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_debug_errno(r, "/etc/udev/udev.conf: failed to set udev log level '%s', ignoring: %m", log);
  61         }
  62
  63         if (ret_children_max && children_max) {
  64                 r = safe_atou(children_max, ret_children_max);
  65                 if (r < 0)
  66                         log_notice_errno(r, "/etc/udev/udev.conf: failed to set parse children_max=%s, ignoring: %m", children_max);
  67         }
  68
  69         if (ret_exec_delay_usec && exec_delay) {
  70                 r = parse_sec(exec_delay, ret_exec_delay_usec);
  71                 if (r < 0)
  72                         log_notice_errno(r, "/etc/udev/udev.conf: failed to set parse exec_delay=%s, ignoring: %m", exec_delay);
  73         }
  74
  75         if (ret_event_timeout_usec && event_timeout) {
  76                 r = parse_sec(event_timeout, ret_event_timeout_usec);
  77                 if (r < 0)
  78                         log_notice_errno(r, "/etc/udev/udev.conf: failed to set parse event_timeout=%s, ignoring: %m", event_timeout);
  79         }
  80
  81         if (ret_resolve_name_timing && resolve_names) {
  82                 ResolveNameTiming t;
  83
  84                 t = resolve_name_timing_from_string(resolve_names);
  85                 if (t < 0)
  86                         log_notice("/etc/udev/udev.conf: failed to set parse resolve_names=%s, ignoring.", resolve_names);
  87                 else
  88                         *ret_resolve_name_timing = t;
  89         }
  90
  91         return 0;
  92 }
  93
  94 struct DeviceMonitorData {
  95         const char *sysname;
  96         sd_device *device;
  97 };
  98
  99 static int device_monitor_handler(sd_device_monitor *monitor, sd_device *device, void *userdata) {
 100         struct DeviceMonitorData *data = userdata;
 101         const char *sysname;
 102
 103         assert(device);
 104         assert(data);
 105         assert(data->sysname);
 106         assert(!data->device);
 107
 108         if (sd_device_get_sysname(device, &sysname) >= 0 && streq(sysname, data->sysname)) {
 109                 data->device = sd_device_ref(device);
 110                 return sd_event_exit(sd_device_monitor_get_event(monitor), 0);
 111         }
 112
 113         return 0;
 114 }
 115
 116 int device_wait_for_initialization(sd_device *device, const char *subsystem, sd_device **ret) {
 117         _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
 118         _cleanup_(sd_event_unrefp) sd_event *event = NULL;
 119         struct DeviceMonitorData data = {};
 120         int r;
 121
 122         assert(device);
 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         if (!subsystem) {
 143                 r = sd_device_get_subsystem(device, &subsystem);
 144                 if (r < 0 && r != -ENOENT)
 145                         return log_device_error_errno(device, r, "Failed to get subsystem: %m");
 146         }
 147
 148         if (subsystem) {
 149                 r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, NULL);
 150                 if (r < 0)
 151                         return log_error_errno(r, "Failed to add %s subsystem match to monitor: %m", subsystem);
 152         }
 153
 154         r = sd_device_monitor_attach_event(monitor, event);
 155         if (r < 0)
 156                 return log_error_errno(r, "Failed to attach event to device monitor: %m");
 157
 158         r = sd_device_monitor_start(monitor, device_monitor_handler, &data);
 159         if (r < 0)
 160                 return log_error_errno(r, "Failed to start device monitor: %m");
 161
 162         /* Check again, maybe things changed. Udev will re-read the db if the device wasn't initialized
 163          * yet. */
 164         if (sd_device_get_is_initialized(device) > 0) {
 165                 if (ret)
 166                         *ret = sd_device_ref(device);
 167                 return 0;
 168         }
 169
 170         r = sd_event_loop(event);
 171         if (r < 0)
 172                 return log_error_errno(r, "Event loop failed: %m");
 173
 174         if (ret)
 175                 *ret = TAKE_PTR(data.device);
 176         return 0;
 177 }
 178
 179 int device_is_renaming(sd_device *dev) {
 180         int r;
 181
 182         assert(dev);
 183
 184         r = sd_device_get_property_value(dev, "ID_RENAMING", NULL);
 185         if (r < 0 && r != -ENOENT)
 186                 return r;
 187
 188         return r >= 0;
 189 }
 190
 191 bool device_for_action(sd_device *dev, DeviceAction action) {
 192         DeviceAction a;
 193
 194         assert(dev);
 195
 196         if (device_get_action(dev, &a) < 0)
 197                 return false;
 198
 199         return a == action;
 200 }