ofproto: Avoid user->kernel->user round-trip for many controller actions.

[sliver-openvswitch.git] / lib / dpif.h

diff --git a/lib/dpif.h b/lib/dpif.h
index a639725..1496c22 100644 (file)
--- a/lib/dpif.h
+++ b/lib/dpif.h
@@ -18,10 +18,12 @@
 #ifndef DPIF_H
 #define DPIF_H 1
 
-#include "openvswitch/datapath-protocol.h"
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
+#include "openflow/openflow.h"
+#include "openvswitch/datapath-protocol.h"
+#include "util.h"
 
 #ifdef  __cplusplus
 extern "C" {
@@ -90,6 +92,14 @@ int dpif_execute(struct dpif *, uint16_t in_port,
                  const union odp_action[], size_t n_actions,
                  const struct ofpbuf *);
 
+/* Minimum number of bytes of headroom for a packet returned by dpif_recv()
+ * member function.  This headroom allows "struct odp_msg" to be replaced by
+ * "struct ofp_packet_in" without copying the buffer. */
+#define DPIF_RECV_MSG_PADDING (sizeof(struct ofp_packet_in) \
+                               - sizeof(struct odp_msg))
+BUILD_ASSERT_DECL(sizeof(struct ofp_packet_in) > sizeof(struct odp_msg));
+BUILD_ASSERT_DECL(DPIF_RECV_MSG_PADDING % 4 == 0);
+
 int dpif_recv_get_mask(const struct dpif *, int *listen_mask);
 int dpif_recv_set_mask(struct dpif *, int listen_mask);
 int dpif_get_sflow_probability(const struct dpif *, uint32_t *probability);