text: /*
   * IPv6 library code, needed by static components when full IPv6 support is
   * not configured or static.
   */
  
  #include <linux/export.h>
  #include <net/ipv6.h>
  #include <net/addrconf.h>
  #include <net/ip.h>
  
  /* if ipv6 module registers this function is used by xfrm to force all
   * sockets to relookup their nodes - this is fairly expensive, be
   * careful
   */
  void (*__fib6_flush_trees)(struct net *);
  EXPORT_SYMBOL(__fib6_flush_trees);
  
  #define IPV6_ADDR_SCOPE_TYPE(scope)	((scope) << 16)
  
  static inline unsigned int ipv6_addr_scope2type(unsigned int scope)
  {
  	switch (scope) {
  	case IPV6_ADDR_SCOPE_NODELOCAL:
  		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_NODELOCAL) |
  			IPV6_ADDR_LOOPBACK);
  	case IPV6_ADDR_SCOPE_LINKLOCAL:
  		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL) |
  			IPV6_ADDR_LINKLOCAL);
  	case IPV6_ADDR_SCOPE_SITELOCAL:
  		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL) |
  			IPV6_ADDR_SITELOCAL);
  	}
  	return IPV6_ADDR_SCOPE_TYPE(scope);
  }
  
  int __ipv6_addr_type(const struct in6_addr *addr)
  {
  	__be32 st;
  
  	st = addr->s6_addr32[0];
  
  	/* Consider all addresses with the first three bits different of
  	   000 and 111 as unicasts.
  	 */
  	if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
  	    (st & htonl(0xE0000000)) != htonl(0xE0000000))
  		return (IPV6_ADDR_UNICAST |
  			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));
  
  	if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
  		/* multicast */
  		/* addr-select 3.1 */
  		return (IPV6_ADDR_MULTICAST |
  			ipv6_addr_scope2type(IPV6_ADDR_MC_SCOPE(addr)));
  	}
  
  	if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
  		return (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST |
  			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));		/* addr-select 3.1 */
  	if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
  		return (IPV6_ADDR_SITELOCAL | IPV6_ADDR_UNICAST |
  			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL));		/* addr-select 3.1 */
  	if ((st & htonl(0xFE000000)) == htonl(0xFC000000))
  		return (IPV6_ADDR_UNICAST |
  			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));			/* RFC 4193 */
  
  	if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
  		if (addr->s6_addr32[2] == 0) {
  			if (addr->s6_addr32[3] == 0)
  				return IPV6_ADDR_ANY;
  
  			if (addr->s6_addr32[3] == htonl(0x00000001))
  				return (IPV6_ADDR_LOOPBACK | IPV6_ADDR_UNICAST |
  					IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));	/* addr-select 3.4 */
  
  			return (IPV6_ADDR_COMPATv4 | IPV6_ADDR_UNICAST |
  				IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.3 */
  		}
  
  		if (addr->s6_addr32[2] == htonl(0x0000ffff))
  			return (IPV6_ADDR_MAPPED |
  				IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.3 */
  	}
  
  	return (IPV6_ADDR_UNICAST |
  		IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.4 */
  }
  EXPORT_SYMBOL(__ipv6_addr_type);
  
  static ATOMIC_NOTIFIER_HEAD(inet6addr_chain);
  static BLOCKING_NOTIFIER_HEAD(inet6addr_validator_chain);
  
  int register_inet6addr_notifier(struct notifier_block *nb)
  {
  	return atomic_notifier_chain_register(&inet6addr_chain, nb);
  }
  EXPORT_SYMBOL(register_inet6addr_notifier);
  
  int unregister_inet6addr_notifier(struct notifier_block *nb)
  {
  	return atomic_notifier_chain_unregister(&inet6addr_chain, nb);
  }
  EXPORT_SYMBOL(unregister_inet6addr_notifier);
  
  int inet6addr_notifier_call_chain(unsigned long val, void *v)
  {
  	return atomic_notifier_call_chain(&inet6addr_chain, val, v);
  }
  EXPORT_SYMBOL(inet6addr_notifier_call_chain);
  
