xref: /illumos-gate/usr/src/cmd/idmap/idmapd/idmapd.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * main() of idmapd(1M)
30  */
31 
32 #include "idmapd.h"
33 #include <atomic.h>
34 #include <signal.h>
35 #include <rpc/pmap_clnt.h> /* for pmap_unset */
36 #include <string.h> /* strcmp */
37 #include <unistd.h> /* setsid */
38 #include <sys/types.h>
39 #include <memory.h>
40 #include <stropts.h>
41 #include <netconfig.h>
42 #include <sys/resource.h> /* rlimit */
43 #include <syslog.h>
44 #include <rpcsvc/daemon_utils.h> /* DAEMON_UID and DAEMON_GID */
45 #include <priv_utils.h> /* privileges */
46 #include <locale.h>
47 #include <sys/systeminfo.h>
48 #include <errno.h>
49 #include <sys/wait.h>
50 #include <sys/time.h>
51 #include <zone.h>
52 #include <door.h>
53 #include <port.h>
54 #include <tsol/label.h>
55 #include <sys/resource.h>
56 #include <sys/sid.h>
57 #include <sys/idmap.h>
58 #include <pthread.h>
59 
60 static void	term_handler(int);
61 static void	init_idmapd();
62 static void	fini_idmapd();
63 
64 #define	_RPCSVC_CLOSEDOWN 120
65 
66 int _rpcsvcstate = _IDLE;	/* Set when a request is serviced */
67 int _rpcsvccount = 0;		/* Number of requests being serviced */
68 mutex_t _svcstate_lock;		/* lock for _rpcsvcstate, _rpcsvccount */
69 idmapd_state_t	_idmapdstate;
70 
71 SVCXPRT *xprt = NULL;
72 
73 static int dfd = -1;		/* our door server fildes, for unregistration */
74 static int degraded = 0;	/* whether the FMRI has been marked degraded */
75 
76 
77 static uint32_t		num_threads = 0;
78 static pthread_key_t	create_threads_key;
79 static uint32_t		max_threads = 40;
80 
81 /*
82  * Server door thread start routine.
83  *
84  * Set a TSD value to the door thread. This enables the destructor to
85  * be called when this thread exits.
86  */
87 /*ARGSUSED*/
88 static void *
89 idmapd_door_thread_start(void *arg)
90 {
91 	static void *value = 0;
92 
93 	/*
94 	 * Disable cancellation to avoid memory leaks from not running
95 	 * the thread cleanup code.
96 	 */
97 	(void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
98 	(void) pthread_setspecific(create_threads_key, value);
99 	(void) door_return(NULL, 0, NULL, 0);
100 
101 	/* make lint happy */
102 	return (NULL);
103 }
104 
105 /*
106  * Server door threads creation
107  */
108 /*ARGSUSED*/
109 static void
110 idmapd_door_thread_create(door_info_t *dip)
111 {
112 	int		num;
113 	pthread_t	thread_id;
114 
115 	if ((num = atomic_inc_32_nv(&num_threads)) > max_threads) {
116 		atomic_dec_32(&num_threads);
117 		idmapdlog(LOG_DEBUG,
118 		    "thread creation refused - %d threads currently active",
119 		    num - 1);
120 		return;
121 	}
122 	(void) pthread_create(&thread_id, NULL, idmapd_door_thread_start, NULL);
123 	idmapdlog(LOG_DEBUG,
124 	    "created thread ID %d - %d threads currently active",
125 	    thread_id, num);
126 }
127 
128 /*
129  * Server door thread cleanup
130  */
131 /*ARGSUSED*/
132 static void
133 idmapd_door_thread_cleanup(void *arg)
134 {
135 	int num;
136 
137 	num = atomic_dec_32_nv(&num_threads);
138 	idmapdlog(LOG_DEBUG,
139 	    "exiting thread ID %d - %d threads currently active",
140 	    pthread_self(), num);
141 }
142 
143 /*
144  * This is needed for mech_krb5 -- we run as daemon, yes, but we want
145  * mech_krb5 to think we're root so it can get host/nodename.fqdn
146  * tickets for us so we can authenticate to AD as the machine account
147  * that we are.  For more details look at the entry point in mech_krb5
148  * corresponding to gss_init_sec_context().
149  *
150  * As a side effect of faking our effective UID to mech_krb5 we will use
151  * root's default ccache (/tmp/krb5cc_0).  But if that's created by
152  * another process then we won't have access to it: we run as daemon and
153  * keep PRIV_FILE_DAC_READ, which is insufficient to share the ccache
154  * with others.  We putenv("KRB5CCNAME=/var/run/idmap/ccache") in main()
155  * to avoid this issue; see main().
