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 40 struct user_namespace; 41 struct proc_dir_entry; 42 struct net_device; 43 struct sock; 44 struct ctl_table_header; 45 struct net_generic; 46 struct uevent_sock; 47 struct netns_ipvs; 48 struct bpf_prog; 49 50 51 #define NETDEV_HASHBITS 8 52 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 53 54 struct net { 55 refcount_t passive; /* To decided when the network 56 * namespace should be freed. 57 */ 58 refcount_t count; /* To decided when the network 59 * namespace should be shut down. 60 */ 61 spinlock_t rules_mod_lock; 62 63 u32 hash_mix; 64 atomic64_t cookie_gen; 65 66 struct list_head list; /* list of network namespaces */ 67 struct list_head exit_list; /* To linked to call pernet exit 68 * methods on dead net ( 69 * pernet_ops_rwsem read locked), 70 * or to unregister pernet ops 71 * (pernet_ops_rwsem write locked). 72 */ 73 struct llist_node cleanup_list; /* namespaces on death row */ 74 75 #ifdef CONFIG_KEYS 76 struct key_tag *key_domain; /* Key domain of operation tag */ 77 #endif 78 struct user_namespace *user_ns; /* Owning user namespace */ 79 struct ucounts *ucounts; 80 spinlock_t nsid_lock; 81 struct idr netns_ids; 82 83 struct ns_common ns; 84 85 struct proc_dir_entry *proc_net; 86 struct proc_dir_entry *proc_net_stat; 87 88 #ifdef CONFIG_SYSCTL 89 struct ctl_table_set sysctls; 90 #endif 91 92 struct sock *rtnl; /* rtnetlink socket */ 93 struct sock *genl_sock; 94 95 struct uevent_sock *uevent_sock; /* uevent socket */ 96 97 struct list_head dev_base_head; 98 struct hlist_head *dev_name_head; 99 struct hlist_head *dev_index_head; 100 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 101 int ifindex; 102 unsigned int dev_unreg_count; 103 104 /* core fib_rules */ 105 struct list_head rules_ops; 106 107 struct list_head fib_notifier_ops; /* Populated by 108 * register_pernet_subsys() 109 */ 110 struct net_device *loopback_dev; /* The loopback */ 111 struct netns_core core; 112 struct netns_mib mib; 113 struct netns_packet packet; 114 struct netns_unix unx; 115 struct netns_nexthop nexthop; 116 struct netns_ipv4 ipv4; 117 #if IS_ENABLED(CONFIG_IPV6) 118 struct netns_ipv6 ipv6; 119 #endif 120 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 121 struct netns_ieee802154_lowpan ieee802154_lowpan; 122 #endif 123 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 124 struct netns_sctp sctp; 125 #endif 126 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 127 struct netns_dccp dccp; 128 #endif 129 #ifdef CONFIG_NETFILTER 130 struct netns_nf nf; 131 struct netns_xt xt; 132 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 133 struct netns_ct ct; 134 #endif 135 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 136 struct netns_nftables nft; 137 #endif 138 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 139 struct netns_nf_frag nf_frag; 140 struct ctl_table_header *nf_frag_frags_hdr; 141 #endif 142 struct sock *nfnl; 143 struct sock *nfnl_stash; 144 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT) 145 struct list_head nfnl_acct_list; 146 #endif 147 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 148 struct list_head nfct_timeout_list; 149 #endif 150 #endif 151 #ifdef CONFIG_WEXT_CORE 152 struct sk_buff_head wext_nlevents; 153 #endif 154 struct net_generic __rcu *gen; 155 156 struct bpf_prog __rcu *flow_dissector_prog; 157 158 /* Note : following structs are cache line aligned */ 159 #ifdef CONFIG_XFRM 160 struct netns_xfrm xfrm; 161 #endif 162 #if IS_ENABLED(CONFIG_IP_VS) 163 struct netns_ipvs *ipvs; 164 #endif 165 #if IS_ENABLED(CONFIG_MPLS) 166 struct netns_mpls mpls; 167 #endif 168 #if IS_ENABLED(CONFIG_CAN) 169 struct netns_can can; 170 #endif 171 #ifdef CONFIG_XDP_SOCKETS 172 struct netns_xdp xdp; 173 #endif 174 struct sock *diag_nlsk; 175 atomic_t fnhe_genid; 176 } __randomize_layout; 177 178 #include <linux/seq_file_net.h> 179 180 /* Init's network namespace */ 181 extern struct net