  int register_inet6addr_validator_notifier(struct notifier_block *nb)
  {
  	return blocking_notifier_chain_register(&inet6addr_validator_chain, nb);
  }
  EXPORT_SYMBOL(register_inet6addr_validator_notifier);
  
  int unregister_inet6addr_validator_notifier(struct notifier_block *nb)
  {
  	return blocking_notifier_chain_unregister(&inet6addr_validator_chain,
  						  nb);
  }
  EXPORT_SYMBOL(unregister_inet6addr_validator_notifier);
  
  int inet6addr_validator_notifier_call_chain(unsigned long val, void *v)
  {
  	return blocking_notifier_call_chain(&inet6addr_validator_chain, val, v);
  }
  EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain);
  
  static struct dst_entry *eafnosupport_ipv6_dst_lookup_flow(struct net *net,
  							   const struct sock *sk,
  							   struct flowi6 *fl6,
  							   const struct in6_addr *final_dst)
  {
  	return ERR_PTR(-EAFNOSUPPORT);
  }
  
  static struct fib6_table *eafnosupport_fib6_get_table(struct net *net, u32 id)
  {
  	return NULL;
  }
  
  static struct fib6_info *
  eafnosupport_fib6_table_lookup(struct net *net, struct fib6_table *table,
  			       int oif, struct flowi6 *fl6, int flags)
  {
  	return NULL;
  }
  
  static struct fib6_info *
  eafnosupport_fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
  			 int flags)
  {
  	return NULL;
  }
  
  static struct fib6_info *
  eafnosupport_fib6_multipath_select(const struct net *net, struct fib6_info *f6i,
  				   struct flowi6 *fl6, int oif,
  				   const struct sk_buff *skb, int strict)
  {
  	return f6i;
  }
  
  static u32
  eafnosupport_ip6_mtu_from_fib6(struct fib6_info *f6i, struct in6_addr *daddr,
  			       struct in6_addr *saddr)
  {
  	return 0;
  }
  
  const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
  	.ipv6_dst_lookup_flow = eafnosupport_ipv6_dst_lookup_flow,
  	.fib6_get_table    = eafnosupport_fib6_get_table,
  	.fib6_table_lookup = eafnosupport_fib6_table_lookup,
  	.fib6_lookup       = eafnosupport_fib6_lookup,
  	.fib6_multipath_select = eafnosupport_fib6_multipath_select,
  	.ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
  };
  EXPORT_SYMBOL_GPL(ipv6_stub);
  
  /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
  const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
  EXPORT_SYMBOL(in6addr_loopback);
  const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
  EXPORT_SYMBOL(in6addr_any);
  const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
  EXPORT_SYMBOL(in6addr_linklocal_allnodes);
  const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
  EXPORT_SYMBOL(in6addr_linklocal_allrouters);
  const struct in6_addr in6addr_interfacelocal_allnodes = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
  EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
  const struct in6_addr in6addr_interfacelocal_allrouters = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
  EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
  const struct in6_addr in6addr_sitelocal_allrouters = IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
  EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
  
  static void snmp6_free_dev(struct inet6_dev *idev)
  {
  	kfree(idev->stats.icmpv6msgdev);
  	kfree(idev->stats.icmpv6dev);
  	free_percpu(idev->stats.ipv6);
  }
  
  static void in6_dev_finish_destroy_rcu(struct rcu_head *head)
  {
  	struct inet6_dev *idev = container_of(head, struct inet6_dev, rcu);
  
  	snmp6_free_dev(idev);
  	kfree(idev);
  }
  
  /* Nobody refers to this device, we may destroy it. */
  
  void in6_dev_finish_destroy(struct inet6_dev *idev)
  {
  	struct net_device *dev = idev->dev;
  
  	WARN_ON(!list_empty(&idev->addr_list));
  	WARN_ON(idev->mc_list);
  	WARN_ON(timer_pending(&idev->rs_timer));
  
  #ifdef NET_REFCNT_DEBUG
  	pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
  #endif
  	dev_put(dev);
  	if (!idev->dead) {
  		pr_warn("Freeing alive inet6 device %p\n", idev);
  		return;
  	}
  	call_rcu(&idev->rcu, in6_dev_finish_destroy_rcu);
  }
  EXPORT_SYMBOL(in6_dev_finish_destroy);
  