【笔记】APN 配置参数 bitmask 数据转换（Android & KaiOS）

一、参数说明

（一）APN配置结构对比

Android: apns-conf.xml

<!-- Android: apns-conf.xml -->
<?xml version="1.0" encoding="utf-8"?>
<apns version="8">
  <apn carrier="T-Mobile US" mcc="001" mnc="01" apn="fast.t-mobile.com" user="" password="" server="" proxy="" port="" mmsc="http://mms.msg.eng.t-mobile.com/mms/wapenc" mmsproxy="" mmsport="" type="default,mms,supl,hipri,xcap,rcs" protocol="IPV6" roaming_protocol="IP" bearer_bitmask="" mvno_type="ecid" mvno_match_data="[4]4310260" class="" user_visible="true" user_editable="true" authtype="0"/>
</apns>

KaiOS: apns.json

特别需要注意格式（很容易出错），数组最后不用加逗号，注意大/中括号的首位一致性。

{
"202": {
  "10": [
    {"carrier":"Wind Internet","apn":"gint.b-online.gr","type":["default","supl"]},
    {"voicemail":"122","type":["operatorvariant"]},
    {"carrier":"Wind MMS","apn":"mnet.b-online.gr","mmsc":"http://192.168.200.95/servlets/mms","mmsproxy":"192.168.200.11","mmsport":"9401","type":["mms"]}
  ],
  "01": [
    {"carrier":"Cosmote Wireless Internet","apn":"","type":["ia"]},
    {"voicemail":"123","type":["operatorvariant"]},
    {"carrier":"Cosmote Wireless Internet","apn":"internet","type":["default","supl"]},
    {"carrier":"Cosmote Mms","apn":"mms","mmsc":"http://mmsc.cosmote.gr:8002","mmsproxy":"10.10.10.20","mmsport":"8080","type":["mms"]}
  ],
  "09": [
    {"carrier":"Q Internet","apn":"myq","type":["default","supl"]},
    {"voicemail":"122","type":["operatorvariant"]},
    {"carrier":"Q-Telecom MMS GPRS","apn":"q-mms.myq.gr","mmsc":"http://mms.myq.gr","mmsproxy":"192.168.80.134","mmsport":"8080","type":["mms"]}
  ]
},
"001": {
  "01": [
    {"carrier":"Testing SIM default","apn":"test","type":["default"],"protocol":"IPV4V6","roaming_protocol":"IPV4V6","user_visible":"true"},
    {"carrier":"IMS","apn":"ims","type":["ims"],"protocol":"IPV4V6","roaming_protocol":"IPV4V6","user_visible":"true"},
    {"carrier":"XCAP","apn":"xcap","type":["xcap"],"protocol":"IPV4V6","roaming_protocol":"IPV4V6","user_visible":"true","authtype":"0"}
  ]
}
}

（二）bearer配置值对比

• 1|2|3|4|5|6|7|8|9|10|11|12|13|14|15|16|17|18|19|20 （The original bearer value in Android，位运算）
• 1048575（The original bearer value in KaiOS using decimalism)

二、代码解析

（一）Android

待完善

（二）KaiOS（DataCallManager.jsm）

1、bitmask的进制转换

可以参考PDN建立逻辑，gecko/dom/system/gonk/radio/DataCallManager.jsm

//DataCallManager.jsm
 
//检查对应的rat是否包含在此APN bearer 配置中
// Check rat value include in the bit map or not.
function bitmaskHasTech(aBearerBitmask, aRadioTech) {
  if (aBearerBitmask == 0) {
    return true;
  } else if (aRadioTech > 0) {
    return (aBearerBitmask & (1 << (aRadioTech - 1))) != 0;
  }
  return false;
}
 
//bearer十进制转成二进制
// Show the detail rat type.
function bitmaskToString(aBearerBitmask) {
  if (aBearerBitmask == 0 || aBearerBitmask === undefined) {
    return 0;
  }
 
  let val = "";
  for (let i = 1; i < RIL.GECKO_RADIO_TECH.length; i++) {
    if ((aBearerBitmask & (1 << (i - 1))) != 0) {
      val = val.concat(i + "|");
    }
  }
  return val;
}
 
function bearerBitmapHasCdma(aBearerBitmask) {
  return (RIL_RADIO_CDMA_TECHNOLOGY_BITMASK & aBearerBitmask) != 0;
}

在bitmaskToString接口中，将bitmask转化成String时，循环RIL.GECKO_RADIO_TECH的长度次，经过位运算转换成与Android原始配置的bearer_bitmask相同格式的bearer位符，用“|”间隔rat类型位。

是如何通过RIL调用ril_consts.js内的GECKO_RADIO_TECH？

在DataCallManager.jsm 中定义RIL对象，并使用XPCOMUtils.defineLazyGetter()方法来实现懒加载，即在要使用时才加载和初始化对象（只有在第一次访问该对象时才会进行初始化和加载），避免不必要的性能开销和资源浪费。
RIL对象是通过ChromeUtils.import 方法从ril_consts.js文件中导入的，该对象由ril_consts.js文件中的代码创建和初始化的。

