src/test/udev-rule-runner.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 /***
   3   Copyright © 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
   4 ***/
   5
   6 #include <errno.h>
   7 #include <sched.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <sys/mount.h>
  11 #include <sys/signalfd.h>
  12 #include <unistd.h>
  13
  14 #include "device-private.h"
  15 #include "fs-util.h"
  16 #include "log.h"
  17 #include "main-func.h"
  18 #include "mkdir-label.h"
  19 #include "mount-util.h"
  20 #include "namespace-util.h"
  21 #include "parse-util.h"
  22 #include "selinux-util.h"
  23 #include "signal-util.h"
  24 #include "string-util.h"
  25 #include "tests.h"
  26 #include "udev-event.h"
  27 #include "version.h"
  28
  29 static int device_new_from_synthetic_event(sd_device **ret, const char *syspath, const char *action) {
  30         _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
  31         sd_device_action_t a;
  32         int r;
  33
  34         assert(ret);
  35         assert(syspath);
  36         assert(action);
  37
  38         a = device_action_from_string(action);
  39         if (a < 0)
  40                 return a;
  41
  42         r = sd_device_new_from_syspath(&dev, syspath);
  43         if (r < 0)
  44                 return r;
  45
  46         r = device_read_uevent_file(dev);
  47         if (r < 0)
  48                 return r;
  49
  50         r = device_set_action(dev, a);
  51         if (r < 0)
  52                 return r;
  53
  54         *ret = TAKE_PTR(dev);
  55         return 0;
  56 }
  57
  58 static int fake_filesystems(void) {
  59         static const struct fakefs {
  60                 const char *src;
  61                 const char *target;
  62                 const char *error;
  63                 bool ignore_mount_error;
  64         } fakefss[] = {
  65                 { "tmpfs/sys", "/sys",                    "Failed to mount test /sys",                        false },
  66                 { "tmpfs/dev", "/dev",                    "Failed to mount test /dev",                        false },
  67                 { "run",       "/run",                    "Failed to mount test /run",                        false },
  68                 { "run",       "/etc/udev/rules.d",       "Failed to mount empty /etc/udev/rules.d",          true },
  69                 { "run",       UDEVLIBEXECDIR "/rules.d", "Failed to mount empty " UDEVLIBEXECDIR "/rules.d", true },
  70         };
  71         int r;
  72
  73         r = detach_mount_namespace();
  74         if (r < 0)
  75                 return log_error_errno(r, "Failed to detach mount namespace: %m");
  76
  77         for (size_t i = 0; i < ELEMENTSOF(fakefss); i++) {
  78                 r = mount_nofollow_verbose(fakefss[i].ignore_mount_error ? LOG_NOTICE : LOG_ERR,
  79                                            fakefss[i].src, fakefss[i].target, NULL, MS_BIND, NULL);
  80                 if (r < 0 && !fakefss[i].ignore_mount_error)
  81                         return r;
  82         }
  83
  84         return 0;
  85 }
  86
  87 static int run(int argc, char *argv[]) {
  88         _cleanup_(udev_rules_freep) UdevRules *rules = NULL;
  89         _cleanup_(udev_event_freep) UdevEvent *event = NULL;
  90         _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
  91         const char *devpath, *devname, *action;
  92         int r;
  93
  94         test_setup_logging(LOG_INFO);
  95
  96         if (!IN_SET(argc, 2, 3, 4))
  97                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
  98                                        "This program needs between one and three arguments, %d given", argc - 1);
  99
 100         r = fake_filesystems();
 101         if (r < 0)
 102                 return r;
 103
 104         /* Let's make sure the test runs with selinux assumed disabled. */
 105 #if HAVE_SELINUX
 106         fini_selinuxmnt();
 107 #endif
 108         mac_selinux_retest();
 109
 110         if (argc == 2) {
 111                 if (!streq(argv[1], "check"))
 112                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
 113                                                "Unknown argument: %s", argv[1]);
 114
 115                 return 0;
 116         }
 117
 118         log_debug("version %s", GIT_VERSION);
 119
 120         r = mac_init();
 121         if (r < 0)
 122                 return r;
 123
 124         action = argv[1];
 125         devpath = argv[2];
 126
 127         if (argv[3]) {
 128                 unsigned us;
 129
 130                 r = safe_atou(argv[3], &us);
 131                 if (r < 0)
 132                         return log_error_errno(r, "Invalid delay '%s': %m", argv[3]);
 133                 usleep(us);
 134         }
 135
 136         assert_se(udev_rules_load(&rules, RESOLVE_NAME_EARLY) == 0);
 137
 138         const char *syspath = strjoina("/sys", devpath);
 139         r = device_new_from_synthetic_event(&dev, syspath, action);
 140         if (r < 0)
 141                 return log_debug_errno(r, "Failed to open device '%s'", devpath);
 142
 143         assert_se(event = udev_event_new(dev, 0, NULL, log_get_max_level()));
 144
 145         assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, SIGHUP, SIGCHLD, -1) >= 0);
 146
 147         /* do what devtmpfs usually provides us */
 148         if (sd_device_get_devname(dev, &devname) >= 0) {
 149                 const char *subsystem;
 150                 mode_t mode = 0600;
 151
 152                 if (sd_device_get_subsystem(dev, &subsystem) >= 0 && streq(subsystem, "block"))
 153                         mode |= S_IFBLK;
 154                 else
 155                         mode |= S_IFCHR;
 156
 157                 if (!streq(action, "remove")) {
 158                         dev_t devnum = makedev(0, 0);
 159
 160                         (void) mkdir_parents_label(devname, 0755);
 161                         (void) sd_device_get_devnum(dev, &devnum);
 162                         if (mknod(devname, mode, devnum) < 0)
 163                                 return log_error_errno(errno, "mknod() failed for '%s': %m", devname);
 164                 } else {
 165                         if (unlink(devname) < 0)
 166                                 return log_error_errno(errno, "unlink('%s') failed: %m", devname);
 167                         (void) rmdir_parents(devname, "/dev");
 168                 }
 169         }
 170
 171         udev_event_execute_rules(event, -1, 3 * USEC_PER_SEC, SIGKILL, NULL, rules);
 172         udev_event_execute_run(event, 3 * USEC_PER_SEC, SIGKILL);
 173
 174         return 0;
 175 }
 176
 177 DEFINE_MAIN_FUNCTION(run);