NAPI Network Driver

An example Linux kernel network driver implementing the NAPI (New API) polling model. The code is heavily commented and intended for students exploring kernel-level networking.

---

Highlights

• NAPI integration – registers a struct napi_struct, uses napi_schedule() / napi_complete() for efficient RX handling under high load.
• DMA ring buffers – demonstrates coherent DMA allocation for TX/RX packet transfer.
• Multicast & VLAN support – shows how to program hardware filters and maintain a VLAN table.
• Interrupt handling – unified ISR processes RX/TX/error bits and wakes the network queue.
• Config-time hooks – implements ndo_change_mtu, ndo_set_config, etc.

---

Build Instructions

1. Install kernel headers matching your running kernel.
2. Create a simple Makefile:

   obj-m += Network-Driver.o
   all:
       make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
   clean:
       make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

3. Build:

   make

4. Load the module (replace IRQ / I/O addresses as needed):

   sudo insmod Network-Driver.ko

5. Check dmesg for init logs and confirm interface appears with ip link.

---

Repository Layout

Network-Driver.c   # Kernel module source
README.md          # Documentation

---

Disclaimer

This driver does not interact with real hardware; many register offsets are placeholders (0xYOUR_*). It serves only as an educational template.
License: GPL-2.0