[KNOWN ISSUE] Valid request but Content Length mismatch

[leske42]

5. If a valid Content-Length header field is present without
   Transfer-Encoding, its decimal value defines the expected message
   body length in octets. If the sender closes the connection or
   the recipient times out before the indicated number of octets are
   received, the recipient MUST consider the message to be
   incomplete and close the connection [RFC 7230 3.3.3]

Because of TCP or read buffer length we might not receive the whole body at once even if they send with content-length option. Then we need a way to decide if we deal with mismatched body size or not (maybe we need to implement some timeout functionality).