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