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