oops, and panics during network 443 * namespace cleanup. So please don't get this wrong. 444 */ 445 int register_pernet_subsys(struct pernet_operations *); 446 void unregister_pernet_subsys(struct pernet_operations *); 447 int register_pernet_device(struct pernet_operations *); 448 void unregister_pernet_device(struct pernet_operations *); 449 450 struct ctl_table; 451 452 #ifdef CONFIG_SYSCTL 453 int net_sysctl_init(void); 454 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 455 struct ctl_table *table); 456 void unregister_net_sysctl_table(struct ctl_table_header *header); 457 #else 458 static inline int net_sysctl_init(void) { return 0; } 459 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 460 const char *path, struct ctl_table *table) 461 { 462 return NULL; 463 } 464 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 465 { 466 } 467 #endif 468 469 static inline int rt_genid_ipv4(const struct net *net) 470 { 471 return atomic_read(&net->ipv4.rt_genid); 472 } 473 474 #if IS_ENABLED(CONFIG_IPV6) 475 static inline int rt_genid_ipv6(const struct net *net) 476 { 477 return atomic_read(&net->ipv6.fib6_sernum); 478 } 479 #endif 480 481 static inline void rt_genid_bump_ipv4(struct net *net) 482 { 483 atomic_inc(&net->ipv4.rt_genid); 484 } 485 486 extern void (*__fib6_flush_trees)(struct net *net); 487 static inline void rt_genid_bump_ipv6(struct net *net) 488 { 489 if (__fib6_flush_trees) 490 __fib6_flush_trees(net); 491 } 492 493 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 494 static inline struct netns_ieee802154_lowpan * 495 net_ieee802154_lowpan(struct net *net) 496 { 497 return &net->ieee802154_lowpan; 498 } 499 #endif 500 501 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 502 static inline void rt_genid_bump_all(struct net *net) 503 { 504 rt_genid_bump_ipv4(net); 505 rt_genid_bump_ipv6(net); 506 } 507 508 static inline int fnhe_genid(const struct net *net) 509 { 510 return atomic_read(&net->fnhe_genid); 511 } 512 513 static inline void fnhe_genid_bump(struct net *net) 514 { 515 atomic_inc(&net->fnhe_genid); 516 } 517 518 #ifdef CONFIG_NET 519 void net_ns_init(void); 520 #else 521 static inline void net_ns_init(void) {} 522 #endif 523 524 #endif /* __NET_NET_NAMESPACE_H */ 525