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 "fd-util.h"
   8 #include "fileio.h"
   9 #include "mount-util.h"
  10 #include "namespace-util.h"
  11 #include "path-util.h"
  12 #include "process-util.h"
  13 #include "rm-rf.h"
  14 #include "string-util.h"
  15 #include "strv.h"
  16 #include "tests.h"
  17 #include "tmpfile-util.h"
  18
  19 static void test_mount_option_mangle(void) {
  20         char *opts = NULL;
  21         unsigned long f;
  22
  23         assert_se(mount_option_mangle(NULL, MS_RDONLY|MS_NOSUID, &f, &opts) == 0);
  24         assert_se(f == (MS_RDONLY|MS_NOSUID));
  25         assert_se(opts == NULL);
  26
  27         assert_se(mount_option_mangle("", 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("ro,nosuid,nodev,noexec", 0, &f, &opts) == 0);
  32         assert_se(f == (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC));
  33         assert_se(opts == NULL);
  34
  35         assert_se(mount_option_mangle("ro,nosuid,nodev,noexec,mode=755", 0, &f, &opts) == 0);
  36         assert_se(f == (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC));
  37         assert_se(streq(opts, "mode=755"));
  38         opts = mfree(opts);
  39
  40         assert_se(mount_option_mangle("rw,nosuid,foo,hogehoge,nodev,mode=755", 0, &f, &opts) == 0);
  41         assert_se(f == (MS_NOSUID|MS_NODEV));
  42         assert_se(streq(opts, "foo,hogehoge,mode=755"));
  43         opts = mfree(opts);
  44
  45         assert_se(mount_option_mangle("rw,nosuid,nodev,noexec,relatime,net_cls,net_prio", MS_RDONLY, &f, &opts) == 0);
  46         assert_se(f == (MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_RELATIME));
  47         assert_se(streq(opts, "net_cls,net_prio"));
  48         opts = mfree(opts);
  49
  50         assert_se(mount_option_mangle("rw,nosuid,nodev,relatime,size=1630748k,mode=700,uid=1000,gid=1000", MS_RDONLY, &f, &opts) == 0);
  51         assert_se(f == (MS_NOSUID|MS_NODEV|MS_RELATIME));
  52         assert_se(streq(opts, "size=1630748k,mode=700,uid=1000,gid=1000"));
  53         opts = mfree(opts);
  54
  55         assert_se(mount_option_mangle("size=1630748k,rw,gid=1000,,,nodev,relatime,,mode=700,nosuid,uid=1000", MS_RDONLY, &f, &opts) == 0);
  56         assert_se(f == (MS_NOSUID|MS_NODEV|MS_RELATIME));
  57         assert_se(streq(opts, "size=1630748k,gid=1000,mode=700,uid=1000"));
  58         opts = mfree(opts);
  59
  60         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);
  61         assert_se(f == (MS_NOSUID|MS_NODEV));
  62         assert_se(streq(opts, "size=8143984k,nr_inodes=2035996,mode=755"));
  63         opts = mfree(opts);
  64
  65         assert_se(mount_option_mangle("rw,relatime,fmask=0022,,,dmask=0022", MS_RDONLY, &f, &opts) == 0);
  66         assert_se(f == MS_RELATIME);
  67         assert_se(streq(opts, "fmask=0022,dmask=0022"));
  68         opts = mfree(opts);
  69
  70         assert_se(mount_option_mangle("rw,relatime,fmask=0022,dmask=0022,\"hogehoge", MS_RDONLY, &f, &opts) < 0);
  71 }
  72
  73 static void test_bind_remount_recursive(void) {
  74         _cleanup_(rm_rf_physical_and_freep) char *tmp = NULL;
  75         _cleanup_free_ char *subdir = NULL;
  76         const char *p;
  77
  78         if (geteuid() != 0) {
  79                 (void) log_tests_skipped("not running as root");
  80                 return;
  81         }
  82
  83         assert_se(mkdtemp_malloc("/tmp/XXXXXX", &tmp) >= 0);
  84         subdir = path_join(tmp, "subdir");
  85         assert_se(subdir);
  86         assert_se(mkdir(subdir, 0755) >= 0);
