net/ipv6/addrconf_core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * IPv6 library code, needed by static components when full IPv6 support is
   4  * not configured or static.
   5  */
   6
   7 #include <linux/export.h>
   8 #include <net/ipv6.h>
   9 #include <net/ipv6_stubs.h>
  10 #include <net/ip.h>
  11
  12 /* if ipv6 module registers this function is used by xfrm to force all
  13  * sockets to relookup their nodes - this is fairly expensive, be
  14  * careful
  15  */
  16 void (*__fib6_flush_trees)(struct net *);
  17 EXPORT_SYMBOL(__fib6_flush_trees);
  18
  19 #define IPV6_ADDR_SCOPE_TYPE(scope)     ((scope) << 16)
  20
  21 static inline unsigned int ipv6_addr_scope2type(unsigned int scope)
  22 {
  23         switch (scope) {
  24         case IPV6_ADDR_SCOPE_NODELOCAL:
  25                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_NODELOCAL) |
  26                         IPV6_ADDR_LOOPBACK);
  27         case IPV6_ADDR_SCOPE_LINKLOCAL:
  28                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL) |
  29                         IPV6_ADDR_LINKLOCAL);
  30         case IPV6_ADDR_SCOPE_SITELOCAL:
  31                 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL) |
  32                         IPV6_ADDR_SITELOCAL);
  33         }
  34         return IPV6_ADDR_SCOPE_TYPE(scope);
  35 }
  36
  37 int __ipv6_addr_type(const struct in6_addr *addr)
  38 {
  39         __be32 st;
  40
  41         st = addr->s6_addr32[0];
  42
  43         /* Consider all addresses with the first three bits different of
  44            000 and 111 as unicasts.
  45          */
  46         if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
  47             (st & htonl(0xE0000000)) != htonl(0xE0000000))
  48                 return (IPV6_ADDR_UNICAST |
  49                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));
  50
  51         if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
  52                 /* multicast */
  53                 /* addr-select 3.1 */
  54                 return (IPV6_ADDR_MULTICAST |
  55                         ipv6_addr_scope2type(IPV6_ADDR_MC_SCOPE(addr)));
  56         }
  57
  58         if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
  59                 return (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST |
  60                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));               /* addr-select 3.1 */
  61         if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
  62                 return (IPV6_ADDR_SITELOCAL | IPV6_ADDR_UNICAST |
  63                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL));               /* addr-select 3.1 */
  64         if ((st & htonl(0xFE000000)) == htonl(0xFC000000))
  65                 return (IPV6_ADDR_UNICAST |
  66                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));                  /* RFC 4193 */
  67
  68         if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
  69                 if (addr->s6_addr32[2] == 0) {
  70                         if (addr->s6_addr32[3] == 0)
  71                                 return IPV6_ADDR_ANY;
  72
  73                         if (addr->s6_addr32[3] == htonl(0x00000001))
  74                                 return (IPV6_ADDR_LOOPBACK | IPV6_ADDR_UNICAST |
  75                                         IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));       /* addr-select 3.4 */
  76
  77                         return (IPV6_ADDR_COMPATv4 | IPV6_ADDR_UNICAST |
  78                                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.3 */
  79                 }
  80
  81                 if (addr->s6_addr32[2] == htonl(0x0000ffff))
  82                         return (IPV6_ADDR_MAPPED |
  83                                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.3 */
  84         }
  85
  86         return (IPV6_ADDR_UNICAST |
  87                 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));  /* addr-select 3.4 */
  88 }
  89 EXPORT_SYMBOL(__ipv6_addr_type);
  90
  91 static ATOMIC_NOTIFIER_HEAD(inet6addr_chain);
  92 static BLOCKING_NOTIFIER_HEAD(inet6addr_validator_chain);
  93
  94 int register_inet6addr_notifier(struct notifier_block *nb)
  95 {
  96         return atomic_notifier_chain_register(&inet6addr_chain, nb);
  97 }
  98 EXPORT_SYMBOL(register_inet6addr_notifier);
  99
 100 int unregister_inet6addr_notifier(struct notifier_block *nb)
 101 {
 102         return atomic_notifier_chain_unregister(&inet6addr_chain, nb);
 103 }
 104 EXPORT_SYMBOL(unregister_inet6addr_notifier);
 105
 106 int inet6addr_notifier_call_chain(unsigned long val, void *v)
 107 {
 108         return atomic_notifier_call_chain(&inet6addr_chain, val, v);
 109 }
 110 EXPORT_SYMBOL(inet6addr_notifier_call_chain);
 111
 112 int register_inet6addr_validator_notifier(struct notifier_block *nb)
 113 {
 114         return blocking_notifier_chain_register(&inet6addr_validator_chain, nb);
 115 }
 116 EXPORT_SYMBOL(register_inet6addr_validator_notifier);
 117
 118 int unregister_inet6addr_validator_notifier(struct notifier_block *nb)
 119 {
 120         return blocking_notifier_chain_unregister(&inet6addr_validator_chain,
