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 <linux/ns_common.h>
  35 #include <linux/idr.h>
  36 #include <linux/skbuff.h>
  37
  38 struct user_namespace;
  39 struct proc_dir_entry;
  40 struct net_device;
  41 struct sock;
  42 struct ctl_table_header;
  43 struct net_generic;
  44 struct sock;
  45 struct netns_ipvs;
  46
  47
  48 #define NETDEV_HASHBITS    8
  49 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  50
  51 struct net {
  52         refcount_t              passive;        /* To decided when the network
  53                                                  * namespace should be freed.
  54                                                  */
  55         atomic_t                count;          /* To decided when the network
  56                                                  *  namespace should be shut down.
  57                                                  */
  58         spinlock_t              rules_mod_lock;
  59
  60         atomic64_t              cookie_gen;
  61
  62         struct list_head        list;           /* list of network namespaces */
  63         struct list_head        cleanup_list;   /* namespaces on death row */
  64         struct list_head        exit_list;      /* Use only net_mutex */
  65
  66         struct user_namespace   *user_ns;       /* Owning user namespace */
  67         struct ucounts          *ucounts;
  68         spinlock_t              nsid_lock;
  69         struct idr              netns_ids;
  70
  71         struct ns_common        ns;
  72
  73         struct proc_dir_entry   *proc_net;
  74         struct proc_dir_entry   *proc_net_stat;
  75
  76 #ifdef CONFIG_SYSCTL
  77         struct ctl_table_set    sysctls;
  78 #endif
  79
  80         struct sock             *rtnl;                  /* rtnetlink socket */
  81         struct sock             *genl_sock;
  82
  83         struct list_head        dev_base_head;
  84         struct hlist_head       *dev_name_head;
  85         struct hlist_head       *dev_index_head;
  86         unsigned int            dev_base_seq;   /* protected by rtnl_mutex */
  87         int                     ifindex;
  88         unsigned int            dev_unreg_count;
  89
  90         /* core fib_rules */
  91         struct list_head        rules_ops;
  92
  93         struct list_head        fib_notifier_ops;  /* protected by net_mutex */
  94
  95         struct net_device       *loopback_dev;          /* The loopback */
  96         struct netns_core       core;
  97         struct netns_mib        mib;
  98         struct netns_packet     packet;
  99         struct netns_unix       unx;
 100         struct netns_ipv4       ipv4;
 101 #if IS_ENABLED(CONFIG_IPV6)
 102         struct netns_ipv6       ipv6;
 103 #endif
 104 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 105         struct netns_ieee802154_lowpan  ieee802154_lowpan;
 106 #endif
 107 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
 108         struct netns_sctp       sctp;
 109 #endif
 110 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
 111         struct netns_dccp       dccp;
 112 #endif
 113 #ifdef CONFIG_NETFILTER
 114         struct netns_nf         nf;
 115         struct netns_xt         xt;
 116 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 117         struct netns_ct         ct;
 118 #endif
 119 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
 120         struct netns_nftables   nft;
 121 #endif
 122 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 123         struct netns_nf_frag    nf_frag;
 124         struct ctl_table_header *nf_frag_frags_hdr;
 125 #endif
 126         struct sock             *nfnl;
 127         struct sock             *nfnl_stash;
 128 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
 129         struct list_head        nfnl_acct_list;
 130 #endif
 131 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 132         struct list_head        nfct_timeout_list;
 133 #endif
 134 #endif
 135 #ifdef CONFIG_WEXT_CORE
 136         struct sk_buff_head     wext_nlevents;
 137 #endif
 138         struct net_generic __rcu        *gen;
 139
 140         /* Note : following structs are cache line aligned */
 141 #ifdef CONFIG_XFRM
 142         struct netns_xfrm       xfrm;
 143 #endif
 144 #if IS_ENABLED(CONFIG_IP_VS)
 145         struct netns_ipvs       *ipvs;
 146 #endif
 147 #if IS_ENABLED(CONFIG_MPLS)
 148         struct netns_mpls       mpls;
 149 #endif
 150 #if IS_ENABLED(CONFIG_CAN)
 151         struct netns_can        can;
 152 #endif
 153         struct sock             *diag_nlsk;
 154         atomic_t                fnhe_genid;
 155 } __randomize_layout;
 156
 157 #include <linux/seq_file_net.h>
 158
 159 /* Init's network namespace */
