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 #include <net/netns/x_tables.h> 27 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 28 #include <net/netns/conntrack.h> 29 #endif 30 #include <net/netns/nftables.h> 31 #include <net/netns/xfrm.h> 32 #include <net/netns/mpls.h> 33 #include <net/netns/can.h> 34 #include <net/netns/xdp.h> 35 #include <net/netns/smc.h> 36 #include <net/netns/bpf.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 struct netns_xt xt; 136 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 137 struct netns_ct ct; 138 #endif 139 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 140 struct netns_nftables nft; 141 #endif 142 #endif 143 #ifdef CONFIG_WEXT_CORE 144 struct sk_buff_head wext_nlevents; 145 #endif 146 struct net_generic __rcu *gen; 147 148 /* Used to store attached BPF programs */ 149 struct netns_bpf bpf; 150 151 /* Note : following structs are cache line aligned */ 152 #ifdef CONFIG_XFRM 153 struct netns_xfrm xfrm; 154 #endif 155 156 u64 net_cookie; /* written once */ 157 158 #if IS_ENABLED(CONFIG_IP_VS) 159 struct netns_ipvs *ipvs; 160 #endif 161 #if IS_ENABLED(CONFIG_MPLS) 162 struct netns_mpls mpls; 163 #endif 164 #if IS_ENABLED(CONFIG_CAN) 165 struct netns_can can; 166 #endif 167 #ifdef CONFIG_XDP_SOCKETS 168 struct netns_xdp xdp; 169 #endif 170 #if IS_ENABLED(CONFIG_CRYPTO_USER) 171 struct sock *crypto_nlsk; 172 #endif 173 struct sock *diag_nlsk; 174 #if IS_ENABLED(CONFIG_SMC) 175 struct netns_smc smc; 176 #endif 177 } __randomize_layout; 178 179 #include <linux/seq_file_net.h> 180 181 /* Init's network namespace */ 182 extern struct net init_net; 183 184 #ifdef CONFIG_NET_NS 185 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 186 struct net *old_net); 187 188 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 189 190 void net_ns_barrier(void); 191 192 struct ns_common *get_net_ns(struct ns_common *ns); 193 struct net *get_net_ns_by_fd(int fd); 194 #else /* CONFIG_NET_NS */ 195 #include <linux/sched.h> 196 #include <linux/nsproxy.h> 197 static inline struct net *copy_net_ns(unsigned long flags, 198 struct user_namespace *user_ns, struct net *old_net) 199 { 200 if (flags & CLONE_NEWNET) 201 return ERR_PTR(-EINVAL); 202 return old_net; 203 } 204 205 static inline void net_ns_get_ownership(const struct net *net, 206 kuid_t *uid, kgid_t *gid) 207 { 208 *uid = GLOBAL_ROOT_UID; 209 *gid = GLOBAL_ROOT_GID; 210 } 211 212 static inline void net_ns_barrier(void) {} 213 214 static inline struct ns_common *get_net_ns(struct ns_common *ns) 215 { 216 return ERR_PTR(-EINVAL); 217 } 218 219 static inline struct net *get_net_ns_by_fd(int fd) 220 { 221 return ERR_PTR(-EINVAL); 222 } 223 #endif /* CONFIG_NET_NS */ 224 225 226 extern struct list_head net_namespace_list; 227 228 struct net *get_net_ns_by_pid(pid_t pid); 229 230 #ifdef CONFIG_SYSCTL 231 void ipx_register_sysctl(void); 232 void ipx_unregister_sysctl(void); 233 #else 234 #define ipx_register_sysctl() 235 #define ipx_unregister_sysctl() 236 #endif 237 238 #ifdef CONFIG_NET_NS 239 void __put_net(struct net *net); 240 241 static inline struct net *get_net(struct net *net) 242 { 243 refcount_inc(&net->ns.count); 244 return net; 245 } 246 247 static inline struct net *maybe_get_net(struct net *net) 248 { 249 /* Used when we know struct net exists but we 250 * aren't guaranteed a previous reference count 251 * exists. If the reference count is zero this 252 * function fails and returns NULL. 253 */ 254 if (!refcount_inc_not_zero(&net->ns.count)) 255 net = NULL; 256 return net; 257 } 258 259 static inline void put_net(struct net *net) 260 { 261 if (refcount_dec_and_test(&net->ns.count)) 262 __put_net(net); 263 } 264 265 static inline 266 int net_eq(const struct net *net1, const struct net *net2) 267 { 268 return net1 == net2; 269 } 270 271 static inline int check_net(const struct net *net) 272 { 273 return refcount_read(&net->ns.count) != 0; 274 } 275 276 void net_drop_ns(void *); 277 278 #else 279 280 static inline struct net *get_net(struct net *net) 281 { 282 return net; 283 } 284 285 static inline void put_net(struct net *net) 286 { 287 } 288 289 static inline struct net *maybe_get_net(struct net *net) 290 { 291 return net; 292 } 293 294 static inline 295 int net_eq(const struct net *net1, const struct net *net2) 296 { 297 return 1; 298 } 299 300 static inline int check_net(const struct net *net) 301 { 302 return 1; 303 } 304 305 #define net_drop_ns NULL 306 #endif 307 308 309 typedef struct { 310 #ifdef CONFIG_NET_NS 311 struct net *net; 312 #endif 313 } possible_net_t; 314 315 static inline void write_pnet(possible_net_t *pnet, struct net *net) 316 { 317 #ifdef CONFIG_NET_NS 318 pnet->net = net; 319 #endif 320 } 321 322 static inline struct net *read_pnet(const possible_net_t *pnet) 323 { 324 #ifdef CONFIG_NET_NS 325 return pnet->net; 326 #else 327 return &init_net; 328 #endif 329 } 330 331 /* Protected by net_rwsem */ 332 #define for_each_net(VAR) \ 333 list_for_each_entry(VAR, &net_namespace_list, list) 334 #define for_each_net_continue_reverse(VAR) \ 335 