src/test/test-mount-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <sys/mount.h>
   4 #include <sys/statvfs.h>
   5
   6 #include "alloc-util.h"
   7 #include "capability-util.h"
   8 #include "fd-util.h"
   9 #include "fileio.h"
  10 #include "missing_mount.h"
  11 #include "mount-util.h"
  12 #include "namespace-util.h"
  13 #include "path-util.h"
  14 #include "process-util.h"
  15 #include "rm-rf.h"
  16 #include "string-util.h"
  17 #include "strv.h"
  18 #include "tests.h"
  19 #include "tmpfile-util.h"
  20
  21 static void test_mount_option_mangle(void) {
  22         char *opts = NULL;
  23         unsigned long f;
  24
  25         log_info("/* %s */", __func__);
  26
  27         assert_se(mount_option_mangle(NULL, MS_RDONLY|MS_NOSUID, &f, &opts) == 0);
  28         assert_se(f == (MS_RDONLY|MS_NOSUID));
  29         assert_se(opts == NULL);
  30
  31         assert_se(mount_option_mangle("", MS_RDONLY|MS_NOSUID, &f, &opts) == 0);
  32         assert_se(f == (MS_RDONLY|MS_NOSUID));
  33         assert_se(opts == NULL);
  34
  35         assert_se(mount_option_mangle("ro,nosuid,nodev,noexec", 0, &f, &opts) == 0);
  36         assert_se(f == (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC));
  37         assert_se(opts == NULL);
  38
  39         assert_se(mount_option_mangle("ro,nosuid,nodev,noexec,mode=755", 0, &f, &opts) == 0);
  40         assert_se(f == (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC));
  41         assert_se(streq(opts, "mode=755"));
  42         opts = mfree(opts);
  43
  44         assert_se(mount_option_mangle("rw,nosuid,foo,hogehoge,nodev,mode=755", 0, &f, &opts) == 0);
  45         assert_se(f == (MS_NOSUID|MS_NODEV));
  46         assert_se(streq(opts, "foo,hogehoge,mode=755"));
  47         opts = mfree(opts);
  48
  49         assert_se(mount_option_mangle("rw,nosuid,nodev,noexec,relatime,net_cls,net_prio", MS_RDONLY, &f, &opts) == 0);
  50         assert_se(f == (MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_RELATIME));
  51         assert_se(streq(opts, "net_cls,net_prio"));
  52         opts = mfree(opts);
  53
  54         assert_se(mount_option_mangle("rw,nosuid,nodev,relatime,size=1630748k,mode=700,uid=1000,gid=1000", MS_RDONLY, &f, &opts) == 0);
  55         assert_se(f == (MS_NOSUID|MS_NODEV|MS_RELATIME));
  56         assert_se(streq(opts, "size=1630748k,mode=700,uid=1000,gid=1000"));
  57         opts = mfree(opts);
  58
  59         assert_se(mount_option_mangle("size=1630748k,rw,gid=1000,,,nodev,relatime,,mode=700,nosuid,uid=1000", MS_RDONLY, &f, &opts) == 0);
  60         assert_se(f == (MS_NOSUID|MS_NODEV|MS_RELATIME));
  61         assert_se(streq(opts, "size=1630748k,gid=1000,mode=700,uid=1000"));
  62         opts = mfree(opts);
  63
  64         assert_se(mount_option_mangle("rw,exec,size=8143984k,nr_inodes=2035996,mode=755", MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, &f, &opts) == 0);
  65         assert_se(f == (MS_NOSUID|MS_NODEV));
  66         assert_se(streq(opts, "size=8143984k,nr_inodes=2035996,mode=755"));
  67         opts = mfree(opts);
  68
  69         assert_se(mount_option_mangle("rw,relatime,fmask=0022,,,dmask=0022", MS_RDONLY, &f, &opts) == 0);
  70         assert_se(f == MS_RELATIME);
  71         assert_se(streq(opts, "fmask=0022,dmask=0022"));
  72         opts = mfree(opts);
  73
  74         assert_se(mount_option_mangle("rw,relatime,fmask=0022,dmask=0022,\"hogehoge", MS_RDONLY, &f, &opts) < 0);
  75
  76         assert_se(mount_option_mangle("mode=1777,size=10%,nr_inodes=400k,uid=496107520,gid=496107520,context=\"system_u:object_r:svirt_sandbox_file_t:s0:c0,c1\"", 0, &f, &opts) == 0);
  77         assert_se(f == 0);
