Nmap Development mailing list archives
Scanning Localhost
From: Wasim <wasim.khan () gmail com>
Date: Wed, 29 Nov 2006 16:29:08 +1200
I have encountered a problem while writing code for scanning Localhost. The problem is i did'nt get the destination port and source port of reply correct. For e.g. if i set source port =62144 and destination port=22 then i must get reply source port = 22 and reply destination port = 62144, but that is not the case. What can be the problem??? can any body help??? I googled it but couldn't find any thing. Here i'm putting the code where i'm sniffing: struct pcap_pkthdr header; const u_char *packet; struct libnet_ipv4_hdr *ipHdr; struct libnet_tcp_hdr *tcpHdr; int reply_dstport = 0; int reply_sport =0 ; int timeout = 3; time_t start; start = time(NULL); /* capture packets until a timeout occurs or the required packet is received */ while ((time(NULL)-start) < timeout) { packet = pcap_next(pcapHandle, &header); if (packet == NULL) { continue; } else { ipHdr = (struct libnet_ipv4_hdr *)(packet + 14); tcpHdr = (struct libnet_tcp_hdr *)(packet + 14 + (ipHdr->ip_hl << 2)); /* if ip packet is not from the expected host then skip this packet */ if ((ipHdr->ip_src.s_addr != destination_ip)) continue; cout << "IP of request and reply is Identical" << endl; int tprotocol; //transport protocol like tcp ,udp tcp 0x06 tprotocol = ipHdr->ip_p; if(tprotocol == 0x06) { /*here the problem occurs */ reply_sport = ntohs(tcpHdr->th_sport); reply_dstport = ntohs(tcpHdr->th_dport); cout << "source port (reply) = " << reply_sport << endl; cout << "dest port (reply) = " << reply_dstport << endl; } } } _______________________________________________ Sent through the nmap-dev mailing list http://cgi.insecure.org/mailman/listinfo/nmap-dev Archived at http://SecLists.Org
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- Scanning Localhost Wasim (Nov 28)