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 proc_dir_entry;
  27 struct net_device;
  28 struct sock;
  29 struct ctl_table_header;
  30 struct net_generic;
  31 struct sock;
  32 struct netns_ipvs;
  33
  34
  35 #define NETDEV_HASHBITS    8
  36 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
  37
  38 struct net {
  39         atomic_t                passive;        /* To decided when the network
  40                                                  * namespace should be freed.
  41                                                  */
  42         atomic_t                count;          /* To decided when the network
  43                                                  *  namespace should be shut down.
  44                                                  */
  45 #ifdef NETNS_REFCNT_DEBUG
  46         atomic_t                use_count;      /* To track references we
  47                                                  * destroy on demand
  48                                                  */
  49 #endif
  50         spinlock_t              rules_mod_lock;
  51
  52         struct list_head        list;           /* list of network namespaces */
  53         struct list_head        cleanup_list;   /* namespaces on death row */
  54         struct list_head        exit_list;      /* Use only net_mutex */
  55
  56         struct proc_dir_entry   *proc_net;
  57         struct proc_dir_entry   *proc_net_stat;
  58
  59 #ifdef CONFIG_SYSCTL
  60         struct ctl_table_set    sysctls;
  61 #endif
  62
  63         struct sock             *rtnl;                  /* rtnetlink socket */
  64         struct sock             *genl_sock;
  65
  66         struct list_head        dev_base_head;
  67         struct hlist_head       *dev_name_head;
  68         struct hlist_head       *dev_index_head;
  69         unsigned int            dev_base_seq;   /* protected by rtnl_mutex */
  70         int                     ifindex;
  71
  72         /* core fib_rules */
  73         struct list_head        rules_ops;
  74
  75
  76         struct net_device       *loopback_dev;          /* The loopback */
  77         struct netns_core       core;
  78         struct netns_mib        mib;
  79         struct netns_packet     packet;
  80         struct netns_unix       unx;
  81         struct netns_ipv4       ipv4;
  82 #if IS_ENABLED(CONFIG_IPV6)
  83         struct netns_ipv6       ipv6;
  84 #endif
  85 #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE)
  86         struct netns_sctp       sctp;
  87 #endif
  88 #if defined(CONFIG_IP_DCCP) || defined(CONFIG_IP_DCCP_MODULE)
  89         struct netns_dccp       dccp;
  90 #endif
  91 #ifdef CONFIG_NETFILTER
  92         struct netns_xt         xt;
  93 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
  94         struct netns_ct         ct;
  95 #endif
  96         struct sock             *nfnl;
  97         struct sock             *nfnl_stash;
  98 #endif
  99 #ifdef CONFIG_WEXT_CORE
 100         struct sk_buff_head     wext_nlevents;
 101 #endif
 102         struct net_generic __rcu        *gen;
 103
 104         /* Note : following structs are cache line aligned */
 105 #ifdef CONFIG_XFRM
 106         struct netns_xfrm       xfrm;
 107 #endif
 108         struct netns_ipvs       *ipvs;
 109         struct sock             *diag_nlsk;
 110 };
 111
 112 /*
 113  * ifindex generation is per-net namespace, and loopback is
 114  * always the 1st device in ns (see net_dev_init), thus any
 115  * loopback device should get ifindex 1
 116  */
 117
 118 #define LOOPBACK_IFINDEX        1
 119
 120 #include <linux/seq_file_net.h>
 121
 122 /* Init's network namespace */
 123 extern struct net init_net;
 124
 125 #ifdef CONFIG_NET
 126 extern struct net *copy_net_ns(unsigned long flags, struct net *net_ns);
 127
 128 #else /* CONFIG_NET */
 129 static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
 130 {
 131         /* There is nothing to copy so this is a noop */
 132         return net_ns;
 133 }
 134 #endif /* CONFIG_NET */
 135
 136
 137 extern struct list_head net_namespace_list;
 138
 139 extern struct net *get_net_ns_by_pid(pid_t pid);
 140 extern struct net *get_net_ns_by_fd(int pid);
 141
 142 #ifdef CONFIG_NET_NS
 143 extern void __put_net(struct net *net);
 144
 145 static inline struct net *get_net(struct net *net)
 146 {
 147         atomic_inc(&net->count);
 148         return net;
 149 }
 150
 151 static inline struct net *maybe_get_net(struct net *net)
 152 {
 153         /* Used when we know struct net exists but we
 154          * aren't guaranteed a previous reference count
 155          * exists.  If the reference count is zero this
 156          * function fails and returns NULL.
