/* NETBIOS name lookup tool - by eSDee of Netric (www.netric.org)
 * yeh.. i was really bored :-)
 * 
 * [esdee@pant0ffel] gcc -o nbtstat nbtstat.c && ./nbtstat 10.0.0.4
 * Request sent, waiting for reply... [ctrl-c to abort]
 * Name                Type
 * ----------------------------------
 * HOEPELKO-ESPU0B <00> UNIQUE Workstation Service
 * HOEPELKO-ESPU0B <20> UNIQUE File Server Service
 * WORKGROUP       <00> GROUP  Domain Name
 * WORKGROUP       <1e> GROUP  Browser Service Elections
 * HOEPELKO-ESPU0B <03> UNIQUE Messenger Service
 * ADMINISTRATOR   <03> UNIQUE Messenger Service
 * WORKGROUP       <1d> UNIQUE Master Browser
 * ..__MSBROWSE__. <01> GROUP  Master Browser
 * MAC-addres = 00-02-a5-e1-fd-b7
 * [/home/esdee/nbtstat] */

#include  <stdio.h>
#include  <string.h>
#include  <sys/types.h>
#include  <sys/socket.h>
#include  <netinet/in.h>
#include  <netdb.h>
#include  <unistd.h>

char
nbtname[]= /* netbios name packet */
{
        0x80,0xf0,0x00,0x10,0x00,0x01,0x00,0x00,
        0x00,0x00,0x00,0x00,0x20,0x43,0x4b,0x41,
        0x41,0x41,0x41,0x41,0x41,0x41,0x41,0x41,
        0x41,0x41,0x41,0x41,0x41,0x41,0x41,0x41,
        0x41,0x41,0x41,0x41,0x41,0x41,0x41,0x41,
        0x41,0x41,0x41,0x41,0x41,0x00,0x00,0x21,
        0x00,0x01
};

int
display();

int
main(int argc, char *argv[])
{
        char temp[16];

        unsigned char recv[256];
  unsigned char *ptr;
  
        struct sockaddr_in server;
        struct hostent        *hp;

        int                     s;
  int         total;

        unsigned int nb_num;
        unsigned int nb_type;

        int i = 0;

        if (argc < 2) {
                fprintf(stderr, "Usage: %s <hostname>\n", argv[0]);
                exit(1);
        }

        if ((hp = gethostbyname(argv[1])) == NULL)  {
                fprintf(stderr,"Error: Unable to resolve %s\n", argv[1]);
                exit(1);
        }

        if ((s = socket(PF_INET, SOCK_DGRAM, 17)) < 0)  { /* 17 = UDP */
                perror("socket");
                exit(1);
        }

        memset(recv,0x0, sizeof(recv));

        bzero((char *) &server, sizeof(server));
        bcopy(hp->h_addr, (char *) &server.sin_addr, hp->h_length);

        server.sin_family = hp->h_addrtype;
        server.sin_port = htons(137); /* netbios-ns */

        if (sendto(s, nbtname, sizeof(nbtname), 0, (struct sockaddr *) &server, sizeof(server)) < 0)  {
                perror("sendto");
                exit(1);
        } else {
                fprintf(stdout, "Request sent, waiting for reply... [ctrl-c to abort]\n");

                read(s, recv, sizeof(recv) - 1);

    fprintf(stdout,"Name                Type\n"
             "----------------------------------\n");  
                ptr=recv+57;
     total=*(ptr - 1); /* max names */

                while(ptr < recv + sizeof(recv)) {

                        memset(temp,0x0, sizeof(temp));
                        strncpy(temp, ptr, 15);   /* copies the name into temp */

                        ptr+=15;
                        nb_num  = *ptr; 
                        nb_type = *(ptr + 1);
                        ptr+=3;

      if (i==total) {    /* max names reached */
        ptr-=19;   /* sets the pointer to the mac_addres field */
        fprintf(stdout,"\nMAC-addres = %02x-%02x-%02x-%02x-%02x-%02x\n\n",
                 *(ptr + 1), *(ptr + 2), *(ptr + 3),
                 *(ptr + 4), *(ptr + 5), *(ptr + 6));
        break;

      }

                        display(temp,nb_num,nb_type);
      i++;
      
                }
        }
        close(s);
        return  0;
}

int
display(char *name, unsigned int number, unsigned int type)
{
        char description[256];
  int i;

        memset(description, 0x0, sizeof(description));

