找出来自IOUSBInterface管道的数据

Question

我正在编写一个Mac应用程序，该应用程序使用IOKit向Personel Video Recorder发送消息并将消息接收到该应用程序。我需要发送消息来改变它的状态，它需要给我关于分辨率或录像等视频的信息。我意识到我必须找到正确的信息发送它，所以首先我想我可以先收到它的一些消息。我已经找到了设备的接口。我将如何能够转储收到的消息？

下面是USB探头日志：

Composite device: "PVR" 
    Port Information: 0x001d 
      Captive 
      Internal Device 
      Connected 
      Enabled 
    Number Of Endpoints (includes EP0): 
     Total Endpoints for Configuration 1 (current): 7 
    Device Descriptor 
     Descriptor Version Number: 0x0200 
     Device Class: 0 (Composite) 
     Device Subclass: 0 
     Device Protocol: 0 
     Device MaxPacketSize: 64 
     Device VendorID/ProductID: 0x2040/0xE502 (Hauppauge Computer Works, Inc.) 
     Device Version Number: 0x0800 
     Number of Configurations: 1 
     Manufacturer String: 1 "Hauppauge" 
     Product String: 2 "WinTV" 
     Serial Number String: 3 "E502-00-00AA3DEE" 
    Configuration Descriptor (current config) 
     Length (and contents): 60 
      Raw Descriptor (hex) 0000: 09 02 3C 00 01 01 00 C0 00 09 04 00 00 06 FF FF 
      Raw Descriptor (hex) 0010: FF 00 07 05 81 02 00 02 00 07 05 84 02 00 02 00 
      Raw Descriptor (hex) 0020: 07 05 88 02 00 02 00 07 05 01 02 00 02 00 07 05 
      Raw Descriptor (hex) 0030: 02 02 00 02 00 07 05 86 02 00 02 00 
     Number of Interfaces: 1 
     Configuration Value: 1 
     Attributes: 0xC0 (self-powered) 
     MaxPower: 0 mA 
     Interface #0 - Vendor-specific 
      Alternate Setting 0 
      Number of Endpoints 6 
      Interface Class: 255 (Vendor-specific) 
      Interface Subclass; 255 (Vendor-specific) 
      Interface Protocol: 255 
      Endpoint 0x81 - Bulk Input 
       Address: 0x81 (IN) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 512 
       Polling Interval: 0 (Endpoint never NAKs) 
      Endpoint 0x84 - Bulk Input 
       Address: 0x84 (IN) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 512 
       Polling Interval: 0 (Endpoint never NAKs) 
      Endpoint 0x88 - Bulk Input 
       Address: 0x88 (IN) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 512 
       Polling Interval: 0 (Endpoint never NAKs) 
      Endpoint 0x01 - Bulk Output 
       Address: 0x01 (OUT) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 512 
       Polling Interval: 0 (Endpoint never NAKs) 
      Endpoint 0x02 - Bulk Output 
       Address: 0x02 (OUT) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 512 
       Polling Interval: 0 (Endpoint never NAKs) 
      Endpoint 0x86 - Bulk Input 
       Address: 0x86 (IN) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 512 
       Polling Interval: 0 (Endpoint never NAKs) 
    Device Qualifier Descriptor 
     Descriptor Version Number: 0x0200 
     Device Class 0 (Composite) 
     Device Subclass 0 
     Device Protocol 0 
     Device MaxPacketSize: 64 
     Number of Configurations: 1 
     bReserved: 0 
    Other Speed Configuration Descriptor 
     Length (and contents): 60 
      Raw Descriptor (hex) 0000: 09 07 3C 00 01 01 00 C0 00 09 04 00 00 06 FF FF 
      Raw Descriptor (hex) 0010: FF 00 07 05 81 02 40 00 00 07 05 84 02 40 00 00 
      Raw Descriptor (hex) 0020: 07 05 88 02 40 00 00 07 05 01 02 40 00 00 07 05 
      Raw Descriptor (hex) 0030: 02 02 40 00 00 07 05 86 02 40 00 00 
     Number of Interfaces: 1 
     Configuration Value: 1 
     Attributes: 0xC0 (self-powered) 
     MaxPower: 0 mA 
     Interface #0 - Vendor-specific 
      Alternate Setting 0 
      Number of Endpoints 6 
      Interface Class: 255 (Vendor-specific) 
      Interface Subclass; 255 (Vendor-specific) 
      Interface Protocol: 255 
      Endpoint 0x81 - Bulk Input 
       Address: 0x81 (IN) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 64 
       Polling Interval: 0 ms 
      Endpoint 0x84 - Bulk Input 
       Address: 0x84 (IN) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 64 
       Polling Interval: 0 ms 
      Endpoint 0x88 - Bulk Input 
       Address: 0x88 (IN) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 64 
       Polling Interval: 0 ms 
      Endpoint 0x01 - Bulk Output 
       Address: 0x01 (OUT) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 64 
       Polling Interval: 0 ms 
      Endpoint 0x02 - Bulk Output 
       Address: 0x02 (OUT) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 64 
       Polling Interval: 0 ms 
      Endpoint 0x86 - Bulk Input 
       Address: 0x86 (IN) 
       Attributes: 0x02 (Bulk) 
       Max Packet Size: 64 
       Polling Interval: 0 ms 

Answer 1

USB主机是驱动。这意味着设备不会发送任何消息，除非作为对来自主机（Mac/PC）的消息的回复。因此，为了从中引出消息，您首先需要发送一条有效的消息。

我从你的问题中假设你实际上没有任何有关该设备的文档/规范？这意味着您需要获取该信息，或者向制造商询问，或者通过逆向工程它。

逆向工程的最简单方法是监听由现有驱动程序生成的消息，例如，一些Windows软件可以执行类似于您想要执行的操作。然后你需要听取数据。在过去，我已经成功地在Linux上的VM上运行Windows软件，并将相关USB设备传递给VM，并使用Linux的USB调试功能记录输出。您应该可以在OSX上使用“USB Prober”应用程序和Apple开发人员下载区提供的“IOUSBFamily Log Release”执行相同的操作。