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 
ipv6_addr_scope2type(unsigned int scope)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 
__ipv6_addr_type(const struct in6_addr * addr)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 
register_inet6addr_notifier(struct notifier_block * nb)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 
unregister_inet6addr_notifier(struct notifier_block * nb)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 
inet6addr_notifier_call_chain(unsigned long val,void * v)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 
register_inet6addr_validator_notifier(struct notifier_block * nb)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 
unregister_inet6addr_validator_notifier(struct notifier_block * nb)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 
inet6addr_validator_notifier_call_chain(unsigned long val,void * v)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 
eafnosupport_ipv6_dst_lookup_flow(struct net * net,const struct sock * sk,struct flowi6 * fl6,const struct in6_addr * final_dst)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 
eafnosupport_ipv6_route_input(struct sk_buff * skb)140 static int eafnosupport_ipv6_route_input(struct sk_buff *skb)
141 {
142 	return -EAFNOSUPPORT;
143 }
144 
eafnosupport_fib6_get_table(struct net * net,u32 id)145 static struct fib6_table *eafnosupport_fib6_get_table(struct net *net, u32 id)
146 {
147 	return NULL;
148 }
149 
150 static int
eafnosupport_fib6_table_lookup(struct net * net,struct fib6_table * table,int oif,struct flowi6 * fl6,struct fib6_result * res,int flags)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
eafnosupport_fib6_lookup(struct net * net,int oif,struct flowi6 * fl6,struct fib6_result * res,int flags)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
eafnosupport_fib6_select_path(const struct net * net,struct fib6_result * res,struct flowi6 * fl6,int oif,bool have_oif_match,const struct sk_buff * skb,int strict)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
eafnosupport_ip6_mtu_from_fib6(const struct fib6_result * res,const struct in6_addr * daddr,const struct in6_addr * saddr)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 
eafnosupport_fib6_nh_init(struct net * net,struct fib6_nh * fib6_nh,struct fib6_config * cfg,gfp_t gfp_flags,struct netlink_ext_ack * extack)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 
eafnosupport_ip6_del_rt(struct net * net,struct fib6_info * rt,bool skip_notify)188 static int eafnosupport_ip6_del_rt(struct net *net, struct fib6_info *rt,
189 				   bool skip_notify)
190 {
191 	return -EAFNOSUPPORT;
192 }
193 
eafnosupport_ipv6_fragment(struct net * net,struct sock * sk,struct sk_buff * skb,int (* output)(struct net *,struct sock *,struct sk_buff *))194 static 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 
eafnosupport_ipv6_dev_find(struct net * net,const struct in6_addr * addr,struct net_device * dev)201 static 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 
207 const 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 };
220 EXPORT_SYMBOL_GPL(ipv6_stub);
221 
222 /* IPv6 Wildcard Address and Loopback Address defined by RFC2553 */
223 const struct in6_addr in6addr_loopback = IN6ADDR_LOOPBACK_INIT;
224 EXPORT_SYMBOL(in6addr_loopback);
225 const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
226 EXPORT_SYMBOL(in6addr_any);
227 const struct in6_addr in6addr_linklocal_allnodes = IN6ADDR_LINKLOCAL_ALLNODES_INIT;
228 EXPORT_SYMBOL(in6addr_linklocal_allnodes);
229 const struct in6_addr in6addr_linklocal_allrouters = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
230 EXPORT_SYMBOL(in6addr_linklocal_allrouters);
231 const struct in6_addr in6addr_interfacelocal_allnodes = IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
232 EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
233 const struct in6_addr in6addr_interfacelocal_allrouters = IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
234 EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
235 const struct in6_addr in6addr_sitelocal_allrouters = IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
236 EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
237 
snmp6_free_dev(struct inet6_dev * idev)238 static void snmp6_free_dev(struct inet6_dev *idev)
239 {
240 	kfree(idev->stats.icmpv6msgdev);
241 	kfree(idev->stats.icmpv6dev);
242 	free_percpu(idev->stats.ipv6);
243 }
244 
in6_dev_finish_destroy_rcu(struct rcu_head * head)245 static void in6_dev_finish_destroy_rcu(struct rcu_head *head)
246 {
247 	struct inet6_dev *idev = container_of(head, struct inet6_dev, rcu);
248 
249 	snmp6_free_dev(idev);
250 	kfree(idev);
251 }
252 
253 /* Nobody refers to this device, we may destroy it. */
254 
in6_dev_finish_destroy(struct inet6_dev * idev)255 void in6_dev_finish_destroy(struct inet6_dev *idev)
256 {
257 	struct net_device *dev = idev->dev;
258 
259 	WARN_ON(!list_empty(&idev->addr_list));
260 	WARN_ON(rcu_access_pointer(idev->mc_list));
261 	WARN_ON(timer_pending(&idev->rs_timer));
262 
263 #ifdef NET_REFCNT_DEBUG
264 	pr_debug("%s: %s\n", __func__, dev ? dev->name : "NIL");
265 #endif
266 	netdev_put(dev, &idev->dev_tracker);
267 	if (!idev->dead) {
268 		pr_warn("Freeing alive inet6 device %p\n", idev);
269 		return;
270 	}
271 	call_rcu(&idev->rcu, in6_dev_finish_destroy_rcu);
272 }
273 EXPORT_SYMBOL(in6_dev_finish_destroy);
274