Expending on usbdevs

[Mario St-Gelais]

Hi list.
I am wondering if someone could shed some light on what I am trying to do.

I have been playing around trying to come up with something that kind of have
the verbosity of lsusb but use OpenBSD's #include <dev/usb/usb.h> and avoid all 
of libusb stuff.

I hit a wall when I try to use USB_DEVICE_GET_FDESC :

Breakpoint 1, get_usb_device_fdesc (f=7, a=1, u=0x7f7ffffd40d0) at usbdevs.c:219
219         int e = ioctl(f, USB_DEVICE_GET_FDESC, u);
(gdb) s
218         u->udf_size=25;
(gdb) 
219         int e = ioctl(f, USB_DEVICE_GET_FDESC, u);
(gdb) 
__cerror () at /usr/src/lib/libc/arch/amd64/sys/cerror.S:48
48              movq    PIC_GOT(_C_LABEL(errno)), %rcx
Current language:  auto; currently asm
(gdb) bt
#0  __cerror () at /usr/src/lib/libc/arch/amd64/sys/cerror.S:48
#1  0x0000048cfe7022cc in usbdev (f=7, a=1, rec=Variable "rec" is not available.
) at usbdevs.c:285
#2  0x0000048cfe70235b in usbdump (f=7) at usbdevs.c:308
#3  0x0000048cfe70259b in main (argc=3, argv=0x7f7ffffd4258) at usbdevs.c:419

At the moment, I can get my small program to produce ouput like this:
Controller /dev/usb0:
Device Information:
  addr 1:
   idVendor     Intel
   VendorNo     0x8086
   idProduct    0x0000
   Product      EHCI root hub
   Release      1.00
   ReleaseNo    0x0100
   Config       1
   Power        0 Self powered
   Speed        3 (High Speed)
   iSerialNumber        none
   Device Name[0]  uhub2
   nPorts       4
    port 1 powered
    port 2 powered
    port 3 powered
    port 4 powered
Device Descriptor:
   bLength      18
   bDescriptorType      1
   bcdUSB       0x0200
   bDeviceClass 9 (Hub)
   bDeviceSubClass      0
   bDeviceProtocol      1
   bMaxPacketSize       64
   idVendor     0x8086
   bNumConfigurations   1
Configuration Descriptor
   bLength              9
   bDescriptorType      2
   wTotalLength         25
   bNumInterface        1
   bConfigurationValue  1
   iConfiguration       0
   bmAttributes         0x40 (Self Powered)
   bMaxPower (mA)       0

So basically I have the following function that fails.  
I set udf_size=25 as this is the value I get from wTotalLength shown above as
 explained in the man.

int
get_usb_device_fdesc(int f, int a, struct usb_device_fdesc *u)
{
    u->udf_addr = a;
    u->udf_config_index = USB_CURRENT_CONFIG_INDEX;
    u->udf_size=25;
    int e = ioctl(f, USB_DEVICE_GET_FDESC, u);
    return e;
}

Clearly I don't seem to use USB_DEVICE_GET_FDESC correctly.  
Grepping /usr/src only reveals little on USB_DEVICE_GET_FDESC

/usr/src:
$>find . -name *.c|xargs grep USB_DEVICE_GET_FDESC 
./sys/dev/usb/usb.c:    case USB_DEVICE_GET_FDESC:
ma...@t61.my.domain:18:40:45
/usr/src:
$>find . -name *.c|xargs grep -n USB_DEVICE_GET_FDESC
./sys/dev/usb/usb.c:752:        case USB_DEVICE_GET_FDESC:


Regards

Mario St-Gelais