Routines Excluded
OpenBSD
Bijan — Tue 26 December 2017

OpenBSD hotplugd scripting

Mount removable USB devices when attached

The OpenBSD hotplugd script

The hotplugd daemon monitors the hotplug(4) pseudo-device, acting on signaled events by executing the scripts in the /etc/hotplug directory.

The following is a modified version of TuM'Fatig's Automount USB stick on OpenBSD. You can also find My OpenBSD Setup post describing my personal experience with OpenBSD as a desktop.

UPDATE 2018-01-21: Since BSDNow guys kindly mentioned this script at one of their latest episode, I managed to look at it again and enhance the script, specifically permission-wise. So mounting MSDOS and NTFS partitions are now done with proper user and grup permissions:

#!/bin/sh

DEVCLASS=$1
DEVNAME=$2
MOUNTROOT="/mnt"
DEBUG=1
mount_helper=/sbin/mount
group_prem=1000
user_perm=1000
export DISPLAY=:0.0
export HOME=/home/bijan

case $DEVCLASS in
2)
    # disk devices
        /sbin/disklabel $DEVNAME 2>&1 | awk -F '[ ]*' '/^  [abd-z]:/' | while read line;
        do
        mount_flags="-o noexec,noatime,nodev"
                slice=`echo $line | awk -F ':' '{print $1}'`
                type=`echo $line | awk -F '[ ]*' '{print $4}'`
                case $type in
        ISO9660 | 4.2BSD)
                        ;;
        ext2fs)
            mount_flags="$mount_flags -r"
            ;;
        NTFS)
            mount_helper=/sbin/mount_ntfs
            mount_flags="$mount_flags -g $group_prem -u $user_perm"
            ;;
        MSDOS)
            mount_helper=/sbin/mount_msdos
            mount_flags="$mount_flags -g $group_prem -u $user_perm"
            ;;
        *)
            continue
            ;;
                esac

                [ $DEBUG == 1 ] && logger -i "hotplugd attaching SLICE $slice of DEVICE $DEVNAME"
        [ ! -d $MOUNTROOT/$DEVNAME$slice ] && mkdir -p -m 1777 $MOUNTROOT/$DEVNAME$slice
        $mount_helper $mount_flags /dev/$DEVNAME$slice $MOUNTROOT/$DEVNAME$slice
        /usr/local/bin/notify-send "Mounted $DEVNAME$slice ($type)"
        done
        ;;
3)
    # network devices; requires hostname.$DEVNAME
    sh /etc/netstart $DEVNAME
    ;;
esac

Original:

$ doas rcctl enable hotplugd
$ cat /etc/hotplug/attach
#!/bin/sh

DEVCLASS=$1
DEVNAME=$2
MOUNTROOT="/mnt"
DEBUG=1
export DISPLAY=:0.0
export HOME=/home/bijan

case $DEVCLASS in
2)
        # disk devices
        /sbin/disklabel $DEVNAME 2>&1 | awk -F '[ ]*' '/^  [abd-z]:/' | while read line;
        do
                slice=`echo $line | awk -F ':' '{print $1}'`
                fs=`echo $line | awk -F '[ ]*' '{print $4}'`
                case $fs in
                MSDOS | ISO9660 | ext2fs | 4.2BSD)
                        [ $DEBUG == 1 ] && logger -i "hotplugd attaching SLICE $slice of DEVICE $DEVNAME"
                        [ ! -d $MOUNTROOT/$DEVNAME$slice ] && mkdir -p -m 1777 $MOUNTROOT/$DEVNAME$slice
                        mount -o ro /dev/$DEVNAME$slice $MOUNTROOT/$DEVNAME$slice;
                        /usr/local/bin/notify-send "Mounted $DEVNAME$slice ($fs)"
                        ;;
                esac
        done
        ;;
3)
    # network devices; requires hostname.$DEVNAME
    sh /etc/netstart $DEVNAME
    ;;
esac