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 */
17void (*__fib6_flush_trees)(struct net *);
18EXPORT_SYMBOL(__fib6_flush_trees);
19
20#define IPV6_ADDR_SCOPE_TYPE(scope)	((scope) << 16)
21
22static 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
38int __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}
90EXPORT_SYMBOL(__ipv6_addr_type);
91
92static ATOMIC_NOTIFIER_HEAD(inet6addr_chain);
93static BLOCKING_NOTIFIER_HEAD(inet6addr_validator_chain);
94
95int register_inet6addr_notifier(struct notifier_block *nb)
96{
97	return atomic_notifier_chain_register(&inet6addr_chain, nb);
98}
99EXPORT_SYMBOL(register_inet6addr_notifier);
100
101int unregister_inet6addr_notifier(struct notifier_block *nb)
102{
103	return atomic_notifier_chain_unregister(&inet6addr_chain, nb);
104}
105EXPORT_SYMBOL(unregister_inet6addr_notifier);
106
107int inet6addr_notifier_call_chain(unsigned long val, void *v)
108{
109	return atomic_notifier_call_chain(&inet6addr_chain, val, v);
110}
111EXPORT_SYMBOL(inet6addr_notifier_call_chain);
112
113int register_inet6addr_validator_notifier(struct notifier_block *nb)
114{
115	return blocking_notifier_chain_register(&inet6addr_validator_chain, nb);
116}
117EXPORT_SYMBOL(register_inet6addr_validator_notifier);
118
119int unregister_inet6addr_validator_notifier(struct notifier_block *nb)
120{
121	return blocking_notifier_chain_unregister(&inet6addr_validator_chain,
122						  nb);
123}
124EXPORT_SYMBOL(unregister_inet6addr_validator_notifier);
125
126int inet6addr_validator_notifier_call_chain(unsigned long val, void *v)
127{
128	return blocking_notifier_call_chain(&inet6addr_validator_chain, val, v);
129}
130EXPORT_SYMBOL(inet6addr_validator_notifier_call_chain);
131
132static 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
140static int eafnosupport_ipv6_route_input(struct sk_buff *skb)
141{
142	return -EAFNOSUPPORT;
143}
144
145static struct fib6_table *eafnosupport_fib6_get_table(struct net *net, u32 id)
146{
147	return NULL;
148}
149
150static int
151eafnosupport_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
158static int
159eafnosupport_fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
160			 struct fib6_result *res, int flags)
161{
162	return -EAFNOSUPPORT;
163}
164
165static void
166eafnosupport_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
172static u32
173eafnosupport_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
180static 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
188static int eafnosupport_ip6_del_rt(struct net *net, struct fib6_info *rt,
189				   bool skip_notify)
190{
191	return -EAFNOSUPPORT;
192}
193
194static int eafnosupport_ipv6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
195				      int (*output)(struct net *, struct sock *, struct sk_buff *))
196{
197	kfree_skb(skb);
198	return -EAFNOSUPPORT;
199}
200
201static struct net_device *eafnosupport_ipv6_dev_find(struct net *net, const struct in6_addr *addr,
202						     struct net_device *dev)
203{
204	return ERR_PTR(-EAFNOSUPPORT);
205}
206
207const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
208	.ipv6_dst_lookup_flow = eafnosupport_ipv6_dst_lookup_flow,
209	.ipv6_route_input  = eafnosupport_ipv6_route_input,
210	.fib6_get_table    = eafnosupport_fib6_get_table,
211	.fib6_table_lookup = eafnosupport_fib6_table_lookup,
212	.fib6_lookup       = eafnosupport_fib6_lookup,
213	.fib6_select_path  = eafnosupport_fib6_select_path,
214	.ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
215	.fib6_nh_init	   = eafnosupport_fib6_nh_init,
216	.ip6_del_rt	   = eafnosupport_ip6_del_rt,
217	.ipv6_fragment	   = eafnosupport_ipv6_fragment,
218	.ipv6_dev_find     = eafnosupport_ipv6_dev_find,
219};
220EXPORT_SYMBOL_GPL(ipv6_stub);
221
222/* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
223const struct in6_addr in6addr_loopback __aligned(BITS_PER_LONG/8)
224	= IN6ADDR_LOOPBACK_INIT;
225EXPORT_SYMBOL(in6addr_loopback);
226const struct in6_addr in6addr_any __aligned(BITS_PER_LONG/8)
227	= IN6ADDR_ANY_INIT;
228EXPORT_SYMBOL(in6addr_any);
229const struct in6_addr in6addr_linklocal_allnodes __aligned(BITS_PER_LONG/8)
230	= IN6ADDR_LINKLOCAL_ALLNODES_INIT;
231EXPORT_SYMBOL(in6addr_linklocal_allnodes);
232const struct in6_addr in6addr_linklocal_allrouters __aligned(BITS_PER_LONG/8)
233	= IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
234EXPORT_SYMBOL(in6addr_linklocal_allrouters);
235const struct in6_addr in6addr_interfacelocal_allnodes __aligned(BITS_PER_LONG/8)
236	= IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
237EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
238const struct in6_addr in6addr_interfacelocal_allrouters __aligned(BITS_PER_LONG/8)
239	= IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
240EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
241const struct in6_addr in6addr_sitelocal_allrouters __aligned(BITS_PER_LONG/8)
242	= IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
243EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
244
245static void snmp6_free_dev(struct inet6_dev *idev)
246{
247	kfree(idev->stats.icmpv6msgdev);
248	kfree(idev->stats.icmpv6dev);
249	free_percpu(idev->stats.ipv6);
250}
251
252static void in6_dev_finish_destroy_rcu(struct rcu_head *head)
253{
254	struct inet6_dev *idev = container_of(head, struct inet6_dev, rcu);
255
256	snmp6_free_dev(idev);
257	kfree(idev);
258}
259
260/* Nobody refers to this device, we may destroy it. */
261
262void in6_dev_finish_destroy(struct inet6_dev *idev)
263{
264	struct net_device *dev = idev->dev;
265
266	WARN_ON(!list_empty(&idev->addr_list));
267	WARN_ON(rcu_access_pointer(idev->mc_list));
268	WARN_ON(timer_pending(&idev->rs_timer));
269
270#ifdef NET_REFCNT_DEBUG
271	pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
272#endif
273	netdev_put(dev, &idev->dev_tracker);
274	if (!idev->dead) {
275		pr_warn("Freeing alive inet6 device %p\n", idev);
276		return;
277	}
278	call_rcu(&idev->rcu, in6_dev_finish_destroy_rcu);
279}
280EXPORT_SYMBOL(in6_dev_finish_destroy);
281