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 __aligned(BITS_PER_LONG/8)
224  	= IN6ADDR_LOOPBACK_INIT;
225  EXPORT_SYMBOL(in6addr_loopback);
226  const struct in6_addr in6addr_any __aligned(BITS_PER_LONG/8)
227  	= IN6ADDR_ANY_INIT;
228  EXPORT_SYMBOL(in6addr_any);
229  const struct in6_addr in6addr_linklocal_allnodes __aligned(BITS_PER_LONG/8)
230  	= IN6ADDR_LINKLOCAL_ALLNODES_INIT;
231  EXPORT_SYMBOL(in6addr_linklocal_allnodes);
232  const struct in6_addr in6addr_linklocal_allrouters __aligned(BITS_PER_LONG/8)
233  	= IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
234  EXPORT_SYMBOL(in6addr_linklocal_allrouters);
235  const struct in6_addr in6addr_interfacelocal_allnodes __aligned(BITS_PER_LONG/8)
236  	= IN6ADDR_INTERFACELOCAL_ALLNODES_INIT;
237  EXPORT_SYMBOL(in6addr_interfacelocal_allnodes);
238  const struct in6_addr in6addr_interfacelocal_allrouters __aligned(BITS_PER_LONG/8)
239  	= IN6ADDR_INTERFACELOCAL_ALLROUTERS_INIT;
240  EXPORT_SYMBOL(in6addr_interfacelocal_allrouters);
241  const struct in6_addr in6addr_sitelocal_allrouters __aligned(BITS_PER_LONG/8)
242  	= IN6ADDR_SITELOCAL_ALLROUTERS_INIT;
243  EXPORT_SYMBOL(in6addr_sitelocal_allrouters);
244  
snmp6_free_dev(struct inet6_dev * idev)245  static 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  
in6_dev_finish_destroy_rcu(struct rcu_head * head)252  static 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  
in6_dev_finish_destroy(struct inet6_dev * idev)262  void 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  }
280  EXPORT_SYMBOL(in6_dev_finish_destroy);
281