init_net; 182 183 #ifdef CONFIG_NET_NS 184 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 185 struct net *old_net); 186 187 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 188 189 void net_ns_barrier(void); 190 #else /* CONFIG_NET_NS */ 191 #include <linux/sched.h> 192 #include <linux/nsproxy.h> 193 static inline struct net *copy_net_ns(unsigned long flags, 194 struct user_namespace *user_ns, struct net *old_net) 195 { 196 if (flags & CLONE_NEWNET) 197 return ERR_PTR(-EINVAL); 198 return old_net; 199 } 200 201 static inline void net_ns_get_ownership(const struct net *net, 202 kuid_t *uid, kgid_t *gid) 203 { 204 *uid = GLOBAL_ROOT_UID; 205 *gid = GLOBAL_ROOT_GID; 206 } 207 208 static inline void net_ns_barrier(void) {} 209 #endif /* CONFIG_NET_NS */ 210 211 212 extern struct list_head net_namespace_list; 213 214 struct net *get_net_ns_by_pid(pid_t pid); 215 struct net *get_net_ns_by_fd(int fd); 216 217 #ifdef CONFIG_SYSCTL 218 void ipx_register_sysctl(void); 219 void ipx_unregister_sysctl(void); 220 #else 221 #define ipx_register_sysctl() 222 #define ipx_unregister_sysctl() 223 #endif 224 225 #ifdef CONFIG_NET_NS 226 void __put_net(struct net *net); 227 228 static inline struct net *get_net(struct net *net) 229 { 230 refcount_inc(&net->count); 231 return net; 232 } 233 234 static inline struct net *maybe_get_net(struct net *net) 235 { 236 /* Used when we know struct net exists but we 237 * aren't guaranteed a previous reference count 238 * exists. If the reference count is zero this 239 * function fails and returns NULL. 240 */ 241 if (!refcount_inc_not_zero(&net->count)) 242 net = NULL; 243 return net; 244 } 245 246 static inline void put_net(struct net *net) 247 { 248 if (refcount_dec_and_test(&net->count)) 249 __put_net(net); 250 } 251 252 static inline 253 int net_eq(const struct net *net1, const struct net *net2) 254 { 255 return net1 == net2; 256 } 257 258 static inline int check_net(const struct net *net) 259 { 260 return refcount_read(&net->count) != 0; 261 } 262 263 void net_drop_ns(void *); 264 265 #else 266 267 static inline struct net *get_net(struct net *net) 268 { 269 return net; 270 } 271 272 static inline void put_net(struct net *net) 273 { 274 } 275 276 static inline struct net *maybe_get_net(struct net *net) 277 { 278 return net; 279 } 280 281 static inline 282 int net_eq(const struct net *net1, const struct net *net2) 283 { 284 return 1; 285 } 286 287 static inline int check_net(const struct net *net) 288 { 289 return 1; 290 } 291 292 #define net_drop_ns NULL 293 #endif 294 295 296 typedef struct { 297 #ifdef CONFIG_NET_NS 298 struct net *net; 299 #endif 300 } possible_net_t; 301 302 static inline void write_pnet(possible_net_t *pnet, struct net *net) 303 { 304 #ifdef CONFIG_NET_NS 305 pnet->net = net; 306 #endif 307 } 308 309 static inline struct net *read_pnet(const possible_net_t *pnet) 310 { 311 #ifdef CONFIG_NET_NS 312 return pnet->net; 313 #else 314 return &init_net; 315 #endif 316 } 317 318 /* Protected by net_rwsem */ 319 #define for_each_net(VAR) \ 320 list_for_each_entry(VAR, &net_namespace_list, list) 321 322 #define for_each_net_rcu(VAR) \ 323 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 324 325 #ifdef CONFIG_NET_NS 326 #define __net_init 327 #define __net_exit 328 #define __net_initdata 329 #define __net_initconst 330 #else 331 #define __net_init __init 332 #define __net_exit __ref 333 #define __net_initdata __initdata 334 #define __net_initconst __initconst 335 #endif 336 337 int peernet2id_alloc(struct net *net, struct net *peer); 338 int peernet2id(struct net *net, struct net *peer); 339 bool peernet_has_id(struct net *net, struct net *peer); 340 struct net *get_net_ns_by_id(struct net *net, int id); 341 342 struct pernet_operations { 343 struct list_head list; 344 /* 345 * Below methods are called without any exclusive locks. 