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/dccp.h>
  19 #include <net/netns/x_tables.h>
  20 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  21 #include <net/netns/conntrack.h>
  22 #endif
  23 #include <net/netns/xfrm.h>
  24
  25 struct proc_dir_entry;
  26 struct net_device;
  27 struct sock;
  28 struct ctl_table_header;
  29 struct net_generic;
  30 struct sock;
  31 struct netns_ipvs;
  32
  33
  34 #define NETDEV_HASHBITS    8
  35 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  36
  37 struct net {
  38         atomic_t                passive;        /* To decided when the network
  39                                                  * namespace should be freed.
  40                                                  */
  41         atomic_t                count;          /* To decided when the network
  42                                                  *  namespace should be shut down.
  43                                                  */
  44 #ifdef NETNS_REFCNT_DEBUG
  45         atomic_t                use_count;      /* To track references we
  46                                                  * destroy on demand
  47                                                  */
  48 #endif
  49         spinlock_t              rules_mod_lock;
  50
  51         struct list_head        list;           /* list of network namespaces */
  52         struct list_head        cleanup_list;   /* namespaces on death row */
  53         struct list_head        exit_list;      /* Use only net_mutex */
  54
  55         struct proc_dir_entry   *proc_net;
  56         struct proc_dir_entry   *proc_net_stat;
  57
  58 #ifdef CONFIG_SYSCTL
  59         struct ctl_table_set    sysctls;
  60 #endif
  61
  62         struct sock             *rtnl;                  /* rtnetlink socket */
  63         struct sock             *genl_sock;
  64
  65         struct list_head        dev_base_head;
  66         struct hlist_head       *dev_name_head;
  67         struct hlist_head       *dev_index_head;
  68         unsigned int            dev_base_seq;   /* protected by rtnl_mutex */
  69
  70         /* core fib_rules */
  71         struct list_head        rules_ops;
  72
  73
  74         struct net_device       *loopback_dev;          /* The loopback */
  75         struct netns_core       core;
  76         struct netns_mib        mib;
  77         struct netns_packet     packet;
  78         struct netns_unix       unx;
  79         struct netns_ipv4       ipv4;
  80 #if IS_ENABLED(CONFIG_IPV6)
  81         struct netns_ipv6       ipv6;
  82 #endif
  83 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
  84         struct netns_dccp       dccp;
  85 #endif
  86 #ifdef CONFIG_NETFILTER
  87         struct netns_xt         xt;
  88 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  89         struct netns_ct         ct;
  90 #endif
  91         struct sock             *nfnl;
  92         struct sock             *nfnl_stash;
  93 #endif
  94 #ifdef CONFIG_WEXT_CORE
  95         struct sk_buff_head     wext_nlevents;
  96 #endif
  97         struct net_generic __rcu        *gen;
  98
  99         /* Note : following structs are cache line aligned */
 100 #ifdef CONFIG_XFRM
 101         struct netns_xfrm       xfrm;
 102 #endif
 103         struct netns_ipvs       *ipvs;
 104         struct sock             *diag_nlsk;
 105         atomic_t                rt_genid;
 106 };
 107
 108
 109 #include <linux/seq_file_net.h>
 110
 111 /* Init's network namespace */
 112 extern struct net init_net;
 113
 114 #ifdef CONFIG_NET
 115 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
 116
 117 #else /* CONFIG_NET */
 118 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
 119 {
 120         /* There is nothing to copy so this is a noop */
 121         return net_ns;
 122 }
 123 #endif /* CONFIG_NET */
 124
 125
 126 extern struct list_head net_namespace_list;
 127
 128 extern struct net *get_net_ns_by_pid(pid_t pid);
 129 extern struct net *get_net_ns_by_fd(int pid);
 130
 131 #ifdef CONFIG_NET_NS
 132 extern void __put_net(struct net *net);
 133
 134 static inline struct net *get_net(struct net *net)
 135 {
 136         atomic_inc(&net->count);
 137         return net;
 138 }
 139
 140 static inline struct net *maybe_get_net(struct net *net)
 141 {
 142         /* Used when we know struct net exists but we
 143          * aren't guaranteed a previous reference count
 144          * exists.  If the reference count is zero this
 145          * function fails and returns NULL.
