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 <linux/ns_common.h> 37 #include <linux/idr.h> 38 #include <linux/skbuff.h> 39 #include <linux/notifier.h> 40 41 struct user_namespace; 42 struct proc_dir_entry; 43 struct net_device; 44 struct sock; 45 struct ctl_table_header; 46 struct net_generic; 47 struct uevent_sock; 48 struct netns_ipvs; 49 struct bpf_prog; 50 51 52 #define NETDEV_HASHBITS 8 53 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 54 55 struct net { 56 /* First cache line can be often dirtied. 57 * Do not place here read-mostly fields. 58 */ 59 refcount_t passive; /* To decide when the network 60 * namespace should be freed. 61 */ 62 refcount_t count; /* To decided when the network 63 * namespace should be shut down. 64 */ 65 spinlock_t rules_mod_lock; 66 67 unsigned int dev_unreg_count; 68 69 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 70 int ifindex; 71 72 spinlock_t nsid_lock; 73 atomic_t fnhe_genid; 74 75 struct list_head list; /* list of network namespaces */ 76 struct list_head exit_list; /* To linked to call pernet exit 77 * methods on dead net ( 78 * pernet_ops_rwsem read locked), 79 * or to unregister pernet ops 80 * (pernet_ops_rwsem write locked). 81 */ 82 struct llist_node cleanup_list; /* namespaces on death row */ 83 84 #ifdef CONFIG_KEYS 85 struct key_tag *key_domain; /* Key domain of operation tag */ 86 #endif 87 struct user_namespace *user_ns; /* Owning user namespace */ 88 struct ucounts *ucounts; 89 struct idr netns_ids; 90 91 struct ns_common ns; 92 93 struct list_head dev_base_head; 94 struct proc_dir_entry *proc_net; 95 struct proc_dir_entry *proc_net_stat; 96 97 #ifdef CONFIG_SYSCTL 98 struct ctl_table_set sysctls; 99 #endif 100 101 struct sock *rtnl; /* rtnetlink socket */ 102 struct sock *genl_sock; 103 104 struct uevent_sock *uevent_sock; /* uevent socket */ 105 106 struct hlist_head *dev_name_head; 107 struct hlist_head *dev_index_head; 108 struct raw_notifier_head netdev_chain; 109 110 /* Note that @hash_mix can be read millions times per second, 111 * it is critical that it is on a read_mostly cache line. 112 */ 113 u32 hash_mix; 114 115 struct net_device *loopback_dev; /* The loopback */ 116 117 /* core fib_rules */ 118 struct list_head rules_ops; 119 120 struct netns_core core; 121 struct netns_mib mib; 122 struct netns_packet packet; 123 struct netns_unix unx; 124 struct netns_nexthop nexthop; 125 struct netns_ipv4 ipv4; 126 #if IS_ENABLED(CONFIG_IPV6) 127 struct netns_ipv6 ipv6; 128 #endif 129 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 130 struct netns_ieee802154_lowpan ieee802154_lowpan; 131 #endif 132 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 133 struct netns_sctp sctp; 134 #endif 135 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 136 struct netns_dccp dccp; 137 #endif 138 #ifdef CONFIG_NETFILTER 139 struct netns_nf nf; 140 struct netns_xt xt; 141 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 142 struct netns_ct ct; 143 #endif 144 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 145 struct netns_nftables nft; 146 #endif 147 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 148 struct netns_nf_frag nf_frag; 149 struct ctl_table_header *nf_frag_frags_hdr; 150 #endif 151 struct sock *nfnl; 152 struct sock *nfnl_stash; 153 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT) 154 struct list_head nfnl_acct_list; 155 #endif 156 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 157 struct list_head nfct_timeout_list; 158 #endif 159 #endif 160 #ifdef CONFIG_WEXT_CORE 161 struct sk_buff_head wext_nlevents; 162 #endif 163 struct net_generic __rcu *gen; 164 165 struct bpf_prog __rcu *flow_dissector_prog; 166 167 /* Note : following structs are cache line aligned */ 168 #ifdef CONFIG_XFRM 169 struct netns_xfrm xfrm; 170 #endif 171 #if IS_ENABLED(CONFIG_IP_VS) 172 struct netns_ipvs *ipvs; 173 #endif 174 #if IS_ENABLED(CONFIG_MPLS) 175 struct netns_mpls mpls; 176 #endif 177 #if IS_ENABLED(CONFIG_CAN) 178 struct netns_can can; 179 #endif 180 #ifdef CONFIG_XDP_SOCKETS 181 struct netns_xdp xdp; 182 #endif 183 #if IS_ENABLED(CONFIG_CRYPTO_USER) 