/*

                          Firewall Builder

                 Copyright (C) 2007 NetCitadel, LLC

  Author:  Vadim Kurland     vadim@fwbuilder.org

  $Id: IPTImporter.cpp 1036 2009-06-04 20:35:53Z vadim $

  This program is free software which we release under the GNU General Public
  License. You may redistribute and/or modify this program under the terms
  of that license as published by the Free Software Foundation; either
  version 2 of the License, or (at your option) any later version.

  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.

  To get a copy of the GNU General Public License, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/

#include "../../config.h"
#include "global.h"
#include "utils_no_qt.h"
#include "platforms.h"


#include "IPTImporter.h"

#include <ios>
#include <iostream>
#include <algorithm>
#include <map>

#ifndef _WIN32
#  include <netdb.h>
#  include <netinet/in.h>
#else
#  include <winsock2.h>
#endif

#include "fwbuilder/Resources.h"
#include "fwbuilder/Network.h"
#include "fwbuilder/Address.h"
#include "fwbuilder/AddressRange.h"
#include "fwbuilder/InetAddr.h"
#include "fwbuilder/IPService.h"
#include "fwbuilder/ICMPService.h"
#include "fwbuilder/TCPService.h"
#include "fwbuilder/UDPService.h"
#include "fwbuilder/TagService.h"
#include "fwbuilder/Policy.h"
#include "fwbuilder/NAT.h"
#include "fwbuilder/RuleElement.h"
#include "fwbuilder/FWServiceReference.h"
#include "fwbuilder/CustomService.h"

using namespace libfwbuilder;

IPTImporter::IPTImporter(FWObject *lib,
                         std::istringstream &input,
                         Logger *log) : Importer(lib, "iptables", input, log)
{
    service_group_name_seed = 0;
    current_ruleset = NULL;
    current_rule = NULL;
    last_mark_rule = NULL;

    clear();

    icmp_specs["echo-reply"] = std::pair<int,int>(0, 0);

    // all "unreachables"
    icmp_specs["destination-unreachable"] = std::pair<int,int>(3, -1);
    icmp_specs["network-unreachable"] = std::pair<int,int>(3, 0);
    icmp_specs["host-unreachable"] = std::pair<int,int>(3, 1);
    icmp_specs["protocol-unreachable"] = std::pair<int,int>(3, 2);
    icmp_specs["port-unreachable"] = std::pair<int,int>(3, 3);
    icmp_specs["fragmentation-needed"] = std::pair<int,int>(3, 4);
    icmp_specs["source-route-failed"] = std::pair<int,int>(3, 5);
    icmp_specs["network-unknown"] = std::pair<int,int>(3, 6);
    icmp_specs["host-unknown"] = std::pair<int,int>(3, 7);
    icmp_specs["host-isolated"] = std::pair<int,int>(3, 8);
    icmp_specs["network-prohibited"] = std::pair<int,int>(3, 9);
    icmp_specs["host-prohibited"] = std::pair<int,int>(3, 10);
    icmp_specs["TOS-network-unreachable"] = std::pair<int,int>(3, 11);
    icmp_specs["TOS-host-unreachable"] = std::pair<int,int>(3, 12);
    icmp_specs["communication-prohibited"] = std::pair<int,int>(3, 13);
    icmp_specs["host-precedence-violation"] = std::pair<int,int>(3, 14);
    icmp_specs["precedence-cutoff"] = std::pair<int,int>(3, 15);

    icmp_specs["source-quench"] = std::pair<int,int>(4, 0);

    icmp_specs["redirect"] = std::pair<int,int>(5, -1);
    icmp_specs["network-redirect"] = std::pair<int,int>(5, 0);
    icmp_specs["host-redirect"] = std::pair<int,int>(5, 1);
    icmp_specs["TOS-network-redirect"] = std::pair<int,int>(5, 2);
    icmp_specs["TOS-host-redirect"] = std::pair<int,int>(5, 3);

    icmp_specs["echo-request"] = std::pair<int,int>(8, 0);

    icmp_specs["router-advertisement"] = std::pair<int,int>(9, 0);

