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 #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 list_head fib_notifier_ops; /* Populated by 107 * register_pernet_subsys() 108 */ 109 struct net_device *loopback_dev; /* The loopback */ 110 struct netns_core core; 111 struct netns_mib mib; 112 struct netns_packet packet; 113 struct netns_unix unx; 114 struct netns_ipv4 ipv4; 115 #if IS_ENABLED(CONFIG_IPV6) 116 struct netns_ipv6 ipv6; 117 #endif 118 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 119 struct netns_ieee802154_lowpan ieee802154_lowpan; 120 #endif 121 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) 122 struct netns_sctp sctp; 123 #endif 124 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE) 125 struct netns_dccp dccp; 126 #endif 127 #ifdef CONFIG_NETFILTER 128 struct netns_nf nf; 129 struct netns_xt xt; 130 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) 131 struct netns_ct ct; 132 #endif 133 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE) 134 struct netns_nftables nft; 135 #endif 136 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) 137 struct netns_nf_frag nf_frag; 138 struct ctl_table_header *nf_frag_frags_hdr; 139 #endif 140 struct sock *nfnl; 141 struct sock *nfnl_stash; 142 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT) 143 struct list_head nfnl_acct_list; 144 #endif 145 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT) 146 struct list_head nfct_timeout_list; 147 #endif 148 #endif 149 #ifdef CONFIG_WEXT_CORE 150 struct sk_buff_head wext_nlevents; 151 #endif 152 struct net_generic __rcu *gen; 153 154 struct bpf_prog __rcu *flow_dissector_prog; 155 156 /* Note : following structs are cache line aligned */ 157 #ifdef CONFIG_XFRM 158 struct netns_xfrm xfrm; 159 #endif 160 #if IS_ENABLED(CONFIG_IP_VS) 161 struct netns_ipvs *ipvs; 162 #endif 163 #if IS_ENABLED(CONFIG_MPLS) 164 struct netns_mpls mpls; 165 #endif 166 #if IS_ENABLED(CONFIG_CAN) 167 struct netns_can can; 168 #endif 169 #ifdef CONFIG_XDP_SOCKETS 170 struct netns_xdp xdp; 171 #endif 172 struct sock *diag_nlsk; 173 atomic_t fnhe_genid; 174 } __randomize_layout; 175 176 #include <linux/seq_file_net.h> 177 178 /* Init's network namespace */ 179 extern struct net init_net; 180 181 #ifdef CONFIG_NET_NS 182 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 183 struct net *old_net); 184 185 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 186 187 void net_ns_barrier(void); 188 #else /* CONFIG_NET_NS */ 189 #include <linux/sched.h> 190 #include <linux/nsproxy.h> 191 static inline struct net *copy_net_ns(unsigned long flags, 192 struct user_namespace *user_ns, struct net *old_net) 193 { 194 if (flags & CLONE_NEWNET) 195 return ERR_PTR(-EINVAL); 196 return old_net; 197 } 198 199 static inline void net_ns_get_ownership(const struct net *net, 200 kuid_t *uid, kgid_t *gid) 201 { 202 *uid = GLOBAL_ROOT_UID; 203 *gid = GLOBAL_ROOT_GID; 204 } 205 206 static inline void net_ns_barrier(void) {} 207 #endif /* CONFIG_NET_NS */ 208 209 210 extern struct list_head net_namespace_list; 211 212 struct net *get_net_ns_by_pid(pid_t pid); 213 struct net *get_net_ns_by_fd(int fd); 214 215 #ifdef CONFIG_SYSCTL 216 void ipx_register_sysctl(void); 217 void ipx_unregister_sysctl(void); 218 #else 219 #define ipx_register_sysctl() 220 #define ipx_unregister_sysctl() 221 #endif 222 223 #ifdef CONFIG_NET_NS 224 void __put_net(struct net *net); 225 226 static inline struct net *get_net(struct net *net) 227 { 228 refcount_inc(&net->count); 229 return net; 230 } 231 232 static inline struct net *maybe_get_net(struct net *net) 233 { 234 /* Used when we know struct net exists but we 235 * aren't guaranteed a previous reference count 236 * exists. If the reference count is zero this 237 * function fails and returns NULL. 238 */ 239 if (!refcount_inc_not_zero(&net->count)) 240 net = NULL; 241 return net; 242 } 243 244 static inline void put_net(struct net *net) 245 { 246 if (refcount_dec_and_test(&net->count)) 247 __put_net(net); 248 } 249 250 static inline 251 int net_eq(const struct net *net1, const struct net *net2) 252 { 253 return net1 == net2; 254 } 255 256 static inline int check_net(const struct net *net) 257 { 258 return refcount_read(&net->count) != 0; 259 } 260 261 void net_drop_ns(void *); 262 263 #else 264 265 static inline struct net *get_net(struct net *net) 266 { 267 return net; 268 } 269 270 static inline void put_net(struct net *net) 271 { 272 } 273 274 static inline struct net *maybe_get_net(struct net *net) 275 { 276 return net; 277 } 278 279 static inline 280 int net_eq(const struct net *net1, const struct net *net2) 281 { 282 return 1; 283 } 284 285 static inline int check_net(const struct net *net) 286 { 287 return 1; 288 } 289 290 #define net_drop_ns NULL 291 #endif 292 293 294 typedef struct { 295 #ifdef CONFIG_NET_NS 296 struct net *net; 297 #endif 298 } possible_net_t; 299 300 static inline void write_pnet(possible_net_t *pnet, struct net *net) 301 { 302 #ifdef CONFIG_NET_NS 