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/nexthop.h> 23 #include <net/netns/ieee802154_6lowpan.h> 24 #include <net/netns/sctp.h> 25 #include <net/netns/dccp.h> 26 #include <net/netns/netfilter.h> 27 #include <net/netns/x_tables.h> 28 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 29 #include <net/netns/conntrack.h> 30 #endif 31 #include <net/netns/nftables.h> 32 #include <net/netns/xfrm.h> 33 #include <net/netns/mpls.h> 34 #include <net/netns/can.h> 35 #include <net/netns/xdp.h> 36 #include <linux/ns_common.h> 37 #include <linux/idr.h> 38 #include <linux/skbuff.h> 39 40 struct user_namespace; 41 struct proc_dir_entry; 42 struct net_device; 43 struct sock; 44 struct ctl_table_header; 45 struct net_generic; 46 struct uevent_sock; 47 struct netns_ipvs; 48 struct bpf_prog; 49 50 51 #define NETDEV_HASHBITS 8 52 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS) 53 54 struct net { 55 refcount_t passive; /* To decide when the network 56 * namespace should be freed. 57 */ 58 refcount_t count; /* To decided when the network 59 * namespace should be shut down. 60 */ 61 spinlock_t rules_mod_lock; 62 63 u32 hash_mix; 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 #ifdef CONFIG_KEYS 75 struct key_tag *key_domain; /* Key domain of operation tag */ 76 #endif 77 struct user_namespace *user_ns; /* Owning user namespace */ 78 struct ucounts *ucounts; 79 spinlock_t nsid_lock; 80 struct idr netns_ids; 81 82 struct ns_common ns; 83 84 struct proc_dir_entry *proc_net; 85 struct proc_dir_entry *proc_net_stat; 86 87 #ifdef CONFIG_SYSCTL 88 struct ctl_table_set sysctls; 89 #endif 90 91 struct sock *rtnl; /* rtnetlink socket */ 92 struct sock *genl_sock; 93 94 struct uevent_sock *uevent_sock; /* uevent socket */ 95 96 struct list_head dev_base_head; 97 struct hlist_head *dev_name_head; 98 struct hlist_head *dev_index_head; 99 unsigned int dev_base_seq; /* protected by rtnl_mutex */ 100 int ifindex; 101 unsigned int dev_unreg_count; 102 103 /* core fib_rules */ 104 struct list_head rules_ops; 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_nexthop nexthop; 112 struct netns_ipv4 ipv4; 113 #if IS_ENABLED(CONFIG_IPV6) 114 struct netns_ipv6 ipv6; 115 #endif 116 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 117 struct netns_ieee802154_lowpan ieee802154_lowpan; 118 #endif 119 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 120 struct netns_sctp sctp; 121 #endif 122 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 123 struct netns_dccp dccp; 124 #endif 125 #ifdef CONFIG_NETFILTER 126 struct netns_nf nf; 127 struct netns_xt xt; 128 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 129 struct netns_ct ct; 130 #endif 131 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 132 struct netns_nftables nft; 133 #endif 134 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 135 struct netns_nf_frag nf_frag; 136 struct ctl_table_header *nf_frag_frags_hdr; 137 #endif 138 struct sock *nfnl; 139 struct sock *nfnl_stash; 140 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT) 141 struct list_head nfnl_acct_list; 142 #endif 143 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 144 struct list_head nfct_timeout_list; 145 #endif 146 #endif 147 #ifdef CONFIG_WEXT_CORE 148 struct sk_buff_head wext_nlevents; 149 #endif 150 struct net_generic __rcu *gen; 151 152 struct bpf_prog __rcu *flow_dissector_prog; 153 154 /* Note : following structs are cache line aligned */ 155 #ifdef CONFIG_XFRM 156 struct netns_xfrm xfrm; 157 #endif 158 #if IS_ENABLED(CONFIG_IP_VS) 159 struct netns_ipvs *ipvs; 160 #endif 161 #if IS_ENABLED(CONFIG_MPLS) 162 struct netns_mpls mpls; 163 #endif 164 #if IS_ENABLED(CONFIG_CAN) 165 struct netns_can can; 166 #endif 167 #ifdef CONFIG_XDP_SOCKETS 168 struct netns_xdp xdp; 169 #endif 170 #if IS_ENABLED(CONFIG_CRYPTO_USER) 171 struct sock *crypto_nlsk; 172 #endif 173 struct sock *diag_nlsk; 174 atomic_t fnhe_genid; 175 } __randomize_layout; 176 177 #include <linux/seq_file_net.h> 178 179 /* Init's network namespace */ 180 extern struct net init_net; 181 182 #ifdef CONFIG_NET_NS 183 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 184 struct net *old_net); 185 186 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 187 188 void net_ns_barrier(void); 189 #else /* CONFIG_NET_NS */ 190 #include <linux/sched.h> 191 #include <linux/nsproxy.h> 192 static inline struct net *copy_net_ns(unsigned long flags, 193 struct user_namespace *user_ns, struct net *old_net) 194 { 195 if (flags & CLONE_NEWNET) 196 return ERR_PTR(-EINVAL); 197 return old_net; 198 } 199 200 static inline void net_ns_get_ownership(const struct net *net, 201 kuid_t *uid, kgid_t *gid) 202 { 203 *uid = GLOBAL_ROOT_UID; 204 *gid = GLOBAL_ROOT_GID; 205 } 206 207 static inline void net_ns_barrier(void) {} 208 #endif /* CONFIG_NET_NS */ 209 210 211 extern struct list_head net_namespace_list; 212 213 struct net *get_net_ns_by_pid(pid_t pid); 214 struct net *get_net_ns_by_fd(int fd); 215 216 #ifdef CONFIG_SYSCTL 217 void ipx_register_sysctl(void); 218 void ipx_unregister_sysctl(void); 219 #else 220 #define ipx_register_sysctl() 221 #define ipx_unregister_sysctl() 222 #endif 223 224 #ifdef CONFIG_NET_NS 225 void __put_net(struct net *net); 226 227 static inline struct net *get_net(struct net *net) 228 { 229 refcount_inc(&net->count); 230 return net; 231 } 232 233 static inline struct net *maybe_get_net(struct net *net) 234 { 235 /* Used when we know struct net exists but we 236 * aren't guaranteed a previous reference count 237 * exists. If the reference count is zero this 238 * function fails and returns NULL. 239 */ 240 if (!refcount_inc_not_zero(&net->count)) 241 net = NULL; 242 return net; 243 } 244 245 static inline void put_net(struct net *net) 246 { 247 if (refcount_dec_and_test(&net->count)) 248 __put_net(net); 249 } 250 251 static inline 252 int net_eq(const struct net *net1, const struct net *net2) 253 { 254 return net1 == net2; 255 } 256 257 static inline int check_net(const struct net *net) 258 { 259 return refcount_read(&net->count) != 0; 260 } 261 262 void net_drop_ns(void *); 263 264 #else 265 266 static inline struct net *get_net(struct net *net) 267 { 268 return net; 269 } 270 271 static inline void put_net(struct net *net) 272 { 273 } 274 275 static inline struct net *maybe_get_net(struct net *net) 276 { 277 return net; 278 } 279 280 static inline 281 int net_eq(const struct net *net1, const struct net *net2) 282 { 283 return 1; 284 } 285 286 static inline int check_net(const struct net *net) 287 { 288 return 1; 289 } 290 291 #define net_drop_ns NULL 292 #endif 293 294 295 typedef struct { 296 #ifdef CONFIG_NET_NS 297 struct net *net; 298 #endif 299 } possible_net_t; 300 301 static inline void write_pnet(possible_net_t *pnet, struct net *net) 302 { 303 #ifdef CONFIG_NET_NS 304 pnet->net = net; 305 #endif 306 } 307 308 static inline struct net *read_pnet(const possible_net_t *pnet) 309 { 310 #ifdef CONFIG_NET_NS 311 return pnet->net; 312 #else 313 return &init_net; 314 #endif 315 } 316 317 /* Protected by net_rwsem */ 318 #define for_each_net(VAR) \ 319 list_for_each_entry(VAR, &net_namespace_list, list) 320 321 #define for_each_net_rcu(VAR) \ 322 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 323 324 #ifdef CONFIG_NET_NS 325 #define __net_init 326 #define __net_exit 327 #define __net_initdata 328 #define __net_initconst 329 #else 330 #define __net_init __init 331 #define __net_exit __ref 332 #define __net_initdata __initdata 333 #define __net_initconst __initconst 334 #endif 335 336 int peernet2id_alloc(struct net *net, struct net *peer); 337 int peernet2id(struct net *net, struct net *peer); 338 bool peernet_has_id(struct net *net, struct net *peer); 339 struct net *get_net_ns_by_id(struct net *net, int id); 340 341 struct pernet_operations { 342 struct list_head list; 343 /* 344 * Below methods are called without any exclusive locks. 