usr/src/cmd/fs.d/smbclnt/umount/umount.c

   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 }