xref: /titanic_41/usr/src/cmd/idmap/idmapd/idmapd.c (revision bda1f129971950880940a17bab0bf096d5744b0c)
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 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 
27 /*
28  * main() of idmapd(1M)
29  */
30 
31 #include "idmapd.h"
32 #include <atomic.h>
33 #include <signal.h>
34 #include <rpc/pmap_clnt.h> /* for pmap_unset */
35 #include <string.h> /* strcmp */
36 #include <unistd.h> /* setsid */
37 #include <sys/types.h>
38 #include <memory.h>
39 #include <stropts.h>
40 #include <netconfig.h>
41 #include <sys/resource.h> /* rlimit */
42 #include <rpcsvc/daemon_utils.h> /* DAEMON_UID and DAEMON_GID */
43 #include <priv_utils.h> /* privileges */
44 #include <locale.h>
45 #include <sys/systeminfo.h>
46 #include <errno.h>
47 #include <sys/wait.h>
48 #include <sys/time.h>
49 #include <zone.h>
50 #include <door.h>
51 #include <port.h>
52 #include <tsol/label.h>
53 #include <sys/resource.h>
54 #include <sys/sid.h>
55 #include <sys/idmap.h>
56 #include <pthread.h>
57 
58 static void	term_handler(int);
59 static void	init_idmapd();
60 static void	fini_idmapd();
61 
62 
63 #define	_RPCSVC_CLOSEDOWN 120
64 
65 int _rpcsvcstate = _IDLE;	/* Set when a request is serviced */
66 int _rpcsvccount = 0;		/* Number of requests being serviced */
67 mutex_t _svcstate_lock;		/* lock for _rpcsvcstate, _rpcsvccount */
68 idmapd_state_t	_idmapdstate;
69 
70 SVCXPRT *xprt = NULL;
71 
72 static int dfd = -1;		/* our door server fildes, for unregistration */
73 static int degraded = 0;	/* whether the FMRI has been marked degraded */
74 
75 
76 static uint32_t		num_threads = 0;
77 static pthread_key_t	create_threads_key;
78 static uint32_t		max_threads = 40;
79 
80 
81 /*
82  * The following structure determines where the log messages from idmapdlog()
83  * go to. It can be stderr (idmapd -d) and/or the real idmapdlog (idmapd).
84  *
85  * logstate.max_pri is integer cutoff necessary to silence low-priority
86  * messages to stderr. idmapdlog has its own means so there a boolean
87  * logstate.write_idmapdlog is enough.
88  *
89  * logstate.degraded is a mode used by idmapd in its degraded state.
90  */
91 
92 static struct {
93 	boolean_t write_syslog;
94 	int max_pri; /* Max priority written to stderr */
95 	boolean_t degraded;
96 } logstate = {B_FALSE, LOG_DEBUG, B_FALSE};
97 
98 /*
99  * Server door thread start routine.
100  *
101  * Set a TSD value to the door thread. This enables the destructor to
102  * be called when this thread exits.
103  */
104 /*ARGSUSED*/
105 static void *
106 idmapd_door_thread_start(void *arg)
107 {
108 	static void *value = 0;
109 
110 	/*
111 	 * Disable cancellation to avoid memory leaks from not running
112 	 * the thread cleanup code.
113 	 */
114 	(void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
115 	(void) pthread_setspecific(create_threads_key, value);
116 	(void) door_return(NULL, 0, NULL, 0);
117 
118 	/* make lint happy */
119 	return (NULL);
120 }
121 
122 /*
123  * Server door threads creation
124  */
125 /*ARGSUSED*/
126 static void
127 idmapd_door_thread_create(door_info_t *dip)
128 {
129 	int		num;
130 	pthread_t	thread_id;
131 
132 	if ((num = atomic_inc_32_nv(&num_threads)) > max_threads) {
133 		atomic_dec_32(&num_threads);
134 		idmapdlog(LOG_DEBUG,
135 		    "thread creation refused - %d threads currently active",
136 		    num - 1);
137 		return;
138 	}
139 	(void) pthread_create(&thread_id, NULL, idmapd_door_thread_start, NULL);
140 	idmapdlog(LOG_DEBUG,
141 	    "created thread ID %d - %d threads currently active",
142 	    thread_id, num);
143 }
144 
145 /*
146  * Server door thread cleanup
147  */
148 /*ARGSUSED*/
149 static void
150 idmapd_door_thread_cleanup(void *arg)
151 {
152 	int num;
153 
154 	num = atomic_dec_32_nv(&num_threads);
155 	idmapdlog(LOG_DEBUG,
156 	    "exiting thread ID %d - %d threads currently active",
157 	    pthread_self(), num);
158 }
159 
160 /*
161  * This is needed for mech_krb5 -- we run as daemon, yes, but we want
162  * mech_krb5 to think we're root so it can get host/nodename.fqdn
163  * tickets for us so we can authenticate to AD as the machine account
164  * that we are.  For more details look at the entry point in mech_krb5
165  * corresponding to gss_init_sec_context().