345 * More than one net may be constructed and destructed 346 * in parallel on several cpus. Every pernet_operations 347 * have to keep in mind all other pernet_operations and 348 * to introduce a locking, if they share common resources. 349 * 350 * The only time they are called with exclusive lock is 351 * from register_pernet_subsys(), unregister_pernet_subsys() 352 * register_pernet_device() and unregister_pernet_device(). 353 * 354 * Exit methods using blocking RCU primitives, such as 355 * synchronize_rcu(), should be implemented via exit_batch. 356 * Then, destruction of a group of net requires single 357 * synchronize_rcu() related to these pernet_operations, 358 * instead of separate synchronize_rcu() for every net. 359 * Please, avoid synchronize_rcu() at all, where it's possible. 360 * 361 * Note that a combination of pre_exit() and exit() can 362 * be used, since a synchronize_rcu() is guaranteed between 363 * the calls. 364 */ 365 int (*init)(struct net *net); 366 void (*pre_exit)(struct net *net); 367 void (*exit)(struct net *net); 368 void (*exit_batch)(struct list_head *net_exit_list); 369 unsigned int *id; 370 size_t size; 371 }; 372 373 /* 374 * Use these carefully. If you implement a network device and it 375 * needs per network namespace operations use device pernet operations, 376 * otherwise use pernet subsys operations. 377 * 378 * Network interfaces need to be removed from a dying netns _before_ 379 * subsys notifiers can be called, as most of the network code cleanup 380 * (which is done from subsys notifiers) runs with the assumption that 381 * dev_remove_pack has been called so no new packets will arrive during 382 * and after the cleanup functions have been called. dev_remove_pack 383 * is not per namespace so instead the guarantee of no more packets 384 * arriving in a network namespace is provided by ensuring that all 385 * network devices and all sockets have left the network namespace 386 * before the cleanup methods are called. 387 * 388 * For the longest time the ipv4 icmp code was registered as a pernet 389 * device which caused kernel oops, and panics during network 390 * namespace cleanup. So please don't get this wrong. 391 */ 392 int register_pernet_subsys(struct pernet_operations *); 393 void unregister_pernet_subsys(struct pernet_operations *); 394 int register_pernet_device(struct pernet_operations *); 395 void unregister_pernet_device(struct pernet_operations *); 396 397 struct ctl_table; 398 struct ctl_table_header; 399 400 #ifdef CONFIG_SYSCTL 401 int net_sysctl_init(void); 402 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 403 struct ctl_table *table); 404 void unregister_net_sysctl_table(struct ctl_table_header *header); 405 #else 406 static inline int net_sysctl_init(void) { return 0; } 407 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 408 const char *path, struct ctl_table *table) 409 { 410 return NULL; 411 } 412 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 413 { 414 } 415 #endif 416 417 static inline int rt_genid_ipv4(struct net *net) 418 { 419 return atomic_read(&net->ipv4.rt_genid); 420 } 421 422 static inline void rt_genid_bump_ipv4(struct net *net) 423 { 424 atomic_inc(&net->ipv4.rt_genid); 425 } 426 427 extern void (*__fib6_flush_trees)(struct net *net); 428 static inline void rt_genid_bump_ipv6(struct net *net) 429 { 430 if (__fib6_flush_trees) 431 __fib6_flush_trees(net); 432 } 433 434 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 435 static inline struct netns_ieee802154_lowpan * 436 net_ieee802154_lowpan(struct net *net) 437 { 438 return &net->ieee802154_lowpan; 439 } 440 #endif 441 442 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 443 static inline void rt_genid_bump_all(struct net *net) 444 { 445 rt_genid_bump_ipv4(net); 446 rt_genid_bump_ipv6(net); 447 } 448 449 static inline int fnhe_genid(struct net *net) 450 { 451 return atomic_read(&net->fnhe_genid); 452 } 453 454 static inline void fnhe_genid_bump(struct net *net) 455 { 456 atomic_inc(&net->fnhe_genid); 457 } 458 459 #endif /* __NET_NET_NAMESPACE_H */ 460