xref: /linux/net/ipv6/addrconf_core.c (revision 827634added7f38b7d724cab1dccdb2b004c13c3)
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 const struct ipv6_stub *ipv6_stub __read_mostly;
111 EXPORT_SYMBOL_GPL(ipv6_stub);
112 
113 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
114 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
115 EXPORT_SYMBOL(in6addr_loopback);
116 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
117 EXPORT_SYMBOL(in6addr_any);
118 const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
119 EXPORT_SYMBOL(in6addr_linklocal_allnodes);
120 const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
121 EXPORT_SYMBOL(in6addr_linklocal_allrouters);
122 const struct in6_addr in6addr_interfacelocal_allnodes = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
123 EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
124 const struct in6_addr in6addr_interfacelocal_allrouters = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
125 EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
126 const struct in6_addr in6addr_sitelocal_allrouters = IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
127 EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
128 
129 static void snmp6_free_dev(struct inet6_dev *idev)
130 {
131 	kfree(idev->stats.icmpv6msgdev);
132 	kfree(idev->stats.icmpv6dev);
133 	free_percpu(idev->stats.ipv6);
134 }
135 
136 /* Nobody refers to this device, we may destroy it. */
137 
138 void in6_dev_finish_destroy(struct inet6_dev *idev)
139 {
140 	struct net_device *dev = idev->dev;
141 
142 	WARN_ON(!list_empty(&idev->addr_list));
143 	WARN_ON(idev->mc_list);
144 	WARN_ON(timer_pending(&idev->rs_timer));
145 
146 #ifdef NET_REFCNT_DEBUG
147 	pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
148 #endif
149 	dev_put(dev);
150 	if (!idev->dead) {
151 		pr_warn("Freeing alive inet6 device %p\n", idev);
152 		return;
153 	}
154 	snmp6_free_dev(idev);
155 	kfree_rcu(idev, rcu);
156 }
157 EXPORT_SYMBOL(in6_dev_finish_destroy);
158