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 #endif
 122 #ifdef CONFIG_WEXT_CORE
 123         struct sk_buff_head     wext_nlevents;
 124 #endif
 125         struct net_generic __rcu        *gen;
 126
 127         /* Note : following structs are cache line aligned */
 128 #ifdef CONFIG_XFRM
 129         struct netns_xfrm       xfrm;
 130 #endif
 131 #if IS_ENABLED(CONFIG_IP_VS)
 132         struct netns_ipvs       *ipvs;
 133 #endif
 134 #if IS_ENABLED(CONFIG_MPLS)
 135         struct netns_mpls       mpls;
 136 #endif
 137         struct sock             *diag_nlsk;
 138         atomic_t                fnhe_genid;
 139 };
 140
 141 #include <linux/seq_file_net.h>
 142
 143 /* Init's network namespace */
 144 extern struct net init_net;
 145
 146 #ifdef CONFIG_NET_NS
 147 struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
 148                         struct net *old_net);
 149
 150 #else /* CONFIG_NET_NS */
 151 #include <linux/sched.h>
 152 #include <linux/nsproxy.h>
 153 static inline struct net *copy_net_ns(unsigned long flags,
 154         struct user_namespace *user_ns, struct net *old_net)
 155 {
 156         if (flags & CLONE_NEWNET)
 157                 return ERR_PTR(-EINVAL);
 158         return old_net;
 159 }
 160 #endif /* CONFIG_NET_NS */
 161
 162
 163 extern struct list_head net_namespace_list;
 164
 165 struct net *get_net_ns_by_pid(pid_t pid);
 166 struct net *get_net_ns_by_fd(int pid);
 167
 168 #ifdef CONFIG_SYSCTL
 169 void ipx_register_sysctl(void);
 170 void ipx_unregister_sysctl(void);
 171 #else
 172 #define ipx_register_sysctl()
 173 #define ipx_unregister_sysctl()
 174 #endif
 175
 176 #ifdef CONFIG_NET_NS
 177 void __put_net(struct net *net);
 178
 179 static inline struct net *get_net(struct net *net)
 180 {
 181         atomic_inc(&net->count);
 182         return net;
 183 }
 184
 185 static inline struct net *maybe_get_net(struct net *net)
 186 {
 187         /* Used when we know struct net exists but we
 188          * aren't guaranteed a previous reference count
 189          * exists.  If the reference count is zero this
 190          * function fails and returns NULL.
 191          */
 192         if (!atomic_inc_not_zero(&net->count))
 193                 net = NULL;
 194         return net;
 195 }
 196
 197 static inline void put_net(struct net *net)
 198 {
 199         if (atomic_dec_and_test(&net->count))
 200                 __put_net(net);
 201 }
 202
 203 static inline
 204 int net_eq(const struct net *net1, const struct net *net2)
 205 {
 206         return net1 == net2;
 207 }
 208
 209 void net_drop_ns(void *);
 210
 211 #else
 212
 213 static inline struct net *get_net(struct net *net)
 214 {
 215         return net;
 216 }
 217
 218 static inline void put_net(struct net *net)
 219 {
 220 }
 221
 222 static inline struct net *maybe_get_net(struct net *net)
 223 {
 224         return net;
 225 }
 226
 227 static inline
 228 int net_eq(const struct net *net1, const struct net *net2)
 229 {
 230         return 1;
 231 }
 232
 233 #define net_drop_ns NULL
 234 #endif
 235
 236
 237 typedef struct {
 238 #ifdef CONFIG_NET_NS
 239         struct net *net;
 240 #endif
 241 } possible_net_t;
 242
 243 static inline void write_pnet(possible_net_t *pnet, struct net *net)
 244 {
 245 #ifdef CONFIG_NET_NS
 246         pnet->net = net;
 247 #endif
 248 }
 249
 250 static inline struct net *read_pnet(const possible_net_t *pnet)
 251 {
 252 #ifdef CONFIG_NET_NS
 253         return pnet->net;
 254 #else
 255         return &init_net;
 256 #endif
 257 }
 258
 259 #define for_each_net(VAR)                               \
 260         list_for_each_entry(VAR, &net_namespace_list, list)
 261
 262 #define for_each_net_rcu(VAR)                           \
 263         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 264
 265 #ifdef CONFIG_NET_NS
 266 #define __net_init
 267 #define __net_exit
 268 #define __net_initdata
 269 #define __net_initconst
 270 #else
 271 #define __net_init      __init
 272 #define __net_exit      __exit_refok
 273 #define __net_initdata  __initdata
 274 #define __net_initconst __initconst
 275 #endif
 276
 277 int peernet2id_alloc(struct net *net, struct net *peer);
 278 int peernet2id(struct net *net, struct net *peer);
 279 bool peernet_has_id(struct net *net, struct net *peer);
 280 struct net *get_net_ns_by_id(struct net *net, int id);
 281
 282 struct pernet_operations {
 283         struct list_head list;
 284         int (*init)(struct net *net);
 285         void (*exit)(struct net *net);
 286         void (*exit_batch)(struct list_head *net_exit_list);
 287         int *id;
 288         size_t size;
 289 };
 290
 291 /*
 292  * Use these carefully.  If you implement a network device and it
 293  * needs per network namespace operations use device pernet operations,
 294  * otherwise use pernet subsys operations.
