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   { "invalidate", 'i', N_("TABLE"), 0,
  88     N_("Invalidate the specified cache") },
  89   { "secure", 'S', N_("TABLE,yes"), 0, N_("Use separate cache for each user")},
  90   { NULL, 0, NULL, 0, NULL }
  91 };
  92
  93 /* Short description of program.  */
  94 static const char doc[] = N_("Name Service Cache Daemon.");
  95
  96 /* Prototype for option handler.  */
  97 static error_t parse_opt __P ((int key, char *arg, struct argp_state *state));
  98
  99 /* Data structure to communicate with argp functions.  */
 100 static struct argp argp =
 101 {
 102   options, parse_opt, NULL, doc,
 103 };
 104
 105 int
 106 main (int argc, char **argv)
 107 {
 108   int remaining;
 109
 110   /* Set locale via LC_ALL.  */
 111   setlocale (LC_ALL, "");
 112   /* Set the text message domain.  */
 113   textdomain (PACKAGE);
 114
 115   /* Parse and process arguments.  */
 116   argp_parse (&argp, argc, argv, 0, &remaining, NULL);
 117
 118   if (remaining != argc)
 119     {
 120       error (0, 0, gettext ("wrong number of arguments"));
 121       argp_help (&argp, stdout, ARGP_HELP_SEE, program_invocation_short_name);
 122       exit (EXIT_FAILURE);
 123     }
 124
 125   /* Check if we are already running. */
 126   if (check_pid (_PATH_NSCDPID))
 127     error (EXIT_FAILURE, 0, _("already running"));
 128
 129   /* Behave like a daemon.  */
 130   if (go_background)
 131     {
 132       int i;
 133
 134       if (fork ())
 135         exit (0);
 136
 137       for (i = 0; i < getdtablesize (); i++)
 138         close (i);
 139
 140       if (fork ())
 141         exit (0);
 142
 143       chdir ("/");
 144
 145       openlog ("nscd", LOG_CONS | LOG_ODELAY, LOG_DAEMON);
 146
 147       if (write_pid (_PATH_NSCDPID) < 0)
 148         dbg_log ("%s: %s", _PATH_NSCDPID, strerror (errno));
 149
 150       /* Ignore job control signals.  */
 151       signal (SIGTTOU, SIG_IGN);
 152       signal (SIGTTIN, SIG_IGN);
 153       signal (SIGTSTP, SIG_IGN);
 154     }
 155
 156   signal (SIGINT, termination_handler);
 157   signal (SIGQUIT, termination_handler);
 158   signal (SIGTERM, termination_handler);
 159   signal (SIGPIPE, SIG_IGN);
 160
 161   /* Cleanup files created by a previous `bind'.  */
 162   unlink (_PATH_NSCDSOCKET);
 163
 164   /* Init databases.  */
 165   nscd_init (conffile);
 166
 167   /* Handle incoming requests */
 168   start_threads ();
 169
 170   return 0;
 171 }
 172
 173
 174 /* Handle program arguments.  */
 175 static error_t
 176 parse_opt (int key, char *arg, struct argp_state *state)
 177 {
 178   switch (key)
 179     {
 180     case 'd':
 181       ++debug_level;
 182       go_background = 0;
 183       break;
 184
 185     case 'f':
 186       conffile = arg;
 187       break;
 188
 189     case 'K':
 190       if (getuid () != 0)
 191         error (EXIT_FAILURE, 0, _("Only root is allowed to use this option!"));
 192       {
 193         int sock = nscd_open_socket ();
 194         request_header req;
 195         ssize_t nbytes;
 196
 197         if (sock == -1)
 198           exit (EXIT_FAILURE);
 199
 200         req.version = NSCD_VERSION;
 201         req.type = SHUTDOWN;
 202         req.key_len = 0;
 203         nbytes = TEMP_FAILURE_RETRY (write (sock, &req,
 204                                             sizeof (request_header)));
 205         close (sock);
 206         exit (nbytes != sizeof (request_header) ? EXIT_FAILURE : EXIT_SUCCESS);
 207       }
 208
 209     case 'g':
 210       if (getuid () != 0)
 211         error (EXIT_FAILURE, 0, _("Only root is allowed to use this option!"));
 212       receive_print_stats ();
 213       /* Does not return.  */
 214
 215     case 'i':
 216       if (getuid () != 0)
 217         error (EXIT_FAILURE, 0, _("Only root is allowed to use this option!"));
 218       else
 219         {
 220           int sock = nscd_open_socket ();
