netfilter-devel April 2010 archive
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netfilter-devel: [PATCH 1/6] netfilter: ipv6: move POSTROUTING i

[PATCH 1/6] netfilter: ipv6: move POSTROUTING invocation before fragmentation

From: Jan Engelhardt <jengelh_at_nospam>
Date: Wed Apr 07 2010 - 18:50:11 GMT
To: Patrick McHardy <kaber@trash.net>

Patrick McHardy notes: "We used to invoke IPv4 POST_ROUTING after
fragmentation as well just to defragment the packets in conntrack
immediately afterwards, but that got changed during the
netfilter-ipsec integration. Ideally IPv6 would behave like IPv4."

This patch makes it so. Sending an oversized frame (e.g. `ping6
-s64000 -c1 ::1`) will now show up in POSTROUTING as a single skb
rather than multiple ones.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
--- net/ipv6/ip6_output.c | 49 +++++++++++++++++++++++-------------------------- 1 files changed, 23 insertions(+), 26 deletions(-) diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 4535b7a..f314ba4 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -82,22 +82,6 @@ int ip6_local_out(struct sk_buff *skb) } EXPORT_SYMBOL_GPL(ip6_local_out); -static int ip6_output_finish(struct sk_buff *skb) -{ - struct dst_entry *dst = skb_dst(skb); - - if (dst->hh) - return neigh_hh_output(dst->hh, skb); - else if (dst->neighbour) - return dst->neighbour->output(skb); - - IP6_INC_STATS_BH(dev_net(dst->dev), - ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); - kfree_skb(skb); - return -EINVAL; - -} - /* dev_loopback_xmit for use with netfilter. */ static int ip6_dev_loopback_xmit(struct sk_buff *newskb) { @@ -111,8 +95,7 @@ static int ip6_dev_loopback_xmit(struct sk_buff *newskb) return 0; } - -static int ip6_output2(struct sk_buff *skb) +static int ip6_finish_output2(struct sk_buff *skb) { struct dst_entry *dst = skb_dst(skb); struct net_device *dev = dst->dev; @@ -150,8 +133,15 @@ static int ip6_output2(struct sk_buff *skb) skb->len); } - return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, skb->dev, - ip6_output_finish); + if (dst->hh) + return neigh_hh_output(dst->hh, skb); + else if (dst->neighbour) + return dst->neighbour->output(skb); + + IP6_INC_STATS_BH(dev_net(dst->dev), + ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); + kfree_skb(skb); + return -EINVAL; } static inline int ip6_skb_dst_mtu(struct sk_buff *skb) @@ -162,21 +152,28 @@ static inline int ip6_skb_dst_mtu(struct sk_buff *skb) skb_dst(skb)->dev->mtu : dst_mtu(skb_dst(skb)); } +static int ip6_finish_output(struct sk_buff *skb) +{ + if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || + dst_allfrag(skb_dst(skb))) + return ip6_fragment(skb, ip6_finish_output2); + else + return ip6_finish_output2(skb); +} + int ip6_output(struct sk_buff *skb) { + struct net_device *dev = skb_dst(skb)->dev; struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); if (unlikely(idev->cnf.disable_ipv6)) { - IP6_INC_STATS(dev_net(skb_dst(skb)->dev), idev, + IP6_INC_STATS(dev_net(dev), idev, IPSTATS_MIB_OUTDISCARDS); kfree_skb(skb); return 0; } - if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || - dst_allfrag(skb_dst(skb))) - return ip6_fragment(skb, ip6_output2); - else - return ip6_output2(skb); + return NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, skb, NULL, dev, + ip6_finish_output); } /* -- 1.7.0.2 -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html