#include <pcap.h>#include <netinet/in_systm.h>#include <netinet/in.h>#include <string.h>#include <sys/types.h>#include <sys/socket.h>#include <stdlib.h>#include <unistd.h>#include <getopt.h>#include <arpa/inet.h>#include <string.h>#include <netinet/udp.h>#include <netinet/ip.h>#include <stdio.h>#include <time.h>#include <signal.h>#include <net/if.h>#include <netinet/if_ether.h>#include <netdb.h>#define SA struct sockaddr#define PORT 1985#define VER "1.4"#define MAXLINE 4096 //max text line length used in parsing CMD for pcap//structsstruct ops {	int sniff;	int cripple;	int defauth;	int hellotime;	char auth[8];	struct in_addr virtualip;	struct in_addr spoofed;	int group;};struct header{	struct iphdr ip; //ip header	struct udphdr udp; //udp header	char buf[20]; //hsrp header};extern struct ops o[];//extern struct hsrphdr hsrph[];//prototypesvoid usage(char *progname);void coup();void hello();void opensniff();void cleanup(int sigio);void sniffedcoup(struct header *headz);void sniffedhello(struct header *headz);unsigned short in_chksum(unsigned short *pts, int nbytes);char *next_pcap(int *);void open_pcap(void);char *Sock_ntop_host(const SA *, socklen_t);int sock_get_port(const SA *, socklen_t);struct header *udpread();struct header *udp_check(char *ptr, int len);//globalsextern struct in_addr addr;extern socklen_t destlen;extern int datalink;extern char *device;extern int fddipad;extern pcap_t *pd;extern int rawfd;extern int snaplen;extern struct sockaddr_in broadcastIP;extern struct sockaddr_in nullIP;extern struct sockaddr_in allocatedIP;