[IPV6]: Fix source address selection.

Two additional labels (RFC 3484, sec. 10.3) for IPv6 addreses
are defined to make a distinction between global unicast
addresses and Unique Local Addresses (fc00::/7, RFC 4193) and
Teredo (2001::/32, RFC 4380). It is necessary to avoid attempts
of connection that would either fail (eg. fec0:: to 2001:feed::)
or be sub-optimal (2001:0:: to 2001:feed::).

Signed-off-by: Łukasz Stelmach <stlman@poczta.fm>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index c2c26fa0943df9e8e7a3e107ffec095c9b08c003..6b361fc3e14d5585f67bee423b562337d5b5e496 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -862,6 +862,8 @@ static int inline ipv6_saddr_label(const struct in6_addr *addr, int type)
   *    2002::/16               2
   *    ::/96                   3
   *    ::ffff:0:0/96           4
+  *    fc00::/7                5
+  *    2001::/32               6
   */
        if (type & IPV6_ADDR_LOOPBACK)
                return 0;
@@ -869,8 +871,12 @@ static int inline ipv6_saddr_label(const struct in6_addr *addr, int type)
                return 3;
        else if (type & IPV6_ADDR_MAPPED)
                return 4;
+       else if (addr->s6_addr32[0] == htonl(0x20010000))
+               return 6;
        else if (addr->s6_addr16[0] == htons(0x2002))
                return 2;
+       else if ((addr->s6_addr[0] & 0xfe) == 0xfc)
+               return 5;
        return 1;
 }