src/internet-stack/ipv4-netfilter.cc
changeset 4638 19aa5f9b4bdf
parent 4637 0882bb6eac0b
     1.1 --- a/src/internet-stack/ipv4-netfilter.cc	Fri Jul 31 00:57:33 2009 +0600
     1.2 +++ b/src/internet-stack/ipv4-netfilter.cc	Thu Aug 06 01:55:49 2009 +0600
     1.3 @@ -18,18 +18,38 @@
     1.4   * Author: Qasim Javed <qasim@utdallas.edu>
     1.5   */
     1.6  #include "ns3/log.h"
     1.7 +#include "ns3/uinteger.h"
     1.8  #include "ipv4-netfilter.h"
     1.9  #include "ip-conntrack-info.h"
    1.10  #include "ipv4-conntrack-l3-protocol.h"
    1.11  #include "tcp-conntrack-l4-protocol.h"
    1.12  #include "udp-conntrack-l4-protocol.h"
    1.13  #include "icmpv4-conntrack-l4-protocol.h"
    1.14 +#include "tcp-header.h"
    1.15 +#include "udp-header.h"
    1.16  
    1.17  NS_LOG_COMPONENT_DEFINE ("Ipv4Netfilter");
    1.18  
    1.19  namespace ns3 {
    1.20 +
    1.21 +NS_OBJECT_ENSURE_REGISTERED (Ipv4Netfilter);
    1.22 +
    1.23 +TypeId 
    1.24 +Ipv4Netfilter::GetTypeId (void)
    1.25 +{
    1.26 +  static TypeId tId = TypeId ("ns3::Ipv4Netfilter")
    1.27 +    .SetParent<Object> ()
    1.28 +    .AddAttribute ("EnableNat", "0 disbales NAT and is the default, 1 enabled NAT",
    1.29 +                   UintegerValue (0),
    1.30 +                   MakeUintegerAccessor (&Ipv4Netfilter::m_enableNat),
    1.31 +                   MakeUintegerChecker <uint8_t> ())
    1.32 +    ;
    1.33 +
    1.34 +  return tId;
    1.35 +}
    1.36    
    1.37  Ipv4Netfilter::Ipv4Netfilter ()
    1.38 +  : m_enableNat (0)
    1.39  {
    1.40    NS_LOG_FUNCTION_NOARGS();
    1.41  
    1.42 @@ -52,23 +72,31 @@
    1.43    /* Create and register ICMP connection tracking module */
    1.44    Ptr<Icmpv4ConntrackL4Protocol> icmpv4 = Create<Icmpv4ConntrackL4Protocol> ();
    1.45    this->RegisterL4Protocol (icmpv4);
    1.46 +  
    1.47 +  //Ptr <NetworkAddressTranslation> networkAddressTranslation = Create<NetworkAddressTranslation> (this);
    1.48  
    1.49    /* Create and register hook callbacks */
    1.50    NetfilterHookCallback preRouting = MakeCallback (&Ipv4Netfilter::NetfilterConntrackIn, this);
    1.51    NetfilterHookCallback localIn = MakeCallback (&Ipv4ConntrackL3Protocol::Ipv4Confirm, PeekPointer (ipv4));
    1.52  
    1.53 -  Ipv4NetfilterHook nfh = Ipv4NetfilterHook (1, NF_INET_PRE_ROUTING, 1, preRouting); 
    1.54 -  Ipv4NetfilterHook nfh1 = Ipv4NetfilterHook (1, NF_INET_LOCAL_OUT, 1, preRouting); 
    1.55 -  Ipv4NetfilterHook nfh2 = Ipv4NetfilterHook (1, NF_INET_POST_ROUTING, 1, localIn); 
    1.56 -  Ipv4NetfilterHook nfh3 = Ipv4NetfilterHook (1, NF_INET_LOCAL_IN, 1, localIn); 
    1.57 +  Ipv4NetfilterHook nfh = Ipv4NetfilterHook (1, NF_INET_PRE_ROUTING, NF_IP_PRI_CONNTRACK , preRouting); 
    1.58 +  Ipv4NetfilterHook nfh1 = Ipv4NetfilterHook (1, NF_INET_LOCAL_OUT, NF_IP_PRI_CONNTRACK, preRouting); 
    1.59 +  Ipv4NetfilterHook nfh2 = Ipv4NetfilterHook (1, NF_INET_POST_ROUTING, NF_IP_PRI_CONNTRACK_CONFIRM, localIn); 
