Wiggly worm

Normal sudoku rules apply. Place the digits 1-9 once each in every row, column and 3x3 box. Digits along a grey line must read the same forwards as backwards. Cells separated by a black dot has one digit double the other (1:2 ratio). Cells separated by a white dot are consecutive. Digits in a dotted cage without repeat sum to the total in the top left corner of the cage (if given).