Add RawNetworkInterfaceDriver, labgrid-raw-interface helper and example

[Bastian-Krause]

Description
The RawNetworkInterfaceDriver allows "raw" control of a network interface (such as Ethernet or WiFi).

The newly added labgrid-raw-interface helper (helpers/labgrid-raw-interface) needs to be installed in the PATH and usable via sudo without password.

It supports:

• recording traffic
• replaying traffic
• basic statistic collection

Checklist

• Documentation for the feature
• Tests for the feature
• The arguments and description in doc/configuration.rst have been updated
• PR has been tested

[codecov]

Codecov Report

Attention: 51 lines in your changes are missing coverage. Please review.

Comparison is base (e8fdd87) 62.9% compared to head (e3ee7f6) 62.7%.
Report is 21 commits behind head on master.

Files	Patch %	Lines
labgrid/driver/rawnetworkinterfacedriver.py	42.6%	51 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##           master   #1157     +/-   ##
========================================
- Coverage    62.9%   62.7%   -0.2%     
========================================
  Files         161     163      +2     
  Lines       11888   12001    +113     
========================================
+ Hits         7486    7535     +49     
- Misses       4402    4466     +64     

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[jluebbe]

Looks good otherwise.

[jluebbe]

We discussed this internally: The wrapper can be simplified by using stdin/stdout to pass packet data, as we don't need to create/open paths as root.

[Bastian-Krause]

Rebased on master.

[Bastian-Krause]

• labgrid-raw-interface: use yaml instead of ini configs
• change argument order
• use shell redirection and stdin/stdout instead of using tcpdump's -Z and letting tcpump/tcpreplay write to capfile directly

[Bastian-Krause]

• labgrid-raw-interface: fix optional count argument
• networkinterfacedriver: simplify capfile copy/close handling in get_record()
• networkinterfacedriver: fix start_replay() for remote network interfaces

[Bastian-Krause]

• added documentation for /etc/labgrid/helpers.yaml
• example: use basicConfig/StepLogger instead of StepReporter
• labgrid-raw-interface: fix deny list defaults, always deny loopback interface
• rawnetworkinterfacedriver: fix get_statistics()

[Bastian-Krause]

• rawnetworinterfacedriver: stdout is now redirected into a file in get_record(), so drop the obsolete out variable

[Bastian-Krause]

The previous comments reflect the development history and should ease reviewing the changes.

[Bastian-Krause]

• labgrid-raw-interface: use longopts for tcpreplay

[Bastian-Krause]

• rawnetworkinterfacedriver: make start_replay() return process handle instead of waiting for the process to complete and returning a CompletedProcess

[Bastian-Krause]

Rebased one more time now that #1249 was merged.

[Bastian-Krause]

• labgrid-raw-interface: fix wrapper path in sudoers comment
• labgrid-raw-interface: raise exception on invalid config structure
• rawnetworkinterfacedriver: keep single handle for record and replay instead of map, add sanity asserts to all record and replay methods
• rawnetworkinterfacedriver: implement smarter _wrap_command() instead of _get_wrapper_prefix() and use it everywhere
• rawnetworkinterfacedriver: add _stop() helper used by both stop_record() and stop_replay()
• rawnetworkinterfacedriver: capture stderr on record/replay, raise CalledProcessError with return code, command, stderr on return code != 0
• rawnetworkinterfacedriver: move filename to start_record()/start_replay() and simplify stdin/stdout handling
• rawnetworkinterfacedriver: add contextmanager for record/replay
• example: reduce example log level to INFO
• example: improve/fix comments
• example: fixed record count to 1
• example: use os.path.join() to join path
• example: use record contextmanager
• example: call get_statistics() and get_address()

Example tested for remote and local use case.

[Bastian-Krause]

Rebased.

[Bastian-Krause]

Addressed the review feedback by @jluebbe. Thanks!

[jluebbe]

Besides #1157 (comment), this looks good. As that doesn't affect behavior, you could merge this as-is and address it in a separate PR.