    icmp_specs["router-solicitation"] = std::pair<int,int>(10, 0);

    icmp_specs["ttl-exceeded"] = std::pair<int,int>(11, 0);
    icmp_specs["time-exceeded"] = std::pair<int,int>(11, 0);
    icmp_specs["ttl-zero-during-transit"] = std::pair<int,int>(11, 0);
    icmp_specs["ttl-zero-during-reassembly"] = std::pair<int,int>(11, 1);

    icmp_specs["parameter-problem"] = std::pair<int,int>(12, 0);
    icmp_specs["ip-header-bad"] = std::pair<int,int>(12, 0);
    icmp_specs["required-option-missing"] = std::pair<int,int>(12, 1);

    icmp_specs["timestamp-request"] = std::pair<int,int>(13, 0);

    icmp_specs["timestamp-reply"] = std::pair<int,int>(14, 0);

    icmp_specs["information-request"] = std::pair<int,int>(15, 0);

    icmp_specs["information-reply"] = std::pair<int,int>(16, 0);

    icmp_specs["address-mask-request"] = std::pair<int,int>(17, 0);

    icmp_specs["address-mask-reply"] = std::pair<int,int>(18, 0);
}



IPTImporter::~IPTImporter()
{
    clear();
}

void IPTImporter::clear()
{
    Importer::clear();
    if (!src_port_list.empty())  src_port_list.clear();
    if (!dst_port_list.empty())  dst_port_list.clear();
    current_state = "";
    i_intf = "";
    o_intf = "";
    target = "";
    tmp_port_range_start = "";
    tmp_port_range_end = "";
    src_neg = dst_neg = srv_neg = intf_neg = false;
    match_mark = "";
    limit_val = "";
    limit_suffix = "";
    limit_burst = "";
    if (!action_params.empty()) action_params.clear();
    nat_addr1 = "";
    nat_addr2 = "";
    nat_nm = "";
    nat_port_range_start = "";
    nat_port_range_end = "";

}

void IPTImporter::startSrcMultiPort()
{
    src_port_list.clear();
}

void IPTImporter::pushTmpPortSpecToSrcPortList()
{
    src_port_list.push_back(
        str_tuple( tmp_port_range_start, tmp_port_range_end ) );
}

void IPTImporter::startDstMultiPort()
{
    dst_port_list.clear();
}

void IPTImporter::pushTmpPortSpecToDstPortList()
{
    dst_port_list.push_back(
        str_tuple( tmp_port_range_start, tmp_port_range_end ) );
}


FWObject* IPTImporter::createAddress(const std::string &addr,
                                     const std::string &netmask)
{
    return Importer::createAddress(addr, netmask);
}

FWObject* IPTImporter::createICMPService()
{
    std::string icmpspec = strip(icmp_spec);
    if (!icmpspec.empty())
    {
        // Cisco is trying to be too helpful, they translate many
        // icmp type/code combinations into stings
        if (icmp_specs.count(icmpspec)!=0)
        {
            std::pair<int,int> pp = icmp_specs[icmpspec];
            std::ostringstream s1, s2;
            s1 << pp.first;
            icmp_type = s1.str();
            s2 << pp.second;
            icmp_code = s2.str();
        } else
        {
            markCurrentRuleBad(
                std::string("Import of icmp protocol '") + icmp_spec + "' failed");
            icmp_code = "-1";
            icmp_type = "-1";
        }
    }
    icmp_spec = "";

    return Importer::createICMPService();
}

FWObject* IPTImporter::createIPService()
{
    struct protoent *pe = getprotobyname(protocol.c_str());
    if (pe!=NULL)
    {
        std::ostringstream s;
        s << pe->p_proto;
        protocol = s.str();
        //free(pe);
    }
    return Importer::createIPService();
}

std::pair<int,int> IPTImporter::convertPortRange(str_tuple &range,
                                                 const char *proto)
{
    return std::pair<int,int>(convertPort(range.first,proto),
                              convertPort(range.second,proto));
}

int IPTImporter::convertPort(const std::string &port_spec,
                             const char *proto)
{
    int port = 0;
    std::string ps = strip(port_spec);
    if (ps=="") return 0;

    struct servent *se = getservbyname(ps.c_str(), proto);
    if (se!=NULL)
    {
        port = ntohs(se->s_port);
        //free(se);
        return port;
    }

    std::istringstream str1(ps);
    str1.exceptions(std::ios::failbit);
    try
    {
        str1 >> port;
    } catch (const std::exception &ex) {
        // could not convert port_spec to an integer
        markCurrentRuleBad(std::string("Port spec '") + port_spec +
                           "' unknown. Error " + ex.what());
    }
    return port;
}

