xref: /illumos-gate/usr/src/cmd/idmap/idmapd/idmapd.c (revision c5866007)
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 (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 
26 /*
27  * main() of idmapd(1M)
28  */
29 
30 #include "idmapd.h"
31 #include <atomic.h>
32 #include <signal.h>
33 #include <rpc/pmap_clnt.h> /* for pmap_unset */
34 #include <string.h> /* strcmp */
35 #include <unistd.h> /* setsid */
36 #include <sys/types.h>
37 #include <memory.h>
38 #include <stropts.h>
39 #include <netconfig.h>
40 #include <sys/resource.h> /* rlimit */
41 #include <rpcsvc/daemon_utils.h> /* DAEMON_UID and DAEMON_GID */
42 #include <priv_utils.h> /* privileges */
43 #include <locale.h>
44 #include <sys/systeminfo.h>
45 #include <errno.h>
46 #include <sys/wait.h>
47 #include <sys/time.h>
48 #include <zone.h>
49 #include <door.h>
50 #include <port.h>
51 #include <tsol/label.h>
52 #include <sys/resource.h>
53 #include <sys/sid.h>
54 #include <sys/idmap.h>
55 #include <pthread.h>
56 
57 static void	term_handler(int);
58 static void	init_idmapd();
59 static void	fini_idmapd();
60 
61 idmapd_state_t	_idmapdstate;
62 
63 SVCXPRT *xprt = NULL;
64 
65 static int dfd = -1;		/* our door server fildes, for unregistration */
66 static int degraded = 0;	/* whether the FMRI has been marked degraded */
67 
68 
69 static uint32_t		num_threads = 0;
70 static pthread_key_t	create_threads_key;
71 static uint32_t		max_threads = 40;
72 
73 
74 /*
75  * The following structure determines where the log messages from idmapdlog()
76  * go to. It can be stderr (idmapd -d) and/or the real idmapdlog (idmapd).
77  *
78  * logstate.max_pri is integer cutoff necessary to silence low-priority
79  * messages to stderr. idmapdlog has its own means so there a boolean
80  * logstate.write_idmapdlog is enough.
81  *
82  * logstate.degraded is a mode used by idmapd in its degraded state.
83  */
84 
85 static struct {
86 	boolean_t write_syslog;
87 	int max_pri; /* Max priority written to stderr */
88 	boolean_t degraded;
89 } logstate = {B_FALSE, LOG_DEBUG, B_FALSE};
90 
91 /*
92  * Server door thread start routine.
93  *
94  * Set a TSD value to the door thread. This enables the destructor to
95  * be called when this thread exits.
96  */
97 /*ARGSUSED*/
98 static void *
99 idmapd_door_thread_start(void *arg)
100 {
101 	static void *value = 0;
102 
103 	/*
104 	 * Disable cancellation to avoid memory leaks from not running
105 	 * the thread cleanup code.
106 	 */
107 	(void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
108 	(void) pthread_setspecific(create_threads_key, value);
109 	(void) door_return(NULL, 0, NULL, 0);
110 
111 	/* make lint happy */
112 	return (NULL);
113 }
114 
115 /*
116  * Server door threads creation
117  */
118 /*ARGSUSED*/
119 static void
120 idmapd_door_thread_create(door_info_t *dip)
121 {
122 	int		num;
123 	pthread_t	thread_id;
124 
125 	if ((num = atomic_inc_32_nv(&num_threads)) > max_threads) {
126 		atomic_dec_32(&num_threads);
127 		idmapdlog(LOG_DEBUG,
128 		    "thread creation refused - %d threads currently active",
129 		    num - 1);
130 		return;
131 	}
132 	(void) pthread_create(&thread_id, NULL, idmapd_door_thread_start, NULL);
133 	idmapdlog(LOG_DEBUG,
134 	    "created thread ID %d - %d threads currently active",
135 	    thread_id, num);
136 }
137 
138 /*
139  * Server door thread cleanup
140  */
141 /*ARGSUSED*/
142 static void
143 idmapd_door_thread_cleanup(void *arg)
144 {
145 	int num;
146 
147 	num = atomic_dec_32_nv(&num_threads);
148 	idmapdlog(LOG_DEBUG,
149 	    "exiting thread ID %d - %d threads currently active",
150 	    pthread_self(), num);
151 }
152 
153 /*
154  * This is needed for mech_krb5 -- we run as daemon, yes, but we want
155  * mech_krb5 to think we're root so it can get host/nodename.fqdn
156  * tickets for us so we can authenticate to AD as the machine account
157  * that we are.  For more details look at the entry point in mech_krb5
158  * corresponding to gss_init_sec_context().
