xref: /titanic_41/usr/src/cmd/idmap/idmapd/idmapd.c (revision 49d3bc91e27cd871b950d56c01398fa2f2e12ab4)
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 #include <stdarg.h>
57 #include <assert.h>
58 #include <note.h>
59 
60 static void	term_handler(int);
61 static void	init_idmapd();
62 static void	fini_idmapd();
63 
64 idmapd_state_t	_idmapdstate;
65 
66 SVCXPRT *xprt = NULL;
67 
68 static int dfd = -1;		/* our door server fildes, for unregistration */
69 static boolean_t degraded = B_FALSE;
70 
71 
72 static uint32_t		num_threads = 0;
73 static pthread_key_t	create_threads_key;
74 static uint32_t		max_threads = 40;
75 
76 /*
77  * Server door thread start routine.
78  *
79  * Set a TSD value to the door thread. This enables the destructor to
80  * be called when this thread exits.
81  */
82 /*ARGSUSED*/
83 static void *
84 idmapd_door_thread_start(void *arg)
85 {
86 	static void *value = 0;
87 
88 	/*
89 	 * Disable cancellation to avoid memory leaks from not running
90 	 * the thread cleanup code.
91 	 */
92 	(void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
93 	(void) pthread_setspecific(create_threads_key, value);
94 	(void) door_return(NULL, 0, NULL, 0);
95 
96 	/* make lint happy */
97 	return (NULL);
98 }
99 
100 /*
101  * Server door threads creation
102  */
103 /*ARGSUSED*/
104 static void
105 idmapd_door_thread_create(door_info_t *dip)
106 {
107 	int		num;
108 	pthread_t	thread_id;
109 
110 	if ((num = atomic_inc_32_nv(&num_threads)) > max_threads) {
111 		atomic_dec_32(&num_threads);
112 		idmapdlog(LOG_DEBUG,
113 		    "thread creation refused - %d threads currently active",
114 		    num - 1);
115 		return;
116 	}
117 	(void) pthread_create(&thread_id, NULL, idmapd_door_thread_start, NULL);
118 	idmapdlog(LOG_DEBUG,
119 	    "created thread ID %d - %d threads currently active",
120 	    thread_id, num);
121 }
122 
123 /*
124  * Server door thread cleanup
125  */
126 /*ARGSUSED*/
127 static void
128 idmapd_door_thread_cleanup(void *arg)
129 {
130 	int num;
131 
132 	num = atomic_dec_32_nv(&num_threads);
133 	idmapdlog(LOG_DEBUG,
134 	    "exiting thread ID %d - %d threads currently active",
135 	    pthread_self(), num);
136 }
137 
138 /*
139  * This is needed for mech_krb5 -- we run as daemon, yes, but we want
140  * mech_krb5 to think we're root so it can get host/nodename.fqdn
141  * tickets for us so we can authenticate to AD as the machine account
142  * that we are.  For more details look at the entry point in mech_krb5
143  * corresponding to gss_init_sec_context().
144  *
145  * As a side effect of faking our effective UID to mech_krb5 we will use
146  * root's default ccache (/tmp/krb5cc_0).  But if that's created by
147  * another process then we won't have access to it: we run as daemon and
148  * keep PRIV_FILE_DAC_READ, which is insufficient to share the ccache
149  * with others.  We putenv("KRB5CCNAME=/var/run/idmap/ccache") in main()
150  * to avoid this issue; see main().
151  *
152  * Someday we'll have gss/mech_krb5 extensions for acquiring initiator
153  * creds with keytabs/raw keys, and someday we'll have extensions to
154  * libsasl to specify creds/name to use on the initiator side, and
155  * someday we'll have extensions to libldap to pass those through to
156  * libsasl.  Until then this interposer will have to do.
157  *
158  * Also, we have to tell lint to shut up: it thinks app_krb5_user_uid()
159  * is defined but not used.
