USB Enumeration problem.

[koumodaki]

I am trying to enumarate an USB device. This is a regular flash drive. I am using this piece of code int main(void) { GUID USBIODS_GUID; USBIODS_GUID.Data1 = 0x4D36E967; USBIODS_GUID.Data2 = 0xE325; USBIODS_GUID.Data3 = 0x11CE; USBIODS_GUID.Data4[0] = 0xBF; USBIODS_GUID.Data4[1] = 0xC1; USBIODS_GUID.Data4[2] = 0x08; USBIODS_GUID.Data4[3] = 0x0; USBIODS_GUID.Data4[4] = 0x2B; USBIODS_GUID.Data4[5] = 0xE1; USBIODS_GUID.Data4[6] = 0x03; USBIODS_GUID.Data4[7] = 0x18; HDEVINFO hInfo = SetupDiGetClassDevs(&USBIODS_GUID, NULL, NULL, DIGCF_PRESENT | DIGCF_INTERFACEDEVICE); for (DWORD i=0; ; ++i) { SP_INTERFACE_DEVICE_DATA Interface_Info; Interface_Info.cbSize = sizeof(Interface_Info); Enumerate device if (!SetupDiEnumDeviceInterfaces(hInfo, NULL, (LPGUID) &USBIODS_GUID,i, &Interface_Info)) { int err = GetLastError(); SetupDiDestroyDeviceInfoList(hInfo); return(i); } } } I obtained the UID for this device from the registry. The SetupDiEnumDeviceInterfaces returns ERROR_NO_MORE_ITEMS Where have I gone wrong? Also what is the difference between functions SetupDiEnumDeviceInterfaces () and SetupDiEnumInterfaceDevice()

[David Crow]

koumodaki wrote:

The SetupDiEnumDeviceInterfaces returns ERROR_NO_MORE_ITEMS Where have I gone wrong?

By possibly not reading the documentation: MemberIndex - Specifies a zero-based index into the list of interfaces in the device information set. The caller should call this function first with MemberIndex set to zero to obtain the first interface. Then, repeatedly increment MemberIndex and retrieve an interface until this function fails and GetLastError returns ERROR_NO_MORE_ITEMS.

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

[koumodaki]

It is set to 0. I am passing a variable i as a parameter which I have initilized to zero in the for loop

[David Crow]

Did you not read that last sentence?

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

[koumodaki]

I saw it and made the chages too. Still I am facting the same problem.

[David Crow]

koumodaki wrote:

I saw it and made the chages too. Still I am facting the same problem.

So are we going to see the changed code? :confused:

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

[koumodaki]

Sorry. I actually modified the code to see if I can atleast get the 1st interface. int main(void) { GUID USBIODS_GUID; USBIODS_GUID.Data1 = 0x4D36E967; USBIODS_GUID.Data2 = 0xE325; USBIODS_GUID.Data3 = 0x11CE; USBIODS_GUID.Data4[0] = 0xBF; USBIODS_GUID.Data4[1] = 0xC1; USBIODS_GUID.Data4[2] = 0x08; USBIODS_GUID.Data4[3] = 0x0; USBIODS_GUID.Data4[4] = 0x2B; USBIODS_GUID.Data4[5] = 0xE1; USBIODS_GUID.Data4[6] = 0x03; USBIODS_GUID.Data4[7] = 0x18; HDEVINFO hInfo = SetupDiGetClassDevs(&USBIODS_GUID, NULL, NULL, DIGCF_PRESENT | DIGCF_INTERFACEDEVICE); if (hInfo == INVALID_HANDLE_VALUE) { return 1; } SP_DEVINFO_DATA DeviceInfoData; DeviceInfoData.cbSize = sizeof(SP_DEVINFO_DATA); SP_INTERFACE_DEVICE_DATA Interface_Info; Interface_Info.cbSize = sizeof(Interface_Info); if(!SetupDiEnumDeviceInterfaces(hInfo, &DeviceInfoData, (LPGUID) &USBIODS_GUID,0, &Interface_Info)) { int err = GetLastError(); SetupDiDestroyDeviceInfoList(hInfo); return(0); } } The function fails even now.

[David Crow]

Your code snippet worked fine for me. With only one item to enumerate, SetupDiEnumDeviceInterfaces() returned 0 and GetLastError() returned ERROR_NO_MORE_ITEMS as expected.

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

[koumodaki]

Oh, I thought the function should return 1 because it was successful in getting the interface. Am I missing something here? Does it mean that I am able to get the interface of the device who’s GUID I have assigned to USBIODS_GUID variable passing as parameter to the function? Could you please explain to me, Mr Crow?

[David Crow]

koumodaki wrote:

Am I missing something here?

Yes. It will return nonzero if it completed without error, or it will return 0 if there are no more items (i.e., GetLastError() returns ERROR_NO_MORE_ITEMS).

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne