xref: /titanic_41/usr/src/cmd/idmap/idmapd/idmapd.c (revision d4660949aa62dd6a963f4913b7120b383cf473c4)
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 	print_idmapdstate();
190 	_idmapdstate.debug_mode = saved_debug_mode;
191 }
192 
193 static int pipe_fd = -1;
194 
195 static void
196 daemonize_ready(void)
197 {
198 	char data = '\0';
199 	/*
200 	 * wake the parent
201 	 */
202 	(void) write(pipe_fd, &data, 1);
203 	(void) close(pipe_fd);
204 }
205 
206 static int
207 daemonize_start(void)
208 {
209 	char	data;
210 	int	status;
211 	int	devnull;
212 	int	filedes[2];
213 	pid_t	pid;
214 
215 	(void) sigset(SIGPIPE, SIG_IGN);
216 	devnull = open("/dev/null", O_RDONLY);
217 	if (devnull < 0)
218 		return (-1);
219 	(void) dup2(devnull, 0);
220 	(void) dup2(2, 1);	/* stderr only */
221 	if (pipe(filedes) < 0)
222 		return (-1);
223 	if ((pid = fork1()) < 0)
224 		return (-1);
225 	if (pid != 0) {
226 		/*
227 		 * parent
228 		 */
229 		(void) close(filedes[1]);
230 		if (read(filedes[0], &data, 1) == 1) {
231 			/* presume success */
232 			_exit(0);
233 		}
234 		status = -1;
235 		(void) wait4(pid, &status, 0, NULL);
236 		if (WIFEXITED(status))
237 			_exit(WEXITSTATUS(status));
238 		else
239 			_exit(-1);
240 	}
241 
242 	/*
243 	 * child
244 	 */
245 	pipe_fd = filedes[1];
246 	(void) close(filedes[0]);
247 	(void) setsid();
248 	(void) umask(0077);
249 	openlog("idmap", LOG_PID, LOG_DAEMON);
250 	return (0);
251 }
252 
253 
254 int
255 main(int argc, char **argv)
256 {
257 	int c;
258 	struct rlimit rl;
259 
260 	_idmapdstate.daemon_mode = TRUE;
261 	_idmapdstate.debug_mode = FALSE;
262 	while ((c = getopt(argc, argv, "d")) != -1) {
263 		switch (c) {
264 			case 'd':
265 				_idmapdstate.daemon_mode = FALSE;
266 				break;
267 			default:
268 				fprintf(stderr, "Usage: /usr/lib/idmapd");
269 				return (SMF_EXIT_ERR_CONFIG);
270 				break;
271 		}
272 	}
273 
274 	/* set locale and domain for internationalization */
275 	(void) setlocale(LC_ALL, "");
276 	(void) textdomain(TEXT_DOMAIN);
277 
278 	if (is_system_labeled() && getzoneid() != GLOBAL_ZONEID) {
279 		idmapdlog(LOG_ERR,
280 		    "with Trusted Extensions idmapd runs only in the "
281 		    "global zone");
282 		exit(1);
283 	}
284 
285 	/*
286 	 * Raise the fd limit to max
287 	 */
288 	if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
289 		idmapdlog(LOG_ERR, "getrlimit failed");
290 	} else if (rl.rlim_cur < rl.rlim_max) {
291 		rl.rlim_cur = rl.rlim_max;
292 		if (setrlimit(RLIMIT_NOFILE, &rl) != 0)
293 			idmapdlog(LOG_ERR,
294 			    "Unable to raise RLIMIT_NOFILE to %d",
295 			    rl.rlim_cur);
296 	}
297 
298 	(void) mutex_init(&_svcstate_lock, USYNC_THREAD, NULL);
299 
300 	if (_idmapdstate.daemon_mode == TRUE) {
301 		if (daemonize_start() < 0) {
302 			(void) idmapdlog(LOG_ERR, "unable to daemonize");
303 			exit(-1);
304 		}
305 	} else
306 		(void) umask(0077);
307 
308 	idmap_init_tsd_key();