184 struct sock *crypto_nlsk; 185 #endif 186 struct sock *diag_nlsk; 187 } __randomize_layout; 188 189 #include <linux/seq_file_net.h> 190 191 /* Init's network namespace */ 192 extern struct net init_net; 193 194 #ifdef CONFIG_NET_NS 195 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 196 struct net *old_net); 197 198 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 199 200 void net_ns_barrier(void); 201 #else /* CONFIG_NET_NS */ 202 #include <linux/sched.h> 203 #include <linux/nsproxy.h> 204 static inline struct net *copy_net_ns(unsigned long flags, 205 struct user_namespace *user_ns, struct net *old_net) 206 { 207 if (flags & CLONE_NEWNET) 208 return ERR_PTR(-EINVAL); 209 return old_net; 210 } 211 212 static inline void net_ns_get_ownership(const struct net *net, 213 kuid_t *uid, kgid_t *gid) 214 { 215 *uid = GLOBAL_ROOT_UID; 216 *gid = GLOBAL_ROOT_GID; 217 } 218 219 static inline void net_ns_barrier(void) {} 220 #endif /* CONFIG_NET_NS */ 221 222 223 extern struct list_head net_namespace_list; 224 225 struct net *get_net_ns_by_pid(pid_t pid); 226 struct net *get_net_ns_by_fd(int fd); 227 228 #ifdef CONFIG_SYSCTL 229 void ipx_register_sysctl(void); 230 void ipx_unregister_sysctl(void); 231 #else 232 #define ipx_register_sysctl() 233 #define ipx_unregister_sysctl() 234 #endif 235 236 #ifdef CONFIG_NET_NS 237 void __put_net(struct net *net); 238 239 static inline struct net *get_net(struct net *net) 240 { 241 refcount_inc(&net->count); 242 return net; 243 } 244 245 static inline struct net *maybe_get_net(struct net *net) 246 { 247 /* Used when we know struct net exists but we 248 * aren't guaranteed a previous reference count 249 * exists. If the reference count is zero this 250 * function fails and returns NULL. 251 */ 252 if (!refcount_inc_not_zero(&net->count)) 253 net = NULL; 254 return net; 255 } 256 257 static inline void put_net(struct net *net) 258 { 259 if (refcount_dec_and_test(&net->count)) 260 __put_net(net); 261 } 262 263 static inline 264 int net_eq(const struct net *net1, const struct net *net2) 265 { 266 return net1 == net2; 267 } 268 269 static inline int check_net(const struct net *net) 270 { 271 return refcount_read(&net->count) != 0; 272 } 273 274 void net_drop_ns(void *); 275 276 #else 277 278 static inline struct net *get_net(struct net *net) 279 { 280 return net; 281 } 282 283 static inline void put_net(struct net *net) 284 { 285 } 286 287 static inline struct net *maybe_get_net(struct net *net) 288 { 289 return net; 290 } 291 292 static inline 293 int net_eq(const struct net *net1, const struct net *net2) 294 { 295 return 1; 296 } 297 298 static inline int check_net(const struct net *net) 299 { 300 return 1; 301 } 302 303 #define net_drop_ns NULL 304 #endif 305 306 307 typedef struct { 308 #ifdef CONFIG_NET_NS 309 struct net *net; 310 #endif 311 } possible_net_t; 312 313 static inline void write_pnet(possible_net_t *pnet, struct net *net) 314 { 315 #ifdef CONFIG_NET_NS 316 pnet->net = net; 317 #endif 318 } 319 320 static inline struct net *read_pnet(const possible_net_t *pnet) 321 { 322 #ifdef CONFIG_NET_NS 323 return pnet->net; 324 #else 325 return &init_net; 326 #endif 327 } 328 329 /* Protected by net_rwsem */ 330 #define for_each_net(VAR) \ 331 list_for_each_entry(VAR, &net_namespace_list, list) 332 #define for_each_net_continue_reverse(VAR) \ 333 list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list) 334 #define for_each_net_rcu(VAR) \ 335 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 336 337 #ifdef CONFIG_NET_NS 338 #define __net_init 339 #define __net_exit 340 #define __net_initdata 341 #define __net_initconst 342 #else 343 #define __net_init __init 344 #define __net_exit __ref 345 #define __net_initdata __initdata 346 #define __net_initconst __initconst 347 #endif 348 349 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp); 350 int peernet2id(struct net *net, struct net *peer); 351 bool peernet_has_id(struct net *net, struct net *peer); 352 struct net *get_net_ns_by_id(struct net *net, int id); 353 354 struct pernet_operations { 355 struct list_head list; 356 /* 357 * Below methods are called without any exclusive locks. 