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