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Commit c40a2c88 authored by Oliver Neukum's avatar Oliver Neukum Committed by David S. Miller
Browse files

CDC: common parser for extra headers 



CDC drivers all implement their own parser for the extra headers.
This patch fixes the code duplication introducing a single common
parser in usbnet.

Signed-off-by: default avatarOliver Neukum <oneukum@suse.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1d147ccb

drivers/net/usb/usbnet.c

+138 −0
Original line number Diff line number Diff line
@@ -42,6 +42,7 @@ 
#include <linux/mii.h>

#include <linux/usb.h>

#include <linux/usb/usbnet.h>

#include <linux/usb/cdc.h>

#include <linux/slab.h>

#include <linux/kernel.h>

#include <linux/pm_runtime.h>
@@ -1962,6 +1963,143 @@ static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype, 
	return err;

}



int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,

				struct usb_interface *intf,

				u8 *buffer,

				int buflen)

{

	/* duplicates are ignored */

	struct usb_cdc_union_desc *union_header = NULL;



	/* duplicates are not tolerated */

	struct usb_cdc_header_desc *header = NULL;

	struct usb_cdc_ether_desc *ether = NULL;

	struct usb_cdc_mdlm_detail_desc *detail = NULL;

	struct usb_cdc_mdlm_desc *desc = NULL;



	unsigned int elength;

	int cnt = 0;



	memset(hdr, 0x00, sizeof(struct usb_cdc_parsed_header));

	hdr->phonet_magic_present = false;

	while (buflen > 0) {

		elength = buffer[0];

		if (!elength) {

			dev_err(&intf->dev, "skipping garbage byte\n");

			elength = 1;

			goto next_desc;

		}

		if (buffer[1] != USB_DT_CS_INTERFACE) {

			dev_err(&intf->dev, "skipping garbage\n");

			goto next_desc;

		}



		switch (buffer[2]) {

		case USB_CDC_UNION_TYPE: /* we've found it */

			if (elength < sizeof(struct usb_cdc_union_desc))

				goto next_desc;

			if (union_header) {

				dev_err(&intf->dev, "More than one union descriptor, skipping ...\n");

				goto next_desc;

			}

			union_header = (struct usb_cdc_union_desc *)buffer;

			break;

		case USB_CDC_COUNTRY_TYPE:

			if (elength < sizeof(struct usb_cdc_country_functional_desc))

				goto next_desc;

			hdr->usb_cdc_country_functional_desc =

				(struct usb_cdc_country_functional_desc *)buffer;

			break;

		case USB_CDC_HEADER_TYPE:

			if (elength != sizeof(struct usb_cdc_header_desc))

				goto next_desc;

			if (header)

				return -EINVAL;

			header = (struct usb_cdc_header_desc *)buffer;

			break;

		case USB_CDC_ACM_TYPE:

			if (elength < sizeof(struct usb_cdc_acm_descriptor))

				goto next_desc;

			hdr->usb_cdc_acm_descriptor =

				(struct usb_cdc_acm_descriptor *)buffer;

			break;

		case USB_CDC_ETHERNET_TYPE:

			if (elength != sizeof(struct usb_cdc_ether_desc))

				goto next_desc;

			if (ether)

				return -EINVAL;

			ether = (struct usb_cdc_ether_desc *)buffer;

			break;

		case USB_CDC_CALL_MANAGEMENT_TYPE:

			if (elength < sizeof(struct usb_cdc_call_mgmt_descriptor))

				goto next_desc;

			hdr->usb_cdc_call_mgmt_descriptor =

				(struct usb_cdc_call_mgmt_descriptor *)buffer;

			break;

		case USB_CDC_DMM_TYPE:

			if (elength < sizeof(struct usb_cdc_dmm_desc))

				goto next_desc;

			hdr->usb_cdc_dmm_desc =

				(struct usb_cdc_dmm_desc *)buffer;

			break;

		case USB_CDC_MDLM_TYPE:

			if (elength < sizeof(struct usb_cdc_mdlm_desc *))

				goto next_desc;

