From fb4c24637de82a81374622d3f2f96452e0fb07d2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Wxcaf=C3=A9?= <wxcafe@wxcafe.net>
Date: Mon, 13 Jul 2020 16:16:14 -0400
Subject: [PATCH 1/3] net: cdc_ether: export generic usbnet_cdc_update_filter

This makes the function avaiable to other drivers, like cdn_ncm.

Other drivers will use different dev->data types, so the exported
function must not use it; instead the exported function takes an
additional pointer to the control interface.

Within cdc_ether the control interface is still taken from the control
field from struct cdc_state stored in dev->data.
---
 drivers/net/usb/cdc_ether.c | 24 ++++++++++++++++--------
 include/linux/usb/usbnet.h  |  2 ++
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index a657943c9f01..b201adc885f6 100644
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c
@@ -63,10 +63,8 @@ static const u8 mbm_guid[16] = {
 	0xa6, 0x07, 0xc0, 0xff, 0xcb, 0x7e, 0x39, 0x2a,
 };
 
-static void usbnet_cdc_update_filter(struct usbnet *dev)
+void usbnet_cdc_update_filter(struct usbnet *dev, struct usb_interface *control)
 {
-	struct cdc_state	*info = (void *) &dev->data;
-	struct usb_interface	*intf = info->control;
 	struct net_device	*net = dev->net;
 
 	u16 cdc_filter = USB_CDC_PACKET_TYPE_DIRECTED
@@ -86,12 +84,22 @@ static void usbnet_cdc_update_filter(struct usbnet *dev)
 			USB_CDC_SET_ETHERNET_PACKET_FILTER,
 			USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 			cdc_filter,
-			intf->cur_altsetting->desc.bInterfaceNumber,
+			control->cur_altsetting->desc.bInterfaceNumber,
 			NULL,
 			0,
 			USB_CTRL_SET_TIMEOUT
 		);
 }
+EXPORT_SYMBOL_GPL(usbnet_cdc_update_filter);
+
+/* the control interface is not always necessarily the probed interface
+ * dev->intf, see rndis handling in usbnet_generic_cdc_bind.
+ */
+static void usbnet_cdc_ether_update_filter(struct usbnet *dev) {
+	struct cdc_state *info = (void *)&dev->data;
+
+	usbnet_cdc_update_filter(dev, info->control);
+}
 
 /* probes control interface, claims data interface, collects the bulk
  * endpoints, activates data interface (if needed), maybe sets MTU.
@@ -336,7 +344,7 @@ int usbnet_ether_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
 	 * don't do reset all the way. So the packet filter should
 	 * be set to a sane initial value.
 	 */
-	usbnet_cdc_update_filter(dev);
+	usbnet_cdc_ether_update_filter(dev);
 
 bail_out:
 	return rv;
@@ -514,7 +522,7 @@ static const struct driver_info	cdc_info = {
 	.bind =		usbnet_cdc_bind,
 	.unbind =	usbnet_cdc_unbind,
 	.status =	usbnet_cdc_status,
-	.set_rx_mode =	usbnet_cdc_update_filter,
+	.set_rx_mode =	usbnet_cdc_ether_update_filter,
 	.manage_power =	usbnet_manage_power,
 };
 
@@ -524,7 +532,7 @@ static const struct driver_info	zte_cdc_info = {
 	.bind =		usbnet_cdc_zte_bind,
 	.unbind =	usbnet_cdc_unbind,
 	.status =	usbnet_cdc_zte_status,
-	.set_rx_mode =	usbnet_cdc_update_filter,
+	.set_rx_mode =	usbnet_cdc_ether_update_filter,
 	.manage_power =	usbnet_manage_power,
 	.rx_fixup = usbnet_cdc_zte_rx_fixup,
 };
@@ -535,7 +543,7 @@ static const struct driver_info wwan_info = {
 	.bind =		usbnet_cdc_bind,
 	.unbind =	usbnet_cdc_unbind,
 	.status =	usbnet_cdc_status,
-	.set_rx_mode =	usbnet_cdc_update_filter,
+	.set_rx_mode =	usbnet_cdc_ether_update_filter,
 	.manage_power =	usbnet_manage_power,
 };
 
diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h
index b0bff3083278..387f3da06e9d 100644
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -286,4 +286,6 @@ extern void usbnet_update_max_qlen(struct usbnet *dev);
 extern void usbnet_get_stats64(struct net_device *dev,
 			       struct rtnl_link_stats64 *stats);
 
+extern void usbnet_cdc_update_filter(struct usbnet *, struct usb_interface *);
+
 #endif /* __LINUX_USB_USBNET_H */
-- 
2.27.0