Hey all, usblogdump outputs the following for a simple transaction between a USB device and the host on a Windows machine:
URB 0, number 0, offset 7904, sequence 1, time 10, allocs 1 Function: GET_DESCRIPTOR_FROM_DEVICE (0x000b) Endpoint: 0 (default) Pipe handle: 0x00000000 Flags: 4 Status: 0 Link: 0 Length: 96 Direction: to URB header: Length: 80 Status: 0 Flags: 34 --------------------------------------------------------- URB 1, number 1, offset 7994, sequence 1, time 10, allocs 2 Function: CONTROL_TRANSFER (0x0008) Endpoint: 0 (default) Pipe handle: 0x82af53d8 Flags: 6 Status: 0 Link: 0 Length: 120 Direction: from URB header: Length: 80 Status: 0 Flags: 34 Transfer size: 18 Data: 0x12 0x01 0x10 0x01 0xff 0xff 0xff 0x08 0x23 0x09 0x0f 0x01 0x01 0x00 0x00 0x00 0x00 0x01 URB control transfer: Transfer flags: 11 Transfer buffer length: 18 Setup packet: bmRequestType: 0x80 (device-to-host standard device) Linux kernel: USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE bRequest: 0x06 GET_DESCRIPTOR [standard] Linux kernel: USB_REQ_GET_DESCRIPTOR wValue: 0x0100 (256) wIndex: 0x0000 (0) wLength: 0x0012 (18) ----- I can see that the GET_DESCRIPTOR_FROM_DEVICE is asking the USB device for some information, and that the CONTROL_TRANSFER is the response. Chapter 9 of the USB spec has helped with that bit. What I can't see is where in the GET_DESCRIPTOR_... is the actual description of the information being requested. Have I misunderstood the whole thing? Is there only one descriptor per device? Thanks for any hints, Mikal PS: If you were looking at this sort of dump of a traffic sniff, which bits of information are actually useful? I can imagine a lot of the header length information for instance is probably considered very boring. -- Michael Still ([EMAIL PROTECTED]) | Stage 1: Steal underpants http://www.stillhq.com | Stage 2: ???? UTC + 10 | Stage 3: Profit ------------------------------------------------------- This SF.Net email sponsored by: Free pre-built ASP.NET sites including Data Reports, E-commerce, Portals, and Forums are available now. Download today and enter to win an XBOX or Visual Studio .NET. http://aspnet.click-url.com/go/psa00100003ave/direct;at.aspnet_072303_01/01 _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
