path: root/drivers/net/usb/cdc_ether.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * CDC Ethernet based networking peripherals
 * Copyright (C) 2003-2005 by David Brownell
 * Copyright (C) 2006 by Ole Andre Vadla Ravnas (ActiveSync)
 */

// #define	DEBUG			// error path messages, extra info
// #define	VERBOSE			// more; success messages

#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/ethtool.h>
#include <linux/workqueue.h>
#include <linux/mii.h>
#include <linux/usb.h>
#include <linux/usb/cdc.h>
#include <linux/usb/usbnet.h>


#if IS_ENABLED(CONFIG_USB_NET_RNDIS_HOST)

static int is_rndis(struct usb_interface_descriptor *desc)
{
	return (desc->bInterfaceClass == USB_CLASS_COMM &&
		desc->bInterfaceSubClass == 2 &&
		desc->bInterfaceProtocol == 0xff);
}

static int is_activesync(struct usb_interface_descriptor *desc)
{
	return (desc->bInterfaceClass == USB_CLASS_MISC &&
		desc->bInterfaceSubClass == 1 &&
		desc->bInterfaceProtocol == 1);
}

static int is_wireless_rndis(struct usb_interface_descriptor *desc)
{
	return (desc->bInterfaceClass == USB_CLASS_WIRELESS_CONTROLLER &&
		desc->bInterfaceSubClass == 1 &&
		desc->bInterfaceProtocol == 3);
}

static int is_novatel_rndis(struct usb_interface_descriptor *desc)
{
	return (desc->bInterfaceClass == USB_CLASS_MISC &&
		desc->bInterfaceSubClass == 4 &&
		desc->bInterfaceProtocol == 1);
}

#else

#define is_rndis(desc)		0
#define is_activesync(desc)	0
#define is_wireless_rndis(desc)	0
#define is_novatel_rndis(desc)	0

#endif

static const u8 mbm_guid[16] = {
	0xa3, 0x17, 0xa8, 0x8b, 0x04, 0x5e, 0x4f, 0x01,
	0xa6, 0x07, 0xc0, 0xff, 0xcb, 0x7e, 0x39, 0x2a,
};

void usbnet_cdc_update_filter(struct usbnet *dev)
{
	struct net_device	*net = dev->net;

	u16 cdc_filter = USB_CDC_PACKET_TYPE_DIRECTED
			| USB_CDC_PACKET_TYPE_BROADCAST;

	/* filtering on the device is an optional feature and not worth
	 * the hassle so we just roughly care about snooping and if any
	 * multicast is requested, we take every multicast
	 */
	if (net->flags & IFF_PROMISC)
		cdc_filter |= USB_CDC_PACKET_TYPE_PROMISCUOUS;
	if (!netdev_mc_empty(net) || (net->flags & IFF_ALLMULTI))
		cdc_filter |= USB_CDC_PACKET_TYPE_ALL_MULTICAST;

	usb_control_msg(dev->udev,
			usb_sndctrlpipe(dev->udev, 0),
			USB_CDC_SET_ETHERNET_PACKET_FILTER,
			USB_TYPE_CLASS | USB_RECIP_INTERFACE,
			cdc_filter,
			dev->intf->cur_altsetting->desc.bInterfaceNumber,
			NULL,
			0,
			USB_CTRL_SET_TIMEOUT
		);
}
EXPORT_SYMBOL_GPL(usbnet_cdc_update_filter);

/* We need to override usbnet_*_link_ksettings in bind() */
static const struct ethtool_ops cdc_ether_ethtool_ops = {
	.get_link		= usbnet_get_link,
	.nway_reset		= usbnet_nway_reset,
	.get_drvinfo		= usbnet_get_drvinfo,
	.get_msglevel		= usbnet_get_msglevel,
	.set_msglevel		= usbnet_set_msglevel,
	.get_ts_info		= ethtool_op_get_ts_info,
	.get_link_ksettings	= usbnet_get_link_ksettings_internal,
	.set_link_ksettings	= NULL,
};

/* probes control interface, claims data interface, collects the bulk
 * endpoints, activates data interface (if needed), maybe sets MTU.
 * all pure cdc, except for certain firmware workarounds, and knowing
 * that rndis uses one different rule.
 */
int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
{
	u8				*buf = intf->cur_altsetting->extra;
	int				len = intf->cur_altsetting->extralen;
	struct usb_interface_descriptor	*d;
	struct cdc_state		*info = (void *) &dev->data;
	int				status;
	int				rndis;
	bool				android_rndis_quirk = false;
	struct usb_driver		*driver = driver_of(intf);
	struct usb_cdc_parsed_header header;

	if (sizeof(dev->data) < sizeof(*info))
		return -EDOM;

	/* expect strict spec conformance for the descriptors, but
	 * cope with firmware which stores them in the wrong place
	 */
	if (len == 0 && dev->udev->actconfig->extralen) {
		/* Motorola SB4100 (and others: Brad Hards says it's
		 * from a Broadcom design) put CDC descriptors here
		 */
		buf = dev->udev->actconfig->extra;
		len = dev->udev->actconfig->extralen;
		dev_dbg(&intf->dev, "CDC descriptors on config\n");
	}

	/* Maybe CDC descriptors are after the endpoint?  This bug has
	 * been seen on some 2Wire Inc RNDIS-ish products.
	 */
	if (len == 0) {
		struct usb_host_endpoint	*hep;

		hep = intf->cur_altsetting->endpoint;
		if (hep) {
			buf = hep->extra;
			len = hep->extralen;
		}
		if (len)
			dev_dbg(&intf->dev,
				"CDC descriptors on endpoint\n");
	}

	/* this assumes that if there's a non-RNDIS vendor variant
	 * of cdc-acm, it'll fail RNDIS requests cleanly.
	 */
	rndis = (is_rndis(&intf->cur_altsetting->desc) ||
		 is_activesync(&intf->cur_altsetting->desc) ||
		 is_wireless_rndis(&intf->cur_altsetting->desc) ||
		 is_novatel_rndis(&intf->cur_altsetting->desc));

	memset(info, 0, sizeof(*info));
	info->control = intf;

	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;
	if (!info->u) {
		if (rndis)
			goto skip;
		else /* in that