nscd/nscd.c

   1 /* Copyright (c) 1998 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.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 and group.  */
  21
  22 #include <argp.h>
  23 #include <errno.h>
  24 #include <error.h>
  25 #include <libintl.h>
  26 #include <locale.h>
  27 #include <pthread.h>
  28 #include <pwd.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 = 0;
  61 int disabled_passwd = 0;
  62 int disabled_group = 0;
  63 int go_background = 1;
  64 const char *conffile = _PATH_NSCDCONF;
  65
  66 static void termination_handler (int signum);
  67 static int check_pid (const char *file);
  68 static int write_pid (const char *file);
  69 static void handle_requests (void);
  70
  71 /* Name and version of program.  */
  72 static void print_version (FILE *stream, struct argp_state *state);
  73 void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
  74
  75 /* Definitions of arguments for argp functions.  */
  76 static const struct argp_option options[] =
  77 {
  78   { "config-file", 'f', N_("NAME"), 0,
  79     N_("Read configuration data from NAME") },
  80   { "debug", 'd', NULL, 0,
  81     N_("Do not fork and display messages on the current tty") },
  82   { "shutdown", 'K', NULL, 0, N_("Shut the server down") },
  83   { "statistic", 'g', NULL, 0, N_("Print current configuration statistic") },
  84   { NULL, 0, NULL, 0, NULL }
  85 };
  86
  87 /* Short description of program.  */
  88 static const char doc[] = N_("Name Switch Cache Daemon.");
  89
  90 /* Prototype for option handler.  */
  91 static error_t parse_opt __P ((int key, char *arg, struct argp_state *state));
  92
  93 /* Data structure to communicate with argp functions.  */
  94 static struct argp argp =
  95 {
  96   options, parse_opt, NULL, doc,
  97 };
  98
  99 int
 100 main (int argc, char **argv)
 101 {
 102   int remaining;
 103
 104   /* Set locale via LC_ALL.  */
 105   setlocale (LC_ALL, "");
 106   /* Set the text message domain.  */
 107   textdomain (PACKAGE);
 108
 109   /* Parse and process arguments.  */
 110   argp_parse (&argp, argc, argv, 0, &remaining, NULL);
 111
 112   if (remaining != argc)
 113     {
 114       error (0, 0, gettext ("wrong number of arguments"));
 115       argp_help (&argp, stdout, ARGP_HELP_SEE, program_invocation_short_name);
 116       exit (EXIT_FAILURE);
 117     }
 118
 119   /* Check if we are already running. */
 120   if (check_pid (_PATH_NSCDPID))
 121     {
 122       fputs (_("already running"), stderr);
 123       exit (EXIT_FAILURE);
 124     }
 125
 126   /* Behave like a daemon.  */
 127   if (go_background)
 128     {
 129       int i;
 130
 131       if (fork ())
 132         exit (0);
 133
 134       for (i = 0; i < getdtablesize (); i++)
 135         close (i);
 136
 137       if (fork ())
 138         exit (0);
 139
 140       chdir ("/");
 141
 142       openlog ("nscd", LOG_CONS | LOG_ODELAY, LOG_DAEMON);
 143
 144       if (write_pid (_PATH_NSCDPID) < 0)
 145         dbg_log ("%s: %s", _PATH_NSCDPID, strerror (errno));
 146
 147       /* Ignore job control signals */
 148       signal (SIGTTOU, SIG_IGN);
 149       signal (SIGTTIN, SIG_IGN);
 150       signal (SIGTSTP, SIG_IGN);
 151     }
 152
 153   signal (SIGINT, termination_handler);
 154   signal (SIGQUIT, termination_handler);
 155   signal (SIGTERM, termination_handler);
 156   signal (SIGPIPE, SIG_IGN);
 157
 158   /* Cleanup files created by a previous `bind' */