160  */
161 /*LINTLIBRARY*/
162 uid_t
163 app_krb5_user_uid(void)
164 {
165 	return (0);
166 }
167 
168 /*ARGSUSED*/
169 static void
170 term_handler(int sig)
171 {
172 	idmapdlog(LOG_INFO, "Terminating.");
173 	fini_idmapd();
174 	_exit(0);
175 }
176 
177 /*ARGSUSED*/
178 static void
179 usr1_handler(int sig)
180 {
181 	NOTE(ARGUNUSED(sig))
182 	print_idmapdstate();
183 }
184 
185 static int pipe_fd = -1;
186 
187 static void
188 daemonize_ready(void)
189 {
190 	char data = '\0';
191 	/*
192 	 * wake the parent
193 	 */
194 	(void) write(pipe_fd, &data, 1);
195 	(void) close(pipe_fd);
196 }
197 
198 static int
199 daemonize_start(void)
200 {
201 	char	data;
202 	int	status;
203 	int	devnull;
204 	int	filedes[2];
205 	pid_t	pid;
206 
207 	(void) sigset(SIGPIPE, SIG_IGN);
208 	devnull = open("/dev/null", O_RDONLY);
209 	if (devnull < 0)
210 		return (-1);
211 	(void) dup2(devnull, 0);
212 	(void) dup2(2, 1);	/* stderr only */
213 	if (pipe(filedes) < 0)
214 		return (-1);
215 	if ((pid = fork1()) < 0)
216 		return (-1);
217 	if (pid != 0) {
218 		/*
219 		 * parent
220 		 */
221 		(void) close(filedes[1]);
222 		if (read(filedes[0], &data, 1) == 1) {
223 			/* presume success */
224 			_exit(0);
225 		}
226 		status = -1;
227 		(void) wait4(pid, &status, 0, NULL);
228 		if (WIFEXITED(status))
229 			_exit(WEXITSTATUS(status));
230 		else
231 			_exit(-1);
232 	}
233 
234 	/*
235 	 * child
236 	 */
237 	pipe_fd = filedes[1];
238 	(void) close(filedes[0]);
239 	(void) setsid();
240 	(void) umask(0077);
241 	openlog("idmap", LOG_PID, LOG_DAEMON);
242 
243 	return (0);
244 }
245 
246 
247 int
248 main(int argc, char **argv)
249 {
250 	int c;
251 	struct rlimit rl;
252 
253 	_idmapdstate.daemon_mode = TRUE;
254 	while ((c = getopt(argc, argv, "d")) != -1) {
255 		switch (c) {
256 			case 'd':
257 				_idmapdstate.daemon_mode = FALSE;
258 				break;
259 			default:
260 				(void) fprintf(stderr,
261 				    "Usage: /usr/lib/idmapd [-d]\n");
262 				return (SMF_EXIT_ERR_CONFIG);
263 		}
264 	}
265 
266 	/* set locale and domain for internationalization */
267 	(void) setlocale(LC_ALL, "");
268 	(void) textdomain(TEXT_DOMAIN);
269 
270 	idmap_set_logger(idmapdlog);
271 	adutils_set_logger(idmapdlog);
272 
273 	if (is_system_labeled() && getzoneid() != GLOBAL_ZONEID) {
274 		idmapdlog(LOG_ERR,
275 		    "with Trusted Extensions idmapd runs only in the "
276 		    "global zone");
277 		exit(1);
278 	}
279 
280 	/*
281 	 * Raise the fd limit to max
282 	 */
283 	if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
284 		idmapdlog(LOG_ERR, "getrlimit failed");
285 	} else if (rl.rlim_cur < rl.rlim_max) {
286 		rl.rlim_cur = rl.rlim_max;
287 		if (setrlimit(RLIMIT_NOFILE, &rl) != 0)
288 			idmapdlog(LOG_ERR,
289 			    "Unable to raise RLIMIT_NOFILE to %d",
290 			    rl.rlim_cur);
291 	}
292 
293 	(void) mutex_init(&_svcstate_lock, USYNC_THREAD, NULL);
294 
295 	if (_idmapdstate.daemon_mode == TRUE) {
