From 292f4f3ce4b57f17a667cb34c72bca081dcc0281 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 9 Nov 2009 08:42:01 +0000 Subject: [PATCH] sit: Clean up DF code by copying from IPIP This patch rearranges the SIT DF bit handling using the new IPIP DF code. The only externally visible effect should be the case where PMTU is enabled and the MTU is exactly 1280 bytes. In this case the previous code would send packets out with DF off while the new code would set the DF bit. This is inline with RFC 4213. Signed-off-by: Herbert Xu Thanks, Signed-off-by: David S. Miller --- net/ipv6/sit.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c index 2362a3397e91..b6e145a673ab 100644 --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -637,6 +637,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, struct iphdr *tiph = &tunnel->parms.iph; struct ipv6hdr *iph6 = ipv6_hdr(skb); u8 tos = tunnel->parms.iph.tos; + __be16 df = tiph->frag_off; struct rtable *rt; /* Route to the other host */ struct net_device *tdev; /* Device to other host */ struct iphdr *iph; /* Our new IP header */ @@ -726,25 +727,28 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, goto tx_error; } - if (tiph->frag_off) + if (df) { mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); - else - mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; - if (mtu < 68) { - stats->collisions++; - ip_rt_put(rt); - goto tx_error; - } - if (mtu < IPV6_MIN_MTU) - mtu = IPV6_MIN_MTU; - if (tunnel->parms.iph.daddr && skb_dst(skb)) - skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); + if (mtu < 68) { + stats->collisions++; + ip_rt_put(rt); + goto tx_error; + } - if (skb->len > mtu) { - icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); - ip_rt_put(rt); - goto tx_error; + if (mtu < IPV6_MIN_MTU) { + mtu = IPV6_MIN_MTU; + df = 0; + } + + if (tunnel->parms.iph.daddr && skb_dst(skb)) + skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); + + if (skb->len > mtu) { + icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); + ip_rt_put(rt); + goto tx_error; + } } if (tunnel->err_count > 0) { @@ -792,11 +796,7 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, iph = ip_hdr(skb); iph->version = 4; iph->ihl = sizeof(struct iphdr)>>2; - if (mtu > IPV6_MIN_MTU) - iph->frag_off = tiph->frag_off; - else - iph->frag_off = 0; - + iph->frag_off = df; iph->protocol = IPPROTO_IPV6; iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); iph->daddr = rt->rt_dst; -- 2.30.2