From 7c9f908f8658126bbe0e9da9dc71be3db45bf940 Mon Sep 17 00:00:00 2001 From: Andrew Topp Date: Fri, 9 May 2025 18:17:01 +1000 Subject: policy: T5069: large-community-list regex validator should allow whitespace * Re-introduce the whitespace/pattern matches ' ' and '_' as allowed * Perform a general Python regex validity check (not 100% 1003.2, but in combination with allowedChars, pretty close) * Introduce a warning against potentially malformed or over-complex patterns, but leave it up to the user to resolve - there are plenty of useful expressions we cannot validate easily --- src/conf_mode/policy.py | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'src/conf_mode/policy.py') diff --git a/src/conf_mode/policy.py b/src/conf_mode/policy.py index a90e33e81..ec9005890 100755 --- a/src/conf_mode/policy.py +++ b/src/conf_mode/policy.py @@ -14,6 +14,7 @@ # You should have received a copy of the GNU General Public License # along with this program. If not, see . +import re from sys import exit from vyos.config import Config @@ -24,9 +25,20 @@ from vyos.frrender import get_frrender_dict from vyos.utils.dict import dict_search from vyos.utils.process import is_systemd_service_running from vyos import ConfigError +from vyos.base import Warning from vyos import airbag airbag.enable() +# Sanity checks for large-community-list regex: +# * Require complete 3-tuples, no blank members. Catch missed & doubled colons. +# * Permit appropriate community separators (whitespace, underscore) +# * Permit common regex between tuples while requiring at least one separator +# (eg, "1:1:1_.*_4:4:4", matching "1:1:1 4:4:4" and "1:1:1 2:2:2 4:4:4", +# but not "1:1:13 24:4:4") +# Best practice: stick with basic patterns, mind your wildcards and whitespace. +# Regex that doesn't match this pattern will be allowed with a warning. +large_community_regex_pattern = r'([^: _]+):([^: _]+):([^: _]+)([ _]([^:]+):([^: _]+):([^: _]+))*' + def community_action_compatibility(actions: dict) -> bool: """ Check compatibility of values in community and large community sections @@ -147,6 +159,10 @@ def verify(config_dict): if 'regex' not in rule_config: raise ConfigError(f'A regex {mandatory_error}') + if policy_type == 'large_community_list': + if not re.fullmatch(large_community_regex_pattern, rule_config['regex']): + Warning(f'"policy large-community-list {instance} rule {rule} regex" does not follow expected form and may not match as expected.') + if policy_type in ['prefix_list', 'prefix_list6']: if 'prefix' not in rule_config: raise ConfigError(f'A prefix {mandatory_error}') -- cgit v1.2.3