From fdeba8da3e99256fe449e331d0b833a941315226 Mon Sep 17 00:00:00 2001 From: sarthurdev <965089+sarthurdev@users.noreply.github.com> Date: Wed, 28 Jul 2021 12:03:21 +0200 Subject: firewall: T2199: Migrate firewall to XML/Python --- python/vyos/configdiff.py | 30 ++++++ python/vyos/firewall.py | 194 ++++++++++++++++++++++++++++++++++++++ python/vyos/ifconfig/interface.py | 45 ++++----- python/vyos/template.py | 26 +++++ 4 files changed, 269 insertions(+), 26 deletions(-) create mode 100644 python/vyos/firewall.py (limited to 'python/vyos') diff --git a/python/vyos/configdiff.py b/python/vyos/configdiff.py index 0e41fbe27..4ad7443d7 100644 --- a/python/vyos/configdiff.py +++ b/python/vyos/configdiff.py @@ -17,7 +17,9 @@ from enum import IntFlag, auto from vyos.config import Config from vyos.configdict import dict_merge +from vyos.configdict import list_diff from vyos.util import get_sub_dict, mangle_dict_keys +from vyos.util import dict_search_args from vyos.xml import defaults class ConfigDiffError(Exception): @@ -134,6 +136,34 @@ class ConfigDiff(object): self._key_mangling[1]) return config_dict + def get_child_nodes_diff_str(self, path=[]): + ret = {'add': {}, 'change': {}, 'delete': {}} + + diff = self.get_child_nodes_diff(path, + expand_nodes=Diff.ADD | Diff.DELETE | Diff.MERGE | Diff.STABLE, + no_defaults=True) + + def parse_dict(diff_dict, diff_type, prefix=[]): + for k, v in diff_dict.items(): + if isinstance(v, dict): + parse_dict(v, diff_type, prefix + [k]) + else: + path_str = ' '.join(prefix + [k]) + if diff_type == 'add' or diff_type == 'delete': + if isinstance(v, list): + v = ', '.join(v) + ret[diff_type][path_str] = v + elif diff_type == 'merge': + old_value = dict_search_args(diff['stable'], *prefix, k) + if old_value and old_value != v: + ret['change'][path_str] = [old_value, v] + + parse_dict(diff['merge'], 'merge') + parse_dict(diff['add'], 'add') + parse_dict(diff['delete'], 'delete') + + return ret + def get_child_nodes_diff(self, path=[], expand_nodes=Diff(0), no_defaults=False): """ Args: diff --git a/python/vyos/firewall.py b/python/vyos/firewall.py new file mode 100644 index 000000000..9b8af7852 --- /dev/null +++ b/python/vyos/firewall.py @@ -0,0 +1,194 @@ +#!/usr/bin/env python3 +# +# Copyright (C) 2021 VyOS maintainers and contributors +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License version 2 or later as +# published by the Free Software Foundation. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + +import re + +from vyos.util import cmd +from vyos.util import dict_search_args + +def find_nftables_rule(table, chain, rule_matches=[]): + # Find rule in table/chain that matches all criteria and return the handle + results = cmd(f'sudo nft -a list chain {table} {chain}').split("\n") + for line in results: + if all(rule_match in line for rule_match in rule_matches): + handle_search = re.search('handle (\d+)', line) + if handle_search: + return handle_search[1] + return None + +def remove_nftables_rule(table, chain, handle): + cmd(f'sudo nft delete rule {table} {chain} handle {handle}') + +# Functions below used by template generation + +def nft_action(vyos_action): + if vyos_action == 'accept': + return 'return' + return vyos_action + +def parse_rule(rule_conf, fw_name, rule_id, ip_name): + output = [] + def_suffix = '6' if ip_name == 'ip6' else '' + + if 'state' in rule_conf and rule_conf['state']: + states = ",".join([s for s, v in rule_conf['state'].items() if v == 'enable']) + output.append(f'ct state {{{states}}}') + + if 'protocol' in rule_conf and rule_conf['protocol'] != 'all': + proto = rule_conf['protocol'] + if proto == 'tcp_udp': + proto = '{tcp, udp}' + output.append('meta l4proto ' + proto) + + for side in ['destination', 'source']: + if side in rule_conf: + prefix = side[0] + side_conf = rule_conf[side] + + if 'address' in side_conf: + output.append(f'{ip_name} {prefix}addr {side_conf["address"]}') + + if 'mac_address' in side_conf: + suffix = side_conf["mac_address"] + if suffix[0] == '!': + suffix = f'!