  87
  88         FOREACH_STRING(p, "/usr", "/sys", "/", tmp) {
  89                 pid_t pid;
  90
  91                 pid = fork();
  92                 assert_se(pid >= 0);
  93
  94                 if (pid == 0) {
  95                         struct statvfs svfs;
  96                         /* child */
  97                         assert_se(detach_mount_namespace() >= 0);
  98
  99                         /* Check that the subdir is writable (it must be because it's in /tmp) */
 100                         assert_se(statvfs(subdir, &svfs) >= 0);
 101                         assert_se(!FLAGS_SET(svfs.f_flag, ST_RDONLY));
 102
 103                         /* Make the subdir a bind mount */
 104                         assert_se(mount_nofollow(subdir, subdir, NULL, MS_BIND|MS_REC, NULL) >= 0);
 105
 106                         /* Ensure it's still writable */
 107                         assert_se(statvfs(subdir, &svfs) >= 0);
 108                         assert_se(!FLAGS_SET(svfs.f_flag, ST_RDONLY));
 109
 110                         /* Now mark the path we currently run for read-only */
 111                         assert_se(bind_remount_recursive(p, MS_RDONLY, MS_RDONLY, STRV_MAKE("/sys/kernel")) >= 0);
 112
 113                         /* Ensure that this worked on the top-level */
 114                         assert_se(statvfs(p, &svfs) >= 0);
 115                         assert_se(FLAGS_SET(svfs.f_flag, ST_RDONLY));
 116
 117                         /* And ensure this had an effect on the subdir exactly if we are talking about a path above the subdir */
 118                         assert_se(statvfs(subdir, &svfs) >= 0);
 119                         assert_se(FLAGS_SET(svfs.f_flag, ST_RDONLY) == !!path_startswith(subdir, p));
 120
 121                         _exit(EXIT_SUCCESS);
 122                 }
 123
 124                 assert_se(wait_for_terminate_and_check("test-remount-rec", pid, WAIT_LOG) == EXIT_SUCCESS);
 125         }
 126 }
 127
 128 static void test_bind_remount_one(void) {
 129         pid_t pid;
 130
 131         if (geteuid() != 0) {
 132                 (void) log_tests_skipped("not running as root");
 133                 return;
 134         }
 135
 136         pid = fork();
 137         assert_se(pid >= 0);
 138
 139         if (pid == 0) {
 140                 /* child */
 141
 142                 _cleanup_fclose_ FILE *proc_self_mountinfo = NULL;
 143
 144                 assert_se(detach_mount_namespace() >= 0);
 145
 146                 assert_se(fopen_unlocked("/proc/self/mountinfo", "re", &proc_self_mountinfo) >= 0);
 147
 148                 assert_se(bind_remount_one_with_mountinfo("/run", MS_RDONLY, MS_RDONLY, proc_self_mountinfo) >= 0);
 149                 assert_se(bind_remount_one_with_mountinfo("/proc/idontexist", MS_RDONLY, MS_RDONLY, proc_self_mountinfo) == -ENOENT);
 150                 assert_se(bind_remount_one_with_mountinfo("/proc/self", MS_RDONLY, MS_RDONLY, proc_self_mountinfo) == -EINVAL);
 151                 assert_se(bind_remount_one_with_mountinfo("/", MS_RDONLY, MS_RDONLY, proc_self_mountinfo) >= 0);
 152
 153                 _exit(EXIT_SUCCESS);
 154         }
 155
 156         assert_se(wait_for_terminate_and_check("test-remount-one", pid, WAIT_LOG) == EXIT_SUCCESS);
 157 }
 158
 159 int main(int argc, char *argv[]) {
 160         test_setup_logging(LOG_DEBUG);
 161
 162         test_mount_option_mangle();
 163         test_bind_remount_recursive();
 164         test_bind_remount_one();
 165
 166         return 0;
 167 }