    1.60 +  Ipv4NetfilterHook nfh3 = Ipv4NetfilterHook (1, NF_INET_LOCAL_IN, NF_IP_PRI_CONNTRACK_CONFIRM, localIn); 
    1.61 +  
    1.62    this->RegisterNetfilterHook (nfh);
    1.63    this->RegisterNetfilterHook (nfh1);
    1.64    this->RegisterNetfilterHook (nfh2);
    1.65    this->RegisterNetfilterHook (nfh3);
    1.66 +
    1.67 +  if (m_enableNat)
    1.68 +    EnableNat ();
    1.69 +
    1.70 +  nextAvailablePort = 1024;
    1.71  }
    1.72  
    1.73  uint32_t 
    1.74 -Ipv4Netfilter::RegisterNetfilterHook (Ipv4NetfilterHook& hook)
    1.75 +Ipv4Netfilter::RegisterNetfilterHook (Ipv4NetfilterHook hook)
    1.76  {
    1.77    //NS_LOG_FUNCTION (this << hook);
    1.78    m_netfilterHooks[hook.GetHookNumber ()].Insert (hook);
    1.79 @@ -138,13 +166,10 @@
    1.80  }
    1.81  
    1.82  int 
    1.83 -Ipv4Netfilter::UpdateConntrackStatus (NetfilterConntrackTuple tuple, uint32_t status)
    1.84 +Ipv4Netfilter::UpdateConntrackInfo (uint8_t info)
    1.85  {
    1.86 -  uint32_t curStatus1 = m_netfilterTupleHash[IP_CT_DIR_ORIGINAL][tuple].GetStatus ();
    1.87 -  m_netfilterTupleHash[IP_CT_DIR_ORIGINAL][tuple].SetStatus (curStatus1 | status);
    1.88 -  uint32_t curStatus2 = m_netfilterTupleHash[IP_CT_DIR_REPLY][tuple].GetStatus ();
    1.89 -  m_netfilterTupleHash[IP_CT_DIR_REPLY][tuple].SetStatus (curStatus2 | status);
    1.90 -
    1.91 +  m_hash[currentOriginalTuple].SetInfo (info);
    1.92 +  m_hash[currentReplyTuple].SetInfo (info);
    1.93    return 0;
    1.94  }
    1.95  
    1.96 @@ -206,7 +231,7 @@
    1.97    NS_LOG_FUNCTION (this << packet);
    1.98    //NetfilterConntrackTuple tuple (ipHeader.GetSource(), 0, ipHeader.GetDestination(), 0);
    1.99    NetfilterConntrackTuple tuple;
   1.100 -  uint8_t conntrackInfo;
   1.101 +  uint8_t conntrackInfo = 0;
   1.102    
   1.103    /* Get a tuple from the information in the packet */
   1.104    if (!NetfilterConntrackGetTuple (packet, protocolFamily, protocol, tuple, l3Protocol, l4Protocol))
   1.105 @@ -223,6 +248,14 @@
   1.106      //TupleHashI newIt = NewConnection(tuple, l3Protocol, l4Protocol, packet);
   1.107      it = NewConnection (tuple, l3Protocol, l4Protocol, packet);
   1.108    }
   1.109 +  
   1.110 +  NetfilterConntrackTuple replyTuple;
   1.111 +
   1.112 +  if (!InvertTuple (replyTuple, tuple, l3Protocol, l4Protocol))
   1.113 +    return -1;
   1.114 +    
   1.115 +  currentOriginalTuple = tuple;
   1.116 +  currentReplyTuple = replyTuple;
   1.117  
   1.118    /* TODO: Add a pointer to the hashed tuple in IpConntrackInfo()
   1.119     * and store these tuples somehwere, when you destruct then you
   1.120 @@ -236,7 +269,8 @@
   1.121      setReply = 1;
   1.122    } else {
   1.123      NS_LOG_DEBUG (":: Packet is in the original direction ::");
   1.124 -    if ( m_hash[tuple].GetStatus () & IPS_SEEN_REPLY_BIT) {
