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         u32                     hash_mix;
  61         atomic64_t              cookie_gen;
  62
  63         struct list_head        list;           /* list of network namespaces */
  64         struct list_head        cleanup_list;   /* namespaces on death row */
  65         struct list_head        exit_list;      /* Use only net_mutex */
  66
  67         struct user_namespace   *user_ns;       /* Owning user namespace */
  68         struct ucounts          *ucounts;
  69         spinlock_t              nsid_lock;
  70         struct idr              netns_ids;
  71
  72         struct ns_common        ns;
  73
  74         struct proc_dir_entry   *proc_net;
  75         struct proc_dir_entry   *proc_net_stat;
  76
  77 #ifdef CONFIG_SYSCTL
  78         struct ctl_table_set    sysctls;
  79 #endif
  80
  81         struct sock             *rtnl;                  /* rtnetlink socket */
  82         struct sock             *genl_sock;
  83
  84         struct list_head        dev_base_head;
  85         struct hlist_head       *dev_name_head;
  86         struct hlist_head       *dev_index_head;
  87         unsigned int            dev_base_seq;   /* protected by rtnl_mutex */
  88         int                     ifindex;
  89         unsigned int            dev_unreg_count;
  90
  91         /* core fib_rules */
  92         struct list_head        rules_ops;
  93
  94         struct list_head        fib_notifier_ops;  /* protected by net_mutex */
  95
  96         struct net_device       *loopback_dev;          /* The loopback */
  97         struct netns_core       core;
  98         struct netns_mib        mib;
  99         struct netns_packet     packet;
 100         struct netns_unix       unx;
 101         struct netns_ipv4       ipv4;
 102 #if IS_ENABLED(CONFIG_IPV6)
 103         struct netns_ipv6       ipv6;
 104 #endif
 105 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 106         struct netns_ieee802154_lowpan  ieee802154_lowpan;
 107 #endif
 108 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
 109         struct netns_sctp       sctp;
 110 #endif
 111 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
 112         struct netns_dccp       dccp;
 113 #endif
 114 #ifdef CONFIG_NETFILTER
 115         struct netns_nf         nf;
 116         struct netns_xt         xt;
 117 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 118         struct netns_ct         ct;
 119 #endif
 120 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
 121         struct netns_nftables   nft;
 122 #endif
 123 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 124         struct netns_nf_frag    nf_frag;
 125         struct ctl_table_header *nf_frag_frags_hdr;
 126 #endif
 127         struct sock             *nfnl;
 128         struct sock             *nfnl_stash;
 129 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
 130         struct list_head        nfnl_acct_list;
 131 #endif
 132 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 133         struct list_head        nfct_timeout_list;
 134 #endif
 135 #endif
 136 #ifdef CONFIG_WEXT_CORE
 137         struct sk_buff_head     wext_nlevents;
 138 #endif
 139         struct net_generic __rcu        *gen;
 140
 141         /* Note : following structs are cache line aligned */
 142 #ifdef CONFIG_XFRM
 143         struct netns_xfrm       xfrm;
 144 #endif
 145 #if IS_ENABLED(CONFIG_IP_VS)
 146         struct netns_ipvs       *ipvs;
 147 #endif
 148 #if IS_ENABLED(CONFIG_MPLS)
 149         struct netns_mpls       mpls;
 150 #endif
 151 #if IS_ENABLED(CONFIG_CAN)
 152         struct netns_can        can;
 153 #endif
 154         struct sock             *diag_nlsk;
 155         atomic_t                fnhe_genid;
 156 } __randomize_layout;
 157
 158 #include <linux/seq_file_net.h>
 159
 160 /* Init's network namespace */
 161 extern struct net init_net;
 162
 163 #ifdef CONFIG_NET_NS
 164 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
 165                         struct net *old_net);
 166
 167 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
 168
 169 void net_ns_barrier(void);
 170 #else /* CONFIG_NET_NS */
 171 #include <linux/sched.h>
 172 #include <linux/nsproxy.h>
 173 static inline struct net *copy_net_ns(unsigned long flags,
