Driving a USB Rocket Launcher from Perl in User Space

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Driving a USB Rocket Launcher from Perl in User
Space

• Mike Schilli, Yahoo!
• 06/23/2009 YAPC, Pittsburgh, PA

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Goals

• How can I use USB gadgets on Linux, even if they
  only come with a Windows driver?

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USB A versatile technology
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USB A versatile technology
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USB A versatile technology
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USB A versatile technology
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Limited Fun on Windows
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Unlimited Fun with Perl

• Defend your Cubicle
• Burglar Alarm with Web Cam and Rocket Launcher

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USB Architecture
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USB Hierarchy
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USB Hierarchy
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USB Hierarchy
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Plug it in
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Plug it in
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Plug it in
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USB Architecture
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USB Architecture
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USB Architecture
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Device Drivers

• Often not available for Linux, just for
  Windows/Mac
• Hard to write
• Highly dependent on kernel version
• Vendors dont want to bother with niche markets

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USB Architecture
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libusb

• Drivers in User Space
• http//libusb.sourceforge.net
• Problem How to find a device?

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Plug it in
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USB Architecture
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USB Architecture
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Install Everything
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USB Rules to set Permissions
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Plug it in
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RocketBaby
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USB Architecture

• Control Transfers (config control)?
• Bulk Transfers (large quantities of
  time-sensitive data)?
• Interrupt Transfers (small amounts of
  time-sensitive data)?
• Isochronous Transfers (real-time data at
  predictable rates)?

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Reverse Engineering Efforts

• RocketBaby comes with Win XP driver
• Protocol sniffed out with USBSniff
• .DLL code investigated with IDA Pro Disassembler
  (see references)?
• Control Transfers for turn/raise/lower/fire
• Bulk Transfers for reading status

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Reverse Engineering Efforts

• Control Transfers (config control)?
• Bulk Transfers (large quantities of
  time-sensitive data)?
• Interrupt Transfers (small amounts of
  time-sensitive data)?
• Isochronous Transfers (real-time data at
  predictable rates)?

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Demo
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Demo

• Attention in the splash zone!
• Incoming rockets!

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References

• Video The Great Office War http//www.youtube.co
  m/watch?vpVKnF26qFFM
• Alessandro Rubini, Linux Device Drivers
  http//lwn.net/images/pdf/LDD3/ch13.pdf
• Essential Linux Device Drivers, Sreekrishnan
  Venkateswaren, Prentice Hall, 2007
• RocketBaby Reverse Engineering Efforts
  http//dvlabs.tippingpoint.com/blog/2009/02/12/pyt
  hon-interfacing-a-usb-missile-launcher