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 struct sock *diag_nlsk; 171 atomic_t fnhe_genid; 172 } __randomize_layout; 173 174 #include <linux/seq_file_net.h> 175 176 /* Init's network namespace */ 177 extern struct net init_net; 178 179 #ifdef CONFIG_NET_NS 180 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns, 181 struct net *old_net); 182 183 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid); 184 185 void net_ns_barrier(void); 186 #else /* CONFIG_NET_NS */ 187 #include <linux/sched.h> 188 #include <linux/nsproxy.h> 189 static inline struct net *copy_net_ns(unsigned long flags, 190 struct user_namespace *user_ns, struct net *old_net) 191 { 192 if (flags & CLONE_NEWNET) 193 return ERR_PTR(-EINVAL); 194 return old_net; 195 } 196 197 static inline void net_ns_get_ownership(const struct net *net, 198 kuid_t *uid, kgid_t *gid) 199 { 200 *uid = GLOBAL_ROOT_UID; 201 *gid = GLOBAL_ROOT_GID; 202 } 203 204 static inline void net_ns_barrier(void) {} 205 #endif /* CONFIG_NET_NS */ 206 207 208 extern struct list_head net_namespace_list; 209 210 struct net *get_net_ns_by_pid(pid_t pid); 211 struct net *get_net_ns_by_fd(int fd); 212 213 #ifdef CONFIG_SYSCTL 214 void ipx_register_sysctl(void); 215 void ipx_unregister_sysctl(void); 216 #else 217 #define ipx_register_sysctl() 218 #define ipx_unregister_sysctl() 219 #endif 220 221 #ifdef CONFIG_NET_NS 222 void __put_net(struct net *net); 223 224 static inline struct net *get_net(struct net *net) 225 { 226 refcount_inc(&net->count); 227 return net; 228 } 229 230 static inline struct net *maybe_get_net(struct net *net) 231 { 232 /* Used when we know struct net exists but we 233 * aren't guaranteed a previous reference count 234 * exists. If the reference count is zero this 235 * function fails and returns NULL. 236 */ 237 if (!refcount_inc_not_zero(&net->count)) 238 net = NULL; 239 return net; 240 } 241 242 static inline void put_net(struct net *net) 243 { 244 if (refcount_dec_and_test(&net->count)) 245 __put_net(net); 246 } 247 248 static inline 249 int net_eq(const struct net *net1, const struct net *net2) 250 { 251 return net1 == net2; 252 } 253 254 static inline int check_net(const struct net *net) 255 { 256 return refcount_read(&net->count) != 0; 257 } 258 259 void net_drop_ns(void *); 260 261 #else 262 263 static inline struct net *get_net(struct net *net) 264 { 265 return net; 266 } 267 268 static inline void put_net(struct net *net) 269 { 270 } 271 272 static inline struct net *maybe_get_net(struct net *net) 273 { 274 return net; 275 } 276 277 static inline 278 int net_eq(const struct net *net1, const struct net *net2) 279 { 280 return 1; 281 } 282 283 static inline int check_net(const struct net *net) 284 { 285 return 1; 286 } 287 288 #define net_drop_ns NULL 289 #endif 290 291 292 typedef struct { 293 #ifdef CONFIG_NET_NS 294 struct net *net; 295 #endif 296 } possible_net_t; 297 298 static inline void write_pnet(possible_net_t *pnet, struct net *net) 299 { 300 #ifdef CONFIG_NET_NS 301 pnet->net = net; 302 #endif 303 } 304 305 static inline struct net *read_pnet(const possible_net_t *pnet) 306 { 307 #ifdef CONFIG_NET_NS 308 return pnet->net; 309 #else 310 return &init_net; 311 #endif 312 } 313 314 /* Protected by net_rwsem */ 315 #define for_each_net(VAR) \ 316 list_for_each_entry(VAR, &net_namespace_list, list) 317 318 #define for_each_net_rcu(VAR) \ 319 list_for_each_entry_rcu(VAR, &net_namespace_list, list) 320 321 #ifdef CONFIG_NET_NS 322 #define __net_init 323 #define __net_exit 324 #define __net_initdata 325 #define __net_initconst 326 #else 327 #define __net_init __init 328 #define __net_exit __ref 329 #define __net_initdata __initdata 330 #define __net_initconst __initconst 331 #endif 332 333 int peernet2id_alloc(struct net *net, struct net *peer); 334 int peernet2id(struct net *net, struct net *peer); 335 bool peernet_has_id(struct net *net, struct net *peer); 336 struct net *get_net_ns_by_id(struct net *net, int id); 337 338 struct pernet_operations { 339 struct list_head list; 340 /* 341 * Below methods are called without any exclusive locks. 