Module development

Module Development

The Architecture

If you want to develop custom payloads, you have to understand how P4wnP1 includes files and invokes functions. When the P4wnP1 boots, the P4wnP1.service is run which invokes the file boot/boot_P4wnP1
It it reads the setup.cfg and the payload in payload/$PAYLOAD which overrides variables defined in setup.cfg. Since this happens at the start, any functionality thats outside the callbacks (seen below) is executed immediately! When P4wnP1 configures the different gadgets, it looks at the variables defined earlier by the setup.cfg and the selected payload.
When running through this routine, P4wnP1 uses declare -f <callback function> > /dev/null && <callback function> to determine if callback function is defined and executes it when it is.
Available callbacks are (listed by their usual sequence of execution:

1. onNetworkUp (gets called when the target connected to the interface)
2. onTargetGotIP (gets called when the target got an IP-address assigned by the P4wnP1)
3. onKeyboardUp (gets called when the target finished installing the driver)
4. onLogin (gets called when somebody ssh's into P4wnP1)

Note: This order isn't guaranteed since some functions are run asynchronously.

Available utility functions:

In addition to having the freedom of bash and 3rd party tools, P4wnP1 comes also in equipped with various functions to interface with its USB-Gadget abilities:

• duckhid,outhid & mousescript Detailed description here
• led_blink Usage: led_blink <blink amount> Causes the Pi's onboard Led to blink times. led_blink 0: Off led_blink 255: On led_blink x blink for x times. blink-cycles are 0.3s long and pause is 0.8s long.

Available utility variables:

• WIFI bool determines if wlan0 interface is present (can be used to check if the Pi has wireless capabilities)

• WIFI_CLIENT_CONNECTION_SUCCESS bool determines if connecting as a wifi client went successful Note: These are supposed to be read-only and only accessible inside the callbacks since this might cause unexpected behavior in the boot process!

• Every setting in setup.cfg these are supposed to be overridden outside the callback functions, not during the boot process

Styleguide

TODO

payload/template.txt is a good place to start and it contains some further documentation.