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
  32 struct user_namespace;
  33 struct proc_dir_entry;
  34 struct net_device;
  35 struct sock;
  36 struct ctl_table_header;
  37 struct net_generic;
  38 struct sock;
  39 struct netns_ipvs;
  40
  41
  42 #define NETDEV_HASHBITS    8
  43 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  44
  45 struct net {
  46         atomic_t                passive;        /* To decided when the network
  47                                                  * namespace should be freed.
  48                                                  */
  49         atomic_t                count;          /* To decided when the network
  50                                                  *  namespace should be shut down.
  51                                                  */
  52         spinlock_t              rules_mod_lock;
  53
  54         atomic64_t              cookie_gen;
  55
  56         struct list_head        list;           /* list of network namespaces */
  57         struct list_head        cleanup_list;   /* namespaces on death row */
  58         struct list_head        exit_list;      /* Use only net_mutex */
  59
  60         struct user_namespace   *user_ns;       /* Owning user namespace */
  61         struct idr              netns_ids;
  62
  63         struct ns_common        ns;
  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 #if IS_ENABLED(CONFIG_MPLS)
 132         struct netns_mpls       mpls;
 133 #endif
 134         struct sock             *diag_nlsk;
 135         atomic_t                fnhe_genid;
 136 };
 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 typedef struct {
 235 #ifdef CONFIG_NET_NS
 236         struct net *net;
 237 #endif
 238 } possible_net_t;
 239
 240 static inline void write_pnet(possible_net_t *pnet, struct net *net)
 241 {
 242 #ifdef CONFIG_NET_NS
 243         pnet->net = net;
 244 #endif
 245 }
 246
 247 static inline struct net *read_pnet(const possible_net_t *pnet)
 248 {
 249 #ifdef CONFIG_NET_NS
 250         return pnet->net;
 251 #else
 252         return &init_net;
 253 #endif
 254 }
 255
 256 #define for_each_net(VAR)                               \
 257         list_for_each_entry(VAR, &net_namespace_list, list)
 258
 259 #define for_each_net_rcu(VAR)                           \
 260         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 261
 262 #ifdef CONFIG_NET_NS
 263 #define __net_init
 264 #define __net_exit
 265 #define __net_initdata
 266 #define __net_initconst
 267 #else
 268 #define __net_init      __init
 269 #define __net_exit      __exit_refok
 270 #define __net_initdata  __initdata
 271 #define __net_initconst __initconst
 272 #endif
 273
 274 int peernet2id_alloc(struct net *net, struct net *peer);
 275 struct net *get_net_ns_by_id(struct net *net, int id);
 276
 277 struct pernet_operations {
 278         struct list_head list;
 279         int (*init)(struct net *net);
 280         void (*exit)(struct net *net);
 281         void (*exit_batch)(struct list_head *net_exit_list);
 282         int *id;
 283         size_t size;
 284 };
 285
 286 /*
 287  * Use these carefully.  If you implement a network device and it
 288  * needs per network namespace operations use device pernet operations,
 289  * otherwise use pernet subsys operations.
 290  *
 291  * Network interfaces need to be removed from a dying netns _before_
 292  * subsys notifiers can be called, as most of the network code cleanup
 293  * (which is done from subsys notifiers) runs with the assumption that
 294  * dev_remove_pack has been called so no new packets will arrive during
 295  * and after the cleanup functions have been called.  dev_remove_pack
 296  * is not per namespace so instead the guarantee of no more packets
 297  * arriving in a network namespace is provided by ensuring that all
 298  * network devices and all sockets have left the network namespace
 299  * before the cleanup methods are called.
 300  *
 301  * For the longest time the ipv4 icmp code was registered as a pernet
 302  * device which caused kernel oops, and panics during network
 303  * namespace cleanup.   So please don't get this wrong.
 304  */
 305 int register_pernet_subsys(struct pernet_operations *);
 306 void unregister_pernet_subsys(struct pernet_operations *);
 307 int register_pernet_device(struct pernet_operations *);
 308 void unregister_pernet_device(struct pernet_operations *);
 309
 310 struct ctl_table;
 311 struct ctl_table_header;
 312
 313 #ifdef CONFIG_SYSCTL
 314 int net_sysctl_init(void);
 315 struct ctl_table_header *register_net_sysctl(struct net *net, const char *path,
 316                                              struct ctl_table *table);
 317 void unregister_net_sysctl_table(struct ctl_table_header *header);
 318 #else
 319 static inline int net_sysctl_init(void) { return 0; }
 320 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 321         const char *path, struct ctl_table *table)
 322 {
 323         return NULL;
 324 }
 325 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 326 {
 327 }
 328 #endif
 329
 330 static inline int rt_genid_ipv4(struct net *net)
 331 {
 332         return atomic_read(&net->ipv4.rt_genid);
 333 }
 334
 335 static inline void rt_genid_bump_ipv4(struct net *net)
 336 {
 337         atomic_inc(&net->ipv4.rt_genid);
 338 }
 339
 340 extern void (*__fib6_flush_trees)(struct net *net);
 341 static inline void rt_genid_bump_ipv6(struct net *net)
 342 {
 343         if (__fib6_flush_trees)
 344                 __fib6_flush_trees(net);
 345 }
 346
 347 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 348 static inline struct netns_ieee802154_lowpan *
 349 net_ieee802154_lowpan(struct net *net)
 350 {
 351         return &net->ieee802154_lowpan;
 352 }
 353 #endif
 354
 355 /* For callers who don't really care about whether it's IPv4 or IPv6 */
 356 static inline void rt_genid_bump_all(struct net *net)
 357 {
 358         rt_genid_bump_ipv4(net);
 359         rt_genid_bump_ipv6(net);
 360 }
 361
 362 static inline int fnhe_genid(struct net *net)
 363 {
 364         return atomic_read(&net->fnhe_genid);
 365 }
 366
 367 static inline void fnhe_genid_bump(struct net *net)
 368 {
 369         atomic_inc(&net->fnhe_genid);
 370 }
 371
 372 #endif /* __NET_NET_NAMESPACE_H */