//DataCallManaer.jsm
"use strict";
 
//XPCOM 是一个用于 实现跨语言组件的技术框架。
//导入XPCOMUtils对象（工具库），简化和封装XPCOM组件的开发和使用。
//使用常量const来定义 XPCOMUtils 对象，以确保在运行时不会发生对象被重新赋值的情况。
const { XPCOMUtils } = ChromeUtils.import(
  "resource://gre/modules/XPCOMUtils.jsm"
);
 
//定义RIL对象，后续调用 RIL.GECKO_RADIO_TECH
XPCOMUtils.defineLazyGetter(this, "RIL", function() {
  return ChromeUtils.import("resource://gre/modules/ril_consts.js");
});
 
 
//ref RIL.GECKO_RADIO_TECH
const TCP_BUFFER_SIZES = [
  null,
  "4092,8760,48000,4096,8760,48000", // gprs
  "4093,26280,70800,4096,16384,70800", // edge
  "58254,349525,1048576,58254,349525,1048576", // umts
  "16384,32768,131072,4096,16384,102400", // is95a = 1xrtt
  "16384,32768,131072,4096,16384,102400", // is95b = 1xrtt
  "16384,32768,131072,4096,16384,102400", // 1xrtt
  "4094,87380,262144,4096,16384,262144", // evdo0
  "4094,87380,262144,4096,16384,262144", // evdoa
  "61167,367002,1101005,8738,52429,262114", // hsdpa
  "40778,244668,734003,16777,100663,301990", // hsupa = hspa
  "40778,244668,734003,16777,100663,301990", // hspa
  "4094,87380,262144,4096,16384,262144", // evdob
  "131072,262144,1048576,4096,16384,524288", // ehrpd
  "524288,1048576,2097152,262144,524288,1048576", // lte
  "122334,734003,2202010,32040,192239,576717", // hspa+
  "4096,87380,110208,4096,16384,110208", // gsm (using default value)
  "4096,87380,110208,4096,16384,110208", // tdscdma (using default value)
  "122334,734003,2202010,32040,192239,576717", // iwlan
  "122334,734003,2202010,32040,192239,576717", // ca
];
 
 
//定义了一个常量RIL_RADIO_CDMA_TECHNOLOGY_BITMASK，用于表示CDMA射频技术类型的掩码值。
//RIL.GECKO_RADIO_TECH.indexOf 查找各个CDMA技术类型在GECKO_RADIO_TECH数组中的下标值，
//-1 的目的是得到对应的掩码位数，并将此转换成掩码值，
//使用按位左移（<<）运算符得到掩码值，
//各个掩码值按位或（|）操作得到最终的掩码值。
const RIL_RADIO_CDMA_TECHNOLOGY_BITMASK =
  (1 << (RIL.GECKO_RADIO_TECH.indexOf("is95a") - 1)) |
  (1 << (RIL.GECKO_RADIO_TECH.indexOf("is95b") - 1)) |
  (1 << (RIL.GECKO_RADIO_TECH.indexOf("1xrtt") - 1)) |
  (1 << (RIL.GECKO_RADIO_TECH.indexOf("evdo0") - 1)) |
  (1 << (RIL.GECKO_RADIO_TECH.indexOf("evdoa") - 1)) |
  (1 << (RIL.GECKO_RADIO_TECH.indexOf("evdob") - 1)) |
  (1 << (RIL.GECKO_RADIO_TECH.indexOf("ehrpd") - 1));
 
 
// set to true in ril_consts.js to see debug messages
var DEBUG = RIL_DEBUG.DEBUG_RIL;   //调试用的log打印标识符

如上代码，CDMA技术类型对应的掩码值RIL_RADIO_CDMA_TECHNO如下：

is95a: 1 << (5-1) = 0x10
is95b: 1 << (6-1) = 0x20
1xrtt: 1 << (7-1) = 0x40
evdo0: 1 << (8-1) = 0x80
evdoa: 1 << (9-1) = 0x100
evdob: 1 << (14-1) = 0x2000
ehrpd: 1 << (15-1) = 0x4000

2、GECKO_RADIO_TECH 定义网络制式 (ril_consts.js)

在KaiOS中，RIL.GECKO_RADIO_TECH数组是在Gecko内核的代码中定义的，其实现位于Gecko代码库的"gecko/dom/system/gonk/radio/ril_consts.js"文件中。该文件定义了一系列RIL层的常量，包括射频技术类型、消息ID等。在该文件中，可以找到以下代码片段，其中定义了RIL.GECKO_RADIO_TECH数组的元素和顺序：

