1  /* Copyright (c) 1997-2023 Free Software Foundation, Inc.
       2     This file is part of the GNU C Library.
       3  
       4     The GNU C Library is free software; you can redistribute it and/or
       5     modify it under the terms of the GNU Lesser General Public
       6     License as published by the Free Software Foundation; either
       7     version 2.1 of the License, or (at your option) any later version.
       8  
       9     The GNU C Library is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      12     Lesser General Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public
      15     License along with the GNU C Library; if not, see
      16     <https://www.gnu.org/licenses/>.  */
      17  
      18  #include <string.h>
      19  #include <rpcsvc/nis.h>
      20  #include <shlib-compat.h>
      21  
      22  /* internal_nis_ismember ()
      23     return codes: -1 principal is in -group
      24                    0 principal isn't in any group
      25  		  1 pirncipal is in group */
      26  static int
      27  internal_ismember (const_nis_name principal, const_nis_name group)
      28  {
      29    size_t grouplen = strlen (group);
      30    char buf[grouplen + 50];
      31    char leafbuf[grouplen + 2];
      32    char domainbuf[grouplen + 2];
      33    nis_result *res;
      34    char *cp, *cp2;
      35    u_int i;
      36  
      37    cp = stpcpy (buf, nis_leaf_of_r (group, leafbuf, sizeof (leafbuf) - 1));
      38    cp = stpcpy (cp, ".groups_dir");
      39    cp2 = nis_domain_of_r (group, domainbuf, sizeof (domainbuf) - 1);
      40    if (cp2 != NULL && cp2[0] != '\0')
      41      {
      42        *cp++ = '.';
      43        strcpy (cp, cp2);
      44      }
      45  
      46    res = nis_lookup (buf, EXPAND_NAME|FOLLOW_LINKS);
      47    if (res == NULL || NIS_RES_STATUS (res) != NIS_SUCCESS)
      48      {
      49        nis_freeresult (res);
      50        return 0;
      51      }
      52  
      53    if ((NIS_RES_NUMOBJ (res) != 1)
      54        || (__type_of (NIS_RES_OBJECT (res)) != NIS_GROUP_OBJ))
      55      {
      56        nis_freeresult (res);
      57        return 0;
      58      }
      59  
      60    /* We search twice in the list, at first, if we have the name
      61       with a "-", then if without. "-member" has priority */
      62    for (i = 0; i < NIS_RES_OBJECT(res)->GR_data.gr_members.gr_members_len; ++i)
      63      {
      64        cp = NIS_RES_OBJECT (res)->GR_data.gr_members.gr_members_val[i];
      65        if (cp[0] == '-')
      66  	{
      67  	  if (strcmp (&cp[1], principal) == 0)
      68  	    {
      69  	      nis_freeresult (res);
      70  	      return -1;
      71  	    }
      72  	  if (cp[1] == '@')
      73  	    switch (internal_ismember (principal, &cp[2]))
      74  	      {
      75  	      case -1:
      76  		nis_freeresult (res);
      77  		return -1;
      78  	      case 1:
      79  		nis_freeresult (res);
      80  		return 1;
      81  	      default:
      82  		break;
      83  	      }
      84  	  else
      85  	    if (cp[1] == '*')
      86  	      {
      87  		char buf1[strlen (principal) + 2];
      88  		char buf2[strlen (cp) + 2];
      89  
      90  		if (strcmp (nis_domain_of_r (principal, buf1, sizeof buf1),
      91  			    nis_domain_of_r (cp, buf2, sizeof buf2)) == 0)
      92  		  {
      93  		    nis_freeresult (res);
      94  		    return -1;
      95  		  }
      96  	      }
      97  	}
      98      }
      99  
     100    for (i = 0; i < NIS_RES_OBJECT (res)->GR_data.gr_members.gr_members_len; ++i)
     101      {
     102        cp = NIS_RES_OBJECT (res)->GR_data.gr_members.gr_members_val[i];
     103        if (cp[0] != '-')
     104  	{
     105  	  if (strcmp (cp, principal) == 0)
     106  	    {
     107  	      nis_freeresult (res);
     108  	      return 1;
     109  	    }
     110  	  if (cp[0] == '@')
     111  	    switch (internal_ismember (principal, &cp[1]))
     112  	      {
     113  	      case -1:
     114  		nis_freeresult (res);
     115  		return -1;
     116  	      case 1:
     117  		nis_freeresult (res);
     118  		return 1;
     119  	      default:
     120  		break;
     121  	      }
     122  	  else
     123  	    if (cp[0] == '*')
     124  	      {
     125  		char buf1[strlen (principal) + 2];
     126  		char buf2[strlen (cp) + 2];
     127  
     128  		if (strcmp (nis_domain_of_r (principal, buf1, sizeof buf1),
     129  			    nis_domain_of_r (cp, buf2, sizeof buf2)) == 0)
     130  		  {
     131  		    nis_freeresult (res);
     132  		    return 1;
     133  		  }
     134  	      }
     135  	}
     136      }
     137    nis_freeresult (res);
     138    return 0;
     139  }
     140  
     141  bool_t
     142  nis_ismember (const_nis_name principal, const_nis_name group)
     143  {
     144    if (group != NULL && group[0] != '\0' && principal != NULL)
     145      return internal_ismember (principal, group) == 1 ? TRUE : FALSE;
     146    else
     147      return FALSE;
     148  }
     149  libnsl_hidden_nolink_def (nis_ismember, GLIBC_2_1)