358 * More than one net may be constructed and destructed 359 * in parallel on several cpus. Every pernet_operations 360 * have to keep in mind all other pernet_operations and 361 * to introduce a locking, if they share common resources. 362 * 363 * The only time they are called with exclusive lock is 364 * from register_pernet_subsys(), unregister_pernet_subsys() 365 * register_pernet_device() and unregister_pernet_device(). 366 * 367 * Exit methods using blocking RCU primitives, such as 368 * synchronize_rcu(), should be implemented via exit_batch. 369 * Then, destruction of a group of net requires single 370 * synchronize_rcu() related to these pernet_operations, 371 * instead of separate synchronize_rcu() for every net. 372 * Please, avoid synchronize_rcu() at all, where it's possible. 373 * 374 * Note that a combination of pre_exit() and exit() can 375 * be used, since a synchronize_rcu() is guaranteed between 376 * the calls. 377 */ 378 int (*init)(struct net *net); 379 void (*pre_exit)(struct net *net); 380 void (*exit)(struct net *net); 381 void (*exit_batch)(struct list_head *net_exit_list); 382 unsigned int *id; 383 size_t size; 384 }; 385 386 /* 387 * Use these carefully. If you implement a network device and it 388 * needs per network namespace operations use device pernet operations, 389 * otherwise use pernet subsys operations. 390 * 391 * Network interfaces need to be removed from a dying netns _before_ 392 * subsys notifiers can be called, as most of the network code cleanup 393 * (which is done from subsys notifiers) runs with the assumption that 394 * dev_remove_pack has been called so no new packets will arrive during 395 * and after the cleanup functions have been called. dev_remove_pack 396 * is not per namespace so instead the guarantee of no more packets 397 * arriving in a network namespace is provided by ensuring that all 398 * network devices and all sockets have left the network namespace 399 * before the cleanup methods are called. 400 * 401 * For the longest time the ipv4 icmp code was registered as a pernet 402 * device which caused kernel oops, and panics during network 403 * namespace cleanup. So please don't get this wrong. 404 */ 405 int register_pernet_subsys(struct pernet_operations *); 406 void unregister_pernet_subsys(struct pernet_operations *); 407 int register_pernet_device(struct pernet_operations *); 408 void unregister_pernet_device(struct pernet_operations *); 409 410 struct ctl_table; 411 struct ctl_table_header; 412 413 #ifdef CONFIG_SYSCTL 414 int net_sysctl_init(void); 415 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 416 struct ctl_table *table); 417 void unregister_net_sysctl_table(struct ctl_table_header *header); 418 #else 419 static inline int net_sysctl_init(void) { return 0; } 420 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 421 const char *path, struct ctl_table *table) 422 { 423 return NULL; 424 } 425 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 426 { 427 } 428 #endif 429 430 static inline int rt_genid_ipv4(struct net *net) 431 { 432 return atomic_read(&net->ipv4.rt_genid); 433 } 434 435 static inline void rt_genid_bump_ipv4(struct net *net) 436 { 437 atomic_inc(&net->ipv4.rt_genid); 438 } 439 440 extern void (*__fib6_flush_trees)(struct net *net); 441 static inline void rt_genid_bump_ipv6(struct net *net) 442 { 443 if (__fib6_flush_trees) 444 __fib6_flush_trees(net); 445 } 446 447 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 448 static inline struct netns_ieee802154_lowpan * 449 net_ieee802154_lowpan(struct net *net) 450 { 451 return &net->ieee802154_lowpan; 452 } 453 #endif 454 455 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 456 static inline void rt_genid_bump_all(struct net *net) 457 { 458 rt_genid_bump_ipv4(net); 459 rt_genid_bump_ipv6(net); 460 } 461 462 static inline int fnhe_genid(struct net *net) 463 { 464 return atomic_read(&net->fnhe_genid); 465 } 466 467 static inline void fnhe_genid_bump(struct net *net) 468 { 469 atomic_inc(&net->fnhe_genid); 470 } 471 472 #endif /* __NET_NET_NAMESPACE_H */ 473