   1.125 +    if ( m_hash[tuple].GetStatus () & IPS_SEEN_REPLY) {
   1.126 +      NS_LOG_DEBUG (":: Connection ESTABLISHED! ::");
   1.127        conntrackInfo = IP_CT_ESTABLISHED;
   1.128      }
   1.129      else {
   1.130 @@ -245,7 +279,10 @@
   1.131      }
   1.132  
   1.133    }
   1.134 -  NS_LOG_DEBUG ("Adding the conntrack packet tag" );
   1.135 +
   1.136 +  m_unconfirmed[tuple].SetInfo (conntrackInfo);
   1.137 +  //UpdateConntrackInfo (conntrackInfo);
   1.138 +  /*NS_LOG_DEBUG ("Adding the conntrack packet tag" );
   1.139    ConntrackTag ctTag;
   1.140    bool tagFound = packet->PeekPacketTag (ctTag);
   1.141  
   1.142 @@ -253,6 +290,7 @@
   1.143      packet->AddPacketTag (ConntrackTag (conntrackInfo));
   1.144    else
   1.145      NS_LOG_DEBUG ("Tag already present");
   1.146 +    */
   1.147  
   1.148    return NF_ACCEPT;
   1.149  
   1.150 @@ -286,6 +324,13 @@
   1.151    // Call layer 4 Packet callback
   1.152    //uint32_t ret = l4proto->packet(packet, protocolFamily, hookNumber);
   1.153  
   1.154 +  if (setReply)
   1.155 +  {
   1.156 +    NS_LOG_DEBUG ("Setting IPS_SEEN_REPLY");
   1.157 +    m_hash[currentOriginalTuple].SetStatus ( IPS_SEEN_REPLY );
   1.158 +    m_hash[currentReplyTuple].SetStatus ( IPS_SEEN_REPLY );
   1.159 +  }
   1.160 +
   1.161    return NF_ACCEPT;
   1.162  
   1.163  }
   1.164 @@ -299,61 +344,187 @@
   1.165    /* If this packet has been seen previously, Ignore. */
   1.166  
   1.167    /* Find layer 3 helper for this packet */
   1.168 -  Ptr<NetfilterConntrackL3Protocol> l3proto = FindL3ProtocolHelper (1);
   1.169 +  /*Ptr<NetfilterConntrackL3Protocol> l3proto = FindL3ProtocolHelper (1);
   1.170  
   1.171 -  Ipv4Header ipHeader;
   1.172 +    Ipv4Header ipHeader;
   1.173  
   1.174    //packet->RemoveHeader(ipHeader);
   1.175    packet->PeekHeader (ipHeader);
   1.176  
   1.177    NS_LOG_DEBUG ( "IP header protocol: " << (int)ipHeader.GetProtocol ());
   1.178 -  
   1.179 +
   1.180    Ptr<NetfilterConntrackL4Protocol> l4proto = FindL4ProtocolHelper (ipHeader.GetProtocol ());
   1.181 -  
   1.182 -  NetfilterConntrackTuple orig;
   1.183 -  
   1.184 +
   1.185 +  NetfilterConntrackTuple orig;*/
   1.186 +
   1.187    /* Get a tuple from the information in the packet */
   1.188 -  if (!NetfilterConntrackGetTuple (packet, 1, ipHeader.GetProtocol (), orig, l3proto, l4proto))
   1.189 -  {
   1.190 +  /*if (!NetfilterConntrackGetTuple (packet, 1, ipHeader.GetProtocol (), orig, l3proto, l4proto))
   1.191 +    {
   1.192      NS_LOG_DEBUG ("Cannot create a tuple from the packet");
   1.193      return -1;
   1.194 -  }
   1.195 -  
   1.196 -  NetfilterConntrackTuple reply;
   1.197 +    }
   1.198  
   1.199 -  InvertTuple (reply, orig, l3proto, l4proto);
   1.200 +    NetfilterConntrackTuple reply;
   1.201 +
   1.202 +
   1.203 +    InvertTuple (reply, orig, l3proto, l4proto);
   1.204 +
   1.205 +    currentOriginalTuple = orig;
