1 /* 2 * Copyright (C) 2019 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.net.util; 18 19 import android.annotation.IntDef; 20 21 import java.lang.annotation.Retention; 22 import java.lang.annotation.RetentionPolicy; 23 24 /** 25 * Collection of utilities for data stall. 26 */ 27 public class DataStallUtils { 28 public static final int DATA_STALL_EVALUATION_TYPE_NONE = 0; 29 /** Detect data stall using dns timeout counts. */ 30 public static final int DATA_STALL_EVALUATION_TYPE_DNS = 1 << 0; 31 /** Detect data stall using tcp connection fail rate. */ 32 public static final int DATA_STALL_EVALUATION_TYPE_TCP = 1 << 1; 33 34 @IntDef(prefix = { "DATA_STALL_EVALUATION_TYPE_" }, 35 flag = true, 36 value = { 37 DATA_STALL_EVALUATION_TYPE_NONE, 38 DATA_STALL_EVALUATION_TYPE_DNS, 39 DATA_STALL_EVALUATION_TYPE_TCP, }) 40 @Retention(RetentionPolicy.SOURCE) 41 public @interface EvaluationType { 42 } 43 44 // Default configuration values for data stall detection. 45 public static final int DEFAULT_CONSECUTIVE_DNS_TIMEOUT_THRESHOLD = 5; 46 public static final int DEFAULT_DATA_STALL_MIN_EVALUATE_TIME_MS = 60 * 1000; 47 public static final int DEFAULT_DATA_STALL_VALID_DNS_TIME_THRESHOLD_MS = 30 * 60 * 1000; 48 /** 49 * The threshold value for the number of consecutive dns timeout events received to be a 50 * signal of data stall. The number of consecutive timeouts needs to be {@code >=} this 51 * threshold to be considered a data stall. Set the value to {@code <= 0} to disable. Note 52 * that the value should be {@code > 0} if the DNS data stall detection is enabled. 53 * 54 */ 55 public static final String CONFIG_DATA_STALL_CONSECUTIVE_DNS_TIMEOUT_THRESHOLD = 56 "data_stall_consecutive_dns_timeout_threshold"; 57 58 /** 59 * The minimal time interval in milliseconds for data stall reevaluation. 60 * 61 */ 62 public static final String CONFIG_DATA_STALL_MIN_EVALUATE_INTERVAL = 63 "data_stall_min_evaluate_interval"; 64 65 /** 66 * DNS timeouts older than this timeout (in milliseconds) are not considered for detecting 67 * a data stall. 68 * 69 */ 70 public static final String CONFIG_DATA_STALL_VALID_DNS_TIME_THRESHOLD = 71 "data_stall_valid_dns_time_threshold"; 72 73 /** 74 * Which data stall detection signal to use. This is a bitmask constructed by bitwise-or-ing 75 * (i.e. {@code |}) the DATA_STALL_EVALUATION_TYPE_* values. 76 * 77 * Type: int 78 * Valid values: 79 * {@link #DATA_STALL_EVALUATION_TYPE_DNS} : Use dns as a signal. 80 * {@link #DATA_STALL_EVALUATION_TYPE_TCP} : Use tcp info as a signal. 81 */ 82 public static final String CONFIG_DATA_STALL_EVALUATION_TYPE = "data_stall_evaluation_type"; 83 public static final int DEFAULT_DATA_STALL_EVALUATION_TYPES = 84 DATA_STALL_EVALUATION_TYPE_DNS | DATA_STALL_EVALUATION_TYPE_TCP; 85 // The default number of DNS events kept of the log kept for dns signal evaluation. Each event 86 // is represented by a {@link com.android.server.connectivity.NetworkMonitor#DnsResult} objects. 87 // It's also the size of array of {@link com.android.server.connectivity.nano.DnsEvent} kept in 88 // metrics. Note that increasing the size may cause statsd log buffer bust. Need to check the 89 // design in statsd when you try to increase the size. 90 public static final int DEFAULT_DNS_LOG_SIZE = 20; 91 92 /** 93 * The time interval for polling tcp info to observe the tcp health. 94 */ 95 public static String CONFIG_DATA_STALL_TCP_POLLING_INTERVAL = "data_stall_tcp_polling_interval"; 96 97 /** 98 * Default polling interval to observe the tcp health. 99 */ 100 public static int DEFAULT_TCP_POLLING_INTERVAL_MS = 20_000; 101 102 /** 103 * Default tcp packets fail rate to suspect as a data stall. 104 * 105 * Calculated by ((# of packets lost)+(# of packets retrans))/(# of packets sent)*100. Ideally, 106 * the percentage should be 100%. However, the ongoing packets may not be considered as neither 107 * lost or retrans yet. It will cause the percentage lower. 108 */ 109 public static final int DEFAULT_TCP_PACKETS_FAIL_PERCENTAGE = 80; 110 111 /** 112 * The percentage of tcp packets fail rate to be suspected as a data stall. 113 * 114 * Type: int 115 * Valid values: 0 to 100. 116 */ 117 public static final String CONFIG_TCP_PACKETS_FAIL_PERCENTAGE = "tcp_packets_fail_percentage"; 118 119 /** Corresponds to enum from bionic/libc/include/netinet/tcp.h. */ 120 public static final int TCP_ESTABLISHED = 1; 121 public static final int TCP_SYN_SENT = 2; 122 public static final int TCP_SYN_RECV = 3; 123 public static final int TCP_MONITOR_STATE_FILTER = 124 (1 << TCP_ESTABLISHED) | (1 << TCP_SYN_SENT) | (1 << TCP_SYN_RECV); 125 126 /** 127 * Threshold for the minimal tcp packets count to evaluate data stall via tcp info. 128 */ 129 public static final int DEFAULT_DATA_STALL_MIN_PACKETS_THRESHOLD = 10; 130 public static final String CONFIG_MIN_PACKETS_THRESHOLD = "tcp_min_packets_threshold"; 131 } 132