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<?php |
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/** |
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* Copyright (C) 2016 SURFnet. |
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* |
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* This program is free software: you can redistribute it and/or modify |
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* it under the terms of the GNU Affero General Public License as |
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* published by the Free Software Foundation, either version 3 of the |
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* License, or (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU Affero General Public License for more details. |
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* |
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* You should have received a copy of the GNU Affero General Public License |
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* along with this program. If not, see <http://www.gnu.org/licenses/>. |
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*/ |
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namespace SURFnet\VPN\Server\Config; |
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use SURFnet\VPN\Server\InstanceConfig; |
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use SURFnet\VPN\Server\PoolConfig; |
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use SURFnet\VPN\Server\IP; |
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class Firewall |
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{ |
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public static function getFirewall4(array $instanceConfigList, $asArray = false) |
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{ |
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return self::getFirewall($instanceConfigList, 4, $asArray); |
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} |
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public static function getFirewall6(array $instanceConfigList, $asArray = false) |
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{ |
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return self::getFirewall($instanceConfigList, 6, $asArray); |
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} |
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private static function getFirewall(array $instanceConfigList, $inetFamily, $asArray) |
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{ |
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$firewall = []; |
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// NAT |
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$firewall = array_merge( |
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$firewall, |
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[ |
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'*nat', |
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':PREROUTING ACCEPT [0:0]', |
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':INPUT ACCEPT [0:0]', |
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':OUTPUT ACCEPT [0:0]', |
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':POSTROUTING ACCEPT [0:0]', |
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] |
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); |
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// add all instances |
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foreach ($instanceConfigList as $instanceConfig) { |
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$firewall = array_merge($firewall, self::getNat($instanceConfig, $inetFamily)); |
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} |
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$firewall[] = 'COMMIT'; |
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// FILTER |
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$firewall = array_merge( |
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$firewall, |
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[ |
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'*filter', |
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':INPUT ACCEPT [0:0]', |
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':FORWARD ACCEPT [0:0]', |
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':OUTPUT ACCEPT [0:0]', |
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] |
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); |
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// INPUT |
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$firewall = array_merge($firewall, self::getInputChain($inetFamily)); |
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// FORWARD |
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$firewall = array_merge( |
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$firewall, |
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[ |
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//sprintf('-A FORWARD -p %s -j ACCEPT', 4 === $inetFamily ? 'icmp' : 'ipv6-icmp'), |
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'-A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT', |
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] |
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); |
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// add all instances |
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foreach ($instanceConfigList as $instanceConfig) { |
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$firewall = array_merge($firewall, self::getForwardChain($instanceConfig, $inetFamily)); |
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} |
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$firewall[] = sprintf('-A FORWARD -j REJECT --reject-with %s', 4 === $inetFamily ? 'icmp-host-prohibited' : 'icmp6-adm-prohibited'); |
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$firewall[] = 'COMMIT'; |
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if ($asArray) { |
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return $firewall; |
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} |
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return implode(PHP_EOL, $firewall).PHP_EOL; |
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} |
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private static function getNat(InstanceConfig $instanceConfig, $inetFamily) |
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{ |
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$nat = []; |
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foreach (array_keys($instanceConfig->v('vpnPools')) as $poolNumber => $poolId) { |
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$poolConfig = new PoolConfig($instanceConfig->v('vpnPools', $poolId)); |
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if ($poolConfig->v('useNat')) { |
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if (4 === $inetFamily) { |
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// get the IPv4 range |
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$srcNet = $poolConfig->v('range'); |
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} else { |
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// get the IPv6 range |
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$srcNet = $poolConfig->v('range6'); |
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} |
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// -i (--in-interface) cannot be specified for POSTROUTING |
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$nat[] = sprintf('-A POSTROUTING -s %s -o %s -j MASQUERADE', $srcNet, $poolConfig->v('extIf')); |
