xref: /illumos-gate/usr/src/cmd/idmap/idmapd/idmapd.c (revision 6bb6b5762ca4b17cd5fb3c6c123f17489d5635aa)
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  * Copyright 2014 Nexenta Systems, Inc.  All rights reserved.
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 #include <stdarg.h>
58 #include <assert.h>
59 #include <note.h>
60 
61 #define	CBUFSIZ 26	/* ctime(3c) */
62 
63 static void	term_handler(int);
64 static void	init_idmapd();
65 static void	fini_idmapd();
66 
67 /* The DC Locator lives inside idmap (for now). */
68 extern void	init_dc_locator(void);
69 extern void	fini_dc_locator(void);
70 
71 idmapd_state_t	_idmapdstate;
72 
73 SVCXPRT *xprt = NULL;
74 
75 static int dfd = -1;		/* our door server fildes, for unregistration */
76 static boolean_t degraded = B_FALSE;
77 
78 
79 static uint32_t		num_threads = 0;
80 static pthread_key_t	create_threads_key;
81 static uint32_t		max_threads = 40;
82 
83 /*
84  * Server door thread start routine.
85  *
86  * Set a TSD value to the door thread. This enables the destructor to
87  * be called when this thread exits.
88  */
89 /*ARGSUSED*/
90 static void *
91 idmapd_door_thread_start(void *arg)
92 {
93 	static void *value = 0;
94 
95 	/*
96 	 * Disable cancellation to avoid memory leaks from not running
97 	 * the thread cleanup code.
98 	 */
99 	(void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
100 	(void) pthread_setspecific(create_threads_key, value);
101 	(void) door_return(NULL, 0, NULL, 0);
102 
103 	/* make lint happy */
104 	return (NULL);
105 }
106 
107 /*
108  * Server door threads creation
109  */
110 /*ARGSUSED*/
111 static void
112 idmapd_door_thread_create(door_info_t *dip)
113 {
114 	int		num;
115 	pthread_t	thread_id;
116 
117 	if ((num = atomic_inc_32_nv(&num_threads)) > max_threads) {
118 		atomic_dec_32(&num_threads);
119 		idmapdlog(LOG_DEBUG,
120 		    "thread creation refused - %d threads currently active",
121 		    num - 1);
122 		return;
123 	}
124 	(void) pthread_create(&thread_id, NULL, idmapd_door_thread_start, NULL);
125 	idmapdlog(LOG_DEBUG,
126 	    "created thread ID %d - %d threads currently active",
127 	    thread_id, num);
128 }
129 
130 /*
131  * Server door thread cleanup
132  */
133 /*ARGSUSED*/
134 static void
135 idmapd_door_thread_cleanup(void *arg)
136 {
137 	int num;
138 
139 	num = atomic_dec_32_nv(&num_threads);
140 	idmapdlog(LOG_DEBUG,
141 	    "exiting thread ID %d - %d threads currently active",
142 	    pthread_self(), num);
143 }
144 
145 /*
146  * This is needed for mech_krb5 -- we run as daemon, yes, but we want
147  * mech_krb5 to think we're root so it can get host/nodename.fqdn
148  * tickets for us so we can authenticate to AD as the machine account
149  * that we are.  For more details look at the entry point in mech_krb5
150  * corresponding to gss_init_sec_context().
151  *
152  * As a side effect of faking our effective UID to mech_krb5 we will use
153  * root's default ccache (/tmp/krb5cc_0).  But if that's created by
154  * another process then we won't have access to it: we run as daemon and
155  * keep PRIV_FILE_DAC_READ, which is insufficient to share the ccache
156  * with others.  We putenv("KRB5CCNAME=/var/run/idmap/ccache") in main()
157  * to avoid this issue; see main().
158  *
159  * Someday we'll have gss/mech_krb5 extensions for acquiring initiator
160  * creds with keytabs/raw keys, and someday we'll have extensions to
161  * libsasl to specify creds/name to use on the initiator side, and
162  * someday we'll have extensions to libldap to pass those through to
163  * libsasl.  Until then this interposer will have to do.
