xref: /illumos-gate/usr/src/cmd/fs.d/nfs/nfsmapid/nfsmapid.c (revision 4f364e7c95ee7fd9d5bbeddc1940e92405bb0e72)
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 2006 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 #include <stdio.h>
29 #include <stdlib.h>
30 #include <stropts.h>
31 #include <signal.h>
32 #include <fcntl.h>
33 #include <door.h>
34 #include <thread.h>
35 #include <priv_utils.h>
36 #include <locale.h>
37 #include <strings.h>
38 #include <syslog.h>
39 #include <unistd.h>
40 #include <nfs/nfs4.h>
41 #include <nfs/nfsid_map.h>
42 #include <rpcsvc/daemon_utils.h>
43 #include <arpa/nameser.h>
44 #include <nfs/nfssys.h>
45 #include <errno.h>
46 #include <pwd.h>
47 #include <grp.h>
48 
49 extern struct group *_uncached_getgrgid_r(gid_t, struct group *, char *, int);
50 extern struct group *_uncached_getgrnam_r(const char *, struct group *,
51     char *, int);
52 extern struct passwd *_uncached_getpwuid_r(uid_t, struct passwd *, char *, int);
53 extern struct passwd *_uncached_getpwnam_r(const char *, struct passwd *,
54     char *, int);
55 
56 /*
57  * seconds to cache nfsmapid domain info
58  */
59 #define	NFSCFG_DEFAULT_DOMAIN_TMOUT	(5 * 60)
60 #define	NFSMAPID_DOOR   "/var/run/nfsmapid_door"
61 
62 extern void	nfsmapid_func(void *, char *, size_t, door_desc_t *, uint_t);
63 
64 extern void	check_domain(int);
65 extern void	idmap_kcall(int);
66 extern void	open_diag_file(void);
67 
68 size_t		pwd_buflen = 0;
69 size_t		grp_buflen = 0;
70 thread_t	sig_thread;
71 static char	*MyName;
72 
73 /*
74  * nfscfg_domain_tmout is used by nfsv4-test scripts to query
75  * the nfsmapid daemon for the proper timeout. Don't delete !
76  */
77 time_t		 nfscfg_domain_tmout = NFSCFG_DEFAULT_DOMAIN_TMOUT;
78 
79 /*
80  * Processing for daemonization
81  */
82 static void
83 daemonize(void)
84 {
85 	switch (fork()) {
86 		case -1:
87 			perror("nfsmapid: can't fork");
88 			exit(2);
89 			/* NOTREACHED */
90 		case 0:		/* child */
91 			break;
92 
93 		default:	/* parent */
94 			_exit(0);
95 	}
96 
97 	if (chdir("/") < 0)
98 		syslog(LOG_ERR, gettext("chdir /: %m"));
99 
100 	/*
101 	 * Close stdin, stdout, and stderr.
102 	 * Open again to redirect input+output
103 	 */
104 	(void) close(0);
105 	(void) close(1);
106 	(void) close(2);
107 	(void) open("/dev/null", O_RDONLY);
108 	(void) open("/dev/null", O_WRONLY);
109 	(void) dup(1);
110 	(void) setsid();
111 }
112 
113 /* ARGSUSED */
114 static void *
115 sig_handler(void *arg)
116 {
117 	siginfo_t	si;
118 	sigset_t	sigset;
119 	struct timespec	tmout;
120 	int		ret;
121 
122 	tmout.tv_nsec = 0;
123 	(void) sigemptyset(&sigset);
124 	(void) sigaddset(&sigset, SIGHUP);
125 	(void) sigaddset(&sigset, SIGTERM);
126 #ifdef	DEBUG
127 	(void) sigaddset(&sigset, SIGINT);
128 #endif
129 
130 	/*CONSTCOND*/
131 	while (1) {
132 		tmout.tv_sec = nfscfg_domain_tmout;
133 		if ((ret = sigtimedwait(&sigset, &si, &tmout)) != 0) {
134 			/*
135 			 * EAGAIN: no signals arrived during timeout.
136 			 * check/update config files and continue.
