nscd/nscd.c

   1 /* Copyright (c) 1998, 1999, 2000, 2001, 2002 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 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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    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 <signal.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <syslog.h>
  34 #include <unistd.h>
  35 #include <sys/socket.h>
  36 #include <sys/un.h>
  37
  38 #include "dbg_log.h"
  39 #include "nscd.h"
  40
  41 /* Get libc version number.  */
  42 #include <version.h>
  43
  44 #define PACKAGE _libc_intl_domainname
  45
  46 /* Structure used by main() thread to keep track of the number of
  47    active threads.  Used to limit how many threads it will create
  48    and under a shutdown condition to wait till all in-progress
  49    requests have finished before "turning off the lights".  */
  50
  51 typedef struct
  52 {
  53   int             num_active;
  54   pthread_cond_t  thread_exit_cv;
  55   pthread_mutex_t mutex;
  56 } thread_info_t;
  57
  58 thread_info_t thread_info;
  59
  60 int do_shutdown;
  61 int disabled_passwd;
  62 int disabled_group;
  63 int go_background = 1;
  64
  65 int secure[lastdb];
  66 int secure_in_use;
  67 static const char *conffile = _PATH_NSCDCONF;
  68
  69 static int check_pid (const char *file);
  70 static int write_pid (const char *file);
  71
  72 /* Name and version of program.  */
  73 static void print_version (FILE *stream, struct argp_state *state);
  74 void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
  75
  76 /* Definitions of arguments for argp functions.  */
  77 static const struct argp_option options[] =
  78 {
  79   { "config-file", 'f', N_("NAME"), 0,
  80     N_("Read configuration data from NAME") },
  81   { "debug", 'd', NULL, 0,
  82     N_("Do not fork and display messages on the current tty") },
  83   { "nthreads", 't', N_("NUMBER"), 0, N_("Start NUMBER threads") },
  84   { "shutdown", 'K', NULL, 0, N_("Shut the server down") },
  85   { "statistic", 'g', NULL, 0, N_("Print current configuration statistic") },
  86   { "invalidate", 'i', N_("TABLE"), 0,
  87     N_("Invalidate the specified cache") },
  88   { "secure", 'S', N_("TABLE,yes"), 0, N_("Use separate cache for each user")},
  89   { NULL, 0, NULL, 0, NULL }
  90 };
  91
  92 /* Short description of program.  */
  93 static const char doc[] = N_("Name Service Cache Daemon.");
  94
  95 /* Prototype for option handler.  */
  96 static error_t parse_opt (int key, char *arg, struct argp_state *state);
  97
  98 /* Data structure to communicate with argp functions.  */
  99 static struct argp argp =
 100 {
 101   options, parse_opt, NULL, doc,
 102 };
 103
 104 int
 105 main (int argc, char **argv)
 106 {
 107   int remaining;
 108
 109   /* Set locale via LC_ALL.  */
 110   setlocale (LC_ALL, "");
 111   /* Set the text message domain.  */
 112   textdomain (PACKAGE);
 113
 114   /* Parse and process arguments.  */
 115   argp_parse (&argp, argc, argv, 0, &remaining, NULL);
 116
 117   if (remaining != argc)
 118     {
 119       error (0, 0, gettext ("wrong number of arguments"));
 120       argp_help (&argp, stdout, ARGP_HELP_SEE, program_invocation_short_name);
 121       exit (EXIT_FAILURE);
 122     }
 123
 124   /* Check if we are already running. */
 125   if (check_pid (_PATH_NSCDPID))
 126     error (EXIT_FAILURE, 0, _("already running"));
 127
 128   /* Behave like a daemon.  */
 129   if (go_background)
 130     {
 131       int i;
 132
 133       if (fork ())
 134         exit (0);
 135
 136       for (i = 0; i < getdtablesize (); i++)
 137         close (i);
 138
 139       if (fork ())
 140         exit (0);
 141
 142       setsid ();
 143
 144       chdir ("/");
 145
 146       openlog ("nscd", LOG_CONS | LOG_ODELAY, LOG_DAEMON);
 147
 148       if (write_pid (_PATH_NSCDPID) < 0)
 149         dbg_log ("%s: %s", _PATH_NSCDPID, strerror (errno));
 150
 151       /* Ignore job control signals.  */
 152       signal (SIGTTOU, SIG_IGN);
 153       signal (SIGTTIN, SIG_IGN);
 154       signal (SIGTSTP, SIG_IGN);
 155     }
 156
 157   signal (SIGINT, termination_handler);
 158   signal (SIGQUIT, termination_handler);
 159   signal (SIGTERM, termination_handler);
 160   signal (SIGPIPE, SIG_IGN);
 161
 162   /* Cleanup files created by a previous `bind'.  */
 163   unlink (_PATH_NSCDSOCKET);
 164
 165   /* Init databases.  */
 166   nscd_init (conffile);
 167
 168   /* Handle incoming requests */
 169   start_threads ();
 170
 171   return 0;
 172 }
 173
 174
 175 /* Handle program arguments.  */
 176 static error_t
 177 parse_opt (int key, char *arg, struct argp_state *state)
 178 {
 179   switch (key)
 180     {
 181     case 'd':
 182       ++debug_level;
 183       go_background = 0;
 184       break;
 185
 186     case 'f':
 187       conffile = arg;
 188       break;
 189
 190     case 'K':
 191       if (getuid () != 0)