   1.206 +    currentReplyTuple = reply;
   1.207 +
   1.208 +    NS_LOG_DEBUG ("Current Original Tuple: " << currentOriginalTuple.GetSource () << ", " << currentOriginalTuple.GetDestination ());
   1.209 +    NS_LOG_DEBUG ("Current Reply Tuple: " << currentReplyTuple.GetSource () << ", " << currentReplyTuple.GetDestination ());
   1.210 +  //currentTuple[IP_CT_DIR_REPLY] = reply;*/
   1.211  
   1.212    /**************************/
   1.213  
   1.214 -  ConntrackTag ctTag;
   1.215 +  /*ConntrackTag ctTag;
   1.216  
   1.217 -  if (!packet->PeekPacketTag (ctTag))
   1.218 -  {
   1.219 +    if (!packet->PeekPacketTag (ctTag))
   1.220 +    {
   1.221      NS_LOG_DEBUG ("ConntrackTag not found");
   1.222      return 0;
   1.223 -  }
   1.224 -  else {
   1.225 +    }
   1.226 +    else {
   1.227      if ( CTINFO2DIR (ctTag.GetConntrack ()) != IP_CT_DIR_ORIGINAL)
   1.228 -      return 0;
   1.229 +    return 0;
   1.230  
   1.231      if (m_hash.find (orig) != m_hash.end () && m_hash.find (reply) != m_hash.end () )
   1.232      {
   1.233 -      NS_LOG_DEBUG ("Entries already present!");
   1.234 -      return NF_DROP;
   1.235 +    NS_LOG_DEBUG ("Entries already present!");
   1.236 +    return NF_DROP;
   1.237      }
   1.238  
   1.239      NS_LOG_DEBUG ("Creating confirmed hash entries");
   1.240 -    //m_hash[orig] = IpConntrackInfo().SetStatus(IPS_CONFIRMED);
   1.241 -    m_hash[orig] = IpConntrackInfo ();
   1.242 -    m_hash[reply] = IpConntrackInfo ();
   1.243 +  //m_hash[orig] = IpConntrackInfo().SetStatus(IPS_CONFIRMED);
   1.244 +  m_hash[orig] = IpConntrackInfo ();
   1.245 +  m_hash[reply] = IpConntrackInfo ();
   1.246  
   1.247 +  }*/
   1.248 +
   1.249 +  if ( CTINFO2DIR (m_unconfirmed[currentOriginalTuple].GetInfo ()) != IP_CT_DIR_ORIGINAL) 
   1.250 +  {
   1.251 +    NS_LOG_DEBUG ("Not a packet in the original direction");
   1.252 +    return NF_ACCEPT;
   1.253    }
   1.254  
   1.255 -  //packet->AddHeader(ipHeader);
   1.256 +  /*if (m_hash.find (currentOriginalTuple) != m_hash.end () && m_hash.find (currentReplyTuple) != m_hash.end () )
   1.257 +  {
   1.258 +    NS_LOG_DEBUG ("Entries already present!");
   1.259 +    return NF_DROP;
   1.260 +  }*/
   1.261 +
   1.262 +  NS_LOG_DEBUG ("Creating confirmed hash entries");
   1.263 +  m_hash[currentOriginalTuple] = m_unconfirmed[currentOriginalTuple];
   1.264 +  m_hash[currentReplyTuple] = m_unconfirmed[currentOriginalTuple];
   1.265  
   1.266    return 0;
   1.267  }
   1.268      
   1.269 +uint32_t 
   1.270 +Ipv4Netfilter::NetfilterDoNat (Hooks_t hookNumber, Ptr<Packet> p, 
   1.271 +                               Ptr<NetDevice> in, Ptr<NetDevice> out, ContinueCallback& ccb)
   1.272 +{
   1.273 +  NS_LOG_FUNCTION ( this << p );
   1.274 +  /*ConntrackTag ctTag;
   1.275 +
   1.276 +  bool found = p->PeekPacketTag (ctTag);
   1.277 +
   1.278 +  if (!found)
   1.279 +  {
   1.280 +    NS_LOG_DEBUG ("Conntrack tag not found");