303 pnet->net = net; 304 #endif 305 } 306 307 static inline struct net *read_pnet(const possible_net_t *pnet) 308 { 309 #ifdef CONFIG_NET_NS 310 return pnet->net; 311 #else 312 return &init_net; 313 #endif 314 } 315 316 /* Protected by net_rwsem */ 317 #define for_each_net(VAR) \ 318 list_for_each_entry(VAR, &net_namespace_list, list) 319 320 #define for_each_net_rcu(VAR) \ 321 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 322 323 #ifdef CONFIG_NET_NS 324 #define __net_init 325 #define __net_exit 326 #define __net_initdata 327 #define __net_initconst 328 #else 329 #define __net_init __init 330 #define __net_exit __ref 331 #define __net_initdata __initdata 332 #define __net_initconst __initconst 333 #endif 334 335 int peernet2id_alloc(struct net *net, struct net *peer); 336 int peernet2id(struct net *net, struct net *peer); 337 bool peernet_has_id(struct net *net, struct net *peer); 338 struct net *get_net_ns_by_id(struct net *net, int id); 339 340 struct pernet_operations { 341 struct list_head list; 342 /* 343 * Below methods are called without any exclusive locks. 344 * More than one net may be constructed and destructed 345 * in parallel on several cpus. Every pernet_operations 346 * have to keep in mind all other pernet_operations and 347 * to introduce a locking, if they share common resources. 348 * 349 * The only time they are called with exclusive lock is 350 * from register_pernet_subsys(), unregister_pernet_subsys() 351 * register_pernet_device() and unregister_pernet_device(). 352 * 353 * Exit methods using blocking RCU primitives, such as 354 * synchronize_rcu(), should be implemented via exit_batch. 355 * Then, destruction of a group of net requires single 356 * synchronize_rcu() related to these pernet_operations, 357 * instead of separate synchronize_rcu() for every net. 358 * Please, avoid synchronize_rcu() at all, where it's possible. 359 */ 360 int (*init)(struct net *net); 361 void (*exit)(struct net *net); 362 void (*exit_batch)(struct list_head *net_exit_list); 363 unsigned int *id; 364 size_t size; 365 }; 366 367 /* 368 * Use these carefully. If you implement a network device and it 369 * needs per network namespace operations use device pernet operations, 370 * otherwise use pernet subsys operations. 371 * 372 * Network interfaces need to be removed from a dying netns _before_ 373 * subsys notifiers can be called, as most of the network code cleanup 374 * (which is done from subsys notifiers) runs with the assumption that 375 * dev_remove_pack has been called so no new packets will arrive during 376 * and after the cleanup functions have been called. dev_remove_pack 377 * is not per namespace so instead the guarantee of no more packets 378 * arriving in a network namespace is provided by ensuring that all 379 * network devices and all sockets have left the network namespace 380 * before the cleanup methods are called. 381 * 382 * For the longest time the ipv4 icmp code was registered as a pernet 383 * device which caused kernel oops, and panics during network 384 * namespace cleanup. So please don't get this wrong. 385 */ 386 int register_pernet_subsys(struct pernet_operations *); 387 void unregister_pernet_subsys(struct pernet_operations *); 388 int register_pernet_device(struct pernet_operations *); 389 void unregister_pernet_device(struct pernet_operations *); 390 391 struct ctl_table; 392 struct ctl_table_header; 393 394 #ifdef CONFIG_SYSCTL 395 int net_sysctl_init(void); 396 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 397 struct ctl_table *table); 398 void unregister_net_sysctl_table(struct ctl_table_header *header); 399 #else 400 static inline int net_sysctl_init(void) { return 0; } 401 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 402 const char *path, struct ctl_table *table) 403 { 404 return NULL; 405 } 406 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 407 { 408 } 409 #endif 410 411 static inline int rt_genid_ipv4(struct net *net) 412 { 413 return atomic_read(&net->ipv4.rt_genid); 414 } 415 416 static inline void rt_genid_bump_ipv4(struct net *net) 417 { 418 atomic_inc(&net->ipv4.rt_genid); 419 } 420 421 extern void (*__fib6_flush_trees)(struct net *net); 422 static inline void rt_genid_bump_ipv6(struct net *net) 423 { 424 if (__fib6_flush_trees) 425 __fib6_flush_trees(net); 426 } 427 428 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 429 static inline struct netns_ieee802154_lowpan * 430 net_ieee802154_lowpan(struct net *net) 431 { 432 return &net->ieee802154_lowpan; 433 } 434 #endif 435 436 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 437 static inline void rt_genid_bump_all(struct net *net) 438 { 439 rt_genid_bump_ipv4(net); 440 rt_genid_bump_ipv6(net); 441 } 442 443 static inline int fnhe_genid(struct net *net) 444 { 445 return atomic_read(&net->fnhe_genid); 446 } 447 448 static inline void fnhe_genid_bump(struct net *net) 449 { 450 atomic_inc(&net->fnhe_genid); 451 } 452 453 #endif /* __NET_NET_NAMESPACE_H */ 454