[ovs-dev] [PATCH v2] datapath: define compat __skb_gso_segment()

[Pravin B Shelar]

OVS correctly define skb_gso_segment() to handle MPLS and VLAN
segmentation correctly. But OVS also uses __skb_gso_segment() in
some cases. Following patch defines compat __skb_gso_segment()
to handle all segmentation cases.

Signed-off-by: Pravin B Shelar <pshelar at nicira.com>
---
Fixed __skb_gso_segment() compatibility.
---
 datapath/linux/compat/gso.c                     |    3 ++
 datapath/linux/compat/include/linux/netdevice.h |   24 +++++++++++-----------
 datapath/linux/compat/netdevice.c               |   17 +++++++++++----
 3 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/datapath/linux/compat/gso.c b/datapath/linux/compat/gso.c
index 552e748..f8a70d0 100644
--- a/datapath/linux/compat/gso.c
+++ b/datapath/linux/compat/gso.c
@@ -219,6 +219,9 @@ static struct sk_buff *tnl_skb_gso_segment(struct sk_buff *skb,
 	 * make copy of it to restore it back. */
 	memcpy(cb, skb->cb, sizeof(cb));
 
+	/* We are handling offloads by segmenting l3 packet, so
+	 * no need to call OVS compat segmentation function. */
+#undef __skb_gso_segment
 	segs = __skb_gso_segment(skb, 0, tx_path);
 	if (!segs || IS_ERR(segs))
 		goto free;
diff --git a/datapath/linux/compat/include/linux/netdevice.h b/datapath/linux/compat/include/linux/netdevice.h
index 38315c2..674a3a0 100644
--- a/datapath/linux/compat/include/linux/netdevice.h
+++ b/datapath/linux/compat/include/linux/netdevice.h
@@ -88,10 +88,19 @@ static inline struct net_device *dev_get_by_index_rcu(struct net *net, int ifind
 typedef u32 netdev_features_t;
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(3,16,0)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,19,0)
+/* define compat version to handle MPLS segmentation offload. */
+#define __skb_gso_segment rpl__skb_gso_segment
+struct sk_buff *rpl__skb_gso_segment(struct sk_buff *skb,
+				    netdev_features_t features,
+				    bool tx_path);
+
 #define skb_gso_segment rpl_skb_gso_segment
-struct sk_buff *rpl_skb_gso_segment(struct sk_buff *skb,
-                                    netdev_features_t features);
+static inline
+struct sk_buff *rpl_skb_gso_segment(struct sk_buff *skb, netdev_features_t features)
+{
+        return rpl__skb_gso_segment(skb, features, true);
+}
 #endif
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,38)
@@ -106,15 +115,6 @@ static inline int rpl_netif_needs_gso(struct sk_buff *skb, int features)
 }
 #endif
 
-#ifndef HAVE___SKB_GSO_SEGMENT
-static inline struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
-						netdev_features_t features,
-						bool tx_path)
-{
-	return skb_gso_segment(skb, features);
-}
-#endif
-
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,9,0)
 
 /* XEN dom0 networking assumes dev->master is bond device
diff --git a/datapath/linux/compat/netdevice.c b/datapath/linux/compat/netdevice.c
index 7bb8f77..f17329a 100644
--- a/datapath/linux/compat/netdevice.c
+++ b/datapath/linux/compat/netdevice.c
@@ -75,9 +75,10 @@ netdev_features_t rpl_netif_skb_features(struct sk_buff *skb)
 EXPORT_SYMBOL_GPL(rpl_netif_skb_features);
 #endif	/* kernel version < 2.6.38 */
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(3,16,0)
-struct sk_buff *rpl_skb_gso_segment(struct sk_buff *skb,
-				    netdev_features_t features)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,19,0)
+struct sk_buff *rpl__skb_gso_segment(struct sk_buff *skb,
+				    netdev_features_t features,
+				    bool tx_path)
 {
 	int vlan_depth = ETH_HLEN;
 	__be16 type = skb->protocol;
@@ -99,14 +100,20 @@ struct sk_buff *rpl_skb_gso_segment(struct sk_buff *skb,
 		type = ovs_skb_get_inner_protocol(skb);
 
 	/* this hack needed to get regular skb_gso_segment() */
-#undef skb_gso_segment
 	skb_proto = skb->protocol;
 	skb->protocol = type;
 
+#ifdef HAVE___SKB_GSO_SEGMENT
+#undef __skb_gso_segment
+	skb_gso = __skb_gso_segment(skb, features, tx_path);
+#else
+#undef skb_gso_segment
 	skb_gso = skb_gso_segment(skb, features);
+#endif
+
 	skb->protocol = skb_proto;
 	return skb_gso;
 }
-EXPORT_SYMBOL_GPL(rpl_skb_gso_segment);
+EXPORT_SYMBOL_GPL(rpl__skb_gso_segment);
 
 #endif	/* kernel version < 3.16.0 */
-- 
1.7.1