path: root/net/ipv4/ip_tunnel.c
diff options
authorTimo Teräs <timo.teras@iki.fi>2015-07-07 08:34:13 +0300
committerDavid S. Miller <davem@davemloft.net>2015-07-08 16:03:09 -0700
commitfc24f2b2094366da8786f59f2606307e934cea17 (patch)
tree69460a93f9a0a24e3392f8bf444aec7c16e34a8f /net/ipv4/ip_tunnel.c
parentrtnetlink: verify IFLA_VF_INFO attributes before passing them to driver (diff)
ip_tunnel: fix ipv4 pmtu check to honor inner ip header df
Frag needed should be sent only if the inner header asked to not fragment. Currently fragmentation is broken if the tunnel has df set, but df was not asked in the original packet. The tunnel's df needs to be still checked to update internally the pmtu cache. Commit 23a3647bc4f93bac broke it, and this commit fixes the ipv4 df check back to the way it was. Fixes: 23a3647bc4f93bac ("ip_tunnels: Use skb-len to PMTU check.") Cc: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: Timo Teräs <timo.teras@iki.fi> Acked-by: Pravin B Shelar <pshelar@nicira.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/ip_tunnel.c')
1 files changed, 5 insertions, 3 deletions
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 4c2c3ba4ba65..626d9e56a6bd 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -586,7 +586,8 @@ int ip_tunnel_encap(struct sk_buff *skb, struct ip_tunnel *t,
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;
@@ -603,7 +604,8 @@ 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;
@@ -737,7 +739,7 @@ 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)) {
goto tx_error;