1 /* Copyright (c) 1997-2022 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
internal_ismember(const_nis_name principal,const_nis_name group)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
nis_ismember(const_nis_name principal,const_nis_name group)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)
150