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list) 336 #define for_each_net_rcu(VAR) \ 337 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 338 339 #ifdef CONFIG_NET_NS 340 #define __net_init 341 #define __net_exit 342 #define __net_initdata 343 #define __net_initconst 344 #else 345 #define __net_init __init 346 #define __net_exit __ref 347 #define __net_initdata __initdata 348 #define __net_initconst __initconst 349 #endif 350 351 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp); 352 int peernet2id(const struct net *net, struct net *peer); 353 bool peernet_has_id(const struct net *net, struct net *peer); 354 struct net *get_net_ns_by_id(const struct net *net, int id); 355 356 struct pernet_operations { 357 struct list_head list; 358 /* 359 * Below methods are called without any exclusive locks. 360 * More than one net may be constructed and destructed 361 * in parallel on several cpus. Every pernet_operations 362 * have to keep in mind all other pernet_operations and 363 * to introduce a locking, if they share common resources. 364 * 365 * The only time they are called with exclusive lock is 366 * from register_pernet_subsys(), unregister_pernet_subsys() 367 * register_pernet_device() and unregister_pernet_device(). 368 * 369 * Exit methods using blocking RCU primitives, such as 370 * synchronize_rcu(), should be implemented via exit_batch. 371 * Then, destruction of a group of net requires single 372 * synchronize_rcu() related to these pernet_operations, 373 * instead of separate synchronize_rcu() for every net. 374 * Please, avoid synchronize_rcu() at all, where it's possible. 375 * 376 * Note that a combination of pre_exit() and exit() can 377 * be used, since a synchronize_rcu() is guaranteed between 378 * the calls. 379 */ 380 int (*init)(struct net *net); 381 void (*pre_exit)(struct net *net); 382 void (*exit)(struct net *net); 383 void (*exit_batch)(struct list_head *net_exit_list); 384 unsigned int *id; 385 size_t size; 386 }; 387 388 /* 389 * Use these carefully. If you implement a network device and it 390 * needs per network namespace operations use device pernet operations, 391 * otherwise use pernet subsys operations. 392 * 393 * Network interfaces need to be removed from a dying netns _before_ 394 * subsys notifiers can be called, as most of the network code cleanup 395 * (which is done from subsys notifiers) runs with the assumption that 396 * dev_remove_pack has been called so no new packets will arrive during 397 * and after the cleanup functions have been called. dev_remove_pack 398 * is not per namespace so instead the guarantee of no more packets 399 * arriving in a network namespace is provided by ensuring that all 400 * network devices and all sockets have left the network namespace 401 * before the cleanup methods are called. 402 * 403 * For the longest time the ipv4 icmp code was registered as a pernet 404 * device which caused kernel oops, and panics during network 405 * namespace cleanup. So please don't get this wrong. 406 */ 407 int register_pernet_subsys(struct pernet_operations *); 408 void unregister_pernet_subsys(struct pernet_operations *); 409 int register_pernet_device(struct pernet_operations *); 410 void unregister_pernet_device(struct pernet_operations *); 411 412 struct ctl_table; 413 414 #ifdef CONFIG_SYSCTL 415 int net_sysctl_init(void); 416 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 417 struct ctl_table *table); 418 void unregister_net_sysctl_table(struct ctl_table_header *header); 419 #else 420 static inline int net_sysctl_init(void) { return 0; } 421 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 422 const char *path, struct ctl_table *table) 423 { 424 return NULL; 425 } 426 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 427 { 428 } 429 #endif 430 431 static inline int rt_genid_ipv4(const struct net *net) 432 { 433 return atomic_read(&net->ipv4.rt_genid); 434 } 435 436 #if IS_ENABLED(CONFIG_IPV6) 437 static inline int rt_genid_ipv6(const struct net *net) 438 { 439 return atomic_read(&net->ipv6.fib6_sernum); 440 } 441 #endif 442 443 static inline void rt_genid_bump_ipv4(struct net *net) 444 { 445 atomic_inc(&net->ipv4.rt_genid); 446 } 447 448 extern void (*__fib6_flush_trees)(struct net *net); 449 static inline void rt_genid_bump_ipv6(struct net *net) 450 { 451 if (__fib6_flush_trees) 452 __fib6_flush_trees(net); 453 } 454 455 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 456 static inline struct netns_ieee802154_lowpan * 457 net_ieee802154_lowpan(struct net *net) 458 { 459 return &net->ieee802154_lowpan; 460 } 461 #endif 462 463 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 464 static inline void rt_genid_bump_all(struct net *net) 465 { 466 rt_genid_bump_ipv4(net); 467 rt_genid_bump_ipv6(net); 468 } 469 470 static inline int fnhe_genid(const struct net *net) 471 { 472 return atomic_read(&net->fnhe_genid); 473 } 474 475 static inline void fnhe_genid_bump(struct net *net) 476 { 477 atomic_inc(&net->fnhe_genid); 478 } 479 480 #endif /* __NET_NET_NAMESPACE_H */ 481