举例

Client端的Preferences发送给Server端的akd

• 概述
  • Client端的Preferences的NSXPCConnection：去发送XPC消息=调用函数
    • -[__NSXPCInterfaceProxy_AKAnisetteProvisioningAndSigningDeamonInterface fetchAnisetteDataAndProvisionIfNecessary:device:completion:]
  • Server端的akd的NSXPCConnection：去接收XPC消息=找到对应函数去处理
    • -[AKAnisetteProvisioningService fetchAnisetteDataAndProvisionIfNecessary:device:completion:]

详解

先明白基础概念和此处所涉及到的内容：

• 当前的NSXPCConnection
  • serviceName=com.apple.ak.anisette.xpc
  • Client端
    • iOS的app：设置=Preferences
      • 包名：com.apple.Preferences
      • 二进制：/Applications/Preferences.app/Preferences
  • Server端=Listener端
    • AuthKit库的daemon服务程序：akd
      • 二进制：/System/Library/PrivateFrameworks/AuthKit.framework/akd

此处最初的情况是：

• Client端的：Preferences 的 NSXPCConnection
  • log信息
    • <NSXPCConnection: 0x282adc640> connection to service with pid 125 named com.apple.ak.anisette.xpc
      • 注：akd的PID=125
  • remoteObjectProxy
    • <__NSXPCInterfaceProxy_AKAnisetteProvisioningAndSigningDeamonInterface: 0x2838ccb40>
  • remoteObjectInterface
    • Protocol: AKAnisetteProvisioningAndSigningDeamonInterface
      • 此处po能查看到：所有的函数
        • fetchAnisetteDataAndProvisionIfNecessary:device:completion:
        • absintheSignatureForData:completion:
        • attestationDataForDevice:withRequest:completion:
        • syncAnisetteWithSIMData:device:completion:
        • eraseAnisetteForDevice:completion:
        • provisionAnisetteForDevice:completion:
        • legacyAnisetteDataForDSID:device:completion:
        • signaturesForData:options:completion:
      • 从头文件中可以确认：其实是conform遵守了2个protocol，且对应的函数正好是2个protocol的函数
        • AKAnisetteProvisioningDaemonProtocol
          • attestationDataForDevice:withRequest:completion:
          • legacyAnisetteDataForDSID:device:completion:
          • fetchAnisetteDataAndProvisionIfNecessary:device:completion:
          • eraseAnisetteForDevice:completion:
          • syncAnisetteWithSIMData:device:completion:
          • provisionAnisetteForDevice:completion:
        • AKAppleIDSigningDaemonProtocol
          • signaturesForData:options:completion:
          • absintheSignatureForData:completion:
• Server端的：akd 的 NSXPCConnection
  • log信息
    • <NSXPCConnection: 0x105204680> connection from pid 17416 on mach service named com.apple.ak.anisette.xpc
      • 注：Preferences的PID=17416
  • exportedObject
    • <AKAnisetteProvisioningService: 0x107412620>
      • 而AKAnisetteProvisioningService这个类，是akd中才有的
      • 且实现了conform了前面的2个protocol
        • AKAnisetteProvisioningDaemonProtocol
        • AKAppleIDSigningDaemonProtocol
  • exportedInterface
    • <NSXPCInterface: 0x107420650>

所以最终的调用的过程是：

• Client端Preferences中的NSXPCConnection，去调用 -[__NSXPCInterfaceProxy_AKAnisetteProvisioningAndSigningDeamonInterface fetchAnisetteDataAndProvisionIfNecessary:device:completion:]

即：

-[<__NSXPCInterfaceProxy_AKAnisetteProvisioningAndSigningDeamonInterface: 0x281c88aa0> fetchAnisetteDataAndProvisionIfNecessary:device:completion:
  1
  0
  <__NSStackBlock__: 0x16dd79ec0
    invoke = "__92-[AKAnisetteProvisioningController fetchAnisetteDataAndProvisionIfNecessary:withCompletion:]_block_invoke.51"
  >
]

过程是：

• 会触发到：Server端的exportedObject的类：AKAnisetteProvisioningService
  • 去调用对应的函数去处理
    • -[AKAnisetteProvisioningService fetchAnisetteDataAndProvisionIfNecessary:device:completion:]
      • 注：因为本身AKAnisetteProvisioningService就conform了对应的2个protocol：AKAnisetteProvisioningDaemonProtocol``、AKAppleIDSigningDaemonProtocol，所以支持这些函数调用

最终是触发：

-[AKAnisetteProvisioningService fetchAnisetteDataAndProvisionIfNecessary:device:completion:]