src/test/test-mountpoint-util.c

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