| /* |
| * Copyright (C) 2019 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. |
| */ |
| |
| package android.net.util; |
| |
| import android.annotation.IntDef; |
| |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.RetentionPolicy; |
| |
| /** |
| * Collection of utilities for data stall. |
| */ |
| public class DataStallUtils { |
| public static final int DATA_STALL_EVALUATION_TYPE_NONE = 0; |
| /** Detect data stall using dns timeout counts. */ |
| public static final int DATA_STALL_EVALUATION_TYPE_DNS = 1 << 0; |
| /** Detect data stall using tcp connection fail rate. */ |
| public static final int DATA_STALL_EVALUATION_TYPE_TCP = 1 << 1; |
| |
| @IntDef(prefix = { "DATA_STALL_EVALUATION_TYPE_" }, |
| flag = true, |
| value = { |
| DATA_STALL_EVALUATION_TYPE_NONE, |
| DATA_STALL_EVALUATION_TYPE_DNS, |
| DATA_STALL_EVALUATION_TYPE_TCP, }) |
| @Retention(RetentionPolicy.SOURCE) |
| public @interface EvaluationType { |
| } |
| |
| // Default configuration values for data stall detection. |
| public static final int DEFAULT_CONSECUTIVE_DNS_TIMEOUT_THRESHOLD = 5; |
| public static final int DEFAULT_DATA_STALL_MIN_EVALUATE_TIME_MS = 60 * 1000; |
| public static final int DEFAULT_DATA_STALL_VALID_DNS_TIME_THRESHOLD_MS = 30 * 60 * 1000; |
| /** |
| * The threshold value for the number of consecutive dns timeout events received to be a |
| * signal of data stall. The number of consecutive timeouts needs to be {@code >=} this |
| * threshold to be considered a data stall. Set the value to {@code <= 0} to disable. Note |
| * that the value should be {@code > 0} if the DNS data stall detection is enabled. |
| * |
| */ |
| public static final String CONFIG_DATA_STALL_CONSECUTIVE_DNS_TIMEOUT_THRESHOLD = |
| "data_stall_consecutive_dns_timeout_threshold"; |
| |
| /** |
| * The minimal time interval in milliseconds for data stall reevaluation. |
| * |
| */ |
| public static final String CONFIG_DATA_STALL_MIN_EVALUATE_INTERVAL = |
| "data_stall_min_evaluate_interval"; |
| |
| /** |
| * DNS timeouts older than this timeout (in milliseconds) are not considered for detecting |
| * a data stall. |
| * |
| */ |
| public static final String CONFIG_DATA_STALL_VALID_DNS_TIME_THRESHOLD = |
| "data_stall_valid_dns_time_threshold"; |
| |
| /** |
| * Which data stall detection signal to use. This is a bitmask constructed by bitwise-or-ing |
| * (i.e. {@code |}) the DATA_STALL_EVALUATION_TYPE_* values. |
| * |
| * Type: int |
| * Valid values: |
| * {@link #DATA_STALL_EVALUATION_TYPE_DNS} : Use dns as a signal. |
| * {@link #DATA_STALL_EVALUATION_TYPE_TCP} : Use tcp info as a signal. |
| */ |
| public static final String CONFIG_DATA_STALL_EVALUATION_TYPE = "data_stall_evaluation_type"; |
| public static final int DEFAULT_DATA_STALL_EVALUATION_TYPES = |
| DATA_STALL_EVALUATION_TYPE_DNS | DATA_STALL_EVALUATION_TYPE_TCP; |
| // The default number of DNS events kept of the log kept for dns signal evaluation. Each event |
| // is represented by a {@link com.android.server.connectivity.NetworkMonitor#DnsResult} objects. |
| // It's also the size of array of {@link com.android.server.connectivity.nano.DnsEvent} kept in |
| // metrics. Note that increasing the size may cause statsd log buffer bust. Need to check the |
| // design in statsd when you try to increase the size. |
| public static final int DEFAULT_DNS_LOG_SIZE = 20; |
| |
| /** |
| * The time interval for polling tcp info to observe the tcp health. |
| */ |
| public static String CONFIG_DATA_STALL_TCP_POLLING_INTERVAL = "data_stall_tcp_polling_interval"; |
| |
| /** |
| * Default polling interval to observe the tcp health. |
| */ |
| public static int DEFAULT_TCP_POLLING_INTERVAL_MS = 20_000; |
| |
| /** |
| * Default tcp packets fail rate to suspect as a data stall. |
| * |
| * Calculated by ((# of packets lost)+(# of packets retrans))/(# of packets sent)*100. Ideally, |
| * the percentage should be 100%. However, the ongoing packets may not be considered as neither |
| * lost or retrans yet. It will cause the percentage lower. |
| */ |
| public static final int DEFAULT_TCP_PACKETS_FAIL_PERCENTAGE = 80; |
| |
| /** |
| * The percentage of tcp packets fail rate to be suspected as a data stall. |
| * |
| * Type: int |
| * Valid values: 0 to 100. |
| */ |
| public static final String CONFIG_TCP_PACKETS_FAIL_PERCENTAGE = "tcp_packets_fail_percentage"; |
| |
| /** Corresponds to enum from bionic/libc/include/netinet/tcp.h. */ |
| public static final int TCP_ESTABLISHED = 1; |
| public static final int TCP_SYN_SENT = 2; |
| public static final int TCP_SYN_RECV = 3; |
| public static final int TCP_MONITOR_STATE_FILTER = |
| (1 << TCP_ESTABLISHED) | (1 << TCP_SYN_SENT) | (1 << TCP_SYN_RECV); |
| |
| /** |
| * Threshold for the minimal tcp packets count to evaluate data stall via tcp info. |
| */ |
| public static final int DEFAULT_DATA_STALL_MIN_PACKETS_THRESHOLD = 10; |
| public static final String CONFIG_MIN_PACKETS_THRESHOLD = "tcp_min_packets_threshold"; |
| } |