166  *
167  * As a side effect of faking our effective UID to mech_krb5 we will use
168  * root's default ccache (/tmp/krb5cc_0).  But if that's created by
169  * another process then we won't have access to it: we run as daemon and
170  * keep PRIV_FILE_DAC_READ, which is insufficient to share the ccache
171  * with others.  We putenv("KRB5CCNAME=/var/run/idmap/ccache") in main()
172  * to avoid this issue; see main().
173  *
174  * Someday we'll have gss/mech_krb5 extensions for acquiring initiator
175  * creds with keytabs/raw keys, and someday we'll have extensions to
176  * libsasl to specify creds/name to use on the initiator side, and
177  * someday we'll have extensions to libldap to pass those through to
178  * libsasl.  Until then this interposer will have to do.
179  *
180  * Also, we have to tell lint to shut up: it thinks app_krb5_user_uid()
181  * is defined but not used.
182  */
183 /*LINTLIBRARY*/
184 uid_t
185 app_krb5_user_uid(void)
186 {
187 	return (0);
188 }
189 
190 /*ARGSUSED*/
191 static void
192 term_handler(int sig)
193 {
194 	idmapdlog(LOG_INFO, "Terminating.");
195 	fini_idmapd();
196 	_exit(0);
197 }
198 
199 /*ARGSUSED*/
200 static void
201 usr1_handler(int sig)
202 {
203 	boolean_t saved_debug_mode = _idmapdstate.debug_mode;
204 
205 	_idmapdstate.debug_mode = B_TRUE;
206 	idmap_log_stderr(LOG_DEBUG);
207 
208 	print_idmapdstate();
209 
210 	_idmapdstate.debug_mode = saved_debug_mode;
211 	idmap_log_stderr(_idmapdstate.daemon_mode ? -1 : LOG_DEBUG);
212 
213 }
214 
215 static int pipe_fd = -1;
216 
217 static void
218 daemonize_ready(void)
219 {
220 	char data = '\0';
221 	/*
222 	 * wake the parent
223 	 */
224 	(void) write(pipe_fd, &data, 1);
225 	(void) close(pipe_fd);
226 }
227 
228 static int
229 daemonize_start(void)
230 {
231 	char	data;
232 	int	status;
233 	int	devnull;
234 	int	filedes[2];
235 	pid_t	pid;
236 
237 	(void) sigset(SIGPIPE, SIG_IGN);
238 	devnull = open("/dev/null", O_RDONLY);
239 	if (devnull < 0)
240 		return (-1);
241 	(void) dup2(devnull, 0);
242 	(void) dup2(2, 1);	/* stderr only */
243 	if (pipe(filedes) < 0)
244 		return (-1);
245 	if ((pid = fork1()) < 0)
246 		return (-1);
247 	if (pid != 0) {
248 		/*
249 		 * parent
250 		 */
251 		(void) close(filedes[1]);
252 		if (read(filedes[0], &data, 1) == 1) {
253 			/* presume success */
254 			_exit(0);
255 		}
256 		status = -1;
257 		(void) wait4(pid, &status, 0, NULL);
258 		if (WIFEXITED(status))
259 			_exit(WEXITSTATUS(status));
260 		else
261 			_exit(-1);
262 	}
263 
264 	/*
265 	 * child
266 	 */
267 	pipe_fd = filedes[1];
268 	(void) close(filedes[0]);
269 	(void) setsid();
270 	(void) umask(0077);
271 	openlog("idmap", LOG_PID, LOG_DAEMON);
272 
273 	return (0);
274 }
275 
276 
277 int
278 main(int argc, char **argv)
279 {
280 	int c;
281 	struct rlimit rl;
282 
283 	_idmapdstate.daemon_mode = TRUE;
284 	_idmapdstate.debug_mode = FALSE;
285 	while ((c = getopt(argc, argv, "d")) != -1) {
286 		switch (c) {
287 			case 'd':
288 				_idmapdstate.daemon_mode = FALSE;
289 				break;
290 			default:
291 				fprintf(stderr, "Usage: /usr/lib/idmapd");
292 				return (SMF_EXIT_ERR_CONFIG);
293 				break;
294 		}
295 	}
296 
297 	/* set locale and domain for internationalization */
298 	(void) setlocale(LC_ALL, "");
299 	(void) textdomain(TEXT_DOMAIN);
300 
301 	idmap_set_logger(idmapdlog);
302 	idmap_log_syslog(B_TRUE);
303 	idmap_log_stderr(_idmapdstate.daemon_mode ? -1 : LOG_DEBUG);
304 
305 	if (is_system_labeled() && getzoneid() != GLOBAL_ZONEID) {
306 		idmapdlog(LOG_ERR,
