<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def recv(self, x=BPF_BUFFER_LENGTH):
 """Receive a frame from the network"""


        if self.buffered_frames():
            # Get a frame from the buffer
            return self.get_frame()

        # Get data from BPF
        try:
            bpf_buffer = os.read(self.ins, x)
        except EnvironmentError as exc:
            if exc.errno != errno.EAGAIN:
                warning("BPF recv()", exc_info=True)
            return

        # Extract all frames from the BPF buffer
        self.extract_frames(bpf_buffer)
        return self.get_frame()