			if (desc)

				return -EINVAL;

			desc = (struct usb_cdc_mdlm_desc *)buffer;

			break;

		case USB_CDC_MDLM_DETAIL_TYPE:

			if (elength < sizeof(struct usb_cdc_mdlm_detail_desc *))

				goto next_desc;

			if (detail)

				return -EINVAL;

			detail = (struct usb_cdc_mdlm_detail_desc *)buffer;

			break;

		case USB_CDC_NCM_TYPE:

			if (elength < sizeof(struct usb_cdc_ncm_desc))

				goto next_desc;

			hdr->usb_cdc_ncm_desc = (struct usb_cdc_ncm_desc *)buffer;

			break;

		case USB_CDC_MBIM_TYPE:

			if (elength < sizeof(struct usb_cdc_mbim_desc))

				goto next_desc;



			hdr->usb_cdc_mbim_desc = (struct usb_cdc_mbim_desc *)buffer;

			break;

		case USB_CDC_MBIM_EXTENDED_TYPE:

			if (elength < sizeof(struct usb_cdc_mbim_extended_desc))

				break;

			hdr->usb_cdc_mbim_extended_desc =

				(struct usb_cdc_mbim_extended_desc *)buffer;

			break;

		case CDC_PHONET_MAGIC_NUMBER:

			hdr->phonet_magic_present = true;

			break;

		default:

			/*

			 * there are LOTS more CDC descriptors that

			 * could legitimately be found here.

			 */

			dev_dbg(&intf->dev, "Ignoring descriptor: type %02x, length %ud\n",

					buffer[2], elength);

			goto next_desc;

		}

		cnt++;

next_desc:

		buflen -= elength;

		buffer += elength;

	}

	hdr->usb_cdc_union_desc = union_header;

	hdr->usb_cdc_header_desc = header;

	hdr->usb_cdc_mdlm_detail_desc = detail;

	hdr->usb_cdc_mdlm_desc = desc;

	hdr->usb_cdc_ether_desc = ether;

	return cnt;

}



EXPORT_SYMBOL(cdc_parse_cdc_header);



/*

 * The function can't be called inside suspend/resume callback,

 * otherwise deadlock will be caused.

include/linux/usb/cdc.h

0 → 100644
+47 −0
Original line number Diff line number Diff line 
/*

 * USB CDC common helpers

 *

 * Copyright (c) 2015 Oliver Neukum <oneukum@suse.com>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * version 2 as published by the Free Software Foundation.

 */



#include <uapi/linux/usb/cdc.h>



/*

 * inofficial magic numbers

 */



#define CDC_PHONET_MAGIC_NUMBER		0xAB



/*

 * parsing CDC headers

 */



struct usb_cdc_parsed_header {

	struct usb_cdc_union_desc *usb_cdc_union_desc;

	struct usb_cdc_header_desc *usb_cdc_header_desc;



	struct usb_cdc_call_mgmt_descriptor *usb_cdc_call_mgmt_descriptor;

	struct usb_cdc_acm_descriptor *usb_cdc_acm_descriptor;

	struct usb_cdc_country_functional_desc *usb_cdc_country_functional_desc;

	struct usb_cdc_network_terminal_desc *usb_cdc_network_terminal_desc;

	struct usb_cdc_ether_desc *usb_cdc_ether_desc;

	struct usb_cdc_dmm_desc *usb_cdc_dmm_desc;

	struct usb_cdc_mdlm_desc *usb_cdc_mdlm_desc;

	struct usb_cdc_mdlm_detail_desc *usb_cdc_mdlm_detail_desc;

	struct usb_cdc_obex_desc *usb_cdc_obex_desc;

	struct usb_cdc_ncm_desc *usb_cdc_ncm_desc;

	struct usb_cdc_mbim_desc *usb_cdc_mbim_desc;

	struct usb_cdc_mbim_extended_desc *usb_cdc_mbim_extended_desc;



	bool phonet_magic_present;

};





int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr,

				struct usb_interface *intf,

				u8 *buffer,

				int buflen);