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 "device-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
  14 static const char* const resolve_name_timing_table[_RESOLVE_NAME_TIMING_MAX] = {
  15         [RESOLVE_NAME_NEVER] = "never",
  16         [RESOLVE_NAME_LATE] = "late",
  17         [RESOLVE_NAME_EARLY] = "early",
  18 };
  19
  20 DEFINE_STRING_TABLE_LOOKUP(resolve_name_timing, ResolveNameTiming);
  21
  22 int udev_parse_config_full(
  23                 unsigned *ret_children_max,
  24                 usec_t *ret_exec_delay_usec,
  25                 usec_t *ret_event_timeout_usec,
  26                 ResolveNameTiming *ret_resolve_name_timing) {
  27
  28         _cleanup_free_ char *log_val = NULL, *children_max = NULL, *exec_delay = NULL, *event_timeout = NULL, *resolve_names = NULL;
  29         int r;
  30
  31         r = parse_env_file(NULL, "/etc/udev/udev.conf",
  32                            "udev_log", &log_val,
  33                            "children_max", &children_max,
  34                            "exec_delay", &exec_delay,
  35                            "event_timeout", &event_timeout,
  36                            "resolve_names", &resolve_names);
  37         if (r == -ENOENT)
  38                 return 0;
  39         if (r < 0)
  40                 return r;
  41
  42         if (log_val) {
  43                 const char *log;
  44                 size_t n;
  45
  46                 /* unquote */
  47                 n = strlen(log_val);
  48                 if (n >= 2 &&
  49                     ((log_val[0] == '"' && log_val[n-1] == '"') ||
  50                      (log_val[0] == '\'' && log_val[n-1] == '\''))) {
  51                         log_val[n - 1] = '\0';
  52                         log = log_val + 1;
  53                 } else
  54                         log = log_val;
  55
  56                 /* we set the udev log level here explicitly, this is supposed
  57                  * to regulate the code in libudev/ and udev/. */
  58                 r = log_set_max_level_from_string_realm(LOG_REALM_UDEV, log);
  59                 if (r < 0)
  60                         log_syntax(NULL, LOG_WARNING, "/etc/udev/udev.conf", 0, r,
  61                                    "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_syntax(NULL, LOG_WARNING, "/etc/udev/udev.conf", 0, r,
  68                                    "failed to set parse children_max=%s, ignoring: %m", children_max);
  69         }
  70
  71         if (ret_exec_delay_usec && exec_delay) {
  72                 r = parse_sec(exec_delay, ret_exec_delay_usec);
  73                 if (r < 0)
  74                         log_syntax(NULL, LOG_WARNING, "/etc/udev/udev.conf", 0, r,
  75                                    "failed to set parse exec_delay=%s, ignoring: %m", exec_delay);
  76         }
  77
  78         if (ret_event_timeout_usec && event_timeout) {
  79                 r = parse_sec(event_timeout, ret_event_timeout_usec);
  80                 if (r < 0)
  81                         log_syntax(NULL, LOG_WARNING, "/etc/udev/udev.conf", 0, r,
  82                                    "failed to set parse event_timeout=%s, ignoring: %m", event_timeout);
  83         }
  84
  85         if (ret_resolve_name_timing && resolve_names) {
  86                 ResolveNameTiming t;
  87
  88                 t = resolve_name_timing_from_string(resolve_names);
  89                 if (t < 0)
  90                         log_syntax(NULL, LOG_WARNING, "/etc/udev/udev.conf", 0, r,
  91                                    "failed to set parse resolve_names=%s, ignoring.", resolve_names);
  92                 else
  93                         *ret_resolve_name_timing = t;
  94         }
  95
  96         return 0;
  97 }
  98
  99 struct DeviceMonitorData {
 100         const char *sysname;
 101         sd_device *device;
 102 };
 103
 104 static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) {
 105         struct DeviceMonitorData *data = userdata;
 106         const char *sysname;
 107
 108         assert(device);
 109         assert(data);
 110         assert(data->sysname);
 111         assert(!data->device);
