The transceiver wraps your payload in some headers that add stuff like MAC
address, frame type, and CRC.
These are the minimum fields that are required so that a WiFi card actually
accepts the frame.
Makes sense. I knew about the headers and CRC, but I wasn’t even
thinking about it being used with an actual WiFi device (as opposed to
two USRPs).
There is currently no option to dump raw bytes, but its a trivial modification
of the Wireshark block (dump
without a PCAP header).
This sounds reasonable to me, but so far I have been unsuccesful. I am
attempting to edit wireshark_connector_impl.cc, but none of my mods have
worked so far. I am not looking for you to do the work, but I wanted to
make sure I am looking at the right file. One of my concerns with it is
that my C++ is really rusty and I haven’t played with the low-level GR
stuff before, so I am muddling through what is going on in that file.
Near the end of the file is the following:
int to_copy = std::min((d_msg_len - d_msg_offset), noutput);
memcpy(out, d_msg + d_msg_offset, to_copy);
I believe that that second line is where the information is put on the
output buffer. So for a test, I changed the memcpy to be:
memcpy(out, d_msg + d_msg_offset + 10, to_copy - 10);
to basically cut off the first 10B (just a quick and dirty test).
I then run:
sudo make uninstall && make clean && make && sudo make install &&
sudo ldconfig
from the gr-foo/build directory.
It builds fine, but when I run my GRC script, the output to a file sink
(for simplicity I am dumping to a file instead of UDP for now), doesn’t
change its length. I did reload blocks in GRC too.