[New Feature] Packet Sniffer

[LuhaoLiu]

Description

Packet Sniffer for Coyote shell. This project was conducted as part of a semester project at ETH Zurich.
The artifact is in ./example_hw/apps/packet_sniffer/ and ./example_sw/apps/packet_sniffer/.
A simple documentation and some annotation about how to use the software (on a deployed Coyote shell) to capture network traffic are provided in ./exmaple_sw/apps/packet_sniffer/README.md.
More details about the system design and performance impact are discussed in another report. Please ask me for the link of this pdf report (still in draft).

Type of change

• Bug fix
• New feature
• Documentation update
• A new research paper code implementation
• Other

Tests & Results

More details will be provided in the aforementioned pdf report.
One point to mention here: When this new feature is disabled by EN_SNIFFER 0 in CMake (which is the default), nothing will be essentially changed thanks to the macros. So merging this branch into the master branch WILL NOT affect anything unless you manually enable the new feature for relevant experiments or debugging.

Checklist

• I have commented my code and made corresponding changes to the documentation.
• Mostly. Please tell me if more is better.
• I have added tests/results that prove my fix is effective or that my feature works.
• This is not a FIX so not applicable. But some performance tests are feature works.
• My changes generate no new warnings or errors & all tests successfully pass.
• As mentioned, this merge will not affect anything by default.