usr.sbin/autofs/automount.c

   1 /*-
   2  * Copyright (c) 2016 The DragonFly Project
   3  * Copyright (c) 2014 The FreeBSD Foundation
   4  * All rights reserved.
   5  *
   6  * This software was developed by Edward Tomasz Napierala under sponsorship
   7  * from the FreeBSD Foundation.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  *
  30  */
  31
  32 #include <sys/types.h>
  33 #include <sys/mount.h>
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <unistd.h>
  38 #include <vfs/autofs/autofs_mount.h>
  39
  40 #include "common.h"
  41
  42 static int
  43 unmount_by_statfs(const struct statfs *sb, bool force)
  44 {
  45         int error, flags;
  46
  47         log_debugx("unmounting %s", sb->f_mntonname);
  48
  49         flags = 0;
  50         if (force)
  51                 flags |= MNT_FORCE;
  52         error = unmount(sb->f_mntonname, flags);
  53         if (error != 0)
  54                 log_warn("cannot unmount %s", sb->f_mntonname);
  55
  56         return (error);
  57 }
  58
  59 static const struct statfs *
  60 find_statfs(const struct statfs *mntbuf, int nitems, const char *mountpoint)
  61 {
  62         int i;
  63
  64         for (i = 0; i < nitems; i++) {
  65                 if (strcmp(mntbuf[i].f_mntonname, mountpoint) == 0)
  66                         return (mntbuf + i);
  67         }
  68
  69         return (NULL);
  70 }
  71
  72 static void
  73 mount_autofs(const char *from, const char *fspath, const char *options,
  74     const char *prefix)
  75 {
  76         struct autofs_mount_info info;
  77         int error;
  78
  79         create_directory(fspath);
  80
  81         log_debugx("mounting %s on %s, prefix \"%s\", options \"%s\"",
  82             from, fspath, prefix, options);
  83
  84         memset(&info, 0, sizeof(info));
  85         info.from = from;
  86         info.master_options = options;
  87         info.master_prefix = prefix;
  88
  89         error = mount("autofs", fspath, 0, &info);
  90         if (error != 0)
  91                 log_err(1, "cannot mount %s on %s", from, fspath);
  92 }
  93
  94 static void
  95 mount_if_not_already(const struct node *n, const char *map, const char *options,
  96     const char *prefix, const struct statfs *mntbuf, int nitems)
  97 {
  98         const struct statfs *sb;
  99         char *mountpoint;
 100         char *from;
 101         int ret;
 102
 103         ret = asprintf(&from, "map %s", map);
 104         if (ret < 0)
 105                 log_err(1, "asprintf");
 106
 107         mountpoint = node_path(n);
 108         sb = find_statfs(mntbuf, nitems, mountpoint);
 109         if (sb != NULL) {
 110                 if (strcmp(sb->f_fstypename, "autofs") != 0) {
 111                         log_debugx("unknown filesystem mounted "
 112                             "on %s; mounting", mountpoint);
 113                         /*
 114                          * XXX: Compare options and 'from',
 115                          *      and update the mount if necessary.
 116                          */
 117                 } else {
 118                         log_debugx("autofs already mounted "
 119                             "on %s", mountpoint);
 120                         free(from);
 121                         free(mountpoint);
 122                         return;
 123                 }
 124         } else {
 125                 log_debugx("nothing mounted on %s; mounting",
 126                     mountpoint);
 127         }
 128
 129         mount_autofs(from, mountpoint, options, prefix);
 130         free(from);
 131         free(mountpoint);
 132 }
 133
 134 static void
 135 mount_unmount(struct node *root)
 136 {
 137         struct statfs *mntbuf;
 138         struct node *n, *n2;
 139         int i, nitems;
 140
 141         nitems = getmntinfo(&mntbuf, MNT_WAIT);
 142         if (nitems <= 0)
 143                 log_err(1, "getmntinfo");
 144
 145         log_debugx("unmounting stale autofs mounts");
 146
 147         for (i = 0; i < nitems; i++) {
 148                 if (strcmp(mntbuf[i].f_fstypename, "autofs") != 0) {
 149                         log_debugx("skipping %s, filesystem type is not autofs",
 150                             mntbuf[i].f_mntonname);
 151                         continue;
 152                 }
 153
 154                 n = node_find(root, mntbuf[i].f_mntonname);
 155                 if (n != NULL) {
 156                         log_debugx("leaving autofs mounted on %s",
 157                             mntbuf[i].f_mntonname);
 158                         continue;
 159                 }
 160
 161                 log_debugx("autofs mounted on %s not found "
 162                     "in new configuration; unmounting", mntbuf[i].f_mntonname);
 163                 unmount_by_statfs(&(mntbuf[i]), false);
 164         }
 165
 166         log_debugx("mounting new autofs mounts");
 167
 168         TAILQ_FOREACH(n, &root->n_children, n_next) {
 169                 if (!node_is_direct_map(n)) {
 170                         mount_if_not_already(n, n->n_map, n->n_options,