= {suffix[1:]}' + output.append(f'ether {prefix}addr {suffix}') + + if 'port' in side_conf: + proto = rule_conf['protocol'] + port = side_conf["port"] + + if isinstance(port, list): + port = ",".join(port) + + if proto == 'tcp_udp': + proto = 'th' + + output.append(f'{proto} {prefix}port {{{port}}}') + + if 'group' in side_conf: + group = side_conf['group'] + if 'address_group' in group: + group_name = group['address_group'] + output.append(f'{ip_name} {prefix}addr $A{def_suffix}_{group_name}') + elif 'network_group' in group: + group_name = group['network_group'] + output.append(f'{ip_name} {prefix}addr $N{def_suffix}_{group_name}') + if 'port_group' in group: + proto = rule_conf['protocol'] + group_name = group['port_group'] + + if proto == 'tcp_udp': + proto = 'th' + + output.append(f'{proto} {prefix}port $P_{group_name}') + + if 'log' in rule_conf and rule_conf['log'] == 'enable': + output.append('log') + + if 'hop_limit' in rule_conf: + operators = {'eq': '==', 'gt': '>', 'lt': '<'} + for op, operator in operators.items(): + if op in rule_conf['hop_limit']: + value = rule_conf['hop_limit'][op] + output.append(f'ip6 hoplimit {operator} {value}') + + for icmp in ['icmp', 'icmpv6']: + if icmp in rule_conf: + if 'type_name' in rule_conf[icmp]: + output.append(icmp + ' type ' + rule_conf[icmp]['type_name']) + else: + if 'code' in rule_conf[icmp]: + output.append(icmp + ' code ' + rule_conf[icmp]['code']) + if 'type' in rule_conf[icmp]: + output.append(icmp + ' type ' + rule_conf[icmp]['type']) + + if 'ipsec' in rule_conf: + if 'match_ipsec' in rule_conf['ipsec']: + output.append('meta ipsec == 1') + if 'match_non_ipsec' in rule_conf['ipsec']: + output.append('meta ipsec == 0') + + if 'fragment' in rule_conf: + # Checking for fragmentation after priority -400 is not possible, + # so we use a priority -450 hook to set a mark + if 'match_frag' in rule_conf['fragment']: + output.append('meta mark 0xffff1') + if 'match_non_frag' in rule_conf['fragment']: + output.append('meta mark != 0xffff1') + + if 'limit' in rule_conf: + if 'rate' in rule_conf['limit']: + output.append(f'limit rate {rule_conf["limit"]["rate"]}/second') + if 'burst' in rule_conf['limit']: + output.append(f'burst {rule_conf["limit"]["burst"]} packets') + + if 'recent' in rule_conf: + count = rule_conf['recent']['count'] + time = rule_conf['recent']['time'] + # output.append(f'meter {fw_name}_{rule_id} {{ ip saddr and 255.255.255.255 limit rate over {count}/{time} burst {count} packets }}') + # Waiting on input from nftables developers due to + # bug with above line and atomic chain flushing. + + if 'time' in rule_conf: + output.append(parse_time(rule_conf['time'])) + + tcp_flags = dict_search_args(rule_conf, 'tcp', 'flags') + if tcp_flags: + output.append(parse_tcp_flags(tcp_flags)) + + output.append('counter') + + if 'action' in rule_conf: + output.append(nft_action(rule_conf['action'])) + else: + output.append('return') + + output.append(f'comment "{fw_name}-{rule_id}"') + return " ".join(output) + +def parse_tcp_flags(flags): + all_flags = [] + include = [] + for flag in flags.split(","): + if flag[0] == '!': + flag = flag[1:] + else: + include.append(flag) + all_flags.append(flag) + return f'tcp flags & ({"|".join(all_flags)}) == {"|".join(include)}' + +def parse_time(time): + out = [] + if 'startdate' in time: + start = time['startdate'] + if 'T' not in start and 'starttime' in time: + start += f' {time["starttime"]}' + out.append(f'time >= "{start}"') + if 'starttime' in time and 'startdate' not in time: + out.append(f'hour >= "{time["starttime"]}"') + if 'stopdate' in time: + stop = time['stopdate'] + if 'T' not in stop and 'stoptime' in time: + stop += f' {time["stoptime"]}' + out.append(f'time < "{stop}"') + if 'stoptime' in time and 'stopdate' not in time: + out.append(f'hour < "{time["stoptime"]}"') + if 'weekdays' in time: + days = time['weekdays'].split(",") + out_days = [f'"{day}"' for day in days if day[0] != '!'] + out.append(f'day {{{",".join(out_days)}}}') + return " ".join(out) diff --git a/python/vyos/ifconfig/interface.py b/python/vyos/ifconfig/interface.py index 58d130ef6..edc99d6f7 100755 --- a/python/vyos/ifconfig/interface.py +++ b/python/vyos/ifconfig/interface.py @@ -544,6 +544,15 @@ class Interface(Control): return None return self.set_interface('arp_cache_tmo', tmo) + def _cleanup_mss_rules(self, table, ifname): + commands = [] + results = self._cmd(f'nft -a list chain {table} VYOS_TCP_MSS').split("\n") + for line in results: + if f'oifname "{ifname}"' in line: + handle_search = re.search('handle (\d+)', line) + if handle_search: + self._cmd(f'nft delete rule {table} VYOS_TCP_MSS handle {handle_search[1]}') + def set_tcp_ipv4_mss(self, mss): """ Set IPv4 TCP MSS value advertised when TCP SYN packets leave this @@ -555,22 +564,14 @@ class Interface(Control): >>> from vyos.ifconfig import Interface >>> Interface('eth0').set_tcp_ipv4_mss(1340) """ - iptables_bin = 'iptables' - base_options = f'-A FORWARD -o {self.ifname} -p tcp -m tcp --tcp-flags SYN,RST SYN' - out = self._cmd(f'{iptables_bin}-save -t mangle') - for line in out.splitlines(): - if line.startswith(base_options): - # remove OLD MSS mangling configuration - line = line.replace('-A FORWARD', '-D FORWARD') - self._cmd(f'{iptables_bin} -t mangle {line}') - - cmd_mss = f'{iptables_bin} -t mangle {base_options} --jump TCPMSS' + self._cleanup_mss_rules('raw', self.ifname) + nft_prefix = 'nft add rule raw VYOS_TCP_MSS' + base_cmd = f'oifname "{self.ifname}" tcp flags & (syn|rst) == syn' if mss == 'clamp-mss-to-pmtu': - self._cmd(f'{cmd_mss} --clamp-mss-to-pmtu') + self._cmd(f"{nft_prefix} '{base_cmd} tcp option maxseg size set rt mtu'") elif int(mss) > 0: - # probably add option to clamp only if bigger: low_mss = str(int(mss) + 1) - self._cmd(f'{cmd_mss} -m tcpmss --mss {low_mss}:65535 --set-mss {mss}') + self._cmd(f"{nft_prefix} '{base_cmd} tcp option maxseg size {low_mss}-65535 tcp option maxseg size set {mss}'") def set_tcp_ipv6_mss(self, mss): """ @@ -583,22 +584,14 @@ class Interface(Control): >>> from vyos.ifconfig import Interface >>> Interface('eth0').set_tcp_mss(1320) """ - iptables_bin = 'ip6tables' - base_options = f'-A FORWARD -o {self.ifname} -p tcp -m tcp --tcp-flags SYN,RST SYN' - out = self._cmd(f'{iptables_bin}-save -t mangle') - for line in out.splitlines(): - if line.startswith(base_options): - # remove OLD MSS mangling configuration - line = line.replace('-A FORWARD', '-D FORWARD') - self._cmd(f'{iptables_bin} -t mangle {line}') - - cmd_mss = f'{iptables_bin} -t mangle {base_options} --jump TCPMSS' + self._cleanup_mss_rules('ip6 raw', self.ifname) + nft_prefix = 'nft add rule ip6 raw VYOS_TCP_MSS' + base_cmd = f'oifname "{self.ifname}" tcp flags & (syn|rst) == syn' if mss == 'clamp-mss-to-pmtu': - self._cmd(f'{cmd_mss} --clamp-mss-to-pmtu') + self._cmd(f"{nft_prefix} '{base_cmd} tcp option maxseg size set rt mtu'") elif int(mss) > 0: - # probably add option to clamp only if bigger: low_mss = str(int(mss) + 1) - self._cmd(f'{cmd_mss} -m tcpmss --mss {low_mss}:65535 --set-mss {mss}') + self._cmd(f"{nft_prefix} '{base_cmd} tcp option maxseg size {low_mss}-65535 tcp option maxseg size set {mss}'") def set_arp_filter(self, arp_filter): """ diff --git a/python/vyos/template.py b/python/vyos/template.py index b32cafe74..55bd04136 100644 --- a/python/vyos/template.py +++ b/python/vyos/template.py @@ -22,6 +22,7 @@ from jinja2 import FileSystemLoader from vyos.defaults import directories from vyos.util import chmod from vyos.util import chown +from vyos.util import dict_search_args from vyos.util import makedir # Holds template filters registered via register_filter() @@ -479,3 +480,28 @@ def get_openvpn_ncp_ciphers(ciphers): else: out.append(cipher) return ':'.join(out).upper() + +@register_filter('nft_action') +def nft_action(vyos_action): + if vyos_action == 'accept': + return 'return' + return vyos_action + +@register_filter('nft_rule') +def nft_rule(rule_conf, fw_name, rule_id, ip_name='ip'): + from vyos.firewall import parse_rule + return parse_rule(rule_conf, fw_name, rule_id, ip_name) + +@register_filter('nft_state_policy') +def nft_state_policy(conf, state): + out = [f'ct state {state}'] + + if 'log' in conf and 'enable' in conf['log']: + out.append('log') + + out.append('counter') + + if 'action' in conf: + out.append(conf['action']) + + return " ".join(out) -- cgit v1.2.3