 174         struct user_namespace *user_ns, struct net *old_net)
 175 {
 176         if (flags & CLONE_NEWNET)
 177                 return ERR_PTR(-EINVAL);
 178         return old_net;
 179 }
 180
 181 static inline void net_ns_get_ownership(const struct net *net,
 182                                         kuid_t *uid, kgid_t *gid)
 183 {
 184         *uid = GLOBAL_ROOT_UID;
 185         *gid = GLOBAL_ROOT_GID;
 186 }
 187
 188 static inline void net_ns_barrier(void) {}
 189 #endif /* CONFIG_NET_NS */
 190
 191
 192 extern struct list_head net_namespace_list;
 193
 194 struct net *get_net_ns_by_pid(pid_t pid);
 195 struct net *get_net_ns_by_fd(int fd);
 196
 197 #ifdef CONFIG_SYSCTL
 198 void ipx_register_sysctl(void);
 199 void ipx_unregister_sysctl(void);
 200 #else
 201 #define ipx_register_sysctl()
 202 #define ipx_unregister_sysctl()
 203 #endif
 204
 205 #ifdef CONFIG_NET_NS
 206 void __put_net(struct net *net);
 207
 208 static inline struct net *get_net(struct net *net)
 209 {
 210         atomic_inc(&net->count);
 211         return net;
 212 }
 213
 214 static inline struct net *maybe_get_net(struct net *net)
 215 {
 216         /* Used when we know struct net exists but we
 217          * aren't guaranteed a previous reference count
 218          * exists.  If the reference count is zero this
 219          * function fails and returns NULL.
 220          */
 221         if (!atomic_inc_not_zero(&net->count))
 222                 net = NULL;
 223         return net;
 224 }
 225
 226 static inline void put_net(struct net *net)
 227 {
 228         if (atomic_dec_and_test(&net->count))
 229                 __put_net(net);
 230 }
 231
 232 static inline
 233 int net_eq(const struct net *net1, const struct net *net2)
 234 {
 235         return net1 == net2;
 236 }
 237
 238 static inline int check_net(const struct net *net)
 239 {
 240         return atomic_read(&net->count) != 0;
 241 }
 242
 243 void net_drop_ns(void *);
 244
 245 #else
 246
 247 static inline struct net *get_net(struct net *net)
 248 {
 249         return net;
 250 }
 251
 252 static inline void put_net(struct net *net)
 253 {
 254 }
 255
 256 static inline struct net *maybe_get_net(struct net *net)
 257 {
 258         return net;
 259 }
 260
 261 static inline
 262 int net_eq(const struct net *net1, const struct net *net2)
 263 {
 264         return 1;
 265 }
 266
 267 static inline int check_net(const struct net *net)
 268 {
 269         return 1;
 270 }
 271
 272 #define net_drop_ns NULL
 273 #endif
 274
 275
 276 typedef struct {
 277 #ifdef CONFIG_NET_NS
 278         struct net *net;
 279 #endif
 280 } possible_net_t;
 281
 282 static inline void write_pnet(possible_net_t *pnet, struct net *net)
 283 {
 284 #ifdef CONFIG_NET_NS
 285         pnet->net = net;
 286 #endif
 287 }
 288
 289 static inline struct net *read_pnet(const possible_net_t *pnet)
 290 {
 291 #ifdef CONFIG_NET_NS
 292         return pnet->net;
 293 #else
 294         return &init_net;
 295 #endif
 296 }
 297
 298 #define for_each_net(VAR)                               \
 299         list_for_each_entry(VAR, &net_namespace_list, list)
 300
 301 #define for_each_net_rcu(VAR)                           \
 302         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 303
 304 #ifdef CONFIG_NET_NS
 305 #define __net_init
 306 #define __net_exit
 307 #define __net_initdata
 308 #define __net_initconst
 309 #else
 310 #define __net_init      __init
 311 #define __net_exit      __ref
 312 #define __net_initdata  __initdata
 313 #define __net_initconst __initconst
 314 #endif
 315
 316 int peernet2id_alloc(struct net *net, struct net *peer, gfp_t gfp);
 317 int peernet2id(struct net *net, struct net *peer);
 318 bool peernet_has_id(struct net *net, struct net *peer);
 319 struct net *get_net_ns_by_id(struct net *net, int id);
 320
 321 struct pernet_operations {
 322         struct list_head list;
 323         int (*init)(struct net *net);
 324         void (*exit)(struct net *net);
 325         void (*exit_batch)(struct list_head *net_exit_list);
 326         unsigned int *id;
 327         size_t size;
 328 };
 329
 330 /*
 331  * Use these carefully.  If you implement a network device and it
 332  * needs per network namespace operations use device pernet operations,
 333  * otherwise use pernet subsys operations.
