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 <sys/socket.h>
  35 #include <sys/un.h>
  36
  37 #include "dbg_log.h"
  38 #include "nscd.h"
  39
  40 /* Get libc version number.  */
  41 #include <version.h>
  42
  43 #define PACKAGE _libc_intl_domainname
  44
  45 /* Structure used by main() thread to keep track of the number of
  46    active threads.  Used to limit how many threads it will create
  47    and under a shutdown condition to wait till all in-progress
  48    requests have finished before "turning off the lights".  */
  49
  50 typedef struct
  51 {
  52   int             num_active;
  53   pthread_cond_t  thread_exit_cv;
  54   pthread_mutex_t mutex;
  55 } thread_info_t;
  56
  57 thread_info_t thread_info;
  58
  59 int do_shutdown = 0;
  60 int disabled_passwd = 0;
  61 int disabled_group = 0;
  62 int go_background = 1;
  63 const char *conffile = _PATH_NSCDCONF;
  64
  65 static void termination_handler (int signum);
  66 static int check_pid (const char *file);
  67 static int write_pid (const char *file);
  68 static void handle_requests (void);
  69
  70 /* Name and version of program.  */
  71 static void print_version (FILE *stream, struct argp_state *state);
  72 void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;
  73
  74 /* Definitions of arguments for argp functions.  */
  75 static const struct argp_option options[] =
  76 {
  77   { "config-file", 'f', N_("NAME"), 0,
  78     N_("Read configuration data from NAME") },
  79   { "debug", 'd', NULL, 0,
  80     N_("Do not fork and display messages on the current tty") },
  81   { "shutdown", 'K', NULL, 0, N_("Shut the server down") },
  82   { "statistic", 'g', NULL, 0, N_("Print current configuration statistic") },
  83   { NULL, 0, NULL, 0, NULL }
  84 };
  85
  86 /* Short description of program.  */
  87 static const char doc[] = N_("Name Switch Cache Daemon.");
  88
  89 /* Prototype for option handler.  */
  90 static error_t parse_opt __P ((int key, char *arg, struct argp_state *state));
  91
  92 /* Data structure to communicate with argp functions.  */
  93 static struct argp argp =
  94 {
  95   options, parse_opt, NULL, doc,
  96 };
  97
  98 int
  99 main (int argc, char **argv)
 100 {
 101   int remaining;
 102
 103   /* Set locale via LC_ALL.  */
 104   setlocale (LC_ALL, "");
 105   /* Set the text message domain.  */
 106   textdomain (PACKAGE);
 107
 108   /* Parse and process arguments.  */
 109   argp_parse (&argp, argc, argv, 0, &remaining, NULL);
 110
 111   if (remaining != argc)
 112     {
 113       error (0, 0, gettext ("wrong number of arguments"));
 114       argp_help (&argp, stdout, ARGP_HELP_SEE, program_invocation_short_name);
 115       exit (EXIT_FAILURE);
 116     }
 117
 118   signal (SIGINT, termination_handler);
 119   signal (SIGQUIT, termination_handler);
 120   signal (SIGTERM, termination_handler);
 121   signal (SIGPIPE, SIG_IGN);
 122
 123   /* Check if we are already running. */
 124   if (check_pid (_PATH_NSCDPID))
 125     {
 126       fputs (_("already running"), stderr);
 127       exit (EXIT_FAILURE);
 128     }
 129
 130   /* Behave like a daemon.  */
 131   if (go_background)
 132     {
 133       openlog ("nscd", LOG_CONS | LOG_ODELAY, LOG_DAEMON);
 134
 135       if (daemon (0, 0) < 0)
 136         {
 137           fprintf (stderr, _("connot auto-background: %s\n"),
 138                    strerror (errno));
 139           exit (EXIT_FAILURE);
 140         }
 141       if (write_pid (_PATH_NSCDPID) < 0)
 142         dbg_log ("%s: %s", _PATH_NSCDPID, strerror (errno));
 143
 144       /* Ignore job control signals */
