On July 14th 2014, just three days before the MH17 incident, an Antonov AN-26 Ukrainian military transport plane was hit at 21 000 feet altitude, so there was a strong indication that SAMs were available to the seperatists. According to the Dutch Safety Board, the airspace should have been closed [1].
[1] http://www.airspacemag.com/daily-planet/dutch-safety-board-u...