Benko Gambit, Nf3 lines with a4 and Ra3, pawn push variation.
1. d4
This is a Benko Gambit with 4.Nf3.
1... Ng8f6 2. c4 c5 3. d5 b5 4. Ng1f3
This sideline sometimes lets white play a4 and Ra3. White should be aware of move order considerations, since an early d6, for instance, is actually not optimal for the second player.
4... g6 5. cxb5 a6 6. e3 Bf8g7 7. Nb1c3 O-O 8. a4
White's plan is clear enough.
8... d6
Better was 8...Bb7 or 8...e6 to take advantage of white's pieces.
9. Ra1a3 axb5 10. Bf1xb5 Bc8a6
Also possible was to try to put the knight there en route to the weak b4 square. Black's bishop can work the long diagonal.