nis/nis_lookup.c

   1 /* Copyright (C) 1997, 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@uni-paderborn.de>, 1997.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <string.h>
  21 #include <rpcsvc/nis.h>
  22 #include "nis_xdr.h"
  23 #include "nis_intern.h"
  24
  25 nis_result *
  26 nis_lookup (const_nis_name name, const u_long flags)
  27 {
  28   nis_result *res;
  29   struct ns_request req;
  30   nis_name *names;
  31   nis_error status;
  32   int count_links = 0;   /* We will follow only 16 links in the deep */
  33   int done = 0;
  34   int name_nr = 0;
  35   nis_name namebuf[2] = {NULL, NULL};
  36
  37   res = calloc (1, sizeof (nis_result));
  38   if (res == NULL)
  39     return NULL;
  40
  41   if (flags & EXPAND_NAME)
  42     {
  43       names = nis_getnames (name);
  44       if (names == NULL)
  45         {
  46           NIS_RES_STATUS (res) = NIS_NAMEUNREACHABLE;
  47           return res;
  48         }
  49     }
  50   else
  51     {
  52       names = namebuf;
  53       names[0] = (nis_name)name;
  54     }
  55
  56   req.ns_name = names[0];
  57   while (!done)
  58     {
  59       req.ns_object.ns_object_len = 0;
  60       req.ns_object.ns_object_val = NULL;
  61       memset (res, '\0', sizeof (nis_result));
  62
  63       status = __do_niscall (req.ns_name, NIS_LOOKUP,
  64                              (xdrproc_t) _xdr_ns_request,
  65                              (caddr_t) & req,
  66                              (xdrproc_t) _xdr_nis_result,
  67                              (caddr_t) res, flags, NULL);
  68       if (status != NIS_SUCCESS)
  69         NIS_RES_STATUS (res) = status;
  70
  71       switch (NIS_RES_STATUS (res))
  72         {
  73         case NIS_PARTIAL:
  74         case NIS_SUCCESS:
  75         case NIS_S_SUCCESS:
  76           if (__type_of(NIS_RES_OBJECT (res)) == NIS_LINK_OBJ &&
  77               flags & FOLLOW_LINKS) /* We are following links */
  78             {
  79               /* if we hit the link limit, bail */
  80               if (count_links > NIS_MAXLINKS)
  81                 {
  82                   NIS_RES_STATUS (res) = NIS_LINKNAMEERROR;
  83                   ++done;
  84                   break;
  85                 }
  86               if (count_links)
  87                 free (req.ns_name);
  88               ++count_links;
  89               req.ns_name = strdup (NIS_RES_OBJECT (res)->LI_data.li_name);
  90               nis_freeresult (res);
  91               res = calloc (1, sizeof (nis_result));
  92               if (res == NULL)
  93                 return NULL;
  94             }
  95           else
  96             ++done;
  97           break;
  98         case NIS_CBRESULTS:
  99           /* The callback is handled in __do_niscall2 */
 100           ++done;
 101           break;
 102         case NIS_UNAVAIL:
 103           /* NIS+ is not installed, or all servers are down */
 104           ++done;
 105           break;
 106         default:
 107           /* Try the next domainname if we don't follow a link */
 108           if (count_links)
 109             {
 110               free (req.ns_name);
 111               NIS_RES_STATUS (res) = NIS_LINKNAMEERROR;
 112               ++done;
 113               break;
 114             }
 115           ++name_nr;
 116           if (names[name_nr] == NULL)
 117             {
 118               ++done;
 119               break;
 120             }
 121           req.ns_name = names[name_nr];
 122           break;
 123         }
 124     }
 125
 126   if (names != namebuf)
 127     nis_freenames (names);
 128
 129   return res;
 130 }