307 		    "with Trusted Extensions idmapd runs only in the "
308 		    "global zone");
309 		exit(1);
310 	}
311 
312 	/*
313 	 * Raise the fd limit to max
314 	 */
315 	if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
316 		idmapdlog(LOG_ERR, "getrlimit failed");
317 	} else if (rl.rlim_cur < rl.rlim_max) {
318 		rl.rlim_cur = rl.rlim_max;
319 		if (setrlimit(RLIMIT_NOFILE, &rl) != 0)
320 			idmapdlog(LOG_ERR,
321 			    "Unable to raise RLIMIT_NOFILE to %d",
322 			    rl.rlim_cur);
323 	}
324 
325 	(void) mutex_init(&_svcstate_lock, USYNC_THREAD, NULL);
326 
327 	if (_idmapdstate.daemon_mode == TRUE) {
328 		if (daemonize_start() < 0) {
329 			idmapdlog(LOG_ERR, "unable to daemonize");
330 			exit(-1);
331 		}
332 	} else
333 		(void) umask(0077);
334 
335 	idmap_init_tsd_key();
336 
337 	init_idmapd();
338 
339 	/* signal handlers that should run only after we're initialized */
340 	(void) sigset(SIGTERM, term_handler);
341 	(void) sigset(SIGUSR1, usr1_handler);
342 	(void) sigset(SIGHUP, idmap_cfg_hup_handler);
343 
344 	if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET,
345 	    DAEMON_UID, DAEMON_GID,
346 	    PRIV_PROC_AUDIT, PRIV_FILE_DAC_READ,
347 	    (char *)NULL) == -1) {
348 		idmapdlog(LOG_ERR, "unable to drop privileges");
349 		exit(1);
350 	}
351 
352 	__fini_daemon_priv(PRIV_PROC_FORK, PRIV_PROC_EXEC, PRIV_PROC_SESSION,
353 	    PRIV_FILE_LINK_ANY, PRIV_PROC_INFO, (char *)NULL);
354 
355 	if (_idmapdstate.daemon_mode == TRUE)
356 		daemonize_ready();
357 
358 	/* With doors RPC this just wastes this thread, oh well */
359 	svc_run();
360 	return (0);
361 }
362 
363 static void
364 init_idmapd()
365 {
366 	int	error;
367 	int	connmaxrec = IDMAP_MAX_DOOR_RPC;
368 
369 
370 	/* create directories as root and chown to daemon uid */
371 	if (create_directory(IDMAP_DBDIR, DAEMON_UID, DAEMON_GID) < 0)
372 		exit(1);
373 	if (create_directory(IDMAP_CACHEDIR, DAEMON_UID, DAEMON_GID) < 0)
374 		exit(1);
375 
376 	/*
377 	 * Set KRB5CCNAME in the environment.  See app_krb5_user_uid()
378 	 * for more details.  We blow away the existing one, if there is
379 	 * one.
380 	 */
381 	(void) unlink(IDMAP_CACHEDIR "/ccache");
382 	putenv("KRB5CCNAME=" IDMAP_CACHEDIR "/ccache");
383 
384 	if (sysinfo(SI_HOSTNAME, _idmapdstate.hostname,
385 	    sizeof (_idmapdstate.hostname)) == -1) {
386 		error = errno;
387 		idmapdlog(LOG_ERR, "unable to determine hostname, error: %d",
388 		    error);
389 		exit(1);
390 	}
391 
392 	if ((error = init_mapping_system()) < 0) {
393 		idmapdlog(LOG_ERR, "unable to initialize mapping system");
394 		exit(error < -2 ? SMF_EXIT_ERR_CONFIG : 1);
395 	}
396 
397 	(void) door_server_create(idmapd_door_thread_create);
398 	if ((error = pthread_key_create(&create_threads_key,
399 	    idmapd_door_thread_cleanup)) != 0) {
400 		idmapdlog(LOG_ERR, "unable to create threads key (%s)",
401 		    strerror(error));
402 		goto errout;
403 	}
404 
405 	xprt = svc_door_create(idmap_prog_1, IDMAP_PROG, IDMAP_V1, connmaxrec);
406 	if (xprt == NULL) {
407 		idmapdlog(LOG_ERR, "unable to create door RPC service");
408 		goto errout;
409 	}
410 
411 	if (!svc_control(xprt, SVCSET_CONNMAXREC, &connmaxrec)) {
412 		idmapdlog(LOG_ERR, "unable to limit RPC request size");
413 		goto errout;
414 	}
415 
416 	dfd = xprt->xp_fd;
417 
418 	if (dfd == -1) {
419 		idmapdlog(LOG_ERR, "unable to register door");
420 		goto errout;
421 	}
422 	if ((error = idmap_reg(dfd)) != 0) {
423 		idmapdlog(LOG_ERR, "unable to register door (%s)",
424 		    strerror(errno));
