include/net/net_namespace.h

   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 */