164  *
165  * Also, we have to tell lint to shut up: it thinks app_krb5_user_uid()
166  * is defined but not used.
167  */
168 /*LINTLIBRARY*/
169 uid_t
170 app_krb5_user_uid(void)
171 {
172 	return (0);
173 }
174 
175 /*ARGSUSED*/
176 static void
177 term_handler(int sig)
178 {
179 	idmapdlog(LOG_INFO, "Terminating.");
180 	fini_dc_locator();
181 	fini_idmapd();
182 	_exit(0);
183 }
184 
185 /*ARGSUSED*/
186 static void
187 usr1_handler(int sig)
188 {
189 	NOTE(ARGUNUSED(sig))
190 	print_idmapdstate();
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 
251 	return (0);
252 }
253 
254 
255 int
256 main(int argc, char **argv)
257 {
258 	int c;
259 	struct rlimit rl;
260 
261 	if (rwlock_init(&_idmapdstate.rwlk_cfg, USYNC_THREAD, NULL) != 0)
262 		return (-1);
263 	if (mutex_init(&_idmapdstate.addisc_lk, USYNC_THREAD, NULL) != 0)
264 		return (-1);
265 	if (cond_init(&_idmapdstate.addisc_cv, USYNC_THREAD, NULL) != 0)
266 		return (-1);
267 
268 	_idmapdstate.daemon_mode = TRUE;
269 	while ((c = getopt(argc, argv, "d")) != -1) {
270 		switch (c) {
271 			case 'd':
272 				_idmapdstate.daemon_mode = FALSE;
273 				break;
274 			default:
275 				(void) fprintf(stderr,
276 				    "Usage: /usr/lib/idmapd [-d]\n");
277 				return (SMF_EXIT_ERR_CONFIG);
278 		}
279 	}
280 
281 	/* set locale and domain for internationalization */
282 	(void) setlocale(LC_ALL, "");
283 	(void) textdomain(TEXT_DOMAIN);
284 
285 	idmap_set_logger(idmapdlog);
286 	adutils_set_logger(idmapdlog);
287 
288 	if (is_system_labeled() && getzoneid() != GLOBAL_ZONEID) {
289 		idmapdlog(LOG_ERR,
290 		    "with Trusted Extensions idmapd runs only in the "
291 		    "global zone");
292 		exit(1);
293 	}
294 
295 	/*
296 	 * Raise the fd limit to max
297 	 */
298 	if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
299 		idmapdlog(LOG_ERR, "getrlimit failed");
300 	} else if (rl.rlim_cur < rl.rlim_max) {
301 		rl.rlim_cur = rl.rlim_max;
302 		if (setrlimit(RLIMIT_NOFILE, &rl) != 0)
303 			idmapdlog(LOG_ERR,
304 			    "Unable to raise RLIMIT_NOFILE to %d",
305 			    rl.rlim_cur);
306 	}
307 
308 	(void) mutex_init(&_svcstate_lock, USYNC_THREAD, NULL);
309 
310 	if (_idmapdstate.daemon_mode == TRUE) {
311 		if (daemonize_start() < 0) {
312 			idmapdlog(LOG_ERR, "unable to daemonize");
313 			exit(-1);
314 		}
315 	} else
316 		(void) umask(0077);
317 
318 	idmap_init_tsd_key();
319 
320 	init_idmapd();
321 	init_dc_locator();
322 
323 	/* signal handlers that should run only after we're initialized */
324 	(void) sigset(SIGTERM, term_handler);
325 	(void) sigset(SIGUSR1, usr1_handler);
326 	(void) sigset(SIGHUP, idmap_cfg_hup_handler);
327 
328 	if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET,
329 	    DAEMON_UID, DAEMON_GID,
330 	    PRIV_PROC_AUDIT, PRIV_FILE_DAC_READ,
331 	    (char *)NULL) == -1) {
332 		idmapdlog(LOG_ERR, "unable to drop privileges");
333 		exit(1);
334 	}
335 
336 	__fini_daemon_priv(PRIV_PROC_FORK, PRIV_PROC_EXEC, PRIV_PROC_SESSION,
337 	    PRIV_FILE_LINK_ANY, PRIV_PROC_INFO, (char *)NULL);
338 
339 	if (_idmapdstate.daemon_mode == TRUE)
340 		daemonize_ready();
341 
342 	/* With doors RPC this just wastes this thread, oh well */
343 	svc_run();
344 	return (0);
345 }
346 
347 static void
348 init_idmapd()
349 {
350 	int	error;
351 	int	connmaxrec = IDMAP_MAX_DOOR_RPC;
352 
353 
354 	/* create directories as root and chown to daemon uid */
355 	if (create_directory(IDMAP_DBDIR, DAEMON_UID, DAEMON_GID) < 0)
356 		exit(1);
357 	if (create_directory(IDMAP_CACHEDIR, DAEMON_UID, DAEMON_GID) < 0)
358 		exit(1);
359 
360 	/*
361 	 * Set KRB5CCNAME in the environment.  See app_krb5_user_uid()
362 	 * for more details.  We blow away the existing one, if there is
363 	 * one.
