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 <net/netns/xdp.h> 35 #include <linux/ns_common.h> 36 #include <linux/idr.h> 37 #include <linux/skbuff.h> 38 39 struct user_namespace; 40 struct proc_dir_entry; 41 struct net_device; 42 struct sock; 43 struct ctl_table_header; 44 struct net_generic; 45 struct uevent_sock; 46 struct netns_ipvs; 47 struct bpf_prog; 48 49 50 #define NETDEV_HASHBITS 8 51 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 52 53 struct net { 54 refcount_t passive; /* To decided when the network 55 * namespace should be freed. 56 */ 57 refcount_t count; /* To decided when the network 58 * namespace should be shut down. 59 */ 60 spinlock_t rules_mod_lock; 61 62 u32 hash_mix; 63 atomic64_t cookie_gen; 64 65 struct list_head list; /* list of network namespaces */ 66 struct list_head exit_list; /* To linked to call pernet exit 67 * methods on dead net ( 68 * pernet_ops_rwsem read locked), 69 * or to unregister pernet ops 70 * (pernet_ops_rwsem write locked). 71 */ 72 struct llist_node cleanup_list; /* namespaces on death row */ 73 74 struct user_namespace *user_ns; /* Owning user namespace */ 75 struct ucounts *ucounts; 76 spinlock_t nsid_lock; 77 struct idr netns_ids; 78 79 struct ns_common ns; 80 81 struct proc_dir_entry *proc_net; 82 struct proc_dir_entry *proc_net_stat; 83 84 #ifdef CONFIG_SYSCTL 85 struct ctl_table_set sysctls; 86 #endif 87 88 struct sock *rtnl; /* rtnetlink socket */ 89 struct sock *genl_sock; 90 91 struct uevent_sock *uevent_sock; /* uevent socket */ 92 93 struct list_head dev_base_head; 94 struct hlist_head *dev_name_head; 95 struct hlist_head *dev_index_head; 96 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 97 int ifindex; 98 unsigned int dev_unreg_count; 99 100 /* core fib_rules */ 101 struct list_head rules_ops; 102 103 struct list_head fib_notifier_ops; /* Populated by 104 * register_pernet_subsys() 105 */ 106 struct net_device *loopback_dev; /* The loopback */ 107 struct netns_core core; 108 struct netns_mib mib; 109 struct netns_packet packet; 110 struct netns_unix unx; 111 struct netns_ipv4 ipv4; 112 #if IS_ENABLED(CONFIG_IPV6) 113 struct netns_ipv6 ipv6; 114 #endif 115 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 116 struct netns_ieee802154_lowpan ieee802154_lowpan; 117 #endif 118 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 119 struct netns_sctp sctp; 120 #endif 121 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 122 struct netns_dccp dccp; 123 #endif 124 #ifdef CONFIG_NETFILTER 125 struct netns_nf nf; 126 struct netns_xt xt; 127 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 128 struct netns_ct ct; 129 #endif 130 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 131 struct netns_nftables nft; 132 #endif 133 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 134 struct netns_nf_frag nf_frag; 135 struct ctl_table_header *nf_frag_frags_hdr; 136 #endif 137 struct sock *nfnl; 138 struct sock *nfnl_stash; 139 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT) 140 struct list_head nfnl_acct_list; 141 #endif 142 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 143 struct list_head nfct_timeout_list; 144 #endif 145 #endif 146 #ifdef CONFIG_WEXT_CORE 147 struct sk_buff_head wext_nlevents; 148 #endif 149 struct net_generic __rcu *gen; 150 151 struct bpf_prog __rcu *flow_dissector_prog; 152 153 /* Note : following structs are cache line aligned */ 154 #ifdef CONFIG_XFRM 155 struct netns_xfrm xfrm; 156 #endif 157 #if IS_ENABLED(CONFIG_IP_VS) 158 struct netns_ipvs *ipvs; 159 #endif 160 #if IS_ENABLED(CONFIG_MPLS) 161 struct netns_mpls mpls; 162 #endif 163 #if IS_ENABLED(CONFIG_CAN) 164 struct netns_can can; 165 #endif 166 #ifdef CONFIG_XDP_SOCKETS 167 struct netns_xdp xdp; 168 #endif 169 struct sock *diag_nlsk; 170 atomic_t fnhe_genid; 171 } __randomize_layout; 172 173 #include <linux/seq_file_net.h> 174 175 /* Init's