xref: /titanic_41/usr/src/cmd/fs.d/nfs/umount/umount.c (revision bf56214c0556fa6864189c826d39dbe156bb22a0)
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * University Copyright- Copyright (c) 1982, 1986, 1988
31  * The Regents of the University of California
32  * All Rights Reserved
33  *
34  * University Acknowledgment- Portions of this document are derived from
35  * software developed by the University of California, Berkeley, and its
36  * contributors.
37  */
38 
39 #pragma ident	"%Z%%M%	%I%	%E% SMI"
40 
41 /*
42  * nfs umount
43  */
44 
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <stdarg.h>
49 #include <signal.h>
50 #include <unistd.h>
51 #include <kstat.h>
52 #include <rpc/rpc.h>
53 #include <sys/mnttab.h>
54 #include <sys/mount.h>
55 #include <sys/mntent.h>
56 #include <nfs/nfs.h>
57 #include <nfs/nfs_clnt.h>
58 #include <rpcsvc/mount.h>
59 #include <errno.h>
60 #include <locale.h>
61 #include <fslib.h>
62 #include <priv.h>
63 #include <tsol/label.h>
64 #include "replica.h"
65 
66 #define	RET_OK	0
67 #define	RET_ERR	32
68 
69 #ifdef __STDC__
70 static void pr_err(const char *fmt, ...);
71 #else
72 static void pr_err(char *fmt, va_dcl);
73 #endif
74 static	void	usage();
75 static	int	nfs_unmount(char *, int);
76 static	void	inform_server(char *, char *, bool_t);
77 static	struct extmnttab *mnttab_find();
78 extern int __clnt_bindresvport();
79 
80 static	int is_v4_mount(struct extmnttab *);
81 
82 static char *myname;
83 static char typename[64];
84 
85 int
86 main(int argc, char *argv[])
87 {
88 	extern int optind;
89 	int c;
90 	int umnt_flag = 0;
91 
92 	(void) setlocale(LC_ALL, "");
93 
94 #if !defined(TEXT_DOMAIN)
95 #define	TEXT_DOMAIN "SYS_TEST"
96 #endif
97 	(void) textdomain(TEXT_DOMAIN);
98 
99 	myname = strrchr(argv[0], '/');
100 	myname = myname ? myname+1 : argv[0];
101 	(void) sprintf(typename, "nfs %s", myname);
102 	argv[0] = typename;
103 
104 	/*
105 	 * Set options
106 	 */
107 	while ((c = getopt(argc, argv, "f")) != EOF) {
108 		switch (c) {
109 		case 'f':
110 			umnt_flag |= MS_FORCE; /* forced unmount is desired */
111 			break;
112 		default:
113 			usage();
114 			exit(RET_ERR);
115 		}
116 	}
117 	if (argc - optind != 1) {
118 		usage();
119 		exit(RET_ERR);
120 	}
121 
122 	if (!priv_ineffect(PRIV_SYS_MOUNT) ||
123 	    !priv_ineffect(PRIV_NET_PRIVADDR)) {
124 		pr_err(gettext("insufficient privileges\n"));
125 		exit(RET_ERR);
126 	}
127 
128 	/*
129 	 * On a labeled system, a MAC flag may be needed if the mount is
130 	 * read-down, so attempt to assert it but ignore errors in any case.
131 	 */
132 	if (is_system_labeled())
133 		(void) setpflags(NET_MAC_AWARE, 1);
134 
135 	/*
136 	 * exit, really
137 	 */
138 	return (nfs_unmount(argv[optind], umnt_flag));
139 }
140 
141 static void
142 pr_err(const char *fmt, ...)
