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_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()
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()