r0 = socket$inet6_tcp(0xa, 0x1, 0x0)
ioctl$sock_inet6_SIOCADDRT(r0, 0x890b, &(0x7f0000002780)={@empty, @mcast1, @initdev={0xfe, 0x88, '\x00', 0x0, 0x0}, 0x0, 0x0, 0x0, 0x100, 0x0, 0x40000000})