platform_bionic/libc/dns/include/resolv_params.h
Pierre Imai 97c9d73a87 Add new info functions to resolver for use by Netd.
android_net_res_stats_get_info_for_net returns the current name servers, search
domains, parameters and stats for the given network ID.

android_net_res_stats_aggregate provides statistics such as errors counts from
the raw stats data reported by android_net_res_stats_get_info_for_net.

android_net_res_stats_get_usable_servers uses the data returned by
android_net_res_stats_aggregate to determine which of the servers are
considered valid or broken by the resolver.

BUG: 25731675

Change-Id: I6059b68e5e8b809027a4d3135f6081588bee8a7d
2016-04-21 10:07:26 +09:00

46 lines
1.8 KiB
C

/*
* 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
} __attribute__((__packed__));
#endif // _RESOLV_PARAMS_H