From 5a21232983aa7acfe7fd26170832a9e0a4a7b4ae Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Sun, 31 Aug 2014 15:12:41 -0700 Subject: net: Support for csum_bad in skbuff This flag indicates that an invalid checksum was detected in the packet. __skb_mark_checksum_bad helper function was added to set this. Checksums can be marked bad from a driver or the GRO path (the latter is implemented in this patch). csum_bad is checked in __skb_checksum_validate_complete (i.e. calling that when ip_summed == CHECKSUM_NONE). csum_bad works in conjunction with ip_summed value. In the case that ip_summed is CHECKSUM_NONE and csum_bad is set, this implies that the first (or next) checksum encountered in the packet is bad. When ip_summed is CHECKSUM_UNNECESSARY, the first checksum after the last one validated is bad. For example, if ip_summed == CHECKSUM_UNNECESSARY, csum_level == 1, and csum_bad is set-- then the third checksum in the packet is bad. In the normal path, the packet will be dropped when processing the protocol layer of the bad checksum: __skb_decr_checksum_unnecessary called twice for the good checksums changing ip_summed to CHECKSUM_NONE so that __skb_checksum_validate_complete is called to validate the third checksum and that will fail since csum_bad is set. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index 6857d57aa294..3774afc3bebf 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3918,7 +3918,7 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff if (!(skb->dev->features & NETIF_F_GRO)) goto normal; - if (skb_is_gso(skb) || skb_has_frag_list(skb)) + if (skb_is_gso(skb) || skb_has_frag_list(skb) || skb->csum_bad) goto normal; gro_list_prepare(napi, skb); -- cgit v1.2.2