 192         error (EXIT_FAILURE, 0, _("Only root is allowed to use this option!"));
 193       {
 194         int sock = nscd_open_socket ();
 195         request_header req;
 196         ssize_t nbytes;
 197
 198         if (sock == -1)
 199           exit (EXIT_FAILURE);
 200
 201         req.version = NSCD_VERSION;
 202         req.type = SHUTDOWN;
 203         req.key_len = 0;
 204         nbytes = TEMP_FAILURE_RETRY (write (sock, &req,
 205                                             sizeof (request_header)));
 206         close (sock);
 207         exit (nbytes != sizeof (request_header) ? EXIT_FAILURE : EXIT_SUCCESS);
 208       }
 209
 210     case 'g':
 211       if (getuid () != 0)
 212         error (EXIT_FAILURE, 0, _("Only root is allowed to use this option!"));
 213       receive_print_stats ();
 214       /* Does not return.  */
 215
 216     case 'i':
 217       if (getuid () != 0)
 218         error (EXIT_FAILURE, 0, _("Only root is allowed to use this option!"));
 219       else
 220         {
 221           int sock = nscd_open_socket ();
 222           request_header req;
 223           ssize_t nbytes;
 224
 225           if (sock == -1)
 226             exit (EXIT_FAILURE);
 227
 228           if (strcmp (arg, "passwd") == 0)
 229             req.key_len = sizeof "passwd";
 230           else if (strcmp (arg, "group") == 0)
 231             req.key_len = sizeof "group";
 232           else if (strcmp (arg, "hosts") == 0)
 233             req.key_len = sizeof "hosts";
 234           else
 235             return ARGP_ERR_UNKNOWN;
 236
 237           req.version = NSCD_VERSION;
 238           req.type = INVALIDATE;
 239           nbytes = TEMP_FAILURE_RETRY (write (sock, &req,
 240                                               sizeof (request_header)));
 241           if (nbytes != sizeof (request_header))
 242             {
 243               close (sock);
 244               exit (EXIT_FAILURE);
 245             }
 246
 247           nbytes = TEMP_FAILURE_RETRY (write (sock, (void *)arg, req.key_len));
 248
 249           close (sock);
 250
 251           exit (nbytes != req.key_len ? EXIT_FAILURE : EXIT_SUCCESS);
 252         }
 253
 254     case 't':
 255       nthreads = atol (arg);
 256       break;
 257
 258     case 'S':
 259       if (strcmp (arg, "passwd,yes") == 0)
 260         secure_in_use = secure[pwddb] = 1;
 261       else if (strcmp (arg, "group,yes") == 0)
 262         secure_in_use = secure[grpdb] = 1;
 263       else if (strcmp (arg, "hosts,yes") == 0)
 264         secure_in_use = secure[hstdb] = 1;
 265       break;
 266
 267     default:
 268       return ARGP_ERR_UNKNOWN;
 269     }
 270
 271   return 0;
 272 }
 273
 274 /* Print the version information.  */
 275 static void
 276 print_version (FILE *stream, struct argp_state *state)
 277 {
 278   fprintf (stream, "nscd (GNU %s) %s\n", PACKAGE, VERSION);
 279   fprintf (stream, gettext ("\
 280 Copyright (C) %s Free Software Foundation, Inc.\n\
 281 This is free software; see the source for copying conditions.  There is NO\n\
 282 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
 283 "), "2002");
 284   fprintf (stream, gettext ("Written by %s.\n"),
 285            "Thorsten Kukuk and Ulrich Drepper");
 286 }
 287
 288
 289 /* Create a socket connected to a name.  */
 290 int
 291 nscd_open_socket (void)
 292 {
 293   struct sockaddr_un addr;
 294   int sock;
 295
 296   sock = socket (PF_UNIX, SOCK_STREAM, 0);
 297   if (sock < 0)
 298     return -1;
 299
 300   addr.sun_family = AF_UNIX;
 301   assert (sizeof (addr.sun_path) >= sizeof (_PATH_NSCDSOCKET));
 302   strcpy (addr.sun_path, _PATH_NSCDSOCKET);
 303   if (connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0)
 304     {
 305       close (sock);
 306       return -1;
 307     }
 308
 309   return sock;
 310 }
 311
 312 /* Cleanup.  */
 313 void
 314 termination_handler (int signum)
 315 {
 316   close_sockets ();
 317
 318   /* Clean up the file created by `bind'.  */
 319   unlink (_PATH_NSCDSOCKET);
 320
 321   /* Clean up pid file.  */
 322   unlink (_PATH_NSCDPID);
 323
 324   exit (EXIT_SUCCESS);
 325 }
 326
 327 /* Returns 1 if the process in pid file FILE is running, 0 if not.  */
 328 static int
 329 check_pid (const char *file)
 330 {
 331   FILE *fp;
 332
 333   fp = fopen (file, "r");
 334   if (fp)
 335     {
 336       pid_t pid;
 337       int n;
 338
 339       n = fscanf (fp, "%d", &pid);
 340       fclose (fp);
 341
 342       if (n != 1 || kill (pid, 0) == 0)
 343         return 1;
 344     }
 345
 346   return 0;
 347 }
 348
 349 /* Write the current process id to the file FILE.
 350    Returns 0 if successful, -1 if not.  */
 351 static int
 352 write_pid (const char *file)
 353 {
 354   FILE *fp;
 355
 356   fp = fopen (file, "w");
 357   if (fp == NULL)
 358     return -1;
 359
 360   fprintf (fp, "%d\n", getpid ());
 361   if (fflush (fp) || ferror (fp))
 362     return -1;
 363
 364   fclose (fp);
 365
 366   return 0;
 367 }