/*
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* NATItem.cpp
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*
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* Created on: 10-01-2017
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* Author: Piotr Dergun
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*/
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#include "NATRouter.h"
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void NATRouter::initalizeNatTable()
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{
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try
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{
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natTable = new NATItem[65536];
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}
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catch (bad_alloc &ba)
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{
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cerr << "Nie mozna zaalokowac pamieci dla tablicy NAT!" << endl;
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exit(1);
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}
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}
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NATRouter::NATRouter()
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{
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this->initalizeNatTable();
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}
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NATRouter::NATRouter(string hostname) : Node(hostname)
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{
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this->initalizeNatTable();
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}
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NATRouter::NATRouter(string hostname, string ip, string mask) : Node(hostname, ip, mask)
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{
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this->initalizeNatTable();
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}
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NATRouter::NATRouter(string hostname, string ip, string mask, string gatewayIp) : Node(hostname, ip, mask, gatewayIp)
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{
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this->initalizeNatTable();
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}
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int NATRouter::getFreePort()
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{
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for (int i=1; i<65536; ++i)
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if (this->natTable[i].isFree())
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return i;
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return -1; // nie ma żadnego wolnego portu
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}
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NATRouter::~NATRouter()
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{
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if (natTable)
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delete [] natTable;
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}
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void NATRouter::onRecv()
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{
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Packet p = this->recv();
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if (p.getSrcPort() != 0)
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{
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// jezeli pakiet idzie z jednego wezla do drugiego w danej possieci to odeslij mu "jak switch"
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if (this->calculateNetwork(p.getDstIp(), this->getMask()) == this->getNetwork())
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{
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this->send(p, true);
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}
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else if (p.getDstIp() != this->getIp() && p.getDstIp() != this->getWanIp())
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{
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this->sNAT(&p);
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}
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else if (p.getDstIp() == this->getWanIp() && !this->natTable[p.getDstPort()].isFree())
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{
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this->dNAT(&p);
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}
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else
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{
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// TUTAJ ew. implementacja obslugi pakietu adresowanego do routera
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}
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}
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}
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void NATRouter::setWanIp(string wanIp)
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{
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this->netWanConf.ip = wanIp;
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this->setWanNetwork();
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}
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void NATRouter::setWanMask(string wanMask)
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{
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this->netWanConf.mask = wanMask;
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this->setWanNetwork();
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}
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void NATRouter::setWanGatewayIp(string wanGatewayIp)
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{
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this->netWanConf.gatewayIp = wanGatewayIp;
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}
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string NATRouter::getWanIp()
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{
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return this->netWanConf.ip;
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}
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string NATRouter::getWanMask()
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{
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return this->netWanConf.mask;
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}
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/*
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* funkcja SNAT zapisuje w tablicy NAT
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* numer portu zrodlowego komputera z LAN
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* oraz jego IP i przeksztalca pakiet, zmieniajac
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* zrodlowy IP na IP zewn. routera oraz wolny
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* port z tablicy NAT. Jezeli portu nie ma to funkcja
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* czeka, az sie zwolni
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*/
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void NATRouter::sNAT(Packet *packet)
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{
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int port;
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NATItem *natItem;
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while ((port = this->getFreePort()) == -1)
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{
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//TESTOWO
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cout << "Brak wolnych portow, czekam 1s" << endl;
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sleep(1);
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}
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// wstawiam do tablicy NAT info ze port zarezerowany na odbior
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natItem = &this->natTable[port];
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natItem->setIp(packet->getSrcIp());
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natItem->setPort(packet->getSrcPort());
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natItem->setTimeout(5);
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packet->setSrcIp(this->getWanIp()); // zamieniam IP lokalne na WAN'owe
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packet->setSrcPort(port); // zamieniam port lokalny na WAN'owy - z tablicy NAT
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this->send(*packet, true); // wysylam dalej
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natItem = NULL;
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}
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/*
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* funkcja DNAT ma za zadanie znalezc w tablicy NAT
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* port i adres IP wezla na ktory ma wrocic odpowiedz
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* z sieci Internet (z zewnatrz), a takze zwolnic ten
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* port
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*/
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void NATRouter::dNAT(Packet* packet)
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{
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NATItem *natItem = &this->natTable[packet->getDstPort()];
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packet->setDstIp(natItem->getIp()); // zamieniam IP lokalne na WAN'owe
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packet->setDstPort(natItem->getPort()); // zamieniam port NAT na lokalny wezla
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natItem->free(); // zwalniam port w routerze
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this->send(*packet, true); // wysylam dalej
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natItem = NULL;
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}
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void NATRouter::setWanNetwork()
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{
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this->netWanConf.network = this->calculateNetwork(this->getWanIp(), this->getWanMask());
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}
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string NATRouter::getWanNetwork()
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{
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return this->netWanConf.network;
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}
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string NATRouter::getWanGatewayIp()
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{
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return this->netWanConf.gatewayIp;
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}
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