cannot read correct len from socket

[wysota]

I want to read it as binary.

You are always reading it as binary, even if it is textual data. It is just a matter of interpreting the data.

what am I missing?

You are missing a couple of hours of learning about computers, their memory and data layout of different data types.

1835094789d = 0x6D615305 = 0x0553616D (swapped byte order) = "\5Sam" interpreted as text. Does that ring a bell?