   1.281 +    return NF_ACCEPT;
   1.282 +  }*/
   1.283 +
   1.284 +  /* Conntrack has a higher priority so currentOriginalTuple and
   1.285 +   * currentReply tuple should always be correct 
   1.286 +   */
   1.287 +
   1.288 +  //std::vector<NatRule>::iterator it = FindNatDevice (out);
   1.289 +
   1.290 +  /*if (it == m_natRules.end ())
   1.291 +  {
   1.292 +    NS_LOG_DEBUG ("No NAT rule for device " << out->GetId ());
   1.293 +    return NF_ACCEPT;
   1.294 +  }*/
   1.295 +        
   1.296 +  NS_LOG_DEBUG ("Current Original Tuple: " << currentOriginalTuple.GetSource () << ", " << currentOriginalTuple.GetDestination ());
   1.297 +  NS_LOG_DEBUG ("Current Reply Tuple: " << currentReplyTuple.GetSource () << ", " << currentReplyTuple.GetDestination ());
   1.298 +
   1.299 +  NS_LOG_DEBUG ("ConntrackInfo: " << (uint16_t)m_unconfirmed[currentOriginalTuple].GetInfo () );
   1.300 +
   1.301 +  /* TODO: Why are you checking m_hash here when the info is in
   1.302 +   * m_unconfirmed. This could be a problem because NAT is sandwiched
   1.303 +   * between conntrack hook callbacks 
   1.304 +   */
   1.305 +  switch (m_unconfirmed[currentOriginalTuple].GetInfo ())
   1.306 +  {
   1.307 +    case IP_CT_RELATED:
   1.308 +    case IP_CT_RELATED + IP_CT_IS_REPLY:
   1.309 +      /* This should be updated when "expectations" are added */
   1.310 +      break;
   1.311 +
   1.312 +    case IP_CT_NEW:
   1.313 +
   1.314 +      if ( hookNumber == NF_INET_POST_ROUTING )
   1.315 +      {
   1.316 +        NS_LOG_DEBUG ("SRC_NAT: New Connection encountered");
   1.317 +
   1.318 +        TupleHashI it;
   1.319 +
   1.320 +
   1.321 +        if ( (it = m_hash.find (currentOriginalTuple)) != m_hash.end ())
   1.322 +        {
   1.323 +          if ( !((it->second).GetStatus () & IPS_SRC_NAT_DONE) )
   1.324 +          {
   1.325 +            /* Get a unique tuple and create a mapping */
   1.326 +
   1.327 +            NS_LOG_DEBUG ("Doing rule lookup at device " << out->GetIfIndex ());
   1.328 +            std::vector<NatRule>::iterator it = 
   1.329 +              FindNatRule ( Ipv4Address (currentOriginalTuple.GetSource ()), out );
   1.330 +
   1.331 +            if ( it == m_natRules.end () )
   1.332 +            {
   1.333 +              NS_LOG_DEBUG ("No rule matched!");
   1.334 +              return NF_ACCEPT;
   1.335 +            }
   1.336 +                                    
   1.337 +            NS_LOG_DEBUG ("Creating a NAT mapping");
   1.338 +
   1.339 +            /* Create a NULL mapping, which does not contain port numbers */
   1.340 +            NetfilterConntrackTuple mapping = 
   1.341 +              NetfilterConntrackTuple (it->GetMangledSource (), nextAvailablePort,
   1.342 +                                         currentOriginalTuple.GetDestination (), 9);
   1.343 +            mapping.SetDirection (IP_CT_DIR_ORIGINAL);
