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/dccp.h> 26 #include <net/netns/netfilter.h> 27 #include <net/netns/x_tables.h> 28 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 29 #include <net/netns/conntrack.h> 30 #endif 31 #include <net/netns/nftables.h> 32 #include <net/netns/xfrm.h> 33 #include <net/netns/mpls.h> 34 #include <net/netns/can.h> 35 #include <net/netns/xdp.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 refcount_t count; /* To decided when the network 64 * namespace should be shut down. 65 */ 66 spinlock_t rules_mod_lock; 67 68 unsigned int dev_unreg_count; 69 70 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 71 int ifindex; 72 73 spinlock_t nsid_lock; 74 atomic_t fnhe_genid; 75 76 struct list_head list; /* list of network namespaces */ 77 struct list_head exit_list; /* To linked to call pernet exit 78 * methods on dead net ( 79 * pernet_ops_rwsem read locked), 80 * or to unregister pernet ops 81 * (pernet_ops_rwsem write locked). 82 */ 83 struct llist_node cleanup_list; /* namespaces on death row */ 84 85 #ifdef CONFIG_KEYS 86 struct key_tag *key_domain; /* Key domain of operation tag */ 87 #endif 88 struct user_namespace *user_ns; /* Owning user namespace */ 89 struct ucounts *ucounts; 90 struct idr netns_ids; 91 92 struct ns_common ns; 93 94 struct list_head dev_base_head; 95 struct proc_dir_entry *proc_net; 96 struct proc_dir_entry *proc_net_stat; 97 98 #ifdef CONFIG_SYSCTL 99 struct ctl_table_set sysctls; 100 #endif 101 102 struct sock *rtnl; /* rtnetlink socket */ 103 struct sock *genl_sock; 104 105 struct uevent_sock *uevent_sock; /* uevent socket */ 106 107 struct hlist_head *dev_name_head; 108 struct hlist_head *dev_index_head; 109 struct raw_notifier_head netdev_chain; 110 111 /* Note that @hash_mix can be read millions times per second, 112 * it is critical that it is on a read_mostly cache line. 113 */ 114 u32 hash_mix; 115 116 struct net_device *loopback_dev; /* The loopback */ 117 118 /* core fib_rules */ 119 struct list_head rules_ops; 120 121 struct netns_core core; 122 struct netns_mib mib; 123 struct netns_packet packet; 124 struct netns_unix unx; 125 struct netns_nexthop nexthop; 126 struct netns_ipv4 ipv4; 127 #if IS_ENABLED(CONFIG_IPV6) 128 struct netns_ipv6 ipv6; 129 #endif 130 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 131 struct netns_ieee802154_lowpan ieee802154_lowpan; 132 #endif 133 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 134 struct netns_sctp sctp; 135 #endif 136 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 137 struct netns_dccp dccp; 138 #endif 139 #ifdef CONFIG_NETFILTER 140 struct netns_nf nf; 141 struct netns_xt xt; 142 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 143 struct netns_ct ct; 144 #endif 145 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 146 struct netns_nftables nft; 147 #endif 148 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 149 struct netns_nf_frag nf_frag; 150 struct ctl_table_header *nf_frag_frags_hdr; 151 #endif 152 struct sock *nfnl; 153 struct sock *nfnl_stash; 154 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT) 155 struct list_head nfnl_acct_list; 156 #endif 157 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 158 struct list_head nfct_timeout_list; 159 #endif 160 #endif 161 #ifdef CONFIG_WEXT_CORE 162 struct sk_buff_head wext_nlevents; 163 #endif 164 struct net_generic __rcu *gen; 165 166 /* Used to store attached BPF programs */ 167 struct netns_bpf bpf; 168 169 /* Note : following structs are cache line aligned */ 170 #ifdef CONFIG_XFRM 171 struct netns_xfrm xfrm; 172 #endif 173 174 atomic64_t net_cookie; /* written once */ 175 176 #if IS_ENABLED(CONFIG_IP_VS) 177 struct netns_ipvs *ipvs; 178 #endif 179 #if IS_ENABLED(CONFIG_MPLS) 180 struct netns_mpls mpls; 181 #endif 182 #if IS_ENABLED(CONFIG_CAN) 183 struct netns_can can; 184 #endif 185 #ifdef CONFIG_XDP_SOCKETS 186 struct netns_xdp xdp; 187 #endif 188 #if IS_ENABLED(CONFIG_CRYPTO_USER) 189 struct sock *crypto_nlsk; 190 #endif 191 struct