FWObject* IPTImporter::createTCPUDPService(str_tuple &src_range,
                                           str_tuple &dst_range,
                                           const std::string &proto)
{
    if (fwbdebug)
    {
        qDebug(QString("Creating %1 service").arg(proto.c_str()).toAscii().constData());
        qDebug(QString("src range: %1 - %2")
               .arg(src_range.first.c_str())
               .arg(src_range.second.c_str()).toAscii().constData());
        qDebug(QString("dst range: %1 - %2")
               .arg(dst_range.first.c_str())
               .arg(dst_range.second.c_str()).toAscii().constData());
    }

//     std::string name = proto + " "
//         + src_range.first + "-" + src_range.second +
//         + ":"
//         + dst_range.first + "-" + dst_range.second;

    std::pair<int,int> pr = convertPortRange(src_range, proto.c_str());
    int srs = pr.first;
    int sre = pr.second;

    pr = convertPortRange(dst_range, proto.c_str());
    int drs = pr.first;
    int dre = pr.second;

    FWObject *o;
    if (proto=="tcp")
    {
        o = getTCPService(srs,sre,
                          drs,dre,
                          established,
                          tcp_flags_mask,tcp_flags_comp);
    } else
        o = getUDPService(srs,sre,drs,dre);
    return o;
}

FWObject* IPTImporter::createTCPUDPService(const std::string &proto)
{
    str_tuple empty_range("0","0");

    // use src_port_list and dst_port_list
    // if this is multiport, should only be either src or dst port
    //
    if (src_port_list.size()>1 || dst_port_list.size()>1)
    {
        std::list<FWObject*> olist;
        std::list<std::string> list_names;
        std::list<str_tuple>::iterator i;

        std::list<str_tuple> *list_ptr;
        if (src_port_list.size()>1) list_ptr = &src_port_list;
        else                        list_ptr = &dst_port_list;

        std::string sig;
        if (src_port_list.size()>1) sig = proto + " src ";
        else                        sig = proto + " dst ";
        for (i = list_ptr->begin(); i != list_ptr->end(); ++i)
        {
            sig += (*i).first + ":" + (*i).second + "_";
        }
        if (all_objects.count(sig)!=0) return all_objects[sig];

        for (i = list_ptr->begin(); i != list_ptr->end(); ++i)
        {
            FWObject *o;

            o = createTCPUDPService(
                (list_ptr == &src_port_list) ? *i : empty_range,
                (list_ptr == &dst_port_list) ? *i : empty_range,
                proto);

            olist.push_back(o);
            list_names.push_back(o->getName());
        }

        std::ostringstream s;
        s << service_group_name_seed;
        service_group_name_seed++;
        std::string name = proto + " group " + s.str();

        if (fwbdebug)
            qDebug(QString("Group of %1 services with name '%2', sig '%3'").arg(proto.c_str()).arg(name.c_str()).arg(sig.c_str()).toAscii().constData());

        ServiceGroup *sg = ServiceGroup::cast(createObject(ServiceGroup::TYPENAME, name));
        for (FWObject::iterator j=olist.begin(); j!=olist.end(); ++j)
        {
            sg->addRef(*j);
        }
        all_objects[sig] = sg;
        return sg;

    } else // single tcp/udp object
    {
        return createTCPUDPService(
            (src_port_list.size()>0) ? src_port_list.front() : empty_range,
            (dst_port_list.size()>0) ? dst_port_list.front() : empty_range,
            proto);
    }
}

FWObject* IPTImporter::createTCPService()
{
    return createTCPUDPService("tcp");
}

