Marzo 22, 2007

            //Create rule for adding a new chain
            NetfilterRule rule = new NetfilterRule();
           
            //Create new chain command
            NewChainCommand cmd = new NewChainCommand();
            cmd.ChainName = this.chainName;
           
            //Set in the rule
            rule.Command = cmd;
           
            //Execute
            FirewallManager.instance.ApplyRule(rule);
            //Execute in default table named filter
            this.ruleSet.ExecRule(rule);
           
            //Create insert rule to redirect INPUT packets to our chain
            rule = new NetfilterRule();
           
            //Create insert command
            InsertRuleCommand iCmd = new InsertRuleCommand();
            iCmd = new InsertRuleCommand();
            iCmd.RuleNum = 1;
            iCmd.ChainName = "INPUT";
           
            rule.Command = iCmd;
           
            //Create jump option to redirect to our chain
            JumpOption jopt = new JumpOption();
            jopt.Target = RuleTargets.CustomTarget;
            jopt.CustomTarget = CustomRuleTargets.UserDefinedChain;
            jopt.CustomTargetName = this.chainName;
            //Add to rule
            rule.Options.Add(jopt);
           
            //Execute
            FirewallManager.instance.ApplyRule(rule);
            //Execute in default table named filter
            this.ruleSet.ExecRule(rule);
           
            //Create rule
            rule = new NetfilterRule();
           
            //Create append rule command
            AppendRuleCommand acmd = new AppendRuleCommand();
            acmd.ChainName = this.chainName;
            //Set in the rule
            rule.Command = acmd;
           
            //Create option to accept loopback traffic
            InInterfaceOption inOpt = new InInterfaceOption();
            inOpt.Interface = "lo";
            //Add to rule
            rule.Options.Add(inOpt);
           
            //Create jump option with accept target
            jopt = new JumpOption();
            jopt.Target = RuleTargets.Accept;
            //Add to rule
            rule.Options.Add(jopt);
           
            //Execute
            FirewallManager.instance.ApplyRule(rule);
            //Execute in default table named filter
            this.ruleSet.ExecRule(rule);
           
            //Create rule to accept new or related connections
            rule = new NetfilterRule();
           
            //Create append rule command
            acmd = new AppendRuleCommand();
            acmd.ChainName = this.chainName;
            //set in the rule
            rule.Command = acmd;
           
            //Load state extension with -m option
            MatchExtensionOption meop = new MatchExtensionOption();
            meop.Extension = MatchExtensions.State;
            //Add to rule
            rule.Options.Add(meop);

            //The previous option causes the extension to be instantiated
            //and added. We add the parameter directly.
            rule.LoadedExtensions[meop.Extension].AddParameter(
                                                                             "state",
                                                                             "RELATED,ESTABLISHED");

            //Create jump option to ACCEPT
            jopt = new JumpOption();
            jopt.Target = RuleTargets.Accept;
            //Add to rule
            rule.Options.Add(jopt);

            //Execute
            FirewallManager.instance.ApplyRule(rule);
            //Execute in default table named filter
            this.ruleSet.ExecRule(rule);
           
            //Create rule to drop anything else
            rule = new NetfilterRule();
           
            //Create append rule command
            acmd = new AppendRuleCommand();
            acmd.ChainName = this.chainName;
            //Set in the rule
            rule.Command = acmd;
           
            //Create jump option with drop target
            jopt = new JumpOption();
            jopt.Target = RuleTargets.Drop;
            //Add to rule
            rule.Options.Add(jopt);
           
            //Execute
            FirewallManager.instance.ApplyRule(rule);
            //Execute in default table named filter
            this.ruleSet.ExecRule(rule);