sock *diag_nlsk; 192 } __randomize_layout; 193 194 #include <linux/seq_file_net.h> 195 196 /* Init's network namespace */ 197 extern struct net init_net; 198 199 #ifdef CONFIG_NET_NS 200 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 201 struct net *old_net); 202 203 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 204 205 void net_ns_barrier(void); 206 #else /* CONFIG_NET_NS */ 207 #include <linux/sched.h> 208 #include <linux/nsproxy.h> 209 static inline struct net *copy_net_ns(unsigned long flags, 210 struct user_namespace *user_ns, struct net *old_net) 211 { 212 if (flags & CLONE_NEWNET) 213 return ERR_PTR(-EINVAL); 214 return old_net; 215 } 216 217 static inline void net_ns_get_ownership(const struct net *net, 218 kuid_t *uid, kgid_t *gid) 219 { 220 *uid = GLOBAL_ROOT_UID; 221 *gid = GLOBAL_ROOT_GID; 222 } 223 224 static inline void net_ns_barrier(void) {} 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 struct net *get_net_ns_by_fd(int fd); 232 233 u64 net_gen_cookie(struct net *net); 234 235 #ifdef CONFIG_SYSCTL 236 void ipx_register_sysctl(void); 237 void ipx_unregister_sysctl(void); 238 #else 239 #define ipx_register_sysctl() 240 #define ipx_unregister_sysctl() 241 #endif 242 243 #ifdef CONFIG_NET_NS 244 void __put_net(struct net *net); 245 246 static inline struct net *get_net(struct net *net) 247 { 248 refcount_inc(&net->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->count)) 260 net = NULL; 261 return net; 262 } 263 264 static inline void put_net(struct net *net) 265 { 266 if (refcount_dec_and_test(&net->count)) 267 __put_net(net); 268 } 269 270 static inline 271 int net_eq(const struct net *net1, const struct net *net2) 272 { 273 return net1 == net2; 274 } 275 276 static inline int check_net(const struct net *net) 277 { 278 return refcount_read(&net->count) != 0; 279 } 280 281 void net_drop_ns(void *); 282 283 #else 284 285 static inline struct net *get_net(struct net *net) 286 { 287 return net; 288 } 289 290 static inline void put_net(struct net *net) 291 { 292 } 293 294 static inline struct net *maybe_get_net(struct net *net) 295 { 296 return net; 297 } 298 299 static inline 300 int net_eq(const struct net *net1, const struct net *net2) 301 { 302 return 1; 303 } 304 305 static inline int check_net(const struct net *net) 306 { 307 return 1; 308 } 309 310 #define net_drop_ns NULL 311 #endif 312 313 314 typedef struct { 315 #ifdef CONFIG_NET_NS 316 struct net *net; 317 #endif 318 } possible_net_t; 319 320 static inline void write_pnet(possible_net_t *pnet, struct net *net) 321 { 322 #ifdef CONFIG_NET_NS 323 pnet->net = net; 324 #endif 325 } 326 327 static inline struct net *read_pnet(const possible_net_t *pnet) 328 { 329 #ifdef CONFIG_NET_NS 330 return pnet->net; 331 #else 332 return &init_net; 333 #endif 334 } 335 336 /* Protected by net_rwsem */ 337 #define for_each_net(VAR) \ 338 list_for_each_entry(VAR, &net_namespace_list, list) 339 #define for_each_net_continue_reverse(VAR) \ 340 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list) 341 #define for_each_net_rcu(VAR) \ 342 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 343 344 #ifdef CONFIG_NET_NS 345 #define __net_init 346 #define __net_exit 347 #define __net_initdata 348 #define __net_initconst 349 #else 350 #define __net_init __init 351 #define __net_exit __ref 352 #define __net_initdata __initdata 353 #define __net_initconst __initconst 354 #endif 355 356 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp); 357 int peernet2id(const struct net *net, struct net *peer); 358 bool peernet_has_id(const struct net *net, struct net *peer); 359 struct net *get_net_ns_by_id(const struct net *net, int id); 360 361 struct pernet_operations { 362 struct list_head list; 363 /* 364 * Below methods are called without any exclusive locks. 365 * More than one net may be constructed and destructed 366 * in parallel on several cpus. Every pernet_operations 367 * have to keep in mind all other pernet_operations and 368 * to introduce a locking, if they share common resources. 