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 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 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 134 struct netns_dccp dccp; 135 #endif 136 #ifdef CONFIG_NETFILTER 137 struct netns_nf nf; 138 struct netns_xt xt; 139 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 140 struct netns_ct ct; 141 #endif 142 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 143 struct netns_nftables nft; 144 #endif 145 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 146 struct netns_nf_frag nf_frag; 147 struct ctl_table_header *nf_frag_frags_hdr; 148 #endif 149 struct sock *nfnl; 150 struct sock *nfnl_stash; 151 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 152 struct list_head nfct_timeout_list; 153 #endif 154 #endif 155 #ifdef CONFIG_WEXT_CORE 156 struct sk_buff_head wext_nlevents; 157 #endif 158 struct net_generic __rcu *gen; 159 160 /* Used to store attached BPF programs */ 161 struct netns_bpf bpf; 162 163 /* Note : following structs are cache line aligned */ 164 #ifdef CONFIG_XFRM 165 struct netns_xfrm xfrm; 166 #endif 167 168 atomic64_t net_cookie; /* written once */ 169 170 #if IS_ENABLED(CONFIG_IP_VS) 171 struct netns_ipvs *ipvs; 172 #endif 173 #if IS_ENABLED(CONFIG_MPLS) 174 struct netns_mpls mpls; 175 #endif 176 #if IS_ENABLED(CONFIG_CAN) 177 struct netns_can can; 178 #endif 179 #ifdef CONFIG_XDP_SOCKETS 180 struct netns_xdp xdp; 181 #endif 182 #if IS_ENABLED(CONFIG_CRYPTO_USER) 183 struct sock *crypto_nlsk; 184 #endif 185 struct sock *diag_nlsk; 186 } __randomize_layout; 187 188 #include <linux/seq_file_net.h> 189 190 /* Init's network namespace */ 191 extern struct net init_net; 192 193 #ifdef CONFIG_NET_NS 194 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 195 struct net *old_net); 196 197 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 198 199 void net_ns_barrier(void); 200 #else /* CONFIG_NET_NS */ 201 #include <linux/sched.h> 202 #include <linux/nsproxy.h> 203 static inline struct net *copy_net_ns(unsigned long flags, 204 struct user_namespace *user_ns, struct net *old_net) 205 { 206 if (flags & CLONE_NEWNET) 207 return ERR_PTR(-EINVAL); 208 return old_net; 209 } 210 211 static inline void net_ns_get_ownership(const struct net *net, 212 kuid_t *uid, kgid_t *gid) 213 { 214 *uid = GLOBAL_ROOT_UID; 215 *gid = GLOBAL_ROOT_GID; 216 } 217 218 static inline void net_ns_barrier(void) {} 219 #endif /* CONFIG_NET_NS */ 220 221 222 extern struct list_head net_namespace_list; 223 224 struct net *get_net_ns_by_pid(pid_t pid); 225 struct net *get_net_ns_by_fd(int fd); 226 227 u64 __net_gen_cookie(struct net *net); 228 229 #ifdef CONFIG_SYSCTL 230 void ipx_register_sysctl(void); 231 void ipx_unregister_sysctl(void); 232 #else 233 #define ipx_register_sysctl() 234 #define ipx_unregister_sysctl() 235 #endif 236 237 #ifdef CONFIG_NET_NS 238 void __put_net(struct net *net); 239 240 static inline struct net *get_net(struct net *net) 241 { 242 refcount_inc(&net->ns.count); 243 return net; 244 } 245 246 static inline struct net *maybe_get_net(struct net *net) 247 { 248 /* Used when we know struct net exists but we 249 * aren't guaranteed a previous reference count 250 * exists. If the reference count is zero this 251 * function fails and returns NULL. 252 */ 253 if (!refcount_inc_not_zero(&net->ns.count)) 254 net = NULL; 255 return net; 256 } 257 258 static inline void put_net(struct net *net) 259 { 260 if (refcount_dec_and_test(&net->ns.count)) 261 __put_net(net); 262 } 263 264 static inline 265 int net_eq(const struct net *net1, const struct net *net2) 266 { 267 return net1 == net2; 268 } 269 270 static inline int check_net(const struct net *net) 271 { 272 return refcount_read(&net->ns.count) != 0; 273 } 274 275 void net_drop_ns(void *); 276 277 #else 278 279 static inline struct net *get_net(struct net *net) 280 { 281 return net; 282 } 283 284 static inline void put_net(struct net *net) 285 { 286 } 287 288 static inline struct net *maybe_get_net(struct net *net) 289 { 290 return net; 291 } 292 293 static inline 294 int net_eq(const struct net *net1, const struct net *net2) 295 { 296 