143 {
144 	va_list ap;
145 
146 	va_start(ap, fmt);
147 	(void) fprintf(stderr, "%s: ", typename);
148 	(void) vfprintf(stderr, fmt, ap);
149 	(void) fflush(stderr);
150 	va_end(ap);
151 }
152 
153 static void
154 usage()
155 {
156 	(void) fprintf(stderr,
157 	    gettext("Usage: nfs umount [-o opts] {server:path | dir}\n"));
158 	exit(RET_ERR);
159 }
160 
161 static int
162 nfs_unmount(char *pathname, int umnt_flag)
163 {
164 	struct extmnttab *mntp;
165 	bool_t quick = FALSE;
166 	int is_v4 = FALSE;
167 
168 	mntp = mnttab_find(pathname);
169 	if (mntp) {
170 		pathname = mntp->mnt_mountp;
171 	}
172 
173 	if (mntp)
174 		is_v4 = is_v4_mount(mntp);
175 
176 	/* Forced unmount will almost always be successful */
177 	if (umount2(pathname, umnt_flag) < 0) {
178 		if (errno == EBUSY) {
179 			pr_err(gettext("%s: is busy\n"), pathname);
180 		} else {
181 			pr_err(gettext("%s: not mounted\n"), pathname);
182 		}
183 		return (RET_ERR);
184 	}
185 
186 	/* All done if it's v4 */
187 	if (is_v4 == TRUE)
188 		return (RET_OK);
189 
190 	/* Inform server quickly in case of forced unmount */
191 	if (umnt_flag & MS_FORCE)
192 		quick = TRUE;
193 
194 	if (mntp) {
195 		inform_server(mntp->mnt_special, mntp->mnt_mntopts, quick);
196 	}
197 
198 	return (RET_OK);
199 }
200 
201 /*
202  *  Find the mnttab entry that corresponds to "name".
203  *  We're not sure what the name represents: either
204  *  a mountpoint name, or a special name (server:/path).
205  *  Return the last entry in the file that matches.
206  */
207 static struct extmnttab *
208 mnttab_find(dirname)
209 	char *dirname;
210 {
211 	FILE *fp;
212 	struct extmnttab mnt;
213 	struct extmnttab *res = NULL;
214 
215 	fp = fopen(MNTTAB, "r");
216 	if (fp == NULL) {
217 		pr_err("%s: %s\n", MNTTAB, strerror(errno));
218 		return (NULL);
219 	}
220 	while (getextmntent(fp, &mnt, sizeof (struct extmnttab)) == 0) {
221 		if (strcmp(mnt.mnt_mountp, dirname) == 0 ||
222 		    strcmp(mnt.mnt_special, dirname) == 0) {
223 			if (res)
224 				fsfreemnttab(res);
225 			res = fsdupmnttab(&mnt);
226 		}
227 	}
228 
229 	fclose(fp);
230 	return (res);
231 }
232 
233 /*
234  * If quick is TRUE, it will try to inform server quickly
235  * as possible.
236  */
237 static void
238 inform_server(char *string, char *opts, bool_t quick)
239 {
240 	struct timeval timeout;
241 	CLIENT *cl;
242 	enum clnt_stat rpc_stat;
243 	struct replica *list;
244 	int i, n;
245 	char *p = NULL;
246 	static struct timeval create_timeout = {5, 0};
247 	static struct timeval *timep;
248 
249 	list = parse_replica(string, &n);
250 
251 	if (list == NULL) {
252 		if (n < 0)
253 			pr_err(gettext("%s is not hostname:path format\n"),
254 				string);
255 		else
256 			pr_err(gettext("no memory\n"));
257 		return;
258 	}
259 
260 	/*
261 	 * If mounted with -o public, then no need to contact server
262 	 * because mount protocol was not used.
263 	 */
264 	if (opts != NULL)
265 		p = strstr(opts, MNTOPT_PUBLIC);
266 
267 	if (p != NULL) {
268 		i = strlen(MNTOPT_PUBLIC);
269 		/*
270 		 * Now make sure the match of "public" isn't a substring
271 		 * of another option.
272 		 */
273 		if (((p == opts) || (*(p-1) == ',')) &&
274 		    ((p[i] == ',') || (p[i] == '\0')))
275 			return;
276 	}
277 
278 	for (i = 0; i < n; i++) {
279 		int vers;
280 
281 		/*
282 		 * Skip file systems mounted using WebNFS, because mount
283 		 * protocol was not used.
