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 14 #include <net/flow.h> 15 #include <net/netns/core.h> 16 #include <net/netns/mib.h> 17 #include <net/netns/unix.h> 18 #include <net/netns/packet.h> 19 #include <net/netns/ipv4.h> 20 #include <net/netns/ipv6.h> 21 #include <net/netns/ieee802154_6lowpan.h> 22 #include <net/netns/sctp.h> 23 #include <net/netns/dccp.h> 24 #include <net/netns/netfilter.h> 25 #include <net/netns/x_tables.h> 26 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 27 #include <net/netns/conntrack.h> 28 #endif 29 #include <net/netns/nftables.h> 30 #include <net/netns/xfrm.h> 31 #include <net/netns/mpls.h> 32 #include <net/netns/can.h> 33 #include <linux/ns_common.h> 34 #include <linux/idr.h> 35 #include <linux/skbuff.h> 36 37 struct user_namespace; 38 struct proc_dir_entry; 39 struct net_device; 40 struct sock; 41 struct ctl_table_header; 42 struct net_generic; 43 struct uevent_sock; 44 struct netns_ipvs; 45 46 47 #define NETDEV_HASHBITS 8 48 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 49 50 struct net { 51 refcount_t passive; /* To decided when the network 52 * namespace should be freed. 53 */ 54 refcount_t count; /* To decided when the network 55 * namespace should be shut down. 56 */ 57 spinlock_t rules_mod_lock; 58 59 atomic64_t cookie_gen; 60 61 struct list_head list; /* list of network namespaces */ 62 struct list_head exit_list; /* To linked to call pernet exit 63 * methods on dead net ( 64 * pernet_ops_rwsem read locked), 65 * or to unregister pernet ops 66 * (pernet_ops_rwsem write locked). 67 */ 68 struct llist_node cleanup_list; /* namespaces on death row */ 69 70 struct user_namespace *user_ns; /* Owning user namespace */ 71 struct ucounts *ucounts; 72 spinlock_t nsid_lock; 73 struct idr netns_ids; 74 75 struct ns_common ns; 76 77 struct proc_dir_entry *proc_net; 78 struct proc_dir_entry *proc_net_stat; 79 80 #ifdef CONFIG_SYSCTL 81 struct ctl_table_set sysctls; 82 #endif 83 84 struct sock *rtnl; /* rtnetlink socket */ 85 struct sock *genl_sock; 86 87 struct uevent_sock *uevent_sock; /* uevent socket */ 88 89 struct list_head dev_base_head; 90 struct hlist_head *dev_name_head; 91 struct hlist_head *dev_index_head; 92 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 93 int ifindex; 94 unsigned int dev_unreg_count; 95 96 /* core fib_rules */ 97 struct list_head rules_ops; 98 99 struct list_head fib_notifier_ops; /* Populated by 100 * register_pernet_subsys() 101 */ 102 struct net_device *loopback_dev; /* The loopback */ 103 struct netns_core core; 104 struct netns_mib mib; 105 struct netns_packet packet; 106 struct netns_unix unx; 107 struct netns_ipv4 ipv4; 108 #if IS_ENABLED(CONFIG_IPV6) 109 struct netns_ipv6 ipv6; 110 #endif 111 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 112 struct netns_ieee802154_lowpan ieee802154_lowpan; 113 #endif 114 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 115 struct netns_sctp sctp; 116 #endif 117 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 118 struct netns_dccp dccp; 119 #endif 120 #ifdef CONFIG_NETFILTER 121 struct netns_nf nf; 122 struct netns_xt xt; 123 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 124 struct netns_ct ct; 125 #endif 126 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 127 struct netns_nftables nft; 128 #endif 129 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 130 struct netns_nf_frag nf_frag; 131 #endif 132 struct sock *nfnl; 133 struct sock *nfnl_stash; 134 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT) 135 struct list_head nfnl_acct_list; 136 #endif 137 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 138 struct list_head nfct_timeout_list; 139 #endif 140 #endif 141 #ifdef CONFIG_WEXT_CORE 142 struct sk_buff_head wext_nlevents; 143 #endif 144 struct net_generic __rcu *gen; 145 146 /* Note : following structs are cache line aligned */ 147 #ifdef CONFIG_XFRM 148 struct netns_xfrm xfrm; 149 #endif 150 #if