 160 extern struct net init_net;
 161
 162 #ifdef CONFIG_NET_NS
 163 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
 164                         struct net *old_net);
 165
 166 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
 167
 168 void net_ns_barrier(void);
 169 #else /* CONFIG_NET_NS */
 170 #include <linux/sched.h>
 171 #include <linux/nsproxy.h>
 172 static inline struct net *copy_net_ns(unsigned long flags,
 173         struct user_namespace *user_ns, struct net *old_net)
 174 {
 175         if (flags & CLONE_NEWNET)
 176                 return ERR_PTR(-EINVAL);
 177         return old_net;
 178 }
 179
 180 static inline void net_ns_get_ownership(const struct net *net,
 181                                         kuid_t *uid, kgid_t *gid)
 182 {
 183         *uid = GLOBAL_ROOT_UID;
 184         *gid = GLOBAL_ROOT_GID;
 185 }
 186
 187 static inline void net_ns_barrier(void) {}
 188 #endif /* CONFIG_NET_NS */
 189
 190
 191 extern struct list_head net_namespace_list;
 192
 193 struct net *get_net_ns_by_pid(pid_t pid);
 194 struct net *get_net_ns_by_fd(int fd);
 195
 196 #ifdef CONFIG_SYSCTL
 197 void ipx_register_sysctl(void);
 198 void ipx_unregister_sysctl(void);
 199 #else
 200 #define ipx_register_sysctl()
 201 #define ipx_unregister_sysctl()
 202 #endif
 203
 204 #ifdef CONFIG_NET_NS
 205 void __put_net(struct net *net);
 206
 207 static inline struct net *get_net(struct net *net)
 208 {
 209         atomic_inc(&net->count);
 210         return net;
 211 }
 212
 213 static inline struct net *maybe_get_net(struct net *net)
 214 {
 215         /* Used when we know struct net exists but we
 216          * aren't guaranteed a previous reference count
 217          * exists.  If the reference count is zero this
 218          * function fails and returns NULL.
 219          */
 220         if (!atomic_inc_not_zero(&net->count))
 221                 net = NULL;
 222         return net;
 223 }
 224
 225 static inline void put_net(struct net *net)
 226 {
 227         if (atomic_dec_and_test(&net->count))
 228                 __put_net(net);
 229 }
 230
 231 static inline
 232 int net_eq(const struct net *net1, const struct net *net2)
 233 {
 234         return net1 == net2;
 235 }
 236
 237 static inline int check_net(const struct net *net)
 238 {
 239         return atomic_read(&net->count) != 0;
 240 }
 241
 242 void net_drop_ns(void *);
 243
 244 #else
 245
 246 static inline struct net *get_net(struct net *net)
 247 {
 248         return net;
 249 }
 250
 251 static inline void put_net(struct net *net)
 252 {
 253 }
 254
 255 static inline struct net *maybe_get_net(struct net *net)
 256 {
 257         return net;
 258 }
 259
 260 static inline
 261 int net_eq(const struct net *net1, const struct net *net2)
 262 {
 263         return 1;
 264 }
 265
 266 static inline int check_net(const struct net *net)
 267 {
 268         return 1;
 269 }
 270
 271 #define net_drop_ns NULL
 272 #endif
 273
 274
 275 typedef struct {
 276 #ifdef CONFIG_NET_NS
 277         struct net *net;
 278 #endif
 279 } possible_net_t;
 280
 281 static inline void write_pnet(possible_net_t *pnet, struct net *net)
 282 {
 283 #ifdef CONFIG_NET_NS
 284         pnet->net = net;
 285 #endif
 286 }
 287
 288 static inline struct net *read_pnet(const possible_net_t *pnet)
 289 {
 290 #ifdef CONFIG_NET_NS
 291         return pnet->net;
 292 #else
 293         return &init_net;
 294 #endif
 295 }
 296
 297 #define for_each_net(VAR)                               \
 298         list_for_each_entry(VAR, &net_namespace_list, list)
 299
 300 #define for_each_net_rcu(VAR)                           \
 301         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 302
 303 #ifdef CONFIG_NET_NS
 304 #define __net_init
 305 #define __net_exit
 306 #define __net_initdata
 307 #define __net_initconst
 308 #else
 309 #define __net_init      __init
 310 #define __net_exit      __ref
 311 #define __net_initdata  __initdata
 312 #define __net_initconst __initconst
 313 #endif
 314
 315 int peernet2id_alloc(struct net *net, struct net *peer);
 316 int peernet2id(struct net *net, struct net *peer);
 317 bool peernet_has_id(struct net *net, struct net *peer);
 318 struct net *get_net_ns_by_id(struct net *net, int id);
 319
 320 struct pernet_operations {
 321         struct list_head list;
 322         int (*init)(struct net *net);
 323         void (*exit)(struct net *net);
 324         void (*exit_batch)(struct list_head *net_exit_list);
 325         unsigned int *id;
 326         size_t size;
 327 };
 328
 329 /*
 330  * Use these carefully.  If you implement a network device and it
 331  * needs per network namespace operations use device pernet operations,
 332  * otherwise use pernet subsys operations.