  78         assert_se(streq(opts, "mode=1777,size=10%,nr_inodes=400k,uid=496107520,gid=496107520,context=\"system_u:object_r:svirt_sandbox_file_t:s0:c0,c1\""));
  79         opts = mfree(opts);
  80 }
  81
  82 static void test_mount_flags_to_string_one(unsigned long flags, const char *expected) {
  83         _cleanup_free_ char *x = NULL;
  84         int r;
  85
  86         r = mount_flags_to_string(flags, &x);
  87         log_info("flags: %#lX → %d/\"%s\"", flags, r, strnull(x));
  88         assert_se(r >= 0);
  89         assert_se(streq(x, expected));
  90 }
  91
  92 static void test_mount_flags_to_string(void) {
  93         log_info("/* %s */", __func__);
  94
  95         test_mount_flags_to_string_one(0, "0");
  96         test_mount_flags_to_string_one(MS_RDONLY, "MS_RDONLY");
  97         test_mount_flags_to_string_one(MS_NOSUID, "MS_NOSUID");
  98         test_mount_flags_to_string_one(MS_NODEV, "MS_NODEV");
  99         test_mount_flags_to_string_one(MS_NOEXEC, "MS_NOEXEC");
 100         test_mount_flags_to_string_one(MS_SYNCHRONOUS, "MS_SYNCHRONOUS");
 101         test_mount_flags_to_string_one(MS_REMOUNT, "MS_REMOUNT");
 102         test_mount_flags_to_string_one(MS_MANDLOCK, "MS_MANDLOCK");
 103         test_mount_flags_to_string_one(MS_DIRSYNC, "MS_DIRSYNC");
 104         test_mount_flags_to_string_one(MS_NOSYMFOLLOW, "MS_NOSYMFOLLOW");
 105         test_mount_flags_to_string_one(MS_NOATIME, "MS_NOATIME");
 106         test_mount_flags_to_string_one(MS_NODIRATIME, "MS_NODIRATIME");
 107         test_mount_flags_to_string_one(MS_BIND, "MS_BIND");
 108         test_mount_flags_to_string_one(MS_MOVE, "MS_MOVE");
 109         test_mount_flags_to_string_one(MS_REC, "MS_REC");
 110         test_mount_flags_to_string_one(MS_SILENT, "MS_SILENT");
 111         test_mount_flags_to_string_one(MS_POSIXACL, "MS_POSIXACL");
 112         test_mount_flags_to_string_one(MS_UNBINDABLE, "MS_UNBINDABLE");
 113         test_mount_flags_to_string_one(MS_PRIVATE, "MS_PRIVATE");
 114         test_mount_flags_to_string_one(MS_SLAVE, "MS_SLAVE");
 115         test_mount_flags_to_string_one(MS_SHARED, "MS_SHARED");
 116         test_mount_flags_to_string_one(MS_RELATIME, "MS_RELATIME");
 117         test_mount_flags_to_string_one(MS_KERNMOUNT, "MS_KERNMOUNT");
 118         test_mount_flags_to_string_one(MS_I_VERSION, "MS_I_VERSION");
 119         test_mount_flags_to_string_one(MS_STRICTATIME, "MS_STRICTATIME");
 120         test_mount_flags_to_string_one(MS_LAZYTIME, "MS_LAZYTIME");
 121         test_mount_flags_to_string_one(MS_LAZYTIME|MS_STRICTATIME, "MS_STRICTATIME|MS_LAZYTIME");
 122         test_mount_flags_to_string_one(UINT_MAX,
 123                                        "MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_SYNCHRONOUS|MS_REMOUNT|"
 124                                        "MS_MANDLOCK|MS_DIRSYNC|MS_NOSYMFOLLOW|MS_NOATIME|MS_NODIRATIME|"
 125                                        "MS_BIND|MS_MOVE|MS_REC|MS_SILENT|MS_POSIXACL|MS_UNBINDABLE|"
 126                                        "MS_PRIVATE|MS_SLAVE|MS_SHARED|MS_RELATIME|MS_KERNMOUNT|"
 127                                        "MS_I_VERSION|MS_STRICTATIME|MS_LAZYTIME|fc000200");
 128 }
 129
 130 static void test_bind_remount_recursive(void) {
 131         _cleanup_(rm_rf_physical_and_freep) char *tmp = NULL;
 132         _cleanup_free_ char *subdir = NULL;
 133         const char *p;
 134
 135         log_info("/* %s */", __func__);
 136
 137         if (geteuid() != 0 || have_effective_cap(CAP_SYS_ADMIN) <= 0) {
 138                 (void) log_tests_skipped("not running privileged");
 139                 return;
 140         }
 141
 142         assert_se(mkdtemp_malloc("/tmp/XXXXXX", &tmp) >= 0);
 143         subdir = path_join(tmp, "subdir");
