/*

       Handy TCP Portscanner 08/03/00
          By ZinC_Sh(C)


 COMPILE: gcc -Wall ports.c -o ports

 RUN IT:
 1) Usage: 'ports 10.0.0.200 - -'  : will scan the remote-host from 1->1024 port
 2) Usage: 'ports 10.0.0.200 20 30'  : will scan the rempte-host from 20->30 port

 DESCRIPTION: Handy TCP Portscanner.-
 
 MADE ON: SlackWare.-
 
               E-MAIL: zinc_sh@hotmail.com
              WEB: http://maxlepi.zap.to

          May The Poula Kapribekou Be With You...

*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/tcp.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <netdb.h>
#include <unistd.h>

#define DEF_STR_PORT 1
#define DEF_STP_PORT 1024
#define OXO 1

struct sockaddr_in addr;
struct hostent *rh;
struct servent *rp;

int sock,i;
int str_ptr, stp_ptr;
int Usage(char *ARG);
int CONNECTION(int port);
                        
int main(int argc, char *argv[])
{

  if (argc != 4)
    Usage(argv[0]);
  
    str_ptr = atoi(argv[2]);
    stp_ptr = atoi(argv[3]);
  if (strcmp(argv[2],"-")==0 && strcmp(argv[3],"-")==0){
    str_ptr = DEF_STR_PORT;
    stp_ptr = DEF_STP_PORT;
  }

  if ( str_ptr > stp_ptr){
    fprintf(stderr,"DetecT ErroR !!! On PortS, <Star-Port> Can't Be Greater Than <Stop-Port>.-\n");
    Usage(argv[0]);
    exit(OXO);
  }

  if ((rh=gethostbyname(argv[1])) == NULL){    
    fprintf(stderr,"Can't Resolve Host %s .-\n",argv[1]);
    Usage(argv[0]);
    exit(OXO);
  }

  printf("ScanninG Host %s From %d TcP Port To %d .-\n",argv[1],str_ptr,stp_ptr);
  for (i=str_ptr; i <= stp_ptr; i++)
  {
    if (CONNECTION(i)==0)
    {
      rp=getservbyport(htons(i),"tcp");
      printf("Port %d Is Open !!! <%s> ServicE.-\n",i,(rp == NULL)?"UknowN":rp->s_name);
    }
  close(sock);
  }

return 0;
}

int CONNECTION(int port)
{

  if ((sock=socket(AF_INET,SOCK_STREAM,0)) == -1){
    perror("SockeT");
    exit(OXO);
  }
          
        addr.sin_family = AF_INET;
  addr.sin_port = htons(port);
  addr.sin_addr = *((struct in_addr *)rh->h_addr);

  if ((connect(sock,(struct sockaddr *) &addr, sizeof(addr))) == 0)
          return 0;
  else
    return 1;
}

int Usage(char *ARG)
{
  fprintf(stderr,"TCPPortS.c By ZinC_Sh(C).-\n");
  fprintf(stderr,"Usage: %s <Remote-Host> <Start-Port> <Stop-Port>.-\n",ARG);
  exit(OXO);
}