ebpf-for-windows/tools/bpf2c/bpf2c_driver.c

// Copyright (c) Microsoft Corporation
// SPDX-License-Identifier: MIT

#include <guiddef.h>
#include <wdm.h>
#include <wsk.h>

#define NO_CRT
#include "bpf2c.h"

DRIVER_INITIALIZE DriverEntry;
DRIVER_UNLOAD DriverUnload;
RTL_QUERY_REGISTRY_ROUTINE static _bpf2c_query_registry_routine;

#define metadata_table ___METADATA_TABLE___##_metadata_table

static GUID _bpf2c_npi_id = {/* c847aac8-a6f2-4b53-aea3-f4a94b9a80cb */
                             0xc847aac8,
                             0xa6f2,
                             0x4b53,
                             {0xae, 0xa3, 0xf4, 0xa9, 0x4b, 0x9a, 0x80, 0xcb}};
static NPI_MODULEID _bpf2c_module_id = {sizeof(_bpf2c_module_id), MIT_GUID, {0}};
static HANDLE _bpf2c_nmr_client_handle;
static HANDLE _bpf2c_nmr_provider_handle;
extern metadata_table_t metadata_table;

static NTSTATUS
_bpf2c_npi_client_attach_provider(
    _In_ HANDLE nmr_binding_handle,
    _In_ void* client_context,
    _In_ const NPI_REGISTRATION_INSTANCE* provider_registration_instance);

static NTSTATUS
_bpf2c_npi_client_detach_provider(_In_ void* client_binding_context);

static const NPI_CLIENT_CHARACTERISTICS _bpf2c_npi_client_characteristics = {
    0,                                  // Version
    sizeof(NPI_CLIENT_CHARACTERISTICS), // Length
    _bpf2c_npi_client_attach_provider,
    _bpf2c_npi_client_detach_provider,
    NULL,
    {0,                                 // Version
     sizeof(NPI_REGISTRATION_INSTANCE), // Length
     &_bpf2c_npi_id,
     &_bpf2c_module_id,
     0,
     &metadata_table}};

static NTSTATUS
_bpf2c_query_npi_module_id(
    _In_ const wchar_t* value_name,
    unsigned long value_type,
    _In_ const void* value_data,
    unsigned long value_length,
    _Inout_ void* context,
    _Inout_ void* entry_context)
{
    UNREFERENCED_PARAMETER(value_name);
    UNREFERENCED_PARAMETER(context);
    UNREFERENCED_PARAMETER(entry_context);

    if (value_type != REG_BINARY) {
        return STATUS_INVALID_PARAMETER;
    }
    if (value_length != sizeof(_bpf2c_module_id.Guid)) {
        return STATUS_INVALID_PARAMETER;
    }

    memcpy(&_bpf2c_module_id.Guid, value_data, value_length);
    return STATUS_SUCCESS;
}

NTSTATUS
DriverEntry(_In_ DRIVER_OBJECT* driver_object, _In_ UNICODE_STRING* registry_path)
{
    NTSTATUS status;
    RTL_QUERY_REGISTRY_TABLE query_table[] = {
        {
            NULL,                      // Query routine
            RTL_QUERY_REGISTRY_SUBKEY, // Flags
            L"Parameters",             // Name
            NULL,                      // Entry contet
            REG_NONE,                  // Default type
            NULL,                      // Default data
            0,                         // Default length
        },
        {
            _bpf2c_query_npi_module_id,  // Query routine
            RTL_QUERY_REGISTRY_REQUIRED, // Flags
            L"NpiModuleId",              // Name
            NULL,                        // Entry contet
            REG_NONE,                    // Default type
            NULL,                        // Default data
            0,                           // Default length
        },
        {0}};

    status = RtlQueryRegistryValues(RTL_REGISTRY_ABSOLUTE, registry_path->Buffer, query_table, NULL, NULL);
    if (!NT_SUCCESS(status)) {
        goto Exit;
    }

    status = NmrRegisterClient(&_bpf2c_npi_client_characteristics, NULL, &_bpf2c_nmr_client_handle);

Exit:
    if (NT_SUCCESS(status)) {
        driver_object->DriverUnload = DriverUnload;
    }

    return status;
}

void
DriverUnload(_In_ DRIVER_OBJECT* driver_object)
{
    NTSTATUS status = NmrDeregisterClient(_bpf2c_nmr_client_handle);
    if (status == STATUS_PENDING) {
        NmrWaitForClientDeregisterComplete(_bpf2c_nmr_client_handle);
    }
    UNREFERENCED_PARAMETER(driver_object);
}

static NTSTATUS
_bpf2c_npi_client_attach_provider(
    _In_ HANDLE nmr_binding_handle,
    _In_ void* client_context,
    _In_ const NPI_REGISTRATION_INSTANCE* provider_registration_instance)
{
    NTSTATUS status = STATUS_SUCCESS;
    void* provider_binding_context = NULL;
    void* provider_dispatch_table = NULL;

    UNREFERENCED_PARAMETER(client_context);
    UNREFERENCED_PARAMETER(provider_registration_instance);

    if (_bpf2c_nmr_provider_handle != NULL) {
        return STATUS_INVALID_PARAMETER;
    }

#pragma warning(push)
#pragma warning( \
    disable : 6387) // Param 3 does not adhere to the specification for the function 'NmrClientAttachProvider'
    // As per MSDN, client dispatch can be NULL, but SAL does not allow it.
    // https://docs.microsoft.com/en-us/windows-hardware/drivers/ddi/netioddk/nf-netioddk-nmrclientattachprovider
    status = NmrClientAttachProvider(
        nmr_binding_handle, client_context, NULL, &provider_binding_context, &provider_dispatch_table);
    if (status != STATUS_SUCCESS) {
        goto Done;
    }
#pragma warning(pop)
    _bpf2c_nmr_provider_handle = nmr_binding_handle;

Done:
    return status;
}

static NTSTATUS
_bpf2c_npi_client_detach_provider(_In_ void* client_binding_context)
{
    _bpf2c_nmr_provider_handle = NULL;
    UNREFERENCED_PARAMETER(client_binding_context);
    return STATUS_SUCCESS;
}

void
division_by_zero(uint32_t address)
{
    UNREFERENCED_PARAMETER(address);
}