xref: /illumos-gate/usr/src/cmd/fs.d/smbclnt/umount/umount.c (revision 42d159821800ff240cc201c8fe07f575b9e8a62b)
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 2010 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * smbfs umount
28  */
29 
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <stdarg.h>
34 #include <signal.h>
35 #include <unistd.h>
36 #include <kstat.h>
37 #include <rpc/rpc.h>
38 #include <sys/mnttab.h>
39 #include <sys/mount.h>
40 #include <sys/mntent.h>
41 #include <errno.h>
42 #include <locale.h>
43 #include <fslib.h>
44 #include <priv_utils.h>
45 
46 #define	RET_OK	0
47 #define	RET_ERR	32
48 
49 static void pr_err(const char *fmt, ...);
50 static void usage();
51 static int smbfs_unmount(char *, int);
52 static struct extmnttab *mnttab_find();
53 
54 static char *myname;
55 static char typename[64];
56 
57 int
58 main(int argc, char *argv[])
59 {
60 	extern int optind;
61 	int c;
62 	int umnt_flag = 0;
63 
64 	(void) setlocale(LC_ALL, "");
65 
66 #if !defined(TEXT_DOMAIN)
67 #define	TEXT_DOMAIN "SYS_TEST"
68 #endif
69 	(void) textdomain(TEXT_DOMAIN);
70 
71 	/*
72 	 * Normal users are allowed to umount smbfs mounts they own.
73 	 * To allow that, this program is installed setuid root, and
74 	 * it adds SYS_MOUNT privilege here (if needed), and then
75 	 * restores the user's normal privileges.
76 	 */
77 	if (__init_suid_priv(0, PRIV_SYS_MOUNT, (char *)NULL) < 0) {
78 		(void) fprintf(stderr,
79 		    gettext("Insufficient privileges, "
80 		    "%s must be set-uid root\n"), argv[0]);
81 		exit(RET_ERR);
82 	}
83 
84 	myname = strrchr(argv[0], '/');
85 	myname = myname ? myname+1 : argv[0];
86 	(void) sprintf(typename, "smbfs %s", myname);
87 	argv[0] = typename;
88 
89 	/*
90 	 * Set options
91 	 */
92 	while ((c = getopt(argc, argv, "f")) != EOF) {
93 		switch (c) {
94 		case 'f':
95 			umnt_flag |= MS_FORCE; /* forced unmount is desired */
96 			break;
97 		default:
98 			usage();
99 			exit(RET_ERR);
100 		}
101 	}
102 	if (argc - optind != 1) {
103 		usage();
104 		exit(RET_ERR);
105 	}
106 
107 	return (smbfs_unmount(argv[optind], umnt_flag));
108 }
109 
110 static void
111 pr_err(const char *fmt, ...)
112 {
113 	va_list ap;
114 
115 	va_start(ap, fmt);
116 	(void) fprintf(stderr, "%s: ", typename);
117 	(void) vfprintf(stderr, fmt, ap);
118 	(void) fflush(stderr);
119 	va_end(ap);
120 }
121 
122 static void
123 usage()
124 {
125 	(void) fprintf(stderr,
126 	    gettext("Usage: smbfs umount [-o opts] {//server/share | dir}\n"));
127 	exit(RET_ERR);
128 }
129 
130 static int
131 smbfs_unmount(char *pathname, int umnt_flag)
132 {
133 	struct extmnttab *mntp;
134 	int rc;
135 
136 	mntp = mnttab_find(pathname);
137 	if (mntp) {
138 		pathname = mntp->mnt_mountp;
139 	}
140 
141 	/* Need sys_mount privilege for the umount call. */
142 	(void) __priv_bracket(PRIV_ON);
143 	rc = umount2(pathname, umnt_flag);
144 	(void) __priv_bracket(PRIV_OFF);
145 
146 	if (rc < 0) {
147 		pr_err(gettext("%s: %s\n"), pathname, strerror(errno));
148 		return (RET_ERR);
149 	}
150 
151 	return (RET_OK);
152 }
153 
154 /*
155  *  Find the mnttab entry that corresponds to "name".
156  *  We're not sure what the name represents: either
157  *  a mountpoint name, or a special name (server:/path).
158  *  Return the last entry in the file that matches.
159  */
160 static struct extmnttab *
161 mnttab_find(dirname)
162 	char *dirname;
163 {
164 	FILE *fp;
165 	struct extmnttab mnt;
166 	struct extmnttab *res = NULL;
167 
168 	fp = fopen(MNTTAB, "r");
169 	if (fp == NULL) {
170 		pr_err("%s: %s\n", MNTTAB, strerror(errno));
171 		return (NULL);
172 	}
173 	while (getextmntent(fp, &mnt, sizeof (struct extmnttab)) == 0) {
174 		if (strcmp(mnt.mnt_mountp, dirname) == 0 ||
175 		    strcmp(mnt.mnt_special, dirname) == 0) {
176 			if (res)
177 				fsfreemnttab(res);
178 			res = fsdupmnttab(&mnt);
179 		}
180 	}
181 
182 	fclose(fp);
183 	return (res);
184 }
185