342 * More than one net may be constructed and destructed 343 * in parallel on several cpus. Every pernet_operations 344 * have to keep in mind all other pernet_operations and 345 * to introduce a locking, if they share common resources. 346 * 347 * The only time they are called with exclusive lock is 348 * from register_pernet_subsys(), unregister_pernet_subsys() 349 * register_pernet_device() and unregister_pernet_device(). 350 * 351 * Exit methods using blocking RCU primitives, such as 352 * synchronize_rcu(), should be implemented via exit_batch. 353 * Then, destruction of a group of net requires single 354 * synchronize_rcu() related to these pernet_operations, 355 * instead of separate synchronize_rcu() for every net. 356 * Please, avoid synchronize_rcu() at all, where it's possible. 357 * 358 * Note that a combination of pre_exit() and exit() can 359 * be used, since a synchronize_rcu() is guaranteed between 360 * the calls. 361 */ 362 int (*init)(struct net *net); 363 void (*pre_exit)(struct net *net); 364 void (*exit)(struct net *net); 365 void (*exit_batch)(struct list_head *net_exit_list); 366 unsigned int *id; 367 size_t size; 368 }; 369 370 /* 371 * Use these carefully. If you implement a network device and it 372 * needs per network namespace operations use device pernet operations, 373 * otherwise use pernet subsys operations. 374 * 375 * Network interfaces need to be removed from a dying netns _before_ 376 * subsys notifiers can be called, as most of the network code cleanup 377 * (which is done from subsys notifiers) runs with the assumption that 378 * dev_remove_pack has been called so no new packets will arrive during 379 * and after the cleanup functions have been called. dev_remove_pack 380 * is not per namespace so instead the guarantee of no more packets 381 * arriving in a network namespace is provided by ensuring that all 382 * network devices and all sockets have left the network namespace 383 * before the cleanup methods are called. 384 * 385 * For the longest time the ipv4 icmp code was registered as a pernet 386 * device which caused kernel oops, and panics during network 387 * namespace cleanup. So please don't get this wrong. 388 */ 389 int register_pernet_subsys(struct pernet_operations *); 390 void unregister_pernet_subsys(struct pernet_operations *); 391 int register_pernet_device(struct pernet_operations *); 392 void unregister_pernet_device(struct pernet_operations *); 393 394 struct ctl_table; 395 struct ctl_table_header; 396 397 #ifdef CONFIG_SYSCTL 398 int net_sysctl_init(void); 399 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path, 400 struct ctl_table *table); 401 void unregister_net_sysctl_table(struct ctl_table_header *header); 402 #else 403 static inline int net_sysctl_init(void) { return 0; } 404 static inline struct ctl_table_header *register_net_sysctl(struct net *net, 405 const char *path, struct ctl_table *table) 406 { 407 return NULL; 408 } 409 static inline void unregister_net_sysctl_table(struct ctl_table_header *header) 410 { 411 } 412 #endif 413 414 static inline int rt_genid_ipv4(struct net *net) 415 { 416 return atomic_read(&net->ipv4.rt_genid); 417 } 418 419 static inline void rt_genid_bump_ipv4(struct net *net) 420 { 421 atomic_inc(&net->ipv4.rt_genid); 422 } 423 424 extern void (*__fib6_flush_trees)(struct net *net); 425 static inline void rt_genid_bump_ipv6(struct net *net) 426 { 427 if (__fib6_flush_trees) 428 __fib6_flush_trees(net); 429 } 430 431 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) 432 static inline struct netns_ieee802154_lowpan * 433 net_ieee802154_lowpan(struct net *net) 434 { 435 return &net->ieee802154_lowpan; 436 } 437 #endif 438 439 /* For callers who don't really care about whether it's IPv4 or IPv6 */ 440 static inline void rt_genid_bump_all(struct net *net) 441 { 442 rt_genid_bump_ipv4(net); 443 rt_genid_bump_ipv6(net); 444 } 445 446 static inline int fnhe_genid(struct net *net) 447 { 448 return atomic_read(&net->fnhe_genid); 449 } 450 451 static inline void fnhe_genid_bump(struct net *net) 452 { 453 atomic_inc(&net->fnhe_genid); 454 } 455 456 #endif /* __NET_NET_NAMESPACE_H */ 457