IS_ENABLED(CONFIG_IP_VS) 151 struct netns_ipvs *ipvs; 152 #endif 153 #if IS_ENABLED(CONFIG_MPLS) 154 struct netns_mpls mpls; 155 #endif 156 #if IS_ENABLED(CONFIG_CAN) 157 struct netns_can can; 158 #endif 159 struct sock *diag_nlsk; 160 atomic_t fnhe_genid; 161 } __randomize_layout; 162 163 #include <linux/seq_file_net.h> 164 165 /* Init's network namespace */ 166 extern struct net init_net; 167 168 #ifdef CONFIG_NET_NS 169 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 170 struct net *old_net); 171 172 void net_ns_barrier(void); 173 #else /* CONFIG_NET_NS */ 174 #include <linux/sched.h> 175 #include <linux/nsproxy.h> 176 static inline struct net *copy_net_ns(unsigned long flags, 177 struct user_namespace *user_ns, struct net *old_net) 178 { 179 if (flags & CLONE_NEWNET) 180 return ERR_PTR(-EINVAL); 181 return old_net; 182 } 183 184 static inline void net_ns_barrier(void) {} 185 #endif /* CONFIG_NET_NS */ 186 187 188 extern struct list_head net_namespace_list; 189 190 struct net *get_net_ns_by_pid(pid_t pid); 191 struct net *get_net_ns_by_fd(int fd); 192 193 #ifdef CONFIG_SYSCTL 194 void ipx_register_sysctl(void); 195 void ipx_unregister_sysctl(void); 196 #else 197 #define ipx_register_sysctl() 198 #define ipx_unregister_sysctl() 199 #endif 200 201 #ifdef CONFIG_NET_NS 202 void __put_net(struct net *net); 203 204 static inline struct net *get_net(struct net *net) 205 { 206 refcount_inc(&net->count); 207 return net; 208 } 209 210 static inline struct net *maybe_get_net(struct net *net) 211 { 212 /* Used when we know struct net exists but we 213 * aren't guaranteed a previous reference count 214 * exists. If the reference count is zero this 215 * function fails and returns NULL. 216 */ 217 if (!refcount_inc_not_zero(&net->count)) 218 net = NULL; 219 return net; 220 } 221 222 static inline void put_net(struct net *net) 223 { 224 if (refcount_dec_and_test(&net->count)) 225 __put_net(net); 226 } 227 228 static inline 229 int net_eq(const struct net *net1, const struct net *net2) 230 { 231 return net1 == net2; 232 } 233 234 static inline int check_net(const struct net *net) 235 { 236 return refcount_read(&net->count) != 0; 237 } 238 239 void net_drop_ns(void *); 240 241 #else 242 243 static inline struct net *get_net(struct net *net) 244 { 245 return net; 246 } 247 248 static inline void put_net(struct net *net) 249 { 250 } 251 252 static inline struct net *maybe_get_net(struct net *net) 253 { 254 return net; 255 } 256 257 static inline 258 int net_eq(const struct net *net1, const struct net *net2) 259 { 260 return 1; 261 } 262 263 static inline int check_net(const struct net *net) 264 { 265 return 1; 266 } 267 268 #define net_drop_ns NULL 269 #endif 270 271 272 typedef struct { 273 #ifdef CONFIG_NET_NS 274 struct net *net; 275 #endif 276 } possible_net_t; 277 278 static inline void write_pnet(possible_net_t *pnet, struct net *net) 279 { 280 #ifdef CONFIG_NET_NS 281 pnet->net = net; 282 #endif 283 } 284 285 static inline struct net *read_pnet(const possible_net_t *pnet) 286 { 287 #ifdef CONFIG_NET_NS 288 return pnet->net; 289 #else 290 return &init_net; 291 #endif 292 } 293 294 /* Protected by net_rwsem */ 295 #define for_each_net(VAR) \ 296 list_for_each_entry(VAR, &net_namespace_list, list) 297 298 #define for_each_net_rcu(VAR) \ 299 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 300 301 #ifdef CONFIG_NET_NS 302 #define __net_init 303 #define __net_exit 304 #define __net_initdata 305 #define __net_initconst 306 #else 307 #define __net_init __init 308 #define __net_exit __ref 309 #define __net_initdata __initdata 310 #define __net_initconst __initconst 311 #endif 312 313 int peernet2id_alloc(struct net *net, struct net *peer); 314 int peernet2id(struct net *net, struct net *peer); 315 bool peernet_has_id(struct net *net, struct net *peer); 316 struct net *get_net_ns_by_id(struct net *net, int id); 317 318 struct pernet_operations { 319 struct list_head list; 320 /* 321 * Below methods are called without any exclusive locks. 