CSI:GO

CSI extraction patches for modern Linux kernels

CSI:GO uses diff-based patching to extract and apply the necessary kernel module changes from the Intel 5300 CSI Tool and Atheros CSI Tool. This lets you run both on modern kernels without full kernel rebuilds.

The Atheros patches differ, addressing potential race conditions while the Intel modifications are adapted only as needed. The Atheros module is also modified to report the MAC Sequence Number, and I removed the frame payload reporting to lighten the load, catering exclusively to CSI reporting.

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Features

• Diff-based patching: Build only the required modules.
• Modular approach: Avoid full kernel builds. Fast and allows using both modules in one system.
• Modern kernel support: No legacy restrictions.
• Easy installation: Load modules directly into a running system.

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Driver (in the driver subdirectory)

This directory contains scripts to build modified CSI extraction kernel modules for ath9k and iwl5300. The patches are curated for newer kernel versions and may not be backwards compatible. However, the diff-based approach makes adapting them straightforward.

Current patch target kernel version:

6.8.0-51

Build & Installation

1. Fetch & Patch:
   Run ./pull_and_apply.sh to download the current kernel sources and apply the patch files. Patched sources will be placed in module_src. Check the output to see if any hunks failed and potentially fix issues manually in the source directory. See below for how to commit updates.

2. Build:
   Use make to build the all target, otherwise use the ath or iwl targets to build only the respective module. This performs an out-of-tree build so that only the affected modules are built.

3. Install:
   Install the modules with:

   sudo make install

   (This target proxies both install_ath and install_iwl, which may be used to perform targeted install). Afterwards reboot. This will install the modules into the updates directory /lib/modules/<ver>/updates. Note that DKMS updates may take precedence. To check which module is used, use sudo modinfo ath9k | grep filename.

Directories such as kernel_source, module_src, and build are created during the process but are not committed. If you want to commit a change to the module, see next section.

Usage

With the kernel modules running, CSI is now being extracted. To actually receive it:

1. Build Extractor

   For the Intel tool, use the original connector to receive CSI from the kernel module.

   The Atheros tool still exposes a character device file, but since we changed the format, you need to use the modified extractor. It's a simple CMake project, so in the extractor directory, run:

   cmake -S . -B build && cmake --build build
   

2. Use extractor

   For the qca extractor, as in the original tool, run:

   ./build/csi-extractor <file>

   This will log data to the specified file. Specifically, it will write the bytes of struct csi_user_info (see driver/patch/current/ath/module_src_ath_ath9k_ath9k_csi.h.patch ) the CSI matrix packed to the file. Aside from the struct, the CSI data is the same as in the original tool. To use it, you can write your own scripts or slightly adapt the original tool.

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Updating Patches

If patch conflicts occur:

• Manually fix the conflicts in module_src/ath or module_src/iwlwifi.

• Regenerate the patch with:

  ./create_diff.sh module_src/ath_original module_src/ath patch/current/ath

• Submit a pull request with your update.

Note: New patches may not work with older kernel versions.

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Supported Hardware

• Intel 5300 Wi-Fi (iwl5300)
• Atheros Wi-Fi (ath9k series)

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License

CSI:GO is licensed under GPLv2, following the original projects.

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Contributing

Pull requests are welcome. Open an issue or contact me directly if you have any suggestions or issues.

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Acknowledgments

• Intel 5300 CSI Tool
• Atheros CSI Tool
• The Linux kernel community