View source for Bbb sniffer

This page explains how to setup a USB sniffer on the BeagleBone Black.<br />
This is possible thanks to the [https://github.com/dominicgs/USBProxy USBProxy] project.

=Requirements=

* a BeagleBone Black
* a micro SD card

=SD card setup=

This section explains how to setup the SD card on a Linux desktop.

 mkdir ~/bbb
 cd ~/bbb

 wget <nowiki>http://debian.beagleboard.org/images/bone-debian-7.5-2014-05-14-2gb.img.xz</nowiki>
 md5sum bone-debian-7.5-2014-05-14-2gb.img.xz
(result should be 35877ce21e8ed0eb1bdc6819ad71c317)
 xz --stdout -d bone-debian-7.5-2014-05-14-2gb.img.xz | sudo dd of=/dev/sdX bs=4096
 sync
Where /dev/sdX is the sdcard device. Don't try anything if you don't know what 'X' should be (you could wipe your hard drive).

Remove the sdcard.

 wget <nowiki>https://github.com/RobertCNelson/linux-dev/archive/3.8.13-bone50.tar.gz</nowiki>
 tar xzvf 3.8.13-bone50.tar.gz 
 cd linux-dev-3.8.13-bone50/

If needed, modify tools/host_det.sh so that it detects your Linux distribution.

 ./build_kernel.sh

This script will eventually tell you to run commands to install missing packages, e.g.:
 sudo apt-get update
 sudo apt-get install device-tree-compiler lzma

 ./build_kernel.sh

Patch and rebuild USB gadget modules:

 cd KERNEL/drivers/usb/gadget/
 wget <nowiki>https://raw.githubusercontent.com/dominicgs/USBProxy/master/doc/inode.c.patch</nowiki>
 patch < inode.c.patch
 cd ~/bbb/linux-dev-3.8.13-bone50
 ./tools/rebuild.sh

Insert and mount the sdcard (e.g. to /mnt/rootfs).

 cp ~/bbb/linux-dev-3.8.13-bone50/KERNEL/drivers/usb/gadget/*.ko /mnt/rootfs/lib/modules/3.8.13-bone50/kernel/drivers/usb/gadget/

Modify the /mnt/rootfs/opt/scripts/boot/am335x_evm.sh file so that the usb0 related lines are commented out.

Unmount the sdcard, plug it in the BBB, and power it on.

=USBProxy installation=

This section explains how to install USBProxy on the BeagleBone Black.

 depmod -a

 apt-get install libudev-dev

 mkdir sniffer
 cd sniffer
 wget <nowiki>https://github.com/libusb/libusb/archive/v1.0.19.tar.gz</nowiki>
 tar xzvf v1.0.19.tar.gz
 cd libusb-1.0.19/
 ./bootstrap.sh
 ./configure
 make
 make install

 mv /etc/ld.so.conf.d/libc.conf /etc/ld.so.conf.d/aa_libc.conf
 ldconfig

Install USBProxy as explained in the [https://github.com/dominicgs/USBProxy/blob/master/README.md README].

Install tcpdump:
 apt-get install tcpdump

=Sniff=

The pcap logger included in USBProxy has many issues.<br />
I recommend using usbmon and tcpdump instead.

Start tcpdump:
 modprobe usbmon
 tcpdump -i usbmon1 -w capture.pcap

Start USBProxy:
 usb-mitm

The capture.pcap file can be opened with wireshark.