322 * More than one net may be constructed and destructed 323 * in parallel on several cpus. Every pernet_operations 324 * have to keep in mind all other pernet_operations and 325 * to introduce a locking, if they share common resources. 326 * 327 * The only time they are called with exclusive lock is 328 * from register_pernet_subsys(), unregister_pernet_subsys() 329 * register_pernet_device() and unregister_pernet_device(). 330 * 331 * Exit methods using blocking RCU primitives, such as 332 * synchronize_rcu(), should be implemented via exit_batch. 333 * Then, destruction of a group of net requires single 334 * synchronize_rcu() related to these pernet_operations, 335 * instead of separate synchronize_rcu() for every net. 336 * Please, avoid synchronize_rcu() at all, where it's possible. 337 */ 338 int (*init)(struct net *net); 339 void (*exit)(struct net *net); 340 void (*exit_batch)(struct list_head *net_exit_list); 341 unsigned int *id; 342 size_t size; 343 }; 344 345 /* 346 * Use these carefully. If you implement a network device and it 347 * needs per network namespace operations use device pernet operations, 348 * otherwise use pernet subsys operations. 349 * 350 * Network interfaces need to be removed from a dying netns _before_ 351 * subsys notifiers can be called, as most of the network code cleanup 352 * (which is done from subsys notifiers) runs with the assumption that 353 * dev_remove_pack has been called so no new packets will arrive during 354 * and after the cleanup functions have been called. dev_remove_pack 355 * is not per namespace so instead the guarantee of no more packets 356 * arriving in a network namespace is provided by ensuring that all 357 * network devices and all sockets have left the network namespace 358 * before the cleanup methods are called. 359 * 360 * For the longest time the ipv4 icmp code was registered as a pernet 361 * device which caused kernel oops, and panics during network 362 * namespace cleanup. So please don't get this wrong. 363 */ 364 int register_pernet_subsys(struct pernet_operations *); 365 void unregister_pernet_subsys(struct pernet_operations *); 366 int register_pernet_device(struct pernet_operations *); 367 void unregister_pernet_device(struct pernet_operations *); 368 369 struct ctl_table; 370 struct ctl_table_header; 371 372 #ifdef CONFIG_SYSCTL 373 int net_sysctl_init(void); 374 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 375 struct ctl_table *table); 376 void unregister_net_sysctl_table(struct ctl_table_header *header); 377 #else 378 static inline int net_sysctl_init(void) { return 0; } 379 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 380 const char *path, struct ctl_table *table) 381 { 382 return NULL; 383 } 384 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 385 { 386 } 387 #endif 388 389 static inline int rt_genid_ipv4(struct net *net) 390 { 391 return atomic_read(&net->ipv4.rt_genid); 392 } 393 394 static inline void rt_genid_bump_ipv4(struct net *net) 395 { 396 atomic_inc(&net->ipv4.rt_genid); 397 } 398 399 extern void (*__fib6_flush_trees)(struct net *net); 400 static inline void rt_genid_bump_ipv6(struct net *net) 401 { 402 if (__fib6_flush_trees) 403 __fib6_flush_trees(net); 404 } 405 406 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 407 static inline struct netns_ieee802154_lowpan * 408 net_ieee802154_lowpan(struct net *net) 409 { 410 return &net->ieee802154_lowpan; 411 } 412 #endif 413 414 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 415 static inline void rt_genid_bump_all(struct net *net) 416 { 417 rt_genid_bump_ipv4(net); 418 rt_genid_bump_ipv6(net); 419 } 420 421 static inline int fnhe_genid(struct net *net) 422 { 423 return atomic_read(&net->fnhe_genid); 424 } 425 426 static inline void fnhe_genid_bump(struct net *net) 427 { 428 atomic_inc(&net->fnhe_genid); 429 } 430 431 #endif /* __NET_NET_NAMESPACE_H */ 432