 121                                                   nb);
 122 }
 123 EXPORT_SYMBOL(unregister_inet6addr_validator_notifier);
 124
 125 int inet6addr_validator_notifier_call_chain(unsigned long val, void *v)
 126 {
 127         return blocking_notifier_call_chain(&inet6addr_validator_chain, val, v);
 128 }
 129 EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain);
 130
 131 static int eafnosupport_ipv6_dst_lookup(struct net *net, struct sock *u1,
 132                                         struct dst_entry **u2,
 133                                         struct flowi6 *u3)
 134 {
 135         return -EAFNOSUPPORT;
 136 }
 137
 138 static int eafnosupport_ipv6_route_input(struct sk_buff *skb)
 139 {
 140         return -EAFNOSUPPORT;
 141 }
 142
 143 static struct fib6_table *eafnosupport_fib6_get_table(struct net *net, u32 id)
 144 {
 145         return NULL;
 146 }
 147
 148 static int
 149 eafnosupport_fib6_table_lookup(struct net *net, struct fib6_table *table,
 150                                int oif, struct flowi6 *fl6,
 151                                struct fib6_result *res, int flags)
 152 {
 153         return -EAFNOSUPPORT;
 154 }
 155
 156 static int
 157 eafnosupport_fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
 158                          struct fib6_result *res, int flags)
 159 {
 160         return -EAFNOSUPPORT;
 161 }
 162
 163 static void
 164 eafnosupport_fib6_select_path(const struct net *net, struct fib6_result *res,
 165                               struct flowi6 *fl6, int oif, bool have_oif_match,
 166                               const struct sk_buff *skb, int strict)
 167 {
 168 }
 169
 170 static u32
 171 eafnosupport_ip6_mtu_from_fib6(const struct fib6_result *res,
 172                                const struct in6_addr *daddr,
 173                                const struct in6_addr *saddr)
 174 {
 175         return 0;
 176 }
 177
 178 static int eafnosupport_fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
 179                                      struct fib6_config *cfg, gfp_t gfp_flags,
 180                                      struct netlink_ext_ack *extack)
 181 {
 182         NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
 183         return -EAFNOSUPPORT;
 184 }
 185
 186 static int eafnosupport_ip6_del_rt(struct net *net, struct fib6_info *rt)
 187 {
 188         return -EAFNOSUPPORT;
 189 }
 190
 191 const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
 192         .ipv6_dst_lookup   = eafnosupport_ipv6_dst_lookup,
 193         .ipv6_route_input  = eafnosupport_ipv6_route_input,
 194         .fib6_get_table    = eafnosupport_fib6_get_table,
 195         .fib6_table_lookup = eafnosupport_fib6_table_lookup,
 196         .fib6_lookup       = eafnosupport_fib6_lookup,
 197         .fib6_select_path  = eafnosupport_fib6_select_path,
 198         .ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
 199         .fib6_nh_init      = eafnosupport_fib6_nh_init,
 200         .ip6_del_rt        = eafnosupport_ip6_del_rt,
 201 };
 202 EXPORT_SYMBOL_GPL(ipv6_stub);
 203
 204 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
 205 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
 206 EXPORT_SYMBOL(in6addr_loopback);
 207 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
 208 EXPORT_SYMBOL(in6addr_any);
 209 const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
 210 EXPORT_SYMBOL(in6addr_linklocal_allnodes);
 211 const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
 212 EXPORT_SYMBOL(in6addr_linklocal_allrouters);
 213 const struct in6_addr in6addr_interfacelocal_allnodes = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
 214 EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
 215 const struct in6_addr in6addr_interfacelocal_allrouters = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
 216 EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
 217 const struct in6_addr in6addr_sitelocal_allrouters = IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
 218 EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
 219
 220 static void snmp6_free_dev(struct inet6_dev *idev)
 221 {
 222         kfree(idev->stats.icmpv6msgdev);
 223         kfree(idev->stats.icmpv6dev);
 224         free_percpu(idev->stats.ipv6);
 225 }
 226
 227 static void in6_dev_finish_destroy_rcu(struct rcu_head *head)
 228 {
 229         struct inet6_dev *idev = container_of(head, struct inet6_dev, rcu);
 230
 231         snmp6_free_dev(idev);
 232         kfree(idev);
 233 }
 234
 235 /* Nobody refers to this device, we may destroy it. */
 236
 237 void in6_dev_finish_destroy(struct inet6_dev *idev)
 238 {
 239         struct net_device *dev = idev->dev;
 240
 241         WARN_ON(!list_empty(&idev->addr_list));
 242         WARN_ON(idev->mc_list);
 243         WARN_ON(timer_pending(&idev->rs_timer));
 244
 245 #ifdef NET_REFCNT_DEBUG
 246         pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
 247 #endif
 248         dev_put(dev);
 249         if (!idev->dead) {
 250                 pr_warn("Freeing alive inet6 device %p\n", idev);
 251                 return;
 252         }
 253         call_rcu(&idev->rcu, in6_dev_finish_destroy_rcu);
 254 }
 255 EXPORT_SYMBOL(in6_dev_finish_destroy);