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