datapath: define compat __skb_gso_segment()

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@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>

diff --git a/datapath/linux/compat/gso.c b/datapath/linux/compat/gso.c
index 552e748..2c19b58 100644 (file)
--- a/datapath/linux/compat/gso.c
+++ b/datapath/linux/compat/gso.c
@@ -52,7 +52,7 @@ MODULE_PARM_DESC(vlan_tso, "Enable TSO for VLAN packets");
 #define vlan_tso true
 #endif
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(3,16,0)
+#ifdef OVS_USE_COMPAT_GSO_SEGMENTATION
 static bool dev_supports_vlan_tx(struct net_device *dev)
 {
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,37)
@@ -66,16 +66,16 @@ static bool dev_supports_vlan_tx(struct net_device *dev)
 }
 
 /* Strictly this is not needed and will be optimised out
- * as this code is guarded by if LINUX_VERSION_CODE < KERNEL_VERSION(3,16,0).
+ * as this code is guarded by if LINUX_VERSION_CODE < KERNEL_VERSION(3,19,0).
  * It is here to make things explicit should the compatibility
  * code be extended in some way prior extending its life-span
- * beyond v3.16.
+ * beyond v3.19.
  */
 static bool supports_mpls_gso(void)
 {
 /* MPLS GSO was introduced in v3.11, however it was not correctly
- * activated using mpls_features until v3.16. */
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,16,0)
+ * activated using mpls_features until v3.19. */
+#ifdef OVS_USE_COMPAT_GSO_SEGMENTATION
        return true;
 #else
        return false;
@@ -120,17 +120,17 @@ int rpl_dev_queue_xmit(struct sk_buff *skb)
                /* As of v3.11 the kernel provides an mpls_features field in
                 * struct net_device which allows devices to advertise which
                 * features its supports for MPLS. This value defaults to
-                * NETIF_F_SG and as of v3.16.
+                * NETIF_F_SG and as of v3.19.
                 *
                 * This compatibility code is intended for kernels older
-                * than v3.16 that do not support MPLS GSO and do not
+                * than v3.19 that do not support MPLS GSO and do not
                 * use mpls_features. Thus this code uses NETIF_F_SG
                 * directly in place of mpls_features.
                 */
                if (mpls)
                        features &= NETIF_F_SG;
 
-               if (netif_needs_gso(skb, features)) {
+               if (netif_needs_gso(skb->dev, skb, features)) {
                        struct sk_buff *nskb;
 
                        nskb = skb_gso_segment(skb, features);
@@ -168,7 +168,7 @@ drop:
        return err;
 }
 EXPORT_SYMBOL_GPL(rpl_dev_queue_xmit);
-#endif /* 3.16 */
+#endif /* OVS_USE_COMPAT_GSO_SEGMENTATION */
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0)
 static __be16 __skb_network_protocol(struct sk_buff *skb)
@@ -219,7 +219,17 @@ 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. */
+
+#ifdef HAVE___SKB_GSO_SEGMENT
+#undef __skb_gso_segment
        segs = __skb_gso_segment(skb, 0, tx_path);
+#else
+#undef skb_gso_segment
+       segs = skb_gso_segment(skb, 0);
+#endif
+
        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..3deb93d 100644 (file)
--- a/datapath/linux/compat/include/linux/netdevice.h
+++ b/datapath/linux/compat/include/linux/netdevice.h
@@ -88,31 +88,42 @@ 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 OVS_USE_COMPAT_GSO_SEGMENTATION
+#endif
+
+#ifdef OVS_USE_COMPAT_GSO_SEGMENTATION
+/* 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)
 #define netif_skb_features rpl_netif_skb_features
 netdev_features_t rpl_netif_skb_features(struct sk_buff *skb);
+#endif
 
-#define netif_needs_gso rpl_netif_needs_gso
-static inline int rpl_netif_needs_gso(struct sk_buff *skb, int features)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,18,0)
+static inline int rpl_netif_needs_gso(struct net_device *dev,
+                                     struct sk_buff *skb, int features)
 {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,38)
        return skb_is_gso(skb) && (!skb_gso_ok(skb, features) ||
                unlikely(skb->ip_summed != CHECKSUM_PARTIAL));
-}
+#else
+       return netif_needs_gso(skb, 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);
 }
+#define netif_needs_gso rpl_netif_needs_gso
 #endif
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,9,0)

diff --git a/datapath/linux/compat/netdevice.c b/datapath/linux/compat/netdevice.c
index 7bb8f77..483d665 100644 (file)
--- 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)
+#ifdef OVS_USE_COMPAT_GSO_SEGMENTATION
+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 */
+#endif /* OVS_USE_COMPAT_GSO_SEGMENTATION */