network namespace */ 176 extern struct net init_net; 177 178 #ifdef CONFIG_NET_NS 179 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 180 struct net *old_net); 181 182 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 183 184 void net_ns_barrier(void); 185 #else /* CONFIG_NET_NS */ 186 #include <linux/sched.h> 187 #include <linux/nsproxy.h> 188 static inline struct net *copy_net_ns(unsigned long flags, 189 struct user_namespace *user_ns, struct net *old_net) 190 { 191 if (flags & CLONE_NEWNET) 192 return ERR_PTR(-EINVAL); 193 return old_net; 194 } 195 196 static inline void net_ns_get_ownership(const struct net *net, 197 kuid_t *uid, kgid_t *gid) 198 { 199 *uid = GLOBAL_ROOT_UID; 200 *gid = GLOBAL_ROOT_GID; 201 } 202 203 static inline void net_ns_barrier(void) {} 204 #endif /* CONFIG_NET_NS */ 205 206 207 extern struct list_head net_namespace_list; 208 209 struct net *get_net_ns_by_pid(pid_t pid); 210 struct net *get_net_ns_by_fd(int fd); 211 212 #ifdef CONFIG_SYSCTL 213 void ipx_register_sysctl(void); 214 void ipx_unregister_sysctl(void); 215 #else 216 #define ipx_register_sysctl() 217 #define ipx_unregister_sysctl() 218 #endif 219 220 #ifdef CONFIG_NET_NS 221 void __put_net(struct net *net); 222 223 static inline struct net *get_net(struct net *net) 224 { 225 refcount_inc(&net->count); 226 return net; 227 } 228 229 static inline struct net *maybe_get_net(struct net *net) 230 { 231 /* Used when we know struct net exists but we 232 * aren't guaranteed a previous reference count 233 * exists. If the reference count is zero this 234 * function fails and returns NULL. 235 */ 236 if (!refcount_inc_not_zero(&net->count)) 237 net = NULL; 238 return net; 239 } 240 241 static inline void put_net(struct net *net) 242 { 243 if (refcount_dec_and_test(&net->count)) 244 __put_net(net); 245 } 246 247 static inline 248 int net_eq(const struct net *net1, const struct net *net2) 249 { 250 return net1 == net2; 251 } 252 253 static inline int check_net(const struct net *net) 254 { 255 return refcount_read(&net->count) != 0; 256 } 257 258 void net_drop_ns(void *); 259 260 #else 261 262 static inline struct net *get_net(struct net *net) 263 { 264 return net; 265 } 266 267 static inline void put_net(struct net *net) 268 { 269 } 270 271 static inline struct net *maybe_get_net(struct net *net) 272 { 273 return net; 274 } 275 276 static inline 277 int net_eq(const struct net *net1, const struct net *net2) 278 { 279 return 1; 280 } 281 282 static inline int check_net(const struct net *net) 283 { 284 return 1; 285 } 286 287 #define net_drop_ns NULL 288 #endif 289 290 291 typedef struct { 292 #ifdef CONFIG_NET_NS 293 struct net *net; 294 #endif 295 } possible_net_t; 296 297 static inline void write_pnet(possible_net_t *pnet, struct net *net) 298 { 299 #ifdef CONFIG_NET_NS 300 pnet->net = net; 301 #endif 302 } 303 304 static inline struct net *read_pnet(const possible_net_t *pnet) 305 { 306 #ifdef CONFIG_NET_NS 307 return pnet->net; 308 #else 309 return &init_net; 310 #endif 311 } 312 313 /* Protected by net_rwsem */ 314 #define for_each_net(VAR) \ 315 list_for_each_entry(VAR, &net_namespace_list, list) 316 317 #define for_each_net_rcu(VAR) \ 318 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 319 320 #ifdef CONFIG_NET_NS 321 #define __net_init 322 #define __net_exit 323 #define __net_initdata 324 #define __net_initconst 325 #else 326 #define __net_init __init 327 #define __net_exit __ref 328 #define __net_initdata __initdata 329 #define __net_initconst __initconst 330 #endif 331 332 int peernet2id_alloc(struct net *net, struct net *peer); 333 int peernet2id(struct net *net, struct net *peer); 334 bool peernet_has_id(struct net *net, struct net *peer); 335 struct net *get_net_ns_by_id(struct net *net, int id); 336 337 struct pernet_operations { 338 struct list_head list; 339 /* 340 * Below methods are called without any exclusive locks. 