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); }
void IP4::bottom(Packet_ptr pckt) { debug2("<IP4 handler> got the data.\n"); auto data = pckt->buffer(); ip_header* hdr = &reinterpret_cast<full_header*>(data)->ip_hdr; debug2("\t Source IP: %s Dest.IP: %s\n", hdr->saddr.str().c_str(), hdr->daddr.str().c_str()); switch(hdr->protocol){ case IP4_ICMP: debug2("\t Type: ICMP\n"); icmp_handler_(pckt); break; case IP4_UDP: debug2("\t Type: UDP\n"); udp_handler_(pckt); break; case IP4_TCP: tcp_handler_(pckt); debug2("\t Type: TCP\n"); break; default: debug("\t Type: UNKNOWN %i\n", hdr->protocol); break; } }
void Ethernet::receive(Packet_ptr pckt) { Expects(pckt->size() > 0); header* eth = reinterpret_cast<header*>(pckt->buffer()); /** Do we pass on ethernet headers? As for now, yes. data += sizeof(header); len -= sizeof(header); */ debug2("<Ethernet IN> %s => %s , Eth.type: 0x%x ", eth->src.str().c_str(), eth->dest.str().c_str(), eth->type); // Stat increment packets received packets_rx_++; bool dropped = false; switch(eth->type) { case ETH_IP4: debug2("IPv4 packet\n"); ip4_upstream_(std::move(pckt)); break; case ETH_IP6: debug2("IPv6 packet\n"); ip6_upstream_(std::move(pckt)); break; case ETH_ARP: debug2("ARP packet\n"); arp_upstream_(std::move(pckt)); break; case ETH_WOL: dropped = true; debug2("Wake-on-LAN packet\n"); break; case ETH_VLAN: dropped = true; debug("VLAN tagged frame (not yet supported)"); break; default: dropped = true; // This might be 802.3 LLC traffic if (net::ntohs(eth->type) > 1500) { debug2("<Ethernet> UNKNOWN ethertype 0x%x\n", ntohs(eth->type)); }else { debug2("IEEE802.3 Length field: 0x%x\n", ntohs(eth->type)); } break; } if(dropped) packets_dropped_++; }
int Arp::bottom(Packet_ptr pckt) { debug2("<ARP handler> got %i bytes of data \n", pckt->size()); header* hdr = (header*) pckt->buffer(); //debug2("\t OPCODE: 0x%x \n",hdr->opcode); //debug2("Chaching IP %s for %s \n", hdr->sipaddr.str().c_str() , hdr->shwaddr.str().c_str()) debug2("Have valid cache? %s \n",is_valid_cached(hdr->sipaddr) ? "YES":"NO"); cache(hdr->sipaddr, hdr->shwaddr); switch(hdr->opcode){ case H_request: debug2("\t ARP REQUEST: "); debug2("%s is looking for %s \n", hdr->sipaddr.str().c_str(),hdr->dipaddr.str().c_str()); if (hdr->dipaddr == ip_) arp_respond(hdr); else { debug2("\t NO MATCH for My IP (%s). DROP!\n", ip().str().c_str()); } break; case H_reply: { debug2("\t ARP REPLY: %s belongs to %s\n", hdr->sipaddr.str().c_str(), hdr->shwaddr.str().c_str()); auto waiting = waiting_packets_.find(hdr->sipaddr); if (waiting != waiting_packets_.end()) { debug ("Had a packet waiting for this IP. Sending\n"); transmit(waiting->second); waiting_packets_.erase(waiting); } } break; default: debug2("\t UNKNOWN OPCODE \n"); break; } // Free the buffer (We're leaf node for this one's path) // @todo Freeing here corrupts the outgoing frame. Why? //free(data); return 0 + 0 * pckt->size(); // yep, it's what you think it is (and what's that?!) };
