/* Attempt to send an ICMP packet, writing the ICMP and IP headers.  * (Lacks adding the time to the end of the packet). * Thamer Al-Herbish shadows@whitefang.com */#include <stdlib.h>#include <stdio.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <netinet/in_systm.h>#include <netinet/ip.h>#include <netinet/ip_icmp.h>#if defined(SOLARIS_CKSUM_BUG)#include <netinet/tcp.h>#endif#include <strings.h>#include <unistd.h>#if !defined(HAVE_INCKSUM)#include <checksum.h>#endif#if !defined(IPVERSION)#define IPVERSION 4  /* Incase some system does not have this definition. */#endif               /* We'll always be using 4 as the version anyway. */#if !defined(LINUX)#define BUFFSIZE (sizeof(struct icmp) + sizeof(struct ip))#else#define BUFFSIZE (sizeof(struct icmphdr) + sizeof(struct iphdr))#endifint main(int argc,char *argv[]){#if !defined (LINUX)  struct icmp *icmphdr;  struct ip *iphdr;#else  struct icmphdr *icmphdr;  struct iphdr *iphdr;#endif  unsigned char buff[BUFFSIZE];  int sockd;  struct sockaddr_in mysocket;  int on = 1;  if(argc < 3) {   fprintf(stderr,"usage: %s source-ip dest-ip\n",argv[0]);   exit(-1); }  if((sockd = socket(AF_INET,SOCK_RAW,IPPROTO_RAW)) < 0)  {    perror("socket");    exit(-1);  }    if(setsockopt(sockd,IPPROTO_IP,IP_HDRINCL,(char *)&on,sizeof(on)) < 0)  {    perror("setsockopt");    exit(-1);  }#if !defined(LINUX)  iphdr = (struct ip *)buff;  bzero((char *)iphdr,sizeof(struct ip));    iphdr->ip_hl = 5;  iphdr->ip_v = IPVERSION;#ifdef IP_LEN_HORDER  iphdr->ip_len = (sizeof(struct ip) + sizeof(struct icmp));#else  iphdr->ip_len = htons(sizeof(struct ip) + sizeof(struct icmp));#endif  iphdr->ip_id = htons(getpid());  iphdr->ip_ttl = 60;  iphdr->ip_p = IPPROTO_ICMP;  iphdr->ip_src.s_addr = inet_addr(argv[1]);  iphdr->ip_dst.s_addr = inet_addr(argv[2]);    iphdr->ip_sum = (unsigned short)in_cksum((unsigned short *)iphdr,					   sizeof(struct ip));    icmphdr = (struct icmp *)(buff + sizeof(struct ip));  bzero((char *)icmphdr,sizeof(struct icmp));    icmphdr->icmp_type = ICMP_ECHO;  icmphdr->icmp_seq = getpid();  icmphdr->icmp_id = getpid();  icmphdr->icmp_cksum = in_cksum((unsigned short *)icmphdr,sizeof(struct icmp));#else  iphdr = (struct iphdr *)buff;  bzero((char *)iphdr,sizeof(struct iphdr));    iphdr->ihl = 5;  iphdr->version = IPVERSION;    #ifdef IP_LEN_HORDER  iphdr->tot_len = (sizeof(struct iphdr) + sizeof(struct icmphdr));#else  iphdr->tot_len = htons(sizeof(struct iphdr) + sizeof(struct icmphdr));#endif    iphdr->id = htons(getpid());  iphdr->ttl = 60;  iphdr->protocol = IPPROTO_ICMP;  iphdr->saddr = inet_addr(argv[1]);  iphdr->daddr = inet_addr(argv[2]);  iphdr->check = in_cksum((unsigned short *)iphdr,sizeof(struct iphdr));    icmphdr = (struct icmphdr *)(buff +sizeof(struct iphdr));  bzero((char *)icmphdr,sizeof(struct icmphdr));    icmphdr->type = ICMP_ECHO;  icmphdr->un.echo.sequence = getpid();  icmphdr->un.echo.id =  getpid();    icmphdr->checksum = in_cksum((unsigned short *)icmphdr,				sizeof(struct icmphdr));#endif /* LINUX */    bzero((char *)&mysocket,sizeof(mysocket));    mysocket.sin_family = AF_INET;  mysocket.sin_addr.s_addr = inet_addr(argv[2]);    if(sendto(sockd,(char *)buff,sizeof(buff),0x0,	    (struct sockaddr *)&mysocket,sizeof(mysocket)) < 0)  {    perror("sendto");    exit(-1);  }   exit(0);}