Frag needed should be sent only if the inner header asked
to not fragment. Currently fragmentation is broken if the
tunnel has df set. The tunnel's df needs to be still checked
to update internally the pmtu cache.
This got broken in commit 23a3647bc4f93bac and this fixes
the pmtu check back to the way it was.
Fixes: 23a3647bc4f93bac (ip_tunnels: Use skb-len to PMTU check.)
Cc: Pravin B Shelar pshe...@nicira.com
---
Should go to -stable queues (3.12.y and never).
net/ipv4/ip_tunnel.c | 8 +---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 0bb8e14..6822572 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -587,7 +587,8 @@ int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel
*t,
EXPORT_SYMBOL(ip_tunnel_encap);
static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb,
- struct rtable *rt, __be16 df)
+ struct rtable *rt, __be16 df,
+ const struct iphdr *inner_iph)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
int pkt_size = skb-len - tunnel-hlen - dev-hard_header_len;
@@ -604,7 +605,8 @@ static int tnl_update_pmtu(struct net_device *dev, struct
sk_buff *skb,
if (skb-protocol == htons(ETH_P_IP)) {
if (!skb_is_gso(skb)
- (df htons(IP_DF)) mtu pkt_size) {
+ (inner_iph-frag_off htons(IP_DF))
+ mtu pkt_size) {
memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
htonl(mtu));
return -E2BIG;
@@ -738,7 +740,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device
*dev,
goto tx_error;
}
- if (tnl_update_pmtu(dev, skb, rt, tnl_params-frag_off)) {
+ if (tnl_update_pmtu(dev, skb, rt, tnl_params-frag_off, inner_iph)) {
ip_rt_put(rt);
goto tx_error;
}
--
2.4.5
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