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 #endif
 125         struct sock             *nfnl;
 126         struct sock             *nfnl_stash;
 127 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
 128         struct list_head        nfnl_acct_list;
 129 #endif
 130 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 131         struct list_head        nfct_timeout_list;
 132 #endif
 133 #endif
 134 #ifdef CONFIG_WEXT_CORE
 135         struct sk_buff_head     wext_nlevents;
 136 #endif
 137         struct net_generic __rcu        *gen;
 138
 139         /* Note : following structs are cache line aligned */
 140 #ifdef CONFIG_XFRM
 141         struct netns_xfrm       xfrm;
 142 #endif
 143 #if IS_ENABLED(CONFIG_IP_VS)
 144         struct netns_ipvs       *ipvs;
 145 #endif
 146 #if IS_ENABLED(CONFIG_MPLS)
 147         struct netns_mpls       mpls;
 148 #endif
 149 #if IS_ENABLED(CONFIG_CAN)
 150         struct netns_can        can;
 151 #endif
 152         struct sock             *diag_nlsk;
 153         atomic_t                fnhe_genid;
 154 } __randomize_layout;
 155
 156 #include <linux/seq_file_net.h>
 157
 158 /* Init's network namespace */
 159 extern struct net init_net;
 160
 161 #ifdef CONFIG_NET_NS
 162 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
 163                         struct net *old_net);
 164
 165 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
 166
 167 void net_ns_barrier(void);
 168 #else /* CONFIG_NET_NS */
 169 #include <linux/sched.h>
 170 #include <linux/nsproxy.h>
 171 static inline struct net *copy_net_ns(unsigned long flags,
 172         struct user_namespace *user_ns, struct net *old_net)
 173 {
 174         if (flags & CLONE_NEWNET)
 175                 return ERR_PTR(-EINVAL);
 176         return old_net;
 177 }
 178
 179 static inline void net_ns_get_ownership(const struct net *net,
 180                                         kuid_t *uid, kgid_t *gid)
 181 {
 182         *uid = GLOBAL_ROOT_UID;
 183         *gid = GLOBAL_ROOT_GID;
 184 }
 185
 186 static inline void net_ns_barrier(void) {}
 187 #endif /* CONFIG_NET_NS */
 188
 189
 190 extern struct list_head net_namespace_list;
 191
 192 struct net *get_net_ns_by_pid(pid_t pid);
 193 struct net *get_net_ns_by_fd(int fd);
 194
 195 #ifdef CONFIG_SYSCTL
 196 void ipx_register_sysctl(void);
 197 void ipx_unregister_sysctl(void);
 198 #else
 199 #define ipx_register_sysctl()
 200 #define ipx_unregister_sysctl()
 201 #endif
 202
 203 #ifdef CONFIG_NET_NS
 204 void __put_net(struct net *net);
 205
 206 static inline struct net *get_net(struct net *net)
 207 {
 208         atomic_inc(&net->count);
 209         return net;
 210 }
 211
 212 static inline struct net *maybe_get_net(struct net *net)
 213 {
 214         /* Used when we know struct net exists but we
 215          * aren't guaranteed a previous reference count
 216          * exists.  If the reference count is zero this
 217          * function fails and returns NULL.
 218          */
 219         if (!atomic_inc_not_zero(&net->count))
 220                 net = NULL;
 221         return net;
 222 }
 223
 224 static inline void put_net(struct net *net)
 225 {
 226         if (atomic_dec_and_test(&net->count))
 227                 __put_net(net);
 228 }
 229
 230 static inline
 231 int net_eq(const struct net *net1, const struct net *net2)
 232 {
 233         return net1 == net2;
 234 }
 235
 236 static inline int check_net(const struct net *net)
 237 {
 238         return atomic_read(&net->count) != 0;
 239 }
 240
 241 void net_drop_ns(void *);
 242
 243 #else
 244
 245 static inline struct net *get_net(struct net *net)
 246 {
 247         return net;
 248 }
 249
 250 static inline void put_net(struct net *net)
 251 {
 252 }
 253
 254 static inline struct net *maybe_get_net(struct net *net)
 255 {
 256         return net;
 257 }
 258
 259 static inline
 260 int net_eq(const struct net *net1, const struct net *net2)
 261 {
 262         return 1;
 263 }
 264
 265 static inline int check_net(const struct net *net)
 266 {
 267         return 1;
 268 }
 269
 270 #define net_drop_ns NULL
 271 #endif
 272
 273
 274 typedef struct {
 275 #ifdef CONFIG_NET_NS
 276         struct net *net;
 277 #endif
 278 } possible_net_t;
 279
 280 static inline void write_pnet(possible_net_t *pnet, struct net *net)
 281 {
 282 #ifdef CONFIG_NET_NS
 283         pnet->net = net;
 284 #endif
 285 }
 286
