ARP请求与接收解析C++源码

#include "Device.h" Device::~Device() { /* At this point, we don't need any more the device list. Free it */ pcap_freealldevs(alldevs); } int Device::obtainDeviceList() { i=0; char errbuf[PCAP_ERRBUF_SIZE]; /* Retrieve the device list from the local machine */ if (pcap_findalldevs_ex(PCAP_SRC_IF_STRING, NULL /* auth is not needed */, &alldevs, errbuf) == -1) { fprintf(stderr,"Error in pcap_findalldevs_ex: %s\n", errbuf); return -1; } /* Print the list */ for(d= alldevs; d != NULL; d= d->next) printf("%d. %s\n", ++i, d->description); if (i == 0) { printf("\nNo interfaces found! Make sure WinPcap is installed.\n"); return -1; } return 0; } int Device::openAdapter() { int inum; char errbuf[PCAP_ERRBUF_SIZE]; printf("Enter the interface number (1-%d):",i); scanf_s("%d", &inum); if(inum < 1 || inum > i) { printf("\nInterface number out of range.\n"); return -1; } /* Jump to the selected adapter */ for(d=alldevs, i=0; i< inum-1 ;d=d->next, i++); /* Open the device */ if ( (adhandle= pcap_open(d->name, // name of the device 65536, // portion of the packet to capture // 65536 guarantees that the whole packet will be captured on all the link layers PCAP_OPENFLAG_PROMISCUOUS, // promiscuous mode 1000, // read timeout NULL, // authentication on the remote machine errbuf // error buffer ) ) == NULL) { fprintf(stderr,"\nUnable to open the adapter. %s is not supported by WinPcap\n", d->name); return -1; } return 0; } int Device::setFilter(const char *packet_filter) { u_int netmask; struct bpf_program fcode; if (d->addresses != NULL) /* Retrieve the mask of the first address of the interface */ netmask=((struct sockaddr_in *)(d->addresses->netmask))->sin_addr.S_un.S_addr; else /* If the interface is without an address we suppose to be in a C class network */ netmask=0xffffff; //compile the filter if (pcap_compile(adhandle, &fcode, packet_filter, 1, netmask) < 0) { fprintf(stderr,"\nUnable to compile the packet filter. Check the syntax.\n"); /* Free the device list */ pcap_freealldevs(alldevs); return -1; } //set the filter if (pcap_setfilter(adhandle, &fcode) < 0) { fprintf(stderr,"\nError setting the filter.\n"); /* Free the device list */ pcap_freealldevs(alldevs); return -1; } return 0; } ULONG Device::getIp() { pcap_addr_t *a; /* IP addresses */ for(a=d->addresses;a;a=a->next) { if(AF_INET == a->addr->sa_family) if (a->addr) return ((struct sockaddr_in *)a->addr)->sin_addr.S_un.S_addr; } return NULL; } void Device::sendPacket(const BYTE *packet) { /* Send down the packet */ if (pcap_sendpacket(adhandle, packet, 60 /* size */) != 0) { fprintf(stderr,"\nError sending the packet: %s\n", pcap_geterr(adhandle)); return; } } DWORD WINAPI Device::recvPacket(LPVOID lpParam) { int res; struct pcap_pkthdr *header; const u_char *pkt_data; timeval send[4], recv[4]; int i=0, j=0; BYTE mac[6]; ARP a; /* Retrieve the packets */ while((res = pcap_next_ex( adhandle, &header, &pkt_data)) >= 0) { if(res == 0) /* Timeout elapsed */ continue; EthernetFrame recvEF((BYTE *)pkt_data); recvEF.macdata2Arp(a); if (htons(ARP_REQUEST) == recvEF.getArpOperationCode()) { send[i] = header->ts; ++i; } if (htons(ARP_REPLY) == recvEF.getArpOperationCode()) { recv[j] = header->ts; ++j; } if(4 == i && 4 == j) { for(int k=0; k<4; ++k) { cout << "Unicast reply from " << Common::dword2Char(recvEF.getArpSourceProtocolAddress()) << " "; memcpy(mac, recvEF.getArpSourceHardwareAddress(), 6); printf("[%02X:%02X:%02X:%02X:%02X:%02X]", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]); cout << " "; cout << Common::timeSub(send[k],recv[k]) << "ms" << endl; } cout << "Sent 4 probes (1 broadcast(s)) Received 4 response(s)" << endl; break; } } if(res == -1){ printf("Error reading the packets: %s\n", pcap_geterr(adhandle)); return -1; } return 0; }