[Fix] Error when installing Scapy + tcpdump missing

[Keiishu]

Put an x into all the boxes [ ] relevant to your issue (like this: [x])

What is the purpose of your issue?

• Bug report (encountered problems with amazon-dash)
• Feature request (request for a new functionality)
• Question
• Other

Guideline for bug reports

• amazon-dash version: 1.3.2
• Python version: 3.7.3
• Pip & Setuptools version: 18.1
• Operating System: Raspbian Buster Lite on a Raspi 3B+ (1.2)

• The pip install or setup install command has been completed without errors
• The python -m amazon_dash.install command has been completed without errors
• The amazon-dash discovery command works without errors
• I have created/edited the configuration file
• Amazon-dash service or amazon-dash --debug run works

Description

• At the end of the installation of Amazon-Dash with sudo pip3 install amazon-dash, there's an error message caused by the installation of Scapy, including a certain LICENSE file.
  ► error: [Errno 2] No such file or directory: 'LICENSE'

• When trying to run sudo amazon-dash discovery, an error message appears :

  File "/usr/local/bin/amazon-dash", line 6, in <module>
    catch(cli)()
  File "/usr/local/lib/python3.7/dist-packages/amazon_dash/exceptions.py", line 91, in wrap
    return fn(*args, **kwargs)
  File "/usr/local/lib/python3.7/dist-packages/click/core.py", line 764, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python3.7/dist-packages/click/core.py", line 717, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python3.7/dist-packages/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python3.7/dist-packages/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python3.7/dist-packages/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/lib/python3.7/dist-packages/amazon_dash/management.py", line 127, in discovery
    discover(interface)
  File "/usr/local/lib/python3.7/dist-packages/amazon_dash/discovery.py", line 98, in discover
    scan_devices(discovery_print, lfilter=lambda d: d.src not in mac_id_list, iface=interface)
  File "/usr/local/lib/python3.7/dist-packages/amazon_dash/scan.py", line 27, in scan_devices
    lfilter=lfilter, iface=iface)
  File "/usr/local/lib/python3.7/dist-packages/scapy/sendrecv.py", line 971, in sniff
    sniffer._run(*args, **kwargs)
  File "/usr/local/lib/python3.7/dist-packages/scapy/sendrecv.py", line 841, in _run
    *arg, **karg)] = iface
  File "/usr/local/lib/python3.7/dist-packages/scapy/arch/linux.py", line 458, in __init__
    attach_filter(self.ins, filter, iface)
  File "/usr/local/lib/python3.7/dist-packages/scapy/arch/linux.py", line 143, in attach_filter
    bp = compile_filter(bpf_filter, iface)
  File "/usr/local/lib/python3.7/dist-packages/scapy/arch/common.py", line 152, in compile_filter
    raise Scapy_Exception("tcpdump is not available. Cannot use filter !")
scapy.error.Scapy_Exception: tcpdump is not available. Cannot use filter !

What I did to get it working

Assuming you're on a Debian-based distro or just using the apt package manager + using Python 3.x . Otherwise, you need to adapt these commands to your configuration.

• This is apparently a known issue with the latest stable version of Scapy. At this day, the way to install it properly is to get the latest Release Candidate (v2.4.3rc3 at this moment).
  ► sudo pip3 install --pre scapy

• This is also a known issue here (Can't run discovery: tcpdump is not available #125) but I repost it here as a "bump", a little reminder, because it's only one little package missing.
  ► sudo apt install tcpdump

[Nekmo]

I didn't know this problem with Scapy. Apparently it only happens in Raspberry PI. I can try to force a fixed version of Scapy, but it should not be forced on other architectures without this error.

secdev/scapy#1864

I will study the best way to solve this issue. Thanks!

[Keiishu]

I didn't know it was only the RPi either lmao
No problem and many thanks for your work!

[Nekmo]

Same error on x86_64:

Collecting scapy
  Using cached https://files.pythonhosted.org/packages/d0/04/b8512e5126a1816581767bf95cbf525e0681a22c055bcd45f47ecff60170/scapy-2.4.2.tar.gz
...
  error: [Errno 2] No such file or directory: 'LICENSE'
  ----------------------------------------
  ERROR: Failed building wheel for scapy
  Running setup.py clean for scapy
Failed to build scapy
Installing collected packages: scapy
  Running setup.py install for scapy ... done
Successfully installed scapy-2.4.2
(tmp-f5b3f44388f340c) [nekmo@homura ~/.virtualenvs/tmp-f5b3f44388f340c]$ pip install scapy

[Nekmo]

Fixed. Thanks!

[gpotter2]

FTR we ended up removing the tcpdump dependency by using libpcap directly (secdev/scapy#2336).

This is not included in a release as of today (will be in 2.4.4+)