1/* Common database routines for nss_db.
2 Copyright (C) 2000-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
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.
9
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.
14
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/>. */
18
19#include <errno.h>
20#include <fcntl.h>
21#include <dlfcn.h>
22#include <stdlib.h>
23#include <string.h>
24#include <unistd.h>
25#include <sys/mman.h>
26#include <not-cancel.h>
27
28#include "nss_db.h"
29
30/* Open the database stored in FILE. If successful, store either a
31 pointer to the mapped file or a file handle for the file in H and
32 return NSS_STATUS_SUCCESS. On failure, return the appropriate
33 lookup status. */
34enum nss_status
35internal_setent (const char *file, struct nss_db_map *mapping)
36{
37 enum nss_status status = NSS_STATUS_UNAVAIL;
38
39 int fd = __open_nocancel (file, O_RDONLY | O_LARGEFILE | O_CLOEXEC);
40 if (fd != -1)
41 {
42 struct nss_db_header header;
43
44 if (read (fd, &header, sizeof (header)) == sizeof (header))
45 {
46 mapping->header = mmap (NULL, header.allocate, PROT_READ,
47 MAP_PRIVATE, fd, 0);
48 mapping->len = header.allocate;
49 if (mapping->header != MAP_FAILED)
50 status = NSS_STATUS_SUCCESS;
51 else if (errno == ENOMEM)
52 status = NSS_STATUS_TRYAGAIN;
53 }
54
55 __close_nocancel_nostatus (fd);
56 }
57
58 return status;
59}
60
61
62/* Close the database. */
63void
64internal_endent (struct nss_db_map *mapping)
65{
66 if (mapping->header != NULL)
67 {
68 munmap (mapping->header, mapping->len);
69 mapping->header = NULL;
70 }
71}
72