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 struct ctl_table_header *nf_frag_frags_hdr; 132 #endif 133 struct sock *nfnl; 134 struct sock *nfnl_stash; 135 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT) 136 struct list_head nfnl_acct_list; 137 #endif 138 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 139 struct list_head nfct_timeout_list; 140 #endif 141 #endif 142 #ifdef CONFIG_WEXT_CORE 143 struct sk_buff_head wext_nlevents; 144 #endif 145 struct net_generic __rcu *gen; 146 147 /* Note : following structs are cache line aligned */ 148 #ifdef CONFIG_XFRM 149 struct netns_xfrm xfrm; 150 #endif 151 #if IS_ENABLED(CONFIG_IP_VS) 152 struct netns_ipvs *ipvs; 153 #endif 154 #if IS_ENABLED(CONFIG_MPLS) 155 struct netns_mpls mpls; 156 #endif 157 #if IS_ENABLED(CONFIG_CAN) 158 struct netns_can can; 159 #endif 160 struct sock *diag_nlsk; 161 atomic_t fnhe_genid; 162 } __randomize_layout; 163 164 #include <linux/seq_file_net.h> 165 166 /* Init's network namespace */ 167 extern struct net init_net; 168 169 #ifdef CONFIG_NET_NS 170 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 171 struct net *old_net); 172 173 void net_ns_barrier(void); 174 #else /* CONFIG_NET_NS */ 175 #include <linux/sched.h> 176 #include <linux/nsproxy.h> 177 static inline struct net *copy_net_ns(unsigned long flags, 178 struct user_namespace *user_ns, struct net *old_net) 179 { 180 if (flags & CLONE_NEWNET) 181 return ERR_PTR(-EINVAL); 182 return old_net; 183 } 184 185 static inline void net_ns_barrier(void) {} 186 #endif /* CONFIG_NET_NS */ 187 188 189 extern struct list_head net_namespace_list; 190 191 struct net *get_net_ns_by_pid(pid_t pid); 192 struct net *get_net_ns_by_fd(int fd); 193 194 #ifdef CONFIG_SYSCTL 195 void ipx_register_sysctl(void); 196 void ipx_unregister_sysctl(void); 197 #else 198 #define ipx_register_sysctl() 199 #define ipx_unregister_sysctl() 200 #endif 201 202 #ifdef CONFIG_NET_NS 203 void __put_net(struct net *net); 204 205 static inline struct net *get_net(struct net *net) 206 { 207 refcount_inc(&net->count); 208 return net; 209 } 210 211 static inline struct net *maybe_get_net(struct net *net) 212 { 213 /* Used when we know struct net exists but we 214 * aren't guaranteed a previous reference count 215 * exists. If the reference count is zero this 216 * function fails and returns NULL. 217 */ 218 if (!refcount_inc_not_zero(&net->count)) 219 net = NULL; 220 return net; 221 } 222 223 static inline void put_net(struct net *net) 224 { 225 if (refcount_dec_and_test(&net->count)) 226 __put_net(net); 227 } 228 229 static inline 230 int net_eq(const struct net *net1, const struct net *net2) 231 { 232 return net1 == net2; 233 } 234 235 static inline int check_net(const struct net *net) 236 { 237 return refcount_read(&net->count) != 0; 238 } 239 240 void net_drop_ns(void *); 241 242 #else 243 244 static inline struct net *get_net(struct net *net) 245 { 246 return net; 247 } 248 249 static inline void put_net(struct net *net) 250 { 251 } 252 253 static inline struct net *maybe_get_net(struct net *net) 254 { 255 return net; 256 } 257 258 static inline 259 int net_eq(const struct net *net1, const struct net *net2) 260 { 261 return 1; 262 } 263 264 static inline int check_net(const struct net *net) 265 { 266 return 1; 267 } 268 269 #define net_drop_ns NULL 270 #endif 271 272 273 typedef struct { 274 #ifdef CONFIG_NET_NS 275 struct net *net; 276 #endif 277 } possible_net_t; 278 279 static inline void write_pnet(possible_net_t *pnet, struct net *net) 280 { 281 #ifdef CONFIG_NET_NS 282 pnet->net = net; 283 #endif 284 } 285 286 static inline struct net *read_pnet(const possible_net_t *pnet) 287 { 288 #ifdef CONFIG_NET_NS 289 return pnet->net; 290 #else 291 return &init_net; 292 #endif 293 } 294 295 /* Protected by net_rwsem */ 296 #define for_each_net(VAR) \ 297 list_for_each_entry(VAR, &net_namespace_list, list) 298 299 #define for_each_net_rcu(VAR) \ 300 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 301 302 #ifdef CONFIG_NET_NS 303 #define __net_init 304 #define __net_exit 305 #define __net_initdata 306 #define __net_initconst 307 #else 308 #define __net_init __init 309 #define __net_exit __ref 310 #define __net_initdata __initdata 311 #define __net_initconst __initconst 312 #endif 313 314 int peernet2id_alloc(struct net *net, struct net *peer); 315 int peernet2id(struct net *net, struct net *peer); 316 bool peernet_has_id(struct net *net, struct net *peer); 317 struct net *get_net_ns_by_id(struct net *net, int id); 318 319 struct pernet_operations { 320 struct list_head list; 321 /* 322 * Below methods are called without any exclusive locks. 