return 1; 297 } 298 299 static inline int check_net(const struct net *net) 300 { 301 return 1; 302 } 303 304 #define net_drop_ns NULL 305 #endif 306 307 308 typedef struct { 309 #ifdef CONFIG_NET_NS 310 struct net *net; 311 #endif 312 } possible_net_t; 313 314 static inline void write_pnet(possible_net_t *pnet, struct net *net) 315 { 316 #ifdef CONFIG_NET_NS 317 pnet->net = net; 318 #endif 319 } 320 321 static inline struct net *read_pnet(const possible_net_t *pnet) 322 { 323 #ifdef CONFIG_NET_NS 324 return pnet->net; 325 #else 326 return &init_net; 327 #endif 328 } 329 330 /* Protected by net_rwsem */ 331 #define for_each_net(VAR) \ 332 list_for_each_entry(VAR, &net_namespace_list, list) 333 #define for_each_net_continue_reverse(VAR) \ 334 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list) 335 #define for_each_net_rcu(VAR) \ 336 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 337 338 #ifdef CONFIG_NET_NS 339 #define __net_init 340 #define __net_exit 341 #define __net_initdata 342 #define __net_initconst 343 #else 344 #define __net_init __init 345 #define __net_exit __ref 346 #define __net_initdata __initdata 347 #define __net_initconst __initconst 348 #endif 349 350 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp); 351 int peernet2id(const struct net *net, struct net *peer); 352 bool peernet_has_id(const struct net *net, struct net *peer); 353 struct net *get_net_ns_by_id(const struct net *net, int id); 354 355 struct pernet_operations { 356 struct list_head list; 357 /* 358 * Below methods are called without any exclusive locks. 359 * More than one net may be constructed and destructed 360 * in parallel on several cpus. Every pernet_operations 361 * have to keep in mind all other pernet_operations and 362 * to introduce a locking, if they share common resources. 363 * 364 * The only time they are called with exclusive lock is 365 * from register_pernet_subsys(), unregister_pernet_subsys() 366 * register_pernet_device() and unregister_pernet_device(). 367 * 368 * Exit methods using blocking RCU primitives, such as 369 * synchronize_rcu(), should be implemented via exit_batch. 370 * Then, destruction of a group of net requires single 371 * synchronize_rcu() related to these pernet_operations, 372 * instead of separate synchronize_rcu() for every net. 373 * Please, avoid synchronize_rcu() at all, where it's possible. 374 * 375 * Note that a combination of pre_exit() and exit() can 376 * be used, since a synchronize_rcu() is guaranteed between 377 * the calls. 378 */ 379 int (*init)(struct net *net); 380 void (*pre_exit)(struct net *net); 381 void (*exit)(struct net *net); 382 void (*exit_batch)(struct list_head *net_exit_list); 383 unsigned int *id; 384 size_t size; 385 }; 386 387 /* 388 * Use these carefully. If you implement a network device and it 389 * needs per network namespace operations use device pernet operations, 390 * otherwise use pernet subsys operations. 391 * 392 * Network interfaces need to be removed from a dying netns _before_ 393 * subsys notifiers can be called, as most of the network code cleanup 394 * (which is done from subsys notifiers) runs with the assumption that 395 * dev_remove_pack has been called so no new packets will arrive during 396 * and after the cleanup functions have been called. dev_remove_pack 397 * is not per namespace so instead the guarantee of no more packets 398 * arriving in a network namespace is provided by ensuring that all 399 * network devices and all sockets have left the network namespace 400 * before the cleanup methods are called. 401 * 402 * For the longest time the ipv4 icmp code was registered as a pernet 403 * device which caused kernel oops, and panics during network 404 * namespace cleanup. So please don't get this wrong. 405 */ 406 int register_pernet_subsys(struct pernet_operations *); 407 void unregister_pernet_subsys(struct pernet_operations *); 408 int register_pernet_device(struct pernet_operations *); 409 void unregister_pernet_device(struct pernet_operations *); 410 411 struct ctl_table; 412 struct ctl_table_header; 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