naveensd101 / char-driver

A simple character driver for linux kernel 5.11.0 which implements the Caesar Cipher

TODO

• pdf project report
• source code
• Readme

Contents of Report

• Problem Statement
• Methodology
• Explanation
• APIs involved/Flow charts if any
• Screenshots

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Simple Caesar Cipher Driver

To run our Driver use the following commands

• make
  • To compile the driver code

• insmod charenc.ko
  • To load the driver to the kernel

• dmesg
  • print or control the kernel message buffer

• mknod -m 777 /dev/charenc c <major-number> <minor-number>
  • This creates a device file with read write and execute permission

Existency check for driver and device

• lsmod
  • Displays all the drivers loaded to the kernel

• cat /proc/devices
  • Displays all the connected devices

User process

• python userProg.py
  • Opens the device file and writes "abczf" into the device file
  • Prints the encrypted text
  • Closes the file
• cat userProg.py
  • Displays the source code
• cat /dev/charenc
  • Shows decrypted text (ie. after closing the file)

Cleanup

• rmmod charenc
  • Unloads the driver
• rm /dev/charenc
  • Removes the device