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 * Copyright 2019 Nexenta by DDN, Inc. All rights reserved.
29 */
30
31 /*
32 * smbfs umount
33 */
34
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <stdarg.h>
39 #include <signal.h>
40 #include <unistd.h>
41 #include <kstat.h>
42 #include <rpc/rpc.h>
43 #include <sys/mnttab.h>
44 #include <sys/mount.h>
45 #include <sys/mntent.h>
46 #include <errno.h>
47 #include <locale.h>
48 #include <fslib.h>
49 #include <priv_utils.h>
50
51 #define RET_OK 0
52 #define RET_ERR 32
53
54 static void pr_err(const char *fmt, ...);
55 static void usage();
56 static int smbfs_unmount(char *, int);
57 static struct extmnttab *mnttab_find();
58
59 int
main(int argc,char * argv[])60 main(int argc, char *argv[])
61 {
62 extern int optind;
63 int c;
64 int umnt_flag = 0;
65
66 (void) setlocale(LC_ALL, "");
67
68 #if !defined(TEXT_DOMAIN)
69 #define TEXT_DOMAIN "SYS_TEST"
70 #endif
71 (void) textdomain(TEXT_DOMAIN);
72
73 /*
74 * Normal users are allowed to umount smbfs mounts they own.
75 * To allow that, this program has an exec_attr that adds
76 * SYS_MOUNT privilege.
77 *
78 * The __init_suid_priv call was designed for SUID programs,
79 * but also works for privileges granted via exec_attr with
80 * one difference: the added privileges are already effective
81 * when the program starts, and remain effective after the call.
82 * To make this work more like the SUID case we'll turn off the
83 * additional privileges with a __priv_bracket() call here.
84 * Later calls to __priv_bracket() make the extra privileges
85 * effective only when we need them.
86 */
87 if (__init_suid_priv(0, PRIV_SYS_MOUNT, (char *)NULL) < 0) {
88 (void) fprintf(stderr,
89 gettext("Insufficient privileges, "
90 "%s should have sys_mount privilege via exec_attr\n"),
91 argv[0]);
92 exit(RET_ERR);
93 }
94 (void) __priv_bracket(PRIV_OFF);
95
96 /*
97 * Set options
98 */
99 while ((c = getopt(argc, argv, "f")) != EOF) {
100 switch (c) {
101 case 'f':
102 umnt_flag |= MS_FORCE; /* forced unmount is desired */
103 break;
104 default:
105 usage();
106 exit(RET_ERR);
107 }
108 }
109 if (argc - optind != 1) {
110 usage();
111 exit(RET_ERR);
112 }
113
114 return (smbfs_unmount(argv[optind], umnt_flag));
115 }
116
117 static void
pr_err(const char * fmt,...)118 pr_err(const char *fmt, ...)
119 {
120 va_list ap;
121
122 va_start(ap, fmt);
123 (void) fprintf(stderr, "smbfs/umount: ");
124 (void) vfprintf(stderr, fmt, ap);
125 (void) fflush(stderr);
126 va_end(ap);
127 }
128
129 static void
usage()130 usage()
131 {
132 (void) fprintf(stderr,
133 gettext("Usage: smbfs umount [-o opts] {//server/share | dir}\n"));
134 exit(RET_ERR);
135 }
136
137 static int
smbfs_unmount(char * pathname,int umnt_flag)138 smbfs_unmount(char *pathname, int umnt_flag)
139 {
140 struct extmnttab *mntp;
141 int rc;
142
143 mntp = mnttab_find(pathname);
144 if (mntp) {
145 pathname = mntp->mnt_mountp;
146 }
147
148 /* Need sys_mount privilege for the umount call. */
149 (void) __priv_bracket(PRIV_ON);
150 rc = umount2(pathname, umnt_flag);
151 (void) __priv_bracket(PRIV_OFF);
152
153 if (rc < 0) {
154 pr_err(gettext("%s: %s\n"), pathname, strerror(errno));
155 return (RET_ERR);
156 }
157
158 return (RET_OK);
159 }
160
161 /*
162 * Find the mnttab entry that corresponds to "name".
163 * We're not sure what the name represents: either
164 * a mountpoint name, or a special name (server:/path).
165 * Return the last entry in the file that matches.
166 */
167 static struct extmnttab *
mnttab_find(char * dirname)168 mnttab_find(char *dirname)
169 {
170 FILE *fp;
171 struct extmnttab mnt;
172 struct extmnttab *res = NULL;
173
174 fp = fopen(MNTTAB, "r");
175 if (fp == NULL) {
176 pr_err("%s: %s\n", MNTTAB, strerror(errno));
177 return (NULL);
178 }
179 while (getextmntent(fp, &mnt, sizeof (struct extmnttab)) == 0) {
180 if (strcmp(mnt.mnt_mountp, dirname) == 0 ||
181 strcmp(mnt.mnt_special, dirname) == 0) {
182 if (res)
183 fsfreemnttab(res);
184 res = fsdupmnttab(&mnt);
185 }
186 }
187
188 (void) fclose(fp);
189 return (res);
190 }
191