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