core: Remove usbi_parse_descriptor() function

The Linux backend was the only caller of this function, but with the
packed structures introduced in commit d06cc52851 its use is no longer
necessary. Convert the function to static and remove the return type as
no callers paid attention to it.

Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>

1 files changed, 23 insertions, 22 deletions

diff --git a/libusb/os/linux_usbfs.c b/libusb/os/linux_usbfs.c
index 31304d6..4dd5337 100644
--- a/libusb/os/linux_usbfs.c
+++ b/libusb/os/linux_usbfs.c
@@ -613,10 +613,10 @@ int linux_get_device_address(struct libusb_context *ctx, int detached,
 static int seek_to_next_descriptor(struct libusb_context *ctx,
 	uint8_t descriptor_type, unsigned char *buffer, int size)
 {
-	struct usbi_descriptor_header header;
+	struct usbi_descriptor_header *header;
 	int i;
 
-	for (i = 0; size >= 0; i += header.bLength, size -= header.bLength) {
+	for (i = 0; size >= 0; i += header->bLength, size -= header->bLength) {
 		if (size == 0)
 			return LIBUSB_ERROR_NOT_FOUND;
 
@@ -624,9 +624,9 @@ static int seek_to_next_descriptor(struct libusb_context *ctx,
 			usbi_err(ctx, "short descriptor read %d/2", size);
 			return LIBUSB_ERROR_IO;
 		}
-		usbi_parse_descriptor(buffer + i, "bb", &header, 0);
 
-		if (i && header.bDescriptorType == descriptor_type)
+		header = (struct usbi_descriptor_header *)(buffer + i);
+		if (i && header->bDescriptorType == descriptor_type)
 			return i;
 	}
 	usbi_err(ctx, "bLength overflow by %d bytes", -size);
@@ -639,7 +639,8 @@ static int seek_to_next_config(struct libusb_device *dev,
 {
 	struct libusb_context *ctx = DEVICE_CTX(dev);
 	struct linux_device_priv *priv = usbi_get_device_priv(dev);
-	struct libusb_config_descriptor config;
+	struct usbi_configuration_descriptor *config;
+	uint16_t config_len;
 
 	if (size == 0)
 		return LIBUSB_ERROR_NOT_FOUND;
@@ -650,15 +651,16 @@ static int seek_to_next_config(struct libusb_device *dev,
 		return LIBUSB_ERROR_IO;
 	}
 
-	usbi_parse_descriptor(buffer, "bbwbbbbb", &config, 0);
-	if (config.bDescriptorType != LIBUSB_DT_CONFIG) {
+	config = (struct usbi_configuration_descriptor *)buffer;
+	if (config->bDescriptorType != LIBUSB_DT_CONFIG) {
 		usbi_err(ctx, "descriptor is not a config desc (type 0x%02x)",
-			 config.bDescriptorType);
+			 config->bDescriptorType);
 		return LIBUSB_ERROR_IO;
 	}
 
+	config_len = libusb_le16_to_cpu(config->wTotalLength);
 	/*
-	 * In usbfs the config descriptors are config.wTotalLength bytes apart,
+	 * In usbfs the config descriptors are wTotalLength bytes apart,
 	 * with any short reads from the device appearing as holes in the file.
 	 *
 	 * In sysfs wTotalLength is ignored, instead the kernel returns a
@@ -673,20 +675,20 @@ static int seek_to_next_config(struct libusb_device *dev,
 		if (next < 0)
 			return next;
 
-		if (next != config.wTotalLength)
+		if (next != config_len)
 			usbi_warn(ctx, "config length mismatch wTotalLength %u real %d",
-				  config.wTotalLength, next);
+				  config_len, next);
 		return next;
 	} else {
-		if (config.wTotalLength < LIBUSB_DT_CONFIG_SIZE) {
-			usbi_err(ctx, "invalid wTotalLength %u", config.wTotalLength);
+		if (config_len < LIBUSB_DT_CONFIG_SIZE) {
+			usbi_err(ctx, "invalid wTotalLength %u", config_len);
 			return LIBUSB_ERROR_IO;
-		} else if (config.wTotalLength > size) {
+		} else if (config_len > size) {
 			usbi_warn(ctx, "short descriptor read %d/%u",
-				  size, config.wTotalLength);
+				  size, config_len);
 			return size;
 		} else {
-			return config.wTotalLength;
+			return config_len;
 		}
 	}
 }
@@ -697,7 +699,7 @@ static int op_get_config_descriptor_by_value(struct libusb_device *dev,
 	struct linux_device_priv *priv = usbi_get_device_priv(dev);
 	unsigned char *descriptors = priv->descriptors;
 	int size = priv->descriptors_len;
-	struct libusb_config_descriptor *config;
+	struct usbi_configuration_descriptor *config;
 
 	*buffer = NULL;
 	/* Unlike the device desc. config descs. are always in raw format */
@@ -713,7 +715,7 @@ static int op_get_config_descriptor_by_value(struct libusb_device *dev,
 
 		if (next < 0)
 			return next;
-		config = (struct libusb_config_descriptor *)descriptors;
+		config = (struct usbi_configuration_descriptor *)descriptors;
 		if (config->bConfigurationValue == value) {
 			*buffer = descriptors;
 			return next;
@@ -917,11 +919,10 @@ static int initialize_device(struct libusb_device *dev, uint8_t busnum,
 		usbi_warn(ctx, "Missing rw usbfs access; cannot determine "
 			       "active configuration descriptor");
 		if (priv->descriptors_len >= (DEVICE_DESC_LENGTH + LIBUSB_DT_CONFIG_SIZE)) {
-			struct libusb_config_descriptor config;
+			struct usbi_configuration_descriptor *config;
 
-			usbi_parse_descriptor(priv->descriptors + DEVICE_DESC_LENGTH,
-					      "bbwbbbbb", &config, 0);
-			priv->active_config = config.bConfigurationValue;
+			config = (struct usbi_configuration_descriptor *)(priv->descriptors + DEVICE_DESC_LENGTH);
+			priv->active_config = config->bConfigurationValue;
 		} else {
 			priv->active_config = -1; /* No config dt */
 		}