From 9ca33a0f1abdefea3811666d9e87af11fd0af6c6 Mon Sep 17 00:00:00 2001 From: Brian Niebuhr Date: Mon, 10 Aug 2009 16:46:59 -0500 Subject: [PATCH] USB: Fix CDC EEM host driver 'sentinel' CRC validation This is an alternate solution to the EEM 'sentinel' CRC valiation issue. CDC EEM allows using a 'sentinel' ethernet frame CRC of 0xdeadbeef in place of a real CRC. The 'sentinel' value is transmitted in big-endian order whereas the normal CRC is little-endian. This patch handles both cases appropriately. Signed-off-by: Brian Niebuhr Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/cdc_eem.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/drivers/net/usb/cdc_eem.c b/drivers/net/usb/cdc_eem.c index 45cebfb302cf..23300656c266 100644 --- a/drivers/net/usb/cdc_eem.c +++ b/drivers/net/usb/cdc_eem.c @@ -300,20 +300,23 @@ static int eem_rx_fixup(struct usbnet *dev, struct sk_buff *skb) return 0; } - crc = get_unaligned_le32(skb2->data - + len - ETH_FCS_LEN); - skb_trim(skb2, len - ETH_FCS_LEN); - /* * The bmCRC helps to denote when the CRC field in * the Ethernet frame contains a calculated CRC: * bmCRC = 1 : CRC is calculated * bmCRC = 0 : CRC = 0xDEADBEEF */ - if (header & BIT(14)) - crc2 = ~crc32_le(~0, skb2->data, skb2->len); - else + if (header & BIT(14)) { + crc = get_unaligned_le32(skb2->data + + len - ETH_FCS_LEN); + crc2 = ~crc32_le(~0, skb2->data, skb2->len + - ETH_FCS_LEN); + } else { + crc = get_unaligned_be32(skb2->data + + len - ETH_FCS_LEN); crc2 = 0xdeadbeef; + } + skb_trim(skb2, len - ETH_FCS_LEN); if (is_last) return crc == crc2;