1 files changed, 22 insertions, 0 deletions
diff --git a/lib/flow.h b/lib/flow.h
index 1f6c1d6ae..902ab1bad 100644
--- a/lib/flow.h
+++ b/lib/flow.h
@@ -1188,4 +1188,26 @@ static inline bool is_stp(const struct flow *flow)
             && eth_addr_equals(flow->dl_dst, eth_addr_stp));
 }
 
+/* Returns true if flow->tp_dst equals 'port'.  If 'wc' is nonnull, sets
+ * appropriate bits in wc->masks.tp_dst to account for the test.
+ *
+ * The caller must already have ensured that 'flow' is a protocol for which
+ * tp_dst is relevant. */
+static inline bool tp_dst_equals(const struct flow *flow, uint16_t port,
+                                 struct flow_wildcards *wc)
+{
+    uint16_t diff = port ^ ntohs(flow->tp_dst);
+    if (wc) {
+        if (diff) {
+            /* Set mask for the most significant mismatching bit. */
+            int ofs = raw_clz64((uint64_t) diff << 48); /* range [0,15] */
+            wc->masks.tp_dst |= htons(0x8000 >> ofs);
+        } else {
+            /* Must match all bits. */
+            wc->masks.tp_dst = OVS_BE16_MAX;
+        }
+    }
+    return !diff;
+}
+
 #endif /* flow.h */