source: trunk/athena/bin/hostinfo/hostinfo.c @ 12494

/* This program looks up a given hostname on the nameserver and prints
 * its Internet address, official name, etc.
 *
 * Win Treese
 * MIT Project Athena
 *
 * Copyright (c) 1986 by the Massachusetts Institute of Technology.
 *
 * Created:     08/29/86
 *
 * Modified:    02/03/87        Doug Alan
 *              Let input also be in form of an internet address.
 *
 * Modified:    02/04/87        Doug Alan
 *              Take flags to control output.
 *
 * Modified:    08/20/90        Tom Coppeto
 *              Added HINFO and MX queries.
 *              List all returned addresses
 *              Allow for multiple hostnames.
 *                      
 */

#ifndef lint
static char rcsid[] = "$Id: hostinfo.c,v 1.14 1999-02-15 15:27:12 ghudson Exp $";
#endif

#include <stdio.h>                      /* Standard IO */
#include <sys/types.h>                  /* System type defs. */
#include <netdb.h>                      /* Networking defs. */
#include <sys/socket.h>                 /* More network defs. */
#include <string.h>                     /* String fct. declarations. */
#include <ctype.h>                      /* Character type macros. */
#include <netinet/in.h>                 /* Internet defs. */
#include <arpa/inet.h>                  /* For inet_addr */

typedef int bool;

#define TRUE            1
#define FALSE           0
#define LINE_LENGTH     128
#define ERROR           -1
#define CPNULL          ((char *) NULL)

extern char *gethinfobyname(), *getmxbyname();
extern struct hostent *hostinfo_gethostbyname(), *hostinfo_gethostbyaddr();

static char *usage[] = {
  "Usage: %s <options> <host-names-or-addresses>",
  "   -h: output only hostname",
  "   -a: output only internet address",
  "   -i: output only host info record",
  "   -m: output only mx record",
  "   -q: disable additional query for hinfo & mx",
  "   -ns <server>: ask specified name server",
  CPNULL,
};

char *myname;                           /* How program was invoked. */
char *hostname = NULL;                  /* desired host */

struct in_addr server_addr;
int server_specified;

bool h_flag = FALSE;
bool a_flag = FALSE;
bool n_flag = FALSE;
bool m_flag = FALSE;
bool i_flag = FALSE;
bool q_flag = FALSE;

static void usage_error();
static void clear_flags();

main(argc, argv)
     int argc;
     char **argv;
     
{
  extern int h_errno;
  struct hostent *host_entry = (struct hostent *)0;     
  unsigned long host_address;
  char *server = NULL;
  char *hinfo = NULL;
  char *mx = NULL;
  int status = 0;
  int set_server = 0;

  myname = (myname = strrchr(argv[0], '/')) ? myname + 1 : argv[0];
  if(argc == 1)
    usage_error();
  if(strcmp(argv[1], "-help") == 0)
    usage_error();

  while(*++argv)
    {
      if(hostname && !(a_flag || m_flag || i_flag || h_flag))
        putchar('\n');

      set_server = 0;
      if(**argv == '-')
        switch((*argv)[1])
          {
          case 'h':
            clear_flags();
            h_flag = TRUE;
            continue;
          case 'a':
            clear_flags();
            a_flag = TRUE;
            continue;
          case 'm':
            clear_flags();
            m_flag = TRUE;
            continue;
          case 'i':
            clear_flags();
            i_flag = TRUE;
            continue;
          case 'q':
            clear_flags();
            q_flag = TRUE;
            continue;
          case 'n':
            if(!*++argv)
              usage_error();
            server = *argv;
            set_server = 1;
            break;
          case '?':
          default:
            usage_error();
            break;
          }
      
      hinfo = NULL;
      mx = NULL;
      host_address = 0;
      host_entry = NULL;
      hostname = *argv;
      
      if (*hostname >= '0' && *hostname <= '9')
        {
          host_address = inet_addr(hostname);
          if (host_address)
            {
              host_entry = hostinfo_gethostbyaddr((char *) &host_address, 4,
                                                  AF_INET);
              if(host_entry)
                if(set_server)            
                  memcpy(&server_addr, host_entry->h_addr,
                         sizeof(server_addr));
                else              
                  print_host(host_entry);
            }
        }

      if (!host_entry)
        {
          host_entry = hostinfo_gethostbyname(hostname);
          if(host_entry)
            {
              if(set_server)
                memcpy(&server_addr, host_entry->h_addr, sizeof(server_addr));
              else
                {
                  print_host(host_entry);
                  if(!q_flag)
                    {
                      hinfo = (char *) gethinfobyname(hostname);
                      if(hinfo)
                        {
                          if(!h_flag && !a_flag && !m_flag)
                            {
                              int i = (int) hinfo[0];
                              hinfo[i+1] = '/';
                              if(i_flag)
                                printf("%s\n", hinfo+1);
                              else
                                printf("Host info:\t%s\n", hinfo+1); 
                            }
                        }
                      if(!h_flag && !a_flag && !i_flag)
                        if(mx = (char *) getmxbyname(hostname))
                          if(m_flag)
                            printf("%s\n", mx); 
                          else
                            printf("MX address:\t%s\n", mx);              
                    }
                }
            }
        }
  
      if(host_entry && set_server)
        {
          struct in_addr internet_address;

          server_specified = 1;
          memcpy(&internet_address, host_entry->h_addr_list[0],
                host_entry->h_length);
          printf("Using domain server:\nHost name:\t%s\nHost Address\t%s\n",
                 host_entry->h_name, inet_ntoa(internet_address));
          continue;
        }

      if (!host_entry)
        {
          switch (h_errno) 
            {
            case HOST_NOT_FOUND:
              printf("No such host '%s'.\n",hostname);
              status = ERROR;
              continue;
              break;
            default:
            case TRY_AGAIN:
            case NO_RECOVERY:
              printf("Cannot resolve name '%s' due to network difficulties.\n",
                     hostname);
              status = ERROR;
              continue;
              break;
            case NO_ADDRESS:
            /* should look up MX record? */
              /* this error return appears if there is some entry for the
                 requested name, but no A record (e.g. only an NS record) */
              printf("No address for '%s'.\n", hostname);
              status = ERROR;
              continue;
              break;
            }
        }
    }
  
  exit(status);
} /* main */


print_host(h)
     struct hostent *h;
{
  struct in_addr internet_address;
  char **alias;                            
  char **addr;

  if(m_flag || i_flag)
    return;

  if (h_flag) 
    printf("%s\n", h->h_name);
  else  
    {
      if(!a_flag)
        {
          printf("Desired host:\t%s\n", hostname);
          printf("Official name:\t%s\n", h->h_name);
          for (alias = h->h_aliases; *alias; alias++)
            printf("Alias:\t\t%s\n", *alias);
        }
          
      for (addr = h->h_addr_list; *addr; addr++) 
        {
          memcpy(&internet_address, *addr, h->h_length);
          if(a_flag)
            printf("%s\n", inet_ntoa(internet_address));
          else
            printf("Host address:\t%s\n", inet_ntoa(internet_address));
        }
    }
}


static void
usage_error()
{
  int line = 0;                         /* current line */
  while (usage[line] != CPNULL)
    {
      fprintf (stderr, usage[line++], myname);
      putc('\n', stderr);
    }
  exit(ERROR);
} /* usage_error */


static void
clear_flags()
{
  i_flag = m_flag = h_flag = a_flag = 0;
}