The RAW socket C programming tutorial with working program examples tested on Linux OSLINUX SOCKET PART 1. Advanced TCPIP THE RAW SOCKET PROGRAM EXAMPLESMenu. This is a continuation from Part IV. Advanced TCPIP Programming Tutorial. Working program examples if any compiled using. IPs, run on Fedora Core 3, with several times of update. SUID 0.   The Fedora machine used for the testing having. This is the first part of How to Calculate IPTCPUDP Checksum. The 2 parts followed are Part 2 Implementation and Part 3 Usage Example and Validation. WindowsLiveWriter/ApplicationisMorethanHeaderDeep_12296/clip_image002_thumb.jpg' alt='Udp Checksum C Program' title='Udp Checksum C Program' />Stack Execute. SELinux set to default configuration. Building and injecting. RAW datagrams program examplesrootbakawali testraw cat. Must be run by root lol Just datagram, no payloaddatainclude lt unistd. UDP Ports UDP 0 Reserved UDP 1 Port Service Multiplexer UDP 2 Management Utility UDP 3 Compression Process UDP 4 Unassigned UDP 5 Remote Job Entry UDP 6. In this example, a company has Class C network address 195. Company network is connected to Internet via IP Service Provider. Company policy is to allow. This tutorial demonstrates how to develop or build the Linux RAW socket or network program. The content includes a stepbystep C programming with the test result run. Support for packages has been discontinued on Sunfreeware. Please Visit our New Website UNIXPackages. UNIX packages provides full package support for all levels. The packet lengthdefine PCKTLEN 8. Can create separate header file. The IP headers structurestruct ipheader  unsigned char      iphihl 5. UDP headers structurestruct udpheader  unsigned short int udphsrcport unsigned short int udphdestport unsigned short int udphlen unsigned short int udphchksum total udp header length 8 bytes 6. Function for checksum calculation. From the RFC, the checksum algorithm is   The checksum field is the 1. For purposes of  computing the checksum, the value of the. Source IP, source port, target IP, target port. No datapayload just datagramchar bufferPCKTLEN Our own headers structuresstruct ipheader ip struct ipheader buffer struct udpheader dp struct udpheader buffer. Source and destination addresses IP and portstruct sockaddrin sin, din int one 1 const int al one memsetbuffer, 0, PCKTLEN ifargc 5printf Invalid parametersn printf Usage s lt source hostnameIP lt source port. IP lt target port n, argv0 exit 1 Create a raw socket with UDP protocolsd socketPFINET, SOCKRAW, IPPROTOUDP ifsd lt 0perrorsocket error If something wrong just exitexit 1 elseprintfsocket Using SOCKRAW socket and UDP protocol. OK. n The source is redundant, may be used later if needed The address familysin. AFINET din. sinfamily AFINET Port numberssin. IP addressessin. sinaddr. Fabricate the IP header or we can use the standard header structures but assign our own values. Low delayip iphlen sizeofstruct ipheader sizeofstruct. UDP Source IP address, can use spoofed address hereThe destination IP addressip iphdestip inetaddrargv3 Fabricate the UDP header. Source port number, redundantudp udphsrcport htonsatoiargv2 Destination port numberudp udphdestport htonsatoiargv4 udp udphlen htonssizeofstruct udpheader Calculate the checksum for integrityip iphchksum csumunsigned short buffer, sizeofstruct. Inform the kernel do not fill up the packet structure. IPPROTOIP, IPHDRINCL, val, sizeofone. OK. n Send loop, send for every 2 second for 1. Trying. n printfUsing raw socket and UDP protocoln printfUsing Source IP s port u, Target IP s port. Verifyperrorsendto error exit 1 elseprintfCount u sendto is OK. Invalid parameters Usage. IP lt source port. IP lt target port rootbakawali testraw. Using SOCKRAW socket and UDP protocol is. OK. setsockopt is OK. Trying. Using raw socket and UDP protocol. Using Source IP 1. Target IP. 2. 03. Count 1 sendto is OK. Count 2 sendto is OK. Count 3 sendto is OK. Count 4 sendto is OK. Count 5 sendto is OK. Count 6 sendto is OK. Count 7 sendto is OK. You can use network monitoring tools to capture. The. following is a raw socket and tcp program example. Run as root or SUID 0, just datagram no datapayloadinclude lt unistd. Packet lengthdefine PCKTLEN 8. May create separate header file. IP headers structurestruct ipheader  unsigned char      iphihl 5, Little endian. Structure of a TCP header struct tcpheader  unsigned short int tcphsrcport unsigned short int tcphdestport unsigned int. Finish flag fin       tcphsyn 1,       ynchronize sequence numbers to start a connection       tcphrst 1. Reset flag        tcphpsh 1. Push, sends data to the application       tcphack 1. Simple checksum function, may use others such as. Cyclic Redundancy Check, CRCunsigned short csumunsigned short uf, int len        unsigned long. No data, just datagramchar bufferPCKTLEN The size of the headersstruct ipheader p struct ipheader buffer struct tcpheader cp struct tcpheader buffer. PCKTLEN ifargc 5printf Invalid parametersn printf Usage s lt source hostnameIP lt source port. IP lt target port n, argv0 exit 1 sd socketPFINET, SOCKRAW, IPPROTOTCP ifsd lt 0   perrorsocket error   exit 1 elseprintfsocket SOCKRAW and tcp protocol is OK. The source is redundant, may be used later if needed Address familysin. AFINET din. sinfamily AFINET Source port, can be any, modify as neededsin. Source IP, can be any, modify as neededsin. IP structureip iphihl 5 ip iphver 4 ip iphtos 1. TCPip iphchksum 0 Done by kernel Source IP, modify as needed, spoofed, we accept. Destination IP, modify as needed, but here we accept. The TCP structure. The source port, spoofed, we. The destination port, we accept through command. Done by kerneltcp tcphurgptr 0 IP checksum calculationip iphchksum csumunsigned short buffer, sizeofstruct. Inform the kernel do not fill up the headers structure. Download Program Tic Tac Toe Visual Basic here. IPPROTOIP, IPHDRINCL, val, sizeofone. OKn printfUsing Source IP s port u, Target IP. Verify   perrorsendto error   exit 1 else   printfCount u sendto is OKn, count sleep2 closesd return 0 rootbakawali testraw gcc rawtcp. Invalid parameters Usage. IP lt source port. IP lt target port rootbakawali. SOCKRAW and tcp protocol is OK. OKUsing Source IP 1. Target. IP 2. 03. Count 0 sendto is OKCount 1 sendto is OKCount 2 sendto is OKCount 3 sendto is OKCount 4 sendto is OK. Network utilities applications such as. Traceroute check UnixLinux. ICMP and raw socket. The following is a very loose ping. ICMP program example. It is taken from ping of death program. Must be root or SUID 0 to open RAW socket include lt stdio. Usage s lt saddress. If enough argument supplied   ifargc 4      Copy the packet number       num atoiargv3    Loop based on the packet number     fori1 ilt num i           on 1       bzerobuf, sizeofbuf       Create RAW socket        ifs socketAFINET. SOCKRAW, IPPROTORAW lt 0               perrorsocket. If something wrong, just exit         exit1              socket options, tell the kernel we provide the IP structure        ifsetsockopts. IPPROTOIP, IPHDRINCL, on, sizeofon lt 0               perrorsetsockopt. IPHDRINCL error        exit1              ifhp gethostbynameargv2. NULL                ifip ipdst. Cant resolve, unknown host. The following source address just redundant for target to collect         ifhp. NULL                 ifip ipsrc.