364 	 */
365 	(void) unlink(IDMAP_CACHEDIR "/ccache");
366 	(void) putenv("KRB5CCNAME=" IDMAP_CACHEDIR "/ccache");
367 	(void) putenv("MS_INTEROP=1");
368 
369 	if (sysinfo(SI_HOSTNAME, _idmapdstate.hostname,
370 	    sizeof (_idmapdstate.hostname)) == -1) {
371 		error = errno;
372 		idmapdlog(LOG_ERR, "unable to determine hostname, error: %d",
373 		    error);
374 		exit(1);
375 	}
376 
377 	if ((error = init_mapping_system()) < 0) {
378 		idmapdlog(LOG_ERR, "unable to initialize mapping system");
379 		exit(error < -2 ? SMF_EXIT_ERR_CONFIG : 1);
380 	}
381 
382 	(void) door_server_create(idmapd_door_thread_create);
383 	if ((error = pthread_key_create(&create_threads_key,
384 	    idmapd_door_thread_cleanup)) != 0) {
385 		idmapdlog(LOG_ERR, "unable to create threads key (%s)",
386 		    strerror(error));
387 		goto errout;
388 	}
389 
390 	xprt = svc_door_create(idmap_prog_1, IDMAP_PROG, IDMAP_V1, connmaxrec);
391 	if (xprt == NULL) {
392 		idmapdlog(LOG_ERR, "unable to create door RPC service");
393 		goto errout;
394 	}
395 
396 	if (!svc_control(xprt, SVCSET_CONNMAXREC, &connmaxrec)) {
397 		idmapdlog(LOG_ERR, "unable to limit RPC request size");
398 		goto errout;
399 	}
400 
401 	dfd = xprt->xp_fd;
402 
403 	if (dfd == -1) {
404 		idmapdlog(LOG_ERR, "unable to register door");
405 		goto errout;
406 	}
407 	if ((error = __idmap_reg(dfd)) != 0) {
408 		idmapdlog(LOG_ERR, "unable to register door (%s)",
409 		    strerror(errno));
410 		goto errout;
411 	}
412 
413 	if ((error = allocids(_idmapdstate.new_eph_db,
414 	    8192, &_idmapdstate.next_uid,
415 	    8192, &_idmapdstate.next_gid)) != 0) {
416 		idmapdlog(LOG_ERR, "unable to allocate ephemeral IDs (%s)",
417 		    strerror(errno));
418 		_idmapdstate.next_uid = IDMAP_SENTINEL_PID;
419 		_idmapdstate.limit_uid = IDMAP_SENTINEL_PID;
420 		_idmapdstate.next_gid = IDMAP_SENTINEL_PID;
421 		_idmapdstate.limit_gid = IDMAP_SENTINEL_PID;
422 	} else {
423 		_idmapdstate.limit_uid = _idmapdstate.next_uid + 8192;
424 		_idmapdstate.limit_gid = _idmapdstate.next_gid + 8192;
425 	}
426 
427 	if (DBG(CONFIG, 1))
428 		print_idmapdstate();
429 
430 	return;
431 
432 errout:
433 	fini_idmapd();
434 	exit(1);
435 }
436 
437 static void
438 fini_idmapd()
439 {
440 	(void) __idmap_unreg(dfd);
441 	fini_mapping_system();
442 	if (xprt != NULL)
443 		svc_destroy(xprt);
444 }
445 
446 static
447 const char *
448 get_fmri(void)
449 {
450 	static char *fmri = NULL;
451 	static char buf[60];
452 	char *s;
453 
454 	membar_consumer();
455 	s = fmri;
456 	if (s != NULL && *s == '\0')
457 		return (NULL);
458 	else if (s != NULL)
459 		return (s);
460 
461 	if ((s = getenv("SMF_FMRI")) == NULL || strlen(s) >= sizeof (buf))
462 		buf[0] = '\0';
463 	else
464 		(void) strlcpy(buf, s, sizeof (buf));
465 
466 	membar_producer();
467 	fmri = buf;
468 
469 	return (get_fmri());
470 }
471 
472 /*
473  * Wrappers for smf_degrade/restore_instance()
474  *
475  * smf_restore_instance() is too heavy duty to be calling every time we
476  * have a successful AD name<->SID lookup.
