yunohost/data/helpers.d/filesystem

CAN_BIND=${CAN_BIND:-1}

# Mark a file or a directory for backup
# Note: currently, SRCPATH will be copied or binded to DESTPATH
#
# usage: ynh_backup srcdir destdir to_bind no_root
# | arg: srcdir - directory to bind or copy
# | arg: destdir - mountpoint or destination directory
# | arg: to_bind - 1 to bind mounting the directory if possible
# | arg: no_root - 1 to execute commands as current user
ynh_backup() {
    local SRCPATH=$1
    local DESTPATH=$2
    local TO_BIND=${3:-0}
    local SUDO_CMD="sudo"
    [[ "${4:-}" = "1" ]] && SUDO_CMD=

    # validate arguments
    [[ -e "${SRCPATH}" ]] || {
        echo "Source path '${SRCPATH}' does not exist" >&2
        return 1
    }

    # prepend the backup directory
    [[ -n "${YNH_APP_BACKUP_DIR:-}" && "${DESTPATH:0:1}" != "/" ]] \
        && DESTPATH="${YNH_APP_BACKUP_DIR}/${DESTPATH}"
    [[ ! -e "${DESTPATH}" ]] || {
        echo "Destination path '${DESTPATH}' already exist" >&2
        return 1
    }

    # attempt to bind mounting the directory
    if [[ "${CAN_BIND}" = "1" && "${TO_BIND}" = "1" ]]; then
        eval $SUDO_CMD mkdir -p "${DESTPATH}"

        if sudo mount --rbind "${SRCPATH}" "${DESTPATH}"; then
            # try to remount destination directory as read-only
            sudo mount -o remount,ro,bind "${SRCPATH}" "${DESTPATH}" \
              || true
            return 0
        else
            CAN_BIND=0
            echo "Bind mounting seems to be disabled on your system."
            echo "You have maybe to check your apparmor configuration."
        fi

        # delete mountpoint directory safely
        mountpoint -q "${DESTPATH}" && sudo umount -R "${DESTPATH}"
        eval $SUDO_CMD rm -rf "${DESTPATH}"
    fi

    # ... or just copy the directory
    eval $SUDO_CMD mkdir -p $(dirname "${DESTPATH}")
    eval $SUDO_CMD cp -a "${SRCPATH}" "${DESTPATH}"
}

# Deprecated helper since it's a dangerous one!
ynh_bind_or_cp() {
    local AS_ROOT=${3:-0}
    local NO_ROOT=0
    [[ "${AS_ROOT}" = "1" ]] || NO_ROOT=1
    echo "This helper is deprecated, you should use ynh_backup instead" >&2
    ynh_backup "$1" "$2" 1 "$NO_ROOT"
}

# Create a directory under /tmp
#
# Deprecated helper
#
# usage: ynh_mkdir_tmp
# | ret: the created directory path
ynh_mkdir_tmp() {
    echo "The helper ynh_mkdir_tmp is deprecated." >&2
    echo "You should use 'mktemp -d' instead and manage permissions \
properly with chmod/chown." >&2
    local TMP_DIR=$(mktemp -d)

    # Give rights to other users could be a security risk.
    # But for retrocompatibility we need it. (This helpers is deprecated)
    chmod 755 $TMP_DIR
    echo $TMP_DIR
}

# Calculate and store a file checksum into the app settings
#
# $app should be defined when calling this helper
#
# usage: ynh_store_file_checksum file
# | arg: file - The file on which the checksum will performed, then stored.
ynh_store_file_checksum () {
	local checksum_setting_name=checksum_${1//[\/ ]/_}	# Replace all '/' and ' ' by '_'
	ynh_app_setting_set $app $checksum_setting_name $(sudo md5sum "$1" | cut -d' ' -f1)
}

# Verify the checksum and backup the file if it's different
# This helper is primarily meant to allow to easily backup personalised/manually 
# modified config files.
#
# $app should be defined when calling this helper
#
# usage: ynh_backup_if_checksum_is_different file
# | arg: file - The file on which the checksum test will be perfomed.
#
# | ret: Return the name a the backup file, or nothing
ynh_backup_if_checksum_is_different () {
	local file=$1
	local checksum_setting_name=checksum_${file//[\/ ]/_}	# Replace all '/' and ' ' by '_'
	local checksum_value=$(ynh_app_setting_get $app $checksum_setting_name)
	if [ -n "$checksum_value" ]
	then	# Proceed only if a value was stored into the app settings
		if ! echo "$checksum_value $file" | sudo md5sum -c --status
		then	# If the checksum is now different
			backup_file="/home/yunohost.conf/backup/$file.backup.$(date '+%Y%m%d.%H%M%S')"
			sudo mkdir -p "$(dirname "$backup_file")"
			sudo cp -a "$file" "$backup_file"	# Backup the current file
			echo "File $file has been manually modified since the installation or last upgrade. So it has been duplicated in $backup_file" >&2
			echo "$backup_file"	# Return the name of the backup file
		fi
	fi
}

# Remove a file or a directory securely
#
# usage: ynh_secure_remove path_to_remove
# | arg: path_to_remove - File or directory to remove
ynh_secure_remove () {
	path_to_remove=$1
	forbidden_path=" \
	/var/www \
	/home/yunohost.app"

	if [[ "$forbidden_path" =~ "$path_to_remove" \
		# Match all paths or subpaths in $forbidden_path
		|| "$path_to_remove" =~ ^/[[:alnum:]]+$ \
		# Match all first level paths from / (Like /var, /root, etc...)
		|| "${path_to_remove:${#path_to_remove}-1}" = "/" ]]
		# Match if the path finishes by /. Because it seems there is an empty variable
	then
		echo "Avoid deleting $path_to_remove." >&2
	else
		if [ -e "$path_to_remove" ]
		then
			sudo rm -R "$path_to_remove"
		else
			echo "$path_to_remove wasn't deleted because it doesn't exist." >&2
		fi
	fi
}