159  *
160  * As a side effect of faking our effective UID to mech_krb5 we will use
161  * root's default ccache (/tmp/krb5cc_0).  But if that's created by
162  * another process then we won't have access to it: we run as daemon and
163  * keep PRIV_FILE_DAC_READ, which is insufficient to share the ccache
164  * with others.  We putenv("KRB5CCNAME=/var/run/idmap/ccache") in main()
165  * to avoid this issue; see main().
166  *
167  * Someday we'll have gss/mech_krb5 extensions for acquiring initiator
168  * creds with keytabs/raw keys, and someday we'll have extensions to
169  * libsasl to specify creds/name to use on the initiator side, and
170  * someday we'll have extensions to libldap to pass those through to
171  * libsasl.  Until then this interposer will have to do.
172  *
173  * Also, we have to tell lint to shut up: it thinks app_krb5_user_uid()
174  * is defined but not used.
175  */
176 /*LINTLIBRARY*/
177 uid_t
178 app_krb5_user_uid(void)
179 {
180 	return (0);
181 }
182 
183 /*ARGSUSED*/
184 static void
185 term_handler(int sig)
186 {
187 	idmapdlog(LOG_INFO, "Terminating.");
188 	fini_idmapd();
189 	_exit(0);
190 }
191 
192 /*ARGSUSED*/
193 static void
194 usr1_handler(int sig)
195 {
196 	boolean_t saved_debug_mode = _idmapdstate.debug_mode;
197 
198 	_idmapdstate.debug_mode = B_TRUE;
199 	idmap_log_stderr(LOG_DEBUG);
200 
201 	print_idmapdstate();
202 
203 	_idmapdstate.debug_mode = saved_debug_mode;
204 	idmap_log_stderr(_idmapdstate.daemon_mode ? -1 : LOG_DEBUG);
205 
206 }
207 
208 static int pipe_fd = -1;
209 
210 static void
211 daemonize_ready(void)
212 {
213 	char data = '\0';
214 	/*
215 	 * wake the parent
216 	 */
217 	(void) write(pipe_fd, &data, 1);
218 	(void) close(pipe_fd);
219 }
220 
221 static int
222 daemonize_start(void)
223 {
224 	char	data;
225 	int	status;
226 	int	devnull;
227 	int	filedes[2];
228 	pid_t	pid;
229 
230 	(void) sigset(SIGPIPE, SIG_IGN);
231 	devnull = open("/dev/null", O_RDONLY);
232 	if (devnull < 0)
233 		return (-1);
234 	(void) dup2(devnull, 0);
235 	(void) dup2(2, 1);	/* stderr only */
236 	if (pipe(filedes) < 0)
237 		return (-1);
238 	if ((pid = fork1()) < 0)
239 		return (-1);
240 	if (pid != 0) {
241 		/*
242 		 * parent
243 		 */
244 		(void) close(filedes[1]);
245 		if (read(filedes[0], &data, 1) == 1) {
246 			/* presume success */
247 			_exit(0);
248 		}
249 		status = -1;
250 		(void) wait4(pid, &status, 0, NULL);
251 		if (WIFEXITED(status))
252 			_exit(WEXITSTATUS(status));
253 		else
254 			_exit(-1);
255 	}
256 
257 	/*
258 	 * child
259 	 */
260 	pipe_fd = filedes[1];
261 	(void) close(filedes[0]);
262 	(void) setsid();
263 	(void) umask(0077);
264 	openlog("idmap", LOG_PID, LOG_DAEMON);
265 
266 	return (0);
267 }
268 
269 
270 int
271 main(int argc, char **argv)
272 {
273 	int c;
274 	struct rlimit rl;
275 
276 	_idmapdstate.daemon_mode = TRUE;
277 	_idmapdstate.debug_mode = FALSE;
278 	while ((c = getopt(argc, argv, "d")) != -1) {
279 		switch (c) {
280 			case 'd':
281 				_idmapdstate.daemon_mode = FALSE;
282 				break;
283 			default:
284 				(void) fprintf(stderr,
285 				    "Usage: /usr/lib/idmapd [-d]\n");
286 				return (SMF_EXIT_ERR_CONFIG);
287 		}
288 	}
289 
290 	/* set locale and domain for internationalization */
291 	(void) setlocale(LC_ALL, "");
292 	(void) textdomain(TEXT_DOMAIN);
293 
294 	idmap_set_logger(idmapdlog);
295 	adutils_set_logger(idmapdlog);
296 	idmap_log_syslog(B_TRUE);
297 	idmap_log_stderr(_idmapdstate.daemon_mode ? -1 : LOG_DEBUG);
298 
299 	if (is_system_labeled() && getzoneid() != GLOBAL_ZONEID) {
