IP_FREEBIND is not supported for SOCK_RAW ipv6 sockets.
See kernel rawv6_setsockopt() for the details.

For the rest of sockets, where they begin to support it:
the actual magic happens in do_ipv6_setsockopt(), and
IPV6_ADDRFORM optname changes sk->sk_prot to refer
to tcp_prot, udp_prot and udplite_prot, which contains
link to ip_setsockopt().
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>