477  */
478 void
479 degrade_svc(int poke_discovery, const char *reason)
480 {
481 	const char *fmri;
482 
483 	membar_consumer();
484 	if (degraded)
485 		return;
486 
487 	idmapdlog(LOG_ERR, "Degraded operation (%s).", reason);
488 
489 	membar_producer();
490 	degraded = B_TRUE;
491 
492 	if ((fmri = get_fmri()) != NULL)
493 		(void) smf_degrade_instance(fmri, 0);
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 
503 void
504 restore_svc(void)
505 {
506 	const char *fmri;
507 
508 	membar_consumer();
509 	if (!degraded)
510 		return;
511 
512 	if ((fmri = get_fmri()) == NULL)
513 		(void) smf_restore_instance(fmri);
514 
515 	membar_producer();
516 	degraded = B_FALSE;
517 
518 	idmapdlog(LOG_NOTICE, "Normal operation restored");
519 }
520 
521 
522 /* printflike */
523 void
524 idmapdlog(int pri, const char *format, ...) {
525 	static time_t prev_ts;
526 	va_list args;
527 	char cbuf[CBUFSIZ];
528 	time_t ts;
529 
530 	ts = time(NULL);
531 	if (prev_ts != ts) {
532 		prev_ts = ts;
533 		/* NB: cbuf has \n */
534 		(void) fprintf(stderr, "@ %s",
535 		    ctime_r(&ts, cbuf, sizeof (cbuf)));
536 	}
537 
538 	va_start(args, format);
539 	(void) vfprintf(stderr, format, args);
540 	(void) fprintf(stderr, "\n");
541 	va_end(args);
542 
543 	/*
544 	 * We don't want to fill up the logs with useless messages when
545 	 * we're degraded, but we still want to log.