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} |
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} |
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return $nat; |
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} |
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private static function getInputChain($inetFamily) |
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{ |
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$inputChain = [ |
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'-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT', |
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sprintf('-A INPUT -p %s -j ACCEPT', 4 === $inetFamily ? 'icmp' : 'ipv6-icmp'), |
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'-A INPUT -i lo -j ACCEPT', |
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'-A INPUT -m state --state NEW -m multiport -p tcp --dports 22,80,443 -j ACCEPT', |
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'-A INPUT -m state --state NEW -m udp -p udp --dport 1194:1201 -j ACCEPT', |
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sprintf('-A INPUT -j REJECT --reject-with %s', 4 === $inetFamily ? 'icmp-host-prohibited' : 'icmp6-adm-prohibited'), |
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]; |
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return $inputChain; |
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} |
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private static function getForwardChain(InstanceConfig $instanceConfig, $inetFamily) |
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{ |
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$forwardChain = []; |
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foreach (array_keys($instanceConfig->v('vpnPools')) as $poolNumber => $poolId) { |
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$poolConfig = new PoolConfig($instanceConfig->v('vpnPools', $poolId)); |
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if (6 === $inetFamily && !$poolConfig->v('forward6')) { |
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// IPv6 forwarding was disabled |
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continue; |
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} |
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if (4 === $inetFamily) { |
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// get the IPv4 range |
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$srcNet = $poolConfig->v('range'); |
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} else { |
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// get the IPv6 range |
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$srcNet = $poolConfig->v('range6'); |
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} |
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$forwardChain[] = sprintf('-N vpn-%s-%s', $instanceConfig->v('instanceNumber'), $poolNumber); |
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$forwardChain[] = sprintf('-A FORWARD -i tun-%s-%s+ -s %s -j vpn-%s-%s', $instanceConfig->v('instanceNumber'), $poolNumber, $srcNet, $instanceConfig->v('instanceNumber'), $poolNumber); |
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// merge outgoing forwarding firewall rules to prevent certain |
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// traffic |
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$forwardChain = array_merge($forwardChain, self::getForwardFirewall($instanceConfig->v('instanceNumber'), $poolNumber, $poolConfig, $inetFamily)); |
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if ($poolConfig->v('clientToClient')) { |
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// allow client-to-client |
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$forwardChain[] = sprintf('-A vpn-%s-%s -o tun-%s-%s+ -d %s -j ACCEPT', $instanceConfig->v('instanceNumber'), $poolNumber, $instanceConfig->v('instanceNumber'), $poolNumber, $srcNet); |
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} |
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if ($poolConfig->v('defaultGateway')) { |
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// allow traffic to all outgoing destinations |
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$forwardChain[] = sprintf('-A vpn-%s-%s -o %s -j ACCEPT', $instanceConfig->v('instanceNumber'), $poolNumber, $poolConfig->v('extIf'), $srcNet); |
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} else { |
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// only allow certain traffic to the external interface |
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foreach ($poolConfig->v('routes') as $route) { |
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$routeIp = new IP($route); |
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if ($inetFamily === $routeIp->getFamily()) { |
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$forwardChain[] = sprintf('-A vpn-%s-%s -o %s -d %s -j ACCEPT', $instanceConfig->v('instanceNumber'), $poolNumber, $poolConfig->v('extIf'), $route); |
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} |
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} |
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} |
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} |
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return $forwardChain; |
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} |
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private static function getForwardFirewall($instanceNumber, $poolNumber, PoolConfig $poolConfig, $inetFamily) |
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{ |
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$forwardFirewall = []; |
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if ($poolConfig->v('blockSmb')) { |
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// drop SMB outgoing traffic |
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// @see https://medium.com/@ValdikSS/deanonymizing-windows-users-and-capturing-microsoft-and-vpn-accounts-f7e53fe73834 |
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foreach (['tcp', 'udp'] as $proto) { |
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$forwardFirewall[] = sprintf( |
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'-A vpn-%s-%s -o %s -m multiport -p %s --dports 137:139,445 -j REJECT --reject-with %s', |
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$instanceNumber, |
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$poolNumber, |
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$poolConfig->v('extIf'), |
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$proto, |
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4 === $inetFamily ? 'icmp-host-prohibited' : 'icmp6-adm-prohibited'); |
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} |
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} |
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return $forwardFirewall; |
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} |
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} |
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eduVPN /
vpn-server-api
Sometimes obsolete code just ends up commented out instead of removed. In this case it is better to remove the code once you have checked you do not need it.
The code might also have been commented out for debugging purposes. In this case it is vital that someone uncomments it again or your project may behave in very unexpected ways in production.
This check looks for comments that seem to be mostly valid code and reports them.