xref: /linux/net/ipv6/addrconf_core.c (revision c98be0c96db00e9b6b02d31e0fa7590c54cdaaac)
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 #define IPV6_ADDR_SCOPE_TYPE(scope)	((scope) << 16)
12 
13 static inline unsigned int ipv6_addr_scope2type(unsigned int scope)
14 {
15 	switch (scope) {
16 	case IPV6_ADDR_SCOPE_NODELOCAL:
17 		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_NODELOCAL) |
18 			IPV6_ADDR_LOOPBACK);
19 	case IPV6_ADDR_SCOPE_LINKLOCAL:
20 		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL) |
21 			IPV6_ADDR_LINKLOCAL);
22 	case IPV6_ADDR_SCOPE_SITELOCAL:
23 		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL) |
24 			IPV6_ADDR_SITELOCAL);
25 	}
26 	return IPV6_ADDR_SCOPE_TYPE(scope);
27 }
28 
29 int __ipv6_addr_type(const struct in6_addr *addr)
30 {
31 	__be32 st;
32 
33 	st = addr->s6_addr32[0];
34 
35 	/* Consider all addresses with the first three bits different of
36 	   000 and 111 as unicasts.
37 	 */
38 	if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
39 	    (st & htonl(0xE0000000)) != htonl(0xE0000000))
40 		return (IPV6_ADDR_UNICAST |
41 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));
42 
43 	if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
44 		/* multicast */
45 		/* addr-select 3.1 */
46 		return (IPV6_ADDR_MULTICAST |
47 			ipv6_addr_scope2type(IPV6_ADDR_MC_SCOPE(addr)));
48 	}
49 
50 	if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
51 		return (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST |
52 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));		/* addr-select 3.1 */
53 	if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
54 		return (IPV6_ADDR_SITELOCAL | IPV6_ADDR_UNICAST |
55 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL));		/* addr-select 3.1 */
56 	if ((st & htonl(0xFE000000)) == htonl(0xFC000000))
57 		return (IPV6_ADDR_UNICAST |
58 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));			/* RFC 4193 */
59 
60 	if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
61 		if (addr->s6_addr32[2] == 0) {
62 			if (addr->s6_addr32[3] == 0)
63 				return IPV6_ADDR_ANY;
64 
65 			if (addr->s6_addr32[3] == htonl(0x00000001))
66 				return (IPV6_ADDR_LOOPBACK | IPV6_ADDR_UNICAST |
67 					IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));	/* addr-select 3.4 */
68 
69 			return (IPV6_ADDR_COMPATv4 | IPV6_ADDR_UNICAST |
70 				IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.3 */
71 		}
72 
73 		if (addr->s6_addr32[2] == htonl(0x0000ffff))
74 			return (IPV6_ADDR_MAPPED |
75 				IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.3 */
76 	}
77 
78 	return (IPV6_ADDR_UNICAST |
79 		IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.4 */
80 }
81 EXPORT_SYMBOL(__ipv6_addr_type);
82 
83 static ATOMIC_NOTIFIER_HEAD(inet6addr_chain);
84 
85 int register_inet6addr_notifier(struct notifier_block *nb)
86 {
87 	return atomic_notifier_chain_register(&inet6addr_chain, nb);
88 }
89 EXPORT_SYMBOL(register_inet6addr_notifier);
90 
91 int unregister_inet6addr_notifier(struct notifier_block *nb)
92 {
93 	return atomic_notifier_chain_unregister(&inet6addr_chain, nb);
94 }
95 EXPORT_SYMBOL(unregister_inet6addr_notifier);
96 
97 int inet6addr_notifier_call_chain(unsigned long val, void *v)
98 {
99 	return atomic_notifier_call_chain(&inet6addr_chain, val, v);
100 }
101 EXPORT_SYMBOL(inet6addr_notifier_call_chain);
102 
103 const struct ipv6_stub *ipv6_stub __read_mostly;
104 EXPORT_SYMBOL_GPL(ipv6_stub);
105 
106 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
107 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
108 EXPORT_SYMBOL(in6addr_loopback);
109 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
110 EXPORT_SYMBOL(in6addr_any);
111 const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
112 EXPORT_SYMBOL(in6addr_linklocal_allnodes);
113 const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
114 EXPORT_SYMBOL(in6addr_linklocal_allrouters);
115 const struct in6_addr in6addr_interfacelocal_allnodes = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
116 EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
117 const struct in6_addr in6addr_interfacelocal_allrouters = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
118 EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
119 const struct in6_addr in6addr_sitelocal_allrouters = IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
120 EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
121 
122 static void snmp6_free_dev(struct inet6_dev *idev)
123 {
124 	kfree(idev->stats.icmpv6msgdev);
125 	kfree(idev->stats.icmpv6dev);
126 	snmp_mib_free((void __percpu **)idev->stats.ipv6);
127 }
128 
129 /* Nobody refers to this device, we may destroy it. */
130 
131 void in6_dev_finish_destroy(struct inet6_dev *idev)
132 {
133 	struct net_device *dev = idev->dev;
134 
135 	WARN_ON(!list_empty(&idev->addr_list));
136 	WARN_ON(idev->mc_list != NULL);
137 	WARN_ON(timer_pending(&idev->rs_timer));
138 
139 #ifdef NET_REFCNT_DEBUG
140 	pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
141 #endif
142 	dev_put(dev);
143 	if (!idev->dead) {
144 		pr_warn("Freeing alive inet6 device %p\n", idev);
145 		return;
146 	}
147 	snmp6_free_dev(idev);
148 	kfree_rcu(idev, rcu);
149 }
150 EXPORT_SYMBOL(in6_dev_finish_destroy);
151