nscd/nscd.c

   1 /* Copyright (c) 1998, 1999 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@suse.de>, 1998.
   4
   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.
   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    Library General Public License for more details.
  14
  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. */
  19
  20 /* nscd - Name Service Cache Daemon. Caches passwd, group, and hosts.  */
  21
  22 #include <argp.h>
  23 #include <assert.h>
  24 #include <errno.h>
  25 #include <error.h>
  26 #include <libintl.h>
  27 #include <locale.h>
  28 #include <pthread.h>
  29 #include <pwd.h>
  30 #include <signal.h>
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <syslog.h>
  35 #include <unistd.h>
  36 #include <sys/socket.h>
  37 #include <sys/un.h>
  38
  39 #include "dbg_log.h"
  40 #include "nscd.h"
  41
  42 /* Get libc version number.  */
  43 #include <version.h>
  44
  45 #define PACKAGE _libc_intl_domainname
  46
  47 /* Structure used by main() thread to keep track of the number of
  48    active threads.  Used to limit how many threads it will create
  49    and under a shutdown condition to wait till all in-progress
  50    requests have finished before "turning off the lights".  */
  51
  52 typedef struct
  53 {
  54   int             num_active;
  55   pthread_cond_t  thread_exit_cv;
  56   pthread_mutex_t mutex;
  57 } thread_info_t;
  58
  59 thread_info_t thread_info;
  60
  61 int do_shutdown;
  62 int disabled_passwd;
  63 int disabled_group;
  64 int go_background = 1;
  65
  66 int secure[lastdb];
  67 int secure_in_use;
  68 static const char *conffile = _PATH_NSCDCONF;
  69
  70 static int check_pid (const char *file);
  71 static int write_pid (const char *file);
  72
  73 /* Name and version of program.  */
  74 static void print_version (FILE *stream, struct argp_state *state);
  75 void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
  76
  77 /* Definitions of arguments for argp functions.  */
  78 static const struct argp_option options[] =
  79 {
  80   { "config-file", 'f', N_("NAME"), 0,
  81     N_("Read configuration data from NAME") },
  82   { "debug", 'd', NULL, 0,
  83     N_("Do not fork and display messages on the current tty") },
  84   { "nthreads", 't', N_("NUMBER"), 0, N_("Start NUMBER threads") },
  85   { "shutdown", 'K', NULL, 0, N_("Shut the server down") },
  86   { "statistic", 'g', NULL, 0, N_("Print current configuration statistic") },
  87   { "secure", 'S', N_("TABLE,yes"), 0, N_("Use separate cache for each user")},
  88   { NULL, 0, NULL, 0, NULL }
  89 };
  90
  91 /* Short description of program.  */
  92 static const char doc[] = N_("Name Service Cache Daemon.");
  93
  94 /* Prototype for option handler.  */
  95 static error_t parse_opt __P ((int key, char *arg, struct argp_state *state));
  96
  97 /* Data structure to communicate with argp functions.  */
  98 static struct argp argp =
  99 {
 100   options, parse_opt, NULL, doc,
 101 };
 102
 103 int
 104 main (int argc, char **argv)
 105 {
 106   int remaining;
 107
 108   /* Set locale via LC_ALL.  */
 109   setlocale (LC_ALL, "");
 110   /* Set the text message domain.  */
 111   textdomain (PACKAGE);
 112
 113   /* Parse and process arguments.  */
 114   argp_parse (&argp, argc, argv, 0, &remaining, NULL);
 115
 116   if (remaining != argc)
 117     {
 118       error (0, 0, gettext ("wrong number of arguments"));
 119       argp_help (&argp, stdout, ARGP_HELP_SEE, program_invocation_short_name);
 120       exit (EXIT_FAILURE);
 121     }
 122
 123   /* Check if we are already running. */
 124   if (check_pid (_PATH_NSCDPID))
 125     error (EXIT_FAILURE, 0, _("already running"));
 126
 127   /* Behave like a daemon.  */
 128   if (go_background)
 129     {
 130       int i;
 131
 132       if (fork ())
 133         exit (0);
 134
 135       for (i = 0; i < getdtablesize (); i++)
 136         close (i);
 137
 138       if (fork ())
 139         exit (0);
 140
 141       chdir ("/");
 142
 143       openlog ("nscd", LOG_CONS | LOG_ODELAY, LOG_DAEMON);
 144
 145       if (write_pid (_PATH_NSCDPID) < 0)
 146         dbg_log ("%s: %s", _PATH_NSCDPID, strerror (errno));
 147
 148       /* Ignore job control signals.  */
 149       signal (SIGTTOU, SIG_IGN);
 150       signal (SIGTTIN, SIG_IGN);
 151       signal (SIGTSTP, SIG_IGN);
 152     }
 153
 154   signal (SIGINT, termination_handler);