137 			 */
138 			if (ret == -1 && errno == EAGAIN) {
139 				check_domain(0);
140 				continue;
141 			}
142 
143 			switch (si.si_signo) {
144 				case SIGHUP:
145 					check_domain(1);
146 					break;
147 #ifdef DEBUG
148 				case SIGINT:
149 					exit(0);
150 #endif
151 				case SIGTERM:
152 				default:
153 					exit(si.si_signo);
154 			}
155 		}
156 	}
157 	/*NOTREACHED*/
158 	return (NULL);
159 }
160 
161 /*
162  * Thread initialization. Mask out all signals we want our
163  * signal handler to handle for us from any other threads.
164  */
165 static void
166 thr_init(void)
167 {
168 	sigset_t sigset;
169 	long	 thr_flags = (THR_NEW_LWP|THR_DAEMON|THR_SUSPENDED);
170 
171 	/*
172 	 * Before we kick off any other threads, mask out desired
173 	 * signals from main thread so that any subsequent threads
174 	 * don't receive said signals.
175 	 */
176 	(void) thr_sigsetmask(NULL, NULL, &sigset);
177 	(void) sigaddset(&sigset, SIGHUP);
178 	(void) sigaddset(&sigset, SIGTERM);
179 #ifdef	DEBUG
180 	(void) sigaddset(&sigset, SIGINT);
181 #endif
182 	(void) thr_sigsetmask(SIG_SETMASK, &sigset, NULL);
183 
184 	/*
185 	 * Create the signal handler thread suspended ! We do things
186 	 * this way at setup time to minimize the probability of
187 	 * introducing any race conditions _if_ the process were to
188 	 * get a SIGHUP signal while creating a new DNS query thread
189 	 * in get_dns_txt_domain().
190 	 */
191 	if (thr_create(NULL, 0, sig_handler, 0, thr_flags, &sig_thread)) {
192 		syslog(LOG_ERR,
193 			gettext("Failed to create signal handling thread"));
194 		exit(4);
195 	}
196 }
197 
198 static void
199 daemon_init(void)
200 {
201 	struct passwd pwd;
202 	struct group grp;
203 	char *pwd_buf;
204 	char *grp_buf;
205 
206 	/*
207 	 * passwd/group reentrant interfaces limits
208 	 */
209 	pwd_buflen = (size_t)sysconf(_SC_GETPW_R_SIZE_MAX);
210 	grp_buflen = (size_t)sysconf(_SC_GETGR_R_SIZE_MAX);
211 
212 	/*
213 	 * MT initialization is done first so that if there is the
214 	 * need to fire an additional thread to continue to query
215 	 * DNS, that thread is started off with the main thread's
216 	 * sigmask.
217 	 */
218 	thr_init();
219 
220 	/*
221 	 * Determine nfsmapid domain.
222 	 */
223 	check_domain(0);
224 
225 	/*
226 	 * In the case of nfsmapid running diskless, it is important
227 	 * to get the initial connections to the nameservices
228 	 * established to prevent problems like opening a devfs
229 	 * node to contact a nameservice being blocked by the
230 	 * resolution of an active devfs lookup.
231 	 * First issue a set*ent to "open" the databases and then
232 	 * get an entry and finally lookup a bogus entry to trigger
233 	 * any lazy opens.
