aboutsummaryrefslogtreecommitdiff
blob: a67da746d6a83eedee12e79c39eea2b01a680ad8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
/* Copyright (c) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Thorsten Kukuk <kukuk@suse.de>, 1998.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA. */

/* nscd - Name Service Cache Daemon. Caches passwd, group, and hosts.  */

#include <argp.h>
#include <assert.h>
#include <errno.h>
#include <error.h>
#include <grp.h>
#include <libintl.h>
#include <locale.h>
#include <pthread.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/un.h>

#include "dbg_log.h"
#include "nscd.h"

/* Get libc version number.  */
#include <version.h>

#define PACKAGE _libc_intl_domainname

/* Structure used by main() thread to keep track of the number of
   active threads.  Used to limit how many threads it will create
   and under a shutdown condition to wait till all in-progress
   requests have finished before "turning off the lights".  */

typedef struct
{
  int             num_active;
  pthread_cond_t  thread_exit_cv;
  pthread_mutex_t mutex;
} thread_info_t;

thread_info_t thread_info;

int do_shutdown;
int disabled_passwd;
int disabled_group;
int go_background = 1;
const char *server_user;

int secure[lastdb];
int secure_in_use;
static const char *conffile = _PATH_NSCDCONF;

static int check_pid (const char *file);
static int write_pid (const char *file);
static void drop_privileges (void);

/* Name and version of program.  */
static void print_version (FILE *stream, struct argp_state *state);
void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;

/* Definitions of arguments for argp functions.  */
static const struct argp_option options[] =
{
  { "config-file", 'f', N_("NAME"), 0,
    N_("Read configuration data from NAME") },
  { "debug", 'd', NULL, 0,
    N_("Do not fork and display messages on the current tty") },
  { "nthreads", 't', N_("NUMBER"), 0, N_("Start NUMBER threads") },
  { "shutdown", 'K', NULL, 0, N_("Shut the server down") },
  { "statistic", 'g', NULL, 0, N_("Print current configuration statistic") },
  { "invalidate", 'i', N_("TABLE"), 0,
    N_("Invalidate the specified cache") },
  { "secure", 'S', N_("TABLE,yes"), 0, N_("Use separate cache for each user")},
  { NULL, 0, NULL, 0, NULL }
};

/* Short description of program.  */
static const char doc[] = N_("Name Service Cache Daemon.");

/* Prototype for option handler.  */
static error_t parse_opt (int key, char *arg, struct argp_state *state);

/* Data structure to communicate with argp functions.  */
static struct argp argp =
{
  options, parse_opt, NULL, doc,
};

int
main (int argc, char **argv)
{
  int remaining;

  /* Set locale via LC_ALL.  */
  setlocale (LC_ALL, "");
  /* Set the text message domain.  */
  textdomain (PACKAGE);

  /* Parse and process arguments.  */
  argp_parse (&argp, argc, argv, 0, &remaining, NULL);

  if (remaining != argc)
    {
      error (0, 0, gettext ("wrong number of arguments"));
      argp_help (&argp, stdout, ARGP_HELP_SEE, program_invocation_short_name);
      exit (EXIT_FAILURE);
    }

  /* Check if we are already running. */
  if (check_pid (_PATH_NSCDPID))
    error (EXIT_FAILURE, 0, _("already running"));

  /* Behave like a daemon.  */
  if (go_background)
    {
      int i;

      if (fork ())
	exit (0);

      for (i = 0; i < getdtablesize (); i++)
	close (i);

      if (fork ())
	exit (0);

      setsid ();

      chdir ("/");

      openlog ("nscd", LOG_CONS | LOG_ODELAY, LOG_DAEMON);

      if (write_pid (_PATH_NSCDPID) < 0)
        dbg_log ("%s: %s", _PATH_NSCDPID, strerror (errno));

      /* Ignore job control signals.  */
      signal (SIGTTOU, SIG_IGN);
      signal (SIGTTIN, SIG_IGN);
      signal (SIGTSTP, SIG_IGN);
    }

  signal (SIGINT, termination_handler);
  signal (SIGQUIT, termination_handler);
  signal (SIGTERM, termination_handler);
  signal (SIGPIPE, SIG_IGN);

  /* Cleanup files created by a previous `bind'.  */
  unlink (_PATH_NSCDSOCKET);

  /* Init databases.  */
  nscd_init (conffile);

  /* Change to unprivileged UID if specifed in config file */
  if(server_user && !secure_in_use)
    drop_privileges ();

