upload android base code part3

android/bionic/libc/dns/include/resolv_params.h

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * 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 _RESOLV_PARAMS_H
+#define _RESOLV_PARAMS_H
+
+#include <stdint.h>
+
+/* Hard-coded defines */
+#define MAXNS			4	/* max # name servers we'll track */
+#define MAXDNSRCH		6	/* max # domains in search path */
+#define MAXDNSRCHPATH		256	/* max length of domain search paths */
+#define MAXNSSAMPLES		64	/* max # samples to store per server */
+
+/* Defaults used for initializing __res_params */
+#define SUCCESS_THRESHOLD	75	/* if successes * 100 / total_samples is less than
+					 * this value, the server is considered failing
+					 */
+#define NSSAMPLE_VALIDITY	1800	/* Sample validity in seconds.
+					 * Set to -1 to disable skipping failing
+					 * servers.
+					 */
+
+/* per-netid configuration parameters passed from netd to the resolver */
+struct __res_params {
+    uint16_t sample_validity; // sample lifetime in s
+    // threshold of success / total samples below which a server is considered broken
+    uint8_t success_threshold; // 0: disable, value / 100 otherwise
+    uint8_t min_samples; // min # samples needed for statistics to be considered meaningful
+    uint8_t max_samples; // max # samples taken into account for statistics
+};
+
+typedef enum { res_goahead, res_nextns, res_modified, res_done, res_error }
+	res_sendhookact;
+
+typedef res_sendhookact (*res_send_qhook)(struct sockaddr * const *,
+					      const u_char **, int *,
+					      u_char *, int, int *);
+
+typedef res_sendhookact (*res_send_rhook)(const struct sockaddr *,
+					      const u_char *, int, u_char *,
+					      int, int *);
+
+#endif // _RESOLV_PARAMS_H