src/shared/udev-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <string.h>
   5
   6 #include "alloc-util.h"
   7 #include "env-file.h"
   8 #include "log.h"
   9 #include "parse-util.h"
  10 #include "string-table.h"
  11 #include "string-util.h"
  12 #include "udev-util.h"
  13 #include "udev.h"
  14
  15 static const char* const resolve_name_timing_table[_RESOLVE_NAME_TIMING_MAX] = {
  16         [RESOLVE_NAME_NEVER] = "never",
  17         [RESOLVE_NAME_LATE] = "late",
  18         [RESOLVE_NAME_EARLY] = "early",
  19 };
  20
  21 DEFINE_STRING_TABLE_LOOKUP(resolve_name_timing, ResolveNameTiming);
  22
  23 int udev_parse_config_full(
  24                 unsigned *ret_children_max,
  25                 usec_t *ret_exec_delay_usec,
  26                 usec_t *ret_event_timeout_usec,
  27                 ResolveNameTiming *ret_resolve_name_timing) {
  28
  29         _cleanup_free_ char *log_val = NULL, *children_max = NULL, *exec_delay = NULL, *event_timeout = NULL, *resolve_names = NULL;
  30         int r;
  31
  32         r = parse_env_file(NULL, "/etc/udev/udev.conf",
  33                            "udev_log", &log_val,
  34                            "children_max", &children_max,
  35                            "exec_delay", &exec_delay,
  36                            "event_timeout", &event_timeout,
  37                            "resolve_names", &resolve_names);
  38         if (r == -ENOENT)
  39                 return 0;
  40         if (r < 0)
  41                 return r;
  42
  43         if (log_val) {
  44                 const char *log;
  45                 size_t n;
  46
  47                 /* unquote */
  48                 n = strlen(log_val);
  49                 if (n >= 2 &&
  50                     ((log_val[0] == '"' && log_val[n-1] == '"') ||
  51                      (log_val[0] == '\'' && log_val[n-1] == '\''))) {
  52                         log_val[n - 1] = '\0';
  53                         log = log_val + 1;
  54                 } else
  55                         log = log_val;
  56
  57                 /* we set the udev log level here explicitly, this is supposed
  58                  * to regulate the code in libudev/ and udev/. */
  59                 r = log_set_max_level_from_string_realm(LOG_REALM_UDEV, log);
  60                 if (r < 0)
  61                         log_debug_errno(r, "/etc/udev/udev.conf: failed to set udev log level '%s', ignoring: %m", log);
  62         }
  63
  64         if (ret_children_max && children_max) {
  65                 r = safe_atou(children_max, ret_children_max);
  66                 if (r < 0)
  67                         log_notice_errno(r, "/etc/udev/udev.conf: failed to set parse children_max=%s, ignoring: %m", children_max);
  68         }
  69
  70         if (ret_exec_delay_usec && exec_delay) {
  71                 r = parse_sec(exec_delay, ret_exec_delay_usec);
  72                 if (r < 0)
  73                         log_notice_errno(r, "/etc/udev/udev.conf: failed to set parse exec_delay=%s, ignoring: %m", exec_delay);
  74         }
  75
  76         if (ret_event_timeout_usec && event_timeout) {
  77                 r = parse_sec(event_timeout, ret_event_timeout_usec);
  78                 if (r < 0)
  79                         log_notice_errno(r, "/etc/udev/udev.conf: failed to set parse event_timeout=%s, ignoring: %m", event_timeout);
  80         }
  81
  82         if (ret_resolve_name_timing && resolve_names) {
  83                 ResolveNameTiming t;
  84
  85                 t = resolve_name_timing_from_string(resolve_names);
  86                 if (t < 0)
  87                         log_notice("/etc/udev/udev.conf: failed to set parse resolve_names=%s, ignoring.", resolve_names);
  88                 else
  89                         *ret_resolve_name_timing = t;
  90         }
  91
  92         return 0;
  93 }
  94
  95 struct DeviceMonitorData {
  96         const char *sysname;
  97         sd_device *device;
  98 };
  99
 100 static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) {
 101         struct DeviceMonitorData *data = userdata;
 102         const char *sysname;
 103
 104         assert(device);
 105         assert(data);
 106         assert(data->sysname);
 107         assert(!data->device);
 108
 109         if (sd_device_get_sysname(device, &sysname) >= 0 && streq(sysname, data->sysname)) {
 110                 data->device = sd_device_ref(device);
 111                 return sd_event_exit(sd_device_monitor_get_event(monitor), 0);
 112         }
 113
 114         return 0;
 115 }
 116
 117 int device_wait_for_initialization(sd_device *device, const char *subsystem, sd_device **ret) {
 118         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
 119         _cleanup_(sd_event_unrefp) sd_event *event = NULL;
 120         struct DeviceMonitorData data = {};
 121         int r;
 122
 123         assert(device);
 124         assert(subsystem);
 125
 126         if (sd_device_get_is_initialized(device) > 0) {
 127                 if (ret)
 128                         *ret = sd_device_ref(device);
 129                 return 0;
 130         }
 131
 132         assert_se(sd_device_get_sysname(device, &data.sysname) >= 0);
 133
 134         /* Wait until the device is initialized, so that we can get access to the ID_PATH property */
 135
 136         r = sd_event_default(&event);
 137         if (r < 0)
 138                 return log_error_errno(r, "Failed to get default event: %m");
 139
 140         r = sd_device_monitor_new(&monitor);
 141         if (r < 0)
 142                 return log_error_errno(r, "Failed to acquire monitor: %m");
 143
 144         r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, NULL);
 145         if (r < 0)
 146                 return log_error_errno(r, "Failed to add %s subsystem match to monitor: %m", subsystem);
 147
 148         r = sd_device_monitor_attach_event(monitor, event);
 149         if (r < 0)
 150                 return log_error_errno(r, "Failed to attach event to device monitor: %m");
 151
 152         r = sd_device_monitor_start(monitor, device_monitor_handler, &data);
 153         if (r < 0)
 154                 return log_error_errno(r, "Failed to start device monitor: %m");
 155
 156         /* Check again, maybe things changed. Udev will re-read the db if the device wasn't initialized
 157          * yet. */
 158         if (sd_device_get_is_initialized(device) > 0) {
 159                 if (ret)
 160                         *ret = sd_device_ref(device);
 161                 return 0;
 162         }
 163
 164         r = sd_event_loop(event);
 165         if (r < 0)
 166                 return log_error_errno(r, "Event loop failed: %m");
 167
 168         if (ret)
 169                 *ret = TAKE_PTR(data.device);
 170         return 0;
 171 }
 172
 173 int device_is_renaming(sd_device *dev) {
 174         int r;
 175
 176         assert(dev);
 177
 178         r = sd_device_get_property_value(dev, "ID_RENAMING", NULL);
 179         if (r < 0 && r != -ENOENT)
 180                 return r;
 181
 182         return r >= 0;
 183 }