296 		if (daemonize_start() < 0) {
297 			idmapdlog(LOG_ERR, "unable to daemonize");
298 			exit(-1);
299 		}
300 	} else
301 		(void) umask(0077);
302 
303 	idmap_init_tsd_key();
304 
305 	init_idmapd();
306 
307 	/* signal handlers that should run only after we're initialized */
308 	(void) sigset(SIGTERM, term_handler);
309 	(void) sigset(SIGUSR1, usr1_handler);
310 	(void) sigset(SIGHUP, idmap_cfg_hup_handler);
311 
312 	if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET,
313 	    DAEMON_UID, DAEMON_GID,
314 	    PRIV_PROC_AUDIT, PRIV_FILE_DAC_READ,
315 	    (char *)NULL) == -1) {
316 		idmapdlog(LOG_ERR, "unable to drop privileges");
317 		exit(1);
318 	}
319 
320 	__fini_daemon_priv(PRIV_PROC_FORK, PRIV_PROC_EXEC, PRIV_PROC_SESSION,
321 	    PRIV_FILE_LINK_ANY, PRIV_PROC_INFO, (char *)NULL);
322 
323 	if (_idmapdstate.daemon_mode == TRUE)
324 		daemonize_ready();
325 
326 	/* With doors RPC this just wastes this thread, oh well */
327 	svc_run();
328 	return (0);
329 }
330 
331 static void
332 init_idmapd()
333 {
334 	int	error;
335 	int	connmaxrec = IDMAP_MAX_DOOR_RPC;
336 
337 
338 	/* create directories as root and chown to daemon uid */
339 	if (create_directory(IDMAP_DBDIR, DAEMON_UID, DAEMON_GID) < 0)
340 		exit(1);
341 	if (create_directory(IDMAP_CACHEDIR, DAEMON_UID, DAEMON_GID) < 0)
342 		exit(1);
343 
344 	/*
345 	 * Set KRB5CCNAME in the environment.  See app_krb5_user_uid()
346 	 * for more details.  We blow away the existing one, if there is
347 	 * one.
348 	 */
349 	(void) unlink(IDMAP_CACHEDIR "/ccache");
350 	(void) putenv("KRB5CCNAME=" IDMAP_CACHEDIR "/ccache");
351 
352 	if (sysinfo(SI_HOSTNAME, _idmapdstate.hostname,
353 	    sizeof (_idmapdstate.hostname)) == -1) {
354 		error = errno;
355 		idmapdlog(LOG_ERR, "unable to determine hostname, error: %d",
356 		    error);
357 		exit(1);
358 	}
359 
360 	if ((error = init_mapping_system()) < 0) {
361 		idmapdlog(LOG_ERR, "unable to initialize mapping system");
362 		exit(error < -2 ? SMF_EXIT_ERR_CONFIG : 1);
363 	}
364 
365 	(void) door_server_create(idmapd_door_thread_create);
366 	if ((error = pthread_key_create(&create_threads_key,
367 	    idmapd_door_thread_cleanup)) != 0) {
368 		idmapdlog(LOG_ERR, "unable to create threads key (%s)",
369 		    strerror(error));
370 		goto errout;
371 	}
372 
373 	xprt = svc_door_create(idmap_prog_1, IDMAP_PROG, IDMAP_V1, connmaxrec);
374 	if (xprt == NULL) {
375 		idmapdlog(LOG_ERR, "unable to create door RPC service");
376 		goto errout;
377 	}
378 
379 	if (!svc_control(xprt, SVCSET_CONNMAXREC, &connmaxrec)) {
380 		idmapdlog(LOG_ERR, "unable to limit RPC request size");
381 		goto errout;
382 	}
383 
384 	dfd = xprt->xp_fd;
385 
386 	if (dfd == -1) {
387 		idmapdlog(LOG_ERR, "unable to register door");
388 		goto errout;
389 	}
390 	if ((error = __idmap_reg(dfd)) != 0) {
391 		idmapdlog(LOG_ERR, "unable to register door (%s)",