156  *
157  * Someday we'll have gss/mech_krb5 extensions for acquiring initiator
158  * creds with keytabs/raw keys, and someday we'll have extensions to
159  * libsasl to specify creds/name to use on the initiator side, and
160  * someday we'll have extensions to libldap to pass those through to
161  * libsasl.  Until then this interposer will have to do.
162  *
163  * Also, we have to tell lint to shut up: it thinks app_krb5_user_uid()
164  * is defined but not used.
165  */
166 /*LINTLIBRARY*/
167 uid_t
168 app_krb5_user_uid(void)
169 {
170 	return (0);
171 }
172 
173 /*ARGSUSED*/
174 static void
175 term_handler(int sig)
176 {
177 	idmapdlog(LOG_INFO, "Terminating.");
178 	fini_idmapd();
179 	_exit(0);
180 }
181 
182 /*ARGSUSED*/
183 static void
184 usr1_handler(int sig)
185 {
186 	bool_t saved_debug_mode = _idmapdstate.debug_mode;
187 
188 	_idmapdstate.debug_mode = TRUE;
189 	idmap_log_stderr(LOG_DEBUG);
190 
191 	print_idmapdstate();
192 
193 	_idmapdstate.debug_mode = saved_debug_mode;
194 	idmap_log_stderr(_idmapdstate.daemon_mode ? -1 : LOG_DEBUG);
195 
196 }
197 
198 static int pipe_fd = -1;
199 
200 static void
201 daemonize_ready(void)
202 {
203 	char data = '\0';
204 	/*
205 	 * wake the parent
206 	 */
207 	(void) write(pipe_fd, &data, 1);
208 	(void) close(pipe_fd);
209 }
210 
211 static int
212 daemonize_start(void)
213 {
214 	char	data;
215 	int	status;
216 	int	devnull;
217 	int	filedes[2];
218 	pid_t	pid;
219 
220 	(void) sigset(SIGPIPE, SIG_IGN);
221 	devnull = open("/dev/null", O_RDONLY);
222 	if (devnull < 0)
223 		return (-1);
224 	(void) dup2(devnull, 0);
225 	(void) dup2(2, 1);	/* stderr only */
226 	if (pipe(filedes) < 0)
227 		return (-1);
228 	if ((pid = fork1()) < 0)
229 		return (-1);
230 	if (pid != 0) {
231 		/*
232 		 * parent
233 		 */
234 		(void) close(filedes[1]);
235 		if (read(filedes[0], &data, 1) == 1) {
236 			/* presume success */
237 			_exit(0);
238 		}
239 		status = -1;
240 		(void) wait4(pid, &status, 0, NULL);
241 		if (WIFEXITED(status))
242 			_exit(WEXITSTATUS(status));
243 		else
244 			_exit(-1);
245 	}
246 
247 	/*
248 	 * child
249 	 */
250 	pipe_fd = filedes[1];
251 	(void) close(filedes[0]);
252 	(void) setsid();
253 	(void) umask(0077);
254 	openlog("idmap", LOG_PID, LOG_DAEMON);
255 
256 	return (0);
257 }
258 
259 
260 int
261 main(int argc, char **argv)
262 {
263 	int c;
264 	struct rlimit rl;
265 
266 	_idmapdstate.daemon_mode = TRUE;
267 	_idmapdstate.debug_mode = FALSE;
268 	while ((c = getopt(argc, argv, "d")) != -1) {
269 		switch (c) {
270 			case 'd':
271 				_idmapdstate.daemon_mode = FALSE;
272 				break;
273 			default:
274 				fprintf(stderr, "Usage: /usr/lib/idmapd");
275 				return (SMF_EXIT_ERR_CONFIG);
276 				break;
277 		}
278 	}
279 
280 	/* set locale and domain for internationalization */
281 	(void) setlocale(LC_ALL, "");
282 	(void) textdomain(TEXT_DOMAIN);
283 
284 	idmap_log_syslog(TRUE);
285 	idmap_log_stderr(_idmapdstate.daemon_mode ? -1 : LOG_DEBUG);
286 
287 	if (is_system_labeled() && getzoneid() != GLOBAL_ZONEID) {
288 		idmapdlog(LOG_ERR,
289 		    "with Trusted Extensions idmapd runs only in the "
290 		    "global zone");
291 		exit(1);
292 	}
293 
294 	/*
295 	 * Raise the fd limit to max
296 	 */
297 	if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