   1.344 +            nextAvailablePort++;
   1.345 +
   1.346 +            NS_LOG_DEBUG ("Creating a NAT mapping for the tuple " << currentOriginalTuple 
   1.347 +                          << ": " << mapping );
   1.348 +            m_natMappings[currentOriginalTuple] = mapping;
   1.349 +            m_natReplyLookup[mapping] = currentOriginalTuple;
   1.350 +          }
   1.351 +
   1.352 +  
   1.353 +          NS_LOG_DEBUG (":: Translating addresses and fixing IP checksum ::");
   1.354 +          NetfilterNatPacket (hookNumber, p);
   1.355 +        }
   1.356 +        else
   1.357 +          NS_LOG_DEBUG ("BUG: currentTuple non-existent in hash!");
   1.358 +      }
   1.359 +
   1.360 +      break;
   1.361 +
   1.362 +    default:
   1.363 +      NS_LOG_DEBUG ("SRC_NAT: Connection is established!");
   1.364 +      NS_LOG_DEBUG (":: Translating addresses and fixing IP checksum ::");
   1.365 +      NetfilterNatPacket (hookNumber, p);
   1.366 +  
   1.367 +  }
   1.368 +
   1.369 +
   1.370 +  return NF_ACCEPT;
   1.371 +}
   1.372 +    
   1.373  bool 
   1.374  Ipv4Netfilter::InvertTuple (NetfilterConntrackTuple& inverse, NetfilterConntrackTuple& orig,
   1.375                      Ptr<NetfilterConntrackL3Protocol> l3Protocol,
   1.376 @@ -369,31 +540,188 @@
   1.377    return l4Protocol->InvertTuple (inverse, orig);
   1.378  
   1.379  }
   1.380 +    
   1.381 +TupleHash&
   1.382 +Ipv4Netfilter::GetHash ()
   1.383 +{
   1.384 +  return m_hash;
   1.385 +}
   1.386 +    
   1.387 +void 
   1.388 +Ipv4Netfilter::AddNatRule (NatRule natRule)
   1.389 +{
   1.390 +  m_natRules.push_back (natRule);
   1.391 +}
   1.392  
   1.393 -/*uint32_t 
   1.394 -Ipv4Netfilter::Ipv4Confirm(Hooks_t hookNumber, Ptr<Packet> packet, Ptr<NetDevice> in,
   1.395 -                      Ptr<NetDevice> out, ContinueCallback& ccb)
   1.396 +std::vector<NatRule>::iterator
   1.397 +Ipv4Netfilter::FindNatRule (NatRule natRule)
   1.398  {
   1.399 -  NS_LOG_DEBUG (":: Executing hook function Ipv4Confirm ::");
   1.400 -  ConntrackTag ctinfo;
   1.401 -  bool tagFound = packet->PeekPacketTag(ctinfo);
   1.402 +  std::vector<NatRule>::iterator it = m_natRules.begin ();
   1.403  
   1.404 -  if (!tagFound || ctinfo.GetConntrack() == IP_CT_RELATED + IP_CT_IS_REPLY)
   1.405 +  for ( ; it != m_natRules.end ();  it++)
   1.406    {
   1.407 -    NS_LOG_DEBUG ("Conntrack tag not found");
   1.408 -    return 0;
   1.409 +    if ( *it == natRule )
   1.410 +      return it;
   1.411    }
   1.412  
   1.413 -  // Call conntrack helper here
   1.414 +  return m_natRules.end ();
   1.415 +}
   1.416  
   1.417 -  // NetfilterConntrackConfirm
   1.418 -  NS_LOG_DEBUG ("Invoking the ContinueCallback");
   1.419 -  ccb (packet);
   1.420 +std::vector<NatRule>::iterator
   1.421 +Ipv4Netfilter::FindNatRule (Ipv4Address orig, Ptr<NetDevice> out)
   1.422 +{
   1.423 +  std::vector<NatRule>::iterator it = m_natRules.begin ();
