Kernel Module Logic

• Specify the module initialization entry function wg_device_init
• Register the virtual network device rtnl_link_register(&link_ops)
• Initialize the net_device struct via wg_setup
• Specify the initialization operation for the ip link add command (where the main functional logic resides) wg_newlink
• Specify the operation when the virtual network device is brought up wg_open
• Specify the operation when the virtual network device is stopped wg_stop
• Specify the operation when the virtual network device starts transmitting the first packet wg_xmit
• The WireGuard initialization steps are:
  • Add a virtual network device via ip link add dev wg0 type wireguard
  • Configure the virtual network device address via ip addr add 10.0.0.4/24 dev wg0
  • Apply WireGuard configuration via wg set wg0
  • Bring up the virtual network device via ip link set wg0 up
• Therefore, we should first look at the logic of wg_newlink, then the logic of wg_open