net/ipv6/addrconf_core.c

   1 /*
   2  * IPv6 library code, needed by static components when full IPv6 support is
   3  * not configured or static.
   4  */
   5
   6 #include <linux/export.h>
   7 #include <net/ipv6.h>
   8 #include <net/addrconf.h>
   9 #include <net/ip.h>
  10
  11 /* if ipv6 module registers this function is used by xfrm to force all
  12  * sockets to relookup their nodes - this is fairly expensive, be
  13  * careful
  14  */
  15 void (*__fib6_flush_trees)(struct net *);
  16 EXPORT_SYMBOL(__fib6_flush_trees);
  17
  18 #define IPV6_ADDR_SCOPE_TYPE(scope)     ((scope) << 16)
  19
  20 static inline unsigned int ipv6_addr_scope2type(unsigned int scope)
  21 {
  22         switch (scope) {
  23         case IPV6_ADDR_SCOPE_NODELOCAL:
  24                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_NODELOCAL) |
  25                         IPV6_ADDR_LOOPBACK);
  26         case IPV6_ADDR_SCOPE_LINKLOCAL:
  27                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL) |
  28                         IPV6_ADDR_LINKLOCAL);
  29         case IPV6_ADDR_SCOPE_SITELOCAL:
  30                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL) |
  31                         IPV6_ADDR_SITELOCAL);
  32         }
  33         return IPV6_ADDR_SCOPE_TYPE(scope);
  34 }
  35
  36 int __ipv6_addr_type(const struct in6_addr *addr)
  37 {
  38         __be32 st;
  39
  40         st = addr->s6_addr32[0];
  41
  42         /* Consider all addresses with the first three bits different of
  43            000 and 111 as unicasts.
  44          */
  45         if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
  46             (st & htonl(0xE0000000)) != htonl(0xE0000000))
  47                 return (IPV6_ADDR_UNICAST |
  48                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));
  49
  50         if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
  51                 /* multicast */
  52                 /* addr-select 3.1 */
  53                 return (IPV6_ADDR_MULTICAST |
  54                         ipv6_addr_scope2type(IPV6_ADDR_MC_SCOPE(addr)));
  55         }
  56
  57         if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
  58                 return (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST |
  59                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));               /* addr-select 3.1 */
  60         if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
  61                 return (IPV6_ADDR_SITELOCAL | IPV6_ADDR_UNICAST |
  62                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL));               /* addr-select 3.1 */
  63         if ((st & htonl(0xFE000000)) == htonl(0xFC000000))
  64                 return (IPV6_ADDR_UNICAST |
  65                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));                  /* RFC 4193 */
  66
  67         if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
  68                 if (addr->s6_addr32[2] == 0) {
  69                         if (addr->s6_addr32[3] == 0)
  70                                 return IPV6_ADDR_ANY;
  71
  72                         if (addr->s6_addr32[3] == htonl(0x00000001))
  73                                 return (IPV6_ADDR_LOOPBACK | IPV6_ADDR_UNICAST |
  74                                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));       /* addr-select 3.4 */
  75
  76                         return (IPV6_ADDR_COMPATv4 | IPV6_ADDR_UNICAST |
  77                                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.3 */
  78                 }
  79
  80                 if (addr->s6_addr32[2] == htonl(0x0000ffff))
  81                         return (IPV6_ADDR_MAPPED |
  82                                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.3 */
  83         }
  84
  85         return (IPV6_ADDR_UNICAST |
  86                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.4 */
  87 }
  88 EXPORT_SYMBOL(__ipv6_addr_type);
  89
  90 static ATOMIC_NOTIFIER_HEAD(inet6addr_chain);
  91
  92 int register_inet6addr_notifier(struct notifier_block *nb)
  93 {
  94         return atomic_notifier_chain_register(&inet6addr_chain, nb);
  95 }
  96 EXPORT_SYMBOL(register_inet6addr_notifier);
  97
  98 int unregister_inet6addr_notifier(struct notifier_block *nb)
  99 {
 100         return atomic_notifier_chain_unregister(&inet6addr_chain, nb);
 101 }
 102 EXPORT_SYMBOL(unregister_inet6addr_notifier);
 103
 104 int inet6addr_notifier_call_chain(unsigned long val, void *v)
 105 {
 106         return atomic_notifier_call_chain(&inet6addr_chain, val, v);
 107 }
 108 EXPORT_SYMBOL(inet6addr_notifier_call_chain);
 109
 110 static int eafnosupport_ipv6_dst_lookup(struct net *net, struct sock *u1,
 111                                         struct dst_entry **u2,
 112                                         struct flowi6 *u3)
 113 {
 114         return -EAFNOSUPPORT;
 115 }
 116
 117 const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
 118         .ipv6_dst_lookup = eafnosupport_ipv6_dst_lookup,
 119 };
 120 EXPORT_SYMBOL_GPL(ipv6_stub);
 121
 122 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
 123 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
 124 EXPORT_SYMBOL(in6addr_loopback);
 125 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
 126 EXPORT_SYMBOL(in6addr_any);
 127 const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 128 EXPORT_SYMBOL(in6addr_linklocal_allnodes);
 129 const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
 130 EXPORT_SYMBOL(in6addr_linklocal_allrouters);
 131 const struct in6_addr in6addr_interfacelocal_allnodes = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
 132 EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
 133 const struct in6_addr in6addr_interfacelocal_allrouters = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
 134 EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
 135 const struct in6_addr in6addr_sitelocal_allrouters = IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
 136 EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
 137
 138 static void snmp6_free_dev(struct inet6_dev *idev)
 139 {
 140         kfree(idev->stats.icmpv6msgdev);
 141         kfree(idev->stats.icmpv6dev);
 142         free_percpu(idev->stats.ipv6);
 143 }
 144
 145 static void in6_dev_finish_destroy_rcu(struct rcu_head *head)
 146 {
 147         struct inet6_dev *idev = container_of(head, struct inet6_dev, rcu);
 148
 149         snmp6_free_dev(idev);
 150         kfree(idev);
 151 }
 152
 153 /* Nobody refers to this device, we may destroy it. */
 154
 155 void in6_dev_finish_destroy(struct inet6_dev *idev)
 156 {
 157         struct net_device *dev = idev->dev;
 158
 159         WARN_ON(!list_empty(&idev->addr_list));
 160         WARN_ON(idev->mc_list);
 161         WARN_ON(timer_pending(&idev->rs_timer));
 162
 163 #ifdef NET_REFCNT_DEBUG
 164         pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
 165 #endif
 166         dev_put(dev);
 167         if (!idev->dead) {
 168                 pr_warn("Freeing alive inet6 device %p\n", idev);
 169                 return;
 170         }
 171         call_rcu(&idev->rcu, in6_dev_finish_destroy_rcu);
 172 }
 173 EXPORT_SYMBOL(in6_dev_finish_destroy);