298 		idmapdlog(LOG_ERR, "getrlimit failed");
299 	} else if (rl.rlim_cur < rl.rlim_max) {
300 		rl.rlim_cur = rl.rlim_max;
301 		if (setrlimit(RLIMIT_NOFILE, &rl) != 0)
302 			idmapdlog(LOG_ERR,
303 			    "Unable to raise RLIMIT_NOFILE to %d",
304 			    rl.rlim_cur);
305 	}
306 
307 	(void) mutex_init(&_svcstate_lock, USYNC_THREAD, NULL);
308 
309 	if (_idmapdstate.daemon_mode == TRUE) {
310 		if (daemonize_start() < 0) {
311 			(void) idmapdlog(LOG_ERR, "unable to daemonize");
312 			exit(-1);
313 		}
314 	} else
315 		(void) umask(0077);
316 
317 	idmap_init_tsd_key();
318 
319 	init_idmapd();
320 
321 	/* signal handlers that should run only after we're initialized */
322 	(void) sigset(SIGTERM, term_handler);
323 	(void) sigset(SIGUSR1, usr1_handler);
324 	(void) sigset(SIGHUP, idmap_cfg_hup_handler);
325 
326 	if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET,
327 	    DAEMON_UID, DAEMON_GID,
328 	    PRIV_PROC_AUDIT, PRIV_FILE_DAC_READ,
329 	    (char *)NULL) == -1) {
330 		idmapdlog(LOG_ERR, "unable to drop privileges");
331 		exit(1);
332 	}
333 
334 	__fini_daemon_priv(PRIV_PROC_FORK, PRIV_PROC_EXEC, PRIV_PROC_SESSION,
335 	    PRIV_FILE_LINK_ANY, PRIV_PROC_INFO, (char *)NULL);
336 
337 	if (_idmapdstate.daemon_mode == TRUE)
338 		daemonize_ready();
339 
340 	/* With doors RPC this just wastes this thread, oh well */
341 	svc_run();
342 	return (0);
343 }
344 
345 static void
346 init_idmapd()
347 {
348 	int	error;
349 	int	connmaxrec = IDMAP_MAX_DOOR_RPC;
350 
351 
352 	/* create directories as root and chown to daemon uid */
353 	if (create_directory(IDMAP_DBDIR, DAEMON_UID, DAEMON_GID) < 0)
354 		exit(1);
355 	if (create_directory(IDMAP_CACHEDIR, DAEMON_UID, DAEMON_GID) < 0)
356 		exit(1);
357 
358 	/*
359 	 * Set KRB5CCNAME in the environment.  See app_krb5_user_uid()
360 	 * for more details.  We blow away the existing one, if there is
361 	 * one.
362 	 */
363 	(void) unlink(IDMAP_CACHEDIR "/ccache");
364 	putenv("KRB5CCNAME=" IDMAP_CACHEDIR "/ccache");
365 
366 	if (sysinfo(SI_HOSTNAME, _idmapdstate.hostname,
367 	    sizeof (_idmapdstate.hostname)) == -1) {
368 		error = errno;
369 		idmapdlog(LOG_ERR, "unable to determine hostname, error: %d",
370 		    error);
371 		exit(1);
372 	}
373 
374 	if ((error = init_mapping_system()) < 0) {
375 		idmapdlog(LOG_ERR, "unable to initialize mapping system");
376 		exit(error < -2 ? SMF_EXIT_ERR_CONFIG : 1);
377 	}
378 
379 	(void) door_server_create(idmapd_door_thread_create);
380 	if ((error = pthread_key_create(&create_threads_key,
381 	    idmapd_door_thread_cleanup)) != 0) {
382 		idmapdlog(LOG_ERR, "unable to create threads key (%s)",
383 		    strerror(error));
384 		goto errout;
385 	}
386 
387 	xprt = svc_door_create(idmap_prog_1, IDMAP_PROG, IDMAP_V1, connmaxrec);
388 	if (xprt == NULL) {
389 		idmapdlog(LOG_ERR, "unable to create door RPC service");
390 		goto errout;
391 	}
392 
393 	if (!svc_control(xprt, SVCSET_CONNMAXREC, &connmaxrec)) {
394 		idmapdlog(LOG_ERR, "unable to limit RPC request size");
395 		goto errout;
396 	}
397 
398 	dfd = xprt->xp_fd;
399 
400 	if (dfd == -1) {
401 		idmapdlog(LOG_ERR, "unable to register door");
402 		goto errout;
403 	}
404 	if ((error = idmap_reg(dfd)) != 0) {
