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
  14 #include <net/flow.h>
  15 #include <net/netns/core.h>
  16 #include <net/netns/mib.h>
  17 #include <net/netns/unix.h>
  18 #include <net/netns/packet.h>
  19 #include <net/netns/ipv4.h>
  20 #include <net/netns/ipv6.h>
  21 #include <net/netns/ieee802154_6lowpan.h>
  22 #include <net/netns/sctp.h>
  23 #include <net/netns/dccp.h>
  24 #include <net/netns/netfilter.h>
  25 #include <net/netns/x_tables.h>
  26 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  27 #include <net/netns/conntrack.h>
  28 #endif
  29 #include <net/netns/nftables.h>
  30 #include <net/netns/xfrm.h>
  31 #include <net/netns/mpls.h>
  32 #include <net/netns/can.h>
  33 #include <linux/ns_common.h>
  34 #include <linux/idr.h>
  35 #include <linux/skbuff.h>
  36
  37 struct user_namespace;
  38 struct proc_dir_entry;
  39 struct net_device;
  40 struct sock;
  41 struct ctl_table_header;
  42 struct net_generic;
  43 struct sock;
  44 struct netns_ipvs;
  45
  46
  47 #define NETDEV_HASHBITS    8
  48 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  49
  50 struct net {
  51         refcount_t              passive;        /* To decided when the network
  52                                                  * namespace should be freed.
  53                                                  */
  54         atomic_t                count;          /* To decided when the network
  55                                                  *  namespace should be shut down.
  56                                                  */
  57         spinlock_t              rules_mod_lock;
  58
  59         u32                     hash_mix;
  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_barrier(void);
 167 #else /* CONFIG_NET_NS */
 168 #include <linux/sched.h>
 169 #include <linux/nsproxy.h>
 170 static inline struct net *copy_net_ns(unsigned long flags,
 171         struct user_namespace *user_ns, struct net *old_net)
 172 {
 173         if (flags & CLONE_NEWNET)
 174                 return ERR_PTR(-EINVAL);
 175         return old_net;
 176 }
 177
 178 static inline void net_ns_barrier(void) {}
 179 #endif /* CONFIG_NET_NS */
 180
 181
 182 extern struct list_head net_namespace_list;
 183
 184 struct net *get_net_ns_by_pid(pid_t pid);
 185 struct net *get_net_ns_by_fd(int fd);
 186
 187 #ifdef CONFIG_SYSCTL
 188 void ipx_register_sysctl(void);
 189 void ipx_unregister_sysctl(void);
 190 #else
 191 #define ipx_register_sysctl()
 192 #define ipx_unregister_sysctl()
 193 #endif
 194
 195 #ifdef CONFIG_NET_NS
 196 void __put_net(struct net *net);
 197
 198 static inline struct net *get_net(struct net *net)
 199 {
 200         atomic_inc(&net->count);
 201         return net;
 202 }
 203
 204 static inline struct net *maybe_get_net(struct net *net)
 205 {
 206         /* Used when we know struct net exists but we
 207          * aren't guaranteed a previous reference count
 208          * exists.  If the reference count is zero this
 209          * function fails and returns NULL.
 210          */
 211         if (!atomic_inc_not_zero(&net->count))
 212                 net = NULL;
 213         return net;
 214 }
 215
 216 static inline void put_net(struct net *net)
 217 {
 218         if (atomic_dec_and_test(&net->count))
 219                 __put_net(net);
 220 }
 221
 222 static inline
 223 int net_eq(const struct net *net1, const struct net *net2)
 224 {
 225         return net1 == net2;
 226 }
 227
 228 static inline int check_net(const struct net *net)
 229 {
 230         return atomic_read(&net->count) != 0;
 231 }
 232
 233 void net_drop_ns(void *);
 234
 235 #else
 236
 237 static inline struct net *get_net(struct net *net)
 238 {
 239         return net;
 240 }
 241
 242 static inline void put_net(struct net *net)
 243 {
 244 }
 245
 246 static inline struct net *maybe_get_net(struct net *net)
 247 {
 248         return net;
 249 }
 250
 251 static inline
 252 int net_eq(const struct net *net1, const struct net *net2)
 253 {
 254         return 1;
 255 }
 256
 257 static inline int check_net(const struct net *net)
 258 {
 259         return 1;
 260 }
 261
 262 #define net_drop_ns NULL
 263 #endif
 264
 265
 266 typedef struct {
 267 #ifdef CONFIG_NET_NS
 268         struct net *net;
 269 #endif
 270 } possible_net_t;
 271
 272 static inline void write_pnet(possible_net_t *pnet, struct net *net)
 273 {
 274 #ifdef CONFIG_NET_NS
 275         pnet->net = net;
 276 #endif
 277 }