234 	 */
235 	setpwent();
236 	setgrent();
237 	(void) getpwent();
238 	(void) getgrent();
239 	if ((pwd_buf = malloc(pwd_buflen)) == NULL)
240 		return;
241 
242 	(void) _uncached_getpwnam_r("NF21dmvP", &pwd, pwd_buf, pwd_buflen);
243 	(void) _uncached_getpwuid_r(1181794, &pwd, pwd_buf, pwd_buflen);
244 
245 	if ((grp_buf = realloc(pwd_buf, grp_buflen)) == NULL) {
246 		free(pwd_buf);
247 		return;
248 	}
249 
250 	(void) _uncached_getgrnam_r("NF21dmvP", &grp, grp_buf, grp_buflen);
251 	(void) _uncached_getgrgid_r(1181794, &grp, grp_buf, grp_buflen);
252 	free(grp_buf);
253 }
254 
255 static int
256 start_svcs(void)
257 {
258 	int doorfd = -1;
259 #ifdef DEBUG
260 	int dfd;
261 #endif
262 
263 	if ((doorfd = door_create(nfsmapid_func, NULL,
264 	    DOOR_REFUSE_DESC | DOOR_NO_CANCEL)) == -1) {
265 		syslog(LOG_ERR, "Unable to create door: %m\n");
266 		return (1);
267 	}
268 
269 #ifdef DEBUG
270 	/*
271 	 * Create a file system path for the door
272 	 */
273 	if ((dfd = open(NFSMAPID_DOOR, O_RDWR|O_CREAT|O_TRUNC,
274 				S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH)) == -1) {
275 		syslog(LOG_ERR, "Unable to open %s: %m\n", NFSMAPID_DOOR);
276 		(void) close(doorfd);
277 		return (1);
278 	}
279 
280 	/*
281 	 * Clean up any stale associations
282 	 */
283 	(void) fdetach(NFSMAPID_DOOR);
284 
285 	/*
286 	 * Register in namespace to pass to the kernel to door_ki_open
287 	 */
288 	if (fattach(doorfd, NFSMAPID_DOOR) == -1) {
289 		syslog(LOG_ERR, "Unable to fattach door: %m\n");
290 		(void) close(dfd);
291 		(void) close(doorfd);
292 		return (1);
293 	}
294 	(void) close(dfd);
295 #endif
296 
297 	/*
298 	 * Now that we're actually running, go
299 	 * ahead and flush the kernel flushes
300 	 * Pass door name to kernel for door_ki_open
301 	 */
302 	idmap_kcall(doorfd);
303 
304 	/*
305 	 * Wait for incoming calls
306 	 */
307 	/*CONSTCOND*/
308 	while (1)
309 		(void) pause();
310 
311 	syslog(LOG_ERR, gettext("Door server exited"));
312 	return (10);
313 }
314 
315 /* ARGSUSED */
316 int
317 main(int argc, char **argv)
318 {
319 	MyName = argv[0];
320 
321 	(void) setlocale(LC_ALL, "");
322 	(void) textdomain(TEXT_DOMAIN);
323 
324 	/* _check_services() framework setup */
325 	(void) _create_daemon_lock(NFSMAPID, DAEMON_UID, DAEMON_GID);
326 
327 	/*
328 	 * Open diag file in /var/run while we've got the perms
329 	 */
330 	open_diag_file();
331 
332 	/*
333 	 * Initialize the daemon to basic + sys_nfs
334 	 */
335 #ifndef	DEBUG
336 	if (__init_daemon_priv(PU_RESETGROUPS|PU_CLEARLIMITSET,
337 	    DAEMON_UID, DAEMON_GID, PRIV_SYS_NFS, (char *)NULL) == -1) {
338 		(void) fprintf(stderr, gettext("%s PRIV_SYS_NFS privilege "
339 			"missing\n"), MyName);
340 		exit(1);
341 	}
342 #endif
343 
344 	/*
345 	 * Take away a subset of basic, while this is not the absolute
346 	 * minimum, it is important that it is unique among other
347 	 * daemons to insure that we get a unique cred that will
348 	 * result in a unique open_owner.  If not, we run the risk
349 	 * of a diskless client deadlocking with a thread holding
350 	 * the open_owner seqid lock while upcalling the daemon.
351 	 * XXX This restriction will go away once we stop holding
352 	 * XXX open_owner lock across rfscalls!
353 	 */
354 	(void) priv_set(PRIV_OFF, PRIV_PERMITTED,
355 		PRIV_FILE_LINK_ANY, PRIV_PROC_SESSION,
356 		(char *)NULL);
357 
358 #ifndef DEBUG
359 	daemonize();
360 	switch (_enter_daemon_lock(NFSMAPID)) {
361 		case 0:
362 			break;
363 
364 		case -1:
365 			syslog(LOG_ERR, "error locking for %s: %s", NFSMAPID,
366 			    strerror(errno));
367 			exit(3);
368 
369 		default:
370 			/* daemon was already running */
371 			exit(0);
372 	}
373 #endif
374 	openlog(MyName, LOG_PID | LOG_NDELAY, LOG_DAEMON);
375 
376 	/* Initialize daemon subsystems */
377 	daemon_init();
378 
379 	/* start services */
380 	return (start_svcs());
381 }
382