1 /* Common code for file-based databases in nss_files module.
2 Copyright (C) 1996 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Library General Public License as
7 published by the Free Software Foundation; either version 2 of the
8 License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Library General Public License for more details.
15 You should have received a copy of the GNU Library General Public
16 License along with the GNU C Library; see the file COPYING.LIB. If not,
17 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA. */
24 #include <libc-lock.h>
27 /* These symbols are defined by the including source file:
29 ENTNAME -- database name of the structure and functions (hostent, pwent).
30 STRUCTURE -- struct name, define only if not ENTNAME (passwd, group).
31 DATABASE -- string of the database file's name ("hosts", "passwd").
33 NEED_H_ERRNO - defined iff an arg `int *herrnop' is used.
35 Also see files-parse.c.
38 #define ENTNAME_r CONCAT(ENTNAME,_r)
40 #define DATAFILE "/etc/" DATABASE
43 # define H_ERRNO_PROTO , int *herrnop
44 # define H_ERRNO_ARG , herrnop
45 # define H_ERRNO_SET(val) (*herrnop = (val))
47 # define H_ERRNO_PROTO
49 # define H_ERRNO_SET(val) ((void) 0)
52 /* Locks the static variables in this file. */
53 __libc_lock_define_initialized (static, lock
)
55 /* Maintenance of the shared stream open on the database file. */
58 static fpos_t position
;
59 static enum { none
, getent
, getby
} last_use
;
60 static int keep_stream
;
62 /* Open database file if not already opened. */
63 static enum nss_status
64 internal_setent (int stayopen
)
66 enum nss_status status
= NSS_STATUS_SUCCESS
;
70 stream
= fopen (DATAFILE
, "r");
73 status
= NSS_STATUS_UNAVAIL
;
78 /* Remember STAYOPEN flag. */
80 keep_stream
|= stayopen
;
86 /* Thread-safe, exported version of that. */
88 CONCAT(_nss_files_set
,ENTNAME
) (int stayopen
)
90 enum nss_status status
;
92 __libc_lock_lock (lock
);
94 status
= internal_setent (stayopen
);
96 if (status
== NSS_STATUS_SUCCESS
&& fgetpos (stream
, &position
) < 0)
100 status
= NSS_STATUS_UNAVAIL
;
105 __libc_lock_unlock (lock
);
111 /* Close the database file. */
113 internal_endent (void)
123 /* Thread-safe, exported version of that. */
125 CONCAT(_nss_files_end
,ENTNAME
) (void)
127 __libc_lock_lock (lock
);
131 /* Reset STAYOPEN flag. */
134 __libc_lock_unlock (lock
);
136 return NSS_STATUS_SUCCESS
;
139 /* Parsing the database file into `struct STRUCTURE' data structures. */
141 static enum nss_status
142 internal_getent (struct STRUCTURE
*result
,
143 char *buffer
, int buflen H_ERRNO_PROTO
)
146 struct parser_data
*data
= (void *) buffer
;
147 int linebuflen
= buffer
+ buflen
- data
->linebuffer
;
149 if (buflen
< (int) sizeof *data
+ 1)
151 __set_errno (ERANGE
);
152 return NSS_STATUS_TRYAGAIN
;
157 /* Terminate the line so that we can test for overflow. */
158 data
->linebuffer
[linebuflen
- 1] = '\0';
160 p
= fgets (data
->linebuffer
, linebuflen
, stream
);
163 /* End of file or read error. */
164 H_ERRNO_SET (HOST_NOT_FOUND
);
165 return NSS_STATUS_NOTFOUND
;
167 else if (data
->linebuffer
[linebuflen
- 1] != '\0')
169 /* The line is too long. Give the user the opportunity to
170 enlarge the buffer. */
171 __set_errno (ERANGE
);
172 H_ERRNO_SET (NETDB_INTERNAL
);
173 return NSS_STATUS_TRYAGAIN
;
176 /* Skip leading blanks. */
180 while (*p
== '\0' || *p
== '#' /* Ignore empty and comment lines. */
181 /* Parse the line. If it is invalid, loop to get the next
182 line of the file to parse. */
183 || ! parse_line (p
, result
, data
, buflen
));
185 /* Filled in RESULT with the next entry from the database file. */
186 return NSS_STATUS_SUCCESS
;
190 /* Return the next entry from the database file, doing locking. */
192 CONCAT(_nss_files_get
,ENTNAME_r
) (struct STRUCTURE
*result
,
193 char *buffer
, size_t buflen H_ERRNO_PROTO
)
195 /* Return next entry in host file. */
196 enum nss_status status
= NSS_STATUS_SUCCESS
;
198 __libc_lock_lock (lock
);
200 /* Be prepared that the set*ent function was not called before. */
202 status
= internal_setent (0);
204 if (status
!= NSS_STATUS_SUCCESS
)
206 /* If the last use was not by the getent function we need the
207 position the stream. */
208 if (last_use
!= getent
)
209 if (fsetpos (stream
, &position
) < 0)
210 status
= NSS_STATUS_UNAVAIL
;
214 if (status
== NSS_STATUS_SUCCESS
)
216 status
= internal_getent (result
, buffer
, buflen H_ERRNO_ARG
);
218 /* Remember this position if we were successful. If the
219 operation failed we give the user a chance to repeat the
220 operation (perhaps the buffer was too small). */
221 if (status
== NSS_STATUS_SUCCESS
)
222 fgetpos (stream
, &position
);
224 /* We must make sure we reposition the stream the next call. */
229 __libc_lock_unlock (lock
);
234 /* Macro for defining lookup functions for this file-based database.
236 NAME is the name of the lookup; e.g. `hostbyname'.
238 KEYSIZE and KEYPATTERN are ignored here but used by ../nss_db/db-XXX.c.
240 PROTO describes the arguments for the lookup key;
241 e.g. `const char *hostname'.
243 BREAK_IF_MATCH is a block of code which compares `struct STRUCTURE *result'
244 to the lookup key arguments and does `break;' if they match. */
246 #define DB_LOOKUP(name, keysize, keypattern, break_if_match, proto...) \
248 _nss_files_get##name##_r (proto, \
249 struct STRUCTURE *result, \
250 char *buffer, size_t buflen H_ERRNO_PROTO) \
252 enum nss_status status; \
254 __libc_lock_lock (lock); \
256 /* Reset file pointer to beginning or open file. */ \
257 status = internal_setent (keep_stream); \
259 if (status == NSS_STATUS_SUCCESS) \
261 /* Tell getent function that we have repositioned the file pointer. */ \
264 while ((status = internal_getent (result, buffer, buflen H_ERRNO_ARG)) \
265 == NSS_STATUS_SUCCESS) \
269 internal_endent (); \
272 __libc_lock_unlock (lock); \