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| author | Neal Cardwell <ncardwell@google.com> | 2014-01-09 20:47:17 -0500 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-01-13 11:53:49 -0800 |
| commit | b884b1a46f205d56e33c0391c1d04644d846f41e (patch) | |
| tree | f444f75b77d4954e8cd0fda24a208fa6ebc377aa /net/ipv4/gre_offload.c | |
| parent | 7eb8896df03d0f4a8b301cb177d7f31c0d70e112 (diff) | |
| download | lwn-b884b1a46f205d56e33c0391c1d04644d846f41e.tar.gz lwn-b884b1a46f205d56e33c0391c1d04644d846f41e.zip | |
gre_offload: simplify GRE header length calculation in gre_gso_segment()
Simplify the GRE header length calculation in gre_gso_segment().
Switch to an approach that is simpler, faster, and more general. The
new approach will continue to be correct even if we add support for
the optional variable-length routing info that may be present in a GRE
header.
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: H.K. Jerry Chu <hkchu@google.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/gre_offload.c')
| -rw-r--r-- | net/ipv4/gre_offload.c | 16 |
1 files changed, 6 insertions, 10 deletions
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c index 31da9f512583..29512e3e7e7c 100644 --- a/net/ipv4/gre_offload.c +++ b/net/ipv4/gre_offload.c @@ -26,7 +26,7 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb, { struct sk_buff *segs = ERR_PTR(-EINVAL); netdev_features_t enc_features; - int ghl = GRE_HEADER_SECTION; + int ghl; struct gre_base_hdr *greh; u16 mac_offset = skb->mac_header; int mac_len = skb->mac_len; @@ -49,15 +49,11 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb, greh = (struct gre_base_hdr *)skb_transport_header(skb); - if (greh->flags & GRE_KEY) - ghl += GRE_HEADER_SECTION; - if (greh->flags & GRE_SEQ) - ghl += GRE_HEADER_SECTION; - if (greh->flags & GRE_CSUM) { - ghl += GRE_HEADER_SECTION; - csum = true; - } else - csum = false; + ghl = skb_inner_network_header(skb) - skb_transport_header(skb); + if (unlikely(ghl < sizeof(*greh))) + goto out; + + csum = !!(greh->flags & GRE_CSUM); if (unlikely(!pskb_may_pull(skb, ghl))) goto out; |