diff options
| -rw-r--r-- | libusb/os/darwin_usb.c | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/libusb/os/darwin_usb.c b/libusb/os/darwin_usb.c index 6ba3fea..7a23c7f 100644 --- a/libusb/os/darwin_usb.c +++ b/libusb/os/darwin_usb.c @@ -360,18 +360,36 @@ static int darwin_get_config_descriptor(struct libusb_device *dev, uint8_t confi struct darwin_device_priv *priv = (struct darwin_device_priv *)dev->os_priv; IOUSBConfigurationDescriptorPtr desc; IOReturn kresult; + usb_device_t **device; + + if (!priv) + return LIBUSB_ERROR_OTHER; + + if (!priv->device) { + kresult = darwin_get_device (priv->location, &device); + if (kresult || !device) { + _usbi_log (DEVICE_CTX (dev), LOG_LEVEL_ERROR, "could not find device: %s", darwin_error_str (kresult)); + return darwin_to_libusb (kresult); + } - kresult = (*(priv->device))->GetConfigurationDescriptorPtr (priv->device, config_index, &desc); + /* don't have to open the device to get a config descriptor */ + } else + device = priv->device; + + kresult = (*device)->GetConfigurationDescriptorPtr (device, config_index, &desc); if (kresult != kIOReturnSuccess) return darwin_to_libusb (kresult); - /* sanity check. is the buffer larger than the returned descriptor */ - if (len > sizeof (*desc)) - len = sizeof (*desc); + if (!priv->device) + (*device)->Release (device); + + /* copy descriptor */ + if (libusb_le16_to_cpu(desc->wTotalLength) < len) + len = libusb_le16_to_cpu(desc->wTotalLength); memmove (buffer, desc, len); - /* GetConfigurationDescriptorPtr returns the descriptor is USB bus order */ + /* GetConfigurationDescriptorPtr returns the descriptor in USB bus order */ *host_endian = 0; return 0; |