xref: /linux/net/ipv6/addrconf_core.c (revision 91a4855d6c03e770e42f17c798a36a3c46e63de2)
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/addrconf.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 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
132 const struct in6_addr in6addr_loopback __aligned(BITS_PER_LONG/8)
133 	= IN6ADDR_LOOPBACK_INIT;
134 EXPORT_SYMBOL(in6addr_loopback);
135 const struct in6_addr in6addr_any __aligned(BITS_PER_LONG/8)
136 	= IN6ADDR_ANY_INIT;
137 EXPORT_SYMBOL(in6addr_any);
138 const struct in6_addr in6addr_linklocal_allnodes __aligned(BITS_PER_LONG/8)
139 	= IN6ADDR_LINKLOCAL_ALLNODES_INIT;
140 EXPORT_SYMBOL(in6addr_linklocal_allnodes);
141 const struct in6_addr in6addr_linklocal_allrouters __aligned(BITS_PER_LONG/8)
142 	= IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
143 EXPORT_SYMBOL(in6addr_linklocal_allrouters);
144 const struct in6_addr in6addr_interfacelocal_allnodes __aligned(BITS_PER_LONG/8)
145 	= IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
146 EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
147 const struct in6_addr in6addr_interfacelocal_allrouters __aligned(BITS_PER_LONG/8)
148 	= IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
149 EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
150 const struct in6_addr in6addr_sitelocal_allrouters __aligned(BITS_PER_LONG/8)
151 	= IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
152 EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
153 
154 static void snmp6_free_dev(struct inet6_dev *idev)
155 {
156 	kfree(idev->stats.icmpv6msgdev);
157 	kfree(idev->stats.icmpv6dev);
158 	free_percpu(idev->stats.ipv6);
159 }
160 
161 static void in6_dev_finish_destroy_rcu(struct rcu_head *head)
162 {
163 	struct inet6_dev *idev = container_of(head, struct inet6_dev, rcu);
164 
165 	snmp6_free_dev(idev);
166 	kfree(idev);
167 }
168 
169 /* Nobody refers to this device, we may destroy it. */
170 
171 void in6_dev_finish_destroy(struct inet6_dev *idev)
172 {
173 	struct net_device *dev = idev->dev;
174 
175 	WARN_ON(!list_empty(&idev->addr_list));
176 	WARN_ON(rcu_access_pointer(idev->mc_list));
177 	WARN_ON(timer_pending(&idev->rs_timer));
178 
179 #ifdef NET_REFCNT_DEBUG
180 	pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
181 #endif
182 	netdev_put(dev, &idev->dev_tracker);
183 	if (!idev->dead) {
184 		pr_warn("Freeing alive inet6 device %p\n", idev);
185 		return;
186 	}
187 	call_rcu(&idev->rcu, in6_dev_finish_destroy_rcu);
188 }
189 EXPORT_SYMBOL(in6_dev_finish_destroy);
190