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/x_tables.h>
  21 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  22 #include <net/netns/conntrack.h>
  23 #endif
  24 #include <net/netns/xfrm.h>
  25
  26 struct user_namespace;
  27 struct proc_dir_entry;
  28 struct net_device;
  29 struct sock;
  30 struct ctl_table_header;
  31 struct net_generic;
  32 struct sock;
  33 struct netns_ipvs;
  34
  35
  36 #define NETDEV_HASHBITS    8
  37 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  38
  39 struct net {
  40         atomic_t                passive;        /* To decided when the network
  41                                                  * namespace should be freed.
  42                                                  */
  43         atomic_t                count;          /* To decided when the network
  44                                                  *  namespace should be shut down.
  45                                                  */
  46 #ifdef NETNS_REFCNT_DEBUG
  47         atomic_t                use_count;      /* To track references we
  48                                                  * destroy on demand
  49                                                  */
  50 #endif
  51         spinlock_t              rules_mod_lock;
  52
  53         struct list_head        list;           /* list of network namespaces */
  54         struct list_head        cleanup_list;   /* namespaces on death row */
  55         struct list_head        exit_list;      /* Use only net_mutex */
  56
  57         struct user_namespace   *user_ns;       /* Owning user namespace */
  58
  59         unsigned int            proc_inum;
  60
  61         struct proc_dir_entry   *proc_net;
  62         struct proc_dir_entry   *proc_net_stat;
  63
  64 #ifdef CONFIG_SYSCTL
  65         struct ctl_table_set    sysctls;
  66 #endif
  67
  68         struct sock             *rtnl;                  /* rtnetlink socket */
  69         struct sock             *genl_sock;
  70
  71         struct list_head        dev_base_head;
  72         struct hlist_head       *dev_name_head;
  73         struct hlist_head       *dev_index_head;
  74         unsigned int            dev_base_seq;   /* protected by rtnl_mutex */
  75         int                     ifindex;
  76
  77         /* core fib_rules */
  78         struct list_head        rules_ops;
  79
  80
  81         struct net_device       *loopback_dev;          /* The loopback */
  82         struct netns_core       core;
  83         struct netns_mib        mib;
  84         struct netns_packet     packet;
  85         struct netns_unix       unx;
  86         struct netns_ipv4       ipv4;
  87 #if IS_ENABLED(CONFIG_IPV6)
  88         struct netns_ipv6       ipv6;
  89 #endif
  90 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
  91         struct netns_sctp       sctp;
  92 #endif
  93 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
  94         struct netns_dccp       dccp;
  95 #endif
  96 #ifdef CONFIG_NETFILTER
  97         struct netns_xt         xt;
  98 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  99         struct netns_ct         ct;
 100 #endif
 101 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
 102         struct netns_nf_frag    nf_frag;
 103 #endif
 104         struct sock             *nfnl;
 105         struct sock             *nfnl_stash;
 106 #endif
 107 #ifdef CONFIG_WEXT_CORE
 108         struct sk_buff_head     wext_nlevents;
 109 #endif
 110         struct net_generic __rcu        *gen;
 111
 112         /* Note : following structs are cache line aligned */
 113 #ifdef CONFIG_XFRM
 114         struct netns_xfrm       xfrm;
 115 #endif
 116         struct netns_ipvs       *ipvs;
 117         struct sock             *diag_nlsk;
 118         atomic_t                rt_genid;
 119 };
 120
 121 /*
 122  * ifindex generation is per-net namespace, and loopback is
 123  * always the 1st device in ns (see net_dev_init), thus any
 124  * loopback device should get ifindex 1
 125  */
 126
 127 #define LOOPBACK_IFINDEX        1
 128
 129 #include <linux/seq_file_net.h>
 130
 131 /* Init's network namespace */
 132 extern struct net init_net;
 133
 134 #ifdef CONFIG_NET_NS
 135 extern struct net *copy_net_ns(unsigned long flags,
 136         struct user_namespace *user_ns, struct net *old_net);
 137
 138 #else /* CONFIG_NET_NS */
 139 #include <linux/sched.h>
 140 #include <linux/nsproxy.h>
 141 static inline struct net *copy_net_ns(unsigned long flags,
 142         struct user_namespace *user_ns, struct net *old_net)
 143 {
 144         if (flags & CLONE_NEWNET)
 145                 return ERR_PTR(-EINVAL);
 146         return old_net;
 147 }
 148 #endif /* CONFIG_NET_NS */
 149
 150
 151 extern struct list_head net_namespace_list;
 152
 153 extern struct net *get_net_ns_by_pid(pid_t pid);
 154 extern struct net *get_net_ns_by_fd(int pid);
 155
 156 #ifdef CONFIG_NET_NS
 157 extern void __put_net(struct net *net);
 158
 159 static inline struct net *get_net(struct net *net)
 160 {
 161         atomic_inc(&net->count);
 162         return net;
 163 }
 164
 165 static inline struct net *maybe_get_net(struct net *net)
 166 {
 167         /* Used when we know struct net exists but we
 168          * aren't guaranteed a previous reference count
 169          * exists.  If the reference count is zero this
 170          * function fails and returns NULL.
