openvswitch: make skb->csum consistent with rest of networking stack.

Following patch keeps skb->csum correct across ovs.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>

5 files changed, 17 insertions, 0 deletions

diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 894b6cbdd929..596d6373399d 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -130,9 +130,13 @@ static int set_eth_addr(struct sk_buff *skb,
         if (unlikely(err))
                 return err;
 
+        skb_postpull_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
+
         memcpy(eth_hdr(skb)->h_source, eth_key->eth_src, ETH_ALEN);
         memcpy(eth_hdr(skb)->h_dest, eth_key->eth_dst, ETH_ALEN);
 
+        ovs_skb_postpush_rcsum(skb, eth_hdr(skb), ETH_ALEN * 2);
+
         return 0;
 }
 
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index 33df0913358d..fca483360ce2 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -618,6 +618,9 @@ int ovs_flow_extract(struct sk_buff *skb, u16 in_port, struct sw_flow_key *key,
         memcpy(key->eth.dst, eth->h_dest, ETH_ALEN);
 
         __skb_pull(skb, 2 * ETH_ALEN);
+        /* We are going to push all headers that we pull, so no need to
+         * update skb->csum here.
+         */
 
         if (vlan_tx_tag_present(skb))
                 key->eth.tci = htons(skb->vlan_tci);
diff --git a/net/openvswitch/vport-internal_dev.c b/net/openvswitch/vport-internal_dev.c
index 84e0a0379186..e284c7e1fec4 100644
--- a/net/openvswitch/vport-internal_dev.c
+++ b/net/openvswitch/vport-internal_dev.c
@@ -221,6 +221,7 @@ static int internal_dev_recv(struct vport *vport, struct sk_buff *skb)
         skb->dev = netdev;
         skb->pkt_type = PACKET_HOST;
         skb->protocol = eth_type_trans(skb, netdev);
+        skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 
         netif_rx(skb);
 
diff --git a/net/openvswitch/vport-netdev.c b/net/openvswitch/vport-netdev.c
index 43712217a372..40de815b4213 100644
--- a/net/openvswitch/vport-netdev.c
+++ b/net/openvswitch/vport-netdev.c
@@ -49,6 +49,8 @@ static void netdev_port_receive(struct vport *vport, struct sk_buff *skb)
                 return;
 
         skb_push(skb, ETH_HLEN);
+        ovs_skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
+
         ovs_vport_receive(vport, skb);
         return;
 
diff --git a/net/openvswitch/vport.h b/net/openvswitch/vport.h
index 1cef5cd3be47..293278c4c2df 100644
--- a/net/openvswitch/vport.h
+++ b/net/openvswitch/vport.h
@@ -192,4 +192,11 @@ void ovs_vport_record_error(struct vport *, enum vport_err_type err_type);
 extern const struct vport_ops ovs_netdev_vport_ops;
 extern const struct vport_ops ovs_internal_vport_ops;
 
+static inline void ovs_skb_postpush_rcsum(struct sk_buff *skb,
+                                      const void *start, unsigned int len)
+{
+        if (skb->ip_summed == CHECKSUM_COMPLETE)
+                skb->csum = csum_add(skb->csum, csum_partial(start, len, 0));
+}
+
 #endif /* vport.h */