#!/usr/bin/env python
#
# Copyright 2020 Free Software Foundation, Inc.
#
# This file is part of GNU Radio
#
# GNU Radio is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3, or (at your option)
# any later version.
#
# GNU Radio is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GNU Radio; see the file COPYING.  If not, write to
# the Free Software Foundation, Inc., 51 Franklin Street,
# Boston, MA 02110-1301, USA.
#

from gnuradio import gr, gr_unittest
from gnuradio import fec
from gnuradio import blocks, analog

# This test tries to checks for the kind of buffer overflows in the
# FECAPI convolutional decoder that were fixed in #2965

class test_fecapi_cc_buffer_overflow(gr_unittest.TestCase):

    def run_with_frame_len(self, frame_len):
        self.tb = gr.top_block()
        noise = analog.noise_source_f(analog.GR_GAUSSIAN, 1, 0)
        head = blocks.head(gr.sizeof_float, self.n_frames * frame_len)
        tag = blocks.stream_to_tagged_stream(gr.sizeof_float, 1, frame_len, "packet_len")
        stream2pdu = blocks.tagged_stream_to_pdu(blocks.float_t, 'packet_len')
        
        viterbi = fec.cc_decoder.make(frame_len//2, 7, 2, [79,-109], 0, -1, fec.CC_TERMINATED, False)
        cc_decoder = fec.async_decoder(viterbi, False, False, frame_len)
        
        self.tb.connect(noise, head, tag, stream2pdu)
        self.tb.msg_connect((stream2pdu, 'pdus'), (cc_decoder, 'in'))
        
        self.tb.run()
        # the test is considered successful if it hasn't segfaulted or aborted

        self.tb = None

    def test_buffer_overflow_00(self):
        self.n_frames = 10

        for frame_len in range(1000, 2000):
            with self.subTest(frame_length = frame_len):
                self.run_with_frame_len(frame_len)
        
if __name__ == '__main__':
    gr_unittest.run(test_fecapi_cc_buffer_overflow)