 146          */
 147         if (!atomic_inc_not_zero(&net->count))
 148                 net = NULL;
 149         return net;
 150 }
 151
 152 static inline void put_net(struct net *net)
 153 {
 154         if (atomic_dec_and_test(&net->count))
 155                 __put_net(net);
 156 }
 157
 158 static inline
 159 int net_eq(const struct net *net1, const struct net *net2)
 160 {
 161         return net1 == net2;
 162 }
 163
 164 extern void net_drop_ns(void *);
 165
 166 #else
 167
 168 static inline struct net *get_net(struct net *net)
 169 {
 170         return net;
 171 }
 172
 173 static inline void put_net(struct net *net)
 174 {
 175 }
 176
 177 static inline struct net *maybe_get_net(struct net *net)
 178 {
 179         return net;
 180 }
 181
 182 static inline
 183 int net_eq(const struct net *net1, const struct net *net2)
 184 {
 185         return 1;
 186 }
 187
 188 #define net_drop_ns NULL
 189 #endif
 190
 191
 192 #ifdef NETNS_REFCNT_DEBUG
 193 static inline struct net *hold_net(struct net *net)
 194 {
 195         if (net)
 196                 atomic_inc(&net->use_count);
 197         return net;
 198 }
 199
 200 static inline void release_net(struct net *net)
 201 {
 202         if (net)
 203                 atomic_dec(&net->use_count);
 204 }
 205 #else
 206 static inline struct net *hold_net(struct net *net)
 207 {
 208         return net;
 209 }
 210
 211 static inline void release_net(struct net *net)
 212 {
 213 }
 214 #endif
 215
 216 #ifdef CONFIG_NET_NS
 217
 218 static inline void write_pnet(struct net **pnet, struct net *net)
 219 {
 220         *pnet = net;
 221 }
 222
 223 static inline struct net *read_pnet(struct net * const *pnet)
 224 {
 225         return *pnet;
 226 }
 227
 228 #else
 229
 230 #define write_pnet(pnet, net)   do { (void)(net);} while (0)
 231 #define read_pnet(pnet)         (&init_net)
 232
 233 #endif
 234
 235 #define for_each_net(VAR)                               \
 236         list_for_each_entry(VAR, &net_namespace_list, list)
 237
 238 #define for_each_net_rcu(VAR)                           \
 239         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 240
 241 #ifdef CONFIG_NET_NS
 242 #define __net_init
 243 #define __net_exit
 244 #define __net_initdata
 245 #else
 246 #define __net_init      __init
 247 #define __net_exit      __exit_refok
 248 #define __net_initdata  __initdata
 249 #endif
 250
 251 struct pernet_operations {
 252         struct list_head list;
 253         int (*init)(struct net *net);
 254         void (*exit)(struct net *net);
 255         void (*exit_batch)(struct list_head *net_exit_list);
 256         int *id;
 257         size_t size;
 258 };
 259
 260 /*
 261  * Use these carefully.  If you implement a network device and it
 262  * needs per network namespace operations use device pernet operations,
 263  * otherwise use pernet subsys operations.
 264  *
 265  * Network interfaces need to be removed from a dying netns _before_
 266  * subsys notifiers can be called, as most of the network code cleanup
 267  * (which is done from subsys notifiers) runs with the assumption that
 268  * dev_remove_pack has been called so no new packets will arrive during
 269  * and after the cleanup functions have been called.  dev_remove_pack
 270  * is not per namespace so instead the guarantee of no more packets
 271  * arriving in a network namespace is provided by ensuring that all
 272  * network devices and all sockets have left the network namespace
 273  * before the cleanup methods are called.
 274  *
 275  * For the longest time the ipv4 icmp code was registered as a pernet
 276  * device which caused kernel oops, and panics during network
 277  * namespace cleanup.   So please don't get this wrong.
 278  */
 279 extern int register_pernet_subsys(struct pernet_operations *);
 280 extern void unregister_pernet_subsys(struct pernet_operations *);
 281 extern int register_pernet_device(struct pernet_operations *);
 282 extern void unregister_pernet_device(struct pernet_operations *);
 283
 284 struct ctl_table;
 285 struct ctl_table_header;
 286
 287 #ifdef CONFIG_SYSCTL
 288 extern int net_sysctl_init(void);
 289 extern struct ctl_table_header *register_net_sysctl(struct net *net,
 290         const char *path, struct ctl_table *table);
 291 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
 292 #else
 293 static inline int net_sysctl_init(void) { return 0; }
 294 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 295         const char *path, struct ctl_table *table)
 296 {
 297         return NULL;
 298 }
 299 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 300 {
 301 }
 302 #endif
 303
 304 static inline int rt_genid(struct net *net)
 305 {
 306         return atomic_read(&net->rt_genid);
 307 }
 308
 309 static inline void rt_genid_bump(struct net *net)
 310 {
 311         atomic_inc(&net->rt_genid);
 312 }
 313
 314 #endif /* __NET_NET_NAMESPACE_H */