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/ipv6_stubs.h>
10 #include <net/addrconf.h>
11 #include <net/ip.h>
12
13 /* if ipv6 module registers this function is used by xfrm to force all
14 * sockets to relookup their nodes - this is fairly expensive, be
15 * careful
16 */
17 void (*__fib6_flush_trees)(struct net *);
18 EXPORT_SYMBOL(__fib6_flush_trees);
19
20 #define IPV6_ADDR_SCOPE_TYPE(scope) ((scope) << 16)
21
22 static inline unsigned int ipv6_addr_scope2type(unsigned int scope)
23 {
24 switch (scope) {
25 case IPV6_ADDR_SCOPE_NODELOCAL:
26 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_NODELOCAL) |
27 IPV6_ADDR_LOOPBACK);
28 case IPV6_ADDR_SCOPE_LINKLOCAL:
29 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL) |
30 IPV6_ADDR_LINKLOCAL);
31 case IPV6_ADDR_SCOPE_SITELOCAL:
32 return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL) |
33 IPV6_ADDR_SITELOCAL);
34 }
35 return IPV6_ADDR_SCOPE_TYPE(scope);
36 }
37
38 int __ipv6_addr_type(const struct in6_addr *addr)
39 {
40 __be32 st;
41
42 st = addr->s6_addr32[0];
43
44 /* Consider all addresses with the first three bits different of
45 000 and 111 as unicasts.
46 */
47 if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
48 (st & htonl(0xE0000000)) != htonl(0xE0000000))
49 return (IPV6_ADDR_UNICAST |
50 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));
51
52 if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
53 /* multicast */
54 /* addr-select 3.1 */
55 return (IPV6_ADDR_MULTICAST |
56 ipv6_addr_scope2type(IPV6_ADDR_MC_SCOPE(addr)));
57 }
58
59 if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
60 return (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST |
61 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL)); /* addr-select 3.1 */
62 if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
63 return (IPV6_ADDR_SITELOCAL | IPV6_ADDR_UNICAST |
64 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL)); /* addr-select 3.1 */
65 if ((st & htonl(0xFE000000)) == htonl(0xFC000000))
66 return (IPV6_ADDR_UNICAST |
67 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL)); /* RFC 4193 */
68
69 if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
70 if (addr->s6_addr32[2] == 0) {
71 if (addr->s6_addr32[3] == 0)
72 return IPV6_ADDR_ANY;
73
74 if (addr->s6_addr32[3] == htonl(0x00000001))
75 return (IPV6_ADDR_LOOPBACK | IPV6_ADDR_UNICAST |
76 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL)); /* addr-select 3.4 */
77
78 return (IPV6_ADDR_COMPATv4 | IPV6_ADDR_UNICAST |
79 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL)); /* addr-select 3.3 */
80 }
81
82 if (addr->s6_addr32[2] == htonl(0x0000ffff))
83 return (IPV6_ADDR_MAPPED |
84 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL)); /* addr-select 3.3 */
85 }
86
87 return (IPV6_ADDR_UNICAST |
88 IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL)); /* addr-select 3.4 */
89 }
90 EXPORT_SYMBOL(__ipv6_addr_type);
91
92 static ATOMIC_NOTIFIER_HEAD(inet6addr_chain);
93 static BLOCKING_NOTIFIER_HEAD(inet6addr_validator_chain);
94
95 int register_inet6addr_notifier(struct notifier_block *nb)
96 {
97 return atomic_notifier_chain_register(&inet6addr_chain, nb);
98 }
99 EXPORT_SYMBOL(register_inet6addr_notifier);
100
101 int unregister_inet6addr_notifier(struct notifier_block *nb)
102 {
103 return atomic_notifier_chain_unregister(&inet6addr_chain, nb);
104 }
105 EXPORT_SYMBOL(unregister_inet6addr_notifier);
106
107 int inet6addr_notifier_call_chain(unsigned long val, void *v)
108 {
109 return atomic_notifier_call_chain(&inet6addr_chain, val, v);
110 }
111 EXPORT_SYMBOL(inet6addr_notifier_call_chain);
112
113 int register_inet6addr_validator_notifier(struct notifier_block *nb)
114 {
115 return blocking_notifier_chain_register(&inet6addr_validator_chain, nb);
116 }
117 EXPORT_SYMBOL(register_inet6addr_validator_notifier);
118
119 int unregister_inet6addr_validator_notifier(struct notifier_block *nb)
120 {
121 return blocking_notifier_chain_unregister(&inet6addr_validator_chain,
122 nb);
123 }
124 EXPORT_SYMBOL(unregister_inet6addr_validator_notifier);
125
126 int inet6addr_validator_notifier_call_chain(unsigned long val, void *v)
127 {
128 return blocking_notifier_call_chain(&inet6addr_validator_chain, val, v);
129 }
