348 lines
12 KiB
C++
348 lines
12 KiB
C++
/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
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/*
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* Copyright (c) 2006 INRIA
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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 General Public License version 2 as
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* published by the Free Software Foundation;
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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 General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
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*/
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#include "ns3/packet.h"
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#include "ns3/log.h"
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#include "ns3/node.h"
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#include "ns3/net-device.h"
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#include "ns3/object-vector.h"
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#include "ns3/trace-source-accessor.h"
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#include "ipv4-l3-protocol.h"
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#include "arp-l3-protocol.h"
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#include "arp-header.h"
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#include "arp-cache.h"
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#include "ipv4-interface.h"
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NS_LOG_COMPONENT_DEFINE ("ArpL3Protocol");
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namespace ns3 {
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const uint16_t ArpL3Protocol::PROT_NUMBER = 0x0806;
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NS_OBJECT_ENSURE_REGISTERED (ArpL3Protocol);
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TypeId
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ArpL3Protocol::GetTypeId (void)
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{
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static TypeId tid = TypeId ("ns3::ArpL3Protocol")
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.SetParent<Object> ()
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.AddConstructor<ArpL3Protocol> ()
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.AddAttribute ("CacheList",
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"The list of ARP caches",
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ObjectVectorValue (),
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MakeObjectVectorAccessor (&ArpL3Protocol::m_cacheList),
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MakeObjectVectorChecker<ArpCache> ())
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.AddTraceSource ("Drop",
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"Packet dropped because not enough room in pending queue for a specific cache entry.",
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MakeTraceSourceAccessor (&ArpL3Protocol::m_dropTrace))
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;
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return tid;
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}
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ArpL3Protocol::ArpL3Protocol ()
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{
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NS_LOG_FUNCTION (this);
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}
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ArpL3Protocol::~ArpL3Protocol ()
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{
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NS_LOG_FUNCTION (this);
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}
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void
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ArpL3Protocol::SetNode (Ptr<Node> node)
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{
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NS_LOG_FUNCTION (this);
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m_node = node;
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}
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/*
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* This method is called by AddAgregate and completes the aggregation
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* by setting the node in the ipv4 stack
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*/
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void
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ArpL3Protocol::NotifyNewAggregate ()
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{
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if (m_node == 0)
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{
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Ptr<Node>node = this->GetObject<Node> ();
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//verify that it's a valid node and that
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//the node was not set before
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if (node != 0)
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{
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this->SetNode (node);
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}
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}
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Object::NotifyNewAggregate ();
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}
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void
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ArpL3Protocol::DoDispose (void)
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{
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NS_LOG_FUNCTION (this);
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for (CacheList::iterator i = m_cacheList.begin (); i != m_cacheList.end (); ++i)
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{
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Ptr<ArpCache> cache = *i;
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cache->Dispose ();
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}
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m_cacheList.clear ();
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m_node = 0;
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Object::DoDispose ();
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}
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Ptr<ArpCache>
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ArpL3Protocol::CreateCache (Ptr<NetDevice> device, Ptr<Ipv4Interface> interface)
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{
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NS_LOG_FUNCTION (this << device << interface);
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Ptr<Ipv4L3Protocol> ipv4 = m_node->GetObject<Ipv4L3Protocol> ();
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Ptr<ArpCache> cache = CreateObject<ArpCache> ();
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cache->SetDevice (device, interface);
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NS_ASSERT (device->IsBroadcast ());
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device->AddLinkChangeCallback (MakeCallback (&ArpCache::Flush, cache));
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cache->SetArpRequestCallback (MakeCallback (&ArpL3Protocol::SendArpRequest, this));
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m_cacheList.push_back (cache);
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return cache;
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}
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Ptr<ArpCache>
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ArpL3Protocol::FindCache (Ptr<NetDevice> device)
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{
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NS_LOG_FUNCTION (this << device);
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for (CacheList::const_iterator i = m_cacheList.begin (); i != m_cacheList.end (); i++)
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{
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if ((*i)->GetDevice () == device)
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{
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return *i;
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}
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}
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NS_ASSERT (false);
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// quiet compiler
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return 0;
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}
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void
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ArpL3Protocol::Receive(Ptr<NetDevice> device, Ptr<const Packet> p, uint16_t protocol, const Address &from,
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const Address &to, NetDevice::PacketType packetType)
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{
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NS_LOG_FUNCTION (this << device << p->GetSize () << protocol << from << to << packetType);
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Ptr<Packet> packet = p->Copy ();
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NS_LOG_LOGIC ("ARP: received packet of size "<< packet->GetSize ());
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Ptr<ArpCache> cache = FindCache (device);
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//
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// If we're connected to a real world network, then some of the fields sizes
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// in an ARP packet can vary in ways not seen in simulations. We need to be
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// able to detect ARP packets with headers we don't recongnize and not process
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// them instead of crashing. The ArpHeader will return 0 if it can't deal
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// with the received header.
