datapath: backport: geneve: fix max_mtu setting

Upstream commit: commit d5d5e8d55732c7c35c354e45e3b0af2795978a57 Author: Haishuang Yan <[email protected]> Date: Sat Jul 2 15:02:48 2016 +0800 geneve: fix max_mtu setting For ipv6+udp+geneve encapsulation data, the max_mtu should subtract sizeof(ipv6hdr), instead of sizeof(iphdr). Signed-off-by: Haishuang Yan <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Pravin B Shelar <[email protected]> Acked-by: Jesse Gross <[email protected]>
ViKingIX · Aug 3, 2016 · 2255777 · 2255777
1 parent f325530
commit 2255777
Showing 1 changed file with 7 additions and 2 deletions.
diff --git a/datapath/linux/compat/geneve.c b/datapath/linux/compat/geneve.c
@@ -1153,12 +1153,17 @@ static netdev_tx_t geneve_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 
 static int __geneve_change_mtu(struct net_device *dev, int new_mtu, bool strict)
 {
+	struct geneve_dev *geneve = netdev_priv(dev);
 	/* The max_mtu calculation does not take account of GENEVE
 	 * options, to avoid excluding potentially valid
 	 * configurations.
 	 */
-	int max_mtu = IP_MAX_MTU - GENEVE_BASE_HLEN - sizeof(struct iphdr)
-		- dev->hard_header_len;
+	int max_mtu = IP_MAX_MTU - GENEVE_BASE_HLEN - dev->hard_header_len;
+
+	if (geneve->remote.sa.sa_family == AF_INET6)
+		max_mtu -= sizeof(struct ipv6hdr);
+	else
+		max_mtu -= sizeof(struct iphdr);
 
 	if (new_mtu < 68)
 		return -EINVAL;