ddwrt-ovpn-client-backup.sh

#!/bin/sh
#set -x # uncomment/comment to enable/disable debug mode

#     name: ddwrt-ovpn-client-backup.sh
#  version: 1.0.0b (beta), 18-aug-2020, by eibgrad
#  purpose: backup/restore openvpn client configuration
#
#  usage: ddwrt-ovpn-client-backup.sh name [options]
#    options:
#      --backup    (optional/default) backup openvpn client config by name
#      --restore   restore named openvpn client config
#      --nocommit  do NOT commit restored openvpn client config to nvram
#
#  example usage:
#    ddwrt-ovpn-client-backup.sh expressvpn
#    ddwrt-ovpn-client-backup.sh expressvpn --backup
#    ddwrt-ovpn-client-backup.sh expressvpn --restore
#    ddwrt-ovpn-client-backup.sh expressvpn --restore --nocommit

# ------------------------------ BEGIN OPTIONS ------------------------------- #

# configuration directory (optional: use $name to embed backup name)
CONFIG_DIR='/jffs/openvpn/client/$name/config'

# ------------------------------- END OPTIONS -------------------------------- #

# ---------------------- DO NOT CHANGE BELOW THIS LINE ----------------------- #

backup() {
    _query() {
        local reply

        read -p "$1 " reply
        [ "$reply" ] && echo "$reply" || echo "$2"
    }

    # obtain permission to overwrite existing files
    if [ -d $CONFIG_DIR ] && [ "$(ls -A $CONFIG_DIR)" ]; then
        while :; do
            case $(_query 'Overwrite existing files (yes/[no])?' no) in
                yes) break;;
                 no) { echo 'Aborted.'; exit 0; };;
            esac
        done
    fi

    # create/cleanup store
    [ -d $CONFIG_DIR ] && rm -f $CONFIG_DIR/* || mkdir -p $CONFIG_DIR

    # backup openvpn client configuration
    nvram show 2>/dev/null | grep -Eo '^openvpncl[^=]*' | \
        while read var; do
            nvram get $var | tr -d '\r' > $CONFIG_DIR/$var
        done
}

restore() {
    [ -d $CONFIG_DIR ] || \
        { echo "ERROR: Directory <$CONFIG_DIR> not found."; exit 1; }

    [ "$(ls -A $CONFIG_DIR)" ] || \
        { echo "ERROR: Directory <$CONFIG_DIR> is empty."; exit 1; }

    # restore openvpn client configuration
    find $CONFIG_DIR -type f -exec sh -c 'nvram set $(basename {})="$(cat {})"' \;

    # commit changes (optional)
    [ ${NOCOMMIT+x} ] || nvram commit
}

[ "$1" ] || { echo 'Nothing to do.'; exit 0; }

# assume backup mode (the default) and name argument
mode='backup'; name="${1//[[:space:]]/}"; shift

# process command line options/arguments
while [ $# -gt 0 ]; do
    case $1 in
        --backup  ) mode='backup';;
        --restore ) mode='restore';;
        --nocommit) NOCOMMIT=;;
        *) { echo "ERROR: Invalid option/argument: $1"; exit 1; }
    esac
    shift
done

# validate input
[ "$name" ] || { echo 'ERROR: Missing name argument.'; exit 1; }
[[ "$mode" == 'backup' && "${NOCOMMIT+x}" ]] && \
    echo 'WARNING: --nocommit ignored; only valid with --restore option.'

# backup name may be embedded in configuration directory; resolve it
eval CONFIG_DIR="${CONFIG_DIR//[[:space:]]/}"

# perform the requested operation
$mode

echo 'Done.'
exit 0