284 		 */
285 		if (strcmp(list[i].host, "nfs") == 0 && strncmp(list[i].path,
286 		    "//", 2) == 0)
287 			continue;
288 
289 		vers =  MOUNTVERS;
290 retry:
291 		/*
292 		 * Use 5 sec. timeout if file system is forced unmounted,
293 		 * otherwise use default timeout to create a client handle.
294 		 * This would minimize the time to force unmount a file
295 		 * system reside on a server that is down.
296 		 */
297 		timep = (quick ? &create_timeout : NULL);
298 		cl = clnt_create_timed(list[i].host, MOUNTPROG, vers,
299 				"datagram_n", timep);
300 		/*
301 		 * Do not print any error messages in case of forced
302 		 * unmount.
303 		 */
304 		if (cl == NULL) {
305 			if (!quick)
306 				pr_err("%s:%s %s\n", list[i].host, list[i].path,
307 				    clnt_spcreateerror(
308 					"server not responding"));
309 			continue;
310 		}
311 		/*
312 		 * Now it is most likely that the NFS client will be able
313 		 * to contact the server since rpcbind is running on
314 		 * the server. There is still a small window in which
315 		 * server can be unreachable.
316 		 */
317 
318 		if (__clnt_bindresvport(cl) < 0) {
319 			if (!quick)
320 				pr_err(gettext(
321 				    "couldn't bind to reserved port\n"));
322 			clnt_destroy(cl);
323 			return;
324 		}
325 		if ((cl->cl_auth = authsys_create_default()) == NULL) {
326 			if (!quick)
327 				pr_err(gettext(
328 				    "couldn't create authsys structure\n"));
329 			clnt_destroy(cl);
330 			return;
331 		}
332 		timeout.tv_usec = 0;
333 		timeout.tv_sec = 5;
334 		clnt_control(cl, CLSET_RETRY_TIMEOUT, (char *)&timeout);
335 		timeout.tv_sec = 25;
336 		rpc_stat = clnt_call(cl, MOUNTPROC_UMNT, xdr_dirpath,
337 			(char *)&list[i].path, xdr_void, (char *)NULL,
338 			timeout);
339 		AUTH_DESTROY(cl->cl_auth);
340 		clnt_destroy(cl);
341 		if (rpc_stat == RPC_PROGVERSMISMATCH && vers == MOUNTVERS) {
342 			/*
343 			 * The rare case of a v3-only server
344 			 */
345 			vers = MOUNTVERS3;
346 			goto retry;
347 		}
348 		if (rpc_stat != RPC_SUCCESS)
349 			pr_err("%s\n", clnt_sperror(cl, "unmount"));
350 	}
351 
352 	free_replica(list, n);
353 }
354 
355 /*
356  * This function's behavior is taken from nfsstat.
357  * Trying to determine what NFS version was used for the mount.
358  */
359 int
360 is_v4_mount(struct extmnttab *mntp)
361 {
362 	kstat_ctl_t *kc = NULL;		/* libkstat cookie */
363 	kstat_t *ksp;
364 	ulong_t fsid;
365 	struct mntinfo_kstat mik;
366 
367 	if (mntp == NULL)
368 		return (FALSE);
369 
370 	if ((kc = kstat_open()) == NULL)
371 		return (FALSE);
372 
373 	for (ksp = kc->kc_chain; ksp; ksp = ksp->ks_next) {
374 		if (ksp->ks_type != KSTAT_TYPE_RAW)
375 			continue;
376 		if (strcmp(ksp->ks_module, "nfs") != 0)
377 			continue;
378 		if (strcmp(ksp->ks_name, "mntinfo") != 0)
379 			continue;
380 		if (mntp->mnt_minor != ksp->ks_instance)
381 			continue;
382 
383 		if (kstat_read(kc, ksp, &mik) == -1)
384 			continue;
385 
386 		if (mik.mik_vers == 4)
387 			return (TRUE);
388 		else
389 			return (FALSE);
390 	}
391 	return (FALSE);
392 }
393