You can use IDA Pro by Hex-Rays. You will usually not get good C++ out of a binary unless you compiled in debugging information. Prepare to spend a lot of manual labor reversing the code.
If you didn't strip the binaries there is some hope as IDA Pro can produce C-alike code for you to work with. Usually it is very rough though, at least when I used it a couple of years ago.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…