releases/4.14.7/usbnet-fix-alignment-for-frames-with-no-ethernet-header.patch

   1 From foo@baz Thu Dec 14 11:45:40 CET 2017
   2 From: Bjørn Mork <bjorn@mork.no>
   3 Date: Wed, 6 Dec 2017 20:21:24 +0100
   4 Subject: usbnet: fix alignment for frames with no ethernet header
   5
   6 From: Bjørn Mork <bjorn@mork.no>
   7
   8
   9 [ Upstream commit a4abd7a80addb4a9547f7dfc7812566b60ec505c ]
  10
  11 The qmi_wwan minidriver support a 'raw-ip' mode where frames are
  12 received without any ethernet header. This causes alignment issues
  13 because the skbs allocated by usbnet are "IP aligned".
  14
  15 Fix by allowing minidrivers to disable the additional alignment
  16 offset. This is implemented using a per-device flag, since the same
  17 minidriver also supports 'ethernet' mode.
  18
  19 Fixes: 32f7adf633b9 ("net: qmi_wwan: support "raw IP" mode")
  20 Reported-and-tested-by: Jay Foster <jay@systech.com>
  21 Signed-off-by: Bjørn Mork <bjorn@mork.no>
  22 Signed-off-by: David S. Miller <davem@davemloft.net>
  23 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  24 ---
  25  drivers/net/usb/qmi_wwan.c |    2 ++
  26  drivers/net/usb/usbnet.c   |    5 ++++-
  27  include/linux/usb/usbnet.h |    1 +
  28  3 files changed, 7 insertions(+), 1 deletion(-)
  29
  30 --- a/drivers/net/usb/qmi_wwan.c
  31 +++ b/drivers/net/usb/qmi_wwan.c
  32 @@ -261,9 +261,11 @@ static void qmi_wwan_netdev_setup(struct
  33                 net->hard_header_len = 0;
  34                 net->addr_len        = 0;
  35                 net->flags           = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
  36 +               set_bit(EVENT_NO_IP_ALIGN, &dev->flags);
  37                 netdev_dbg(net, "mode: raw IP\n");
  38         } else if (!net->header_ops) { /* don't bother if already set */
  39                 ether_setup(net);
  40 +               clear_bit(EVENT_NO_IP_ALIGN, &dev->flags);
  41                 netdev_dbg(net, "mode: Ethernet\n");
  42         }
  43
  44 --- a/drivers/net/usb/usbnet.c
  45 +++ b/drivers/net/usb/usbnet.c
  46 @@ -484,7 +484,10 @@ static int rx_submit (struct usbnet *dev
  47                 return -ENOLINK;
  48         }
  49
  50 -       skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
  51 +       if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
  52 +               skb = __netdev_alloc_skb(dev->net, size, flags);
  53 +       else
  54 +               skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
  55         if (!skb) {
  56                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
  57                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
  58 --- a/include/linux/usb/usbnet.h
  59 +++ b/include/linux/usb/usbnet.h
  60 @@ -81,6 +81,7 @@ struct usbnet {
  61  #              define EVENT_RX_KILL    10
  62  #              define EVENT_LINK_CHANGE        11
  63  #              define EVENT_SET_RX_MODE        12
  64 +#              define EVENT_NO_IP_ALIGN        13
  65  };
  66
  67  static inline struct usb_driver *driver_of(struct usb_interface *intf)