323 * More than one net may be constructed and destructed 324 * in parallel on several cpus. Every pernet_operations 325 * have to keep in mind all other pernet_operations and 326 * to introduce a locking, if they share common resources. 327 * 328 * The only time they are called with exclusive lock is 329 * from register_pernet_subsys(), unregister_pernet_subsys() 330 * register_pernet_device() and unregister_pernet_device(). 331 * 332 * Exit methods using blocking RCU primitives, such as 333 * synchronize_rcu(), should be implemented via exit_batch. 334 * Then, destruction of a group of net requires single 335 * synchronize_rcu() related to these pernet_operations, 336 * instead of separate synchronize_rcu() for every net. 337 * Please, avoid synchronize_rcu() at all, where it's possible. 338 */ 339 int (*init)(struct net *net); 340 void (*exit)(struct net *net); 341 void (*exit_batch)(struct list_head *net_exit_list); 342 unsigned int *id; 343 size_t size; 344 }; 345 346 /* 347 * Use these carefully. If you implement a network device and it 348 * needs per network namespace operations use device pernet operations, 349 * otherwise use pernet subsys operations. 350 * 351 * Network interfaces need to be removed from a dying netns _before_ 352 * subsys notifiers can be called, as most of the network code cleanup 353 * (which is done from subsys notifiers) runs with the assumption that 354 * dev_remove_pack has been called so no new packets will arrive during 355 * and after the cleanup functions have been called. dev_remove_pack 356 * is not per namespace so instead the guarantee of no more packets 357 * arriving in a network namespace is provided by ensuring that all 358 * network devices and all sockets have left the network namespace 359 * before the cleanup methods are called. 360 * 361 * For the longest time the ipv4 icmp code was registered as a pernet 362 * device which caused kernel oops, and panics during network 363 * namespace cleanup. So please don't get this wrong. 364 */ 365 int register_pernet_subsys(struct pernet_operations *); 366 void unregister_pernet_subsys(struct pernet_operations *); 367 int register_pernet_device(struct pernet_operations *); 368 void unregister_pernet_device(struct pernet_operations *); 369 370 struct ctl_table; 371 struct ctl_table_header; 372 373 #ifdef CONFIG_SYSCTL 374 int net_sysctl_init(void); 375 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 376 struct ctl_table *table); 377 void unregister_net_sysctl_table(struct ctl_table_header *header); 378 #else 379 static inline int net_sysctl_init(void) { return 0; } 380 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 381 const char *path, struct ctl_table *table) 382 { 383 return NULL; 384 } 385 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 386 { 387 } 388 #endif 389 390 static inline int rt_genid_ipv4(struct net *net) 391 { 392 return atomic_read(&net->ipv4.rt_genid); 393 } 394 395 static inline void rt_genid_bump_ipv4(struct net *net) 396 { 397 atomic_inc(&net->ipv4.rt_genid); 398 } 399 400 extern void (*__fib6_flush_trees)(struct net *net); 401 static inline void rt_genid_bump_ipv6(struct net *net) 402 { 403 if (__fib6_flush_trees) 404 __fib6_flush_trees(net); 405 } 406 407 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 408 static inline struct netns_ieee802154_lowpan * 409 net_ieee802154_lowpan(struct net *net) 410 { 411 return &net->ieee802154_lowpan; 412 } 413 #endif 414 415 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 416 static inline void rt_genid_bump_all(struct net *net) 417 { 418 rt_genid_bump_ipv4(net); 419 rt_genid_bump_ipv6(net); 420 } 421 422 static inline int fnhe_genid(struct net *net) 423 { 424 return atomic_read(&net->fnhe_genid); 425 } 426 427 static inline void fnhe_genid_bump(struct net *net) 428 { 429 atomic_inc(&net->fnhe_genid); 430 } 431 432 #endif /* __NET_NET_NAMESPACE_H */ 433