net_namespace.h (13096B)
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 43struct user_namespace; 44struct proc_dir_entry; 45struct net_device; 46struct sock; 47struct ctl_table_header; 48struct net_generic; 49struct uevent_sock; 50struct netns_ipvs; 51struct bpf_prog; 52 53 54#define NETDEV_HASHBITS 8 55#define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 56 57struct 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 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 */ 186extern struct net init_net; 187 188#ifdef CONFIG_NET_NS 189struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 190 struct net *old_net); 191 192void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 193 194void net_ns_barrier(void); 195 196struct ns_common *get_net_ns(struct ns_common *ns); 197struct net *get_net_ns_by_fd(int fd); 198#else /* CONFIG_NET_NS */ 199#include <linux/sched.h> 200#include <linux/nsproxy.h> 201static 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 209static 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 216static inline void net_ns_barrier(void) {} 217 218static inline struct ns_common *get_net_ns(struct ns_common *ns) 219{ 220 return ERR_PTR(-EINVAL); 221} 222 223static inline struct net *get_net_ns_by_fd(int fd) 224{ 225 return ERR_PTR(-EINVAL); 226} 227#endif /* CONFIG_NET_NS */ 228 229 230extern struct list_head net_namespace_list; 231 232struct net *get_net_ns_by_pid(pid_t pid); 233 234#ifdef CONFIG_SYSCTL 235void ipx_register_sysctl(void); 236void ipx_unregister_sysctl(void); 237#else 238#define ipx_register_sysctl() 239#define ipx_unregister_sysctl() 240#endif 241 242#ifdef CONFIG_NET_NS 243void __put_net(struct net *net); 244 245/* Try using get_net_track() instead */ 246static inline struct net *get_net(struct net *net) 247{ 248 refcount_inc(&net->ns.count); 249 return net; 250} 251 252static 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 */ 265static inline void put_net(struct net *net) 266{ 267 if (refcount_dec_and_test(&net->ns.count)) 268 __put_net(net); 269} 270 271static inline 272int net_eq(const struct net *net1, const struct net *net2) 273{ 274 return net1 == net2; 275} 276 277static inline int check_net(const struct net *net) 278{ 279 return refcount_read(&net->ns.count) != 0; 280} 281 282void net_drop_ns(void *); 283 284#else 285 286static inline struct net *get_net(struct net *net) 287{ 288 return net; 289} 290 291static inline void put_net(struct net *net) 292{ 293} 294 295static inline struct net *maybe_get_net(struct net *net) 296{ 297 return net; 298} 299 300static inline 301int net_eq(const struct net *net1, const struct net *net2) 302{ 303 return 1; 304} 305 306static inline int check_net(const struct net *net) 307{ 308 return 1; 309} 310 311#define net_drop_ns NULL 312#endif 313 314 315static 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 323static 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 331static 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 339static inline void put_net_track(struct net *net, netns_tracker *tracker) 340{ 341 netns_tracker_free(net, tracker); 342 put_net(net); 343} 344 345typedef struct { 346#ifdef CONFIG_NET_NS 347 struct net *net; 348#endif 349} possible_net_t; 350 351static 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 358static 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 387int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp); 388int peernet2id(const struct net *net, struct net *peer); 389bool peernet_has_id(const struct net *net, struct net *peer); 390struct net *get_net_ns_by_id(const struct net *net, int id); 391 392struct 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 */ 443int register_pernet_subsys(struct pernet_operations *); 444void unregister_pernet_subsys(struct pernet_operations *); 445int register_pernet_device(struct pernet_operations *); 446void unregister_pernet_device(struct pernet_operations *); 447 448struct ctl_table; 449 450#ifdef CONFIG_SYSCTL 451int net_sysctl_init(void); 452struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 453 struct ctl_table *table); 454void unregister_net_sysctl_table(struct ctl_table_header *header); 455#else 456static inline int net_sysctl_init(void) { return 0; } 457static inline struct ctl_table_header *register_net_sysctl(struct net *net, 458 const char *path, struct ctl_table *table) 459{ 460 return NULL; 461} 462static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 463{ 464} 465#endif 466 467static 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) 473static inline int rt_genid_ipv6(const struct net *net) 474{ 475 return atomic_read(&net->ipv6.fib6_sernum); 476} 477#endif 478 479static inline void rt_genid_bump_ipv4(struct net *net) 480{ 481 atomic_inc(&net->ipv4.rt_genid); 482} 483 484extern void (*__fib6_flush_trees)(struct net *net); 485static 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) 492static inline struct netns_ieee802154_lowpan * 493net_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 */ 500static inline void rt_genid_bump_all(struct net *net) 501{ 502 rt_genid_bump_ipv4(net); 503 rt_genid_bump_ipv6(net); 504} 505 506static inline int fnhe_genid(const struct net *net) 507{ 508 return atomic_read(&net->fnhe_genid); 509} 510 511static inline void fnhe_genid_bump(struct net *net) 512{ 513 atomic_inc(&net->fnhe_genid); 514} 515 516#ifdef CONFIG_NET 517void net_ns_init(void); 518#else 519static inline void net_ns_init(void) {} 520#endif 521 522#endif /* __NET_NET_NAMESPACE_H */