 145       signal (SIGTTOU, SIG_IGN);
 146       signal (SIGTTIN, SIG_IGN);
 147       signal (SIGTSTP, SIG_IGN);
 148     }
 149   /* Cleanup files created by a previous `bind' */
 150   unlink (_PATH_NSCDSOCKET);
 151
 152   nscd_parse_file (conffile);
 153
 154   /* Create first sockets */
 155   init_sockets ();
 156   /* Init databases */
 157   if ((cache_pwdinit () < 0) || (cache_grpinit () < 0))
 158     {
 159       fputs (_("Not enough memory\n"), stderr);
 160       return 1;
 161     }
 162   /* Handle incoming requests */
 163   handle_requests ();
 164
 165   return 0;
 166 }
 167
 168
 169 /* Handle program arguments.  */
 170 static error_t
 171 parse_opt (int key, char *arg, struct argp_state *state)
 172 {
 173   switch (key)
 174     {
 175     case 'd':
 176       debug_flag = 1;
 177       go_background = 0;
 178       break;
 179     case 'f':
 180       conffile = arg;
 181       break;
 182     case 'K':
 183       if (getuid () != 0)
 184         {
 185           printf (_("Only root is allowed to use this option!\n\n"));
 186           exit (EXIT_FAILURE);
 187         }
 188       {
 189         int sock = __nscd_open_socket ();
 190         request_header req;
 191         ssize_t nbytes;
 192
 193         if (sock == -1)
 194           exit (EXIT_FAILURE);
 195
 196         req.version = NSCD_VERSION;
 197         req.type = SHUTDOWN;
 198         req.key_len = 0;
 199         nbytes = write (sock, &req, sizeof (request_header));
 200         close (sock);
 201         if (nbytes != req.key_len)
 202           exit (EXIT_FAILURE);
 203         else
 204           exit (EXIT_SUCCESS);
 205       }
 206     case 'g':
 207       print_stat ();
 208       exit (EXIT_SUCCESS);
 209     default:
 210       return ARGP_ERR_UNKNOWN;
 211     }
 212   return 0;
 213 }
 214
 215 /* Print the version information.  */
 216 static void
 217 print_version (FILE *stream, struct argp_state *state)
 218 {
 219   fprintf (stream, "nscd (GNU %s) %s\n", PACKAGE, VERSION);
 220   fprintf (stream, gettext ("\
 221 Copyright (C) %s Free Software Foundation, Inc.\n\
 222 This is free software; see the source for copying conditions.  There is NO\n\
 223 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
 224 "), "1998");
 225   fprintf (stream, gettext ("Written by %s.\n"), "Thorsten Kukuk");
 226 }
 227
 228
 229 /* Create a socket connected to a name. */
 230 int
 231 __nscd_open_socket (void)
 232 {
 233   struct sockaddr_un addr;
 234   int sock;
 235
 236   sock = socket (PF_UNIX, SOCK_STREAM, 0);
 237   if (sock < 0)
 238     return -1;
 239
 240   addr.sun_family = AF_UNIX;
 241   strcpy (addr.sun_path, _PATH_NSCDSOCKET);
 242   if (connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0)
 243     {
 244       close (sock);
 245       return -1;
 246     }
 247
 248   return sock;
 249 }
 250
 251 /* Cleanup.  */
 252 static void
 253 termination_handler (int signum)
 254 {
 255   close_sockets ();
 256
 257   /* Clean up the files created by `bind'.  */
 258   unlink (_PATH_NSCDSOCKET);
 259
 260   /* Clean up pid file.  */
 261   unlink (_PATH_NSCDPID);
 262
 263   exit (EXIT_SUCCESS);
 264 }
 265
 266 /* Returns 1 if the process in pid file FILE is running, 0 if not.  */
 267 static int
 268 check_pid (const char *file)
 269 {
 270   FILE *fp;
 271
 272   fp = fopen (file, "r");
 273   if (fp)
 274     {
 275       pid_t pid;
 276
 277       fscanf (fp, "%d", &pid);
 278       fclose (fp);
 279
 280       if (kill (pid, 0) == 0)
 281         return 1;
 282     }
 283
 284   return 0;
 285 }
 286
 287 /* Write the current process id to the file FILE.