  /* list taken from https://support.microsoft.com/default.aspx?scid=KB;EN-US;q163409& */
        /* 0x04 - UNIQUE */
        /* 0x80 - GROUP */

        switch(number) {
                case 0x00:
                        if (type <= 0x80) { 
        strncpy(description, "UNIQUE Workstation Service", sizeof(description) - 1);
                        } else { 
        strncpy(description, "GROUP  Domain Name", sizeof(description) - 1);
      }
                        break;
    
    case 0x01:
      if (type <= 0x80) {
        strncpy(description, "UNIQUE Messenger Service", sizeof(description) - 1);
      } else {
        strncpy(description, "GROUP  Master Browser", sizeof(description) - 1);
      }
      break;
    case 0x03:
      strncpy(description, "UNIQUE Messenger Service", sizeof(description) - 1);
      break;
    case 0x06:
      strncpy(description, "UNIQUE RAS Server Service", sizeof(description) - 1);
      break;
    case 0x1b:
      strncpy(description, "UNIQUE Domain Master Browser", sizeof(description) - 1);
      break;
    case 0x1c:
      strncpy(description, "GROUP  Domain Controllers", sizeof(description) - 1);
      break;
    case 0x1d:
      strncpy(description, "UNIQUE Master Browser", sizeof(description) - 1);
      break;
    case 0x1e:
      if (type >= 0x80) strncpy(description, "GROUP  Browser Service Elections", sizeof(description) - 1);
                        break;      
    case 0x1F:
      strncpy(description, "UNIQUE NetDDE Service", sizeof(description) - 1);
      break;
                case 0x20:
                        strncpy(description, "UNIQUE File Server Service", sizeof(description) - 1);
                        break;
    case 0x21:
      strncpy(description, "UNIQUE RAS Client Service", sizeof(description) - 1);
                        break;
    case 0x22:
                        strncpy(description, "UNIQUE Microsoft Exchange Interchange(MSMail Connector)", sizeof(description) - 1);
                        break;
    case 0x23:
      strncpy(description, "UNIQUE Microsoft Exchange Store", sizeof(description) - 1);
      break;
    case 0x24:
      strncpy(description, "UNIQUE Microsoft Exchange Directory", sizeof(description) - 1);
      break;
    case 0x30:
      strncpy(description, "UNIQUE Modem Sharing Server Service", sizeof(description) - 1);
                        break;
    case 0x31:
                        strncpy(description, "UNIQUE Modem Sharing Client Service", sizeof(description) - 1);
                        break;      
    case 0x42:
                        strncpy(description, "UNIQUE Mcaffee Anti-Virus", sizeof(description) - 1);
                        break;
    case 0x43:
                        strncpy(description, "UNIQUE SMS Clients Remote Control", sizeof(description) - 1);
                        break;
    case 0x44:
      strncpy(description, "UNIQUE SMS Administrators Remote Control Tool", sizeof(description) - 1);
      break;
    case 0x45:
                        strncpy(description, "UNIQUE SMS Clients Remote Chat", sizeof(description) - 1);
                        break;      
    case 0x46:
                        strncpy(description, "UNIQUE SMS Clients Remote Transfer", sizeof(description) - 1);
                        break;      
    case 0x4C:
                        strncpy(description, "UNIQUE DEC Pathworks TCPIP service on Windows NT", sizeof(description) - 1);
                        break;    
    case 0x52:
                        strncpy(description, "UNIQUE DEC Pathworks TCPIP service on Windows NT", sizeof(description) - 1);
                        break;
    case 0x6a:
                        strncpy(description, "UNIQUE Microsoft Exchange IMC", sizeof(description) - 1);
                        break;
    case 0x87:
                        strncpy(description, "UNIQUE Microsoft Exchange MTA", sizeof(description) - 1);
                        break;
    case 0xbe:
                        strncpy(description, "UNIQUE Network Monitor Agent", sizeof(description) - 1);
                        break;
    case 0xbf:
                        strncpy(description, "UNIQUE Network Monitor Application", sizeof(description) - 1);
                        break;
    default:
      strncpy(description, "UNIQUE Unknown", sizeof(description) - 1);
      break;
        }

  for (i=0; i < strlen(name); i++) /* replaces weird chars with dots */ 
    if (name[i] < 31 || name[i] > 126) name[i] = '.';

        if (name) fprintf(stdout, "%s <%02x> %s\n", name, number, description);
        return 0;

}