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authorsarthurdev <965089+sarthurdev@users.noreply.github.com>2021-07-28 12:03:21 +0200
committersarthurdev <965089+sarthurdev@users.noreply.github.com>2021-12-06 21:20:49 +0100
commitfdeba8da3e99256fe449e331d0b833a941315226 (patch)
treec6181ec7b84796a52a72d61e7d89ad6974f6f5f6 /src/conf_mode/firewall.py
parent025f0609cea8591e93b8cb4a7d0256e43e23323b (diff)
downloadvyos-1x-fdeba8da3e99256fe449e331d0b833a941315226.tar.gz
vyos-1x-fdeba8da3e99256fe449e331d0b833a941315226.zip
firewall: T2199: Migrate firewall to XML/Python
Diffstat (limited to 'src/conf_mode/firewall.py')
-rwxr-xr-xsrc/conf_mode/firewall.py267
1 files changed, 256 insertions, 11 deletions
diff --git a/src/conf_mode/firewall.py b/src/conf_mode/firewall.py
index 8e6ce5b14..5ac48c9ba 100755
--- a/src/conf_mode/firewall.py
+++ b/src/conf_mode/firewall.py
@@ -16,50 +16,295 @@
import os
+from glob import glob
+from json import loads
from sys import exit
from vyos.config import Config
from vyos.configdict import dict_merge
-from vyos.configdict import node_changed
-from vyos.configdict import leaf_node_changed
+from vyos.configdiff import get_config_diff, Diff
from vyos.template import render
-from vyos.util import call
+from vyos.util import cmd
+from vyos.util import dict_search_args
+from vyos.util import process_named_running
+from vyos.util import run
+from vyos.xml import defaults
from vyos import ConfigError
from vyos import airbag
-from pprint import pprint
airbag.enable()
+nftables_conf = '/run/nftables.conf'
-def get_config(config=None):
+sysfs_config = {
+ 'all_ping': {'sysfs': '/proc/sys/net/ipv4/icmp_echo_ignore_all', 'enable': '0', 'disable': '1'},
+ 'broadcast_ping': {'sysfs': '/proc/sys/net/ipv4/icmp_echo_ignore_broadcasts', 'enable': '0', 'disable': '1'},
+ 'ip_src_route': {'sysfs': '/proc/sys/net/ipv4/conf/*/accept_source_route'},
+ 'ipv6_receive_redirects': {'sysfs': '/proc/sys/net/ipv6/conf/*/accept_redirects'},
+ 'ipv6_src_route': {'sysfs': '/proc/sys/net/ipv6/conf/*/accept_source_route', 'enable': '0', 'disable': '-1'},
+ 'log_martians': {'sysfs': '/proc/sys/net/ipv4/conf/all/log_martians'},
+ 'receive_redirects': {'sysfs': '/proc/sys/net/ipv4/conf/*/accept_redirects'},
+ 'send_redirects': {'sysfs': '/proc/sys/net/ipv4/conf/*/send_redirects'},
+ 'source_validation': {'sysfs': '/proc/sys/net/ipv4/conf/*/rp_filter', 'disable': '0', 'strict': '1', 'loose': '2'},
+ 'syn_cookies': {'sysfs': '/proc/sys/net/ipv4/tcp_syncookies'},
+ 'twa_hazards_protection': {'sysfs': '/proc/sys/net/ipv4/tcp_rfc1337'}
+}
+
+preserve_chains = [
+ 'INPUT',
+ 'FORWARD',
+ 'OUTPUT',
+ 'VYOS_FW_IN',
+ 'VYOS_FW_OUT',
+ 'VYOS_FW_LOCAL',
+ 'VYOS_FW_OUTPUT',
+ 'VYOS_POST_FW',
+ 'VYOS_FRAG_MARK',
+ 'VYOS_FW6_IN',
+ 'VYOS_FW6_OUT',
+ 'VYOS_FW6_LOCAL',
+ 'VYOS_FW6_OUTPUT',
+ 'VYOS_POST_FW6',
+ 'VYOS_FRAG6_MARK'
+]
+
+valid_groups = [
+ 'address_group',
+ 'network_group',
+ 'port_group'
+]
+
+snmp_change_type = {
+ 'unknown': 0,
+ 'add': 1,
+ 'delete': 2,
+ 'change': 3
+}
+snmp_event_source = 1
+snmp_trap_mib = 'VYATTA-TRAP-MIB'
+snmp_trap_name = 'mgmtEventTrap'
+def get_firewall_interfaces(conf):
+ out = {}
+ interfaces = conf.get_config_dict(['interfaces'], key_mangling=('-', '_'), get_first_key=True,
+ no_tag_node_value_mangle=True)
+ def find_interfaces(iftype_conf, output={}, prefix=''):
+ for ifname, if_conf in iftype_conf.items():
+ if 'firewall' in if_conf:
+ output[prefix + ifname] = if_conf['firewall']
+ for vif in ['vif', 'vif_s', 'vif_c']:
+ if vif in if_conf:
+ output.update(find_interfaces(if_conf[vif], output, f'{prefix}{ifname}.'))
