include/net/net_namespace.h

   1 /*
   2  * Operations on the network namespace
   3  */
   4 #ifndef __NET_NET_NAMESPACE_H
   5 #define __NET_NET_NAMESPACE_H
   6
   7 #include <linux/atomic.h>
   8 #include <linux/refcount.h>
   9 #include <linux/workqueue.h>
  10 #include <linux/list.h>
  11 #include <linux/sysctl.h>
  12
  13 #include <net/flow.h>
  14 #include <net/netns/core.h>
  15 #include <net/netns/mib.h>
  16 #include <net/netns/unix.h>
  17 #include <net/netns/packet.h>
  18 #include <net/netns/ipv4.h>
  19 #include <net/netns/ipv6.h>
  20 #include <net/netns/ieee802154_6lowpan.h>
  21 #include <net/netns/sctp.h>
  22 #include <net/netns/dccp.h>
  23 #include <net/netns/netfilter.h>
  24 #include <net/netns/x_tables.h>
  25 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  26 #include <net/netns/conntrack.h>
  27 #endif
  28 #include <net/netns/nftables.h>
  29 #include <net/netns/xfrm.h>
  30 #include <net/netns/mpls.h>
  31 #include <net/netns/can.h>
  32 #include <linux/ns_common.h>
  33 #include <linux/idr.h>
  34 #include <linux/skbuff.h>
  35
  36 struct user_namespace;
  37 struct proc_dir_entry;
  38 struct net_device;
  39 struct sock;
  40 struct ctl_table_header;
  41 struct net_generic;
  42 struct sock;
  43 struct netns_ipvs;
  44
  45
  46 #define NETDEV_HASHBITS    8
  47 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  48
  49 struct net {
  50         refcount_t              passive;        /* To decided when the network
  51                                                  * namespace should be freed.
  52                                                  */
  53         atomic_t                count;          /* To decided when the network
  54                                                  *  namespace should be shut down.
  55                                                  */
  56         spinlock_t              rules_mod_lock;
  57
  58         atomic64_t              cookie_gen;
  59
  60         struct list_head        list;           /* list of network namespaces */
  61         struct list_head        cleanup_list;   /* namespaces on death row */
  62         struct list_head        exit_list;      /* Use only net_mutex */
  63
  64         struct user_namespace   *user_ns;       /* Owning user namespace */
  65         struct ucounts          *ucounts;
  66         spinlock_t              nsid_lock;
  67         struct idr              netns_ids;
  68
  69         struct ns_common        ns;
  70
  71         struct proc_dir_entry   *proc_net;
  72         struct proc_dir_entry   *proc_net_stat;
  73
  74 #ifdef CONFIG_SYSCTL
  75         struct ctl_table_set    sysctls;
  76 #endif
  77
  78         struct sock             *rtnl;                  /* rtnetlink socket */
  79         struct sock             *genl_sock;
  80
  81         struct list_head        dev_base_head;
  82         struct hlist_head       *dev_name_head;
  83         struct hlist_head       *dev_index_head;
  84         unsigned int            dev_base_seq;   /* protected by rtnl_mutex */
  85         int                     ifindex;
  86         unsigned int            dev_unreg_count;
  87
  88         /* core fib_rules */
  89         struct list_head        rules_ops;
  90
  91
  92         struct net_device       *loopback_dev;          /* The loopback */
  93         struct netns_core       core;
  94         struct netns_mib        mib;
  95         struct netns_packet     packet;
  96         struct netns_unix       unx;
  97         struct netns_ipv4       ipv4;
  98 #if IS_ENABLED(CONFIG_IPV6)
  99         struct netns_ipv6       ipv6;
 100 #endif
 101 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 102         struct netns_ieee802154_lowpan  ieee802154_lowpan;
 103 #endif
 104 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
 105         struct netns_sctp       sctp;
 106 #endif
 107 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
 108         struct netns_dccp       dccp;
 109 #endif
 110 #ifdef CONFIG_NETFILTER
 111         struct netns_nf         nf;
 112         struct netns_xt         xt;
 113 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 114         struct netns_ct         ct;
 115 #endif
 116 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
