datapath: Avoid using wrong metadata for recic action.

Recirc action needs to extract flow key from packet, it uses tun_info
from OVS_CB for setting tunnel meta data in flow key. But tun_info
can be overwritten by tunnel send action. This would result in wrong
flow key for the recirculation.
Following patch copies flow-key meta data from OVS_CB packet key
itself thus avoids this bug.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Andy Zhou <azhou@nicira.com>

datapath/actions.c

@@ -649,17 +649,15 @@ static int execute_recirc(struct datapath *dp, struct sk_buff *skb,
 				 const struct nlattr *a)
 {
 	struct sw_flow_key recirc_key;
-	uint32_t hash = OVS_CB(skb)->pkt_key->ovs_flow_hash;
 	int err;
 
-	err = ovs_flow_key_extract(skb, &recirc_key);
+	err = ovs_flow_key_extract_recirc(nla_get_u32(a), OVS_CB(skb)->pkt_key,
+					  skb, &recirc_key);
 	if (err) {
 		kfree_skb(skb);
 		return err;
 	}
 
-	recirc_key.ovs_flow_hash = hash;
-	recirc_key.recirc_id = nla_get_u32(a);
 
 	ovs_dp_process_packet_with_key(skb, &recirc_key, true);
 

datapath/flow.c

@@ -718,3 +718,13 @@ int ovs_flow_key_extract_userspace(const struct nlattr *attr,
 
 	return key_extract(skb, key);
 }
+
+int ovs_flow_key_extract_recirc(u32 recirc_id,
+				const struct sw_flow_key *key,
+				struct sk_buff *skb,
+				struct sw_flow_key *new_key)
+{
+	memcpy(new_key, key, OVS_SW_FLOW_KEY_METADATA_SIZE);
+	new_key->recirc_id = recirc_id;
+	return key_extract(skb, new_key);
+}

datapath/flow.h

@@ -87,6 +87,11 @@ static inline void ovs_flow_tun_info_init(struct ovs_tunnel_info *tun_info,
 	tun_info->options_len = opts_len;
 }
 
+#define OVS_SW_FLOW_KEY_METADATA_SIZE			\
+	(offsetof(struct sw_flow_key, recirc_id) +	\
+	FIELD_SIZEOF(struct sw_flow_key, recirc_id))
+
+
 struct sw_flow_key {
 	u8 tun_opts[255];
 	u8 tun_opts_len;
@@ -222,5 +227,9 @@ int ovs_flow_key_extract(struct sk_buff *skb, struct sw_flow_key *key);
 int ovs_flow_key_extract_userspace(const struct nlattr *attr,
 				   struct sk_buff *skb,
 				   struct sw_flow_key *key);
+int ovs_flow_key_extract_recirc(u32 recirc_id,
+				const struct sw_flow_key *key,
+				struct sk_buff *skb,
+				struct sw_flow_key *new_key);
 
 #endif /* flow.h */

datapath/flow_netlink.c

@@ -1016,13 +1016,8 @@ int ovs_nla_get_flow_metadata(const struct nlattr *attr,
 	memset(&match, 0, sizeof(match));
 	match.key = key;
 
-	key->tun_opts_len = 0;
-	memset(&key->tun_key, 0, sizeof(key->tun_key));
-	key->phy.priority = 0;
-	key->phy.skb_mark = 0;
+	memset(key, 0, OVS_SW_FLOW_KEY_METADATA_SIZE);
 	key->phy.in_port = DP_MAX_PORTS;
-	key->ovs_flow_hash = 0;
-	key->recirc_id = 0;
 
 	return metadata_from_nlattrs(&match, &attrs, a, false);
 }