nis/nis_lookup.c

   1 /* Copyright (C) 1997, 1998, 1999 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 unsigned int flags)
  27 {
  28   nis_result *res = calloc (1, sizeof (nis_result));
  29   struct ns_request req;
  30   nis_name *names;
  31   nis_error status;
  32   int link_first_try = 0;
  33   int count_links = 0;   /* We will follow only 16 links in the deep */
  34   int done = 0;
  35   int name_nr = 0;
  36   nis_name namebuf[2] = {NULL, NULL};
  37
  38   if (res == NULL)
  39     return NULL;
  40
  41   if ((flags & EXPAND_NAME) && (name[strlen (name) - 1] != '.'))
  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       dir_binding bptr;
  60       directory_obj *dir = NULL;
  61       req.ns_object.ns_object_len = 0;
  62       req.ns_object.ns_object_val = NULL;
  63
  64       status = __nisfind_server (req.ns_name, &dir);
  65       if (status != NIS_SUCCESS)
  66         {
  67           NIS_RES_STATUS (res) = status;
  68           return res;
  69         }
  70
  71       status = __nisbind_create (&bptr, dir->do_servers.do_servers_val,
  72                                  dir->do_servers.do_servers_len, flags);
  73       if (status != NIS_SUCCESS)
  74         {
  75           NIS_RES_STATUS (res) = status;
  76           nis_free_directory (dir);
  77           return res;
  78         }
  79
  80       while (__nisbind_connect (&bptr) != NIS_SUCCESS)
  81         {
  82           if (__nisbind_next (&bptr) != NIS_SUCCESS)
  83             {
  84               __nisbind_destroy (&bptr);
  85               nis_free_directory (dir);
  86               NIS_RES_STATUS (res) = NIS_NAMEUNREACHABLE;
  87               return res;
  88             }
  89         }
  90
  91       do
  92         {
  93           static struct timeval RPCTIMEOUT = {10, 0};
  94           enum clnt_stat result;
  95
  96         again:
  97           result = clnt_call (bptr.clnt, NIS_LOOKUP,
  98                               (xdrproc_t) _xdr_ns_request,
  99                               (caddr_t) &req, (xdrproc_t) _xdr_nis_result,
 100                               (caddr_t) res, RPCTIMEOUT);
 101
 102           if (result != RPC_SUCCESS)
 103             status = NIS_RPCERROR;
 104           else
 105             {
 106               status = NIS_SUCCESS;
 107
 108               if (NIS_RES_STATUS (res) == NIS_SUCCESS)
 109                 {
 110                     if (__type_of(NIS_RES_OBJECT (res)) == NIS_LINK_OBJ &&
 111                         flags & FOLLOW_LINKS) /* We are following links */
 112                       {
 113                         if (count_links)
 114                           free (req.ns_name);
 115                         /* if we hit the link limit, bail */
 116                         if (count_links > NIS_MAXLINKS)
 117                           {
 118                             NIS_RES_STATUS (res) = NIS_LINKNAMEERROR;
 119                             break;
 120                           }
 121                         ++count_links;
 122                         req.ns_name =
 123                           strdup (NIS_RES_OBJECT (res)->LI_data.li_name);
 124                         nis_freeresult (res);
 125                         res = calloc (1, sizeof (nis_result));
 126                         if (res == NULL)
 127                           {
 128                             __nisbind_destroy (&bptr);
 129                             nis_free_directory (dir);
 130                             return NULL;
 131                           }
 132                         link_first_try = 1; /* Try at first the old binding */
 133                         goto again;
 134                       }
 135                 }
 136               else
 137                 if ((NIS_RES_STATUS (res) == NIS_SYSTEMERROR) ||
 138                     (NIS_RES_STATUS (res) == NIS_NOSUCHNAME) ||
 139                     (NIS_RES_STATUS (res) == NIS_NOT_ME))
 140                   {
 141                     if (link_first_try)
 142                       {
 143                         __nisbind_destroy (&bptr);
 144                         nis_free_directory (dir);
 145
 146                         if (__nisfind_server (req.ns_name, &dir) != NIS_SUCCESS)
 147                           return res;
 148
 149                         if (__nisbind_create (&bptr,
 150                                               dir->do_servers.do_servers_val,
 151                                               dir->do_servers.do_servers_len,
 152                                               flags) != NIS_SUCCESS)
 153                           {
 154                             nis_free_directory (dir);
 155                             return res;
 156                           }
 157                       }
 158                     else
 159                       if (__nisbind_next (&bptr) != NIS_SUCCESS)
 160                         break; /* No more servers to search */
 161
 162                     while (__nisbind_connect (&bptr) != NIS_SUCCESS)
 163                       {
 164                         if (__nisbind_next (&bptr) != NIS_SUCCESS)
 165                           {
 166                             __nisbind_destroy (&bptr);
 167                             nis_free_directory (dir);
 168                             return res;
 169                           }
 170                       }
 171                     goto again;
 172                   }
 173               break;
 174             }
 175           link_first_try = 0; /* Set it back */
 176         }
 177       while ((flags & HARD_LOOKUP) && status == NIS_RPCERROR);
 178
 179       __nisbind_destroy (&bptr);
 180       nis_free_directory (dir);
 181
 182       if (status != NIS_SUCCESS)
 183         {
 184           NIS_RES_STATUS (res) = status;
 185           return res;
 186         }
 187
 188       switch (NIS_RES_STATUS (res))
 189         {
 190         case NIS_PARTIAL:
 191         case NIS_SUCCESS:
 192         case NIS_S_SUCCESS:
 193         case NIS_LINKNAMEERROR: /* We follow to max links */
 194         case NIS_UNAVAIL: /* NIS+ is not installed, or all servers are down */
 195           ++done;
 196           break;
 197         default:
 198           /* Try the next domainname if we don't follow a link */
 199           if (count_links)
 200             {
 201               free (req.ns_name);
 202               NIS_RES_STATUS (res) = NIS_LINKNAMEERROR;
 203               ++done;
 204               break;
 205             }
 206           ++name_nr;
 207           if (names[name_nr] == NULL)
 208             {
 209               ++done;
 210               break;
 211             }
 212           req.ns_name = names[name_nr];
 213           break;
 214         }
 215     }
 216
 217   if (names != namebuf)
 218     nis_freenames (names);
 219
 220   return res;
 221 }