1/* Copyright (C) 1996-2016 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 <http://www.gnu.org/licenses/>. */
17
18#include <ctype.h>
19#include <errno.h>
20#include <stdio.h>
21#include <stdio_ext.h>
22#include <stdlib.h>
23#include <string.h>
24#include <libc-lock.h>
25
26#include <libnsl.h>
27
28
29/* Path of the file. */
30static const char default_nss[] = "/etc/default/nss";
31
32/* Flags once read from the file. */
33static int default_nss_flags;
34
35/* Code to make sure we call 'init' once. */
36__libc_once_define (static, once);
37
38/* Table of the recognized variables. */
39static const struct
40{
41 char name[23];
42 unsigned int len;
43 int flag;
44} vars[] =
45 {
46#define STRNLEN(s) s, sizeof (s) - 1
47 { STRNLEN ("NETID_AUTHORITATIVE"), NSS_FLAG_NETID_AUTHORITATIVE },
48 { STRNLEN ("SERVICES_AUTHORITATIVE"), NSS_FLAG_SERVICES_AUTHORITATIVE },
49 { STRNLEN ("SETENT_BATCH_READ"), NSS_FLAG_SETENT_BATCH_READ },
50 { STRNLEN ("ADJUNCT_AS_SHADOW"), NSS_FLAG_ADJUNCT_AS_SHADOW },
51 };
52#define nvars (sizeof (vars) / sizeof (vars[0]))
53
54
55static void
56init (void)
57{
58 int saved_errno = errno;
59 FILE *fp = fopen (default_nss, "rce");
60 if (fp != NULL)
61 {
62 char *line = NULL;
63 size_t linelen = 0;
64
65 __fsetlocking (fp, FSETLOCKING_BYCALLER);
66
67 while (!feof_unlocked (fp))
68 {
69 ssize_t n = getline (&line, &linelen, fp);
70 if (n <= 0)
71 break;
72
73 /* Recognize only
74
75 <THE-VARIABLE> = TRUE
76
77 with arbitrary white spaces. */
78 char *cp = line;
79 while (isspace (*cp))
80 ++cp;
81
82 /* Recognize comment lines. */
83 if (*cp == '#')
84 continue;
85
86 int idx;
87 for (idx = 0; idx < nvars; ++idx)
88 if (strncmp (cp, vars[idx].name, vars[idx].len) == 0)
89 break;
90 if (idx == nvars)
91 continue;
92
93 cp += vars[idx].len;
94 while (isspace (*cp))
95 ++cp;
96 if (*cp++ != '=')
97 continue;
98 while (isspace (*cp))
99 ++cp;
100
101 if (strncmp (cp, "TRUE", 4) != 0)
102 continue;
103 cp += 4;
104
105 while (isspace (*cp))
106 ++cp;
107
108 if (*cp == '\0')
109 default_nss_flags |= vars[idx].flag;
110 }
111
112 free (line);
113
114 fclose (fp);
115 }
116 __set_errno (saved_errno);
117}
118
119
120int
121_nsl_default_nss (void)
122{
123 /* If we have not yet read the file yet do it now. */
124 __libc_once (once, init);
125
126 return default_nss_flags;
127}
128