 295  *
 296  * Network interfaces need to be removed from a dying netns _before_
 297  * subsys notifiers can be called, as most of the network code cleanup
 298  * (which is done from subsys notifiers) runs with the assumption that
 299  * dev_remove_pack has been called so no new packets will arrive during
 300  * and after the cleanup functions have been called.  dev_remove_pack
 301  * is not per namespace so instead the guarantee of no more packets
 302  * arriving in a network namespace is provided by ensuring that all
 303  * network devices and all sockets have left the network namespace
 304  * before the cleanup methods are called.
 305  *
 306  * For the longest time the ipv4 icmp code was registered as a pernet
 307  * device which caused kernel oops, and panics during network
 308  * namespace cleanup.   So please don't get this wrong.
 309  */
 310 int register_pernet_subsys(struct pernet_operations *);
 311 void unregister_pernet_subsys(struct pernet_operations *);
 312 int register_pernet_device(struct pernet_operations *);
 313 void unregister_pernet_device(struct pernet_operations *);
 314
 315 struct ctl_table;
 316 struct ctl_table_header;
 317
 318 #ifdef CONFIG_SYSCTL
 319 int net_sysctl_init(void);
 320 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
 321                                              struct ctl_table *table);
 322 void unregister_net_sysctl_table(struct ctl_table_header *header);
 323 #else
 324 static inline int net_sysctl_init(void) { return 0; }
 325 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 326         const char *path, struct ctl_table *table)
 327 {
 328         return NULL;
 329 }
 330 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 331 {
 332 }
 333 #endif
 334
 335 static inline int rt_genid_ipv4(struct net *net)
 336 {
 337         return atomic_read(&net->ipv4.rt_genid);
 338 }
 339
 340 static inline void rt_genid_bump_ipv4(struct net *net)
 341 {
 342         atomic_inc(&net->ipv4.rt_genid);
 343 }
 344
 345 extern void (*__fib6_flush_trees)(struct net *net);
 346 static inline void rt_genid_bump_ipv6(struct net *net)
 347 {
 348         if (__fib6_flush_trees)
 349                 __fib6_flush_trees(net);
 350 }
 351
 352 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 353 static inline struct netns_ieee802154_lowpan *
 354 net_ieee802154_lowpan(struct net *net)
 355 {
 356         return &net->ieee802154_lowpan;
 357 }
 358 #endif
 359
 360 /* For callers who don't really care about whether it's IPv4 or IPv6 */
 361 static inline void rt_genid_bump_all(struct net *net)
 362 {
 363         rt_genid_bump_ipv4(net);
 364         rt_genid_bump_ipv6(net);
 365 }
 366
 367 static inline int fnhe_genid(struct net *net)
 368 {
 369         return atomic_read(&net->fnhe_genid);
 370 }
 371
 372 static inline void fnhe_genid_bump(struct net *net)
 373 {
 374         atomic_inc(&net->fnhe_genid);
 375 }
 376
 377 #endif /* __NET_NET_NAMESPACE_H */