From 5ca3b72c5da47d95b83857b768def6172fbc080a Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 8 Feb 2012 08:51:50 +0000 Subject: [PATCH] gro: more generic L2 header check Shlomo Pongratz reported GRO L2 header check was suited for Ethernet only, and failed on IB/ipoib traffic. He provided a patch faking a zeroed header to let GRO aggregates frames. Roland Dreier, Herbert Xu, and others suggested we change GRO L2 header check to be more generic, ie not assuming L2 header is 14 bytes, but taking into account hard_header_len. __napi_gro_receive() has special handling for the common case (Ethernet) to avoid a memcmp() call and use an inline optimized function instead. Signed-off-by: Eric Dumazet Reported-by: Shlomo Pongratz Cc: Roland Dreier Cc: Or Gerlitz Cc: Herbert Xu Tested-by: Sean Hefty Signed-off-by: David S. Miller --- net/core/dev.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 115dee1d985d..6ca32f6b3105 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3500,14 +3500,20 @@ static inline gro_result_t __napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb) { struct sk_buff *p; + unsigned int maclen = skb->dev->hard_header_len; for (p = napi->gro_list; p; p = p->next) { unsigned long diffs; diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev; diffs |= p->vlan_tci ^ skb->vlan_tci; - diffs |= compare_ether_header(skb_mac_header(p), - skb_gro_mac_header(skb)); + if (maclen == ETH_HLEN) + diffs |= compare_ether_header(skb_mac_header(p), + skb_gro_mac_header(skb)); + else if (!diffs) + diffs = memcmp(skb_mac_header(p), + skb_gro_mac_header(skb), + maclen); NAPI_GRO_CB(p)->same_flow = !diffs; NAPI_GRO_CB(p)->flush = 0; } -- 2.39.2