xref: /linux/net/ipv6/addrconf_core.c (revision 8b4483658364f05b2e32845c8f445cdfd9452286)
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/ipv6_stubs.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 static BLOCKING_NOTIFIER_HEAD(inet6addr_validator_chain);
92 
93 int register_inet6addr_notifier(struct notifier_block *nb)
94 {
95 	return atomic_notifier_chain_register(&inet6addr_chain, nb);
96 }
97 EXPORT_SYMBOL(register_inet6addr_notifier);
98 
99 int unregister_inet6addr_notifier(struct notifier_block *nb)
100 {
101 	return atomic_notifier_chain_unregister(&inet6addr_chain, nb);
102 }
103 EXPORT_SYMBOL(unregister_inet6addr_notifier);
104 
105 int inet6addr_notifier_call_chain(unsigned long val, void *v)
106 {
107 	return atomic_notifier_call_chain(&inet6addr_chain, val, v);
108 }
109 EXPORT_SYMBOL(inet6addr_notifier_call_chain);
110 
111 int register_inet6addr_validator_notifier(struct notifier_block *nb)
112 {
113 	return blocking_notifier_chain_register(&inet6addr_validator_chain, nb);
114 }
115 EXPORT_SYMBOL(register_inet6addr_validator_notifier);
116 
117 int unregister_inet6addr_validator_notifier(struct notifier_block *nb)
118 {
119 	return blocking_notifier_chain_unregister(&inet6addr_validator_chain,
120 						  nb);
121 }
122 EXPORT_SYMBOL(unregister_inet6addr_validator_notifier);
123 
124 int inet6addr_validator_notifier_call_chain(unsigned long val, void *v)
125 {
126 	return blocking_notifier_call_chain(&inet6addr_validator_chain, val, v);
127 }
128 EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain);
129 
130 static int eafnosupport_ipv6_dst_lookup(struct net *net, struct sock *u1,
131 					struct dst_entry **u2,
132 					struct flowi6 *u3)
133 {
134 	return -EAFNOSUPPORT;
135 }
136 
137 static int eafnosupport_ipv6_route_input(struct sk_buff *skb)
138 {
139 	return -EAFNOSUPPORT;
140 }
141 
142 static struct fib6_table *eafnosupport_fib6_get_table(struct net *net, u32 id)
143 {
144 	return NULL;
145 }
146 
147 static int
148 eafnosupport_fib6_table_lookup(struct net *net, struct fib6_table *table,
149 			       int oif, struct flowi6 *fl6,
150 			       struct fib6_result *res, int flags)
151 {
152 	return -EAFNOSUPPORT;
153 }
154 
155 static int
156 eafnosupport_fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
157 			 struct fib6_result *res, int flags)
158 {
159 	return -EAFNOSUPPORT;
160 }
161 
162 static void
163 eafnosupport_fib6_select_path(const struct net *net, struct fib6_result *res,
164 			      struct flowi6 *fl6, int oif, bool have_oif_match,
165 			      const struct sk_buff *skb, int strict)
166 {
167 }
168 
169 static u32
170 eafnosupport_ip6_mtu_from_fib6(const struct fib6_result *res,
171 			       const struct in6_addr *daddr,
172 			       const struct in6_addr *saddr)
173 {
174 	return 0;
175 }
176 
177 static int eafnosupport_fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
178 				     struct fib6_config *cfg, gfp_t gfp_flags,
179 				     struct netlink_ext_ack *extack)
180 {
181 	NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
182 	return -EAFNOSUPPORT;
183 }
184 
185 const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
186 	.ipv6_dst_lookup   = eafnosupport_ipv6_dst_lookup,
187 	.ipv6_route_input  = eafnosupport_ipv6_route_input,
188 	.fib6_get_table    = eafnosupport_fib6_get_table,
189 	.fib6_table_lookup = eafnosupport_fib6_table_lookup,
190 	.fib6_lookup       = eafnosupport_fib6_lookup,
191 	.fib6_select_path  = eafnosupport_fib6_select_path,
192 	.ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
193 	.fib6_nh_init	   = eafnosupport_fib6_nh_init,
194 };
195 EXPORT_SYMBOL_GPL(ipv6_stub);
196 
197 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
198 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
199 EXPORT_SYMBOL(in6addr_loopback);
200 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
201 EXPORT_SYMBOL(in6addr_any);
202 const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
203 EXPORT_SYMBOL(in6addr_linklocal_allnodes);
204 const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
205 EXPORT_SYMBOL(in6addr_linklocal_allrouters);
206 const struct in6_addr in6addr_interfacelocal_allnodes = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
207 EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
208 const struct in6_addr in6addr_interfacelocal_allrouters = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
209 EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
210 const struct in6_addr in6addr_sitelocal_allrouters = IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
211 EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
212 
213 static void snmp6_free_dev(struct inet6_dev *idev)
214 {
215 	kfree(idev->stats.icmpv6msgdev);
216 	kfree(idev->stats.icmpv6dev);
217 	free_percpu(idev->stats.ipv6);
218 }
219 
220 static void in6_dev_finish_destroy_rcu(struct rcu_head *head)
221 {
222 	struct inet6_dev *idev = container_of(head, struct inet6_dev, rcu);
223 
224 	snmp6_free_dev(idev);
225 	kfree(idev);
226 }
227 
228 /* Nobody refers to this device, we may destroy it. */
229 
230 void in6_dev_finish_destroy(struct inet6_dev *idev)
231 {
232 	struct net_device *dev = idev->dev;
233 
234 	WARN_ON(!list_empty(&idev->addr_list));
235 	WARN_ON(idev->mc_list);
236 	WARN_ON(timer_pending(&idev->rs_timer));
237 
238 #ifdef NET_REFCNT_DEBUG
239 	pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
240 #endif
241 	dev_put(dev);
242 	if (!idev->dead) {
243 		pr_warn("Freeing alive inet6 device %p\n", idev);
244 		return;
245 	}
246 	call_rcu(&idev->rcu, in6_dev_finish_destroy_rcu);
247 }
248 EXPORT_SYMBOL(in6_dev_finish_destroy);
249