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/ieee802154_6lowpan.h> 23 #include <net/netns/sctp.h> 24 #include <net/netns/dccp.h> 25 #include <net/netns/netfilter.h> 26 #include <net/netns/x_tables.h> 27 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 28 #include <net/netns/conntrack.h> 29 #endif 30 #include <net/netns/nftables.h> 31 #include <net/netns/xfrm.h> 32 #include <net/netns/mpls.h> 33 #include <net/netns/can.h> 34 #include <linux/ns_common.h> 35 #include <linux/idr.h> 36 #include <linux/skbuff.h> 37 38 struct user_namespace; 39 struct proc_dir_entry; 40 struct net_device; 41 struct sock; 42 struct ctl_table_header; 43 struct net_generic; 44 struct uevent_sock; 45 struct netns_ipvs; 46 47 48 #define NETDEV_HASHBITS 8 49 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 50 51 struct net { 52 refcount_t passive; /* To decided when the network 53 * namespace should be freed. 54 */ 55 refcount_t count; /* To decided when the network 56 * namespace should be shut down. 57 */ 58 spinlock_t rules_mod_lock; 59 60 atomic64_t cookie_gen; 61 62 struct list_head list; /* list of network namespaces */ 63 struct list_head exit_list; /* To linked to call pernet exit 64 * methods on dead net ( 65 * pernet_ops_rwsem read locked), 66 * or to unregister pernet ops 67 * (pernet_ops_rwsem write locked). 68 */ 69 struct llist_node cleanup_list; /* namespaces on death row */ 70 71 struct user_namespace *user_ns; /* Owning user namespace */ 72 struct ucounts *ucounts; 73 spinlock_t nsid_lock; 74 struct idr netns_ids; 75 76 struct ns_common ns; 77 78 struct proc_dir_entry *proc_net; 79 struct proc_dir_entry *proc_net_stat; 80 81 #ifdef CONFIG_SYSCTL 82 struct ctl_table_set sysctls; 83 #endif 84 85 struct sock *rtnl; /* rtnetlink socket */ 86 struct sock *genl_sock; 87 88 struct uevent_sock *uevent_sock; /* uevent socket */ 89 90 struct list_head dev_base_head; 91 struct hlist_head *dev_name_head; 92 struct hlist_head *dev_index_head; 93 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 94 int ifindex; 95 unsigned int dev_unreg_count; 96 97 /* core fib_rules */ 98 struct list_head rules_ops; 99 100 struct list_head fib_notifier_ops; /* Populated by 101 * register_pernet_subsys() 102 */ 103 struct net_device *loopback_dev; /* The loopback */ 104 struct netns_core core; 105 struct netns_mib mib; 106 struct netns_packet packet; 107 struct netns_unix unx; 108 struct netns_ipv4 ipv4; 109 #if IS_ENABLED(CONFIG_IPV6) 110 struct netns_ipv6 ipv6; 111 #endif 112 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 113 struct netns_ieee802154_lowpan ieee802154_lowpan; 114 #endif 115 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 116 struct netns_sctp sctp; 117 #endif 118 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 119 struct netns_dccp dccp; 120 #endif 121 #ifdef CONFIG_NETFILTER 122 struct netns_nf nf; 123 struct netns_xt xt; 124 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 125 struct netns_ct ct; 126 #endif 127 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 128 struct netns_nftables nft; 129 #endif 130 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 131 struct netns_nf_frag nf_frag; 132 struct ctl_table_header *nf_frag_frags_hdr; 133 #endif 134 struct sock *nfnl; 135 struct sock *nfnl_stash; 136 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT) 137 struct list_head nfnl_acct_list; 138 #endif 139 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 140 struct list_head nfct_timeout_list; 141 #endif 142 #endif 143 #ifdef CONFIG_WEXT_CORE 144 struct sk_buff_head wext_nlevents; 145 #endif 146 struct net_generic __rcu *gen; 147 148 /* Note : following structs are cache line aligned */ 149 #ifdef CONFIG_XFRM 150 struct netns_xfrm xfrm; 151 #endif 152 #if IS_ENABLED(CONFIG_IP_VS) 153 struct netns_ipvs *ipvs; 154 #endif 155 #if IS_ENABLED(CONFIG_MPLS) 156 struct netns_mpls mpls; 157 #endif 158 #if IS_ENABLED(CONFIG_CAN) 159 struct netns_can can; 160 #endif 