1 /* Common code for file-based databases in nss_files module.
2 Copyright (C) 1996-2023 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 Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the 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 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
23 #include <libc-lock.h>
25 #include <nss_files.h>
27 #include <kernel-features.h>
29 /* These symbols are defined by the including source file:
31 ENTNAME -- database name of the structure and functions (hostent, pwent).
32 STRUCTURE -- struct name, define only if not ENTNAME (passwd, group).
33 DATABASE -- string of the database file's name ("hosts", "passwd").
35 NEED_H_ERRNO - defined iff an arg `int *herrnop' is used.
37 Also see files-parse.c.
40 #define ENTNAME_r CONCAT(ENTNAME,_r)
42 #define DATAFILE "/etc/" DATABASE
46 # define H_ERRNO_PROTO , int *herrnop
47 # define H_ERRNO_ARG , herrnop
48 # define H_ERRNO_ARG_OR_NULL herrnop
49 # define H_ERRNO_SET(val) (*herrnop = (val))
51 # define H_ERRNO_PROTO
53 # define H_ERRNO_ARG_OR_NULL NULL
54 # define H_ERRNO_SET(val) ((void) 0)
59 # define EXTRA_ARGS_DECL
60 # define EXTRA_ARGS_VALUE
64 /* Maintenance of the stream open on the database file. For getXXent
65 operations the stream needs to be held open across calls, the other
66 getXXbyYY operations all use their own stream. */
68 /* Open database file if not already opened. */
69 static enum nss_status
70 internal_setent (FILE **stream)
72 enum nss_status status = NSS_STATUS_SUCCESS;
76 *stream = __nss_files_fopen (DATAFILE);
79 status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
88 /* Thread-safe, exported version of that. */
90 CONCAT(_nss_files_set,ENTNAME) (int stayopen)
92 return __nss_files_data_setent (CONCAT (nss_file_, ENTNAME), DATAFILE);
94 libc_hidden_def (CONCAT (_nss_files_set,ENTNAME))
97 CONCAT(_nss_files_end,ENTNAME) (void)
99 return __nss_files_data_endent (CONCAT (nss_file_, ENTNAME));
101 libc_hidden_def (CONCAT (_nss_files_end,ENTNAME))
104 /* Parsing the database file into `struct STRUCTURE' data structures. */
105 static enum nss_status
106 internal_getent (FILE *stream, struct STRUCTURE *result,
107 char *buffer, size_t buflen, int *errnop H_ERRNO_PROTO
110 struct parser_data *data = (void *) buffer;
111 size_t linebuflen = buffer + buflen - data->linebuffer;
112 int saved_errno = errno; /* Do not clobber errno on success. */
114 if (buflen < sizeof *data + 2)
117 H_ERRNO_SET (NETDB_INTERNAL);
118 return NSS_STATUS_TRYAGAIN;
123 off64_t original_offset;
124 int ret = __nss_readline (stream, data->linebuffer, linebuflen,
129 H_ERRNO_SET (HOST_NOT_FOUND);
130 __set_errno (saved_errno);
131 return NSS_STATUS_NOTFOUND;
135 ret = __nss_parse_line_result (stream, original_offset,
136 parse_line (data->linebuffer,
137 result, data, buflen,
141 /* Line has been parsed successfully. */
142 __set_errno (saved_errno);
143 return NSS_STATUS_SUCCESS;
145 else if (ret == EINVAL)
146 /* If it is invalid, loop to get the next line of the file
152 H_ERRNO_SET (NETDB_INTERNAL);
154 /* Request larger buffer. */
155 return NSS_STATUS_TRYAGAIN;
157 /* Other read failure. */
158 return NSS_STATUS_UNAVAIL;
163 /* Return the next entry from the database file, doing locking. */
165 CONCAT(_nss_files_get,ENTNAME_r) (struct STRUCTURE *result, char *buffer,
166 size_t buflen, int *errnop H_ERRNO_PROTO)
168 /* Return next entry in host file. */
170 struct nss_files_per_file_data *data;
171 enum nss_status status = __nss_files_data_open (&data,
172 CONCAT (nss_file_, ENTNAME),
174 errnop, H_ERRNO_ARG_OR_NULL);
175 if (status != NSS_STATUS_SUCCESS)
178 status = internal_getent (data->stream, result, buffer, buflen, errnop
179 H_ERRNO_ARG EXTRA_ARGS_VALUE);
181 __nss_files_data_put (data);
184 libc_hidden_def (CONCAT (_nss_files_get,ENTNAME_r))
186 /* Macro for defining lookup functions for this file-based database.
188 NAME is the name of the lookup; e.g. `hostbyname'.
190 DB_CHAR, KEYPATTERN, KEYSIZE are ignored here but used by db-XXX.c
191 e.g. `1 + sizeof (id) * 4'.
193 PROTO is the potentially empty list of other parameters.
195 BREAK_IF_MATCH is a block of code which compares `struct STRUCTURE *result'
196 to the lookup key arguments and does `break;' if they match. */
198 #define DB_LOOKUP(name, db_char, keysize, keypattern, break_if_match, proto...)\
200 _nss_files_get##name##_r (proto, \
201 struct STRUCTURE *result, char *buffer, \
202 size_t buflen, int *errnop H_ERRNO_PROTO) \
204 enum nss_status status; \
205 FILE *stream = NULL; \
208 status = internal_setent (&stream); \
210 if (status == NSS_STATUS_SUCCESS) \
212 while ((status = internal_getent (stream, result, buffer, buflen, errnop \
213 H_ERRNO_ARG EXTRA_ARGS_VALUE)) \
214 == NSS_STATUS_SUCCESS) \
222 libc_hidden_def (_nss_files_get##name##_r)