xref: /illumos-gate/usr/src/cmd/idmap/idmapd/idmapd.c (revision b779d3e04b6c453fc372ef1dbf8df01a8c2e10dc)
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 
59 static void	term_handler(int);
60 static void	init_idmapd();
61 static void	fini_idmapd();
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  * This is needed for mech_krb5 -- we run as daemon, yes, but we want
77  * mech_krb5 to think we're root so it can get host/nodename.fqdn
78  * tickets for us so we can authenticate to AD as the machine account
79  * that we are.  For more details look at the entry point in mech_krb5
80  * corresponding to gss_init_sec_context().
81  *
82  * As a side effect of faking our effective UID to mech_krb5 we will use
83  * root's default ccache (/tmp/krb5cc_0).  But if that's created by
84  * another process then we won't have access to it: we run as daemon and
85  * keep PRIV_FILE_DAC_READ, which is insufficient to share the ccache
86  * with others.  We putenv("KRB5CCNAME=/var/run/idmap/ccache") in main()
87  * to avoid this issue; see main().
88  *
89  * Someday we'll have gss/mech_krb5 extensions for acquiring initiator
90  * creds with keytabs/raw keys, and someday we'll have extensions to
91  * libsasl to specify creds/name to use on the initiator side, and
92  * someday we'll have extensions to libldap to pass those through to
93  * libsasl.  Until then this interposer will have to do.
94  *
95  * Also, we have to tell lint to shut up: it thinks app_krb5_user_uid()
96  * is defined but not used.
97  */
98 /*LINTLIBRARY*/
99 uid_t
100 app_krb5_user_uid(void)
101 {
102 	return (0);
103 }
104 
105 /*ARGSUSED*/
106 static void
107 term_handler(int sig)
108 {
109 	idmapdlog(LOG_INFO, "Terminating.");
110 	fini_idmapd();
111 	_exit(0);
112 }
113 
114 /*ARGSUSED*/
115 static void
116 usr1_handler(int sig)
117 {
118 	bool_t saved_debug_mode = _idmapdstate.debug_mode;
119 
120 	_idmapdstate.debug_mode = TRUE;
121 	print_idmapdstate();
122 	_idmapdstate.debug_mode = saved_debug_mode;
123 }
124 
125 static int pipe_fd = -1;
126 
127 static void
128 daemonize_ready(void)
129 {
130 	char data = '\0';
131 	/*
132 	 * wake the parent
133 	 */
134 	(void) write(pipe_fd, &data, 1);
135 	(void) close(pipe_fd);
136 }
137 
138 static int
139 daemonize_start(void)
140 {
141 	char	data;
142 	int	status;
143 	int	devnull;
144 	int	filedes[2];
145 	pid_t	pid;
146 
147 	(void) sigset(SIGPIPE, SIG_IGN);
148 	devnull = open("/dev/null", O_RDONLY);
149 	if (devnull < 0)
150 		return (-1);
151 	(void) dup2(devnull, 0);
152 	(void) dup2(2, 1);	/* stderr only */
153 	if (pipe(filedes) < 0)
154 		return (-1);
155 	if ((pid = fork1()) < 0)
156 		return (-1);
157 	if (pid != 0) {
158 		/*
159 		 * parent
160 		 */
161 		(void) close(filedes[1]);
162 		if (read(filedes[0], &data, 1) == 1) {
