iproute2: fix changing of ip6ip6 tunnel parameters

When changing ip6ip6 parameters (ip -6 tun change), ip passes zeroed
struct ip6_tnl_parm to the kernel. The kernel then tries to change all of
the tunnel parameters to the passed values, including zeroing of local and
remote address. This fails (-EEXIST in net/ipv6/ip6_tunnel.c:ip6_tnl_ioctl).

For other tunnel types, ip fetches the current parameters first and applies
the required changes on top of them. This patch applies the same code as in
ip/iptunnel.c to ip/ip6tunnel.c.

See http://bugzilla.redhat.com/730627 for the original bug report.

Signed-off-by: Jiri Benc <jbenc@redhat.com>
1 file changed