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/netns/core.h>
  13 #include <net/netns/mib.h>
  14 #include <net/netns/unix.h>
  15 #include <net/netns/packet.h>
  16 #include <net/netns/ipv4.h>
  17 #include <net/netns/ipv6.h>
  18 #include <net/netns/sctp.h>
  19 #include <net/netns/dccp.h>
  20 #include <net/netns/netfilter.h>
  21 #include <net/netns/x_tables.h>
  22 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  23 #include <net/netns/conntrack.h>
  24 #endif
  25 #include <net/netns/nftables.h>
  26 #include <net/netns/xfrm.h>
  27
  28 struct user_namespace;
  29 struct proc_dir_entry;
  30 struct net_device;
  31 struct sock;
  32 struct ctl_table_header;
  33 struct net_generic;
  34 struct sock;
  35 struct netns_ipvs;
  36
  37
  38 #define NETDEV_HASHBITS    8
  39 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  40
  41 struct net {
  42         atomic_t                passive;        /* To decided when the network
  43                                                  * namespace should be freed.
  44                                                  */
  45         atomic_t                count;          /* To decided when the network
  46                                                  *  namespace should be shut down.
  47                                                  */
  48 #ifdef NETNS_REFCNT_DEBUG
  49         atomic_t                use_count;      /* To track references we
  50                                                  * destroy on demand
  51                                                  */
  52 #endif
  53         spinlock_t              rules_mod_lock;
  54
  55         struct list_head        list;           /* list of network namespaces */
  56         struct list_head        cleanup_list;   /* namespaces on death row */
  57         struct list_head        exit_list;      /* Use only net_mutex */
  58
  59         struct user_namespace   *user_ns;       /* Owning user namespace */
  60
  61         unsigned int            proc_inum;
  62
  63         struct proc_dir_entry   *proc_net;
  64         struct proc_dir_entry   *proc_net_stat;
  65
  66 #ifdef CONFIG_SYSCTL
  67         struct ctl_table_set    sysctls;
  68 #endif
  69
  70         struct sock             *rtnl;                  /* rtnetlink socket */
  71         struct sock             *genl_sock;
  72
  73         struct list_head        dev_base_head;
  74         struct hlist_head       *dev_name_head;
  75         struct hlist_head       *dev_index_head;
  76         unsigned int            dev_base_seq;   /* protected by rtnl_mutex */
  77         int                     ifindex;
  78         unsigned int            dev_unreg_count;
  79
  80         /* core fib_rules */
  81         struct list_head        rules_ops;
  82
  83
  84         struct net_device       *loopback_dev;          /* The loopback */
  85         struct netns_core       core;
  86         struct netns_mib        mib;
  87         struct netns_packet     packet;
  88         struct netns_unix       unx;
  89         struct netns_ipv4       ipv4;
  90 #if IS_ENABLED(CONFIG_IPV6)
  91         struct netns_ipv6       ipv6;
  92 #endif
  93 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
  94         struct netns_sctp       sctp;
  95 #endif
  96 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
  97         struct netns_dccp       dccp;
  98 #endif
  99 #ifdef CONFIG_NETFILTER
 100         struct netns_nf         nf;
 101         struct netns_xt         xt;
 102 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 103         struct netns_ct         ct;
 104 #endif
 105 #if defined(CONFIG_NF_TABLES) || defined(CONFIG_NF_TABLES_MODULE)
 106         struct netns_nftables   nft;
 107 #endif
 108 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 109         struct netns_nf_frag    nf_frag;
 110 #endif
 111         struct sock             *nfnl;
 112         struct sock             *nfnl_stash;
 113 #endif
 114 #ifdef CONFIG_WEXT_CORE
 115         struct sk_buff_head     wext_nlevents;
 116 #endif
 117         struct net_generic __rcu        *gen;
 118
 119         /* Note : following structs are cache line aligned */
 120 #ifdef CONFIG_XFRM
 121         struct netns_xfrm       xfrm;
 122 #endif
 123 #if IS_ENABLED(CONFIG_IP_VS)
 124         struct netns_ipvs       *ipvs;
 125 #endif
 126         struct sock             *diag_nlsk;
 127         atomic_t                fnhe_genid;
 128 };
 129
 130 /*
 131  * ifindex generation is per-net namespace, and loopback is
 132  * always the 1st device in ns (see net_dev_init), thus any
 133  * loopback device should get ifindex 1
 134  */
 135
 136 #define LOOPBACK_IFINDEX        1
 137
 138 #include <linux/seq_file_net.h>
 139
 140 /* Init's network namespace */
 141 extern struct net init_net;
 142
 143 #ifdef CONFIG_NET_NS
 144 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
 145                         struct net *old_net);
 146
 147 #else /* CONFIG_NET_NS */
 148 #include <linux/sched.h>
 149 #include <linux/nsproxy.h>
 150 static inline struct net *copy_net_ns(unsigned long flags,
 151         struct user_namespace *user_ns, struct net *old_net)
 152 {
 153         if (flags & CLONE_NEWNET)
 154                 return ERR_PTR(-EINVAL);
 155         return old_net;
 156 }
 157 #endif /* CONFIG_NET_NS */
 158
 159
 160 extern struct list_head net_namespace_list;
 161
 162 struct net *get_net_ns_by_pid(pid_t pid);
 163 struct net *get_net_ns_by_fd(int pid);
 164
 165 #ifdef CONFIG_SYSCTL
 166 void ipx_register_sysctl(void);
 167 void ipx_unregister_sysctl(void);
 168 #else
 169 #define ipx_register_sysctl()
 170 #define ipx_unregister_sysctl()
 171 #endif
 172
 173 #ifdef CONFIG_NET_NS
 174 void __put_net(struct net *net);
 175
 176 static inline struct net *get_net(struct net *net)
 177 {
 178         atomic_inc(&net->count);
 179         return net;
 180 }
 181
 182 static inline struct net *maybe_get_net(struct net *net)
 183 {
 184         /* Used when we know struct net exists but we
 185          * aren't guaranteed a previous reference count
 186          * exists.  If the reference count is zero this
 187          * function fails and returns NULL.