341 * More than one net may be constructed and destructed 342 * in parallel on several cpus. Every pernet_operations 343 * have to keep in mind all other pernet_operations and 344 * to introduce a locking, if they share common resources. 345 * 346 * The only time they are called with exclusive lock is 347 * from register_pernet_subsys(), unregister_pernet_subsys() 348 * register_pernet_device() and unregister_pernet_device(). 349 * 350 * Exit methods using blocking RCU primitives, such as 351 * synchronize_rcu(), should be implemented via exit_batch. 352 * Then, destruction of a group of net requires single 353 * synchronize_rcu() related to these pernet_operations, 354 * instead of separate synchronize_rcu() for every net. 355 * Please, avoid synchronize_rcu() at all, where it's possible. 356 */ 357 int (*init)(struct net *net); 358 void (*exit)(struct net *net); 359 void (*exit_batch)(struct list_head *net_exit_list); 360 unsigned int *id; 361 size_t size; 362 }; 363 364 /* 365 * Use these carefully. If you implement a network device and it 366 * needs per network namespace operations use device pernet operations, 367 * otherwise use pernet subsys operations. 368 * 369 * Network interfaces need to be removed from a dying netns _before_ 370 * subsys notifiers can be called, as most of the network code cleanup 371 * (which is done from subsys notifiers) runs with the assumption that 372 * dev_remove_pack has been called so no new packets will arrive during 373 * and after the cleanup functions have been called. dev_remove_pack 374 * is not per namespace so instead the guarantee of no more packets 375 * arriving in a network namespace is provided by ensuring that all 376 * network devices and all sockets have left the network namespace 377 * before the cleanup methods are called. 378 * 379 * For the longest time the ipv4 icmp code was registered as a pernet 380 * device which caused kernel oops, and panics during network 381 * namespace cleanup. So please don't get this wrong. 382 */ 383 int register_pernet_subsys(struct pernet_operations *); 384 void unregister_pernet_subsys(struct pernet_operations *); 385 int register_pernet_device(struct pernet_operations *); 386 void unregister_pernet_device(struct pernet_operations *); 387 388 struct ctl_table; 389 struct ctl_table_header; 390 391 #ifdef CONFIG_SYSCTL 392 int net_sysctl_init(void); 393 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 394 struct ctl_table *table); 395 void unregister_net_sysctl_table(struct ctl_table_header *header); 396 #else 397 static inline int net_sysctl_init(void) { return 0; } 398 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 399 const char *path, struct ctl_table *table) 400 { 401 return NULL; 402 } 403 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 404 { 405 } 406 #endif 407 408 static inline int rt_genid_ipv4(struct net *net) 409 { 410 return atomic_read(&net->ipv4.rt_genid); 411 } 412 413 static inline void rt_genid_bump_ipv4(struct net *net) 414 { 415 atomic_inc(&net->ipv4.rt_genid); 416 } 417 418 extern void (*__fib6_flush_trees)(struct net *net); 419 static inline void rt_genid_bump_ipv6(struct net *net) 420 { 421 if (__fib6_flush_trees) 422 __fib6_flush_trees(net); 423 } 424 425 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 426 static inline struct netns_ieee802154_lowpan * 427 net_ieee802154_lowpan(struct net *net) 428 { 429 return &net->ieee802154_lowpan; 430 } 431 #endif 432 433 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 434 static inline void rt_genid_bump_all(struct net *net) 435 { 436 rt_genid_bump_ipv4(net); 437 rt_genid_bump_ipv6(net); 438 } 439 440 static inline int fnhe_genid(struct net *net) 441 { 442 return atomic_read(&net->fnhe_genid); 443 } 444 445 static inline void fnhe_genid_bump(struct net *net) 446 { 447 atomic_inc(&net->fnhe_genid); 448 } 449 450 #endif /* __NET_NET_NAMESPACE_H */ 451