again modify to me again and send.

#include "my_proto_headers.h"

#define ETH_FRAME_LENX 98

#define ETH_HDRLEN 14  // Ethernet header length
#define IP4_HDRLEN 20  // IPv4 header length
#define ICMP_HDRLEN 8  // ICMP header length for echo request, excludes data

extern char sourceip[30];
extern char destinip[30];
extern int type_replyc;//important field to check before modifing
extern int type_reqc;//important field to check before modifing
extern int seq_num;  //important field to check before modifing
extern int smac[6];
extern int dmac[6];
extern int icmp_typec;
extern int icmp_chksumc;
extern int icmp_idc;
extern int proto_used;
extern char datagram[8096];
extern int datalen;
extern int iptotlen;
extern int iptos;
extern int ipfrag;
extern int sizeofdata;
extern int eth_prototype;
//FILE *fp;

//grandson variables
extern char sourceipxx[30];
extern char destinipxx[30];
extern int type_replycxx;//important field to check before modifing
extern int type_reqcxx;//important field to check before modifing
extern int seq_numxx;  //important field to check before modifing
extern int smacxx[6];
extern int dmacxx[6];
extern int icmp_typecxx;
extern int icmp_chksumcxx;
extern int icmp_idcxx;
extern int proto_usedxx;
extern char datagramxx[8096];
extern int datalenxx;
extern int sizeofdataxx;
extern int eth_prototypexx;
extern int icmp_seqxx;

extern int imp_flag;
//.................





//for getting interface_index number
extern int interface_index ;


char * the_fucker();
char *dup_ip;

//USING RAW SOCKET: FOR SENDING THE NEW MODIFIED PACKET



//.....................................
void create_modi_reply_pack()
{
 
 
  int rd2;
  int minus;
  char copy_data[1000];
  printf("IN CREATE_MODIFIED _ REPLY_PACKET \n");
  rd2=socket(AF_PACKET,SOCK_RAW,htons(ETH_P_ALL));
  int i,j;
   int xsize;
 
 //   fp=fopen("/home/sourav/Desktop/table","r");
  
  /*
   printf("*****destinip: %s \n",destinip);
   printf("*****sourceip: %s \n",sourceip);
    printf("icmp_typec :%d \n",icmp_typec);
  */
    void *send_buffer=(void*)malloc(ETH_FRAME_LENX);//for creation of modified packet
  //  unsigned char* etherhead = send_buffer + 14; /*userdata in ethernet frame*/
    struct sockaddr_ll socket_address;
 
 
  //constructing thernet header
    struct ethhdr *eth2 = (struct ethhdr *)send_buffer;
   
   
    eth2->h_source[0]=dmac[0];
    eth2->h_source[1]=dmac[1];
    eth2->h_source[2]=dmac[2];
    eth2->h_source[3]=dmac[3];
    eth2->h_source[4]=dmac[4];
    eth2->h_source[5]=dmac[5];
 
  // for(i=0,j=0;i<6,j<6;i++,j++)
  //{
    eth2->h_dest[0]=smacxx[0];
    eth2->h_dest[1]=smacxx[1];
    eth2->h_dest[2]=smacxx[2];
    eth2->h_dest[3]=smacxx[3];
    eth2->h_dest[4]=smacxx[4];
    eth2->h_dest[5]=smacxx[5];
   
   
    //}
  eth2->h_proto=eth_prototype;

 
 
 
 
 
 
 
 
  //socket_address********************************************************************************************************
 
  socket_address.sll_family   = PF_PACKET;   
/*we don't use a protocoll above ethernet layer
  ->just use anything here*/
socket_address.sll_protocol = htons(ETH_P_IP);   


socket_address.sll_ifindex  = interface_index;

/*ARP hardware identifier is ethernet*/
socket_address.sll_hatype   = 0;
   
/*target is another host*/
socket_address.sll_pkttype  = 0;

/*address length*/
socket_address.sll_halen    = ETH_ALEN;