 287 static inline struct net *read_pnet(const possible_net_t *pnet)
 288 {
 289 #ifdef CONFIG_NET_NS
 290         return pnet->net;
 291 #else
 292         return &init_net;
 293 #endif
 294 }
 295
 296 #define for_each_net(VAR)                               \
 297         list_for_each_entry(VAR, &net_namespace_list, list)
 298
 299 #define for_each_net_rcu(VAR)                           \
 300         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 301
 302 #ifdef CONFIG_NET_NS
 303 #define __net_init
 304 #define __net_exit
 305 #define __net_initdata
 306 #define __net_initconst
 307 #else
 308 #define __net_init      __init
 309 #define __net_exit      __ref
 310 #define __net_initdata  __initdata
 311 #define __net_initconst __initconst
 312 #endif
 313
 314 int peernet2id_alloc(struct net *net, struct net *peer);
 315 int peernet2id(struct net *net, struct net *peer);
 316 bool peernet_has_id(struct net *net, struct net *peer);
 317 struct net *get_net_ns_by_id(struct net *net, int id);
 318
 319 struct pernet_operations {
 320         struct list_head list;
 321         int (*init)(struct net *net);
 322         void (*exit)(struct net *net);
 323         void (*exit_batch)(struct list_head *net_exit_list);
 324         unsigned int *id;
 325         size_t size;
 326 };
 327
 328 /*
 329  * Use these carefully.  If you implement a network device and it
 330  * needs per network namespace operations use device pernet operations,
 331  * otherwise use pernet subsys operations.
 332  *
 333  * Network interfaces need to be removed from a dying netns _before_
 334  * subsys notifiers can be called, as most of the network code cleanup
 335  * (which is done from subsys notifiers) runs with the assumption that
 336  * dev_remove_pack has been called so no new packets will arrive during
 337  * and after the cleanup functions have been called.  dev_remove_pack
 338  * is not per namespace so instead the guarantee of no more packets
 339  * arriving in a network namespace is provided by ensuring that all
 340  * network devices and all sockets have left the network namespace
 341  * before the cleanup methods are called.
 342  *
 343  * For the longest time the ipv4 icmp code was registered as a pernet
 344  * device which caused kernel oops, and panics during network
 345  * namespace cleanup.   So please don't get this wrong.
 346  */
 347 int register_pernet_subsys(struct pernet_operations *);
 348 void unregister_pernet_subsys(struct pernet_operations *);
 349 int register_pernet_device(struct pernet_operations *);
 350 void unregister_pernet_device(struct pernet_operations *);
 351
 352 struct ctl_table;
 353 struct ctl_table_header;
 354
 355 #ifdef CONFIG_SYSCTL
 356 int net_sysctl_init(void);
 357 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
 358                                              struct ctl_table *table);
 359 void unregister_net_sysctl_table(struct ctl_table_header *header);
 360 #else
 361 static inline int net_sysctl_init(void) { return 0; }
 362 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 363         const char *path, struct ctl_table *table)
 364 {
 365         return NULL;
 366 }
 367 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 368 {
 369 }
 370 #endif
 371
 372 static inline int rt_genid_ipv4(struct net *net)
 373 {
 374         return atomic_read(&net->ipv4.rt_genid);
 375 }
 376
 377 static inline void rt_genid_bump_ipv4(struct net *net)
 378 {
 379         atomic_inc(&net->ipv4.rt_genid);
 380 }
 381
 382 extern void (*__fib6_flush_trees)(struct net *net);
 383 static inline void rt_genid_bump_ipv6(struct net *net)
 384 {
 385         if (__fib6_flush_trees)
 386                 __fib6_flush_trees(net);
 387 }
 388
 389 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 390 static inline struct netns_ieee802154_lowpan *
 391 net_ieee802154_lowpan(struct net *net)
 392 {
 393         return &net->ieee802154_lowpan;
 394 }
 395 #endif
 396
 397 /* For callers who don't really care about whether it's IPv4 or IPv6 */
 398 static inline void rt_genid_bump_all(struct net *net)
 399 {
 400         rt_genid_bump_ipv4(net);
 401         rt_genid_bump_ipv6(net);
 402 }
 403
 404 static inline int fnhe_genid(struct net *net)
 405 {
 406         return atomic_read(&net->fnhe_genid);
 407 }
 408
 409 static inline void fnhe_genid_bump(struct net *net)
 410 {
 411         atomic_inc(&net->fnhe_genid);
 412 }
 413
 414 #endif /* __NET_NET_NAMESPACE_H */