FWObject* IPTImporter::createUDPService()
{
    return createTCPUDPService("udp");
}

void IPTImporter::addSrv()
{
    PolicyRule *rule = PolicyRule::cast(current_rule);
    RuleElementSrv* srv = rule->getSrv();
    assert(srv!=NULL);

    if (match_mark.empty())
    {
        Importer::addSrv();
        return;
    }

    srv->addRef( getTagService(match_mark) );
}

void IPTImporter::pushRule()
{
//    assert(current_ruleset!=NULL);
    if (current_rule==NULL) return;

    if (current_table=="nat")  pushNATRule();
    else                       pushPolicyRule();
}
 
void IPTImporter::pushPolicyRule()
{
    // populate all elements of the rule

    PolicyRule *rule = PolicyRule::cast(current_rule);
    rule->setLogging(false);

    FWOptions  *fwopt = getFirewallObject()->getOptionsObject();
    assert(fwopt!=NULL);

    FWOptions  *ropt = current_rule->getOptionsObject();
    assert(ropt!=NULL);

    bool skip_rule = false;

    PolicyRule::Action action = PolicyRule::Unknown;

    if (target=="ACCEPT")   action = PolicyRule::Accept;

    if (target=="DROP")     action = PolicyRule::Deny;

    if (target=="REJECT")
    {
        action = PolicyRule::Reject;
        if (action_params["reject_with"]=="tcp-reset")
            ropt->setStr("action_on_reject", "TCP RST");
        else
            ropt->setStr("action_on_reject", action_params["reject_with"]);
    }

    if (target=="QUEUE")    action = PolicyRule::Pipe;

    if (target=="CLASSIFY") action = PolicyRule::Classify;

    if (target=="LOG")
    {
        action = PolicyRule::Continue;
        rule->setLogging(true);
        ropt->setStr("log_prefix", action_params["log_prefix"]);
        ropt->setStr("log_tcp_seq", action_params["log_tcp_seq"]);
        ropt->setStr("log_tcp_options", action_params["log_tcp_options"]);
        ropt->setStr("log_ip_options", action_params["log_ip_options"]);
        ropt->setStr("log_level", action_params["log_level"]);
        if (!limit_val.empty())
        {
            ropt->setStr("limit_value", limit_val);
            ropt->setStr("limit_suffix", std::string("/")+limit_suffix);
            if (!limit_burst.empty())
                ropt->setStr("limit_burst", limit_burst);
        }
    }

    if (target=="ULOG")
    {
        action = PolicyRule::Continue;
        rule->setLogging(true);
        fwopt->setBool("use_ULOG", true);
        ropt->setStr("log_prefix", action_params["log_prefix"]);
    }

    if (target=="MARK")
    {
        action = PolicyRule::Tag;
        last_mark_rule = rule;
        std::string mark_code = action_params["set_mark"];
        FWObject *tag_service = getTagService(mark_code);
        rule->setTagObject(tag_service);
    }
    if (target=="CONNMARK")        action = PolicyRule::Continue;

    if (target=="ROUTE")
    {
        action = PolicyRule::Route;

        if (!action_params["route_iif"].empty())
            newInterface(action_params["route_iif"]);
        if (!action_params["route_oif"].empty())
            newInterface(action_params["route_oif"]);

        ropt->setStr("ipt_iif",        action_params["route_iif"]);
        ropt->setStr("ipt_oif",        action_params["route_oif"]);
        ropt->setStr("ipt_gw",         action_params["route_gw"]);
        ropt->setBool("ipt_continue", !action_params["route_continue"].empty());
        ropt->setBool("ipt_tee",      !action_params["route_tee"].empty());
    }

    if (target=="RETURN")
    {
        action = PolicyRule::Continue;
    }

    if (target=="TCPMSS" && action_params["clamp-mss-to-pmtu"]=="--clamp-mss-to-pmtu")
    {
        fwopt->setBool("clamp_mss_to_mtu", true);
        skip_rule = true;
        *Importer::logger
            << "Using automatic rule controlled by option "
            << "Clamp MSS to MTU"
            << "\n";
    }

    if (target=="TOS")
    {
        // special-case target TOS, create custom action
        // this is not very useful though because compiler can not properly
        // put such rule in POSTROUTING chain.
        action = PolicyRule::Custom;
        ropt->setStr("custom_str",
                     "-j TOS --set-tos " + action_params["set_tos"]);
    }

    if (action==PolicyRule::Unknown)
    {
        if (fwbdebug)
            qDebug("Unknown target %s, creating branch", target.c_str());

