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