 155   signal (SIGQUIT, termination_handler);
 156   signal (SIGTERM, termination_handler);
 157   signal (SIGPIPE, SIG_IGN);
 158
 159   /* Cleanup files created by a previous `bind'.  */
 160   unlink (_PATH_NSCDSOCKET);
 161
 162   /* Init databases.  */
 163   nscd_init (conffile);
 164
 165   /* Handle incoming requests */
 166   start_threads ();
 167
 168   return 0;
 169 }
 170
 171
 172 /* Handle program arguments.  */
 173 static error_t
 174 parse_opt (int key, char *arg, struct argp_state *state)
 175 {
 176   switch (key)
 177     {
 178     case 'd':
 179       ++debug_level;
 180       go_background = 0;
 181       break;
 182
 183     case 'f':
 184       conffile = arg;
 185       break;
 186
 187     case 'K':
 188       if (getuid () != 0)
 189         error (EXIT_FAILURE, 0, _("Only root is allowed to use this option!"));
 190       {
 191         int sock = nscd_open_socket ();
 192         request_header req;
 193         ssize_t nbytes;
 194
 195         if (sock == -1)
 196           exit (EXIT_FAILURE);
 197
 198         req.version = NSCD_VERSION;
 199         req.type = SHUTDOWN;
 200         req.key_len = 0;
 201         nbytes = TEMP_FAILURE_RETRY (write (sock, &req,
 202                                             sizeof (request_header)));
 203         close (sock);
 204         exit (nbytes != sizeof (request_header) ? EXIT_FAILURE : EXIT_SUCCESS);
 205       }
 206
 207     case 'g':
 208       if (getuid () != 0)
 209         error (EXIT_FAILURE, 0, _("Only root is allowed to use this option!"));
 210       receive_print_stats ();
 211       /* Does not return.  */
 212
 213     case 't':
 214       nthreads = atol (arg);
 215       break;
 216
 217     case 'S':
 218       if (strcmp (arg, "passwd,yes") == 0)
 219         secure_in_use = secure[pwddb] = 1;
 220       else if (strcmp (arg, "group,yes") == 0)
 221         secure_in_use = secure[grpdb] = 1;
 222       else if (strcmp (arg, "hosts,yes") == 0)
 223         secure_in_use = secure[hstdb] = 1;
 224       break;
 225
 226     default:
 227       return ARGP_ERR_UNKNOWN;
 228     }
 229
 230   return 0;
 231 }
 232
 233 /* Print the version information.  */
 234 static void
 235 print_version (FILE *stream, struct argp_state *state)
 236 {
 237   fprintf (stream, "nscd (GNU %s) %s\n", PACKAGE, VERSION);
 238   fprintf (stream, gettext ("\
 239 Copyright (C) %s Free Software Foundation, Inc.\n\
 240 This is free software; see the source for copying conditions.  There is NO\n\
 241 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
 242 "), "1999");
 243   fprintf (stream, gettext ("Written by %s.\n"),
 244            "Thorsten Kukuk and Ulrich Drepper");
 245 }
 246
 247
 248 /* Create a socket connected to a name.  */
 249 int
 250 nscd_open_socket (void)
 251 {
 252   struct sockaddr_un addr;
 253   int sock;
 254
 255   sock = socket (PF_UNIX, SOCK_STREAM, 0);
 256   if (sock < 0)
 257     return -1;
 258
 259   addr.sun_family = AF_UNIX;
 260   assert (sizeof (addr.sun_path) >= sizeof (_PATH_NSCDSOCKET));
 261   strcpy (addr.sun_path, _PATH_NSCDSOCKET);
 262   if (connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0)
 263     {
 264       close (sock);
 265       return -1;
 266     }
 267
 268   return sock;
 269 }
 270
 271 /* Cleanup.  */
 272 void
 273 termination_handler (int signum)
 274 {
 275   close_sockets ();
 276
 277   /* Clean up the file created by `bind'.  */
 278   unlink (_PATH_NSCDSOCKET);
 279
 280   /* Clean up pid file.  */
 281   unlink (_PATH_NSCDPID);
 282
 283   exit (EXIT_SUCCESS);
 284 }
 285
 286 /* Returns 1 if the process in pid file FILE is running, 0 if not.  */
 287 static int
 288 check_pid (const char *file)
 289 {
 290   FILE *fp;
 291
 292   fp = fopen (file, "r");
 293   if (fp)
 294     {
 295       pid_t pid;
 296       int n;
 297
 298       n = fscanf (fp, "%d", &pid);
 299       fclose (fp);
 300
 301       if (n != 1 || kill (pid, 0) == 0)
 302         return 1;
 303     }
 304
 305   return 0;
 306 }
 307
 308 /* Write the current process id to the file FILE.
 309    Returns 0 if successful, -1 if not.  */
 310 static int
 311 write_pid (const char *file)
 312 {
 313   FILE *fp;
 314
 315   fp = fopen (file, "w");
 316   if (fp == NULL)
 317     return -1;
 318
 319   fprintf (fp, "%d\n", getpid ());
 320   if (fflush (fp) || ferror (fp))
 321     return -1;
 322
 323   fclose (fp);
 324
 325   return 0;
 326 }