392 		    strerror(errno));
393 		goto errout;
394 	}
395 
396 	if ((error = allocids(_idmapdstate.new_eph_db,
397 	    8192, &_idmapdstate.next_uid,
398 	    8192, &_idmapdstate.next_gid)) != 0) {
399 		idmapdlog(LOG_ERR, "unable to allocate ephemeral IDs (%s)",
400 		    strerror(errno));
401 		_idmapdstate.next_uid = IDMAP_SENTINEL_PID;
402 		_idmapdstate.limit_uid = IDMAP_SENTINEL_PID;
403 		_idmapdstate.next_gid = IDMAP_SENTINEL_PID;
404 		_idmapdstate.limit_gid = IDMAP_SENTINEL_PID;
405 	} else {
406 		_idmapdstate.limit_uid = _idmapdstate.next_uid + 8192;
407 		_idmapdstate.limit_gid = _idmapdstate.next_gid + 8192;
408 	}
409 
410 	if (DBG(CONFIG, 1))
411 		print_idmapdstate();
412 
413 	return;
414 
415 errout:
416 	fini_idmapd();
417 	exit(1);
418 }
419 
420 static void
421 fini_idmapd()
422 {
423 	(void) __idmap_unreg(dfd);
424 	fini_mapping_system();
425 	if (xprt != NULL)
426 		svc_destroy(xprt);
427 }
428 
429 static
430 const char *
431 get_fmri(void)
432 {
433 	static char *fmri = NULL;
434 	static char buf[60];
435 	char *s;
436 
437 	membar_consumer();
438 	s = fmri;
439 	if (s != NULL && *s == '\0')
440 		return (NULL);
441 	else if (s != NULL)
442 		return (s);
443 
444 	if ((s = getenv("SMF_FMRI")) == NULL || strlen(s) >= sizeof (buf))
445 		buf[0] = '\0';
446 	else
447 		(void) strlcpy(buf, s, sizeof (buf));
448 
449 	membar_producer();
450 	fmri = buf;
451 
452 	return (get_fmri());
453 }
454 
455 /*
456  * Wrappers for smf_degrade/restore_instance()
457  *
458  * smf_restore_instance() is too heavy duty to be calling every time we
459  * have a successful AD name<->SID lookup.
460  */
461 void
462 degrade_svc(int poke_discovery, const char *reason)
463 {
464 	const char *fmri;
465 
466 	membar_consumer();
467 	if (degraded)
468 		return;
469 
470 	idmapdlog(LOG_ERR, "Degraded operation (%s).", reason);
471 
472 	membar_producer();
473 	degraded = B_TRUE;
474 
475 	if ((fmri = get_fmri()) != NULL)
476 		(void) smf_degrade_instance(fmri, 0);
477 
478 	/*
479 	 * If the config update thread is in a state where auto-discovery could
480 	 * be re-tried, then this will make it try it -- a sort of auto-refresh.
481 	 */
482 	if (poke_discovery)
483 		idmap_cfg_poke_updates();
484 }
485 
486 void
487 restore_svc(void)
488 {
489 	const char *fmri;
490 
491 	membar_consumer();
492 	if (!degraded)
493 		return;
494 
495 	if ((fmri = get_fmri()) == NULL)
496 		(void) smf_restore_instance(fmri);
497 
498 	membar_producer();
499 	degraded = B_FALSE;
500 
501 	idmapdlog(LOG_NOTICE, "Normal operation restored");
502 }
503 
504 
505 /* printflike */
506 void
507 idmapdlog(int pri, const char *format, ...) {
508 	va_list args;
509 
510 	va_start(args, format);
511 	(void) vfprintf(stderr, format, args);
512 	(void) fprintf(stderr, "\n");
513 	va_end(args);
514 
515 	/*
516 	 * We don't want to fill up the logs with useless messages when
517 	 * we're degraded, but we still want to log.
