src/test/test-mount-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2016 Lennart Poettering
   6
   7   systemd is free software; you can redistribute it and/or modify it
   8   under the terms of the GNU Lesser General Public License as published by
   9   the Free Software Foundation; either version 2.1 of the License, or
  10   (at your option) any later version.
  11
  12   systemd is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   Lesser General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  19 ***/
  20
  21 #include <sys/mount.h>
  22
  23 #include "alloc-util.h"
  24 #include "def.h"
  25 #include "fd-util.h"
  26 #include "fileio.h"
  27 #include "hashmap.h"
  28 #include "log.h"
  29 #include "log.h"
  30 #include "mount-util.h"
  31 #include "path-util.h"
  32 #include "rm-rf.h"
  33 #include "string-util.h"
  34
  35 static void test_mount_propagation_flags(const char *name, int ret, unsigned long expected) {
  36         long unsigned flags;
  37
  38         assert_se(mount_propagation_flags_from_string(name, &flags) == ret);
  39
  40         if (ret >= 0) {
  41                 const char *c;
  42
  43                 assert_se(flags == expected);
  44
  45                 c = mount_propagation_flags_to_string(flags);
  46                 if (isempty(name))
  47                         assert_se(isempty(c));
  48                 else
  49                         assert_se(streq(c, name));
  50         }
  51 }
  52
  53 static void test_mnt_id(void) {
  54         _cleanup_fclose_ FILE *f = NULL;
  55         Hashmap *h;
  56         Iterator i;
  57         char *p;
  58         void *k;
  59         int r;
  60
  61         assert_se(f = fopen("/proc/self/mountinfo", "re"));
  62         assert_se(h = hashmap_new(&trivial_hash_ops));
  63
  64         for (;;) {
  65                 _cleanup_free_ char *line = NULL, *path = NULL;
  66                 int mnt_id;
  67
  68                 r = read_line(f, LONG_LINE_MAX, &line);
  69                 if (r == 0)
  70                         break;
  71                 assert_se(r > 0);
  72
  73                 assert_se(sscanf(line, "%i %*s %*s %*s %ms", &mnt_id, &path) == 2);
  74
  75                 assert_se(hashmap_put(h, INT_TO_PTR(mnt_id), path) >= 0);
  76                 path = NULL;
  77         }
  78
  79         HASHMAP_FOREACH_KEY(p, k, h, i) {
  80                 int mnt_id = PTR_TO_INT(k), mnt_id2;
  81
  82                 r = path_get_mnt_id(p, &mnt_id2);
  83                 if (r == -EOPNOTSUPP) { /* kernel or file system too old? */
  84                         log_debug("%s doesn't support mount IDs\n", p);
  85                         continue;
  86                 }
  87                 if (IN_SET(r, -EACCES, -EPERM)) {
  88                         log_debug("Can't access %s\n", p);
  89                         continue;
  90                 }
  91
  92                 log_debug("mnt id of %s is %i\n", p, mnt_id2);
  93
  94                 if (mnt_id == mnt_id2)
  95                         continue;
  96
  97                 /* The ids don't match? If so, then there are two mounts on the same path, let's check if that's really
  98                  * the case */
  99                 assert_se(path_equal_ptr(hashmap_get(h, INT_TO_PTR(mnt_id2)), p));
 100         }
 101
 102         hashmap_free_free(h);
 103 }
 104
 105 static void test_path_is_mount_point(void) {
 106         int fd;
 107         char tmp_dir[] = "/tmp/test-path-is-mount-point-XXXXXX";
 108         _cleanup_free_ char *file1 = NULL, *file2 = NULL, *link1 = NULL, *link2 = NULL;
 109         _cleanup_free_ char *dir1 = NULL, *dir1file = NULL, *dirlink1 = NULL, *dirlink1file = NULL;
 110         _cleanup_free_ char *dir2 = NULL, *dir2file = NULL;
 111
 112         assert_se(path_is_mount_point("/", NULL, AT_SYMLINK_FOLLOW) > 0);
 113         assert_se(path_is_mount_point("/", NULL, 0) > 0);
