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
|
/* Common code for DB-based databases in nss_db module.
Copyright (C) 1996, 1997 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., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <db.h>
#include <fcntl.h>
#include <bits/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).
DATABASE -- database file name, ("hosts", "passwd")
NEED_H_ERRNO - defined iff an arg `int *herrnop' is used.
*/
#define ENTNAME_r CONCAT(ENTNAME,_r)
#include <paths.h>
#define DBFILE _PATH_VARDB DATABASE ".db"
#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 handle open on the database. */
static DB *db;
static int keep_db;
static unsigned int entidx; /* Index for `getENTNAME'. */
/* Open database file if not already opened. */
static enum nss_status
internal_setent (int stayopen)
{
enum nss_status status = NSS_STATUS_SUCCESS;
if (db == NULL)
{
db = __dbopen (DBFILE, O_RDONLY, 0, DB_BTREE, NULL);
if (db == NULL)
status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
else
{
/* We have to make sure the file is `closed on exec'. */
int result, flags;
result = flags = fcntl ((*db->fd) (db), F_GETFD, 0);
if (result >= 0)
{
flags |= FD_CLOEXEC;
result = fcntl ((*db->fd) (db), F_SETFD, flags);
}
if (result < 0)
{
/* Something went wrong. Close the stream and return a
failure. */
(*db->close) (db);
db = NULL;
status = NSS_STATUS_UNAVAIL;
}
}
}
/* Remember STAYOPEN flag. */
if (db != NULL)
keep_db |= stayopen;
return status;
}
/* Thread-safe, exported version of that. */
enum nss_status
CONCAT(_nss_db_set,ENTNAME) (int stayopen)
{
enum nss_status status;
__libc_lock_lock (lock);
status = internal_setent (stayopen);
/* Reset the sequential index. */
entidx = 0;
__libc_lock_unlock (lock);
return status;
}
/* Close the database file. */
static void
internal_endent (void)
{
if (db != NULL)
{
(*db->close) (db);
db = NULL;
}
}
/* Thread-safe, exported version of that. */
enum nss_status
CONCAT(_nss_db_end,ENTNAME) (void)
{
__libc_lock_lock (lock);
internal_endent ();
/* Reset STAYOPEN flag. */
keep_db = 0;
__libc_lock_unlock (lock);
return NSS_STATUS_SUCCESS;
}
/* Do a database lookup for KEY. */
static enum nss_status
lookup (const DBT *key, struct STRUCTURE *result,
void *buffer, int buflen H_ERRNO_PROTO)
{
enum nss_status status;
DBT value;
/* Open the database. */
status = internal_setent (keep_db);
if (status != NSS_STATUS_SUCCESS)
return status;
/* Succeed iff it matches a value that parses correctly. */
status = (((*db->get) (db, key, &value, 0) == 0 &&
parse_line (value.data, result, buffer, buflen))
? NSS_STATUS_SUCCESS : NSS_STATUS_NOTFOUND);
if (! keep_db)
internal_endent ();
return status;
}
/* Macro for defining lookup functions for this DB-based database.
NAME is the name of the lookup; e.g. `pwnam'.
KEYPATTERN gives `printf' args to construct a key string;
e.g. `(".%s", name)'.
KEYSIZE gives the allocation size of a buffer to construct it in;
e.g. `1 + strlen (name)'.
PROTO describes the arguments for the lookup key;
e.g. `const char *name'.
BREAK_IF_MATCH is ignored, but used by ../nss_files/files-XXX.c. */
#define DB_LOOKUP(name, keysize, keypattern, break_if_match, proto...) \
enum nss_status \
_nss_db_get##name##_r (proto, \
struct STRUCTURE *result, \
char *buffer, size_t buflen H_ERRNO_PROTO) \
{ \
DBT key; \
enum nss_status status; \
const size_t size = (keysize); \
key.data = __alloca (size); \
key.size = KEYPRINTF keypattern; \
__libc_lock_lock (lock); \
status = lookup (&key, result, buffer, buflen H_ERRNO_ARG); \
__libc_lock_unlock (lock); \
return status; \
}
#define KEYPRINTF(pattern, args...) snprintf (key.data, size, pattern ,##args)
/* Return the next entry from the database file, doing locking. */
enum nss_status
CONCAT(_nss_db_get,ENTNAME_r) (struct STRUCTURE *result,
char *buffer, size_t buflen H_ERRNO_PROTO)
{
/* Return next entry in host file. */
enum nss_status status;
char buf[20];
DBT key;
__libc_lock_lock (lock);
key.size = 1 + snprintf (key.data = buf, sizeof buf, "0%u", entidx++);
status = lookup (&key, result, buffer, buflen H_ERRNO_ARG);
__libc_lock_unlock (lock);
return status;
}
|
