From 18fdbe16de40062c63f9119a6beef17602f4b233 Mon Sep 17 00:00:00 2001
From: Jesse Gross <jesse@nicira.com>
Date: Wed, 28 Oct 2009 14:36:52 -0700
Subject: [PATCH] datapath: Allow TCP flags to be cleared.

When querying flow stats allow the TCP flags to be reset.  Since
the datapath ORs together all flags that have previously been
seen it is otherwise impossible to determine the set of flags from
after a particular time.
---
 datapath/datapath.c                     | 13 +++++++++----
 include/openvswitch/datapath-protocol.h |  4 ++++
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 1ae1d771..6e97c345 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -975,13 +975,18 @@ static int put_actions(const struct sw_flow *flow, struct odp_flow __user *ufp)
 	return 0;
 }
 
-static int answer_query(struct sw_flow *flow, struct odp_flow __user *ufp)
+static int answer_query(struct sw_flow *flow, u32 query_flags,
+			struct odp_flow __user *ufp)
 {
 	struct odp_flow_stats stats;
 	unsigned long int flags;
 
 	spin_lock_irqsave(&flow->lock, flags);
 	get_stats(flow, &stats);
+
+	if (query_flags & ODPFF_ZERO_TCP_FLAGS) {
+		flow->tcp_flags = 0;
+	}
 	spin_unlock_irqrestore(&flow->lock, flags);
 
 	if (__copy_to_user(&ufp->stats, &stats, sizeof(struct odp_flow_stats)))
@@ -1016,7 +1021,7 @@ static int del_flow(struct datapath *dp, struct odp_flow __user *ufp)
 	 * we get completely accurate stats, but that blows our performance,
 	 * badly. */
 	dp->n_flows--;
-	error = answer_query(flow, ufp);
+	error = answer_query(flow, uf.flags, ufp);
 	flow_deferred_free(flow);
 
 error:
@@ -1041,7 +1046,7 @@ static int query_flows(struct datapath *dp, const struct odp_flowvec *flowvec)
 		if (!flow)
 			error = __put_user(ENOENT, &ufp->stats.error);
 		else
-			error = answer_query(flow, ufp);
+			error = answer_query(flow, 0, ufp);
 		if (error)
 			return -EFAULT;
 	}
@@ -1062,7 +1067,7 @@ static int list_flow(struct sw_flow *flow, void *cbdata_)
 
 	if (__copy_to_user(&ufp->key, &flow->key, sizeof flow->key))
 		return -EFAULT;
-	error = answer_query(flow, ufp);
+	error = answer_query(flow, 0, ufp);
 	if (error)
 		return error;
 
diff --git a/include/openvswitch/datapath-protocol.h b/include/openvswitch/datapath-protocol.h
index 04423d94..ab7eb9e3 100644
--- a/include/openvswitch/datapath-protocol.h
+++ b/include/openvswitch/datapath-protocol.h
@@ -165,11 +165,15 @@ struct odp_flow_key {
     __u8   reserved;             /* Pad to 64 bits. */
 };
 
+/* Flags for ODP_FLOW. */
+#define ODPFF_ZERO_TCP_FLAGS (1 << 0) /* Zero the TCP flags. */
+
 struct odp_flow {
     struct odp_flow_stats stats;
     struct odp_flow_key key;
     union odp_action *actions;
     __u32 n_actions;
+    __u32 flags;
 };
 
 /* Flags for ODP_FLOW_PUT. */
-- 
2.30.2