 171          */
 172         if (!atomic_inc_not_zero(&net->count))
 173                 net = NULL;
 174         return net;
 175 }
 176
 177 static inline void put_net(struct net *net)
 178 {
 179         if (atomic_dec_and_test(&net->count))
 180                 __put_net(net);
 181 }
 182
 183 static inline
 184 int net_eq(const struct net *net1, const struct net *net2)
 185 {
 186         return net1 == net2;
 187 }
 188
 189 extern void net_drop_ns(void *);
 190
 191 #else
 192
 193 static inline struct net *get_net(struct net *net)
 194 {
 195         return net;
 196 }
 197
 198 static inline void put_net(struct net *net)
 199 {
 200 }
 201
 202 static inline struct net *maybe_get_net(struct net *net)
 203 {
 204         return net;
 205 }
 206
 207 static inline
 208 int net_eq(const struct net *net1, const struct net *net2)
 209 {
 210         return 1;
 211 }
 212
 213 #define net_drop_ns NULL
 214 #endif
 215
 216
 217 #ifdef NETNS_REFCNT_DEBUG
 218 static inline struct net *hold_net(struct net *net)
 219 {
 220         if (net)
 221                 atomic_inc(&net->use_count);
 222         return net;
 223 }
 224
 225 static inline void release_net(struct net *net)
 226 {
 227         if (net)
 228                 atomic_dec(&net->use_count);
 229 }
 230 #else
 231 static inline struct net *hold_net(struct net *net)
 232 {
 233         return net;
 234 }
 235
 236 static inline void release_net(struct net *net)
 237 {
 238 }
 239 #endif
 240
 241 #ifdef CONFIG_NET_NS
 242
 243 static inline void write_pnet(struct net **pnet, struct net *net)
 244 {
 245         *pnet = net;
 246 }
 247
 248 static inline struct net *read_pnet(struct net * const *pnet)
 249 {
 250         return *pnet;
 251 }
 252
 253 #else
 254
 255 #define write_pnet(pnet, net)   do { (void)(net);} while (0)
 256 #define read_pnet(pnet)         (&init_net)
 257
 258 #endif
 259
 260 #define for_each_net(VAR)                               \
 261         list_for_each_entry(VAR, &net_namespace_list, list)
 262
 263 #define for_each_net_rcu(VAR)                           \
 264         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 265
 266 #ifdef CONFIG_NET_NS
 267 #define __net_init
 268 #define __net_exit
 269 #define __net_initdata
 270 #define __net_initconst
 271 #else
 272 #define __net_init      __init
 273 #define __net_exit      __exit_refok
 274 #define __net_initdata  __initdata
 275 #define __net_initconst __initconst
 276 #endif
 277
 278 struct pernet_operations {
 279         struct list_head list;
 280         int (*init)(struct net *net);
 281         void (*exit)(struct net *net);
 282         void (*exit_batch)(struct list_head *net_exit_list);
 283         int *id;
 284         size_t size;
 285 };
 286
 287 /*
 288  * Use these carefully.  If you implement a network device and it
 289  * needs per network namespace operations use device pernet operations,
 290  * otherwise use pernet subsys operations.
 291  *
 292  * Network interfaces need to be removed from a dying netns _before_
 293  * subsys notifiers can be called, as most of the network code cleanup
 294  * (which is done from subsys notifiers) runs with the assumption that
 295  * dev_remove_pack has been called so no new packets will arrive during
 296  * and after the cleanup functions have been called.  dev_remove_pack
 297  * is not per namespace so instead the guarantee of no more packets
 298  * arriving in a network namespace is provided by ensuring that all
 299  * network devices and all sockets have left the network namespace
 300  * before the cleanup methods are called.
 301  *
 302  * For the longest time the ipv4 icmp code was registered as a pernet
 303  * device which caused kernel oops, and panics during network
 304  * namespace cleanup.   So please don't get this wrong.
 305  */
 306 extern int register_pernet_subsys(struct pernet_operations *);
 307 extern void unregister_pernet_subsys(struct pernet_operations *);
 308 extern int register_pernet_device(struct pernet_operations *);
 309 extern void unregister_pernet_device(struct pernet_operations *);
 310
 311 struct ctl_table;
 312 struct ctl_table_header;
 313
 314 #ifdef CONFIG_SYSCTL
 315 extern int net_sysctl_init(void);
 316 extern struct ctl_table_header *register_net_sysctl(struct net *net,
 317         const char *path, struct ctl_table *table);
 318 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
 319 #else
 320 static inline int net_sysctl_init(void) { return 0; }
 321 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 322         const char *path, struct ctl_table *table)
 323 {
 324         return NULL;
 325 }
 326 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 327 {
 328 }
 329 #endif
 330
 331 static inline int rt_genid(struct net *net)
 332 {
 333         return atomic_read(&net->rt_genid);
 334 }
 335
 336 static inline void rt_genid_bump(struct net *net)
 337 {
 338         atomic_inc(&net->rt_genid);
 339 }
 340
 341 #endif /* __NET_NET_NAMESPACE_H */