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