 114         assert_se(path_is_mount_point("//", NULL, AT_SYMLINK_FOLLOW) > 0);
 115         assert_se(path_is_mount_point("//", NULL, 0) > 0);
 116
 117         assert_se(path_is_mount_point("/proc", NULL, AT_SYMLINK_FOLLOW) > 0);
 118         assert_se(path_is_mount_point("/proc", NULL, 0) > 0);
 119         assert_se(path_is_mount_point("/proc/", NULL, AT_SYMLINK_FOLLOW) > 0);
 120         assert_se(path_is_mount_point("/proc/", NULL, 0) > 0);
 121
 122         assert_se(path_is_mount_point("/proc/1", NULL, AT_SYMLINK_FOLLOW) == 0);
 123         assert_se(path_is_mount_point("/proc/1", NULL, 0) == 0);
 124         assert_se(path_is_mount_point("/proc/1/", NULL, AT_SYMLINK_FOLLOW) == 0);
 125         assert_se(path_is_mount_point("/proc/1/", NULL, 0) == 0);
 126
 127         assert_se(path_is_mount_point("/sys", NULL, AT_SYMLINK_FOLLOW) > 0);
 128         assert_se(path_is_mount_point("/sys", NULL, 0) > 0);
 129         assert_se(path_is_mount_point("/sys/", NULL, AT_SYMLINK_FOLLOW) > 0);
 130         assert_se(path_is_mount_point("/sys/", NULL, 0) > 0);
 131
 132         /* we'll create a hierarchy of different kinds of dir/file/link
 133          * layouts:
 134          *
 135          * <tmp>/file1, <tmp>/file2
 136          * <tmp>/link1 -> file1, <tmp>/link2 -> file2
 137          * <tmp>/dir1/
 138          * <tmp>/dir1/file
 139          * <tmp>/dirlink1 -> dir1
 140          * <tmp>/dirlink1file -> dirlink1/file
 141          * <tmp>/dir2/
 142          * <tmp>/dir2/file
 143          */
 144
 145         /* file mountpoints */
 146         assert_se(mkdtemp(tmp_dir) != NULL);
 147         file1 = path_join(NULL, tmp_dir, "file1");
 148         assert_se(file1);
 149         file2 = path_join(NULL, tmp_dir, "file2");
 150         assert_se(file2);
 151         fd = open(file1, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 152         assert_se(fd > 0);
 153         close(fd);
 154         fd = open(file2, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 155         assert_se(fd > 0);
 156         close(fd);
 157         link1 = path_join(NULL, tmp_dir, "link1");
 158         assert_se(link1);
 159         assert_se(symlink("file1", link1) == 0);
 160         link2 = path_join(NULL, tmp_dir, "link2");
 161         assert_se(link1);
 162         assert_se(symlink("file2", link2) == 0);
 163
 164         assert_se(path_is_mount_point(file1, NULL, AT_SYMLINK_FOLLOW) == 0);
 165         assert_se(path_is_mount_point(file1, NULL, 0) == 0);
 166         assert_se(path_is_mount_point(link1, NULL, AT_SYMLINK_FOLLOW) == 0);
 167         assert_se(path_is_mount_point(link1, NULL, 0) == 0);
 168
 169         /* directory mountpoints */
 170         dir1 = path_join(NULL, tmp_dir, "dir1");
 171         assert_se(dir1);
 172         assert_se(mkdir(dir1, 0755) == 0);
 173         dirlink1 = path_join(NULL, tmp_dir, "dirlink1");
 174         assert_se(dirlink1);
 175         assert_se(symlink("dir1", dirlink1) == 0);
 176         dirlink1file = path_join(NULL, tmp_dir, "dirlink1file");
 177         assert_se(dirlink1file);
 178         assert_se(symlink("dirlink1/file", dirlink1file) == 0);
 179         dir2 = path_join(NULL, tmp_dir, "dir2");
 180         assert_se(dir2);
 181         assert_se(mkdir(dir2, 0755) == 0);
 182
 183         assert_se(path_is_mount_point(dir1, NULL, AT_SYMLINK_FOLLOW) == 0);
 184         assert_se(path_is_mount_point(dir1, NULL, 0) == 0);
 185         assert_se(path_is_mount_point(dirlink1, NULL, AT_SYMLINK_FOLLOW) == 0);
 186         assert_se(path_is_mount_point(dirlink1, NULL, 0) == 0);
 187
 188         /* file in subdirectory mountpoints */
 189         dir1file = path_join(NULL, dir1, "file");
 190         assert_se(dir1file);
 191         fd = open(dir1file, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 192         assert_se(fd > 0);
 193         close(fd);
 194