309 
310 	init_idmapd();
311 
312 	/* signal handlers that should run only after we're initialized */
313 	(void) sigset(SIGTERM, term_handler);
314 	(void) sigset(SIGUSR1, usr1_handler);
315 	(void) sigset(SIGHUP, idmap_cfg_hup_handler);
316 
317 	if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET,
318 	    DAEMON_UID, DAEMON_GID,
319 	    PRIV_PROC_AUDIT, PRIV_FILE_DAC_READ,
320 	    (char *)NULL) == -1) {
321 		idmapdlog(LOG_ERR, "unable to drop privileges");
322 		exit(1);
323 	}
324 
325 	__fini_daemon_priv(PRIV_PROC_FORK, PRIV_PROC_EXEC, PRIV_PROC_SESSION,
326 	    PRIV_FILE_LINK_ANY, PRIV_PROC_INFO, (char *)NULL);
327 
328 	if (_idmapdstate.daemon_mode == TRUE)
329 		daemonize_ready();
330 
331 	/* With doors RPC this just wastes this thread, oh well */
332 	svc_run();
333 	return (0);
334 }
335 
336 static void
337 init_idmapd()
338 {
339 	int	error;
340 	int	connmaxrec = IDMAP_MAX_DOOR_RPC;
341 
342 
343 	/* create directories as root and chown to daemon uid */
344 	if (create_directory(IDMAP_DBDIR, DAEMON_UID, DAEMON_GID) < 0)
345 		exit(1);
346 	if (create_directory(IDMAP_CACHEDIR, DAEMON_UID, DAEMON_GID) < 0)
347 		exit(1);
348 
349 	/*
350 	 * Set KRB5CCNAME in the environment.  See app_krb5_user_uid()
351 	 * for more details.  We blow away the existing one, if there is
352 	 * one.
353 	 */
354 	(void) unlink(IDMAP_CACHEDIR "/ccache");
355 	putenv("KRB5CCNAME=" IDMAP_CACHEDIR "/ccache");
356 
357 	if (sysinfo(SI_HOSTNAME, _idmapdstate.hostname,
358 	    sizeof (_idmapdstate.hostname)) == -1) {
359 		error = errno;
360 		idmapdlog(LOG_ERR, "unable to determine hostname, error: %d",
361 		    error);
362 		exit(1);
363 	}
364 
365 	if ((error = init_mapping_system()) < 0) {
366 		idmapdlog(LOG_ERR, "unable to initialize mapping system");
367 		exit(error < -2 ? SMF_EXIT_ERR_CONFIG : 1);
368 	}
369 
370 	(void) door_server_create(idmapd_door_thread_create);
371 	if ((error = pthread_key_create(&create_threads_key,
372 	    idmapd_door_thread_cleanup)) != 0) {
373 		idmapdlog(LOG_ERR, "unable to create threads key (%s)",
374 		    strerror(error));
375 		goto errout;
376 	}
377 
378 	xprt = svc_door_create(idmap_prog_1, IDMAP_PROG, IDMAP_V1, connmaxrec);
379 	if (xprt == NULL) {
380 		idmapdlog(LOG_ERR, "unable to create door RPC service");
381 		goto errout;
382 	}
383 
384 	if (!svc_control(xprt, SVCSET_CONNMAXREC, &connmaxrec)) {
385 		idmapdlog(LOG_ERR, "unable to limit RPC request size");
386 		goto errout;
387 	}
388 
389 	dfd = xprt->xp_fd;
390 
391 	if (dfd == -1) {
392 		idmapdlog(LOG_ERR, "unable to register door");
393 		goto errout;
394 	}
395 	if ((error = idmap_reg(dfd)) != 0) {
396 		idmapdlog(LOG_ERR, "unable to register door (%s)",
397 		    strerror(errno));
398 		goto errout;
399 	}
400 
401 	if ((error = allocids(_idmapdstate.new_eph_db,
402 	    8192, &_idmapdstate.next_uid,
403 	    8192, &_idmapdstate.next_gid)) != 0) {