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//
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ArpHeader arp;
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uint32_t size = packet->RemoveHeader (arp);
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if (size == 0)
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{
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NS_LOG_LOGIC ("ARP: Cannot remove ARP header");
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return;
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}
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NS_LOG_LOGIC ("ARP: received "<< (arp.IsRequest ()? "request" : "reply") <<
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" node="<<m_node->GetId ()<<", got request from " <<
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arp.GetSourceIpv4Address () << " for address " <<
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arp.GetDestinationIpv4Address () << "; we have addresses: ");
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for (uint32_t i = 0; i < cache->GetInterface ()->GetNAddresses (); i++)
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{
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NS_LOG_LOGIC (cache->GetInterface ()->GetAddress (i).GetLocal () << ", ");
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}
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/**
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* Note: we do not update the ARP cache when we receive an ARP request
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* from an unknown node. See bug #107
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*/
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bool found = false;
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for (uint32_t i = 0; i < cache->GetInterface ()->GetNAddresses (); i++)
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{
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if (arp.IsRequest () && arp.GetDestinationIpv4Address () ==
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cache->GetInterface ()->GetAddress (i).GetLocal ())
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{
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found = true;
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NS_LOG_LOGIC ("node="<<m_node->GetId () <<", got request from " <<
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arp.GetSourceIpv4Address () << " -- send reply");
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SendArpReply (cache, arp.GetDestinationIpv4Address (), arp.GetSourceIpv4Address (),
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arp.GetSourceHardwareAddress ());
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break;
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}
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else if (arp.IsReply () &&
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arp.GetDestinationIpv4Address ().IsEqual (cache->GetInterface ()->GetAddress (i).GetLocal ()) &&
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arp.GetDestinationHardwareAddress () == device->GetAddress ())
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{
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found = true;
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Ipv4Address from = arp.GetSourceIpv4Address ();
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ArpCache::Entry *entry = cache->Lookup (from);
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if (entry != 0)
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{
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if (entry->IsWaitReply ())
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{
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NS_LOG_LOGIC ("node="<< m_node->GetId () <<
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", got reply from " << arp.GetSourceIpv4Address ()
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<< " for waiting entry -- flush");
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Address from_mac = arp.GetSourceHardwareAddress ();
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entry->MarkAlive (from_mac);
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Ptr<Packet> pending = entry->DequeuePending();
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while (pending != 0)
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{
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cache->GetInterface ()->Send (pending,
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arp.GetSourceIpv4Address ());
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pending = entry->DequeuePending();
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}
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}
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else
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{
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// ignore this reply which might well be an attempt
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// at poisening my arp cache.