 221           request_header req;
 222           ssize_t nbytes;
 223
 224           if (sock == -1)
 225             exit (EXIT_FAILURE);
 226
 227           if (strcmp (arg, "passwd") == 0)
 228             req.key_len = sizeof "passwd";
 229           else if (strcmp (arg, "group") == 0)
 230             req.key_len = sizeof "group";
 231           else if (strcmp (arg, "hosts") == 0)
 232             req.key_len = sizeof "hosts";
 233           else
 234             return ARGP_ERR_UNKNOWN;
 235
 236           req.version = NSCD_VERSION;
 237           req.type = INVALIDATE;
 238           nbytes = TEMP_FAILURE_RETRY (write (sock, &req,
 239                                               sizeof (request_header)));
 240           if (nbytes != sizeof (request_header))
 241             {
 242               close (sock);
 243               exit (EXIT_FAILURE);
 244             }
 245
 246           nbytes = TEMP_FAILURE_RETRY (write (sock, (void *)arg, req.key_len));
 247
 248           close (sock);
 249
 250           exit (nbytes != req.key_len ? EXIT_FAILURE : EXIT_SUCCESS);
 251         }
 252
 253     case 't':
 254       nthreads = atol (arg);
 255       break;
 256
 257     case 'S':
 258       if (strcmp (arg, "passwd,yes") == 0)
 259         secure_in_use = secure[pwddb] = 1;
 260       else if (strcmp (arg, "group,yes") == 0)
 261         secure_in_use = secure[grpdb] = 1;
 262       else if (strcmp (arg, "hosts,yes") == 0)
 263         secure_in_use = secure[hstdb] = 1;
 264       break;
 265
 266     default:
 267       return ARGP_ERR_UNKNOWN;
 268     }
 269
 270   return 0;
 271 }
 272
 273 /* Print the version information.  */
 274 static void
 275 print_version (FILE *stream, struct argp_state *state)
 276 {
 277   fprintf (stream, "nscd (GNU %s) %s\n", PACKAGE, VERSION);
 278   fprintf (stream, gettext ("\
 279 Copyright (C) %s Free Software Foundation, Inc.\n\
 280 This is free software; see the source for copying conditions.  There is NO\n\
 281 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
 282 "), "1999");
 283   fprintf (stream, gettext ("Written by %s.\n"),
 284            "Thorsten Kukuk and Ulrich Drepper");
 285 }
 286
 287
 288 /* Create a socket connected to a name.  */
 289 int
 290 nscd_open_socket (void)
 291 {
 292   struct sockaddr_un addr;
 293   int sock;
 294
 295   sock = socket (PF_UNIX, SOCK_STREAM, 0);
 296   if (sock < 0)
 297     return -1;
 298
 299   addr.sun_family = AF_UNIX;
 300   assert (sizeof (addr.sun_path) >= sizeof (_PATH_NSCDSOCKET));
 301   strcpy (addr.sun_path, _PATH_NSCDSOCKET);
 302   if (connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0)
 303     {
 304       close (sock);
 305       return -1;
 306     }
 307
 308   return sock;
 309 }
 310
 311 /* Cleanup.  */
 312 void
 313 termination_handler (int signum)
 314 {
 315   close_sockets ();
 316
 317   /* Clean up the file created by `bind'.  */
 318   unlink (_PATH_NSCDSOCKET);
 319
 320   /* Clean up pid file.  */
 321   unlink (_PATH_NSCDPID);
 322
 323   exit (EXIT_SUCCESS);
 324 }
 325
 326 /* Returns 1 if the process in pid file FILE is running, 0 if not.  */
 327 static int
 328 check_pid (const char *file)
 329 {
 330   FILE *fp;
 331
 332   fp = fopen (file, "r");
 333   if (fp)
 334     {
 335       pid_t pid;
 336       int n;
 337
 338       n = fscanf (fp, "%d", &pid);
 339       fclose (fp);
 340
 341       if (n != 1 || kill (pid, 0) == 0)
 342         return 1;
 343     }
 344
 345   return 0;
 346 }
 347
 348 /* Write the current process id to the file FILE.
 349    Returns 0 if successful, -1 if not.  */
 350 static int
 351 write_pid (const char *file)
 352 {
 353   FILE *fp;
 354
 355   fp = fopen (file, "w");
 356   if (fp == NULL)
 357     return -1;
 358
 359   fprintf (fp, "%d\n", getpid ());
 360   if (fflush (fp) || ferror (fp))
 361     return -1;
 362
 363   fclose (fp);
 364
 365   return 0;
 366 }