//GECKO_RADIO_TECH 数组定义射频技术（网络连接）
this.GECKO_RADIO_TECH = [
  null,
  "gprs",     //1 GPRS
  "edge",     //2 EDGE
  "umts",     //3 UMTS
  "is95a",    //4 IS-95A
  "is95b",    //5 IS-95B
  "1xrtt",    //6 cdma1x?一种CDMA2000射频技术，是CDMAOne技术的升级版(1x Radio Transmission Technology)
  "evdo0",    //7 EVDO-0
  "evdoa",    //8 EVDO-A
  "hsdpa",    //9
  "hsupa",    //10
  "hspa",     //11
  "evdob",    //12 EVDO-B
  "ehrpd",    //13 EVDO-D
  "lte",      //14 LTE
  "hspa+",    //15 HSPA+
  "gsm",      //16 GSM
  "tdscdma",  //17 TD-SCDMA
  "iwlan",    //18 iWLAN(wifi)
  "lte_ca",   //19 LTE_CA
];
 
//定义遵循的协议类型
this.GECKO_PROFILE_INFO_TYPE_COMMON = 0;
this.GECKO_PROFILE_INFO_TYPE_3GPP = 1;
this.GECKO_PROFILE_INFO_TYPE_3GPP2 = 2;

3、DataCall 对 rat 的使用案例

  dataRegistrationChanged(aRadioTech) {
    let targetBearer;
    if (this.apnSetting.bearer === undefined) {
      targetBearer = 0;
    } else {
      targetBearer = this.apnSetting.bearer;
    }
    if (DEBUG) {
      this.debug(
        "dataRegistrationChanged: targetBearer: " +
          bitmaskToString(targetBearer)
      );
    }
 
    if (bitmaskHasTech(targetBearer, aRadioTech)) {
      // Ignore same rat type. Let handler process the retry.
    } else {
      if (DEBUG) {
        this.debug(
          "dataRegistrationChanged: current APN do not support this rat reset DC. APN:" +
            JSON.stringify(this.apnSetting)
        );
      // Clean the requestedNetworkInterfaces due to current DC can not support this rat under DC retrying state.
      // Let handler process the retry.
      let targetRequestedNetworkInterfaces = this.requestedNetworkInterfaces.slice();
      for (let networkInterface of targetRequestedNetworkInterfaces) {
        this.disconnect(networkInterface);
      }
    }
  },

gecko/koost/telephony/TelephonyBinderService.h

// Cover the GECKO_RADIO_TECH to NETWORK_TYPE_*
int32_t convertRadioTech(const nsAString& rat);

三、日志分析

追溯在PDN建立过程中，读取apn配置的bearer参数到DataCall使用的radio类型的bearer值变化情况。

四、方案开发

相关介绍：KaiOS 新增APN信息字段的代码实现-CSDN博客

在 APN Editor中实现bearer显示

代码模块：gaia/apps/settings/js/panels/apn_editor/apn_editor.js

/**
 * The apn editor module
 */
'use strict';
define(function(require) { //eslint-disable-line
  const ApnEditorConst = require('panels/apn_editor_tct/apn_editor_const');
  const ApnEditorSession = require('panels/apn_editor_tct/apn_editor_session');
  const ApnUtils = require('modules/apn_tct/apn_utils');
 
  //以下三个常量都是从ApnEditorConst模块中导入的
  const { APN_PROPERTIES } = ApnEditorConst;
  const { APN_PROPERTY_DEFAULTS } = ApnEditorConst;
  const { VALUE_CONVERTERS } = ApnEditorConst;
 
 
  return function apnEditor(rootElement) {
    return new ApnEditor(rootElement);
  };
});

将kaios中十进制的bearer转换同Android原始配置的bitmask

测试代码

// 功能：将十进制bearer转换成1-20字符串（同Android）
function bitmaskToString(aBearerBitmask) {
  if (aBearerBitmask == 0 || aBearerBitmask === undefined) {
    return 0;
  }
 
  let val = "";
  for (let i = 1; i < 20; i++) {
    if ((aBearerBitmask & (1 << (i - 1))) != 0) {
      val = val.concat(i + "|");
    }
  }
  return val;
}
 
//常量数组，定义rat
const GECKO_RADIO_TECH = [
  null,
  "gprs",
  "edge",
  "umts",
  "is95a",
  "is95b",
  "1xrtt",
  "evdo0",
  "evdoa",
  "hsdpa",
  "hsupa",
  "hspa",
  "evdob",
  "ehrpd",
  "lte",
  "hspa+",
  "gsm",
  "tdscdma",
  "iwlan",
  "lte_ca",
];
 
//将1-20的bitmask转换成对应的网络制式
function bitmaskToRatString(aBitmask) {
   if (aBitmask == 0 || aBitmask === undefined) {
    return "unspecified";
  }
  let rat = "";
  let splitResult = aBitmask.split("|");
  console.log('splitResult = '+ splitResult);
  rat = splitResult.map(x => GECKO_RADIO_TECH[x]).join(",").slice(0,-1);
  //slice(startIndex,endIndex) 用于去掉最后一个逗号
  return rat;
}
 
// 测试代码
let apnBearer = '312312';  //apn.json原始配置值
let targetBearer;  //1-20转换目标值
let bearerString = '';
 
if (apnBearer === undefined) {
    targetBearer = 0;
} else {
    targetBearer = apnBearer;
}
 
bearerString = bitmaskToString(targetBearer);
 
 
// 输出结果
console.log('targetBearer = ' + targetBearer);
console.log('bearerString = '+ bearerString);