Commit 823bd343 authored by Oliver Neukum's avatar Oliver Neukum Committed by David S. Miller
Browse files

cdc-ether: switch to common CDC parser 



This patch uses the common parser to parse extra CDC
headers in order to reduce code duplication.

Signed-off-by: default avatarOliver Neukum <oneukum@suse.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 77b0a099

drivers/net/usb/cdc_ether.c

+81 −149
Original line number Diff line number Diff line
@@ -112,8 +112,7 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) 
	int				rndis;

	bool				android_rndis_quirk = false;

	struct usb_driver		*driver = driver_of(intf);

	struct usb_cdc_mdlm_desc	*desc = NULL;

	struct usb_cdc_mdlm_detail_desc *detail = NULL;

	struct usb_cdc_parsed_header header;



	if (sizeof(dev->data) < sizeof(*info))

		return -EDOM;
@@ -155,59 +154,12 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) 


	memset(info, 0, sizeof(*info));

	info->control = intf;

	while (len > 3) {

		if (buf[1] != USB_DT_CS_INTERFACE)

			goto next_desc;



		/* use bDescriptorSubType to identify the CDC descriptors.

		 * We expect devices with CDC header and union descriptors.

		 * For CDC Ethernet we need the ethernet descriptor.

		 * For RNDIS, ignore two (pointless) CDC modem descriptors

		 * in favor of a complicated OID-based RPC scheme doing what

		 * CDC Ethernet achieves with a simple descriptor.

		 */

		switch (buf[2]) {

		case USB_CDC_HEADER_TYPE:

			if (info->header) {

				dev_dbg(&intf->dev, "extra CDC header\n");

				goto bad_desc;

			}

			info->header = (void *) buf;

			if (info->header->bLength != sizeof(*info->header)) {

				dev_dbg(&intf->dev, "CDC header len %u\n",

					info->header->bLength);

				goto bad_desc;

			}

			break;

		case USB_CDC_ACM_TYPE:

			/* paranoia:  disambiguate a "real" vendor-specific

			 * modem interface from an RNDIS non-modem.

			 */

			if (rndis) {

				struct usb_cdc_acm_descriptor *acm;



				acm = (void *) buf;

				if (acm->bmCapabilities) {

					dev_dbg(&intf->dev,

						"ACM capabilities %02x, "

						"not really RNDIS?\n",

						acm->bmCapabilities);

					goto bad_desc;

				}

			}

			break;

		case USB_CDC_UNION_TYPE:

			if (info->u) {

				dev_dbg(&intf->dev, "extra CDC union\n");

				goto bad_desc;

			}

			info->u = (void *) buf;

			if (info->u->bLength != sizeof(*info->u)) {

				dev_dbg(&intf->dev, "CDC union len %u\n",

					info->u->bLength);

				goto bad_desc;

			}

	cdc_parse_cdc_header(&header, intf, buf, len);



	info->u = header.usb_cdc_union_desc;

	info->header = header.usb_cdc_header_desc;

	info->ether = header.usb_cdc_ether_desc;

	/* we need a master/control interface (what we're

	 * probed with) and a slave/data interface; union

	 * descriptors sort this all out.
@@ -226,7 +178,7 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) 
		/* fall back to hard-wiring for RNDIS */

		if (rndis) {

			android_rndis_quirk = true;

					goto next_desc;

			goto skip;

		}

		goto bad_desc;

	}
@@ -244,7 +196,7 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) 


	/* some devices merge these - skip class check */

	if (info->control == info->data)

				goto next_desc;

		goto skip;



	/* a data interface altsetting does the real i/o */

	d = &info->data->cur_altsetting->desc;
@@ -253,57 +205,37 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf) 
			d->bInterfaceClass);

		goto bad_desc;

	}

			break;

		case USB_CDC_ETHERNET_TYPE:

			if (info->ether) {

				dev_dbg(&intf->dev, "extra CDC ether\n");

				goto bad_desc;

			}

			info->ether = (void *) buf;

			if (info->ether->bLength != sizeof(*info->ether)) {

				dev_dbg(&intf->dev, "CDC ether len %u\n",

					info->ether->bLength);

skip:

	if (	rndis &&

		header.usb_cdc_acm_descriptor &&

		header.usb_cdc_acm_descriptor->bmCapabilities) {

			dev_dbg(&intf->dev,

				"ACM capabilities %02x, not really RNDIS?\n",

				header.usb_cdc_acm_descriptor->bmCapabilities);

			goto bad_desc;

	}

			dev->hard_mtu = le16_to_cpu(

						info->ether->wMaxSegmentSize);



	if (header.usb_cdc_ether_desc) {

		dev->hard_mtu = le16_to_cpu(info->ether->wMaxSegmentSize);

		/* because of Zaurus, we may be ignoring the host

		 * side link address we were given.

		 */

			break;

		case USB_CDC_MDLM_TYPE:

			if (desc) {

				dev_dbg(&intf->dev, "extra MDLM descriptor\n");

				goto bad_desc;

	}



			desc = (void *)buf;



			if (desc->bLength != sizeof(*desc))

	if (header.usb_cdc_mdlm_desc &&

		memcmp(header.usb_cdc_mdlm_desc->bGUID, mbm_guid, 16)) {

		dev_dbg(&intf->dev, "GUID doesn't match\n");

		goto bad_desc;

	}



			if (memcmp(&desc->bGUID, mbm_guid, 16))

				goto bad_desc;

			break;

		case USB_CDC_MDLM_DETAIL_TYPE:

			if (detail) {

				dev_dbg(&intf->dev, "extra MDLM detail descriptor\n");

	if (header.usb_cdc_mdlm_detail_desc &&

		header.usb_cdc_mdlm_detail_desc->bLength <

			(sizeof(struct usb_cdc_mdlm_detail_desc) + 1)) {

		dev_dbg(&intf->dev, "Descriptor too short\n");

		goto bad_desc;

	}



			detail = (void *)buf;



			if (detail->bGuidDescriptorType == 0) {

				if (detail->bLength < (sizeof(*detail) + 1))

					goto bad_desc;

			} else

				goto bad_desc;

			break;

		}

next_desc:

		len -= buf[0];	/* bLength */

		buf += buf[0];

	}



	/* Microsoft ActiveSync based and some regular RNDIS devices lack the

	 * CDC descriptors, so we'll hard-wire the interfaces and not check