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