   1.424  
   1.425 +  NS_LOG_DEBUG ("Number of rules: " << m_natRules.size () );
   1.426 +  NS_LOG_DEBUG ("Orig: " << orig );
   1.427  
   1.428 +  for ( ; it != m_natRules.end ();  it++)
   1.429 +  {
   1.430 +    NS_LOG_DEBUG ("Rule source: " << it->GetOriginalSource () << ", passed in source: " << orig);
   1.431 +    NS_LOG_DEBUG ("Rule device: " << it->GetDevice () << ", passed in dev: " << out);
   1.432 +    if ( it->GetOriginalSource () == orig && it->GetDevice () == out)
   1.433 +    {
   1.434 +      NS_LOG_DEBUG ("Rule match found!");
   1.435 +      return it;
   1.436 +    }
   1.437 +  }
   1.438  
   1.439 +  return m_natRules.end ();
   1.440 +}
   1.441 +    
   1.442 +void 
   1.443 +Ipv4Netfilter::EnableNat ()
   1.444 +{
   1.445 +  m_enableNat = 1;
   1.446  
   1.447 -  return 0;
   1.448 -}*/
   1.449 +  NS_LOG_DEBUG (":: Enabling NAT ::");
   1.450 +
   1.451 +  NetfilterHookCallback doNat = MakeCallback (&Ipv4Netfilter::NetfilterDoNat, this);
   1.452 +
   1.453 +  Ipv4NetfilterHook natCallback1 = Ipv4NetfilterHook (1, NF_INET_POST_ROUTING, NF_IP_PRI_NAT_SRC, doNat); 
   1.454 +  Ipv4NetfilterHook natCallback2 = Ipv4NetfilterHook (1, NF_INET_PRE_ROUTING, NF_IP_PRI_NAT_DST, doNat); 
   1.455 +  
   1.456 +
   1.457 +  this->RegisterNetfilterHook (natCallback1);
   1.458 +  this->RegisterNetfilterHook (natCallback2);
   1.459 +}
   1.460 +
   1.461 +uint32_t 
   1.462 +Ipv4Netfilter::NetfilterNatPacket (Hooks_t hookNumber, Ptr<Packet> p)
   1.463 +{
   1.464 +  NS_LOG_FUNCTION ( this << p );
   1.465 +  Ipv4Header ipHeader;
   1.466 +  uint16_t dstPort; //, srcPort;
   1.467 +  Ipv4Address dstAddress, srcAddress;
   1.468 +
   1.469 +  p->RemoveHeader (ipHeader);
   1.470 +
   1.471 +  uint16_t protocol = ipHeader.GetProtocol ();
   1.472 +
   1.473 +  if (hookNumber == NF_INET_POST_ROUTING)
   1.474 +  {
   1.475 +    NetfilterConntrackTuple mapped = m_natMappings[currentOriginalTuple];
   1.476 +
   1.477 +    ipHeader.SetSource (mapped.GetSource ());
   1.478 +
   1.479 +    if (protocol == IPPROTO_TCP)
   1.480 +    {
   1.481 +      TcpHeader tcpHeader;
   1.482 +
   1.483 +      p->RemoveHeader (tcpHeader);
   1.484 +
   1.485 +      tcpHeader.SetSourcePort (mapped.GetSourcePort ());
   1.486 +
   1.487 +      p->AddHeader (tcpHeader);
   1.488 +
   1.489 +    }
   1.490 +    else
   1.491 +    {
   1.492 +      UdpHeader udpHeader;
   1.493 +
   1.494 +      p->RemoveHeader (udpHeader);
   1.495 +
   1.496 +      udpHeader.SetSourcePort (mapped.GetSourcePort ());
   1.497 +
   1.498 +      p->AddHeader (udpHeader);
   1.499 +    }
   1.500 +
   1.501 +    p->AddHeader (ipHeader);
   1.502 +
   1.503 +    NetfilterConntrackTuple oldOriginalTuple = currentOriginalTuple;
   1.504 +
   1.505 +
   1.506 +    currentOriginalTuple = NetfilterConntrackTuple (mapped.GetSource(), mapped.GetSourcePort (),
   1.507 +                                                    currentOriginalTuple.GetDestination (),
