Re: [security-discuss] gnuradio project DoS attacks GNU wget users

[Alfred M. Szmidt]

   It is impossible to access full documentation on that page by using
   lynx. Have you tried using links?

I just accessed the link from lynx. so where where you get that it is
"impossible" I have no idea.

   I mean, it is Hypertext Markup Language, and all links are
   "javascript:void(0)"

That is blatantly false.

<p>This example is found in the dial_tone.py file and constructs a very simple 
GNU Radio application that combines two sine waves to create a dial tone. It 
calls a function to construct the flowgraph which handles generating the signal 
sources.</p>
<p>The build_graph function sets up the sampling rate, which we will use to set 
the rate of the audio sink as well as the amplitude, which we use to scale the 
signal to control the volume of the output. We then create a top_block. The 
top_block is the object that holds the flowgraph, the basic data structure of a 
GNU
+Radio application. We will use the top_block to connect together and hold the 
signal processing blocks, which we build next.</p>
<p>This example uses three signal processing blocks. The first two are <a 
class="el" href="classgr_1_1analog_1_1sig__source__f.html" title="signal 
generator with float output. ">gr::analog::sig_source_f</a> blocks, which 
generate sine waves at frequencies 350 and 440 Hz. We next create the 
connection to the speaker sy
+stem using <a class="el" href="classgr_1_1audio_1_1sink.html" title="Creates a 
sink from an audio device. ">gr::audio::sink</a>, which takes in the sample 
rate it will use to produce the output signal. The audio sink block can also 
take in a second parameter to set the output device name, which we use if there 
is a r
+esource conflict or if using a sampling rate that the hardware won't naturally 
support. Common device names are "pulse" if using PulseAudio or "plughw:0,0", 
which is an ALSA device that can handle resampling.</p>
<p>We next take the three blocks we've built and connect together the 
flowgraph. The flowgraph connects sources to sinks through other signal 
processing blocks. Here, we are directly connecting two sources to a single 
sink. The next example uses more complex flowgraphs to farther explore these 
concepts. The two lines
+containing the "tb.connect" statements are where the connections are made. The 
flowgraph will look like:</p>