546 	 */
547 	if (degraded)
548 		pri = LOG_DEBUG;
549 
550 	va_start(args, format);
551 	vsyslog(pri, format, args);
552 	va_end(args);
553 }
554 
555 static void
556 trace_str(nvlist_t *entry, char *n1, char *n2, char *str)
557 {
558 	char name[IDMAP_TRACE_NAME_MAX+1];	/* Max used is only about 11 */
559 
560 	(void) strlcpy(name, n1, sizeof (name));
561 	if (n2 != NULL)
562 		(void) strlcat(name, n2, sizeof (name));
563 
564 	(void) nvlist_add_string(entry, name, str);
565 }
566 
567 static void
568 trace_int(nvlist_t *entry, char *n1, char *n2, int64_t i)
569 {
570 	char name[IDMAP_TRACE_NAME_MAX+1];	/* Max used is only about 11 */
571 
572 	(void) strlcpy(name, n1, sizeof (name));
573 	if (n2 != NULL)
574 		(void) strlcat(name, n2, sizeof (name));
575 
576 	(void) nvlist_add_int64(entry, name, i);
577 }
578 
579 static void
580 trace_sid(nvlist_t *entry, char *n1, char *n2, idmap_sid *sid)
581 {
582 	char *str;
583 
584 	(void) asprintf(&str, "%s-%u", sid->prefix, sid->rid);
585 	if (str == NULL)
586 		return;
587 
588 	trace_str(entry, n1, n2, str);
589 	free(str);
590 }
591 
592 static void
593 trace_id(nvlist_t *entry, char *fromto, idmap_id *id, char *name, char *domain)
594 {
595 	trace_int(entry, fromto, IDMAP_TRACE_TYPE, (int64_t)id->idtype);
596 	if (IS_ID_SID(*id)) {
597 		if (name != NULL) {
598 			char *str;
599 
600 			(void) asprintf(&str, "%s%s%s", name,
601 			    domain == NULL ? "" : "@",
602 			    domain == NULL ? "" : domain);
603 			if (str != NULL) {
604 				trace_str(entry, fromto, IDMAP_TRACE_NAME, str);
605 				free(str);
606 			}
607 		}
608 		if (id->idmap_id_u.sid.prefix != NULL) {
609 			trace_sid(entry, fromto, IDMAP_TRACE_SID,
610 			    &id->idmap_id_u.sid);
611 		}
612 	} else if (IS_ID_POSIX(*id)) {
613 		if (name != NULL)
614 			trace_str(entry, fromto, IDMAP_TRACE_NAME, name);
615 		if (id->idmap_id_u.uid != IDMAP_SENTINEL_PID) {
616 			trace_int(entry, fromto, IDMAP_TRACE_UNIXID,
617 			    (int64_t)id->idmap_id_u.uid);
618 		}
619 	}
620 }
621 
622 /*
623  * Record a trace event.  TRACE() has already decided whether or not
624  * tracing is required; what we do here is collect the data and send it
625  * to its destination - to the trace log in the response, if
626  * IDMAP_REQ_FLG_TRACE is set, and to the SMF service log, if debug/mapping
627  * is greater than zero.
628  */
629 int
630 trace(idmap_mapping *req, idmap_id_res *res, char *fmt, ...)
631 {
632 	va_list va;
633 	char *buf;
634 	int err;
635 	nvlist_t *entry;
636 
637 	assert(req != NULL);
638 	assert(res != NULL);
639 
640 	err = nvlist_alloc(&entry, NV_UNIQUE_NAME, 0);
641 	if (err != 0) {
642 		(void) fprintf(stderr, "trace nvlist_alloc(entry):  %s\n",
643 		    strerror(err));
644 		return (0);
645 	}
646 
647 	trace_id(entry, "from", &req->id1, req->id1name, req->id1domain);
648 	trace_id(entry, "to", &res->id, req->id2name, req->id2domain);
649 
650 	if (IDMAP_ERROR(res->retcode)) {
651 		trace_int(entry, IDMAP_TRACE_ERROR, NULL,
652 		    (int64_t)res->retcode);
653 	}
654 
655 	va_start(va, fmt);
656 	(void) vasprintf(&buf, fmt, va);
657 	va_end(va);
658 	if (buf != NULL) {
659 		trace_str(entry, IDMAP_TRACE_MESSAGE, NULL, buf);
660 		free(buf);
661 	}
662 
663 	if (DBG(MAPPING, 1))
664 		idmap_trace_print_1(stderr, "", entry);
665 
666 	if (req->flag & IDMAP_REQ_FLG_TRACE) {
667 		/* Lazily allocate the trace list */
668 		if (res->info.trace == NULL) {
669 			err = nvlist_alloc(&res->info.trace, 0, 0);
670 			if (err != 0) {
671 				res->info.trace = NULL; /* just in case */
672 				(void) fprintf(stderr,
673 				    "trace nvlist_alloc(trace):  %s\n",
674 				    strerror(err));
675 				nvlist_free(entry);
676 				return (0);
677 			}
678 		}
679 		(void) nvlist_add_nvlist(res->info.trace, "", entry);
680 		/* Note that entry is copied, so we must still free our copy */
681 	}
682 
683 	nvlist_free(entry);
684 
685 	return (0);
686 }
687