 188          */
 189         if (!atomic_inc_not_zero(&net->count))
 190                 net = NULL;
 191         return net;
 192 }
 193
 194 static inline void put_net(struct net *net)
 195 {
 196         if (atomic_dec_and_test(&net->count))
 197                 __put_net(net);
 198 }
 199
 200 static inline
 201 int net_eq(const struct net *net1, const struct net *net2)
 202 {
 203         return net1 == net2;
 204 }
 205
 206 void net_drop_ns(void *);
 207
 208 #else
 209
 210 static inline struct net *get_net(struct net *net)
 211 {
 212         return net;
 213 }
 214
 215 static inline void put_net(struct net *net)
 216 {
 217 }
 218
 219 static inline struct net *maybe_get_net(struct net *net)
 220 {
 221         return net;
 222 }
 223
 224 static inline
 225 int net_eq(const struct net *net1, const struct net *net2)
 226 {
 227         return 1;
 228 }
 229
 230 #define net_drop_ns NULL
 231 #endif
 232
 233
 234 #ifdef NETNS_REFCNT_DEBUG
 235 static inline struct net *hold_net(struct net *net)
 236 {
 237         if (net)
 238                 atomic_inc(&net->use_count);
 239         return net;
 240 }
 241
 242 static inline void release_net(struct net *net)
 243 {
 244         if (net)
 245                 atomic_dec(&net->use_count);
 246 }
 247 #else
 248 static inline struct net *hold_net(struct net *net)
 249 {
 250         return net;
 251 }
 252
 253 static inline void release_net(struct net *net)
 254 {
 255 }
 256 #endif
 257
 258 #ifdef CONFIG_NET_NS
 259
 260 static inline void write_pnet(struct net **pnet, struct net *net)
 261 {
 262         *pnet = net;
 263 }
 264
 265 static inline struct net *read_pnet(struct net * const *pnet)
 266 {
 267         return *pnet;
 268 }
 269
 270 #else
 271
 272 #define write_pnet(pnet, net)   do { (void)(net);} while (0)
 273 #define read_pnet(pnet)         (&init_net)
 274
 275 #endif
 276
 277 #define for_each_net(VAR)                               \
 278         list_for_each_entry(VAR, &net_namespace_list, list)
 279
 280 #define for_each_net_rcu(VAR)                           \
 281         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 282
 283 #ifdef CONFIG_NET_NS
 284 #define __net_init
 285 #define __net_exit
 286 #define __net_initdata
 287 #define __net_initconst
 288 #else
 289 #define __net_init      __init
 290 #define __net_exit      __exit_refok
 291 #define __net_initdata  __initdata
 292 #define __net_initconst __initconst
 293 #endif
 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 #if IS_ENABLED(CONFIG_IPV6)
 359 static inline int rt_genid_ipv6(struct net *net)
 360 {
 361         return atomic_read(&net->ipv6.rt_genid);
 362 }
 363
 364 static inline void rt_genid_bump_ipv6(struct net *net)
 365 {
 366         atomic_inc(&net->ipv6.rt_genid);
 367 }
 368 #else
 369 static inline int rt_genid_ipv6(struct net *net)
 370 {
 371         return 0;
 372 }
 373
 374 static inline void rt_genid_bump_ipv6(struct net *net)
 375 {
 376 }
 377 #endif
 378
 379 /* For callers who don't really care about whether it's IPv4 or IPv6 */
 380 static inline void rt_genid_bump_all(struct net *net)
 381 {
 382         rt_genid_bump_ipv4(net);
 383         rt_genid_bump_ipv6(net);
 384 }
 385
 386 static inline int fnhe_genid(struct net *net)
 387 {
 388         return atomic_read(&net->fnhe_genid);
 389 }
 390
 391 static inline void fnhe_genid_bump(struct net *net)
 392 {
 393         atomic_inc(&net->fnhe_genid);
 394 }
 395
 396 #endif /* __NET_NET_NAMESPACE_H */