 117         struct netns_nftables   nft;
 118 #endif
 119 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 120         struct netns_nf_frag    nf_frag;
 121 #endif
 122         struct sock             *nfnl;
 123         struct sock             *nfnl_stash;
 124 #if IS_ENABLED(CONFIG_NETFILTER_NETLINK_ACCT)
 125         struct list_head        nfnl_acct_list;
 126 #endif
 127 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
 128         struct list_head        nfct_timeout_list;
 129 #endif
 130 #endif
 131 #ifdef CONFIG_WEXT_CORE
 132         struct sk_buff_head     wext_nlevents;
 133 #endif
 134         struct net_generic __rcu        *gen;
 135
 136         /* Note : following structs are cache line aligned */
 137 #ifdef CONFIG_XFRM
 138         struct netns_xfrm       xfrm;
 139 #endif
 140 #if IS_ENABLED(CONFIG_IP_VS)
 141         struct netns_ipvs       *ipvs;
 142 #endif
 143 #if IS_ENABLED(CONFIG_MPLS)
 144         struct netns_mpls       mpls;
 145 #endif
 146 #if IS_ENABLED(CONFIG_CAN)
 147         struct netns_can        can;
 148 #endif
 149         struct sock             *diag_nlsk;
 150         atomic_t                fnhe_genid;
 151 } __randomize_layout;
 152
 153 #include <linux/seq_file_net.h>
 154
 155 /* Init's network namespace */
 156 extern struct net init_net;
 157
 158 #ifdef CONFIG_NET_NS
 159 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
 160                         struct net *old_net);
 161
 162 void net_ns_barrier(void);
 163 #else /* CONFIG_NET_NS */
 164 #include <linux/sched.h>
 165 #include <linux/nsproxy.h>
 166 static inline struct net *copy_net_ns(unsigned long flags,
 167         struct user_namespace *user_ns, struct net *old_net)
 168 {
 169         if (flags & CLONE_NEWNET)
 170                 return ERR_PTR(-EINVAL);
 171         return old_net;
 172 }
 173
 174 static inline void net_ns_barrier(void) {}
 175 #endif /* CONFIG_NET_NS */
 176
 177
 178 extern struct list_head net_namespace_list;
 179
 180 struct net *get_net_ns_by_pid(pid_t pid);
 181 struct net *get_net_ns_by_fd(int fd);
 182
 183 #ifdef CONFIG_SYSCTL
 184 void ipx_register_sysctl(void);
 185 void ipx_unregister_sysctl(void);
 186 #else
 187 #define ipx_register_sysctl()
 188 #define ipx_unregister_sysctl()
 189 #endif
 190
 191 #ifdef CONFIG_NET_NS
 192 void __put_net(struct net *net);
 193
 194 static inline struct net *get_net(struct net *net)
 195 {
 196         atomic_inc(&net->count);
 197         return net;
 198 }
 199
 200 static inline struct net *maybe_get_net(struct net *net)
 201 {
 202         /* Used when we know struct net exists but we
 203          * aren't guaranteed a previous reference count
 204          * exists.  If the reference count is zero this
 205          * function fails and returns NULL.
 206          */
 207         if (!atomic_inc_not_zero(&net->count))
 208                 net = NULL;
 209         return net;
 210 }
 211
 212 static inline void put_net(struct net *net)
 213 {
 214         if (atomic_dec_and_test(&net->count))
 215                 __put_net(net);
 216 }
 217
 218 static inline
 219 int net_eq(const struct net *net1, const struct net *net2)
 220 {
 221         return net1 == net2;
 222 }
 223
 224 void net_drop_ns(void *);
 225
 226 #else
 227
 228 static inline struct net *get_net(struct net *net)
 229 {
 230         return net;
 231 }
 232
 233 static inline void put_net(struct net *net)
 234 {
 235 }
 236
 237 static inline struct net *maybe_get_net(struct net *net)
 238 {
 239         return net;
 240 }
 241
 242 static inline
 243 int net_eq(const struct net *net1, const struct net *net2)
 244 {
 245         return 1;
 246 }
 247
 248 #define net_drop_ns NULL
 249 #endif
 250
 251
 252 typedef struct {
 253 #ifdef CONFIG_NET_NS
 254         struct net *net;
 255 #endif
 256 } possible_net_t;
 257
 258 static inline void write_pnet(possible_net_t *pnet, struct net *net)
 259 {
 260 #ifdef CONFIG_NET_NS
 261         pnet->net = net;
 262 #endif
 263 }
 264
 265 static inline struct net *read_pnet(const possible_net_t *pnet)
 266 {
 267 #ifdef CONFIG_NET_NS
 268         return pnet->net;
 269 #else
 270         return &init_net;
 271 #endif
 272 }
 273