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NS_LOG_LOGIC("node="<<m_node->GetId ()<<", got reply from " <<
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arp.GetSourceIpv4Address () <<
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" for non-waiting entry -- drop");
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m_dropTrace (packet);
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}
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}
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else
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{
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NS_LOG_LOGIC ("node="<<m_node->GetId ()<<", got reply for unknown entry -- drop");
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m_dropTrace (packet);
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}
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break;
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}
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}
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if (found == false)
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{
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NS_LOG_LOGIC ("node="<<m_node->GetId ()<<", got request from " <<
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arp.GetSourceIpv4Address () << " for unknown address " <<
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arp.GetDestinationIpv4Address () << " -- drop");
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}
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}
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bool
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ArpL3Protocol::Lookup (Ptr<Packet> packet, Ipv4Address destination,
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Ptr<NetDevice> device,
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Ptr<ArpCache> cache,
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Address *hardwareDestination)
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{
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NS_LOG_FUNCTION (this << packet << destination << device << cache);
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ArpCache::Entry *entry = cache->Lookup (destination);
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if (entry != 0)
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{
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if (entry->IsExpired ())
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{
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if (entry->IsDead ())
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{
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NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
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", dead entry for " << destination << " expired -- send arp request");
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entry->MarkWaitReply (packet);
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SendArpRequest (cache, destination);
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}
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else if (entry->IsAlive ())
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{
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NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
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", alive entry for " << destination << " expired -- send arp request");
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entry->MarkWaitReply (packet);
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SendArpRequest (cache, destination);
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}
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else if (entry->IsWaitReply ())
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{
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NS_FATAL_ERROR ("Test for possibly unreachable code-- please file a bug report, with a test case, if this is ever hit");
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}
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}
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else
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{
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if (entry->IsDead ())
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{
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NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
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", dead entry for " << destination << " valid -- drop");
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m_dropTrace (packet);
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}
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else if (entry->IsAlive ())
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{
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NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
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", alive entry for " << destination << " valid -- send");
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*hardwareDestination = entry->GetMacAddress ();
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return true;
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}
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else if (entry->IsWaitReply ())
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{
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NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
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", wait reply for " << destination << " valid -- drop previous");
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if (!entry->UpdateWaitReply (packet))
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{
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m_dropTrace (packet);
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}
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}
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}
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}
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else
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{
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// This is our first attempt to transmit data to this destination.
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NS_LOG_LOGIC ("node="<<m_node->GetId ()<<
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", no entry for " << destination << " -- send arp request");
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entry = cache->Add (destination);
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entry->MarkWaitReply (packet);
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SendArpRequest (cache, destination);
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}
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return false;
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}
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void
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ArpL3Protocol::SendArpRequest (Ptr<const ArpCache> cache, Ipv4Address to)
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{
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NS_LOG_FUNCTION (this << cache << to);
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ArpHeader arp;
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// need to pick a source address; use routing implementation to select
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Ptr<Ipv4L3Protocol> ipv4 = m_node->GetObject<Ipv4L3Protocol> ();
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Ptr<NetDevice> device = cache->GetDevice ();
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NS_ASSERT (device != 0);
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Ipv4Header header;
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header.SetDestination (to);
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Ptr<Packet> packet = Create<Packet> ();
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Ipv4Address source = ipv4->SelectSourceAddress (device, to, Ipv4InterfaceAddress::GLOBAL);
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NS_LOG_LOGIC ("ARP: sending request from node "<<m_node->GetId ()<<
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" || src: " << device->GetAddress () << " / " << source <<
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" || dst: " << device->GetBroadcast () << " / " << to);
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arp.SetRequest (device->GetAddress (), source, device->GetBroadcast (), to);
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packet->AddHeader (arp);
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cache->GetDevice ()->Send (packet, device->GetBroadcast (), PROT_NUMBER);
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}
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void
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ArpL3Protocol::SendArpReply (Ptr<const ArpCache> cache, Ipv4Address myIp, Ipv4Address toIp, Address toMac)
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{
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NS_LOG_FUNCTION (this << cache << toIp << toMac);
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ArpHeader arp;
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NS_LOG_LOGIC ("ARP: sending reply from node "<<m_node->GetId ()<<
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"|| src: " << cache->GetDevice ()->GetAddress () <<
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" / " << myIp <<
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" || dst: " << toMac << " / " << toIp);
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arp.SetReply (cache->GetDevice ()->GetAddress (), myIp, toMac, toIp);
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Ptr<Packet> packet = Create<Packet> ();
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packet->AddHeader (arp);
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cache->GetDevice ()->Send (packet, toMac, PROT_NUMBER);
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}
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}//namespace ns3
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