int Ethernet::bottom(Packet_ptr pckt) { assert(pckt->size() > 0); header* eth = (header*) pckt->buffer(); /** Do we pass on ethernet headers? As for now, yes. data += sizeof(header); len -= sizeof(header); */ debug2("<Ethernet IN> %s => %s , Eth.type: 0x%x ", eth->src.str().c_str(), eth->dest.str().c_str(),eth->type); switch(eth->type){ case ETH_IP4: debug2("IPv4 packet \n"); return ip4_handler_(pckt); case ETH_IP6: debug2("IPv6 packet \n"); return ip6_handler_(pckt); case ETH_ARP: debug2("ARP packet \n"); return arp_handler_(pckt); case ETH_WOL: debug2("Wake-on-LAN packet \n"); break; case ETH_VLAN: debug("VLAN tagged frame (not yet supported)"); default: // This might be 802.3 LLC traffic if (net::ntohs(eth->type) > 1500){ debug("<Ethernet> UNKNOWN ethertype 0x%x\n",ntohs(eth->type)); }else{ debug2("IEEE802.3 Length field: 0x%x\n",ntohs(eth->type)); } break; } return -1; }
void Arp::bottom(Packet_ptr pckt) { debug2("<ARP handler> got %i bytes of data\n", pckt->size()); header* hdr = reinterpret_cast<header*>(pckt->buffer()); debug2("Have valid cache? %s\n", is_valid_cached(hdr->sipaddr) ? "YES" : "NO"); cache(hdr->sipaddr, hdr->shwaddr); switch(hdr->opcode) { case H_request: { // Stat increment requests received requests_rx_++; debug2("\t ARP REQUEST: "); debug2("%s is looking for %s\n", hdr->sipaddr.str().c_str(), hdr->dipaddr.str().c_str()); if (hdr->dipaddr == inet_.ip_addr()) { arp_respond(hdr); } else { debug2("\t NO MATCH for My IP (%s). DROP!\n", inet_.ip_addr().str().c_str()); } break; } case H_reply: { // Stat increment replies received replies_rx_++; debug2("\t ARP REPLY: %s belongs to %s (waiting: %u)\n", hdr->sipaddr.str().c_str(), hdr->shwaddr.str().c_str(), waiting_packets_.size()); auto waiting = waiting_packets_.find(hdr->sipaddr); if (waiting != waiting_packets_.end()) { debug("Had a packet waiting for this IP. Sending\n"); transmit(std::move(waiting->second)); waiting_packets_.erase(waiting); } break; } default: debug2("\t UNKNOWN OPCODE\n"); break; } //< switch(hdr->opcode) }
int Ethernet::transmit(Packet_ptr pckt){ header* hdr = (header*)pckt->buffer(); // Verify ethernet header assert(hdr->dest.major != 0 || hdr->dest.minor !=0); assert(hdr->type != 0); // Add source address hdr->src.major = _mac.major; hdr->src.minor = _mac.minor; debug2("<Ethernet OUT> Transmitting %i b, from %s -> %s. Type: %i \n", pckt->size(),hdr->src.str().c_str(), hdr->dest.str().c_str(),hdr->type); return physical_out_(pckt); }
int ICMP::bottom(Packet_ptr pckt){ if (pckt->size() < sizeof(full_header)) //Drop if not a full header. return -1; full_header* full_hdr = (full_header*)pckt->buffer(); icmp_header* hdr = &full_hdr->icmp_hdr; switch(hdr->type) { case (ICMP_ECHO): debug("<ICMP> PING from %s \n",full_hdr->ip_hdr.saddr.str().c_str()); ping_reply(full_hdr); break; case (ICMP_ECHO_REPLY): debug("<ICMP> PING Reply from %s \n",full_hdr->ip_hdr.saddr.str().c_str()); break; } return 0; }
void ICMPv4::bottom(Packet_ptr pckt) { if (pckt->size() < sizeof(full_header)) // Drop if not a full header return; full_header* full_hdr = reinterpret_cast<full_header*>(pckt->buffer()); icmp_header* hdr = &full_hdr->icmp_hdr; #ifdef DEBUG auto ip_address = full_hdr->ip_hdr.saddr.str().c_str(); #endif switch(hdr->type) { case (ICMP_ECHO): debug("<ICMP> PING from %s\n", ip_address); ping_reply(full_hdr, pckt->size()); break; case (ICMP_ECHO_REPLY): debug("<ICMP> PING Reply from %s\n", ip_address); break; } }
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)); }