path: root/nscd/nscd.c

/* Copyright (c) 1998-2025 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published
   by the Free Software Foundation; version 2 of the License, or
   (at your option) any later version.

   This program 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 General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, see <https://www.gnu.org/licenses/>.  */

/* nscd - Name Service Cache Daemon. Caches passwd, group, and hosts.  */

#include <argp.h>
#include <assert.h>
#include <dirent.h>
#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <libintl.h>
#include <locale.h>
#include <paths.h>
#include <pthread.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <stdarg.h>

#include "dbg_log.h"
#include "nscd.h"
#include "selinux.h"
#include "../nss/nsswitch.h"
#include <device-nrs.h>
#ifdef HAVE_INOTIFY
# include <sys/inotify.h>
#endif
#include <kernel-features.h>

/* Get libc version number.  */
#include <version.h>

#define PACKAGE _libc_intl_domainname

int do_shutdown;
int disabled_passwd;
int disabled_group;

typedef enum
{
  /* Running in background as daemon.  */
  RUN_DAEMONIZE,
  /* Running in foreground but otherwise behave like a daemon,
     i.e., detach from terminal and use syslog.  This allows
     better integration with services like systemd.  */
  RUN_FOREGROUND,
  /* Run in foreground in debug mode.  */
  RUN_DEBUG
} run_modes;

static run_modes run_mode = RUN_DAEMONIZE;

static const char *conffile = _PATH_NSCDCONF;

static const char *print_cache = NULL;

time_t start_time;

uintptr_t pagesize_m1;

int paranoia;
time_t restart_time;
time_t restart_interval = RESTART_INTERVAL;
const char *oldcwd;
uid_t old_uid;
gid_t old_gid;

static int check_pid (const char *file);
static int write_pid (const char *file);
static int monitor_child (int fd);

/* Name and version of program.  */
static void print_version (FILE *stream, struct argp_state *state);
void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;

/* Function to print some extra text in the help message.  */
static char *more_help (int key, const char *text, void *input);

/* Definitions of arguments for argp functions.  */
static const struct argp_option options[] =
{
  { "config-file", 'f', N_("NAME"), 0,
    N_("Read configuration data from NAME") },
  { "debug", 'd', NULL, 0,
    N_("Do not fork and display messages on the current tty") },
  { "print", 'p', N_("NAME"), 0,
    N_("Print contents of the offline cache file NAME") },
  { "foreground", 'F', NULL, 0,
    N_("Do not fork, but otherwise behave like a daemon") },