Beispiel #1
0
static int find_device(
                const struct rfkill_event *event,
                sd_device **ret) {
        _cleanup_(sd_device_unrefp) sd_device *device = NULL;
        _cleanup_free_ char *sysname = NULL;
        const char *name;
        int r;

        assert(event);
        assert(ret);

        if (asprintf(&sysname, "rfkill%i", event->idx) < 0)
                return log_oom();

        r = sd_device_new_from_subsystem_sysname(&device, "rfkill", sysname);
        if (r < 0)
                return log_full_errno(IN_SET(r, -ENOENT, -ENXIO, -ENODEV) ? LOG_DEBUG : LOG_ERR, r,
                                      "Failed to open device '%s': %m", sysname);

        r = sd_device_get_sysattr_value(device, "name", &name);
        if (r < 0)
                return log_debug_errno(r, "Device has no name, ignoring: %m");

        log_debug("Operating on rfkill device '%s'.", name);

        *ret = TAKE_PTR(device);
        return 0;
}
Beispiel #2
0
/* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
int util_resolve_subsys_kernel(const char *string, char *result, size_t maxsize, bool read_value) {
        char temp[UTIL_PATH_SIZE], *subsys, *sysname, *attr;
        _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
        const char *val;
        int r;

        if (string[0] != '[')
                return -EINVAL;

        strscpy(temp, sizeof(temp), string);

        subsys = &temp[1];

        sysname = strchr(subsys, '/');
        if (!sysname)
                return -EINVAL;
        sysname[0] = '\0';
        sysname = &sysname[1];

        attr = strchr(sysname, ']');
        if (!attr)
                return -EINVAL;
        attr[0] = '\0';
        attr = &attr[1];
        if (attr[0] == '/')
                attr = &attr[1];
        if (attr[0] == '\0')
                attr = NULL;

        if (read_value && !attr)
                return -EINVAL;

        r = sd_device_new_from_subsystem_sysname(&dev, subsys, sysname);
        if (r < 0)
                return r;

        if (read_value) {
                r = sd_device_get_sysattr_value(dev, attr, &val);
                if (r < 0 && r != -ENOENT)
                        return r;
                if (r == -ENOENT)
                        result[0] = '\0';
                else
                        strscpy(result, maxsize, val);
                log_debug("value '[%s/%s]%s' is '%s'", subsys, sysname, attr, result);
        } else {
                r = sd_device_get_syspath(dev, &val);
                if (r < 0)
                        return r;

                strscpyl(result, maxsize, val, attr ? "/" : NULL, attr ?: NULL, NULL);
                log_debug("path '[%s/%s]%s' is '%s'", subsys, sysname, strempty(attr), result);
        }
        return 0;
}
Beispiel #3
0
/**
 * udev_device_get_sysattr_value:
 * @udev_device: udev device
 * @sysattr: attribute name
 *
 * The retrieved value is cached in the device. Repeated calls will return the same
 * value and not open the attribute again.
 *
 * Returns: the content of a sys attribute file, or #NULL if there is no sys attribute value.
 **/
_public_ const char *udev_device_get_sysattr_value(struct udev_device *udev_device, const char *sysattr)
{
        const char *value;
        int r;

        assert_return_errno(udev_device, NULL, EINVAL);

        r = sd_device_get_sysattr_value(udev_device->device, sysattr, &value);
        if (r < 0) {
                errno = -r;
                return NULL;
        }

        return value;
}