 157          */
 158         if (!atomic_inc_not_zero(&net->count))
 159                 net = NULL;
 160         return net;
 161 }
 162
 163 static inline void put_net(struct net *net)
 164 {
 165         if (atomic_dec_and_test(&net->count))
 166                 __put_net(net);
 167 }
 168
 169 static inline
 170 int net_eq(const struct net *net1, const struct net *net2)
 171 {
 172         return net1 == net2;
 173 }
 174
 175 extern void net_drop_ns(void *);
 176
 177 #else
 178
 179 static inline struct net *get_net(struct net *net)
 180 {
 181         return net;
 182 }
 183
 184 static inline void put_net(struct net *net)
 185 {
 186 }
 187
 188 static inline struct net *maybe_get_net(struct net *net)
 189 {
 190         return net;
 191 }
 192
 193 static inline
 194 int net_eq(const struct net *net1, const struct net *net2)
 195 {
 196         return 1;
 197 }
 198
 199 #define net_drop_ns NULL
 200 #endif
 201
 202
 203 #ifdef NETNS_REFCNT_DEBUG
 204 static inline struct net *hold_net(struct net *net)
 205 {
 206         if (net)
 207                 atomic_inc(&net->use_count);
 208         return net;
 209 }
 210
 211 static inline void release_net(struct net *net)
 212 {
 213         if (net)
 214                 atomic_dec(&net->use_count);
 215 }
 216 #else
 217 static inline struct net *hold_net(struct net *net)
 218 {
 219         return net;
 220 }
 221
 222 static inline void release_net(struct net *net)
 223 {
 224 }
 225 #endif
 226
 227 #ifdef CONFIG_NET_NS
 228
 229 static inline void write_pnet(struct net **pnet, struct net *net)
 230 {
 231         *pnet = net;
 232 }
 233
 234 static inline struct net *read_pnet(struct net * const *pnet)
 235 {
 236         return *pnet;
 237 }
 238
 239 #else
 240
 241 #define write_pnet(pnet, net)   do { (void)(net);} while (0)
 242 #define read_pnet(pnet)         (&init_net)
 243
 244 #endif
 245
 246 #define for_each_net(VAR)                               \
 247         list_for_each_entry(VAR, &net_namespace_list, list)
 248
 249 #define for_each_net_rcu(VAR)                           \
 250         list_for_each_entry_rcu(VAR, &net_namespace_list, list)
 251
 252 #ifdef CONFIG_NET_NS
 253 #define __net_init
 254 #define __net_exit
 255 #define __net_initdata
 256 #else
 257 #define __net_init      __init
 258 #define __net_exit      __exit_refok
 259 #define __net_initdata  __initdata
 260 #endif
 261
 262 struct pernet_operations {
 263         struct list_head list;
 264         int (*init)(struct net *net);
 265         void (*exit)(struct net *net);
 266         void (*exit_batch)(struct list_head *net_exit_list);
 267         int *id;
 268         size_t size;
 269 };
 270
 271 /*
 272  * Use these carefully.  If you implement a network device and it
 273  * needs per network namespace operations use device pernet operations,
 274  * otherwise use pernet subsys operations.
 275  *
 276  * Network interfaces need to be removed from a dying netns _before_
 277  * subsys notifiers can be called, as most of the network code cleanup
 278  * (which is done from subsys notifiers) runs with the assumption that
 279  * dev_remove_pack has been called so no new packets will arrive during
 280  * and after the cleanup functions have been called.  dev_remove_pack
 281  * is not per namespace so instead the guarantee of no more packets
 282  * arriving in a network namespace is provided by ensuring that all
 283  * network devices and all sockets have left the network namespace
 284  * before the cleanup methods are called.
 285  *
 286  * For the longest time the ipv4 icmp code was registered as a pernet
 287  * device which caused kernel oops, and panics during network
 288  * namespace cleanup.   So please don't get this wrong.
 289  */
 290 extern int register_pernet_subsys(struct pernet_operations *);
 291 extern void unregister_pernet_subsys(struct pernet_operations *);
 292 extern int register_pernet_device(struct pernet_operations *);
 293 extern void unregister_pernet_device(struct pernet_operations *);
 294
 295 struct ctl_table;
 296 struct ctl_table_header;
 297
 298 #ifdef CONFIG_SYSCTL
 299 extern int net_sysctl_init(void);
 300 extern struct ctl_table_header *register_net_sysctl(struct net *net,
 301         const char *path, struct ctl_table *table);
 302 extern void unregister_net_sysctl_table(struct ctl_table_header *header);
 303 #else
 304 static inline int net_sysctl_init(void) { return 0; }
 305 static inline struct ctl_table_header *register_net_sysctl(struct net *net,
 306         const char *path, struct ctl_table *table)
 307 {
 308         return NULL;
 309 }
 310 static inline void unregister_net_sysctl_table(struct ctl_table_header *header)
 311 {
 312 }
 313 #endif
 314
 315
 316 #endif /* __NET_NET_NAMESPACE_H */