This document provides a learning track for people new to the Linux wireless world who are self-learners. It outlines key areas to focus on including the kernel side, control path, data path, and driver reference. It recommends cloning necessary repositories, familiarizing with MAC drivers and modules, understanding the interaction between applications and the driver/firmware, and using the mac80211_hwsim driver for testing without real hardware. References for further reading on protocols are also provided.

1. Linux Wireless Kickstart
Table of Contents
Intro......................................................................................................................................................2
SCM/Version Control......................................................................................................................2
Understanding "upstream"...............................................................................................................2
Userspace apps.................................................................................................................................2
Learning Track......................................................................................................................................3
Kernel side.......................................................................................................................................3
Control Path.....................................................................................................................................3
Data Path..........................................................................................................................................3
Driver Reference..............................................................................................................................3
Testing..............................................................................................................................................4

2. This is for people who are new to opensource Linux wireless world and are self-learners.
Intro
SCM/Version Control
Git:
"git.kernel.org" has list of all repos and its respective maintainers
Understanding "upstream"
The below links should give full details on the kernel side.
https://wireless.wiki.kernel.org/en/developers/documentation/
https://wireless.wiki.kernel.org/en/developers/process
<repo>-next: indicates latest DEV snapshot, <repo> - indicates a stable snapshot.
Tools
https://www.kernel.org/doc/html/latest/dev-tools/index.html
Userspace apps
Setup and install hostap.git: https://w1.fi/cgit/hostap/
Setup and install iw: http://git.kernel.org/?p=linux/kernel/git/jberg/iw.git
https://w1.fi/wpa_supplicant/devel/

3. Learning Track
These are the rough roadmap and high level milestones to aid in self-learning.
For a overview diagram and details refer https://wire-less-comm.blogspot.com/2013/01/wireless-
lan-and-linux-together.html
Kernel side
• clone all necessary repos
• kernel Compilation and understanding build system for customization.
• setup build and code browsing environment
◦ ctags, cscope, csope + vim/gvim
• familiarity with FMAC and SMAC drivers
• familiarity with cfg80211 & mac80211 modules
Control Path
• wpa_supplicant to cfg80211 interaction (nl80211/wext)
• Track Scan from iw/wpa_supplicant to driver/FW
• Track Scan from network manager to driver/FW
Data Path
• tcp/ip stack interaction in FMAC/SMAC architectures.
• socket layer functionality and performance tuning
• Qdisc layer and understanding profiles
• Queue Management/flow control in data path (including QoS) in Driver.
Driver Reference
The apps and stack are common but there are plenty of driver, so, for any driver reference I would
recommend using below drivers, choose a FMAC (qtnfmac/ath6kl/wil6210) and SMAC driver
(iwlwifi/ath10k, most laptops should have this).
drivers/net/wireless/ath
drivers/net/wireless/intel
drivers/net/wireless/mac80211_hwsim.c (best starting point)

4. Testing
drivers/net/wireless/mac80211_hwsim.c (SMAC driver with no Real HW)
- creates wlan0 and wlan1,
- you can run wpa_supplicant on wlan0 and hostapd on wlan1 and make a connection,
- modify/add debugs in wpa_supplicant/hostapd/cfg80211/mac80211 to get deeper understanding.
Protocol
https://www.amazon.in/802-11-Wireless-Networks-Definitive-Guide/dp/1491963549
https://www.amazon.in/802-11ac-Survival-Guide-Gigabit-Beyond-ebook/dp/B00FM0OC66/
ref=dp_kinw_strp_1 (Free PDF available)