usbcap

#!/bin/bash
#
# Copyright (C) 2011 Austin Leirvik <aua at pdx.edu>
# Copyright (C) 2011 Wil Cooley <wcooley at pdx.edu>
# Copyright (C) 2011 Joanne McBride <jirab21@yahoo.com>
# Copyright (C) 2011 Danny Aley <danny.aley@gmail.com>
# Copyright (C) 2011 Erich Ulmer <blurrymadness@gmail.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

 
# check for tcpdump
[[ -x `which tcpdump` ]] || { echo "Couldn't find tcpdump." >&2; exit 1; }

# check for debugfs
[[ `stat -f /sys/kernel/debug` = *debugfs* ]] || { echo -e "debugfs not mounted -- try\nmount -t debugfs none_debugs /sys/kernel/debug" >&2; exit 1; }

# check for usbmon
[[ -f '/sys/kernel/debug/usb/usbmon/0u' ]] || { echo -e "usbmon not loaded -- try\nmodprobe usbmon" >&2; exit 1; }

# check for valid bus (default is 0)
bus=${1:-0}
[[ $bus != *[!0-9]* ]] || { echo -e "Invalid bus number $bus.\nUsage: $0 [busnum]" >&2; exit 1; }

tcpdump -i usbmon${bus}u -U -w - || { echo "tcpdump failed. Maybe try with sudo?" >&2; exit 1; }