xref: /openbmc/linux/net/ipv6/addrconf_core.c (revision 37185b33)
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 
9 #define IPV6_ADDR_SCOPE_TYPE(scope)	((scope) << 16)
10 
11 static inline unsigned int ipv6_addr_scope2type(unsigned int scope)
12 {
13 	switch (scope) {
14 	case IPV6_ADDR_SCOPE_NODELOCAL:
15 		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_NODELOCAL) |
16 			IPV6_ADDR_LOOPBACK);
17 	case IPV6_ADDR_SCOPE_LINKLOCAL:
18 		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL) |
19 			IPV6_ADDR_LINKLOCAL);
20 	case IPV6_ADDR_SCOPE_SITELOCAL:
21 		return (IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL) |
22 			IPV6_ADDR_SITELOCAL);
23 	}
24 	return IPV6_ADDR_SCOPE_TYPE(scope);
25 }
26 
27 int __ipv6_addr_type(const struct in6_addr *addr)
28 {
29 	__be32 st;
30 
31 	st = addr->s6_addr32[0];
32 
33 	/* Consider all addresses with the first three bits different of
34 	   000 and 111 as unicasts.
35 	 */
36 	if ((st & htonl(0xE0000000)) != htonl(0x00000000) &&
37 	    (st & htonl(0xE0000000)) != htonl(0xE0000000))
38 		return (IPV6_ADDR_UNICAST |
39 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));
40 
41 	if ((st & htonl(0xFF000000)) == htonl(0xFF000000)) {
42 		/* multicast */
43 		/* addr-select 3.1 */
44 		return (IPV6_ADDR_MULTICAST |
45 			ipv6_addr_scope2type(IPV6_ADDR_MC_SCOPE(addr)));
46 	}
47 
48 	if ((st & htonl(0xFFC00000)) == htonl(0xFE800000))
49 		return (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST |
50 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));		/* addr-select 3.1 */
51 	if ((st & htonl(0xFFC00000)) == htonl(0xFEC00000))
52 		return (IPV6_ADDR_SITELOCAL | IPV6_ADDR_UNICAST |
53 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_SITELOCAL));		/* addr-select 3.1 */
54 	if ((st & htonl(0xFE000000)) == htonl(0xFC000000))
55 		return (IPV6_ADDR_UNICAST |
56 			IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));			/* RFC 4193 */
57 
58 	if ((addr->s6_addr32[0] | addr->s6_addr32[1]) == 0) {
59 		if (addr->s6_addr32[2] == 0) {
60 			if (addr->s6_addr32[3] == 0)
61 				return IPV6_ADDR_ANY;
62 
63 			if (addr->s6_addr32[3] == htonl(0x00000001))
64 				return (IPV6_ADDR_LOOPBACK | IPV6_ADDR_UNICAST |
65 					IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_LINKLOCAL));	/* addr-select 3.4 */
66 
67 			return (IPV6_ADDR_COMPATv4 | IPV6_ADDR_UNICAST |
68 				IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.3 */
69 		}
70 
71 		if (addr->s6_addr32[2] == htonl(0x0000ffff))
72 			return (IPV6_ADDR_MAPPED |
73 				IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.3 */
74 	}
75 
76 	return (IPV6_ADDR_UNICAST |
77 		IPV6_ADDR_SCOPE_TYPE(IPV6_ADDR_SCOPE_GLOBAL));	/* addr-select 3.4 */
78 }
79 EXPORT_SYMBOL(__ipv6_addr_type);
80 
81