+ return output
+ for iftype, iftype_conf in interfaces.items():
+ out.update(find_interfaces(iftype_conf))
+ return out
+
+def get_config(config=None):
if config:
conf = config
else:
conf = Config()
- base = ['nfirewall']
+ base = ['firewall']
+
+ if not conf.exists(base):
+ return {}
+
firewall = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True,
no_tag_node_value_mangle=True)
- pprint(firewall)
+ default_values = defaults(base)
+ firewall = dict_merge(default_values, firewall)
+
+ firewall['interfaces'] = get_firewall_interfaces(conf)
+
+ if 'config_trap' in firewall and firewall['config_trap'] == 'enable':
+ diff = get_config_diff(conf)
+ firewall['trap_diff'] = diff.get_child_nodes_diff_str(base)
+ firewall['trap_targets'] = conf.get_config_dict(['service', 'snmp', 'trap-target'],
+ key_mangling=('-', '_'), get_first_key=True,
+ no_tag_node_value_mangle=True)
return firewall
+def verify_rule(firewall, rule_conf, ipv6):
+ if 'action' not in rule_conf:
+ raise ConfigError('Rule action must be defined')
+
+ if 'fragment' in rule_conf:
+ if {'match_frag', 'match_non_frag'} <= set(rule_conf['fragment']):
+ raise ConfigError('Cannot specify both "match-frag" and "match-non-frag"')
+
+ if 'ipsec' in rule_conf:
+ if {'match_ipsec', 'match_non_ipsec'} <= set(rule_conf['ipsec']):
+ raise ConfigError('Cannot specify both "match-ipsec" and "match-non-ipsec"')
+
+ if 'recent' in rule_conf:
+ if not {'count', 'time'} <= set(rule_conf['recent']):
+ raise ConfigError('Recent "count" and "time" values must be defined')
+
+ for side in ['destination', 'source']:
+ if side in rule_conf:
+ side_conf = rule_conf[side]
+
+ if 'group' in side_conf:
+ if {'address_group', 'network_group'} <= set(side_conf['group']):
+ raise ConfigError('Only one address-group or network-group can be specified')
+
+ for group in valid_groups:
+ if group in side_conf['group']:
+ group_name = side_conf['group'][group]
+
+ fw_group = f'ipv6_{group}' if ipv6 and group in ['address_group', 'network_group'] else group
+
+ if not dict_search_args(firewall, 'group', fw_group):
+ error_group = fw_group.replace("_", "-")
+ raise ConfigError(f'Group defined in rule but {error_group} is not configured')
+
+ if group_name not in firewall['group'][fw_group]:
+ error_group = group.replace("_", "-")
+ raise ConfigError(f'Invalid {error_group} "{group_name}" on firewall rule')
+
+ if 'port' in side_conf or dict_search_args(side_conf, 'group', 'port_group'):
+ if 'protocol' not in rule_conf:
+ raise ConfigError('Protocol must be defined if specifying a port or port-group')
+
+ if rule_conf['protocol'] not in ['tcp', 'udp', 'tcp_udp']:
+ raise ConfigError('Protocol must be tcp, udp, or tcp_udp when specifying a port or port-group')
+
def verify(firewall):
# bail out early - looks like removal from running config
if not firewall:
return None
+ if 'config_trap' in firewall and firewall['config_trap'] == 'enable':
+ if not firewall['trap_targets']:
+ raise ConfigError(f'Firewall config-trap enabled but "service snmp trap-target" is not defined')
+
+ for name in ['name', 'ipv6_name']:
+ if name in firewall:
+ for name_id, name_conf in firewall[name].items():
+ if name_id in preserve_chains:
+ raise ConfigError(f'Firewall name "{name_id}" is reserved for VyOS')
+
+ if 'rule' in name_conf:
+ for rule_id, rule_conf in name_conf['rule'].items():
+ verify_rule(firewall, rule_conf, name == 'ipv6_name')
+
+ for ifname, if_firewall in firewall['interfaces'].items():
+ for direction in ['in', 'out', 'local']:
+ name = dict_search_args(if_firewall, direction, 'name')