163 			/* presume success */
164 			_exit(0);
165 		}
166 		status = -1;
167 		(void) wait4(pid, &status, 0, NULL);
168 		if (WIFEXITED(status))
169 			_exit(WEXITSTATUS(status));
170 		else
171 			_exit(-1);
172 	}
173 
174 	/*
175 	 * child
176 	 */
177 	pipe_fd = filedes[1];
178 	(void) close(filedes[0]);
179 	(void) setsid();
180 	(void) umask(0077);
181 	openlog("idmap", LOG_PID, LOG_DAEMON);
182 	return (0);
183 }
184 
185 
186 int
187 main(int argc, char **argv)
188 {
189 	int c;
190 
191 	_idmapdstate.daemon_mode = TRUE;
192 	_idmapdstate.debug_mode = FALSE;
193 	while ((c = getopt(argc, argv, "d")) != -1) {
194 		switch (c) {
195 			case 'd':
196 				_idmapdstate.daemon_mode = FALSE;
197 				break;
198 			default:
199 				fprintf(stderr, "Usage: /usr/lib/idmapd");
200 				return (SMF_EXIT_ERR_CONFIG);
201 				break;
202 		}
203 	}
204 
205 	/* set locale and domain for internationalization */
206 	(void) setlocale(LC_ALL, "");
207 	(void) textdomain(TEXT_DOMAIN);
208 
209 	if (is_system_labeled() && getzoneid() != GLOBAL_ZONEID) {
210 		idmapdlog(LOG_ERR,
211 		    "with Trusted Extensions idmapd runs only in the "
212 		    "global zone");
213 		exit(1);
214 	}
215 
216 	(void) mutex_init(&_svcstate_lock, USYNC_THREAD, NULL);
217 
218 	if (_idmapdstate.daemon_mode == TRUE) {
219 		if (daemonize_start() < 0) {
220 			(void) idmapdlog(LOG_ERR, "unable to daemonize");
221 			exit(-1);
222 		}
223 	} else
224 		(void) umask(0077);
225 
226 	idmap_init_tsd_key();
227 
228 	init_idmapd();
229 
230 	/* signal handlers that should run only after we're initialized */
231 	(void) sigset(SIGTERM, term_handler);
232 	(void) sigset(SIGUSR1, usr1_handler);
233 	(void) sigset(SIGHUP, idmap_cfg_hup_handler);
234 
235 	if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET,
236 	    DAEMON_UID, DAEMON_GID,
237 	    PRIV_PROC_AUDIT, PRIV_FILE_DAC_READ,
238 	    (char *)NULL) == -1) {
239 		idmapdlog(LOG_ERR, "unable to drop privileges");
240 		exit(1);
241 	}
242 
243 	__fini_daemon_priv(PRIV_PROC_FORK, PRIV_PROC_EXEC, PRIV_PROC_SESSION,
244 	    PRIV_FILE_LINK_ANY, PRIV_PROC_INFO, (char *)NULL);
245 
246 	if (_idmapdstate.daemon_mode == TRUE)
247 		daemonize_ready();
248 
249 	/* With doors RPC this just wastes this thread, oh well */
250 	svc_run();
251 	return (0);
252 }
253 
254 static void
255 init_idmapd()
256 {
257 	int	error;
258 	int connmaxrec = IDMAP_MAX_DOOR_RPC;
259 
260 	/* create directories as root and chown to daemon uid */
261 	if (create_directory(IDMAP_DBDIR, DAEMON_UID, DAEMON_GID) < 0)
262 		exit(1);
263 	if (create_directory(IDMAP_CACHEDIR, DAEMON_UID, DAEMON_GID) < 0)
264 		exit(1);
265 
266 	/*
267 	 * Set KRB5CCNAME in the environment.  See app_krb5_user_uid()
268 	 * for more details.  We blow away the existing one, if there is
269 	 * one.
