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