glibc/nss/nss_db/db-open.c

73 lines
2.1 KiB
C

/* Common database routines for nss_db.
Copyright (C) 2000-2014 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <fcntl.h>
#include <dlfcn.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <not-cancel.h>
#include <kernel-features.h>
#include "nss_db.h"
/* Open the database stored in FILE. If succesful, store either a
pointer to the mapped file or a file handle for the file in H and
return NSS_STATUS_SUCCESS. On failure, return the appropriate
lookup status. */
enum nss_status
internal_setent (const char *file, struct nss_db_map *mapping)
{
enum nss_status status = NSS_STATUS_UNAVAIL;
int mode = O_RDONLY | O_LARGEFILE;
#ifdef O_CLOEXEC
mode |= O_CLOEXEC;
#endif
int fd = open_not_cancel_2 (file, mode);
if (fd != -1)
{
struct nss_db_header header;
if (read (fd, &header, sizeof (header)) == sizeof (header))
{
mapping->header = mmap (NULL, header.allocate, PROT_READ,
MAP_PRIVATE, fd, 0);
mapping->len = header.allocate;
if (mapping->header != MAP_FAILED)
status = NSS_STATUS_SUCCESS;
else if (errno == ENOMEM)
status = NSS_STATUS_TRYAGAIN;
}
close_not_cancel_no_status (fd);
}
return status;
}
/* Close the database. */
void
internal_endent (struct nss_db_map *mapping)
{
munmap (mapping->header, mapping->len);
}