270 	 */
271 	(void) unlink(IDMAP_CACHEDIR "/ccache");
272 	putenv("KRB5CCNAME=" IDMAP_CACHEDIR "/ccache");
273 
274 	if (sysinfo(SI_HOSTNAME, _idmapdstate.hostname,
275 	    sizeof (_idmapdstate.hostname)) == -1) {
276 		error = errno;
277 		idmapdlog(LOG_ERR, "unable to determine hostname, error: %d",
278 		    error);
279 		exit(1);
280 	}
281 
282 	if ((error = init_mapping_system()) < 0) {
283 		idmapdlog(LOG_ERR, "unable to initialize mapping system");
284 		exit(error < -2 ? SMF_EXIT_ERR_CONFIG : 1);
285 	}
286 
287 	xprt = svc_door_create(idmap_prog_1, IDMAP_PROG, IDMAP_V1, connmaxrec);
288 	if (xprt == NULL) {
289 		idmapdlog(LOG_ERR, "unable to create door RPC service");
290 		goto errout;
291 	}
292 
293 	if (!svc_control(xprt, SVCSET_CONNMAXREC, &connmaxrec)) {
294 		idmapdlog(LOG_ERR, "unable to limit RPC request size");
295 		goto errout;
296 	}
297 
298 	dfd = xprt->xp_fd;
299 
300 	if (dfd == -1) {
301 		idmapdlog(LOG_ERR, "unable to register door");
302 		goto errout;
303 	}
304 	if ((error = idmap_reg(dfd)) != 0) {
305 		idmapdlog(LOG_ERR, "unable to register door (%s)",
306 		    strerror(errno));
307 		goto errout;
308 	}
309 
310 	if ((error = allocids(_idmapdstate.new_eph_db,
311 	    8192, &_idmapdstate.next_uid,
312 	    8192, &_idmapdstate.next_gid)) != 0) {
313 		idmapdlog(LOG_ERR, "unable to allocate ephemeral IDs (%s)",
314 		    strerror(errno));
315 		_idmapdstate.next_uid = _idmapdstate.limit_uid = SENTINEL_PID;
316 		_idmapdstate.next_gid = _idmapdstate.limit_gid = SENTINEL_PID;
317 	} else {
318 		_idmapdstate.limit_uid = _idmapdstate.next_uid + 8192;
319 		_idmapdstate.limit_gid = _idmapdstate.next_gid + 8192;
320 	}
321 
322 	print_idmapdstate();
323 
324 	return;
325 
326 errout:
327 	fini_idmapd();
328 	exit(1);
329 }
330 
331 static void
332 fini_idmapd()
333 {
334 	idmap_unreg(dfd);
335 	fini_mapping_system();
336 	if (xprt != NULL)
337 		svc_destroy(xprt);
338 }
339 
340 static
341 const char *
342 get_fmri(void)
343 {
344 	static char *fmri = NULL;
345 	static char buf[60];
346 	char *s;
347 
348 	membar_consumer();
349 	s = fmri;
350 	if (s != NULL && *s == '\0')
351 		return (NULL);
352 	else if (s != NULL)
353 		return (s);
354 
355 	if ((s = getenv("SMF_FMRI")) == NULL || strlen(s) >= sizeof (buf))
356 		buf[0] = '\0';
357 	else
358 		(void) strlcpy(buf, s, sizeof (buf));
359 
360 	membar_producer();
361 	fmri = buf;
362 
363 	return (get_fmri());
364 }
365 
366 /*
367  * Wrappers for smf_degrade/restore_instance()
368  *
369  * smf_restore_instance() is too heavy duty to be calling every time we
370  * have a successful AD name<->SID lookup.
371  */
372 void
373 degrade_svc(const char *reason)
374 {
375 	const char *fmri;
376 
377 	/*
378 	 * If the config update thread is in a state where auto-discovery could
379 	 * be re-tried, then this will make it try it -- a sort of auto-refresh.
380 	 */
381 	idmap_cfg_poke_updates();
382 
383 	membar_consumer();
384 	if (degraded)
385 		return;
386 	membar_producer();
387 	degraded = 1;
388 
389 	if ((fmri = get_fmri()) != NULL)
390 		(void) smf_degrade_instance(fmri, 0);
391 
392 	idmapdlog(LOG_ERR, "Degraded operation (%s)", reason);
393 }
394 
395 void
396 restore_svc(void)
397 {
398 	const char *fmri;
399 
400 	membar_consumer();
401 	if (!degraded)
402 		return;
403 
404 	if ((fmri = get_fmri()) == NULL)
405 		(void) smf_restore_instance(fmri);
406 
407 	membar_producer();
408 	degraded = 0;
409 	idmapdlog(LOG_INFO, "Normal operation restored");
410 }
411 
412 void
413 idmapdlog(int pri, const char *format, ...)
414 {
415 	va_list args;
416 
417 	va_start(args, format);
418 
419 	if (_idmapdstate.debug_mode == TRUE ||
420 	    _idmapdstate.daemon_mode == FALSE) {
421 		(void) vfprintf(stderr, format, args);
422 		(void) fprintf(stderr, "\n");
423 	}
424 
425 	/*
426 	 * We don't want to fill up the logs with useless messages when
427 	 * we're degraded, but we still want to log.
428 	 */
429 	if (degraded)
430 		pri = LOG_DEBUG;
431 
432 	(void) vsyslog(pri, format, args);
433 	va_end(args);
434 }
435