        // unknown target, consider it a branch
        //
        std::string branch_ruleset_name = target;
        action = PolicyRule::Branch;
        UnidirectionalRuleSet *rs = branch_rulesets[branch_ruleset_name];
        if (rs==NULL)
            rs = getUnidirRuleSet(branch_ruleset_name);

        branch_rulesets[branch_ruleset_name] = rs;

        //current_rule->add(rs->ruleset);
        //ropt->setStr("branch_name", branch_ruleset_name);
        //getFirewallObject()->remove(rs->ruleset, false);

        rs->ruleset->setName(target);
        rule->setBranch(rs->ruleset);
    }

    rule->setAction(action);

    if (target!="LOG" && !limit_val.empty())
    {
        ropt->setStr("limit_value", limit_val);
        ropt->setStr("limit_suffix", std::string("/") + limit_suffix);
        if (!limit_burst.empty())
            ropt->setStr("limit_burst", limit_burst);
    }

    addSrc();
    addDst();
    addSrv();

/* Recognize some typical rule patterns and set firewall and rule
 * options appropriately
 */
    if (current_state=="NEW")
    {
        ropt->setBool("stateless", false);
    }
    RuleElementSrc      *nsrc;
    RuleElementDst      *ndst;

    rule->getSrc()->setNeg(src_neg);
    rule->getDst()->setNeg(dst_neg);
    rule->getSrv()->setNeg(srv_neg);
    rule->getItf()->setNeg(intf_neg);

    if (current_state == "RELATED,ESTABLISHED")
    {
        if (rule->getSrc()->isAny() &&
            rule->getDst()->isAny() &&
            rule->getSrv()->isAny())
        {
            fwopt->setBool("accept_established", true);
            skip_rule = true;
            *Importer::logger
                << "Using automatic rule controlled by option "
                << "'Accept established,related states' to match "
                << "states RELATED,ESTABLISHED"
                << "\n";
        } else
        {
            RuleElementSrv *srv = rule->getSrv();
            std::string protocol = "";
            if (!rule->getSrv()->isAny())
            {
                Service *srv_obj = Service::cast(FWServiceReference::getObject(
                                                     srv->front()));
                protocol = srv_obj->getProtocolName();
            }
            FWObject *established = getCustomService(
                "iptables", "-m state --state RELATED,ESTABLISHED", protocol);
            srv->clearChildren();
            srv->addRef(established);
        }
    }

    if (rule->getSrc()->isAny() &&
        rule->getDst()->isAny() &&
        rule->getSrv()->isAny() &&
        current_state == "INVALID")
    {
        if (target=="DROP") fwopt->setBool("drop_invalid", true);
        if (target=="LOG")  fwopt->setBool("log_invalid", true);
        skip_rule = true;
        *Importer::logger
            << "Using automatic rule controlled by option "
            << "'Drop packet that do not match any known connection' to match "
            << "state INVALID"
            << "\n";
    }

    if (target=="CONNMARK" &&
        last_mark_rule != NULL &&
        !action_params["connmark_save_mark"].empty())
    {
        FWOptions  *lmr_ropt = last_mark_rule->getOptionsObject();
        assert(lmr_ropt!=NULL);
        lmr_ropt->setBool("ipt_mark_connections", true);
        skip_rule = true;
        *Importer::logger
            << "Turned option on in previous rule with action Mark "
            << "for '-j CONNMARK --save-mark' "
            << "\n";
    }

    if (target=="CONNMARK" &&
        !action_params["connmark_restore_mark"].empty())
    {
        // this rule is added automatically in
        // MangleTableCompiler_ipt::flushAndSetDefaultPolicy()
        // if we have at least one rule with CONNMARK target in the policy
        skip_rule = true;
        *Importer::logger
            << "Skip command with '-j CONNMARK --restore-mark' "
            << "This rule is generated automatically."
            << "\n";
    }