   1.508 +                                                    currentOriginalTuple.GetDestinationPort ());
   1.509 +
   1.510 +    currentOriginalTuple.SetDirection (IP_CT_DIR_ORIGINAL);
   1.511 +    
   1.512 +    currentReplyTuple = NetfilterConntrackTuple (currentOriginalTuple.GetDestination (),
   1.513 +                                                  currentOriginalTuple.GetDestinationPort (),
   1.514 +                                                  mapped.GetSource (), mapped.GetSourcePort ());
   1.515 +    
   1.516 +    currentReplyTuple.SetDirection (IP_CT_DIR_REPLY);
   1.517 +    
   1.518 +    std::cout <<" New Original Tuple: " << currentOriginalTuple << std::endl;
   1.519 +    std::cout <<" New Reply Tuple: " << currentReplyTuple << std::endl;
   1.520 +
   1.521 +    m_unconfirmed[currentOriginalTuple] = m_unconfirmed[oldOriginalTuple];
   1.522 +
   1.523 +  }
   1.524 +  else if (hookNumber == NF_INET_PRE_ROUTING)
   1.525 +  {
   1.526 +    NS_LOG_DEBUG ("Mapping back to LAN address");
   1.527 +    //NetfilterConntrackTuple mapped = m_natMappings[currentReplyTuple];
   1.528 +    NetfilterConntrackTuple temp = currentReplyTuple;
   1.529 +    temp.SetDirection (IP_CT_DIR_ORIGINAL);
   1.530 +    TranslationMapI transIt = m_natReplyLookup.find (temp);
   1.531 +
   1.532 +    if (transIt == m_natMappings.end ())
   1.533 +    {
   1.534 +      NS_LOG_DEBUG ("No such mapping found!");
   1.535 +      return NF_ACCEPT;
   1.536 +    }
   1.537 +
   1.538 +    dstPort = (transIt->second).GetSourcePort ();
   1.539 +    dstAddress = (transIt->second).GetSource ();
   1.540 +  
   1.541 +    currentOriginalTuple = NetfilterConntrackTuple ((transIt->second).GetSource (), (transIt->second).GetSourcePort (), dstAddress, dstPort);
   1.542 +    currentReplyTuple = NetfilterConntrackTuple (dstAddress, dstPort, (transIt->second).GetSource (), (transIt->second).GetSourcePort ());
   1.543 +
   1.544 +    NS_LOG_DEBUG ("Setting Destination IP address to : " << dstAddress);
   1.545 +    ipHeader.SetDestination (dstAddress);
   1.546 +
   1.547 +    if (protocol == IPPROTO_TCP)
   1.548 +    {
   1.549 +      TcpHeader tcpHeader;
   1.550 +
   1.551 +      p->RemoveHeader (tcpHeader);
   1.552 +
   1.553 +      tcpHeader.SetDestinationPort (dstPort);
   1.554 +
   1.555 +      p->AddHeader (tcpHeader);
   1.556 +
   1.557 +    }
   1.558 +    else
   1.559 +    {
   1.560 +      UdpHeader udpHeader;
   1.561 +
   1.562 +      p->RemoveHeader (udpHeader);
   1.563 +
   1.564 +      udpHeader.SetDestinationPort (dstPort);
   1.565 +      NS_LOG_DEBUG ("Setting destination port to: " << dstPort);
   1.566 +
   1.567 +      p->AddHeader (udpHeader);
   1.568 +    }
   1.569 +
   1.570 +    p->AddHeader (ipHeader);
   1.571 +  }
   1.572 +
   1.573 +
   1.574 +
   1.575 +  return NF_ACCEPT;
   1.576 +
   1.577 +}
   1.578  
   1.579  } // Namespace ns3