def _parse_check(rule):
    """Parse a single base check rule into an appropriate Check object."""

    # Handle the special checks
    if rule == '!':
        return FalseCheck()
    elif rule == '@':
        return TrueCheck()

    try:
        kind, match = rule.split(':', 1)
    except Exception:
        LOG.exception(_LE("Failed to understand rule %s") % rule)
        # If the rule is invalid, we'll fail closed
        return FalseCheck()

    # Find what implements the check
    if kind in _checks:
        return _checks[kind](kind, match)
    elif None in _checks:
        return _checks[None](kind, match)
    else:
        LOG.error(_LE("No handler for matches of kind %s") % kind)
        return FalseCheck()
Example #2
0
def _parse_check(rule):
    """Parse a single base check rule into an appropriate Check object."""

    # Handle the special checks
    if rule == '!':
        return FalseCheck()
    elif rule == '@':
        return TrueCheck()

    try:
        kind, match = rule.split(':', 1)
    except Exception:
        LOG.exception(_LE("Failed to understand rule %s") % rule)
        # If the rule is invalid, we'll fail closed
        return FalseCheck()

    # Find what implements the check
    if kind in _checks:
        return _checks[kind](kind, match)
    elif None in _checks:
        return _checks[None](kind, match)
    else:
        LOG.error(_LE("No handler for matches of kind %s") % kind)
        return FalseCheck()
def _parse_text_rule(rule):
    """Parses policy to the tree.

    Translates a policy written in the policy language into a tree of
    Check objects.
    """

    # Empty rule means always accept
    if not rule:
        return TrueCheck()

    # Parse the token stream
    state = ParseState()
    for tok, value in _parse_tokenize(rule):
        state.shift(tok, value)

    try:
        return state.result
    except ValueError:
        # Couldn't parse the rule
        LOG.exception(_LE("Failed to understand rule %s") % rule)

        # Fail closed
        return FalseCheck()
Example #4
0
def _parse_text_rule(rule):
    """Parses policy to the tree.

    Translates a policy written in the policy language into a tree of
    Check objects.
    """

    # Empty rule means always accept
    if not rule:
        return TrueCheck()

    # Parse the token stream
    state = ParseState()
    for tok, value in _parse_tokenize(rule):
        state.shift(tok, value)

    try:
        return state.result
    except ValueError:
        # Couldn't parse the rule
        LOG.exception(_LE("Failed to understand rule %s") % rule)

        # Fail closed
        return FalseCheck()