369 * 370 * The only time they are called with exclusive lock is 371 * from register_pernet_subsys(), unregister_pernet_subsys() 372 * register_pernet_device() and unregister_pernet_device(). 373 * 374 * Exit methods using blocking RCU primitives, such as 375 * synchronize_rcu(), should be implemented via exit_batch. 376 * Then, destruction of a group of net requires single 377 * synchronize_rcu() related to these pernet_operations, 378 * instead of separate synchronize_rcu() for every net. 379 * Please, avoid synchronize_rcu() at all, where it's possible. 380 * 381 * Note that a combination of pre_exit() and exit() can 382 * be used, since a synchronize_rcu() is guaranteed between 383 * the calls. 384 */ 385 int (*init)(struct net *net); 386 void (*pre_exit)(struct net *net); 387 void (*exit)(struct net *net); 388 void (*exit_batch)(struct list_head *net_exit_list); 389 unsigned int *id; 390 size_t size; 391 }; 392 393 /* 394 * Use these carefully. If you implement a network device and it 395 * needs per network namespace operations use device pernet operations, 396 * otherwise use pernet subsys operations. 397 * 398 * Network interfaces need to be removed from a dying netns _before_ 399 * subsys notifiers can be called, as most of the network code cleanup 400 * (which is done from subsys notifiers) runs with the assumption that 401 * dev_remove_pack has been called so no new packets will arrive during 402 * and after the cleanup functions have been called. dev_remove_pack 403 * is not per namespace so instead the guarantee of no more packets 404 * arriving in a network namespace is provided by ensuring that all 405 * network devices and all sockets have left the network namespace 406 * before the cleanup methods are called. 407 * 408 * For the longest time the ipv4 icmp code was registered as a pernet 409 * device which caused kernel oops, and panics during network 410 * namespace cleanup. So please don't get this wrong. 411 */ 412 int register_pernet_subsys(struct pernet_operations *); 413 void unregister_pernet_subsys(struct pernet_operations *); 414 int register_pernet_device(struct pernet_operations *); 415 void unregister_pernet_device(struct pernet_operations *); 416 417 struct ctl_table; 418 struct ctl_table_header; 419 420 #ifdef CONFIG_SYSCTL 421 int net_sysctl_init(void); 422 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 423 struct ctl_table *table); 424 void unregister_net_sysctl_table(struct ctl_table_header *header); 425 #else 426 static inline int net_sysctl_init(void) { return 0; } 427 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 428 const char *path, struct ctl_table *table) 429 { 430 return NULL; 431 } 432 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 433 { 434 } 435 #endif 436 437 static inline int rt_genid_ipv4(const struct net *net) 438 { 439 return atomic_read(&net->ipv4.rt_genid); 440 } 441 442 #if IS_ENABLED(CONFIG_IPV6) 443 static inline int rt_genid_ipv6(const struct net *net) 444 { 445 return atomic_read(&net->ipv6.fib6_sernum); 446 } 447 #endif 448 449 static inline void rt_genid_bump_ipv4(struct net *net) 450 { 451 atomic_inc(&net->ipv4.rt_genid); 452 } 453 454 extern void (*__fib6_flush_trees)(struct net *net); 455 static inline void rt_genid_bump_ipv6(struct net *net) 456 { 457 if (__fib6_flush_trees) 458 __fib6_flush_trees(net); 459 } 460 461 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 462 static inline struct netns_ieee802154_lowpan * 463 net_ieee802154_lowpan(struct net *net) 464 { 465 return &net->ieee802154_lowpan; 466 } 467 #endif 468 469 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 470 static inline void rt_genid_bump_all(struct net *net) 471 { 472 rt_genid_bump_ipv4(net); 473 rt_genid_bump_ipv6(net); 474 } 475 476 static inline int fnhe_genid(const struct net *net) 477 { 478 return atomic_read(&net->fnhe_genid); 479 } 480 481 static inline void fnhe_genid_bump(struct net *net) 482 { 483 atomic_inc(&net->fnhe_genid); 484 } 485 486 #endif /* __NET_NET_NAMESPACE_H */ 487