From 69a9efb689b43fedf5f19431f1889aa6b8d35d55 Mon Sep 17 00:00:00 2001 From: Lech Perczak Date: Fri, 1 Apr 2022 22:04:01 +0200 Subject: [PATCH 2/3] rndis_host: enable the bogus MAC fixup for ZTE devices from cdc_ether MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Certain ZTE modems, namely: MF823. MF831, MF910, built-in modem from MF286R, expose both CDC-ECM and RNDIS network interfaces. They have a trait of ignoring the locally-administered MAC address configured on the interface both in CDC-ECM and RNDIS part, and this leads to dropping of incoming traffic by the host. However, the workaround was only present in CDC-ECM, and MF286R explicitly requires it in RNDIS mode. Re-use the workaround in rndis_host as well, to fix operation of MF286R module, some versions of which expose only the RNDIS interface. Do so by introducing new flag, RNDIS_DRIVER_DATA_DST_MAC_FIXUP, and testing for it in rndis_rx_fixup. This is required, as RNDIS uses frame batching, and all of the packets inside the batch need the fixup. This might introduce a performance penalty, because test is done for every returned Ethernet frame. Apply the workaround to both "flavors" of RNDIS interfaces, as older ZTE modems, like MF823 found in the wild, report the USB_CLASS_COMM class interfaces, while MF286R reports USB_CLASS_WIRELESS_CONTROLLER. Suggested-by: Bjørn Mork Cc: Kristian Evensen Cc: Oliver Neukum Signed-off-by: Lech Perczak --- drivers/net/usb/rndis_host.c | 32 ++++++++++++++++++++++++++++++++ include/linux/usb/rndis_host.h | 1 + 2 files changed, 33 insertions(+) --- a/drivers/net/usb/rndis_host.c +++ b/drivers/net/usb/rndis_host.c @@ -485,10 +485,14 @@ EXPORT_SYMBOL_GPL(rndis_unbind); */ int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb) { + bool dst_mac_fixup; + /* This check is no longer done by usbnet */ if (skb->len < dev->net->hard_header_len) return 0; + dst_mac_fixup = !!(dev->driver_info->data & RNDIS_DRIVER_DATA_DST_MAC_FIXUP); + /* peripheral may have batched packets to us... */ while (likely(skb->len)) { struct rndis_data_hdr *hdr = (void *)skb->data; @@ -523,10 +527,17 @@ int rndis_rx_fixup(struct usbnet *dev, s break; skb_pull(skb, msg_len - sizeof *hdr); skb_trim(skb2, data_len); + + if (unlikely(dst_mac_fixup)) + usbnet_cdc_zte_rx_fixup(dev, skb2); + usbnet_skb_return(dev, skb2); } /* caller will usbnet_skb_return the remaining packet */ + if (unlikely(dst_mac_fixup)) + usbnet_cdc_zte_rx_fixup(dev, skb); + return 1; } EXPORT_SYMBOL_GPL(rndis_rx_fixup); @@ -600,6 +611,17 @@ static const struct driver_info rndis_po .tx_fixup = rndis_tx_fixup, }; +static const struct driver_info zte_rndis_info = { + .description = "ZTE RNDIS device", + .flags = FLAG_ETHER | FLAG_POINTTOPOINT | FLAG_FRAMING_RN | FLAG_NO_SETINT, + .data = RNDIS_DRIVER_DATA_DST_MAC_FIXUP, + .bind = rndis_bind, + .unbind = rndis_unbind, + .status = rndis_status, + .rx_fixup = rndis_rx_fixup, + .tx_fixup = rndis_tx_fixup, +}; + /*-------------------------------------------------------------------------*/ static const struct usb_device_id products [] = { @@ -609,6 +631,16 @@ static const struct usb_device_id produc USB_CLASS_COMM, 2 /* ACM */, 0x0ff), .driver_info = (unsigned long) &rndis_poll_status_info, }, { + /* ZTE WWAN modules */ + USB_VENDOR_AND_INTERFACE_INFO(0x19d2, + USB_CLASS_WIRELESS_CONTROLLER, 1, 3), + .driver_info = (unsigned long)&zte_rndis_info, +}, { + /* ZTE WWAN modules, ACM flavour */ + USB_VENDOR_AND_INTERFACE_INFO(0x19d2, + USB_CLASS_COMM, 2 /* ACM */, 0x0ff), + .driver_info = (unsigned long)&zte_rndis_info, +}, { /* Hytera Communications DMR radios' "Radio to PC Network" */ USB_VENDOR_AND_INTERFACE_INFO(0x238b, USB_CLASS_COMM, 2 /* ACM */, 0x0ff), --- a/include/linux/usb/rndis_host.h +++ b/include/linux/usb/rndis_host.h @@ -197,6 +197,7 @@ struct rndis_keepalive_c { /* IN (option /* Flags for driver_info::data */ #define RNDIS_DRIVER_DATA_POLL_STATUS 1 /* poll status before control */ +#define RNDIS_DRIVER_DATA_DST_MAC_FIXUP 2 /* device ignores configured MAC address */ extern void rndis_status(struct usbnet *dev, struct urb *urb); extern int