300 		idmapdlog(LOG_ERR,
301 		    "with Trusted Extensions idmapd runs only in the "
302 		    "global zone");
303 		exit(1);
304 	}
305 
306 	/*
307 	 * Raise the fd limit to max
308 	 */
309 	if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
310 		idmapdlog(LOG_ERR, "getrlimit failed");
311 	} else if (rl.rlim_cur < rl.rlim_max) {
312 		rl.rlim_cur = rl.rlim_max;
313 		if (setrlimit(RLIMIT_NOFILE, &rl) != 0)
314 			idmapdlog(LOG_ERR,
315 			    "Unable to raise RLIMIT_NOFILE to %d",
316 			    rl.rlim_cur);
317 	}
318 
319 	(void) mutex_init(&_svcstate_lock, USYNC_THREAD, NULL);
320 
321 	if (_idmapdstate.daemon_mode == TRUE) {
322 		if (daemonize_start() < 0) {
323 			idmapdlog(LOG_ERR, "unable to daemonize");
324 			exit(-1);
325 		}
326 	} else
327 		(void) umask(0077);
328 
329 	idmap_init_tsd_key();
330 
331 	init_idmapd();
332 
333 	/* signal handlers that should run only after we're initialized */
334 	(void) sigset(SIGTERM, term_handler);
335 	(void) sigset(SIGUSR1, usr1_handler);
336 	(void) sigset(SIGHUP, idmap_cfg_hup_handler);
337 
338 	if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET,
339 	    DAEMON_UID, DAEMON_GID,
340 	    PRIV_PROC_AUDIT, PRIV_FILE_DAC_READ,
341 	    (char *)NULL) == -1) {
342 		idmapdlog(LOG_ERR, "unable to drop privileges");
343 		exit(1);
344 	}
345 
346 	__fini_daemon_priv(PRIV_PROC_FORK, PRIV_PROC_EXEC, PRIV_PROC_SESSION,
347 	    PRIV_FILE_LINK_ANY, PRIV_PROC_INFO, (char *)NULL);
348 
349 	if (_idmapdstate.daemon_mode == TRUE)
350 		daemonize_ready();
351 
352 	/* With doors RPC this just wastes this thread, oh well */
353 	svc_run();
354 	return (0);
355 }
356 
357 static void
358 init_idmapd()
359 {
360 	int	error;
361 	int	connmaxrec = IDMAP_MAX_DOOR_RPC;
362 
363 
364 	/* create directories as root and chown to daemon uid */
365 	if (create_directory(IDMAP_DBDIR, DAEMON_UID, DAEMON_GID) < 0)
366 		exit(1);
367 	if (create_directory(IDMAP_CACHEDIR, DAEMON_UID, DAEMON_GID) < 0)
368 		exit(1);
369 
370 	/*
371 	 * Set KRB5CCNAME in the environment.  See app_krb5_user_uid()
372 	 * for more details.  We blow away the existing one, if there is
373 	 * one.
374 	 */
375 	(void) unlink(IDMAP_CACHEDIR "/ccache");
376 	putenv("KRB5CCNAME=" IDMAP_CACHEDIR "/ccache");
377 
378 	if (sysinfo(SI_HOSTNAME, _idmapdstate.hostname,
379 	    sizeof (_idmapdstate.hostname)) == -1) {
380 		error = errno;
381 		idmapdlog(LOG_ERR, "unable to determine hostname, error: %d",
382 		    error);
383 		exit(1);
384 	}
385 
386 	if ((error = init_mapping_system()) < 0) {
387 		idmapdlog(LOG_ERR, "unable to initialize mapping system");
388 		exit(error < -2 ? SMF_EXIT_ERR_CONFIG : 1);
389 	}
390 
391 	(void) door_server_create(idmapd_door_thread_create);
392 	if ((error = pthread_key_create(&create_threads_key,
393 	    idmapd_door_thread_cleanup)) != 0) {
394 		idmapdlog(LOG_ERR, "unable to create threads key (%s)",
395 		    strerror(error));
396 		goto errout;
397 	}
398 
399 	xprt = svc_door_create(idmap_prog_1, IDMAP_PROG, IDMAP_V1, connmaxrec);
400 	if (xprt == NULL) {
401 		idmapdlog(LOG_ERR, "unable to create door RPC service");
402 		goto errout;
403 	}
404 
405 	if (!svc_control(xprt, SVCSET_CONNMAXREC, &connmaxrec)) {
406 		idmapdlog(LOG_ERR, "unable to limit RPC request size");
407 		goto errout;
408 	}
409 
410 	dfd = xprt->xp_fd;
411 
412 	if (dfd == -1) {
413 		idmapdlog(LOG_ERR, "unable to register door");
414 		goto errout;
415 	}
416 	if ((error = __idmap_reg(dfd)) != 0) {
417 		idmapdlog(LOG_ERR, "unable to register door (%s)",
418 		    strerror(errno));
419 		goto errout;
420 	}