161 struct sock *diag_nlsk; 162 atomic_t fnhe_genid; 163 } __randomize_layout; 164 165 #include <linux/seq_file_net.h> 166 167 /* Init's network namespace */ 168 extern struct net init_net; 169 170 #ifdef CONFIG_NET_NS 171 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 172 struct net *old_net); 173 174 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 175 176 void net_ns_barrier(void); 177 #else /* CONFIG_NET_NS */ 178 #include <linux/sched.h> 179 #include <linux/nsproxy.h> 180 static inline struct net *copy_net_ns(unsigned long flags, 181 struct user_namespace *user_ns, struct net *old_net) 182 { 183 if (flags & CLONE_NEWNET) 184 return ERR_PTR(-EINVAL); 185 return old_net; 186 } 187 188 static inline void net_ns_get_ownership(const struct net *net, 189 kuid_t *uid, kgid_t *gid) 190 { 191 *uid = GLOBAL_ROOT_UID; 192 *gid = GLOBAL_ROOT_GID; 193 } 194 195 static inline void net_ns_barrier(void) {} 196 #endif /* CONFIG_NET_NS */ 197 198 199 extern struct list_head net_namespace_list; 200 201 struct net *get_net_ns_by_pid(pid_t pid); 202 struct net *get_net_ns_by_fd(int fd); 203 204 #ifdef CONFIG_SYSCTL 205 void ipx_register_sysctl(void); 206 void ipx_unregister_sysctl(void); 207 #else 208 #define ipx_register_sysctl() 209 #define ipx_unregister_sysctl() 210 #endif 211 212 #ifdef CONFIG_NET_NS 213 void __put_net(struct net *net); 214 215 static inline struct net *get_net(struct net *net) 216 { 217 refcount_inc(&net->count); 218 return net; 219 } 220 221 static inline struct net *maybe_get_net(struct net *net) 222 { 223 /* Used when we know struct net exists but we 224 * aren't guaranteed a previous reference count 225 * exists. If the reference count is zero this 226 * function fails and returns NULL. 227 */ 228 if (!refcount_inc_not_zero(&net->count)) 229 net = NULL; 230 return net; 231 } 232 233 static inline void put_net(struct net *net) 234 { 235 if (refcount_dec_and_test(&net->count)) 236 __put_net(net); 237 } 238 239 static inline 240 int net_eq(const struct net *net1, const struct net *net2) 241 { 242 return net1 == net2; 243 } 244 245 static inline int check_net(const struct net *net) 246 { 247 return refcount_read(&net->count) != 0; 248 } 249 250 void net_drop_ns(void *); 251 252 #else 253 254 static inline struct net *get_net(struct net *net) 255 { 256 return net; 257 } 258 259 static inline void put_net(struct net *net) 260 { 261 } 262 263 static inline struct net *maybe_get_net(struct net *net) 264 { 265 return net; 266 } 267 268 static inline 269 int net_eq(const struct net *net1, const struct net *net2) 270 { 271 return 1; 272 } 273 274 static inline int check_net(const struct net *net) 275 { 276 return 1; 277 } 278 279 #define net_drop_ns NULL 280 #endif 281 282 283 typedef struct { 284 #ifdef CONFIG_NET_NS 285 struct net *net; 286 #endif 287 } possible_net_t; 288 289 static inline void write_pnet(possible_net_t *pnet, struct net *net) 290 { 291 #ifdef CONFIG_NET_NS 292 pnet->net = net; 293 #endif 294 } 295 296 static inline struct net *read_pnet(const possible_net_t *pnet) 297 { 298 #ifdef CONFIG_NET_NS 299 return pnet->net; 300 #else 301 return &init_net; 302 #endif 303 } 304 305 /* Protected by net_rwsem */ 306 #define for_each_net(VAR) \ 307 list_for_each_entry(VAR, &net_namespace_list, list) 308 309 #define for_each_net_rcu(VAR) \ 310 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 311 312 #ifdef CONFIG_NET_NS 313 #define __net_init 314 #define __net_exit 315 #define __net_initdata 316 #define __net_initconst 317 #else 318 #define __net_init __init 319 #define __net_exit __ref 320 #define __net_initdata __initdata 321 #define __net_initconst __initconst 322 #endif 323 324 int peernet2id_alloc(struct net *net, struct net *peer); 325 int peernet2id(struct net *net, struct net *peer); 326 bool peernet_has_id(struct net *net, struct net *peer); 327 struct net *get_net_ns_by_id(struct net *net, int id); 328 329 struct pernet_operations { 330 struct list_head list; 331 /* 332 * Below methods are called without any exclusive locks. 