hardware.c

/**
 * PROJECT:         Native Shell
 * COPYRIGHT:       LGPL; See LICENSE in the top level directory
 * FILE:            hardware.c
 * DESCRIPTION:     Device tree routines.
 * DEVELOPERS:      See CONTRIBUTORS.md in the top level directory
 */

#include "precomp.h"

#define MAX_DEVICE_ID_LEN 200
#define ROOT_NAME L"HTREE\\ROOT\\0"

ULONG Level = 0;
HANDLE RootKey = 0;

NTSTATUS
RtlCliGetEnumKey(OUT PHANDLE KeyHandle)
{
    OBJECT_ATTRIBUTES ObjectAttributes;
    UNICODE_STRING KeyName = RTL_CONSTANT_STRING(L"\\Registry\\Machine\\System"
                                                 L"\\CurrentControlSet\\Enum");

    // Initialize the object attributes
    InitializeObjectAttributes(&ObjectAttributes,
                               &KeyName,
                               OBJ_CASE_INSENSITIVE,
                               NULL,
                               NULL);

    // Open the key for read access
    return NtOpenKey(KeyHandle, KEY_READ, &ObjectAttributes);
}

NTSTATUS
RtlCliGetChildOrSibling(IN PWCHAR Name,
                        OUT PWCHAR ChildName,
                        IN ULONG Type)
{
    NTSTATUS Status;
    PLUGPLAY_CONTROL_RELATED_DEVICE_DATA PlugPlayData;

    // Initialize the Root Device Node name
    RtlInitUnicodeString(&PlugPlayData.TargetDeviceInstance, Name);

    // Initialize the request
    PlugPlayData.Relation = Type;
    PlugPlayData.RelatedDeviceInstanceLength = MAX_DEVICE_ID_LEN;
    PlugPlayData.RelatedDeviceInstance = ChildName;

    // Get the root child node
    Status = NtPlugPlayControl(PlugPlayControlGetRelatedDevice,
                               (PVOID)&PlugPlayData,
                               sizeof(PLUGPLAY_CONTROL_RELATED_DEVICE_DATA));
    return Status;
}

NTSTATUS
RtlCliPrintDeviceName(IN PWCHAR Name)
{
    NTSTATUS Status = STATUS_SUCCESS;
    HANDLE RegHandle;
    OBJECT_ATTRIBUTES ObjectAttributes;
    UNICODE_STRING KeyName;
    PKEY_VALUE_FULL_INFORMATION FullInformation;
    ULONG ResultLength;
    WCHAR Buffer[MAX_DEVICE_ID_LEN];
    ULONG i;

    // If we don't already have a root key, get it now
    if (!RootKey)
        Status = RtlCliGetEnumKey(&RootKey);
    if (NT_SUCCESS(Status))
    {
        // Root key opened, now initialize the device instance key name
        RtlInitUnicodeString(&KeyName, Name);

        // Setup the object attributes and open the key
        InitializeObjectAttributes(&ObjectAttributes,
                                   &KeyName,
                                   0,
                                   RootKey,
                                   NULL);
        Status = NtOpenKey(&RegHandle, KEY_READ, &ObjectAttributes);
        if (NT_SUCCESS(Status))
        {
            // Setup and allocate the key data structure
            ResultLength = sizeof(*FullInformation) + 256;
            FullInformation = RtlAllocateHeap(RtlGetProcessHeap(),
                                              0,
                                              ResultLength);

            // Now check for a friendly name
            RtlInitUnicodeString(&KeyName, L"FriendlyName");
            Status = NtQueryValueKey(RegHandle,
                                     &KeyName,
                                     KeyValueFullInformation,
                                     FullInformation,
                                     ResultLength,
                                     &ResultLength);
            if (!NT_SUCCESS(Status))
            {
                // No friendly name found, try the device description key
                RtlInitUnicodeString(&KeyName, L"DeviceDesc");
                Status = NtQueryValueKey(RegHandle,
                                         &KeyName,
                                         KeyValueFullInformation,
                                         FullInformation,
                                         ResultLength,
                                         &ResultLength);
            }

            // Check if we have success until here
            if (NT_SUCCESS(Status))
            {
                // Get the pointer to the name
                Name = (PWCHAR)((ULONG_PTR)FullInformation +
                                FullInformation->DataOffset);

                // Indent the name to create the appeareance of a tree
                for (i = 0; i < (Level * 2); i++)
                    Buffer[i] = ' ';
                Buffer[i] = UNICODE_NULL;

                // Add the device name or description, and display it
                wcscat(Buffer, Name);
                RtlCliDisplayString("%S\n", Buffer);
                DbgPrint("%S\n", Buffer);
            }

            // Close the key to the device instance name
            NtClose(RegHandle);
        }
    }

    // Return status to caller
    return Status;
}

NTSTATUS
RtlCliListSubNodes(IN PWCHAR Parent,
                   IN PWCHAR Sibling,
                   IN PWCHAR Current)
{
    NTSTATUS Status;
    WCHAR FoundSibling[MAX_DEVICE_ID_LEN];
    WCHAR FoundChild[MAX_DEVICE_ID_LEN];

    // Start looping
    do
    {
        // Get the first sibling
        Status = RtlCliGetChildOrSibling(Current, FoundSibling, PNP_GET_SIBLING_DEVICE);
        if (!NT_SUCCESS(Status))
            *FoundSibling = UNICODE_NULL;

        // Print its name
        Status = RtlCliPrintDeviceName(Current);

        // Get its children
        Status = RtlCliGetChildOrSibling(Current, FoundChild, PNP_GET_CHILD_DEVICE);
        if (NT_SUCCESS(Status))
        {
            // Get it's children's subnodes
            Level++;
            RtlCliListSubNodes(Current, NULL, FoundChild);
            Level--;
        }

        // Move to the next sibling
        Current = FoundSibling;
    } while (*Current);

    // Return status
    return Status;
}

NTSTATUS
RtlCliListHardwareTree(VOID)
{
    NTSTATUS Status;
    WCHAR Buffer[MAX_DEVICE_ID_LEN];

    // Get the root node's child
    Status = RtlCliGetChildOrSibling(ROOT_NAME, Buffer, PNP_GET_CHILD_DEVICE);
    if (!NT_SUCCESS(Status))
    {
        RtlCliDisplayString("NtPlugPlayControl get root node failed.\n");
    }

    // Now get the entire tree
    Status = RtlCliListSubNodes(ROOT_NAME, NULL, Buffer);
    if (!NT_SUCCESS(Status))
    {
        RtlCliDisplayString("NtPlugPlayControl get child nodes failed.\n");
    }
    return Status;
}