src/shared/udev-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4
   5 #include "alloc-util.h"
   6 #include "env-file.h"
   7 #include "log.h"
   8 #include "parse-util.h"
   9 #include "string-table.h"
  10 #include "string-util.h"
  11 #include "udev-util.h"
  12
  13 static const char* const resolve_name_timing_table[_RESOLVE_NAME_TIMING_MAX] = {
  14         [RESOLVE_NAME_NEVER] = "never",
  15         [RESOLVE_NAME_LATE] = "late",
  16         [RESOLVE_NAME_EARLY] = "early",
  17 };
  18
  19 DEFINE_STRING_TABLE_LOOKUP(resolve_name_timing, ResolveNameTiming);
  20
  21 int udev_parse_config_full(
  22                 unsigned *ret_children_max,
  23                 usec_t *ret_exec_delay_usec,
  24                 usec_t *ret_event_timeout_usec,
  25                 ResolveNameTiming *ret_resolve_name_timing) {
  26
  27         _cleanup_free_ char *log_val = NULL, *children_max = NULL, *exec_delay = NULL, *event_timeout = NULL, *resolve_names = NULL;
  28         int r;
  29
  30         r = parse_env_file(NULL, "/etc/udev/udev.conf",
  31                            "udev_log", &log_val,
  32                            "children_max", &children_max,
  33                            "exec_delay", &exec_delay,
  34                            "event_timeout", &event_timeout,
  35                            "resolve_names", &resolve_names);
  36         if (r == -ENOENT)
  37                 return 0;
  38         if (r < 0)
  39                 return r;
  40
  41         if (log_val) {
  42                 const char *log;
  43                 size_t n;
  44
  45                 /* unquote */
  46                 n = strlen(log_val);
  47                 if (n >= 2 &&
  48                     ((log_val[0] == '"' && log_val[n-1] == '"') ||
  49                      (log_val[0] == '\'' && log_val[n-1] == '\''))) {
  50                         log_val[n - 1] = '\0';
  51                         log = log_val + 1;
  52                 } else
  53                         log = log_val;
  54
  55                 /* we set the udev log level here explicitly, this is supposed
  56                  * to regulate the code in libudev/ and udev/. */
  57                 r = log_set_max_level_from_string_realm(LOG_REALM_UDEV, log);
  58                 if (r < 0)
  59                         log_debug_errno(r, "/etc/udev/udev.conf: failed to set udev log level '%s', ignoring: %m", log);
  60         }
  61
  62         if (ret_children_max && children_max) {
  63                 r = safe_atou(children_max, ret_children_max);
  64                 if (r < 0)
  65                         log_notice_errno(r, "/etc/udev/udev.conf: failed to set parse children_max=%s, ignoring: %m", children_max);
  66         }
  67
  68         if (ret_exec_delay_usec && exec_delay) {
  69                 r = parse_sec(exec_delay, ret_exec_delay_usec);
  70                 if (r < 0)
  71                         log_notice_errno(r, "/etc/udev/udev.conf: failed to set parse exec_delay=%s, ignoring: %m", exec_delay);
  72         }
  73
  74         if (ret_event_timeout_usec && event_timeout) {
  75                 r = parse_sec(event_timeout, ret_event_timeout_usec);
  76                 if (r < 0)
  77                         log_notice_errno(r, "/etc/udev/udev.conf: failed to set parse event_timeout=%s, ignoring: %m", event_timeout);
  78         }
  79
  80         if (ret_resolve_name_timing && resolve_names) {
  81                 ResolveNameTiming t;
  82
  83                 t = resolve_name_timing_from_string(resolve_names);
  84                 if (t < 0)
  85                         log_notice("/etc/udev/udev.conf: failed to set parse resolve_names=%s, ignoring.", resolve_names);
  86                 else
  87                         *ret_resolve_name_timing = t;
  88         }
  89
  90         return 0;
  91 }
  92
  93 struct DeviceMonitorData {
  94         const char *sysname;
  95         sd_device *device;
  96 };
  97
  98 static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) {
  99         struct DeviceMonitorData *data = userdata;
 100         const char *sysname;
 101
 102         assert(device);
 103         assert(data);
 104         assert(data->sysname);
 105         assert(!data->device);
 106
 107         if (sd_device_get_sysname(device, &sysname) >= 0 && streq(sysname, data->sysname)) {
 108                 data->device = sd_device_ref(device);
 109                 return sd_event_exit(sd_device_monitor_get_event(monitor), 0);
 110         }
 111
 112         return 0;
 113 }
 114
 115 int device_wait_for_initialization(sd_device *device, const char *subsystem, sd_device **ret) {
 116         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
 117         _cleanup_(sd_event_unrefp) sd_event *event = NULL;
 118         struct DeviceMonitorData data = {};
 119         int r;
 120
 121         assert(device);
 122         assert(subsystem);
 123
 124         if (sd_device_get_is_initialized(device) > 0) {
 125                 if (ret)
 126                         *ret = sd_device_ref(device);
 127                 return 0;
 128         }
 129
 130         assert_se(sd_device_get_sysname(device, &data.sysname) >= 0);
 131
 132         /* Wait until the device is initialized, so that we can get access to the ID_PATH property */
 133
 134         r = sd_event_new(&event);
 135         if (r < 0)
 136                 return log_error_errno(r, "Failed to get default event: %m");
 137
 138         r = sd_device_monitor_new(&monitor);
 139         if (r < 0)
 140                 return log_error_errno(r, "Failed to acquire monitor: %m");
 141
 142         r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, NULL);
 143         if (r < 0)
 144                 return log_error_errno(r, "Failed to add %s subsystem match to monitor: %m", subsystem);
 145
 146         r = sd_device_monitor_attach_event(monitor, event);
 147         if (r < 0)
 148                 return log_error_errno(r, "Failed to attach event to device monitor: %m");
 149
 150         r = sd_device_monitor_start(monitor, device_monitor_handler, &data);
 151         if (r < 0)
 152                 return log_error_errno(r, "Failed to start device monitor: %m");
 153
 154         /* Check again, maybe things changed. Udev will re-read the db if the device wasn't initialized
 155          * yet. */
 156         if (sd_device_get_is_initialized(device) > 0) {
 157                 if (ret)
 158                         *ret = sd_device_ref(device);
 159                 return 0;
 160         }
 161
 162         r = sd_event_loop(event);
 163         if (r < 0)
 164                 return log_error_errno(r, "Event loop failed: %m");
 165
 166         if (ret)
 167                 *ret = TAKE_PTR(data.device);
 168         return 0;
 169 }
 170
 171 int device_is_renaming(sd_device *dev) {
 172         int r;
 173
 174         assert(dev);
 175
 176         r = sd_device_get_property_value(dev, "ID_RENAMING", NULL);
 177         if (r < 0 && r != -ENOENT)
 178                 return r;
 179
 180         return r >= 0;
 181 }
 182
 183 bool device_for_action(sd_device *dev, DeviceAction action) {
 184         DeviceAction a;
 185
 186         assert(dev);
 187
 188         if (device_get_action(dev, &a) < 0)
 189                 return false;
 190
 191         return a == action;
 192 }