  /* Handle incoming requests */
  start_threads ();

  return 0;
}


/* Handle program arguments.  */
static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
  switch (key)
    {
    case 'd':
      ++debug_level;
      go_background = 0;
      break;

    case 'f':
      conffile = arg;
      break;

    case 'K':
      if (getuid () != 0)
	error (EXIT_FAILURE, 0, _("Only root is allowed to use this option!"));
      {
	int sock = nscd_open_socket ();
	request_header req;
	ssize_t nbytes;

	if (sock == -1)
	  exit (EXIT_FAILURE);

	req.version = NSCD_VERSION;
	req.type = SHUTDOWN;
	req.key_len = 0;
	nbytes = TEMP_FAILURE_RETRY (write (sock, &req,
					    sizeof (request_header)));
	close (sock);
	exit (nbytes != sizeof (request_header) ? EXIT_FAILURE : EXIT_SUCCESS);
      }

    case 'g':
      if (getuid () != 0)
	error (EXIT_FAILURE, 0, _("Only root is allowed to use this option!"));
      receive_print_stats ();
      /* Does not return.  */

    case 'i':
      if (getuid () != 0)
	error (EXIT_FAILURE, 0, _("Only root is allowed to use this option!"));
      else
	{
	  int sock = nscd_open_socket ();
	  request_header req;
	  ssize_t nbytes;

	  if (sock == -1)
	    exit (EXIT_FAILURE);

	  if (strcmp (arg, "passwd") == 0)
	    req.key_len = sizeof "passwd";
	  else if (strcmp (arg, "group") == 0)
	    req.key_len = sizeof "group";
	  else if (strcmp (arg, "hosts") == 0)
	    req.key_len = sizeof "hosts";
	  else
	    return ARGP_ERR_UNKNOWN;

	  req.version = NSCD_VERSION;
	  req.type = INVALIDATE;
	  nbytes = TEMP_FAILURE_RETRY (write (sock, &req,
					      sizeof (request_header)));
	  if (nbytes != sizeof (request_header))
	    {
	      close (sock);
	      exit (EXIT_FAILURE);
	    }

	  nbytes = TEMP_FAILURE_RETRY (write (sock, (void *)arg, req.key_len));

	  close (sock);

	  exit (nbytes != req.key_len ? EXIT_FAILURE : EXIT_SUCCESS);
	}

    case 't':
      nthreads = atol (arg);
      break;

    case 'S':
      if (strcmp (arg, "passwd,yes") == 0)
	secure_in_use = secure[pwddb] = 1;
      else if (strcmp (arg, "group,yes") == 0)
	secure_in_use = secure[grpdb] = 1;
      else if (strcmp (arg, "hosts,yes") == 0)
	secure_in_use = secure[hstdb] = 1;
      break;

    default:
      return ARGP_ERR_UNKNOWN;
    }

  return 0;
}

/* Print the version information.  */
static void
print_version (FILE *stream, struct argp_state *state)
{
  fprintf (stream, "nscd (GNU %s) %s\n", PACKAGE, VERSION);
  fprintf (stream, gettext ("\
Copyright (C) %s Free Software Foundation, Inc.\n\
This is free software; see the source for copying conditions.  There is NO\n\
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
"), "2001");
  fprintf (stream, gettext ("Written by %s.\n"),
	   "Thorsten Kukuk and Ulrich Drepper");
}


/* Create a socket connected to a name.  */
int
nscd_open_socket (void)
{
  struct sockaddr_un addr;
  int sock;

  sock = socket (PF_UNIX, SOCK_STREAM, 0);
  if (sock < 0)
    return -1;

  addr.sun_family = AF_UNIX;
  assert (sizeof (addr.sun_path) >= sizeof (_PATH_NSCDSOCKET));
  strcpy (addr.sun_path, _PATH_NSCDSOCKET);
  if (connect (sock, (struct sockaddr *) &addr, sizeof (addr)) < 0)
    {
      close (sock);
      return -1;
    }

  return sock;
}

/* Cleanup.  */
void
termination_handler (int signum)
{
  close_sockets ();

  /* Clean up the file created by `bind'.  */
  unlink (_PATH_NSCDSOCKET);

  /* Clean up pid file.  */
  unlink (_PATH_NSCDPID);

  exit (EXIT_SUCCESS);
}

/* Returns 1 if the process in pid file FILE is running, 0 if not.  */
static int
check_pid (const char *file)
{
  FILE *fp;

  fp = fopen (file, "r");
  if (fp)
    {
      pid_t pid;
      int n;

      n = fscanf (fp, "%d", &pid);
      fclose (fp);

      if (n != 1 || kill (pid, 0) == 0)
        return 1;
    }

  return 0;
}

/* Write the current process id to the file FILE.
   Returns 0 if successful, -1 if not.  */
static int
write_pid (const char *file)
{
  FILE *fp;

  fp = fopen (file, "w");
  if (fp == NULL)
    return -1;

  fprintf (fp, "%d\n", getpid ());
  if (fflush (fp) || ferror (fp))
    return -1;

  fclose (fp);

  return 0;
}

/* Look up the uid and gid associated with the user we are supposed to run
   the server as, and then call setgid(), setgroups(), and setuid().
   Otherwise, abort- we should not run as root if the configuration file
   specifically tells us not to. */

static void
drop_privileges (void)
{
  int buflen = 256;
  char *buffer = alloca (buflen);
  struct passwd resultbuf;
  struct passwd *pwd;

  while (__getpwnam_r (server_user, &resultbuf, buffer, buflen, &pwd) != 0
	 && errno == ERANGE)
    {
      errno = 0;
      buflen += 256;
      buffer = alloca (buflen);
    }

  if(!pwd)
    {
      dbg_log (_("Failed to look up user '%s' to run server as"),
	       server_user);
      exit(1);
    }

  setgroups (0, NULL);
  setgid (pwd->pw_gid);
  setuid (pwd->pw_uid);
}