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_NF_CT_NETLINK_TIMEOUT) 155 struct list_head nfct_timeout_list; 156 #endif 157 #endif 158 #ifdef CONFIG_WEXT_CORE 159 struct sk_buff_head wext_nlevents; 160 #endif 161 struct net_generic __rcu *gen; 162 163 /* Used to store attached BPF programs */ 164 struct netns_bpf bpf; 165 166 /* Note : following structs are cache line aligned */ 167 #ifdef CONFIG_XFRM 168 struct netns_xfrm xfrm; 169 #endif 170 171 atomic64_t net_cookie; /* written once */ 172 173 #if IS_ENABLED(CONFIG_IP_VS) 174 struct netns_ipvs *ipvs; 175 #endif 176 #if IS_ENABLED(CONFIG_MPLS) 177 struct netns_mpls mpls; 178 #endif 179 #if IS_ENABLED(CONFIG_CAN) 180 struct netns_can can; 181 #endif 182 #ifdef CONFIG_XDP_SOCKETS 183 struct netns_xdp xdp; 184 #endif 185 #if IS_ENABLED(CONFIG_CRYPTO_USER) 186 struct sock *crypto_nlsk; 187 #endif 188 struct sock *diag_nlsk; 189 } __randomize_layout; 190 191 #include <linux/seq_file_net.h> 192 193 /* Init's network namespace */ 194 extern struct net init_net; 195 196 #ifdef CONFIG_NET_NS 197 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 198 struct net *old_net); 199 200 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 201 202 void net_ns_barrier(void); 203 #else /* CONFIG_NET_NS */ 204 #include <linux/sched.h> 205 #include <linux/nsproxy.h> 206 static inline struct net *copy_net_ns(unsigned long flags, 207 struct user_namespace *user_ns, struct net *old_net) 208 { 209 if (flags & CLONE_NEWNET) 210 return ERR_PTR(-EINVAL); 211 return old_net; 212 } 213 214 static inline void net_ns_get_ownership(const struct net *net, 215 kuid_t *uid, kgid_t *gid) 216 { 217 *uid = GLOBAL_ROOT_UID; 218 *gid = GLOBAL_ROOT_GID; 219 } 220 221 static inline void net_ns_barrier(void) {} 222 #endif /* CONFIG_NET_NS */ 223 224 225 extern struct list_head net_namespace_list; 226 227 struct net *get_net_ns_by_pid(pid_t pid); 228 struct net *get_net_ns_by_fd(int fd); 229 230 u64 __net_gen_cookie(struct net *net); 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->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->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->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->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 struct ctl_table_header; 416 417 #ifdef CONFIG_SYSCTL 418 int net_sysctl_init(void); 419 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 420 struct ctl_table *table); 421 void unregister_net_sysctl_table(struct ctl_table_header *header); 422 #else 423 static inline int net_sysctl_init(void) { return 0; } 424 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 425 const char *path, struct ctl_table *table) 426 { 427 return NULL; 428 } 429 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 430 { 431 } 432 #endif 433 434 static inline int rt_genid_ipv4(const struct net *net) 435 { 436 return atomic_read(&net->ipv4.rt_genid); 437 } 438 439 #if IS_ENABLED(CONFIG_IPV6) 440 static inline int rt_genid_ipv6(const struct net *net) 441 { 442 return atomic_read(&net->ipv6.fib6_sernum); 443 } 444 #endif 445 446 static inline void rt_genid_bump_ipv4(struct net *net) 447 { 448 atomic_inc(&net->ipv4.rt_genid); 449 } 450 451 extern void (*__fib6_flush_trees)(struct net *net); 452 static inline void rt_genid_bump_ipv6(struct net *net) 453 { 454 if (__fib6_flush_trees) 455 __fib6_flush_trees(net); 456 } 457 458 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 459 static inline struct netns_ieee802154_lowpan * 460 net_ieee802154_lowpan(struct net *net) 461 { 462 return &net->ieee802154_lowpan; 463 } 464 #endif 465 466 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 467 static inline void rt_genid_bump_all(struct net *net) 468 { 469 rt_genid_bump_ipv4(net); 470 rt_genid_bump_ipv6(net); 471 } 472 473 static inline int fnhe_genid(const struct net *net) 474 { 475 return atomic_read(&net->fnhe_genid); 476 } 477 478 static inline void fnhe_genid_bump(struct net *net) 479 { 480 atomic_inc(&net->fnhe_genid); 481 } 482 483 #endif /* __NET_NET_NAMESPACE_H */ 484