src/test/test-mountpoint-util.c

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