404 		idmapdlog(LOG_ERR, "unable to allocate ephemeral IDs (%s)",
405 		    strerror(errno));
406 		_idmapdstate.next_uid = _idmapdstate.limit_uid = SENTINEL_PID;
407 		_idmapdstate.next_gid = _idmapdstate.limit_gid = SENTINEL_PID;
408 	} else {
409 		_idmapdstate.limit_uid = _idmapdstate.next_uid + 8192;
410 		_idmapdstate.limit_gid = _idmapdstate.next_gid + 8192;
411 	}
412 
413 	print_idmapdstate();
414 
415 	return;
416 
417 errout:
418 	fini_idmapd();
419 	exit(1);
420 }
421 
422 static void
423 fini_idmapd()
424 {
425 	idmap_unreg(dfd);
426 	fini_mapping_system();
427 	if (xprt != NULL)
428 		svc_destroy(xprt);
429 }
430 
431 static
432 const char *
433 get_fmri(void)
434 {
435 	static char *fmri = NULL;
436 	static char buf[60];
437 	char *s;
438 
439 	membar_consumer();
440 	s = fmri;
441 	if (s != NULL && *s == '\0')
442 		return (NULL);
443 	else if (s != NULL)
444 		return (s);
445 
446 	if ((s = getenv("SMF_FMRI")) == NULL || strlen(s) >= sizeof (buf))
447 		buf[0] = '\0';
448 	else
449 		(void) strlcpy(buf, s, sizeof (buf));
450 
451 	membar_producer();
452 	fmri = buf;
453 
454 	return (get_fmri());
455 }
456 
457 /*
458  * Wrappers for smf_degrade/restore_instance()
459  *
460  * smf_restore_instance() is too heavy duty to be calling every time we
461  * have a successful AD name<->SID lookup.
462  */
463 void
464 degrade_svc(int poke_discovery, const char *reason)
465 {
466 	const char *fmri;
467 
468 	/*
469 	 * If the config update thread is in a state where auto-discovery could
470 	 * be re-tried, then this will make it try it -- a sort of auto-refresh.
471 	 */
472 	if (poke_discovery)
473 		idmap_cfg_poke_updates();
474 
475 	membar_consumer();
476 	if (degraded)
477 		return;
478 
479 	idmapdlog(LOG_ERR, "Degraded operation (%s).  If you are running an "
480 	    "SMB server in workgroup mode, or if you're not running an SMB "
481 	    "server, then you can ignore this message", reason);
482 
483 	membar_producer();
484 	degraded = 1;
485 
486 	if ((fmri = get_fmri()) != NULL)
487 		(void) smf_degrade_instance(fmri, 0);
488 }
489 
490 void
491 restore_svc(void)
492 {
493 	const char *fmri;
494 
495 	membar_consumer();
496 	if (!degraded)
497 		return;
498 
499 	if ((fmri = get_fmri()) == NULL)
500 		(void) smf_restore_instance(fmri);
501 
502 	membar_producer();
503 	degraded = 0;
504 	idmapdlog(LOG_NOTICE, "Normal operation restored");
505 }
506 
507 void
508 idmapdlog(int pri, const char *format, ...)
509 {
510 	va_list args;
511 
512 	va_start(args, format);
513 
514 	if (_idmapdstate.debug_mode == TRUE ||
515 	    _idmapdstate.daemon_mode == FALSE) {
516 		(void) vfprintf(stderr, format, args);
517 		(void) fprintf(stderr, "\n");
518 	}
519 
520 	/*
521 	 * We don't want to fill up the logs with useless messages when
522 	 * we're degraded, but we still want to log.
523 	 */
524 	if (degraded)
525 		pri = LOG_DEBUG;
526 
527 	(void) vsyslog(pri, format, args);
528 	va_end(args);
529 }
530