    if (!skip_rule)
    {
/* we set "firewall_is_part_of_any_and_networks" to False */
        rule_comment += "Chain " + current_chain + ". ";

        if (current_chain=="INPUT")
        {
            ndst = rule->getDst();
            if (ndst->isAny()) ndst->addRef(getFirewallObject());
            else
                rule_comment += "Does DST match one of the firewall's addresses?";
        }

        if (current_chain=="OUTPUT")
        {
            nsrc = rule->getSrc();
            if (nsrc->isAny()) nsrc->addRef(getFirewallObject());
            else
                rule_comment += "Does SRC match one of the firewall's addresses?";
        }

        //  add rule to the right ruleset
        std::string ruleset_name = "";
        if (isStandardChain(current_chain))
        {
            RuleSet *policy = RuleSet::cast(
                getFirewallObject()->getFirstByType(Policy::TYPENAME));
            assert( policy!=NULL );
            policy->add(current_rule);
        } else
        {
            UnidirectionalRuleSet *rs = getUnidirRuleSet(current_chain);
            assert(rs!=NULL);
            rs->ruleset->add(current_rule);
        }
    
        rule->setDirection(PolicyRule::Both);

        if ( !i_intf.empty() && !o_intf.empty())
        {
            markCurrentRuleBad(
                std::string("Can not set inbound and outbound interface simultaneously. Was: -i ") + i_intf + " -o " + o_intf);
        } else
        {
            if ( !i_intf.empty())
            {
                rule->setDirection(PolicyRule::Inbound);
                newInterface(i_intf);
                Interface *intf = all_interfaces[i_intf];
                RuleElementItf* re =rule->getItf();
                re->addRef(intf);
            }

            if ( !o_intf.empty())
            {
                rule->setDirection(PolicyRule::Outbound);
                newInterface(o_intf);
                Interface *intf = all_interfaces[o_intf];
                RuleElementItf* re =rule->getItf();
                re->addRef(intf);
            }
        }

        current_rule->setComment(rule_comment);

    }

//     *Importer::logger << "Rule: " << rule->getActionAsString() << " "
//                       << "protocol=" << protocol << " "
//                       << "src=" << src_a << "/" << src_nm << " ";
//      if (dst_a!="")
//          *Importer::logger << "dst=" <<  dst_a << "/" << dst_nm << " ";
//      *Importer::logger << "\n";

    current_rule = NULL;
    rule_comment = "";

    clear();
}

void IPTImporter::pushNATRule()
{
    // populate all elements of the rule

    NATRule *rule = NATRule::cast(current_rule);

    FWOptions  *fwopt = getFirewallObject()->getOptionsObject();
    assert(fwopt!=NULL);

    FWOptions  *ropt = current_rule->getOptionsObject();
    assert(ropt!=NULL);

    addOSrc();
    addODst();
    addOSrv();

    if (src_nm.empty()) src_nm = InetAddr::getAllOnes().toString();
    if (dst_nm.empty()) dst_nm = InetAddr::getAllOnes().toString();
    if (nat_nm.empty()) nat_nm = InetAddr::getAllOnes().toString();

    if (target=="ACCEPT")
    {
        rule->setRuleType(NATRule::NONAT);
    }
    if (target=="MASQUERADE")
    {
        rule->setRuleType(NATRule::Masq);
        RuleElementTSrc *re = rule->getTSrc();
        assert(re!=NULL);
        if ( !o_intf.empty() )
        {
            newInterface(o_intf);
            Interface *intf = all_interfaces[o_intf];
            re->addRef(intf);
        } else
        {
            re->addRef(getFirewallObject());
        }
    }
    if (target=="SNAT")
    {
        rule->setRuleType(NATRule::SNAT);
        FWObject *tsrc = NULL;
        if (nat_addr1!=nat_addr2)
            tsrc = createAddressRange(nat_addr1, nat_addr2);
        else
            tsrc = createAddress(nat_addr1, nat_nm);

