net: factor out skb_mac_gso_segment() from skb_gso_segment()

This function will be used in next GRE_GSO patch. This patch does
not change any functionality. It only exports skb_mac_gso_segment()
function.

[ Use skb_reset_mac_len() -DaveM ]

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 9deb672d999f7552334c305808a1547b784a3759..920361bc27e7b3cbdc0d634b470eee420081bbc3 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2671,6 +2671,8 @@ extern void netdev_upper_dev_unlink(struct net_device *dev,
 extern int skb_checksum_help(struct sk_buff *skb);
 extern struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
        netdev_features_t features, bool tx_path);
+extern struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
+                                         netdev_features_t features);
 
 static inline
 struct sk_buff *skb_gso_segment(struct sk_buff *skb, netdev_features_t features)

diff --git a/net/core/dev.c b/net/core/dev.c
index f44473696b8b9e8239351c54f4a19074270e83d1..67deae60214cb0967a665f0ac8266b48788456cb 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2327,37 +2327,20 @@ out:
 }
 EXPORT_SYMBOL(skb_checksum_help);
 
-/* openvswitch calls this on rx path, so we need a different check.
- */
-static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
-{
-       if (tx_path)
-               return skb->ip_summed != CHECKSUM_PARTIAL;
-       else
-               return skb->ip_summed == CHECKSUM_NONE;
-}
-
 /**
- *     __skb_gso_segment - Perform segmentation on skb.
+ *     skb_mac_gso_segment - mac layer segmentation handler.
  *     @skb: buffer to segment
  *     @features: features for the output path (see dev->features)
- *     @tx_path: whether it is called in TX path
- *
- *     This function segments the given skb and returns a list of segments.
- *
- *     It may return NULL if the skb requires no segmentation.  This is
- *     only possible when GSO is used for verifying header integrity.
  */
-struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
-                                 netdev_features_t features, bool tx_path)
+struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
+                                   netdev_features_t features)
 {
        struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
        struct packet_offload *ptype;
        __be16 type = skb->protocol;
-       int vlan_depth = ETH_HLEN;
-       int err;
 
        while (type == htons(ETH_P_8021Q)) {
+               int vlan_depth = ETH_HLEN;
                struct vlan_hdr *vh;
 
                if (unlikely(!pskb_may_pull(skb, vlan_depth + VLAN_HLEN)))
@@ -2368,22 +2351,14 @@ struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
                vlan_depth += VLAN_HLEN;
        }
 
-       skb_reset_mac_header(skb);
-       skb->mac_len = skb->network_header - skb->mac_header;
        __skb_pull(skb, skb->mac_len);
 
-       if (unlikely(skb_needs_check(skb, tx_path))) {
-               skb_warn_bad_offload(skb);
-
-               if (skb_header_cloned(skb) &&
-                   (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
-                       return ERR_PTR(err);
-       }
-
        rcu_read_lock();
        list_for_each_entry_rcu(ptype, &offload_base, list) {
                if (ptype->type == type && ptype->callbacks.gso_segment) {
                        if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
+                               int err;
+
                                err = ptype->callbacks.gso_send_check(skb);
                                segs = ERR_PTR(err);
                                if (err || skb_gso_ok(skb, features))
@@ -2401,6 +2376,48 @@ struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
 
        return segs;
 }
+EXPORT_SYMBOL(skb_mac_gso_segment);
+
+
+/* openvswitch calls this on rx path, so we need a different check.
+ */
+static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
+{
+       if (tx_path)
+               return skb->ip_summed != CHECKSUM_PARTIAL;
+       else
+               return skb->ip_summed == CHECKSUM_NONE;
+}
+
+/**
+ *     __skb_gso_segment - Perform segmentation on skb.
+ *     @skb: buffer to segment
+ *     @features: features for the output path (see dev->features)
+ *     @tx_path: whether it is called in TX path
+ *
+ *     This function segments the given skb and returns a list of segments.
+ *
+ *     It may return NULL if the skb requires no segmentation.  This is
+ *     only possible when GSO is used for verifying header integrity.
+ */
+struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
+                                 netdev_features_t features, bool tx_path)
+{
+       if (unlikely(skb_needs_check(skb, tx_path))) {
+               int err;
+
+               skb_warn_bad_offload(skb);
+
+               if (skb_header_cloned(skb) &&
+                   (err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
+                       return ERR_PTR(err);
+       }
+
+       skb_reset_mac_header(skb);
+       skb_reset_mac_len(skb);
+
+       return skb_mac_gso_segment(skb, features);
+}
 EXPORT_SYMBOL(__skb_gso_segment);
 
 /* Take action when hardware reception checksum errors are detected. */