 195         assert_se(path_is_mount_point(dir1file, NULL, AT_SYMLINK_FOLLOW) == 0);
 196         assert_se(path_is_mount_point(dir1file, NULL, 0) == 0);
 197         assert_se(path_is_mount_point(dirlink1file, NULL, AT_SYMLINK_FOLLOW) == 0);
 198         assert_se(path_is_mount_point(dirlink1file, NULL, 0) == 0);
 199
 200         /* these tests will only work as root */
 201         if (mount(file1, file2, NULL, MS_BIND, NULL) >= 0) {
 202                 int rf, rt, rdf, rdt, rlf, rlt, rl1f, rl1t;
 203                 const char *file2d;
 204
 205                 /* files */
 206                 /* capture results in vars, to avoid dangling mounts on failure */
 207                 log_info("%s: %s", __func__, file2);
 208                 rf = path_is_mount_point(file2, NULL, 0);
 209                 rt = path_is_mount_point(file2, NULL, AT_SYMLINK_FOLLOW);
 210
 211                 file2d = strjoina(file2, "/");
 212                 log_info("%s: %s", __func__, file2d);
 213                 rdf = path_is_mount_point(file2d, NULL, 0);
 214                 rdt = path_is_mount_point(file2d, NULL, AT_SYMLINK_FOLLOW);
 215
 216                 log_info("%s: %s", __func__, link2);
 217                 rlf = path_is_mount_point(link2, NULL, 0);
 218                 rlt = path_is_mount_point(link2, NULL, AT_SYMLINK_FOLLOW);
 219
 220                 assert_se(umount(file2) == 0);
 221
 222                 assert_se(rf == 1);
 223                 assert_se(rt == 1);
 224                 assert_se(rdf == -ENOTDIR);
 225                 assert_se(rdt == -ENOTDIR);
 226                 assert_se(rlf == 0);
 227                 assert_se(rlt == 1);
 228
 229                 /* dirs */
 230                 dir2file = path_join(NULL, dir2, "file");
 231                 assert_se(dir2file);
 232                 fd = open(dir2file, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC, 0664);
 233                 assert_se(fd > 0);
 234                 close(fd);
 235
 236                 assert_se(mount(dir2, dir1, NULL, MS_BIND, NULL) >= 0);
 237
 238                 log_info("%s: %s", __func__, dir1);
 239                 rf = path_is_mount_point(dir1, NULL, 0);
 240                 rt = path_is_mount_point(dir1, NULL, AT_SYMLINK_FOLLOW);
 241                 log_info("%s: %s", __func__, dirlink1);
 242                 rlf = path_is_mount_point(dirlink1, NULL, 0);
 243                 rlt = path_is_mount_point(dirlink1, NULL, AT_SYMLINK_FOLLOW);
 244                 log_info("%s: %s", __func__, dirlink1file);
 245                 /* its parent is a mount point, but not /file itself */
 246                 rl1f = path_is_mount_point(dirlink1file, NULL, 0);
 247                 rl1t = path_is_mount_point(dirlink1file, NULL, AT_SYMLINK_FOLLOW);
 248
 249                 assert_se(umount(dir1) == 0);
 250
 251                 assert_se(rf == 1);
 252                 assert_se(rt == 1);
 253                 assert_se(rlf == 0);
 254                 assert_se(rlt == 1);
 255                 assert_se(rl1f == 0);
 256                 assert_se(rl1t == 0);
 257
 258         } else
 259                 printf("Skipping bind mount file test: %m\n");
 260
 261         assert_se(rm_rf(tmp_dir, REMOVE_ROOT|REMOVE_PHYSICAL) == 0);
 262 }
 263
 264 int main(int argc, char *argv[]) {
 265
 266         log_set_max_level(LOG_DEBUG);
 267
 268         test_mount_propagation_flags("shared", 0, MS_SHARED);
 269         test_mount_propagation_flags("slave", 0, MS_SLAVE);
 270         test_mount_propagation_flags("private", 0, MS_PRIVATE);
 271         test_mount_propagation_flags(NULL, 0, 0);
 272         test_mount_propagation_flags("", 0, 0);
 273         test_mount_propagation_flags("xxxx", -EINVAL, 0);
 274         test_mount_propagation_flags(" ", -EINVAL, 0);
 275
 276         test_mnt_id();
 277         test_path_is_mount_point();
 278
 279         return 0;
 280 }