130 EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain);
131
132 static struct dst_entry *eafnosupport_ipv6_dst_lookup_flow(struct net *net,
133 const struct sock *sk,
134 struct flowi6 *fl6,
135 const struct in6_addr *final_dst)
136 {
137 return ERR_PTR(-EAFNOSUPPORT);
138 }
139
140 static int eafnosupport_ipv6_route_input(struct sk_buff *skb)
141 {
142 return -EAFNOSUPPORT;
143 }
144
145 static struct fib6_table *eafnosupport_fib6_get_table(struct net *net, u32 id)
146 {
147 return NULL;
148 }
149
150 static int
151 eafnosupport_fib6_table_lookup(struct net *net, struct fib6_table *table,
152 int oif, struct flowi6 *fl6,
153 struct fib6_result *res, int flags)
154 {
155 return -EAFNOSUPPORT;
156 }
157
158 static int
159 eafnosupport_fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
160 struct fib6_result *res, int flags)
161 {
162 return -EAFNOSUPPORT;
163 }
164
165 static void
166 eafnosupport_fib6_select_path(const struct net *net, struct fib6_result *res,
167 struct flowi6 *fl6, int oif, bool have_oif_match,
168 const struct sk_buff *skb, int strict)
169 {
170 }
171
172 static u32
173 eafnosupport_ip6_mtu_from_fib6(const struct fib6_result *res,
174 const struct in6_addr *daddr,
175 const struct in6_addr *saddr)
176 {
177 return 0;
178 }
179
180 static int eafnosupport_fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
181 struct fib6_config *cfg, gfp_t gfp_flags,
182 struct netlink_ext_ack *extack)
183 {
184 NL_SET_ERR_MSG(extack, "IPv6 support not enabled in kernel");
185 return -EAFNOSUPPORT;
186 }
187
188 static int eafnosupport_ip6_del_rt(struct net *net, struct fib6_info *rt)
189 {
190 return -EAFNOSUPPORT;
191 }
192
193 const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
194 .ipv6_dst_lookup_flow = eafnosupport_ipv6_dst_lookup_flow,
195 .ipv6_route_input = eafnosupport_ipv6_route_input,
196 .fib6_get_table = eafnosupport_fib6_get_table,
197 .fib6_table_lookup = eafnosupport_fib6_table_lookup,
198 .fib6_lookup = eafnosupport_fib6_lookup,
199 .fib6_select_path = eafnosupport_fib6_select_path,
200 .ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
201 .fib6_nh_init = eafnosupport_fib6_nh_init,
202 .ip6_del_rt = eafnosupport_ip6_del_rt,
203 };
204 EXPORT_SYMBOL_GPL(ipv6_stub);
205
206 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
207 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
208 EXPORT_SYMBOL(in6addr_loopback);
209 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
210 EXPORT_SYMBOL(in6addr_any);
211 const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
212 EXPORT_SYMBOL(in6addr_linklocal_allnodes);
213 const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
214 EXPORT_SYMBOL(in6addr_linklocal_allrouters);
215 const struct in6_addr in6addr_interfacelocal_allnodes = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
216 EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
217 const struct in6_addr in6addr_interfacelocal_allrouters = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
218 EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
219 const struct in6_addr in6addr_sitelocal_allrouters = IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
220 EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
221
222 static void snmp6_free_dev(struct inet6_dev *idev)
223 {
224 kfree(idev->stats.icmpv6msgdev);
225 kfree(idev->stats.icmpv6dev);
226 free_percpu(idev->stats.ipv6);
227 }
228
229 static void in6_dev_finish_destroy_rcu(struct rcu_head *head)
230 {
231 struct inet6_dev *idev = container_of(head, struct inet6_dev, rcu);
232
233 snmp6_free_dev(idev);
234 kfree(idev);
235 }
236
237 /* Nobody refers to this device, we may destroy it. */
238
239 void in6_dev_finish_destroy(struct inet6_dev *idev)
240 {
241 struct net_device *dev = idev->dev;
242
243 WARN_ON(!list_empty(&idev->addr_list));
244 WARN_ON(idev->mc_list);
245 WARN_ON(timer_pending(&idev->rs_timer));
246
247 #ifdef NET_REFCNT_DEBUG
248 pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
249 #endif
250 dev_put(dev);
251 if (!idev->dead) {
252 pr_warn("Freeing alive inet6 device %p\n", idev);
253 return;
254 }
255 call_rcu(&idev->rcu, in6_dev_finish_destroy_rcu);
256 }
257 EXPORT_SYMBOL(in6_dev_finish_destroy);
258
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