333 * More than one net may be constructed and destructed 334 * in parallel on several cpus. Every pernet_operations 335 * have to keep in mind all other pernet_operations and 336 * to introduce a locking, if they share common resources. 337 * 338 * The only time they are called with exclusive lock is 339 * from register_pernet_subsys(), unregister_pernet_subsys() 340 * register_pernet_device() and unregister_pernet_device(). 341 * 342 * Exit methods using blocking RCU primitives, such as 343 * synchronize_rcu(), should be implemented via exit_batch. 344 * Then, destruction of a group of net requires single 345 * synchronize_rcu() related to these pernet_operations, 346 * instead of separate synchronize_rcu() for every net. 347 * Please, avoid synchronize_rcu() at all, where it's possible. 348 */ 349 int (*init)(struct net *net); 350 void (*exit)(struct net *net); 351 void (*exit_batch)(struct list_head *net_exit_list); 352 unsigned int *id; 353 size_t size; 354 }; 355 356 /* 357 * Use these carefully. If you implement a network device and it 358 * needs per network namespace operations use device pernet operations, 359 * otherwise use pernet subsys operations. 360 * 361 * Network interfaces need to be removed from a dying netns _before_ 362 * subsys notifiers can be called, as most of the network code cleanup 363 * (which is done from subsys notifiers) runs with the assumption that 364 * dev_remove_pack has been called so no new packets will arrive during 365 * and after the cleanup functions have been called. dev_remove_pack 366 * is not per namespace so instead the guarantee of no more packets 367 * arriving in a network namespace is provided by ensuring that all 368 * network devices and all sockets have left the network namespace 369 * before the cleanup methods are called. 370 * 371 * For the longest time the ipv4 icmp code was registered as a pernet 372 * device which caused kernel oops, and panics during network 373 * namespace cleanup. So please don't get this wrong. 374 */ 375 int register_pernet_subsys(struct pernet_operations *); 376 void unregister_pernet_subsys(struct pernet_operations *); 377 int register_pernet_device(struct pernet_operations *); 378 void unregister_pernet_device(struct pernet_operations *); 379 380 struct ctl_table; 381 struct ctl_table_header; 382 383 #ifdef CONFIG_SYSCTL 384 int net_sysctl_init(void); 385 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 386 struct ctl_table *table); 387 void unregister_net_sysctl_table(struct ctl_table_header *header); 388 #else 389 static inline int net_sysctl_init(void) { return 0; } 390 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 391 const char *path, struct ctl_table *table) 392 { 393 return NULL; 394 } 395 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 396 { 397 } 398 #endif 399 400 static inline int rt_genid_ipv4(struct net *net) 401 { 402 return atomic_read(&net->ipv4.rt_genid); 403 } 404 405 static inline void rt_genid_bump_ipv4(struct net *net) 406 { 407 atomic_inc(&net->ipv4.rt_genid); 408 } 409 410 extern void (*__fib6_flush_trees)(struct net *net); 411 static inline void rt_genid_bump_ipv6(struct net *net) 412 { 413 if (__fib6_flush_trees) 414 __fib6_flush_trees(net); 415 } 416 417 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 418 static inline struct netns_ieee802154_lowpan * 419 net_ieee802154_lowpan(struct net *net) 420 { 421 return &net->ieee802154_lowpan; 422 } 423 #endif 424 425 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 426 static inline void rt_genid_bump_all(struct net *net) 427 { 428 rt_genid_bump_ipv4(net); 429 rt_genid_bump_ipv6(net); 430 } 431 432 static inline int fnhe_genid(struct net *net) 433 { 434 return atomic_read(&net->fnhe_genid); 435 } 436 437 static inline void fnhe_genid_bump(struct net *net) 438 { 439 atomic_inc(&net->fnhe_genid); 440 } 441 442 #endif /* __NET_NET_NAMESPACE_H */ 443