 159   unlink (_PATH_NSCDSOCKET);
 160
 161   nscd_parse_file (conffile);
 162
 163   /* Create first sockets */
 164   init_sockets ();
 165   /* Init databases */
 166   if ((cache_pwdinit () < 0) || (cache_grpinit () < 0))
 167     {
 168       fputs (_("Not enough memory\n"), stderr);
 169       return 1;
 170     }
 171   /* Handle incoming requests */
 172   handle_requests ();
 173
 174   return 0;
 175 }
 176
 177
 178 /* Handle program arguments.  */
 179 static error_t
 180 parse_opt (int key, char *arg, struct argp_state *state)
 181 {
 182   switch (key)
 183     {
 184     case 'd':
 185       debug_flag = 1;
 186       go_background = 0;
 187       break;
 188     case 'f':
 189       conffile = arg;
 190       break;
 191     case 'K':
 192       if (getuid () != 0)
 193         {
 194           printf (_("Only root is allowed to use this option!\n\n"));
 195           exit (EXIT_FAILURE);
 196         }
 197       {
 198         int sock = __nscd_open_socket ();
 199         request_header req;
 200         ssize_t nbytes;
 201
 202         if (sock == -1)
 203           exit (EXIT_FAILURE);
 204
 205         req.version = NSCD_VERSION;
 206         req.type = SHUTDOWN;
 207         req.key_len = 0;
 208         nbytes = write (sock, &req, sizeof (request_header));
 209         close (sock);
 210         if (nbytes != req.key_len)
 211           exit (EXIT_FAILURE);
 212         else
 213           exit (EXIT_SUCCESS);
 214       }
 215     case 'g':
 216       print_stat ();
 217       exit (EXIT_SUCCESS);
 218     default:
 219       return ARGP_ERR_UNKNOWN;
 220     }
 221   return 0;
 222 }
 223
 224 /* Print the version information.  */
 225 static void
 226 print_version (FILE *stream, struct argp_state *state)
 227 {
 228   fprintf (stream, "nscd (GNU %s) %s\n", PACKAGE, VERSION);
 229   fprintf (stream, gettext ("\
 230 Copyright (C) %s Free Software Foundation, Inc.\n\
 231 This is free software; see the source for copying conditions.  There is NO\n\
 232 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
 233 "), "1998");
 234   fprintf (stream, gettext ("Written by %s.\n"), "Thorsten Kukuk");
 235 }
 236
 237
 238 /* Create a socket connected to a name. */
 239 int
 240 __nscd_open_socket (void)
 241 {
 242   struct sockaddr_un addr;
 243   int sock;
 244
 245   sock = socket (PF_UNIX, SOCK_STREAM, 0);
 246   if (sock < 0)
 247     return -1;
 248
 249   addr.sun_family = AF_UNIX;
 250   strcpy (addr.sun_path, _PATH_NSCDSOCKET);
 251   if (connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0)
 252     {
 253       close (sock);
 254       return -1;
 255     }
 256
 257   return sock;
 258 }
 259
 260 /* Cleanup.  */
 261 static void
 262 termination_handler (int signum)
 263 {
 264   close_sockets ();
 265
 266   /* Clean up the files created by `bind'.  */
 267   unlink (_PATH_NSCDSOCKET);
 268
 269   /* Clean up pid file.  */
 270   unlink (_PATH_NSCDPID);
 271
 272   exit (EXIT_SUCCESS);
 273 }
 274
 275 /* Returns 1 if the process in pid file FILE is running, 0 if not.  */
 276 static int
 277 check_pid (const char *file)
 278 {
 279   FILE *fp;
 280
 281   fp = fopen (file, "r");
 282   if (fp)
 283     {
 284       pid_t pid;
 285
 286       fscanf (fp, "%d", &pid);
 287       fclose (fp);
 288
 289       if (kill (pid, 0) == 0)
 290         return 1;
 291     }
 292
 293   return 0;
 294 }
 295
 296 /* Write the current process id to the file FILE.