 112
 113         if (sd_device_get_sysname(device, &sysname) >= 0 && streq(sysname, data->sysname)) {
 114                 data->device = sd_device_ref(device);
 115                 return sd_event_exit(sd_device_monitor_get_event(monitor), 0);
 116         }
 117
 118         return 0;
 119 }
 120
 121 static int device_timeout_handler(sd_event_source *s, uint64_t usec, void *userdata) {
 122         return sd_event_exit(sd_event_source_get_event(s), -ETIMEDOUT);
 123 }
 124
 125 int device_wait_for_initialization(sd_device *device, const char *subsystem, usec_t timeout, sd_device **ret) {
 126         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
 127         _cleanup_(sd_event_source_unrefp) sd_event_source *timeout_source = NULL;
 128         _cleanup_(sd_event_unrefp) sd_event *event = NULL;
 129         struct DeviceMonitorData data = {};
 130         int r;
 131
 132         assert(device);
 133
 134         if (sd_device_get_is_initialized(device) > 0) {
 135                 if (ret)
 136                         *ret = sd_device_ref(device);
 137                 return 0;
 138         }
 139
 140         assert_se(sd_device_get_sysname(device, &data.sysname) >= 0);
 141
 142         /* Wait until the device is initialized, so that we can get access to the ID_PATH property */
 143
 144         r = sd_event_new(&event);
 145         if (r < 0)
 146                 return log_error_errno(r, "Failed to get default event: %m");
 147
 148         r = sd_device_monitor_new(&monitor);
 149         if (r < 0)
 150                 return log_error_errno(r, "Failed to acquire monitor: %m");
 151
 152         if (!subsystem) {
 153                 r = sd_device_get_subsystem(device, &subsystem);
 154                 if (r < 0 && r != -ENOENT)
 155                         return log_device_error_errno(device, r, "Failed to get subsystem: %m");
 156         }
 157
 158         if (subsystem) {
 159                 r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, NULL);
 160                 if (r < 0)
 161                         return log_error_errno(r, "Failed to add %s subsystem match to monitor: %m", subsystem);
 162         }
 163
 164         r = sd_device_monitor_attach_event(monitor, event);
 165         if (r < 0)
 166                 return log_error_errno(r, "Failed to attach event to device monitor: %m");
 167
 168         r = sd_device_monitor_start(monitor, device_monitor_handler, &data);
 169         if (r < 0)
 170                 return log_error_errno(r, "Failed to start device monitor: %m");
 171
 172         if (timeout != USEC_INFINITY) {
 173                 r = sd_event_add_time(event, &timeout_source,
 174                                       CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + timeout, 0,
 175                                       device_timeout_handler, NULL);
 176                 if (r < 0)
 177                         return log_error_errno(r, "Failed to add timeout event source: %m");
 178         }
 179
 180         /* Check again, maybe things changed. Udev will re-read the db if the device wasn't initialized
 181          * yet. */
 182         if (sd_device_get_is_initialized(device) > 0) {
 183                 if (ret)
 184                         *ret = sd_device_ref(device);
 185                 return 0;
 186         }
 187
 188         r = sd_event_loop(event);
 189         if (r < 0)
 190                 return log_error_errno(r, "Failed to wait for device to be initialized: %m");
 191
 192         if (ret)
 193                 *ret = TAKE_PTR(data.device);
 194         return 0;
 195 }
 196
 197 int device_is_renaming(sd_device *dev) {
 198         int r;
 199
 200         assert(dev);
 201
 202         r = sd_device_get_property_value(dev, "ID_RENAMING", NULL);
 203         if (r < 0 && r != -ENOENT)
 204                 return r;
 205
 206         return r >= 0;
 207 }
 208
 209 bool device_for_action(sd_device *dev, DeviceAction action) {
 210         DeviceAction a;
 211
 212         assert(dev);
 213
 214         if (device_get_action(dev, &a) < 0)
 215                 return false;
 216
 217         return a == action;
 218 }