From eb85569fe2d06c2fbf4de7b66c263ca095b397aa Mon Sep 17 00:00:00 2001 From: Emil Goode Date: Thu, 13 Feb 2014 17:50:19 +0100 Subject: usbnet: remove generic hard_header_len check This patch removes a generic hard_header_len check from the usbnet module that is causing dropped packages under certain circumstances for devices that send rx packets that cross urb boundaries. One example is the AX88772B which occasionally send rx packets that cross urb boundaries where the remaining partial packet is sent with no hardware header. When the buffer with a partial packet is of less number of octets than the value of hard_header_len the buffer is discarded by the usbnet module. With AX88772B this can be reproduced by using ping with a packet size between 1965-1976. The bug has been reported here: https://bugzilla.kernel.org/show_bug.cgi?id=29082 This patch introduces the following changes: - Removes the generic hard_header_len check in the rx_complete function in the usbnet module. - Introduces a ETH_HLEN check for skbs that are not cloned from within a rx_fixup callback. - For safety a hard_header_len check is added to each rx_fixup callback function that could be affected by this change. These extra checks could possibly be removed by someone who has the hardware to test. - Removes a call to dev_kfree_skb_any() and instead utilizes the dev->done list to queue skbs for cleanup. The changes place full responsibility on the rx_fixup callback functions that clone skbs to only pass valid skbs to the usbnet_skb_return function. Signed-off-by: Emil Goode Reported-by: Igor Gnatenko Signed-off-by: David S. Miller --- drivers/net/usb/usbnet.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) (limited to 'drivers/net/usb/usbnet.c') diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 4671da755e7b..dd10d5817d2a 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -542,17 +542,19 @@ static inline void rx_process (struct usbnet *dev, struct sk_buff *skb) } // else network stack removes extra byte if we forced a short packet - if (skb->len) { - /* all data was already cloned from skb inside the driver */ - if (dev->driver_info->flags & FLAG_MULTI_PACKET) - dev_kfree_skb_any(skb); - else - usbnet_skb_return(dev, skb); + /* all data was already cloned from skb inside the driver */ + if (dev->driver_info->flags & FLAG_MULTI_PACKET) + goto done; + + if (skb->len < ETH_HLEN) { + dev->net->stats.rx_errors++; + dev->net->stats.rx_length_errors++; + netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len); + } else { + usbnet_skb_return(dev, skb); return; } - netif_dbg(dev, rx_err, dev->net, "drop\n"); - dev->net->stats.rx_errors++; done: skb_queue_tail(&dev->done, skb); } @@ -574,13 +576,6 @@ static void rx_complete (struct urb *urb) switch (urb_status) { /* success */ case 0: - if (skb->len < dev->net->hard_header_len) { - state = rx_cleanup; - dev->net->stats.rx_errors++; - dev->net->stats.rx_length_errors++; - netif_dbg(dev, rx_err, dev->net, - "rx length %d\n", skb->len); - } break; /* stalls need manual reset. this is rare ... except that -- cgit v1.2.2