 278
 279 static inline struct net *read_pnet(const possible_net_t *pnet)
 280 {
 281 #ifdef CONFIG_NET_NS
 282         return pnet->net;
 283 #else
 284         return &init_net;
 285 #endif
 286 }
 287
 288 #define for_each_net(VAR)                               \
 289         list_for_each_entry(VAR, &net_namespace_list, list)
 290
 291 #define for_each_net_rcu(VAR)                           \
 292         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 293
 294 #ifdef CONFIG_NET_NS
 295 #define __net_init
 296 #define __net_exit
 297 #define __net_initdata
 298 #define __net_initconst
 299 #else
 300 #define __net_init      __init
 301 #define __net_exit      __ref
 302 #define __net_initdata  __initdata
 303 #define __net_initconst __initconst
 304 #endif
 305
 306 int peernet2id_alloc(struct net *net, struct net *peer);
 307 int peernet2id(struct net *net, struct net *peer);
 308 bool peernet_has_id(struct net *net, struct net *peer);
 309 struct net *get_net_ns_by_id(struct net *net, int id);
 310
 311 struct pernet_operations {
 312         struct list_head list;
 313         int (*init)(struct net *net);
 314         void (*exit)(struct net *net);
 315         void (*exit_batch)(struct list_head *net_exit_list);
 316         unsigned int *id;
 317         size_t size;
 318 };
 319
 320 /*
 321  * Use these carefully.  If you implement a network device and it
 322  * needs per network namespace operations use device pernet operations,
 323  * otherwise use pernet subsys operations.
 324  *
 325  * Network interfaces need to be removed from a dying netns _before_
 326  * subsys notifiers can be called, as most of the network code cleanup
 327  * (which is done from subsys notifiers) runs with the assumption that
 328  * dev_remove_pack has been called so no new packets will arrive during
 329  * and after the cleanup functions have been called.  dev_remove_pack
 330  * is not per namespace so instead the guarantee of no more packets
 331  * arriving in a network namespace is provided by ensuring that all
 332  * network devices and all sockets have left the network namespace
 333  * before the cleanup methods are called.
 334  *
 335  * For the longest time the ipv4 icmp code was registered as a pernet
 336  * device which caused kernel oops, and panics during network
 337  * namespace cleanup.   So please don't get this wrong.
 338  */
 339 int register_pernet_subsys(struct pernet_operations *);
 340 void unregister_pernet_subsys(struct pernet_operations *);
 341 int register_pernet_device(struct pernet_operations *);
 342 void unregister_pernet_device(struct pernet_operations *);
 343
 344 struct ctl_table;
 345 struct ctl_table_header;
 346
 347 #ifdef CONFIG_SYSCTL
 348 int net_sysctl_init(void);
 349 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
 350                                              struct ctl_table *table);
 351 void unregister_net_sysctl_table(struct ctl_table_header *header);
 352 #else
 353 static inline int net_sysctl_init(void) { return 0; }
 354 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 355         const char *path, struct ctl_table *table)
 356 {
 357         return NULL;
 358 }
 359 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 360 {
 361 }
 362 #endif
 363
 364 static inline int rt_genid_ipv4(struct net *net)
 365 {
 366         return atomic_read(&net->ipv4.rt_genid);
 367 }
 368
 369 static inline void rt_genid_bump_ipv4(struct net *net)
 370 {
 371         atomic_inc(&net->ipv4.rt_genid);
 372 }
 373
 374 extern void (*__fib6_flush_trees)(struct net *net);
 375 static inline void rt_genid_bump_ipv6(struct net *net)
 376 {
 377         if (__fib6_flush_trees)
 378                 __fib6_flush_trees(net);
 379 }
 380
 381 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 382 static inline struct netns_ieee802154_lowpan *
 383 net_ieee802154_lowpan(struct net *net)
 384 {
 385         return &net->ieee802154_lowpan;
 386 }
 387 #endif
 388
 389 /* For callers who don't really care about whether it's IPv4 or IPv6 */
 390 static inline void rt_genid_bump_all(struct net *net)
 391 {
 392         rt_genid_bump_ipv4(net);
 393         rt_genid_bump_ipv6(net);
 394 }
 395
 396 static inline int fnhe_genid(struct net *net)
 397 {
 398         return atomic_read(&net->fnhe_genid);
 399 }
 400
 401 static inline void fnhe_genid_bump(struct net *net)
 402 {
 403         atomic_inc(&net->fnhe_genid);
 404 }
 405
 406 #endif /* __NET_NET_NAMESPACE_H */