 171                             n->n_key, mntbuf, nitems);
 172                         continue;
 173                 }
 174
 175                 TAILQ_FOREACH(n2, &n->n_children, n_next) {
 176                         mount_if_not_already(n2, n->n_map, n->n_options,
 177                             "/", mntbuf, nitems);
 178                 }
 179         }
 180 }
 181
 182 static void
 183 flush_autofs(const char *fspath)
 184 {
 185         int error;
 186
 187         log_debugx("flushing %s", fspath);
 188
 189         error = mount("autofs", fspath, MNT_UPDATE, NULL);
 190         if (error != 0)
 191                 log_err(1, "cannot flush %s", fspath);
 192 }
 193
 194 static void
 195 flush_caches(void)
 196 {
 197         struct statfs *mntbuf;
 198         int i, nitems;
 199
 200         nitems = getmntinfo(&mntbuf, MNT_WAIT);
 201         if (nitems <= 0)
 202                 log_err(1, "getmntinfo");
 203
 204         log_debugx("flushing autofs caches");
 205
 206         for (i = 0; i < nitems; i++) {
 207                 if (strcmp(mntbuf[i].f_fstypename, "autofs") != 0) {
 208                         log_debugx("skipping %s, filesystem type is not autofs",
 209                             mntbuf[i].f_mntonname);
 210                         continue;
 211                 }
 212
 213                 flush_autofs(mntbuf[i].f_mntonname);
 214         }
 215 }
 216
 217 static void
 218 unmount_automounted(bool force)
 219 {
 220         struct statfs *mntbuf;
 221         int i, nitems;
 222
 223         nitems = getmntinfo(&mntbuf, MNT_WAIT);
 224         if (nitems <= 0)
 225                 log_err(1, "getmntinfo");
 226
 227         log_debugx("unmounting automounted filesystems");
 228
 229         for (i = 0; i < nitems; i++) {
 230                 if (strcmp(mntbuf[i].f_fstypename, "autofs") == 0) {
 231                         log_debugx("skipping %s, filesystem type is autofs",
 232                             mntbuf[i].f_mntonname);
 233                         continue;
 234                 }
 235
 236                 if ((mntbuf[i].f_flags & MNT_AUTOMOUNTED) == 0) {
 237                         log_debugx("skipping %s, not automounted",
 238                             mntbuf[i].f_mntonname);
 239                         continue;
 240                 }
 241
 242                 unmount_by_statfs(&(mntbuf[i]), force);
 243         }
 244 }
 245
 246 static void
 247 usage_automount(void)
 248 {
 249
 250         fprintf(stderr, "usage: automount [-D name=value][-o opts][-Lcfuv]\n");
 251         exit(1);
 252 }
 253
 254 int
 255 main_automount(int argc, char **argv)
 256 {
 257         struct node *root;
 258         int ch, debug = 0, show_maps = 0;
 259         char *options = NULL;
 260         bool do_unmount = false, force_unmount = false, flush = false;
 261
 262         /*
 263          * Note that in automount(8), the only purpose of variable
 264          * handling is to aid in debugging maps (automount -L).
 265          */
 266         defined_init();
 267
 268         while ((ch = getopt(argc, argv, "D:Lfco:uv")) != -1) {
 269                 switch (ch) {
 270                 case 'D':
 271                         defined_parse_and_add(optarg);
 272                         break;
 273                 case 'L':
 274                         show_maps++;
 275                         break;
 276                 case 'c':
 277                         flush = true;
 278                         break;
 279                 case 'f':
 280                         force_unmount = true;
 281                         break;
 282                 case 'o':
 283                         options = concat(options, ',', optarg);
 284                         break;
 285                 case 'u':
 286                         do_unmount = true;
 287                         break;
 288                 case 'v':
 289                         debug++;
 290                         break;
 291                 case '?':
 292                 default:
 293                         usage_automount();
 294                 }
 295         }
 296         argc -= optind;
 297         if (argc != 0)
 298                 usage_automount();
 299
 300         if (force_unmount && !do_unmount)
 301                 usage_automount();
 302
 303         log_init(debug);
 304
 305         if (flush) {
 306                 flush_caches();
 307                 return (0);
 308         }
 309
 310         if (do_unmount) {
 311                 unmount_automounted(force_unmount);
 312                 return (0);
 313         }
 314
 315         root = node_new_root();
 316         parse_master(root, AUTO_MASTER_PATH);
 317
 318         if (show_maps) {
 319                 if (show_maps > 1) {
 320                         node_expand_indirect_maps(root);
 321                         node_expand_ampersand(root, NULL);
 322                 }
 323                 node_expand_defined(root);
 324                 node_print(root, options);
 325                 return (0);
 326         }
 327
 328         mount_unmount(root);
 329
 330         return (0);
 331 }