 144         assert_se(subdir);
 145         assert_se(mkdir(subdir, 0755) >= 0);
 146
 147         FOREACH_STRING(p, "/usr", "/sys", "/", tmp) {
 148                 pid_t pid;
 149
 150                 pid = fork();
 151                 assert_se(pid >= 0);
 152
 153                 if (pid == 0) {
 154                         struct statvfs svfs;
 155                         /* child */
 156                         assert_se(detach_mount_namespace() >= 0);
 157
 158                         /* Check that the subdir is writable (it must be because it's in /tmp) */
 159                         assert_se(statvfs(subdir, &svfs) >= 0);
 160                         assert_se(!FLAGS_SET(svfs.f_flag, ST_RDONLY));
 161
 162                         /* Make the subdir a bind mount */
 163                         assert_se(mount_nofollow(subdir, subdir, NULL, MS_BIND|MS_REC, NULL) >= 0);
 164
 165                         /* Ensure it's still writable */
 166                         assert_se(statvfs(subdir, &svfs) >= 0);
 167                         assert_se(!FLAGS_SET(svfs.f_flag, ST_RDONLY));
 168
 169                         /* Now mark the path we currently run for read-only */
 170                         assert_se(bind_remount_recursive(p, MS_RDONLY, MS_RDONLY, STRV_MAKE("/sys/kernel")) >= 0);
 171
 172                         /* Ensure that this worked on the top-level */
 173                         assert_se(statvfs(p, &svfs) >= 0);
 174                         assert_se(FLAGS_SET(svfs.f_flag, ST_RDONLY));
 175
 176                         /* And ensure this had an effect on the subdir exactly if we are talking about a path above the subdir */
 177                         assert_se(statvfs(subdir, &svfs) >= 0);
 178                         assert_se(FLAGS_SET(svfs.f_flag, ST_RDONLY) == !!path_startswith(subdir, p));
 179
 180                         _exit(EXIT_SUCCESS);
 181                 }
 182
 183                 assert_se(wait_for_terminate_and_check("test-remount-rec", pid, WAIT_LOG) == EXIT_SUCCESS);
 184         }
 185 }
 186
 187 static void test_bind_remount_one(void) {
 188         pid_t pid;
 189
 190         log_info("/* %s */", __func__);
 191
 192         if (geteuid() != 0 || have_effective_cap(CAP_SYS_ADMIN) <= 0) {
 193                 (void) log_tests_skipped("not running privileged");
 194                 return;
 195         }
 196
 197         pid = fork();
 198         assert_se(pid >= 0);
 199
 200         if (pid == 0) {
 201                 /* child */
 202
 203                 _cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
 204
 205                 assert_se(detach_mount_namespace() >= 0);
 206
 207                 assert_se(fopen_unlocked("/proc/self/mountinfo", "re", &proc_self_mountinfo) >= 0);
 208
 209                 assert_se(bind_remount_one_with_mountinfo("/run", MS_RDONLY, MS_RDONLY, proc_self_mountinfo) >= 0);
 210                 assert_se(bind_remount_one_with_mountinfo("/proc/idontexist", MS_RDONLY, MS_RDONLY, proc_self_mountinfo) == -ENOENT);
 211                 assert_se(bind_remount_one_with_mountinfo("/proc/self", MS_RDONLY, MS_RDONLY, proc_self_mountinfo) == -EINVAL);
 212                 assert_se(bind_remount_one_with_mountinfo("/", MS_RDONLY, MS_RDONLY, proc_self_mountinfo) >= 0);
 213
 214                 _exit(EXIT_SUCCESS);
 215         }
 216
 217         assert_se(wait_for_terminate_and_check("test-remount-one", pid, WAIT_LOG) == EXIT_SUCCESS);
 218 }
 219
 220 int main(int argc, char *argv[]) {
 221         test_setup_logging(LOG_DEBUG);
 222
 223         test_mount_option_mangle();
 224         test_mount_flags_to_string();
 225         test_bind_remount_recursive();
 226         test_bind_remount_one();
 227
 228         return 0;
 229 }