1 files changed, 41 insertions, 0 deletions
diff --git a/src/core/ext/transport/chttp2/alpn/alpn.cc b/src/core/ext/transport/chttp2/alpn/alpn.cc
new file mode 100644
index 0000000000..ca2e801ec8
--- /dev/null
+++ b/src/core/ext/transport/chttp2/alpn/alpn.cc
@@ -0,0 +1,41 @@
+/*
+ *
+ * Copyright 2015 gRPC authors.
+ *
+ * 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.
+ *
+ */
+
+#include "src/core/ext/transport/chttp2/alpn/alpn.h"
+#include <grpc/support/log.h>
+#include <grpc/support/useful.h>
+
+/* in order of preference */
+static const char *const supported_versions[] = {"grpc-exp", "h2"};
+
+int grpc_chttp2_is_alpn_version_supported(const char *version, size_t size) {
+  size_t i;
+  for (i = 0; i < GPR_ARRAY_SIZE(supported_versions); i++) {
+    if (!strncmp(version, supported_versions[i], size)) return 1;
+  }
+  return 0;
+}
+
+size_t grpc_chttp2_num_alpn_versions(void) {
+  return GPR_ARRAY_SIZE(supported_versions);
+}
+
+const char *grpc_chttp2_get_alpn_version_index(size_t i) {
+  GPR_ASSERT(i < GPR_ARRAY_SIZE(supported_versions));
+  return supported_versions[i];
+}