 288    Returns 0 if successful, -1 if not.  */
 289 static int
 290 write_pid (const char *file)
 291 {
 292   FILE *fp;
 293
 294   fp = fopen (file, "w");
 295   if (fp == NULL)
 296     return -1;
 297
 298   fprintf (fp, "%d\n", getpid ());
 299   if (ferror (fp))
 300     return -1;
 301
 302   fclose (fp);
 303
 304   return 0;
 305 }
 306
 307 /* Type of the lookup function for netname2user.  */
 308 typedef int (*pwbyname_function) (const char *name, struct passwd *pw,
 309                                    char *buffer, size_t buflen);
 310
 311 /* Hanlde incoming requests.  */
 312 static
 313 void handle_requests (void)
 314 {
 315   request_header req;
 316   int conn; /* Handle on which connection (client) the request came from.  */
 317   int done = 0;
 318   char *key;
 319
 320   while (!done)
 321     {
 322       key = NULL;
 323       get_request (&conn, &req, &key);
 324       if (debug_flag)
 325         dbg_log (_("handle_requests: request received (Version = %d)"),
 326                  req.version);
 327       switch (req.type)
 328         {
 329         case GETPWBYNAME:
 330           {
 331             param_t *param = malloc (sizeof (param_t));
 332             pthread_t thread;
 333
 334             if (debug_flag)
 335               dbg_log ("\tGETPWBYNAME (%s)", key);
 336             param->key = key;
 337             param->conn = conn;
 338             if (disabled_passwd)
 339               pthread_create (&thread, NULL, cache_pw_disabled, (void *)param);
 340             else
 341               pthread_create (&thread, NULL, cache_getpwnam, (void *)param);
 342             pthread_detach (thread);
 343           }
 344           break;
 345         case GETPWBYUID:
 346           {
 347             param_t *param = malloc (sizeof (param_t));
 348             pthread_t thread;
 349
 350             if (debug_flag)
 351               dbg_log ("\tGETPWBYUID (%s)", key);
 352             param->key = key;
 353             param->conn = conn;
 354             if (disabled_passwd)
 355               pthread_create (&thread, NULL, cache_pw_disabled, (void *)param);
 356             else
 357               pthread_create (&thread, NULL, cache_getpwuid, (void *)param);
 358             pthread_detach (thread);
 359           }
 360           break;
 361         case GETGRBYNAME:
 362           {
 363             param_t *param = malloc (sizeof (param_t));
 364             pthread_t thread;
 365
 366             if (debug_flag)
 367               dbg_log ("\tGETGRBYNAME (%s)", key);
 368             param->key = key;
 369             param->conn = conn;
 370             if (disabled_group)
 371               pthread_create (&thread, NULL, cache_gr_disabled, (void *)param);
 372             else
 373               pthread_create (&thread, NULL, cache_getgrnam, (void *)param);
 374             pthread_detach (thread);
 375           }
 376           break;
 377         case GETGRBYGID:
 378           {
 379             param_t *param = malloc (sizeof (param_t));
 380             pthread_t thread;
 381
 382             if (debug_flag)
 383               dbg_log ("\tGETGRBYGID (%s)", key);
 384             param->key = key;
 385             param->conn = conn;
 386             if (disabled_group)
 387               pthread_create (&thread, NULL, cache_gr_disabled, (void *)param);
 388             else
 389               pthread_create (&thread, NULL, cache_getgrgid, (void *)param);
 390             pthread_detach (thread);
 391           }
 392           break;
 393         case GETHOSTBYNAME:
 394           /* Not yetimplemented.  */
 395           close_socket (conn);
 396           break;
 397         case GETHOSTBYADDR:
 398           /* Not yet implemented. */
 399           close_socket (conn);
 400           break;
 401         case SHUTDOWN:
 402           do_shutdown = 1;
 403           close_socket (0);
 404           close_socket (conn);
 405           /* Clean up the files created by `bind'.  */
 406           unlink (_PATH_NSCDSOCKET);
 407           /* Clean up pid file.  */
 408           unlink (_PATH_NSCDPID);
 409           done = 1;
 410           break;
 411         case GETSTAT:
 412           {
 413             stat_response_header resp;
 414
 415             if (debug_flag)
 416               dbg_log ("\tGETSTAT");
 417
 418             get_pw_stat (&resp);
 419             get_gr_stat (&resp);
 420             resp.debug_level = debug_flag;
 421             resp.pw_enabled = !disabled_passwd;
 422             resp.gr_enabled = !disabled_group;
 423
 424             stat_send (conn, &resp);
 425
 426             close_socket (conn);
 427           }
 428           break;
 429         default:
 430           dbg_log (_("Unknown request (%d)"), req.type);
 431           break;
 432         }
 433     }
 434 }