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/ipv6_stubs.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 static BLOCKING_NOTIFIER_HEAD(inet6addr_validator_chain);
  92
  93 int register_inet6addr_notifier(struct notifier_block *nb)
  94 {
  95         return atomic_notifier_chain_register(&inet6addr_chain, nb);
  96 }
  97 EXPORT_SYMBOL(register_inet6addr_notifier);
  98
  99 int unregister_inet6addr_notifier(struct notifier_block *nb)
 100 {
 101         return atomic_notifier_chain_unregister(&inet6addr_chain, nb);
 102 }
 103 EXPORT_SYMBOL(unregister_inet6addr_notifier);
 104
 105 int inet6addr_notifier_call_chain(unsigned long val, void *v)
 106 {
 107         return atomic_notifier_call_chain(&inet6addr_chain, val, v);
 108 }
 109 EXPORT_SYMBOL(inet6addr_notifier_call_chain);
 110
 111 int register_inet6addr_validator_notifier(struct notifier_block *nb)
 112 {
 113         return blocking_notifier_chain_register(&inet6addr_validator_chain, nb);
 114 }
 115 EXPORT_SYMBOL(register_inet6addr_validator_notifier);
 116
 117 int unregister_inet6addr_validator_notifier(struct notifier_block *nb)
 118 {
 119         return blocking_notifier_chain_unregister(&inet6addr_validator_chain,
 120                                                   nb);
 121 }
 122 EXPORT_SYMBOL(unregister_inet6addr_validator_notifier);
 123
 124 int inet6addr_validator_notifier_call_chain(unsigned long val, void *v)
 125 {
 126         return blocking_notifier_call_chain(&inet6addr_validator_chain, val, v);
 127 }
 128 EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain);
 129
 130 static int eafnosupport_ipv6_dst_lookup(struct net *net, struct sock *u1,
 131                                         struct dst_entry **u2,
 132                                         struct flowi6 *u3)
 133 {
 134         return -EAFNOSUPPORT;
 135 }
 136
 137 static int eafnosupport_ipv6_route_input(struct sk_buff *skb)
 138 {
 139         return -EAFNOSUPPORT;
 140 }
 141
 142 static struct fib6_table *eafnosupport_fib6_get_table(struct net *net, u32 id)
 143 {
 144         return NULL;
 145 }
 146
 147 static struct fib6_info *
 148 eafnosupport_fib6_table_lookup(struct net *net, struct fib6_table *table,
 149                                int oif, struct flowi6 *fl6, int flags)
 150 {
 151         return NULL;
 152 }
 153
 154 static struct fib6_info *
 155 eafnosupport_fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
 156                          int flags)
 157 {
 158         return NULL;
 159 }
 160
 161 static void
 162 eafnosupport_fib6_select_path(const struct net *net, struct fib6_result *res,
 163                               struct flowi6 *fl6, int oif, bool have_oif_match,
 164                               const struct sk_buff *skb, int strict)
 165 {
 166 }
 167
 168 static u32
 169 eafnosupport_ip6_mtu_from_fib6(const struct fib6_result *res,
 170                                const struct in6_addr *daddr,
 171                                const struct in6_addr *saddr)
 172 {
 173         return 0;
 174 }
 175
 176 static int eafnosupport_fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
 177                                      struct fib6_config *cfg, gfp_t gfp_flags,
 178                                      struct netlink_ext_ack *extack)
 179 {
 180         NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
 181         return -EAFNOSUPPORT;
 182 }
 183
 184 const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
 185         .ipv6_dst_lookup   = eafnosupport_ipv6_dst_lookup,
 186         .ipv6_route_input  = eafnosupport_ipv6_route_input,
 187         .fib6_get_table    = eafnosupport_fib6_get_table,
 188         .fib6_table_lookup = eafnosupport_fib6_table_lookup,
 189         .fib6_lookup       = eafnosupport_fib6_lookup,
 190         .fib6_select_path  = eafnosupport_fib6_select_path,
 191         .ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
 192         .fib6_nh_init      = eafnosupport_fib6_nh_init,
 193 };
 194 EXPORT_SYMBOL_GPL(ipv6_stub);
 195
 196 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
 197 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
 198 EXPORT_SYMBOL(in6addr_loopback);
 199 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
 200 EXPORT_SYMBOL(in6addr_any);
 201 const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 202 EXPORT_SYMBOL(in6addr_linklocal_allnodes);
 203 const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
 204 EXPORT_SYMBOL(in6addr_linklocal_allrouters);
 205 const struct in6_addr in6addr_interfacelocal_allnodes = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
 206 EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
 207 const struct in6_addr in6addr_interfacelocal_allrouters = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
 208 EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
 209 const struct in6_addr in6addr_sitelocal_allrouters = IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
 210 EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
 211
 212 static void snmp6_free_dev(struct inet6_dev *idev)
 213 {
 214         kfree(idev->stats.icmpv6msgdev);
 215         kfree(idev->stats.icmpv6dev);
 216         free_percpu(idev->stats.ipv6);
 217 }
 218
 219 static void in6_dev_finish_destroy_rcu(struct rcu_head *head)
 220 {
 221         struct inet6_dev *idev = container_of(head, struct inet6_dev, rcu);
 222
 223         snmp6_free_dev(idev);
 224         kfree(idev);
 225 }
 226
 227 /* Nobody refers to this device, we may destroy it. */
 228
 229 void in6_dev_finish_destroy(struct inet6_dev *idev)
 230 {
 231         struct net_device *dev = idev->dev;
 232
 233         WARN_ON(!list_empty(&idev->addr_list));
 234         WARN_ON(idev->mc_list);
 235         WARN_ON(timer_pending(&idev->rs_timer));
 236
 237 #ifdef NET_REFCNT_DEBUG
 238         pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
 239 #endif
 240         dev_put(dev);
 241         if (!idev->dead) {
 242                 pr_warn("Freeing alive inet6 device %p\n", idev);
 243                 return;
 244         }
 245         call_rcu(&idev->rcu, in6_dev_finish_destroy_rcu);
 246 }
 247 EXPORT_SYMBOL(in6_dev_finish_destroy);