 297    Returns 0 if successful, -1 if not.  */
 298 static int
 299 write_pid (const char *file)
 300 {
 301   FILE *fp;
 302
 303   fp = fopen (file, "w");
 304   if (fp == NULL)
 305     return -1;
 306
 307   fprintf (fp, "%d\n", getpid ());
 308   if (ferror (fp))
 309     return -1;
 310
 311   fclose (fp);
 312
 313   return 0;
 314 }
 315
 316 /* Type of the lookup function for netname2user.  */
 317 typedef int (*pwbyname_function) (const char *name, struct passwd *pw,
 318                                    char *buffer, size_t buflen);
 319
 320 /* Handle incoming requests.  */
 321 static
 322 void handle_requests (void)
 323 {
 324   request_header req;
 325   int conn; /* Handle on which connection (client) the request came from.  */
 326   int done = 0;
 327   char *key;
 328   pthread_attr_t th_attr;
 329
 330   /* We will create all threads detached.  Therefore prepare an attribute
 331      now.  */
 332   pthread_attr_init (&th_attr);
 333   pthread_attr_setdetachstate (&th_attr, PTHREAD_CREATE_DETACHED);
 334
 335   while (!done)
 336     {
 337       key = NULL;
 338       get_request (&conn, &req, &key);
 339       if (debug_flag)
 340         dbg_log (_("handle_requests: request received (Version = %d)"),
 341                  req.version);
 342       switch (req.type)
 343         {
 344         case GETPWBYNAME:
 345           {
 346             param_t *param = malloc (sizeof (param_t));
 347             pthread_t thread;
 348             int status;
 349
 350             if (debug_flag)
 351               dbg_log ("\tGETPWBYNAME (%s)", key);
 352             param->key = key;
 353             param->conn = conn;
 354             if (disabled_passwd)
 355               status = pthread_create (&thread, &th_attr, cache_pw_disabled,
 356                                        (void *)param);
 357             else
 358               status = pthread_create (&thread, &th_attr, cache_getpwnam,
 359                                        (void *)param);
 360             if (status != 0)
 361               {
 362                 dbg_log (_("Creation of thread failed: %s"), strerror (errno));
 363                 close_socket (conn);
 364               }
 365             pthread_detach (thread);
 366           }
 367           break;
 368         case GETPWBYUID:
 369           {
 370             param_t *param = malloc (sizeof (param_t));
 371             pthread_t thread;
 372             int status;
 373
 374             if (debug_flag)
 375               dbg_log ("\tGETPWBYUID (%s)", key);
 376             param->key = key;
 377             param->conn = conn;
 378             if (disabled_passwd)
 379               status = pthread_create (&thread, &th_attr, cache_pw_disabled,
 380                               (void *)param);
 381             else
 382               status = pthread_create (&thread, &th_attr, cache_getpwuid,
 383                                        (void *)param);
 384             if (status != 0)
 385               {
 386                 dbg_log (_("Creation of thread failed: %s"), strerror (errno));
 387                 close_socket (conn);
 388               }
 389           }
 390           break;
 391         case GETGRBYNAME:
 392           {
 393             param_t *param = malloc (sizeof (param_t));
 394             pthread_t thread;
 395             int status;
 396
 397             if (debug_flag)
 398               dbg_log ("\tGETGRBYNAME (%s)", key);
 399             param->key = key;
 400             param->conn = conn;
 401             if (disabled_group)
 402               status = pthread_create (&thread, &th_attr, cache_gr_disabled,
 403                                        (void *)param);
 404             else
 405               status = pthread_create (&thread, &th_attr, cache_getgrnam,
 406                                        (void *)param);
 407             if (status != 0)
 408               {
 409                 dbg_log (_("Creation of thread failed: %s"), strerror (errno));
 410                 close_socket (conn);
 411               }
 412           }
 413           break;
 414         case GETGRBYGID:
 415           {
 416             param_t *param = malloc (sizeof (param_t));
 417             pthread_t thread;
 418             int status;
 419
 420             if (debug_flag)
 421               dbg_log ("\tGETGRBYGID (%s)", key);
 422             param->key = key;
 423             param->conn = conn;
 424             if (disabled_group)
 425               status = pthread_create (&thread, &th_attr, cache_gr_disabled,
 426                                        (void *)param);
 427             else
 428               status = pthread_create (&thread, &th_attr, cache_getgrgid,
 429                                        (void *)param);
 430             if (status != 0)
 431               {
 432                 dbg_log (_("Creation of thread failed: %s"), strerror (errno));
 433                 close_socket (conn);
 434               }
 435           }
 436           break;
 437         case GETHOSTBYNAME:
 438           /* Not yetimplemented.  */
 439           close_socket (conn);
 440           break;
 441         case GETHOSTBYADDR:
 442           /* Not yet implemented. */
 443           close_socket (conn);
 444           break;
 445         case SHUTDOWN:
 446           do_shutdown = 1;
 447           close_socket (0);
 448           close_socket (conn);
 449           /* Clean up the files created by `bind'.  */
 450           unlink (_PATH_NSCDSOCKET);
 451           /* Clean up pid file.  */
 452           unlink (_PATH_NSCDPID);
 453           done = 1;
 454           break;
 455         case GETSTAT:
 456           {
 457             stat_response_header resp;
 458
 459             if (debug_flag)
 460               dbg_log ("\tGETSTAT");
 461
 462             get_pw_stat (&resp);
 463             get_gr_stat (&resp);
 464             resp.debug_level = debug_flag;
 465             resp.pw_enabled = !disabled_passwd;
 466             resp.gr_enabled = !disabled_group;
 467
 468             stat_send (conn, &resp);
 469
 470             close_socket (conn);
 471           }
 472           break;
 473         default:
 474           dbg_log (_("Unknown request (%d)"), req.type);
 475           break;
 476         }
 477     }
 478
 479   pthread_attr_destroy (&th_attr);
 480 }