405 		idmapdlog(LOG_ERR, "unable to register door (%s)",
406 		    strerror(errno));
407 		goto errout;
408 	}
409 
410 	if ((error = allocids(_idmapdstate.new_eph_db,
411 	    8192, &_idmapdstate.next_uid,
412 	    8192, &_idmapdstate.next_gid)) != 0) {
413 		idmapdlog(LOG_ERR, "unable to allocate ephemeral IDs (%s)",
414 		    strerror(errno));
415 		_idmapdstate.next_uid = _idmapdstate.limit_uid = SENTINEL_PID;
416 		_idmapdstate.next_gid = _idmapdstate.limit_gid = SENTINEL_PID;
417 	} else {
418 		_idmapdstate.limit_uid = _idmapdstate.next_uid + 8192;
419 		_idmapdstate.limit_gid = _idmapdstate.next_gid + 8192;
420 	}
421 
422 	print_idmapdstate();
423 
424 	return;
425 
426 errout:
427 	fini_idmapd();
428 	exit(1);
429 }
430 
431 static void
432 fini_idmapd()
433 {
434 	idmap_unreg(dfd);
435 	fini_mapping_system();
436 	if (xprt != NULL)
437 		svc_destroy(xprt);
438 }
439 
440 static
441 const char *
442 get_fmri(void)
443 {
444 	static char *fmri = NULL;
445 	static char buf[60];
446 	char *s;
447 
448 	membar_consumer();
449 	s = fmri;
450 	if (s != NULL && *s == '\0')
451 		return (NULL);
452 	else if (s != NULL)
453 		return (s);
454 
455 	if ((s = getenv("SMF_FMRI")) == NULL || strlen(s) >= sizeof (buf))
456 		buf[0] = '\0';
457 	else
458 		(void) strlcpy(buf, s, sizeof (buf));
459 
460 	membar_producer();
461 	fmri = buf;
462 
463 	return (get_fmri());
464 }
465 
466 /*
467  * Wrappers for smf_degrade/restore_instance()
468  *
469  * smf_restore_instance() is too heavy duty to be calling every time we
470  * have a successful AD name<->SID lookup.
471  */
472 void
473 degrade_svc(int poke_discovery, const char *reason)
474 {
475 	const char *fmri;
476 
477 	/*
478 	 * If the config update thread is in a state where auto-discovery could
479 	 * be re-tried, then this will make it try it -- a sort of auto-refresh.
480 	 */
481 	if (poke_discovery)
482 		idmap_cfg_poke_updates();
483 
484 	membar_consumer();
485 	if (degraded)
486 		return;
487 
488 	idmapdlog(LOG_ERR, "Degraded operation (%s).  If you are running an "
489 	    "SMB server in workgroup mode, or if you're not running an SMB "
490 	    "server, then you can ignore this message", reason);
491 
492 	membar_producer();
493 	degraded = 1;
494 	idmap_log_degraded(TRUE);
495 
496 	if ((fmri = get_fmri()) != NULL)
497 		(void) smf_degrade_instance(fmri, 0);
498 }
499 
500 void
501 restore_svc(void)
502 {
503 	const char *fmri;
504 
505 	membar_consumer();
506 	if (!degraded)
507 		return;
508 
509 	if ((fmri = get_fmri()) == NULL)
510 		(void) smf_restore_instance(fmri);
511 
512 	membar_producer();
513 	degraded = 0;
514 	idmap_log_degraded(FALSE);
515 
516 	idmapdlog(LOG_NOTICE, "Normal operation restored");
517 }
518 
519 #if 0
520 void
521 idmapdlog(int pri, const char *format, ...)
522 {
523 	va_list args;
524 
525 	va_start(args, format);
526 
527 	if (_idmapdstate.debug_mode == TRUE ||
528 	    _idmapdstate.daemon_mode == FALSE) {
529 		(void) vfprintf(stderr, format, args);
530 		(void) fprintf(stderr, "\n");
531 	}
532 
533 	/*
534 	 * We don't want to fill up the logs with useless messages when
535 	 * we're degraded, but we still want to log.
536 	 */
537 	if (degraded)
538 		pri = LOG_DEBUG;
539 
540 	(void) vsyslog(pri, format, args);
541 	va_end(args);
542 }
543 #endif
544