| Message ID | 20150904052106.GA5689@gondor.apana.org.au |
|---|---|
| State | Awaiting Upstream, archived |
| Delegated to: | David Miller |
| Headers | show |
On Fri, Sep 04, 2015 at 01:21:06PM +0800, Herbert Xu wrote: > On Mon, Aug 31, 2015 at 03:35:26PM +0800, Herbert Xu wrote: > > > > I see where the bug came from. Indeed IPv6 does do fragmentation > > but only for tunnel mode. While your patch added a check that also > > affected transport mode. So in addition to the GSO fix we should > > also make the MTU check conditional to tunnel mode. > > Here is the patch: > > ---8<--- > ipv6: Fix IPsec pre-encap fragmentation check > > The IPv6 IPsec pre-encap path performs fragmentation for tunnel-mode > packets. That is, we perform fragmentation pre-encap rather than > post-encap. > > A check was added later to ensure that proper MTU information is > passed back for locally generated traffic. Unfortunately this > check was performed on all IPsec packets, including transport-mode > packets. > > What's more, the check failed to take GSO into account. > > The end result is that transport-mode GSO packets get dropped at > the check. > > This patch fixes it by moving the tunnel mode check forward as well > as adding the GSO check. > > Fixes: dd767856a36e ("xfrm6: Don't call icmpv6_send on local error") > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Applied to the ipsec tree, thanks Herbert! -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c index 09c76a7..be033f2 100644 --- a/net/ipv6/xfrm6_output.c +++ b/net/ipv6/xfrm6_output.c @@ -136,6 +136,7 @@ static int __xfrm6_output(struct sock *sk, struct sk_buff *skb) struct dst_entry *dst = skb_dst(skb); struct xfrm_state *x = dst->xfrm; int mtu; + bool toobig; #ifdef CONFIG_NETFILTER if (!x) { @@ -144,25 +145,29 @@ static int __xfrm6_output(struct sock *sk, struct sk_buff *skb) } #endif + if (x->props.mode != XFRM_MODE_TUNNEL) + goto skip_frag; + if (skb->protocol == htons(ETH_P_IPV6)) mtu = ip6_skb_dst_mtu(skb); else mtu = dst_mtu(skb_dst(skb)); - if (skb->len > mtu && xfrm6_local_dontfrag(skb)) { + toobig = skb->len > mtu && !skb_is_gso(skb); + + if (toobig && xfrm6_local_dontfrag(skb)) { xfrm6_local_rxpmtu(skb, mtu); return -EMSGSIZE; - } else if (!skb->ignore_df && skb->len > mtu && skb->sk) { + } else if (!skb->ignore_df && toobig && skb->sk) { xfrm_local_error(skb, mtu); return -EMSGSIZE; } - if (x->props.mode == XFRM_MODE_TUNNEL && - ((skb->len > mtu && !skb_is_gso(skb)) || - dst_allfrag(skb_dst(skb)))) { + if (toobig || dst_allfrag(skb_dst(skb))) return ip6_fragment(sk, skb, x->outer_mode->afinfo->output_finish); - } + +skip_frag: return x->outer_mode->afinfo->output_finish(sk, skb); }