        RuleElementTSrc *re = rule->getTSrc();
        assert(re!=NULL);
        re->addRef(tsrc);

        if (!nat_port_range_start.empty())
        {
            str_tuple empty_range("0", "0");
            str_tuple nat_port_range(nat_port_range_start, nat_port_range_end);
            FWObject *s = createTCPUDPService(nat_port_range, empty_range,
                                              protocol);
            RuleElementTSrv *re = rule->getTSrv();
            assert(re!=NULL);
            re->addRef(s);
        }
        if (!o_intf.empty())
            markCurrentRuleBad(
                std::string("Original rule defines outbound interface '") + o_intf + "'.\n Replace address in TSrc with matching interface of the firewall.");

    }
    if (target=="DNAT")
    {
        rule->setRuleType(NATRule::DNAT);
        FWObject *tdst = NULL;
        if (nat_addr1!=nat_addr2)
            tdst = createAddressRange(nat_addr1, nat_addr2);
        else
            tdst = createAddress(nat_addr1, nat_nm);

        RuleElementTDst *re = rule->getTDst();
        assert(re!=NULL);
        re->addRef(tdst);

        if (!nat_port_range_start.empty())
        {
            str_tuple empty_range("0", "0");
            str_tuple nat_port_range(nat_port_range_start, nat_port_range_end);
            FWObject *s = createTCPUDPService(empty_range, nat_port_range,
                                              protocol);
            RuleElementTSrv *re = rule->getTSrv();
            assert(re!=NULL);
            re->addRef(s);
        }
        if (!i_intf.empty())
            markCurrentRuleBad(
                std::string("Original rule defines inbound interface '") + i_intf + "'.\n Replace address in ODst with matching interface of the firewall.");

    }
    if (target=="NETMAP")
    {
        FWObject *o = NULL;
        if (!src_a.empty())
        {
            rule->setRuleType(NATRule::SNetnat);
            o = createAddress(src_a, src_nm);
            RuleElementOSrc *osrc = rule->getOSrc();
            osrc->addRef(o);
            RuleElementTSrc *tsrc = rule->getTSrc();
            assert(tsrc!=NULL);
            o = createAddress(nat_addr1, nat_nm);
            tsrc->addRef(o);
        }
        if (!dst_a.empty())
        {
            rule->setRuleType(NATRule::DNetnat);
            o = createAddress(dst_a, dst_nm);
            RuleElementOSrc *odst = rule->getOSrc();
            odst->addRef(o);
            RuleElementTDst *tdst = rule->getTDst();
            assert(tdst!=NULL);
            o = createAddress(nat_addr1, nat_nm);
            tdst->addRef(o);
        }
    }

    current_rule->setComment(rule_comment);

    RuleSet *nat = RuleSet::cast(
        getFirewallObject()->getFirstByType(NAT::TYPENAME));
    assert( nat!=NULL );
    nat->add(current_rule);

    current_rule = NULL;
    rule_comment = "";

    clear();
}

Firewall* IPTImporter::finalize()
{
    // scan all UnidirectionalRuleSet objects, set interface and
    // direction in all rules of corresponding RuleSet and merge all
    // UnidirectionalRuleSet into one RuleSet object. Attach this
    // object to the firewall.

    if (fwbdebug) qDebug("IPTImporter::finalize()");

    if (haveFirewallObject())
    {
        FWObject *f = getFirewallObject();
        f->setStr("host_OS", "linux24");

        FWOptions  *fwopt = Firewall::cast(f)->getOptionsObject();
        assert(fwopt!=NULL);

        fwopt->setBool("firewall_is_part_of_any_and_networks", false);

        return getFirewallObject();
    }
    else
        return NULL;
}

void IPTImporter::newUnidirRuleSet(const std::string &ruleset_name)
{
    if (!isStandardChain(ruleset_name))
        Importer::newUnidirRuleSet(ruleset_name);
}


bool IPTImporter::isStandardChain(const std::string &ipt_chain)
{
    return (ipt_chain == "INPUT" ||
            ipt_chain == "OUTPUT" ||
            ipt_chain == "FORWARD" ||
            ipt_chain == "PREROUTING" ||
            ipt_chain == "POSTROUTING");
}