346 * More than one net may be constructed and destructed 347 * in parallel on several cpus. Every pernet_operations 348 * have to keep in mind all other pernet_operations and 349 * to introduce a locking, if they share common resources. 350 * 351 * The only time they are called with exclusive lock is 352 * from register_pernet_subsys(), unregister_pernet_subsys() 353 * register_pernet_device() and unregister_pernet_device(). 354 * 355 * Exit methods using blocking RCU primitives, such as 356 * synchronize_rcu(), should be implemented via exit_batch. 357 * Then, destruction of a group of net requires single 358 * synchronize_rcu() related to these pernet_operations, 359 * instead of separate synchronize_rcu() for every net. 360 * Please, avoid synchronize_rcu() at all, where it's possible. 361 * 362 * Note that a combination of pre_exit() and exit() can 363 * be used, since a synchronize_rcu() is guaranteed between 364 * the calls. 365 */ 366 int (*init)(struct net *net); 367 void (*pre_exit)(struct net *net); 368 void (*exit)(struct net *net); 369 void (*exit_batch)(struct list_head *net_exit_list); 370 unsigned int *id; 371 size_t size; 372 }; 373 374 /* 375 * Use these carefully. If you implement a network device and it 376 * needs per network namespace operations use device pernet operations, 377 * otherwise use pernet subsys operations. 378 * 379 * Network interfaces need to be removed from a dying netns _before_ 380 * subsys notifiers can be called, as most of the network code cleanup 381 * (which is done from subsys notifiers) runs with the assumption that 382 * dev_remove_pack has been called so no new packets will arrive during 383 * and after the cleanup functions have been called. dev_remove_pack 384 * is not per namespace so instead the guarantee of no more packets 385 * arriving in a network namespace is provided by ensuring that all 386 * network devices and all sockets have left the network namespace 387 * before the cleanup methods are called. 388 * 389 * For the longest time the ipv4 icmp code was registered as a pernet 390 * device which caused kernel oops, and panics during network 391 * namespace cleanup. So please don't get this wrong. 392 */ 393 int register_pernet_subsys(struct pernet_operations *); 394 void unregister_pernet_subsys(struct pernet_operations *); 395 int register_pernet_device(struct pernet_operations *); 396 void unregister_pernet_device(struct pernet_operations *); 397 398 struct ctl_table; 399 struct ctl_table_header; 400 401 #ifdef CONFIG_SYSCTL 402 int net_sysctl_init(void); 403 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 404 struct ctl_table *table); 405 void unregister_net_sysctl_table(struct ctl_table_header *header); 406 #else 407 static inline int net_sysctl_init(void) { return 0; } 408 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 409 const char *path, struct ctl_table *table) 410 { 411 return NULL; 412 } 413 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 414 { 415 } 416 #endif 417 418 static inline int rt_genid_ipv4(struct net *net) 419 { 420 return atomic_read(&net->ipv4.rt_genid); 421 } 422 423 static inline void rt_genid_bump_ipv4(struct net *net) 424 { 425 atomic_inc(&net->ipv4.rt_genid); 426 } 427 428 extern void (*__fib6_flush_trees)(struct net *net); 429 static inline void rt_genid_bump_ipv6(struct net *net) 430 { 431 if (__fib6_flush_trees) 432 __fib6_flush_trees(net); 433 } 434 435 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 436 static inline struct netns_ieee802154_lowpan * 437 net_ieee802154_lowpan(struct net *net) 438 { 439 return &net->ieee802154_lowpan; 440 } 441 #endif 442 443 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 444 static inline void rt_genid_bump_all(struct net *net) 445 { 446 rt_genid_bump_ipv4(net); 447 rt_genid_bump_ipv6(net); 448 } 449 450 static inline int fnhe_genid(struct net *net) 451 { 452 return atomic_read(&net->fnhe_genid); 453 } 454 455 static inline void fnhe_genid_bump(struct net *net) 456 { 457 atomic_inc(&net->fnhe_genid); 458 } 459 460 #endif /* __NET_NET_NAMESPACE_H */ 461