[net-next PATCH v3 1/6] udp: Record gso_segs when supporting UDP segmentation offload

[Alexander Duyck <alexander.duyck@gmail.com>]

From: Alexander Duyck <alexander.h.duyck@intel.com>

We need to record the number of segments that will be generated when this
frame is segmented. The expectation is that if gso_size is set then
gso_segs is set as well. Without this some drivers such as ixgbe get
confused if they attempt to offload this as they record 0 segments for the
entire packet instead of the correct value.

Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 net/ipv4/udp.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index dd3102a37ef9..e07db83b311e 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -793,6 +793,8 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
 
 		skb_shinfo(skb)->gso_size = cork->gso_size;
 		skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
+		skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(len - sizeof(uh),
+							 cork->gso_size);
 		goto csum_partial;
 	}