nis/nis_local_names.c

   1 /* Copyright (c) 1997-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@vt.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 Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <string.h>
  21 #include <unistd.h>
  22 #include <libintl.h>
  23 #include <rpcsvc/nis.h>
  24 #include <shlib-compat.h>
  25
  26 nis_name
  27 nis_local_group (void)
  28 {
  29   static char __nisgroup[NIS_MAXNAMELEN + 1];
  30
  31   char *cptr;
  32   if (__nisgroup[0] == '\0'
  33       && (cptr = getenv ("NIS_GROUP")) != NULL
  34       && cptr[0] != '\0'
  35       && strlen (cptr) < NIS_MAXNAMELEN)
  36     {
  37       char *cp = stpcpy (__nisgroup, cptr);
  38
  39       if (cp[-1] != '.')
  40         {
  41           cptr = nis_local_directory ();
  42           if ((cp - __nisgroup) + strlen (cptr) + 1 < NIS_MAXNAMELEN)
  43             {
  44               *cp++ = '.';
  45               strcpy (cp, cptr);
  46             }
  47           else
  48             __nisgroup[0] = '\0';
  49         }
  50     }
  51
  52   return __nisgroup;
  53 }
  54 libnsl_hidden_nolink_def (nis_local_group, GLIBC_2_1)
  55
  56 nis_name
  57 nis_local_directory (void)
  58 {
  59   static char __nisdomainname[NIS_MAXNAMELEN + 1];
  60
  61   if (__nisdomainname[0] == '\0')
  62     {
  63       if (getdomainname (__nisdomainname, NIS_MAXNAMELEN) < 0)
  64         __nisdomainname[0] = '\0';
  65       else
  66         {
  67           char *cp = rawmemchr (__nisdomainname, '\0');
  68
  69           /* Missing trailing dot? */
  70           if (cp[-1] != '.')
  71             {
  72               *cp++ = '.';
  73               *cp = '\0';
  74             }
  75         }
  76     }
  77
  78   return __nisdomainname;
  79 }
  80 libnsl_hidden_nolink_def (nis_local_directory, GLIBC_2_1)
  81
  82 nis_name
  83 nis_local_principal (void)
  84 {
  85   static char __principal[NIS_MAXNAMELEN + 1];
  86
  87   if (__principal[0] == '\0')
  88     {
  89       char buf[NIS_MAXNAMELEN + 1];
  90       nis_result *res;
  91       uid_t uid = geteuid ();
  92
  93       if (uid != 0)
  94         {
  95           int len = snprintf (buf, NIS_MAXNAMELEN - 1,
  96                               "[auth_name=%d,auth_type=LOCAL],cred.org_dir.%s",
  97                               uid, nis_local_directory ());
  98
  99           if (len >= NIS_MAXNAMELEN - 1)
 100             nobody:
 101             /* XXX The buffer is too small.  Can this happen???  */
 102             return strcpy (__principal, "nobody");
 103
 104           if (buf[len - 1] != '.')
 105             {
 106               buf[len++] = '.';
 107               buf[len] = '\0';
 108             }
 109
 110           res = nis_list (buf, USE_DGRAM + NO_AUTHINFO + FOLLOW_LINKS
 111                           + FOLLOW_PATH, NULL, NULL);
 112
 113           if (res == NULL)
 114             goto nobody;
 115
 116           if (NIS_RES_STATUS (res) == NIS_SUCCESS)
 117             {
 118               if (res->objects.objects_len > 1)
 119                 {
 120                   /* More than one principal with same uid?  something
 121                      wrong with cred table.  Should be unique.  Warn user
 122                      and continue.  */
 123                   printf (_("\
 124 LOCAL entry for UID %d in directory %s not unique\n"),
 125                           uid, nis_local_directory ());
 126                 }
 127               strcpy (__principal, ENTRY_VAL (res->objects.objects_val, 0));
 128               nis_freeresult (res);
 129               return __principal;
 130             }
 131           else
 132             {
 133               nis_freeresult (res);
 134               goto nobody;
 135             }
 136         }
 137       else
 138         return strcpy (__principal, nis_local_host ());
 139
 140       /* Should be never reached */
 141       goto nobody;
 142     }
 143   return __principal;
 144 }
 145 libnsl_hidden_nolink_def (nis_local_principal, GLIBC_2_1)
 146
 147 nis_name
 148 nis_local_host (void)
 149 {
 150   static char __nishostname[NIS_MAXNAMELEN + 1];
 151
 152   if (__nishostname[0] == '\0')
 153     {
 154       if (gethostname (__nishostname, NIS_MAXNAMELEN) < 0)
 155         __nishostname[0] = '\0';
 156       else
 157         {
 158           char *cp = rawmemchr (__nishostname, '\0');
 159           int len = cp - __nishostname;
 160
 161           /* Hostname already fully qualified? */
 162           if (cp[-1] == '.')
 163             return __nishostname;
 164
 165           if (len + strlen (nis_local_directory ()) + 1 > NIS_MAXNAMELEN)
 166             {
 167               __nishostname[0] = '\0';
 168               return __nishostname;
 169             }
 170
 171           *cp++ = '.';
 172           strncpy (cp, nis_local_directory (), NIS_MAXNAMELEN - len -1);
 173           __nishostname[NIS_MAXNAMELEN] = '\0';
 174         }
 175     }
 176
 177   return __nishostname;
 178 }
 179 libnsl_hidden_nolink_def (nis_local_host, GLIBC_2_1)