udp: increase inner ip header ID during segmentation

Similar to GRE tunnel, UDP tunnel should take care of IP header ID
too.

Cc: Pravin B Shelar <pshelar@nicira.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 1 deletions

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 7117d1467b02..3c362eee3f2d 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2304,7 +2304,8 @@ static struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
         struct sk_buff *segs = ERR_PTR(-EINVAL);
         int mac_len = skb->mac_len;
         int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
-        int outer_hlen;
+        int outer_hlen, id;
+        struct iphdr *iph;
         netdev_features_t enc_features;
 
         if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
@@ -2315,6 +2316,8 @@ static struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
         skb_reset_mac_header(skb);
         skb_set_network_header(skb, skb_inner_network_offset(skb));
         skb->mac_len = skb_inner_network_offset(skb);
+        iph = ip_hdr(skb);
+        id = ntohs(iph->id);
 
         /* segment inner packet. */
         enc_features = skb->dev->hw_enc_features & netif_skb_features(skb);
@@ -2329,6 +2332,8 @@ static struct sk_buff *skb_udp_tunnel_segment(struct sk_buff *skb,
                 int udp_offset = outer_hlen - tnl_hlen;
 
                 skb->mac_len = mac_len;
+                iph = (struct iphdr *)skb_inner_network_header(skb);
+                iph->id = htons(id++);
 
                 skb_push(skb, outer_hlen);
                 skb_reset_mac_header(skb);