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