1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
/* Common code for file-based databases in nss_files module.
Copyright (C) 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <stdio.h>
#include <ctype.h>
#include <assert.h>
#include <libc-lock.h>
#include "nsswitch.h"
/* These symbols are defined by the including source file:
ENTNAME -- database name of the structure and functions (hostent, pwent).
STRUCTURE -- struct name, define only if not ENTNAME (passwd, group).
DATAFILE -- string of the database file's name.
NEED_H_ERRNO - defined iff an arg `int *herrnop' is used.
MIDLINE_COMMENTS - defined iff # before \n terminates a database line.
*/
#define ENTNAME_r CONCAT(ENTNAME,_r)
#ifdef NEED_H_ERRNO
#define H_ERRNO_PROTO , int *herrnop
#define H_ERRNO_ARG , herrnop
#define H_ERRNO_SET(val) (*herrnop = (val))
#else
#define H_ERRNO_PROTO
#define H_ERRNO_ARG
#define H_ERRNO_SET(val) ((void) 0)
#endif
/* Locks the static variables in this file. */
__libc_lock_define_initialized (static, lock);
/* Maintenance of the shared stream open on the database file. */
static FILE *stream;
static int keep_stream;
/* Open database file if not already opened. */
static int
internal_setent (int stayopen)
{
int status = NSS_STATUS_SUCCESS;
if (stream == NULL)
{
stream = fopen (DATAFILE, "r");
if (stream == NULL)
status = NSS_STATUS_UNAVAIL;
}
else
rewind (stream);
/* Remember STAYOPEN flag. */
if (stream != NULL)
keep_stream |= stayopen;
return status;
}
/* Thread-safe, exported version of that. */
int
CONCAT(_nss_files_set,ENTNAME) (int stayopen)
{
int status;
__libc_lock_lock (lock);
status = internal_setent (stayopen);
__libc_lock_unlock (lock);
return status;
}
/* Close the database file. */
static void
internal_endent (void)
{
if (stream != NULL)
{
fclose (stream);
stream = NULL;
}
}
/* Thread-safe, exported version of that. */
int
CONCAT(_nss_files_end,ENTNAME) (void)
{
__libc_lock_lock (lock);
internal_endent ();
/* Reset STAYOPEN flag. */
keep_stream = 0;
__libc_lock_unlock (lock);
return NSS_STATUS_SUCCESS;
}
/* Parsing the database file into `struct STRUCTURE' data structures. */
static enum nss_status
internal_getent (struct STRUCTURE *result,
char *buffer, int buflen H_ERRNO_PROTO)
{
char *p;
struct parser_data *data = (void *) buffer;
int linebuflen = buffer + buflen - data->linebuffer;
/* Be prepared that the set*ent function was not called before. */
if (stream == NULL)
{
enum nss_status status;
status = internal_setent (0);
if (status != NSS_STATUS_SUCCESS)
return status;
}
if (buflen < (int) sizeof *data + 1)
{
errno = ERANGE;
return NSS_STATUS_NOTFOUND;
}
do
{
p = fgets (data->linebuffer, linebuflen, stream);
if (p == NULL)
{
/* End of file or read error. */
H_ERRNO_SET (HOST_NOT_FOUND);
return NSS_STATUS_NOTFOUND;
}
/* Terminate the line for any case. */
data->linebuffer[linebuflen - 1] = '\0';
/* Skip leading blanks. */
while (isspace (*p))
++p;
} while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */
/* Parse the line. If it is invalid, loop to
get the next line of the file to parse. */
! parse_line (p, result, data, buflen));
/* Filled in RESULT with the next entry from the database file. */
return NSS_STATUS_SUCCESS;
}
/* Return the next entry from the database file, doing locking. */
int
CONCAT(_nss_files_get,ENTNAME_r) (struct STRUCTURE *result,
char *buffer, int buflen H_ERRNO_PROTO)
{
/* Return next entry in host file. */
int status;
__libc_lock_lock (lock);
status = internal_getent (result, buffer, buflen H_ERRNO_ARG);
__libc_lock_unlock (lock);
return status;
}
/* Macro for defining lookup functions for this file-based database.
NAME is the name of the lookup; e.g. `hostbyname'.
PROTO describes the arguments for the lookup key;
e.g. `const char *hostname'.
BREAK_IF_MATCH is a block of code which compares `struct STRUCTURE *result'
to the lookup key arguments and does `break;' if they match. */
#define DB_LOOKUP(name, break_if_match, proto...) \
enum nss_status \
_nss_files_get##name##_r (proto, \
struct STRUCTURE *result, \
char *buffer, int buflen H_ERRNO_PROTO) \
{ \
enum nss_status status; \
\
__libc_lock_lock (lock); \
\
/* Reset file pointer to beginning or open file. */ \
internal_setent (keep_stream); \
\
while ((status = internal_getent (result, buffer, buflen H_ERRNO_ARG)) \
== NSS_STATUS_SUCCESS) \
{ break_if_match } \
\
if (! keep_stream) \
internal_endent (); \
\
__libc_lock_unlock (lock); \
\
return status; \
}
|