+ ipv6_name = dict_search_args(if_firewall, direction, 'ipv6_name')
+
+ if name and not dict_search_args(firewall, 'name', name):
+ raise ConfigError(f'Firewall name "{name}" is still referenced on interface {ifname}')
+
+ if ipv6_name and not dict_search_args(firewall, 'ipv6_name', ipv6_name):
+ raise ConfigError(f'Firewall ipv6-name "{ipv6_name}" is still referenced on interface {ifname}')
+
return None
+def cleanup_commands(firewall):
+ commands = []
+ for table in ['ip filter', 'ip6 filter']:
+ json_str = cmd(f'nft -j list table {table}')
+ obj = loads(json_str)
+ if 'nftables' not in obj:
+ continue
+ for item in obj['nftables']:
+ if 'chain' in item:
+ if item['chain']['name'] not in preserve_chains:
+ chain = item['chain']['name']
+ if table == 'ip filter' and dict_search_args(firewall, 'name', chain):
+ commands.append(f'flush chain {table} {chain}')
+ elif table == 'ip6 filter' and dict_search_args(firewall, 'ipv6_name', chain):
+ commands.append(f'flush chain {table} {chain}')
+ else:
+ commands.append(f'delete chain {table} {chain}')
+ return commands
+
def generate(firewall):
- if not firewall:
- return None
+ if not os.path.exists(nftables_conf):
+ firewall['first_install'] = True
+ else:
+ firewall['cleanup_commands'] = cleanup_commands(firewall)
+ render(nftables_conf, 'firewall/nftables.tmpl', firewall)
return None
-def apply(firewall):
- if not firewall:
+def apply_sysfs(firewall):
+ for name, conf in sysfs_config.items():
+ paths = glob(conf['sysfs'])
+ value = None
+
+ if name in firewall:
+ conf_value = firewall[name]
+
+ if conf_value in conf:
+ value = conf[conf_value]
+ elif conf_value == 'enable':
+ value = '1'
+ elif conf_value == 'disable':
+ value = '0'
+
+ if value:
+ for path in paths:
+ with open(path, 'w') as f:
+ f.write(value)
+
+def post_apply_trap(firewall):
+ if 'first_install' in firewall:
return None
+ if 'config_trap' not in firewall or firewall['config_trap'] != 'enable':
+ return None
+
+ if not process_named_running('snmpd'):
+ return None
+
+ trap_username = os.getlogin()
+
+ for host, target_conf in firewall['trap_targets'].items():
+ community = target_conf['community'] if 'community' in target_conf else 'public'
+ port = int(target_conf['port']) if 'port' in target_conf else 162
+
+ base_cmd = f'snmptrap -v2c -c {community} {host}:{port} 0 {snmp_trap_mib}::{snmp_trap_name} '
+
+ for change_type, changes in firewall['trap_diff'].items():
+ for path_str, value in changes.items():
+ objects = [
+ f'mgmtEventUser s "{trap_username}"',
+ f'mgmtEventSource i {snmp_event_source}',
+ f'mgmtEventType i {snmp_change_type[change_type]}'
+ ]
+
+ if change_type == 'add':
+ objects.append(f'mgmtEventCurrCfg s "{path_str} {value}"')
+ elif change_type == 'delete':
+ objects.append(f'mgmtEventPrevCfg s "{path_str} {value}"')
+ elif change_type == 'change':
+ objects.append(f'mgmtEventPrevCfg s "{path_str} {value[0]}"')
+ objects.append(f'mgmtEventCurrCfg s "{path_str} {value[1]}"')
+
+ cmd(base_cmd + ' '.join(objects))
+
+def apply(firewall):
+ if 'first_install' in firewall:
+ run('nfct helper add rpc inet tcp')
+ run('nfct helper add rpc inet udp')
+ run('nfct helper add tns inet tcp')
+
+ install_result = run(f'nft -f {nftables_conf}')
+ if install_result == 1:
+ raise ConfigError('Failed to apply firewall')
+
+ if 'state_policy' in firewall:
+ for chain in ['INPUT', 'OUTPUT', 'FORWARD']:
+ cmd(f'nft insert rule ip filter {chain} jump VYOS_STATE_POLICY')
+ cmd(f'nft insert rule ip6 filter {chain} jump VYOS_STATE_POLICY6')
+
+ apply_sysfs(firewall)
+
+ post_apply_trap(firewall)
+
return None
if __name__ == '__main__':