 274 #define for_each_net(VAR)                               \
 275         list_for_each_entry(VAR, &net_namespace_list, list)
 276
 277 #define for_each_net_rcu(VAR)                           \
 278         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 279
 280 #ifdef CONFIG_NET_NS
 281 #define __net_init
 282 #define __net_exit
 283 #define __net_initdata
 284 #define __net_initconst
 285 #else
 286 #define __net_init      __init
 287 #define __net_exit      __ref
 288 #define __net_initdata  __initdata
 289 #define __net_initconst __initconst
 290 #endif
 291
 292 int peernet2id_alloc(struct net *net, struct net *peer);
 293 int peernet2id(struct net *net, struct net *peer);
 294 bool peernet_has_id(struct net *net, struct net *peer);
 295 struct net *get_net_ns_by_id(struct net *net, int id);
 296
 297 struct pernet_operations {
 298         struct list_head list;
 299         int (*init)(struct net *net);
 300         void (*exit)(struct net *net);
 301         void (*exit_batch)(struct list_head *net_exit_list);
 302         unsigned int *id;
 303         size_t size;
 304 };
 305
 306 /*
 307  * Use these carefully.  If you implement a network device and it
 308  * needs per network namespace operations use device pernet operations,
 309  * otherwise use pernet subsys operations.
 310  *
 311  * Network interfaces need to be removed from a dying netns _before_
 312  * subsys notifiers can be called, as most of the network code cleanup
 313  * (which is done from subsys notifiers) runs with the assumption that
 314  * dev_remove_pack has been called so no new packets will arrive during
 315  * and after the cleanup functions have been called.  dev_remove_pack
 316  * is not per namespace so instead the guarantee of no more packets
 317  * arriving in a network namespace is provided by ensuring that all
 318  * network devices and all sockets have left the network namespace
 319  * before the cleanup methods are called.
 320  *
 321  * For the longest time the ipv4 icmp code was registered as a pernet
 322  * device which caused kernel oops, and panics during network
 323  * namespace cleanup.   So please don't get this wrong.
 324  */
 325 int register_pernet_subsys(struct pernet_operations *);
 326 void unregister_pernet_subsys(struct pernet_operations *);
 327 int register_pernet_device(struct pernet_operations *);
 328 void unregister_pernet_device(struct pernet_operations *);
 329
 330 struct ctl_table;
 331 struct ctl_table_header;
 332
 333 #ifdef CONFIG_SYSCTL
 334 int net_sysctl_init(void);
 335 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
 336                                              struct ctl_table *table);
 337 void unregister_net_sysctl_table(struct ctl_table_header *header);
 338 #else
 339 static inline int net_sysctl_init(void) { return 0; }
 340 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 341         const char *path, struct ctl_table *table)
 342 {
 343         return NULL;
 344 }
 345 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 346 {
 347 }
 348 #endif
 349
 350 static inline int rt_genid_ipv4(struct net *net)
 351 {
 352         return atomic_read(&net->ipv4.rt_genid);
 353 }
 354
 355 static inline void rt_genid_bump_ipv4(struct net *net)
 356 {
 357         atomic_inc(&net->ipv4.rt_genid);
 358 }
 359
 360 extern void (*__fib6_flush_trees)(struct net *net);
 361 static inline void rt_genid_bump_ipv6(struct net *net)
 362 {
 363         if (__fib6_flush_trees)
 364                 __fib6_flush_trees(net);
 365 }
 366
 367 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 368 static inline struct netns_ieee802154_lowpan *
 369 net_ieee802154_lowpan(struct net *net)
 370 {
 371         return &net->ieee802154_lowpan;
 372 }
 373 #endif
 374
 375 /* For callers who don't really care about whether it's IPv4 or IPv6 */
 376 static inline void rt_genid_bump_all(struct net *net)
 377 {
 378         rt_genid_bump_ipv4(net);
 379         rt_genid_bump_ipv6(net);
 380 }
 381
 382 static inline int fnhe_genid(struct net *net)
 383 {
 384         return atomic_read(&net->fnhe_genid);
 385 }
 386
 387 static inline void fnhe_genid_bump(struct net *net)
 388 {
 389         atomic_inc(&net->fnhe_genid);
 390 }
 391
 392 #endif /* __NET_NET_NAMESPACE_H */