 334  *
 335  * Network interfaces need to be removed from a dying netns _before_
 336  * subsys notifiers can be called, as most of the network code cleanup
 337  * (which is done from subsys notifiers) runs with the assumption that
 338  * dev_remove_pack has been called so no new packets will arrive during
 339  * and after the cleanup functions have been called.  dev_remove_pack
 340  * is not per namespace so instead the guarantee of no more packets
 341  * arriving in a network namespace is provided by ensuring that all
 342  * network devices and all sockets have left the network namespace
 343  * before the cleanup methods are called.
 344  *
 345  * For the longest time the ipv4 icmp code was registered as a pernet
 346  * device which caused kernel oops, and panics during network
 347  * namespace cleanup.   So please don't get this wrong.
 348  */
 349 int register_pernet_subsys(struct pernet_operations *);
 350 void unregister_pernet_subsys(struct pernet_operations *);
 351 int register_pernet_device(struct pernet_operations *);
 352 void unregister_pernet_device(struct pernet_operations *);
 353
 354 struct ctl_table;
 355 struct ctl_table_header;
 356
 357 #ifdef CONFIG_SYSCTL
 358 int net_sysctl_init(void);
 359 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
 360                                              struct ctl_table *table);
 361 void unregister_net_sysctl_table(struct ctl_table_header *header);
 362 #else
 363 static inline int net_sysctl_init(void) { return 0; }
 364 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 365         const char *path, struct ctl_table *table)
 366 {
 367         return NULL;
 368 }
 369 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 370 {
 371 }
 372 #endif
 373
 374 static inline int rt_genid_ipv4(struct net *net)
 375 {
 376         return atomic_read(&net->ipv4.rt_genid);
 377 }
 378
 379 static inline void rt_genid_bump_ipv4(struct net *net)
 380 {
 381         atomic_inc(&net->ipv4.rt_genid);
 382 }
 383
 384 extern void (*__fib6_flush_trees)(struct net *net);
 385 static inline void rt_genid_bump_ipv6(struct net *net)
 386 {
 387         if (__fib6_flush_trees)
 388                 __fib6_flush_trees(net);
 389 }
 390
 391 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 392 static inline struct netns_ieee802154_lowpan *
 393 net_ieee802154_lowpan(struct net *net)
 394 {
 395         return &net->ieee802154_lowpan;
 396 }
 397 #endif
 398
 399 /* For callers who don't really care about whether it's IPv4 or IPv6 */
 400 static inline void rt_genid_bump_all(struct net *net)
 401 {
 402         rt_genid_bump_ipv4(net);
 403         rt_genid_bump_ipv6(net);
 404 }
 405
 406 static inline int fnhe_genid(struct net *net)
 407 {
 408         return atomic_read(&net->fnhe_genid);
 409 }
 410
 411 static inline void fnhe_genid_bump(struct net *net)
 412 {
 413         atomic_inc(&net->fnhe_genid);
 414 }
 415
 416 #endif /* __NET_NET_NAMESPACE_H */