425 		goto errout;
426 	}
427 
428 	if ((error = allocids(_idmapdstate.new_eph_db,
429 	    8192, &_idmapdstate.next_uid,
430 	    8192, &_idmapdstate.next_gid)) != 0) {
431 		idmapdlog(LOG_ERR, "unable to allocate ephemeral IDs (%s)",
432 		    strerror(errno));
433 		_idmapdstate.next_uid = _idmapdstate.limit_uid = SENTINEL_PID;
434 		_idmapdstate.next_gid = _idmapdstate.limit_gid = SENTINEL_PID;
435 	} else {
436 		_idmapdstate.limit_uid = _idmapdstate.next_uid + 8192;
437 		_idmapdstate.limit_gid = _idmapdstate.next_gid + 8192;
438 	}
439 
440 	print_idmapdstate();
441 
442 	return;
443 
444 errout:
445 	fini_idmapd();
446 	exit(1);
447 }
448 
449 static void
450 fini_idmapd()
451 {
452 	idmap_unreg(dfd);
453 	fini_mapping_system();
454 	if (xprt != NULL)
455 		svc_destroy(xprt);
456 }
457 
458 static
459 const char *
460 get_fmri(void)
461 {
462 	static char *fmri = NULL;
463 	static char buf[60];
464 	char *s;
465 
466 	membar_consumer();
467 	s = fmri;
468 	if (s != NULL && *s == '\0')
469 		return (NULL);
470 	else if (s != NULL)
471 		return (s);
472 
473 	if ((s = getenv("SMF_FMRI")) == NULL || strlen(s) >= sizeof (buf))
474 		buf[0] = '\0';
475 	else
476 		(void) strlcpy(buf, s, sizeof (buf));
477 
478 	membar_producer();
479 	fmri = buf;
480 
481 	return (get_fmri());
482 }
483 
484 /*
485  * Wrappers for smf_degrade/restore_instance()
486  *
487  * smf_restore_instance() is too heavy duty to be calling every time we
488  * have a successful AD name<->SID lookup.
489  */
490 void
491 degrade_svc(int poke_discovery, const char *reason)
492 {
493 	const char *fmri;
494 
495 	/*
496 	 * If the config update thread is in a state where auto-discovery could
497 	 * be re-tried, then this will make it try it -- a sort of auto-refresh.
498 	 */
499 	if (poke_discovery)
500 		idmap_cfg_poke_updates();
501 
502 	membar_consumer();
503 	if (degraded)
504 		return;
505 
506 	idmapdlog(LOG_ERR, "Degraded operation (%s).  If you are running an "
507 	    "SMB server in workgroup mode, or if you're not running an SMB "
508 	    "server, then you can ignore this message", reason);
509 
510 	membar_producer();
511 	degraded = 1;
512 	idmap_log_degraded(B_TRUE);
513 
514 	if ((fmri = get_fmri()) != NULL)
515 		(void) smf_degrade_instance(fmri, 0);
516 }
517 
518 void
519 restore_svc(void)
520 {
521 	const char *fmri;
522 
523 	membar_consumer();
524 	if (!degraded)
525 		return;
526 
527 	if ((fmri = get_fmri()) == NULL)
528 		(void) smf_restore_instance(fmri);
529 
530 	membar_producer();
531 	degraded = 0;
532 	idmap_log_degraded(B_FALSE);
533 
534 	idmapdlog(LOG_NOTICE, "Normal operation restored");
535 }
536 
537 
538 /* printflike */
539 void
540 idmapdlog(int pri, const char *format, ...) {
541 	va_list args;
542 
543 	if (pri <= logstate.max_pri) {
544 		va_start(args, format);
545 		(void) vfprintf(stderr, format, args);
546 		(void) fprintf(stderr, "\n");
547 		va_end(args);
548 	}
549 
550 	/*
551 	 * We don't want to fill up the logs with useless messages when
552 	 * we're degraded, but we still want to log.
553 	 */
554 	if (logstate.degraded)
555 		pri = LOG_DEBUG;
556 
557 	if (logstate.write_syslog) {
558 		va_start(args, format);
559 		vsyslog(pri, format, args);
560 		va_end(args);
561 	}
562 }
563 
564 void
565 idmap_log_stderr(int pri)
566 {
567 	logstate.max_pri = pri;
568 }
569 
570 void
571 idmap_log_syslog(boolean_t what)
572 {
573 	logstate.write_syslog = what;
574 }
575 
576 void
577 idmap_log_degraded(boolean_t what)
578 {
579 	logstate.degraded = what;
580 }
581