 333  *
 334  * Network interfaces need to be removed from a dying netns _before_
 335  * subsys notifiers can be called, as most of the network code cleanup
 336  * (which is done from subsys notifiers) runs with the assumption that
 337  * dev_remove_pack has been called so no new packets will arrive during
 338  * and after the cleanup functions have been called.  dev_remove_pack
 339  * is not per namespace so instead the guarantee of no more packets
 340  * arriving in a network namespace is provided by ensuring that all
 341  * network devices and all sockets have left the network namespace
 342  * before the cleanup methods are called.
 343  *
 344  * For the longest time the ipv4 icmp code was registered as a pernet
 345  * device which caused kernel oops, and panics during network
 346  * namespace cleanup.   So please don't get this wrong.
 347  */
 348 int register_pernet_subsys(struct pernet_operations *);
 349 void unregister_pernet_subsys(struct pernet_operations *);
 350 int register_pernet_device(struct pernet_operations *);
 351 void unregister_pernet_device(struct pernet_operations *);
 352
 353 struct ctl_table;
 354 struct ctl_table_header;
 355
 356 #ifdef CONFIG_SYSCTL
 357 int net_sysctl_init(void);
 358 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
 359                                              struct ctl_table *table);
 360 void unregister_net_sysctl_table(struct ctl_table_header *header);
 361 #else
 362 static inline int net_sysctl_init(void) { return 0; }
 363 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 364         const char *path, struct ctl_table *table)
 365 {
 366         return NULL;
 367 }
 368 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 369 {
 370 }
 371 #endif
 372
 373 static inline int rt_genid_ipv4(struct net *net)
 374 {
 375         return atomic_read(&net->ipv4.rt_genid);
 376 }
 377
 378 static inline void rt_genid_bump_ipv4(struct net *net)
 379 {
 380         atomic_inc(&net->ipv4.rt_genid);
 381 }
 382
 383 extern void (*__fib6_flush_trees)(struct net *net);
 384 static inline void rt_genid_bump_ipv6(struct net *net)
 385 {
 386         if (__fib6_flush_trees)
 387                 __fib6_flush_trees(net);
 388 }
 389
 390 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 391 static inline struct netns_ieee802154_lowpan *
 392 net_ieee802154_lowpan(struct net *net)
 393 {
 394         return &net->ieee802154_lowpan;
 395 }
 396 #endif
 397
 398 /* For callers who don't really care about whether it's IPv4 or IPv6 */
 399 static inline void rt_genid_bump_all(struct net *net)
 400 {
 401         rt_genid_bump_ipv4(net);
 402         rt_genid_bump_ipv6(net);
 403 }
 404
 405 static inline int fnhe_genid(struct net *net)
 406 {
 407         return atomic_read(&net->fnhe_genid);
 408 }
 409
 410 static inline void fnhe_genid_bump(struct net *net)
 411 {
 412         atomic_inc(&net->fnhe_genid);
 413 }
 414
 415 #endif /* __NET_NET_NAMESPACE_H */