518 	 */
519 	if (degraded)
520 		pri = LOG_DEBUG;
521 
522 	va_start(args, format);
523 	vsyslog(pri, format, args);
524 	va_end(args);
525 }
526 
527 static void
528 trace_str(nvlist_t *entry, char *n1, char *n2, char *str)
529 {
530 	char name[IDMAP_TRACE_NAME_MAX+1];	/* Max used is only about 11 */
531 
532 	(void) strlcpy(name, n1, sizeof (name));
533 	if (n2 != NULL)
534 		(void) strlcat(name, n2, sizeof (name));
535 
536 	(void) nvlist_add_string(entry, name, str);
537 }
538 
539 static void
540 trace_int(nvlist_t *entry, char *n1, char *n2, int64_t i)
541 {
542 	char name[IDMAP_TRACE_NAME_MAX+1];	/* Max used is only about 11 */
543 
544 	(void) strlcpy(name, n1, sizeof (name));
545 	if (n2 != NULL)
546 		(void) strlcat(name, n2, sizeof (name));
547 
548 	(void) nvlist_add_int64(entry, name, i);
549 }
550 
551 static void
552 trace_sid(nvlist_t *entry, char *n1, char *n2, idmap_sid *sid)
553 {
554 	char *str;
555 
556 	(void) asprintf(&str, "%s-%u", sid->prefix, sid->rid);
557 	if (str == NULL)
558 		return;
559 
560 	trace_str(entry, n1, n2, str);
561 	free(str);
562 }
563 
564 static void
565 trace_id(nvlist_t *entry, char *fromto, idmap_id *id, char *name, char *domain)
566 {
567 	trace_int(entry, fromto, IDMAP_TRACE_TYPE, (int64_t)id->idtype);
568 	if (IS_ID_SID(*id)) {
569 		if (name != NULL) {
570 			char *str;
571 
572 			(void) asprintf(&str, "%s%s%s", name,
573 			    domain == NULL ? "" : "@",
574 			    domain == NULL ? "" : domain);
575 			if (str != NULL) {
576 				trace_str(entry, fromto, IDMAP_TRACE_NAME, str);
577 				free(str);
578 			}
579 		}
580 		if (id->idmap_id_u.sid.prefix != NULL) {
581 			trace_sid(entry, fromto, IDMAP_TRACE_SID,
582 			    &id->idmap_id_u.sid);
583 		}
584 	} else if (IS_ID_POSIX(*id)) {
585 		if (name != NULL)
586 			trace_str(entry, fromto, IDMAP_TRACE_NAME, name);
587 		if (id->idmap_id_u.uid != IDMAP_SENTINEL_PID) {
588 			trace_int(entry, fromto, IDMAP_TRACE_UNIXID,
589 			    (int64_t)id->idmap_id_u.uid);
590 		}
591 	}
592 }
593 
594 /*
595  * Record a trace event.  TRACE() has already decided whether or not
596  * tracing is required; what we do here is collect the data and send it
597  * to its destination - to the trace log in the response, if
598  * IDMAP_REQ_FLG_TRACE is set, and to the SMF service log, if debug/mapping
599  * is greater than zero.
600  */
601 int
602 trace(idmap_mapping *req, idmap_id_res *res, char *fmt, ...)
603 {
604 	va_list va;
605 	char *buf;
606 	int err;
607 	nvlist_t *entry;
608 
609 	assert(req != NULL);
610 	assert(res != NULL);
611 
612 	err = nvlist_alloc(&entry, NV_UNIQUE_NAME, 0);
613 	if (err != 0) {
614 		(void) fprintf(stderr, "trace nvlist_alloc(entry):  %s\n",
615 		    strerror(err));
616 		return (0);
617 	}
618 
619 	trace_id(entry, "from", &req->id1, req->id1name, req->id1domain);
620 	trace_id(entry, "to", &res->id, req->id2name, req->id2domain);
621 
622 	if (IDMAP_ERROR(res->retcode)) {
623 		trace_int(entry, IDMAP_TRACE_ERROR, NULL,
624 		    (int64_t)res->retcode);
625 	}
626 
627 	va_start(va, fmt);
628 	(void) vasprintf(&buf, fmt, va);
629 	va_end(va);
630 	if (buf != NULL) {
631 		trace_str(entry, IDMAP_TRACE_MESSAGE, NULL, buf);
632 		free(buf);
633 	}
634 
635 	if (DBG(MAPPING, 1))
636 		idmap_trace_print_1(stderr, "", entry);
637 
638 	if (req->flag & IDMAP_REQ_FLG_TRACE) {
639 		/* Lazily allocate the trace list */
640 		if (res->info.trace == NULL) {
641 			err = nvlist_alloc(&res->info.trace, 0, 0);
642 			if (err != 0) {
643 				res->info.trace = NULL; /* just in case */
644 				(void) fprintf(stderr,
645 				    "trace nvlist_alloc(trace):  %s\n",
646 				    strerror(err));
647 				nvlist_free(entry);
648 				return (0);
649 			}
650 		}
651 		(void) nvlist_add_nvlist(res->info.trace, "", entry);
652 		/* Note that entry is copied, so we must still free our copy */
653 	}
654 
655 	nvlist_free(entry);
656 
657 	return (0);
658 }
659