c:/opt/VirtualBox$ ls -l | grep 'r-s'
-r-s--x--x 1 root root   18620 Sep  9 23:16 VBoxHeadless
-r-s--x--x 1 root root    6620 Sep  9 23:16 VBoxNetAdpCtl
-r-s--x--x 1 root root   18616 Sep  9 23:16 VBoxNetDHCP
-r-s--x--x 1 root root   18612 Sep  9 23:16 VBoxSDL
-r-s--x--x 1 root root   18616 Sep  9 23:16 VirtualBox

none             /proc/bus/usb    usbfs       devgid=102,devmode=664 0 0

usbfs            /proc/bus/usb    usbfs       auto             0   0

cat 10*
KERNEL=="vboxdrv", NAME="vboxdrv", OWNER="root", GROUP="root", MODE="0600"
SUBSYSTEM=="usb_device", GROUP="vboxusers", MODE="0664"
SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", GROUP="vboxusers", MODE="0664"

golyaht@boaz:~/testing> ./virtualbox_usb.sh 
VirtualBox PUEL version found.  OK
Name of user used to run VirtualBox: golyaht
usbfs line found in /etc/fstab.  OK.
Here is the usbfs line from /etc/fstab: usbfs /proc/bus/usb usbfs gid=500 0 0
ERROR: No devgid option on usbfs line in /etc/fstab
golyaht@boaz:~/testing>

/dev/disk/by-id/ata-ST3750630AS_9QK1C3A5-part3 swap                 swap       defaults              0 0
/dev/disk/by-id/ata-ST3750630AS_9QK1C3A5-part2 /                    reiserfs   acl,user_xattr        1 1
/dev/disk/by-id/ata-ST3750630AS_9QK1C3A5-part1 /boot                reiserfs   acl,user_xattr        1 2
proc                 /proc                proc       defaults              0 0
sysfs                /sys                 sysfs      noauto                0 0
debugfs              /sys/kernel/debug    debugfs    noauto                0 0
usbfs                /proc/bus/usb        usbfs      gid=500                0 0
devpts               /dev/pts             devpts     mode=0620,gid=5       0 0

#! /bin/bash

# ck_vbox_USB.sh, a quick-and-dirty script to sanity-check host config for VirtualBox USB.

# Usage: no arguments or options

# Change history
# 18oct9 Charles
#    * Added RPM enquiry (and skeleton dpkg enquiry).
# 20oct9 Charles
#    * Added udev rules detection (fstab usbfs line no longer mandatory).
#    * Added vboxdrv kernel module detection.
#    * Added temporary file removal.

# Set up environment
PATH="/usr/bin:/bin:/usr/sbin:/sbin"
set -o nounset
unset IFS
tmp_afn="$(mktemp "/tmp/$0.XXXXXX")"
[[ $? -ne 0 ]] && \echo "ERROR: unable to create temporary file (this is not a VirtualBox USB problem)" >&2 && \exit 1
trap "rm -f $tmp_afn" EXIT

# Set up line feed
lf=$'\n'

function ck_PUEL {

    typeset msg OK_flag ERROR_flag
    OK_flag='NO'
    ERROR_flag='NO'

    # Default (?) VBox config file
    if [[ -r '/etc/vbox/vbox.cfg' ]]; then
        . /etc/vbox/vbox.cfg
        license_afn="$INSTALL_DIR/LICENSE"
        if [[ -r "$license_afn" ]]; then
            if grep 'PUEL' "$license_afn" > /dev/null ; then
                OK_flag='YES'
            else
                ERROR_flag='YES'
            fi
        else
            echo "WARNING: Could not read '$license_afn' identified by /etc/vbox/vbox.cfg" >&2
        fi
    fi

    # RPM
    if type rpm > /dev/null 2>&1 ; then
        case "$( rpm -qi VirtualBox 2>&1 )" in
            *PUEL* )
                OK_flag='YES'
                ;;
            *'is not installed'* )
                ;;
            * )
                ERROR_flag='YES'
        esac
    fi

    # .deb
    if type dpkg > /dev/null 2>&1 ; then
       \echo 'WARNING: this script is not programmed for .deb package systems'
    fi

    # Report findings
    if [[ "$OK_flag" = 'YES' ]]; then
        \echo 'VirtualBox PUEL version found.  OK'
        if [[ "$ERROR_flag" = 'YES' ]]; then
            \echo 'WARNING: VirtualBox non-PUEL version also found.  ???' >&2
        fi
    elif [[ "$ERROR_flag" = 'YES' ]]; then
        \echo 'ERROR: Installed VirtualBox is not the PUEL version so USB not supported' >&2 && \exit 1
    else
        \echo 'WARNING: unable to determine which version of VirtualBox, if any, is installed'
    fi

} # ck_PUEL

# Check for VirtualBox PUEL version
ck_PUEL

# Get user name
while true
do
    \echo -n 'Name of user used to run VirtualBox: '
    read user
    grep "^$user:" /etc/passwd > /dev/null && break
    echo "User $user not found in /etc/passwd. Try again (or Ctrl+C to exit)"
done

# Is VirtualBox using udev rules?
vbox_udev_rules_afn='/etc/udev/rules.d/10-vboxdrv.rules'
if [[ -e "$vbox_udev_rules_afn" ]]; then
    \echo "This computer has udev rules file for VirtualBox, $vbox_udev_rules_afn.  OK"

