xref: /illumos-gate/usr/src/cmd/fs.d/smbclnt/umount/umount.c (revision 6a1a5bb98a625f9f7115565ac77e5c4170a030cc)
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  * Copyright (c) 2018, Joyent, Inc.
28  */
29 
30 /*
31  * smbfs umount
32  */
33 
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <stdarg.h>
38 #include <signal.h>
39 #include <unistd.h>
40 #include <kstat.h>
41 #include <rpc/rpc.h>
42 #include <sys/mnttab.h>
43 #include <sys/mount.h>
44 #include <sys/mntent.h>
45 #include <errno.h>
46 #include <locale.h>
47 #include <fslib.h>
48 #include <priv_utils.h>
49 
50 #define	RET_OK	0
51 #define	RET_ERR	32
52 
53 static void pr_err(const char *fmt, ...);
54 static void usage();
55 static int smbfs_unmount(char *, int);
56 static struct extmnttab *mnttab_find();
57 
58 static char *myname;
59 static char typename[64];
60 
61 int
62 main(int argc, char *argv[])
63 {
64 	extern int optind;
65 	int c;
66 	int umnt_flag = 0;
67 
68 	(void) setlocale(LC_ALL, "");
69 
70 #if !defined(TEXT_DOMAIN)
71 #define	TEXT_DOMAIN "SYS_TEST"
72 #endif
73 	(void) textdomain(TEXT_DOMAIN);
74 
75 	/*
76 	 * Normal users are allowed to umount smbfs mounts they own.
77 	 * To allow that, this program is installed setuid root, and
78 	 * it adds SYS_MOUNT privilege here (if needed), and then
79 	 * restores the user's normal privileges.
80 	 */
81 	if (__init_suid_priv(0, PRIV_SYS_MOUNT, (char *)NULL) < 0) {
82 		(void) fprintf(stderr,
83 		    gettext("Insufficient privileges, "
84 		    "%s must be set-uid root\n"), argv[0]);
85 		exit(RET_ERR);
86 	}
87 
88 	myname = strrchr(argv[0], '/');
89 	myname = myname ? myname+1 : argv[0];
90 	(void) sprintf(typename, "smbfs %s", myname);
91 	argv[0] = typename;
92 
93 	/*
94 	 * Set options
95 	 */
96 	while ((c = getopt(argc, argv, "f")) != EOF) {
97 		switch (c) {
98 		case 'f':
99 			umnt_flag |= MS_FORCE; /* forced unmount is desired */
100 			break;
101 		default:
102 			usage();
103 			exit(RET_ERR);
104 		}
105 	}
106 	if (argc - optind != 1) {
107 		usage();
108 		exit(RET_ERR);
109 	}
110 
111 	return (smbfs_unmount(argv[optind], umnt_flag));
112 }
113 
114 static void
115 pr_err(const char *fmt, ...)
116 {
117 	va_list ap;
118 
119 	va_start(ap, fmt);
120 	(void) fprintf(stderr, "%s: ", typename);
121 	(void) vfprintf(stderr, fmt, ap);
122 	(void) fflush(stderr);
123 	va_end(ap);
124 }
125 
126 static void
127 usage()
128 {
129 	(void) fprintf(stderr,
130 	    gettext("Usage: smbfs umount [-o opts] {//server/share | dir}\n"));
131 	exit(RET_ERR);
132 }
133 
134 static int
135 smbfs_unmount(char *pathname, int umnt_flag)
136 {
137 	struct extmnttab *mntp;
138 	int rc;
139 
140 	mntp = mnttab_find(pathname);
141 	if (mntp) {
142 		pathname = mntp->mnt_mountp;
143 	}
144 
145 	/* Need sys_mount privilege for the umount call. */
146 	(void) __priv_bracket(PRIV_ON);
147 	rc = umount2(pathname, umnt_flag);
148 	(void) __priv_bracket(PRIV_OFF);
149 
150 	if (rc < 0) {
151 		pr_err(gettext("%s: %s\n"), pathname, strerror(errno));
152 		return (RET_ERR);
153 	}
154 
155 	return (RET_OK);
156 }
157 
158 /*
159  *  Find the mnttab entry that corresponds to "name".
160  *  We're not sure what the name represents: either
161  *  a mountpoint name, or a special name (server:/path).
162  *  Return the last entry in the file that matches.
163  */
164 static struct extmnttab *
165 mnttab_find(dirname)
166 	char *dirname;
167 {
168 	FILE *fp;
169 	struct extmnttab mnt;
170 	struct extmnttab *res = NULL;
171 
172 	fp = fopen(MNTTAB, "r");
173 	if (fp == NULL) {
174 		pr_err("%s: %s\n", MNTTAB, strerror(errno));
175 		return (NULL);
176 	}
177 	while (getextmntent(fp, &mnt, sizeof (struct extmnttab)) == 0) {
178 		if (strcmp(mnt.mnt_mountp, dirname) == 0 ||
179 		    strcmp(mnt.mnt_special, dirname) == 0) {
180 			if (res)
181 				fsfreemnttab(res);
182 			res = fsdupmnttab(&mnt);
183 		}
184 	}
185 
186 	(void) fclose(fp);
187 	return (res);
188 }
189