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. */ |
30 | static const char default_nss[] = "/etc/default/nss" ; |
31 | |
32 | /* Flags once read from the file. */ |
33 | static 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. */ |
39 | static 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 | |
55 | static void |
56 | init (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 | |
120 | int |
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 | |