421 
422 	if ((error = allocids(_idmapdstate.new_eph_db,
423 	    8192, &_idmapdstate.next_uid,
424 	    8192, &_idmapdstate.next_gid)) != 0) {
425 		idmapdlog(LOG_ERR, "unable to allocate ephemeral IDs (%s)",
426 		    strerror(errno));
427 		_idmapdstate.next_uid = IDMAP_SENTINEL_PID;
428 		_idmapdstate.limit_uid = IDMAP_SENTINEL_PID;
429 		_idmapdstate.next_gid = IDMAP_SENTINEL_PID;
430 		_idmapdstate.limit_gid = IDMAP_SENTINEL_PID;
431 	} else {
432 		_idmapdstate.limit_uid = _idmapdstate.next_uid + 8192;
433 		_idmapdstate.limit_gid = _idmapdstate.next_gid + 8192;
434 	}
435 
436 	print_idmapdstate();
437 
438 	return;
439 
440 errout:
441 	fini_idmapd();
442 	exit(1);
443 }
444 
445 static void
446 fini_idmapd()
447 {
448 	__idmap_unreg(dfd);
449 	fini_mapping_system();
450 	if (xprt != NULL)
451 		svc_destroy(xprt);
452 }
453 
454 static
455 const char *
456 get_fmri(void)
457 {
458 	static char *fmri = NULL;
459 	static char buf[60];
460 	char *s;
461 
462 	membar_consumer();
463 	s = fmri;
464 	if (s != NULL && *s == '\0')
465 		return (NULL);
466 	else if (s != NULL)
467 		return (s);
468 
469 	if ((s = getenv("SMF_FMRI")) == NULL || strlen(s) >= sizeof (buf))
470 		buf[0] = '\0';
471 	else
472 		(void) strlcpy(buf, s, sizeof (buf));
473 
474 	membar_producer();
475 	fmri = buf;
476 
477 	return (get_fmri());
478 }
479 
480 /*
481  * Wrappers for smf_degrade/restore_instance()
482  *
483  * smf_restore_instance() is too heavy duty to be calling every time we
484  * have a successful AD name<->SID lookup.
485  */
486 void
487 degrade_svc(int poke_discovery, const char *reason)
488 {
489 	const char *fmri;
490 
491 	membar_consumer();
492 	if (degraded)
493 		return;
494 
495 	idmapdlog(LOG_ERR, "Degraded operation (%s).  If you are running an "
496 	    "SMB server in workgroup mode, or if you're not running an SMB "
497 	    "server, then you can ignore this message", reason);
498 
499 	membar_producer();
500 	degraded = 1;
501 	idmap_log_degraded(B_TRUE);
502 
503 	if ((fmri = get_fmri()) != NULL)
504 		(void) smf_degrade_instance(fmri, 0);
505 
506 	/*
507 	 * If the config update thread is in a state where auto-discovery could
508 	 * be re-tried, then this will make it try it -- a sort of auto-refresh.
509 	 */
510 	if (poke_discovery)
511 		idmap_cfg_poke_updates();
512 }
513 
514 void
515 restore_svc(void)
516 {
517 	const char *fmri;
518 
519 	membar_consumer();
520 	if (!degraded)
521 		return;
522 
523 	if ((fmri = get_fmri()) == NULL)
524 		(void) smf_restore_instance(fmri);
525 
526 	membar_producer();
527 	degraded = 0;
528 	idmap_log_degraded(B_FALSE);
529 
530 	idmapdlog(LOG_NOTICE, "Normal operation restored");
531 }
532 
533 
534 /* printflike */
535 void
536 idmapdlog(int pri, const char *format, ...) {
537 	va_list args;
538 
539 	if (pri <= logstate.max_pri) {
540 		va_start(args, format);
541 		(void) vfprintf(stderr, format, args);
542 		(void) fprintf(stderr, "\n");
543 		va_end(args);
544 	}
545 
546 	/*
547 	 * We don't want to fill up the logs with useless messages when
548 	 * we're degraded, but we still want to log.
549 	 */
550 	if (logstate.degraded)
551 		pri = LOG_DEBUG;
552 
553 	if (logstate.write_syslog) {
554 		va_start(args, format);
555 		vsyslog(pri, format, args);
556 		va_end(args);
557 	}
558 }
559 
560 void
561 idmap_log_stderr(int pri)
562 {
563 	logstate.max_pri = pri;
564 }
565 
566 void
567 idmap_log_syslog(boolean_t what)
568 {
569 	logstate.write_syslog = what;
570 }
571 
572 void
573 idmap_log_degraded(boolean_t what)
574 {
575 	logstate.degraded = what;
576 }
577