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/* SPDX-License-Identifier: GPL-2.0-or-later */
#include <errno.h>
#include "alloc-util.h"
#include "bus-error.h"
#include "bus-util.h"
#include "device-private.h"
#include "path-util.h"
#include "udevadm-util.h"
#include "unit-name.h"
static int find_device_from_path(const char *path, sd_device **ret) {
if (path_startswith(path, "/sys/"))
return sd_device_new_from_syspath(ret, path);
if (path_startswith(path, "/dev/")) {
struct stat st;
if (stat(path, &st) < 0)
return -errno;
return device_new_from_stat_rdev(ret, &st);
}
return -EINVAL;
}
static int find_device_from_unit(const char *unit_name, sd_device **ret) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
_cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
_cleanup_free_ char *unit_path = NULL, *syspath = NULL;
int r;
if (!unit_name_is_valid(unit_name, UNIT_NAME_PLAIN))
return -EINVAL;
if (unit_name_to_type(unit_name) != UNIT_DEVICE)
return -EINVAL;
r = bus_connect_system_systemd(&bus);
if (r < 0) {
_cleanup_free_ char *path = NULL;
log_debug_errno(r, "Failed to open connection to systemd, using unit name as syspath: %m");
r = unit_name_to_path(unit_name, &path);
if (r < 0)
return log_debug_errno(r, "Failed to convert \"%s\" to a device path: %m", unit_name);
return find_device_from_path(path, ret);
}
unit_path = unit_dbus_path_from_name(unit_name);
if (!unit_path)
return -ENOMEM;
r = sd_bus_get_property_string(
bus,
"org.freedesktop.systemd1",
unit_path,
"org.freedesktop.systemd1.Device",
"SysFSPath",
&error,
&syspath);
if (r < 0)
return log_debug_errno(r, "Failed to get SysFSPath= dbus property for %s: %s",
unit_name, bus_error_message(&error, r));
return sd_device_new_from_syspath(ret, syspath);
}
int find_device(const char *id, const char *prefix, sd_device **ret) {
_cleanup_free_ char *path = NULL;
int r;
assert(id);
assert(ret);
if (prefix) {
if (!path_startswith(id, prefix)) {
id = path = path_join(prefix, id);
if (!path)
return -ENOMEM;
}
} else {
/* In cases where the argument is generic (no prefix specified),
* check if the argument looks like a device unit name. */
r = find_device_from_unit(id, ret);
if (r >= 0)
return r;
}
return find_device_from_path(id, ret);
}
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