BIER API and load-balancing fixes

Change-Id: Ibda19d786070c942c75016ab568c8361de2f24af
Signed-off-by: Neale Ranns <nranns@cisco.com>
diff --git a/src/vnet/bier/bier_fwd.h b/src/vnet/bier/bier_fwd.h
new file mode 100644
index 0000000..3b0b93b
--- /dev/null
+++ b/src/vnet/bier/bier_fwd.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2018 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __BIER_FWD_H__
+#define __BIER_FWD_H__
+
+#include <vnet/bier/bier_types.h>
+#include <vnet/bier/bier_hdr_inlines.h>
+
+static_always_inline u32
+bier_compute_flow_hash (const bier_hdr_t *hdr)
+{
+    u32 first_word = clib_net_to_host_u32(hdr->bh_first_word);
+
+    return ((first_word &
+             BIER_HDR_ENTROPY_FIELD_MASK) >>
+            BIER_HDR_ENTROPY_FIELD_SHIFT);
+}
+
+#endif