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