| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.10 64/86] net: ipv6: send pkttoobig immediately if orig frag size > mtu | Date | Wed, 28 May 2014 21:37:39 -0700 |
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3.10-stable review patch. If anyone has any objections, please let me know.
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From: Florian Westphal <fw@strlen.de>
[ Upstream commit 418a31561d594a2b636c1e2fa94ecd9e1245abb1 ]
If conntrack defragments incoming ipv6 frags it stores largest original frag size in ip6cb and sets ->local_df.
We must thus first test the largest original frag size vs. mtu, and not vice versa.
Without this patch PKTTOOBIG is still generated in ip6_fragment() later in the stack, but
1) IPSTATS_MIB_INTOOBIGERRORS won't increment 2) packet did (needlessly) traverse netfilter postrouting hook.
Fixes: fe6cc55f3a9 ("net: ip, ipv6: handle gso skbs in forwarding path") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/ipv6/ip6_output.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
--- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -347,12 +347,16 @@ static inline int ip6_forward_finish(str static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) { - if (skb->len <= mtu || skb->local_df) + if (skb->len <= mtu) return false; + /* ipv6 conntrack defrag sets max_frag_size + local_df */ if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu) return true; + if (skb->local_df) + return false; + if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu) return false;
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