/*MAC - begin*/
socket_address.sll_addr[0]  = smacxx[0];       
socket_address.sll_addr[1]  = smacxx[1];       
socket_address.sll_addr[2]  = smacxx[2];
socket_address.sll_addr[3]  = smacxx[3];
socket_address.sll_addr[4]  = smacxx[4];
socket_address.sll_addr[5]  = smacxx[5];
/*MAC - end*/
socket_address.sll_addr[6]  = 0x00;/*not used*/
socket_address.sll_addr[7]  = 0x00;/*not used*/

 
 //******************************************************************************************
 
 
  //printf("source address : %.x-%.x-%.x-%.x-%.x-%.x \n",eth2->h_source[0],eth2->h_source[1],eth2->h_source[2],eth2->h_source[3],eth2->h_source[4],eth2->h_source[5]); 
  //printf("destination address : %.x-%.x-%.x-%.x-%.x-%.x \n", eth2->h_dest[0] ,eth2->h_dest[1],eth2->h_dest[2],eth2->h_dest[3],eth2->h_dest[4],eth2->h_dest[5]); 
   
    struct iphdr *iph2 = (struct iphdr *)(send_buffer + sizeof(struct ethhdr));
      //constructiing new ip header
        iph2->version=4;
       iph2->ihl=5;
        iph2->tos=iptos;
        iph2->ttl=64;
        iph2->tot_len=sizeof(struct iphdr)+sizeof(struct icmpheader);
        iph2->id=htons(54321);
        iph2->frag_off=0x00;
        //iph2->ident=htons(54321);
        iph2->protocol=1;//for icmp
        printf("ok 0 \n");
       // dup_ip=the_fucker()    ;
       // printf("dup_ip: %s \n",dup_ip);
        iph2->saddr=inet_addr(sourceipxx);//source add changed
        iph2->daddr=inet_addr(destinipxx);
        iph2->check=in_cksum((unsigned short *)iph2, sizeof(struct iphdr));
       printf("ok 2 \n");
       
 struct icmpheader *icmphdr2=(struct icmpheader *)(send_buffer+sizeof(struct iphdr)+sizeof(struct ethhdr));       
        //constructing the icmp header
     
        icmphdr2->icmp_code=0;
        icmphdr2->icmp_id=icmp_idc;
        icmphdr2->icmp_seq=icmp_seqxx+2;
        icmphdr2->icmp_type= 0; //icmp_typec;
        icmphdr2->icmp_cksum= 0;
       
        xsize=sizeof(struct icmpheader)+sizeofdata;
      
         
       
        //copying the older datagram
          minus=(sizeof(struct icmpheader)+sizeof(struct iphdr)+sizeof( struct ethhdr));
        bzero(copy_data,1000);
        printf("datagram in create_modi_pack reply: %s : \n",datagram);
        strcpy(copy_data,datagram);
        strcpy(send_buffer+datalen,copy_data);
         icmphdr2->icmp_cksum=in_cksum((unsigned short *)icmphdr2, xsize);

        
        
        //sending this packet through the second socket
       
       
         if(sendto(rd2, send_buffer, ETH_FRAME_LENX, 0, (struct sockaddr *)&socket_address, sizeof(socket_address)) < 0)
         {
         
           printf("ok 3 \n");
           perror("sendto");
          }
          else
          {
        printf("server %d :\n",socket_address.sll_ifindex);
       
        printf("send successs");
          }
       
       close(rd2);
   


}

/*the fucker function
char * the_fucker()
{
 
  int offset;
  char * ip_string;
  char *str_chr;

  if(fp<= 0)
  {
    perror("fopen");
  }
  else
    printf("file got: fp= %d \n",fp);
 
  if(fscanf(fp,"%s",ip_string))
  {
    printf("yes \n");
    printf("%s \n",ip_string);
    return ip_string;
 
  }
  else
    printf("fscanf failed \n");
    fclose(fp);
    return 0;
 
}
*/