Ejemplo n.º 1
0
  void IP4::transmit(Packet_ptr pckt) {
    assert(pckt->size() > sizeof(IP4::full_header));

    auto ip4_pckt = std::static_pointer_cast<PacketIP4>(pckt);
    ip4_pckt->make_flight_ready();

    IP4::ip_header& hdr = ip4_pckt->ip4_header();
    // Create local and target subnets
    addr target = hdr.daddr        & stack_.netmask();
    addr local  = stack_.ip_addr() & stack_.netmask();
    
    // Compare subnets to know where to send packet
    pckt->next_hop(target == local ? hdr.daddr : stack_.router());

    debug("<IP4 TOP> Next hop for %s, (netmask %s, local IP: %s, gateway: %s) == %s\n",
          hdr.daddr.str().c_str(),
          stack_.netmask().str().c_str(),
          stack_.ip_addr().str().c_str(),
          stack_.router().str().c_str(),
          target == local ? "DIRECT" : "GATEWAY");

    debug("<IP4 transmit> my ip: %s, Next hop: %s, Packet size: %i IP4-size: %i\n",
          stack_.ip_addr().str().c_str(),
          pckt->next_hop().str().c_str(),
          pckt->size(),
          ip4_pckt->ip4_segment_size()
          );

    linklayer_out_(pckt);
  }
Ejemplo n.º 2
0
void Arp::await_resolution(Packet_ptr pckt, IP4::addr){
  auto queue =  waiting_packets_.find(pckt->next_hop());
  if (queue != waiting_packets_.end()) {
    debug("<ARP Resolve> Packets allready queueing for this IP\n");
    queue->second->chain(pckt);    
  } else {
    debug("<ARP Resolve> This is the first packet going to that IP\n");
    waiting_packets_.emplace(std::make_pair(pckt->next_hop(), pckt));
  }            
}
Ejemplo n.º 3
0
int Arp::arp_resolve(Packet_ptr pckt){
  debug("<ARP RESOLVE> %s \n", pckt->next_hop().str().c_str());
  
  await_resolution(pckt, pckt->next_hop());
  
  auto req = std::static_pointer_cast<PacketArp>(inet_.createPacket(sizeof(header)));
  req->init(mac_, ip_);
  
  req->set_dest_mac(Ethernet::addr::BROADCAST_FRAME);
  req->set_dest_ip(pckt->next_hop());
  req->set_opcode(H_request);
  
  linklayer_out_(req);
  
  return 0;
}
Ejemplo n.º 4
0
  void Arp::arp_resolve(Packet_ptr pckt) {
    debug("<ARP RESOLVE> %s\n", pckt->next_hop().str().c_str());
    const auto next_hop = pckt->next_hop();
    await_resolution(std::move(pckt), next_hop);

    auto req = static_unique_ptr_cast<PacketArp>(inet_.create_packet(sizeof(header)));
    req->init(mac_, inet_.ip_addr());

    req->set_dest_mac(Ethernet::BROADCAST_FRAME);
    req->set_dest_ip(next_hop);
    req->set_opcode(H_request);

    // Stat increment requests sent
    requests_tx_++;

    linklayer_out_(std::move(req));
  }
Ejemplo n.º 5
0
int Arp::transmit(Packet_ptr pckt){
  
  assert(pckt->size());
  
  /** Get destination IP from IP header   */
  IP4::ip_header* iphdr = (IP4::ip_header*)(pckt->buffer() 
                                            + sizeof(Ethernet::header));
  IP4::addr sip = iphdr->saddr;
  IP4::addr dip = pckt->next_hop();

  debug2("<ARP -> physical> Transmitting %i bytes to %s \n",
        pckt->size(),dip.str().c_str());
  
  Ethernet::addr mac;
  
  if (iphdr->daddr == IP4::INADDR_BCAST)
  {
    // when broadcasting our source IP should be either
    // our own IP or 0.0.0.0
    static const IP4::addr INADDR_NONE  {{0}};
    if (sip != ip_ && sip != INADDR_NONE)
    {
      debug2("<ARP> Dropping outbound broadcast packet due to "
             "invalid source IP %s\n",  sip.str().c_str());
      return -1;
    }
    mac = Ethernet::addr::BROADCAST_FRAME;
  }
  else
  {
    if (sip != ip_)
    {
      debug2("<ARP -> physical> Not bound to source IP %s. My IP is %s. DROP!\n",
            sip.str().c_str(), ip_.str().c_str());
      return -1;
    }
    
    // If we don't have a cached IP, get mac from next-hop (Håreks c001 hack)
    if (!is_valid_cached(dip))  
        return arp_resolver_(pckt);
    
    // Get mac from cache
    mac = cache_[dip].mac_;
  }
  
  /** Attach next-hop mac and ethertype to ethernet header  */  
  Ethernet::header* ethhdr = (Ethernet::header*)pckt->buffer();    
  ethhdr->src = mac_;
  ethhdr->dest.major = mac.major;
  ethhdr->dest.minor = mac.minor;
  ethhdr->type = Ethernet::ETH_IP4;
  
  debug2("<ARP -> physical> Sending packet to %s \n",mac.str().c_str());
  return linklayer_out_(pckt);
}
Ejemplo n.º 6
0
  void Arp::transmit(Packet_ptr pckt) {
    assert(pckt->size());

    /** Get destination IP from IP header */
    IP4::ip_header* iphdr = reinterpret_cast<IP4::ip_header*>(pckt->buffer()
                                                              + sizeof(Ethernet::header));
    IP4::addr sip = iphdr->saddr;
    IP4::addr dip = pckt->next_hop();

    debug2("<ARP -> physical> Transmitting %i bytes to %s\n",
           pckt->size(), dip.str().c_str());

    Ethernet::addr dest_mac;

    if (iphdr->daddr == IP4::INADDR_BCAST) {
      // When broadcasting our source IP should be either
      // our own IP or 0.0.0.0

      if (sip != inet_.ip_addr() && sip != IP4::INADDR_ANY) {
        debug2("<ARP> Dropping outbound broadcast packet due to "
               "invalid source IP %s\n",  sip.str().c_str());
        return;
      }
      // mui importante
      dest_mac = Ethernet::BROADCAST_FRAME;

    } else {
      if (sip != inet_.ip_addr()) {
        debug2("<ARP -> physical> Not bound to source IP %s. My IP is %s. DROP!\n",
               sip.str().c_str(), inet_.ip_addr().str().c_str());
        return;
      }

      // If we don't have a cached IP, perform address resolution
      if (!is_valid_cached(dip)) {
        arp_resolver_(std::move(pckt));
        return;
      }

      // Get MAC from cache
      dest_mac = cache_[dip].mac_;
    }

    /** Attach next-hop mac and ethertype to ethernet header */
    auto* ethhdr = reinterpret_cast<Ethernet::header*>(pckt->buffer());
    ethhdr->src  = mac_;
    ethhdr->dest = dest_mac;
    ethhdr->type = Ethernet::ETH_IP4;

    /** Update chain as well */
    auto* next = pckt->tail();
    while(next) {
      auto* headur = reinterpret_cast<Ethernet::header*>(next->buffer());
      headur->src  = mac_;
      headur->dest = dest_mac;
      headur->type = Ethernet::ETH_IP4;
      next = next->tail();
    }

    debug2("<ARP -> physical> Sending packet to %s\n", mac_.str().c_str());
    linklayer_out_(std::move(pckt));
  }