發信人: lgwu (亂世糊涂蟲), 信區: Security 

標  題: a simple port scan 

發信站: 武漢白云黃鶴站 (Fri Jan 29 21:00:02 1999) , 站內信件 

  

static char sccsid[] = "@(#)pscan.c     1.0     (KRAD) 08/25/94"; 

                    #include <stdio.h> 

                    #include <sys/types.h> 

                    #include <sys/socket.h> 

                    #include <netinet/in.h> 

                    #include <netdb.h> 

  

                    #define MAX_PORT 1024 /* scan up to this port */ 

                    int s; 

                    struct sockaddr_in addr; 

                    char rmt_host[100]; 

  

                    int skan(port) 

                    int port; 

                    { 

                     int r; 

                        s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP); 

                        if (s < 0) { 

                           /* fprintf("ERROR: socket() failed\n"); */ 

                           /* Changed to printf for my Linux 1.1.18 box */ 

                           printf("ERROR: socket() failed\n"); 

                           exit(0); 

                      } 

  

                        addr.sin_family = PF_INET; 

                        addr.sin_port = htons(port); 

                        addr.sin_addr.s_addr = inet_addr(rmt_host); 

  

                        r = connect(s,(struct sockaddr *) &addr, sizeof(addr)); 

  

                        close(s); 

                        if (r==-1) { 

                           return (1 == 0); 

                        } 

  

                        return (1 == 1); 

                    } 

  

                    main(argc,argv) 

                    int argc; 

                    char *argv[]; 

                    { 

                     int a,b,c,d,e,f; 

                     struct hostent *foo; 

                    struct servent *bar; 

  

                       if (argc < 2) { 

                          fprintf(stderr,"usage: %s <host> [highest port]\n",arg 

v[0]); 

                          exit(0); 

                       } 

  

                       if (sscanf(argv[1],"%d.%d.%d.%d",&a,&b,&c,&d) != 4) { 

                          foo = gethostbyname(argv[1]); 

                          if (foo == NULL) { 

                             fprintf(stderr,"error: cannot resolve host %s\n",ar 

gv[1]); 

                             exit(0); 

                          } 

                          sprintf(rmt_host,"%d.%d.%d.%d",(unsigned char )foo->h_ 

addr_list[0][0], 

                                  (unsigned char ) foo->h_addr_list[0][1], 

                                  (unsigned char ) foo->h_addr_list[0][2], 

                                  (unsigned char ) foo->h_addr_list[0][3]); 

                       } else { 

                          strncpy(rmt_host,argv[1],99); 

                       } 

  

  

                       if (argc > 2) { 

                          f = atoi(argv[2]); 

                       } else 

                          f = MAX_PORT; 

  

                       fprintf(stdout,"Scanning host %s - TCP ports 1 through %d 

\n",rmt_host,f); 

  

                       for (e =1;e<=f;e++) { 

                        char serv[100]; 

                          if (skan(e)) { 

                             bar = getservbyport(htons(e),"tcp"); 

                             printf("%d (%s) is running.\n",e,(bar == NULL) ? "U 

NKNOWN" : 

                                    bar->s_name); 



                          } 

                       } 

                    } 

 /* This simple port scan program can be found in /var/log/messages */ 

But if u use nmap( half connect,NULL connect,a normal TCPwarp couldn't 

find it out. As a patch,you can use tcplog.I  posted it before. 

  

  

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