    # Get group and access mode
    [[ ! -r "$vbox_udev_rules_afn" ]] && \echo "ERROR: $vbox_udev_rules_afn not readable by this script (OK for VirtualBox USB if readable by root)" >&2 && \exit 1
    grep -E '^SUBSYSTEM=="(usb")|(usb_device")' "$vbox_udev_rules_afn" > "$tmp_afn"
    while read line
    do
        IFS=','; array=($line); unset IFS
        for ((i=1; i<${#array[*]}; i++))
        do
            field="${array[$i]}"
            case "$field" in
                *'GROUP="'* )
                    buf="${field#*GROUP=\"}"
                    buf="${buf%\"*}"
                    if [[ "${group:-}" = '' ]];then
                        group="$buf"
                    elif [[ "$buf" != "$group" ]]; then
                        \echo "WARNING: different groups ('$group' and '$buf') in $vbox_udev_rules_afn. Ignoring '$buf'"
                    fi
                    ;;
                *'MODE="'* )
                    buf="${field#*MODE=\"}"
                    buf="${buf%\"*}"
                    if [[ "${mode:-}" = '' ]];then
                        mode="$buf"
                    elif [[ "$buf" != "$mode" ]]; then
                        \echo "WARNING: different modes ('$mode' and '$buf') in $vbox_udev_rules_afn. Ignoring '$buf'"
                    fi
                    ;;
            esac
        done
    done < "$tmp_afn"
    [[ "${group:-}" = '' ]] && \echo "ERROR: No group found for 'usb' or 'usb_device' in $vbox_udev_rules_afn" >&2 && \exit 1
    [[ "${mode:-}" = '' ]] && \echo "ERROR: No mode found for 'usb' or 'usb_device' in $vbox_udev_rules_afn" >&2 && \exit 1

    \echo "Group used for VirtualBox USB access is $group."
else
    # No udev rues -- needs fstab with usbfs line
    \echo "This computer does not have udev rules file for VirtualBox, $vbox_udev_rules_afn. Checking fstab"
    grep -v '^#' /etc/fstab | grep usbfs > /"$tmp_afn"
    while read line
    do
        [[ "${array:-}" != '' ]] && echo "WARNING: More than one usbfs line in /etc/fstab. Effect on VirtualBox unknown$lfHere is fstab:$lf$(cat /etc/fstab)" >&2 && break
        \echo "usbfs line found in /etc/fstab.  OK."
        \echo "Here is the usbfs line from /etc/fstab: "$line

        # Get GID and access mode
        array=($line)
        options="${array[3]}"
        IFS=','; array=($options); unset IFS
        for ((i=0; i<${#array[*]}; i++))
        do
            option="${array[$i]}"
            case "$option" in
                'devgid='* )
                    gid="${option#devgid=}"
                    ;;
                'devmode='* )
                    mode="${option#devmode=}"
                    ;;
            esac
        done
        [[ "${gid:-}" = '' ]] && \echo "ERROR: No devgid option on usbfs line in /etc/fstab" >&2 && \exit 1
        [[ "${mode:-}" = '' ]] && \echo "ERROR: No devmode option on usbfs line in /etc/fstab" >&2 && \exit 1
    done < "$tmp_afn"
    [[ "${array:-}" = '' ]] && echo "ERROR: no usbfs line in /etc/fstab" >&2 && \exit 1
    \echo "Group ID (GID) used for VirtualBox USB access is $gid."
fi

# Check group by name or ID
if [[ "${group:-}" != '' ]]; then
    group_line="$(grep "^$group:" /etc/group)"
    [[ "$group_line" = '' ]] && \echo "ERROR: group '$group' does not exist in /etc/group" >&2 && \exit 1
    \echo "Group $group found in /etc/group.  OK."
    \echo "Here is group $group from /etc/group: $group_line"
else
    group_line="$(grep "^[^:]*:[^:]*:$gid:" /etc/group)"
    [[ "$group_line" = '' ]] && \echo "ERROR: GID $gid does not exist in /etc/group" >&2 && \exit 1
    \echo "GID $gid found in /etc/group.  OK."
    \echo "Here is group $gid from /etc/group: $group_line"
fi
IFS=':'; array=($group_line)
group="${array[0]}"; gid="${array[2]}"
IFS=','; array=(${array[3]}); unset IFS
OK='no'
for ((i=0; i<${#array[*]}; i++))
do
    user_in_group="${array[$i]}"
    case "$user_in_group" in
        "$user" )
            OK='yes'
            break
            ;;
    esac
done
[[ "$OK" = 'no' ]] && \echo "ERROR: User ($user) is not in  GID $gid" >&2 && \exit 1
\echo "User $user is in group $group with GID $gid.  OK."

# Check access mode
# udev rules usually has 4 digits, fstab 3 digits.  Assume it's OK for either to have 3-4 ...
\echo "Access mode used for VirtualBox USB access is $mode."
[[ "${#mode}" -lt 3 ||  "${#mode}" -gt 4 || "${mode//[0-9]/}" != '' ]] && \echo "ERROR: access mode ($mode) is not 3 to 4 integers" >&2 && \exit 1
group_mode="${mode:((${#mode} - 2)):1}"
let group_write=group_mode-4
[[ $group_write -lt 2 ]] && \echo "ERROR: access mode ($mode) does not include 'group write'" >&2 && \exit 1
\echo "Access mode ($mode) includes 'group write'.  OK"

# Check kernel module vboxdrv loaded
if ! lsmod | grep '^vboxdrv' > /dev/null ; then
    \echo "ERROR: kernel module vboxdrv not loaded" >&2 && \exit 1
else
    \echo "Kernel module vboxdrv loaded.  OK"
fi

\echo "All tests passed.  OK.  :-)"

exit 0